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This application claims the benefit of provisional application No. 60/075,666 filed Feb. 23, 1998.
BACKGROUND OF THE INVENTION
This application describes an improvement over the disclosure of Patents Nos. 5,583,324 and 5,691,516, an improvement whereby a vibration absorber according to the invention of any of those applications is tunable to a select broad band of continuously varying frequencies upon installation into a speaker cabinet or other speaker enclosure.
In this invention the stack of viscoelastic damping plates, secured together with spacers preferably at one edge, is connected to the speaker panel with an angular shaped tuning mounting plate between the damping unit's base or mounting plate and the speaker panel. As in U.S. Pat. Nos. 5,583,324 and 5,691,516, the stack of plates is secured together and to the unit's mounting plate at one edge, with spacers between plates at the bound edge. Upon installation on the panel of a speaker enclosure, the edge of the unit where all plates are secured together is cantilevered over the edge of the angular shaped tuning mounting plate. The degree of cantilever between the bound edge and the edge of the angular shaped mounting plate varies according to a selected shape and angle such that the unit may be tuned to a select broad band of continuously varying frequencies. The vibration absorbing unit is then fixed to the angular-shaped mounting plate to absorb vibration over the selected broad band of continuously varying frequencies.
It is therefore among the objects of this invention to improve the vibration absorbing capability of vibration damping units such as described in U.S. Pat. Nos. 5,583,324, and 5,691,516 with a simple and efficient procedure. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a vibration damping unit with which the procedure and apparatus of the invention may be used.
FIG. 2 is a similar view, showing the unit of FIG. 1 positioned against a rectangular shaped mounting plate, for installation on a panel of a speaker enclosure.
FIG. 3 is another perspective view showing the unit of FIG. 1 positioned against an angular shaped mounting plate, for installation of a speaker enclosure.
FIG. 4 is similar to FIG. 3 showing the relative shape and position of the angular shaped mounting plate fixed to the unit of FIG. 1 .
FIGS. 5, 6 , 7 and 8 are graphs showing amplitude of vibrations versus frequency, in reference to the tuning method of the invention
FIGS. 9 and 9A show rear and side views of a wall-mounted speaker showing the location where the assembly of FIG. 3 is mounted onto a plastic speaker baffle.
FIGS. 10 and 10A are similar to FIGS. 9 and 9A, showing the location of an accelerometer used to measure the amplitude of vibrations versus frequency in reference to the tuning method of the invention.
FIG. 11 is a perspective exploded view showing a procedure for mounting the assembly of FIG. 3 onto the plastic baffle of a wall-mounted speaker.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the drawings, FIG. 1 shows a vibration damping unit 10 in accordance with U.S. Pat. No. 5,583,324, the disclosure of which is incorporated herein by reference. The damping unit 10 includes a series of vibration damping plates 10 a , 10 b , 10 c , 10 d , and 10 e (the number of plates can be greater or smaller), secured together and to a mounting plate 12 via spacers 11 and fasteners 13 passing through holes 14 at one edge of the assembly. Outer edges of the damping plates 10 a - 10 e, generally identified by the reference number 16 in FIG. 1, are freely suspended, i.e., cantilevered, the plates and the mounting plate 12 being secured together only at the left edge 18 of the assembly as seen in the drawing. This construction is in accordance with an embodiment described in U.S. Pat. No. 5,583,324 incorporated by reference.
FIG. 2 is similar to FIG. 1 but shows the damping unit 10 secured to a separate rectangular mounting plate 20 which serves as a tuning mounting plate for the vibration damping assembly. This construction is in accordance with embodiments described in U.S. Pat. No. 5,691,516, incorporated by reference.
FIG. 3 is similar to FIGS. 1 and 2 but shows the damping unit 10 secured to a separate angular shaped mounting plate 30 , preferably triangular or trapezoidal in shape, as shown. The mounting plate 30 serves as a spacer between the unit's mounting plate 12 and a panel of a speaker enclosure (not shown). It can be seen from the drawing in FIG. 3 that the angular shaped mounting plate 30 affects a corresponding angular shaped cantilever area of the region of the unit 10 which is adjacent to the spacers 11 , that is, the left edge 18 as seen in the drawing. In FIG. 3, it will also be seen by those skilled in the art that the degree to which the angle of the plate 30 is adjusted relative to the mounting plate 12 causes the cantilevered region of the unit 10 to vary in size across its surface, thus enabling the vibration absorbing unit 10 to resonate over a selected broad band of continuously varying frequencies.
FIG. 4 is similar to FIG. 3 but shows that the cantilever distances A and B are adjusted according to the dimensions assigned to the distances C and D. Thus, the cantilevered area formed on the mounting plate 12 is free to resonate independently from the plates 10 a, 10 b, etc., which are also free to resonate relative to the secured-together edge 18 of the damping unit. The variable tuning mounting plate or spacer 30 , which is preferably made of a one-fourth inch think, high density material such as fiberboard, is bonded securely to the mounting plate 12 , which may be accomplished using a solvent such as acetone. Acetone, by its chemical action momentarily melts (liquefies) the surface of the plastic mounting plate 12 thereby causing the mounting plate 12 and the variable tuning mounting plate or spacer 30 to be permanently fused together.
In the assembly as shown in FIG. 4, the variable tuning mounting plate or spacer 30 may be assigned a specific shape or angle relative to the mounting plate 12 by varying the dimensions shown as C and D in FIG. 4, thereby providing the assembly of FIG. 4 with a cantilevered portion described by the dimensions A and B. Varying the dimensions A and B therefore assigns to the structure an infinite series of mass-compliance product factors which, in accordance with the mathematical relationship governing the resonance frequency of a mass-spring system, causes the resonance frequency of the cantilevered portion of the structure of FIG. 4 to vary continuously over a broad band of frequencies.
It will be seen by those skilled in the art that the vibration damping unit 10 , shown in FIG. 1, and as in U.S. Pat. No. 5,583,324, forms an integral part of the assemblies of FIG. 2 and FIG. 3 but with two important distinctions: In the assembly of FIG. 2, it is seen that the vibration damping unit 10 incorporates a rectangular spacer plate 20 secured to mounting plate 12 . And in the assembly of FIG. 3, it is seen that the vibration damping unit 10 incorporates an angular spacer plate 30 secured to the mounting plate 12 . These important distinctions in construction between the assemblies of FIG. 1, FIG. 2, and FIG. 3 are therefore confined to the mounting plate 12 through which mechanical energy propagating in the form of periodic stress transfers from a vibrating body into the assemblies of FIG. 1, FIG. 2, and FIG. 3 . Thus, the range and level of vibration damping that can be obtained by the damping unit 10 can be varied by adjusting the spacer means 20 of FIG. 2 and spacer means 30 of FIG. 3, both of which form the means for transferring mechanical energy from a vibrating body into the damping unit 10 of FIG. 1 .
For example, the graph in FIG. 5 shows the frequency spectrum from 80Hz to 1000 Hz for a sweep signal applied to a laboratory test panel. The same reference spectrum shown in FIG. 5 was used in plotting the accelerometer-generated graphs shown in FIGS. 6 and 7 showing amplitude of vibrations versus frequency in reference to the vibration attenuating characteristics of the assemblies of FIGS. 2 and 1, respectively.
It can be seen in the assembly of FIG. 1 that the mounting plate 12 does not include a spacer plate and is therefore in full contact with the vibrating panel to which the assembly of FIG. 1 is attached. Therefore, the degree to which the magnitude of vibrations in the panel to which the assembly of FIG. 1 is attached is reduced and the frequencies over which such reduction in panel vibrations occurs is governed solely by modes of transverse vibrations in the series of damping plates 10 a, 10 b , 10 c, 10 d and 10 e. In reference to the graphs in FIG. 6 and FIG. 8, which show the vibration damping characteristics of the assemblies of FIG. 2 and FIG. 3 respectively, the graph in FIG. 7 shows that the assembly of FIG. 1 is more effective in reducing panel vibration at the higher frequency of 440 Hz than the assembly of FIG. 2 . This is due to the larger area of contact that the mounting plate 12 in the assembly of FIG. 1 makes with the vibrating panel to which the assembly is attached, thereby enabling a greater proportion of the higher frequency excitation forces originating in the vibrating panel to transfer into the assembly of FIG. 1 therein exciting into sympathetic resonance the higher frequency overtones which are normally exhibited by modes of transverse vibrations in the damping plates 10 a, 10 b, 10 c, 10 d and 10 e of the assembly of FIG. 1 .
The assembly of FIG. 2, in contrast to the assembly of FIG. 1, includes an intermediate mounting spacer or tuning plate 20 positioned between the mounting plate 12 of the damping unit 10 and the vibrating panel to which the assembly of FIG. 2 is attached. Therefore, it can be seen from the graph in FIG. 6 that the assembly of FIG. 2, by including the intermediate spacer member or tuning mounting plate 20 shown in FIG. 2 is more efficient than the assembly of FIG. 1 in reducing panel vibrations at the lower frequency approximating 110 Hz. By including in the assembly of FIG. 2 the intermediate spacer or tuning mounting plate 20 with the damping unit 10 and adjusting the tuning plate to the dimensions prescribed for a particular selected low frequency as disclosed in U.S. Pat. No. 5,691,516, a cantilevered portion of the damping unit 10 of FIG. 2 is formed which, due to its select tuning, is disposed by its mass-compliance product factor to respond independently of the damping plates 10 a , 10 b, 10 c, 10 d and 10 e of the assembly of FIG. 2 . By vibrating at a selected low frequency which, in this example, is shown in the graph of FIG. 6 to be tuned to vibrate in the vicinity of 110 Hz but which, depending on its intended application, can be varied in accordance with U.S. Pat. No. 5,691,515 to vibrate at any selected low frequency by adjusting the dimensions of the tuning mounting plate 20 in the assembly of FIG. 2 .
To those skilled in the art to which this invention relates, it will be seen from the graph in FIG. 6 that the damping plates 10 a , 10 b , 10 c , 10 d and 10 e , acting independently of the cantilevered portion of the assembly of FIG. 2, are not as efficient as they are in the assembly of FIG. 1 in reducing panel vibrations as the frequencies of vibrations rise and which, in this instance, are shown in the graph of FIG. 6 to occur at 440 Hz. As the frequency of vibrations rise, the intermediate mounting or tuning plate 20 of the assembly of FIG. 2, since it provides an area of contact with a vibrating panel to which it is attached that is smaller than the contact area provided by the mounting plate 12 of the damping unit 10 , and since it is positioned on the side opposite from side 18 of the damping unit 10 , mechanical energy originating in a vibrating panel is prevented from being transferred directly and efficiently into the damping plates 10 a , 10 b , 10 c , 10 d and 10 e which are shown in FIG. 1 to be secured together at edge 18 and free to vibrate on the other.
The assemblies of FIG. 1 and FIG. 2, as in U.S. Pat. Nos. 5,583,324 and 5,691,516 respectively, have been used extensively to reduce enclose panel resonances in loudspeaker systems that employ rigid enclosures made of such materials as medium density fiberboard. Whenever such loudspeaker systems are in operation, their drive units, in addition to air modes generated within the enclosure, subject the enclosure to periodic or oscillating stress. The resulting strain that is released during each cycle excites the enclosure panels into resonance. The distorted sound from these panel resonances causes response errors in the loudspeaker's sound radiation pattern.
The assembly of FIG. 1 and FIG. 2 are attached to rigid loudspeaker enclosures at locations where panel resonances are found to occur. The assembly of FIG. 1, which does not include a tuning mounting plate 20 , and is therefore not tunable to respond efficiently at very low frequencies, is used on enclosure panels to reduce resonances above 200 Hz while the assembly of FIG. 2, which includes a tuning mounting plate 20 and is therefore tunable to respond efficiently at very low frequencies, is typically used on enclosure panels to reduce resonances below 200 Hz.
The assembly of FIG. 3 has been shown to be more effective than either of the assemblies of FIG. 1 or FIG. 2 in reducing panel resonances that occur in loudspeakers which, instead of employing rigid enclosures, are mounted into walls. Such loudspeakers, which are commonly referred to as in-wall speakers, employ thin plastic baffles onto which the loudspeaker's drive units are attached. Whenever such in-wall speakers are in operation, the reaction forces from the drive units combined with air moves within the wall cavity cause the in-wall speaker's thin plastic baffle to resonate at very high magnitude levels. The distorted sound that results from such severe baffle resonances are disturbing to listeners and it would therefore be advantageous to substantially reduce such resonance thereby making the sound from in-wall speakers enjoyable rather than disturbing.
The chart in FIG. 8 shows the extent to which the assembly of FIG. 3 reduces baffle resonances in a typical 8-inch 2-way in-wall speaker. The shaded area of the graph in FIG. 8 shows the absorption of energy by the assembly of FIG. 3 along with the corresponding reduction in baffle resonances measured by an accelerometer positioned immediately above the in-wall speaker's low frequency drive unit as shown in FIGS. 10 and 10A (drive not shown). It will therefore be seen by those skilled in the art that the assembly of FIG. 3, by including the variably tuned angular mounting plate 30 , is tunable to respond efficiently, not only at very low frequencies but also at higher frequencies and therefore, when used on the plastic baffles of in-wall speakers, the assembly of FIG. 3 is able substantially to reduce resonances over a broad frequency band extending from the in-wall speaker's fundamental frequency of 50 Hz to 1 KHz as shown by the graph in FIG. 8 .
FIGS. 9, 9 A show the assembly of FIG. 3 mounted onto the plastic baffle or speaker base 32 at an area located immediately above the low frequency drive unit 31 of the in-wall speaker 31 a . The side view elevation in FIG. 9A shows projected plastic stand-off connections 33 which are threaded inside to receive mounting screws for securing the assembly of FIG. 3 to the plastic baffle or speaker base 32 .
FIGS. 10, 10 A show a rear and side view of a wall-mounted speaker with a cutaway view of the area at the top of the wall-mounted speaker. In both the rear and side view is shown an accelerometer 40 attached to measure the amplitude of vibrations versus frequency in reference to the tuning method of the invention. The location immediately above the cutout hole for mounting the low-frequency drive unit is the location where a plastic in-wall speaker baffle is prone, by its high compliance, to vibrate most energetically and an accelerometer attached at this location measures the magnitude of these vibrations. The graph in FIG. 8 shows the reduction in baffle vibrations measured by the accelerometer attached as shown in FIG. 10 .
FIG. 11 is a perspective, exploded view showing a procedure for attaching the assembly of FIG. 3 to an in-wall speaker's plastic baffle. The attachment plate 34 is first secured to the threaded projections 33 by means of screws 36 . The attachment plate 35 and the angular tuning plate 30 are bonded or fused together with the damping unit 10 to form a monolithic structure. The monolithic structure thus formed is then secured to the attachment plate 34 by means of screws 38 and the screws 36 projected beyond the surface of the attachment plate 34 are free to pass into the holes 37 on attachment plate 35 . The completed installation of the assembly of FIG. 3 is shown in FIG. 9 .
FIG. 4 is similar to FIG. 3 showing the dimensions A, B, C and D which are adjusted to change the frequency range and the level of magnitude to which the assembly attenuates vibrations in the panel to which the assembly is attached. It is seen by those skilled in the art that reducing the distance C while increasing the distance D broadens the range of frequencies over which the cantilevered portion of the assembly described by dimensions A and B vibrates and that increasing the distance C while reducing the distance D narrows the range of frequencies over which the cantilever portion of the assembly described by dimensions A and B vibrates. The angular shape of the tuning plate 30 relative to the rectangular mounting plate 12 of the assembly is therefore seen to govern the range of continuously varying frequencies of vibrations that the assembly may be assigned to operate over in attenuating vibrations in the panel to which the assembly of FIG. 3 is attached.
The above-described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to this preferred embodiment will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims. | An in-wall speaker has a variably tuned vibration absorber to absorb and dissipate vibrations in the speaker and surroundings that tend to cause distortions. The vibration absorbing device, including a stack of viscoelastic damping plates, is secured to the speaker or connected structure via a trapezoidally shaped tuning plate, which provides a varying degree of cantilever in different portions of the stack of plates. The effect is to absorb vibrations over a broad range of frequencies. | 5 |
TECHNICAL FIELD
[0001] This application relates to the field of ink jet printing.
BACKGROUND
[0002] Ink jet printing is a non-impact method that produces droplets of ink that are deposited on a substrate such as paper or transparent film in response to an electronic digital signal. In various commercial or consumer applications, there is a general need to provide ink jet images that are printed edge-to-edge on a substrate. There is also a need for printing images on irregular and/or small substrates such as candy and cookies.
[0003] Ink jet printing systems generally are of two types: continuous stream and drop-on-demand. In continuous stream ink jet systems, ink is emitted in a continuous stream under pressure through at least one orifice or nozzle. Multiple orifices or nozzles also may be used to increase imaging speed and throughput. The ink is ejected out of orifices and perturbed, causing it to break up into droplets at a fixed distance from the orifice. At the break-up point, the electrically charged ink droplets are passed through an applied electric field that is controlled and switched on and off in accordance with digital data signals. Charged ink droplets are passed through a controllable electric field, which adjusts the trajectory of each droplet in order to direct it to either a gutter for ink deletion and recirculation or a specific location on a recording medium to create images. The image creation is controlled by electronic signals.
[0004] In drop-on-demand systems, a droplet is ejected from an orifice directly to a position on a recording medium by pressure created by, for example, a piezoelectric device, an acoustic device, or a thermal device controlled in accordance with digital data signals. An ink droplet is not generated and ejected through the nozzles of an imaging device unless it is to be placed on the recording medium.
SUMMARY
[0005] In one aspect, an ink jet printing system has an ink jet print head configured to eject ink drops, and a perforated substrate support comprising a plurality of holes and configured to carry a substrate over a first surface of the perforated substrate support, and a collector disposed beneath the perforated substrate support. The ink jet print head and the holes in the perforated substrate support are configured to allow at least a portion of ejected ink drops not received by the substrate to pass through the holes, and the collector is configured to collect at least a portion of the ejected ink drops not received by the substrate.
[0006] In another aspect, an ink jet printing system includes an ink jet print head configured to eject ink drops, a perforated substrate support comprising a plurality of holes and configured to carry a substrate over a first surface of the perforated substrate support, a conveying mechanism configured to cause relative movement between the ink jet print head and the perforated substrate support, a collector disposed behind the second surface of the perforated substrate support, and a cleaning station configured to clean the ink fluid captured on perforated substrate support. The ink jet print head and the holes in the perforated substrate support are configured to allow at least a portion of ejected ink drops to pass through the holes, and the collector is configured to collect at least a portion of the ejected ink drops not received by the substrate.
[0007] In yet another aspect, a method for printing an image on a substrate includes placing a substrate over a first surface of a perforated substrate support comprising a plurality of holes, causing relative movement between the substrate and an ink jet print head, disposing ink drops from the ink jet print head on the substrate to form an image, and collecting ink drops disposed outside of the edge of the substrate behind a second surface of the perforated substrate support.
[0008] Implementations of the system may include one or more of the following. The ink jet printing system can further include a conveying mechanism configured to cause relative movement between the ink jet print head and the perforated substrate support. The ink jet printing system can further include an ink absorbing material over the collector adapted to collect ink drops ejected by the ink jet print head. The ink jet printing system can further include a cleaning station configured to remove ink from the perforated substrate support. The ink jet printing system can further include a substrate handling mechanism configured to feed the substrate to the conveying mechanism or to retrieve the substrate from the conveying mechanism. The second surface of the perforated substrate support can be opposite to the first surface of the perforated substrate support. The perforated substrate support can include a cylindrical surface adapted to receive the substrate. The perforated substrate support can include a conveyance belt driven by one or more rollers. The ink jet printing system can further include a print head transport mechanism capable of moving the ink jet print head relative to the substrate. The ink jet printing system can further include one or more sensors configured to detect the location or the orientation of the substrate. The ink jet print head can deliver ink drops to form an image on the substrate. The ink jet print head can print the image full bleed along at least one edge of the substrate.
[0009] Embodiments may include one or more of the following advantages. The disclosed ink jet system is capable of full bleed printing while preventing the contamination of the substrate by the overspray inks. The system provides effective arrangements for collecting and cleaning the overspray inks. Furthermore, the disclosed ink jet system is capable of printing images on small and irregular shaped ink substrates without the need of pre-aligning the substrates before printing.
[0010] Implementations of the method for printing an image can include printing an image that is full bleed along at least one edge of the substrate.
[0011] The details of one or more embodiments are set forth in the accompanying drawing and in the description below. Other features, objects, and advantages of the invention will become apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates an ink jet printing system having an ink jet print head and a substrate transport system comprising a perforated substrate support.
[0013] FIG. 2 illustrates an ink jet printing system having an ink jet print head and a substrate transport system comprising a perforated substrate support having a cylindrical surface.
[0014] FIG. 3 is a top view of a substrate over a perforated substrate support in the substrate transport system of FIG. 1 and FIG. 2 .
DETAILED DESCRIPTION
[0015] FIG. 1 shows an ink jet printing system 10 including an ink jet print head 20 , a controller unit 30 that provides image data and other digital data to the ink jet print head 20 , and an ink reservoir 40 for supplying ink to the ink jet print head 20 . A substrate 50 is transported by a substrate transport system 100 . The substrate transport system 100 includes a conveyor belt 70 , rollers 120 and 130 for driving the conveyor belt 70 , and a motor 110 that can drive the roller 120 under the control of the control unit 30 .
[0016] One or more sensors 150 can detect the position and orientation of the substrate 50 . The detection of the positions of the substrate 50 can be triggered by the edges of the substrate 50 . The detection of the position of the substrate can facilitate the printing of the ink pattern on the substrate 50 from the leading edge and around the edges of the substrate 50 . In another embodiment, the sensors 150 can detect both the position and the orientation of the substrate 50 on the perforated substrate support of the conveyor belt 70 . In response to the signal received from the sensors 150 , the control unit 30 can rotate the input digital image to compensate for the orientation variation of the substrate 50 . As a result, an image can be printed with desired orientation over the substrate 50 .
[0017] At least a portion of the conveyor belt 70 includes a perforated substrate support that includes holes that extend through the belt. The perforated substrate support can include a mesh of metal wires or a plastic sheet punched with holes. Preferably, the holes take a majority of the surface area of the conveyor belt 70 to allow overspray inks to pass through. The openings in the mesh or the punched holes can have dimensions in the range of 0.1 inch to one inch to allow ink drops to pass through while also keeping the substrate 50 flat. The top surface of the perforated substrate support preferably comprises an ink repelling material such as Teflon that helps to prevents ink accumulation in the solid portion of the perforated substrate support. The substrate 50 is carried by the perforated substrate support of the conveyor belt 70 to positions under the ink jet print head 20 to receive ink drops 140 ejected by the ink jet print head 20 . As shown in FIG. 1 , the substrate 50 can be carried by a flat portion of the conveyor belt 70 when the image is printed on the substrate 50 by the ink jet print head 20 . Alternatively, the perforated substrate support carrying the substrate may be fixed during printing. The image is printed by scanning the ink jet print head over the substrate.
[0018] An example of the perforated substrate support 370 is shown in a top view in FIG. 3 . The perforated substrate support 370 includes a plurality of holes 310 that occupy a large portion of the area. A substrate 350 is placed over a perforated substrate support 370 spanning over a plurality of holes 310 .
[0019] The disclosed ink jet printing system 10 is capable of producing an image that is full bleed along at least one edge of the substrate 50 . One known problem with full bleed printing is that the inks ejected from the print heads often sprays outside of the substrate along the edges of substrate where the image is printed full bleed to that edge. The overspray inks can contaminate the supporting substrate and the back surface of the substrate if not handled properly.
[0020] In one embodiment, the ink jet printing system 10 includes a collector 90 under the perforated substrate support in the conveyor belt 70 . The overspray ink fluids outside of the edges of the substrate 50 can fall through the through holes of the perforated substrate support and be captured by the collector 90 . The collector 90 can further include absorbent material 95 . The absorbent material 95 can be replaceable or disposable to keep substrate transport mechanism 100 clean. The absorbent material 95 can include man made or natural materials. The absorbent material 95 can also be selected to be most effective in absorbing the specific types of inks used for each batch of substrates: for example, aqueous, solvent types of inks.
[0021] In another embodiment, the ink jet printing system 10 includes a cleaning station 80 that is capable of cleaning the conveyor belt 70 after the printing and after the substrate 50 is received. The cleaning station 80 can include a rubber blade 81 that can blade off the ink accumulated on the conveyor belt 70 and a sponge 82 that can wipe and absorb inks on the conveyor belt 70 . The conveyor belt 70 can be cleaned regularly by wiping, blotting, washing, etc. after printing one or more a batch of substrates 50 .
[0022] The ink jet printing system is particularly useful for printing small and/or irregular shaped substrates such as cookies and candy. The term irregular shape refers to a substrate that has at least one edge that is not straight. The positions and the orientations of the small and/or irregular shaped substrates can be detected by one or more sensors 150 . The ink pattern printed can be full bleed along at least one edge of the substrate 50 . The overspray inks can be captured by the collector 90 without contaminating the undersides of the substrates. The ink pattern can also be automatically adjusted according to the specific orientation of the substrate 50 . The ink jet printing system therefore enables the ink jet printing on irregular shaped substrates without the need for aligning the substrates 50 on the conveyor belt 70 .
[0023] In another embodiment as shown in FIG. 2 , the ink jet printing system 310 includes an ink jet print head 320 , a controller unit 330 that provides image data and other digital data to the ink jet print head 320 , and ink reservoir 340 for supplying ink to the ink jet print head 320 . A substrate 350 is transported by a substrate transport system 300 that includes a drum platen 370 and a motor 410 that can drive the drum platen 370 under the control of the control unit 330 .
[0024] One or more sensors 450 can detect position and orientation of the substrate 350 . The detection of the positions of the substrate 350 can be triggered by the edges of the substrate 350 . The detection of the position of the substrate can facilitate the printing of the ink pattern on the substrate 350 from the leading edge and around the edges of the substrate 350 . In another embodiment, the sensors 450 can detect both the position and the orientation of the substrate 530 on the perforated substrate support of the drum platen 370 . In response to the signal received from the sensors 450 , the control unit 330 can rotate the input digital image to compensate for the orientation variation of the substrate 350 . As a result, an image can be printed with desired orientation over the substrate 350 .
[0025] The drum platen 370 is bounded by a cylindrical surface adapted to receive the substrate 350 . At least a portion of the drum platen 370 includes a perforated substrate support that includes through holes. The substrate 350 is attached to the perforated substrate support of the drum platen 370 by clamping or vacuum sucking. The substrate 350 is transported to positions under the ink jet print head 320 to receive ink drops 440 ejected by the ink jet print head 320 . The overspray inks passing the through holes of the perforated substrate support are captured by a collector 390 that is fixed under the printing area inside the drum platen 370 . The collector 390 may include ink absorbing materials 395 . The surface of the drum platen can be cleaned regularly by a blade 381 and a sponge 382 when the contaminated area of the surface of the drum platen 370 is rotated to a cleaning station 380 .
[0026] The substrate transport system 300 can further comprise a substrate picking mechanism for feeding the substrate 350 onto the drum platen 370 , and a substrate retrieval mechanism for retrieving the substrate 350 from the drum platen 370 . The released substrates 425 containing images can be held in a substrate tray 420 .
[0027] Substrates compatible with the present invention include natural paper or man-made materials for displaying images including opaque, translucent, or transparent materials. The substrates can also include foods such as cookies, candies, and cakes. The substrates can also comprise plastics, ceramics, stone, metallic substrate, wood, and fabrics. Ink types compatible with the ink jet printing system described include water-based inks, solvent-based inks, and hot melt inks. The colorants in the inks can comprise dye or pigment. Furthermore, the ink jet printing system disclosed is also compatible with delivering other fluids such as polymer solutions, gel solutions, solutions containing particles or low molecular-weight molecules, which may or may not include any colorant.
[0028] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | An ink jet printing system including an ink jet print head configured to eject ink drops, a perforated substrate support having a plurality of holes, configured to carry a substrate over a first surface of the perforated substrate support, wherein the ink jet print head and the holes in the perforated substrate support are configured to allow at least a portion of ejected ink drops not received by the substrate to pass through the holes, and a collector disposed beneath the perforated substrate support, configured to collect at least a portion of the ejected ink drops not received by the substrate. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation in part of patent application Ser. No. 11/265,839. The prior application listed the same inventors.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of building materials. More specifically, the invention comprises a method for producing a simulated limestone finish on the surface of cast concrete tiles.
[0006] 2. Description of the Related Art
[0007] Concrete has been used to cast functional and decorative building materials for many years. It may be used, as an example, to pour a monolithic floor slab. A finished surface can be created on such a slab, so that no further flooring material is needed.
[0008] Concrete is long-lasting and relatively inexpensive. One drawback, however, is its perceived lack of visual appeal. While some recent innovations in decorative surfaces have improved the appeal of concrete, it does not rival natural stone. Stone pavers or tiles display a natural variation in texture, luster, and color which many people find appealing. Stone pavers also feature cavities of varying depths with complex surface textures. For these reasons, most people prefer the look of natural stone. However, the price of stone—which can be ten times more expensive than concrete—often drives the consumer toward concrete. It would therefore be advantageous to provide a cast concrete product which mimics the desired surface look of natural stone.
BRIEF SUMMARY OF THE PRESENT INVENTION
[0009] The present invention comprises a new process for creating a decorative surface on a cast concrete tile. A mold is prepared by coating with mold release. An aggregate of water, coloring dye, sand, Portland cement, and pea gravel is pre-mixed. Baking soda is mixed with a significant volume of water to create a high-viscosity paste. The paste preferably has a high solid to liquid ratio so that it can be crumbled into baking soda clumps of various sizes. The dampened baking soda clumps are sprinkled randomly onto the bottom surface of the mold (which will bear against what becomes the top surface of the cast tile). The pre-mixed aggregate is then added to the mold. The aggregate is then screed and compressed in the mold to minimize voids. A plastic cover is next added to reduce the moisture loss rate and increase the curing time.
[0010] The wet aggregate comes into contact with the baking soda clumps. The baking soda reacts with the water in the aggregate to form sodium hydroxide and carbonic acid. A portion of the carbonic acid then tends to break down into water and carbon dioxide gas. The carbon dioxide gas produces voids and channels around the baking soda clumps as the aggregate cures.
[0011] Once the aggregate is cured, the mold is separated into its component pieces and the cast concrete tile is removed. The residual baking soda is preferably removed. The upper surface of the cast tile will have been etched by the dampened baking soda, producing a variation in color and texture. The size of the baking soda clumps will also produce significant cavities in the surface. The production of the carbon dioxide gas provides a complex texture to the surface of these cavities. The ultimate effect is similar to natural stone.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 is a perspective view, showing a mold used to create a cast tile.
[0013] FIG. 2 is a perspective view, showing the mold in an assembled state.
[0014] FIG. 3 is a perspective view, showing the addition of the dampened baking soda.
[0015] FIG. 4 is a perspective view, showing the filling of the mold.
[0016] FIG. 5 is a perspective view, showing the concrete curing in the mold.
[0017] FIG. 6 is a detail view, showing the surface finish of a cast tile.
[0018] FIG. 7 is a perspective view, showing the process of adding water to the baking soda to form a high viscosity paste.
[0019] FIG. 8 is an elevation view, showing the baking soda clumps on the bottom surface of the mold.
[0020] FIG. 9 is a sectional elevation view, showing the reaction between the baking soda clump and the surrounding wet concrete.
[0021] FIG. 10 is a sectional elevation view, showing the surface of the concrete after it has cured.
[0000]
REFERENCE NUMERALS IN THE DRAWINGS
10
mold
12
base
14
half frame
16
half frame
18
upper tab
20
lower tab
22
upper tab
24
lower tab
26
hole
28
pin
30
pin hole
32
mold cavity
34
baking soda
36
aggregate
38
shovel
40
filled mold
42
completed tile
44
void
46
color variation
48
back side
50
mixing container
52
water
54
mixer
56
water infused baking soda
58
soda clump
60
wet concrete
62
carbon dioxide bubble
64
large cavity
66
bubble cavity
68
bubble channel
70
dry concrete
72
textured surface
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 shows the components of the mold used to create a cast tile. The mold is created by joining half frame 14 and half frame 16 to base 12 . Half frame 14 and half frame 16 are both “L” shaped pieces that form a square when joined at their ends. Half frame 14 has upper tab 18 that mates with lower tab 24 of half frame 16 when the two half frames are joined to form a square. Half frame 14 also has lower tab 20 that mates with upper tab 22 of half frame 16 when the square-framed mold is formed. Corresponding holes 26 of upper tab 18 and lower tab 24 and corresponding holes 26 of upper tab 22 and lower tab 20 align when the two frames are joined and the upper and lower tabs are mated.
[0023] Base 12 has two pin holes 30 which are adapted to receive pins 28 when the frame is placed on the base. As described above, corresponding holes 26 of upper tab 18 and lower tab 24 and corresponding holes 26 of upper tab 22 and lower tab 20 are aligned when half frame 14 and half frame 16 are joined to form a square. Pins 28 are then inserted through holes 26 and pin holes 30 in base 12 .
[0024] The assembled mold is illustrated in FIG. 2 . Half frame 14 and half frame 16 form a square that is connected together and to base 12 by pins 28 as described above. Mold cavity 32 results from the attachment of the two half frames to the base.
[0025] FIG. 3 shows how the mold is prepared to produce concrete tiles with a stone-like appearance. The surfaces of the mold are first prepared with mold release to prevent bondage of the concrete to the mold. Those skilled in the art are familiar with this part of the process and the various products that can be used to prevent bondage. Baking soda 34 , sodium bicarbonate, is next applied to the base 12 . The baking soda must be prepared in a controlled fashion.
[0026] FIG. 7 shows one method of preparing the baking soda. The baking soda is placed in mixing container 50 . Water 52 is added while mixer rotates within the mixing container to mix the water into the baking soda. The mixing continues until the water is completely infused through the baking soda. Sufficient water should be added to produce a high-viscosity paste which can then be mechanically broken into clumps of a desired size. The baking soda to water ratio is significant. The table presented below describes the performance of various mixtures of baking soda and water, with the ratios being stated in terms of volume.
[0000]
TABLE ONE
Baking Soda
to Water Ratio
Result
5.00 to 1
Clumps are 0.5 mm to 2.0 mm
4.75 to 1
Clumps are 1.0 mm to 10.0 mm (avg. 5.0 mm)
4.50 to 1
Clumps are 2.0 mm to 13.0 mm (avg. 6.0 mm)
4.25 to 1
Clumps are 4.0 mm to 24.0 mm (avg. 12.0 mm)
3.75 to 1
Clumps are 25.0 mm+
2.50 to 1
Forms a slurry that will not crumble
[0027] The particle size of the unwetted baking soda is quite small—well under 0.2 mm. The creation of the high viscosity paste allows the baking soda to be aggregated into much larger clumps. The clumps are created by mechanically shearing the water infused baking soda to break it into clumps. The shearing may be performed manually, or by using a mechanical shearing device. One skilled in the production process may create a suitable collection of clumps by kneading the paste using his or her hands. The sheared clumps will simply fall out of the hands where they may be collected.
[0028] The size of the clumps used is significant. The reader may need an initial understanding of how the clumps are used to appreciate the significance of the clump size. A brief explanation of use will thus be provided at this time, with a more detailed explanation to follow.
[0029] The water infused baking soda clumps are spread onto the lower surface of the concrete mold. Wet aggregate is then placed in the mold and left to cure. The baking soda clumps perform three basic functions: (1) They create large cavities in what will become the upper surface of the decorative tile; (2) The baking soda forms bubbles which displace some concrete and create a deeply textured surface in the large cavities; and (3) A small portion of the baking soda dissolves in water and flows away from the clumps over what will become the upper surface—thereby providing a conventional etching effect.
[0030] The goal is to mimic natural stone. Thus, baking soda clumps below about 2.0 mm in size are not very useful because they will not create a cavity in the finished product that is large enough for an observer to see and appreciate. Adding more water to the baking soda paste tends to permit the creation of large clumps. However, adding more water also creates a clump which tends to slump and flatten when the concrete is added to the mold. Experimentation has shown that a usable range of baking soda to water ratio (state in terms of volume) is between about 5 to 1 and about 4 to 1. A more preferable range is between about 4.75 to 1 and about 4.25 to 1. The most preferred range is around 4.50 to 1. This ratio produces a good clump size and a nice variation in clump size. The clumps produced are fairly rigid and able to hold their shape when the wet concrete is added—thereby creating a large and fairly deep void in the finished surface.
[0031] The exact baking soda to water ratio will depend somewhat upon the ambient temperature and humidity (as well as how long the baking soda has been exposed to ambient humidity). Thus, in humid conditions the ideal volumetric ratio could be 4.60 to 1, while in dry conditions it might drop to 4.40 to 1. Some adjustment may be needed to maintain the desired distribution of baking soda clump sizes—which is the ultimate objective.
[0032] It is known in the art to spread fine baking soda powder over wet concrete to etch the surface. A typical particle size distribution of baking soda is 0.001 to 0.004 mm in diameter. These small particles simply dissolve in the water and create the etching effects via reacting with the water, calcium compounds, and silicon compounds in the concrete aggregate. They are too small to create voids or other visually discernible surface features. The baking soda clumps used in the present inventive process must be of a substantial size in order to create the desired voids and other visual effects. As explained previously, this means that most of the clumps need to be 2.0 mm or larger.
[0033] Those skilled in the art will realize that the water infused baking soda can be mixed and crumbled using a wide variety of techniques. However this is done, the baking soda clumps thus produced are randomly spread across the surface of the base of the mold. FIG. 8 shows a variety of soda clumps 58 resting on base 12 . Some of the clumps are fairly small (2 mm) while others are fairly large (10 mm) with a broad distribution of intermediate sizes.
[0034] Concrete aggregate must then be made to produce the tiles. The aggregate can be any combination of concrete sand, gravel, cement, coloring agent and water. Those skilled in the art know that the precise formula can be varied to produce concrete with different appearances and properties. The aggregate is formed by mixing the aforementioned ingredients in a mixer. Additionally, the use of an ochre coloring agent is especially effective in creating stone-like coloration. A heterogenous coloration of the mixture can be enhanced by mixing the ingredients for three to five minutes, i.e., the coloring dye is unevenly distributed.
[0035] The mold is then filled as shown in FIG. 4 . The mold cavity is filled with aggregate 36 using shovel 38 or a variety of other known techniques. The mold cavity is filled completely with special care given to insure that the corners of the mold are filled and that the aggregate surface is even and level with the mold frame. A screed bar can be raked back and forth across the top of the mold frame to prevent the formation of ridges, lumps, or raised corners.
[0036] The aggregate is then allowed to cure as shown in FIG. 5 . Filled mold 40 is allowed to sit long enough for the aggregate to dry. Those skilled in the art know that the drying time required is dependent upon the aggregate's recipe and environmental conditions like temperature and humidity. The tiles can be covered with plastic wrap during the curing process to help the tiles hold in moisture.
[0037] FIG. 9 shows a sectional elevation view through the soda clumps as the concrete aggregate is curing. Wet concrete 60 surrounds an envelopes soda clumps 58 . The baking soda (sodium bicarbonate) mildly reacts with the water in the surrounding concrete (as well as with the water within the clump) as expressed in the following reaction:
[0000] NaHCO 3 +H 2 O→NaOH+H 2 CO 3
[0038] Some of the carbonic acid then breaks down as expressed in the following reaction:
[0000] NaHCO 3 +H 2 O→H 2 O+CO 2
[0039] The reaction thus gives off a small quantity of carbon dioxide gas in the vicinity of the surface of the soda clumps. This is a mild reaction and not to be confused with the relatively violent reaction created when baking soda is mixed with an acidic substance such as citric acid or vinegar. The concrete aggregate is fairly alkaline and the gas formation rate is limited. A moderate quantity of carbon dioxide bubbles 62 form in the water surrounding the soda clumps. Some bubbles are small while others grow larger. Some bubbles aggregate and form channels in the wet concrete 60 (as seen in the right hand soda clump 58 shown in FIG. 9 ).
[0040] Those skilled in the art will know that the alkalinity of the concrete aggregate can be adjusted by adjusting the ratio of Portland cement to the other materials, as well as by adding modifiers such as weak acids. Adjusting the alkalinity will alter the carbon dioxide gas formation rate around the baking soda clumps. This will alter the amount of surface texture added by the gas bubbles to the voids created by the soda clumps. As explained in the present inventive method, the size of the baking soda clumps can be adjusted by varying the water content of the high-viscosity baking soda paste. Varying the clump size will vary the overall size of the voids in the finished surface produced by the clumps. Thus, one practicing the inventive process has the ability to vary the size of the voids and the surface texture of the voids. This permits many different types of stone to be accurately simulated.
[0041] A small portion of the baking soda tends to dissolve in the surrounding water and spread as a film across base 12 . This portion acts like the prior art technique of spreading dry powdered baking soda across a concrete mold. It mildly etches the surface and produces pleasing color variations.
[0042] Those skilled in the art will know that humidity and temperature control can be added to the curing process to produce a more evenly cured product. Once cured, the tile is released from the mold by removing the pins and tapping the frame with a hammer.
[0043] The resulting tile that is produced by this process is shown in FIG. 6 . Completed tile 42 serves as an illustration of some of the features and added benefits of this process. First, voids 44 are created where the aggregate cures around the space occupied by the baking soda and gases produced by the reaction of baking soda with the aggregate. This gives the surface of the tile a porous texture that is a similar to the surface of tiles made from natural stone. Additionally, color variation 46 is produced. The line illustrated in FIG. 6 represents the boundary between subtly different hues. This boundary may actually appear blurry or mottled. Color variation is also influenced by the reaction of the baking soda and aggregate. This variation in color is often desirable as it mimics the coloration of natural stone.
[0044] FIG. 10 shows the textured surface in much more detail. The reader should note that the resulting texture of FIG. 10 corresponds to the soda clumps illustrated in FIG. 9 . The soda clumps produce large and richly textured voids. Textured surface 72 includes large cavities 64 created by the baking soda clumps. Many smaller bubble cavities 66 lie along the boundary of each large cavity—producing a texture reminiscent of coral. Bubble channels 68 extending deep into the dried concrete are also formed at various locations. The reader should appreciate that the depiction in FIG. 10 is two dimensional. The effect is in reality three dimensional with a great deal of pleasing complexity. The result is very similar (visually) to the appearance of natural stone.
[0045] Different coloring agents can be used to mimic many variety of natural stone colors. 548 Ochre color, an effective coloring agent for producing a natural stone look, is commercially available from the New Riverside Ochre Company located in Cartersville, Ga. Other coloring agents can be used to imitate other naturally occurring stone colorations including dolphin grey, champagne, and rice white. Multiple coloring agents can even be used in the same batch to produce tiles with “swirls” of different colors. Furthermore, the degree of color variation can be controlled by adjusting the mixing time of the aggregate. A longer mixing time will result in a more homogenous coloration, and a shorter mixing time will result in greater color variation across the tile's surface.
[0046] The process can be automated as well. One example of an automated process utilizes multi-cavity automated machinery to produce the tiles with limited human assistance. An automated mixer can be used to prepare the aggregate, and a controller can be used to coordinate mixing and pouring time intervals. An automated mixer and shearer can also be used to produce the water infused baking soda and to distribute the baking soda clumps into the molds. Using a conveyer belt or other means of locomotion, mold trays can be fed through various stations. First, the mold trays can be run through a station that sprays mold release. Second, the mold trays can be run through a station that randomly distributes baking soda across a two-dimensional field. The mold trays can then be sent to an injection site to be filled with aggregate. Finally, the trays can be circulated through an autoclave or other drying means to cure the concrete. A controller, like a programmable logic controller, can be used to coordinate the entire process.
[0047] Although the preceding descriptions contain significant detail they should not be viewed as limiting the invention but rather as providing examples of the preferred embodiments of the invention. As one example, many types and shapes of molds can be used to produce the concrete tiles. Accordingly, the scope of the invention should be determined by the following claims, rather than the examples given. | A new process for creating a decorative surface on a cast concrete tile. A mold is prepared by coating with mold release. An aggregate of water, coloring dye, sand, Portland cement, and preferably filler material such as pea gravel is pre-mixed. Baking soda is mixed with a significant volume of water to create a high-viscosity paste. The paste preferably has a high solid to liquid ratio so that it can be crumbled into baking soda clumps of various sizes. The dampened baking soda clumps are sprinkled randomly onto the bottom surface of the mold (which will bear against what becomes the top surface of the cast tile). The pre-mixed aggregate is then added to the mold. Once the aggregate is cured, the cast concrete tile is removed. The baking soda clumps create complex voids in the tile's upper surface, producing a surface texture similar to limestone. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an embroidery frame used to retain in tension region to be embroidered of a cloth on which embroidery is to be made by an embroidering machine.
2. Description of the Prior Art
The embroidery frame of this kind includes the following. A driving frame is adapted to be moved horizontally by a driving means in the embroidering machine. A cloth spreading frame is joined to the driving frame so that the cloth spreading frame projects horizontally from the driving frame. The cloth spreading frame is provided with an embroidery hole used to expose a region to be embroidered of a cloth thereto.
When this conventional embroidery frame is used, a small article, such as a sock can be embroidered without any trouble with the sock held on a cloth spreading frame so that a region to be embroidered thereof is positioned in the embroidery hole in the cloth spreading frame. However, in order to make embroidery on a wide region, such as the whole surface of the back of, for example, a sports jacket, it is necessary that a cloth spreading frame be formed to a larger size accordingly. In order that a larger-sized cloth spreading frame can follow up a horizontal movement of the driving frame without being vibrated laterally, it is necessary that the cloth spreading frame be made of a material of a large diameter and a material of a large thickness. If a cloth spreading frame is formed with such materials, the weight thereof increases. If embroidery is made on a cloth by using such a cloth spreading frame, a free end portion of the cloth spreading frame lowers due to its own weight. If the free end portion of the cloth spreading frame thus lowers, the lower surface of the region to be embroidered of a cloth rubs against a bed of the embroidering machine, so that the cloth wears out. In some cases, the region being embroidered of the cloth becomes unable to be moved in accordance with the movement of the driving frame due to the resistance occurring in the cloth rubbing against the bed of the embroidering machine, to cause a deformed embroidered pattern to be produced. These are the problems encountered in a conventional embroidery frame.
In order to prevent the free end portion of the cloth spreading frame from lowering as mentioned above, the cloth spreading frame may be formed with materials of a further larger diameter and a further larger thickness which permit the resultant cloth spreading frame to withstand its own weight. However, if the cloth spreading frame is formed in this manner, the weight thereof becomes very large. A heavy cloth spreading frame constitutes an unbalanced load with respect to the driving frame. This prevents a regular driving mechanism from providing a high-speed horizontal movement of the driving frame. A large and heavy cloth spreading frame has such problems.
SUMMARY OF THE INVENTION
The present invention has been developed with a view to solving the problems (technical problems) of the above-described prior art embroidery frame.
An object of the present invention is to provide an embroidery frame in which a free end portion of a cloth spreading frame is supported on a leg, whereby, even when the cloth spreading frame is formed to a large size and, moreover, with materials of a large diameter and a large thickness so that the cloth spreading frame can follow up a horizontal movement of a driving frame without being vibrated laterally, the lowering of the free end portion of the cloth spreading frame can be prevented, so that the embroidering on a cloth can be done properly.
In the embroidery frame according to the present invention, embroidery hole-carrying cloth spreading frame is joined to a driving frame, which is adapted to be moved horizontally by driving means in the embroidering machine, so as to project horizontally therefrom, a leg for supporting the cloth spreading frame being provided on the side of the free end portion of the cloth spreading frame so that the leg is moved horizontally with the cloth spreading frame.
A cloth to be embroidered is held in tension on the cloth spreading frame so that the region to be embroidered of the cloth is exposed to the embroidery hole. When the driving frame is then moved horizontally, the cloth spreading frame is also moved horizontally therewith, and the region to be embroidered of the cloth in the embroidery hole is moved horizontally. Embroidery is made on the region while it is moved in this manner. In this embroidery frame, the cloth spreading frame is supported at its free end portion on the leg, so that the lowering of the same portion is prevented.
The present invention having the above-described construction has the following effects. When the cloth spreading frame is formed to a larger size so as to make embroidery on a region of a large area of a cloth, and, moreover, with materials of a large diameter and a large thickness so as to enable the cloth spreading frame to follow up a horizontal movement of the driving frame without being vibrated laterally thereby, the weight of the cloth spreading frame increases. However, the present invention has advantageous features that the cloth spreading frame is supported at its free end portion on the leg, whereby the lowering of the free end portion can be prevented even when the weight of the cloth spreading frame is thus increased. Owing to this advantageous structure, the abrasion of the lower surface of the region to be embroidered of a cloth against the bed of an embroidering machine and the deformation of embroidered patterns, which are encountered in a conventional embroidering machine, can be prevented. Accordingly, proper embroidery can be made on a cloth.
While the cloth spreading frame is moved horizontally, load on the free end portion thereof is supported on the leg mentioned above, though the cloth spreading frame is joined in a projecting state to the driving frame. Therefore, the occurrence of an unbalanced load imparted to a prior art driving frame can be prevented. This enables the driving frame to be moved lightly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embroidering machine;
FIG. 2 is an exploded view in perspective of an embroidery frame;
FIG. 3A is a sectional view, which is taken along the line A--A in FIG. 5, of a movable portion in a raised position of a table;
FIG. 3B is a sectional view, which is taken along the line B--B in FIG. 5, of the movable portion in the same condition;
FIG. 4A is a sectional view, which is taken along the line A--A in FIG. 5, of the movable portion in a lowered position of the table;
FIG. 4B is a sectional view, which is taken along the line B--B in FIG. 5, of the movable portion in the same condition;
FIG. 5 is a sectional view taken along the line V--V in FIG. 4A;
FIG. 6 is a partially cutaway view in side elevation of an arm and a leg fastened thereto;
FIG. 7 is a partial view showing the relation between the arm and the leg; and
FIG. 8 is a construction diagram of a different embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention will now be described with reference to the drawings. Referring to FIG. 1, a reference numeral 1 denotes an embroidering machine, 2 a regular embroidery frame used when embroidery is made on a sheet type cloth or flat goods such as open shirts in the embroidering machine 1, and 3 an embroidery frame used when embroidery is made on a cylindrical cloth or three dimensional goods. This embroidering machine 1 has ordinary construction except that a part of a table is made vertically movable. A reference numeral 4 denotes a table, 5 a top plate or a table top consisting of a fixed portion 6 and a vertically movable portion 7, 8 a plurality of beds or cylinder arms, for example, eight (four beds only are shown in the drawing) beds attached to the fixed portion 6 in parallel with one another, 9 driving means for moving the embroidery frame in the longitudinal direction, and 11 driving means for moving the embroidery frame in the lateral direction, these driving means 9, 11 being exposed to the upper side of the top plate 5 through slits 10, 12 provided in the top plate and comprised of rollers. The driving means 9 are fastened to a driving plate 9a (refer to FIG. 3A) adapted to be moved by a driving unit provided in the table 4. The driving means 11 are formed in the same manner, though the construction thereof is not shown. A reference numeral 13 denotes a support frame provided in a horizontally-laid state above the table 4. Heads 14 are fixed to this support frame 13 so that the head 14 are positioned above the beds 8.
The embroidery frame 2 is a known frame, which is provided in the lower surface thereof with recesses in which the driving means 9, 11 are to be fitted.
The embroidery frame 3 consists of a driving frame 16, and cloth spreading frames 18 capable of being attached to and detached from the driving frame 16. The driving frame 16 has recesses, in which the driving means 9, 11 are to be fitted, just as in the embroidery frame 2. The cloth spreading frames 18 are provided so that the number of the cloth spreading frames corresponds to that of the beds 8. A reference numeral 19 denotes embroidery holes formed in the cloth spreading frames 18.
A structure for vertically moving the movable portion 7 in the embroidering machine 1 will now be described on the basis of what are shown in FIGS. 3 and 5. A reference numeral 21 denotes base frames of the table 4, 22 a leg sheathing plate, and 23 a vertically extending rail fixed to the base frames 21 via the leg sheathing plate 22. On the other hand a reference numeral 24 denotes a support frame having on its rear surface slide members 25 vertically movable along the rail 23, and 26 a table support member of the support frame 24, which consists, for example, of an angle material to which the movable portion 7 is fixed. A reference numeral 27 denotes a spring member for lifting the movable portion 7, which spring member is adapted to apply an upward urging force to the support frame 24. For example, a gas cylinder is used as the spring member 27, which is connected at one end to the support frame 24 and at the other end to the base frame 21 via a bracket 28. A reference numeral 29 denotes a stopper fixed to the base frame 21 and used to stop an upward movement of the support frame 24 in a position in which the upper surfaces of the movable and fixed portions 7, 6 become flush with each other as shown in FIG. 3B, 30 a main body of a lowered state holding unit, which is fixed to the lower portion of the support frame 24, and 31 a locking member of the lowered state holding unit, which is fixed to the base frame 21. These parts are adapted to hold the lowered state of the movable portion 7 with the locking member 31 engaging the main body 30 when the movable portion 7 of the top plate is moved down. This lowered state holding unit consists, for example, of a part called a lock. The movable portion 7 is normally held in a position, in which the upper surfaces of the movable and fixed portions 7, 6 become flush with each other, by the urging force of the spring member 27 and the positioning force of the stepper 29. When the movable portion 7 is pressed down, for example, manually against the urging force of the spring member 27, the main body 30 of the lowered state holding unit and locking member 31 are engaged with each other, so that the movable portion 7 is held in a lowered position as shown in FIG. 4A.
The embroidery frame 3 will now be described with reference to FIG. 2. First, a cloth spreading frame 18 will be described. A reference numeral 33 denotes a base plate having ribs 34, 35 at the left, right and rear end portions thereof and formed so that it has a sufficiently high strength even when it consists of a comparatively thin material. This base plate 33 is formed by pressing, for example, a steel plate. The width W of the base plate 33 is, for example, 460 mm, and the length L thereof 570 mm. The rib 35 constitutes a contact member to be engaged with a receiving member which will be described later. The rib 35 is provided at the end portions thereof with positioning through holes 36. A reference numeral 37 denotes connecting members provided integrally with the ribs 34 and having positioning through holes 38. The embroidery hole 19 referred to above is formed in this base plate 33 (to a diameter of, for example, 420 mm). An inner frame 39 is attached to the lower surface of the base plate 33. A reference numeral 40 demotes a known outer frame. The outer frame 40 is cut off at one portion of its circularly extending body. The resultant end portions of the outer frame are formed so as to be tightened together with a tightening screw 41. The tightening of these end portions enables a cloth to be embroidered to be set firm between the outer circumferential surface of the outer frame 39. and the inner circumferential surface of the outer frame 40.
A structure for connecting the cloth spreading frame 18 to the driving frame 16 will now be described. A reference numeral 43 denotes arms fixed at their base end portions to the driving frame 16, formed to an L-shaped cross section and having a length of about 400 mm. A horizontal portion at the free end section of each arm 43 constitutes a support portion 44 for supporting the relative connecting portion 37 referred to above. A reference numeral 45 denotes a receiving member fixed to the driving frame 16 and provided thereon with magnets 46 for connecting the cloth spreading frame 18 to the driving frame 16, and pins 47 for positioning the cloth spreading frame 18 with respect to the driving frame 16. These pins 47 are provided in the positions corresponding to the through holes 36 mentioned above. A reference numeral 48 denotes a connecting magnet provided on the support portion 44 and similar to the magnets 46, and 49 a positioning pin similar to the pins 47 and provided in the position corresponding to the relative through hole 38.
A reference numeral 51 denotes a leg for supporting the cloth spreading frame 18 at the free end portion thereof and fastened detachably to the lower surfaces of adjacent arms 43. The portions of adjacent arms 43 to which the leg 51 is fastened are, for example, about 280 mm away from the base end portions of the arms 43. These leg-fastening portions of the arms 43 may be closer to the free end portions thereof. The leg 51 will now be described in detail with reference to FIGS. 6 and 7. As shown in FIG. 6, the leg 51 is formed with an upper cylindrical member 52 and a lower cylindrical member 53 inserted withdrawably into the upper cylindrical member 52 so that the length of the leg 51 can be increased and decreased. The lower member 53 can be fixed to the upper member 52 by means of a tightener 54 provided on the lower end portion of the upper member 52. A reference numeral 55 denotes a connecting structure provided on the upper end portion of the upper member 52 and formed as follows. A reference numeral 56 denotes a threaded portion formed at the upper section of the upper member 52, 57 a flange type stopper member fixed to the upper end portion of the upper member 52, and 58 a tightening member engaged with the threaded portion 56. Reference numerals 61, 61 denote stopper members fixed to the lower surfaces of adjacent arms 43 so that the stopper members 61, 61 are spaced in an opposed state by a distance G which corresponds to the diameter of the threaded portion 56. A reference numeral 62 denotes a roller provided at the lower end portion of the lower member 53 so that the roller 62 can be moved horizontally and smoothly on the movable portion 7 of the top plate, and 63 a skirt provided so as to prevent a cloth from entering the lower side of the roller 62. The legs 51 formed as described above are used in the positions shown in FIG. 1, in such a manner that each of the cloth spreading frames 18 can be supported at either the left side or the right side thereof. Such legs 51 may be fastened to all the arms 43 so as to support each cloth spreading frame 18 at both the left and right sides thereof.
A cloth embroidering operation carried out by using the embroidering machine 1 will now be described. In the case where embroidery is made on an ordinary sheet type cloth and a flat cloth, the embroidery frame 2 is used. This embroidering operation is as generally known. Namely, a cloth to be embroidered is set on the embroidery frame 2. The resultant embroidery frame 2 is joined to the driving means 9, 11 with the movable portion 7 in the lifted condition as shown in FIGS. 3A and 3B. Embroidery is then made on the cloth in a usual manner by operating the embroidering machine 1.
In the case where embroidery is made on a cylindrical cloth, for example, the back of a sports jacket, the embroidery frame 3 is used. In this case, the movable portion 7 of the top plate 5 is held in the lowered condition as shown in FIGS. 4A and 4B. First, in a place away from the embroidering machine 1, a cloth is set on the cloth spreading frame 18 so that a region (back) to be embroidered thereof is positioned in the hole 19. This operation is identical with a cloth setting operation using a conventional cloth spreading frame. In such an operation, the relation between the inner and outer frame 39, 40 in the cloth spreading frame 18 is as shown in a partial enlarged illustration in FIG. 5. In FIG. 5, cloths are designated by a reference numeral 65, and regions to be embroidered by a reference numeral 65a. In the meantime, the driving frame 16 is joined to the driving means 9, 11 on the embroidering machine 1, and legs 51 are fastened to the arms 43. In order to fasten a leg 51 to arms 43, the leg 51 in the condition shown in FIG. 7 is first placed under the arms 43 so as to insert the stopper members 61 into a clearance 59 between the stopper member 57 and tightening member 58 of the leg 51. The tightening member 58 is then tightened to obtain a leg-fastened condition shown in FIG. 6.
The cloth spreading frame 18 on which the cloth 65 has been set is then connected to the driving frame 16 in the following manner. First, the cloth spreading frame 18 is inclined so that the front portion (lower left portion in FIGS. 1 and 2) thereof becomes higher with the rear portion (the portion on the side of the contact member 35) thereof becoming lower. The contact member 35 is then applied to the receiving member 45 so that the pins 47 are fitted into the through holes 36. The front portion of the cloth spreading frame 18 is then lowered, and the pins 49 are fitted into the through holes 38. Consequently, the magnets 46 attract the contact member 35, and the magnets 48 the connecting members 37. As a result, the cloth spreading frame 18 is joined reliably to the driving frame 16. Owing to these steps taken, the leg 51 supports the cloth spreading frame 18 at the free end portion thereof.
The embroidering machine 1 is then operated in a usual manner with the cloth spreading frame 18 in this condition. Consequently, the driving frame 16 is moved horizontally by the driving means 9, 11, and the cloth spreading frame 18 is moved horizontally with the driving frame 16. Accordingly, the region to be embroidered, which is positioned in the hole 19, of the cloth is moved horizontally. Embroidery is then made on this region of the cloth in accordance with the operations of an embroidery needle 14a provided on the head 14 and the rotating hook on the bed 8. During this time, the leg 51 is moved horizontally with the cloth spreading frame 18 owing to the roller 62 lightly rolling on the movable portion 7 of the top plate, thus preventing the free end portion of the cloth spreading frame 18 from lowering.
A different mode of embodiment will now be described. The arm 43 may be provided fixedly on the base plate 33 of the cloth spreading frame 18 with the base end portion of the arm 43 detachably joined to the driving frame 16. The leg 51 may be fastened directly to the free end, or a portion close to the free end, of the cloth spreading frame 18. A structure for connecting the cloth spreading frame 18 in a horizontally projecting state to the driving frame 16 may be formed as follows. Namely, a fork-like holder is attached to the driving frame so as to project horizontally therefrom. The connecting members provided at the left and right edges of the cloth spreading frame are then joined to the front end portions of the holder.
Another embodiment of the present invention will now be described with reference to FIG. 8. In this embodiment, the lower ends of legs 51e for supporting the cloth spreading frames are supported on a support frame 66 which is moved horizontally with a driving frame 16e. Referring to the drawing, the support frame 66 is provided below the cloth spreading frames, and, in this embodiment, below the arms 43e for holding the cloth spreading frames, in such a manner that the support frame 66 can be moved horizontally. A timing belt 68 is connected to a pulse motor 67, which is adapted to move the driving frame 16e forward and backward, in such a manner that the timing belt 68 can be turned in accordance with an operation of the pulse motor 67. A driving means 9ae similar to that mentioned above is attached to this timing belt 68. Another timing belt 70 is connected via a timing belt 69 to the pulse motor 67 so that the timing belt 70 can be turned in accordance with an operation of the pulse motor 67. A driving means 71 is attached to the timing belt 70. The relation between the driving means 71 and support frame 66 is the same as that between the driving means 9ae and driving frame 16e. The movements of the driving means 71 in the directions of a dual arrow are transmitted to the support frame 66, and the support frame 66 can be moved freely in the horizontal direction which is at right angles to this dual arrow, with respect to the driving means 71. A reference numeral 72 denotes a pulse motor for use in moving the driving frame 16e in the lateral direction, and a timing belt 73 is joined to this motor. Driving means identical with the driving means 11 shown in FIG. 1 are fixed to this timing belt 73. Another timing belt 75 is connected to the pulse motor 72 via a timing belt 74. The support frame 66 is connected to the timing belt 75 so as to have relation identical with that between the timing belt 73 and driving frame 16e.
In the embodiment having such construction, the driving frame 16e and support frame 66 are moved together in the horizontal direction, and the legs 51e and cloth spreading frames together horizontally. Therefore, the driving frame 16e and the cloth spreading frames mounted thereto are moved together in the horizontal direction. The timing belts 70, 75 may be operated by other pulse motors adapted to be turned synchronously with the pulse motors 67, 72, respectively. The parts of this embodiment which are considered functionally identical with or equivalent to any parts of the embodiment of the previously-mentioned drawings are designated by the same reference numerals as are used in the latter drawings with the letter "e" added thereto, whereby duplicated descriptions of the parts are omitted. | A cloth spreading frame is joined to a driving frame so that the cloth spreading frame projects horizontally therefrom. This cloth spreading frame is supported at the free end portion thereof on a leg which can be moved horizontally therewith. Accordingly, even when the cloth spreading frame is formed to a large size so that a cloth having a large region to be embroidered can be set thereon, and, moreover, even when the cloth spreading frame is formed with material of a large diameter and a large thickness so that the cloth spreading frame can follow up a movement of a driving frame without being vibrated laterally, the lowering of the free end portion of the cloth spreading frame can be prevented, so that the embroidering of a cloth can be done properly. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of connection technology, and relates in particular to a connecting box for connection of wiring to an appliance, in particular for connection of wiring to a photovoltaic module (photovoltaic collector, solar panel, solar cell).
[0003] 2. Description of Related Art
[0004] Photovoltaic solar installations are generally of modular design and comprise a multiplicity of solar cells which are connected via external wiring. In order to achieve a higher voltage, the individual solar cells are connected at least in groups in series, by the positive pole of a first solar cell being connected to the negative pole of a further solar cell. One problem that arises in this case is that, when a solar cell is partially covered, for example, as a result of a shadow thrown by surrounding objects or by clouds, this solar cell becomes passive and contributes only slightly, if at all, to the electricity production. In consequence, when connected in series, the current from the adjacent solar cell flows through the covered solar cell, which can thus be damaged or, at least, its life may be reduced. For this reason, it is known for solar cells to be temporarily bridged by means of an electronic circuit, which generally has diodes as protective elements, and thus to be decoupled from the electricity production during the disturbance. These electronic circuits are frequently accommodated in connecting boxes which are at the same time used for connection of the wiring.
[0005] EP999601 from Sumitomo Wiring Systems Ltd. discloses a connecting box for solar cells having a housing with a lower and an upper cover, which can be connected to one another via plug connections. The upper cover has connections for external electrical wiring, as well as electrical plug contacts which are arranged such that, when the housing is in the closed position, they result in an electrical connection to corresponding electrical contacts on the lower cover. Diodes are arranged in the upper cover, and are used for protection of the solar cell. In order to make the arrangement weather-resistant, the diodes are encapsulated in a filler material, for example silicone. One particular disadvantage of these arrangements is that they are unsuitable for present-day high-power solar cells, since they have an inadequate cooling. A further disadvantage is that the proposed encapsulation in silicone unnecessarily increases the material consumption and the weight, and is time-consuming.
[0006] U.S. Pat. No. 6,582,249 from Tyco Electronics AMP GmbH discloses a connecting box for solar modules having a housing composed of plastic and having a cover which is connected to a hinge strip. The housing lower part has an opening for connections of a solar panel, and connections for external electrical wiring. Electrical components, for example diodes, are fitted between the connections in the housing lower part. The electrical components may be protected against direct contact by a protective cover which is fitted to the side inner wall of the housing such that it can pivot. The components are preferably encapsulated with a filler material through an opening in the protective cover, after the protective cover has been fixed in the correct position in the housing.
[0007] EP1605554 from Mantenimiento Instalaciones Malaga S L discloses a connecting box for solar cells having a housing lower part and a cover with a detachable plug connection. The housing has a first opening for connections of a solar cell, and a second opening for connections of external electrical wiring. A printed circuit board can be mounted in the housing by means of a screw.
[0008] German Utility Model DE202005018884U1, from Multi-Holding AG, discloses a connecting box for a solar panel. The connecting box has a housing lower part and a cover which is connected to the housing lower part such that it can pivot. The housing lower part has openings for connections of a solar panel, and has external electrical wiring. Contact elements for attachment of electrical components, in particular diodes, are provided in the interior of the housing. The contact elements are designed such that they are intended to absorb and dissipate the heat which is created by the diodes.
[0009] EP1501133 from Tyco Electronic AMP GmbH discloses a connecting box for a solar panel. The connecting box has a housing lower part and a cover which is connected to the housing lower part via a hinge such that it can pivot. In the area of the bottom, the housing lower part has an opening for connections of a solar panel and, in a side wall, it has openings for external electrical wiring. Busbars and contact elements are arranged in the interior of the housing. One embodiment has a printed circuit board with diodes, which are held firmly by holding elements of the housing.
[0010] JP20022359389 from Kitani Denki K K, discloses a connecting box for solar cells having a housing with a housing lower part and a removable cover. Openings in the area of the bottom of the housing lower part are used for connection to a solar panel. Openings in a side wall are used for connection of electrical wiring. Diodes which are arranged such that they can be replaced are used as protective elements.
[0011] DE102005044939 from Spelsberg Guenther GmbH Co KG discloses a connecting box for solar cells. The connecting box has a protective device, for example in the form of a bypass diode. The printed circuit board is connected to a cooling element, which is passed out of the housing and is connected to the frame of the solar panel, in order to dissipate heat.
[0012] One disadvantage of the connecting boxes which are known from the prior art is the inadequate cooling of the electronic components, and the thermal loading of the solar cells which this results in.
[0013] One object of the invention is therefore to disclose a connecting box which does not have the disadvantages to which the prior art is subject.
[0014] This object is achieved by the invention as defined in the patent claims.
SUMMARY OF THE INVENTION
[0015] A connecting box according to the invention generally has an integral or multi-part housing, which surrounds a printed circuit board with electrical/electronic components. Dependent on the embodiment, the housing is formed from a plurality of parts and has a housing lower part and a housing upper part. Alternatively, the housing can be formed by insert molding of the internal parts.
[0016] The connecting box is generally designed such that it can be mounted by means of a mounting cap on a base surface, for example the rear face of a solar panel. The mounting cap may in this case be in the form of a separate part, to which a housing part is operatively connected. In order to achieve better force distribution and/or in order to influence convectional cooling, the mounting cap may be designed in a segmented form.
[0017] In general, the contact lugs or the contact wires for example of a solar cell are guided into a connecting slot in the connecting box, where they are operatively connected to the printed circuit board via connections which are provided for this purpose. Depending on the embodiment, this connecting slot may be integrally formed peripherally at the edge of the connecting box, or else may be placed within the connecting box. In general, the connecting slot is open at the top and at the bottom.
[0018] In one embodiment, external connecting cables are passed into the housing of the connecting box, where they are operatively connected to the printed circuit board (board or stamped grid). If required, the connecting cables have standardized plug connections, thus allowing simple connection externally. Holders for the plug connections and the cables can be provided on the housing of the connecting box, in which the plug connections can be suspended in a defined position for transportation and automatic testing, for example during fitting.
[0019] The connecting slot may be closed by a cover, if required. The cover may be designed such that it actively prevents an encapsulation compound that has been introduced but is not yet cured from running out. For example, this means that it is possible to position a completely prefabricated solar panel independently of the position, immediately after the encapsulation of the connecting slot, without the encapsulation compound flowing out again. This shortens the time required for fitting. The cover is advantageously in the form of a displacer, thus reducing the amount of encapsulation compound required for the encapsulation process. In order to monitor the filling level, the cover may, furthermore, be produced from a transparent material.
[0020] If required, the cover has one or more openings for introduction of an encapsulation compound and for venting. In one embodiment, the cover has two openings, with one of the two being used for filling, and the other for venting. Since, for example, these are arranged diagonally opposite one another and close to the edge of the encapsulation slot, one of the openings is always lower than the other, thus simplifying the filling process. For example, the opening which is located lower can be filled, as a result of which the air that is enclosed can escape from the connecting slot at the opening which is located higher. Another embodiment has a central opening for filling and one or more vent holes at the edge. Other arrangements are possible. If required, the filling openings have so-called connecting stubs which allow connection of a filling apparatus.
[0021] By way of example, the cover of the connecting slot may be closed by snapping in, screwing, adhesive bonding or ultrasound welding, or a combination thereof If the connecting slot is intended to be encapsulated, the cover is preferably designed such that the required encapsulation compound is minimized. For this purpose, the cover has a displacer, for example on its inside, projecting into the connecting slot. Alternatively, a separate part, a displacer, can be introduced into the connecting slot before closure with the cover, without this displacer being integrated in the cover or connected to it. In one embodiment, the cover presses in the intended manner against the connections and against the contact lugs/contact wires, thus improving the electrical contact between the contact lugs/contact wires and the connections. The described type of cover may also be used to close connecting slots of other connecting boxes, and is therefore not restricted to use with the variant disclosed here.
[0022] One embodiment of the connecting box is designed such that the rear face of the connecting box does not rest flat on the solar cell, but is held at a certain distance from it by means of the mounting cap. Such raising from the base area has the advantage that the thermal load between the electronic components of the connecting box and the solar panel is reduced. Furthermore, the connecting box may have air guide plates/cooling ribs, which influence the air circulation on the rear face of the box and thus improve the cooling, or prevent heat accumulations. The air guide plates may be produced from the same material as the housing of the connecting box. In order to improve the mechanical robustness and/or to positively influence the air circulation, the air guide plates may be curved, and/or may be used for support on a solar panel in the fitted state. The connecting slot may itself be in the form of a mounting cap. If required, further supports can be provided. The distance between the base area and the rear wall of the connecting box is generally 2-30 mm, although other distances are possible, depending on the embodiment.
[0023] In one embodiment, the mounting cap is segmented such that it projects from the connecting box only on two mutually opposite sides thereof, thus assisting free air circulation. Feet which are parts of the mounting cap as well as the lower edge of the connecting slot are operatively connected to the surface of a solar panel, preferably by adhesive bonding. Air channels can be formed by webs on the housing lower part, and assist convectional cooling. The air guide plates are used to pass the air flow around the connecting slot, thus reducing the risk of heat accumulations. Depending on the position of the solar panel and the position of the connecting box on the solar panel, connecting boxes are used which have the webs aligned approximately parallel to the X axis or Y axis, as a result of which the air flow always passes upwards from the bottom.
[0024] Alternatively, the webs may also run in any other direction.
[0025] Single-layer or multiple-layer solutions may be provided as a printed circuit board for connection of the electrical/electronic components. In addition to etched printed circuit boards with a copper layer applied on an electrically insulating mount material, it is possible to use a grid produced by stamping from a metal sheet (stamped grid). In one corresponding embodiment, the housing has correspondingly designed holding means, for example in the form of snap-action or clamping connections, for holding the stamped grid. Furthermore, stamped grids have the advantage that they can easily be insert molded together with the electronic components arranged on them, in an injection mold. This makes it possible to ensure that the interior is hermetically sealed. A further advantage is that the heat that is created is dissipated efficiently outward through stamped grids or printed circuit boards which rest on the housing.
[0026] The sheet-metal thickness of a stamped grid is 0.4 mm, depending on the embodiment. Because it is solid, the board is also used as a cooling plate for the electrical/electronic components. Electrically and thermally sufficiently conductive materials are used as the material. Inter alia, for example, CuSn0.15, CuFe2P or Cu-ETP may be used, in addition to copper, steel or aluminum alloys.
[0027] The housing parts of the connecting box are generally designed such that the board rests closely on them, in order to dissipate the heat from the electrical/electronic components via the printed circuit boards and the housing to the exterior. Since, in one embodiment, the electrical/electronic components, for example diodes, as well as the external cables must be connected at least on one side of the board, corresponding cutouts are in each case provided in the housing. One advantage of a stamped grid is that the resultant heat can be dissipated well both downwards and upwards via a housing resting closely on it. In order to further optimize the thermal conductivity between the board and the housing, said cutouts as well as further air spaces, which may be present, are filled with a thermally conductive and electrically insulating compound (for example thermally conductive paste), before the housing is closed.
[0028] The housing parts are preferably produced by injection molding or diecasting, although other production methods are also feasible. In general, a sufficiently temperature-resistant material is used for this purpose, for example polyamide (PA), polyphenylether (PPO, PPE), polycarbonate (PC), polybutylene terephthalate (PBT) or polyethylene terephthalate (PET). These materials may be filled with fibers, for example 10% to 60% glass fibers. Other materials are possible, depending on the embodiment.
[0029] In order to protect the electronics in the connecting box against moisture and other environmental influences, the housing parts can be sealed from the outside by a circumferential seal. This seal may be in the form of a separate part or may be integrally formed on the housing by means of multicomponent injection molding. It is also feasible to provide a simple circumferential groove in one housing part and a correspondingly projecting circumferential rib in the other housing part, which correspond to one another in the closed position. Alternatively or additionally, the groove can be filled with a sealing compound, for example silicone, before closure. In a further refinement, this groove can be deliberately made larger, such that the sealing compound can be introduced into the resultant cavity retrospectively, when the housing is closed. Corresponding openings and connecting stubs are provided.
[0030] In the situation in which a connecting box is intended to be attached using an adhesive which cures slowly, the time required for processing can be bridged by the use of a supplementary holding means. Good results are achieved by means of double-sided adhesive tape. Depending on the field of application, it is possible to also attach the connecting box exclusively by double-sided adhesive tape. Double-sided adhesive tape allows immediate fixing of the connecting box on a base surface, and this can have a positive influence both on the processing time and on automated processing. Further sealing means may be provided between the connecting box and a base surface.
[0031] One refinement of a connecting box having a housing and a connecting slot, which is used for connection of at least one electronic component, which is arranged on a printed circuit board in the interior of the housing, to electrical connections of a solar panel, with the housing having a projecting mounting cap which is used for attachment of the connecting box to a surface of the solar panel, is designed such that the rear wall of the housing, when in the fitted state, is at a distance from the solar panel such that this results in convectional cooling of the housing. In this case, the connecting slot can be fitted peripherally to the housing of the connecting box. In a further embodiment, the mounting cap is formed from a variety of parts and can surround the connecting slot. One specific embodiment has at least one adhesive surface for holding an adhesive and/or a double-sided adhesive tape on the mounting cap. A further embodiment of a connecting box has air guide plates which are arranged on the housing rear face. These air guide plates can be designed such that, in the assembled state, they are used to support the housing with respect to a solar panel. It is also possible for the housing to rest at least in places closely on the printed circuit board, as a result of which heat that is created is transported outwards through the housing. The printed circuit board may in this case be in the form of a traditional printed circuit board, a stamped grid or as simple wiring. In a further variant of the connecting box, the housing, which comprises a housing lower part and a housing upper part, closely surrounds the printed circuit board and the at least one electronic component. In particular, the housing may be formed integrally by insert molding of the printed circuit board and the at least one electronic component. In one preferred embodiment, the connecting slot is suitable for holding an encapsulation means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Embodiments of the invention will be explained in more detail with reference to the following figures, in which:
[0033] FIG. 1 shows a perspective illustration of a connecting box obliquely from in front and above;
[0034] FIG. 2 shows a perspective illustration of the connecting box shown in FIG. 1 , obliquely from the front and underneath;
[0035] FIG. 3 shows a view from underneath of the connecting box shown in FIG. 1 ;
[0036] FIG. 4 shows a section illustration along the line DD in FIG. 3 ;
[0037] FIG. 5 shows a plan view of the connecting box shown in FIG. 1 , and
[0038] FIG. 6 shows a perspective illustration of the connecting box shown in FIG. 1 , with the housing upper part removed, obliquely from the front and above.
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1 shows a perspective illustration of a connecting box 1 obliquely from the front and above, and FIG. 2 shows the same connecting box 1 obliquely from the front and underneath. FIG. 3 shows the connecting box 1 from underneath, FIG. 4 shows a section illustration (section line DD as shown in FIG. 3 ) from the side, FIG. 5 shows it from above, and FIG. 6 shows it in the open state, obliquely from above.
[0040] The figures show a housing 10 , comprising a housing upper part 40 and a housing lower part 20 . The two housing parts 20 , 40 are in this case connected to one another, inter alia, by means of snap-action tabs 18 , that can alternatively or additionally be adhesively bonded to one another, for example, if required. Feet 31 project at the side from the housing 10 and are part of a mounting cap 30 which is segmented here and projects downwards. The mounting cap 30 is used for the actual attachment of the housing 10 to a surface of a solar panel (neither is illustrated in any more detail). In the illustrated embodiment, the mounting cap 30 is an integral component of the housing 10 , but may also be in the form of a separate part. The mounting cap 30 governs the distance A (cf. FIG. 4 ) which is required for convectional cooling on the housing lower face, between the housing rear wall and the solar panel 80 .
[0041] In the front area, the housing 10 has a connecting slot 60 with connections 52 , which are used for connection of contact lugs or contact wires, for example of a solar panel (none of which is illustrated in any more detail here). The connecting slot 60 is open all the way through and can be closed separately from the rest of the housing 10 . This allows the connecting box 1 to be fitted and closed independently of the assembly process. In consequence, the interior of the connecting box 1 is not subject to any damaging environmental influences. Depending on the embodiment, the connecting slot 60 is open at the top or side. Depending on the field of application, it is arranged in the center of the connecting box 1 , or peripherally.
[0042] The connections 52 are operatively connected to a printed circuit board 50 , for example in the form of a stamped grid 50 (cf. FIG. 6 ) or of a board, which is located in the interior of the housing 10 . The connecting slot 60 is likewise a component of the mounting cap 30 . The outer wall of the connecting slot 60 , which essentially has an O-shaped cross section (XY plane) is formed by a circumferential frame 62 , which opens at the lower end into a circumferential mounting surface 69 (adhesive surface). The mounting surface 69 is designed such that it is suitable for holding adhesive and/or double-sided adhesive tape, and can be used for attachment of the housing 10 to the solar panel and/or for sealing of the connecting slot 60 against external influences. Other refinements of a separately closeable connecting slot, for example arranged peripherally on the housing 10 and open at the side with an essentially U-shaped cross section, are possible.
[0043] Cable entries 11 can be seen in the area of the connecting box 1 located further backwards, through which connecting cables 70 are introduced into the housing 10 . If the intention is only to connect electronic components to a solar panel, there is no need for external wiring. In the illustrated embodiment, the cable entries 11 are used at the same time as strain relief for the connecting cables 70 , fixing them via a clamping apparatus. In the illustrated embodiment, the connecting cables 70 are terminated by plug connectors 71 , thus allowing simple connection or disconnection, for example to or from an external load. The plug connectors 71 are each fixed by means of a holder 15 , which is arranged at the side on the housing 10 . In this case, the holder 15 comprises a plug bracket 16 and a cable bracket 17 , and is arranged such that the plug connectors 71 are located in a position which is advantageous for automatic functional testing and for transport. A position arranged at the side on the housing 10 has been proven in practical use. However, it is clear to a person skilled in the art that the holder 15 can also be fitted at some other point, or that the plug connector 71 can be held firmly oriented in a different direction.
[0044] In FIG. 2 , which shows the connecting box 1 obliquely from underneath, the housing lower part 20 with the connecting slot 60 and the mounting cap 30 , as well as the feet 31 fitted thereto, can be seen. Bulges 24 for electronic components, for example diodes, and cables can be seen on the lower face of the housing lower part 20 .
[0045] Air guide plates 23 are integrally formed on the housing lower part 20 and, in the illustrated embodiment, run approximately parallel to one another and to the feet 31 of the mounting cap 30 . The air guide plates 23 extend approximately over the entire extent of the connecting box 1 . The air guide plates 23 may vary in height with respect to one another or within their length, thus also allowing a flow transversely with respect to them. They may be designed at some points to be sufficiently high that, in addition to the feet 31 of the mounting cap 30 , they allow the housing 10 to be supported on the solar panel. In addition to providing robustness and a supporting effect for the housing lower part 20 , the air guide plates 23 also form air channels 25 , thus making it possible to deliberately pass an air flow through them. In the illustrated embodiment, the air guide plates 23 pass the air flow through under the housing 10 and therefore have a positive effect on the cooling of the housing 10 . The S-shaped configuration provides more robustness. Depending on the field of application, the air guide plates 23 may be entirely omitted or may be designed correspondingly differently, for example such that air can also circulate in the lateral direction.
[0046] In the illustrated embodiment, the mounting cap 30 has openings 35 at the side, which allow an additional air exchange under the housing lower part 20 .
[0047] The mounting cap 30 is designed such that the entire connecting box 1 is raised off the base surface 82 . The feet 31 which project at the side from the mounting cap 30 , and the lower edge of the connecting slot 60 , are formed with adhesive surfaces 32 which are used to hold an adhesive and to which the connecting box 1 is adhesively bonded on a base surface, for example the rear face of a solar cell. In addition to the adhesive surfaces 32 , the feet 31 have second mounting surfaces 33 to which, for example, a double-sided adhesive tape 34 can be fitted. This double-sided adhesive tape 34 allows immediate fixing of the connecting box 1 on the base surface before the adhesive between the adhesive surface 32 and the surface of the solar cell has cured.
[0048] FIG. 4 shows a section illustration along the line DD shown in FIG. 3 . In this case, the connecting box 1 is mounted on a base surface 82 , for example the rear face of a schematically illustrated solar panel 80 (the solar panel is not illustrated in FIG. 3 ). Starting from the rear face of the solar panel 80 , contact lugs or the contact wires (not illustrated in any more detail) of the solar cell 81 are introduced into the connecting slot 60 , and are connected there to the connections 52 of the board 50 . In the illustrated embodiment, the contact lugs are soldered to the connections 52 , although alternative forms of making contact, for example using terminals, are feasible. The connecting slot 60 is closed by a cover 63 . The cover 63 has a central opening 66 for filling the connecting slot 60 with an encapsulation compound. Furthermore, the cover 63 is designed such that it projects into the connecting slot 60 , thus reducing the amount of encapsulation compound required to fill the cavity. The encapsulation compound seals the connections 52 of the board 50 as well as the contact lugs or contact wires of the solar cell 81 with respect to environmental influences. The electrical connecting cable 70 is clamped in as strain relief by means of a cable clamp 11 between the housing lower part and the housing upper part.
[0049] Circumferentially at their edge, the two housing parts 20 , 40 have a seal 12 which, in the illustrated case, is formed by a tongue and groove system 13 . Alternatively, however, the seal 12 may also be provided by a conventional sealing ring, which is inserted into a groove, either on the housing upper part 40 or on the housing lower part 20 , directly by a sealing compound introduced by means of two-component injection molding, or by a labyrinth seal. The board 50 , with its electrical/electronic components 51 fitted on the lower face, rests flat on the two housing halves 20 , 40 , with diode and cable cutouts 21 , 22 being provided in the housing lower part 20 for the electrical/electronic components 51 and the external connecting cables 70 , which are arranged on the board, where contact is made with them. Alternatively, these cutouts 21 , 22 may be formed in the housing upper part 40 , and the corresponding components may be mounted on the upper face of the board 50 . The board 50 or at least the connections 52 project out of the two closed housing parts 20 , 40 into the connecting slot 60 .
[0050] FIG. 6 shows a perspective illustration of the connecting box 1 , with the housing part 40 as shown in FIG. 1 removed, obliquely from the front and above. The figure shows the printed circuit board 50 which has been placed on the housing lower part 20 and is manufactured by stamping from a solid metal sheet (stamped grid). The board 50 is designed to have as large an area as possible in order to dissipate the heat, which is produced in the electrical/electronic components 51 , as efficiently as possible via the housing to the exterior. The board 50 is subdivided by insulating separating joints 54 into subareas which are connected to the connections 52 . The subareas of the board 50 are connected to one another via the electrical/electronic components 51 .
[0051] The feet 31 project at the side of the housing lower part 20 and, together with the connecting slot 60 , form the mounting cap 30 . A holder 15 for a plug connection 71 is arranged on each foot 31 , and the plug connection 71 essentially comprises a cable bracket 70 and a plug bracket 16 . | The invention relates to a receptacle ( 1 ) particularly suitable for wiring one or more solar cells ( 81 ). The receptacle ( 1 ) comprises a housing ( 10 ) and a connecting shaft ( 60 ) that can be separately closed by a cover ( 63 ). The receptacle ( 1 ) is raised from the back side of the solar panel ( 80 ). | 7 |
CROSS-REFERENCE
This application claims the benefit of U.S. Provisional Application No. 61/117,782, filed Nov. 25, 2008, which application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Engines are used in a variety of situations from automotive to marine. Basic engine components are often similar from engine to engine. For example, alternators, water pumps and cooling fans are usually driven via a belt drive by a crankshaft of the engine. Consequently, a belt drive is normally mounted on the side of an engine perpendicular to the crank shaft, using a pulley/sheave system to drive other components. With a belt mechanical drive, the drive components always have a rotation speed which is dependent on the speed of the engine.
Common to methods in the field of mechanical drives is the sole facility to reduce or increase a rotation speed relative to that which would be produced by the engine crank shaft.
Engines are designed to provide pulleys and belts which control other aspects of the engine (such as fans and alternators). Converting an engine to use a different pulley or belt is a complicated and expensive endeavor. It would be beneficial to have devices, systems, assemblies, and means for mounting that enable a user to install and mount an alternator in a variety of situations and/or a more efficient pulley system replacing an existing one.
SUMMARY OF THE INVENTION
The invention relates to devices and kits adapted and configured to convert engine systems to enable the engine to use, for example, wider more efficient belts. The engine systems suitable for conversion can include, for example, an internal combustion engine, a water pump/cooler of a cooling circuit, an electric generator driven by the engine from a face of the engine which is other than that which faces the cooler, and a fan for moving air through the cooler, all disposed in an engine compartment. The output shaft of the alternator can be disposed in the engine compartment near a mechanical power take-off of the engine. The mechanical power take-off includes a belt pulley connected to a free end of an engine crankshaft.
An aspect of the invention is directed to a pulley or sheave adaptor. The pulley adaptor is typically configurable to have a substantially cylindrical shape having a first substantially planar surface, a grooved cylindrical side wall surface adaptable and configurable to engage a belt, and a second recessed surface opposing the first substantially planar surface wherein the adaptor has a height and a radius and further wherein the second recessed surface opposing the first substantially planar surface is adaptable and configurable to engage an existing engine pulley. Additionally, the second recessed surface can be flanked by perpendicular side walls defining a recess within which an engine pulley fits. The grooved cylindrical side wall can be configurable to have a single groove adaptable and configurable to accommodate a belt, or a plurality of grooves to accommodate a serpentine belt. Typically, the radius of the adaptor is greater than the height of the adaptor. Additionally, two or more apertures in the substantially planar first surface can be provided to facilitate securing the adaptor to the original engine crankshaft pulley. In some embodiments, there is a central aperture in the substantially planar first surface.
An additional aspect of the invention is directed to a method of modifying an engine. The methods include obtaining a pulley adaptor such as the ones described herein, placing the pulley adaptor over an existing engine pulley, and securing the pulley adaptor to the existing engine pulley. Additionally, two or more bolts can be used to secure the pulley adaptor to the existing engine pulley. Once the adaptor is in place, a user can obtain a belt, and then install the belt such that it is in communication with an alternator and the adaptor. The belts can be standard belts, multi-V or serpentine belts.
Still another aspect of the invention is directed to kits for converting an engine pulley system. The kits typically comprise a pulley adaptor, such as those described herein. Additionally, the kits can include one or more of each of the following: attachment mechanisms (such as bolts), washers, and belts.
INCORPORATION BY REFERENCE
All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
FIG. 1A is a perspective view of a portion of an engine block adapted and configured to have a pulley and belt communication therewith; FIG. 1B is a side the engine block of FIG. 1A ;
FIG. 2A is a perspective view of a serpentine pulley adaptor of the invention; FIG. 2B is a side view of the pulley adaptor; FIG. 2C is a top view of the pulley adaptor; FIG. 2D is a bottom view of the pulley; FIG. 2E is a cross-sectional view of the pulley adaptor of FIG. 2D along the lines of A-A; and
FIG. 3A is a perspective view of a pulley adaptor of FIG. 2 coming into contact with the engine block of FIG. 1 ; FIG. 3B is a side view thereof; FIG. 3C is a perspective view of the pulley adaptor of FIG. 2 installed on the engine block of FIG. 1 ; FIG. 3D is a side view thereof.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A is a perspective view of a portion of an engine block 10 adapted and configured to have a pulley 12 and belt (not shown) communication therewith. As is well known to those skilled in the art, belts are used in the engine to transmit power from the crankshaft to other rotating components of the engine. Depending on the design of the belts, belts can be subject to wear and loosening, thus requiring more maintenance. Engines are not currently adaptable to provide a mechanism to enable the use of different, or sturdier, belts. FIG. 1B is a side the engine block of FIG. 1A wherein a channel 14 is provided into which a belt fits. The pulley 12 is configured to be connected to the engine 10 using a suitable mechanism such as a center crank bolt 16 .
FIG. 2A is a perspective view of a substantially cylindrical serpentine pulley adaptor 20 having a height and a radius wherein the pulley adaptor 20 is further configured to have one or more channels 22 , 22 ′ circumferentially around the circumferential exterior of the pulley. Two or more apertures 24 , 24 are provided on a substantially planar face of the cylindrical pulley adaptor to facilitate connecting the adaptor to an existing pulley, such as pulley 12 illustrated in FIG. 1 . A central larger aperture 26 is also provided. The central aperture provides a basis for alignment of the adaptor to the engine block. Additionally, the central aperture can be used to facilitate adding additional pulleys. For example, a second alternator kit can be provided wherein the central aperture is used for providing alignment to the crank shaft and for providing access to a center crank bolt, such as center crank bolt 16 illustrated in FIG. 1A .
FIG. 2B is a side view of the pulley adaptor illustrated which illustrates the one or more channels 22 , 22 ′. FIG. 2C is a top view of the pulley adaptor 20 . The face 30 of the pulley adaptor 20 is generally planar as illustrated herein. FIG. 2D is a bottom view of the pulley wherein a trough 32 is configured to provide a bottom face 34 and a wall 36 . FIG. 2E is a cross-sectional view of the pulley adaptor of FIG. 2D along the lines of A-A wherein the trough 32 formed on the rear surface of the pulley 20 is apparent. The trough 32 is adapted and configured to fit over the pulley 12 of an engine 10 , such as that shown in FIG. 1 . As illustrated, the trough 32 has perpendicular cylindrical walls. As will be appreciated by those skilled in the art, the size and configuration of the trough 32 can vary depending on the size, shape and configuration of the engine pulley being adapted. The pulley/sheave can be mounted on the existing pulleys, such that the alignment avoids vibrations from being off center.
FIG. 3A is a perspective view of a pulley adaptor 20 of FIG. 2 coming into contact with the engine block 10 of FIG. 1 as would occur in a method of adapting an engine. As is appreciated by reviewing FIG. 3B , a side view thereof, the pulley adaptor 20 is sized such that it fits snugly over the pulley 10 . This enables the pulley adaptor 20 to be engaged by the pulley 12 after the adaptor 20 is installed. Bolts are provided to attach to, for example, a marine engine block; adjustable axial alternator mount provides alignment for multiple engine models. Thus, a pulley can be mounted to existing engine pulley. The pulley is designed for a serpentine belt but can be replaced with a dual groove or a single groove belt such as a typical automotive fan belt, as would be appreciated by those skilled in the art. FIG. 3C is a perspective view of the pulley adaptor 20 of FIG. 2 installed on the engine 10 of FIG. 1 with the pulley adaptor 20 secured to the engine 10 by one or more attachers 28 , illustrated here as bolts 28 , 28 ′. FIG. 3D is a side view thereof.
The pulley adaptor can be made of any suitable material, including stainless steel, brass and aluminum. However, as will be appreciated by those skilled in the art, the pulley adaptor could also be made out of some of the more recent SLS and SLA processes using material such as 3D Systems (Valencia, Calif.) Duraform® EX (nylon 11) and Duraform® PA (nylon 12). The two pulleys are for multi groove serpentine belts and attach to the stock Yanmar® model 4JH4 marine engine. The turnbuckle is used as a tensioning devise for the alternator belt and one end is mounted to existing bolt holes in the Yanmar engine. The upper arm attachment is mounted to an existing area the Yanmar engine uses for a 2 nd alternator that Yanmar makes specifically.
As will be appreciated by those skilled in the art, the various components described herein can be put together in a kit for converting an engine pulley system. Kits typically would include a pulley adaptor, such as those described herein. Additionally, the kits can include one or more of each of the following: water pump pulley, alternator pulley, tensioning brackets, supporting hardware and attachment mechanisms (such as bolts), washers, and belts (including but not limited to standard belts, multi-V belts, and serpentine belts).
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. | The invention relates to devices and kits adapted and configured to convert engine systems to enable the engine to use wider belts. The engine systems suitable for conversion can include, for example, an internal combustion engine, an electric alternator driven by the engine from its mechanical power take off, all disposed in an engine compartment. The mechanical power take-off includes a belt pulley connected to a free end of an engine crankshaft. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application of Application No. 62/281,414, filed Jan. 21, 2016 and claims priority from that application which is also deemed incorporated by reference in its entirety in this application.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] I. Field of the Invention
[0004] The present invention relates generally to the field of catheter-based RF tissue ablation devices and techniques and, more particularly, to catheter devices and methods for assessing the efficiency of electrode-tissue contact related to the effectiveness of tissue ablation to relieve atrial cardiac arrhythmias. Specifically, the invention provides a device and method for determining ablation electrode to tissue contact before and during an ablation procedure and the estimation of tissue heating during RF application.
[0005] II. Related Art
[0006] Cardiac arrhythmias, particularly atrial fibrillation, are common and dangerous medical conditions causing abnormal, erratic cardiac function. Atrial fibrillation is observed particularly in elderly patients and results from abnormal conduction and automaticity in regions of cardiac tissue. Chronic atrial fibrillation (AF) may lead to serious conditions including stroke, heart failure, fatigue and palpitations. The treatment of chronic AF requires the creation of a number of transmural contiguous linear lesions. The use of a pattern of surgical incisions and thus surgical scars to block abnormal electrical circuits, and passageways known as the Cox Maze procedure, has become the standard surgical procedure for effective surgical cure of AF. The procedure requires a series of full-thickness incisions to isolate the pulmonary veins and the posterior wall of the left atria. Additional lines involve the creation of lesions from the posterior wall to the mitral valve, at the atrial isthmus line and superior vena cava (SVC) to the inferior vena cava (IVC) with a connection to the right atrial appendage.
[0007] Catheters have been developed that make the corrective procedure less invasive. They are designed to create lesions by ablation of tissue that perform the function of the surgical incisions. These include catheters that attempt to connect a series of local or spot lesions made using single electrodes into linear lesions. Devices that use a linear array of spaced electrodes or electrodes that extend along the length of a catheter have also been used.
[0008] Important drawbacks found fundamental in the current catheter-based ablation approaches can be attributed to several factors including a lack of consistent contact between the ablation devices and the target tissues, and the inability to accurately determine the degree of ablation electrode contact with the targeted tissue prior to and during the ablation procedure.
[0009] Effective RF tissue ablation is a function of the ablation electrode contact with the targeted tissue and the current density that result in tissue heating and tissue destruction. The most effective lesion is created if the ablation electrode is imbedded in the tissue. Clearly, the assumption that the application of increasing force increases the tissue surface contact with the ablation tip resulting in an effective lesion. However, in a thick, stiff tissue, such as the AV junction, increasing force may translate to only a small improvement in contact area, whereas in thin pliable tissues, such as the PV/LA junction, the same contact force results in the catheter creating a pouch that is likely to lead to extra-cardiac injuries and possible cardiac perforation. Several technologies are currently in clinical use measuring the ablation catheter contact force. These technologies utilizing laser and electromagnetic sensors do not provide any information regarding the ablation electrode to tissue contact and also are costly. Another approach that is also used is an algorithm assessment of contact based on impedance change associated with the impedance differences of blood vs. tissue.
[0010] Additional limitation of the current ablation technologies is the lack of information regarding the tissue temperature. To avoid char formation from overheating the tissue that can lead to stroke most if not all ablation procedures applied in the left atria employ open irrigated catheters. The irrigation flow cools the ablation electrode and removes/dilutes the blood trapped between the electrode and the tissues preventing char formation during the RF application. As a result of the cooling by the irrigation the temperature measurement of RF tissue heating is not possible. The proposed technology will allow not only assessment of the catheter-to-tissue contact but also an assessment of tissue heating during the RF application.
SUMMARY OF THE INVENTION
[0011] The current disclosure capitalizes on using saline irrigation and embedded temperature sensors to define the extent of contact based on a temperature profile and/or the pressure of saline flow.
[0012] One embodiment uses fixed volume pulses of relatively cold saline. If the catheter is floating in the cardiac chamber and not imbedded, a pulse injection of saline at a temperature, for example, of ˜2° C. will minimally affect the catheter temperature sensors with no increase in resistance to flow above baseline. In contrast, if the catheter is totally embedded in the tissues, the injection of ˜2° C. cold saline will bathe the catheter tip and prolong rewarming from the surrounding tissues and blood flow creating a unique temperature profile. In addition, the resistance to flow of the injection will be incrementally higher, as well.
[0013] A second aspect of this application is associated with the estimation of tissue heating based on the post ˜2° C. pulse injection during RF ablation application. In a similar profile of temperature change, the injection of a fixed volume over a fixed time period, such as 2 seconds during RF application, will result in a temperature change recorded by the catheter temperature sensors that will be tempered by heat load emanating from tissues. Whereas the blood is at a constant temperature, the tissues are heated by RF current to levels of 50-80 and at times even >100 degrees above the circulating blood temperature.
[0014] The higher the tissue temperature, with an embedded ablation tip after the injection of cold saline, the faster it will rewarm vs. pre-ablation cold saline injection. A pre-ablation cold (˜2° C.) saline injection is used to establish a reference profile. Tissue overheating that can lead to boiling will rapidly overcome the cold saline injection whereas low tissue heating will result in prolong temperature recovery. These measurements need to be done under fixed power control.
[0015] Catheter tissue contact information can also be derived using pulses of ambient or room temperature saline irrigation at a 2 cc/min at about 20° C.-24° C. The temperature profile of a plurality of temperature sensors is an indication of the tip to tissue contact. It has been found that an irrigated RF catheter will undergo a significantly greater temperature reduction when the catheter is in good contact with tissues particularly in the distal region of the catheter tip. Minimal or no temperature change will occur in poor contact or floating catheter situations.
Several Technology Requirements Need to be Considered:
[0000]
1) The ablation tip needs to be constructed from highly conductive metal;
2) The temperature sensors need to be close to the outer surface of the ablation tip;
3) The temperature measurement sensors need to be high fidelity rapid response, preferably, several sensors are placed around the ablation tip;
4) Irrigation ports need to be evenly distributed and it has been found that, generally, there should be a plurality of small irrigation ports, as many as 16 or more, preferably.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the drawings:
[0021] FIGS. 1A-1C are enlarged two dimensional images of ablation catheter tip areas showing temperature sensors and irrigation ports in accordance with the invention;
[0022] FIGS. 2A and 2B illustrate good or effective contact between an ablation catheter tip and relatively thick tissues;
[0023] FIGS. 3A and 3B illustrate less effective or poor contact between an ablation catheter tip and thick tissue;
[0024] FIGS. 4A and 4B illustrate good or effective contact between an ablation catheter tip and relatively thin tissue;
[0025] FIGS. 5A and 5B illustrate less effective or poor contact between an ablation catheter tip and relatively thin tissue;
[0026] FIG. 6 illustrates an estimation of three temperature profiles based on temperature dip and recovery reacting to a saline injection at the site of tissue contact as a measure of contact level;
[0027] FIG. 7 is a figure similar to FIG. 6 with the temperature profiles further used to define tissue temperature before and during ablation; and
[0028] FIG. 8 shows further profiles representing catheter to tissue contact for post 3 cc 2° C. cold saline injection dip and recovery profile.
DETAILED DESCRIPTION
[0029] The following description is meant to illustrate the concepts of the present invention without limiting the scope thereof.
[0030] In one embodiment, it has been found that an irrigated ablation catheter equipped with a plurality of temperature sensors placed at the surface and insulated from the ablation electrodes is one embodiment that can be used to evaluate tissue contact in accordance with the invention. Such a catheter tip is shown in FIG. 1A with tip 10 and sensors 12 . Irrigation is accomplished using saline solution administered from multiple irrigation ports in the catheter tip as an injected pulse of fixed volume.
[0031] In other embodiments, a plurality of temperature sensors may be placed below the outer surface of the ablation catheter, as shown at 14 in FIG. 1C , or a single temperature sensor 14 may be placed at the center of the ablation electrode of interest as shown in FIG. 1B . Irrigation ports are shown at 16 .
[0032] Each of the embodiments can be used to map a pressure (optional) or temperature profile after a pulsed saline injection using a fixed dose and rate. Integration of the area associated with the curve has been found to be directly related to the contact level. Algorithms are being developed to determine actual catheter to tissue contact values based on the temperature or pressure profile and to determine tissue heating during RF ablation based on the temperature profile associated with the injection of cold saline, a fixed dose, rate and intervals. As seen in FIGS. 6 and 7 , the hotter the tissue, the faster and smaller the temperature change, with a cold saline injection and, thus, a smaller area associated with the curve. The heat load within the tissue is related to the area of contact (determined prior to the initiation of RF) and during the application of the RF power. The curve is based on pre-ablation treatment, as in area A of FIG. 7 . The area under curve B is associated with a tissue temperature plotted during 10 sec. of CF ablation when recovery is faster. Curve B may relate to a tissue temperature of about 50° C. Curve C represents an even hotter tissue temperature of perhaps 80° C.
[0033] As shown in FIGS. 2A-5B , the cooled saline 20 accumulates under the catheter with when the catheter is in good contact whereas in poor contact the cooled saline rapidly dissipates into the blood circulation.
[0034] The preferred ablation catheter has many irrigation ports at or near the catheter tip and a plurality of temperature sensors around the catheter placed very close to the surface or at the surface of the tip area. The RF ablation tip should be highly conductive to transmit temperature accurately.
[0035] Temperature drops at high irrigation rates also appear to be indicative of contact quality. Table I summarizes, over N=5 tests, the average distal temperature drop measured with an irrigation flow rate of 15 ml/min and a temperature monitoring period of 5 s. It shows that higher contact force values (in grams) result in larger temperature drops.
[0000]
TABLE I
Distal temp drop
Force (g)
(C.)
Ogr_ABL.txt
−2.0
1gr_ABL.txt
−2.3
5gr_ABL.txt
−3.0
10gr_ABL.txt
−3.3
15gr_ABL.txt
−3.6
20gr_ABL.txt
−3.5
30gr_ABL.txt
−3.8
40gr_ABL.txt
−4.3
[0036] FIG. 8 shows catheter-to-tissue contact based on post 3 cc 1 sec. cold saline injection temperature drop and recovery profile based on a catheter tip having four thermocouple temperature sensors related to the ablation electrode. The uppermost curve represents the most proximal temperature sensor and the lowest curve represents the most distal temperature sensor. Contact level 1 represents a reaction based on good catheter-to-tissue contact and contact level 2 represents poor catheter-to-tissue contact. In contact level 1, the temperature of the thermocouple or thermistor temperature sensors uniformly drop to a low level and recovery is relatively slow and uniform as well. In contact level 2, where the catheter is just touching the tissue, one temperature sensor (bottom) shows good tissue contact and the others show significantly less and less contact with lower reduction in temperature and more rapid temperature recovery.
Example I
[0037] An irrigated RF catheter with 6 temperature sensors positioned circumferentially distally and proximally on the surface of the ablation tip was used to test the hypothesis that irrigation at 2 cc/min with room temperature saline (20° C.) will result in significantly lower baseline temperatures when the ablation tip is in contact with tissues. Conversely, minimal or no temperature change will occur when the catheter ablation tip is in poor or no contact with tissues.
[0038] Objective: Utilize an inexpensive, non-invasive and simple technology to reliably determine tissue contact.
[0039] Methods: In 5 animals 85 RF lesions were placed in well-defined identifiable anatomical locations guided by 3D navigation in both atria and ventricles. The catheter contact variability was adjusted to good, fair, and poor based on pace threshold, local electrogram amplitude (EGM), and confirmed by the maximal impedance reduction during ablation and lesion width, length and depth.
[0040] Results: As shown in Table II, significant and distinct temperature differentiation is noted between good, fair, and poor contact. This is confirmed by the significant differences in pre/post pace threshold, EGM amplitude, impedance drop during RF application, and finally, lesion size.
[0041] Conclusion: Surface mounted temperature sensors on an irrigation catheter allows for distinct differentiation of catheter to tissue contact levels at 2 cc of irrigation and may eliminate the need for expensive complicated force contact technology.
[0000]
TABLE II
Contact
Lesion Dimensions
Impedance
Assessment
Temp Reduction
(mm)
Decrease
Contact Level
Distal
Proximal
Length
Width
Depth
Ohms
Good
−6.2 ± 0.8¶*, †*
−4.2 ± 1.7¶*, †*
7.4 ± 3.9¶ NS , †*
7.5 ± 4.0¶ NS , †*
2.7 ± 2.4¶ NS ,†*
30 ± 9¶*, †*
Fair
−4.6 ± 0.2‡*
−2.5 ± 0.6‡*
6.9 ± 4.4‡*
6.8 ± 3.4‡*
2.7 ± 2.4‡*
28 ± 11‡*
Poor
−2.8 ± 1.4
−1.3 ± 1.1
2.4 ± 3.1
2.9 ± 3.7
0.3 ± 0.4
9 ± 4
¶= Good versus Fair,
†= Good versus Poor,
‡= Fair versus Poor,
Significance M
[0042] This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself. | A device and method for determining ablation electrode to tissue contact to assess the effectiveness of an ablation procedure by determining the effect of saline irrigation on catheter tip temperature. | 0 |
[0001] The invention relates to a composite yarn. The invention also relates to a textile obtained with the composite yarn, used alone or in combination with other textile materials. The invention also relates to an article of clothing or of packaging made from this composite yarn.
[0002] In general, one function of a textile is as a protective covering for packaging, covering and protecting living or inert materials against the main factors harmful to their safety. Textiles provide protection against biological attack, such as by bacteria, fungi, yeasts, viruses, allergens or algae, against chemical attack, such as by gases, fumes or dust, against physical attack, such as by irradiation, hot or cold air or moisture and against mechanical attack, such as by friction, impacts, bites and cuts. A yarn is a basic constituent of a textile and has characteristics of flexibility, of fineness and of a long length relative to its diameter.
[0003] The therapeutic properties of certain metals have been widely recognized for a long time. Copper, zinc and silver in metal form are highly biocidal or germicidal, through action against microorganisms such as bacteria, yeasts and fungi, and algicidal through action against algae, according to a specific mechanism called “oligodynamic effect”. These metals are virtually insoluble in water. The few ions produced penetrate into the cells of the microorganisms or of the algae and act by complexation of the metal ions formed (Cu 2+ for copper, Zn 2+ for zinc, Ag + for silver) on the thiol (—SH), carboxylic (—COOH), phosphate (—PO 4 H 2 ), hydroxyl (—OH), amine (—NH 2 ), imidazole or indole groups of the proteins and on the bases of the nucleic acids of the RNAs in the cell nucleus. The growth of these microorganisms or of these algae is inhibited by biocidal action. The bacterial cells are in a state of bacteriostasis, since they are rendered sterile and can no longer divide. Consequently, the bacterial population no longer multiplies.
PRIOR ART
[0004] According to the literature, the antibacterial activity of copper is limited to Staphylococcus and Streptococcus (Gram + ). Copper-based compounds, and in particular copper sulfate, are especially endowed with antifungal properties. Copper is active on fungi such as Trichophyton interdigitale or Trichophyton gypseum. Copper is inactive against other filamentous fungi such as Aspergillus niger. The antibacterial activity is greater on Gram − bacteria than Gram + bacteria.
[0005] In order to combat the microbiological risks, one technique consists in enriching the textiles with active agents. These agents are added to the fibers, to the yarns and/or to the textile. To date, various antimicrobial, antibacterial and antifungal agents exist and are widely used in this field.
[0006] First of all, minerals or zeolites, for example calcium or alkali aluminosilicates or tectosilicates, are combined with metals, such as principally copper, silver and zinc. They are incorporated into fibers obtained by a melt route. By way of example, mention will be made of ceramic based on silver and zirconium phosphate, marketed under the name AlphaSan® RC 5000.
[0007] These agents are also added at the surface of several fibers. These are, for example, a nylon-6,6 polyamide filament, known as X-static™, sold by the company Noble Fiber Technologie. These mineral treatments are suitable for textiles which have high melting points, greater than 250° C., such as polyamides or polyesters.
[0008] Next, chemical molecules, such as triclosan (Irgasan® from the company Ciba Specialty Chemicals), constitute agents with a broad antibacterial and antimicrobial spectrum. Triclosan can only be integrated into materials with a melting point below 215° C.
[0009] Finally, chitosan is a natural polymer derived from chitin which is used in health and agricultural applications, and also as a dyeing auxiliary for fabrics. It also cleans and clarifies swimming pool water, by eliminating the algae and other impurities.
[0010] However, these processes have the problem of the amount of antimicrobial agents to be incorporated in order to obtain probative results without modifying the characteristics of the fiber. In fact, zeolites are minerals that make the yarn brittle. Furthermore, the thermal stresses can also modify, or even destroy, the chemical characteristics of the antimicrobial agents, such as triclosan. In addition, these antimicrobial agents can also be incorporated after extrusion, during sizing of the yarns or in processes for coating and/or dyeing the yarns. However, the permanence of the metal and of the metal ions over time is only very random. The size will undergo friction and its resistance in an aqueous medium remains limited. These treatments with zeolites, gaseous metal deposits or coating, or impregnation with triclosan or chitosan, are labile and can be extracted with solvents, with laundry detergent, with sweat or with other chemical dyeing or bleaching agents, or through the temperature. This means that the effectiveness of the antimicrobial agents will decrease and disappear as the textile is used.
[0011] In order to be active against the microorganisms which exist on the surface of the fibers, a part of the active ingredient incorporated into the polymer must be located on the surface. The depletion of active ingredient due to the dyeing treatment, to abrasion or to extraction by sweat or by maintenance products must be compensated for by a slow migration through the filament or fiber to the surface. The concentration by mass of active ingredient, its distribution, its mobility in the polymer and the diameter of the filament or the fiber are therefore important parameters.
[0012] While maintaining a high effectiveness, the textiles obtained with sizing or finishing product exhibit cleaning better resistance than the textiles which have been subjected to simple deposition without binder. However, the presence of binder will modify the surface properties of the fibers, the bonding of the fibers to one another and, consequently, the properties of the fabrics (flexibility, handle and appearance) and will partly mask the effectiveness of the biocidal molecules. The durability of these treatments depends on many factors, the main one of which is strength of attachment of the active ingredient to the surface of fibers with respect to the dyeing conditions, to abrasion and to washing.
DISCLOSURE OF THE INVENTION
[0013] The main problem that the invention is intended to solve is that of producing a yarn that prevents the development of bacteria, fungi, algae or even other living elements. A second problem is that of keeping the “textile” handle for a yarn with bacteriostatic properties. A third problem consists in making the bacteriostatic properties of a yarn long-lasting, without alterations over time and independently of the conditions under which the textile is used. A fourth problem is that of preventing the formation of unpleasant odors, and of allergies, by developing a new type of yarn for a textile. A fifth problem consists in producing a yarn that can be finished without any specific precautions, dyeing, printing, and the like. A sixth problem is that of preventing the formation of static electricity in a textile through the addition of a specific yarn. Finally, a last problem is that of producing a textile article or an article of clothing, comprising at least one yarn with biocidal properties.
[0014] In accordance with the present invention, a composite yarn comprising a core and a sheath, characterized in that the core is made from at least one continuous yarn of one or more metallic materials with biocidal properties and in that the sheath is made from one or more textile fibers directly covering all or part of the core.
[0015] In other words, the core provides the biocidal properties and the sheath provides the characteristics of yarns conventionally used in the textile field. The term “biocidal” is understood to mean properties which refer to the European Biocide Guidelines 98-8. The expression “yarn of one or more metallic materials” is also intended to mean sections of continuous yarn, which may be calibrated or isotropic and spun together with a fiber tape. The expression “one or more textile fibers” is also intended to mean yarns or a continuous filament.
[0016] The yarn will thus have bacteriostatic, fungistatic and/or algicidal properties, with slow and controlled diffusion. It is therefore a yarn which, by virtue of its composition, prevents the development of elements that are potentially pathogenic for living beings. The yarn and the embodiments thereof it are no longer a source of contamination for materials with which they come into contact. The metal ions released by the core of the yarn penetrate and complex with the ribonucleic acids and the proteins of the microorganisms, thus blocking any multiplication. The presence and the low solubility of this metallic core in a liquid medium confer on it an extreme longevity, related to the fact that it is permanently present in the yarn. The sheath will provide the properties usually known for the textile yarns of the prior art.
[0017] By virtue of its characteristics, this type of yarn is used in the field of human and animal hygiene, food safety, the medical environment, the agricultural environment, and the filtration of aqueous and gaseous media. The yarn is suitable for possible use according to all the techniques used in the textile, winding, dressmaking, weaving, knitting, braiding, embroidery or napping field, and the like.
[0018] In a specific embodiment, the yarn(s) of the core can be plated (coated by electrolysis) with one or more metal materials with biocidal properties. This embodiment makes it possible to obtain a composite yarn, only the metallic surface of which has the desired biocidal properties. In another variant, this same embodiment relates to a composite yarn of a first metallic material with the desired biocidal properties which is plated using a second metallic material with other desired biocidal properties. The presence of two materials, copper and silver, prevents any oxidation of the two metals. On the yarn, there are no black traces (in the case of silver) or bluish traces (in the case of copper).
[0019] Very preferably, in order to promote the hold of the textile yarns or fibers on the core of the yarn, the core can have an apparent surface with a structure which forms points of attachment for the textile fiber(s) of the sheath. All the types of structuring of a metallic yarn are possible. Thus, the core has a geometrical structure, such as, for example, a strand, a strip, a star, a scale, a filamentous structure or any other shapes, which facilitate the attachment and the grip of the textile. Depending on the type of fibers used for the sheath, the metal core may be striated or peened, or undergo any type of treatment, in order to facilitate the attachment of the sheath. Similarly, a porous nonplanar structure may be produced in order to trap microbubbles of air, the aim of which being to increase the exchange surface areas and to improve the thermoregulatory characteristics of the yarn.
[0020] If the intention is to influence the microbial and antistatic characteristics of the core, its geometrical structure may be adjusted. In fact, depending on the type of migration desired, it will be possible, by virtue of the geometrical structure used for the core, to affect either the degree of solubility or the oligodynamic effect. This effect lies in the mass/area ratio of the core and the mass/area ratio of the yarn. If the desire is to have a greater effect on a given yarn, with an identical mass for the core, a strip is then preferred in place of a strand. A greater chemical exchange surface area will thus be obtained for an equivalent mass. This phenomenon can be further increased by producing a nonplanar, granular, striated or scaly surface. These various factors make it possible to regulate the levels of migration so as to comply with the regulations for individual and overall migration required for approval for contact with food products.
[0021] According to the desired biocidal activity, the metallic material(s) with biocidal properties can be preferably chosen, as individual metals or as an alloy, from the group comprising zinc, silver, tin, copper, gold and nickel. Through this choice of metallic materials, the targeting of the bacteria and other pathogenic elements to be destroyed results in a broad-spectrum effectiveness or, conversely, an effectiveness with a precisely targeted specific action. For a food-related application, the objective of which will be to verify pathogenic colonies, such as Listeria, Salmonella, Escherichia coli, Staphylococcus aureus, etc. the mixtures will be predominantly composed of zinc and silver, the presence of copper being less essential. On the other hand, if the yarn is intended for the prevention of odors in a shoe insole, the fungistatic function will be more predominant and, in this case, the proportion of copper will be greater.
[0022] The presence of the metallic core, which is an electrically conducting material, in the yarn of the present invention will therefore be sufficient to dissipate static electricity charges. The presence of a metallic core, at the core of a composite yarn, gives the latter a cutting resistance function.
[0023] Depending on the textile desired at the end, the textile fiber(s) of the sheath can be chosen, alone or as a mixture, from the group comprising fibers of natural, artificial and synthetic origin. In a first case, the fibers of natural origin may be advantageously chosen, alone or as a mixture, from the group comprising animal and/or plant fibers, for example cotton, wool, silk, flax, cellulose, and the like. By way of example, depending on the textile fiber used in the sheath, good heat resistance is obtained. If the sheath is made of wool, a good heat withstand capability is obtained.
[0024] In a second case and advantageously, the synthetic fibers can be chosen, alone or as a mixture, from the group comprising acrylics, polyamides, polypropylenes, and the like. The yarn according to the present invention will be able to withstand dyeing, printing and thermosetting, under the same treatment conditions as conventional textiles. Thus, if the yarn in a specific embodiment is made up of an outer layer of cotton, the latter may be bleached, dyed or printed under the same chemical conditions as a yarn of pure cotton.
[0025] The sheath can be preferably made by a process of assembly, wrapping, lapping, twisting, throwing, Dref™ friction spinning (from the company Fehrer AG), and the like. The mechanical implementation of the textile sheath by textile fibers, which may be short or long, by a staple fiber yarn, by a card tape, by a comb-shaped tape, which may be monofilament or multifilament, continuous or discontinuous, makes it possible to preserve the “textile handle” of the yarn. In another embodiment, all or part of the core can be covered with a porous coating so as to facilitate the attachment of the textile fiber(s) of the sheath.
[0026] In a second aspect of the present invention, a textile is characterized in that it comprises at least one composite yarn as described above. The textile can be produced by a weaving, knitting, braiding, embroidery, napping or nonwoven (by needle-punching) process, and the like. The fineness of the cross section of the strand(s) making up the core allows the composite yarn to keep its flexibility. The fineness of the cross section limits the “shape memory” phenomenon associated with the metallic yarn with a larger cross section (spring effect). The yarn of the present invention will withstand the shaping stresses specific to the use of textiles, such as shrinkage, passage of the needle, sewing machine tension, etc. The textile is pleasant to wear and will not cause the wearer any problems due to contact or, in the case of wrapping, will not cause the transported or packaged material any problems due to contact.
[0027] According to a third aspect of the invention, an article of clothing is characterized in that it is assembled using at least one composite yarn as described above.
BRIEF DESCRIPTION OF THE FIGURES
[0028] The invention will be clearly understood and its various advantages and characteristics will emerge more clearly from the following description of the nonlimiting exemplary embodiments, with reference to the attached schematic drawings in which:
[0029] FIG. 1 represents a round core (strand) of a composite yarn according to a first embodiment;
[0030] FIG. 2 represents a side view of a first process for treating the core of FIG. 1 in order to obtain a flat core (strip) and a composite yarn according to a second embodiment;
[0031] FIG. 3 represents a side view of a second process for treating the core of FIG. 1 in order to obtain a core and a composite yarn according to a third embodiment;
[0032] FIG. 4 represents a view from above of a third process for treating the core of FIG. 2 in order to obtain a core and a composite yarn according to a fourth embodiment;
[0033] FIG. 5 represents a view from above of a fourth process for treating the core of FIG. 2 in order to obtain a core and a composite yarn according to a fourth embodiment;
[0034] FIG. 6 represents a side view of a composite yarn according to a first exemplary embodiment; and
[0035] FIG. 7 represents a view in cross section of a composite yarn according to a second exemplary embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0036] As shown in FIGS. 1 and 2 , and in a preferred embodiment, the core ( 1 ) of a composite yarn consists of a strand or monofilament, i.e. of a continuous round yarn, of copper ( 2 ) covered with a fine layer of silver or of tin ( 3 ). The copper yarn ( 2 ) has a diameter of approximately 67 μm. The layer of silver ( 3 ) has a thickness of approximately 5 one thousandths of the copper.
[0037] As is represented in FIG. 2 , the core ( 1 ) is rolled by passing it between two rollers ( 4 and 6 ) of a smooth cold-rolling mill. A new continuous rolled core ( 7 ) of silver-plated or tinned copper, approximately 5 μm thick and with a width approximately equal to 0.20 mm, is obtained.
[0038] FIG. 3 shows a process for treating the surface of the core ( 1 ) of FIG. 1 with two knurling cylinders ( 8 and 9 ). The core of silver-plated copper yarn obtained ( 11 ) is marked in order to improve the attachment of textile yarns and/or fibers and to optimize the mass/area ratio of the metals.
[0039] FIG. 4 shows a process for treating the surface of the core ( 7 ) of FIG. 2 with two simple knurling rolls ( 12 ). The strip ( 13 ), forming the core, has transverse striations parallel to one another.
[0040] FIG. 5 shows a process for treating the surface of the core ( 7 ) of FIG. 2 with two cross knurling rolls ( 14 ). The strip ( 16 ), forming the core, has striations in staggered rows due to cross knurling.
[0041] In a first example of realization (see FIG. 6 ), the core in the shape of a strip ( 16 ), for example that obtained and shown according to the process of FIG. 5 , is covered with a continuous textile fiber ( 17 ) by throwing or wrapping. The composite yarn obtained ( 18 ) is thus wrapped. For example, the core ( 16 ) is wrapped with a cotton of 28 metric number. Wrapping consists in covering a core yarn with one or more sheaths consisting of different yarns. The monofilament strip ( 16 ) is placed under tension in order to be wrapped with a single or double sheath. In the specific embodiment, the cotton of the first winding provides its solidity and its softness. In the case of a double wrapping, there may be an outer winding. The wrapping fiber ( 17 ) is chosen according to its characteristics, so that it provides its own qualities (heat regulation, textured fiber, etc).
[0042] In a second example of realization ( FIG. 7 ), the core in the shape of a strip ( 16 ), for example that obtained and shown according to the process of FIG. 5 , is covered with discontinuous fibers ( 19 ). The composite yarn ( 21 ) is thus obtained according to the Dref™ friction spinning technique.
[0000] Tests Carried Out with the Composite Yarns According to the Invention
[0043] The antibacterial and antifungal properties of various yarns (see Table 1 below), made up of metallic monofilaments (silver and copper) wrapped with cotton fiber, were evaluated. The yarns are converted into knits in order to be tested according to the standardized microbiological tests, according to:
[0044] Swiss standard SNV 195 920, a qualitative test which determines the antibacterial activity by diffusion on agar; this standard demonstrates the antibacterial activity of a textile support which has undergone a finishing treatment or contains a treated fiber in the mass, and which gives rise to diffusion of the active ingredient in the nutritive medium;
[0045] Swiss standard SNV 195 921, a qualitative test which determines the antifungal activity by diffusion on agar; this standard demonstrates the antifungal activity of a textile support which has undergone a finishing treatment or contains a treated fiber in the mass, and which gives rise to diffusion of the active ingredient in the nutritive medium;
[0046] French standard XP G 39-010, a quantitative test which measures the bacteriostatic properties by contact on agar; this standard makes it possible to determine the bacteriostatic activity at the surface of fabrics and polymeric surfaces acting by contact or by diffusion of the antibacterial active agent, irrespective of whether the fabrics are hydrophilic or hydrophobic; and
[0047] the French standard under preparation, a quantitative test which measures the fungistatic properties by contact on agar.
[0048] The control knit, in order to validate the microbiological assays and calculate the bacteriostatic and fungistatic effectiveness, is made from a 100% cotton yarn.
[0000]
TABLE 1
Knit
Nature of the yarn
Silver
Copper
Cotton
No. 1
round yarn
40%
0%
60%
No. 2
round yarn
0%
40%
60%
No. 3
round yarn
20%
20%
60%
No. 4
flat yarn or strip
40%
0%
60%
No. 5
round yarn
0%
40% tinned
60%
copper
No. 7
yarn with a
copper partially coated
low %
rectangular cross
with silver
section
Cotton
0%
0%
100%
control
[0049] The knits are vapor-sterilized before any microbiological test. Before the microbiological tests are carried out, a part of the knit test pieces is washed 10 times at 40° C., according to standard ISO 6330, in the presence of ECE laundry detergent at 3 g/l, and cold-rinsed. Table 2 indicates the results of the microbiological tests obtained using the qualitative standards SNV 195 920 and SNV 195 921. Table 3 indicates the results of the microbiological tests obtained using the quantitative standard XP G 39-010, for the various knit samples and the various strains, before and after the 10 washes at 40° C.
[0050] The strains used for the tests are Staphylococcus aureus (Gram + ), strain present on the skin and responsible for infection, Candida albicans (yeast), strain responsible for mucosal infection, and Aspergillus niger (fungus), commonplace strain present in the environment.
[0000]
TABLE 2
Standard
SNV 195 920
SNV 195 921
SNV 195 921
Microorganism
Staphylococcus
Candida
Aspergillus
aureus
albicans
niger
Knit No. 1
Knit No. 2
Knit No. 3
Weak activity
Weak activity
Activity
Absence of
Absence of
Absence of
inhibition zone
inhibition zone
inhibition zone
Cotton control
No activity
No activity
No activity
Absence of
Absence of
Absence of
inhibition zone
inhibition zone
inhibition zone
[0051] According to the results indicated in the table above, corresponding to the qualitative tests, and within the meaning of the standards used, the absence of an inhibition zone signifies weak activity. In reality, the absence of an inhibition zone signifies a low release of metal ions into the agar. In first approximation, a low release of metal ions into the agar heralds a weak diffusion of the metal ions to the surface which will be in contact during use (the skin in the case of an undergarment, a food product in the case of a packaging, etc). This weak diffusion heralds good biocompatibility.
[0052] The bacterial concentrations are expressed as CFU (colony forming units), as log of CFU or as difference in log of CFU (values which appear in Table 3 below), for a contact time of 24 hours. The concentrations of fungal or yeast cells are expressed as CFU (colony forming units), as log of CFU, or as difference in log of CFU (values which appear in Table 3 below), for two contact times of 24 hours and 7 days.
[0000]
TABLE 3
Microorganism
Staphylococcus
Aspergillus
Candida
aureus
niger
albicans
10
10
10
Sample
washes
washes
washes
Knit No. 1
3.26
Knit No. 2
2.89
Knit No. 3
3.36
Knit No. 4
0.08
1.34
2.27-2.09
2.10
1.58
2.27
Knit No. 5
0.05-0.32-
1.13
1.53
Knit No. 7
1.18
1.90
Cotton
3.90
3.62
2.68-2.26
2.68
2.47
2.47
control
[0053] Under the experimental conditions, knit No. 3, which is made up of 20% of copper and 20% of silver by mass, exhibits a fungistatic activity on Aspergillus niger (qualitative tests).
[0054] Knit No. 4 (containing 40% of silver) and knit No. 5 (containing 40% tinned copper) have a bacteriostatic activity on Staphylococcus aureus before washing and after 10 washes at 40° C. This activity is due to the presence of metal in the knit:
[0055] presence of silver on the flat yarn (strip),
[0056] presence of copper and of tin at the surface of the round yarn.
[0057] Knit No. 7 (based on silver and copper) has a fungistatic activity on Aspergillus niger before washing. This activity is due to the presence of a mixture of copper and silver in the yarn with a rectangular cross section which constitutes the knit.
[0058] The yarns which constitute knits Nos. 4, 5 and 7 therefore have a bacteriostatic and/or fungistatic activity with respect to the same strains, respectively.
[0059] A flat yarn. (or strip: knit 4) is more active than a round yarn (knit 1) with respect to Staphylococcus aureus due to its structure. The round tinned copper yarn (knit 5) is more active than the other round yarns (knit 2) with respect to Staphylococcus aureus, because of the presence of tin at the surface due to the tin-plating.
[0060] The present invention is not limited to the embodiments described and illustrated. Many modifications can be made, without however departing from the context defined by the scope of the set of claims.
[0061] The uses of the yarn and of the textile according to the invention are extremely varied. By way of example, mention will be made of coiling of yarn in cartridges for swimming pool filters or air conditioning filters, yarn for assembling textiles, leathers for shoes, fabrics for furniture, mattresses, towels, clothes, food packagings, geotextiles for agriculture, horticulture, viticulture, and the like. | The invention relates to a composite thread ( 18 ), comprising a core ( 16 ) and a shell ( 17 ). The core ( 16 ) is produced from at least one thread of one or more metallic materials with biocidal properties. The shell ( 17 ) is made from one or more textile fibres directly covering all or part of the core ( 16 ). | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation-in-part of U.S. application Ser. No. 835,817, filed Sept. 22, 1977 now abandoned. This is a division of application Ser. No. 33,895 filed Apr. 27, 1979, now U.S. Pat. No. 4,223,007.
BACKGROUND OF THE INVENTION
This invention relates to microbial insecticides. More particularly, the invention relates to a novel microbial insecticide composition and to the production and utilization thereof.
Microbial insecticides of viral, bacterial, or fungal origin offer significant advantages over conventional chemical insecticides. Microbial insect pathogens are generally nontoxic and harmless to other forms of life. In addition, microbial insecticides demonstrate a relatively high degree of specificity, and hence do not endanger beneficial insects. Moreover, a susceptible insect host is quite slow to develop resistance to microbial pathogens. Microbial insecticides may be used in relatively low dosages, may be effectively applied as dusts or sprays, and may be used in combination with chemical insecticides.
For example, the Douglas fir tussock moth nuclear polyhedrosis virus (NPV) is a microbial insect pathogen useful for controlling the tussock moth. Likewise, Bacillus thuringiensis (B.t.), a spore-forming bacterium, is well-known as a microbial insect pathogen useful against numerous leaf-chewing insects in their larval stages, including, for example, alfalfa caterpillars, tomato hornworms, tobacco hornworms, cabbage loopers, cabbage web worms, army worms, gypsy moths, walnut caterpillars, diamondback moths, cosmopolitan green bettles, European corn borers, and other members of the order Lepidoptera.
Unfortunately, the effectiveness and usefulness in the field of many microbial insect pathogens as insecticides are severely limited by their extreme sensitivity to sunlight. It is known, for example, that one of the problems encountered when using B.t. as an insecticide is its short period of effectiveness in the field, which is due, in part, to sunlight-induced inactivation of the microorganism. It is also known that nonionizing radiation having a high photon energy (e.g. ultraviolet rays) exerts an inactivating effect on B.t. See, "Photoprotection Against Inactivation of Bacillus thuringiensis Spores by Ultraviolet Rays," Aloysius Krieg, Journal of Invertebrate Pathology, Vol. 25, pp. 267-268 (1975). In particular, it is known that ultraviolet (UV) rays with a wavelength of 253.7 nm induce a marked, extraordinary inactivation of B.t. spores, so that they are unable to germinate and grow out. A dosage of 18 m W sec/cm 2 of such 253.7 nm wavelength radiation will inactivate 99.9% of the B.t. spores. However, since UV radiation of wavelengths shorter than about 285 nm do not reach the earth's surface, such inactivation at 253.7 nm is of little practical concern in the field.
We have determined that the half life of B.t. subjected to sunlight is approximately six minutes. Likewise, it has been determined by others that the half lives of certain occluded viruses subjected to sunlight is one-half to one hour. Thus, the effectiveness of a typical spray application of such microbial insecticides is rapidly lost in the field.
Since nucleic acids show a maximum of extinction near a wavelength of 260 nm, it has been suggested by others that the UV induced death of B.t. at 253.7 nm, and of certain occluded viruses at comparable wavelengths, may be caused by a photoreaction of the genetic material, especially DNA. Thus, it has been suggested, ibid., at p. 267, that B.t. spores could be protected from inactivation by such UV radiation (253.7 nm) by physically mixing the B.t. spores with DNA, or a comparable nucleic acid which would absorb the UV rays. Such a comparable nucleic acid would be RNA, Ribonucleic Acid, which has a maximum of extinction near 260 nm. However, this technique proved to be ineffective. Furthermore, as noted above, since wavelengths shorter than about 285 nm do not reach the earth's surface, the usefulness of DNA or RNA as a protectant against sunlight-induced (i.e. at wavelengths greater than about 285 nm) inactivation is unproven.
SUMMARY OF THE INVENTION
The present invention comprises a microbial insecticide composition and methods for the production and utilization of such composition. Typically the composition comprises a microbial insect pathogen of viral, bacterial, or fungal origin which is susceptible to sunlight-induced inactivation embedded in a coacervate microbead which is comprised of a nucleic acid, typically RNA, and a proteinaceous material, whereby the microbead structure itself effectively shields the pathogen from sunlight-induced inactivation. The microbead is typically stabilized by chemical crosslinking.
One typical method for preparing the microbial insecticide composition comprises: (a) preparing a paste-like mixture comprising (i) nucleic acid particles, (ii) proteinaceous material particles, (iii) microbial insect pathogens of viral, bacterial, or fungal origin, and (iv) an amount of water sufficient to wet (i.e. hydrate) substantially the entire mixture; and (b) agitating the paste-like mixture in a manner adapted to break up the mixture into discrete microbeads, whereby the microbial insect pathogens are embedded in the microbeads. Preferably the discrete microbeads are stabilized by treatment with a chemical crosslinking agent such as tannic acid, glutaraldehyde or a similar agent. In one preferred embodiment of the invention the agitation of the paste-like mixture takes place in a solution containing the chemical crosslinking agent.
Another typical method for preparing the composition comprises: (a) preparing an aqueous solution containing a nucleic acid; (b) preparing an aqueous solution containing a proteinaceous material; (c) preparing an aqueous suspension of strongly positively or negatively surface-charged microbial insect pathogens; and (d) mixing the aqueous solutions and suspension prepared in steps (a), (b), and (c) together, thereby spontaneously forming microbeads having the insect pathogens embedded therein. In one preferred embodiment the suspension prepared in step (c) is first mixed with the solution prepared in step (a), and then this mixture is mixed with the solution prepared in step (b). In another preferred embodiment the suspension prepared in step (c) is first mixed with the solution prepared in step (b), and then this mixture is mixed with the solution prepared in step (a).
Typically the surface change of the pathogens is made strongly negative or strongly positive by the addition of a protein-modifying agent to a buffered aqueous suspension of the pathogens. The microbeads are typically crosslinked.
The present invention also comprises a method for controlling insect pests in insect infested areas which typically comprises applying an effective amount of the insecticide composition described above to the insect infested areas.
The present invention further comprises the insecticide composition made by the processes described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing the optical density, over the solar UV and visible range, of two typical types of microbeads suitable for use in the present invention.
FIGS. 2-12 are graphs showing the comparative experimental data from Examples 1, 2, and 4-12, below, respectively. In FIGS. 2-4 the number of viable spores, extrapolated to 1 ml of original sample, is shown as a function of the length of time of exposure to the UV radiation. In FIGS. 5, 6, and 8 the percentage of microbes remaining as survivors is shown as a function of the exposure time. In FIGS. 7 and 10 the number of viable spores per filter is shown as a function of the exposure time. FIGS. 9, 11, and 12 show LD 50 data as a function of the exposure time.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, microbial insect pathogens of viral, bacterial or fungal origin which are susceptible to sunlight-induced inactivation are embedded in coacervate microbeads comprised of a nucleic acid, typically RNA, and a proteinaceous material. We have found that such microbeads provide excellent protection of the pathogens against sunlight-induced inactivation. The microbeads act as protective shields, serving to intercept and block the harmful radiation wavelengths (i.e. those wavelengths of sunlight which tend to inactivate the pathogen) before they reach the light-sensitive material of the insect pathogen.
We have successfully embedded Douglas fir tussock moth nuclear polyhedrosis virus, Autographa californica nuclear polyhedrosis virus, Bacillus thuringiensis cells, spores, and toxin crystals, and the following vegatative bacterial cells: Pseudomonas fluorescens, Serratia marcescens, and Escherichia coli in the microbeads of the present invention. Based on this, we believe that any microbial insect pathogen, whether of viral, bacterial, or fungal origin, including, but not limited to, the insect pathogens disclosed in Microbial Control of Insects and Mites, H. D. Burges and N. W. Hussey, Eds., Academic Press, 1971, may be successfully embedded in the microbeads of the present invention. Furthermore, based on the experimental data reported in the Examples below, there is little doubt that any insect pathogen embedded in such microbeads will be protected against sunlight-induced inactivation.
Various proteinaceous materials may be used in combination with the nucleic acid to form the microbeads, depending on the specific insect pathogen to be protected and the microbead system to be used, including, but not limited to: protamine, cytochrome c, soy protein, hemoglobin, gelatin, synthetic amino acid polymers, etc. In general any proteinaceous material can be used if the conditions are adjusted so as to facilitate formation of the microbeads. Such conditions may include charge modification techniques, adjustments in pH, component concentrations, etc.
The microbeads in which the microbial insect pathogens are embedded may be advantageously produced using known techniques for forming what have been called coacervate droplets or microbeads. One such technique was developed in conjunction with the study of the origin of life on earth, and has been used to construct precellular models. See, for example, Evreinova, et al., Journal of Colloid and Interface Science, Vol. 36, No. 1 (1971). According to this technique, an aqueous solution containing a nucleic acid (preferably ribonucleic acid, RNA) and, if necessary, a buffering agent (e.g. sodium phosphate or sodium acetate) designed to maintain the pH at a position which optimizes the charge on the nucleic acid, the protein and the microbe, e.g. with respect to the desired pI (where the microbe is sensitive to pH, this should be taken into account as well), is mixed with an aqueous solution containing an appropriate proteinaceous material. Proteinnucleic acid microbeads which are essentially solid and roughly spherical form spontaneously upon the mixing of these two solutions. In the discussion which follows, the above-described technique will be referred to as the "solution formulation" technique, and microbeads formed according to this technique will be referred to as "solution formulation" microbeads.
In an equally preferred embodiment of the invention the microbeads in which the microbial insect pathogens are embedded may be produced using a new technique which we have developed. In the discussion which follows, this new technique will be referred to as the "paste formulation" technique, and microbeads formed according to this technique will be referred to as "paste formulation" microbeads. According to this new paste formulation technique, a paste-like mixture is prepared comprising nucleic acid (preferably RNA) particles, proteinaceous material particles, and an amount of water sufficient to wet substantially the entire mixture, and then this paste-like mixture is agitated in a manner designed to break up the mixture into discrete microbeads. Such agitation may be accomplished by conventional techniques such as, for example, rapid stirring or blending (in a conventional blender), sonification, shaking, pressure extrusion, etc. In order to facilitate the breaking up of the mixture into discrete microbeads, it may be desirable, in certain embodiments, to extrude the paste-like mixture into filaments, pellets, etc. prior to agitation. It is generally preferred to stabilize the discrete microbeads by treatment with a chemical crosslinking agent (e.g. tannic acid, etc.) either during or after agitation. However, crosslinking may be unnecessary where stabilization may be effected by other means, such as, for example, freeze drying.
With respect to the solution formulation technique, and to a certain extent the paste formulation technique, it should be noted that while all of the above-named proteinaceous materials, and others, can be used satisfactorily in forming the microbeads, care must be taken to maintain the pH of the mixture of solutions on the acid side of the isoelectric point of the particular protein being used, since this is required for formation of the microbeads. For example, when using protamine the pH should be maintained below about 11, and when using hemoglobin the pH should be maintained below about 7. Furthermore, if a protein is used that is insoluble at a given pH, the pH may have to be put in a range in which the protein is soluble, or other steps may have to be taken to make the protein soluble. These steps could include partial degradation, charge modification or adding other components in the buffers (e.g. detergents, alcohols, surfactants, etc.). If foaming of one or more components is a problem, simethicone type agents (U.S. Pat. No. 2,441,098) can be included. When RNA is being used as the nucleic acid in the solution formulation technique, the pH of the mixture of solutions must be maintained at or above about 4.3 to prevent the RNA from precipitating out of the microbead, with the protein necessarily leaving the microbead and going back into solution.
As can be seen, in the above-described solution and paste formulation techniques for forming microbeads (i.e., coacervate droplets), the materials to be utilized to intercept and absorb the harmful radiation form the microbead structure, thereby producing a highly protective coating.
The bimolecular structure of the microbeads creates a thermodynamically stable cooperation between the components, so that even without subsequent chemical crosslinking, as described below, the components will not individually diffuse out of the microbeads. The bimolecular structure also causes the microbeads to be highly charged. These charges should aid the microbeads in sticking to plant surfaces. These charges can be controlled by selecting the appropriate protein to be used in forming the microbead.
It has been reported that, the size of the microbeads (solution formulation) can be controlled by controlling the concentration of the nucleic acid and the protein in the formation vessel. We have determined, for example, that 100μ diameter solution formulation microbeads can be made by mixing an equal volume of 5% RNA and 10% protamine sulfate. Microbeads will form and settle to the bottom of the vessel. Most of these will be in the 100μ range. We have also found that the size of the microbeads can be controlled, to some extent, by the degree of agitation during formation, with greater agitation producing smaller microbeads. While microbeads having an effective diameter within the range of from about 10 to about 200 microns should be suitable for use in the present invention, it will generally be preferred to utilize microbeads having an effective diameter within the range of from about 40 to about 100 microns. In general, the type of vegetation (i.e. crops, trees, etc.) to be treated and the method of application will determine the desired microbead size.
While a relatively wide range of nucleic acid and proteinaceous material concentrations can be used to make these microbeads generally, in preparing microbeads for use in the present invention (i.e. for entrapping microbial insect pathogens) it is preferred to use a nucleic acid: protein ratio in the range from about 1:5 to 5:1.
In those embodiments of the invention wherein it is desired to utilize the solution formulation microbeads described above, the microbial insect pathogens may be embedded (i.e., entrapped) in the microbeads by simply placing them in suspension in water (a buffering agent, e.g. phosphate, acetate, etc. may optionally be added if necessary to control pH) and then mixing this suspension with an aqueous solution containing the desired nucleic acid. The resulting suspension is then mixed with the aqueous protein solution as described above and the pathogen is spontaneously embedded in the proteinaceous material-nucleic acid microbeads which form. As a less preferred alternate procedure, the buffered suspension of microbes may be first mixed with the proteinaceous material solution and then the resulting suspension mixed with an aqueous solution containing the nucleic acid. It has been found that subsequent shaking of the vessel in which the solutions have been mixed will cause the microbeads to coalesce and spontaneously reform, usually resulting in additional pathogens being embedded in the microbeads.
In those embodiments of the invention wherein it is desired to utilize the paste formulation microbeads described above, the microbial insect pathogens may be embedded in the microbeads by simply placing them in suspension in water (as above, a buffering agent may be added as necessary) and then mixing this suspension with the mixture of nucleic acid particles and proteinaceous material particles (care should be taken to use only an amount of water sufficient to wet the mixture and give it a paste-like consistency). The resulting paste-like mixture is then agitated as described above so as to break it up into discrete microbeads. As an alternative procedure, nucleic acid particles and proteinaceous material particles may be mixed with an amount of water sufficient to wet the mixture and give it a paste-like consistency, and then the microbial insect pathogens may be mixed with this paste-like mixture and embedded in discrete microbeads by agitation of the mixture as described above.
While the microbeads produced according to the above-described solution formulation and paste formulation techniques possess a certain degree of stability, it will generally be advantageous to increase their stability to faciliate separation of embedded pathogens from non-embedded pathogens and to further facilitate handling. This is particularly so with respect to paste formulation microbeads. In a preferred embodiment of the invention, such stabilization is accomplished by chemically crosslinking the microbead molecules by treating them with crosslinking agents such as, for example, tannic acid, glutaraldehyde, imidoester agent, dithiobissuccimidyl propionate, etc. using conventional crosslinking techniques. If it is desired to use glutaraldehyde, an aqueous solution of 0.25%, or less, (by weight) should be used, since we have found that as the glutaraldehyde concentration is increased, certain pathogens, in particular, Bicillus thuringiensis, will tend to become inactivated. We have found that buffered tannic acid is non-toxic to bacterial spores at a concentration of 10% (w/v), and we believe that it will be non-toxic to most microbial insect pathogens at concentrations of 1% or less (w/v). While buffered tannic acid having a concentration within the range of from about 0.001% to 10% should be suitable for use, concentrations within the range of from about 0.5% to 1.5% will generally be preferred.
It should be noted that the depth of crosslinking can be controlled rather easily by controlling the time, concentration, temperature, and other conditions of crosslinking. For example, the depth of crosslinking may be controlled by stopping the crosslinking reaction by adding a small molecule which reacts with the crosslinking reagent (e.g lysine added to glutaraldehyde) or by using low crosslinking reagent concentrations.
Such chemical crosslinking of the microbeads yields several advantages, including: (1) stabilization against the shear forces created by spray application of the insecticide; (2) maintenance, if desired, of fluid centers within the microbeads; (3) maintenance, if desired, of a pH level inside the microbead which is lower than that of the environment surrounding the microbead (i.e., alkaline digestive juices of the insect gut) so that the interior of the microbead may be kept at a pH value near the optimum pH value for viability, storage, etc. of the microbial pathogen; (4) control of the position in the insect gut where the pathogen is released (i.e. the greater the crosslinking, the further along in the gut release will occur and vice-versa), thereby increasing the infectivity of the pathogen. In addition, the use of tannic acid as the crosslinking agent increases the optical density of the resulting crosslinked microbeads (see FIG. 1), thereby providing improved shielding of the embedded microbes against sunlight-induced inactivation.
We have also found that the microbial insect pathogen may be embedded (i.e. entrapped) in the above-described solution formulation microbeads much more readily and in much greater numbers if its net surface charge is first modified so as to be made nearly totally (i.e. strongly) negative or nearly totally positive. We believe this will also be the case with regard to paste formulation microbeads. This surface charge modification may be accomplished, for example, by the controlled addition of a protein modifying agent such as, for example, succinic anhydride (to make strongly negative) and similar compounds (see e.g., Gary E. Means and Robert E. Feeney, Chemical Modifications of Proteirs, Holden Day, Inc., 1971). However, care must be taken to select a protein-modifying agent which will not inactivate or harm the pathogen to be embedded. For example, we have found that succinic anhydride is not suitable for use with vegetative bacterial cells (e.g. Serratia marsescens, etc.), since it tends to inactivate these cells. Modification to a strongly positive surface charge may be accomplished, for example, by using tannic acid to link positively charged proteins (e.g. protamine) to the surface of the pathogen. We have found, in comparative studies, that in the absence of any charge modification, only about 1% of the available B.t. spores are embedded in the microbeads (solution formulation), and that using strongly negatively surface charged B.t. spores (succinic anhydride treatment) results in about 10-20% of the B.t. spores being embedded in the microbeads, and that using strongly positively surface charged B.t. spores (treatment with tannic acid then protamine sulfate) results in about 20-40% of the B.t. spores being embedded in the microbeads. The effectiveness of these charge modification techniques may be increased by first washing the microbial insect pathogen, and it may be desirable, in certain embodiments, to wash in separate organic (e.g. 60% ethanol solution, by weight) and inorganic (e.g. 1 M sodium chloride solution) washes, provided the pathogen being used is not sensitive to such materials. We have found that, prior to attempting any of the above-described charge modification techniques on insect viruses, it will generally be preferred to purify the viruses (e.g. by centrifugation, filtration, etc.) in order to remove the insect debris.
Since the charge-modified pathogen apparently competes with the like-charged component of the microbead for positions in the bead, it may be necessary to reduce the concentration of such like-charged component to a level which will faciliate incorporation of the pathogen into the microbead. For example, if it is desired to entrap microbial insect pathogens which have been modified to a strongly negative surface charge in an RNA-protein microbead as described above, it may be necessary to reduce slightly the concentration of the RNA solution (RNA is also negatively charged) prior to mixing with the protein solution.
Likewise, in such a microbead system, if the surface charge of the pathogen has been modified to a strongly positive surface charge, then it may be necessary to reduce slightly the concentration of the protein solution (protein is positively charged) prior to mixing with the RNA solution. This latter system may be more attractive for purposes of the present invention since it does not require reduction of the amount of radiation-absorbing material (i.e. RNA). inactivation by harmful radiation from the sun, it is obviously important, in selecting the materials to be used in formulating the microbeads, to select materials which strongly absorb and/or reflect such harmful radiation. Preferred materials for use in constructing the microbeads are RNA (ribonucleic acid) and a proteinaceous material such as, for example, hemoglobin, protamine, or a synthetic amino acid polymer. The optical density (i.e. absorption+reflection) of microbeads comprised of RNA and protamine, produced according to the above-described solution formulation technique, is shown in FIG. 1. The solid line in FIG. 1 shows the optical density of a solution of microbeads made by combining equal volumes of 0.33% RNA and 0.5% Protamine (crosslinked with glutaraldehyde) over the solar UV range. The dashed line in FIG. 1 shows the optical density of a solution of microbeads made by combining equal volumes of 0.67% RNA and 1% Protamine (crosslinked with tannic acid) over the solar UV and visible (to 600 nm) range.
In many cases the presence of a nucleic acid in the microbead will offer a second advantage. It has been suggested that the damage caused by wavelengths of sunlight greater than 313 nm is, in the case of many microbes, primarily the result of the reaction of the microbe's nucleic acids with free radicals (it is believed that radiation damage to tyrosine produces H 2 O 2 which, in turn, produces free radicals). The nucleic acid present in the microbead structure will tend to react specifically with the free radicals which would otherwise react with the microbe's nucleic acids, thus preventing any damage.
Since the pathogenic effect of the microbial agent cannot be realized so long as the agent remains embedded within the microbead, care must be taken in selecting the materials to be used in formulating the microbeads to select those which will permit release of the agent after ingestion of the microbeads by the insect. While other materials might be selected, we have found that microbeads comprised of a protein and a nucleic acid (e.g. RNA) provide quite satisfactory release characteristics.
After ingestion of the microbeads by the insect, the microbeads will be attacked by proteases and nucleases in the insect digestive tract (i.e., gut), which will lead to release of the microbe. Thus, it is important to select microbead materials which are not resistant to such type of attack. We have found that if Bacillus thuringiensis (cells, spores and toxin crystals) embedded in microbeads comprised of RNA and protamine (produced according to the above-described solution formulation technique) are incubated at room temperature in the presence of insect digestive juices, release of the B.t. begins within minutes, with progressive and complete release following within one half hour.
We have also found that if Bacillus thuringiensis embedded in microbeads comprised of RNA and protamine (produced according to the above-described technique) are incubated at room temperature in the presence of amino acids and/or sugars such as would be found in an insect digestive tract, the germinating spores themselves dissolve the microbeads in approximately two hours. This does not occur in water or buffer alone, so that the microbeads will remain intact on leaf surfaces.
Furthermore, the experimental data shown in FIGS. 9, 11 and 12 indicate the Douglas fir tussock moth NPV viruses and Autographa californica NPV viruses embedded in the microbeads of the present invention are, in fact, released in the insect gut, and that upon being so released they exert a killing effect as desired.
It should be noted that the present invention is suitable for use with any light sensitive microbial insect pathogen, including those of viral, bacterial, or fungal origin. Examples 1-5, 7 and 10 below, illustrate the applicability of the present invention to a typical spore-forming bacteria (i.e. B.t. cells, spores, and toxin crystals), and Example 8, below, illustrates the applicability of the invention to three species of vegetative bacterial cells. Example 6, below, shows the applicability of the present invention to a bacterial virus. The positive results shown in Example 6 indicate that the present invention should be suitable for use in protecting non-occluded insect viruses against sunlight induced inactivation. Examples 9, 11 and 12 illustrate the applicability of the present invention to two species of occluded insect viruses.
In the Examples (and FIGS. ) which follow, the microbial insect pathogens which are labelled and/or referred to as "unprotected" comprise pathogens which were not embedded in microbeads. In each example the "unprotected" pathogens were treated, exposed, and tested for viability in a manner as nearly identical as possible to the pathogens which were embedded in microbeads (i.e. the "unprotected" pathogens constituted control experiments).
The following Examples illustrate several different embodiments of the present invention. It is intended that all matter in these Examples and in the foregoing description of the preferred embodiments and accompanying drawings be interpreted as merely illustrative and not in a limiting sense.
EXAMPLE 1
1×10 9 spores of Bacillus thuringiensis, including bacterial cells, spores and asporal (crystalline) bodies, obtained from a sporulation medium culture, were mixed in 10 ml of a 0.15 N phosphate buffer at pH 7.5. 1.5 ml of this solution was mixed with 1.5 ml of a buffered 1.34% aqueous solution (by weight) of yeast RNA (obtained from Sigma as grade B). Then 0.4 ml of this suspension was mixed with constant stirring in 1.9 ml of a buffered 0.36% aqueous solution (by weight) of protamine sulfate (obtained from Sigma as grade B).
RNA-protamine microbeads formed spontaneously, each entrapping some of the bacterial cells and/or spores and/or asporal bodies. Shaking the mixture resulted in breakage and subsequent spontaneous reformation of additional microbeads. The microbeads were placed in a glass petri dish and exposed to a General Electric G30T8 30 watt germicidal lamp. The petri dishes were placed on a rotary shaker 78 cm below the lamp and shaken at 40 rpm. Viability was determined by plating on brain heart infusion agar obtained from Difco.
When exposed to germicidal ultraviolet radiation (peak radiation at 254 nm) sufficient to kill 99.99% of any unprotected B.t. the B.t. which was embedded in the microbeads (i.e., the protected bacterial cells and/or spores and/or asporal bodies) nearly all survived. This is shown in FIG. 2. The early die-off shown by the line marked "protected B.t." is thought to be due to the low percentage of B.t. actually embedded in the microbeads. Under microscopic observation the percentage of B.t. actually embedded was observed to range from 0.5% to 1.5%.
EXAMPLE 2
Microbeads with B.t. embedded therein were prepared as in Example 1, and then 1 mg/ml dithiobissuccimidyl propionate in DMSO was added to crosslink and stabilize the microbeads. 0.2 ml of this solution were placed on a 0.22μ Millipore filter and allowed to dry under vacuum. The filters were exposed as in Example 1 without shaking. After shaking, the filters were washed off in dilution buffer and plated as in Example 1. Results of this procedure are shown in FIG. 3.
EXAMPLE 3
1×10 9 spores of B.t. obtained from culture in sporulation medium were first washed in a 60% ethanol solution and then washed in a 1 M NaCl solution, with the B.t. being separated from these washes by centrifugation. The washed B.t. was then suspended in 20 ml of a 1 M carbonate buffer solution at a pH of 8.0.
Next, dry succinic anhydride, a protein modifying agent, was added to the suspension as six separate additions of 2.5 mg/ml each. The additions were made under constant stirring and the mixture was stirred for 10 minutes between each addition. The pH was held at 8.0±0.1 by addition of NaOH. When the reaction was completed, as indicated by the pH ceasing to change, the B.t. was separated out (centifuged) and washed.
This modified B.t. (negatively charged) was then incorporated into RNA-protamine microbeads according to the procedures set forth in Example 1 and the microbeads were crosslinked as in Example 2.
It was found that this modified B.t. entered the microbeads much more readily and in much higher numbers than the unmodified B.t. used in Examples 1 and 2. Presumably this was due to the modification of the surface charge on the B.t. from neutral to negative.
EXAMPLE 4
A solution of unprotected B.t. (cells, spores, and toxin crystals) and protected B.t. (i.e., embedded in microbeads as described in Example 3, but without crosslinking), 60% unprotected and 40% protected (determined microscopically), was subjected to 254 nm radiation as described in Example 1.
Essentially no unprotected spores remained viable after 15 minutes of such irradiation, while 1×10 6 protected spores (i.e., 40% of the total original mixture) remained viable after one hour of such irradiation. Viability was determined as in Example 1. The results of this experiment are shown in FIG. 4.
EXAMPLE 5
A concentration of 1×10 9 spores of Bacillus thuringiensis (including cells, spores and asporal crystals) of B.t. was suspended in 10 ml of 0.15 N phosphate buffer, pH 7.5 (B.t. preparation was obtained and modified as in Example 3). 0.5 grams of RNA (Calbiochem, grade B) was dissolved into this suspension and mixed by vigorous mixing in a Vortex mixing device. The suspension was then added to a buffered 10% solution of protamine sulfate (Calbiochem, grade B, by weight) and vigorously shaken for 5 seconds. Glutaraldehyde (25%, from Sigma) was added to the solution to a final concentration of 0.15% (by volume). After 30 minutes a pellet formed at the bottom of the tube which consisted of large microbeads (100-150μ). The supernate was drawn off and the pellet was resuspended to a final volume of 20 ml by shaking. This solution was placed on a 0.22μ Millipore filter and dried overnight under vacuum. The filters were exposed to sunlight (1:00 pm, RH 23%, temperature 89° F.). The filters were then washed in acetate buffer (0.15 N, pH 4.0) to break up the microbeads and release the B.t., which was plated as in Example 1.
The results of this experiment are shown in FIG. 5. Unprotected spores were nearly all killed after 30 minutes.
EXAMPLE 6
The purpose of this example was to demonstrate protection of a virus according to the present invention. The reactions and response of an insect virus and a bacterial virus (called bacterial phage) should be similar since both are composed basically of a nucleic acid in a protein coat. Accordingly, we chose to model our system with the bacterial virus of E. coli, phage T-4.
T-4 bacterial phages were grown in nutrient broth with 0.5% NaCl (P-broth). E. coli BB was inoculated into 100 ml P-broth and allowed to grow overnight. In the morning a 1:100 dilution was made to fresh broth and growth was allowed to proceed for one hour. 1×10 7 phages were added to this rapidly growing E. coli BB culture and allowed to grow for six hours (37° C., rapid shaking). At the end of the period, 5 drops of chloroform were added to kill all bacteria in the culture. This is the phage stock.
Microbeads were prepared by mixing 0.100 grams of protamine sulfate (Calbiochem, grade B) in 10 ml phage stock. This suspension was added to 1% RNA (by weight) in P-broth. The microbeads formed spontaneously. The UV exposure was carried out as in Example 1. Timed samples were taken and dilutions were made in P-broth. The viable phages were determined by the method described in the following text: Grace C. Rovozzo and Carroll N. Burk, A Manual of Basic Virological Techniques, Prentice-Hall Biological Techniques Series, 1973, page 168, using P-broth agar and E. coli BB as the indicator bacteria.
The results of this experiment are shown in FIG. 6. These data show that unprotected virus were all killed in approximately 5 minutes. On the other hand, after an initial drop similar to that seen in the bacterial tests, the virus which was embedded in the microbeads show strong UV light resistance (approximately 40% are protected from inactivation).
EXAMPLE 7
Microbeads having B.t. (cells, spores, and toxin crystals) embedded therein were prepared as in Example 3, except that dithiobissuccimidyl propionate in DMSO was not used to crosslink the microbeads. In this example the microbeads were crosslinked and stabilized by adding phosphate-buffered tannic acid (1% w/v) to the microbead suspension, and allowing it to stand at room temperature for about 30 minutes. The suspension of crosslinked microbeads was diluted with dilution buffer (phosphate) in a manner selected to produce a diluted suspension containing approximately 100 spores per ml, and 1 ml samples of this diluted suspension were pulled onto separate 0.22μ Millipore® filters and permitted to dry overnight. The filters were exposed under a General Electric sunlamp measured at 1572 watts/m 2 at 15 inches and providing radiation in the wavelength range of about 290 nm to 400 nm. One hour exposure under this sunlamp was equivalent to approximately 151 hours under direct sunlight on a July day at a location of approximately 45° latitude (i.e. about 15 days). After exposure, the spores were placed directly on plate count agar, and after 24 hours incubation the colonies growing on the filters were counted. The experimental data are shown in FIG. 7.
EXAMPLE 8
Vegetative bacterial cells of the species Pseudomonas fluorescens, Serratia marcescens, and Escherichia coli were treated with succinic anhydride, in three separate series of experiments, by placing approximately 1×10 9 cells in 20 ml of 1 M carbonate buffer solution (at pH 8.0), then adding 50 mg of succinic anhydride. The pH was not maintained because the resultant pH, about 7.5, was believed to be more advantageous for bacterial survival during harvesting and washing. The succinic anhydride treated cells of the three species were suspended, again in separate tests, in 4 ml of a 0.15 N phosphste buffer solution (at pH 7.5), and 1 ml of this suspension was then mixed with 1 ml of a buffered 1.34% (w/v) RNA (obtained from Sigma) solution. The resulting suspension was mixed with 2 ml of a buffered 1% (w/v) Protamine sulfate (obtained from Cal Biochem.) solution, spontaneously forming the microbeads, and then 0.4 ml of a 10% (w/v) tannic acid solution was added to the suspension of microbeads. (Note: the buffer referred to above was 0.15 N phosphate buffer solution at pH 7.5). The suspension of microbeads in tannic acid was allowed to stand for 30 minutes at room temperature, and then was washed three times in the phosphate buffer solution described above by centrifuging.
Microscopic observation revealed that approximately 30% of each of the three species tested were embedded in the microbeads.
The suspensions of microbeads produced in the three series of experiments were exposed, separately, under the General Electric sunlamp described in Example 7 using the experimental procedure described in Example 1 (i.e. exposure while on a rotary shaker), except that a greater number of microbeads were present in the suspension. Data from a representative test of the P. fluorescens bacterial cells are shown in FIG. 8. The data from the tests of the Serratia marcescens and Escherichia coli bacterial cells (not shown) were similar to that shown in FIG. 8.
It should be noted however, that in performing the experiments for which data are shown in FIG. 8, it was assumed that any bacterial cells in the microbead suspension which had not been embedded in the microbeads would be killed during exposure of the suspension while on the rotary shaker. To test the correctness of this assumption a second control experiment (in addition to the control shown in FIG. 8) was run. In this second control, B.t. spores were treated as described above, except that they were not embedded in microbeads, but were merely mixed in a suspension containing already-formed microbeads (using approximately the same number of microbeads as used in the experiments described above), and this mixture was exposed under the sunlamp as described above. If the assumption was correct, then most of the cells should be killed. We found, however, that the cells were killed at roughly the same rate as the cells which had been embedded in the microbeads. We attribute this to the relatively large number of microbeads present in the suspensions which were exposed (i.e. the microbead suspensions were too heavy). We believe that the large number of microbeads present restricted the movement of the cells which were outside the microbeads, so that any cells which were underneath a microbead essentially remained there throughout the exposure and were protected. Thus, we feel that this example, including the second control, does show that the microbeads protect the cells against sunlight-induced inactivation (whether the cells are in or outside, but under, the microbeads). Also, as noted above, microscopic observation revealed that cells of each of the three bacterial species tested were embedded in the microbeads.
EXAMPLE 9
1×10 8 Douglas fir tussock moth nuclear polyhedrosis virus was suspended in a 0.5 N phosphate buffer (20 ml) at pH 7.5 and treated with six 50 mg additions of succinic anhydride. 1.0 N NaOH was used to hold thepH at 7.5. After treatment, the virus suspension was harvested by centrifugation and washed twice in 0.15 N phosphate buffer and resuspended in 1 ml of the buffer. This suspension was then treated as described in Example 8 to form crosslinked microbeads having the virus embedded therein. The suspension was exposed under the General Electric sunlamp as described in Example 8, then diluted with buffer and tested for infectivity as described in Example 12. The infectivity data is shown in FIG. 9. This data suffers the same error as described in Example 8 (i.e. microbead suspension which was exposed was too heavy to permit kill off of virus which were not embedded in the microbeads). However, as in Example 8, microscopic observation did reveal that about 30% of the virus was embedded in the microbeads, and that the microbeads offered protection against sunlight-induced inactivation (whether the virus are inside or outside, but under, the microbeads).
EXAMPLE 10
1 gram of hemoglobin (crude powder) was mixed with 0.34 gram of RNA in dry powder form. Approximately 1×10 9 spores of B.t. were suspended in a buffer solution (0.15 N acetate, pH 5.0), and then added to the RNA-hemoglobin mixture. Additional buffer solution was added in an amount sufficient to form a hydrated (i.e. wet) mass having a paste-like consistency. The total amount of buffer solution mixed with the RNA-hemoglobin mixture was about 1 ml. This paste was forced (i.e. extruded) through an 18 gauge needle (using a 5 cc syringe) into a buffered (0.15 N acetate) 1% (w/v) tannic acid solution and subjected to magnetic stirring in a beaker. After about 30 minutes of stirring, the extruded paste had been broken into discrete, crosslinked microbeads approximately 100μ or smaller in size having the B.t. incorporated therein. The microbead suspension was diluted and exposed under a General Electric sunlamp as described in Example 7 (i.e. on filters). The experimental data are shown in FIG. 10.
EXAMPLE 11
Autographa californica nuclear polyhedrosis virus (approximately 1×10 7 polyhedral inclusion bodies) was embedded in RNA-Protamine microbeads using the technique described in Example 10. In this example, 1 gram of protamine (dry powder form) and 0.67 grams of RNA (dry powder form) were used, the buffer was 0.15 N phosphate solution at pH 7.5, and tannic acid was used to crosslink and stabilize the microbeads. The microbead suspensions were washed twice in distilled water and then diluted 1:100 in distilled water. The diluted suspensions were exposed under a General Electric sunlamp using the technique described in Example 1, and the exposed suspensions were diluted in phosphate buffer as needed for the infectivity tests, described below. Trichoplusia ni larvae were used to measure infectivity of the protected virus (i.e. embedded in the microbeads) and the unprotected virus (i.e. the control). Infectivity was determined by placing 10 μl of separate dilutions (1:10 2 to 1:10 7 ) on a 0.2 gram piece of diet. The larvae were allowed to eat the entire piece of diet, and then a new piece of diet (2 grams) was placed in the vial. When all the control larvae (not fed virus microbeads) had pupated, the dead larvae were autopsied to verify that death was caused by infection caused by the Autographa californica virus (this was found to be the case). LD 50 's for the T. ni. larvae were determined for virus which had been protected by the microbeads and for the control virus, which had not been protected by an microbeads. The general procedures for making LD 50 determinations are described in Microbiology, at p. 639, B. D. Davis, et al., Harper and Row, 1973. The LD 50 data are shown in FIG. 11.
EXAMPLE 12
Example 11 was repeated using Douglas fir tussock moth nuclear polyhedrosis visus in place of the Autographa californica virus and Douglas fir tussock moth larvae in place of the T. ni. larvae, except that the larvae were autopsied at the end of a 10 day period. The LD 50 data are shown in FIG. 12.
It should be understood that the term "nucleic acid" as used through this specification and in the claims is intended to include all polynucleotides. Likewise, the term "protein" is intended to include all polypeptides.
It is also to be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. | An improved microbial insecticide composition, and methods for the production and utilization thereof, are disclosed. The disclosed composition comprises a microbial insect pathogen of viral, bacterial, or fungal origin which is susceptible to sunlight-induced inactivation embedded in a coacervate microbead which is comprised of a nucleic acid, typically RNA, and a proteinaceous material, whereby the microbead structure itself effectively shields the agent from sunlight-induced inactivation. The microbead is typically stabilized by chemical crosslinking. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a Continuation-in-Part of the application Ser. No. 08/463,150, filed Jun. 5, 1995, now U.S. Pat. No. 5,574,091.
BACKGROUND OF THE INVENTION
Aqueous dispersions of polyolefins are known in the art, although none are reported to have been derived from polyolefins having molecular weights above 40,000. For example, in U.S. Pat. No. 3,734,686, incorporated herein by reference, Douglas et al. discloses a mechanically stable aqueous emulsion of polyethylene particles having an average molecular weight ranging from about 7,000 to 40,000. These dispersions are taught to be useful for treating carpets.
In U.S. Pat. No. 3,418,265, McClain teaches that aqueous film-forming ethylene polymer latexes containing ethylene polymer particles of submicron size can be prepared by dispersing in water an ethylene polymer and a water-soluble block copolymer of ethylene oxide and propylene oxide. No examples of stable dispersions of ethylene polymers having a molecular weight above 27,000 are reported.
Many of the polyolefin latexes previously described are actually not purely polyolefinic, but rather contain polar groups, such as acids or halides. Since the film-forming properties of these so-called polyolefin latexes are often adversely influenced by the presence of these polar substituents, it would be desirable to prepare latexes derived from higher molecular weight polyethylenes that did not contain polar groups. It would be of further value if these latexes were film forming at room temperatures.
SUMMARY OF THE INVENTION
The present invention is a film-forming, artificial latex comprising a stable aqueous dispersion of a copolymer of ethylene and a C 3 -C 20 α-olefin having: a) a polydispersity index not greater than 2.5; b) a random distribution of comonomer units along the polymer backbone; c) a homogeneity index of at least 75; and d) an absence of polar substituents.
It has surprisingly been discovered that film-forming latexes can be prepared from this class of olefin polymer in the absence of polar substituents on the polymer backbone.
DETAILED DESCRIPTION OF THE INVENTION
The olefin polymer used to prepare the stable aqueous dispersion of the present invention is from a family of olefin polymers that are described in U.S. Pat. No. 3,645,992 by Elston. This family of olefin polymers can be characterized by being a linear copolymer of ethylene and at least one other α-olefin having four or more carbon atoms, such as 1-butene, 1-hexene, 1-octene, and 1-octadecene. Interpolymers, such as ethylene-octene-butene are also suitable for the preparation of the aqueous dispersions of the present invention. The olefin polymer is further characterized by a narrow molecular weight distribution, more particularly, a polydispersity index not greater than 2.5, more preferably from about 1.5 to not greater than 2.5, and a homogeneity index of at least 75, as described by Elston in column 6, lines 45-75. Inclusive of such polymers are EXACT™ plastomers (a trademark of Exxon Chemical, Co.).
The weight average molecular weight of the polymer used to prepare the aqueous dispersion is preferably at least about 45,000 amu, more preferably at least about 60,000 amu. The molecular weights are preferably measured by a procedure described in U.S. Pat. No. 5,278,272, column 5, line 56 to column 6, line 20, incorporated herein by reference. The olefin copolymer preferably contains no polar groups, such as acetate, ester, ether, amine, alcohol, acrylic, methacrylic, halogen, nitrile, nitro, sulfate, phosphate, or mercaptan groups; and there is preferably no post-modification step to add polar groups.
The latexes of the olefin polymers are prepared in the presence of a stabilizing and an emulsifying amount of a suitable surfactant. A preferred surfactant is a sulfate of an ethoxylated phenol represented by the formula:
X--Φ--O--(CH.sub.2 --CH.sub.2 --O).sub.n --SO.sub.3.sup.- Z.sup.+
wherein X is a C 6 -C 18 linear or branched alkyl group, preferably octyl, nonyl, or lauryl, more preferably octyl or nonyl, most preferably nonyl; Φ is phenylene, preferably p-phenylene; n is from 4 to 32, preferably from 4 to 12; and Z is sodium, potassium, or ammonium, preferably ammonium. Some of the preferred sulfates of ethoxylated alkylphenols are commercially available, for example, poly(oxy- 1,2-ethanediyl) alpha-sulfo-ω(nonylphenoxy) ammonium salt.
Stable aqueous dispersions of the olefin polymers can be prepared by any suitable technique, including those described in U.S. Pat. Nos. 3,360,599; 3,503,917; 4,123,403; and 5,037,864, all incorporated herein by reference. It has surprisingly been discovered that a film having a substantially uniform thickness across a substrate or form can be prepared at room temperature (that is, from about 20° C. to about 30° C.) from the aqueous dispersion described hereinabove. The film is further characterized by an absence of cracking or foramina.
The film can be prepared by any suitable means such as casting, coagulating, or spraying. If films are prepared by coagulation, it is generally preferred to use fatty acid based surfactants, such as the sodium salt of oleic acid.
The following example is for illustrative purposes only and is not intended to limit the scope of the invention. All percentages are by weight unless otherwise noted.
EXAMPLE 1
A Cast Film of an Ethylene-l-Butene Latex
To a 2-liter vessel is added a solution of EXACT® 4028 plastomer in cyclohexane (612 g, 10 percent solids), a solution of RHODAPEX™ CO- 436 surfactant (a trademark of Rhone-Poulenc, 11.5 g, 28 percent solids), and water (288 g). The weight average molecular weight of the plastomer is determined to be 62,300 amu (number average molecular weight 32,700 amu) by gel permeation chromatography using a Waters 150° C. high temperature chromatographic unit equipped with three linear-mixed columns (10-micron particle size), operating at 140° C. (100 μL injection of 0.5 percent polymer in 1,2,4-trichlorobenzene, flow rate of 1 ml/minute).
The polymer solution, the surfactant, and water are emulsified using a Siverson homogenizer by mixing at the highest setting (nominally 8000 rpm) for 10 minutes. The cyclohexane solvent is removed in vacuo from the emulsion by heating in a glass rotovap maintained at 40° C. The resulting artificial latex is concentrated by applying a vacuum of 25 inches of Hg to the latex with continued heating. After the latex reached 36 percent solids, the latex is removed from the heat and allowed to cool.
A film of the latex is prepared as follows: A small quantity of the latex is poured on a glass plate and is uniformly spread using a draw bar with a nominal gap of 0.25 mm. The latex is allowed to dry at room temperature and form a coherent film upon drying. The film is placed into a forced air oven at 60° C. for a few minutes to drive off any remaining water. The film is allowed to cool on the glass plate and then removed and tested. The film is found to have an ultimate tensile of 2080 psi and a percent elongation of 787 percent. | Artificial latexes that are film forming at room temperature can be prepared from a copolymer of ethylene and a C 3 -C 20 α-olefin. The copolymer is characterized by having a polydispersity index not greater than 2.5; random distribution of comonomer units along the polymer backbone; and a homogeneity index of at least 75. The copolymer preferably contains no polar substituents, which are generally necessary to make useful latexes from polyethylene. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a National Phase Entry of PCT/CA2010/000117 filed on Jan. 25, 2010 and claiming priority on U.S. Provisional Application No. 61/148,571 filed on Jan. 30, 2009.
FIELD OF THE INVENTION
The application relates generally to the manufacturing of tongue and groove profiles on wood floorboards and, more particularly, to a process for controlling the evenness of tongue and groove joints between adjacent floorboards.
BACKGROUND ART
The interlocking tongue and groove profiles along opposed longitudinal sides of hardwood floor boards, such as planks and strips, are typically made by milling. The boards are advanced on a table of a moulding machine (also known as a planning and grooving machine) between a pair of rotary cutters carrying cutting inserts or knives having cutting profiles corresponding to the profiles to be cut along the opposed sides of the boards. The relative height of the groove and tongue cutters must be precisely adjusted to ensure evenness of the boards when assembled together. Also, the position of the successive boards relative to the cutting tools must not vary from one board to another in order to provide for a smooth tongue and groove fit between the boards and ensure proper mating of the eased edges (also known as the micro-bevelled edges) of adjacent boards. If the vertical position of the boards relative to the groove and tongue cutters vary from one board to the next or if the relative vertical position of the groove and tongue cutters is not well adjusted, there will likely be a vertical offset V between the micro-bevelled edges of adjacent mating boards once assembled together, as shown in FIG. 4 b . This can also result in unevenness of the floor boards once laid down on the sub-floor.
In order to prevent the delivery of such “defective” floor boards, many floorboard manufacturers have established a quality control process at the exit of the moulding machine. Such a quality control process typically consists of manually measuring with a vernier the thickness of the top or bottom lip of the groove profile of the boards combined with a visual inspection of the evenness of the joint between two assembled sample boards. The visual inspection can be carried out by placing a level or the like on one face of two assembled boards and verifying if there is any visually perceivable gap between the assembled boards and the level. If the measured thickness is substantially the same from one board to another and the results of the visual inspection are satisfactory, it is assumed that the joining of the boards will provide even tongue and groove joints. If the thickness varies or the gap between the level and the assembled boards is considered outside of the acceptable manufacturing tolerances, then the defective floorboard production is rejected or, whenever possible, re-processed to ensure proper mating of the different board batches.
Such a quality control process has several drawbacks. First, the measurements obtained with a vernier may vary depending on the person taking the measurements. Also the visual inspection is subjective and the appreciation thereof may vary from one person to another. The results of the quality control process are, thus, greatly dependent on the skills of the operators and as such not always reliable.
Furthermore, even if the measurements are taken correctly, the thickness of the top or bottom lip of the groove profile may not be sufficient to guarantee perfect matching of the tongue and groove profiles or of the micro-bevelled edges of the boards.
There is thus a need to improve consistency in the production of tongue and groove floorboards.
SUMMARY
In view of the foregoing, it would be desirable to provide a new process by which the evenness of the tongue and groove joints between adjacent floorboards could be reliably and readily controlled.
According to a general aspect of the invention, it has been found that the precision of the quality control measurement process could be improved by using the undersurface of the floorboards as a reference surface and by measuring a depth on the groove profile and/or on the tongue profile of the boards relative to the undersurface of the boards rather than a thickness of the top or bottom lip of the groove profile. Such a depth can be measured by using a conventional depth gage, a laser or other electronic distance-measuring device. The selected measuring device or tool could, for instance, be used to measure the distance between the undersurface of a floorboard and the underside of the tongue thereof. The manufacturing process could also be modified to integrate a recess or groove/undercut in the undersurface of the bottom lip of the groove profile of the boards and the depth of the undercut could be measured to evaluate the positioning of the groove profile relative to the undersurface of the floorboard.
According to a further general aspect, the depth of the undercut in the bottom lip of the groove profile can be measured with a spring-loaded plunger gage. The base of the gage is abutted against the undersurface of the board with the tip of the spring-loaded plunger abutting against the bottom of the groove or undercut. Such a measurement procedure with a depth gage has proven to be accurate and less sensitive to the skills of the person taking the measurement. The modification of the groove profile of the boards (and thus the modification of the cutting profile of the knives used to cut the groove in the boards) to incorporate the longitudinal undercut in the undersurface of the bottom lip of the groove profile allows the integration of a depth reading procedure relative to the undersurface of the board on the groove profile side thereof as part of a quality control process of the floorboard tongue and groove joints.
According to a further aspect of the present invention, a measurement can be taken not only on one side of the boards but on both sides thereof that is on the groove profile side and on the tongue profile side. The two measurements are taken from a common plane of reference, namely the undersurface of the board. These measurements allow to precisely adjusting the relative positioning of the groove and tongue cutter heads of the moulding machine in order to avoid any unacceptable mismatch or vertical offsets between the tongue and groove profiles of the floorboards when assembled together on a sub-floor structure. The measurement on the groove profile side of the board can be obtained by measuring a depth Y of the undercut defined in the bottom lip of the groove profile (i.e. the distance between the bottom surface of the undercut and the undersurface of the board). The measurement on the tongue profile side of the board can be obtained by using again the undersurface of the board as a reference plane to measure the distance X between the underside of the tongue and the undersurface of the board. The same depth measuring tool can be used to measure both the depth Y of the undercut on the groove profile side and the distance X between the undersurface of the board and the underside of the tongue on the tongue profile side of the board. If the groove and tongue cutters of the moulding machine are well adjusted, the difference between the X value and the Y value shall be equal (±the manufacturing tolerances) to the thickness Z of the bottom lip of the groove profile of the board, which is a constant fixed by the cutting profile of the groove cutter. The relative positioning of the groove and tongue cutters is adequate, when the equation: X−Y=Z is satisfied. Any deviations from constant Z provide a direct indication of the distance by which the groove cutter head and the tongue cutter head must be displaced relative to one another to avoid a vertical offset between the tongue and groove profiles of assembled floorboards.
According to a further general aspect of the present invention, the tongue and groove floorboard manufacturing process is characterized by taking measurements on both first and second longitudinal sides of a floorboard relative to a common plane of reference corresponding to an undersurface of the floorboard. A first measurement on the first longitudinal side of the floorboard is indicative of the position of the groove relative to the undersurface of the floorboard. A second measurement on the second longitudinal side of the floorboard is indicative of the position of the tongue relative to the undersurface of the floorboard. The first and second measurements are then used to adjust the position of the groove and tongue profile cutters relative to one another on the moulding machine.
According to a further general aspect of the invention, there is provided a tongue and groove floor board quality control process for the production of hardwood floorboards having interconnecting tongue and groove profiles defined along opposed longitudinal sides thereof, the process comprising: using the undersurface of the floorboards as a reference plane for taking some measurements, measuring a distance between a downwardly facing surface of at least one of said tongue and groove profiles and the undersurface of selected ones of the floorboards, and determining if the measured distance is contained within acceptable manufacturing tolerances.
According to a still further general aspect, there is provided a tongue and groove floorboard manufacturing process comprising milling interlocking tongue and groove profiles along opposed sides of incoming floorboards, the groove profile comprising a groove bounded by top and bottom lips, the bottom lip having an undercut defined therein; measuring a distance Y between the bottom of said undercut and an undersurface of selected ones of said floorboard, and determining if the measured distances fall within an acceptable range of deviations from a predetermined value.
The term “floorboard” should not be strictly construed to the preliminary meaning of the word and is intended to broadly refer to any floor planks, floor strips and the like used in the fabrication of hardwood and solid wood flooring.
The floorboard thickness is herein used to refer to the distance between the top surface and the undersurface of the boards.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the accompanying drawings in which:
FIG. 1 is a schematic perspective view illustrating a solid wood floorboard in the process of being planed and profiled in a moulding machine according to a floorboard manufacturing process;
FIG. 2 is a schematic cross-sectional end view of a hardwood floorboard engaged between the moulding machine rotary cutters used to respectively cut the groove and tongue profiles along the opposed sides of the board while the same is being advanced through the machine shown in FIG. 1 ;
FIG. 3 illustrates a quality control inspection step of the floorboard manufacturing process, the inspection step comprising measuring with a spring-loaded plunger dial gage the depth of an undercut defined in the bottom lip of the groove profile cut in one side of the board by the rotary cutter shown on the left hand side of FIG. 2 ;
FIGS. 4 a and 4 b respectively illustrate even and uneven tongue and groove joints, the defective tongue and groove joint shown in FIG. 4 b illustrating a vertical offset between the micro-bevelled edges of two adjacent floorboards as one potential consequences of an undetected groove and tongue profiling error.
DETAILED DESCRIPTION
FIG. 1 illustrates a tongue and groove floorboard 10 in the process of being machined in a moulding machine M. Such machines typically include two or three pairs of top and bottom planer cylinders 12 , 14 and a pair of axially staggered rotary cutter heads 16 and 18 disposed for receiving therebetween the boards to be planed and profiled. The boards are advanced on a steel table 15 between the cylinders 12 , 14 and the profile cutter heads 16 and 18 . The top planer cylinders 12 planed the undersurface 20 (see FIG. 3 ) of the floorboards, whereas the bottom cylinders 14 planed what will constitute the top facing surface 22 (see FIG. 3 ) of the floorboards after final sanding and varnishing operations (not shown).
Referring to FIG. 2 , the rotary cutter head 16 carries a number of circumferentially distributed knives or cutting inserts having a cutting profile 17 configured for machining a tongue profile 24 along one longitudinal side of the board 10 . Likewise, the rotary cutter head 18 carries a number of circumferentially distributed knives having a cutting profile 19 configured for machining a corresponding groove profile 26 in the opposed longitudinal side of the board 10 . The tongue and grooves profiles 24 and 26 are configured to provide for tongue and groove interlocking engagement of adjacent floorboards 10 . In the illustrated example, both cutting profiles 17 and 19 include a slanted cutting edge portion 21 , 23 for forming eased edges or micro-bevelled edges 25 ( FIG. 3 ) at the top sides of the board 10 . The groove cutting profile 19 provided by the rotary cutter head 18 (i.e. the groove cutter head) comprises a central outwardly projecting cutting portion 28 adapted to cut a groove 30 ( FIG. 3 ) in the side of the board with a top lip 32 and a bottom lip 34 . In addition to the central outwardly projecting cutting portion 28 , the cutting profile 19 is provided at a top end thereof with an outwardly projecting cutting portion 36 for machining a groove or undercut 29 ( FIG. 3 ) in the undersurface of the groove bottom lip 34 . The groove bottom lip 34 is thus not only machined on a top side thereof but also on its bottom side. This provides for a constant thickness Z of the groove bottom lip 34 from one floorboard to another and that irrespective of possible height variations in the positioning of the boards relative to the groove cutter head 18 . However, there is still a need to ensure that the groove profiles of the boards all start at the same height from a common reference surface in order to ensure smooth tongue and groove fit and prevent vertical offsets between the eased edges of the boards when laid down side by side in interlocking engagement on a sub-floor structure.
This can be verified and controlled by referencing the profiled underside of the bottom lip 34 to the planed undersurface 20 of the boards 10 . As shown in FIG. 3 , this can be conveniently achieved by measuring the depth Y of the undercut 29 with a conventional spring-loaded plunger dial depth gage G at the exit of the boards from the moulding machine. The base B of the gage G is abutted against the undersurface 20 with the tip of the spring-loaded plunger P resting against the bottom of the undercut 29 . In the illustrated embodiment, a dial allows the operator to easily read the measured depth D of the undercut 29 . It is understood that other suitable depth gage could be used as well to measure the depth of the undercut 29 (i.e. the distance between the reference surface, namely the board undersurface 20 and the underside of the bottom lip 34 ). This measuring procedure has proven to be more precise and less sensible to human intervention. According to a further aspect, the measuring of the distance between the reference surface, (i.e. the undersurface 20 ) and the cut underside of the bottom lip 34 of the groove profile 26 could be automated and accomplished through the use of any suitable sensors, laser measuring devices or the like.
As shown in FIG. 4 a , if the measured depth D 1 , D 2 of boards 10 and 10 ′ respective undercuts 29 are substantially equal (i.e. contained within the established manufacturing tolerances), the top and bottom lips 32 and 34 will fit smoothly over the tongue 24 of board 10 with a perfect match of the micro-bevelled edges 25 , thereby providing for levelled and precise micro V joint between the boards with no vertical offset between the tongue and groove profiles of the boards when the same are laid down on an underlying sub-floor. If one board is thicker than the other, the top surface of thicker board can be readily sanded to remove the excessive thickness of material therefrom without altering the apex of the V joint and the overall interlocking tongue and groove profile of the boards 10 and 10 ′.
On the contrary if the measured undercut depths are different from one another (i.e. outside of the acceptable manufacturing tolerances) as illustrated in FIG. 4 b , where the depth D 3 is greater than the depth D 4 , then there will be a corresponding vertical offset “V” between the micro-bevelled edges and that even if the boards have the same overall thickness. If the difference between D 3 and D 4 is too important, it might even be difficult or even impossible to engage the tongue of the first board into the corresponding groove of the adjacent board when the same are laid down on the underlying sub-floor structure. The difference between D 3 and D 4 provides an indication that the position of the tongue and groove cutter heads 16 and 18 must be adjusted.
By using the depth of the undercut as the reference measurement in production instead of the thickness of the top lip of the groove profile, any variation of thickness between the floorboards can be corrected by sanding the top surface of the boards without altering the vertical match of tongue and groove profiles of the boards. By so measuring the floorboards during the production, it is possible to ensure consistency between the various production batches, thereby allowing floorboards of different batches to be assembled together in a substantially perfect co-planarity.
The relative vertical position of the tongue cutter head 16 and of the groove cutter head 18 must be well adjusted before the production of each batch of floorboards to ensure proper matching of the tongue and groove profiles of adjacent boards. This adjustment can be initially made and periodically verified by taking measurements on both the groove and tongue sides of the floorboards at their exit from the moulding machine M. For each inspected board, the board undersurface is used as a common plane of reference for the measurements taken on the two sides of the board.
As explained herein above, the measurement on the groove profile side of a floorboard can be obtained by measuring a depth Y ( FIG. 3 ) of the undercut 29 defined in the bottom lip 34 of the groove profile (i.e. the distance between the bottom surface of the undercut 29 and the undersurface 20 of the board). As shown in FIG. 3 , the measurement on the tongue profile side of the board 10 can be obtained by using again the undersurface 20 of the board as a reference plane to measure the distance X between the underside of the tongue 24 and the undersurface 20 of the board 10 . The same depth measuring tool can be used to measure both the depth Y of the undercut 29 on the groove profile side and the distance X between the undersurface 20 of the board 10 and the underside of the tongue 24 on the tongue profile side of the board. If the tongue and groove cutter heads 16 and 18 of the moulding machine M are well adjusted, the difference between the X value and the Y value shall be equal (±the manufacturing tolerances) to the thickness Z of the bottom lip 34 of the groove profile of the board 10 , Z being a constant fixed by the cutting profile 19 of the groove cutter head 18 . The relative positioning of the tongue and groove cutter heads 16 and 18 is adequate, when the equation: X−Y=Z is satisfied. Any deviations from the constant Z provide a direct indication of the distance by which the groove cutter head 18 and the tongue cutter head 16 must be displaced relative to one another to avoid a vertical offset between the tongue and groove profiles of the floorboards. This provides a very precise and rigorous method for adjusting the tongue and groove profile cutter heads 16 and 18 as compared to the prior art visual inspection of the evenness of two assembled boards.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, it is understood that the same measuring methods could be used with floorboards having no micro-bevelled edges. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the equivalents accorded to the appended claims. | The undersurface ( 22 ) of the floorboards ( 10 ) is used as a main reference for taking measurements in a tongue and groove floorboard quality control process. The process comprises measuring at least one distance (X, Y) between the undersurface ( 22 ) and a downwardly facing surface of at least one of a tongue and a groove profile of selected ones of the floorboards ( 10 ). Measurements can be taken from the undersurface ( 22 ) of the selected boards ( 10 ) on both sides thereof to vertically adjust the relative position of groove cutter head ( 18 ) and the tongue cutter head ( 16 ) of the molding machine (M) used to manufacture the boards ( 10 ). A depth gage (G) can be used to take the measurements. | 4 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention pertains to disinfection apparatus for use with hemodialysis apparatus.
(2) Description of the Prior Art
One of the features of blood dialysis apparatuses--so-called hemodialysis devices--is a circulation system for dialysis fluid. This circulation system features a water supply and a dialyzer. The water supply and dialyzer are connected to one another by an initial fluid line. A second fluid line leads from the dialyzer to the discharge. The first and second fluid lines each feature a connector which connects the respective line to the dialyzer. While the dialysis fluid circulation system is being disinfected, a disinfecting apparatus is interposed into this circulation system, and the two fluid lines are connected in a bypassing manner by a shunt piece between their respective connectors.
The disinfection of hemodialysis devices is an essential cleaning step between successive dialysis processes. The goal of this disinfection is the complete cleaning and sterilization of all surfaces and devices which come into contact with the dialysis fluid and/or its concentrates or thinning fluids. Inadequate disinfection of the dialysis fluid circulation system can lead to considerable damage to the health of the patient being treated. However, the only parts of the hemodialysis device which undergo disinfection are those which can be considered part of the dialysis fluid circulation system. The reason for this is that all parts of the blood circulation system are removed and replaced by new, sterile parts after each dialysis process.
In a familiar method for cleaning hemodialysis devices, the dialysis concentrate is replaced by a disinfectant concentrate (typically from a 10-liter canister), which is pumped through the hemodialysis device. In this method, the two fluid lines (i.e., water supply line and dialysis fluid discharge line) are not shunted together. When disinfection has been completed, the disinfecting fluid remains inside the device. Before beginning the next dialysis process, the dialysis device is flushed with water. This process requires the use of a great quantity of the disinfectant. It accomplishes the cleaning of only that portion of the dialysis apparatus which is located downstream from the point at which the disinfectant is added. The applicant's hemodialysis devices A2008C-E are typical embodiments of these devices.
Improved embodiments--as represented, for example, in DE 3 447 989 and DE 3 941 103--recirculate the disinfecting solution after interposing a shunt connection between the first and second fluid lines. For one thing, this results in the complete cleaning of the dialysis fluid circulation system. It also reduces the consumption of disinfectants.
Liquid cleaning agents (e.g., formaldehyde, peracetic acid, sodium hypochlorite, or similar chemicals) are ordinarily used as disinfectants. These cleaning agents are aggressive, environmentally unsound, unhealthy, and even somewhat poisonous. It is especially necessary to exercise great caution when using mixtures of the above-mentioned cleaning agents, since an explosion or a release of elemental chlorine can occur. It has only recently been discovered that citric acid functions as a disinfectant at high temperatures. Concentrated citric acid is also aggressive and can cause dangerous reactions when mixed with other chemicals.
Aside from the high cost of transporting the disinfectant (which consists mainly of water), it is necessary to exercise great caution when replacing the concentrates for the dialysis fluid and disinfectant. To this end, special precautions have been taken to prevent the different liquids from being misrouted, i.e, to prevent these concentrates from being accidentally exchanged with one another. Examples of such precautions include special provisions for connecting the different canisters to the hemodialysis device and separate controls for the fluid lines.
There is therefore an urgent need for a disinfecting apparatus which reduces the danger of accidental exchange described above, while ensuring a safe, complete disinfection of the hemodialysis device.
SUMMARY OF THE INVENTION
This problem is solved by providing the disinfecting device with a container which features two adapters for the purpose of attachment to the first and second connectors. This container contains a predetermined dose of a disinfectant.
The container of the disinfecting apparatus can take the form of an apparatus which is rigidly attached to the machine and features a stopper, or it can be a disposable or recyclable container which is externally refillable.
In one advantageous embodiment of the invention, the adapters are designed in accordance with DIN (German Industrial Standard) 58 352. This prevents the connections from being accidentally exchanged and makes the adapters universally applicable.
It is also advantageous to provide the container with a closable fill opening which is suitable for receiving a dose of the disinfectant when refilling.
In one preferred embodiment of the invented apparatus, a filter is provided inside the disinfectant container, in the vicinity of the discharge adapter. The pores or grid openings of this filter are smaller than the grain size of the disinfectant powder. Portions of the disinfectant powder which have not yet dissolved are thus retained.
An upwards flow through the container of the disinfecting apparatus and a tangential inflow of water into the container prove to be especially favorable to the distribution and dissolution (where applicable) of the disinfectant.
When a liquid disinfectant is used, it is advantageous to provide a non-return valve in the refillable container, in the region of the discharge adapter. The non-return valve can be opened by the pressure of the onrushing water. It is located in a lower position during operation.
In an especially preferred embodiment of this invention, a powdered disinfectant (e.g., crystalline or granulated citric acid) is used for disinfection. A special advantage of using solid disinfectants is that it prevents the accidental exchange of disinfecting fluid and dialysis fluid, which has occasionally occurred in the past. This makes the disinfection of hemodialysis devices considerably safer. The citric acid is provided in a suitable dose--for example, in a quantity of 5-30 grams for each liter of the volume to be disinfected. The container is designed to hold such a quantity. When the container is full, an unhindered flow can occur through the container. This ensures that the citric acid solution is recirculated within the hemodialysis device in a sufficiently high concentration. It also ensures that disinfection will occur safely and completely.
In another embodiment of the invention, it is also possible for the closable container of the disinfection apparatus to be filled with a liquid cleaning agent (e.g., solutions of peracetic acid, formaldehyde, or sodium hypochlorite). The use of individual packages of concentrate solutions also offers the considerable advantage of allowing the refill packages to be unmistakably distinguished from the containers of dialysis fluid, so that accidental exchanges can be prevented more effectively than in the past. Another advantage of using cleaning agent concentrates is a reduction in the transport volume of the cleaning agent, which in turn results in cost savings.
The dialysis fluid tubes are connected to the dialyzer during dialysis. After dialysis is concluded, the dialyzer is removed and the respective connectors of the first and second fluid lines are connected to the container of the disinfecting device. It is advantageous for a holder and sensor to be mounted on the hemodialysis device. The sensor allows the positioning of the container to be determined with certainty, so that the presence and appropriate arrangement of the disinfecting device can be monitored simply and with certainty at all times.
In order to further ensure the certainty of monitoring the disinfecting device, one preferred embodiment of the invention provides additional sensors in the connectors which connect the refillable container of the disinfecting apparatus to the first and second fluid lines. These sensors make it possible to check for secure connections between these connectors and the container. The sensors do not allow the disinfecting operation to begin until this connection exists.
In order to allow a clear distinction between a simple rinsing of the hemodialysis device and a complete disinfection process, the container of the disinfecting apparatus can be controlled by means of a bypass valve. This bypass valve can be either electrically controllable or mechanically operable and electrically readable.
In one advantageous embodiment of this invention, the supply line, discharge line and/or dialysis fluid supply are connected by a recirculation line. The apparatus features a closing device for the purpose of creating the recirculation system. With the recirculation system closed in this manner, a complete cleaning of all parts and surfaces of the dialysis fluid circulation system is ensured.
DESCRIPTION OF THE DRAWING
A preferred embodiment of the invention is represented in FIGS. 1 and 2 below.
FIG. 1 represents a diagram of a hemodialysis device during the disinfecting process, in a sectional view.
FIG. 2 represents a section through a container of the disinfecting apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hemodialysis device 10 represented in FIG. 1 features a water supply 11, which empties into a mixing container 14 (dialysis fluid supply) via a line 12, in which a valve 13 is inserted. The mixing container is in turn connected to a supply 16 of an electrolyte concentrate. An initial fluid line 18 exits the mixing container 14. The end of this initial fluid line protrudes from the hemodialysis device 10 and features an initial connector 20. This initial connector 20 is ordinarily connected to a dialyzer (not shown) during dialysis.
A second fluid line 22 leads back into the hemodialysis device 10. This second fluid line features a second connector 24 on the end which is located outside the hemodialysis device 10. This second connector is connected to the discharge of the dialyzer (not shown) during dialysis.
A pump 26 is interposed in the second line 22 inside the hemodialysis device 10. The other end of the second line 22 is ultimately connected with the discharge 28. This type of dialysis device represents the state of the art and is therefore not the object of this invention.
The hemodialysis device 10 is represented in FIG. 1 as it functions during the disinfection phase. For this purpose, a disinfectant container 30 is provided between the two connectors 20 and 24. It is advantageous for this container to display a hollow cylindrical form. This disinfectant container 30 features a supply adapter 32 and 34 at each of its two ends. These two adapters 32 and 34 can be connected in a form-fitting manner to the two connectors 20 and 24. It is advantageous for these adapters to display a form identical to that of the adapters of the dialyzer (not shown), since the latter are subject to international standards of uniformity. In accordance with this embodiment, these adapters take the form of the connection specified by DIN (German Industrial Standard) 58 352. Connectors 20 and 24 are also designed in accordance with this standard. According to one preferred embodiment, at least one of the adapters 32 or 34--through which the fluid flows into the container 30--is arranged tangentially to the longitudinal axis of the hollow cylindrical container 30. This optimizes the flow of fluid into, and out of, the container 30.
The disinfectant container 30 is filled with a disinfectant 36 which can display a granular (i.e., powdered) structure, as represented in FIG. 1.
A grid-shaped cylindrical filter 38 is provided inside the disinfectant container 30, in the region of the discharge adapter 34. This filter is completely enclosed and displays an average mesh opening size which is smaller than the disinfectant particles. The purpose of this filter 38 is to retain undissolved disinfectant within the disinfectant container 30. In the embodiment represented in FIG. 2, a liquid disinfectant concentrate 36 is provided inside the disinfectant container 30. The container 30 represented in FIG. 2 is shown as positioned for use; in other words, the discharge adapter 34 is located on the bottom. In order to prevent the liquid disinfectant 36 from flowing out while the connections are being made, a non-return valve 40 is provided in the discharge adapter 34. This non-return valve can be opened by the pressure of the onrushing mixture of water and disinfectant.
Before being used, the disinfectant container 30 features caps 42 and 44 at both of its connections 32 and 34. These caps close off the two connections 32 and 34 and can be opened when necessary.
A fill opening 46 can also be provided in the container 30. This opening is closed off by a cover 48.
A holder 50 for the disinfectant container 30 is mounted on the hemodialysis device 10. In the example represented here, this holder takes the form of two clamping jaws 50 which can be folded open. An initial sensor 52 is also mounted on the hemodialysis device 10 in the vicinity of this holder 50. This sensor is activated by the container 30 when the container is inserted into the holder 50. The sensor displays a predetermined positioning of the container 30. This sensor 52 is activated by the container 30, but not by the dialyzer, in the event that the dialyzer is inserted into the holder 50. This ensures that a container 30 is inserted and mounted on the dialysis device 10 in a predetermined position.
Connectors 20 and 24 can also be equipped with contact sensors 54 and 56, which are connected to the hemodialysis device 10 via a connecting line, as shown symbolically in FIG. 1. With these contact sensors 54 and 56, it is possible to monitor the connection between the connectors 20 and 24 and the connections 32 and 34.
In another embodiment, the second line 22 is connected to the mixing container 14 via a bypass line 58. Here the point of connection between the bypass line 58 and the line 22 features a valve arrangement 59. This valve arrangement provides the options of connecting the second line 22 to the discharge 28 or--in the recirculating operation--to the mixing container 14 via the bypass line 58.
The supply line 16 and discharge line 22 are connected to the conventional bypass line 60, and a bypass valve 61 is provided at the point at which the two lines are connected. The sensors 52-56, valve arrangement 59, fresh water valve 13 and dialysis fluid pump 26 are connected to a control unit 74 via lines 62-72. The control unit is connected to an input unit 76 via line 78.
As represented by the indicated arrows, the control unit 74 for performing disinfection can not be activated until the sensors 52-56 have sent the connection signal to the control unit 74 via lines 62-66 and the input unit 76 has been activated by the operator.
The hemodialysis device 10 is operated in the following manner, in order to begin disinfection:
The dialyzer is first detached from the connectors 20 and 24. The container 30, which has been filled with fresh disinfectant, is then connected to the two connectors 20 and 24 by its adapters 32 and 34. The contact sensors 54 and 56 ensure a form-fitting connection and notify the control unit 74 of this connection.
The container 30 is then moved into a predetermined position in relation to the hemodialysis device 10. This is accomplished by inserting the container into the holder 50, where it activates the sensor 52. This sensor notifies the control unit 74--via the connecting line 62--of the appropriate predetermined position. The disinfection program can now be started by activating the input unit 76. In addition, the water supply 11 is activated by opening the valve 13, and the valve arrangement 59 is put into the recirculating operation. In accordance with an initial predetermined program sequence, which is stored in the control unit 74, the water is then led through the entire arrangement of lines 18, 22, 58, 14. This continues until the entire quantity of disinfectant is uniformly distributed within this system of lines. The disinfecting solution is then allowed to act upon the hemodialysis device 10 long enough to ensure that the entire dialysis system has been disinfected. A fresh water rinse is then performed by connecting the valve arrangement 59 alternately with the discharge 28 and the recirculation line 58 for rinsing. On the other hand, it is also possible to leave the device 10 filled with the disinfecting solution and rinse it shortly before using it again. Finally, it can also be advantageous to activate the bypass valve 61 via the connecting line 65 when it is intended that the water or disinfecting solution shall flow through the entire apparatus except the container 30. The hemodialysis device 10--which is now sterile and filled with fresh water--can then be used for another dialysis process. To this end, the disinfectant container 30 is detached from the connectors 20 and 24. These connectors are then connected to a sterile, unused dialyzer.
In accordance with another method--the parameters of which are also stored in the control unit 74--the flow through the container occurs in an upwards direction when the container is positioned for operation. To this end, the pump 26 is switched by the control unit to pump in the opposite direction. The advantage of this type of method is that the powder 36 in the container 30 is swirled upwards, so that the discharge adapter 34 does not become clogged. On the other hand, this type of operation can also be achieved by mounting the end of the supply line 18 with the connector 20 at the bottom of the container 30 when positioned for use, while the discharge line 22 is attached at the top of the container 30. In this case, it is not necessary to reverse the output direction of the pump 16. When the flow occurs upwards within the container 30, it is also advantageous to arrange a filter 39 at the upper adapter 32. (This filter may be similar to the other filter 38.) As a result, the discharge of undissolved powder is prevented.
For example, if solid citric acid granulate is used for disinfection, between 10 and 60 grams should be sufficient to fill the container 30 while achieving a disinfectant concentration of 0.5-3.0%. (This number of grams corresponds to a required volume of less than 100 milliliters. It also assumes that the filling volume of the hemodialysis device is 2 liters, and that the density of the granulated citric acid is approximately 1.) This amount of disinfectant can be put into the empty container 30 through the fill opening 46. The container can then again be used for disinfection. In order to ensure that the container is filled with the required amount of disinfectant, the container 30 can feature markings 80 on its outside. These markings can be used to determine the correct fill level and the quantity of disinfectant which has actually been added, provided that a transparent plastic material (e.g., polycarbonate) is used. | A hemodialysis device (10) which features an improved disinfection apparatus. Before disinfection begins, a container (30) of disinfectant (36) is interposed into the dialysis fluid circulation system in place of the dialyzer. The dialysis fluid circulation system is shunted, and the disinfecting solution which is present in this closed circulation system is flushed out of the container (30) and through the entire path of the dialysis fluid, in order to achieve a complete cleaning of the hemodialysis device (10). It is possible to use solid, soluble disinfectant (36) as well as liquid disinfectant. | 0 |
TECHNICAL FIELD
[0001] This disclosure relates to a method of intersecting a first well bore by a second well bore and plugging methods for the first well bore.
BACKGROUND
[0002] Well bores can be drilled into the earth to tap into underground reservoirs of oil or gas. Such well bores can be lined with a casing (e.g., a metal casing) to add structural stability to the well bores. Well bores are typically abandoned after use. In some cases, a well bore may be abandoned and closed after the volume of oil or gas produced by the well drops below suitably economical levels. Alternatively, in some cases, a well bore is abandoned and closed as a result of a loss of control (blowout) in a well bore. Different regulatory bodies have different requirements for such abandoning operations. Some regulatory bodies require that the abandoned well bore be plugged (e.g., with cement plugs).
SUMMARY
[0003] The present disclosure relates methods and systems for intersecting well bores. In a general aspect, a method for intersecting a first, cased well bore includes drilling a second well bore that has a distal end proximal to the first, cased well bore to be intersected, disposing a mill guiding device in the second well bore near a casing of the first, cased well bore, the mill guiding device being configured to direct a mill of a milling assembly away from a central axis of the second well bore and towards the first, cased well bore, inserting the milling assembly into the second well bore, operating the mill of the mill assembly and guiding the milling assembly along the mill guide and into the casing of the first well bore, and removing material from the casing of the first well bore until the first, cased well bore and the second well bore are fluidly connected.
[0004] In another general aspect, a method for intersecting a first, cased well bore includes forming a second well bore that extends to a region of the first, cased well bore to be intersected, arranging a mill guiding device in the second well bore near a casing coupling of a casing of the first, cased well bore, inserting a milling assembly into the second well bore, guiding the milling assembly along the mill guiding device and operating a mill of the mill assembly so that the mill first removes material from an upper surface of the casing coupling, and removing material from the casing coupling and the adjacent casing until the first, cased well bore and the second well bore are fluidly connected.
[0005] In another general aspect, a method for intersecting a first, cased well bore includes forming a second well bore that extends to a region of the first, cased well bore to be intersected, inserting a milling assembly into the second well bore, where the milling assembly has a mill guide, a mill, and a mill alignment device to align the mill and the mill guide as the mill advances along the mill guide, operating the mill and guiding the mill along the mill guide and into a casing of the first, cased well bore, and removing material from the casing until the first, cased well bore and the second well bore are fluidly connected.
[0006] In more specific aspects, the methods may further include removing the milling assembly from the second well bore.
[0007] The methods may further include inserting a plugging material into the first, cased well bore from the second well bore to form an obstruction. In some cases, the plugging material may include cement. In some cases, the obstruction limits an amount of fluid that can pass through the first, cased well bore. In some cases, the fluid is a gas.
[0008] The methods may further include running and setting an anchor packer assembly in the second well bore below the mill guiding device.
[0009] Disposing the mill guiding device may include running and positioning the mill using a drill string.
[0010] The mill guiding device may include a wedge-like member that is arranged in the second well bore to force the mill towards the casing of the first well bore as the mill is inserted into the second well bore.
[0011] The milling assembly may include the mill guiding device and the mill guiding device may include a wedge-like mill guiding device that is arranged in the second well bore to force the mill towards the casing of the first well bore as the mill is inserted into the second well bore.
[0012] The mill may include a rotating drill bit. In some cases, the rotating drill bit may be powered hydraulically.
[0013] The methods may further include running and setting an anchor packer assembly in the second well bore below the mill guide.
[0014] The mill alignment device may include one or more grooved rails disposed longitudinally along the mill guiding device that force the mill towards the casing as the mill is inserted into the second well bore. The mill may include one or more tabs that are sized to slide within the grooved rails. In some cases, as the mill moves along the mill guide device, the grooved guide rails limit the extent to which the mill may move transverse to the longitudinal direction of the mill guide.
[0015] In another general aspect, a method for intersecting a first, cased well bore includes forming a second well bore that extends to a region of the first, cased well bore to be intersected, inserting a laser tool assembly into the second well bore and aligning the laser tool assembly with the region of the first, cased well bored to be obstructed, operating the laser tool assembly and forming an opening in a casing of the first, cased well bore, and removing material from the casing until the first, cased well bore and the second well bore are fluidly connected.
[0016] In more specific aspects, the method may further include removing the laser tool assembly from the second well bore.
[0017] The laser tool assembly may include a laser perforator having a laser beam generator that generates a laser beam, and a focusing array through which the laser beam passes.
[0018] In another general aspect, a system for intersecting a first, cased well bore includes a drilling assembly that is configured to drill a second well bore having a distal end proximal to the first, cased well bore, a milling assembly, and a mill guiding device. The drilling assembly includes a drill string, and a drill bit disposed at an end of the drill string. The milling assembly includes a mill drill string and a mill disposed at an end of the mill drill string, the mill having a mill drill bit that is configured to cut and remove material from a casing wall of the first, cased well bore. The mill guiding device is configured to direct the mill drill bit towards the casing wall of the first, cased well bore.
[0019] In more specific aspects, the system may further include a plugging material delivery device that is configured to deliver a plugging material into the first, cased well bore. In some cases, the plugging material may be cement.
[0020] The system may further include an anchor packer assembly that is configured to be disposed at the distal end of the second well bore.
[0021] The mill guiding device may include a wedge-like member.
[0022] In another general aspect, a system for intersecting a first, cased well bore includes a drilling assembly that is configured to drill a second well bore having a distal end proximal to a casing coupling of the first, cased well bore, a milling assembly, and a mill guiding device. The drilling assembly includes a drill string and a drill bit disposed at an end of the drill string. The milling assembly includes a mill drill string and a mill disposed at an end of the mill drill string, the mill having a mill drill bit that is configured to rest along a surface of a casing coupling of the first, cased well bore and cut and remove material from a casing wall of the first, cased well bore and the casing coupling of the first, cased well bore. The mill guiding device is configured to direct the mill drill bit towards the casing wall of the first, cased well bore.
[0023] In more specific aspects, the surface of the casing coupling is an upper, generally flat surface along which the mill drill bit can rest while beginning a cut into the casing wall.
[0024] The mill guiding device may include a wedge-like member.
[0025] The system may further include a plugging material delivery device that is configured to deliver a plugging material into the first, cased well bore. In some cases, the plugging material is cement.
[0026] The system may further include an anchor packer assembly that is configured to be disposed at the distal end of the second well bore.
[0027] In another general aspect, a system for intersecting a first, cased well bore includes a drilling assembly that is configured to drill a second well bore having a distal end proximal to the first, cased well bore, a milling assembly, and a mill guiding device. The drilling assembly includes a drill string and a drill bit disposed at an end of the drill string. The milling assembly includes a mill drill string and a mill disposed at an end of the mill drill string, the mill having a mill drill bit that is configured to cut and remove material from a casing wall of the first, cased well bore. The mill guiding device is configured to direct the mill drill bit towards the casing wall of the first, cased well bore, the mill guiding device comprising alignment features that are configured to limit the relative motion of the mill drill bit relative to the mill guiding device as the mill drill bit moves longitudinally along the mill guiding device.
[0028] In more specific aspects, the alignment features may include one of more grooved guide rails disposed longitudinally along the mill guiding device. The mill drill bit may include one or more tabs that are sized to slide within the grooved rails. In some cases, as the mill drill bit moves along the mill guiding device, the grooved guide rails limit the extent to which the mill drill bit can move transverse to the longitudinal direction of the mill guiding device.
[0029] The system may further include a plugging material delivery device that is configured to deliver a plugging material into the first, cased well bore. In some cases, the plugging material is cement.
[0030] The system may further include an anchor packer assembly that is configured to be disposed at the distal end of the second well bore.
[0031] The mill guiding device may be a wedge-like member.
[0032] In another general aspect, a system for intersecting a first, cased well bore includes a drilling assembly that is configured to drill a second well bore having a distal end proximal to the first, cased well bore, and a laser tool assembly. The drilling assembly includes a drill string and a drill bit disposed at an end of the drill string. The laser tool assembly includes a laser perforator that is configured to emit a laser cutting beam that can penetrate a casing wall of the first, cased well bore and form an opening between the first, cased well bored and the second well bore.
[0033] In more specific aspects, the system may further include a plugging material delivery device that is configured to deliver a plugging material into the first, cased well bore. In some cases, the plugging material is cement.
[0034] The laser tool assembly may further include a first, cased well bore detector. The first, cased well bore detector may include an ultrasonic tool that is configured to detect noise from fluid flow within the first, cased well bore.
[0035] The laser perforator may include a laser beam generator that generates the laser beam, and the laser tool assembly may include a focusing array through which the laser cutting beam passes.
[0036] The laser tool assembly may further include a laser alignment device that is configured to detect the orientation of the laser perforator relative to the casing wall. The laser alignment device may include a metal detector. The metal detector may include a magnetic sensor.
[0037] A portion of the second well bore, where the laser tool assembly will be positioned for emitting a laser cutting beam, is substantially parallel to the first, cased well bore.
[0038] Embodiments may include one or more of the following advantages.
[0039] Using the methods and systems described herein, a cased well bore can be intersected, and in some cases obstructed, more easily than some other intersection methods by reducing the likelihood that a mill cutting into a casing of the cased well bore will walk laterally along the casing during cutting.
[0040] In some embodiments, a mill cutting into a casing of the cased well bore can begin removing material from the casing in a more controlled manner by seating along a generally flat surface of a casing coupling.
[0041] In some embodiments, the cased well bore is more easily intersected by using a laser tool which can be used to cut material from the casing in a more controlled manner than some other intersection methods.
[0042] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0043] FIG. 1 illustrates a cross-sectional schematic diagram of a first, cased well bore.
[0044] FIG. 2 illustrates an enlarged cross-sectional schematic diagram of the first well bore of FIG. 1 showing well bore casings connected by a casing coupling.
[0045] FIG. 3A illustrates a schematic diagram of an example milling assembly disposed in an second, intersecting well bore that is being drilled proximal to the first well bore of FIG. 1 .
[0046] FIG. 3B illustrates a schematic diagram of the milling assembly of FIG. 3A anchoring a whipstock in the second well bore.
[0047] FIG. 3C illustrates a schematic diagram of a mill of the milling assembly of FIG. 3A released from the whipstock.
[0048] FIG. 3D illustrates a schematic diagram of the mill of FIG. 3C disposed in a second well bore wherein the mill is seated on a well bore casing coupling and is milling a hole in the casing wall above and through the casing collar of the first well bore.
[0049] FIG. 3E illustrates a schematic diagram of the mill of FIG. 3C penetrating the casing wall and coupling of the first well bore of FIG. 3A and intersecting the first well bore of FIG. 3A .
[0050] FIG. 3F illustrates the milling assembly of FIG. 3A being removed from the second well bore.
[0051] FIG. 3G illustrates a cement plugging assembly inserted into the second well bore and pumping a plugging material into the first well bore of FIG. 3A .
[0052] FIG. 4A is a side view of a milling assembly including a mill and whipstock.
[0053] FIG. 4B is a top view of the milling assembly of FIG. 4A .
[0054] FIG. 4C is a cross-section view of the milling assembly of FIG. 4A taken at Section C-C.
[0055] FIG. 4D is an open hole anchor assembly.
[0056] FIG. 4E is an open hole packer assembly.
[0057] FIGS. 4F and 4G are cross-sectional side views, shown in segments, of an exemplary milling assembly.
[0058] FIG. 4H is a cross-sectional front view of a milling guide of the milling assembly of FIG. 4A .
[0059] FIG. 4I is a cross-sectional front view of a mill of the milling assembly of FIG. 4A .
[0060] FIG. 5A illustrates a schematic diagram of an example of forming a second, adjacent well bore adjacent to the first, cased well bore of FIG. 1 .
[0061] FIG. 5B illustrates a schematic diagram of a laser tool being lowered in the second well bore of FIG. 5A .
[0062] FIG. 5C illustrates the laser tool of FIG. 5B penetrating a casing of the first well bore of FIG. 1 .
DETAILED DESCRIPTION
[0063] Well bores, such as those used to deliver oil or gas from wells within the earth are periodically abandoned, for example, once a suitable amount of oil or gas has been withdrawn from the well or in the event of a well bore blowout. In some cases, a well bore is filled with a material (e.g., plugged with cement) to stop or prevent oil or gas from being inadvertently expelled from the well bore.
[0064] FIG. 1 illustrates a cross-sectional schematic diagram of a cased well bore (e.g., a first well bore) 10 arranged in a formation 12 . For example, the first well bore 10 can be a well bore to be abandoned. The well bore 10 includes a casing 14 that adds structural integrity, as well acts as a conduit to deliver oil or gas from a well. As shown in FIG. 2 , the casing 14 is typically made of multiple casing segments 16 that are connected by casing couplings 18 . In some cases, it is necessary to penetrate the well bore to be abandoned in order to pump a filling material, such as cement, to form an obstruction and plug the well bore. The obstruction formed in the well bore limits oil or gas from being inadvertently expelled from the well bore. FIG. 2 illustrates an example region of the well bore 10 to be intersected near one of the casing couplings 18 .
[0065] FIG. 3A illustrates a schematic diagram of an example drilling assembly 50 (e.g., having a drill bit 52 and drill string 54 ) forming an intersecting second well bore 20 adjacent to the first well bore 10 of FIG. 1 . The intersecting well bore 20 is typically arranged at an angle of about 0 degrees to about 90 degrees (e.g., about 0 degrees to about 6 degrees, e.g., about 3 degrees) relative to the cased well bore 10 to be intersected.
[0066] The intersecting well bore 20 can be formed by any of various suitable conventional well bore drilling techniques. In some embodiments, a drill rig includes a series of drill string segments that have a drill bit attached to a distal end of the drill string. The drill bit drills (e.g., cuts) through subterranean geologic formations. Drilling fluid (e.g., drilling mud) is pumped down a bore inside of the drill pipe and exits through nozzles in the drill bit. Drilling mud can be a mixture of fluids, solids, and chemicals that are designed to have suitable physical and chemical characteristics to safely drill into the ground material and deliver removed material from the drilled well bore. For example, the drilling mud can be used to remove heat from the drill bit, to lift rock cuttings from the well bore to the surface, to reduce destabilization of the rock in the well bore walls, and to overcome the pressure of fluids inside the rock so that these fluids do not enter the well bore during drilling.
[0067] The rock cuttings generated during drilling are removed by the drilling mud as it circulates to surface outside of the drill string. The drilling mud can then be circulated through filters (e.g., shakers) that strain the rock cuttings from the drilling mud. The filtered drilling mud can then be returned to the well bore being drilled.
[0068] The drilling rig rotates the drill pipe at the surface and rotational torque is transmitted down the drill string to the bit. The bit is rotated and drills through the geologic formations. In other embodiments, the drill string is not rotated by the drilling rig but a down hole mud motor is installed at the distal end of the drill string and drilling mud is pumped down the drill string and passes through the down hole motor. The mud drives the motor as known in the art. The down hole motor provides rotational torque to the drill bit enabling the drill bit to drill through the formations. The drill bit is typically drilled through the formations and towards the first, cased well bore until it is within a desired distance away from the first well bore 10 . Any of various suitable distance, depth, and/or location measurement techniques and devices can be used to monitor and control the position of the drill bit (i.e., and the profile of the intersecting well bore) relative to the first, cased well bore. For example, in some embodiments, sensors (e.g., magnetic sensors) arranged on or near the drill bit can detect the drill bit's proximity to a location through which the first, cased well bore is to be penetrated. The sensors are connected (e.g., wirelessly or via a wired connection) to a control unit of the drilling rig so that the trajectory of the drill bit can be properly controlled.
[0069] When the sensors determine that the drill bit is at a suitable position relative to the first well bore 10 , the drilling rig can stop rotating the drill bit and withdraw the drill bit 52 and the drill string 54 from the newly formed second, intersecting well bore. A milling assembly is then connected to the lower end of the drill string and inserted into the second well bore 20 for penetrating the first cased well bore 10 .
[0070] FIG. 3B illustrates a schematic diagram of a milling assembly 100 anchoring a mill guide (e.g., a whipstock) 102 and an anchor packer 104 into the intersecting well bore 20 . The intersecting well bore 20 is formed so that its end 22 is proximal to one of the casing couplings 18 along the casing 16 of the first well bore 10 .
[0071] The milling assembly 100 includes a drill string 106 that is connected to a mill 108 having a mill that is configured to, when operated, cut away material surrounding the mill 108 . Like the drilling assembly 50 , the drill string 106 can include a down hole mud motor installed at the distal end of the drill string 106 and drilling fluid (e.g., drilling mud) can be pumped down the drill string 106 and pass through the down hole motor. The drilling mud drives the down hole motor, as known in the art. The down hole motor provides rotational torque to the mill drill bit enabling the drill bit to drill through the formations 12 or the casing 16 .
[0072] The anchor packer 104 and whipstock 102 are set into the intersecting well bore 20 . For example, the anchor packer 104 and whipstock 102 are run into the intersecting well bore 20 on the distal end of the drill string 106 and may be connected to and positioned below the milling assembly 100 .
[0073] The whipstock 102 is a wedge-like structure having an angled wedge-like surface 110 to create a taper within the intersecting well bore 20 . In some embodiments, the whipstock 102 has a concave surface formed along the angled wedge-like surface 110 that is shaped to accommodate the outer diameter of the milling 108 . The whipstock 102 is arranged within the intersecting well bore 20 so that the angled wedge-like surface 110 directs a mill 108 of the milling assembly 100 towards a portion of the cased well bore above a casing coupling 18 . FIGS. 4A to 4C illustrate a milling assembly 100 that includes a mill 108 on a hydraulic running tool log and a whipstock 102 .
[0074] The anchor packer 104 and whipstock 102 are typically positioned into (e.g., run into) the intersecting well bore 20 as an assembly that is released from the drill string 106 once the anchor packer 104 contacts a surface, such as the end 22 of the intersecting well bore 20 . Once released, the anchor packer 104 is expanded and contacts the walls of the ground surrounding the intersecting well bore 20 to provide structural stability to the anchor packer 104 and the whipstock 102 . In some embodiments, the anchor packer 104 and the whipstock 102 are each run into the intersecting well bore 20 individually on separate trips of the drill string. In some embodiments, the anchor packer 104 is an anchor assembly 101 and a packer assembly 103 . FIG. 4D illustrates an open hole anchor 101 available from Halliburton under model no. 635.69. FIG. 4E illustrates an open hole packer 103 available from Halliburton as model no. 630.345.
[0075] FIG. 3C illustrates a schematic diagram of a mill 108 of the milling assembly 100 of FIG. 3B released from the whipstock 102 . Once the anchor packer 104 is set into the intersecting well bore 20 , the milling assembly 100 (e.g., the mill 108 of the milling assembly 100 ) is released from the whipstock 102 .
[0076] Typically, the mill 108 is connected to the whipstock 102 by connecting bolts that can be sheared due to axial force applied to the drill string 106 or due to torque applied to rotate the mill 108 and shear the connecting bolts. Once disconnected from the whipstock 102 , the mill 108 can be rotated. For example, hydraulic drilling fluid (e.g., drilling mud) is pumped down the drill string 106 which drives a down hole motor that provides rotational torque to the mill 108 to begin cutting into the formation 12 between the intersecting well bore 20 and the cased well bore 10 and, due to the orientation of the whipstock 102 , the mill 108 is directed towards the cased well bore 10 . When the mill 108 is proximal to the casing 16 of the cased well bore 10 , the mill 108 may drill though a cement sheath surrounding the casing 16 in the first well bore 10 (i.e., if the casing 16 has been cemented into the cased well bore 10 ). After milling though the cement sheath the mill 108 will contact the casing 16 of the cased well bore 10 .
[0077] FIG. 3D illustrates a schematic diagram of the mill 108 of FIG. 3C milling a well bore casing 16 above the casing coupling 18 . Due to the arrangement of the intersecting well bore 20 and the set anchor packer 104 and whipstock 102 , the mill 108 rides on an upper end of the casing collar 18 and cuts away the casing 16 above the collar 18 and begins to also cut away the collar 18 . The relatively flat upper surface of the collar 18 provides an engaging surface that the mill 108 is able to begin cutting from. The mill 108 will preferentially cut into the casing wall 16 above the collar 18 and also cut collar. The whipstock 102 , and its curved angular surface, also helps to guide the mill 108 and reduce the likelihood that the mill 108 will walk laterally along the outer surface of the casing 16 .
[0078] FIG. 3E illustrates a schematic diagram of the mill 108 of FIG. 3C penetrating the well bore casing wall 16 and grinding off the upper portion of the coupling 18 of FIG. 3D and intersecting the cased well bore 10 of FIG. 3B . The mill 108 continues to operate and cuts through the casing wall 16 and the coupling 18 until it penetrates them to hydraulically connect the cased well bore 10 and the intersecting well bore 20 .
[0079] The cutting path of the mill 108 within intersecting well bore 20 can depend on various factors, such as, for example, the size of the intersecting well bore 20 , and the design and shape of the whipstock 102 and mill 108 . For example, in some embodiments, depending on the desired size (e.g., the width) of the hole to be formed in the casing 16 being intersected and the taper angle of the inclined whipstock 102 , the length of the cut can be estimated according to the following formula, Tan(x)=(w)/(2*L), where x is the taper angle of the whipstock (in degrees), w is the width of the mill 108 and L is the length of the cut. As shown, w is divided by 2 because the mill 108 would typically only need to travel a distance that is half of its diameter inward to fully penetrate the casing 16 . In some implementations, the whipstock has a taper angle of 3 degrees (x=3 degrees). When forming holes using such whipstocks, if a mill with an 8.5 inch outer diameter is used, and therefore a hole that is generally a maximum of 8.5 inches wide would be formed in the casing 16 when the mill travels halfway into the casing then the length that the cut can be estimated by, Tan(3 deg)=8.5/(2*L). The length, L, would be about 81 inches. Therefore, in order to fully penetrate the casing 16 and casing coupling 18 , the mill 108 travels about 81 inches longitudinally while being driven into the casing by the whipstock 102 .
[0080] The width and length of the cut to be formed in the casing 16 is generally determined based on the processes to be performed following intersection of the cased well bore 10 . For example, in some cases, tubing or piping may be inserted into the cased well bore 10 to pump mud or cement into the cased well bore 10 . In such cases, the width of the opening would likely be large enough to insert the tubing or piping, including a margin of error. Alternatively, in some cases, a long and wide enough opening is preferred to pump cement or mud directly into the intersecting well bore 20 in order to obstruct the cased well bore 10 without needing to insert tubing or piping directly into the cased well bore 10 .
[0081] Typically, an opening is cut that has a greater flow area that the flow area of the tubing or piping used to pump the mud or cement so that the opening would not restrict the flow of the mud or cement being pumped. However, an even larger opening can be cut if needed, for example, if there was a need to insert something directly into the cased well bore 10 being intersected or to avoid a significant pressure loss through the opening if a large volume and/or high velocity of fluid is to be pumped through the opening.
[0082] While cutting, the mill 108 is rotates and cuts away the casing wall 16 and the casing coupling 18 until the cased well bore 10 is fully penetrated and a hole 24 is formed according to the desired hole parameters (as discussed above). Full penetration of the casing coupling 18 and the well bore casing wall 16 can be detected using any of various suitable techniques and devices. For example, the resisting torque at the mill 108 can be measured and monitored to predict (e.g., determine) the material through which the mill 108 is cutting. The resisting torque typically increases when the mill 108 begins cutting the metal casing wall 16 or casing coupling 18 . Monitoring the amount the milling string advances (i.e., the depth of the milling string) from this point would give an indication of how wide an opening is being created.
[0083] FIG. 3F illustrates the milling assembly 100 of FIG. 3B being removed from the intersecting well bore 20 . The milling assembly 100 is removed from the intersecting well bore 20 so that a plugging material (e.g., cement) can be delivered from the intersecting well bore 20 through the penetrated hole 24 and into the cased well bore 10 .
[0084] Typically, the anchor packer 104 and whipstock 102 are left in the intersecting well bore 20 during cement delivery. In some embodiments, the whipstock 102 and anchor packer 104 are removed prior to pumping cement.
[0085] FIG. 3G illustrates a cement delivery assembly 150 inserted into the intersecting well 20 and pumping a plugging material (e.g., cement) into the cased well bore 10 . Once the penetrated hole 24 is formed and the cased well bore 10 and the intersecting well bore 20 are fluidly connected, the cement delivery assembly 150 pumps cement into the cased well bore 10 . For example, cement can be pumped from the intersecting well bore 20 through the penetrated hole 24 formed in the casing wall 16 and the coupling 18 and into the cased well bore 10 .
[0086] Cement is pumped until an amount of cement that is sufficient for forming a structurally suitable barrier within the cased bore 10 is delivered. For example, in some cases, cement is pumped into the cased well bore 10 until a barrier is formed that can prevent a gas or oil from exiting the cased well bore 10 . The volume of cement that is pumped is typically dependent upon the conditions of the well bore and, in some cases, regulatory requirements. In some embodiments, the cement delivery assembly 150 includes a check valve that permits cements to flow into the well bores while reducing the likelihood that fluid in either of the well bores (e.g., gas or oil) can flow upward in the drill string located in the intersecting well bore 20 and out of the intersecting well bore 20 . For example, check valves can be used when intersecting and delivering cement to a well bore that has suffered a blowout. In some embodiments, cement is delivered using other systems. For example, cement can be pumped through the drill string 106 of the milling assembly 100 .
[0087] In some embodiments, other types of equipment are used to deliver and guide a mill within the intersecting well bore 20 . For example, milling assemblies can include alignment features to constrain the path of a mill along a mill guide. For example, referring to FIGS. 4F-4I , a milling assembly 200 can include a tapered mill guide 202 that engages with corresponding features of the mill 208 to help reduce the likelihood of the mill 208 from walking away from the mill guide 202 , for example moving laterally along the well bore casing 16 of the cased well bore 10 during milling. For example, as shown, the MillRite style milling assembly 200 from Halliburton includes a mill guide 202 having alignment grooves 212 that span longitudinally along the mill guide 202 and help to align the mill 208 with the mill guide 202 and reduce the likelihood that the mill 208 will walk along the casing 16 . The mill 208 includes tabs 214 that are sized and configured to be received within the grooves 212 of the mill guide 202 .
[0088] The MillRite milling assembly 200 can be inserted into an intersecting well bore 20 until seated against the end 22 of the intersecting well bore 20 (e.g., using an anchor packer 104 ) (shown in FIG. 3B ). Once in position near the cased well bore 20 , hydraulic fluid (e.g., drilling mud) can be pumped down the drill string of the milling assembly 200 , as discussed above with reference to FIGS. 3B-3E . Hydraulic pressure applied can be used to release a hydraulic mill 208 running tool from the mill guide 202 and the mill 208 can begin rotating and advancing along the wedge-like mill guide 202 . Due the shape of the mill guide 202 , the mill 208 slowly advances into and against the casing 16 of the cased well bore 10 and a hole can be cut that fluidly connects the cased well bore 10 and the intersecting well bore 20 . Plugging material (e.g., cement) can then be inserted into the cased well bore 10 to obstruct the cased well bore 10 , as discussed above and illustrated in FIG. 3G .
[0089] Laser Perforation
[0090] While mechanical machining devices have been described as forming the opening in the cased well bore 10 , other techniques are possible.
[0091] FIG. 5A illustrates a schematic diagram of an example drilling assembly 50 forming a second, adjacent well bore 20 proximal to the first, cased well bore 10 of FIG. 1 . The drilling assembly 50 includes any of various suitable conventional drilling devices, such as the drilling rig discussed above. The adjacent well bore 20 is arranged so that a laser tool can be lowered downward generally vertically into the adjacent well bore 20 . For example, the adjacent well bore 20 can be arranged relative to the cased well bore 10 so that a laser tool (e.g., a wireline laser tool) can be deployed at an angle of about 0 degrees to about 65 degrees relative to a vertically oriented cased well bore 10 . The adjacent well bore 20 extends to a depth that at least reaches a desired location for penetrating the cased well bore 10 . Once the adjacent well bore 20 is formed to the desired depth, the drilling assembly 50 (e.g., a drill bit 52 and drill string 54 ) can be raised and removed from the adjacent well bore 20 .
[0092] FIG. 5B illustrates a schematic diagram of a laser tool 300 being lowered in the adjacent well bore 20 of FIG. 4A . The laser tool 300 is lowered to the desired depth where a perforation in the casing of the cased well bore 10 is to be formed. Various techniques and devices can be used to determine the depth that the laser tool 300 has been lowered into the adjacent well bore 20 . For example, a wire line measurement could be monitored as a cable 302 supporting the laser tool 300 is spooled off at the surface. However, in some cases, these measurements may have errors associated with stretching of the cable 302 . In some embodiments, a magnetic ranging tool is used to detect the proximity of the laser tool 300 relative to the cased well bore 10 . Alternatively or additionally, in some embodiments, the laser tool 300 includes an ultrasonic tool is arranged above a laser perforator 304 , where the ultrasonic tool can detect the noise from the gas and/or fluid flow in the cased well bore 10 when the laser tool 300 reaches an area proximal to the cased well bore 10 .
[0093] Once at the desired depth to form a perforation, the laser perforator 304 of the laser tool 300 is aligned with the casing 16 of the cased well bore 10 . For example, the laser tool 300 can include metal detectors (e.g., magnetic sensors) so that as the laser tool 300 is rotated, it can detect when the laser perforator 304 is aimed at the metal casing 16 . Alternatively or additionally, in some embodiments, ultrasonic tools are used to detect the orientation of the laser perforator 304 relative to the cased well bore 10 and for aiming the laser perforator 304 at the metal casing 16 .
[0094] FIG. 4C illustrates a laser perforator 304 of the laser tool 300 of FIG. 4B penetrating the casing 16 of the cased well bore 10 . Once aligned with the desired portion of the cased well bore 10 , the laser of the laser perforator 304 can be operated to laser cut (e.g., perforate) an opening in the casing wall 16 of cased well bore 10 . While the laser perforator 304 emits a laser cutting beam, the laser perforator 304 can be moved relative to the casing 16 to create an opening. Various devices can be used to move the laser perforator 304 and therefore also the emitted laser to form the opening. For example, hydraulic or electromechanical devices or system can be used to articulate the laser tool within the adjacent well bore to cut an opening. Prior art devices and systems that may be used to articulate a laser tool are disclosed in U.S. Pat. No. 7,938,175.
[0095] Once the opening is formed in the casing wall 16 of the cased wellbore 10 , the laser tool 300 can be removed from the adjacent well bore 20 . As discussed above, a cement pumping assembly can then be lowered down into the adjacent well bore 20 to the region of the opening formed along the casing wall 16 of the cased well bore 10 by the laser tool 300 . Cement is then pumped from a cement pumping head of the cement pumping assembly into the opening. Cement is pumped until an amount of cement that is sufficient for forming a structurally suitable barrier within the cased well bore 10 . For example, in some cases, cement is pumped into the cased well bore 10 until a barrier is formed that can prevent a gas or oil from exiting the cased well bore 10 .
[0096] A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other embodiments are within the scope of the following claims. | In some general aspects, methods for intersecting a first, cased well bore include drilling a second well bore that has a distal end proximal to the first, cased well bore to be intersected, disposing a mill guiding device in the second well bore near a casing of the first, cased well bore, the mill guiding device being configured to direct a mill of a milling assembly away from a central axis of the second well bore and towards the first, cased well bore, inserting the milling assembly into the second well bore, operating the mill of the mill assembly and guiding the milling assembly along the mill guide and into the casing of the first well bore, and removing material from the casing of the first well bore until the first, cased well bore and the second well bore are fluidly connected. | 4 |
FIELD OF THE INVENTION
[0001] The present disclosure relates to suppressors of interferon-gamma (IFN-γ) comprising inactive variants of IFN-γ, and methods of using hIFN-γ variants to treat a disorder associated with aberrant function of hIFN-γ.
BACKGROUND OF THE INVENTION
[0002] Immune system protects organism from pathogenic microorganisms and foreign macromolecular substances. It identifies exogenous (foreign) bodies of molecular mass exceeding 5000 Da and produces specific antibodies for their neutralization. Immune response is regulated by numerous protein-factors (Gyiukines)-produced by specialized cells. In case of dysfunction (due to genetic disorders or infection diseases) the immune system misidentifies certain body proteins as exogenous products and produces specific antibodies for their neutralization. This process lies in the etiology of a great number of autoimmune diseases such as asthma, rheumatoid arthritis, infertility, alopecia areata, multiple sclerosis (MS) and other neurodegenerative pathologies leading to disability and early death of about 2% of the human population. There is substantial evidence that immune responses resulting in IFN-γ production are associated also with the development of graft arteriosclerosis (GA) in allograft transplanted patients. The chronic rejection of allografts (including heart) is preceded by a luminal stenosis of the blood vessels and is denoted as “graft arteriosclerosis”. As many as 50% of heart transplant recipients develop angiographically detectable GA three to five years following transplantation. The only treatment currently available for GA is retransplantation, which is costly and not always possible because of shortage of suitable donors. In that sense, the demand of therapeutics for treatment autoimmune diseases and GA is a major priority of the experimental medicine and pharmacy.
[0003] Inflammation reaction accompanying the autoimmune process is related with a lavish infiltration of the target tissue with T-lymphocytes and macrophages. They are represented by CD4 + cells producing Th1 proinflammatory cytokines such as interleukin 12 (IL-12) and hIFN-γ. The latter activates mononuclear cells to produce destructive substances like lymphotoxins and tumor necrosis factor alpha (TNF-α). It is shown that the pathogenesis of most autoimmune diseases is related with an abnormal production of hIFN-γ [1-6].
[0004] The overproduction of hIFN-γ (as in the case of MS) is inhibited by parenteral application of hIFN-β 3 (see patents U.S. Pat. No. 082,138, WO9530435, CA2361081). In other patents (RU2073522, RU2187332, RU02166959) mixtures of the three different interferons IFN-α, IFN-β and IFN-γ are recommended. It is reported that high dosage (8,000,000 IU/day) of IFN-β provoke unfavorable effects such as: a) T-cells proliferation blockade; b) neutralization of IL-12 thus enhancing the IFN-γ effect; c) decreased CD4+ (Th1, Th2) and CD8+ (Tcl) cell content without changing the Th1/Th2 cell ratio [7; d) decreased levels of both pro- and anti-inflammatory cytokines [8], etc.
[0005] Another approach for neutralization of the overproduced hIFN-γ in autoimmune disease is based on the application of humanized anti-IFN-γ antibodies (patent application WO0145747 and [9-11]). The anti-hIFN-γ antibodies, however, deprive the organism from hIFN-γ and their long-term application worsens the patients' conditions.
[0006] An alternative way for decreasing the abnormal production of hIFN-γ in autoimmune diseases is based on the application of the so called “consensus interferons” IFN-con 1 , IFN-con 2 and IFN-con 3 , derivatives of the Type I hIFN-α, hIFN-β and hIFN-t (U.S. Pat. No. 0,086,534 and CA2299361). They show various side effects including toxicity.
[0007] Proteins with aminoacid sequence partly coinciding with that of the human IFN-γ have been applied as antiviral, antiproliferative and immunomodulating agents (U.S. Pat. No. 4,832,959, WO02081507, AT393690). Their effects, however, can not be presently assessed since the cited patents are not supported by clinica! data.
[0008] In a recent patent application, published as WO20061099701, it is described a new approach for inhibition of the endogenous hIFN-γ using inactive recombinant analogues of the hIFN-γ with preserved affinity to the hIFN-γ receptor. Subject of the patent application are three different inactive variants of hIFN-γ (a truncated hIFN-γ lacking 27 C-terminal aminoacids, a fusion hIFN-γ-hIFN-α1 protein and a UV inactivated hIFN-γ) which compete with the natural (endogenous) hIFN-γ for the hIFN-γ receptor. Thus, competing with the hIFN-γ receptor, the inactive variants of IFN-γ suppress its activity. Since that effect is dose dependant, the effect of endogenous IFN-γ could be modulated by varying blood concentration of the hIFN-γ derivative proteins. This approach is applicable in the cases when the overproduction of endogenous hIFN-γ causes health problems as in the case of autoimmune diseases, including MS. Although these proteins are good competitors of hIFN-γ for its receptor, their tertiary structure is quite different in comparison with the native wild-type hIFN-γ, which in turn is a potential risk of formation of conformational antibodies. Related with this there is a need of new inactive variants of the hIFN-γ containing negligible changes in domains responsible for triggering the signal transduction pathway. replace.
SUMMARY OF THE INVENTION
[0009] One aspect of the invention encompasses a composition comprising a suppressor of hIFN-γ. The suppressor of hIFN-γ is a variant hIFN-γ of SEQ ID NO: 5 deficient in inducing signal transduction and with preserved affinity to the hIFN-γ receptor, and comprises amino acid sequence modifications selected from the group consisting of amino acid substitutions at positions 86, 87, and 88, and an amino acid substitution at position 88 with a deletion of C-terminal amino acid residues.
[0010] A further aspect of the invention provides a method of modulating the biological activity of hIFN-γ. The method comprises suppressing the biological activity of hIFN-γ in a subject by administering to the subject a therapeutically effective amount of a composition comprising a suppressor of hIFN-γ. The suppressor of hIFN-γ is a variant hIFN-γ of SEQ ID NO: 5 deficient in inducing signal transduction and with preserved affinity to the hIFN-γ receptor, and comprises amino acid sequence modifications selected from the group consisting of amino acid substitutions at positions 86, 87, and 88, and an amino acid substitution at position 88 with a deletion of C-terminal amino acid residues.
[0011] Yet another aspect of the invention provides a method of treating a hIFN-γ-mediated disorder. The method comprises suppressing the biological activity of hIFN-γ in a subject by administering to the subject a therapeutically effective amount of a composition comprising a suppressor of hIFN-γ. The suppressor of hIFN-γ is a variant hIFN-γ of SEQ ID NO: 5 deficient in inducing signal transduction and with preserved affinity to the hIFN-γ receptor, and comprises amino acid sequence modifications selected from the group consisting of amino acid substitutions at positions 86, 87, and 88, and an amino acid substitution at position 88 with a deletion of C-terminal amino acid residues.
[0012] Other features and aspects of the invention are described in more detail herein.
DETAILED DESCRIPTION
[0013] The present invention provides suppressors of IFN-γ and compositions comprising suppressors of IFN-γ. A suppressor of the disclosure comprises an inactive variant of IFN-γ. IFN-γ is a cytokine that is critical for innate and adaptive immunity against viral and intracellular bacterial infections, and for tumor control. Cellular responses to IFN-γ during an immune response are activated through its binding to interferon gamma receptor (IFNGR) on the cell surface, and activation of the JAK-STAT signal transduction pathway through the receptor. As such, at a minimum, an IFN-γ protein comprises a receptor binding domain and a receptor activation domain.
[0014] The inventors have discovered minor modifications in receptor activation domains of IFN-γ that inactivate IFN-γ-mediated signal transduction. Importantly, the inventors also discovered that inactive IFN-γ variants of the disclosure comprising said minor modifications are capable of competing with, and suppressing the bioactivity of IFN-γ, in vivo or in vitro. Advantageously, the ability of a suppressor of the present disclosure to compete with bioactivity of IFN-γ is reversible, and provides a means for controlling the extent of inhibition of bioactive IFN-γ in vivo or in vitro in a dose-dependent manner by varying the concentration of suppressors of the present disclosure relative to active IFN-γ. As such, IFN-γ suppressors of the present disclosure may be used to modulate immune responses resulting from elevated IFN-γ activity without irreversibly sequestering wild type IFN-γ. Additionally, IFN-γ variants of the present disclosure resemble allelic variants of IFN-γ and are therefore not predicted to be immunogenic.
[0015] Accordingly, the present invention provides a composition comprising suppressors of IFN-γ and methods of using said suppressors of IFN-γ to treat a disorder resulting from elevated IFN-γ activity. Various aspects of the invention are described in further detail in the following sections.
I. IFN-γ Suppressor Compositions
[0016] One aspect of the present invention provides compositions comprising a suppressor of IFN-γ. A suppressor of the disclosure is an inactive variant of IFN-γ comprising modifications of IFN-γ receptor activation domains that inactivate IFN-γ-mediated signal transduction. An inactive variant of IFN-γ is capable of competing with and suppressing the bioactivity of a wild type form of IFN-γ in vivo or in vitro. While not wishing to be bound by theory, it is believed that minor modifications of the present disclosure do not alter the overall tertiary structure of IFN-γ, thereby preserving the affinity of inactive variants of IFN-γ to the IFN-γ receptor complex to compete with wild type IFN-γ. Additionally, preserved overall structure of inactive IFN-γ variants of the disclosure minimizes the potential risk of the formation of conformational antibodies against the suppressor IFN-γ variants. As such, a suppressor of the present disclosure is a variant of IFN-γ, inactive in signal transduction, but with preserved ability to bind a cell surface IFNGR.
(a) Inactive IFN-γ Variant
[0017] An inactive IFN-γ suppressor of the present disclosure comprises modifications of IFN-γ receptor activation domains. Modifications of IFN-γ activation domains may be amino acid substitutions, amino acid deletions, or amino acid insertions. Any modification of receptor activation domains of IFN-γ is contemplated herein, provided the modification inactivates signal transduction but preserves the ability of inactivated IFN-γ to compete with, and suppress the bioactivity of IFN-γ, in vivo or in vitro. Preferably, inactive IFN-γ variants of the present disclosure are derived from the wild type human IFN-γ (hIFN-γ). Numbering of amino acid residues used herein is from the N-terminus of the wild type hIFN-γ polypeptide of SEQ ID NO: 5.
[0018] Biologically active hIFN-γ is a homodimer of hIFN-γ polypeptides wherein each hIFN-γ polypeptide consists of a core of six α-helices and an extended unfolded sequence in the C-terminal region. The bioactive hIFN-γ dimer is formed by anti-parallel inter-locking of the two monomers. An inactive hIFN-γ variant of the present disclosure comprises at least one modified hIFN-γ polypeptide. As such, an inactive variant of hIFN-γ may comprise a dimer of one modified hIFN-γ polypeptide and one wild type hIFN-γ polypeptide. Preferably, an inactive variant of hIFN-γ comprises a dimer of two modified hIFN-γ polypeptides. When an inactive variant of hIFN-γ comprises a dimer of two modified hIFN-γ polypeptides, each hIFN-γ polypeptide of the hIFN-γ variant may comprise a different modification of hIFN-γ receptor activation domains. Preferably, when an inactive variant of hIFN-γ comprises a dimer of two modified hIFN-γ polypeptides, each hIFN-γ polypeptide of the hIFN-γ variant comprises the same modification of hIFN-γ receptor activation domains.
[0019] As used herein, the term “receptor activation domain” may be any amino acid residue or group of amino acid residues of hIFN-γ necessary for triggering a signal transduction pathway through the hIFN-γ receptor. Non-limiting examples of a receptor activation domain of hIFN-γ may comprise amino acid residue 86, amino acid residue 87, amino acid residue 88, the extended unfolded sequence in the C-terminal region of hIFN-γ, or combinations thereof.
[0020] Inactive hIFN-γ variants comprising amino acid modifications in amino acid residues 86, 87, 88, or combinations thereof, are contemplated herein. Preferably, amino acid modifications of amino acid residues 86, 87, 88, or combinations thereof are substituted. Preferably, amino acid residues 86, 87, and 88 are substituted. Even more preferably, amino acid residues 86, 87, and 88 are substituted using amino acid residues as described in Table 1.
[0000]
TABLE 1
Constructs and amino acid substitutions
hIFNg gene: Nucleotide
sequence corresponding to
the amino acids at
hIFNg: Amino acid residues
Construct No.
positions 86-88
at positions 86-88
2
CCG TAC CTC
Pro Tyr Leu
3
CCC AAT TAT
Pro Asn Tyr
4
TGG TCC TCG
Trp Ser Ser
5-3
GTT AGT CGC
Val Ser Arg
5-4
CCG CTA AGC
Pro Leu Ser
6
CAC GTC TGT
His Val Cys
8
CCC TAC GTT
Pro Tyr Val
9-1
CGG TCT TCG
Arg Ser Ser
9-2
TTC TCT AGA
Phe Ser Arg
10
CCC TGT TGC
Pro Cys Cys
11
CCG TCC GTG
Pro Ser Val
12
ACC TTC TGG
Thr Phe Trp
14
CTC CCT TTC
Leu Pro Phe
15
GAC TTG CTG
Asp Leu Leu
16
GCC CAT CTT
Ala His Leu
17
ACC GTC CTC
Thr Val Leu
18
TGC TTC CCG
Cys Phe Pro
19
TCC ACT TTT
Ser Thr Phe
21
CCC TCT CCC
Pro Ser Pro
22
AGC TCC CTC
Ser Ser Leu
23
GTC TCT GGA
Val Ser Gly
24
ACT CCT ACC
Thr Pro Thr
25
TGT CAT TTC
Cys His Phe
26
TCA GTT TCC
Ser Val Ser
27
GAA ATG CCC
Glu Met Pro
28
CTC ACC CCT
Leu Thr Pro
32
CTG CCT CCG
Leu Pro Pro
33
CCC CCT ACT
Pro Pro Thr
34
TTC TCT CTG
Phe Ser Leu
35
TTT TTT CCC
Phe Phe Pro
36
CTG TGT CCC
Leu Cys Pro
39-11
CCC TCT GCT
Pro Ser Ala
39-12
GAC CTT CTT
Asp Leu Leu
41
GCT TTT TTT
Ala Phe Phe
45
CTG CTT CAC
Leu Leu His
46-1
ACC CTC CTC
Thr Leu Leu
54
TTC ACC GCC
Phe Thr Ala
61
CAT CCT CTC
His Pro Leu
62
TTT ACC AGA
Phe Thr Arg
63
CGT CTC CGT
Arg Leu Arg
66
CCA CTT GCT
Pro Leu Ala
71
TTC TGC CGT
Phe Cys Arg
72
CAC TCC CGC
His Ser Arg
73
CCT TAC CCC
Pro Tyr Pro
74
TCC CTG CTG
Ser Leu Leu
75 = 76
TGG TCT GCG
Trp Ser Ala
76 = 75
TGG TCT GCG
Trp Ser Ala
77
GCT ATC CCC
Ala Ile Pro
81
CGT CCT GTC
Arg Pro Val
82-34
TTC TGC CGT
Phe Cys Arg
84
CCC TTT GCC
Pro Phe Ala
85
CGA CGG AGC
Arg Arg Ser
87
CGC CCC TCC
Arg Pro Ser
88
CGC TCC TGC
Arg Ser Cys
92
CCC TTT CTT
Pro Phe Leu
93
CTG TAC CCC
Leu Tyr Pro
94
CCC GTC TTC
Pro Val Phe
96
CCT ATG TTC
Pro Met Phe
97
TCT TTT TTT
Ser Phe Phe
103
CAC GCT GCC
His Ala Ala
104
CCT TTT TCT
Pro Phe Ser
105-2
GCT ACA GCC
Ala Thr Ala
106-1
CTC TTC TCC
Leu Phe Ser
106-2
CTT GTC TCG
Leu Val Ser
107 or 108
TTC CTT GTC
Phe Leu Val
109
CCT CGC TCC
Pro Arg Ser
110
CCT CGC TCC
Pro Arg Ser
111
CCT CGC TCC
Pro Arg Ser
112
TTC TCC CGG
Phe Ser Arg
113
CTA TAC TTT
Leu Tyr Phe
114-1
CGT TCC GCG
Arg Ser Ala
115
CAG TTT CAT
Gln Phe His
116
GTA CTC CTC
Val Leu Leu
117
GTT CTG CCT
Val Leu Pro
118
GTC TCC GCT
Val Ser Ala
119
ACC CTC GTT
Thr Leu Val
120
CAA GCC GGC
Gln Ala Gly
121
CTC TCC GTC
Leu Ser Val
123
TCT TTA TTT
Ser Leu Phe
126
TAC GCT TTC
Tyr Ala Phe
127-1
CAC TAT CCT
His Tyr Pro
129
GCT AGT CTC
Ala Ser Leu
131
TTT CCC CTT
Phe Pro Leu
133
CCG CCC TCC
Pro Pro Ser
134
ACC AAT GGT
Thr Asn Gly
135
GTT TCC CCC
Val Ser Pro
136
TCC CCT CCC
Ser Pro Pro
140
TTT CCG TCT
Phe Pro Ser
143
TGT TCT CCC
Cys Ser Pro
144
TGC GCC CCT
Cys Ala Pro
145
TCC TTT TGT
Ser Phe Cys
146
CTT TTC GAG
Leu Phe Glu
148
TTC ACG CCC
Phe Thr Pro
149-1
CAC CAG CGC
His Gln Arg
149-2 or 150-1
CTT TCC TCG
Leu Ser Ser
150-2
TGG CTC TCT
Trp Leu Ser
151
CTC ACA GCG
Leu Thr Ala
153
TCT TTT TGC
Ser Phe Cys
155
ATT TCC GAT
Ile Ser Asp
157
TTT TAC ACT
Phe Tyr Thr
[0021] Inactive hIFN-γ variants comprising amino acid modifications in the extended unfolded C-terminus of hIFN-γ are also contemplated herein. Preferably, inactive variants of hIFN-γ comprise deletion of part or all amino acid residues in the C-terminus of hIFN-γ. For instance, inactive variants of hIFN-γ may comprise deletion of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or more amino acid residues within the C-terminal of hIFN-γ. Preferably, inactive variants of hIFN-γ comprise a deletion of 21 C-terminal amino acid residues of hIFN-γ.
[0022] Also contemplated herein are inactive hIFN-γ variants comprising amino acid modifications in amino acid residues 86, 87, 88, or combinations thereof, and amino acid modifications in the extended unfolded C-terminus of hIFN-γ. Preferably, inactive variants of hIFN-γ comprise modification of one amino acid residue selected from the group of amino acid residues 86, 87, and 88, in combination with a deletion of 21 C-terminal amino acid residues of hIFN-γ. More preferably, inactive variants of hIFN-γ comprise modification of amino acid residue 88 in combination with a deletion of 21 C-terminal amino acid residues of hIFN-γ.
[0023] An exemplary inactive variant of hIFN-γ of the present disclosure comprises substitution of amino acid residues 86, 87, and 88 with glutamic acid, methionine, and proline residues, respectively (Construct No. 27; SEQ ID NO: 6). Another exemplary inactive variant of hIFN-γ of the present disclosure comprises substitution of amino acid residues 86, 87, and 88 with threonine, asparagine, and glycine residues, respectively (Construct No. 134; SEQ ID NO: 7). Yet another exemplary inactive variant of hIFN-γ of the present disclosure comprises substitution of amino acid residue 88 with a proline residue, and deletion of 21 C-terminal amino acid residues of hIFN-γ (Construct No. Lys/Gln88/T7; SEQ ID NO: 8).
[0024] As described above, suppressors of hIFN-γ of the disclosure are inactive variants of hIFN-γ. Methods of determining in vitro and in vivo bioactivity of hIFN-γ are known in the art. Non-limiting examples of methods of determining hIFN-γ activity include measuring antiviral activity or antiproliferative activity of hIFN-γ, induction of protein kinase by hIFN-γ, oligoadenylate 2,5-A synthetase or phosphodiesterase activities, immunomodulatory assays, growth inhibition assays, and measurement of binding to cells that express interferon receptors. Preferably, antiviral activity of hIFN-γ variants is measured. Methods of measuring antiviral activity of hIFN-γ are known in the art, and may be determined by measuring the protective effect of hIFN-γ variants against the cytopathic action of the vesicular stomatitis virus (VSV) on a cell and may be as described in the examples herein and in Forti et al., 1986, Methods in Enzymology 119: 533-540, the disclosure of which is incorporated herein in its entirety. Measurement of antiproliferative activity of hIFN-γ variants is also preferred. Methods of measuring antiproliferative activity of hIFN-γ are known in the art, and may be determined using a kynurenin bioassay and may be as described in the examples herein and in Boyanova et al., 2002, Analytical Biochemistry 308: 178-181, the disclosure of which is incorporated herein in its entirety.
[0025] Inactive hIFN-γ variants may have no detectable bioactivity. Alternatively, inactive hIFN-γ variants may have reduced hIFN-γ bioactivity when compared to a wild type hIFN-γ counterpart. When inactive hIFN-γ variants have reduced bioactivity in comparison to a wild type hIFN-γ counterpart, inactive variants may have about 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 300, 400, 500, 1000, 2000, 3000, 4000, 5000, or about 10,000 fold or more reduced activity than a wild type hIFN-γ counterpart. Preferably, when inactive hIFN-γ variants have reduced bioactivity in comparison to a wild type hIFN-γ counterpart, inactive variants have about 10, 50, 100, or about 1000 fold reduced activity compared with a wild type hIFN-γ counterpart.
[0026] When inactive hIFN-γ variants have reduced bioactivity in comparison to a wild type hIFN-γ counterpart, inactive variants may have a specific activity of about 1×10 2 , 1×10 3 , 1×10 4 , 1×10 5 , or about 1×10 6 IU/mg of the variant. Preferably, when inactive hIFN-γ variants have reduced bioactivity in comparison to a wild type hIFN-γ counterpart, inactive variants have about 1×10 3 , 1×10 4 , 1×10 5 , or about 1×10 6 IU/mg of hIFN-γ of the variant.
[0027] As described above, IFN-γ variants are capable of competing with and suppressing the bioactivity of IFN-γ, in vivo or in vitro. Methods of determining the ability of a molecule to compete with an active molecule such as IFN-γ are known in the art and generally comprise determining the activity of the active molecule using a known method of bioactivity measurement, but in the presence of the competing molecule. For instance, hIFN-γ variants of the present disclosure may be mixed with equimolar amounts with wild type hIFN-γ, and the antiproliferative or antiviral activity of the mixtures may be determined using wild-type hIFN-γ as a standard. The results may be interpreted as follows: if the hIFN-γ variant has the same affinity to the hIFN-γ receptor as that of the wild type hIFN-γ and zero antiproliferative or antiviral activity, the activity of the equimolar mixture of both substances is 50% of that of the control (pure wild type hIFN-γ). Using this method, competition of hIFN-γ variants may be classified into high competition hIFN-γ variants, intermediate competition variants, and low competition variants. Preferably, hIFN-γ of the disclosure are high competition hIFN-γ variants.
[0028] In addition to the amino acid modifications of IFN-γ described herein, it will be appreciated by those skilled in the art that IFN-γ of the disclosure may further comprise amino acid changes other than those described above, provided the amino acid changes do not alter the functional activity of IFN-γ variants. For instance, amino acid sequence polymorphisms of IFN-γ may exist within a population (e.g., the human population). Such genetic polymorphism may exist among individuals within a population due to natural allelic variation. Such natural allelic variations may result in as much as 15% variance in the amino acid sequence of an IFN-γ of the invention. Any and all such amino acid variations and resulting polymorphisms in IFN-γ that are the result of natural allelic variation and that do not alter the functional activity of IFN-γ of the invention are intended to be within the scope of the invention. Thus, e.g., 1%, 2%, 3%, 4%, or 5% of the amino acids in IFN-γ of the invention may be replaced by another amino acid.
[0029] In addition to naturally occurring allelic variants of IFN-γ that may exist in the population, the skilled artisan will further appreciate that changes may be introduced by mutation into the amino acid sequence of IFN-γ variants of the disclosure, without altering the functional ability of the polypeptide. For instance, the polypeptides may further comprise conservatively substituted variants of the polypeptides described above. The term “conservatively substituted variant” may refer to a polypeptide wherein one or more residues have been conservatively substituted with a functionally similar residue and which displays the IFN-γ repressor activity as described herein. The phrase “conservatively substituted variant” also includes polypeptides wherein a residue is replaced with a chemically derivatized residue, provided that the resulting polypeptide displays IFN-γ repressor activity as disclosed herein.
[0030] Examples of conservative substitutions include the substitution of one non-polar (hydrophobic) residue such as isoleucine, valine, leucine or methionine for another; the substitution of one polar (hydrophilic) residue for another such as between arginine and lysine, between glutamine and asparagine, and between glycine and serine; the substitution of one basic residue such as lysine, arginine or histidine for another; or the substitution of one acidic residue, such as aspartic acid or glutamic acid, for another.
[0031] Polypeptides of the present invention also include peptides comprising one or more additions and/or deletions of residues relative to the sequence of a polypeptide whose sequence is disclosed herein, so long as the requisite hIFN-γ-suppressing activity of the polypeptide is maintained.
[0032] Additional residues may also be added at either terminus of a polypeptide for the purpose of providing a “linker” by which the polypeptides of the present invention can be conveniently affixed to a label or solid matrix, or carrier. Amino acid residue linkers are usually at least one residue and may be 40 or more residues, more often 1 to 10 residues. Typical amino acid residues used for linking are tyrosine, cysteine, lysine, glutamic and aspartic acid, or the like. In addition, a peptide may be modified by terminal-NH2 acylation (e.g., acetylation or thioglycolic acid amidation) or by terminal-carboxylamidation (e.g., with ammonia, methylamine, and the like terminal modifications). Terminal modifications are useful, as is well known, to reduce susceptibility by proteinase digestion, and therefore serve to prolong half-life of the peptides in solutions, particularly biological fluids where proteases may be present.
[0033] Polypeptides of the invention may comprise naturally occurring amino acids, synthetic amino acids, genetically encoded amino acids, non-genetically encoded amino acids, and combinations thereof. Polypeptides may include both L-form and D-form amino acids.
[0034] Representative non-genetically encoded amino acids may include but are not limited to: 2-aminoadipic acid; 3-aminoadipic acid; β-aminopropionic acid; 2-aminobutyric acid; 4-aminobutyric acid (piperidinic acid); 6-aminocaproic acid; 2-aminoheptanoic acid; 2-aminoisobutyric acid; 3-aminoisobutyric acid; 2-aminopimelic acid; 2,4-diaminobutyric acid; desmosine; 2,2′-diaminopimelic acid; 2,3-diaminopropionic acid; N-ethylglycine; N-ethylasparagine; hydroxylysine; allo-hydroxylysine; 3-hydroxyproline; 4-hydroxyproline; isodesmosine; allo-isoleucine; N-methylglycine (sarcosine); N-methylisoleucine; N-methylvaline; norvaline; norleucine; and ornithine.
[0035] Representative derivatized amino acids may include, for example, those molecules in which free amino groups have been derivatized to form amine hydrochlorides, p-toluene sulfonyl groups, carbobenzoxy groups, t-butyloxycarbonyl groups, chloroacetyl groups, or formyl groups. Free carboxyl groups can be derivatized to form salts, methyl and ethyl esters, or other types of esters or hydrazides. Free hydroxyl groups can be derivatized to form O-acyl or O-alkyl derivatives. The imidazole nitrogen of histidine can be derivatized to form N-im-benzylhistidine.
[0036] Polypeptides of the present disclosure may be produced using, e.g., recombinant technologies, phage display technologies, synthetic technologies, or combinations of such technologies and other technologies readily known in the art.
[0037] Polypeptides of the present invention may be synthesized by any of the techniques that are known to those skilled in the art of peptide synthesis. Synthetic chemistry techniques, such as a solid-phase Merrifield-type synthesis, may be preferred for reasons of purity, antigenic specificity, freedom from undesired side products, ease of production and the like. A summary of representative techniques can be found in Stewart & Young (1969) Solid Phase Peptide Synthesis, Freeman, San Francisco; Merrifield (1969) Adv Enzymol Relat Areas Mol Biol 32:221-296; Fields & Noble (1990) Int J Pept Protein Res 35:161-214; and Bodanszky (1993) Principles of Peptide Synthesis. 2nd rev. ed. Springer-Verlag, Berlin, New York. Solid phase synthesis techniques can be found in Andersson et al. (2000) Biopolymers 55:227-250, references cited therein, and in U.S. Pat. Nos. 6,015,561; 6,015,881; 6,031,071; and 4,244,946. Peptide synthesis in solution is described by Schröder & Lübke (1965) The Peptides, Academic Press, New York. Appropriate protective groups usable in such synthesis are described in the above texts and in McOmie (1973) Protective Groups in Organic Chemistry, Plenum Press, London, New York. Peptides that include naturally occurring amino acids can also be produced using recombinant DNA technology. In addition, peptides comprising a specified amino acid sequence can be purchased from commercial sources (e.g., Biopeptide Co., LLC of San Diego, Calif. and PeptidoGenics of Livermore, Calif.).
[0038] Preferably, hIFN-γ polypeptides are produced by nucleic acid recombinant techniques. For instance, hIFN-γ variant polypeptides may be obtained by site directed mutagenesis of a hIFN-γ nucleic acid sequence encoding a wild type IFN-γ polypeptide to introduce nucleic acid changes encoding amino acid modifications of the present disclosure. Resulting nucleic acid sequences encoding hIFN-γ variants may be used to produce the hIFN-γ variants in an expression system using methods known in the art. Additional information may be found in Sambrook et al., Molecular Cloning: A Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989).
[0039] All the nucleic acid sequences of the invention may be obtained using a variety of different techniques known in the art. The nucleotide sequences, as well as homologous sequences, may be isolated using standard techniques purchased or obtained from a depository.
[0040] Recombinantly-produced hIFN-γ variants may be purified before administration. Methods of purifying proteins are generally known in the art of protein biochemistry. For example, the polypeptides may be purified via standard methods including electrophoretic, molecular, immunological and chromatographic techniques, ion exchange, hydrophobic, affinity, and reverse-phase HPLC chromatography, and chromatofocusing. As another example, the polypeptide may be purified from the flow through of reverse-phase beads. Ultrafiltration and diafiltration techniques, in conjunction with protein concentration, may also be used. For general guidance in suitable purification techniques, see Scopes, R., Protein Purification, Springer-Vertag, NY (1982). Preferably, hIFN-γ variants are purified in two steps by Octyl-Sepharose and CM-Sepharose chromatography as described in the examples and in European Patent Publication No. EPO446582, the disclosure of which is incorporated herein in its entirety.
(b) Compositions
[0041] Inactive hIFN-γ variants of the present disclosure may be incorporated into compositions suitable for administration. A composition of the invention may comprise one, or more than one hIFN-γ variant of the disclosure. For instance, a composition of the invention may comprise about 1, 2, 3, 4, 5, 6, 7, 8, 9, or about 10 or more hIFN-γ variants of the disclosure. Preferably, a composition of the disclosure comprises one hIFN-γ variant of the invention.
[0042] As used herein, the language “pharmaceutically acceptable carrier” is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with hIFN-γ variants of the present disclosure, use thereof in the compositions is contemplated. Supplementary active compounds may also be incorporated into the compositions.
[0043] A composition of the disclosure may be formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral, e.g., intravenous, intradermal, subcutaneous, oral (e.g., inhalation), transdermal (topical), transmucosal, and rectal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol, or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates; and agents for the adjustment of tonicity such as sodium chloride or dextrose. The pH may be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation may be enclosed in ampoules, disposable syringes, or multiple dose vials made of glass or plastic.
[0044] Oral compositions generally may include an inert diluent or an edible carrier. Oral compositions may be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound may be incorporated with excipients and used in the form of tablets, troches, or capsules. Oral compositions may also be prepared using a fluid carrier for use as a mouthwash, wherein the compound in the fluid carrier is applied orally and swished and expectorated or swallowed. Pharmaceutically compatible binding agents and/or adjuvant materials may be included as part of the composition. The tablets, pills, capsules, troches, and the like may contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose; a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring. For administration by inhalation, the compounds are delivered in the form of an aerosol spray from a pressured container or dispenser which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebulizer.
[0045] Preferably, a composition of the invention is formulated to be compatible with parenteral administration. For instance, compositions suitable for injectable use may include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, Cremophor EL (BASF; Parsippany, N.J.), or phosphate buffered saline (PBS).
[0046] In all cases, a composition may be sterile and may be fluid to the extent that easy syringeability exists. A composition may be stable under the conditions of manufacture and storage, and may be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier may be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. The proper fluidity may be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion, and by the use of surfactants. Prevention of the action of microorganisms may be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like. In many cases, it may be preferable to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride, in the composition. Prolonged absorption of the injectable compositions may be brought about by including in the composition an agent which delays absorption, for example, aluminum monostearate and gelatin.
[0047] Sterile injectable solutions may be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying, which yields a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.
[0048] Systemic administration may also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and may include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal administration may be accomplished through the use of nasal sprays or suppositories. For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as generally known in the art. The compounds may also be prepared in the form of suppositories (e.g., with conventional suppository bases such as cocoa butter and other glycerides) or retention enemas for rectal delivery.
[0049] In one embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers may be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. These may be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No. 4,522,811.
[0050] Additional formulations of pharmaceutical compositions may be found in, for example, Hoover, John E., Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pa. (1975), and Liberman, H. A. and Lachman, L., Eds., Pharmaceutical Dosage Forms, Marcel Decker, New York, N.Y. (1980).
[0051] One of skill in the art will recognize that the concentration of a hIFN-γ variant of the invention in a composition can and will vary depending in part on the route of administration, the subject, and the reason for the administration, and may be determined experimentally. Methods of experimentally determining the concentration of an active agent, such as hIFN-γ variants of the invention in a composition, are known in the art.
[0052] The amount of hIFN-γ variant that may be combined with materials to produce a single dose of an adjuvant composition can and will vary depending upon the hIFN-γ variant, the subject, the formulation, and the particular mode of administration. Those skilled in the art will appreciate that dosages may also be determined with guidance from Goodman & Goldman's The Pharmacological Basis of Therapeutics, Ninth Edition (1996), Appendix II, pp. 1707-1711, and from Goodman & Goldman's The Pharmacological Basis of Therapeutics, Tenth Edition (2001), Appendix II, pp. 475-493.
II. Methods
[0053] In other aspects, the invention encompasses methods of modulating the biological activity of hIFN-γ. As such, methods of the invention may be used to treat disorders resulting from aberrant activity of hIFN-γ. A method of the invention comprises suppressing the biological activity of hIFN-γ in a subject by administering to the subject a therapeutically effective amount of a composition of the invention comprising a suppressor of hIFN-γ. A suppressor of hIFN-γ and a composition of the invention may be as described in Section I.
(a) Subject
[0054] As used herein, the tem “subject” may refer to a living organism having an immune system. In particular, subjects may include, but are not limited to, human subjects or patients and companion animals. Exemplary companion animals may include domesticated mammals (e.g., dogs, cats, horses), mammals with significant commercial value (e.g., dairy cows, beef cattle, pigs, sporting animals), mammals with significant scientific value (e.g., captive or free specimens of endangered species), or mammals which otherwise have value. Suitable subjects may also include: mice, rats, dogs, cats, ungulates such as cattle, swine, sheep, horses, and goats, lagomorphs such as rabbits and hares, other rodents, and primates such as monkeys, chimps, and apes. Preferably, a subject is a human. Subjects may be of any age, including newborn, adolescent, adult, middle age, or elderly.
[0055] A suppressor composition of the present disclosure may also be administered in vitro to a cell from a cell line. The cell line may be a primary cell line that is not yet described. Alternatively, a cell line may be an established cell line. A cell line may be adherent or non-adherent, or a cell line may be grown under conditions that encourage adherent, non-adherent or organotypic growth using standard techniques known to individuals skilled in the art. A cell line may be contact inhibited or non-contact inhibited. Preferably, a cell line is an established human cell line. An exemplary cell contacted by a composition of the invention is the amniotic cell line WISH.
(b) Administration
[0056] Suppressor IFN-γ variants or compositions comprising suppressor IFN-γ of the present disclosure may also be formulated and administered to a subject by several different means as described in Section I(b). In preferred embodiments, a pharmaceutical composition of the invention is administered by injection.
[0057] One of skill in the art will recognize that the amount and concentration of the composition administered to a subject will depend in part on the subject and the reason for the administration. Methods for determining optimal amounts are known in the art. In general, the concentration of a peptide-polynucleotide complex of the invention in a pharmaceutical composition may be as described in Section I(b).
[0058] Compositions of the present disclosure are typically administered to a subject in an amount sufficient to provide a benefit to the subject. This amount is defined as a “therapeutically effective amount.” A therapeutically effective amount may be determined by the efficacy or potency of the particular composition, the disorder being treated, the duration or frequency of administration, the method of administration, and the size and condition of the subject, including that subject's particular treatment response. A therapeutically effective amount may be determined using methods known in the art, and may be determined experimentally, derived from therapeutically effective amounts determined in model animals such as the mouse, or a combination thereof. Additionally, the route of administration may be considered when determining the therapeutically effective amount. In determining therapeutically effective amounts, one skilled in the art may also consider the existence, nature, and extent of any adverse effects that accompany the administration of a particular compound in a particular subject.
[0059] When a composition of the invention is administered to a subject by injection, a composition may be administered to the subject in a bolus. A composition may also be administered by injecting more than one bolus into the subject over a period of time. For instance, a composition may be administered by injecting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more boluses into the subject.
[0000] (c) Treating a hIFN-γ-Mediated Disorder
[0060] By modulating the biological activity of hIFN-γ, a method of the invention may be used to treat a hIFN-γ-mediated disorder. The term “hIFN-γ-mediated disorder” encompasses any medical condition associated with aberrant function of hIFN-γ. Preferably, a hIFN-γ-mediated disorder is any medical condition associated with increased levels of IFN-γ or increased sensitivity to IFN-γ. As such, a method of the present disclosure may be used to treat an inflammation disorder or an autoimmune disease. For example, the disorder may be Acquired Immune Deficiency Syndrome (AIDS), arthritis, including, but not limited to, rheumatoid arthritis including juvenile rheumatoid arthritis, spondyloarthropathies including ankylosing spondylitis, Sjogren's syndrome, gouty arthritis, osteoarthritis, systemic lupus erythematosus (SLE), lupus nephritis, or juvenile arthritis, Addison's disease, epididymitis, glomerulonephritis, Graves' disease, Guillain-Barre syndrome, Hashimoto's disease, pemphigus, erythropoietin resistance, graft versus host disease, transplant rejection, autoimmune hepatitis-induced hepatic injury, biliary cirrhosis, alcohol-induced liver injury including alcoholic cirrhosis, scleroderma, osteoporosis, vasculitis, alopecia areata, myastenia gravis, and Alzheimer's disease. In some embodiments, the inflammation may be associated with asthma, bronchitis, menstrual cramps, premature labor, tendinitis, bursitis, skin-related conditions such as psoriasis, eczema, psoriatic arthritis, burns and dermatitis, or from post-operative inflammation including from ophthalmic surgery such as cataract surgery and refractive surgery. In a further embodiment, the inflammatory disorder may be a gastrointestinal condition such as inflammatory bowel disease, Crohn's disease, gastritis, irritable bowel syndrome, or ulcerative colitis. In yet another embodiment, the inflammation may be associated with diseases such as vascular diseases, migraine headaches, periarteritis nodosa, thyroiditis, hemolytic anemia, aplastic anemia, Hodgkin's disease, sclerodoma, rheumatic fever, type I diabetes, neuromuscular junction disease including myasthenia gravis, white matter disease including multiple sclerosis, sarcoidosis, nephrotic syndrome, Behcet's syndrome, polymyositis, gingivitis, nephritis, hypersensitivity, swelling occurring after injury, myocardial ischemia, allergic rhinitis, respiratory distress syndrome, endotoxin shock syndrome, atherosclerosis, and the like. In an alternate embodiment, the inflammatory disorder may be associated with an ophthalmic disease, such as retinitis, retinopathies, uveitis, ocular photophobia, or of acute injury to the eye tissue. In still another embodiment, the inflammation may be a pulmonary inflammation, such as that associated with viral infections or cystic fibrosis.
[0061] Preferably, a method of the invention may be used to treat multiple sclerosis, alopecia areata, myastenia gravis, as well as for graft arteriosclerosis in post-transplanted patients.
[0062] Treatment of an IFN-γ-mediated disorder encompasses alleviation of at least one symptom of the disorder, a reduction in the severity of the disorder, or the delay or prevention of progression to a more serious disease that occurs with some frequency following the treated condition. Treatment need not mean that the disorder is totally cured. A useful therapeutic agent needs only to reduce the severity of a disorder, reduce the severity of a symptom or symptoms associated with the disorder or its treatment, or provide improvement to a patient's quality of life, or delay the onset of a more serious disease that can occur with some frequency following the treated condition. For example, if the disorder is graft arteriosclerosis after transplant, a therapeutic agent of the disclosure may prevent graft arteriosclerosis, delay the onset of graft arteriosclerosis, or reduce the luminal stenosis characteristic of graft arteriosclerosis in transplant subjects. When the disorder is alopecia areata, sometimes called spot baldness because it causes bald spots on the scalp, a therapeutic agent of the disclosure may prevent formation of bald spots, may reduce the number of bald spots formed, or may reduce the size of the formed bald spots in a subject.
[0063] It will be appreciated by those skilled in the art that a composition of the present disclosure may be used in combination with other therapeutic agents before, after, and/or during treatment with the repressor composition of the disclosure.
DEFINITIONS
[0064] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art. All patents, applications, published applications and other publications are incorporated by reference in their entirety. In the event that there is a plurality of definitions for a term herein, those in this section prevail unless stated otherwise.
[0065] The terms “IFN-γ” and “hIFN-γ” refer to the dimeric biologically active form of IFN-γ and hIFN-γ independently of whether this molecule is a wild type or modified form of IFN-γ and hIFN-γ. The terms “IFN-γ polypeptide” and “hIFN-γ polypeptide” refer to a IFN-γ and hIFN-γ monomer.
[0066] As used herein, “administering” is used in its broadest sense to mean contacting a subject with a composition of the invention.
[0067] As used herein, a “pharmaceutical composition” includes a pharmacologically effective amount of a therapeutic agent of the invention and a pharmaceutically acceptable carrier. As used herein, “pharmacologically effective amount,” “therapeutically effective amount” or simply “effective amount” refers to that amount of an agent effective to produce the intended pharmacological, therapeutic or preventive result. For example, if a given clinical treatment is considered effective when there is at least a 15% reduction in a measurable parameter associated with a disease or disorder, a therapeutically effective amount of an agent for the treatment of that disorder or disease is the amount necessary to effect at least a 15% reduction in that parameter.
[0068] The term “pharmaceutically acceptable carrier” refers to a carrier for administration of a therapeutic agent. Such carriers may include, but are not limited to, saline, buffered saline, dextrose, water, glycerol, ethanol, and combinations thereof. The term specifically excludes cell culture medium. For drugs administered orally, pharmaceutically acceptable carriers may include, but are not limited to, pharmaceutically acceptable excipients such as inert diluents, disintegrating agents, binding agents, lubricating agents, sweetening agents, flavoring agents, coloring agents and preservatives. Suitable inert diluents may include sodium and calcium carbonate, sodium and calcium phosphate, and lactose, while corn starch and alginic acid are suitable disintegrating agents. Binding agents may include starch and gelatin, while the lubricating agent, if present, may generally be magnesium stearate, stearic acid or talc. If desired, the tablets may be coated with a material such as glyceryl monostearate or glyceryl distearate to delay absorption in the gastrointestinal tract.
[0069] The terms “homologous,” “identical,” or percent “identity” in relation to two or more peptides, refers to two or more sequences or subsequences that have a specified percentage of amino acid residues that are the same (i.e., about 60% identity, preferably 70%, 75%, 80%, 85%, 90%, 91%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or higher identity over a specified region, when compared and aligned for maximum correspondence over a comparison window or designated region) as measured using a BLAST or BLAST 2.0 sequence comparison algorithms with default parameters described below, or by manual alignment and visual inspection (see, e.g., NCBI web site http://www.ncbi.nlm.nih.gov/BLAST/ or the like). The definition also includes sequences that have deletions and/or additions, as well as those that have substitutions, as well as naturally occurring, e.g., polymorphic or allelic variants, and man-made variants. As described below, the preferred algorithms can account for gaps and the like.
[0070] The terms “isolated,” “purified,” or “biologically pure” refer to material that is substantially or essentially free from components that normally accompany it as found in its native state. Purity and homogeneity are typically determined using analytical chemistry techniques such as polyacrylamide gel electrophoresis or high performance liquid chromatography. A protein or nucleic acid that is the predominant species present in a preparation is substantially purified. The term “purified” in some embodiments denotes that a nucleic acid or protein gives rise to essentially one band in an electrophoretic gel. Preferably, it means that the nucleic acid or protein is at least 85% pure, more preferably at least 95% pure, and most preferably at least 99% pure. “Purify” or “purification” in other embodiments means removing at least one contaminant from the composition to be purified. In this sense, purification does not require that the purified compound be homogenous, e.g., 100% pure.
[0071] Biologically active hIFN-γ is a noncovalent homodimer formed by the self-association of two mature polypeptides in an antiparallel orientation. The mature form of each polypeptide comprises 143 amino acid residues (SEQ ID NO: 5) derived from a precursor form thereof comprising 166 amino acid residues. Numbering of amino acids is from the N-terminus of hIFN-γ of SEQ ID NO: 5.
[0072] In practicing the present invention, many conventional techniques in molecular biology, microbiology, and recombinant DNA may be used. These techniques are well known and are explained in, for example, Current Protocols in Molecular Biology, Volumes I, II, and III, 1997 (F. M. Ausubel ed.); Sambrook et al., 1989, Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.; DNA Cloning: A Practical Approach, Volumes I and II, 1985 (D. N. Glover ed.); Oligonucleotide Synthesis, 1984 (M. L. Gait ed.); Nucleic Acid Hybridization 1985, (Hames and Higgins eds.); Transcription and Translation, 1984 (Hames and Higgins eds.); Animal Cell Culture, 1986 (R. I. Freshney ed.); Immobilized Cells and Enzymes, 1986 (IRL Press); Perbal, 1984, A Practical Guide to Molecular Cloning; the series, Methods in Enzymology (Academic Press, Inc.); Gene Transfer Vectors for Mammalian cells, 1987 (J. H. Miller and M. P. Calos eds., Cold Spring Harbor Laboratory); and Methods in Enzymology, Vol. 154 and Vol. 155 (Wu and Grossman, and Wu, eds., respectively).
EXAMPLES
[0073] The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples that follow represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
Example 1
Construction of hIFN-γ Derivative Proteins with Amino Acid Substitutions at Positions 86, 87 and 88
[0074] Recombinant proteins derivative of the hIFN-γ with amino acid substitutions at positions 86, 87 and 88 were prepared by PCR mutagenesis of a synthetic hIFN-γ gene using appropriate primers. The latter were synthesized on a Cyclon Plus (MilliGene) synthesizer using the phosphoramidite method and purified on a 15% polyacrylamide gel. Two primers (forward and reverse) were synthesized and their primary structure is presented in the sequence listing. The forward primer (SEQ ID NO: 1) was designed to introduce a HindIII site and the reverse primer (SEQ ID NO: 2) contains a randomized 9 nucleotide long region plus an AsulI site. The HindIII and AsulI restriction sites were used for cloning PCR fragments into the pJP1R3-hIFN-γ expression vector as described in the International Patent Publication No. WO2006099701, the disclosure of which is incorporated herein in its entirety. A synthetic hIFN-γ nucleic acid sequence encoding wild type hIFN-γ of SEQ ID NO: 5 was used as a template. The PCR conditions used are presented in Tables 2 and 5.
[0000]
TABLE 2
PCR conditions for primers SEQ ID NO: 1 and SEQ ID NO: 2
Number of
Time
Temperature
Program
cycles
(min)
(° C.)
I
1
5
94
II
5
0.5
94
0.5
38
0.5
74
III
35
0.5
94
0.5
55
0.5
74
IV
1
10
74
[0075] The PCR fragments were purified by electrophoresis in 1.5% Agarose Type II gel (Sigma), digested with HindIII and AsulI, and cloned into the pJP1R3-hIFN-γ expression vector that was pre-digested with HindIII and AsulI as described in International Publication No. WO2006099701. To this end 20 μg plasmid (vector) DNA was dissolved in 150 μl HindIII buffer and digested with 20 U HindIII for 3 h at 37° C. The reaction mixture was treated consecutively with phenol and chloroform and DNA was precipitated with 3 v/v of ethanol at −20° C. The precipitate was dissolved in 150 μl AsulI buffer and digested with 20 U AsulI for 3 h at 37° C. The linear vector was dephosphorylated with calf intestinal alkaline phosphatase (CIAP, Boehringer Mannhein), purified using agarose gel electrophoresis, and mixed in T4 DNA ligase buffer with the PCR fragments at a ratio 3:1. The ligase reaction was carried out overnight at 4° C., and used for transformation of competent E. coli LE392 cells.
[0076] The transformed cells were grown in standard Luria-Bertani (LB) broth and/or LB-agar containing 50 μg/ml ampicillin and 10 μg/ml tetracycline. A set of 162 clones were selected, plasmid DNA was isolated from each clone, and the exact nucleotide sequence of the randomized region was determined by DNA sequence analysis. Thus, the number of individual clones was reduced to 101 (Table 1), all of which were tested for production of hIFN-γ derivative proteins. The level of expression of the latter was determined by ELISA using hIFN-γ specific monoclonal antibodies.
[0077] The hIFN-γ derivative proteins were purified in two steps using Octyl-Sepharose and CM-Sepharose (Pharmacia) chromatography as previously described in European Patent Application No. EPO446582, the disclosure of which is incorporated herein in its entirety.
[0078] Two biological activities, antiviral and antiproliferative, were determined for the hIFN-γ derivative proteins. The antiviral activity (expressed in International Units) was measured by the protective effect of hIFN-γ against the cytopathic action of vesicular stomatitis virus (VSV) on the amniotic cell line WISH [12], and the antiproliferative activity was determined using the kynurenine bioassay [13]. Table 3 presents activity data of some of the mutant hIFN-γ proteins. Both activities vary between 4.3×10 4 and 1.2×10 4 IU/mg for constructs 19 and 46-1, respectively. This is much lower in comparison with the activity of intact hIFN-γ (10 7 -10 8 IU/mg). No biological activity was registered for the constructs 27, 36, 134, 135 and 144.
[0000]
TABLE 3
hIFNg: Amino
Specific Biological
acids at
Activity
positions 86,
(IU/mg) measured
Construct No
87, 88
in cell lysates
19
Ser Thr Phe
2 × 10 4
22
Ser Ser Leu
3 × 10 5
27
Glu Met Pro
No
(SEQ ID NO: 6)
28
Leu Thr Pro
No
36
Leu Cys Pro
No
39-12
Asp Leu Leu
No
46-1
Thr Leu Leu
4.9 × 10 6
63
Arg Leu Arg
No
72
His Ser Arg
No
74
Ser Leu Leu
2.4 × 10 7
85
Arg Arg Ser
No
105-2
Ala Thr Ala
No
115
Gln Phe His
No
120
Gln Ala Gly
No
134
Thr Asn Gly
No
(SEQ ID NO: 7)
135
Val Ser Pro
No
143
Cys Ser Pro
No
144
Cys Ala Pro
No
Example 2
Construction of hIFN-γ Derivative Protein with Gln at Position 88
[0079] A recombinant protein derivative of hIFN-γ comprising Gln instead of Lys at position 88 (Gln/Lys88) was prepared by PCR mutagenesis using a synthetic hIFN-γ gene as a template and the primers having the nucleic acid sequences of SEQ ID NO: 1 and SEQ ID NO: 3. The forward primer (SEQ ID NO: 1) is as described in Example 1 above, and the reverse primer (SEQ ID NO: 3) comprises a single nucleotide transition (A→G) to substitute Gln for Lys at position 88. It also carries an AsulI site for cloning into the expression vector pJP1R3-hIFN-γ. PCR conditions are presented in Tables 4 and 5 and all subsequent procedures were performed as described in Example 1.
[0000]
TABLE 4
PCR conditions for primers SEQ ID NO: 1 (forward) and
the reverse primers SEQ ID NO: 3 or SEQ ID NO: 4
Number of
Time
Temperature
Program
cycles
(min)
(° C.)
I
1
5
94
II
5
1
94
1
50
1
74
III
35
1
94
1
65
1
74
IV
1
10
74
[0000]
TABLE 5
Composition of PCR reaction mixture
Ingredients
Quantity (μl)
Template DNA (50 pg/μl)
1
Forward primer (20 pmol/μl)
1
Reverse primer (20 pmol/μl)
1
Taq-polymerase (3 U/μl)
1
10 × PCR buffer
2
2 mM dNTP's
2
H 2 O
12
Total
20
[0080] The resulting Gln/Lys88 derivative hIFN-γ demonstrated almost 1000 fold lower antiviral and antiproliferative activities in comparison with the wild type hIFN-γ (Table 6).
Example 3
Construction of a hIFN-γ Derivative Protein with Gln at Position 88 and Deleted 21 C-Terminal Amino Acids
[0081] A recombinant protein derivative of the hIFN-γ containing both a Lys88→Gln substitution and deletion of 21 C-terminal aminoacids (Lys/Gln88/T7) was prepared by PCR mutagenesis using the hIFN-γ derivative described in Example 2, and the primers SEQ ID NO: 1 and SEQ ID NO: 4. The forward primer (SEQ ID NO: 1) is as described in Example 1, and the reverse primer (SEQ ID NO: 4) was designed to eliminate 21 3′-terminal codons from the hIFN-γ gene during PCR amplification. The resulting PCR product is a nucleic acid sequence coding for 122 amino acids and a substitution of Gln for Lys at position 88. It carries two restriction sites (HindIII and BamHI) for cloning into the expression vector pJP1R3-hIFN-γ also digested with HindIII and BamHI. The PCR reaction conditions are presented in Tables 4 and 5. All subsequent procedures were performed as in Example 1.
[0082] As it is seen in Table 6, the Gln/Lys88/T7 mutant demonstrates more than 1000 fold decrease in both antiviral and antiproliferative activities in comparison to the wild type hIFN-γ.
[0000]
TABLE 6
hIFNg: Amino
Specific Biological
acids at
Activity
positions 86,
(IU/mg) measured
Construct No
87, 88
in cell lysates
LG88
Lys Lys Gln
1.7 × 10 5
(SEQ ID NO: 9)
Lys/Gln88/T7
Lys Lys Gln +
6.7 × 10 3
truncated
C-terminus
T8
Lys Lys Lys +
No
Truncated 24
C-terminal aa
T9
Lys Lys Lys +
No
Truncated 27
C-terminal aa
Example 4
Examination of the Suppressor Activity of Mutant hIFN-γ Proteins
[0083] The ability of mutant hIFN-γ derivative proteins described in the previous examples to compete with the wild-type hIFN-γ for the hIFN-γ receptor was examined using the amniotic cell line WISH (enriched in hIFN-γ receptors). The competition assay measured the decrease in antiproliferative activity of standard (wild-type) hIFN-γ in the presence of mutant hIFN-γ derivative proteins. The antiproliferative activity was determined using the kynurenine bioassay [13] based on the hIFN-γ induction of indoleamine-2,3-dioxygenase (IDO), which is the first and rate-limiting enzyme in the tryptophan catabolism. IDO catalyzes oxidative cleavage of tryptophan, to N-formylkynurenine. Following a hydrolysis step, N-formylkynurenine is transformed into kynurenine which gives a yellow-colored compound when contacted with Ehrlich's reagent. The level of the yellow-colored compound may be measured at 490 nm. It is known that the amount of produced kynurenine is directly proportional to the concentration of hIFN-γ used for cell activation.
[0084] To measure the suppressor activity, mutant proteins were mixed in equimolar amounts in sterile bacterial lysates with purified hIFN-γ, and the antiproliferative activity of the mixtures was determined by the kynurenine bioassay using wild-type hIFN-γ as a standard. Experimentally, clear cell lysates of E. coli LE392 cells transformed with plasmids expressing mutant hIFN-γ proteins were prepared after cultivation in LB broth supplemented with 50 μg/ml ampicillin to a cell density of A 590 =0.7. Samples of 2 OD 590 cells were centrifuged, the cells were resuspended in 1 ml 0.14 M NaCl, 10 mM Tris pH 8.0, 0.1 mM PMSF and disrupted by sonication. The lysates were cleared by centrifugation at 12000 rpm for 15 min at 4° C., and used for further analyses.
[0085] Total protein content was determined using the Bradford assay with bovine serum albumin (fraction V) as a standard. The samples were diluted by PBS (14.7 mM Na 2 CO 3 , 34 mM NaHCO 3 , pH 9.6) to a final concentration of 27 μg/ml protein. Samples of 50 μl were added (11 times per sample) to PVC 96 well microplates (Costar Ltd., USA), incubated overnight at 4° C., and the content of hIFN-γ or hIFN-γ derivative proteins was measured by ELISA using hIFN-γ specific monoclonal antibodies.
[0086] To measure the suppressive effect of the hIFN-γ mutant proteins against binding of wild-type hIFN-γ to the cell receptors, clear cell lysates were serially diluted, and samples of 50 μl were mixed with 50 μl of standard hIFN-γ and added to PVC 96 well microplates. WISH cell suspension (50 μl) in MEM Eagle medium supplemented with HEPES, and 2% BFS was added, mixed with 50 μl L-tryptophan and the kynurenine bioassay was performed as described [13]. The final concentration of the standard hIFN-γ in the analyzed samples was 25 IU/ml, 50 IU/ml and 100 IU/ml, corresponding to 0.027 nmol, 0.055 nmol and 0.11 nmol, respectively. Samples containing standard hIFN-γ (alone) were used as positive control, and clear cell lysates obtained from host (non-transformed E. coli LE392) cells were used as negative controls in this assay.
[0087] The results can be interpreted as follows: if a mutant protein has the same affinity to the hIFN-γ receptor as that of the wild type hIFN-γ and zero antiproliferative activity, the activity of the equimolar mixture of both substances should be 50% of that of the control (pure wild type hIFN-γ). The data presented in Table 6 show that the constructs with zero antiproliferative activity (constructs 27 and 134), and also the C-terminally truncated construct Lys/Gln88/T7, demonstrate strongest suppressive effect.
[0000]
TABLE 6
Mutant hIFN-γ gene variants
Specific
Nucleotide
activity of the
Competition
sequence between
Amino acids at
mutant hIFN-γ
with the
Clone
nucleotides
positions 86,
proteins
wild type
signature
218 and 227
87 and 88
(IU/mg)
hIFN-γ
19
TCC ACT TTT
Ser Thr Phe
*7.2 × 10 5
+
**2 × 10 4
27
GAA ATG CCC
Glu Met Pro
0
+++
36
CTG TGT CCC
Leu Cys Pro
0
++
46-1
ACC CTC CTC
Thr Leu Leu
*3.0 × 10 4
+
134
ACC AAT GGT
Thr Asn Gly
0
+++
135
GTT TCC CCC
Val Ser Pro
0
+
144
TGC GCC CCT
Cys Ala Pro
0
+
Lys/Gln88
CCG TAC CTC
Lys Lys Gln
*1.7 × 10 5
+
**1.2 × 10 4
Lys/Gln88/T7
CCC AAT TAT
Lys Lys Gln and
*6.7 × 10 3
+++
C-terminus
**4.3 × 10 4
deleted
*antiproliferative activity;
**antiviral activity;
“+” Competition with the wild type hIFN-y,
“+++” high competition,
“+++” intermediate competition,
“+” low competition
[0088] The invention illustratively disclosed herein suitably may be practiced in the absence of any element, which is not specifically disclosed herein. It is apparent to those skilled in the art, however, that many changes, variations, modifications, other uses, and applications to the method are possible, and also changes, variations, modifications, other uses, and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.
REFERENCES
[0000]
1. Johnson, K. P. (1988) Treatment of multiple sclerosis with various interferons. The Cons. Neurology, 38 (suppl. 2) 52-64.
2. Martino, G., Moiola, L., Brambilla, E., Clementi, E., Comi, G., Grimaldi, L. M. (1995). Interferon gamma induces T lymphocyte proliferation in multiple sclerosis via a Ca2+-dependent mechanism. J. Neuroimmunol. 62, 169-176.
3. Vartanian, V., Li, Y., Zhao, M., Stefansson, K. (1995) Interferon-gamma-induced oligodendrocyte cell death: implications for the pathogenesis of multiple sclerosis. Mol. Med. 1, 732-743.
4. Tellides, G., Pober, J. (2007) Interferon-γ axis in graft arteriosclerosis. Circ. Res. 100, 622-632.
5. Panitch, H. L., Hirsch, R. L., Schindler, J., Johnson, K. P. (1987) Treatment of multiple sclerosis with gamma interferon: Exacerbations associated with activation of the immune system. Neurology 37, 1097-1102.
6. Beck, J., Rondot, P., Catinot, L., Falcoff, E., Kirchner, H., Wietzerbin, J. (1988) Increased production of interferon gamma and tumor necrosis factor precedes clinical manifestation in multiple sclerosis: do cytokines trigger off exacerbations? Acta Neurol. Scand. 78, 318-323.
7. Furlan, R., Bergamim A., Lang, R., Brambilla, E., Franciotta, D., Martinelli, V., Comi, G., Paninam P., Martino. G. (2000) Interferon-beta treatment in multiple sclerosis patients decreases the number of circulating T cells producing interferon-gamma and interleukin-4. J. Neuroimmunol. 111, 86-92.
8. Khademi, M., Wallstrom, E., Andersson, M., Piehl, F., Di Marco, R., Olsson, T. (2000) Reduction of both pro and anti-inflammatory cytokines after 6 months of interferon beta-1a treatment of multiple sclerosis. J. Neuroimmunol. 103, 202-210.
9. Skurkovich, S., Boiko, A., Beliaeva, I., Buglak, A., Alekseeva, T., Smirnova, N., Kulakova, O., Tchechonin, V., Gurova, O., Deomina, T., Favorova, O. O., Skurkovic, B., Gusev, E. (2001) Randomized study of antibodies to IFN-gamma and TNF-alpha in secondary progressive multiple sclerosis. Mult. Scler. 7, 277-284.
10. Skurkovich, B., Skurkovich, S. (2003) Anti-interferon-gamma antibodies in the treatment of autoimmune diseases. Curr. Opin. Mol. Ther. 5, 52-57.
11. Espejo, C., Penkowa, M., Satz-Torres, I., Xaus, J., Celada, A., Montalban, X., Martinez-Caceres, E. M. (2001) Treatment with anti-interferon-gamma monoclonal antibodies modifies experimental autoimmune encephalomyelitis in interferon-gamma receptor knockout mice. Exp. Neurol. 172, 460-468.
12. Forti, R. L., Schuffman, S. S., Davies, H. A. and Mitchell, W. M. (1986) Objective antiviral assay of the interferons by computer assisted data collection and analysis. Methods in Enzymol. 119, 533-540.
13. Boyanova, M., Tsanev, R. and Ivanov, I. (2002) A modified kynurenine bioassay for quantitative determination of human interferon gamma. Analyt. Biochem. 308, 178-181. | The invention relates to suppressors of endogenous human interferon-gamma (INF-γ) applicable in treatment of diseases associated with impaired activity of endogenous IFN-γ. The suppressors of the invention are useful in treating autoimmune diseases and for prevention of graft arteriosclerosis and rejection of organs in allograft transplanted patients. The invention includes inactive analogues or variants of IFN-γ having preserved affinity to the IFN-γ receptor, genetically modified in the domain responsible for triggering the signal transduction pathway. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application No. 60/620,600, filed Oct. 20, 2004, which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention generally relates to a human machine interface (“HMI”) for a vehicle and more particularly for an HMI for a vehicle.
[0004] 2. Description of Related Art
[0005] Generally, interface designs try to maintain a one-to-one relationship between the controls and functions of the interface. Maximizing the one-to-one relationship of the functions to the controls of an interface provides intuitive navigation and improves ease of use of the system. In practice, many interfaces have buttons that control multiple functions of the interface by graphically associating the buttons with menu choices on a common display.
[0006] Today the number of controls for many interface units is limited by the cost of creating individual buttons and controls for each function. Additionally, as the number of controls increase, the space required for the additional controls translates into higher cost and creates implementation problems for the design engineers. Often budget and space constraints drive a reduction in interface optimization, even for high end customers.
[0007] In view of the above, it is apparent that there exists a need for an improved human machine interface.
SUMMARY
[0008] In satisfying the above need, as well as overcoming the enumerated drawbacks and other limitations of the related art, the present invention provides such an improved human machine interface.
[0009] The human machine interface (HMI) includes a large ring knob with an integrated display, in the center of the ring knob, for operation with multiple functions. A plurality of buttons are located about the ring knob in the form of a circle and correspond to menu selections provided on the display. In addition, a finger rest is located above the ring knob for hand stabilization during use of the ring knob or buttons.
[0010] A proximity sensor is provided to sense user motion proximate the HMI unit. The proximity sensor signals a controller to copy content from the integrated display to a multifunction display in the instrument cluster or a heads up display to enable blind operation. In addition, a touch sensor is integrated on the ring knob to enlarge the adjustment display upon user contact. To avoid confusion of the driver, an enlarged display of the control function currently being manipulated is provided to the user. In addition, the enlarged display may include a symbol corresponding to the control function being manipulated. A portion of the background or other part of the display may be “filled-in”, where the fill area corresponds to the setting or level of the current control function. The background filling provides maximum visualization to the user and is easily rationalized by analogy, such as, the filling of a glass with water.
[0011] Menu buttons are provided for each function category. Preferably, each category function has no more than two menus per menu button. Two menus per button, allows the user to return to the desired main menu with one activation of any menu button. This enables an easily learnable HMI and reduces driver distraction while manipulating menus.
[0012] An arrangement of four ring segment buttons is provided around the display and ring knob. The operation of each button is supported by a visual feedback including the activation feedback and status feedback within the associated quarter segments of the round display integrated into the ring knob. Using a round display allows more styling flexibility and the division of the circle into four quarters provides a clean way for associating the four control functions to the four buttons that can be operated simultaneously. To provide further styling, the layout of the four ring segment buttons appear as a single ring or circle in the HMI unit.
[0013] In an additional embodiment, the HMI unit is a panel that can be flipped up to provide access to a storage unit behind the HMI controls. This area is usually used for audio or climate control electronics, and as such the audio and climate control electronics can be located elsewhere in the car and remotely operated by the HMI unit. In addition, a storage unit in the center console is a preferred location for personal storage because it can be accessed while driving. Typical storage units are much further away from the driver's view, such as, the glove box or under a seat. Further, wireless data streaming may be used to communicate with mobile consumer and communication electronics located in the storage unit. A transmitter/receiver may be integrated to the storage unit and connected to a controller to wirelessly integrate the function of stored electronics into the vehicle electronic system.
[0014] For each function category, the HMI includes a set of dedicated controls. In addition, some controls are multiplexed to manipulate functions belonging to all function categories. The layout of the HMI is designed such that controls corresponding to each function category are contained in a unique region and multiplexed controls associated with multiple categories are located between each of the unique regions. As such, the driver can build a mental model of the control elements, because the functional groups are in separate areas. Further, the display color including a ring light or menu accents are manipulated to be consistent with the currently active function category. Each function category has a predefined color which may be altered based on daylight or nighttime illumination.
[0015] In addition, each of the knobs include a unique tactile indicator, for differentiation by feel. The tactile indicator may include the profile of the knob surface which is different for each knob. Using unique knob surface profiles is a cost effective solution to enable blind operation of the controls and improved differentiation for a number of similarly styled control knobs.
[0016] Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a front perspective view of an HMI unit in accordance with the principles of the present invention;
[0018] FIG. 2 is a schematic view of an HMI unit in accordance with the present invention;
[0019] FIG. 3 is a front perspective view illustrating use of a finger rest in accordance with the present invention;
[0020] FIG. 4 is a front perspective view illustrating activation of the touch sensor in accordance with the present invention;
[0021] FIGS. 5A, 5B and 5 C are a front view of the integrated display illustrating an enlarged display with background filled-in accordance with the present invention;
[0022] FIG. 6 is a schematic view of the menu control of the HMI in accordance with the present invention;
[0023] FIGS. 7A and 7B is a front view of the electronic display illustrating visual confirmation of control manipulation in accordance with the present invention;
[0024] FIG. 8 is a front perspective view illustrating use of the proximity sensor in accordance with the present invention;
[0025] FIG. 9 is a front perspective view of the HMI unit and a instrument cluster illustrating remote display of the HMI display information in accordance with the present invention;
[0026] FIG. 10 is a front perspective view illustrating the first region containing controls associated with a first function category in accordance with the present invention;
[0027] FIG. 11 is a front perspective view illustrating the second region containing controls associated with a second function category in accordance with the present invention;
[0028] FIG. 12 is a front perspective view of the HMI unit including a storage unit in accordance with the present invention; and
[0029] FIG. 13 is a front perspective view of the HMI unit including an integrated air register unit in accordance with the present invention.
DETAILED DESCRIPTION
[0030] Referring now to FIGS. 1 and 2 , a human machine interface (HMI) unit embodying the principles of the present invention is illustrated therein and designated at 10 . The HMI unit 10 includes various controls, an integrated display and a controller in communication with both the controls and display.
[0031] One control comprises a first knob 12 located central to the HMI unit 10 and includes an integrated electronic display 16 . The first knob 12 includes a rotatable ring portion 14 located about the electronic display 16 . The rotatable ring portion 14 has finger grips 17 , preferably a tacky material for improved manipulation of the first knob 12 . Positioned immediately above the first knob 12 and partially extends around the first knob 12 is a protrusion 15 . As such, the protrusion 15 is available to the user as a finger rest allowing hand stabilization as the user manipulates the first knob 12 , as illustrated in FIG. 3 .
[0032] The first knob 12 also includes a touch sensor 40 , to determine when the first knob 12 is being touched by the user as illustrated in FIG. 4 . A controller 46 , in communication with the touch sensor 40 , is configured to alter the information provided on the electronic display 16 based on the touch sensor 40 . The information may be altered such that display information related to the controlled setting may be formatted to temporarily occupy the full display area. In addition, the information may include graphics indicating the setting for the function of the first knob 12 .
[0033] One example of the graphics provided to the electronic display 16 is depicted in FIG. 5 . If the first knob 12 is configured to control the treble selection of an audio device, when the first knob 12 is touched the electronic display 16 may be altered to include additional information or formatting about the treble selection. For example, the electronic display 16 may include a treble cleft symbol 66 indicating the treble selection is being manipulated. The symbol 66 may be an illuminated outline of the symbol with textual naming of the control function across the bottom of the electronic display 16 . The controller 46 may further be configured to control the electronic display 16 and provide visual indicators showing the level of the current setting. For example, along the top of the display, a box graph 68 may be provided to indicate the current treble setting. An animated filling of the boxes on the box graph 68 provides a somewhat linear indication of the treble setting. Further, an animated filling of the background 70 around the symbol provides an alternative or additional area based visual indication of the current setting. If the treble setting is half way between the maximum and minimum treble setting, the background 70 would be half filled, as seen in FIG. 5C . Similarly, a treble setting one quarter of the way toward the maximum treble setting would result in the background 70 being one quarter filled, as seen in FIG. 5B . In addition, the filled portion may also be indicated by a change in color, brightness, or other visual characteristic.
[0034] Ring segment buttons 22 , 24 , 26 , 28 are located around the first knob 12 . In the embodiment shown, there are four ring segment buttons. The ring segment buttons are in the shape of an arc and are located in a circular arrangement around the first knob 12 . The ring segment buttons may extent around the first knob 12 such that the ring segment buttons appear as a continuous circle surrounding the first knob 12 . The four ring segment buttons 22 , 24 , 26 , 28 are in communication with the controller 46 and are coordinated with the electronic display 16 , such that, the function of each button is indicated in an adjacent quadrant of the electronic display 16 . Further, the function of each button may change based on the menu or control mode of the HMI unit 10 .
[0035] The HMI unit 10 also includes at least two menu buttons 18 , 20 . The menu buttons 18 , 20 allow the user to index through menus for a category of functions. As shown, the HMI unit 10 includes a first menu button 18 for accessing comfort functions and a second menu button 20 for accessing audio functions. Preferably, each menu button indexes through four menus 72 , 74 , 76 , 78 that assign functionality to the ring segment buttons and the rotatable ring portion 14 of the first knob 12 . As such, any menu may be accessed with two presses of an associated menu button, as shown in FIG. 6 . The menu buttons may be color coded, for example, red for audio and blue for comfort. The menu colors or accents may also correspond to the color theme for the associated menu categories (comfort or audio). In addition a ring light located proximate the first knob may be provided to illuminate a portion of the HMI unit in a color corresponding to the current menu category.
[0036] Illustratively, the first menu button 18 provides the user with the ability to manipulate comfort functions. If the first menu button 18 is pressed once, the most important comfort functions would be provided to the user. Generally, these functions would include functions such as AUTO/MANUAL, RECIRCULATION ON/OFF, BLOWER ON/OFF, AC ON/OFF. The electronic display 16 provides indicia in each of the four quadrants of the display area indicating either the function or the status of each function controlled by the corresponding ring-segment button. When the ring-segment button is pressed the corresponding quadrant of the electronic display is highlighted 79 . As shown in FIG. 7 , the information in the corresponding quadrant is inverted (bright background and dark lettering) as the button is depressed. Further, the quadrant remains outlined using a bold line 80 while the function remains active.
[0037] The buttons may directly toggle the setting for the function and update the electronic display 16 . For example, the upper left quadrant of the electronic display 16 includes indicia indicating the status of the MANUAL/AUTO temperature function. If the status was AUTO, “AUTO” would be displayed in the upper left quadrant of the electronic display 16 . Pressing the upper left ring-segment button 22 would index the status of the MANUAL/AUTO function and update the indicia on the electronic display 16 . Therefore, if the status was AUTO and the upper left ring-segment button 22 were pressed, the status would index to MANUAL and “MAN” would be displayed in the upper left quadrant of the electronic display 16 .
[0038] In addition, other sections of the electronic display, including the middle and periphery of the screen, may show, on demand information such as, Radio Data System (RDS) information, reception frequency, selected temperature, volume, or other useful variables.
[0039] Similar to the MANUAL/AUTO function, the upper right ring segment button 24 would index the recirculation ON/OFF setting. While the lower left ring segment button and lower right ring segment button would index the status of AC ON/OFF and BLOWER ON/OFF functions respectively.
[0040] Pressing the menu button 18 a second time will provide a menu including additional functions relating to the comfort category. This menu will specifically include functions related to air distribution and seat heating controls. Pressing the upper left ring segment button 22 increases the driver's seat heat and pressing the upper right segment button 24 increases the passenger's seat heat. Similarly, pressing the lower left ring segment button 26 decreases the driver's seat heat and pressing the lower right segment button 28 decreases the passenger's seat heat. In addition, rotation of the first knob 12 controls the air distribution settings. Further the electronic display 16 includes symbols indicating the function of each corresponding ring segment button.
[0041] The second menu button 20 provides the user with the ability to manipulate audio functions. If the second menu button 20 is pressed once, the menu will provide the user with an audio source selection. The upper left quadrant of the electronic display includes an “FM” indicator indicating the upper left ring selection button 22 controls the “FM” source selection. To visually confirm the upper left ring segment button 22 has been pressed, the “FM” in the upper left quadrant of the electronic display will be inverted. Pressing the upper left ring-segment button 22 would select the FM audio source. To continuously indicate the FM sources selection, the “FM” on the electronic display will be highlighted. These visual confirmations are depicted in FIGS. 7A and 7B .
[0042] After the FM audio source has been selected, the ring segment buttons may be used for additional functions relating to the FM audio source. For example, the upper left ring button 22 may be used for a traffic program on/off function. The upper right ring segment button 24 may be used for an auto search on/off function. While the lower left and lower right ring segment buttons 26 , 28 may be used for seek down and seek up functions, respectively. In addition, the rotatable ring portion of the first knob 12 may be used to control manual tuning of radio. Unused portions of the electronic display may be used to provide related information, such as the current reception frequency.
[0043] Referring again to the menu provided after the pressing the second menu control button 20 , the upper right quadrant includes a “CD” designation indicating the upper right ring segment button 24 selects the CD audio source. Accordingly, if the upper right ring segment button 24 is selected, the ring segment buttons may be used for CD related control functions.
[0044] The lower left quadrant includes an “AM” designation indicating the lower left ring segment button 26 selects the AM radio audio source. Accordingly, if the lower left ring segment button 26 is selected, the ring segment buttons may be used for AM radio related control functions.
[0045] The lower right quadrant includes an “AUX” designation indicating the lower right ring segment button 28 selects the AUX audio source. Accordingly, if the lower right ring segment button 28 is selected, the ring segment buttons may be used for auxiliary related control functions.
[0046] For each of the above audio sources, unused portions of the electronic display may be used to provide related information including on/off status, station, song title, artist information, etc.
[0047] Pressing the second menu button 20 a second time will provide a menu including additional functions relating to the audio category. This menu may specifically include functions related to sound control. For example, pressing the upper left ring segment button 22 selects the treble function. After the treble function is selected, the rotation of the first knob 12 adjusts the current treble settings. Pressing the upper right segment button 24 will select the bass function. The rotation of the first knob 12 therefore adjusts the current bass settings, after the bass function has been selected. Similarly, pressing the lower left ring segment button 26 selects the balance function and pressing the lower right segment button 28 selects the fade function. After the balance or fade function is selected, the rotation of the first knob 12 adjusts the current balance or fade setting respectively. If none of the functions on the menu are selected then the rotation of the first knob 12 has no effect. Further the electronic display includes symbols in each quadrant indicating the function of each corresponding ring segment button.
[0048] Referring now to FIGS. 8 and 9 , the HMI unit 10 includes a proximity sensor configured to detect if the users hand is approaching the HMI unit 10 . The controller 46 is in communication with the proximity sensor 42 and configured to display information related the HMI unit 10 on an additional display unit. In one instance, the display information is provided to the main instrument cluster 48 located in front of the driver. In another instance, the display information may be provided to a heads-up display 50 and projected into the driver's field of view. The projected display information 82 may be a duplicate of the information provided in the electronic display 16 and may even have the same graphical format. Alternatively, the information may be reformatted to better utilize the display area of the additional display unit.
[0049] The HMI unit 10 includes four additional knobs 30 , 32 , 34 , 36 located about the first knob 12 . Each of the additional knobs is in communication with the controller 16 . Each knob is rotatable and includes integrated push button capability, such that the knob will provide the controller 46 a signal when the knob is depressed. Two of the knobs, knobs 30 , 32 , are located above the first knob 12 and may control primarily audio related functions. As such, an audio control area 86 is defined where the primary audio controls are located above the first knob 12 , as indicated in FIG. 11 . Similarly, the other two knobs, knobs 34 , 36 , may control comfort related functions and define a comfort control area 84 below the first knob 12 , as indicated in FIG. 10 . Further, each knob includes a unique tactile indicator for differentiation by feel. The unique tactile indicator may include a unique knob surface profile or knob geometry. The discussion that follows is illustrative of how the knobs 30 , 32 , 34 and 36 may be employed.
[0050] The knob 30 is located on the upper left of the first knob and is configured to control the volume of the audio system when rotated. Pressing the knob 30 toggles the audio system on and off.
[0051] The knob 32 is located on the upper right side of the first knob 12 . Rotating the knob 32 controls the station selection or title selection depending on the active audio input device. One short push on the knob 32 causes the controller 46 to scan the station or skip the current song. A sustained push of the knob 32 would cause the controller 46 to store the station or add the current title to a play list.
[0052] The knob 34 is located on the lower left of the first knob 12 . The knob 34 is rotated to control the desired temperature for the driver of the vehicle. Pressing the knob 34 also activates a windshield demist function.
[0053] Located on the lower right of the first knob 12 is the knob 36 . Rotating the knob 36 controls the desired temperature for the passenger of the vehicle. The knob 36 also activates rear window heating when pressed.
[0054] A storage unit 60 may be located behind the HMI unit 10 such that the face of the HMI unit 10 acts a cover for the storage unit 60 . To access the storage unit 60 , the face of the HMI unit 10 flips upwardly, as shown in FIG. 12 , or alternatively downward. The storage unit 60 may include a cross sectional area as large as the face of the HMI unit 10 or larger. The storage unit 60 is in communication with the controller 46 to communicate with a personal device located in the storage unit 60 . For example, if a PDA (personal digital assistant) or similar device is located in the storage unit, the storage unit 60 may include a transmitter/receiver 62 to wirelessly communicate with the PDA. One such wireless communication technology is Bluetooth™. The controller 46 may communicate with the personal device to access information, such as songs, for playing in the vehicle entertainment system, contact information for use in phone or navigation systems, or various other application software to provide trip information for expense software or text or verbal information for word processing.
[0055] As shown in FIG. 13 , the HMI unit 10 also includes an integrated air register unit 90 with an audio CD drive 92 and hazard warning 94 switch. The integrated air register unit 90 provides for improved space usage and unique styling options.
[0056] As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims. | A human machine interface includes a knob with an integrated electronic display located in the center of the knob. The knob may be used for operation with multiple functions corresponding to a menu on the electronic display. A plurality of buttons are located about the knob in the form of a circle and correspond to menu selections provided on the display. | 6 |
This application is a Continuation application of application Ser. No. 09/933,163, filed Aug. 21, 2001, which is a Divisional application of application Ser. No. 09/245,743, filed Feb. 8, 1999, now U.S. Pat. No. 6,300,237, which is a Divisional application of application Ser. No. 08/584,065, filed Jan. 11, 1996, now U.S. Pat. No. 5,904,556.
BACKGROUND OF THE INVENTION
This invention relates to a semiconductor integrated circuit device and also to a method for making the device. More particularly, the invention relates to a technique which is effective when applied to an interconnection structure and an interconnecting process of LSI having multiplayer interconnections.
In recent years, integration of LSI has been in progress. This leads to increased aspect ratios (i.e., the depth of a connection hole formed on an inter-layer insulating film between a given Al interconnection and a low conductor layer, semiconductor region or a lower Al interconnection. In order to prevent the breakage of the Al interconnections in the inside of the connection holes, a so-called tungsten plug technique has been utilized wherein a W (tungsten) film is filled in the connection holes.
To fill the W film up in the connection hole, a W film is deposited, according to the CVD method, on the entire surface of an insulating film in which connection holes have been formed. Subsequently, the W film on the insulating film is etched back, thereby leaving the W film only in the connection holes. For the etching back of the W film, a F (fluorine) plasma is used. In order to prevent the underlying insulating film (silicon oxide film) from being etched out with the F plasma, a underlying layer, which is constituted of stacked films including a Ti film and a TiN film, has been formed beneath the W film.
The underlying film constituted of the Ti/TiN stacked films is very resistant to electromigration or stress migration, and has been employed for interconnection of LSI which is fabricated according to the design rule on the order of submicrons. Interconnections having such a stacked structure as of Ti/TiN/Al—Cu/TiN formed in this order and tungsten plug techniques for this are set out, for example, in LVSI Multi-level Conference Jun. 7-8, 1994, pp. 36-43.
SUMMARY OF THE INVENTION
The semiconductor integrated circuit device to which the invention is directed is of the type which comprises three-layered metallic interconnections including a first layer made of a tungsten film, and second and third layers made of an aluminium alloy film, respectively.
A titanium (Ti) film and a titanium nitride (TiN) film, both serving as a underlying layer, are provided beneath the first-layered tungsten film. The interconnection for the first layer is constituted of a three-layered structure made of Ti/TiN/W formed in this order.
Likewise, a titanium (Ti) underlying film, a titanium nitride (TiN) underlying film and a titanium (Ti) underlying film are provided beneath each of the second and third-layered aluminium alloy (Al—Si—Cu) layers. Ti/TiN cap films are provided on each of the second and third-layered aluminum alloy (Al—Si—Cu) layers. More particularly, a six-layered structure of Ti/TiN/Ti/Al—Si—Cu/Ti/TiN as viewed from the bottom is established. As a matter of course, a tungsten (W) film is filled in connection holes connecting the first and second layers and the second and third layers therewith. Each tungsten film exists in the connection hole between the titanium nitride (TiN) underlying film and the titanium (Ti) underlying film formed on the TiN film.
We found that the semiconductor integrated circuit having such an interconnection structure as set out above has the following problems.
(1) The process of filling the tungsten (W) film in the connection holes essentially requires removal of the W film from the insulating film through etching-back by use of a fluorine (F) plasma as set out hereinbefore. This permits part of the fluorine in the plasma to be left on the surface of the underlying film (Ti/TiN stacked film) formed on the insulating film and exposed by the etching-back step. The thus left fluorine reacts with titanium to provide a solid compound. Hence, the compound is left on the underlying film. When another underlying film (Ti film) is formed on the first-mentioned underlying film, or when an aluminium alloy film is deposited subsequently to the etching-back step, the bonding force at the interface between the underlying film on which the compound has remained and the film formed on this underlying film lowers by the influence of the fluorine (F) residue.
Especially, the uppermost interconnection layer partly serves as a bonding pad. When a wire is bonded to the bonding pad, the pad may separate owing to the impact of the bonding. More particularly, it has been found that the underlying film on which the compound has been left separates from another underlying film formed thereon at the bonding pad portion.
(2) The process of filling the W film in the connection holes includes the etching-back step wherein the W film is allowed to be left only in the connection holes. This requires over-etching in order to completely remove the W film from the surface of the insulating film. At the time, the W film in the connection holes is also etched out from the outer surface thereof. This leaves a step between the surface of the insulating film or the surface of the underlying film and the surface of the W film in each connection hole.
In this condition, when an Al interconnection is formed on the insulating film, the Al interconnection is stepped at a surface portion just above the connection hole owing to the above-mentioned step. If a second connection hole is formed in the interlayer insulating film just above the first-mentioned connection hole in order to connect the Al interconnection and the upper Al interconnection therewith and the second connection hole is filled up with the W film, an insulating martial made of AlF 3 is formed in the second connection hole at the time of the formation of the W film. This presents the problem that the conduction failure takes place between the Al interconnection and the upper Al interconnection.
Owing to the step appearing at the surface of the Al interconnection, the upper layer film formed on the Al interconnection suffers a coverage failure, thus Al being partially exposed from the upper layer film. The thus exposed Al reacts with F left at the time of the formation of the W film, thereby forming an insulating AlF 3 film. This is the reason why there arises the problem that the conduction failure or an increase in contact resistance between the Al interconnection and the upper Al interconnection takes place.
(3) As having set out hereinabove, the Al interconnection is constituted of multi-layered interconnection (Ti/TiN/Ti/Al—Si—Cu/Ti/TiN). Usually, an uppermost interconnection is used as a bonding pad. However, if the uppermost interconnection is constituted of this type of multi-layered interconnection and part of a passivation film covering the uppermost interconnection therewith is removed by etching to form a bonding pad, a compound formed by reaction between Al and Ti is deposited at the interface between the Al film and the upper film (Ti/TiN stacked film) formed on the Al film. This compound is so hard that the bonding force between the bonding pad and a wire lowers. It should be noted that the etching of the passivation film does not make it possible to fully remove the compound of Al and Ti.
(4) The Al interconnections are formed by depositing the Al composite film by sputtering and dry etching the deposited film. If the coverage of the Al film on deposition of the Al composite film lowers by the influence of the step formed in the underlying layer, the processing accuracy of the interconnection through dry etching unfavorably lowers. To avoid this, a so-called high temperature Al sputtering technique has been proposed. In the technique, a semiconductor substrate is maintained at high temperatures, and the Al film is deposited while re-flowing the Al film by application of heat from the substrate, thereby ensuring a good coverage of the Al.
In this connection, however, when an Al film, particularly an Al—Si—Cu film or an Al—Cu film, is deposited according to the high temperature sputtering method, a reaction product is also precipitated in the film. The reaction product is left after dry etching, thus creating another cause of lowering the processing accuracy of the Al interconnection.
It is therefore an object of the invention to provide a technique whereby a bonding pad constituted of multi-layered interconnection is prevented from separation.
It is another object of the invention to provide a technique whereby an bonding force between a bonding pad constituted of multi-layered interconnection and a wire is improved.
It is a further object of the invention to provide a technique which is able to realize a stack-on-plug structure wherein connection holes for an upper layer are located just above connection holes of an interlayer insulating film, respectively.
It is a still further object of the invention to provide a technique wherein when an Al film is deposited according to a high temperature sputtering method, any reaction product is prevented from formation as precipitated in the Al film.
These and other objects and novel features of the invention will become apparent from the following description and the accompanying drawings.
Typical embodiments of the invention are summarized below.
According to one embodiment of the invention, there is provided a method for making a semiconductor integrated circuit device which comprises the steps of:
(a) forming a first insulating film formed on a semiconductor substrate and having a plurality of through-holes;
(b) forming a first underlying film on the first insulating film and in the plurality of through-holes and forming a tungsten film on the underlying film in such a thickness that the through-holes are filled therewith;
(c) etching the tungsten film to remove the tungsten film from said first insulating film thereby exposing the surface of the first underlying film and selectively leaving the tungsten film in the through-holes;
(d) sputter etching the surface of the first underlying film;
(e) forming a first metallic film on the sputter-etched first underlying film; and
(f) electrically connecting a metallic wire to the first metallic film in regions other than regions where the through-holes are formed.
According to another embodiment of the invention, there is also provided a semiconductor integrated circuit device which comprises:
(a) a semiconductor substrate;
(b) a first interconnection film formed on the semiconductor substrate;
(c) an insulating film formed on the first interconnection film and having a plurality of through-holes;
(d) a second interconnection film connected with the first interconnection film through the through-holes and formed on the insulating film; and
(e) a bonding wire connected to the second interconnection film, wherein the first interconnection film is constituted of a first aluminium alloy film, a titanium film formed on the first aluminium film, and a first titanium nitride formed on the titanium film, and the second interconnection film is constituted of a second aluminium alloy film and a second titanium nitride film formed on the second aluminium alloy film.
According to a further embodiment of the invention, there is provided a method for making a semiconductor integrated circuit device, which method comprising forming an aluminium film on a main surface of a semiconductor substrate by sputtering, characterized in that a first aluminium film is formed on the-semiconductor substrate which is kept at a relatively low temperature, and a second aluminium film is formed at a substrate temperature which is higher than the first-mentioned temperature
According to a still further embodiment of the invention, there is provided a method for making a semiconductor integrated circuit device, which comprises the steps of:
(a) forming a first insulating film formed on a semiconductor substrate and having a plurality of first through-holes;
(b) forming a tungsten film formed on the first insulating film and in the first through-holes in such a thickness that the first through-holes are filled with the tungsten film;
(c) etching the tungsten film to remove it from the first insulating film until the surface of the first insulating film is exposed while selectively leaving the tungsten film in the individual first through-holes;
(d) forming a first aluminium film on the exposed surface of the first insulating film and on the tungsten film in the first through-holes; and
(e) re-flowing the first aluminium film at a given temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 11 and 15 to 17 are, respectively, a sectional view of an essential part of a semiconductor substrate which illustrates a method for making a semiconductor integrated circuit device according to one embodiment of the invention;
FIG. 12 is an AES spectrum chart of the surface of a TiN film prior to sputter etching;
FIG. 13 is a graph showing the relation between the content of F at the interface of Ti/TiN films and the thickness of a sputter etched titanium nitride film; and
FIG. 14 is a graph showing the relation between the intensity of F ions at the interface of Ti/TiN films and the thickness of sputter-etched titanium nitride.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention are described in detail with reference to the accompanying drawings, in which like reference numerals indicate like parts or members throughout the specification.
Reference is now made to FIGS. 1 to 17 which illustrate an embodiment of the invention applied to MOS·LSI having a three-layered interconnection structure.
Initially, as shown in FIG. 1, a semiconductor substrate 1 made of p − -type single crystal silicon is ion-implanted with a p-type impurity (boron) on the main surface thereof to form a p-type well 2 . Thereafter, a field oxide film 3 is formed on the main surface of the p-type well according to a selective oxidation (LOCOS) method. Subsequently, a gate oxide 5 is formed on the main surface of the p-type well 2 surrounded with the field oxide film 3 according to a thermal oxidation method, followed by ion implantation of a p-type impurity (boron) into the p-type well 2 , thereby creating a p-type channel stopper layer 4 in the p-type well 2 including the lower portion of the field oxide film 3 .
Next, a polysilicon film and a silicon oxide film 9 are successively deposited on the semiconductor substrate 1 according to a CVD method, followed by patterning of this two-layered film by drying etching through a photoresist mask to form gate electrodes 6 of MISFET made of the polysilicon film. The polysilicon forming each gate electrode 6 is introduced with an n-type impurity (e.g. P) in order to reduce the resistance thereof. It will be noted that the gate electrodes 6 may be constituted of a polyside film which is made of a refractory metal silicide film, such as WSix, MoSix, TiSix or TaSix, built on the top of the polysilicon film.
An n-type impurity (e.g. P) is ion-implanted into the p-type well 2 in self-aligned with the gate electrodes 6 , so that a pair of n-type semiconductor regions 7 , 7 , which constitute source and drain regions of the MISFET, are formed in the p-type well 2 at opposite sides of each gate electrode 6 .
Thereafter, a silicon oxide film is deposited over the semiconductor substrate 1 by a CVD method, followed by anisotropic etching of the silicon oxide film by a reactive ion etching (RIE) method to form side wall spacers 8 at side walls of the gate electrode 6 , respectively.
Then, as shown in FIG. 2, an oxide film 10 and a BPSG film 11 are successively formed over the semiconductor substrate 1 by a CVD method, followed by dry etching the BPSG film 11 and the silicon oxide film 10 through a photoresist mask, thereby forming a connection hole 12 arriving at one of the paired semiconductor regions 7 , 7 of the MISFET.
As shown in FIG. 3, an underlying film comprising a first underlying Ti film 13 (30 nm in thickness) and a second underlying TiN film 14 (70 nm in thickness) is deposited on the BPSG film 11 including the inner surfaces of the connection hole 12 according to a sputtering method, followed by further deposition of a W film 15 (250 nm in thickness) on the TiN film 14 by a CVD method. Subsequently, as shown in FIG. 4, the W film 15 and the underlying film (consisting of the TiN film 14 and the Ti film 13 ) are subjected to patterning through a photoresist mask, thereby forming a tungsten (W) interconnection 16 which is a first interconnection layer.
The first underlying titanium (Ti) film 13 is provided for the following reason: the film 13 is in contact with the n-type and p-type semiconductor regions (not shown) formed on the main surface of the semiconductor substrate 1 to form titanium silicide (TiSi); and hence the contact resistance can be reduced.
On the other hand, the second underlying titanium nitride (TiN) film 14 is provided in order to prevent the reaction between the gas (WF 6 ) used to form the tungsten film (W) 15 and the titanium film 13 .
As shown in FIG. 5, a first interlayer insulating film 17 is deposited on the top of the W interconnection 16 . The interlayer insulating film 17 is constituted, for example, of a three-layer film made of a silicon oxide film deposited by a CVD method, a spin-on-glass film deposited by spin coating, and a silicon oxide film deposited by the CVD method.
Next, a connection hole 18 is formed in the insulating film 17 on the W interconnection 16 by dry etching using a photoresist as a mask, followed by deposition, on the interlayer insulating film 17 including the inner surfaces of the connection hole 18 , of an underlying film consisting of a titanium (Ti) film 19 (30 nm in thickness), a titanium nitride (TiN) film 20 (100 nm in thickness) according to a sputtering method. Thereafter, a tungsten (W) film 21 (500 nm in thickness) is formed on the titanium nitride (TiN) film 20 by the CVD method.
It will be noted that the underlying titanium (Ti) film 19 is provided so that it properly controls the crystal orientation of an aluminium alloy film to be subsequently formed, thereby imparting a high electromigration resistance thereto. Likewise, the underlying titanium nitride (TiN) film 20 is provided in order to prevent the reaction between the gas (WF 6 ) used to form the tungsten (W) film 21 and the titanium (Ti) film 19 , like the afore-stated titanium nitride (TiN) film 14 .
As shown in FIG. 6, the tungsten (W) film 21 is etched back by use of a fluorine (F) plasma (e.g. SF 6 gas) to remove the tungsten (W) film 21 from the interlayer insulating film 17 but to leave the tungsten (W) film 21 only in the connection holes 18 . In order to completely remove the tungsten (W) film 21 from the interlayer insulating film 17 , the tungsten (W) film 21 has to be over-etched. This permits the tungsten (W) film 21 in each connection hole 18 to be removed to a degree, thereby establishing a step with the surface of the interlayer insulating film 17 or the underlying titanium nitride film 20 . The underlying film, particularly the TiN film 20 , formed on the interlayer insulating film 17 serves as an etching stopper at the time of the etching-back.
Then, as shown in FIG. 7, a titanium (Ti) film 22 (10 nm in thickness) and an Al—Si—Cu film 23 (400 nm in thickness) are successively deposited, by a sputtering method, on the titanium nitride (TiN) film 20 exposed at the surface thereof on the interlayer insulating film 17 . At the time, the aluminium alloy (Al—Si—Cu) film 23 has a stepped surface at position just above the connection hole 18 formed in the insulating film 17 , correspondingly stepped between the surfaces of the interlayer insulating film 17 and the W film 21 in the connection hole 18 .
To avoid this, according to this embodiment, the semiconductor substrate 1 is heated after deposition of the aluminium alloy (Al—Si—Cu) film 23 as is particularly shown in FIG. 8, so that the aluminium alloy (Al—Si—Cu) film 23 is re-flown thereby permitting the surface to be flattened. The re-flowing conditions include a substrate temperature of 450° C., a pressure of 1 mTorr, and a heating time of 180 seconds. The re-flown aluminium (Al—Si—Cu) film 23 has a surface reflectivity of 91% (wavelength: 365 nm) and is thus very flat.
Next, as shown in FIG. 9, an upper film comprising a titanium (Ti) film 24 (10 nm in thickness) and a titanium nitride (TiN) film (60 nm in thickness) is deposited on the aluminium alloy (Al—Si—Cu) film 23 by a sputtering method, followed by patterning the titanium nitride (TiN) film 25 , titanium (Ti) film 24 , aluminium alloy (Al—Si—Cu) film 23 , titanium nitride (TiN) film 20 , titanium (Ti) film 19 by dry etching using a photoresist as a mask, thereby forming an aluminium (Al) interconnection 26 which is a second layer interconnection.
The titanium nitride (TiN) upper film 25 serves as an antireflection film which prevents halation occurring during the course of the patterning of the aluminium second interconnection 26 . The titanium film 24 is provided in order to prevent formation of an aluminium nitride (Al 3 N) film when the titanium nitride (TiN) film 25 is formed on the aluminium alloy (Al—Si—Cu) film 23 .
As shown in FIG. 10, a second interlayer insulating film 27 is deposited on the top of the aluminium (Al) interconnection 26 . The interlayer insulating film 27 is constituted, for example, of a three-layered film consisting of a silicon oxide film deposited by a CVD method, a spin-on-glass film deposited by a spin coating method, and a silicon oxide film deposited by a CVD method.
Next, according to the dry etching using photoresist as a mask, a connection hole 28 is formed in the interlayer insulating film 27 at a position just above the connection hole 18 formed in the first interlayer insulating film 17 . The aluminium (Al) interconnection 26 is flattened on the surface thereof (i. e. the bottom of the connection hole 28 ) by the re-flowing. Accordingly, when the connection hole 28 is located at a position just above the connection hole 18 and then formed with a Ti film 29 , a TiN film 30 and a W film in this order, the conduction failure between the Al interconnection 26 and the upper Al interconnection layer can be appropriately prevented without formation of any insulating film in the connection hole 28 .
Then, as shown in FIG. 11, an underlying film comprising a titanium (Ti) film 29 (30 nm in thickness) and a titanium nitride (TiN) film 30 (100 nm in thickness) is deposited on the interlayer insulating film 27 including the inner surfaces of the connection hole 28 . Thereafter, a tungsten (W) film 31 (500 nm in thickness) is deposited on the titanium nitride (TiN) film 30 . Subsequently, the tungsten (W) film 31 on the insulating film 27 is etched back by use of a fluorine (F) plasma to remove the film 31 from the film 27 while leaving the tungsten (W) film 31 within the connection hole 28 . Because part of F from the plasma undesirably remains on the surface of the titanium nitride (TiN) film 30 on the top of the interlayer insulating film 27 exposed by the etching-back, the titanium nitride (TiN) film 30 is subjected to sputter etching with argon (Ar) gas to an extent of approximately 15 nm, calculated as a thermally oxidized film (silicon oxide film), thereby removing the remaining fluorine (F).
The reason why the titanium nitride (TiN) film 30 is sputter-etched on the surface thereof is that when the surface of the titanium nitride (TiN) film 30 is contaminated with the fluorine (F), bonding at the interface with a film to be further deposited lowers. More particularly, we have found that when a wire is bonded to a bonding pad in a subsequent step, separation takes place at the interface beneath the bonding pad. It will be noted that the underlying titanium nitride (TiN) film 30 may be replaced by a zirconium nitride (ZrN) film.
FIG. 12 is a graph showing AES (Auger Electron Spectroscopy) spectra of the surface of the titanium nitride (TiN) film 30 prior to the sputter etching. From the spectral analysis, the content of fluorine (F) in or on the surfaces of the titanium nitride (TiN) film 30 is calculated as 12 atomic percent.
FIG. 13 is a graph showing the relation between the content of fluorine (F) and the thickness of the sputter etched titanium nitride. The content of fluorine is determined by successively depositing, as will be described hereinafter, a titanium (Ti) film 32 and an aluminium alloy (Al—Si—Cu) film 33 on the titanium nitride (TiN) film 30 by a sputtering method and measuring the content of fluorine at the interface between the titanium nitride (TiN) film 30 and the titanium (Ti) film 32 by the SIMS analysis. For convenience's sake, the thickness of the sputter-etched titanium nitride (TiN) film 30 is indicated as a thickness of a sputter-etched silicon oxide film formed by thermal oxidation (wherein the sputter etching rate of the TiN film is 40% of the sputter etching rate of the silicon oxide film). From this, it has been calculated that the content of fluorine at the time when no sputter etching is conducted (A point in the figure) is 12 atomic percent, and the content of fluorine (F) at the time when the thickness of the sputter etched titanium nitride is 5 nm (B point in the figure) is 6 atomic percent.
FIG. 14 is a graph showing the relation between the fluorine (F) ion intensity at the interface between the titanium nitride (TiN) film 30 and the titanium (Ti) film 32 and the thickness of sputter-etched titanium nitride film (calculated as a silicon oxide film). The relation is determined from the results of the AES spectra of FIG. 12 and the SIMS analysis of FIG. 13 . The thickness of the sputter etched film and the bonding failure is shown in Table 1.
TABLE 1
Relation between the thickness of the sputter etched
film and the bonding failure
thickness of sputter etched film (nm)
0
5
10
20
30
50
bonding failure
x
∘
∘
∘
∘
∘
*The thickness of sputter etched film is calculated as that of SiO 2 .
As will be apparent from Table 1, when the titanium nitride (TiN) film 30 is not sputter etched on the surface thereof, separation in the bonding pad takes place. On the other hand, when the thickness of the sputter etched film is 5, 10, 20, 30 or 50 nm, no separation takes place. This reveals that the separation in the bonding pad can be prevented when the sputter etching is performed until the content of the fluorine (F) is 6 atomic percent or below (i.e. the thickness of the sputter etching is not smaller than 5 nm calculated as the silicon oxide film or not smaller than 2 nm for the titanium nitride film).
Since any bonding pad is formed at the second-layered interconnection (Al interconnection 26 ), the above problem does not arise. However, when the titanium nitride (TiN) film 20 is contaminated with fluorine (F) on the surface thereof, the bonding force at the interface with the titanium (Ti) film 22 being deposited thereon lowers. Accordingly, it is preferred to subject the surface of the titanium nitride (TiN) film 20 to sputter etching prior to the deposition of the titanium (Ti) film 22 . The lowering of the bonding force by the action of the fluorine (F) does not take place only when the titanium (Ti) film is deposited on the titanium nitride (TiN) film. For instance, it will be highly possible that such a lowering occurs on direct deposition of the aluminium alloy (Al—Si—Cu) film on the titanium nitride (TiN) film 20 . In the case, the titanium nitride (TiN) film should preferably be sputter etched prior to the deposition of the aluminium alloy (Al—Si—Cu) film.
Next, as shown in FIG. 15, a titanium (Ti) film 32 (20 nm in thickness) and an aluminium alloy (Al—Si—Cu) film 33 (600 nm in thickness) are successively deposited on the titanium nitride (TiN) film 30 by a sputtering method. In this embodiment, the aluminium alloy (Al—Si—Cu) film 33 is deposited at two stages. More particularly, the semiconductor substrate 1 is kept at a temperature not higher than 150° C. at which first-stage deposition is carried out at a sputtering rate of approximately 1300 to 1700 nm/minute (300 nm in thickness). Subsequently, the semiconductor substrate 1 is kept at a temperature of 250 to 350° C., at which second-stage deposition is performed at a sputtering rate of approximately 400 to 800 nm (300 nm in thickness).
The sheet resistance and reflectivity of the aluminium alloy (Al—Si—Cu) film deposited under such conditions as set out hereinabove are shown in Table 2. Point A in Table 2 shows the case where the substrate temperature is maintained at 165° C., and the aluminium alloy (Al—Si—Cu) film 33 is deposited by one stage. With points B, C and D, the substrate temperature at the second stage is, respectively, maintained at 250° C., 300° C. and 350° C., and the respective aluminium alloy (Al—Si—Cu) films 33 are formed by two stages.
TABLE 2
Resistance and reflectivity under different Al sputtering conditions
Film
Sputtering
thick-
Rate
Temperature
Sheet
Reflect-
ness of
(nm/minute)
(° C.)
Resist-
ivity (%)
AlCuSi
first
second
first
second
ance
(Wavelength:
(nm)
stage
stage
stage
stage
(mΩ)
365 nm)
A 600
1500
—
165
—
51.7
97.5
B 600
1500
600
165
250
50
97.9
C 600
1500
600
165
300
49.1
96.4
D 600
1500
600
165
350
49.6
83.3
The above results reveal that when the aluminium alloy (Al—Si—Cu) films 33 (B, C, D) are deposited by the two-stage sputtering process including a stage of a low temperature (165° C.) and a high sputtering rate (1500 nm/minute) and a stage of a high temperature (250 to 350° C.) and a low sputtering rate (600 nm/minute), they have sheet resistances and reflectivities almost the same as those of the film obtained by the one-stage sputtering process (A), but have reduced numbers of surface irregularities and precipitates of a reaction product in the film. Thus, the aluminium alloy (Al—Si—Cu) films 33 (B, C, D) exhibit a good coverage for all the cases.
As shown in FIG. 16, an upper film is further deposited on the aluminium alloy (Al—Si—Cu) film 33 . The upper film is constituted of a single-layered titanium nitride (TiN) film 34 (60 nm in film thickness). In other words, any titanium (Ti) film is not formed on the aluminium alloy (Al—Si—Cu) film 33 . If a titanium (Ti) film is provided, the compound of titanium and the aluminium alloy is formed, thereby causing the bonding failure. As a mater of course, if a titanium (Ti) film is not provided, the compound of aluminium and the nitride is formed on the surface of the aluminium alloy film. However, this compound can be removed during the step of removing the titanium nitride at the time of making an opening for the bonding pad. After the deposition of the aluminium alloy (Al—Si—Cu) film 33 , the re-flowing as set out hereinbefore may be carried out to cause the surface to be more flattened. Alternatively, after the deposition of the aluminium alloy (Al—Si—Cu) film 33 , the semiconductor substrate may be removed to outside of the sputtering apparatus, and thus the aluminium alloy (Al—Si—Cu) film 33 may be exposed to the air to form an oxide film on the surface thereof. Thereafter, the upper film (TiN film 34 ) may be deposited thereon. In the case, the formation of the compound of aluminium and the nitride can be prevented.
The procedure of forming the aluminium alloy film by the two-stage process may also be applied to the formation of the aluminium alloy film 23 of the second-layered aluminium interconnection 26 . In this case, the re-flowing step of the aluminium interconnection 26 may be omitted.
Then, the titanium nitride (TiN) film 34 , aluminium alloy (Al—Si—Cu) film 33 , titanium (Ti) film 32 , titanium nitride (TiN) film 30 and titanium (Ti) film 29 are, respectively, patterned by dry etching using photoresist as a mask to form an uppermost aluminium (Al) interconnection 35 , followed by further deposition of a passivation film 36 on the top of the aluminium (Al) interconnection 35 . The passivation film 36 is constituted, for example, of a two-layered film consisting of a silicon oxide film deposited by a CVD method and a silicon nitride film deposited by a CVD method.
Next, as shown in FIG. 17, part of the passivation film 36 is made with a hole by dry etching using photoresist as a mask, thereby exposing part of the aluminium (Al) interconnection film 35 to form a bonding pad 37 . The upper film on the surface of the bonding pad 37 (Al interconnection 35 ) is constituted of the single-layered titanium nitride (TiN) film 34 (provided that where the Al—Si—Cu film 33 is oxidized on the surface thereof, it is made of TiN film and oxide film). Accordingly, the bonding pad 37 is not deposited with the compound of aluminium (Al) and titanium (Ti) unlike the case where the upper film is constituted of a builtup film of the titanium nitride (TiN) film and the titanium (Ti) film.
Thus, according to this embodiment of the invention, when a gold (Au) wire 38 (i.e. a metallic wire) is bonded to the bonding pad 37 , good bonding force between the bonding pad 37 and the wire 38 is ensured.
Moreover, according to the embodiment, the titanium nitride (TiN) film 30 which is a part of the uppermost aluminium (Al) interconnection is sputter etched on the surface thereof to remove the fluorine (F) therefrom, so that a satisfactory bonding force at the interface between the titanium nitride (TiN) film 30 and the titanium film (Ti) film 32 deposited thereon can be attained. Thus, the bonding pad 37 does not separate such as by impact of bonding of the wire 38 to the surface of the bonding pad 37 .
In this embodiment, the upper film on the top of the uppermost interconnection is constituted of a titanium nitride (TiN) film. Accordingly, when part of the passivation film covering the uppermost interconnection is removed by etching to form the bonding pad, the reaction product of the aluminium alloy and titanium is prevented from precipitation at the interface between the Al film and the upper film.
Furthermore, the underlying film is sputter etched on the surface thereof with use of Ar gas to remove fluorine from the surface. This contributes to improving the bonding force at the interface between the underlying film and the underlying film or aluminium alloy film deposited on the first-mentioned underlying film.
The aluminium (Al) film is deposited by two stages including a first stage of deposing an aluminium (Al) film under low temperature and high sputtering rate conditions and a second stage of depositing another aluminium film under high temperature and low sputtering rate conditions. By this, the precipitation of a reaction product in the aluminium (Al) film can be prevented. Thus, the aluminium (Al) film obtained has a good coverage and a reduced degree of surface irregularities.
In addition, after deposition of the aluminium (Al) film by a sputtering method, the film is re-flown at such high temperatures that the aluminium(Al) interconnection just above the connection hole filled up with the tungsten (W) film can be flattened.
Having been described based on the embodiments, the invention should not be construed as limiting thereto. Many modifications and variations may be possible without departing from the scope of the invention.
For instance, applications to MOS·LSI having a three-layered interconnection have been set out in the embodiments, and the invention is applicable to LSI having a four-layered or multi-layered interconnection.
The effects attained by typical embodiments of the invention may be summarized below.
(1) According to the invention, the bonding force between a bonding pad and a metallic wire increases, thereby improving the reliability of connection between the bonding pad and the wire.
(2) The bonding force at the interface between the underlying films at the uppermost interconnection increases, thereby preventing separation of the bonding pad.
(3) An Al film is obtained as having a good coverage and a reduced degree of surface irregularities, thereby leading to improved processability of the Al interconnections.
(4) A stack-on-plug structure wherein an upper connection hole is made in an interlayer insulating film at a position just above a lower connection hole is realized, thereby ensuring a reduced chip area. | A method for making a semiconductor integrated circuit device comprises the steps of: (a) depositing a first underlying film made of titanium nitride, on an insulating film having a plurality of through-holes; (b) depositing a tungsten film on the first underlying film, and etching the tungsten film back by means of a fluorine-containing plasma thereby leaving the tungsten film only in the connection holes; (c) sputter etching the surface of the first underlying film to remove the fluorine from the surface of the first underlying film; and (d) forming an aluminum film on the first underlying film. The semiconductor integrated circuit device obtained by the method is also described. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a technology for classifying signals during communication and particularly to exchange, authentication, and error correction of secret keys during a classified communication using a secret key.
[0003] 2. Description of Related Art
[0004] The classification is a technology that scrambles original text (plaintext) and prevents it from being read by anyone other than interested parties who know a rule (key) of the scrambling. A sender creates encrypted text using an encryption key. A recipient decodes the received encrypted text to the original text by using a decryption key. When the encryption key is the same as the decryption key, these are referred to as common secret keys or simply as secret keys. For a data communications system, the technology for classifying communication contents is important. The conventional classification technique generally provides encryption at Layer 2 or higher according to the OSI model. No classification is applied to at least portions other than the payload at Layer 2. In an IP communication network, for example, the encryption is available for portions higher than the payload at Layer 3. No encryption is performed for IP headers or Ethernet frame headers. Accordingly, there is a problem in that a third party can directly monitor or intercept packets by means of hardware probing or using electromagnetic waves and noises generated from devices, and thus falsify a sender and a recipient or monitor the traffic.
[0005] [0005]FIG. 12 shows an applicable scope of the conventional classification. The conventional technique can classify the payload at Layer 3 or higher. The payload's header and trailer cannot be classified. However, the following information is contained in portions that cannot be classified by the conventional technique. Therefore, there are security problems just because each of the information cannot be classified.
[0006] 1. A packet header contains address information about a sender or a recipient. This information can uniquely specify the sender or the recipient and is linked to individuals and organizations. Accordingly, this information is associated with very important privacies. Falsifying or monitoring this information causes various security problems such as “disguise”, “action monitoring”, “a loss of means for specifying an intruder when an unauthorized access occurs”, etc.
[0007] 2. The packet header further contains information such as protocol types. This information can be used to specify types of services provided. Consequently, it is possible to specify whether the traffic content is mail, a Web access, or a credit card number or other confidential documents according to https etc. Falsifying or monitoring this information can enable to “disorder or stop services”, “illegally access a system or easily falsify information by specifying classified information”, and “specify and monitor services in progress”. Even if the internal information is classified according to https or the like, no classification is applied to header information in a layer lower than the associated layer. When this portion contains critical information, it is possible to “falsify or monitor information in a higher-layer header”.
[0008] 3. If a user does not intentionally classify a higher layer, the payload information is not classified. Although an ordinary classification technique can be used as a solution, it becomes possible to view a plaintext password by means of communication probing, falsify or monitor all work contents, accesses, documents, mail messages, etc.
[0009] 4. An IPv6 header contains a classified identifier that indicates classification of the payload. The IPv6 header and the IPv6 trailer are not classified. No classification is applied to the Ethernet frame or header in the lower data link layer. Generally, IPv6 is recognized to be safe because it has the classification technique by default. However, it becomes possible anew to obtain levels of importance for packets as information newly contained in the IPv6 header, transit points for source routing, classification methods, and the other information.
[0010] Classification systems include a secret key cryptosystem and a public key cryptosystem. The secret key cryptosystem uses the same key for encryption and decryption. The public key cryptosystem uses a set of an encryption key and a decryption key. The encryption key is used as a public key and is shared by parties who interchange information. Only a recipient owns the decryption key as a secret key for cryptographic processing. The secret key cryptosystem can execute 100 to 1,000 times faster than the public key cryptosystem. Generally, the public key system is used to interchange secret keys associated with the classification. However, since the public key system is accompanied by complicated computation, the hardware implementation increases implementation costs. Accordingly, the classification based on the secret key cryptosystem is optimal for the hardware implementation. However, there has been no method of easily and safely interchanging secret keys between hardware components.
[0011] As known examples, P2001-203679A uses a terminal key and a group key for double locking to hide terminals that perform the classified communication. P2000-49769A provides a technique using a public key that can be difficultly transformed to hardware. P2001-345795A uses another common secret key to interchange secret keys. JP-A No. 298470/1999 uses a separate means for distributing keys offline. P2000-261426A uses a selected selection key and a hold key to create a conversion and needs to send selection parameter information. Accordingly, the parameter and the hold key need to be interchanged as plaintext.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to complete the classification at Layers 1 and 2 even if whatever protocol is provided at a higher layer. The other object of the present invention is to provide means for: authentication to prevent a third party from being disguised as an interested party for communication; error detection in classified information; and recovery from an error state. The present invention paid attention to the following problems in the prior art.
[0013] 1. P2001-203679A hides terminals that perform the classified communication, but cannot hide a group to which the terminals belong, and cannot hide the traffic. A means for classifying all signals is required.
[0014] 2. P2000-49769A is a technique using a public key. The generally used public key cryptosystem has difficulty in implementation because many procedures are needed for a hardware configuration; a large amount of hardware is required; or the algorithm is inappropriate for parallel processing. Even if a secret key is used, the software implementation increases processing costs. Accordingly, the classification processing becomes a bottleneck for high-speed communication in which a network communication rate exceeds a processor's processing rate.
[0015] 3. P2001-345795A uses another common secret key to interchange secret keys. Since interchanging secret keys requires a key other than the secret keys needed for an interchange, a storage area is needed for that extra key, increasing the amount of hardware. Therefore, there is required a technique that does not use information other than the keys needed for the interchange.
[0016] 4. Since JP-A No. 298470/1999 uses a separate means for distributing keys offline, it is necessary to separately provide the means for distributing keys. Further, extra classification is needed for key distribution. There is required a means that does not require a communication means for the key interchange except physical signal paths for actually interchanging information.
[0017] 5. Since P2000-261426A uses a selected selection key and a hold key to create a conversion, it is necessary to send selection parameter information. The parameter and the hold key need to be interchanged as plaintext. Accordingly, it is necessary to eliminate the need for sending parameters other than the selected keys, allow the lower layer to independently and freely create a secret key, and send a key by classification. The inventors further paid attention to the following problems.
[0018] 6. It is necessary to combine the conventionally needed protocol with hardware needed for interchange procedures and encryption of secret keys, thus decreasing the amount of additional hardware needed.
[0019] 7. The safe interchange of secret keys requires authentication. When information is classified at Layer 1 or 2, an error detection means is required in a classified state. Further, when an error is detected, it is necessary to provide a means for recovery from the state including the error
[0020] In order to solve the above-mentioned problems, the present invention use the following means.
[0021] With respect to a physical configuration for classification, it is impossible to classify portions other than layers processed by the software as long as only the software classification is used. The hardware classification is needed to classify information such as the header, the trailer, etc. in a lower layer other than the payload. The hardware classification is used to provide a configuration that allows the use of plaintext only for a die in LSI or the like where internal analysis is difficult physically. This is called the complete classification.
[0022] For hardware classification, it is desirable to provide the classification using a secret key that can be easily realized by hardware.
[0023] When a classification procedure is taken into consideration, the following describes a typical procedure for a classified communication method of interchanging secret keys in communication according to the present invention.
[0024] (1) A sending side classifies its secret key KA to fA(KA) using the secret key KA and sends fA(KA) to a receiving side.
[0025] (2) When receiving fA(KA), the receiving side classifies fA(KA) to fB·fA(KA) using its secret key KB and returns fB·fA(KA) to the sending side.
[0026] (3) When receiving fB·fA(KA), the sending side converts fB·fA(KA) to fB(KA) using the sending side's secret key KA and sends fB(KA) to the receiving side.
[0027] (4) The receiving side receives fB(KA) using the receiving side's secret key KB and converts fB(KA) to plaintext to obtain the secret key KA.
[0028] The above-mentioned procedure allows the secret key KA to be transferred over the network with the confidentiality maintained. Here, the procedure uses the following commutative law.
f A - 1 · f B · f A ( K A ) = f A - 1 · f A · f B ( K A ) = f B ( K A ) Equation 1
[0029] The above-mentioned procedure is implementable by means of software or hardware. The use of this secret key interchange technique can decrease the hardware amount without requiring information such as other keys or parameters for interchanging secret keys. Further, the above-mentioned key interchange means does not need an extra communication means performed on a physical connection for actually interchanging information.
[0030] The present invention classifies a key itself during interchange of keys. After secret keys are interchanged, the present invention classifies all signals carried over an associated physical connection. Accordingly, it becomes difficult to retrieve information even if the physical connection is directly monitored. Secret keys used in the present invention may be freely generated by random numbers and the like at Layer 1 or 2 that actually performs classification.
[0031] The present invention can encrypt a secret key, safely and easily interchange it, and confirm a successful connection of outward and homeward routes, eliminating the need for an extra confirmation means. When a signal after classification is DC-balanced-encoded according to some classification conversions, an extra DC balanced encoding means need not be provided. The DC balanced encoding can encode clocks and data and ensure band characteristics of an optical fiber etc. used for communication.
[0032] The present invention includes an authentication means for ensuring safe key interchange, a means for determining an error, and, when an error is detected, a means for recovery from an erratic state. According to one aspect of the present invention, a node for performing communication comprises an encode and decode means for classification; a means for generating factors needed for the classification used by the encode and decode means; and a control means for interchanging a secret key and confirming connection of outward and homeward routes.
[0033] For example, a node apparatus implements communication classified by a secret key between two nodes. The node apparatus comprises an encoder which classifies information to be sent; a circuit which generates factors needed for the classification used by the encoder; a decoder which converts received information to plaintext; a circuit which generates factors needed for the classification used by the decoder; and a circuit which simultaneously provides control to confirm normal connection of outward and homeward routes and to interchange keys. Further, it is possible to provide sending and receiving sides with a buffer for storing keys used for authentication.
[0034] The present invention provides communication based on secret keys and enables the classification for Layers 1 and 2. This enables a safe interchange of secret keys during communication through the use of secret keys. It is possible to use both the DC balanced encoding system and the connection confirmation procedure based on Ping/Pong by expanding both mechanisms.
[0035] Accordingly, the present invention can provide a means for classifying not only information to be transmitted, but also the management or path information attendant on that information, and communication states and frequency even if a higher layer uses whatever protocol and the software or hardware is used to provide a monitoring means for directly probing a communication path. Further, there is a small increase in the amount of hardware. It is possible to provide authentication and error detection means for preventing any third party from being disguised as an interested party for communication and a means for recovery from an error state.
[0036] Other and further objects, features and advantages of the invention will appear more fully from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] [0037]FIG. 1 is a flowchart showing a communication sequence at initial connection and a flow of processing between hosts to simultaneously perform a process for confirming connection of outward and homeward routes and a process for interchanging secret keys;
[0038] [0038]FIG. 2 is a flowchart showing a communication sequence at initial connection and a flow of processing between hosts to simultaneously perform a process for confirming connection of outward and homeward routes and a process for interchanging secret keys by focusing on transmission of secret keys on a single host only;
[0039] [0039]FIG. 3 is a flowchart showing a communication sequence at initial connection and a flow of processing between hosts to simultaneously perform a process for confirming connection of outward and homeward routes and a process for interchanging secret keys by focusing on reception of secret keys on a single host only;
[0040] [0040]FIG. 4 is a block diagram showing a configuration of hardware according to the present invention;
[0041] [0041]FIG. 5 is a state transition diagram showing state transition of a communication sequence at initial connection between hosts to simultaneously perform a process for confirming connection of outward and homeward routes and a process for interchanging secret keys;
[0042] [0042]FIG. 6 is a flowchart showing state transition of some operations in a Ping/Pong control circuit as an applicable example of state transition of a communication sequence at initial connection between hosts to simultaneously perform a process for confirming connection of outward and homeward routes and a process for interchanging secret keys;
[0043] [0043]FIG. 7 depicts four types of packet formats used for performing a Ping/Pong sequence according to the present invention;
[0044] [0044]FIG. 8 is a flowchart in a transition form showing a procedure to determine whether input data in FIG. 5 is a packet used for Ping/Pong or classified data wherein the input data in FIG. 5 is information needed for state transition of operations in the Ping/Pong control circuit in FIG. 4;
[0045] [0045]FIG. 9 is a flowchart in a transition form showing determination whether or not an error occurs during classified communication and a procedure needed for recovery;
[0046] [0046]FIG. 10 is a flowchart in a transition form showing determination whether or not an error occurs during classified communication provided with an error correction code and a procedure needed for recovery;
[0047] [0047]FIG. 11 is a block diagram showing a hardware configuration provided with a authentication mechanism according to the present invention; and
[0048] [0048]FIG. 12 diagrams an applicable scope of a conventional classified connection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] Embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, a classification means uses random numbers but is not limited thereto. An error detection code in the following embodiments may be an error correction code.
[0050] (Exemplary Embodiment 1)
[0051] [0051]FIG. 1 shows a procedure for interchanging secret keys according to the present invention. When a secret key system is used, it is necessary to provide a method of safely interchanging keys between interfaces at remote places. The present invention uses a conversion capable of applying an commutative law to secret keys, i.e., a technique called double locking. The commutative law is applicable to the secret key system that generally adds terms of a random number sequence to plaintext or performs an XOR operation for these terms. The secret key system is usable for the double locking technique. When the commutative law can be applied to a conversion according to the classification, it may be preferable to reverse the order of a locking sequence and an unlocking sequence. When this feature is used, it is possible to safely interchange secret keys between interfaces. FIG. 1 shows a flow of interchanging respective secret keys between a node A 1 and a node B 2 adjacent to each other.
[0052] [0052]FIG. 2 shows a flow of sending keys when one node is focused.
[0053] [0053]FIG. 3 shows a flow of receiving keys when one node is focused.
[0054] A secret key managed by the node A 1 is assumed to be KA; a secret key managed by the node B 2 to be KB; a conversion by KA to be fA; and a conversion by KB to be fB. The respective nodes may freely generate KA and KB by using random numbers. With reference to FIG. 1, procedures will now be described by paying attention to the node A.
[0055] Procedure 1 : The node A 1 creates and uses the key KA. The node A 1 locks the key KA with the key KA itself to generate fA(KA) and sends it to the node B. Namely, the node A 1 locks its key by using the key itself and sends the same key. Since fA(KA) is classified, it is difficult to view keys during communication.
[0056] Procedure 2 : When receiving fA(KA), the node B double-locks it using the key KB the node B creates and uses. The node B converts fA(KA) to fB·fA(KA) and sends it to the node A. The data fB·fA(KA) during communication is classified.
[0057] Procedure 3 : The node A uses the commutative law (fB·fA(KA)−fA·fB(KA)) to unlock the received fB·fA(KA) using the key KA.
f A - 1 · f B · f A ( K A ) = f A - 1 · f A · f B ( K A ) = f B ( K A ) Equation 2
[0058] Since this equation is satisfied, fB(KA) is obtained. This is resent to the node B. The data fB·fA(KA) during communication is classified.
[0059] Procedure 4 : The node B unlocks the received fB(KA) using the key KB to obtain KA. Further, the node B interchanges the key KB in the same manner as for the node A (see FIG. 1). By following the above-mentioned procedures, the nodes A and B can interchange the respective secret keys without generating an extra secret key while maintaining the classification during the secret key interchange. After these keys are interchanged, they are used to classify all signals flowing through a link including an IDLE signal indicating that no information flows. Since all signals flowing through a link are classified, whether or not data flows is classified. It is difficult to intercept not only packet header information, but also even the traffic.
[0060] The keys just need to be interchanged once. Upon completion of the interchange, the interchanged secret keys can be used for communication without interchanging the secret keys again.
[0061] The above-mentioned procedures are implementable by means of software or hardware. The description here shows an example by means of hardware more appropriate for the classification.
[0062] [0062]FIG. 4 shows a hardware configuration according to the present invention. Encoders 404 and 412 use random numbers generated from corresponding random number generators 403 and 411 to classify signals from internal logics 401 and 414 . Adversely, decoders 406 and 410 use random numbers generated from random number generators 405 and 409 to convert the signals to plaintext and pass the signals to internal logics. Since secret keys are interchanged with each other, the random number generator 403 and the random number generator 409 generate the same random number sequence. The random number generator 405 and the random number generator 411 generates the same random number sequence. Accordingly, the encoder and the decoder corresponding to each of these generators can operate in pairs.
[0063] A procedure to confirm normal connection of outward and homeward routes is called Ping/Pong. In addition, Ping/Pong control circuits 402 and 408 simultaneously control a procedure for interchanging secret keys. Namely, secret keys are classified and interchanged between outward and homeward routes during a process of confirming normal connection of the outward and homeward routes at the sending and receiving sides. Each node stores a secret key interchanged at an initial connection and a secret key generated by the node itself. The node adds these secret keys to the next connection for authentication.
[0064] [0064]FIG. 6 shows an operation in the Ping/Pong control circuit. FIG. 7 show four types of packet formats used for the assumed Ping/Pong sequence. The present invention uses the following packets: Ping to send a first key; Pong as a response to Ping; Pang as a response to Pong; and Ready to indicate a communicable state.
[0065] [0065]FIG. 5 shows simplified state transition of key interchange and Ping/Pong sequences according to this system. The state transition includes a Ping state at S 501 equivalent to three interchanges of a key, a Pong state at S 502 as a response to Ping, a Pang state at S 503 as a response to Pong, and then a state capable of starting the classified communication at S 504 . FIG. 6 shows a more specific and detailed state transition diagram.
[0066] As an embodiment, FIG. 6 shows a specific state transition diagram for a means to interchange secret keys and simultaneously confirm communicability of the outward and homeward routes. At S 601 , the node A first generates its own key KA. At S 602 , the node A classifies its key KA using the same key KA to generate fA(KA). At S 603 , the node A checks if a packet arrives from the node B as a communication destination. When no packet arrives or a packet other than Ping and Pong packets arrives, the process proceeds to S 602 . When Ping is received, the process proceeds to S 604 . When Pong is received, the process proceeds to S 606 . At S 604 , the node A classifies fB(KB) included in the received Ping packet using its key KA to generate fA·fB(KB). The node A sends fA·fB(KB) together with Pong to the node B. At S 605 , the node A checks if a packet arrives from the node B. When no packet arrives or a packet other than Ping and Pong packets arrives, the process returns to S 604 . When Pong arrives, the process proceeds to S 606 . When Pang arrives, the process proceeds to S 608 . At S 606 , the node A converts fB·fA(KA) included in the received Pong packet to plaintext using its own key KA. The plaintexting process generates fB(KA) using the following equation according to the commutative law.
f A - 1 · f B · f A ( K A ) = f A - 1 · f A · f B ( K A ) = f B ( K A ) Equation 3
[0067] The node A sends fB(KA) together with Pang to the node B. At S 607 , the node A checks if a packet arrives from the node B. When no packet or Pong arrives, the process proceeds to S 604 . When Ping arrives, the process proceeds to S 602 again because the node B is considered to return to the initial state. When Pang arrives, the process proceeds to S 608 . At S 608 , the node A converts fA(KB) included in Pang to plaintext and obtains the node B's secret key KB. The key interchange process is now complete. The node A starts synchronization with the node B. The node A sends Ready at S 609 , and checks if a packet arrives from the node B at S 620 . When no packet or Pang arrives, the process proceeds to S 609 again because the node B is not Ready yet. When Ping or Pong arrives, the process proceeds to S 602 again because the node B is considered to return to the initial state. When Ready arrives, the process proceeds to S 611 and starts the classified communication.
[0068] At S 611 , the node A starts generating a random number for plaintexting at the timing when the node A receives the first classified information. The use of an error detection code helps identify whether or not the information is classified.
[0069] [0069]FIG. 7 depicts four types of packet formats used for performing a Ping/Pong sequence according to the present invention.
[0070] [0070]FIG. 8 is a flowchart in a transition form showing a procedure to determine whether input data in FIG. 5 is a packet used for Ping/Pong or classified data wherein the input data in FIG. 5 is information needed for state transition of operations in the Ping/Pong control circuit in FIG. 4.
[0071] [0071]FIG. 9 is a flowchart in a transition form showing determination whether or not an error occurs during classified communication and a procedure needed for recovery.
[0072] [0072]FIG. 10 is a flowchart in a transition form showing determination whether or not an error occurs during classified communication provided with an error correction code and a procedure needed for recovery.
[0073] As shown in FIG. 7, an error detection code is provided for each of Ping, Pong, Pang, and Ready. The means in FIGS. 8, 9, and 10 determine whether or not Ping/Pong is classified. Through the use of these means, it is possible to determine whether the procedure is classified communication or an initial Ping/Pong procedure, and to enable error detection and recovery. These procedures make it possible to confirm connected communication for both the outward and homeward routes simultaneously.
[0074] The key interchange according to the above-mentioned procedures in this embodiment performs an extended Ping/Pong procedure to confirm communicability of both the outward and homeward routes for communication between the nodes. Consequently, applying the present invention does not greatly increase the necessary traffic.
[0075] (Exemplary Embodiment 2)
[0076] The following describes a case where an error detection capability is provided to the present invention according to the embodiment 1. When there is not provided an error detection code or the like other than classified data, it is difficult to determine whether or not an error occurs just by viewing the classified content. Accordingly, the error detection first requires plaintexting, and then detects an error. At S 801 in FIG. 8, the error detection is performed on the assumption that a received Ping/Pong packet is provided with the error detection code. When no error is detected, it is assumed that a packet for correct Ping/Pong has arrived. Then, the Ping/Pong sequence is performed at S 802 . That is, the control procedure in FIG. 6 is performed. When an error is detected, two possibilities are available. One is that the error detection is unsuccessful due to classification. The other is that an error occurs actually. At S 803 , the same packet is converted to plaintext on the assumption that the packet is classified. At S 804 thereafter, the error detection at a higher layer is used to determined whether or not an error is detected. When no error is detected at S 805 , it is found that the classified communication was performed. Data is passed to a packet processing section to terminate Ping/Pong. When an error is detected at S 806 , it is found that an error actually occurred. The packet concerned is ignored. The procedure in FIG. 6 is configured to ensure the operation even if any of the Ping, Pong, Pang, and Ready packets is processed unsuccessfully. No problem arises if these packets are ignored. The following describes a recovery technique when the Ping/Pong sequence terminates and an error occurs during an interchange of the classified information. FIG. 9 shows a recovery operation when an error occurs. At S 901 , the system performs plaintexting and simultaneously generates a conversion needed for the next plaintexting. At S 902 , the system checks whether or not an error is detected during the error detection at the higher layer. When no error is detected, the communication is normal. At S 903 , data is passed to the packet processing section of the higher layer. When an error is detected, a request for forced transition to the Ping state is issued to the control circuit in FIG. 6 in order to perform the error recovery at S 904 . As a result, a Ping/Pong handshake is reperformed.
[0077] (Exemplary Embodiment 3)
[0078] Regarding the error detection capability in the embodiment 2, the following describes an embodiment of successively detecting an error by directly providing an error detection code to classified information in addition to the use of the error detection method at a higher layer. In this case, the frequency of error occurrences at an interested physical layer leaks as information. Since this information has no significance on the security, however, a leak of such information causes no problem. FIG. 10 shows a recovery operation in a classified connection having this error detection code. At S 1001 , it is determined whether or not the error detection detects an error. When an error occurs, the process proceeds to S 1004 . When no error occurs, the process proceeds to S 1002 . At S 1004 , a request for forced transition to the Ping state is issued to the control circuit in FIG. 4 in order to perform the error recovery. As a result, the Ping/Pong handshake is reperformed. When no error occurs, data arrives correctly. The Ping/Pong sequence is assumed and the error detection is performed. It is determined whether the data is classified data or Ping/Pong. When an error is detected, the plaintexting is performed at S 1005 because the classified data is received. At the same time, a conversion needed for the next plaintexting is generated. Subsequently, the data converted to plaintext is passed to the packet processing section for the higher layer. When no error occurs, the Ping/Pong sequence is performed at S 1003 .
[0079] (Exemplary Embodiment 4)
[0080] The following describes a case of providing the embodiments 1, 2, and 3 with a capability to confirm whether the other party is reliable before a classified connection is performed. If there is provided a capability of automatic reconnection in the event of disconnected communication, an unauthorized user can retrieve plaintext by temporarily disconnecting the communication and inserting another node between the existing nodes. On the contrary, if the capability of automatic reconnection is not provided, it is necessary to confirm the other party for reconnection each time a communication error occurs, complicating the management. Therefore, a means for authentication is provided. The authentication means assumes a first successful connection to be reliable and allows succeeding connections only with the first connection destination.
[0081] Each node first stores an initially interchanged secret key as an authentication key in nonvolatile memory or the like contained in the respective hardware. When an external connection is intended, the connection must be classified to prevent probing at the interface. During the classification, the second and later connections use a combination of conversions by means of the secret key and the authentication key or use both keys as parameters for the random number generation sequence as a basis. This permits communication only for the nodes that interchanged the secret key for the first time.
[0082] [0082]FIG. 11 shows a hardware configuration having an authentication mechanism. There is provided a key storage buffer S 1101 needed for authentication. Only during an initial operation, each of the Ping/Pong control circuits 402 and 408 stores the received secret key and its secret key created by itself in the key storage buffer and uses them as authentication keys. After the Ping/Pong sequence is reexecuted, the encoders 404 and 412 perform the subsequent classification based on the key created by the node A 1 or B 2 itself and the key that is initially created by the corresponding node itself and is stored in the key storage buffer. The decoders 406 and 410 perform plaintexting based on the key interchanged by the node A 1 or B 2 with each other and the key that is initially interchanged and is stored in the key storage buffer.
[0083] When one node is switched to the other, this authentication key is unnecessary. Before the authentication key is removed, it is necessary to perform a procedure to delete the authentication key beforehand or to call a manager's attention before a new connection is made. To delete the authentication key, it just needs to issue a request for deleting information about the key storage buffer in the information to be classified.
[0084] If a conversion used for the classification generates uniform random numbers, values locked by this technique can be used in place of DC balanced encoding systems such as 4B5B, 8B10B, 64B66B, etc. needed for the remote and high-speed signal transmission in order to restrict bands and encode clocks together. When uniform random numbers are used, the DC balanced encoding method provides high performance compared to 64B66B.
[0085] When a high-speed line is constructed, there are normally provided both this DC balanced encoding system and the connection confirmation procedure based on Ping/Pong. Since the present invention can be incorporated by expanding both mechanisms, the present invention will cause a small addition to hardware components and a small increase in the amount of hardware.
[0086] The foregoing invention has been described in terms of preferred embodiments. However, those skilled, in the art will recognize that many variations of such embodiments exist. Such variations are intended to be within the scope of the present invention and the appended claims. | Disclosed is a proposal for a technique of classifying communication for Layers 1 and 2 or higher, and thereby establishment of a necessary method of safely and simply interchanging a secret key, an authentication method, an error detection method, and a recovery method. It is necessary to decrease the amount of hardware needed for establishing these. We invented a hardware-based method of safely and simply interchanging a key needed for classified connection. A procedure according to the invention interchanges a key using a feature attributed to a classification conversion to which an commutative law is applicable. The procedure can simultaneously confirm normal connection of both outward and homeward routes and is also usable as an DC balanced encoding system as a result of classification. Layers 1 and 2 can be classified because the classified connection is based on hardware. Even if a signal is monitored directly or a generated noise is observed, it becomes difficult to retrieve not only information included in a packet's payload, but also information such as a header and a trailer where information such as a destination, a packet type, etc. is described, and communication state information such as a congestion degree of packets. With respect thereto, we also invented an authentication method, an error detection method, and a method of recovery from an error-detected state. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/287,657 filed Apr. 30, 2001, now pending (hereby incorporated by reference for all purposes).
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The field of this invention relates generally to a system, method and device for biometric identification, and more particularly to a system, method and portable device configured for personal identification through biometric features and/or allowing video-conferencing.
[0006] 2. General Background of the Invention
[0007] Iris recognition is one of the most accurate, reliable and convenient methods to authenticate the identity of a person. Various algorithms have been defined to reduce the pattern of the human iris into a code that may be used for identification of a person. For example, one algorithm for iris feature extraction, developed by Yong Zhu, Tieniu Tan and Yunhong Wang, is based on texture analysis using multi-channel Gabor filtering and wavelet transforms, employing 2-D information of the iris and is translation, rotation, and scale invariant.
[0008] Other use of iris identification is disclosed in certain patent references. U.S. Pat. No. 5,386,104 to Sime, the disclosure of which is incorporated by reference is titled “System and method for detecting user fraud in automated teller machine transactions.” The Doster reference discloses a self-service automated teller system including a fraud detection module which uses a biometric recognition technique, including iris scanning.
[0009] U.S. Pat. No. 5,956,122 to Doster, the disclosure of which is incorporated by reference, is titled “Iris recognition apparatus and method.” The Doster reference discloses an iris recognition apparatus and method including a camera for imaging the human retina as seen through the pupil. The Doster reference teaches that the reflective retina and pupil are imaged as a luminous or retro-reflective spot located in a field of view. A direction to the spot (i.e., the retina spot at the pupil within the iris) in the field of view is determined, and a fine-focus video camera is directed along this direction to capture an image of the iris surrounding the pupil of the eye. The captured iris image can be used for unique and individual identification of the human whose eye is imaged using known data storage, retrieval, and comparison methods.
[0010] U.S. Pat. No. 6,247,813 to Kim, et al., the disclosure of which is incorporated by reference, is titled “Iris identification system and method of identifying a person through iris recognition. The Kim reference discloses an iris identification system and method of identifying the identity of an animate being through iris scanning. The system features an iris system pick-up unit including a camera for capturing iris images to create input image signals. The iris image pick-up unit is operated with a control unit that is interfaced with a data processing unit for preprocessing the input image signals into processed data.
[0011] A need exists for convenient and portable devices that provide for biometric identification through iris recognition.
SUMMARY OF THE INVENTION
[0012] The invention as described herein utilizes a camera to capture an image (the pattern) of the iris. The captured image is then processed into an iris pattern code. As used herein an iris pattern code is any value or information that identifies the pattern of the iris of a person. Additionally, biometric features include biometric information about an individual such as the iris pattern, facial bone structure physiognomy, and retna patterns. The code is matched against a pre-stored iris pattern code to authenticate the identity of a person. The conversion of the iris pattern can be done using those algorithms and processes as known to one skilled in the art. The iris pattern code is associated to the identity of the individual. Initially, the iris pattern code is generated for an individual and information associated to that individual is stored on a electronic or optical media. For example, by way of illustration, but not limitation, the electronic or optical media, may be a hard drive, smart card, or compact disc.
[0013] The personal information of an individual and iris pattern code are preferably stored in a secured encrypted manner such that the information can not be changed or manipulated without proper access or authority.
[0014] The information associated with the iris pattern code includes various data about the individual. For example, by way of illustration, but not limitation, the information may include the individuals name, date of birth, country of citizenship, gender, eye color, height, weight, ethnicity, and organizational affiliations. Additionally, such information as visa and passport expiration dates may be associated to iris pattern code.
[0015] One aspect of the invention is a miniature camera installed into a portable communications device that allows for (1) video-conferencing, and (2) personal identification through biometric features, e.g. iris scan, facial bone structure physiognomy, to allow secure access to confidential databases and transaction capabilities, e.g., e-banking and brokerage activities. The camera has several focal distances: (a) 12-24 inches for videoconferencing, and (b) 6-12 inches for facial bone structure physiognomy recognition, and (c) 1-6 inches for iris scan. Personal biometric identification features are maintained on a central database or embedded in a microchip installed in the device.
[0016] Another aspect of the invention is a portable computer, e.g., laptop computer with a miniature camera installed, that allows for (1) video-conferencing, and (2) personal identification through biometric features, e.g. iris scan, facial bone structure physiognomy, to allow secure access to confidential databases and transaction capabilities, e.g., e-banking and brokerage activities. The camera has several focal distances: (a) 12-24 inches for videoconferencing, and (b) 6-12 inches for facial bone structure physiognomy recognition, and (c) 1-6 inches for iris scan. Personal biometric identification features will be maintained on a central database or embedded in a microchip installed in the device. The computer will be equipped with a transceiver and satellite to permit transmission of communications, including videoconferencing and biometric feature identification, via satellite.
[0017] Another aspect of the invention is portable computer, e.g., laptop computer, with an installed miniature camera installed that allows for (1) video-conferencing, and (2) personal identification through biometric features, e.g. iris scan, facial bone structure physiognomy, to allow secure access to confidential databases and transaction capabilities, e.g., e-banking and brokerage activities. The camera has several focal distances: (a) 12-24 inches for videoconferencing, and (b) 6-12 inches for facial bone structure physiognomy recognition, and (c) 1-6 inches for iris scan. Personal biometric identification features are maintained on a central database, embedded in a microchip installed in the device, or other electronic medium. The computer has a port to connect with a satellite telephone unit to permit transmission of communications, including videoconferencing and biometric feature identification, via satellite.
[0018] Another aspect of the invention is a desktop device utilizing biometric iris identification and authentication for credit card, bank card or smart card transactions. The device may be connected into a point of sale system. The first camera is used for video conferencing. The second camera is used for iris recognition. The iris camera captures the pattern of the iris. The captured image is processed into an iris pattern code. The code is checked against a pre-stored code to authenticate the user. The first camera has focal distances 12-24 inches for videoconferencing. The second camera has focal distances of 6-12 inches for facial bone structure physiognomy recognition, and 1-6 inches for iris scan.
[0019] Another aspect of the invention is a portable device that may be used at airports, check points, security zones or carried by patrol police. The device has a built-in camera that captures the pattern of the iris. The captured image is then processed into an iris pattern code. The code is matched against a pre-stored code to authenticate the person. The device may have a resident database with iris pattern codes for individuals. Additionally, the portable device may be connected to a network or through wireless communications such as cellular telephony or satellite communications to access a remote database. The camera has focal distances of 6-12 inches for facial bone structure physiognomy recognition, and 1-6 inches for iris scan.
[0020] Another aspect of the invention is a computer keyboard that has two built-in cameras. One camera is used as a video conferencing camera. The other camera is an iris identification camera. The first camera has focal distances 12-24 inches for videoconferencing. The second camera has focal distances of 6-12 inches for facial bone structure physiognomy recognition, and 1-6 inches for iris scan. The iris camera captures the pattern of the human iris. The captured image is processed into a numeric or alphanumeric iris pattern code. The iris pattern code is checked against a pre-stored iris pattern code at the computer or at a smart card. The keyboard has a smart card reader. The computer keyboard may utilize a combination camera that provides for video conferencing and iris recognition. The keyboard is attached to a computer which processes the iris pattern of the eye.
[0021] Another aspect of the invention is a computer monitor or display device with two built-in cameras. The first camera is used for video conferencing. The second camera is used for iris recognition. The first camera has focal distances 12-24 inches for videoconferencing. The second camera has focal distances of 6-12 inches for facial bone structure physiognomy recognition, and 1-6 inches for iris scan. The camera used for iris identification captures the pattern of the iris. The captured image is processed into an iris pattern code. The code is checked against a pre-stored code to authenticate the user. The computer monitor or display device may utilized a combination camera that provides for video conferencing and iris recognition.
[0022] The inventive devices have particular utility for use with networked applications, especially with Internet-based applications. For example, an Internet application may require authentication of a user by biometric means, with the devices discussed herein, the user of a device may readily scan his iris pattern and submit a generated iris pattern code to the networked application. The networked application use that iris pattern code to determine access and authorization for security purposes. The application may store an second iris pattern code remotely and non-accessible by the user. The networked application may then compare the generated iris pattern code with the remotely stored iris pattern code. Upon verification of a match, then the networked application may provide authorized access. The verification for example may be used to verify identity before authorizing a financial transaction, such as a credit card or electronic funds transfer.
[0023] The iris scan camera as used with the devices described herein, preferably adjusts the focus of the camera to obtain a clear reading of the iris. However, a manual focus camera may also may utilized.
[0024] Another aspect of the invention is a biometric identification system including a computer processing unit coupled with an iris scanning camera. A magnetic card reader is coupled with the computer processing unit for reading a first iris pattern code stored on a magnetic card. The computer processing unit is configured (in other words pre-programmed) to process the image of an iris of a person to generate a second iris pattern code. The image of the person's eye is obtained from the iris scanning camera. The computer processing unit is configured to compare the first iris pattern code with the second iris pattern code to determine if a match exists between the new iris pattern code and the one or more iris pattern codes.
[0025] Another aspect of the invention is a biometric identification system including a computer processing unit coupled with an iris scanning camera. A database is coupled with the computer processing unit. The database is populated with one or more iris pattern codes of individuals. The computer processing unit is programmed to process an image (obtained through the camera) of an iris of a person to generate a new iris pattern code. The computer processing unit is configured to compare the new iris pattern code with the one or more iris pattern codes housed on the database to determine if a match exists between the new iris pattern code and the one or more iris pattern codes.
[0026] Another aspect of the invention is a method of biometric identification. The method includes storing a first iris pattern code on a magnetic media, converting an image of a person's iris to a second iris pattern code, and comparing the first iris pattern code with the second iris pattern code to determine if a match exists between the first iris pattern code and the second iris pattern code. The first iris pattern code is preferably encrypted such that no one can tamper with the code. The first iris pattern code may be stored on and read from a smart card, other electronic media or a database of one or more iris pattern codes.
[0027] Accordingly, one many objects of the invention is to identify the iris of an individual to determine their identification utilizing a portable communications device, such as a cellular telephone, or a portable computer.
[0028] It is yet another object of the invention to perform iris identification in remote locations.
[0029] Another object of the invention to provide a portable communications device or portable computer that allows for video-conferencing, and personal identification through biometric features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] A better understanding of the invention can be obtained from the detailed description of exemplary embodiments set forth below, when considered in conjunction with the appended drawings, in which:
[0031] [0031]FIG. 1 is an illustration of a portable biometric identification device having a camera for personal identification through biometric features;
[0032] [0032]FIG. 2 is an illustration of a portable computer having a camera for video-conferencing, and personal identification through biometric features;
[0033] [0033]FIG. 3 is an illustration of a keyboard having a camera for video-conferencing, and personal identification through biometric features; and
[0034] [0034]FIG. 4 is an illustration of a self-contained unit for personal identification through biometric features; and
[0035] [0035]FIG. 5 is an illustration of a monitor having a camera for video conferencing, and personal identification through biometric features.
DETAILED DESCRIPTION
[0036] [0036]FIG. 1 is an illustration of a portable biometric identification device having a camera for personal identification through biometric features. The biometric identification device 10 has an digital camera for iris recognition 11 . A central processing unit is coupled to the digital camera. The portable device may have software for translating the image of the iris to a iris pattern code stored in firmware (such a microchip) or a hardrive on the unit. This desktop/counter-top device is especially useful for credit card, bank card or smart card transactions utilizing biometric iris identification and authentication. The device may be connected into a point of sale system. The digital camera for iris recognition 11 is preferably positioned at the top portion of the body of the portable device. The device for example may be positioned on a counter-top and a person whose identity is to be authenticated peers into the camera. The angle of the camera may be repositioned to accommodate different heights of persons peering into the camera. The device has one or more ports to allow for connection to a point of sale system. Additionally, the portable device has a card reading device 12 to allow reading of an iris pattern code from a smart card or other card that allows for the storing of magnetic or optical data.
[0037] [0037]FIG. 2 is an illustration of a portable computer (more commonly referred to as a laptop) 20 having a camera that allows for video-conferencing 21 , and a camera 22 used for personal identification through biometric features. The improved portable computer 20 provides for easy biometric identification and video-conferencing. The video-conferencing camera 21 and digital camera for iris recognition 22 also may combined in a single unit. The video-conferencing camera 21 captures video streams and images of the user of the laptop. This allows for video communication with an intended recipient. The digital camera for iris recognition 22 scans the pattern of the iris. The laptop can be configured such that use of the laptop is limited to an individual having an authorized iris pattern code. The iris pattern code may be stored on a portable computer resident-database or chip embedded in the laptop. Likewise, the iris pattern code may be remotely stored and accessible if the laptop has wireless communication functionality, such as a PC card for cellular communications or a connection for satellite telephony. If the portable computer is network accessed, access to the computer network may be limited to those users having authenticated iris pattern codes. The cameras are preferably positioned at the top of the screen. This allows the user to move the screen to the appropriate angle for iris scanning.
[0038] [0038]FIG. 3 is an illustration of a keyboard having a camera for video-conferencing, and personal identification through biometric features. The video-conferencing camera 33 and digital camera for iris recognition 32 also may be combined in a single unit. The keyboard 30 has a digital camera for iris recognition 32 and a camera 33 for video-conferencing. An adjustable platform 31 allows the keyboard user to adjust the angle of the platform 31 and cameras. Additionally, the keyboard 20 has a card reader 34 for reading a smart card or other digital card having an iris pattern code stored therein. The keyboard can be interfaced with a computer thereby providing a convenient way to provide a way to enable the CPU with iris authentication. The keyboard has a cable for connecting the keyboard to a computer. The cable may be a USB cable, serial cable, or other interface cable providing transmission of the video information to a computer.
[0039] For example, the operating system of the interfaced CPU may employ security software to require authentication of the user by iris authentication. A image obtained by the digital camera for iris recognition is processed by the CPU which generates an iris pattern code. The generated iris pattern code may then be authenticated with an iris pattern code stored on a database accessible by the CPU or other electronic media or other storage devices. Additionally, the iris pattern code may be stored on a smart card. The CPU may uses the stored iris pattern code to authenticate the user.
[0040] Now referring to FIG. 4, a self-contained unit for personal identification through biometric features is illustrated. The self-contained unit 40 , has a display device 41 , and adjustable holder 43 holding a digital camera for iris recognition 42 , a manual input device (as shown a keyboard) 44 , and a electronic card reader 45 (as shown a smart card reader). The devices are coupled to a central processing unit. A resident database may be interfaced to the central processing unit. Likewise the self-contained unit may employ wireless communications, such as cellular or wireless telephony for access to remote databases. This device is especially useful for setting up security checkpoints. For example, a resident database may be populated with iris pattern codes associated with information about individuals. Any person passing through the security checkpoint must be authenticated. The device will read the iris pattern of an individual and convert it to an iris pattern code. If the iris pattern code does not match those iris pattern codes on the database, then the person is not authorized to pass the security checkpoint.
[0041] [0041]FIG. 5 is an illustration of an improved monitor having a camera for video-conferencing, and personal identification through biometric features. The monitor 50 has a digital camera for iris recognition 52 and a camera 51 for video-conferencing. The video-conferencing camera 51 and digital camera for iris recognition 52 also may combined in a single unit. A flat LCD screen monitor 50 with a stand 53 is illustrated in FIG. 5, but any monitor size or type may be used. The cameras are moveable to allow adjustment of the orientation and angle of the cameras. Additionally, the monitor may have for a smart card reader or other digital card reader 54 to read a card having an iris pattern code stored therein. The monitor can be interfaced with a computer thereby providing a convenient way to provide iris authentication. The monitor 50 has a cable for connecting the monitor 50 to a computer. The cable may be a USB cable, serial cable, or other interface cable providing transmission of the video information to a computer.
[0042] For example, the operating system of the interfaced CPU may employ security software to require authentication of the user by iris authentication. The CPU will scan the iris pattern of the user using the digital camera for iris recognition and generate an iris pattern code. The generated iris pattern code may then be authenticated with an iris pattern code stored on a database accessible by the CPU or other electronic media or other storage devices. Additionally, the iris pattern code may be stored on a smart card. The CPU may uses the stored iris pattern code to authenticate the user.
[0043] Additionally, the self-contained unit may be used to electronically authenticate the identity of a person holding an identification card. For example, the iris pattern code of a person may be stored on an identification card. The iris pattern code is preferably encrypted such that the iris pattern code on the card can not be manipulated. The iris pattern of the individual is taken by the digital camera for iris recognition 42 . The individual inserts the identification card into the electronic card reader 45 . The self-contained unit the decrypts the encrypted iris pattern code and compares the stored iris pattern code from the identification card to that of the generated iris pattern code. The self-contained unit indicates whether a match between the code exists.
[0044] Moreover, the embodiments described are further intended to explain the best modes for practicing the invention, and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appending claims be construed to included alternative embodiments to the extent that it is permitted by the prior art. For example, in lieu of the biometric features of the iris pattern, one could utilize the facial bone structure physiognomy of a person or use the retnal pattern of a person eye. | A system, method and apparatus for biometric identification employing an iris scanning camera for biometric identification of a person. An iris scanning camera is coupled with a laptop, keyboard, or employed in portable unit. An iris pattern code for an individual is stored on a database, or other electronic media. The CPU of the portable device or a CPU of an attached or remote computer if utilizing the keyboard, converts the reading of an iris pattern into an iris pattern code. The stored iris pattern code is compared with the generated iris pattern code and a an iris pattern code match is determined. | 6 |
FIELD OF THE INVENTION
[0001] The invention concerns a method and system for water dew point depression in subsea transport of produced gas.
BACKGROUND
[0002] In development of remote or marginal offshore oil and gas fields, subsea developments are often selected in order to reduce investments in production facilities. Although the hydrocarbons produced on site need processing, the number of subsea process units is preferably low and the units of reduced complexity for minimal maintenance and in order to avoid malfunctions. For further processing it is desirable to utilise process capacity within existing infrastructure either offshore or onshore, which may require transportation over long distances by pipelines.
[0003] The hydrocarbon well fluid will often contain both oil and gas which may be separated in a subsea separation unit and then either transported separately to the same processing unit or be transported to different processing units to utilize capacity of surrounding infrastructure. The produced hydrocarbon-containing fluid is warm when entering the wellhead, generally in the range of 60-130° C. and will in addition to hydrocarbons contain liquid water and water in the gas phase corresponding to the water vapour pressure at the current temperature and pressure. If the gas is transported untreated over long distances, it will cool, the water in gas phase will condense and below the hydrate formation temperature, hydrates will form. The hydrate formation temperature is in the range of 20-30° C. between 100-400 bara.
[0004] Hydrates are ice-like crystalline solids composed of water and gas, and hydrate depositions at the inside wall of gas and/or oil pipelines is a severe problem in today's oil and gas production infrastructure. When warm hydrocarbon fluid containing water flows through a pipeline with cold walls, hydrates will precipitate and adhere to the inner walls. This in turn will reduce the pipeline cross-sectional area, which without proper counter measures will lead to a loss of pressure and ultimately to a complete blockage of the pipeline or other process equipment. Transportation of gas over distance will therefore normally require hydrate control.
[0005] Existing technologies that deal with the problem of removing such deposits or avoiding them include:
Addition of inhibitors (thermodynamic or kinetic), which prevent hydrate deposition. Electric heating and insulation keeping the pipeline warm (above the hydrate appearance temperature). Mechanical scraping off the deposits from the inner pipe wall at regular intervals by pigging.
[0009] To avoid formation of hydrate, a thermodynamic or kinetic hydrate inhibitor can be added, such as an alcohol (methanol or ethanol) or a glycol such as Monoethylene Glycol (MEG or 1,2-ethanediol), which is inexpensive and simple to inject. However, if the water content is high, proportional large amounts of inhibitor are needed which at the receiving end or on site will require a hydrate inhibitor regeneration process unit with sufficient capacity to recover and recycle the inhibitor. A recovery may be performed by a MEG regeneration unit, but will contribute to an increase in both costs and investments, especially if installed on site at subsea level.
[0010] Therefore, there is a need for removing both liquid water and water in the gas phase from a produced hydrocarbon-containing fluid, wherein the ratio of liquid and gas phase is dependent on the water vapour pressure at the prevailing temperature and pressure. The water removal in a hydrocarbon-containing gas, or the water dew-point depression, should be performed before the temperature of the fluid drops below the hydrate formation temperature and. In addition, reduced quantities of hydrate inhibitors compared to prior art should be used to avoid regeneration at subsea, i.e. before long transport by pipeline subsea in cold sea water, such as 5 km or more, for example 10, 20, 30, 50, 75 or 100 km or more.
[0011] Electric heating above the hydrate formation temperature is very expensive due to both high installation and operational costs. Accordingly, electric heating is not feasible for long-distance transport.
[0012] Another method to reduce or avoid the use of hydrate inhibitor is to insulate the pipeline and reduce the diameter to increase the flow rate and thereby reduce temperature loss and water accumulation. If the pipeline is not too long, such as in the order of 1-30 km, it will be possible to keep the temperature above the hydrate formation temperature, at which hydrates form. However, this reduces the operational window of the pipeline, and it will not have capacity for future higher gas rates and cannot be operated at low gas rates. Boosting might also be required, as the pipeline pressure drop will be important due to a small sized pipeline. In addition, hydrate formation will occur during production stops and shut downs as the hydrocarbons are cooled below the formation temperature.
[0013] Pigging is a complex and expensive operation. If no loop is available, a pig has to be inserted sub-sea using remote-operated vehicles. If more hydrates are deposited than the pig diameter is designed for, the pig might get stuck in the pipeline, resulting in costly operations and stop in production to remove the pig.
[0014] RU 2199375 concerns a method for absorption drying of hydrocarbon gas by using a primary separation step and a cooling step where the gas temperature and dew point of gas is controlled by addition of an absorbent before the cooler, and a second separation step where the absorbent is regenerated for further transport of the gas. The removal of bulk water in the first separation step reduces the load on the absorber, but with the use of an absorber at least one regeneration unit is necessary, which is undesirable in subsea installations.
[0015] U.S. Pat. No. 5,127,231 concerns the treatment of a gas from a production well by contacting the gas with a liquid phase, containing water and anti-hydrate additive, in a unit separating off a liquid phase and an additive charged gas which is transported over long distances, which may be several kilometres. An almost conventional drying process is described involving a contactor with absorbent (glycol). The gas is cooled during transport before entering a heat exchanger where condensate of water solvent and additive is separated from the gas in a settlement vessel. The liquid phase is recycled to the production site. Hence, anti-hydrate additive is added during the first separation and is present during the main transport before cooling, after which the additive is separated at the end reception terminal where the gas is treated.
[0016] The methods described above make use of recirculation of anti-hydrate additive introduced during the first separation step on the well stream. This introduction of additive necessitates an absorber unit for regeneration of the additive.
[0017] CA 2,040,833 concerns a method for preventing formation of hydrates in subsea piping by passing a well stream through a separator at controlled pressure, and boiling off light hydrocarbons form the liquid phase in such an extent that substantially no hydrates are formed. The formation may additionally be prevented by addition of glycol as hydrate inhibitor. The choking of the well stream to evaporate light components and water, results in a reduced pressure, which must be regained by a compressor. Depending on the gas/oil ratio (GOR) the amount of water and the composition of the stream resulting from the pressure reduction will vary and the application is therefore limited to fluids with a suitable phase diagram. In addition the entire well stream is cooled in this document, which requires a large capacity cooler.
[0018] An important object of the present invention is to reduce the number of process units at subsea and to minimize the amount of anti-hydrate additive is used, so that the gas phase from a production well that may be transported over large distances in cold water without causing hydrate formation, while requiring no or little additive regeneration when reaching a process unit.
SHORT DESCRIPTION
[0019] The invention concerns a method and system for water dew point depression subsea to avoid hydrate formation by water removal from produced gas. The purpose of the invention is to reduce the water content in a produced gas to an acceptable level where the amount of hydrate inhibitor needed is correspondingly low.
[0020] In one aspect the invention concerns a method for water dew point depression subsea in a produced multiphase hydrocarbon fluid stream containing water, the method comprising the steps of:
i) separating the hydrocarbon fluid stream into a first liquid phase and a first gas phase; ii) cooling the first gas phase in a controlled manner to knock out water or condense water and optionally other condensates into a second liquid phase while keeping the fluid above a hydrate formation temperature thereof; and iii) separating off the second liquid phase and a second gas;
wherein the second gas phase has a water dew point which is lower than that of the first gas phase and/or the initial multiphase hydrocarbon fluid stream.
[0024] In this manner the first gas phase is cooled down to a temperature above 20° C., or in the range of 20-30° C., or about 25° C., and in addition the cooled first gas phase may be free of hydrate inhibitor and/or absorbent.
[0025] A hydrate inhibitor may then be added to the second gas phase before further transport over a distance subsea. Also, the second gas phase may be compressed before addition of hydrate inhibitor and transported over a distance subsea.
[0026] Further, the method may comprise the additional steps of:
iv) adding hydrate inhibitor (such as a small amount) to the second gas phase; v) cooling the second gas phase in a controlled manner to knock out water or condense water and optionally other condensates into a third liquid phase; and vi) separating off the third liquid phase and a third gas phase;
wherein the third gas phase has a lower water dew point than the second gas phase, and/or the first gas phase and/or the initial multiphase hydrocarbon fluid stream.
[0030] The cooling step v may be performed by a heat exchanger using surrounding seawater or a cooling medium, or it may be done by choking the gas stream to obtain Joule Thomson cooling, or a combination of heat exchanging and choking.
[0031] The second gas phase may hence be cooled down to a temperature below 0° C., or in the range of about 0-25° C., or in the range of about 0-4° C., or to about the surrounding seawater temperature.
[0032] Hence, the second gas phase may be cooled down to a temperature of about sea temperature, or below sea temperature. With this additional cooling no liquid water drop out will occur in the gas pipeline if kept at the same pressure or lower pressure. Further inhibition of the third gas phase is therefore normally not necessary. Inhibitor injection (such as glycol) may still be required depending on degree of cooling by choking, hence water dew point depression, and dependent on pressure increase by compression.
[0033] Additionally, a hydrate inhibitor may be added to the third gas phase before further transport over a distance subsea. Also, the third gas phase may be compressed before optional addition of hydrate inhibitor and transport over a distance subsea.
[0034] In one alternative the cooled second gas phase may be choked after cooling in step v) and before separation in step vi) in order to further cool the gas, and the second gas phase may hence be cooled down to a temperature of about sea temperature, or below sea temperature.
[0035] In a further alternative, liquid water may additionally be separated from the produced multiphase hydrocarbon fluid stream in step i) and said separated liquid water may be re-injected in sub terrain formations.
[0036] In another alternative the second liquid phase of knocked out water or condensed water and other condensates from the separation in step iii) and optionally the third liquid phase from step vi) are mixed with the first liquid phase from the separation in step i). In yet another alternative the second liquid phase of knocked out water or condensed water and other condensates from the separation in step iii) and optionally the third liquid phase from step vi) are recycled to the separation in step i), optionally by use of a pump.
[0037] The first liquid phase, optionally mixed with the second luquid phase and optionally the third liquid phase may be transported to further processing plants, alternatively with the help of boosting.
[0038] The hydrate inhibitor(s) may be chosen from one or more of:
thermodynamic inhibitors, such as alcohols, e.g. ethanol, methanol, glycols, such as monoethylene glycol (MEG), diethylene glycol (DEG) or triethylene glycol (TEG), or amines such as monoethanolamine (MEA) or methyldiethanolamine (MDEA); or kinetic inhibitors or anti-agglomerants, known as low dosage hydrate inhibitors (LDHI), e.g. polyemers, copolymers or surfactants.
[0041] With the additional steps above, a hydrate inhibitor may alternatively be added to the second gas phase before cooling and the cooled second gas phase may be choked after cooling in step iv) and before separation in step v).
[0042] In a second aspect the invention concerns a system for water dew point depression subsea in a produced multiphase stream, wherein the system comprises:
i) a first separator having a multiphase stream inlet, a first gas phase outlet and a first liquid phase outlet; ii) a first gas cooler with temperature control for water knock out having an inlet and outlet; and iii) a second separator having an inlet, a condensate outlet and a gas outlet;
wherein the gas phase outlet of the first separator is in fluid communication with the gas cooler inlet and the gas cooler outlet being in fluid communication with the second separator inlet and wherein gas exiting the second separator gas outlet has a water dew point which is lower than that of the multiphase stream entering the first separator.
[0046] The gas outlet of the second separator may be connected to a gas transport conduit for further transport subsea and the gas transport conduit may also comprise an addition point for hydrate inhibitor.
[0047] In addition, the gas transport conduit may comprise a compressor or pump, and in the case of the presence of an hydrate inhibitor addition point the compressor or pump is positioned upstream of said addition point.
[0048] Further, the system above may additionally comprise:
iv) an addition point for hydrate inhibitor; v) a second gas cooler with temperature control for water knock out having an inlet and outlet; and vi) a third separator having an inlet, a condensate outlet and a gas outlet;
wherein the second separator outlet is in fluid communication with the inlet of the second gas cooler, said fluid communication comprising the addition point for hydrate inhibitor, and wherein the second gas cooler outlet is in fluid communication with the third separator inlet and wherein gas exiting the third separator gas outlet has a water dew point which is lower than that of the fluid entering the second separator.
[0052] The gas outlet of the third separator may be connected to a gas transport conduit for further transport subsea and the gas transport conduit may comprise a further addition point for hydrate inhibitor. In addition, the gas transport conduit may comprise a compressor or pump and in the case of the presence of an hydrate inhibitor addition point the compressor or pump is positioned upstream of said addition point.
[0053] The conduit connecting the second separator outlet with the inlet of the second gas cooler and said conduit comprises a hydrate inhibitor addition point.
[0054] In another alternative, a conduit connects the second gas cooler outlet to the inlet of the third separator wherein said conduit comprises a regulating choke.
[0055] A compact separation technology may be used for one or more of the separators, such as inline separation technology or a scrubber. Also, the first separator may be a three-phase separator comprising a fluid inlet, a gas phase outlet, a liquid condensate outlet and a liquid water outlet. Further, the liquid water outlet of the three-phase separator may be connected to a wellhead for re-injecting in sub terrain formations.
[0056] The condensate outlets of the separators may be connected to a conduit for transport to a further processing plant, optionally connected to a pump or compressor for boosting of said transport. Alternatively one or both of the condensate outlets of the second and third separators are connected to a conduit for recycling said condensates to the first separator.
[0057] Hence, by using a subsea cooler, the present invention avoids pressure reduction and is flexible with regards to what cooling temperature is required.
[0058] In addition the resulting liquid phase remains warm, and having a much greater heat capacity than the gas phase, the separated liquid stream may be transported over long distances, such as from 5 km or more, before it is cooled to the extent that hydrates form. Hence, the method according to the present invention is also suitable for liquid dominated systems.
[0059] None of the known applications use a separator-cooler-scrubber setup as in the present invention in order to remove water and then transferring the gas with minimum injection of hydrate inhibitor. Also, none of the known processes combines a water knock-out process with a gas transport process.
DRAWINGS
[0060] The invention will in the following be described in further detail by example embodiments with reference to the appended drawings, none of which should be construed as limiting the scope of the invention.
[0061] FIG. 1 shows a schematic view of a subsea plant for water dew point depression and water removal according to the present invention.
[0062] FIG. 2 shows a schematic view of an alternative embodiment of a subsea plant for water dew point depression and water removal according to the present invention.
DETAILED DESCRIPTION
[0063] In the following, it is of importance to specify certain differences between the two terms of “water removal” and gas “drying”.
[0064] “Water removal” means removing a bulk amount of water from a stream and does not result in a dry gas per se. In the example shown later in the example embodiments, about 97% of the water is removed by cooling which for practical use is considered as a removal of almost all water. During transport of the gas, the above removal of water will make it necessary to add much less hydrate inhibitor than if no water had been removed by cooling.
[0065] “Gas drying” concerns the drying of a gas in order to satisfy a specification of a pipeline, which often requires having a water dew point of −18° C., and wherein the water content must be reduced to the ppm-range to satisfy such requirements.
[0066] The most common method for achieving gas drying is by the aid of absorption wherein water is absorbed by an absorbent. The absorbent may for example be a glycol, such as TriEthylenGlycol (TEG). The mentioned need for a low level of water content by use of absorption also requires a regeneration plant in order to remove water from the glycol.
[0067] Another method to obtain such low water content in gas drying is by the aid of expansion and thereby cooling. This method may be performed by a valve or a (turbo) expander, where the work generated by the expanding gas may be re-used in a compressor in order to partly regain the pressure. The temperature of an expander may reach very low temperatures, such as below −25° C., and it is therefore necessary to add a hydrate/ice inhibitor to the gas before it enters the expander.
[0068] The present invention concerns water dew point depression and water removal and not gas drying in order to satisfy the need for few components and secure operations with low maintenance needs.
[0069] By “dew-point depression” is understood the process of reducing the liquid-vapour dew point of a gas by removing a fraction of the liquid from the gas.
[0070] By “water knock-out” is understood the removal of water by condensation.
[0071] FIG. 1 shows one embodiment of a process layout for a system and method according to the invention wherein a multiphase hydrocarbon-containing well stream in a pipeline 1 is first separated into a first gas phase in a conduit 2 and a first liquid phase in a conduit 3 by a first separator 10 , which may be a conventional separator or of more compact separation technology, e.g. of inline separation technology.
[0072] The separator 10 may be a two-phase separator or more preferably a three-phase separator as shown in FIG. 1 . In the former case of a two-phase separator, gas is separated from a mixture of hydrocarbon and water in a liquid phase exiting in conduit 3 . In the latter case as shown in FIG. 1 , the liquid phase is additionally separated into a separate liquid water phase in conduit 4 and a liquid hydrocarbon phase is separated out in conduit 3 .
[0073] The composition and phase distribution of the well stream may vary according to temperature, pressure and the specific production field, but will often contain a certain amount of water of which the bulk part is separated off in separator 10 . The separated liquid water phase in conduit 4 may lead to a well head 40 to be re-injected in the sub terrain formations.
[0074] The first gas phase in conduit 2 is then cooled in a multiphase gas cooler 20 to a temperature as low as possible to knock out water, but not into the hydrate formation temperature region. The gas and condensed liquids of water and condensate are passed from the cooler 20 by conduit 5 to a second separator 30 such as a condensed water scrubber, where they are separated into a second liquid phase exiting in conduit 6 and a second gas phase exiting the second separator by conduit 8 . The second separator 30 may be a conventional separator or of more compact separation technology, e.g. of inline separation technology or a scrubber.
[0075] The condensed liquids in the second liquid phase from the second separator 30 leaving in conduit 6 are mixed with the first liquid phase 3 , which may be a mainly a hydrocarbon stream, from the first separator to a combined liquid phase in conduit 7 . A regulating valve 60 on conduit 3 upstream of the mixing point of conduits 6 and 3 may be present, in order to prevent flashback into the first separator and/or to regulate the mixing rate and composition of said streams. Said combined liquid phase being warm, may be transported over long distances as mentioned above before cooling to a temperature level of hydrate formation occurring.
[0076] The reduction in water content of the first gas phase in conduit 2 in relation to the second gas phase in conduit 8 , is in the range of 80-98% or about 97%, by the use of the cooler 20 and separator 30 .
[0077] A pressure increasing device such as a compressor 50 or pump may in addition be installed on the resulting second gas phase stream of conduit 8 , wherein the second gas phase will exit said compressor 50 or pump at elevated pressure in a conduit 11 . In order to transport the second gas phase with reduced water content of conduit 8 , possibly compressed of conduit 11 , to a processing unit, such as a process plant on land, a small amount of hydrate inhibitor may be added to the second gas phase by an inhibitor addition/injection conduit 9 . Any hydrate inhibitor addition, such as glycol injection into the second gas phase stream, must be performed after the optional compressor 50 in order to avoid liquid in said compressor 50 .
[0078] The amount of hydrate inhibitor needed for transporting the second gas phase with reduced water content in conduit 8 or 11 , compared to the amount of inhibitor needed for the same transport of the first gas phase exiting the first separator 10 in conduit 2 , is significantly reduced. The resulting reduction in hydrate inhibitor needed (such as MEG) in said gas phases is typically in the order of 80-98%.
[0079] In addition, a compressor or a pump on the combined liquid phase of conduit 7 (not shown) may be used for boosting, or for ease of transport of the first liquid phase to further processing plants.
[0080] A key element in the present process setup is the subsea gas cooler 20 where the gas outlet temperature of the first gas phase 5 may be controlled. Such a cooler is the subject of a separate patent application with a more detailed description of this unit.
[0081] FIG. 2 shows an alternative two-step cooling section 300 wherein an additional second cooler 121 and third separator 131 is used for accurate cooling of the second gas phase in the embodiment above and separating a third gas phase in a conduit 182 and water in a third liquid phase in a conduit 161 .
[0082] Hence, FIG. 2 shows an alternative embodiment of a process layout for a system and method according to the invention wherein a multiphase hydrocarbon-containing well stream in a pipeline 101 is first separated into:
a first gas phase in a conduit 102 ; a first hydrocarbon liquid phase in a conduit 103 ; and a liquid water phase in a conduit 104
by a first three-phase separator 110 , which may be a conventional separator as described above.
[0086] The well stream may contain a certain amount of water of which the bulk part is separated off in separator 110 . The separated liquid water phase in conduit 104 may be re-injected in the sub terrain formations by well head 140 .
[0087] The first gas phase in conduit 102 is then, as above, cooled in a first multiphase gas cooler 120 to a temperature as low as possible to knock out water, but not into the hydrate formation temperature region. Condensed liquids of water and condensate are passed together with gas from the cooler 120 by conduit 105 to a second separator 130 such as a condensed water scrubber, where the phases are separated into a second gas phase exiting at the top of the separator by conduit 108 and a liquid phase exiting at the bottom of the separator 130 by conduit 106 . The second separator 130 may, as mentioned earlier, be a conventional separator or of more compact separation technology, e.g. of inline separation technology or a scrubber.
[0088] The condensed liquids from the second separator 130 are taken off in conduit 106 and mixed with the bulk liquid phase in conduit 103 , which may be a mainly hydrocarbon containing stream from the first separator, to a combined liquid phase in conduit 133 .
[0089] The water content of the first gas phase in conduit 102 is hence reduced in relation to the gas phase in conduit 105 after the cooler 120 and the second gas phase in conduit 108 after the separator 130 , in the order of 80-98% or about 97%.
[0090] The second gas phase in conduit 108 contains a reduced amount of water and its temperature may be close to the hydrate formation temperature. Before further cooling and removal of water, a hydrate inhibitor, such as MEG, is added to the second gas phase before entering a second cooler 121 , by an addition/injection conduit 191 in order to prevent hydrate formation within the cooler.
[0091] The hydrate inhibitor addition allows the second gas phase to be cooled to a lower temperature than that of the first gas phase, such as close to or about equal to the surrounding sea water temperature, for example in the range of 0-5° C. or further to a temperature as low as possible to knock out the maximum amount of water.
[0092] The cooled second gas phase and condensed liquids of water and condensate thereof are passed from the cooler 121 by a conduit 181 to a third separator 131 , which may be similar to the second separator 130 , where the phases are separated into a third gas phase exiting at the top by conduit 182 and a third liquid phase exiting at the bottom by conduit 161 .
[0093] Conduit 181 may additionally be equipped with a choke valve 151 . The choke valve 151 enables to regulate the expansion of the second gas phase and thereby cooling down said phase due to the Joule Thomson or Joule-Kelvin effect, such as below the seawater temperature. The second cooler 121 and choke valve 151 may be used together or separately in order to obtain the desired cooling of the fluid in conduit 181 .
[0094] As mentioned above, the two-step cooling and separation system comprising the first and second coolers 120 and 121 and the second and third separators 130 and 131 , may be regarded as one cooling unit 300 , wherein a first gas phase enters by conduit 102 and where nearly dry gas phase, possibly inhibited by a small amount of hydrate inhibitor exits by conduit 182 . Liquid water and possible additional condensates exits the cooling and separation system of cooling unit 300 by one or more conduits 106 and 161 , which may be combined before mixing with the liquid stream in conduit 103 from the first separator 110 to a common conduit 107 .
[0095] A pressure increasing device such as a compressor 150 or pump may in addition be installed on the resulting third gas phase stream of conduit 182 , exiting at elevated pressure in conduit 111 .
[0096] In order to transport the third dry and possibly compressed gas phase safely to a processing unit, a small amount of hydrate inhibitor may be added, if not added earlier or in addition to earlier injections (such as before the second cooler 121 ), to the gas phase by an inhibitor addition conduit 109 . If added, the hydrate inhibitor addition is as mention above, performed after the compressor 150 to avoid liquid in the compressor 150 .
[0097] However, by adding hydrate inhibitor before the second cooler 121 by conduit 191 , the third gas phase may contain sufficient hydrate inhibitor when exiting the separator 131 which is not condensed and removed therein, to be inhibited for further transport. Said gas phase may be transported as a one-phased stream without the need for any additional hydrate inhibitor and wherein condensation in the pipeline is avoided.
[0098] The condensed liquids from the second separator 130 leaving in conduit 106 and the condensed liquids from the third separator 131 leaving in conduit 161 are mixed with the bulk liquid phase in conduit 103 , from the first separator 110 into a first combined liquid phase in conduit 133 and a second liquid phase in conduit 107 respectively. A regulating valve 160 on conduit 103 upstream of the mixing points of conduits 106 and 161 may be present, in order to prevent flashback into the separator and/or to regulate the mixing rate and composition of said streams. Similar valves may be present on conduits 106 and 161 or as part of separators 130 and 131 respectively, before said mixing points to regulate the levels of said separator tanks (not shown). Alternatively, the liquid phase form the second separator 130 may be fed by a conduit 162 back into the first three-phase separator 110 , for example to reduce the amount of water in the bulk liquid phase and hence reducing the risk of hydrate formation in conduit 107 .
[0099] A compressor or a pump 170 on conduit 107 may be used for boosting or for ease of transport of the bulk liquid phase to further processing plants.
[0100] Said combined liquid phases in conduit 107 are warm and may be transported over long distances as mentioned above before cooling to a temperature level where hydrate formation may occur.
[0101] With the present invention it may be possible to reduce the amount of hydrate inhibitor/MEG needed to prevent hydrate formation by 97% as will be shown in the example below. This reduces the impact on existing hydrate inhibitor (such as MEG) regeneration units, currently used on the receiving facilities. If the hydrate inhibitor volumes are small enough, the amounts may be collected and transported for regeneration elsewhere and do not necessitate regeneration units on the receiving site. By use of alternative hydrate inhibitors to the current inhibitors, at low dosages, such hydrate inhibitors may follow the water production and need not be reused or regenerated. A low consumption of hydrate inhibitor made possible by the above described subsea water knock out, is therefore favourable both with respect to economy and the environment.
[0102] With the new technology of the present invention, the gas stream is fully inhibited for hydrate formation over long distances and a larger un-insulated and more economic pipelines may be used. Such pipelines provides less pressure drop, which eliminates or reduces the need for boosting and increases flexibility with respect to production rates and tie in of new fields, especially compared to existing insulated pipelines of reduced diameter.
[0103] With the aid of the present invention, it may also be possible to produce marginal fields to existing infrastructure in a flexible and efficient way, i.e. without increasing the current capacity of regeneration of hydrate inhibitor. Unfavourable and inflexible solutions may also be avoided in the sense that the pipelines which may be used, as described above, have a larger operational window.
Example 1
[0104] With a temperature of the multiphase hydrocarbon-containing stream 1 and the first separator 10 of 100° C., the water content of the gas is 1.5 mol %. For a certain specific gas rate it would require about 24 m 3 /d 90 wt % hydrate inhibitor (MEG) to prevent hydrates forming in a gas pipeline. By cooling the gas to 30° C. according to the present invention, and separating out condensed water, the required consumption of 90 wt % hydrate inhibitor (MEG) is reduced to about 0.8 m 3 /d, which corresponds to a reduction in MEG of about 97%. | The present invention concerns a method for lowering the water dew point subsea in a produced multiphase hydrocarbon fluid stream containing water, the method comprising the steps of: separating ( 10 ) the hydrocarbon fluid stream ( 1 ) into a liquid phase ( 3 ) and a first gas phase ( 2 ); cooling ( 20 ) the first gas phase in a controlled manner to knock out water or condensing water and optionally other condensates while keeping the fluid above a hydrate formation temperature thereof; separating off condensed liquids ( 6 ) and a second gas phase; wherein the second gas phase ( 8 ) has a water dew point which is lower than that of the initial multiphase hydrocarbon fluid stream. The invention also concerns a system for lowering the water dew point subsea. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to analytical systems and, more particularly, to gas chromatography systems. A major objective of the invention is to provide a compact, thermally agile, gas chromatography system.
Gas chromatography (GC) is a method of separating volatile organic and inorganic sample components. In GC, a sample is progressively heated through the boiling points of its components so that they can be differentially swept through a sorbent-coated column by a carrier gas. Components are separated according to the extent they preferentially bind to the sorbent material. To ensure maximum resolution, spatial temperature gradients in the column should be minimized. The required isothermal conditions are achieved by careful design of the heating system and oven geometry and by use of a fan to promote thorough mixing of the air that circulates past the column.
To ensure repeatability and comparability of results with standard retention-time tables, a GC oven must regulate temperature to match a selected demand ramp (or, more precisely, "demand function"). A demand ramp is a prescribed temperature-versus-time function that generally includes one or more periods of constant positive slope. In addition, a demand ramp can include one or more constant temperature periods to stabilize conditions at the beginning and/or end of a run, or to dwell temperature that favors separation of closely eluting components, thus, creating, so to speak, a chromatographic "sweet spot.
Typically, oven temperature is monitored during a ramp so that it can be compared with the temperature assigned at any given instant by the demand ramp. If the measured temperature is below the demand temperature, the power to the heater is increased. If the measured temperature is above the demand temperature, the power to the heater is decreased.
If the temperature remains high after power to the heater has been decreased to zero, the error cannot be corrected by further control of the heater. This problem typically arises when heat contributed by uncontrolled heat sources, even with the heater power off, exceeds that required by the demand ramp.
There are several such uncontrolled heat sources. Capillary inlets and outlets are continuously heated to avoid condensation; thus, these inlets and outlets function as uncontrolled heat sources that can raise the oven temperature even while the main heat source is off. In addition, heat dissipated by a stirring fan is an uncontrolled heat source. Even the heating element, to the extent that its thermal mass prevents instantaneous control of its output, can be considered to be in part a source of uncontrolled heat.
Furthermore, heat remaining in oven insulation from prior sample runs functions as an uncontrolled passive heat source. This last uncontrolled heat source can be addressed by allowing a longer cool down period between runs. Note that insulator heat is lower for a first run than for subsequent runs. This causes the first run to not be precisely comparable to subsequent runs. This phenomenon is known as the "first run effect". Often the first run is simply discarded at the expense of instrument productivity.
Long cooldown periods are undesirable because they lengthen the sample cycle time, further reducing instrument productivity. Most GC ovens employ ventilation in some form to increase the rate of heat removal during cool down. Furthermore, the availability of ventilation during a ramp means that heat remaining in the insulation does not have to be fully removed between runs. Thus, ventilation reduces cooldown time in two ways: 1) the availability of ventilation for ramp temperature control reduces the amount of cooling required between runs; and 2) the use of ventilation during cooldown decreases the time required to achieve a required amount of cooling.
A ventilation system used for ramp control must be carefully designed so that the ventilation does not introduce temperature gradients in the column. To minimize local temperature deviations at the column, the ventilation can be mixed with circulating air in a separate stirring chamber at the rear of the oven enclosure.
In one exemplary oven, intake and exhaust vents on the rear face of the oven enclosure can be used to cool the air in a stirring chamber to the rear of a main "column" chamber. Air from the stirring chamber is then circulated with air in the column chamber. The main chamber and stirring chamber are separated by a partition. The partition is spaced from the top and side faces of the oven enclosure to define an annular aperture through which stirred air flows to the main chamber. An aperture through the center of the partition provides a return path to the stirring chamber. A fan in the stirring chamber mixes ventilation flow with circulation flow and forces the mixed air out through the annular aperture.
Even with the use of ventilation during cooldown to increase the rate of cooling and the use of ventilation for near-ambient temperature control to reduce the amount of cooling required, instrument performance and productivity can be limited. A typical ramp from near-ambient temperature to a maximum of about 400° C. consumes about one-half hour, while another half hour can be required for cooldown for a full-hour cycle time. Near ambient temperature control is not generally available within 10° C. of ambient. Given the insatiable demand for GC performance and productivity, control at lower temperatures as well as faster ramp and cooldown times are sought.
To provide a fast run, a demand ramp can have a steep positive slope to a maximum temperature, at which the slope drops suddenly to zero (followed by a negative slope during cooldown). The fast ramp requires a heating element that is much hotter (e.g., 100° C. hotter) than the temperature at the column. When the heating element is turned off at the maximum demand column temperature (e.g., 400° C.), the heating element continues to glow for several seconds due to its thermal mass. The resulting excess heat causes the column temperature to surpass the demand maximum by several degrees. A similar overshoot can occur at an intermediate temperature; a user can select a ramp that has a sudden reduction of slope at an intermediate temperature selected to promote separation of otherwise difficult-to-separate sample components.
One problem with thermal overshoot is that the oven temperature temporarily deviates from the demand ramp; this makes it difficult to compare a chromatogram obtained using one manufacturer's GC system with those from other manufacturers and with standard retention-time tables. Another problem that is not widely recognized in the art can be an even greater concern. During overshoot, the oven temperature is not controlled and is therefore variable from run to run according to such factors as external temperature and first run effect. Thus, thermal overshoot impairs comparison of chromatograms even across successive runs from the same instrument.
One approach to minimizing thermal overshoot would be to "smooth" or "round" demand ramp corners (slope transition points). Since there are many ways of rounding a corner, this approach introduces another variable along which instruments can differ; this makes inter-instrument comparisons and comparisons with standardized retention-time tables problematic.
In addition to problems with instrument productivity and with reproducibility due to temperature control, it is well recognized that GC ovens are undesirably large. GC ovens typically constitute over half the volume of a GC system, which in turn consumes valuable laboratory bench space. What is needed is a compact, thermally agile GC system that provides for fast ramps and quick cooldowns, closer-to-ambient temperature control, and minimal thermal overshoot.
SUMMARY OF THE INVENTION
The present invention provides a thermally agile gas chromatography system comprising: 1) a sample manipulation assembly including a GC column, a sample source, and a detector; and 2) an oven including a chamber enclosure, a heat source within the oven, a ventilation system, and a temperature ramp controller. In accordance with the present invention, a ventilation fan is disposed between the ventilation intake and exhaust vent apertures so that its rotational axis extends through both apertures. The effective diameter of the intake aperture is preferably less than the effective diameter of the exhaust aperture. Preferably, the GC column is wound as a coil having an axis of cylindrical symmetry coincident to or parallel to the fan axis.
In one realization of the invention, each vent includes a poppet that can be moved to selectively open and close the including vent. The ramp controller can move the intake and exhaust puppets concurrently to implement at least part of a temperature ramp. Preferably, the poppets are rigidly coupled so that a single servo motor can be used to control ventilation through vents by moving the puppets along the fan axis. Provision is made for decoupling the puppets to provide access to the oven cavity through the exhaust vent.
A further aspect of the invention provides a support within the oven that holds and slightly radially compresses a helically wound capillary GC column. This arrangement provides a simple and secure method of holding the GC column in place over the wide temperature range imposed by the GC oven. The arrangement further disposes of unreliable attachment clips, or other structures, used to secure columns to internal supports.
The novel ventilation arrangement provides a low-resistance flow path directly through the helically wound column. The combination of a radially inward rear vent aperture and a relatively large radius front aperture accommodates the centrifugal effect of the stirring fan on the ventilation flow. Thus, the invention provides a near optimal direct conical flow path through the oven that facilitates the thousands of air interchanges required to remove the thermal energy stored in the oven insulation. The flow can be further enhanced by angling the fan blades forward.
The ventilation flow is also symmetrical about the fan axis. Where the column is in the form of a helix that is coaxial with the fan, a circumferentially uniform temperature is presented to the column. Thus, the ventilation does not induce thermal gradients in the column. Due to the inherent thermal symmetry, a separate stirring chamber is not required to mix ventilation flow with circulation flow. Thus, there is no partition to impede ventilation flow. By omitting the partition, the bulk and thermal mass of the oven are reduced, and the cooling efficiency increased.
The resulting efficient ventilation flow provides for mass transfer cooling several orders of magnitude greater than is provided by prior art GC ovens. Accordingly, cooldown time can be reduced by an order of magnitude. Cooperative movement of vent poppets along the fan axis provides precise control of the ventilation rate throughout a wide dynamic thermal range. The precisely controlled cooling can be used to compensate uncontrolled heat sources so as to tightly control ramp temperatures while only a few degrees Celsius above ambient.
In addition, efficient and precisely controlled ventilation can be used at intermediate and high temperatures to minimize overshoot even for ramps with sudden slope reductions. This affords a user a much wider selection of demand ramps, including ramps that provide for greater sample throughput as well as ramps that dwell on a selected chromatographic "sweet spot" without prolonging the rest of the ramp. By rapidly opening and closing the vents slightly at the time overshoot would occur, the overshoot can be snubbed (i.e., "cut off"). Thus, the present invention provides a "thermally agile" oven that allows a wider range of demand ramps to be tracked precisely.
The present invention provides excellent downward scalability. While some uncontrolled heat sources scale downward with oven dimensions, others do not. For example, insulation bulk decreases with downward scaling and therefore is of less concern as a heat source. However, heat sources such as capillary inlets and detectors do not scale proportionally to oven size; as an oven design is scaled downward, they constitute an increasingly significant source of uncontrolled heat. Thus, while ventilation capacity reduces with vent aperture diameters in proportion to oven size, the heat that must be removed by the ventilation does not scale to the same extent. The net effect is that the minimum controllable ramp temperature increases with decreasing oven size.
This principle applies to the present invention as well as to the prior art. However, some of the superior ventilation effectiveness of the present invention can be traded for compactness, resulting in an oven which is both smaller and better at near-ambient temperature control than prior art GC ovens. In fact, the present invention can provide a field-portable GC system that has higher performance than prior art laboratory GC systems.
In the case of the prior art, scaling a laboratory size oven to a size practical for field use would increase the minimum usable temperatures from about fifteen degrees Celsius above ambient to, for example, a not-very-useful sixty degrees Celsius above ambient. In the case of the present invention, a corresponding reduction in scale would raise the minimum temperatures from less than one degree Celsius above ambient to only a few degrees above ambient. Thus, the present invention provides for a high-performance, field-portable GC system.
The advantages of a high-performance, field-portable GC system are substantial, especially in applications such as contamination cleanup. Contamination cleanup can involve removal of large quantities of material, e.g., soil contaminated with industrial waste. The bulk and potentially hazardous character of the contaminated soil makes removal expensive and cumbersome. It is therefore important to determine onsite when all the contaminated material has been removed so that money and effort are not wasted on removing uncontaminated material. Such an onsite determination can be made with a field-portable GC system.
Furthermore, since sample components can degrade during transit to a laboratory, field-portable GC systems can provide more accurate analyses. More generally, the delay involved in transit, laboratory backlog, and delays in communication of lab results often takes two weeks which is often unacceptable. The delay is particularly harmful when the laboratory results indicate that further collection is required, especially where the further collection involves returning to a remote site. A high-performance, thermally agile, field-portable GC oven system addresses all these problems.
The present invention provides a compact, thermally agile GC oven. In addition, some thermal agility can be exchanged for field portability, while achieving GC performance superior to prior art laboratory GC systems. These and other features and advantages of the present invention are apparent from the description below with reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a gas chromatography system in accordance with the present invention.
FIG. 2 is a graph of power removal and temperature over time characterizing the operation of the gas chromatography system of FIG. 1.
FIG. 3 is a view through the right side of a gas chromatography oven of the GC system of FIG. 1.
FIG. 4 is a view through the top of the GC oven of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, a gas chromatography system A1 comprises a sample handler 10 and an oven 20. Sample handler 10 includes a sample source 12, a helically wound sorbent coated column 14, and a detector 16. Sample source 12 conventionally includes a sample injection port, a carrier gas source, and a flow controller. The sample injection port is hydraulically coupled to an inlet end of the column, while an effluent end of the column is hydraulically coupled to detector 16. Oven 20 includes an insulated chamber enclosure 22, a column support assembly 24, an oven temperature sensor 26, a ramp controller 28, a heating system 30, and a ventilation subsystem 40. Heating assembly 30 includes a resistive heater 32 and an amplifier 34. To either end of heater 32 are shields 33 to protect column 14 from direct radiant heat.
Ventilation system 40 includes a fan assembly 42 and a vent assembly 50. Fan assembly 42 includes a fan 44, a fan shaft 46, and a fan motor 48. Vent assembly 50 includes an intake poppet 52 with an associated ring seal 53, an exhaust poppet 54 with an associated ring seal 55, a carriage assembly 56, and a vent servo 58. In FIG. 1, vent poppets 52 and 54 are shown in their fully open ventilation positions.
Carriage assembly 56 is indicated schematically in FIG. 1 by a lead screw 56A, a rear linkage 56B to intake poppet 52, and a front linkage 56C to exhaust poppet 54; the preferred constitution for carriage assembly 56 is presented below with references to FIGS. 3 and 4. During a temperature ramp, poppets 52 and 54 are rigidly coupled in the sense that they, together with carriage assembly 56 that couples them, define a rigid body.
Fan 44 is located within oven cavity 60 between intake aperture 64 and exhaust aperture 68. Fan 44 rotates about a fan axis 49 that extends through the centers of vent apertures 64 and 68 as well as the center of the helix defined by column 14. When closed, ventilation system 40 effects circulation as indicated by arrows 59. The predominant flow with vents fully open is indicated by flow arrows 69. The generally direct conical flow path through chamber enclosure 22 provides high ventilation efficiency with thermal symmetry at column 14. In alternative embodiments, the fan axis extends through intake and exhaust apertures without being aligned with the aperture centers.
Chamber enclosure 22 defines an oven cavity 60 that contains column 14, column support assembly 24, sensor 26, resistive heater 32, fan 44 along with a portion of fan shaft 46, and intake poppet 52 (along with a portion of carriage assembly 56 during ventilation). Chamber enclosure 22 has an opening through its rear face 62 defining an intake aperture 64; chamber enclosure 22 is open at its front face 66, defining an exhaust aperture 68. Intake aperture 64 and intake poppet 52 constitute a controllable intake vent 70; exhaust aperture 68 and exhaust poppet 54 constitute a controllable exhaust vent 72.
A demand ramp is selected by programming ramp controller 28. Typically, the ramp includes constant temperature periods and periods of constant positive slope. In system A1, the maximum slope is about 2° C. per second (about five times the rate of prior art GC ovens).
When the measured temperature deviates from demand temperature, ramp controller 28 implements an error response algorithm to control power to heater 32 and the opening and closing of ventilation subsystem 40. Generally, errors are compensated primarily by adjusting the power to heater 32 while vents 70 and 72 are closed and by adjusting the vents while the vents are open. To avoid singularities in the error response, the heating and ventilation error responses are cross-faded. For examples, the heater can start heating before the vents are fully closed, and the vents can begin to open before the heater is turned completely off.
Ramp controller 28 is coupled to the output of oven temperature sensor 26 for monitoring the temperature within oven cavity 60 to provide a measured temperature readout. The measured temperature is used first to determine when to begin a ramp. Between runs it takes time to cool down to the initial temperature for the next ramp. Once a desired initial minimum temperature is reached, a typical demand ramp holds the minimum temperature for a few seconds to allow the thermal conditions in oven 20 to stabilize. For GC system A1, the stabilization temperature can be as low as a few degrees Celsius above ambient.
Ventilation subsystem 40 is partially open most of the time during stabilization. To adjust ventilation, ramp controller 28 actuates vent servo 58, which drives carriage assembly 56. Intake poppet 52 and exhaust poppet 54 are rigidly coupled to drive carriage assembly 56 so that they open and close in unison. During a stabilization interval and before ventilation system 40 is completely closed, ramp controller 28 activates current source 34, which is electrically coupled to resistive heater 32. Thus, heating begins as ventilation subsides, as dictated by the implemented cross fade.
The positive slope portion of a ramp typically begins with ventilation subsystem 40 closed; heater 32 is controlled to maintain a differential relative to the demand temperature. The differential increases with temperature to compensate for greater thermal losses. Once a maximum demand temperature is achieved, ventilation subsystem 40 can be opened briefly to control overshoot as the demand temperature levels off. Between runs, ramp controller 28, upon sensing an enormous disparity between the demand and the measured temperature, fully opens ventilation subsystem 40, thereby minimizing cooldown time.
Ramp controller 28 constantly compares measured and demand temperatures and implements proportional-integrated-differential (PID) error correction. If the measured temperature falls below the demand temperature, the current is further increased. If the measured temperature rises slightly above the demand temperature, the current is reduced or turned off. If reducing heat input does not fully compensate for overheating, ventilation subsystem 40 is opened.
The functioning of GC system A1 is indicated in the graph of FIG. 2, which shows four time-varying variables: 1) the temperature demand ramp is indicated by a line marked with squares; 2) the measured temperature is indicated by a line (which, for the most part coincides with the demand temperature) marked with circles; 3) the heater temperature is indicated by a line marked with downward pointing triangles; and 4) the amount of heat (in watts) being removed by ventilation is indicated by a line marked with upward pointing triangles. To accentuate certain features, crossfading is only minimally implemented in the sample runs depicted in FIG. 2.
The demand ramp begins with an initial constant temperature period D1 at 30° C., followed by a period D2 of constant positive slope, followed by a period D3 of constant temperature (e.g., at a chromatographic sweet spot), followed by another period D4 of constant positive slope, followed by a period D5 at a constant maximum temperature near 400° C. The next period D6 is a drop to the minimum temperature in preparation for a second sample run. A period D7 is a constant minimum temperature to stabilize conditions for the second run. The final illustrated second-run period D8 has a constant positive slope.
As would be desired, the measured temperature tracks the demand temperature precisely during sample runs. Before the first run, the measured temperature is at ambient, 25° C. The minimum demand temperature of 30° C. is achieved within the few seconds of a period D2. At this point, the first sample run can begin. During the first and subsequent sample runs, measured temperature matches demand temperature as required. Of course, the measured temperature cannot match the precipitous drop of the demand ramp cooldown period D6. During cooldown at period D2, the measured temperature approaches the constant minimum demand temperature asymptotically, stabilizing near the end of period D7.
The heater is turned on briefly and fully at H1 at the onset of the stabilization portion of the demand ramp. It should be noted that the maximum temperature that the heater can attain is limited by the surrounding temperature. The peak at H1 represents the maximum temperature the heater can achieve at the initial, first-run, 25° C. (ambient) temperature of the oven. Once 30° C. is achieved, the heater is turned off, as indicated at H2. The heater is turned on again at H3 during positive sloping period D2 of the demand ramp. The temperature of the heater is increased to maintain a gradually increasing differential temperature relative to the measured temperature to compensate for greater heat loss at higher oven temperatures.
The heater temperature is suddenly reduced (by temporarily turning off the power to the heater) at the onset of sweet spot period H4, and then gradually reduced to maintain a constant measured temperature. Heater period H5 begins with a sudden increase in heater temperature and then is positively sloping to achieve a gradually increasing temperature differential relative to positively sloping period D4 of the demand ramp. The heater power is briefly turned off at the onset of heater period H6 to implement constant maximum demand temperature period D5. The heater is off at H7 so that the temperature of the heater element quickly drops to the oven temperature. During cooldown period D2, during which the heater temperature tracks the measured oven temperature.
The heater is turned on again to initiate heater period H8. The heater temperature is increased to maintain a gradually increasing differential relative to demand period D8. This differential is smaller in period H8 than for period H3 because of the first run effect. In other words, stored heat deep inside the chamber insulation contributes more heat during second run period H8 than during first run period H3.
Ventilation subsystem 40 is opened briefly at period V1 primarily to compensate for excess heat from heater 32 after power to heater 32 is removed. Ventilation subsystem 40 is opened slightly during period V2 primarily to compensate for constant uncontrolled heat sources while oven temperature stabilizes. A brief vent opening at V3 is used to compensate for thermal overshoot as sweet spot period D3 is reached. Similarly, a brief vent opening at V4 compensates for thermal overshoot as maximum demand period D5 is reached. Ventilation subsystem 40 is fully open at V5 to maximize heat transfer during cooldown period M2. Note that the reduction in cooling at V6 is not due to the closing of vents, but to the reduced differential between internal oven temperature and the ambient temperature. Ventilation subsystem 40 is closed at V7 to initiate second sample period D8.
As most clearly shown in FIG. 3, vent servo 58 has a pivoting armature 80 that couples to a linkage 82 that in turn couples to a carriage 84. Fan motor 48 and intake poppet 52 are rigidly coupled to carriage 84 so that these elements move along fan axis 49 when vent servo 58 is actuated. Fan shaft 46 and fan 44 also move along axis 49 by virtue of their coupling to fan motor 48. A guide rod 86 helps stabilize the axial motion of carriage 84.
As most clearly shown in FIG. 4, exhaust poppet 54 is attached to a pair of rods 88 by fasteners 90. Access to oven cavity 60 can be obtained by removing fasteners 90 and exhaust poppet 54. Rods 88 are rigidly coupled to carriage 84. Rods 88 slide relative to chamber enclosure 22 through journals 92 attached to chamber enclosure 22. Poppets 52 and 54 open and close intake and exhaust apertures 64 and 68 in unison when vent servo 58 is actuated. Note that carriage assembly 56 of FIG. 1 comprises carriage linkage 82 shown in FIG. 3, carriage 84 shown in FIGS. 2 and 3, guide rod 86 shown in FIG. 3, and exhaust poppet rods 88 shown in FIG. 4.
On a top face 100, shown in FIG. 3, of chamber enclosure 22, is a detector mount 102 for detector 16 (shown in FIG. 1). Also on top face 100, is an injector mount 104 for the injection port of sample source 12, shown in FIG. 4. Shown in both FIGS. 3 and 4 is a capillary support assembly 110 that includes resistive heater 32. Assembly 110 can be removed from oven cavity 60 when exhaust poppet 54 is removed. When inserted into cavity 60, a cylindrical skirt 112 frictionally engages chamber enclosure 22. A base 114 of resistive heater 32 is bolted to skirt 112. Welded to skirt 112 are four spring supports 116, each of which supports a respective capillary support post 118. (Two supports and two posts are shown in FIG. 3 and the other two supports and the other two posts are shown in FIG. 4.)
Each capillary support post 118 includes alternating shallow grooves 120 and deep grooves 122, referenced in FIG. 3. Grooves 120 and 122 are dimensioned to engage the turns of capillary column 14. Deep grooves 122 hold the turns from injection source 12 that wind from the front to the back of oven cavity 60. Shallow grooves 120 hold the turns as the capillary helix returns from back to front to detector 16. Spring supports 116 provide low-thermal-mass support for capillary column 14 and apply a slight compression to the helical form of column 14.
Resistive heater 32 is a low mass heater, allowing higher servo gain increased accuracy and reduced overshoot. It is fabricated from a nickel-chrome alloy, such as nichrome, which is flattened to maximize the convective heat transfer from it while at the same time minimizing its thermal mass.
Fan motor 48 is a brushless motor so as to further optimize dynamics by reducing the time constant of the heater; it combines the speed of a brush motor with the reliability and explosion proof characteristics of induction motors. Fan 44 is mounted on thin, low-conductivity titanium alloy hollow shaft 46 so as to minimize conductive heat loss into fan motor 48.
By using a single structure for both the exhaust poppet and the access door, shunt conductive paths are minimized and simplified. This reduces static thermal loss from the oven to the ambient. This in turn, enhances the thermal efficiency of the oven. In practice, oven 20 can implement a full-range 30° C. to 400° C. ramp and re-equilibrate with a cycle time of only eight minutes (about six minutes for the sample run plus about two minutes for cooldown).
Unlike ovens used for other applications, e.g., cooking, the thermal mass of oven 20 is minimized to enhance dynamic performance. Toward this end, the insulator is 0.8 pounds per cubic foot (pcf) micropore ceramic fiber and the chamber wall liner is 0.010" stainless steel. Such insulation has low thermal conductivity and yet low thermal capacity. Alternatively, other low-density insulators, such as Aerogel (available from Aerojet Corporation, Sacramento, Calif.) can be used. In a dynamic oven, the mass of the inner layers of the insulation must be carried up to near oven temperature. Further, most of the heat absorbed by the insulation must be pumped out during the cooling cycle. The low thermal conductivity of the ceramic fiber insures effective insulation, while the low thermal capacity facilitates rapid cooldown. Where it is necessary to couple interior and exterior surfaces, e.g., at vent openings, mica board is used to separate stainless steel liners to minimize conduction from interior to exterior.
The external dimensions of oven 20 are about 150 millimeters (mm)×150 mm×150 mm, providing internal dimensions of about 100 mm (wide)×100 mm (high)×70 (deep-between apertures 64 and 68). The total mass is about 1.5 kilograms. The linear dimensions are less than half those of comparable prior art GC systems. The volume and mass are about an order of magnitude less than comparable prior art GC systems. Furthermore, while prior art GC systems can require kilowatts of power or more, the total power consumption of system A1 need not exceed 350 watts. Such power can be readily provided by an inverter from a vehicle or by a field-portable generator. Interfacing for system A1 can be provided by a laptop computer, completing the miniaturized field-portable package.
While in the preferred embodiment, the fan axis extends through the centers of the intake and exhaust apertures, in alternative embodiments, the axis extends through these apertures off center. In an alternative embodiment, an exhaust poppet is hinged and lockable. When locked, it is rigidly coupled to an intake poppet; when unlocked, it swings open to provide access to the oven cavity. These and other variations upon and modifications to the embodiments described above are provided for by the present invention, the scope of which is defined by the following claims. | A high-performance, field-portable, thermally agile, gas chromatography (GC) system employs a low-thermal-mass oven in which intake and exhaust vent apertures are aligned with respect to the rotational axis of the stirring fan. The poppets of the vent dynamically vent to ambient the air-flow generated by the stirring fan. The geometry of the vents cooperates with the axial and radial components of the stirring fan to promote conical vortex air flow, to facilitate rapid and controllable mass-flow interchange with ambient air. The resulting cooling performance in a small GC oven promotes more rapid requilibration between runs, control at temperatures closer to ambient, and the reduction of thermal overshoot; thus enhancing the performance and productivity of a field instrument. | 6 |
This is a continuation of application Ser. No. 09/930,405 filed on Aug. 15, 2001.
TECHNICAL FIELD
The present invention is directed to a process for preparing aluminum and aluminum alloy and other metal tubes, plates and other components used in heat exchangers such as condensers, radiators and evaporators for brazing by depositing thereon a kinetic sprayed brazing composition. The single-step process deposits monolith or composite coatings that may comprise one or more brazing materials such as a corrosion protector, a brazing filler and a brazing flux.
INCORPORATION BY REFERENCE
U.S. Pat. No. 6,139,913, entitled “Kinetic Spray Coating Method and Apparatus” is incorporated by reference herein.
BACKGROUND OF THE INVENTION
Heat exchangers such as condensers, radiators, evaporators, heater cores and coolers made of aluminum or aluminum alloy (generally referred to hereinafter as “aluminum”) or other metals are widely used today. These heat exchangers generally include perforated fins brazed to the external surfaces of tubes and plates that form the structure of the heat exchanger. The tubes are usually extruded and the fins are usually made from sheets.
Prior to assembly into heat exchangers the tubes and plates are typically coated (or plated) with a corrosion protector using known techniques such as twin-wire arc thermal spraying. Zinc or zinc-aluminum alloys are generally used as the corrosion protector, but any known corrosion inhibitor may be used. The fins are prepared prior to assembly to carry the brazing filler that fills the joints between the tube and fins during brazing. The brazing filler is applied to fin sheet stock as a cladding layer in the form of an overlaid sheet that is rolled and bonded onto the aluminum fin sheet. The cladding consists of a material or materials known in the art to be capable of melting at a temperature lower than the heat exchanger aluminum such as an aluminum-silicon alloy so that, during brazing, the cladding will form brazed joints. The use of such clad brazing sheets is well known and commonly used, even though it is well known that the use of clad brazing sheets adds to production costs and accelerates tool wear.
Prior to brazing of aluminum heat exchangers, tube cladding and plate surfaces must be cleaned and de-oxidized. Removal of the oxidation layer is necessary in order to form strong joints. This is generally accomplished using a material commonly known as flux that chemically cleans and de-oxidizes the surface and protects the aluminum from further oxidation. The flux is applied to the aluminum surfaces of plates and tubes prior to brazing using techniques such as flux showering or electrostatic spraying. During brazing, the flux material further serves to reduce the filler metal's surface tension and promote wetting of the materials to assist in joint formation. While many flux materials are known and used, Nocolok® Flux (a mixture of potassium fluoroaluminate salts manufactured by Solvay Fluor), and similarly formulated fluxes, are preferred due to their non-corrosive effect on aluminum after brazing. The components of the heat exchanger are finally joined together by bringing the assembly to brazing temperature in a controlled atmosphere brazing furnace, a vacuum furnace, or the like.
To summarize, aluminum heat exchangers for automotive vehicles and other applications, today, are manufactured by flux brazing of filler-clad fin sheets to zinc-coated plates and tubes. The fin sheets are clad with brazing filler in one process, the plates and tubes are coated with zinc in a second process and the brazing flux is applied in a third process.
An alternative method of preparing heat exchanger components for aluminum brazing is disclosed in U.S. Pat. No. 5,907,761. In the '761 patent, a solvent-based brazing composition is coated onto components using known techniques such as dip coating or liquid spray coating. The disclosed brazing composition includes, (1) a powdered alloy of aluminum, silicon, zinc, and indium (or beryllium), (2) a polymeric resin binder, (3) an aliphatic alcohol solvent, and (4) a brazing flux. In the patent, an alloy is first formed from powders of aluminum, silicon, zinc and indium. The alloy is then made into a powder and mixed with the polymer binder, solvent and flux. The resulting liquid brazing composition is then applied to the substrate using known techniques and becomes bound to the substrate by action of the polymer resin. Brazing follows.
SUMMARY OF THE INVENTION
By the process of the present invention, aluminum and other metal heat exchanger components are prepared for brazing using a new technique that replaces the multi-step operations of the prior art. The present invention provides a means to simultaneously clean and deoxidize heat exchanger components and bond all braze materials onto the components in a single operation. Individual zinc plating, filler cladding and separate flux application (for pre-cleaning, deoxidizing and braze flux deposition) can thereby be replaced. In addition, no solvent base or other liquid system is necessary.
The present invention generally applies a new technique for producing coatings known as kinetic spray or cold gas dynamic spray to brazing. This new technology has been reported in an article by T. H. Van Steenkiste et al., entitled “Kinetic Spray Coatings,” published in Surface and Coatings Technology, vol. 111, pages 62-71, Jan. 10, 1999. The article discusses producing continuous layer coatings having low porosity, high adhesion, low oxide content and low thermal stress. The article describes coatings being produced by entraining metal powders in an accelerated air stream and projecting them against a target substrate. It was found that the particles that formed the coating did not melt or thermally soften prior to impingement onto the substrate.
The Van Steenkiste et al. work improved upon earlier work by Alkimov et al. as disclosed in U.S. Pat. No. 5,302,414, issued Apr. 12, 1994. Alkimov et al. disclosed an apparatus and process for producing dense layer coatings with powder particles having a particle size of from 1 to 50 microns using a supersonic spray operating at low temperatures and pressures.
The Van Steenkiste et al. article reported on work conducted by the National Center for Manufacturing Sciences (NCMS) to improve on the earlier Alkimov process and apparatus. Van Steenkiste et al. demonstrated that Alkimov's apparatus and process could be modified to produce kinetic sprayed continuous layer coatings using particle sizes of greater than 50 microns and up to about 106 microns. This modified process and apparatus for producing such larger particle size kinetic spray continuous layer coatings is disclosed in U.S. Pat. No. 6,139,913, Van Steenkiste et al., that issued on Oct. 31, 2000. The process and apparatus provide for heating a high pressure air flow up to about 650° C. and accelerating it with entrained particles through a de Laval-type nozzle to an exit velocity of between about 300 m/s (meters per second) to about 1000 m/s. The thus accelerated particles are directed toward and impact upon a target substrate with sufficient kinetic energy to impinge the particles to the surface of the substrate. The temperatures and pressures used are sufficiently lower than that necessary to cause particle melting or thermal softening of the selected particle so that no phase transformation occurs in the particles prior to impingement.
The present invention provides a method for replacing, with a single process, the several processes currently used in brazing heat exchangers such as condensers, radiators, evaporators, and the like. The single spraying operation can generate a single layer or multiple layers of a monolith or composite coating.
The process of the invention involves kinetic spraying onto metal substrates a brazing composition that comprises corrosion protector, brazing filler and/or flux. In a preferred embodiment, the brazing composition comprises zinc or zinc-aluminum alloy as a corrosion protector, silicon or aluminum-silicon alloy as a brazing filler, and Nocolok® Flux or similar fluxing material as the flux. In another preferred embodiment, the brazing composition comprises a ternary alloy of aluminum-zinc-silicon powder and flux. In yet another preferred embodiment, the brazing composition comprises a pre-homogenized mechanical mixture of separate powders of aluminum, zinc, silicon and flux.
The process of the present invention may be used for brazing any metal surface and is not limited to use in heat exchangers. The advantage of the present invention is that it offers a simple yet versatile process for brazing metal surfaces.
The process provides an effective means for coating a brazing composition onto aluminum substrates that obviates the need for pre-fluxing, filler cladding and separate corrosion protector application. The process of the present invention may be used advantageously during any stage of processing including, for example, from immediately following tube extrusion to immediately prior to brazing.
Kinetic spray deposition is a relatively new technique where powders, especially of metal (or ceramic) particles, are accelerated in a pre-heated gas stream toward a substrate at high velocities between about 300 m/s (meters per second) to about 1000 m/s. Upon impact, the metal particles initially grit blast the surface and then plastically deform and impinge bond onto the surface. Subsequent particles bond with the deposited particles upon impact to form a surface layer coating.
Prior to the present invention, it was unexpected that kinetic spray could be suitably used to deposit braze compositions onto aluminum surfaces in a manner that would produce satisfactory braze joints. The process as used in the present invention applies the kinetic spray technology disclosed in U.S. Pat. No. 6,139,913, incorporated herein by reference, to the preparation of aluminum surfaces for brazing.
The process of the present invention is superior over known techniques. The kinetic sprayed powders in the braze composition never reach their melting temperature and always remain in their original solid phase during the spray process. Since the powders do not reach the molten state, little oxidation of the powders occur and a relatively oxide free coating can be formed. In addition, kinetic sprayed braze compositions offer the added advantage in that the aluminum components being coated need not be pre-fluxed (i.e., pre-cleaned and deoxidized) since the initial grit blasting action inherently cleans and de-oxidizes the surface as the brazing composition surface layer is being applied. Furthermore, while inert atmosphere processing is generally required for thermal spraying, as used in prior art processes to lessen the formation of oxidation during coating deposition, an inert atmosphere is not necessary in kinetic spray deposition, and the associated costs are thereby avoided.
A primary benefit of the present invention is the ability to mix different materials having different properties together and apply them as a composite coating. Because the powders are not melted in the kinetic spray process, the materials do not chemically combine or alloy in the kinetic spray process. The synergistic benefits of the various materials may, thereby, be taken advantage of in the most effective and efficient manner.
In development of the present invention, it was further discovered that kinetic spray is useful in coating alloys onto aluminum surfaces that have a substantially greater hardness than aluminum. It has now been found that ternary alloys such as zinc-aluminum-silicon alloys may be kinetic spray-coated onto aluminum substrates such as plate and tube surfaces. While specific materials are disclosed herein, it is clear from the versatility of the present invention that alloys of other braze materials may be similarly used.
Using the process of the present invention in aluminum brazing, any conceivable brazing composition may now be used as a single stage coating. Pre-fluxing and the use of a separate flux coating are no longer required. Instead, cleaning and deoxidizing are accomplished simultaneous to coating, and brazing flux may be incorporated into the coating itself. Accordingly, fluxless brazing is now possible. The present process also allows the incorporation of brazing filler into the coating so that cladding is no longer required. Accordingly, cladless brazing is now also possible. The brazing composition can comprise monoliths or composites of individual powders, alloy powders or their combinations to provide maximum versatility.
Cladless and fluxless brazing are now possible and a pre-coating of a corrosion protector is no longer necessary. The present invention provides the ability to incorporate corrosion protector, brazing filler and flux into a single coating composition and the means for coating that composition onto aluminum surfaces while simultaneously cleaning and deoxidizing the surface.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are SEM micrographs showing microstructures of two composite coatings of aluminum-silicon alloy and zinc of the present invention.
FIGS. 2A , 2 B, 2 C, and 2 D are SEM images of composite coatings of aluminum and zinc of the present invention.
FIGS. 3A , 3 B, 3 C, and 3 D are cross-sectional SEM images of the same coatings, respectively, as shown in FIG. 2 .
FIGS. 4A , 4 B, 4 C, and 4 D are mappings of the elements of a composite coating of aluminum, zinc and silicon of the present invention. FIG. 4E is an energy dispersive spectrum of the composite coating.
FIGS. 5A , 5 B, 5 C, 5 D and 5 E are mappings of various elements of zinc and aluminum-silicon alloy coating with directly incorporated Nocolok® flux as in the present invention. FIG. 5F is the energy dispersive spectrum of the alloy coating.
FIGS. 6A and 6B are elemental mappings of a fin-tube assembly brazed with aluminum-zinc-silicon alloys according to the present invention, and FIG. 6C depicts a mapping of an assembly brazed with an alloy according to the prior art.
FIGS. 7A and 7B are SEM micrographs of the brazing results for zinc and aluminum-silicon alloy coatings of the present invention.
FIG. 8 depicts a small assembly of tubes brazed to aluminum fin material using a composite coating of aluminum and zinc of the present invention.
FIGS. 9A and 9B are SEM micrographs showing the surface morphology of a tube as in FIG. 8 before and after brazing, respectively.
FIGS. 10A and 10B are examples of the joints brazed according to the present invention using an aluminum-rich coating and a zinc-rich coating, respectively (both are composite coatings of aluminum and zinc).
FIGS. 11A and 11B are elemental mapping results showing that zinc deposited on aluminum tubes according to the present invention is uniformly distributed on the surface after brazing.
FIGS. 12A and 12B are elemental mappings of aluminum-zinc-silicon alloy coatings showing brazed fin and tube assemblies of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the construction of a heat exchanger comprising fins and tubes, an extruded aluminum condenser tube is prepared for brazing aluminum fins thereon by kinetic spraying a brazing composition on the tube or other surface. The brazing composition is a solid phase monolith or composite that generally comprises particles of corrosion protector, filler material, and/or flux.
The brazing composition is selected from solid phase particles having a particle size (diameter or equivalent) distribution in the range of about 10 microns to about 150 microns, with a particle size distribution of greater than about 45 microns being preferred. The particles may further be either spherical or irregular shaped (such as granular). When the solid phase material is a monolith, it is preferred that the composition be selected from zinc, zinc-aluminum alloy, aluminum-silicon alloy, aluminum-zinc-silicon alloy and aluminum-zinc-silicon-copper alloy. When the solid phase material is a composite, it is preferred that the composition be selected from a combination of two or more of the following: zinc, zinc-aluminum alloy, aluminum, silicon, aluminum-silicon alloy, aluminum-zinc-silicon alloy and aluminum-zinc-silicon-copper alloy. It is preferred that a non-corrosive flux, such as Nocolok® flux or the like, be added to monolith or composite particles in preparing the brazing composition to be used.
The kinetic spray technique used in the present invention is primarily as disclosed in U.S. Pat. No. 6,139,913, the teachings of which are incorporated herein by reference.
In the present invention, the brazing composition is introduced into a focused gas stream traveling at a velocity of about 300 m/s (meters per second) to about 1000 m/s. The gas stream is preferably preheated to a temperature of from about 100° C. to about 300° C., and more preferably to about 200° C. As the particles of the brazing composition are entrained into the gas stream, they begin to gain kinetic and thermal energy. The brazing composition is then accelerated through a de Laval-type nozzle to achieve an exit velocity of up to about 1000 m/s directed toward the tube surface (i.e., the substrate being sprayed). The tube is moved across the path of the exit stream (or vice versa) to lay a coating on the surface of the tube. The tube is passed across the exit stream as necessary to create one or more layers.
As particles of the brazing composition impact the surface, kinetic energy is transferred to the aluminum surface. The impact of the particles initially grit blast the surface thereby fracturing any surface oxide layer, and simultaneously begin mechanically deforming and impingement bonding the particles to the surface. Successive layers are formed by the entrained particles impacting and bonding to other particles deposited on the surface. The particles deposited on the surface while undergoing plastic deformation remain in their original solid phase (i.e., they do not melt).
An aluminum substrate made according to the invention comprises an aluminum surface and a kinetically impinged coating bonded to its surface. The coating is a solid phase monolith or composite comprising one or more of corrosion protector for aluminum, filler material for brazing, and/or brazing flux. The coating may have multiple layers kinetically bonded directly to the aluminum surface. Each layer is substantially free of oxides and retains the physical properties and solid phase of the original pre-coating composition.
According to the present invention, the following coatings were prepared, kinetically sprayed onto aluminum brazing substrates and brazed. All showed good brazing results. While representative of the present invention, the following examples are not intended to limit the scope of the invention in any way.
EXAMPLES
Both monolith and composite coatings of various compositions were prepared including:
(a) zinc coatings with an average loading of about 50 g/sq.m. (grams per square meter) to about 400 g/sq.m.;
(b) zinc-aluminum alloy coatings with an average loading of about 100 g/sq.m. to about 600 g/sq.m. (having melting points of alloys lower that 600° C.);
(c) aluminum-silicon alloy coatings with an average loading of about 10 g/sq.m. to about 200 g/sq.m. with aluminum-silicon alloy starting powders having a composition of about 12% silicon by weight (i.e. the eutectic composition);
(d) aluminum-zinc-silicon ternary alloy coatings with starting powders having about 50% to about 78% aluminum, about 12% to about 45% zinc, and about 5% to about 10% silicon (all %'s by weight);
(e) aluminum-zinc-silicon-copper quaternary alloy coatings with average loading of about 20 g/sq.m. to about 150 g/sq.m. and with starting powders having about 50% to about 78% aluminum, about 10% to about 45% zinc, about 4% to about 10% silicon, about 0.1% to about 5% copper and trace amounts of other alloying elements such as iron, nickel, titanium and bismuth (all %'s by weight);
(f) composite coatings of aluminum and zinc, preferably with greater than about 40% by weight of zinc in the starting mixture;
(g) composite coatings of zinc and aluminum-silicon, preferably with about 6% to about 70% by weight of zinc in the starting mixture;
(h) composite coatings of aluminum, zinc and silicon with about 10% to about 20% silicon by weight in the starting powder, and preferably with about 15% silicon by weight; with the ratio of aluminum to zinc in the range of about 4 to about 0.6;
(i) coatings with starting powders as provided in (a), (b), (d), (e), (f), (g) and (h) with directly incorporated Nocolok® flux;
(j) coatings of (i) with a larger amount of Nocolok® flux incorporated as a metallized flux (in which the mixed powders of metals and flux were melted or sintered into ingots and then powdered and used as the kinetic sprayed composition).
Microstructural and chemical analyses of the above coatings were performed. Selected results are shown in FIGS. 1 through 5 that illustrate the general characteristics of these kinetic spray-deposited coatings.
FIGS. 1A and 1B are plane-view SEM micrographs showing the microstructures of the aluminum-silicon alloy and zinc coatings as in (g), above, deposited from starting powders with 6% and 10% zinc, respectively. The spherical-shaped particles with darker contrast are the aluminum-silicon alloy and the remainder is zinc.
FIGS. 2A , 2 B, 2 C, and 2 D show the plane view SEM images of the composite coatings of aluminum and zinc as in (c), above, which were deposited from two types of starting powders using two traverse speeds. Similar to FIG. 1 , the spherical-shaped particles with darker contrast are the aluminum and the remainder is zinc.
FIGS. 3A , 3 B, 3 C, and 3 D are the cross-sectional SEM images of the same coatings shown in FIG. 2 . In these cross-sectional images, aluminum and zinc particles can be readily distinguished by their respective contrasts, with aluminum shown with the dark contrast and zinc shown with the bright contrast.
FIGS. 4A-D present the cross-sectional elemental mappings of a composite coating of aluminum, zinc and silicon as in (h), above, showing mappings of aluminum (FIG. 4 A), zinc (FIG. 4 B), silicon (FIG. 4 C); and FIG. 4D shows an overlay of FIGS. A-C. These mappings and the energy dispersive spectrum in FIG. 4E indicate the incorporation of silicon in the coating. Silicon is a rapid diffuser in aluminum and can effectively promote the melting of aluminum at the brazing temperature.
FIG. 5A is a SEM image of a zinc and aluminum-silicon alloy coating with directly incorporated Nocolok® flux as in (i) combined with (g), above; and FIGS. 5B-E are elemental mappings of zinc (FIG. 5 B), silicon (FIG. 5 C), fluorine ( FIG. 5D ) and potassium (FIG. 5 E). The starting powder used for this coating contains about 6% by weight flux and about 94% of a mixture of zinc and aluminum-silicon alloy. Both elements F (fluorine) and K (potassium), which are chemical constituents of Nocolok® Flux (that has a general chemical formula of KA1F), displayed strong peaks in the energy dispersive spectrum of FIG. 5 F. This shows that a significant amount of flux was incorporated into the coating via the kinetic spray process. Moreover, the relatively uniform distribution of K and F presented by the elemental mappings of FIGS. 5A-E indicates that the flux was uniformly distributed.
FIGS. 6A , 6 B and 6 C are zinc elemental mappings of brazed fin-tube assemblies: FIGS. 6A and 6B show alloy assemblies prepared according to the present invention, while FIG. 6C shows an alloy prepared according to the prior art. As shown, the mappings of FIGS. 6A and 6B compare well with FIG. 6C demonstrating uniform zinc distribution in the surface layer (as a corrosion protector) for the assemblies in FIGS. 6A and 6B .
The brazability of the coatings, using known processes, was examined using small assemblies of cladless fin stock and extruded aluminum tubes with the kinetic sprayed coatings. Brazing was conducted at a brazing temperature of about 600° C. for about 5 to about 15 minutes under about 1 atmosphere of nitrogen. The brazing properties of the coatings were evaluated by cross-sectional SEM examination of the brazed joints. Pull tests were also performed to demonstrate the critical load needed to pull off a fin from the aluminum tube. The results are summarized as follows.
Composite coatings of zinc and aluminum-silicon alloy: These coatings generally exhibited good brazability under pre-fluxing conditions. The flux was applied prior to brazing experiments by either dipping or spraying the small assemblies with an alcohol or a water solution having a flux concentration of from about 5% to about 20%. FIGS. 7A and 7B provide SEM micrographs of the brazing results for 15% and 20% by weight zinc, respectively. As shown, very homogeneous and well-shaped brazing joints were formed. Pull tests were also conducted on the brazed joints as shown in table 1 below. Brazed components of the present invention compared well with commercially available products known in the art (having a threshold of about 10.2±1.2 kg). The results further showed that there was no significant dependence of brazing results based upon variations in the tested compositions or the average coating thickness (i.e. the loading of a coating).
TABLE 1
Brazing properties of small fin and tube assemblies
using kinetic spray deposited composite coatings of
zinc and aluminum-silicon alloy
Results of Brazing
Brazing Conditions
Pre-fluxed
Temp
Time
N 2
Brazing
Not-fluxed
Starting Powders
(° C.)
(Min)
(atm)
Result
Pull Tests
Brazing Result
6% Zn +
600° C.
10
1
Good
12.8 ± 0.9 kg
BWH
94% Al—Si
Failed at
Fin/Joint
10% Zn +
600° C.
10
1
Good
13.8 ± 1.0 kg
BWH
90% Al—Si
Failed at
Fin/Joint
15% Zn +
600° C.
10
1
Good
10.9 ± 0.8 kg
BWH
85% Al—Si
Failed at
Fin/Joint
20% Zn +
600° C.
10
1
Good
11.4 ± 1.1 kg
BWH
80% Al—Si
Failed at Fin
BWH: breakable with hands
For the standard product, failures under the pull test occur at 10.2 ± 1.2 kg. and breakage predominantly takes place at braze joint.
Composite coatings of aluminum and zinc: Without using flux, good brazing results were achieved for high zinc-content coatings. FIG. 8 depicts a small assembly of tubes brazed to aluminum fin material using a high zinc-content aluminum/zinc coating according to the process of the present invention. The assembly was brazed at 600° C. for 8 minutes in a nitrogen atmosphere without flux. Scanning electron micrographs show the difference in the surface morphology of the tube before brazing ( FIG. 9A ) and after brazing (FIG. 9 B), showing that the braze composition coating on the tube surface melted as necessary to form a joint. The brazing results for selected aluminum and zinc coatings are summarized in Table 2. While brazability was better for pre-fluxed substrates, brazing without pre-fluxing was demonstrated.
TABLE 2
Brazing conditions and results using the composite
aluminum and zinc coatings
Brazing Results
Starting Powder A
Starting Powder B
Brazing Conditions
Al (40%) + Zn (60%)
Al (60%) + Zn (40%)
N 2
Temp
Time
Pull Test
Flux
(atm)
(° C.)
(min)
Brazability
Load/Failure
Brazability
Pull Test
No
1
600
5
Not Brazed
Not Brazed
1
600
10
Brazed
2.7 kg
Not Brazed
(UBWH)
Joint only
1
600
15
Brazed
Brazed
(UBWH)
(BWH)
Yes
1
600
5
Brazed
8.2 ± 3.8 kg
Brazed
9.4 ± 4.1 kg
(UBWH)
Joint only
(UBWH)
Joint only
1
600
10
Brazed
10.7 ± 1.0 kg
Brazed
10.7 ± 1.8 kg
(UBWH)
Joint only
(UBWH)
Joint only
1
600
15
Brazed
8.1 ± 2.2 kg
Brazed
10.1 ± 2.1 kg
(UBWH)
Joint only
(UBWH)
Joint only
UBWH: unbreakable with hands;
BWH: Breakable with hands
Composite coatings of aluminum zinc and silicon (i.e., the tri-powder coating): Coatings were tested with compositions having about 34% to about 68% aluminum, about 17% to about 51% zinc, and about 15% silicon (all by weight) with loadings of about 75 g/sq.m. (grams per square meter) to about 375 g/sq.m. All of the coatings generally showed very good brazing properties. FIGS. 10A and 10B show examples of the brazing joints produced using an aluminum-rich coating and a zinc-rich coating, respectively. Since silicon is a rapid diffuser in aluminum, the incorporation of silicon helps the melting of aluminum during the brazing process. As a result, good brazability was achieved for the tri-powder coatings with a large variation in the aluminum to zinc ratios.
Composite coatings of zinc and aluminum-silicon alloy with directly incorporated flux: Good brazability was found using flux-incorporated coatings without pre-fluxing the test assembly.
For both composite coatings of aluminum and zinc, and composite coatings of aluminum alloy and zinc, zinc was incorporated into the coatings primarily to promote coating formation as a binder and to enhance corrosion resistance. Because of the volatile nature of zinc, some loss of zinc during the brazing process is expected, while a major loss of zinc would be of concern. Elemental mapping was performed on selected specimens. The results indicate that substantially larger amounts of zinc remained on the surface of tubes than expected. FIGS. 11A and 11B show an example of elemental mapping results, indicating that zinc uniformly distributed on the surface of aluminum tubes.
Coatings of aluminum-zinc-silicon alloy: The coatings exhibited superior brazing properties. With alloy coatings, it was found that a continuous layer coating was not required to achieve satisfactory brazing results. It was also found, as shown in FIGS. 12A and 12B that the zinc was uniformly distributed in the coating, which is more desirable for corrosion protection. The results of a SWAAT test (a standard corrosion test for condensers) indicates that the assemblies brazed with aluminum-zinc-silicon alloys can have the corrosion performance equivalent to or better than a product produced using the prior art.
While the preferred embodiment of the present invention has been described so as to enable one skilled in the art to practice the process of preparing aluminum surfaces for brazing, it is to be understood that variations and modifications may be employed without departing from the concept and intent of the present invention as defined by the following claims. The preceding description is intended to be exemplary and should not be used to limit the scope of the invention. The scope of the invention should be determined only by reference to the following claims. | The present invention is directed to a process for preparing aluminum and aluminum alloy surfaces in heat exchangers for brazing by depositing thereon a kinetic sprayed brazing composition. The process simultaneously deposits monolith or composite coatings that can include all braze materials and corrosion protection materials used in the brazing of aluminum fins to plates and tubes in a single stage. | 8 |
CLAIM OF PRIORITY UNDER 35 U.S.C. §119
[0001] The present Application is a divisional of U.S. patent application Ser. No. 11/709,635, filed Feb. 22, 2007, which claims priority to Provisional Application No. 60/777,135 filed Feb. 27, 2006, and assigned to the assignee hereof and hereby expressly incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates generally to flex circuit technology. More specifically, the invention relates to using flex circuit technology to create an electrode.
BACKGROUND
[0003] Flex circuits have been used in the micro-electronics industry for many years. In recent years, flex circuits have been used to design microelectrodes for in vivo applications. One flex circuit design involves a laminate of a conductive foil (e.g., copper) on a flexible dielectric substrate (e.g., polyimide). The flex circuit is formed on the conductive foil using masking and photolithography techniques. Flex circuits are desirable due to their low manufacturing cost, ease in design integration, and flexibility in motion applications.
SUMMARY
[0004] The invention relates to a method of creating an active electrode that may include providing a flex circuit having an electrode made of a first material and providing a first mask over the flex circuit, the first mask having an offset region and an opening that exposes the electrode. The method may also include depositing a second material over the offset region and the opening, the second material being different from the first material and providing a second mask over the second material, the second mask having an opening over a portion of the second material that is over the offset region.
[0005] The invention relates to an electrode that may include a substrate having a conductive trace made of a first material, and a first mask positioned over the conductive trace, the first mask having a first opening over a portion of the conductive trace. The electrode may also include a material of interest made of a second material and positioned over a portion of the conductive trace and over a portion of the first mask and a second mask over the material of interest, the second mask having a second opening over a portion of the material of interest, the second opening being offset from the first opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The features, objects, and advantages of the invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, wherein:
[0007] FIG. 1 is a cross-section view of an active electrode that is created using a flex circuit according to an embodiment of the invention.
[0008] FIG. 2 is a top view of a flex circuit according to an embodiment of the invention.
[0009] FIG. 3 is a top view of a mask that is used to cover the flex circuit of FIG. 1 according to an embodiment of the invention.
[0010] FIG. 4 is a top view showing one or more materials of interest deposited into and above the openings in the mask according to an embodiment of the invention.
[0011] FIG. 5 is a top view of a mask that is used to cover the material of interest shown in FIG. 4 according to an embodiment of the invention.
[0012] FIGS. 6A and 6B are top views showing vertical and horizontal offsets according to various embodiments of the invention.
[0013] FIG. 7 is a flow chart showing a method of creating the electrode of FIG. 1 according to an embodiment of the invention.
DETAILED DESCRIPTION
[0014] The invention is directed toward using a flex circuit to create an active electrode. The flex circuit has a copper trace that is masked and imaged onto a polyimide substrate. Flex circuits with copper traces have a low manufacturing cost. The end of the copper trace may be plated with a first material of interest (e.g., gold). A first mask is used to create an opening for an active electrode. A second material of interest (e.g., graphite and/or platinum) may be deposited or screen-printed into the opening and on an offset region. A second mask is used to cover the second material of interest that is over the opening. A membrane may be placed over the offset region to form the active electrode. The second material of interest over the offset region acts as a diffusion barrier to prevent, for example, electrolytes from coming into contact with the copper trace. The offset region prevents the copper trace from oxidizing at a positive potential, such as would be the case for a glucose electrode measuring peroxide vs. silver-silver chloride for example.
[0015] FIG. 1 is a cross-section view of an active electrode 10 that is created using a flex circuit 100 according to an embodiment of the invention. The flex circuit 100 may include a substrate 105 , one or more contacts 110 , one or more traces 115 , and one or more electrodes 120 ( 705 ). For illustrative purposes, the contacts 110 , the traces 115 , and the electrodes 120 are shown as different elements; however, the contacts 110 , the traces 115 , and the electrodes 120 may be collectively referred to as traces and may be formed using the same material (e.g., copper). The contacts 110 , traces 115 and electrodes 120 are masked and imaged onto the substrate 105 . A mask 200 is placed over the flex circuit 100 ( 710 ). The mask 200 may have an opening 220 that expose the electrodes 120 and that receive a material of interest 300 , which is used to form the active electrode 10 ( 715 ). The material of interest 300 is also deposited over the mask 200 in an offset region 305 . The offset region 305 is shown to be adjacent to the opening 220 . A mask 400 having an opening 405 is deposited over the material of interest 300 ( 720 ). The opening 405 is located above the offset region 305 and is used for placement of a membrane 500 ( 725 ). The opening 220 is positioned along a first axis or plane and the opening 405 is positioned along a second axis or plane. The first axis or plane is not coincident with the second axis or plane. Hence, the first axis or plane is vertically and/or horizontally offset from the second axis or plane. FIGS. 1 and 6B show a horizontal offset and FIG. 6A shows a vertical offset. The horizontal offset may be along the length of the substrate 105 and the vertical offset may be along the width of the substrate 105 . The mask 200 and/or the material of interest 300 may act as a diffusion barrier to prevent electrolytes coming in from the membrane 500 from contacting the electrodes 120 . The offset region 305 prevents the electrodes 120 from undesirable electrochemical activity.
[0016] FIG. 2 is a top view of a flex circuit 100 according to an embodiment of the invention. The contacts 110 , the traces 115 , and the electrodes 120 are made of a copper material and are formed on the substrate 105 using masking and photolithography techniques. The substrate 105 may be a flexible dielectric substrate such as a polyimide. The contacts 110 are used to connect to measurement devices such as a potentiostat. The traces 115 are used to carry voltage or current from the electrodes 120 to the contacts 110 . As an example, FIG. 1 shows the flex circuit 100 having the substrate 105 , three contacts 110 a - c , three traces 115 a - c , and three electrodes 120 a - c.
[0017] FIG. 3 is a top view of a mask 200 that is used to cover the flex circuit 100 shown in FIG. 2 according to an embodiment of the invention. The mask 200 may be made of a dielectric material such as a photoimagable epoxy or an ultraviolet curable epoxy material. The mask 200 has openings 210 a - c and 220 a - c . In one embodiment, the mask 200 covers the entire top surface of the flex circuit 100 except for areas that are above the contacts 110 and/or the electrodes 120 . Hence, the openings 210 a - c are positioned directly above the contacts 110 a - c so that the contacts 110 a - c are exposed through the openings 210 a - c of the mask 200 . Similarly, the openings 220 a - c are located directly above the electrodes 120 a - c so that the electrodes 120 a - c are exposed through the openings 220 a - c of the mask 200 . Conventional lithography techniques may be used to deposit or place the mask 200 on the flex circuit 100 .
[0018] FIG. 4 is a top view showing one or more materials of interest 300 a - c deposited into and above the openings 220 a - c in the mask 200 according to an embodiment of the invention. The materials of interest 300 a - c provide a working surface for the electrodes 120 a - c . The same material of interest 300 or different materials of interest 300 may be deposited over each of the openings 220 a - c . The materials of interest 300 may be an ink or material made of carbon, gold, graphite, platinum, silver-silver chloride, rodium, palladium, other metals, and other materials having specific electrochemical properties. As an example, a platinum ink or material may be deposited over the openings 220 a and 220 c and a silver-silver chloride ink or material may be deposited over the opening 220 b. The one or more materials of interest 300 may also be deposited over offset regions 305 a - c that are adjacent to the openings 220 a - c but are not directly over the openings 220 a - c . The size of the offset regions 305 a - c may vary depending on the particular application and the arrangement and configuration of the electrodes 120 a - c . In one embodiment, the sizes of the offset regions 305 a - c are about 0.010 inches, 0.003 inches and 0.050 inches, respectively.
[0019] FIG. 5 is a top view of the mask 400 that is used to cover the material of interest 300 shown in FIG. 4 according to an embodiment of the invention. The mask 400 may be made of a dielectric material such as a photoimagable epoxy or an ultraviolet curable epoxy material. The mask 400 has an opening 405 located above the offset region 305 . In one embodiment, the mask 400 covers the entire top surface of the materials of interest 300 except for an area that is above the offset region 305 . Hence, the opening 405 may be positioned directly above the material of interest 300 , which is directly above the offset region 305 . Conventional lithography techniques may be used to deposit or place the mask 400 on the material of interest 300 .
[0020] Referring back to FIG. 1 , a membrane 500 is deposited in the opening 405 and on the material of interest 300 (i.e., a working surface) to act as a sensing region. The membrane 500 may contain, for example, a glucose oxidase enzyme. The membrane 500 may allow molecules to pass at a certain rate so the material of interest 300 can accurately measure, for example, the glucose level in blood. That is, molecules in the blood can pass through the membrane 500 at a certain rate to the material of interest 300 for a specific measurement of the glucose in the blood. The membrane 500 and/or the material of interest 300 may be suitable for immersion into a fluid or solution containing species of interest (e.g., blood) and/or electrolyte. The contacts 110 , the traces 115 , and/or the electrodes 120 may not be suitable for immersion into a fluid or solution containing species of interest and therefore should be protected by a suitable encapsulant with appropriate dielectric properties.
[0021] While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific constructions and arrangements shown and described, since various other changes, combinations, omissions, modifications and substitutions, in addition to those set forth in the above paragraphs, are possible. Those skilled in the art will appreciate that various adaptations and modifications of the just described embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A method of creating an active electrode that may include providing a flex circuit having an electrode made of a first material and providing a first mask over the flex circuit, the first mask having an offset region and an opening that exposes the electrode. The method may also include depositing a second material over the offset region and the opening, the second material being different from the first material and providing a second mask over the second material, the second mask having an opening over a portion of the second material that is over the offset region. | 8 |
CROSS-REFERENCE TO PRIOR APPLICATIONS
This application is the U.S. National Phase application under 35 U.S.C. §371 of International Application Serial No. PCT/IB2012/052902, filed on Jun. 8, 2012, which claims the benefit of U.S. Provisional Application Ser. No. 61/495,429, filed on Jun. 10, 2011. These applications are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to physiological data acquisition systems, such as polysomnography systems, and in particular to a method and apparatus for selecting differential input leads for such a system.
2. Description of the Related Art
Polysomnography, also known as a sleep study, is a multi-parametric test that is used for the purpose of diagnosing sleep disorders in people. During polysomnography, physiological data is acquired from a patient while he or she sleeps for subsequent analysis by a trained clinician. In a typical polysomnograph, the monitored parameters include such things as electrical encephalographic activity (via an electroencephalogram (EEG)); eye movements (via an electrooculogram (EOG)), muscle activity (via an electromyogram (EMG), heart rhythm (via an electrocardiogram (ECG)), respiratory effort, nasal and/or oral airflow, blood oxygen saturation (SpO 2 ), body position, exhalation CO 2 , esophageal pH, and breathing sounds (for snoring). These parameters are typically each monitored during sleep by sensors that produce analog signals which are then transmitted to an acquisition device where the data is processed and stored for analysis by a trained clinician.
For a number of the parameters that are monitored during a polysomnograph, the sensors that collect the data are electrical leads that are attached to the patient's body. For example, a polysomnograph often includes collection of EMG data relating to leg movements by attaching leads to the legs of the patient and facial muscle movement and tension by attaching leads to the patient's chin. EEG, EOG, and ECG are also monitored using electrical leads attached to the patient's body.
A recurring problem in polysomnography is the detachment of such leads from the patient during the study as a result of, for example, patient movement during sleep. When a lead becomes detached, a signal is lost from a key sleep parameter or diagnostic indicator, which adversely affects the quality of testing. In addition, detached lead(s), if discovered, require intervention by someone during the study to reattach the lead(s) to the patient. Should the clinician choose to try to reattach the lead(s), they will need to enter the patient's room, turn on the lights, and awaken the patient. This causes a disruption in the patient's sleep and a disruption in the study, since a minimum number of hours of sleep must be recorded. And, again, the clinician will need to repeat the process of traveling back and forth between the patient room and the central control room to assure the impedance is at an acceptable level upon reapplication of the leads.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provided a method and apparatus for selecting differential input leads for a physiological data acquisition system which addresses the problem of lead detachment by ensuring that an optimal pair of leads is used for data acquisition.
In one embodiment, an apparatus for acquiring physiological data from a patient is provided that includes three or more leads structured to be placed on a body of the patient, each of the leads being adapted to collect a signal relating to a particular physiological parameter from the patient, at least one AC current source, a switching mechanism structured to selectively couple the at least one AC current source to selected pairs of the leads such that at any one time the at least one AC current source will inject an AC current across only a current selected pair of the leads, wherein in response to the injected AC current, an AC voltage will be generated across the current selected pair of the leads, and a processing device. The processing device is programmed/structured to (i) determine an impedance across the current selected pair of the leads based on the AC voltage, (ii) determine whether the impedance is less than a predetermined impedance threshold, (iii) if the impedance is less than the predetermined impedance threshold cause the current selected pair of the leads to be used for generating data relating to the particular physiological parameter; and (iv) if the impedance is not less than the predetermined impedance threshold cause the switching mechanism to couple the at least one AC current source to a new current selected pair of the leads such that the AC current is injected across the new current selected pair of the leads.
In another embodiment, a method of acquiring physiological data from a patient using three or more leads placed on a body of the patient is provided, wherein each of the leads is adapted to collect a signal relating to a particular physiological parameter from the patient. The method includes injecting an AC current across a first pair of the leads, wherein in response to the injected AC current, a first AC voltage is generated across the first pair of the leads, determining a first impedance across the first pair of the leads based on the first AC voltage, determining that the first impedance is not less than a predetermined impedance threshold, responsive to determining that the first impedance is not less than the predetermined impedance threshold, injecting the AC current across a second pair of the leads, wherein in response to the injected AC current, a second AC voltage will be generated across the second pair of the leads, determining a second impedance across the second pair of the leads based on the second AC voltage, determining that the second impedance is less than the predetermined impedance threshold, and responsive to determining that the second impedance is less than the predetermined impedance threshold, using the second pair of the leads for generating data relating to the particular physiological parameter.
These and other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a polysomnography system according to an exemplary embodiment of the present invention; and
FIG. 2 is a schematic diagram of headbox 20 according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
As used herein, the singular form of “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are “coupled” shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, “directly coupled” means that two elements are directly in contact with each other. As used herein, “fixedly coupled” or “fixed” means that two components are coupled so as to move as one while maintaining a constant orientation relative to each other.
As used herein, the word “unitary” means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a “unitary” component or body. As employed herein, the statement that two or more parts or components “engage” one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
Directional phrases used herein, such as, for example and without limitation, top, bottom, left, right, upper, lower, front, back, and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.
FIG. 1 is a schematic diagram of a polysomnography system 2 according to an exemplary embodiment of the present invention. As described in greater detail below, polysomnography system 2 employs hardware and software to add redundancy to the sleep diagnostic testing in situations (e.g., EMG, EEG, etc.) wherein a differential pair of leads is needed to make physiological measurements. More particularly, three or more leads are utilized to acquire parameter signals and polysomnography system 2 continuously monitors signal integrity in differential pairs of the leads to sense degradation in a lead(s) (indicative of a wire that has become detached). If degradation is sensed, polysomnography system 2 will attempt to find and switch to an optimal pair of leads for the measurement in question.
Referring to FIG. 1 , polysomnography system 2 includes a plurality of exemplary sensors 4 that are operatively coupled to a patient 6 that is undergoing a sleep study. In the exemplary embodiment, sensors 4 include a pair of EOG leads 8 positioned near the eyes of patient 6 for measuring eye movement, a pressure transducer 10 positioned near the nostrils of patient 6 for measuring nasal and/or oral airflow, three EMG leads 12 ( 12 a , 12 b , 12 c ) positioned near the chin of patient 6 for measuring facial muscle actively and tension, a pair of ECG leads 14 positioned on opposite sides of the chest of patient 6 for measuring heart related parameters, an SpO 2 sensor 16 positioned on the finger (or, alternatively, the ear) of patient 6 for measuring blood oxygen saturation, and three EMG leads 18 ( 18 a , 18 b , 18 c ) positioned near the leg of patient 6 for measuring leg movements. It should be understood that the particular sensors 4 shown in FIG. 1 are exemplary, and that other sensors in addition to and/or in place of the sensors 4 may also be used in connection with the present invention.
As seen in FIG. 1 , polysomnography system 2 further includes a headbox 20 and a base station 22 . Each of the sensors 4 is operatively coupled to headbox 20 . Headbox 20 is an electronic processing device that receives the analog parameter signal from each of the sensors 4 , amplifies and filters each signal and converts each signal to digital form. The digital parameter signals are then output by headbox 20 to base station 22 , which is also an electronic processing device. Base station 22 then packetizes the data and further processes and stores the received digital parameter data. In addition, in the exemplary embodiment, base station 22 includes an Ethernet output that enables base station 22 to be connected to a LAN 24 . LAN 24 carries the digital parameter data to a central station or tech room where a sleep technician and/or other staff can view and analyze the data on a PC 26 using proprietary host software associated with polysomnography system 2 .
FIG. 2 is a schematic diagram of headbox 20 according to an exemplary embodiment of the present invention. For purposes of illustrating and describing the present invention, FIG. 2 only shows EMG leads 12 a , 12 b , 12 c being operatively coupled to (i.e., input into) headbox 20 . It will be appreciated, however, that as shown in FIG. 1 , the other sensors 4 are also operatively coupled to (i.e., input into) headbox 20 .
Headbox 20 includes conductors 30 and 32 to which EMG lead 12 a is coupled, conductors 34 and 36 to which EMG lead 12 b is coupled, and conductors 38 and 40 to which EMG lead 12 c is coupled. Headbox 20 also includes programmable analog switch 42 which can be selectively coupled to any one of conductors 30 , 34 and 38 , and programmable analog switch 44 which can be selectively coupled to any one of conductors 32 , 36 and 40 . Programmable analog switches 42 and 44 are controlled by a microprocessor or DSP 46 (or another suitable processing device) provided as part of headbox 20 (as shown by the dotted lines in FIG. 2 ). In addition, headbox 20 includes an instrumentation amplifier 48 or some other suitable differential amplifier device. As seen in FIG. 2 , programmable analog switch 42 is also electrically coupled to the non-inverting (+) input of instrumentation amplifier 48 through a conductor 50 , and programmable analog switch 44 is also electrically coupled to the inverting (−) input of instrumentation amplifier 48 through a conductor 52 . Headbox 20 further includes a first AC current source 54 that is coupled to conductor 50 and a second AC current source 56 that is coupled to conductor 52 . First AC current source 54 and second AC current source 56 are structured to output AC current that are 180 degrees out of phase with one another. In the exemplary, non-limiting embodiment, first AC current source 54 and second AC current source 56 is each structured to provide a low level (e.g., 2 nA peak) current set at a particular frequency (e.g., a 100 Hz or a 250 Hz square wave). This current level is well below the safety margins required by IEC60601-1 and is small enough so as to not adversely impact the physiological data carried by leads 12 a , 12 b , and 12 c . The output of instrumentation amplifier 48 is provided to an analog-to-digital converter (ADC) 58 . The output of ADC 58 is provided to microprocessor or DSP 46 .
As described below, headbox 20 is adapted to receive input from the three EMG leads 12 a , 12 b , and 12 c and automatically find the first pair of the leads 12 a , 12 b , and 12 c wherein the impedance between the leads is below a preset impedance threshold. An impedance between the pair of leads in question below the preset impedance threshold indicates that neither of the leads of the pair is detached. That pair of leads may then be used to make the EMG measurement that is needed for the polysomnography study.
In operation, an initial, default pair of leads 12 a , 12 b , 12 c is selected by coupling programmable analog switch 42 to a particular one of the leads 12 a , 12 b , 12 c (through the appropriate one of conductors 30 , 34 and 38 ) and coupling programmable analog switch 44 to another particular one of the leads 12 a , 12 b , 12 c (through the appropriate one of conductors 32 , 36 and 40 ). In the exemplary embodiment shown in FIG. 2 , that initial, default pair of leads is lead 12 a and lead 12 b . Current is then injected across the selected pair of leads 12 a , 12 b by first AC current source 54 and second AC current source 56 . As stated above, in the exemplary embodiment, the injected AC current is a low level AC current (e.g., a 2 nA peak current set at a 100 Hz or a 250 Hz square wave). In response to the injected current, an AC voltage will be generated across leads 12 a , 12 b that is proportional to the impedance between the leads 12 a , 12 b . That voltage difference is input into and differentially measured by instrumentation amplifier 48 . More specifically, as will be appreciated by those of skill in the art, instrumentation amplifier 48 will output an AC voltage that is equal to the difference in the voltage at its two inputs (+ and −) multiplied by a gain factor. Thus, the output of instrumentation amplifier 48 will be an AC voltage that is proportional to the impedance between the leads 12 a , 12 b because it is equal to the AC voltage across leads 12 a , 12 b multiplied by the gain factor of instrumentation amplifier 48 .
Next, the AC voltage output by instrumentation amplifier 48 is passed to ADC 58 where it is converted to digital form. The digital version of the AC voltage output by instrumentation amplifier 48 is then provided to microprocessor or DSP 46 . Inside microprocessor or DSP 46 , the digital AC voltage is first narrow band pass filtered (digitally). The narrow band pass filtering extracts the portion/component of the voltage signal that corresponds to and represents the voltage generated in response to the injected AC current and thus that corresponds to and represents the impedance between the selected leads 12 a , 12 b . The narrow band pass filtering does not pass the portion/component of the voltage signal that corresponds to physiological parameter measures by leads 12 a , 12 b (EMG in the exemplary embodiment). The narrow band pass filtered signal is then fully rectified (digitally) inside microprocessor or DSP 46 . The peak voltage of the rectified signal is measured and converted to an impedance value that represents the impedance between the leads 12 a , 12 b using a standard linear mathematical translation. The translation can be stated as Z=mV+b, where Z is the translated impedance value, V is the measured voltage level, and m and b are the slope and intercept of the linear translation. The values of m and b are a function of the circuit used to create the injected AC current, and are determined in practice by a calibration process which measures the observed voltage level, V, for specific known impedance values Z.
The resulting impedance value is then compared to the preset impedance threshold. In the exemplary embodiment, the preset impedance threshold is 5000 ohms, although other values may also be appropriate depending on the particulars of the application. If the resulting impedance value is less than the preset impedance threshold, then leads 12 a , 12 b are deemed to be in satisfactory condition and polysomnography system 2 will use leads 12 a , 12 b as good leads. This means headbox 20 will extract the EMG signal from the leads 12 a , 12 b , using a digital notch filtering process, and will pass that digital data on to base station 22 for further processing as discussed elsewhere herein. If, however, the resulting impedance value is not less than the preset impedance threshold, then leads 12 a , 12 b are deemed to not be a good pair. In response, microprocessor or DSP 46 will select a different pair of the leads 12 a , 12 b , 12 c (e.g., 12 a and 12 c ) by controlling programmable analog switches 42 , 44 to couple to the selected leads and the verification process just described will be repeated to determine whether that pair of leads is good. This process will continuously cycle through the three possible lead pair combinations ( 12 a and 12 b , 12 a and 12 c , 12 b and 12 c ) until a satisfactory pair is found or until the study is concluded.
In an alternative exemplary embodiment, when the digital AC voltage signal is received in microprocessor or DSP 46 from ADC 58 , a Discrete Fourier Transform (DFT) or a Fast Fourier Transform (FFT) is performed on the signal. The power level of the DFT or FFT output is then measured at the frequency that corresponds to the frequency of the injected AC current (e.g., 100 Hz or 250 Hz). That power level is then converted to an impedance value that represents the impedance between the leads 12 a , 12 b using a standard linear mathematical translation similar to the translation used for the main exemplary embodiment. The slope, m, and the intercept, b, of the alternative exemplary embodiment translation function would likewise be determined by a calibration process which measures the observed power level, V, for specific known impedance values Z. The resulting impedance value is then compared to the preset impedance threshold and processing and operation proceeds as described in connection with the main exemplary embodiment.
It should be appreciated that the present invention as just described in connection with above exemplary embodiments is not limited to using just three leads. Rather, more than three leads examined in pairs as just described may also be used to add further redundancy to polysomnography system 2 .
Furthermore, while the present invention has been described in connection with EMG leads 12 shown in FIG. 1 , it should be appreciated that it may also be used with leads that measure other parameters or make measurements at other locations. For example, as noted elsewhere herein, three EMG leads 18 are positioned near the leg of patient 6 for measuring leg movements. Those three leads 18 may be coupled to a circuit configuration within headbox 20 that is identical to that shown in FIG. 2 so that headbox 20 can find a satisfactory pair of the leads 18 by automatically finding the first pair of the leads 18 wherein the impedance between the leads is below a preset impedance threshold as described above. Also, the present invention may be applied to leads other than EMG leads. For example, an additional one or more EOG leads 8 or ECG leads 14 may be provided (resulting in three or more of such leads) so that the present invention may be employed in connection with EOG and/or ECG measurements.
Moreover, the present invention is not limited to in connection with polysomnography, but may also be used with other physiological data acquisition systems and applications. For example, and without limitation, the present invention may be employed in dedicated EEG systems and/or studies or dedicated EMG systems and/or studies.
In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” or “including” does not exclude the presence of elements or steps other than those listed in a claim. In a device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. In any device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain elements are recited in mutually different dependent claims does not indicate that these elements cannot be used in combination.
Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. | An physiological data acquisition apparatus includes three or more leads, at least one AC current source, a switching mechanism structured to selectively couple the current source to selected lead pairs to inject an AC current across the selected lead pairs which produces an AC voltage across the selected lead pair, and a processing device. The processing device is structured to (i) determine an impedance across the current selected lead pair based on the AC voltage, (ii) determine whether the impedance is less than a predetermined threshold, (iii) if the impedance is less than the predetermined impedance threshold cause the current selected lead pair to be used for generating physiological parameter data, and (iv) if the impedance is not less than the threshold cause the switching mechanism to couple the at least one AC current source to a new selected pair of the leads. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/718,862 entitled COLLAPSIBLE UMBRELLA GYM filed Sep. 20, 2005.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] The present invention generally to infant activity toys and, more particularly, to an activity gym/mat which is configured to allow toys, mobiles or similar devices to be suspended from a frame assembly thereof, and is quickly collapsible to a configuration which lends itself to easy portability.
[0004] An item known to most parents and popular with many infants toddlers is commonly referred to as an activity arch of gym. Activity arches/gyms typically comprise a rigid frame or bar having a plurality of detachable toys suspended therefrom. In those activity arches which comprise a rigid frame, such frame is typically positioned upon a horizontal support surface such as a floor, with the infant or toddler being positioned under the frame so as to be able to grasp the toys suspended therefrom. Other activity arches comprise a single bar which is adapted to be attached to a car seat or stroller in a manner allowing the infant or toddler within the car seat or stroller to be able to play with those toys suspended from the bar.
[0005] Another item known to most parents and also popular with infants and toddlers is referred to as an activity mat. Activity mats typically comprise a layer of cushioned or padded material having decorative indicia and various activity items disposed on one side or face thereof. The mat is also typically placed upon a horizontal support surface such as a floor, and provides a comfortable, clean surface upon which the infant or toddler can play or sleep.
[0006] While activity mats are able to be folded and thus are easily portable, activity arches/gyms are typically not configured in a manner facilitating portability. In this regard, those activity arches/gyms which are specifically configured for retrofit attachment to a car seat or stroller do not have the structural attributes which allow for use upon a floor or other horizontal support surface. Those activity arches/gyms which are specifically configured for such usage are typically not easily portable due to the rigid construction of the frame thereof. It would be highly desirable to provide an activity arch/gym which is easily collapsible and thus portable to allow for usage in conjunction with a mat such as an activity mat at any desired location.
[0007] The present invention addresses this particular need by providing a gym which combines the attributes of an activity arch and an activity mat, and is quickly collapsible to a configuration which lends itself to easy portability. These and other attributes of the present invention will be described in more detail below.
BRIEF SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, there is provided a collapsible umbrella gym for an infant or toddler which is highly portable, and combines the desirable attributes of an activity arch and support mat such as an activity mat. The gym comprises a frame assembly which is selectively movable between collapsed and uncollapsed states. When in its fully deployed, uncollapsed state, the frame assembly assumes a configuration which provides the functional attributes of an activity gym or activity arch, with multiple toys or mobiles being suspended from the frame assembly at locations which are easily accessible to an infant or toddler lying underneath the frame assembly.
[0009] Operatively connected to the frame assembly is a mat which is foldable into the interior of the frame assembly when the frame assembly is actuated to its collapsed state. Due to the manner in which the frame assembly is attached to the mat, the movement of the frame assembly to its fully deployed, uncollapsed state effectively maintains the mat in a fully extended, spread out orientation underneath the frame assembly, thus providing a soft, comfortable and clean surface for the infant or toddler lying under the frame assembly and playing with the toys or mobiles suspended therefrom. The frame assembly itself further includes a uniquely configured central support mechanism which is operative to maintain the frame assembly in its fully uncollapsed, deployed state, and includes a cam handle which, when actuated, quickly and easily facilitates the movement of the frame assembly to its collapsed state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] These as well as other features of the present invention will become more apparent upon reference to the drawings wherein:
[0011] FIG. 1 is a front elevational view of the umbrella gym of the present invention in its collapsed state;
[0012] FIG. 2 is a top perspective view of the gym of the present invention in its partially deployed state;
[0013] FIG. 3 is a top perspective view of the gym of the present invention in its fully deployed, uncollapsed state;
[0014] FIG. 4 is a top plan view of the central support mechanism of the frame assembly of the gym of the present invention;
[0015] FIG. 5 is an exploded view of the central support mechanism of the gym of the present invention; and
[0016] FIG. 6 is a top perspective view of the cam handle of the central support mechanism shown in FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now to the drawings wherein the showings are for the purposes of illustrating a preferred embodiment of the present invention only, and not for the purposes of limiting the same, FIG. 1 illustrates a collapsible gum 10 constructed in accordance with the present invention. In FIG. 1 , the gym 10 is shown in its fully folded, collapsed state. The gym 10 is shown in a partially deployed state in FIG. 2 , and in a fully deployed, uncollasped state in FIG. 3 .
[0018] As is best seen in FIGS. 2 and 3 , the gym 10 comprises a frame assembly 12 which itself includes a central support mechanism 14 having a plurality (i.e., four) support legs 16 attached thereto and extending therefrom. Referring now to FIGS. 4 and 5 , the central support mechanism 14 comprises an upper housing section 18 and a lower housing section 20 which, when attached to each other, collectively define an interior chamber. The combined upper and lower housing sections 18 , 20 further collectively define four radially presented openings 22 which are separated from each other by intervals of approximately ninety degrees, and are used to accommodate portions of respective ones of the support legs 16 in a manner which will be described in more detail below.
[0019] Positioned within the interior chamber collectively defined by the upper and lower housing sections 18 , 20 is a cam handle 24 , an enlargement of which is shown in FIG. 6 . A lower portion of the cam handle 24 resides within a complimentary recess 26 formed in the lower housing section 20 . The upper portion of the cam handle 24 resides within a complimentary aperture 28 formed in the approximate center of the upper housing section 18 . Cooperatively engaged to both the lower housing section 20 and cam handle 24 is a torsion spring 30 , the use of which will be described below.
[0020] As best seen in FIG. 6 , the cam handle 24 includes four arcuate cam portions 32 which protrude radially therefrom. When the cam handle 24 is operatively coupled to the upper and lower housing sections 18 , 20 , the cam portions 32 reside in the interior chamber collectively defined by the upper and lower housing sections 18 , 20 . In the central support mechanism 14 , the cam handle 24 is selectively rotatable from a locked position to an unlocked position, and is normally biased to the locked position as a result of the engagement of the torsion spring 30 thereto. The actuation/rotation of the cam handle 24 to its unlocked position is used to facilitate the movement of the frame assembly 12 to its collapsed state in a manner which will also be discussed in more detail below. In the central support mechanism 14 , the upper and lower housing sections 18 , 20 are maintained in attached relation to each other by a series of attachment pins 34 which are advanced through respective openings 36 within the lower housing section 20 and into complimentary apertures within the upper housing section 18 .
[0021] Referring now to FIGS. 2 and 5 , each of the support legs 16 comprises a rigid upper section 16 a which is pivotally connected to the central support mechanism 14 . More particularly, the upper section 16 a of each support leg 16 includes an opposed pair of outwardly protruding attachment bosses 38 which are separated from each other at an interval of approximately 180° and are each sized and configured to be rotatably nestable into respective ones of a pair of notches 40 which are formed in each of the openings 22 collectively defined by the attached upper and lower housing sections 18 , 20 . In this regard, when the bosses 38 of each upper section 16 a are captured in a respective pair of notches 40 as a result of the attachment of the upper and lower housing sections 18 , 20 to each other, each upper section 16 a is pivotally moveable relative to the central support mechanism 14 between a first position (shown in FIG. 3 ) wherein the upper sections 16 a extend radially from the central support mechanism 14 , and second position (shown in FIG. 1 ) wherein the upper sections 16 a extend in generally parallel relation to the axis of the aperture 28 , and hence the rotational axis of the cam handle 24 .
[0022] In addition to the attachment bosses 38 , the upper section 16 a of each support leg 16 includes an engagement pin 42 which protrudes axially from that end thereof disposed closest to the attachment bosses 38 . The engagement pin 42 of each upper section 16 is sized and configured to interact with the cam portions 32 of the cam handle 24 in a manner wherein the upper sections 16 a are maintained in their first positions described above when the cam handle 24 is in its normal locked position, and are pivotally moveable to their second positions described above when the cam handle 24 is actuated/rotated to its unlocked position.
[0023] Each support leg 16 of the gym 10 further comprises a rigid lower section 16 b . In the gym 10 , the lower sections 16 b of the support legs 16 are attached to a common face or side of a generally quadrangular (e.g., square or rectangular) mat 44 adjacent respective ones the four corners defined thereby. The mat 44 of the gym 10 is preferably fabricated from soft, pliable and washable materials, and may be provided with an intermediate layer of cushioning material to enhance the comfort of a toddler or infant rested thereupon. Preferably included on the side or face of the mat 44 to which the lower sections 16 b of the support legs 16 are attached is decorative indicia. It is contemplated that the lower sections 16 b of the support legs 16 may be releasably attached to the mat 44 , as opposed to being permanently secured thereto.
[0024] In addition to the upper and lower sections 16 a , 16 b , each support leg 16 comprises a flexible middle section 16 c . The middle section 16 c of each support leg 16 is attached to and extends between the upper and lower sections 16 a , 16 b . Because of its flexible construction, the middle section 16 c of each support leg 16 is preferably fabricated from a material having decorative indicia thereon which corresponds to that included on that side of the mat 44 having the lower sections 16 b attached thereto.
[0025] As indicated above, FIG. 1 depicts the gym 10 in its folded, fully collapsed state. When the gym 10 is collapsed, the upper sections 16 a of the support legs 16 are oriented in their second positions extending in generally parallel relation to the axis of the cam handle 24 of the central support mechanism 14 as explained above. As a result, the middle and lower sections 16 c , 16 b of the support legs 16 also extend in generally parallel relation to the axis of the cam handle 24 . The mat 44 is folded upwardly into the space or area defined between the collapsed support legs 16 . As is further shown in FIG. 1 , it is contemplated that the mat 44 may be outfitted with a fastening strap 46 , a portion of the mat 44 being extended about the collapsed support legs 16 and secured to itself through the use of the fastening strap 46 for purposes of maintaining the gym 10 in its fully collapsed state.
[0026] The release of the fastening strap 46 allows the support legs 16 to be pivoted outwardly relative to the central support mechanism 14 to assume the partially deployed configuration shown in FIG. 2 . When the gym 10 is in its partially deployed configuration, the mat 44 is removed from in between the support legs 16 and expanded or unfolded into a generally planar configuration. The frame assembly 12 (i.e., the combination of the central support mechanism 14 and support legs 16 ) assumes a generally pyramid shape, with the support legs 16 extending generally linearly between respective corner regions of the mat 44 and the central support mechanism 14 .
[0027] After the gym 10 has been unfolded to the partially deployed state shown in FIG. 2 , downward pressure is applied to the central support mechanism 14 in the manner shown in FIG. 3 . The application of such downward pressure causes the upper sections 16 a of the support legs 16 to be pivoted into an orientation wherein the upper sections 16 a extend generally radially from the central support mechanism 14 , thus assuming their first positions described above. Due to the configuration of the central support mechanism 14 and in particular the manner in which the cam portions 32 of the cam handle 24 engage the pins 42 of the support legs 16 , the upper sections 16 a are effectively locked into their radially extending orientations relative to the central support mechanism 14 when pivoted to the first positions as a result of the application of downward pressure to the central support mechanism 14 . As is further seen in FIG. 3 , the application of the downward pressure to the central support mechanism 14 also results in the flexible middle sections 16 c of the support legs 16 each assuming a generally arcuate configuration. Importantly, the middle sections 16 c are maintained in such arcuate configurations when the upper sections 16 a are locked into their first positions in the above-described manner. As seen in FIGS. 2 and 3 , the support legs 16 , and in particular, the middle sections 16 c thereof, each have activity items 48 such as plush toys or mobiles attached thereto and suspended therefrom. When the upper sections 16 a are locked into their first positions, the resultant arcuate configurations of the middle sections 15 c effectively places the items 48 dangling therefrom into easy, graspable reach of an infant or toddler lying upon the underlying mat 44 . It is contemplated that the items 48 may be detachably connected to the support legs 16 . The movement of the upper sections 16 a into their locked first positions effectively places the gym 10 into its fully deployed, uncollapsed state.
[0028] The return of the gym 10 to its fully folded, collapsed state is accomplished by actuating the cam handle 24 from its normal locked position, to its unlocked position. Upon the rotation of the cam handle 24 to its unlocked position, the cam portions 32 of the cam handle 24 act against the engagement pins 42 and the support legs 16 in a manner allowing the upper sections 16 a to be pivoted from their first positions extending radially from the central support mechanism 14 , downwardly back toward their second positions. Such downward pivotal movement of the upper sections 16 a effectively returns each of the middle sections 16 c of the support legs 16 to a generally linear configuration, and allows for the folding of the mat 44 back upwardly into the interior of the collapsed support legs 16 in the manner shown in FIG. 1 . Thus, the gym 10 is easily moveable between its collapsed and uncollapsed states, and is highly portable when in its fully folded, collapsed state.
[0029] Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention. | A collapsible umbrella gym for an infant or toddler which is highly portable, and combines the desirable attributes of an activity arch and support mat such as an activity mat. The gym comprises a frame assembly which is selectively movable between collapsed and uncollapsed states. When in its fully deployed, uncollapsed state, the frame assembly assumes a configuration which provides the functional attributes of an activity gym or activity arch, with multiple toys or mobiles being suspended from the frame assembly at locations which are easily accessible to an infant or toddler lying underneath the frame assembly. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to an enzymatic process for producing cytidine diphosphate choline (hereinafter referred to as CDP-choline) which is useful as a medicine.
CDP-choline is a biosynthetic intermediate for phosphatidyl choline (lecithin), which is a phospholipid, and is useful for the treatment of head injuries, disturbance of consciousness following cerebral surgery, Parkinson's disease, postapoplectic hemiplegia, etc.
Two kinds of processes are known for producing CDP-choline: chemical synthetic processes disclosed in Japanese Published Examined Patent Applications Nos. 6541/64, 1384/67, 6558/88, etc.; and enzymatic processes utilizing cells of microorganisms such as yeast disclosed in Japanese Published Examined Patent Applications Nos. 2358/73, 40757/73 and 40758/73 and Japanese Published Unexamined Patent Applications Nos. 109996/78, 14593/79 and 313594/88.
A feature common to these known processes is the use of cytosine nucleotides such as cytidine-5′-monophosphate (hereinafter referred to as CMP), cytidine-5′-diphosphate (hereinafter referred to as CDP), cytidine-5′-triphosphate (hereinafter referred to as CTP), and cytosine, or their precursors as starting materials.
Of these starting materials, the basic starting material, CMP, is mainly produced by the RNA (ribonucleic acid) decomposition method which provides four types of nucleotides at the same time. This method is inefficient in that it is impossible to selectively obtain CMP.
SUMMARY OF THE INVENTION
The present invention provides a process for producing CDP-choline, which comprises carrying out an enzymatic reaction using cultures of microorganisms having enzyme activities responsible for the production of CDP-choline from orotic acid and choline and/or phosphorylcholine or treatment products of the cultures as the enzyme sources and orotic acid and choline and/or phosphorylcholine as the substrates, allowing CDP-choline to accumulate in the reaction mixture, and recovering CDP-choline from said reaction mixture.
According to the present invention, CDP-choline can be produced with a high efficiency by enzymatic treatment from orotic acid which is easily available from industrial sources, not from a cytosine nucleotide or its precursor.
Orotic acid is a precursor of pyrimidine nucleotides which is used as a hepatotonic. An industrially applicable process is known for producing orotic acid by fermentation of microorganisms belonging to the genus Corynebacterium (EP-A-0312912). As a result of studies to develop a process for producing CDP-choline using orotic acid as a starting material, it has been found that CDP-choline can be produced in a high yield by enzymatic reaction in which a microorganism carrying a recombinant DNA prepared by incorporating into a vector DNA a DNA fragment containing genes coding for CTP synthetase (hereinafter referred to as pyrG), cholinephosphate cytidylyltransferase (hereinafter referred to as CCT) and choline kinase (hereinafter referred to as CKI) and a microorganism which has a high activity of producing uridine-5′-triphosphate (hereinafter referred to as UTP) from orotic acid are used in combination as enzyme sources, and orotic acid and choline and/or phosphorylcholine are used as substrates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a process for the construction of plasmid pCKG55.
FIG. 2 illustrates the structure of CCT/CKI fused protein encoded by plasmid pCK1.
FIG. 3 shows the nucleotide sequence of the N-terminal region of the gene coding for CCT/CKI fused protein carried on plasmids pCK1 and pCK55. The nucleotide sequence and the corresponding amino acid sequence is represented by, SEQ ID NO:1 and SEQ ID NO:2. The nucleotide sequence and corresponding amino acid sequence after the deletion is removed is represented by SEQ ID NO:3 and SEQ ID NO:4.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, enzymatic reaction is carried out using cultures of microorganisms having enzyme activities responsible for the production of CDP-choline from orotic acid and choline and/or phosphorylcholine or treated products of the cultures as the enzyme sources, and orotic acid and choline and/or phosphorylcholine as the substrates, whereby CDP-choline is accumulated in the reaction mixture.
In cases where orotic acid and phosphorylcholine are used as the substrates, CDP-choline can be produced by a 6-step enzymatic reaction from (1) to (6) as represented by the scheme given below. In cases where orotic acid and choline are used as the substrates, the additional step (7) is required.
The abbreviations used in the scheme stand for the following:
OMP: Orotidine-5′-monophosphate
UMP: Uridine-5′-monophosphate
UDP: Uridine-5′-diphosphate
UTP: Uridine-5′-triphosphate
The enzymes which catalyze the reactions of the steps (1) through (7) are listed below.
(1) Orotate phosphoribosyltransferase (EC 2.4.2.10)
(2) OMP decarboxylase (EC 4.1.1.23)
(3) Nucleosidemonophosphate kinase (EC 2.7.4.4)
(4) Nucleosidediphosphate kinase (EC 2.7.4.6)
(5) CTP synthetase (EC 6.3.4.2)
(6) Cholinephosphate cytidylyltransferase (EC 2.7.7.15)
(7) Choline kinase (EC 2.7.1.32)
In the reaction of the above step (1), phosphoribosyl pyrophosphate (hereinafter referred to as PRPP) is consumed and pyrophosphoric acid is formed, and in the reactions of the above steps (3), (4), (5) and (7), adenosine-5′-triphosphate (hereinafter referred to as ATP) is consumed and adenosine-5′-diphosphate (hereinafter referred to as ADP) is formed.
Therefore, it is preferred to use microorganisms which have the enzyme activities of (1)-(7) mentioned above, and further the activities of supplying PRPP and regenerating ATP. The number of microorganisms used is not limited so far as the above requirements are satisfied.
For example, as described below, it is possible to use a mixture of two kinds of microorganisms, one having some of the required activities and the other having the remaining activities. More particularly, it is possible to use a mixture of: (i) a microorganism having the enzyme activities of (5), (6) and (7) (hereinafter referred to as Microorganism A1) or a microorganism having the enzyme activities of (5) and (6) (hereinafter referred to as Microorganism A2) (Microorganisms A1 and A2 are sometimes collectively referred to as Microorganism A hereinafter); and (ii) a microorganism having the sufficient enzyme activities of (1) through (4) to form UTP from orotic acid and preferably further having the high activities of supplying PRPP and regenerating ATP (hereinafter referred to as Microorganism B).
As Microorganism A1 or A2, strains belonging to the genus Escherichia whose enzymatic activities are enhanced by recombinant DNA technology are preferably used. An example of such preferred strain is a transformant obtained by introducing a recombinant DNA pCKG55 containing the CCT and CKI genes derived from Saccharomyces cerevisiae (hereinafter referred to as yeast) and the pyrG gene derived from Escherichia coli (hereinafter referred to as E. coli ) into E. coli MM294 strain (FPRM BP-526, ATCC 33625).
The CCT gene is cloned from the yeast chromosome making use of the complementation of yeast CCT gene deficiency mutation as an index, and its entire nucleotide sequence has been determined (Eur. J. Biochem., 169, 477-486, 1987). An example of the CCT gene source is plasmid pCC41 (Biochemistry, 60, 701, 1988) constructed by inserting a Dra I fragment of 1,296 base pairs (hereinafter referred to as bp) which contains the CCT gene derived from the yeast into E. coli vector pUC18 (Gene, 33, 103-119, 1985) at Sma I site of the multi-cloning sites.
The CKI gene is similarly cloned from the yeast chromosome, and its entire nucleotide sequence has also been determined (J. Biol. Chem., 264, 2053-2059, 1989). An example of the CKI gene source is plasmid pCK1D constructed by inserting a Pst I-Hind III fragment of 2,692 bp which contains the CKI gene derived from the yeast into shuttle vector YEpM4 for the yeast and E. coli (Mol. Cell. Biol., 7, 3629-3636, 1987).
The pyrG gene is cloned from the E. coli chromosome, and its entire nucleotide sequence has been determined (J. Biol. Chem., 261, 5568-5574, 1986). An example of the pyrG gene source is plasmid pMW6 constructed by inserting a Nru I-Pst I fragment of 2,426 bp which contains the pyrG gene derived from E. coli into E. coli vector pUC8 (Gene, 19, 259-268, 1982) at the Sma I-Pst I site of multi-cloning sites.
Isolation of the plasmid DNAs from E. coli strains carrying them may be carried out according to a known method (Nuc. Acids Res., 7, 1513-1523, 1979). Cleavage of the plasmid DNAs with restriction enzymes, isolation of DNA fragments formed by the cleavage, enzymatic ligation of the DNA fragments, transformation of a host E. coli strain with a recombinant DNA, and other various procedures for genetic recombination may be carried out by known methods (e.g., T. Maniatis et al., “Molecular Cloning, A Laboratory Manual,” Cold Spring Harbor Laboratory, 1982).
Any vector can be used so far as it is capable of replication in a host microorganism. For example, when E. coli is used as the host, pUC8, pBR322 (Gene, 2, 95-113, 1977), etc. may be used.
Any microorganism can be used as the host so far as an introduced recombinant DNA can be expressed in it and it can be used in a reaction for the production of CDP-choline. For example, E. coli MM294 strain mentioned above may be used.
As Microorganism B, strains belonging to the genus Corynebacterium are preferably used. An example of preferred strain is Corynebacterium ammoniagenes (old designation: Brevibacterium ammoniagenes ) ATCC 21170.
As the medium for culturing Microorganisms A1, A2 and B, any of natural media and synthetic media can be used, so far as they appropriately contain carbon sources, nitrogen sources, inorganic matters, amino acids, vitamins, etc. which can be assimilated by the microorganisms used. The microorganisms may be cultured in a conventional manner at a controlled temperature and pH under aerobic conditions.
As the carbon sources, carbohydrates such as glucose, fructose, sucrose, maltose, mannitol and sorbitol, sugar alcohols, glycerol, starch hydrolysate, molasses, various organic acids such as pyruvic acid, lactic acid and citric acid, and amino acids such as glutamic acid, methionine and lysine can be used. Natural organic nutrient sources such as bran, cassava, bagasse and corn steep liquor can also be used.
As the nitrogen sources, ammonia, various inorganic and organic ammonium salts such as ammonium chloride, ammonium sulfate, ammonium carbonate and ammonium acetate, amino acids such as glutamic acid, glutamine and methionine, and nitrogen-containing organic materials such as peptone, NZ amine, corn steep liquor, meat extract, yeast extract, casein hydrolysate, fish meal or its digest, and chrysalis hydrolysate can be used.
Further, if necessary, potassium dihydrogen phosphate, disodium hydrogenphosphate, magnesium sulfate, sodium chloride, calcium chloride, iron chloride, copper sulfate, manganese chloride, ammonium molybdate, zinc sulfate, and other inorganic matters may be added. Vitamins, amino acids, nucleic acids, etc. may also be added, but it is not necessary to add them if they are supplied by the other components of the medium mentioned above.
Culturing is carried out under aerobic conditions, for example, by shaking culture or aeration-agitation culture. Culturing temperature is usually in the range of 15° C. to 40° C., preferably 20° C. to 35° C. It is preferred to keep the pH of the medium around neutrality during the culturing. Culturing time is usually 5 to 72 hours.
Microorganism A which is capable of producing CDP-choline from UTP and choline and/or phosphorylcholine and Microorganism B which is capable of producing UTP from orotic acid may be cultured separately, and mixed after the completion of the culturing. Alternatively, they may be inoculated in the same fermentor simultaneously and subjected to mixed culture. Further, one of the microorganisms may be cultured first and the other may be added during the culturing or after the completion of the culturing.
The thus obtained cultures of Microorganisms A and B are subjected to the reaction for CDP-choline production, as such or after being treated in various manners. For the reaction, the mixed culture of Microorganisms A and B or its treated product may be brought into contact with orotic acid and choline and/or phosphorylcholine. Alternatively, the culture of Microorganism B or its treated product may be brought into contact with orotic acid to produce UTP, and then the culture of Microorganism A or its treated product may be added together with choline and/or phosphorylcholine.
The treated products of the culture include concentrates and dried products thereof, cells recovered from the culture by centrifugation, dried cells, surfactant and/or organic solvent-treated products, lytic enzyme-treated products, immobilized cells, and preparations of enzymes extracted from the cells.
To a mixture of the culture or its treated product and the substrates are further added substances required for the reaction for the production of CDP-choline, and the reaction is carried out at pH 6 to 10, preferably 7 to 8 at a temperature of 20° C. to 50° C. for 2 to 48 hours. Examples of the substances required for the reaction include energy donors necessary for the regeneration of ATP, phosphate ions, magnesium ions, ammonium ions, surfactants, and organic solvents. It is not necessary to add these substances if the culture of the microorganisms contains them in sufficient amounts.
As the orotic acid, purified preparations and any orotic acid-containing substances which do not inhibit the reaction, for example, .orotic acid fermentation broth of a microorganism or its partially purified product, can be used. Orotic acid is used at a concentration of 0.01 to 1.0 mol/l, preferably 0.01 to 0.3 mol/l. As the choline and/or phosphorylcholine, purified preparations and any substances containing choline and/or phosphorylcholine which do not inhibit the reaction can be used. The concentration of the choline and/or phosphorylcholine is within the range of 0.01 to 3.0 mol/l, preferably within the range of 0.02 to 1.0 mol/l.
As the energy donor, carbohydrates such as glucose, fructose and sucrose, molasses, starch hydrolysate, organic acids such as pyruvic acid, lactic acid, acetic acid and α-ketoglutaric acid, and amino acids such as glycine, alanine, aspartic acid and glutamic acid can be used. The energy donor is used at a concentration of 0.02 to 2.0 mol/l.
As the phosphate ion, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acids such as tripolyphosphoric acid and tetrapolyphosphoric acid, polymetaphosphoric acids such as tetrapolymetaphosphoric acid, and inorganic phosphates such as potassium dihydrogenphosphate, dipotassium hydrogenphosphate, sodium dihydrogenphosphate and disodium hydrogenphosphate can be used. The phosphate ion is used at a concentration of 0.01 to 0.5 mol/l.
As the magnesium ion, inorganic magnesium salts such as magnesium sulfate, magnesium nitrate and magnesium chloride, and organic magnesium salts such as magnesium citrate can be used. The magnesium ion is usually added to the reaction mixture in an amount of 0.005 to 0.2 mol/l.
As the ammonium ion, aqueous ammonia, ammonia gas, various inorganic and organic ammonium salts, glutamine, yeast extract, Casamino acid, corn steep liquor, and other natural products containing glutamine can be used. The ammonium ion is usually added to the reaction mixture in an amount of 0.01 to 2.0 mol/l.
As the surfactant, any surfactant can be used so far as it promotes the production of CDP-choline. Examples of suitable surfactants include anionic surfactants such as sodium dioctyl sulfosuccinate (e.g. Rapisol manufactured by Nippon Oil and Fats Co., Ltd.) and lauroyl sarcosinate, nonionic surfactants such as polyoxyethylene cetyl ether (e.g. Nonion P-208 manufactured by Nippon Oil and Fats Co., Ltd.), and tert-amines such as alkyl dimethylamine (e.g. Tert-amine FB manufactured by Nippon. Oil and Fats Co., Ltd.). The surfactant is usually used at a concentration of 0.1 to 50 g/l, preferably 1 to 20 g/l.
As the organic solvent, xylene, toluene, aliphatic alcohols, acetone, ethyl acetate, etc. can be used. The organic solvent is usually used at a concentration of 0.1 to 50 ml/l, preferably 1 to 20 ml/l.
Recovery of the CDP-choline produced in the reaction mixture may be carried out in a conventional manner using activated carbon or anion exchange resin.
Certain embodiments of the present invention are illustrated in the following representative examples.
EXAMPLE 1
Construction of a recombinant plasmid for expressing CCT, CKI and pyrG simultaneously:
The method for the construction of a recombinant plasmid for expressing CCT, CKI and pyrG simultaneously is described below. The steps for the construction are shown in FIG. 1 .
1) Expression of CCT/CKI Fused Protein
E. coli MM294/pCC41 strain carrying plasmid pCC41 containing the CCT gene derived from the yeast chromosome (hereinafter a plasmid-carrying strain is represented in the following manner: name of host strain/name of plasmid) was inoculated into 400 ml of L medium containing 10 g/l Bacto-tryptone (Difco Laboratories), 5 g/l yeast extract (Difco Laboratories) and 5 g/l sodium chloride, and adjusted to pH 7.2. Culturing was carried out at 30° C. for 18 hours. Plasmid pCC41 was isolated from the cultured cells by the known method mentioned above. Separately, plasmid pCK1D containing the CKI gene derived from the yeast chromosome was isolated from E. coli MM294/pCK1D strain in the same manner.
The obtained pCC41 plasmid DNA (5 μg) was dissolved in 50 μl of a buffer solution comprising 10 mM Tris-HCl (pH 7.5), 50 mM NaCl, 7 mM MgCl 2 and 6 mM 2-mercaptoethanol (hereinafter buffer solutions used for the digestion reaction with restriction enzymes are named, for example, “Y-50 buffer solution” according to the NaCl concentration). To the solution were added 20 units of Hind III (Takara Shuzo Co., Ltd.; hereinafter, all the restriction enzymes used were obtained from Takara Shuzo Co., Ltd.) and 20 units of Hpa I, and digestion reaction was carried out at 37° C. for 2 hours. The reaction mixture was subjected to agarose gel electrophoresis, and the larger DNA fragment of 3,808 bp was extracted from the gel and isolated. Separately, 5 μg of pCK1D plasmid DNA was digested with Hind III and Hpa I in the same manner, and a DNA fragment of 2,297 bp was isolated.
About 0.2 μg of the thus obtained DNA fragment derived from pCC41 and about 0.05 μg of the DNA fragment derived from pCK1D were subjected to ligation reaction with 2 units of T4 ligase (Takara Shuzo Co., Ltd.) in 40 μl of a buffer solution comprising 20 mM Tris-HCl (pH 7.6), 10 mM MgCl 2 , 10 mM dithiothreitol and 0.5 mM ATP (hereinafter referred to as T4 ligase buffer) at 4° C. for 18 hours. The obtained recombinant DNA was used to transform E. coli MM294 strain, and a transformant resistant to ampicillin (50 μg/ml) was obtained.
A plasmid DNA was isolated from this transformant, and its structure was analyzed by digestion with restriction enzymes such as Hind III, Hpa I and Kpn I. As the result, it was confirmed that a plasmid of 6.1 kilobase pairs (hereinafter referred to as kb) having the desired structure was constructed. This plasmid was named pCK1 (see FIG. 1 ).
FIG. 2 shows the structure of the CCT/CKI fused protein encoded by pCK1. pCC41 has the structure wherein the Dra I fragment of 1,296 bp derived from the yeast chromosome is inserted into E. coli vector pUC18 at the Sma I cleavage site of its multi-cloning sites. pCC41 comprises a DNA sequence wherein the region coding for 24 N-terminal amino acids was deleted from the DNA sequence of the CCT gene by the Dra I digestion and the sequence coding for 11 amino acids derived from the vector lacZ gene was attached instead (see FIG. 3 ). Plasmid pCK1 comprises, as a result of the Hpa I cleavage and ligation, the DNA sequence of the CCT gene further modified by the deletion of the region coding for 14 C-terminal amino acids and, ligated thereto, the DNA sequence wherein the region coding for 31 N-terminal amino acids was deleted from the DNA sequence of the CKI gene. Thus the fused protein encoded by pCK1 has the 948 amino acid sequence.
MM294/pCK1 strain was subjected to reaction according to the method for the determination of the CCT activity described below. The reaction in which CTP and phosphorylcholine were used as the substrates resulted in the formation of CDP-choline. The same result was obtained when 5 mM choline chloride was used instead of 5 mM phosphorylcholine, and 5 mM ATP was added. These results revealed that the pCK1-carrying strain had both CCT and CKI activities.
2) Preparation of CCT/CKI Fused Protein Lacking the N-Terminal Region
In order to increase the amount of the CCT/CKI fused protein produced by the expression of the gene, CCT/CKI fused protein lacking the N-terminal region was prepared according to the method described below.
In 30 μl of Y-50 buffer solution was dissolved 2 μg of pCK1 plasmid DNA, and 15 units of Kpn I was added to the solution. Digestion reaction was carried out at 37° C. for 2 hours. To the reaction mixture were added 20 μl of Bal 31 buffer solution [100 mM Tris-HCl (pH 8.0), 60 mM MgCl 2 , 60 mM CaCl 2 and 3 M NaCl] at five-fold concentration, 46 μl of distilled water and 0.1 unit of Bal 31 nuclease (Takara Shuzo Co., Ltd.), and digestion reaction was carried out at 30° C. for 3 minutes.
Then, 100 μl of a phenol/chloroform mixture (volume ratio=1:1) was added to the reaction mixture, followed by adequate stirring to stop the reaction. The reaction mixture was subjected to centrifugation and the upper layer was separated. (The foregoing procedure is hereinafter referred to as phenol/chloroform extraction.) To the obtained aqueous layer was added a two-fold volume of ice-cooled ethanol, and the mixture was allowed to stand at −80° C. for 30 minutes, followed by centrifugation. The supernatant was discarded and the precipitate was dried under reduced pressure. (This procedure is hereinafter referred to as ethanol precipitation.) The supernatant was dissolved in 50 μl of T4 ligase buffer solution, and 1 unit of T4 ligase was added to the solution. The ligation reaction was carried out at 4° C. for 18 hours.
The thus obtained recombinant DNA was used to transform E. coli MM294 strain, and ampicillin-resistant transformants were selected and cultured. They were examined for CCT activity by the method described below, and the strain with the highest CCT activity was selected. A plasmid DNA was isolated from this transformant. By digestion with Hind III, Hpa I, Pvu II, etc. it was confirmed that the plasmid had the desired structure. The plasmid was named pCK55 (see FIG. 1 ).
The nucleotide sequence of the N-terminal region of the gene encoding the CCT/CKI fused protein on pCK55 was determined by the dideoxy method of F. Sanger at a. (J. Mol. Biol., 143, 161-178, 1980). As shown in FIG. 3, the gene codes for the fused protein which has the 936 amino acid sequence lacking the 12 amino acid sequence consisting of the 9 amino acid sequence derived from E. coli vector pUC18 and the 3 amino acid sequence derived from the CCT gene owing to the deletion of 36 bp sequence including the Kpn I cleavage site by the Bal 31 nuclease digestion.
3) Construction of a Plasmid for Expressing CCT, CKI and PyrG Simultaneously
A plasmid DNA was isolated from E. coli MM294/pMW6 strain carrying plasmid pMW6 containing the pyrG gene derived from the E. coli chromosome. pMW6 plasmid DNA (5 μg) was dissolved in 50 μl of Y-150 buffer, and 20 units of Mlu I was added to the solution. The digestion reaction was carried out at 37° C. for 2 hours. Then, phenol/chloroform extraction and ethanol precipitation were carried out, and the obtained DNA fragment was dissolved in 50 μl (total volume) of a DNA polymerase buffer solution comprising 50 mM Tris-HCl (pH 8.8), 7 mM MgCl 2 , 6 mM 2-mercaptoethanol, 7 μM EDTA, 0.25 mM dATP, 0.25 mM dCTP, 0.25 mM dGTP and 0.25 mM dTTP, and 5 units of T4 DNA polymerase (Takara Shuzo Co., Ltd.) was added to the solution. The reaction was carried out at 37° C. for 2 hours, whereby the 5′-protruding end formed by the Mlu I digestion was changed to a blunt end. The reaction mixture was subjected to phenol/chloroform extraction and ethanol precipitation, and the resulting DNA fragment was dissolved in 50 μl of Y-50 buffer solution. To the solution was added 15 units of Hind III and digestion reaction was carried out at 37° C. for 2 hours. The digest was subjected to agarose gel electrophoresis, and the larger DNA fragment of 4,652 bp was extracted from the gel and isolated. Separately, plasmid pCK55 was isolated from MM294/pCK55 strain in the same manner. The obtained pCK55 plasmid DNA (5 μg) was dissolved in 50 μl of Y-50 buffer, and 20 units of Hind III and 20 units of Pvu II were added to the solution. Digestion reaction was carried out at 37° C. for 2 hours. The digest was subjected to agarose gel electrophoresis, and the larger DNA fragment of 3,610 bp containing the CCT/CKI gene was isolated. About 0.05 μg of the thus obtained DNA fragment derived from pMW6 and about 0.2 μg of the DNA fragment derived from pCK55 were subjected to ligation reaction with 2 units of T4 ligase in 50 μl of T4 ligase buffer at 40° C. for 18 hours. The obtained recombinant DNA was used to transform E. coli MM294 strain to give an ampicillin-resistant transformant.
A plasmid DNA was isolated from this transformant, and its structure was analyzed by digestion with restriction enzymes such as Hind III, Hpa I and Kpn I. As the result, it was confirmed that the desired plasmid of 8.3 kb was constructed. The plasmid was named pCKG55 (see FIG. 1 ).
4) CCT and PyrG Activities of the Strains Carrying Recombinant DNAS
The CCT and pyrG activities of the strains carrying recombinant DNAs were determined in the following manner.
Each of the E. coli strains to be examined was inoculated into 10 ml of L medium containing 50 μl/ml ampicillin in a large test tube, and cultured at 25° C. for 18 hours with shaking. The resulting seed culture (100 μl) was inoculated into 10 ml of L medium containing 50 μl/ml ampicillin in a large test tube and cultured at 33° C. for 10 hours with shaking. The culture (500 μl) was subjected to centrifugation and the supernatant was discarded. The obtained cells were suspended in 500 μl of a 20 mM potassium phosphate buffer (pH 7.0), followed by addition of 5 μl of xylene. The mixture was stirred at 30° C. for 10 minutes. The thus obtained xylene-treated product was used as a crude enzyme solution whose enzymatic activity was determined in the following manner.
Determination of CCT Activity
A mixture (500 μl) comprising a 150 mM potassium phosphate buffer solution (pH 7.5), 25 mM magnesium chloride, 5 mM CTP, 5 mM phosphorylcholine and the crude enzyme solution was subjected to reaction at 30° C. for 2 hours. The reaction mixture was intermittently taken in 50 μl portions, and 50 μl of 0.2 M acetic acid was added, followed by heating at 100° C. for 2 minutes to stop the reaction. The obtained product was centrifuged, and the supernatant was appropriately diluted with distilled water. The amount of CDP-choline produced was determined by high performance liquid chromatography. The enzyme activity was indicated as unit (U) per ml culture, one unit being defined as the amount of the enzyme which catalyzes the formation of 1 μmol of CDP-choline in one minute.
Determination of PyrG Activity
A mixture (2 ml) comprising 40 mM Tris-HCl (pH 7.1), 10 mM magnesium chloride, 1 mM ATP, 1 mM UTP, 0.2 mM GTP, 2 mM glutamine, 8 mM phosphoenolpyruvic acid and the crude enzyme solution was subjected to reaction at 38° C. for 60 minutes. The reaction mixture was intermittently taken in 200 μl portions, and 1.8 ml of 3.5% perchloric acid was added to stop the reaction.
This acid-treated reaction mixture was centrifuged, and the absorbance of the supernatant at 291 nm was measured using a calorimeter. In the 3.5% perchloric acid, little absorption of light is observed for the substrate UTP at 291 nm, whereas the product CTP shows absorption of light. Thus, the measurement of the absorbance at 291 nm provides data on the quantity of the CTP produced. The enzyme activity was indicated as unit (U) per ml culture, one unit being defined as the amount of the enzyme which catalyzes the formation of 1 μmol of CTP in one minute.
Table 1 shows the results of the determination of the CCT and pyrG activities of the strains which carry the plasmids constructed according to the present invention.
The pCKG55-carrying E. coli MM294 strain, Escherichia coli MM294/pCKG55 was deposited with the Fermentation Research Institute, Agency of Industrial Science and Technology, on Jan. 27, 1992 under the Budapest Treaty with the accession number of FERM BP-3717.
TABLE 1
CCT
pyrG
Host
activity
activity
strain
Plasmid
(U/ml)
(U/ml)
MM294
pCC41
0.052
0
MM294
pMW6
0
0.27
MM294
pCK1
0.035
0
MM294
pCK55
0.053
0
MM294
pCKG55
0.048
0.21
EXAMPLE 2
E. coli MM294/pCKG55 strain obtained in Example 1 was inoculated into 10 ml of L medium containing 50 μg/ml ampicillin in a large test tube, and cultured with shaking at 300 rpm at 25° C. for 24 hours. The resulting culture (20 ml) was inoculated into 400 ml of L medium containing 50 μg/ml ampicillin in a 2-l Erlenmeyer flask with baffles, and cultured with rotary shaking at 190 rpm at 25° C. for 16 hours.
The culture (125 ml) was transferred to a 5-l jar fermentor containing 2.5 l of a liquid medium (no pH adjustment) comprising 5 g/l glucose (separately sterilized), 5 g/l peptone (Kyokuto Seiyaku Kogyo Co., Ltd.), 6 g/l Na 2 HPO 4 , 3 g/l KH 2 PO 4 , 5 g/l NaCl, 1 g/l NH 4 Cl, 250 mg/l MgSO 4 .7H 2 O (separately sterilized), and 4 mg/l vitamin B1 (separately sterilized). Culturing was carried out at 25° C. for 11 hours, and then at 32° C. for 13 hours, with stirring (600 rpm) and aeration (2.5 l/min.). During the culturing, the pH was adjusted to 7.0 with 14% aqueous ammonia. Addition of a feed solution composed of 167 g/l glucose and 167 g/l peptone to the culture using a Perista pump was started 11 hours after the start of culturing and was continued for 13 hours at a rate of 30 ml per hour.
On the other hand, Corynebacterium ammoniagenes ATCC 21170 was inoculated into 10 ml of a liquid medium in a large test tube, the medium comprising 50 g/l glucose, 10 g/l polypeptone (Daigo Eiyo Kagaku Co., Ltd.), 10 g/l yeast extract (Daigo Eiyo Kagaku Co., Ltd.), 5 g/l urea, 5 g/l (NH 4 ) 2 SO 4 , 1 g/l KH 2 PO 4 , 3 g/l K 2 HPO 4 , 1 g/l MgSO 4 .7H 2 O, 0.1 g/l CaCl 2 .2H 2 O, 10 mg/l FeSO 4 .7H 2 O, 10 mg/l ZnSO 4 .7H 2 O, 20 mg/l MnSO 4 .4-6H 2 O, 20 mg/l L-cysteine, 10 mg/l calcium D-pantothenate, 5 mg/l vitamin B1, 5 mg/l nicotinic acid, and 30 μg/l biotin, and being adjusted to pH 7.2 with sodium hydroxide. Reciprocative shaking culture was carried out at 300 rpm at 28° C. for 24 hours.
The resulting culture (20 ml) was inoculated into 230 ml of a liquid medium having the same composition as mentioned above in a 2-l Erlenmeyer flask with baffles, and cultured with rotary shaking at 190 rpm at 28° C. for 24 hours.
The culture (250 ml) was then inoculated into 2.5 l of a liquid medium in a 5-l jar fermentor, the medium comprising 100 g/l glucose, 10 g/l meat extract, 10 g/l polypeptone, 1 g/l KH 2 PO 4 , 1 g/l K 2 HPO 4 , 1 g/l MgSO 4 .7H 2 O, 0.1 g/l CaCl 2 .2H 2 O, 20 mg/l FeSO 4 .7H 2 O, 10 mg/l ZnSO 4 .7H 2 O, 20 mg/l MnSO 4 .4-6H 2 O, 15 mg/l β-alanine, 20 mg/l L-cysteine, 100 μg/l biotin, 2 g/l urea (separately sterilized), and 5 μg/l vitamin B1 (separately sterilized), and being adjusted to pH 7.2 with sodium hydroxide. Seed culturing was carried out at 32° C. with stirring (600 rpm) and aeration (2.5 l/min.). During the culturing, the pH was adjusted to 6.8 with concentrated aqueous ammonia.
When the glucose in the supernatant of the above seed culture was completely consumed, a 350 ml portion of the culture was harvested aseptically, and inoculated into 2.5 l of a liquid medium in a 5-l jar fermentor, the medium comprising 180 g/l glucose, 10 g/l KH 2 PO 4 , 10 g/l K 2 HPO 4 , 10 g/l MgSO 4 .7H 2 O, 0.1 g/l CaCl 2 .2H 2 O, 20 mg/l FeSO 4 .7H 2 O, 10 mg/l ZnSO 4 .7H 2 O, 20 mg/l MnSO 4 .4-6H 2 O (separately sterilized), 15 mg/l β-alanine, 20 mg/l L-cysteine, 1 g/l sodium glutamate, 100 μg/l biotin, 2 g/l urea (separately sterilized), and 5 mg/l vitamin B1 (separately sterilized), and being adjusted to pH 7.2 with sodium hydroxide. The main culturing was carried out at 32° C. with stirring (600 rpm) and aeration (2.5 l/min.). During the culturing, the pH was adjusted to 6.8 with concentrated aqueous ammonia. The culturing was terminated when the glucose in the supernatant of the culture was completely consumed.
Then, 360 ml of the culture of E. coli MM294/pCKG55 and 360 ml of the culture of Corynebacterium ammoniagenes ATCC 21170 were poured into a 2-l jar fermentor, to which 100 g/l glucose, 10 g/l (47 mM) orotic acid, 8.4 g/l (60 mM) choline chloride, 5 g/l MgSO 4 .7H 2 O, and 20 ml/l xylene were added, followed by addition of distilled water to make a total volume of 800 ml. The mixture was subjected to reaction at 32° C. with stirring (800 rpm) and aeration (0.8 l/min.). During the reaction, the pH was adjusted to 7.2 with 10N sodium hydroxide, and KH 2 PO 4 was added appropriately so that the KH 2 PO 4 concentration of the supernatant of the reaction mixture could be kept at 1 to 5 g/l. By the reaction for 23 hours, 11.0 g/l (21.5 mM) CDP-choline was produced. In contrast, no CDP-choline was produced in the reaction in which 360 ml of distilled water was used instead of the culture of E. coli MM294/pCKG55. When 360 ml of distilled water was used in place of the culture of Corynebacterium ammoniagenes ATCC 21170, the quantity of CDP-choline produced was 0.7 g/l (1.4 mM).
EXAMPLE 3
The reaction was carried out in the same manner as in Example 2 except that 16.5 g/l (50 mM) phosphorylcholine was used as the substrate instead of choline chloride. By the reaction for 23 hours, 9.5 g/l (18.6 mM) CDP-choline was produced. | A process for producing cytidine diphosphate choline is provided. The process comprises carrying out an enzymatic reaction using microorganisms having the enzyme activities of cytidine-5′-triphosphate synthetase (pyrG), cholinephosphate cytidylyltransferase (CCT) and choline kinase (CKI) and a microorganism capable of producing uridine-5′-triphosphate from orotic acid as the enzyme sources, and orotic acid and choline and/or phosphorylcholine as the substrates; allowing cytidine diphosphate choline to accumulate in the reaction mixture; and recovering cytidine diphosphate choline from said reaction mixture. | 2 |
FIELD OF THE INVENTION
The present invention generally relates to the detection of alpha radiation, and, more specifically, to an alpha detector capable of detecting radiation in a high gas flow application. This invention was made with Government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
In any area where radioactive materials are handled, it is imperative, both for the protection of personnel and to avoid contamination of the environment, to continuously monitor personnel, air vents, smoke stacks, surfaces, equipment, and clothing to prevent the release of radioactive contamination. Alpha contaminants, such as plutonium and uranium, are particularly difficult to detect because plutonium primarily emits alpha radiation, and alpha radiation has very limited penetration in air. Alpha particles from typical contaminants travel only a few inches in air. It is because of this characteristic that prior alpha detectors have been useful only when used in close proximity to the point of possible radioactive emission.
In the past, several instrument designs have been utilized to detect alpha radiation. Among these are GM tubes, ionization chambers, count rate detectors, and scintillation or gas flow proportional probes. While these instruments are capable of detecting alpha particles, they do so by directly detecting incident radiation, and must be within an inch of the source of the radiation. Also, these conventional alpha particle detectors can only scan an area approximately equal to the size of the detector, and are of little value in detecting radiation in a high gas flow situation.
As used herein, the terms "long range," or "long distance," when referring to the detection capabilities of the present invention, shall mean detection from a range or distance of more than one (1) inch from the source of alpha radiation.
The primary reason for an alpha particle's short flight path in gas is its collision with air or other gas molecules. In almost all of these collisions, various of the molecular species in air or a gas are ionized. These ions, referred to herein as "gas ions," have a sufficiently long lifetime that they may be transported by mass flow of the surrounding air, or by the direct attraction of an electric field, and detected at distances much greater than the penetration distances of the original alpha particles. That is, the gas ions thus created have a longer life and area of influence than the alpha particles that created them. These are the ions that are detected by the present invention. The fact that the gas ions have a longer range than the alpha particles relieves the necessity for having a detector moved in close proximity over a person or equipment in order to detect the presence of alpha radiation.
The present invention provides an alpha monitor for use with high gas flows. It is based on technology which is contained in several U.S. Patents which disclose various devices for the long range detection of alpha particles. The first is U.S. Pat. No. 5,184,019, issued Feb. 2, 1993, for a Long Range Alpha Particle Detector. The second is U.S. Pat. No. 5,194,737, issued Mar. 16, 1993, for Single and Double Grid Long Range Alpha Detectors. The third is U.S. Pat. No. 5,187,370, issued Feb. 16, 1993, for Alternating Current Long Range Alpha Particle Detectors. The fourth is U.S. Pat. No. 5,281,824, issued Jan. 25, 1994, for Radon Detection. The fifth is U.S. Pat. No. 5,311,025, issued May 10, 1994, for Fan-less Long Range Alpha Detector. Another recently filed application bears Ser. No. 08/833020, filed Nov. 1, 1994, and is entitled "Event Counting Alpha Detector." Still another recently filed application bears Ser. No. 08/382,333, filed Feb. 1, 1995, and is entitled "Background Canceling Surface Alpha Detector." As previously described, the principle underlying each of these patents and patent applications is that alpha particles, although themselves of very short range in air, ionize various of the molecular species in air. The present invention modifies this apparatus to provide for reliable detection of alpha radiation from high gas flows, such as through an air vent or a smokestack.
The fact that long range alpha detectors, as described in the above-referenced patents and application, can detect alpha radiation at a considerable distance from its point of emanation allows for monitoring of contamination in several areas which are extremely difficult or even impossible for current detectors. However, these previous detectors would lose many ions if the gas flow velocity exceeds a certain level. The current invention is able to overcome this problem through the use of multiple signal collectors positioned parallel to the gas flow, the collectors being of alternating polarity.
It is therefore an object of the present invention to provide apparatus capable of the detection of alpha radiation in a high flow of air or other gas.
It is another object of the present invention to detect gas ions created by collision with alpha particles of both positive and negative polarities.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided an alpha detector for detecting alpha radiation in a high volume flow of gas comprising an enclosure defining openings at two ends with an odd-numbered plurality of spaced apart signal collectors insulatively mounted in the enclosure and defining first and last signal collectors. The odd-numbered plurality of spaced apart signal collectors are arranged parallel to the high volume flow of gas through the openings and comprise sufficient numbers to substantially span the enclosure so that gas ions generated within the flow of gas are electrostatically captured by the odd-numbered plurality of spaced apart signal collectors. Electrometer means are connected between the first and last signal collectors and alternating signal collectors therebetween of the odd-numbered plurality of spaced apart signal collectors and ground for measuring the flow of electrical current between adjacent signal collectors generated by the capture of the gas ions. A voltage source is connected between ground and signal planes of the odd-numbered plurality of spaced apart signal collectors not connected to the electrometer means for generating an electric field between the adjacent signal collectors. Wherein gas ions created through collision of gas molecules with alpha particles will be attracted to the plurality of spaced apart signal collectors and produce a signal in the electrometer.
In another aspect of the present invention there is provided an alpha detector for detecting alpha radiation in a high volume flow of gas comprising an enclosure defining openings at two ends with an odd-numbered plurality of spaced apart signal collectors insulatively mounted in the enclosure and defining first and last signal collectors. The odd-numbered plurality of spaced apart signal collectors are arranged parallel to the high volume flow of gas through the openings and comprises sufficient numbers to substantially span the enclosure so that gas ions generated within flow of gas are electrostatically captured by the odd-numbered plurality of spaced apart signal collectors. A voltage source is connected to the first and last signal collectors and to alternating signal collectors therebetween of the plurality of spaced apart signal collectors for generating an electric field between the adjacent signal collectors. Electrometer means are connected to the voltage source and to signal planes of the plurality of spaced apart signal collectors not connected to the voltage source for measuring a flow of electrical current between adjacent signal collectors generated by the capture of the gas ions. Wherein the gas ions created through collision of gas molecules with alpha particles will be attracted to one of the plurality of spaced apart signal collectors and produce a signal in the electrometer.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiment(s) of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematical cross-sectional side view of one embodiment of the present invention in which eleven (11) signal collectors are mounted inside an enclosure which is open to a detection volume with the signal collectors grounded through an electrometer.
FIG. 2 is a cutaway perspective view of an embodiment of the present invention employing cylindrical signal collectors for use in cylindrical applications such as smokestacks.
FIG. 3 is a schematical cross-sectional side view of one embodiment of the present invention in which eleven (11) signal collectors are mounted inside an enclosure which is open to a detection volume with the signal collectors floating ungrounded.
FIG. 4 is a graph illustrating the sensitivity of one of the embodiments of the present invention to a flow of air over a radioactive source.
DETAILED DESCRIPTION
The present invention provides apparatus for the detection of alpha radiation in a large volume flow of gas such as through air vents and smokestacks. It accomplishes this through the use of an odd number of multiple signal collectors arranged parallel to one another and to the flow of gas. The invention can be best understood through reference to the drawings.
Turning now to FIG. 1, there can be seen a cross-sectional view of one embodiment of the present invention in which detector 10 is shown connected to detection volume 11. It should be understood that although detector 10 is illustrated as having a smaller diameter than detection volume 11, this does not limit the size of detector 10 in relation to the size of a detection volume 11. Detection volume 11 is merely representative of any application to which detector 10 is applied, such as the ducting of an air vent, or the lower section of a smokestack.
As shown detector 10 includes an enclosure 12 in which an odd-numbered plurality of signal collectors 13 are insulatively mounted to one another and to enclosure 12. Use of the term "odd-numbered" plurality refers to any odd number of signal collectors 13 greater than one. Signal collectors 13 are arranged so that they are parallel both to one another and to the high volume flow of gas, and substantially span enclosure 12.
Signal collectors 13 can comprise any convenient electrically conductive material. For normal conditions, copper or aluminum could be used. Aluminum may be preferred because of its lighter weight. For more severe applications, such as in a corrosive environment, stainless steel could be used. In high temperature applications, tungsten could be used. Each signal collector 13 is spaced apart from its adjacent signal collectors 13 by a distance related to the expected gas flow speed. For many applications, a spacing distance of approximately 1.5 cm will be appropriate.
As signal collectors 13 are to collect gas ions 20 created in detector volume 11 by collisions of gas molecules with alpha radiation 21, electrometer 17 passes insulatively through enclosure 12 and is connected to the first and last signal collectors 13 which, in this embodiment, are adjacent to enclosure 12, and to alternating signal collectors 13 therebetween. Positive post 16a insulatively passes through enclosure 12 and is connected to the individual signal planes 13 which are not connected to electrometer 17, by way of conductor 17a. Negative post 16b of voltage source 16 is connected to electrometer 17 as well as to ground through electrical ground connection 18, which also grounds enclosure 12. By the use of an odd-numbered plurality of signal collectors 13, the present embodiment of the invention detects the current between the outer signal planes 13 and ground.
Signal collectors 13, for many applications can be planar as illustrated in FIG. 1. This would be preferred for square or rectangular applications, such as in air ducts. However, it may be advantageous in smokestack or other applications for signal collectors 13 to be cylindrically shaped. Such an embodiment is illustrated in FIG. 2, in which signal collectors 13 are shown inside a cylindrical enclosure 12. The wiring to the individual signal collectors 13 is omitted for clarity. The wiring of this embodiment is similar to that for planar signal collectors 13, except that the first and last signal collectors 13 are now the outer signal collector 13, and the innermost signal collector 13, respectively. The electric field for capturing ions now exists between adjacent cylindrical signal collectors 13, and between the first signal collector 13 and enclosure 12.
Enclosure 12 is preferably an electrically conductive enclosure. However, depending on the application, enclosure 12 need not necessarily be made of a conductor. The invention, for example, might be used in brick smokestacks, or in plastic duct work of some type. In this type of application, the invention might be more noisy, but would still render satisfactory output.
In these embodiments, with alternating signal collectors 13 being at the same electrical potential, an electrical field is established between adjacent signal collectors 13. Alpha decays in the gas contained in detection volume 11 will produce gas ions 20. These gas ions 20 will be transported to detector 10 and therefore to signal collectors 13, and will be attracted to either high or low polarity signal collectors 13, depending on the polarity of gas ions 20, due to the electrostatic field between adjacent signal collectors 13. The collection of gas ions 20 by signal collectors 13 produces a current in electrometer 17.
The increased ion collection area of signal collectors 13, resulting from the multiple electrostatic fields between adjacent signal collectors 13, enables detector 10 to collect a reasonable percentage of all of the gas ions 20 created in detection volume 11 even in the case of high gas flow rates. Of course, with enclosure 12 grounded along with negative post 16b, no electric field will exist between the outer signal collectors 13 and enclosure 12. Because of this, a relatively small number of ions may pass through this volume undetected.
Signal collectors 13 are insulated from each other and insulatively mounted to enclosure 12 using insulators (not shown), which must be made of a high bulk resistivity material such as LEXAN® or TEFLON®. The main requirements for the insulators are that they be capable of insulating signal collectors 13 from one another and from enclosure 12, and that they provide the necessary structural integrity to signal collectors 13.
Voltage source 16 need supply an electrostatic field of typically 10 to 200 V/cm between adjacent signal collectors 13 for proper operation of detector 10. When detector 10 is used in remote operations, it may be convenient if voltage source 16 is a battery. In many other applications, as well, use of a battery or other direct current source may be preferred.
In operation, detector 10 is placed in the flow of air or other gas to be monitored for alpha radiation. This may involve placing detector 10 into a smokestack or ducting of an air vent. Using a direct current voltage source 16, gas ions 20 created by collisions of air or other gas molecules with the short range alpha particles 21 in the air or other gas passing through detector 10 are attracted to signal collectors 13, and to the walls of enclosure 12, depending on their polarity, because of the electric field established between adjacent signal collectors 13.
In another embodiment of the present invention, a different wiring arrangement is employed. In FIG. 3 it can be seen that in this embodiment voltage source 16 has its positive post 16a connected to the signal collectors 13 which are adjacent to enclosure 12, and to alternating signal collectors 13 therebetween. Electrometer 17 is connected between the individual signal collectors 13 not connected to voltage source 16 and negative post 16b of voltage source 16. In this embodiment, enclosure 12 and negative post 16b are not grounded. This allows for collection of both positive and negative gas ions 20, improving the sensitivity of detector 10.
In a test of this embodiment, signal collectors 13 were 8 cm by 48 cm copper plates, separated from one another by a distance of 1.5 cm. Voltage source 16 supplied 45 V between adjacent signal collectors 13. Insulators were used to isolate signal collectors 13 from enclosure 12, which was electrically conductive, and were made of LEXAN®. A 2.2×10 5 dpm 238 PU source was placed at locations of 10 cm, 30 cm and 50 cm from the edges of signal collectors 13. The percentage of gas ions 20 captured by detector 10, a measure of the efficiency of detector 10, was obtained by dividing the current measured by electrometer 17 by the theoretical current expected from the radioactive source. The results are illustrated in FIG. 4, with "Detector Efficiency" plotted versus the distance of the radioactive source from signal collectors 13. Plot 30 represents the sensitivity at an airlow speed of 51 fpm; plot 31 represents the sensitivity at an airflow speed of 42 fpm; plot 32 represents the sensitivity at an airflow speed of 33 fpm; and plot 33 represents the sensitivity at an airflow speed of 11 fpm. As expected, the higher airflow speeds in this test produced the higher efficiencies. This is because more ions can reach signal collectors 13 before recombining. It should be noted that at an extremely high gas speed gas ions 20 could be transported through signal collectors 13 without being collected by signal collectors 13.
The foregoing description of the embodiments of the invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an integrated circuit package comprising an insulating substrate for receiving a number of conductor poles that pass signals powers, and ground from an integrated circuit mounted on the integrated circuit package.
2. Discussion of the Related Art
Recently, there has been a demand in the field of integrated circuit packaging to reduce the pitch of the conductor poles received in the insulating substrates of integrated circuit packages in order to increase the speed and density, and decrease the size, of the integrated circuits that are mounted on integrated circuit packages.
The art has not been able to overcome two fundamental problems which occur when the pitch of the conductor poles becomes narrow. First, crosstalk noise becomes significantly high between the conductor poles. Accordingly, the art has failed to reach the desired density of the conductor poles and also reduce crosstalk noise. A second problem is that the characteristic impedance of the conductor poles is scatterd which causes a signal reflection noise and deteriorates signal transmission characteristics.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances and has as an object to provide an integrated circuit package having a high density of conductor poles.
A further object of the present invention is to provide an integrated circuit package having a high density of conductor poles, and reduced crosstalk noise between the conductor poles.
A still further object of the present invention is to provide an integrated circuit package having a high density of conductor poles, which have impedance matching.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects in accordance with the purpose of the invention, as embodied and broadly described herein, the integrated circuit package according to the present invention comprises an insulating substrate having holes which receive conductor poles. Metallized layers constitute a portion of the walls of a selected number of the holes to shield them for the purpose of grounding. In addition, insulating layers for insulating the metallized layers from the conductor poles are formed intermediate to the metallized layers and the conductor poles.
In the integrated circuit package according to the present invention, the conductor poles have coaxial structures in which they are shielded perfectly by the metallized layer, so that crosstalk noise between the conductor poles is greatly reduced in comparison with the prior art integrated circuit packages. Lower crosstalk noise is achieved even when the distance between the conductor poles is largely reduced to increase their density. Further, the present integrated circuit package achieves characteristic impedance matching of the conductor poles, producing reduced signal reflection noise and improved signal transmission characteristics. Still further, the present integrated circuit package provides a shielding effect even when the conductor poles are used for supplying power and not for signal transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention and, together with the description, serve to explain the objects, advantages, and principles of the invention. In the drawings;
FIG. 1 is a cross-sectional view of a main portion of an embodiment of the integrated circuit package according to the present invention;
FIG. 2 is a schematic view of an embodiment of the integrated circuit package according to the present invention; and
FIG. 3 is a graphical illustration of the relationship between the pitch of the conductor poles and crosstalk noise for a prior art integrated circuit package and the integrated circuit package according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the integrated circuit package according to the present invention will be described with reference to the drawings.
FIG. 1 depicts a cross-sectional view of a main portion of an embodiment of the present integrated circuit package, and FIG. 2 depicts a schematic view of an embodiment of the present integrated circuit package. The integrated circuit package 1 comprises an insulating substrate 2 composed of ceramic, having holes 2a which receive a selected number of conductor poles 3. Two or three layers of wiring (not shown) for leading signals are formed on one side of the integrated circuit package 1 through a polyimide layer 4. A flip chip 5 integrated circuit is mounted on a surface of the polyimide layer 4. After the flip chip 5 has been mounted, a sealing cap (not shown) is secured about the circumference of the insulating substrate 2 to seal the flip chip 5. In a further embodiment of the present invention, the integrated circuit is mounted by TAB or wire bonding.
The insulating substrate 2 is composed of AlN, Al 2 O 3 , mullite, glass ceramic, crystallized glass, Si 3 N 4 , or like ceramic materials, and it has a thickness of from about 0.5 mm to about 2 mm. Metallized layers 6 for shielding the conductor poles 3 are formed on the walls of a selected number of holes 2a which traverse the insulating substrate 2. In addition, insulating layers 7 for insulating the metallized layers 6 from the conductor poles 3 are formed on the inner surfaces of the metallized layers 6. Thus, the conductor poles 3 do not directly contact the metallized layers 6. The metallized layers 6 are connected electrically to each other through a conductive layer 9. The conductive layer 9 may be formed either on the side of the insulating substrate 2 that is adjacent to bumps 8 formed on an end portion of each conductor pole 3, or inside of the insulating substrate 2 (not shown). The bumps 8 are connected electrically to an electrode on a mother board (not shown). In a further embodiment of the present invention, instead of providing the bumps 8 on an insulating substrate, the present invention may be applied to a PGA package having pins. The conductive layer 9 is connected to a ground (not shown). In addition, an insulating film 10 composed of, e.g., polyimide resin, is formed on a surface of the conductive layer 9. The end portions of the conductor poles 3 are exposed as depicted in FIG. 1.
To produce the insulating substrate 2, first, a thin plate-like green sheet is formed of Al 2 O 3 , AlN, mullite, or a like ceramic material. The sheet is sintered in a furnace to obtain insulating substrate 2, having a thickness of from about 0.5 mm to about 2 mm. Next, a number of through holes 2a having a diameter of from about 0.1 mm to about 0.2 mm, are formed in the insulating substrate 2 by a laser, or like process. In a further embodiment of the present invention, the holes 2a may be formed in the insulating substrate 2 by a drilling or punching process prior to sintering. The pitch of the conductor poles 3 is made very narrow, preferably from about 0.20 mm to about 0.40 mm.
The metallized layers 6 are then formed on the walls of a selected number of holes 2a using a sputtering, plating, evaporating, or like process. The metallized layers 6 are formed of Al, Cu, Ag, or the like, to a thickness of not more than about 10 μm, more preferably about 5 μm. Next, the insulating layers 7 are formed on the inner surfaces of the metallized layers 6. The insulating layers 7 are composed of polyimide, glass paste, chemical vapor deposited (CVD) SiO 2 film, or the like, and have a thickness of from about 2 μm to about 20 μm. The conductor poles 3 are then formed by filling the insulating layers 7 with metals such as Al, Cu, Ag, or the like, by sputtering, plating, or casting techniques. In a further embodiment of the present invention, the conductor poles 3 may be formed as separate pin members, which are coated with an insulating layer, inserted into a selected number of the holes 2a in the insulating substrate 2, and then cured or baked.
Next, the conductive layer 9 and the insulating film 10 are formed on one side of the insulating substrate 2 by conventional techniques, and the bumps 8 are formed on the end portions of the conductor poles 3.
The relationship between the crosstalk noise and the pitch of the conductor poles is graphically illustrated in FIG. 3. The data was measured for integrated circuit packages having an insulating substrate thickness of 1.2 mm. Line A represents the measured data for the present integrated circuit package which incorporates shielding, and line B represents the measured data for a prior art integrated circuit package in which the pitch of the conductor poles in the insulating substrate was made narrow without using shielding. The data was directly measured by a TRD method.
As evident from the two plots in FIG. 3, crosstalk noise is greatly reduced in the integrated circuit package that uses shielding according to the present invention, in comparison to the prior art integrated circuit package which lacks shielding, when the pitch of the conductor poles is made narrow.
The crosstalk noise is greatly reduced in the present integrated circuit package because the holes 2a are coated with metallized layers 6 that are then coated with insulating layers 7 so that each conductor pole 3 has a coaxial structure in which the conductor pole 3 is shielded perfectly. The present invention achieves characteristic impedance matching of the conductor poles 3 which reduces the signal reflection noise to obtain an integrated circuit package 1 having improved signal transmission characteristics.
In addition, because the shielding effect persists when the pitch of the conductor poles is made narrow, the present invention achieves an integrated circuit package having a high density of the conductor poles, that is small and lightweight.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. | The present integrated circuit package provides both a high density of conductor poles, and reduced crosstalk noise between the conductor poles. The conductor poles are arranged within a selected number of holes in an insulating substrate. Metallized layers for shielding the conductor poles are provided on the walls of the holes in the insulating substrate which receive the conductor poles. In addition, an insulating layer is provided on the inner circumferences of the metallized layers, which insulating layers directly surround the conductor poles to preclude direct contact between the conductor poles and the metallized layers. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International Patent Application No. PCT/CH2012/000235 filed Oct. 15, 2012, which claims priority to Swiss Patent Application No. CH 1767/11 filed Nov. 3, 2011, the entire contents of both of which are incorporated herein by reference.
BACKGROUND
[0002] The invention concerns an administration device, in particular, an administration device with a container and a mixing device for the mixing of an active substance with a dilution liquid in the container.
[0003] An administration device with a mixing device is known from WO2008/122132A1. With this administration device, the active substance is mixed with the dilution liquid by means of a relative rotation between a two-chamber cartridge, which holds an active substance and a dilution liquid, and a mixing device.
[0004] The disadvantage with the administration device in accordance with WO2008/122132A1 is that there is the danger that the user attempts to mix the active substance with the dilution liquid, before the needle was thrust into the two-chamber cartridge and consequently, an effective mixing is hindered, since, in particular, a gas formed during the mixing or a gas already contained in the two-chamber cartridge cannot escape. Moreover, there is the risk that the user may inject into the skin a fluid active substance that is only partially mixed.
[0005] In the following, the proximal direction with an administration device with an injection needle unit denotes the direction to the administration device and the distal direction, the direction to the injection needle unit.
SUMMARY
[0006] A goal of the device is to make available an administration device for the administration of a fluid active substance from a container, which ensures a previous thrust of the injection needle into the container and a mixing and/or priming of the active substance with the dilution liquid for the active substance.
[0007] The goal is attained by the administration device in accordance with Claim 1 . Advantageous embodiments of such an administration device can be deduced from the dependent claims.
[0008] The device is based on an administration device for the administration of a fluid active substance from a container with at least one chamber with an active substance and a second chamber with a dilution liquid for the active substance. The container can be a cartridge, in which the active substance and the dilution liquid are directly held, or a cartridge holder, which comprises a cartridge with the active substance and the dilution liquid.
[0009] The container also has a membrane for sealing at one end. Preferably, the first chamber of the container can be limited by a first stopper and the second chamber, by the first and a second stopper. The chambers can be connected, via a bypass, in one wall, so as to make possible a mixing of the active substance with the dilution liquid.
[0010] Moreover, the administration device comprises a mixing device for the mixing of the active substance with the dilution liquid for the active substance. The mixing device can provide a sealing with respect to the second stopper. By a movement of the container relative to the mixing device, the second stopper and the first stopper can be pushed within the container as a result of the transfer of the force of the dilution liquid in the second chamber, until the first stopper has reached the area of the bypass. With additional movement of the container, relative to the mixing device, the second stopper is moved relative to the container, so that the dilution liquid arrives at the first chamber through the bypass and is mixed with the active substance. The mixing device can comprise a drive element, in particular, a piston rod, for the mixing of the active substance with the dilution liquid and for the administration of the mixed product, and a housing to hold the piston rod. During the mixing operation, the container can move axially, relative to the piston rod and the housing, and can preferably rotate. The container can be preferably thrust radially into the administration device, between the piston rod and the housing. The piston rod can be designed as a toothed rod or as a threaded rod and can be actuated manually as well as be driven by an electrical or mechanical drive, in particular, a spring.
[0011] The mixing device can thus be part of an administration mechanism of the administration device, wherein the container can be uncoupled from the administration mechanism, so as to couple a new container, after the old emptied container was disposed of. The administration mechanism can also provide a release knob and the administration mechanism is activated by its actuation, so that a mixed active substance from the container can be injected into the skin with an injection needle unit installed on the administration device. Furthermore, the administration device can comprise another safety device, which ensures that an injection can be carried out only after a complete mixing and/or priming of the active substance with the dilution liquid. To this end, the administration mechanism can have a blocking unit, which prevents the actuation of the release knob if the blocking device is in the blocking position. The blocking device can be moved from the blocking position into a release position, in which the release knob can be actuated for the administration of the mixed active substance. By rotating the container, relative to the mixing device, it is possible to move the blocking device from the blocking position to the release position. Therefore, by rotating the container, the administration device can be released and the administration mechanism can be released with the release knob. Such a blocking unit is described in WO2009/100550A1. WO2009/100550A1 is hereby completely assumed, by reference, into the document under consideration.
[0012] In one embodiment, the piston rod can also be designed in such a manner that it comprises a holding device, which holds the cartridge in a cartridge holder, in a defined position, relative to the housing. This arrangement can prevent too large a clearance between the individual components of the administration device and ensure a precise mode of functioning of the administration device. Such an arrangement is described in WO2009/100549A1, wherein WO2009/100549A1 is hereby completely incorporated by reference into this document.
[0013] Moreover, the administration device comprises an injection needle unit, which has a distal needle portion, turned away from the container, for piercing the skin, and a proximal needle portion, which lies opposite, facing the membrane, in an initial position of the administration device and which is thrust through the membrane into the container in a mixing position. If the proximal needle portion is thrust through the membrane into the container, the proximal needle portion can bring about a fluid connection with the container. Thus, during the mixing of the active substance with the dilution liquid, a formed gas or a gas already contained in the container can escape, during the mixing operation and/or the priming operation, through the injection needle of the injection needle unit.
[0014] The injection needle unit can be designed as a safety needle unit, which comprises a protective shield, which, during the injection into the skin, can be moved from a distal position, in which the protective shield surrounds the distal needle portion for the piercing of the skin, into a proximal position, in which the distal needle portion is exposed. After the injection, the protective shield can again go to a distal position, in which the protective shield is locked so that it cannot be detached, so as to prevent another injection with the injection needle unit used. Such an injection needle unit is described in WO2008/028394A1, wherein WO2008/028304A1 is hereby completely incorporated by reference into this document.
[0015] The administration device also comprises a protective sleeve, which can be arranged coaxially around the injection needle unit and which, in the initial position, relative to the container, with the injection needle unit, held by the protective sleeve, can be moved in the proximal direction, in particular, only in the proximal direction.
[0016] According to another aspect of the device under consideration, the protective sleeve can be rotated, in the initial position, relative to the container.
[0017] Moreover, in the mixing position, the protective sleeve can be connected with the container so it cannot rotate and so it can rotate relative to the mixing device, so as to mix the active substance with the dilution liquid for the active substance. A torque transfer from the protective sleeve to the container can be carried out directly via a detachable connection between the protective sleeve and the container or, indirectly, via a torque transfer means, in particular, via a sleeve, wherein the torque transfer means can enter into a detachable connection with the protective sleeve and/or the container. Before the nonrotating connection between the protective sleeve and the container can be brought about in the mixing position, at least the proximal needle portion of the injection needle unit must be thrust through the membrane into the container.
[0018] Preferably, a sleeve, in particular, a guide sleeve, can be situated between the injection needle unit and the protective sleeve. The guide sleeve can be connected firmly and axially on a proximal end with the container. Preferably, the guide sleeve can rotate, relative to the container. The connection between the guide sleeve and the container can be brought about by form locking or force locking. With particular preference, a recess can be provided in the guide sleeve, which interacts with a projection that protrudes to the outside and is located on the container, in particular, a surrounding wedge toward the outside, in such a way that an axially firm and preferably rotatable connection between the guide sleeve and the container can be brought about. The projection of the container can lock into the recess of the guide sleeve. In an alternative embodiment, it is possible to lock a projection provided on the guide sleeve, in particular, a surrounding wedge, into a recess provided on the container.
[0019] In accordance with the device, the guide sleeve can be advantageously rotated, relative to the container, in the initial position or in the mixing position. Furthermore, the protective sleeve can be stationary, relative to the guide sleeve, in the initial position or in the mixing position.
[0020] Moreover, the injection needle unit can be preferably held so it can move axially in the guide sleeve. The injection needle unit can be held so it can move axially in the guide sleeve, in such a way, that the proximal needle portion of the injection needle unit, in the initial position of the administration device, is opposite, facing the membrane, and wherein, the proximal needle portion of the injection needle unit, in the mixing position, is thrust through the membrane into the container.
[0021] Preferably, the protective sleeve can have a locking element that can be clamped, which, in the initial position, interacts with the guide sleeve, in such a way, that the protective sleeve with the injection needle unit held therein can be moved, relative to the container, in the proximal direction, in particular, only in the proximal direction. The locking element can be designed so it can be clamped in an elastic manner. The locking element can have the shape of a flap, in particular, as a bendable or bending-elastic flap. Preferably, the locking element, shaped as one piece on the protective sleeve, or the locking element, placed on the protective sleeve, can swivel radially, relative to the protective sleeve, or be radially and elastically deformable, relative to the protective sleeve. Preferably, the locking element can be, in the initial position, in a stop contact with the guide sleeve, and can prevent a relative movement of the protective sleeve to the guide sleeve or to the injection needle unit or to the container in the distal direction. Alternatively, the protective sleeve, in the initial position, can first be moved, relative to the guide sleeve, in the distal direction, until an additional relative movement in the distal direction is prevented by a stop contact between the locking element and the guide sleeve. Preferably, the guide sleeve can have a recess which is designed, in such a way, that a relative movement of the protective sleeve of the protective sleeve to the guide sleeve is permitted in the proximal direction and is prevented in the distal direction.
[0022] A stop surface of the locking element and a counter-surface of the recess of the guide sleeve form the stop contact between the locking element of the protective sleeve and the recess of the guide sleeve.
[0023] In the initial position, the protective sleeve can be held firmly and axially, relative to the guide sleeve, via a force- or form-locking connection, in particular, a groove/cam connection; in particular, it can be held firmly and axially in the proximal direction. The user can apply a force in the proximal direction which exceeds the holding force of the groove/cam connection, against the protective sleeve. The groove/cam connection can be loosened and the protective sleeve held with the injection needle unit can be moved, relative to the container, in the proximal direction.
[0024] Depending on the arrangement of the groove/cam connection, relative to the locking element of the protective sleeve and to the recess of the guide sleeve, a relative movement may be at least partially possible, in the initial position, between the protective sleeve and the guide sleeve, in the distal direction, until the locking element arrives at the stop contact with the recess. In the stop contact, between the locking element and the recess, the protective sleeve cannot be moved in the distal direction, relative to the guide sleeve. The protective sleeve cannot be removed from the injection needle unit.
[0025] Furthermore, the locking element of the protective sleeve can interact, in the mixing position, with the guide sleeve, in such a way, that the protective sleeve can be moved, relative to the container, in the distal direction.
[0026] In one embodiment of the device, the guide sleeve can have a guide mechanism, wherein the locking element of the protective sleeve can be guided along the guide mechanism. The guide mechanism can have a ramp on one end of the guide and a steep front edge on the other end of the guide. In the initial position, the locking element can impact, with a stop surface, against the front edge of the guide mechanism. The locking element can thus form a stop and the front edge of the guide mechanism, a counterstop. The locking element of the protective sleeve can be brought to a mixing position, via a piercing position, wherein the proximal needle portion of the injection needle pierces the membrane. In the mixing position, the locking element can slide over the ramp-like slope. By a rotation of the protective sleeve, relative to the guide sleeve, the administration device can arrive at the mixing position. The protective sleeve can be moved, with the locking element in the distal direction, relative to the guide sleeve or to the injection needle unit or to the container, only if a rotational movement of the protective sleeve with the locking element has taken place, relative to the guide sleeve. In the mixing position, the protective sleeve can be removed from the injection needle unit.
[0027] In one embodiment of the device, the locking element of the protective sleeve can be sufficiently moved in the proximal direction, relative to the guide sleeve, so as to attain the mixing position, until, on the one hand, the proximal needle portion of the injection needle unit has pierced the membrane and until, on the other hand, the locking element has slid over the proximal end of the guide sleeve and has relaxed, in particular, has relaxed in an elastic manner. The locking element can then protrude into a recess of the container or into a recess formed by the proximal end of the guide sleeve and a shoulder of the container or between projections, in particular, ribs, placed on the container. If the protective sleeve is moved, relative to the guide sleeve or to the injection needle unit or to the container, in the distal direction, the locking element of the protective sleeve is pretensioned by the guide sleeve; in particular, it is elastically pretensioned and can then slide over the guide sleeve and its recess. The protective sleeve can, therefore, be removed from the injection needle unit.
[0028] In one embodiment, the nonrotary connection between the protective sleeve and the container can be brought about, in the mixing position, by an intrusion between the container, in particular, the projection provided on the container, and a snap arm, which is located on the guide sleeve. On the guide sleeve, several snap arms can be provided, and on the container, several projections. The snap arm placed on the guide sleeve can form the torque transfer means. The guide sleeve can intrude in a nonrotary connection with the protective sleeve—in particular, a connection which does not rotate in a rotary direction. The guide sleeve, which is connected in a nonrotary manner with the protective sleeve, can transfer a rotating movement of the protective sleeve to the container by means of the snap arm provided on the guide sleeve.
[0029] If the protective sleeve is moved, relative to the container in the proximal direction, with the injection needle unit, held therein, the protective sleeve can slide over the guide sleeve and place the snap arm under tension, radially inwards. The snap arm can be pretensioned, radially inwards, in the piercing position and in the mixing position, in particular, elastically pretensioned. Preferably, the snap arm can act against the projection placed on the container, in the mixing position, and forms the intrusion between the container and the snap arm of the guide sleeve. The intrusion is used to bring about a nonrotary connection, in particular, a connection that does not rotate in a rotary direction, via the snap arm, between the protective sleeve and the container. If the user takes hold of the protective sleeve and rotates it relative to the mixing device, the container can be rotated, via the snap arm of the guide sleeve, relative to the mixing device, so as to mix the active substance with the dilution liquid for the active substance in the container. After the mixing operation has ended, the administration device can also be primed with another relative rotation between the container and the mixing device. A gas contained in the container and/or in the injection needle is thereby expelled, so that the administration device is ready for the injection into the skin.
[0030] In order to arrive at the mixing position, the protective sleeve, connected with the guide sleeve, in a manner that does not rotate, at least in one rotary direction, must preferably be rotated for the moment, before the snap arm placed on the guide sleeve acts against the projection placed on the container and brings about the intrusion between the container and the snap arm. In a particularly preferred embodiment, the protective sleeve must, for the moment, be rotated with the locking element, relative to the guide sleeve, so that the locking element is guided along the guide mechanism of the guide sleeve, until a connection between the locking element and the guide sleeve, which does not rotate in at least one rotary direction, is formed. With a further rotation of the protective sleeve, the locking element takes along the guide sleeve by means of the stop contact between the locking element and the guide mechanism, until the snap arm of the guide sleeve strikes on a projection provided on the container and takes along the container.
[0031] The user can thus also rotate the container, via the guide sleeve, relative to the mixing device by means of a rotation of the protective sleeve, relative to the mixing device, and bring about an effective mixing of the active substance with the dilution liquid. In particular, the user can radially screw the container, via the guide sleeve, into the administration device, between the housing and the drive element, in particular, the piston rod, by rotating the protective sleeve, relative to the mixing device, wherein the drive element, in particular, the piston rod, acts on the second stopper and brings about a mixing operation and/or priming operation.
[0032] In one embodiment, the nonrotary connection between the protective sleeve and the container can be brought about in the mixing position by an intrusion between the container and the protective sleeve or the locking element of the protective sleeve. The protective sleeve can move axially, relative to the guide sleeve, in the proximal direction. In the mixing position, the locking element or a part of the protective sleeve can protrude into a recess of the container or into a recess formed by the proximal end of the guide sleeve and a shoulder of the container or between projections placed on the container, especially, ribs, and strike against a projection provided on the container, especially, a rib, or against a stop surface surrounding the recess, and thus bring about the intrusion between the container and the protective sleeve or the locking element. In the mixing position, a connection that does not rotate, at least in one rotary direction, is brought about between the protective sleeve and the container. The locking element or the part of the protective sleeve can essentially extend, relaxed or elastically relaxed, into the recess of the container or into the recess formed by the proximal end of the guide sleeve and a shoulder of the container, or between projections placed on the container, especially, ribs.
[0033] Preferably, in the mixing position, the intrusion between the container and the protective sleeve or the locking element can be formed in such a way that, for the moment, the protective sleeve must be rotated, relative to the container, before the locking element or a part of the protective sleeve interferes with the container.
[0034] By a rotation of the protective sleeve, relative to the mixing device, the container can be rotated radially, relative to the mixing device; in particular, relative to the administration device, it can be screwed in between a housing and the piston rod. The mixing operation and/or the priming operation can thus be effectively accomplished.
[0035] The intrusion between the container and the snap arm of the protective sleeve as well as the intrusion between the locking element or the part of the protective sleeve can also be formed by another form-locking and/or force-locking intrusion. The intrusion can be a ribbed connection, groove/wedge connection, pin/borehole connection, stop connection, or snap connection.
[0036] Preferably, the administration device can have an indicating device, which comprises at least a first indication for the marking of a position of the container, relative to the mixing device, after ending the mixing operation and a second indication for the marking of a position of the container, relative to the mixing device, after ending the priming operation. To this purpose, a visual, acoustic, or tactile indicating device can be provided on the administration device, in particular, on the container, which indicates the position of the container, relative to the mixing device. Furthermore, locking positions can be provided for the indication of the individual position with the individual steps of the preparation of the administration device, such as the mixing and priming, which are formed by a reverse lock, by means of which it is no longer possible to remove the container, contrary to its introduction direction, from the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The device is described below on several figures. The features hereby disclosed refine the device advantageously, individually and in combination. The figures show the following:
[0038] FIG. 1 a shows a first embodiment of an administration device, in an initial position, in an external view.
[0039] FIG. 1 b shows the administration device of the first embodiment, in the initial position, in a longitudinal section.
[0040] FIG. 2 shows an enlarged, detailed view in a longitudinal section of an injection needle unit of FIG. 1 b , placed on the administration device.
[0041] FIG. 3 shows a perspective representation of the position of a locking element of a protective sleeve in a guide mechanism of a guide sleeve of the administration device of the first embodiment, in the initial position.
[0042] FIG. 4 shows an enlarged, perspective top view, in a longitudinal section of the injection needle of FIG. 1 b , placed on the administration device.
[0043] FIG. 5 shows an enlarged, perspective detailed view, in an external view of the injection needle unit of FIG. 1 b , placed on the administration device.
[0044] FIG. 6 a shows the administration device of the first embodiment, in a piercing position, in an external view.
[0045] FIG. 6 b shows the administration device of the first embodiment, in the piercing position, in a longitudinal section.
[0046] FIG. 7 shows an enlarged detailed view, in a longitudinal section of the injection needle unit of FIG. 6 b , placed on the administration device.
[0047] FIG. 8 shows a perspective representation of the position of the locking element of the protective sleeve in the guide mechanism of the guide sleeve of the administration device of the first embodiment, in the piercing position.
[0048] FIG. 9 shows an enlarged, perspective, detailed view, in a longitudinal section of the injection needle unit of FIG. 6 b , placed on the administration device.
[0049] FIG. 10 a shows the administration device of the first embodiment, in the mixing position, in an external view.
[0050] FIG. 10 b shows the administration device of the first embodiment, in the mixing position, in a longitudinal section.
[0051] FIG. 11 shows a perspective representation of the position of the locking element of the protective sleeve in the guide mechanism of the guide sleeve of the administration device of the first embodiment, in the mixing position.
[0052] FIG. 12 a shows the administration device of the first embodiment, in the mixed and/or primed position, in an external view, wherein the protective sleeve can be removed from the injection needle unit.
[0053] FIG. 12 b shows the administration device of the first embodiment, in the mixed and/or primed position, in a longitudinal section, wherein the protective sleeve can be removed from the injection needle unit.
[0054] FIG. 13 shows a perspective representation of the position of the locking element of the protective sleeve, in the guide mechanism of the guide sleeve of the administration device of the first embodiment, during the removal of the protective sleeve from the injection needle unit.
[0055] FIG. 14 a shows the administration device of the first embodiment, in the shaken out state, in an external view.
[0056] FIG. 14 b shows the administration device of the first embodiment, in a shaken-out state, in a longitudinal section.
[0057] FIG. 15 a shows a second embodiment of an administration device, in an initial position, in an external view.
[0058] FIG. 15 b shows the administration device of the second embodiment, in the initial position, in a longitudinal section.
[0059] FIG. 16 shows an, enlarged, detailed view, in a longitudinal section of an injection needle unit of FIG. 15 b , placed on the administration device.
[0060] FIG. 17 shows an enlarged, detailed view, in a longitudinal section of the intrusion between a locking element of a protective sleeve and a recess of a guide sleeve, in the initial position of the injection needle unit of FIG. 15 b , placed on the administration device.
[0061] FIG. 18 a shows the administration device of the second embodiment, in a mixing position, in an external view.
[0062] FIG. 18 b shows the administration device of the second embodiment, in the mixing position, in a longitudinal section.
[0063] FIG. 19 shows an enlarged, detailed view, in a longitudinal section of the injection needle unit of FIG. 18 b , placed on the administration device.
[0064] FIG. 20 shows an enlarged, detailed view, in a longitudinal section of the intrusion between the locking element of the protective sleeve and the projection of the cartridge holder, in the mixing position of the injection needle unit of FIG. 18 b , placed on the administration device.
DETAILED DESCRIPTION
[0065] FIGS. 1 a and 1 b show a first embodiment of an administration device, in an initial position, in an external view and in a longitudinal section. The administration device comprises a cylindrical cartridge holder ( 1 ), in which a cartridge ( 1 d ) is supported, and a mixing device for the mixing of an active substance, held in a first chamber ( 1 e ) of the cartridge ( 1 d ), with a dilution liquid, which is contained in a second chamber ( 1 f ) of the cartridge ( 1 d ). The chambers ( 1 e , 1 f ) of the cartridge ( 1 d ) can be connected, via a bypass ( 1 g ), in a wall of the cartridge ( 1 d ). The cartridge ( 1 d ) has a first stopper ( 1 h ) and a second stopper ( 1 j ). The second stopper ( 1 j ) seals the cartridge ( 1 d ) on the proximal end. On the distal end, the cartridge ( 1 d ) exhibits a tapering, whose opening is sealed off by a membrane ( 2 ). An injection needle unit ( 4 ) is placed on the administration device, on the distal end of the administration device and is connected with the cartridge ( 1 d ), via a cylindrical guide sleeve ( 6 ) and the cartridge holder ( 1 ). A proximal needle portion ( 4 b ) of the injection needle unit ( 4 ) lies, in the initial position of the administration deice, opposite the membrane ( 2 ) of the cartridge ( 1 d ), wherein the proximal needle portion ( 4 b ) protrudes into the guide sleeve ( 6 ) on the distal end of the guide sleeve ( 6 ). A sleeve-shaped protective sleeve ( 5 ) surrounds the injection needle unit ( 4 ). The protective sleeve ( 5 ) comprises a grip ( 5 a ) with longitudinal ribs, which make it possible for the user to have a better grip of the protective sleeve ( 5 ), and a protective part ( 5 b ), which surrounds the injection needle unit ( 4 ), so that the user is protected from an injury with an injection needle of the injection needle unit ( 4 ), in particular, a distal needle portion ( 4 a ). The grip ( 5 a ) and the protective part ( 5 b ) of the protective sleeve are axially connected with one another in a firm and nonrotary manner.
[0066] The injection needle unit ( 4 ) is designed as a safety needle unit, wherein the injection needle unit ( 4 ) comprises a protective shield ( 4 f ). The protective shield ( 4 f ) is situated on the injection needle unit ( 4 ) in such a manner that, during the injection, the protective shield can be moved into a proximal position, in which the distal needle portion ( 4 a ) is exposed, from a distal position, in which the protective shield ( 40 surrounds the distal needle portion ( 4 a ) for the piercing of the skin. After the injection, the protective shield ( 4 f ) can again move into the distal position as a result of an impingement of a spring force of a spring ( 4 g ) of the safety needle unit ( 4 ), wherein the protective shield ( 4 f ) is locked, in a nondetachable manner, by means of a locking device, so as to prevent another injection with the used injection needle unit ( 4 ).
[0067] A piston rod ( 3 a ) and a housing ( 3 b ) form the mixing device. The cartridge holder ( 1 ) is situated radially between the piston rod ( 3 a ) and the housing. The cartridge holder ( 1 ) has an outside thread, which is engaged with an inside thread of the housing ( 3 b ). The piston rod ( 3 a ) is designed in the shape of a sleeve. The piston rod ( 3 a ) preferably comprises two holding arms ( 3 a ′, 3 a ″), which hold the cartridge ( 1 d ) in the cartridge holder ( 1 ) in a defined position, relative to the housing ( 3 b ). A spring ( 3 c ) for the automatic release of the administration device is located on the inside of the piston rod ( 3 a ); it is clamped between a distal stop on the bottom of the sleeve ( 3 f ) of the piston rod ( 3 a ) and a proximal stop on an element ( 3 g ), fixed to the housing. Preferably, the administration device can have a release knob ( 3 e ) and a blocking ring ( 3 d ), wherein the release knob ( 3 e ) and the blocking ring ( 3 d ) are designed in such a way that the blocking ring ( 3 d ) blocks an actuation of the release knob ( 3 e ) in the initial position. The blocking ring ensures that the administration device can be released by actuation of the release knob ( 3 e ) only after the complete mixing operation and/or priming operation.
[0068] Alternatively, the administration device can be released by a manual actuation of the release knob ( 3 e ), and that is the reason that the piston rod ( 3 a ) does not have a spring ( 3 c ). Moreover, alternatively, the administration device cannot have a blocking ring ( 3 d ) and/or the piston rod ( 3 a ) cannot have holding arms ( 3 a ′, 3 a ″) and/or the injection needle unit ( 4 ) cannot have a protective shield ( 4 f ).
[0069] FIG. 2 shows an enlarged, detailed view, in a longitudinal section of the injection needle unit ( 4 ), placed on the administration device, in the initial position. The injection needle unit ( 4 ) comprises a distal needle portion ( 4 a ), turned away from the cartridge holder ( 1 ), for piercing the skin and a proximal needle portion ( 4 b ), which, in the initial position of the administration device, lies opposite, facing the cartridge holder ( 1 ). The injection needle unit ( 4 ) is connected with the protective shield ( 5 ), in an axially stationary manner, and is preferably nonrotary. To this end, the injection needle unit ( 4 ) has a cam or ring ( 4 d ), protruding outwards and provided on the outside surface of the jacket; it protrudes into a recess of the annular groove ( 5 d ) of the protective shield ( 5 ), provided on the inside surface of the jacket. The cartridge holder ( 1 ) comprises an opening, provided on the front side, on its distal end, which is situated in the axial alignment to the membrane ( 2 ) of the cartridge ( 1 d ). The guide sleeve ( 6 ) is concentrically situated between the injection needle unit ( 4 ) and the protective sleeve ( 5 ), wherein the guide sleeve ( 6 ) is connected with the proximal end with the cartridge holder ( 1 ), in an axially stationary and nonrotary manner. In order to form the axially and nonrotary connection, a recess ( 6 c ) is provided in the guide sleeve ( 6 ), into which projection ( 1 b ), provided on the cartridge holder ( 1 ), can lock—especially, a wedge ( 1 b ) that projects outward, extending in the circumferential direction. The wedge ( 1 b ) can have a steep and a flat flank in such a way that during the installation on the cartridge holder ( 1 ), the flat flank of the guide sleeve ( 6 ) can be pushed, relative to the cartridge holder ( 1 ), over the ramp-shaped proximal end of the cartridge holder ( 1 ), until the wedge ( 1 b ) of the cartridge holder ( 1 ) arrives at the recess ( 6 c ) of the guide sleeve ( 6 ). The steep flank of the wedge ( 1 b ) of the cartridge holder ( 1 ) is in a stop contact with a front side of the guide sleeve ( 6 ), which is formed by the recess ( 6 c ) of the guide sleeve ( 6 ). The distal end of the cartridge holder ( 1 ) can strike against a proximal side of a counterstop plane ( 6 h ) of the guide sleeve ( 6 ).
[0070] In the initial position, the protective sleeve ( 5 ) is connected with the guide sleeve ( 6 ) in such a way that it does not rotate, wherein the protective sleeve ( 5 ), relative to the guide sleeve ( 6 ), can move axially in a sliding contact. The nonrotary connection between the protective sleeve ( 5 ) and the guide sleeve ( 6 ) can be produced by a stop connection.
[0071] The injection needle unit ( 4 ) can be held in the guide sleeve ( 6 ) so it can move axially. The injection needle unit ( 4 ) can move axially in the guide sleeve ( 6 ) in such a way that the proximal needle portion ( 4 b ) of the injection needle ( 4 ), in the initial position of the administration device, is opposite, facing the membrane ( 2 ), and in the mixing position is thrust, through the membrane ( 2 ), into the container ( 1 ). The injection needle unit ( 4 ) is guided, via a sliding contact, within the guide sleeve ( 6 ) and relative to the guide sleeve ( 6 ). The injection needle unit ( 4 ) is supported so it can move axially in the guide sleeve, in such a way, that, in the mixing position, the proximal needle portion ( 4 b ) can penetrate the membrane ( 2 ) of the cartridge ( 1 d ), through the opening of the cartridge holder ( 1 ), so as to form a fluid connection between the injection needle of the injection needle unit ( 4 ) and the cartridge ( 1 d ).
[0072] In the initial position, the protective sleeve ( 5 ), held, in an axially stationary manner, with the injection needle ( 4 ), can move only in the proximal direction, relative to the cartridge container ( 1 ), held with the cartridge ( 1 d ). To this end, the protective sleeve ( 5 ) has a locking element ( 5 c ) that can be clamped, in particular, can be elastically clamped; in the initial position, it interacts, in such a way, with a guide mechanism ( 6 b ), provided in the guide sleeve ( 6 ), that the protective sleeve ( 5 ) can move only in the proximal direction, with the injection needle unit ( 4 ), held therein, relative to the cartridge holder ( 1 ).
[0073] In the initial position, the protective sleeve ( 5 ) is held tight axially, relative to the guide sleeve ( 6 ), via a groove/cam connection—it is held tight axially, especially in the proximal direction. The user can apply a force that exceeds the holding force of the groove/cam connection against the protective sleeve ( 5 ), in the proximal direction. The groove/cam connection is loosened and the protective sleeve ( 5 ), held with the injection needle unit ( 4 ), can be moved, relative to the cartridge holder ( 1 ), in the proximal direction. A relative movement between the protective sleeve ( 5 ) and the guide sleeve ( 6 ) in the distal direction is prevented by the stop contact between the locking element ( 5 c ) of the protective sleeve ( 5 ) and the guide mechanism ( 6 b ) of the guide sleeve ( 6 ).
[0074] FIG. 3 shows the guide sleeve ( 6 ) in interaction with the locking element ( 5 c ) of the protective sleeve ( 5 ) in the initial position. The locking element ( 5 c ) of the protective sleeve ( 5 ) engages the guide mechanism ( 6 b ) of the guide sleeve ( 6 ). The guide mechanism ( 6 b ) is designed in the shape of a U and has a steep front edge ( 6 b ′) on one end, wherein the other end is designed in the shape of a ramp. The locking element ( 5 c ) is shaped as a bendable flap, in particular, a flap that can bend elastically. A stop surface ( 5 c ′) of the locking element ( 5 c ) can form a stop contact with the steep front edge ( 6 b ′) of the guide mechanism ( 6 b ) of the guide sleeve ( 6 ) in the initial position, so as to prevent that, in the initial position, the protective sleeve ( 5 ) can be moved with the injection needle ( 4 ) in the distal direction, in particular, that it can be removed from the injection needle unit ( 4 ).
[0075] At least one snap arm ( 6 a ) that can be clamped inwards is provided on the proximal end of the guide sleeve ( 6 ). The snap arm ( 6 a ) is designed in the shape of a heel and protrudes outwards from the outside jacket surface of the guide sleeve ( 6 ).
[0076] The recess ( 6 c ) of the guide sleeve ( 6 ), which can interact with the wedge ( 1 b ) of the cartridge holder ( 1 ), so as to form an axially stationary and nonrotary connection between the guide sleeve ( 6 ) and the cartridge holder ( 1 ), is designed in the form of a slit. The inside surface of the jacket of the guide sleeve ( 6 ) has a longitudinal crosslink ( 6 e ) that protrudes inwards, wherein the slit-shaped recess ( 6 c ) is located in the area of the longitudinal crosslink ( 6 e ). The wedge ( 1 b ) that protrudes outwards and extends in the circumferential direction is placed on the cartridge holder ( 1 ). In order to ensure an axially stationary and nonrotary connection between the guide sleeve and the cartridge holder ( 1 ), the steep side of the wedge ( 1 b ) can protrude in the direction of the recess ( 6 c ), on the one hand, and impact against the stop surface ( 6 f ), formed by the longitudinal crosslink ( 6 e ) and the recess ( 6 c ), and the distal end of the cartridge holder ( 1 ) can impact against the proximal side of the counterstop plane ( 6 h ) of the guide sleeve ( 6 ), on the other hand.
[0077] The guide sleeve ( 6 ) has an additional recess ( 6 d ), in axial alignment to the proximal recess ( 6 c ), which, with the surrounding wedge ( 1 b ) of the cartridge holder ( 1 ), is used for the axial and rotary securing of the guide sleeve ( 6 ) with the cartridge holder ( 1 ). The two recesses ( 6 c , 6 d ) are designed essentially the same. The recess ( 6 d ), which is provided on the distal end of the guide sleeve ( 6 ), makes possible an axially stationary connection of the injection needle unit ( 4 ) with the guide sleeve ( 6 ), if the injection needle unit is in the mixing position, wherein a projection ( 4 c ) that protrudes outwards on the injection needle unit ( 4 ) arrives at the distal recess ( 6 d ) of the guide sleeve ( 6 ).
[0078] The longitudinal crosslink ( 6 e ), placed on the inside of the jacket of the guide sleeve ( 6 ), is in sliding contact with the injection needle unit, wherein the injection needle unit ( 4 ) can move relative to the guide sleeve ( 6 ). The sliding contact between the guide sleeve ( 6 ) and the injection needle unit ( 4 ) is used for the longitudinal guiding of the injection needle ( 4 ), held by the protective sleeve ( 5 ), from the initial position—in which the proximal needle portion ( 4 b ) of the injection needle unit ( 4 ) lies opposite, facing the membrane ( 2 ) of the cartridge ( 1 d )—into the mixing position, in which the proximal needle portion ( 4 b ) is thrust, through the membrane ( 2 ), into the cartridge ( 1 d ).
[0079] FIG. 4 shows an enlarged, perspective, detailed view, in a longitudinal section of the injection needle, placed on the administration device, in the initial position. The elastically clampable snap arm ( 6 a ) of the guide sleeve 6 is situated radially relaxed between the cartridge holder ( 1 ) and the protective sleeve ( 5 ), especially, the grip ( 5 a ) of the protective sleeve ( 5 ), and protrudes beyond the proximal end of the grip ( 5 a ) of the protective sleeve ( 5 ), in the longitudinal direction of the administration device. As shown in FIG. 5 , a projection provided on the cartridge holder ( 1 ), especially, a cam ( 1 a ), is provided in the circumferential direction, staggered, relative to the snap arm ( 6 a ) of the guide sleeve ( 6 ). The protective sleeve ( 5 ) can be rotated, relative to the administration device, in particular, the mixing device, wherein the guide sleeve ( 6 ), which is connected so it cannot rotate with the protective sleeve ( 5 ), is also rotated in the initial position. The locking element ( 5 c ) of the protective sleeve ( 5 ) strikes a flank of the guide mechanism ( 6 b ) of the guide sleeve ( 6 ) and forms the nonrotary connection between the protective sleeve ( 5 ) and the guide sleeve ( 6 ). The relaxed snap arm ( 6 a ) of the guide sleeve ( 6 ) does not arrive at a rotation of the protective sleeve in a stop contact with the cam ( 1 a ) of the cartridge holder ( 1 ), since the relaxed snap arm ( 6 a ) is at a distance radially from the cam ( 1 a ). Consequently, the cartridge holder ( 1 ) cannot be screwed into the housing ( 3 b ) of the administration device, via the stop contact, between the cam ( 1 a ) of the cartridge holder ( 1 ) and the snap arm ( 6 a ) of the guide sleeve ( 6 ), so as to mix the active substance with the dilution liquid in the cartridge ( 1 d ).
[0080] FIGS. 6 a and 6 b show the administration device of the first embodiment in a piercing position, in an outside view and in a longitudinal section, wherein FIG. 7 shows an enlarged, detailed view in a longitudinal section of the injection needle unit ( 4 ) of FIG. 6 b , placed on the administration device. In the initial position, the protective sleeve ( 5 ), held with the injection needle unit ( 4 ), can be moved only in the proximal direction because of the stop contact between the locking element ( 5 c ) of the protective sleeve ( 5 ) and the steep front edge ( 6 b ′) of the guide mechanism ( 6 b ) of the guide sleeve ( 6 ). To this end, the user presses the protective sleeve ( 5 ) in the proximal direction, relative to the mixing device, in order to arrive at the piercing position. The protective sleeve ( 5 ) moves with the injection needle unit ( 4 ), connected in an axially stationary manner, in a sliding contact, relative to the guide sleeve ( 6 ), until the injection needle element ( 4 ), with a stop cam or a stop ring ( 4 e ), impacts a distal side of the counter stop plane ( 6 h ) of the guide sleeve ( 6 ), which lies on the distal end of the cartridge holder ( 1 ). If the injection needle unit ( 4 ) lies on the distal side of the counterstop plane ( 6 ) of the guide sleeve ( 6 ), the proximal portion ( 4 b ) of the injection needle unit ( 4 ) penetrates the opening of the cartridge holder ( 1 ) as well as the membrane ( 2 ) of the cartridge ( 1 d ), wherein a fluid connection is present between the injection needle of the injection needle unit ( 4 ) and the cartridge ( 1 d ).
[0081] The projection ( 4 c ), protruding outwards on the injection needle unit ( 4 ), has a steep flank in the distal direction and a flat flank in the proximal direction. The projection ( 4 c ) can be designed as a surrounding wedge, situated on the outside surface of the jacket of the injection needle unit ( 4 ). During the movement into the mixing position, the flat flank of the projection ( 4 c ) slides, via the ramp ( 6 j ) of the guide sleeve ( 6 ), until the projection ( 4 c ) arrives at the distal recess ( 6 c ) of the guide sleeve ( 6 ). The injection needle unit ( 4 ) is axially connected with the guide sleeve, since the steep flank of the projection ( 4 c ) impacts against a stop surface ( 6 g ) of the recess ( 6 c ) and the stop cam or the stop ring ( 4 e ) of the injection needle unit ( 4 ) strikes the distal side of the counterstop plane ( 6 h ) of the guide sleeve ( 6 ).
[0082] FIG. 8 shows the position of the locking element ( 5 c ) of the protective sleeve ( 5 ) in the guide mechanism ( 6 b ) of the guide sleeve ( 6 ) in the piercing position. The locking element ( 5 c ) arrives at the proximal position, along the guide mechanism ( 6 b ). If, in this position, the user would like to remove the protective sleeve ( 5 ) from the injection needle unit ( 4 ), without carrying out a mixing operation, the locking element ( 5 c ) of the protective sleeve moves in the distal direction, relative to the guide sleeve ( 6 ), until the locking element ( 5 c ) strikes the steep front edge ( 6 b ′) of the guide sleeve ( 6 ). Thus, the protective sleeve ( 5 ) cannot be removed from the injection needle unit ( 4 ) without a mixing operation.
[0083] As a result of the axial movement of the protective sleeve ( 5 ), firmly connected, axially, with the injection needle unit ( 4 ), in the proximal direction, relative to the guide sleeve ( 6 ), the snap arm ( 6 a ), provided on the guide sleeve ( 6 ), is clamped radially inwards, as shown in FIG. 9 . With the axial movement, the inside surface of the jacket of the protective sleeve slides over the snap arm ( 6 a ) and presses the snap arm ( 6 ) radially inwards.
[0084] FIGS. 10 a and 10 b show the administration device of the first embodiment in a mixing position, in an outside view and in a longitudinal section. For the mixing, the protective sleeve ( 5 ) is rotated relative to the mixing device of the administration device. To this end, the user grabs the grip ( 5 a ) of the protective sleeve ( 5 ) and rotates the protective sleeve ( 5 ), relative to the housing ( 3 b ). As shown in FIG. 11 , the protective sleeve ( 5 ) is thereby rotated, relative to the guide sleeve ( 6 ), until the locking element ( 5 c ) of the protective sleeve arrives at the guide mechanism ( 6 b ), in a stop contact with a flank of the guide mechanism ( 6 b ) of the guide sleeve ( 6 ). With an additional rotation of the protective sleeve ( 5 ), the locking element ( 5 c ) moves along the guide sleeve ( 6 ), until the snap arm ( 6 a ) of the guide sleeve ( 6 ) impacts the cam ( 1 a ) of the cartridge holder ( 1 ). The protective sleeve ( 5 ) is connected in a nonrotary manner, via the guide sleeve ( 6 ), with the cartridge holder ( 1 ) in at least one rotary direction, wherein the locking element ( 5 c ) of the protective sleeve is in a stop contact with the flank of the guide mechanism ( 6 b ) of the guide sleeve ( 6 ) and the snap arm ( 6 a ) of the guide sleeve ( 6 ) in a stop contact with the cam ( 1 a ) of the cartridge holder ( 1 ). As a result of the nonrotary connection between the protective sleeve and the cartridge holder ( 1 ), the active substance can be mixed with the dilution liquid for the active substance by a rotation of the protective sleeve ( 5 ), relative to the mixing device, namely, the housing ( 3 b ) and the piston rod ( 3 a ). The cartridge holder ( 1 ) is screwed in between the housing ( 3 b ) and the piston rod ( 3 a ), wherein the piston rod ( 3 a ) impacts the two stoppers ( 1 j ) of the cartridge ( 1 d ) with the two holding arms ( 3 a ′, 3 a ″). To screw in the cartridge holder ( 1 ), an inside thread is provided on the inside of the housing 93 b ) and an outside thread, on the outside of the cartridge container ( 1 ). As a result of the transfer of force of the dilution liquid between the second and the first stoppers ( 1 j , 1 h ), the two stoppers ( 1 h , 1 j ) are pushed in the distal direction within and relative to the cartridge ( 1 d ), until the first stopper ( 1 h ) comes to lie on the bypass ( 1 g ), through which the dilution liquid can flow into the first chamber ( 1 e ), and the second stopper ( 1 j ) comes to lie on the first stopper ( 1 h ). In the mixed position, the active substance of the first chamber ( 1 e ) is mixed with the dilution liquid of the second chamber ( 1 f ). The end of the mixing can be indicated by a tactile, acoustic, and/or visual signal of a display device ( 3 h ). With an additional slight rotation of the cartridge container ( 1 ), a priming operation can be carried out, wherein this operation leads to another movement forward of the two stoppers ( 1 h , 1 j ), so that a gas contained in the cartridge ( 1 d ) and/or in the injection needle can escape from the injection needle, until a slight quantity of mixed active substances exits from the injection needle of the injection needle unit ( 4 ). The conclusion of the priming operation can be indicated by a tactile, acoustic, and/or visual signal of the display device ( 3 h ). With the last screwing movement of the cartridge container ( 1 ) into the housing ( 3 b ), the blocking ring ( 3 d ) can be moved from the blocking position into a release position. By a rotation, a stop of the cartridge holder ( 1 ) can move along the blocking ring ( 3 d ), so that it is rotated, relative to the housing ( 3 b ) and the release knob ( 3 e ). By this rotary movement, the blocking ring ( 3 d ) is moved from the blocking position into the release position. In the release position, the release knob ( 3 e ) can be actuated in that, relative to the housing ( 3 b ), the release knob ( 3 e ) can be pressed into the housing ( 3 b ), along the longitudinal axis.
[0085] FIGS. 12 a and 12 b show the administration device of the first embodiment in the mixed and/or primed position, in an outside view and in a longitudinal section, wherein the protective sleeve ( 5 ) can be removed from the injection needle unit ( 4 ). FIG. 13 shows the position of the locking element ( 5 c ) of the protective sleeve ( 5 ) in the guide mechanism ( 6 b ) of the guide sleeve ( 6 ) of the administration device when the protective sleeve ( 5 ) is removed from the injection needle unit ( 4 ). The locking element ( 5 c ) is in a stop contact with the flank of the guide mechanism ( 6 b ) after a relative rotation of the protective sleeve ( 5 ) to the guide sleeve ( 6 ). If the protective sleeve ( 5 ) is moved, relative to the guide sleeve ( 6 ), in the distal direction, the locking element ( 5 c ) of the protective sleeve ( 5 ) slides, along the guide mechanism ( 6 c ), over the ramp ( 6 b ″) of the guide sleeve ( 6 ). The protective sleeve ( 5 ) can be removed from the injection needle unit ( 4 ).
[0086] FIGS. 14 a and 14 b show the administration device of the embodiment in an emptied state, in an outside view and in a longitudinal section. To release the administration device, the release knob ( 3 e ) can be pressed, relative to the housing ( 3 b ), along the longitudinal axis into the housing ( 3 b ). The release knob ( 3 e ) is designed in such a manner that the release knob ( 3 e ) releases a securing of the piston rod ( 3 a ) on a housing element when the release knob ( 3 e ) is moved forward. When released, the spring force of the spring ( 3 c ) begins to act and presses against the piston rod ( 3 a ). The piston rod ( 3 a ) is pushed by the force of the spring ( 3 c ), relative to the cartridge ( 1 d ), wherein the holding arms ( 3 a ′, 3 a ″) of the piston rod ( 3 a ) drive the stoppers ( 1 j , 1 h ) within the cartridge ( 1 d ), so that the mixed active substance is emptied from the first chamber ( 1 e ). The spring ( 3 c ) pushes the piston rod ( 3 a ) into the cartridge ( 1 d ) until a projection, which is provided on the piston rod ( 3 a ), strikes an edge of the housing ( 3 b ). As soon as the projection strikes the housing ( 3 b ), the emptying of the mixed active substance has ended. A tactile, acoustic, and/or visual signal of the display device ( 3 h ) can indicate that the emptying has ended.
[0087] After the injection into the skin, the protective sleeve ( 5 ) can again be placed on the injection needle unit ( 4 ). The protective sleeve ( 5 ) can be moved, relative to the guide sleeve ( 6 ), in the proximal direction, until the groove/cam connection is again established between the protective sleeve ( 5 ) and the guide sleeve ( 6 ). The cartridge holder, held with the cartridge, can be uncoupled, with the injection needle unit, from the administration device, in order to couple a cartridge holder with a new cartridge.
[0088] Alternatively, the used administration device can be disposed of after the injection.
[0089] In an initial position, FIGS. 15 a and 15 b show the administration device of a second embodiment, in an outside view and in a longitudinal section. The administration device essentially differs from the administration device of the first embodiment example only with reference to the design of the guide sleeve ( 7 ), with reference to the interaction of the guide sleeve ( 7 ) with the locking element ( 5 c ), and with reference to the interaction of the locking element ( 5 c ) with the cartridge container ( 1 ). FIG. 16 shows an enlarged, detailed view, in a longitudinal section of the injection needle unit ( 4 ) of FIG. 15 b , placed on the administration device. And FIG. 17 shows an enlarged, detailed view, in a longitudinal section of the intrusion between the locking element ( 5 c ) of the protective sleeve ( 5 ) and a recess ( 7 a ) of the guide sleeve ( 7 ), in the initial position of the injection needle unit ( 4 ) of FIG. 15 b , placed on the administration device. The guide sleeve ( 7 ) can be connected with the protective sleeve ( 5 ), via a nonrotary ribbed connection. Alternatively, the recess ( 7 a ) of the guide sleeve ( 7 ) and the locking element ( 5 c ) can be designed in such a way that the guide sleeve ( 7 ) is connected, in a nonrotary manner, with the protective sleeve ( 5 )—at least in the initial position. The recess ( 7 a ) in the guide sleeve ( 7 ) has a steep edge ( 7 a ′) and a flat edge ( 7 a ″). The locking element ( 5 c ) is designed in such a manner that, in the initial position, it impacts with the stop surface ( 5 c ′) against the steep edge ( 7 a ′) of the guide sleeve ( 7 ), so as to prevent the protective sleeve ( 5 ) with the held injection needle unit ( 4 ) from being movable in the distal direction, relative to the guide sleeve ( 7 )—in particular, from it being possible to remove the protective sleeve from the injection needle unit ( 4 ). In the initial position, the protective sleeve ( 5 ) is firmly held axially, relative to the guide sleeve ( 7 ), via a groove/cam connection—in particular, it is firmly held axially, in the proximal direction. The user can apply a force in the proximal direction, against the protective sleeve ( 5 ), which exceeds the holding force of the groove/cam connection. The groove/cam connection is loosened and the protective sleeve ( 5 ), held with the injection needle unit ( 4 ), can be moved, relative to the cartridge container ( 1 ), in the proximal direction, until the injection needle unit, with the stop cam or the stop ring ( 4 e ), impacts the distal side of the counterstop plane ( 6 h ) of the guide sleeve ( 6 ), which lies on the distal end of the cartridge holder ( 1 ). The locking element ( 5 c ), which is designed in a deformable manner, in particular, in an elastically clampable manner, slides thereby, relative to the guide sleeve ( 7 ) over the flat edge ( 7 a ″) of the guide sleeve ( 7 ), from the recess ( 7 a ), onto the outside surface of the jacket of the guide sleeve ( 7 ). The locking element ( 5 c ) is thereby under even more tension. The protective sleeve ( 5 ) and the injection needle unit ( 4 ) thereby move, in a sliding contact, with the guide sleeve. The protective sleeve ( 5 ), with the injection needle unit ( 4 ) held therein, moves, relative to the guide sleeve ( 7 ), in the proximal direction. With the movement in the proximal direction, the injection needle of the injection needle unit ( 4 ) penetrates the membrane of the cartridge ( 1 d ). The locking element ( 5 c ) slides over the proximal end of the guide sleeve ( 7 ) and can relax, in particular, relax elastically, between the recess formed by the shoulder ( 1 c ) of the cartridge holder ( 1 ) and the recess formed by the proximal end of the guide sleeve ( 7 ).
[0090] FIGS. 18 a and 18 b show the administration device of the second embodiment in a mixing position, in an outside view and in a longitudinal section. FIG. 19 shows an enlarged, detailed view in a longitudinal section of the injection needle unit ( 4 ) of FIG. 18 b , placed on the administration device. FIG. 20 depicts an enlarged, detailed view, in a longitudinal section of the intrusion between the locking element ( 5 c ) of the protective sleeve ( 5 ) and the projection ( 1 a ), placed on the cartridge holder, in particular, a cam ( 1 a ), in the mixing position of the injection needle unit of FIG. 18 b , placed on the administration device. With a rotation of the protective sleeve ( 5 ), relative to the cartridge holder ( 1 d ), so as to mix the active substance with the dilution liquid, the relaxed—in particular, elastically relaxed—locking element ( 5 c ) of the protective sleeve ( 5 ) can impact a projection ( 1 a ), provided on the cartridge holder, in particular, a cam ( 1 a ). Via the nonrotary connection between the protective sleeve ( 5 ), in particular, the locking element ( 5 c ), and the cartridge holder ( 1 ), in particular, a cam ( 1 a ), the cartridge holder ( 1 ) can be conducted into the housing ( 3 b ), in a thread engagement with the housing ( 3 b ). If the mixing operation has ended, the protective sleeve ( 5 ) can be removed from the injection needle unit ( 4 ) in that the protective sleeve ( 5 ) is moved, relative to the cartridge holder ( 1 ), in the distal direction. As a result of its deformability, in particular, its elastic clamping capacity, the locking element ( 5 c ) can be clamped via the proximal end of the cartridge holder ( 1 ), in that the locking element ( 5 c ) slides over the proximal end of the cartridge holder ( 1 ), relative to the cartridge holder ( 1 ). The locking element ( 5 c ) slides on the outside surface of the jacket of the guide sleeve ( 7 ), relative to the guide sleeve ( 7 ), via the recess of the guide sleeve ( 7 ). The protective sleeve ( 5 ) can thus be removed from the injection needle unit ( 4 ). | An administration device comprises a container and a mixing device for mixing an active substance (in a first chamber) with a dilution liquid (in a second chamber). The container has a membrane seal at one end and is combined with a mixing device for mixing the active substance. The administration device has an injection needle unit with a distal needle portion facing away from the container for piercing the skin, and disposed opposite thereto is a proximal needle portion facing the membrane when the administration device is in the initial position, which is thrust through the membrane into the container in a mixing position. The administration device includes a protective sleeve arranged coaxially about the injection needle, movable from the initial position only in the proximal direction relative to the container. The protective sleeve can be non-rotatably connected to the container in the mixing position and rotated relative to the mixing device to perform mixing. | 0 |
This application is a continuation of application Ser. No. 209,960 filed June 22, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a photoelectric conversion device, and more particularly a photoelectric conversion device adapted for use in an image reading apparatus such as a facsimile apparatus, an image reader, a digital copying machine, an electronic black-board or the like.
2. Related Background Art
In recent years there have been developed long line sensors having a same-size optical system, as the image conversion device for the facsimile apparatus, the image reader or the like. This is mainly due to the compactization and high density structure of the photoelectric conversion device enabled by the progress in the technology of printed-circuit, wiring boards. In the long image sensor having the same-size optical system, a linear array of photoelectric converting elements is capable of reading an original image in contact therewith, so that the apparatus can be compactized and can achieve a high image reading speed in comparison with the conventional method of reading the original image point by point with a photoelectric converting element and an optical system utilizing lenses
In the conventional long line sensor with same-size optical system, the photoelectric converting elements constituting an array are respectively connected to signal processing IC's composed, for example, of switch devices. However, for example in the G3 facsimile format, 1728 photoelectric converting elements are required for A4 size originals are required, therefore many signal processing IC's are required. For this reason, there are required a large number of device mounting steps, and there has not been obtained an apparatus satisfactory in terms of production cost and reliability.
For the purpose of reducing the number of signal processing IC's and the number of steps of board mounting, there has been employed a structure utilizing matrix wirings. FIG. 1 shows a photoelectric conversion device utilizing such matrix wirings, wherein there are shown a photoelectric conversion device 1 consisting of a linear array of plural photoelectric conversion elements; a scanning unit 2; a signal processing unit 3; and matrix wirings 4. Among the wirings connecting the scanning unit 2 and the signal processing unit 3, vertical ones constitute individual electrodes while horizontal one constitute common lines.
In such a matrix wiring, the individual electrodes and common lines are inevitably close in order to compactize the matrix wiring. Consequently floating capacitances are present between the wirings, thus generating crosstalk among the output signals, and deteriorating the obtained image signals This drawback can be most simply resolved by increasing the distances between the wirings. However, such solution increases the dimension of the matrix wiring, and is not desirable for a device requiring a large number of photoelectric conversion elements as explained before.
There has also been proposed a photoelectric conversion device in which a conductor layer and a wiring capable of maintaining a constant potential at each crossing point of the individual electrode and the common line, thereby controlling the floating capacity between the individual electrodes and the common lines and preventing the crosstalk of the output signals released through such floating capacitances.
FIG. 2A is a plan view of matrix wiring in which a conductor layer of a constant potential is formed at the insulated crossing point of the individual electrode and the common line, while FIG. 2B is a cross-sectional view along a line B--B' of the matrix wiring shown in FIG. 2A. In FIGS. 2A and 2B there are shown individual electrodes 301-304; common lines 305-308; intermediate lines 309-313 positioned in the spaces of the common lines 305-308; a conductor layer 314 positioned between the individual electrodes 301-304 and the common lines 305-308 in the insulated crossing points thereof and is connected to an unrepresented power source capable of maintaining a constant potential; and contact holes 315 for ohmic contact of the individual electrodes 301-304 and the common lines 305-308.
However the photoelectric conversion device with such matrix wiring having a conductor layer of a constant potential in the insulated crossing points of the individual electrodes and the common lines have been associated with the following drawbacks.
In such matrix wiring, there is provided a conductor layer of a constant potential in the insulated crossing points of the individual electrodes and the common lines for reducing the capacitances therebetween.
Though such structure can reduce the floating capacitances between the individual electrodes and the common lines, new floating capacitances are formed between the conductor layer of constant potential and the individual electrodes and between said conductor layer and the common lines.
The floating capacitances are generated between the conductor layer of constant potential and all the individual electrodes and between said conductor layer and all the common lines because the conductor layer is extended over the entire area of the matrix wiring, and are practically not negligible.
FIG. 3 is an equivalent circuit of an accumulating photoelectric conversion device employing said conductor layer of constant potential. In this drawing, 501 denotes a photoelectric conversion unit. 503 denotes a storage capacitor. 502 denotes a switch unit. 505 denotes a load capacitor. 506 denotes a signal output terminal unit. If the above-explained matrix wiring is employed in the output side of the accumulating photoelectric conversion circuit shown in FIG. 3, a floating capacitance 504 not negligible in comparison with the load capacitor 505 which may deteriorate the efficiency of charge transfer.
SUMMARY OF THE INVENTION
In consideration of the foregoing, the object of the present invention is to provide a photoelectric conversion device equipped with matrix wiring capable of suppressing the crosstalks among the output signals and also suppressing the floating capacitances resulting from a structure for suppressing said cross-talks.
The photoelectric conversion device of the present invention is featured by a structure provided with plural photoelectric conversion elements arranged in a linear array; plural common lines each connecting in common at least two of the individual output electrodes of said plural photoelectric conversion elements; conductor layers of a constant potential positioned in the vicinity of crossing points of said individual output electrodes and said common lines; and wirings mutually connecting said conductor layers.
The principal feature of the present invention is the presence of a conductor layer of a constant potential in the vicinity of the crossing point of the individual output electrode and the common line. The conductor layer is maintained at a constant potential for example by connection to a constant voltage source.
The present invention is capable of suppressing the floating capacitance formed at the insulated crossing point of the individual output electrode and the common line, and also suppressing the floating capacitances between said conductor layer of constant potential and the individual electrode and between said conductor layer and the common line.
As the conductor layer provided at the insulated crossing point of the individual output electrode and the common line is maintained at a constant potential, the potential difference between the individual output electrode and the conductor layer is made independent from the potential difference between the common line and the conductor layer Consequently the change in potential or current in the individual output electrodes does not influence the common line since the conductor layer positioned between is maintained at a constant potential despite of such change. Similarly the change in the potential or current in the common line does not affect the individual output electrode. In this manner the influence of the floating capacitance between the individual output electrode and the common line can be suppressed.
Outside the crossing area of the individual output electrode and the common line, the conductor layer is eliminated except the wirings therefor to reduce the crossing area between the conductor layers of constant potential and the individual output electrodes and between said conductor layers and the common lines, thereby reducing the newly generated capacitances and preventing the deterioration of the transfer efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a photoelectric conversion device with matrix wiring;
FIG. 2A is a plan view of conventional matrix wiring;
FIG. 2B is a cross-sectional view along a line B--B' in FIG. 2A;
FIG. 3 is an equivalent circuit diagram of an accumulating photoelectric conversion device with conventional matrix wiring;
FIGS. 4A-C shows illustratively a photoelectric conversion device according to the present invention, FIG. 4A shows a plan view thereof, FIG. 4B shows a cross-sectional view along line X--X' in FIG. 4A, and FIG. 4C show a sectional view along line Y--Y' in FIG. 4A;
FIG. 5A is a plan view of matrix wiring embodying the present invention;
FIG. 5B is a cross-sectional view along a line A--A' in FIG. 5A;
FIG. 6A is a plan view of matrix wiring constituting another embodiment of the present invention; and
FIG. 6B is a cross-sectional view along a line A--A' in FIG. 6A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the accompanying drawings, the embodiments of the present invention are explained as follows.
FIGS. 4A-C illustratively shows a portion corresponding to 1-bit of the photoelectric conversion device according to the present invention. FIG. 4A shows plan view. FIG. 4B shows a sectional view along line X--X' in FIG. 4A. FIG. 4C shows a sectional view along line Y--Y' in FIG. 4A. FIG. 4A shows only upper and lower wiring pattern and contact hole unit, for the purpose of prevention of complex illustration.
In FIG. 4A, 13 denotes a signal line matrix unit 14 denotes a photoelectric conversion unit, 15 denotes a contact hole for connection between gate and source, 16 denotes a storage capacitor; 17 denotes a transfer TFT; 18 denotes reset TFT. 19 denotes a wiring unit of gate driving line. In the embodiment, so called lensless structure directly contacting an original to read it is used. Accordingly, a window 20 for illuminating the original is provided Further, a lower gate electrode of the senser unit is made of opaque material for use as a light shielding film.
Referring to FIGS. 4B and 4C, a substrate 1, is made of a material such as glass. Lower electrode 21 is a gate electrode of the sensor in FIG. 4B and is a gate electrode of TFT in FIG. 4C.
An insulating layer 3 is made of SiNxH, SiO 2 or the like.
A photoconducting semiconductor layer 4 is made of a-Si:H or the like.
An n + layer 5 is provided for ohmic contact to the upper electrode. Upper electrode 22 is a source electrode of sensor unit in FIG. 4B, and upper electrode 23 is source drain electrode of TFT in FIG. 4C. Element 6 denotes an insulating layer.
The photoelectric conversion device of the present invention is produced by using, as a photoconductive semiconductor material, a-Si:H film formed by a glow discharge process to provide on a common substrate TFT type photoelectric conversion portion, the storage capacitor, the transfer and reset TFT, and the matrix wiring portion as a stacked layer structure comprising a lower electrode, SiNH insulating layer, a-Si:H layer, n + layer and upper electrode, in a single process simultaneously.
FIGS. 5A and 6A are schematic plan views of matrix wiring embodying the present invention, and FIGS. 5B and 6B are cross-sectional views respectively along lines A--A' in FIGS. 5A and 6A.
In FIGS. 5A, 5B, 6A and 6B there are shown individual electrodes 101-106, 201-206 at the lowermost position; common lines 107-110, 207-210 at the uppermost position; intermediate lines 111-115, 211-215 positioned between the common lines at the uppermost position; and conductor layers and wirings connecting said conductor layers 116, 216 positioned between the individual electrodes at the lowermost position and the common lines at the uppermost position and connected to a power source (not shown) capable of maintaining a constant potential.
In FIG. 6A there are shown conductor layers 217 of constant potential, and wirings 218 connecting said conductor layers.
In the structure shown in FIG. 5A, the conductor layers and the wirings therefor are integrally constructed.
In the embodiments shown in FIGS. 5A, 5B, 6A and 6B, the conductor layers of constant potential exist only in the vicinity 120, 220 of the crossing points of the individual electrodes at the lowermost position and the common lines in the uppermost position, as shown in the cross sectional views in FIGS. 5B and 6B. In this manner it is rendered possible to suppress the floating capacitances between said individual electrodes and said common lines, thereby preventing the crosstalks among the output signals.
Also as shown in the plan views in FIGS. 5A and 6A, the crossing areas between the wirings for connecting the conductor layers of constant potential and said individual electrodes or said common lines are reduced to suppress the floating capacitances in comparison with the conventional matrix wiring, thereby preventing the deterioration of the transfer efficiency.
The photoelectric conversion device of the present invention may be prepared by any known process.
As explained in the foregoing, these embodiments provide a photoelectric conversion device with compact matrix wiring capable of suppressing the crosstalk among the output signals, and also suppressing the formation of floating capacitances in the structure for suppressing said crosstalks, thereby preventing the deterioration of the transfer efficiency. | A photoelectric conversion device comprises plural photoelectric conversion elements arranged in a linear array, plural common lines each connecting at least two of individual output electrodes of the plural photoelectric conversion elements, conductor layers of a constant potential provided in the vicinity of crossing portions of the individual output electrodes and said common lines, and wirings mutually connecting the conductor layers. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the field of shingle removing apparatus in general, and in particular to a powered shingle removing machine, which is pushed across a shingled roof, and which uses a powered, oscillating blade mechanism to lift and remove previously installed shingles.
[0002] Residential and commercial building constructions generally have roof decks which are covered with a protective layer of shingles. Shingles are generally placed in overlapping, aligned rows and the shingles are secured in place by a combination of nails, staples or other fasteners and adhesive.
[0003] Any shingle, regardless of type, will eventually deteriorate due to exposure to ultraviolet light from the sun, moisture from precipitation, etc. While it is common to install a second layer of new shingles over a single existing layer, eventually the older shingles must be removed for roof refurbishing. Building codes will typically limit the permissible number of shingle layers. This is a physically demanding task when performed by hand without the use of power machinery. Generally, various manually operated scraping tools, such as modified flat shovels, are used to wedge between the shingles and the underlying roofing paper or sheathing, with the front edge of the shovel shearing or pulling the roofing nails which held the shingles in place and breaking adhesive bonds between shingles. The physical effort involved, particularly when performed on a steep sloping roof, is taxing.
[0004] As any roofer is all too well aware, mechanical shingle removing devices substantially reduce the amount of physical exertion that is required to strip shingles from a roof. However, they are also difficult to maneuver on a roof surface due to the fast and continuous oscillating movement of the blade. Thus, the workman must stop the motor to push the machine forward for removing additional shingles, which slows the removal process and increases the cost of removal.
[0005] It is therefore desirable to provide a shingle removing apparatus which improves the driving mechanism and improves the time efficiency and workman efficiency for removing shingles.
[0006] Accordingly, the present invention is directed to a shingle removing apparatus which overcomes one or more of the problems as set forth above.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention overcomes many of the shortcomings and limitations of the prior art devices discussed above and teaches the construction and operation of several embodiments of a shingle removing apparatus adapted for continuously removing the shingles without having to stop the motor to move removal apparatus. The present apparatus can improve the overall efficiency of the entire shingle removing process as compared to the prior art with respect to work efficiency.
[0008] In one aspect of the present invention, the present shingle removing apparatus includes a handle, a stripper member, a drive assembly and a drive linkage assembly with lost motion mechanism. The handle has a proximal end and a distal end. The stripper member is adapted for inserting under a shingle and has a first end portion and a second end portion. The first end portion of the stripper member is operatively coupled to the proximal end of the handle such that the second end portion of the stripper member is reciprocally moveable up and down. The drive assembly drives at least a portion of the stripper member and the drive linkage assembly causes at least a portion at a free end of the stripper member through a lost motion mechanism to reciprocally move up and down to thereby remove shingles. The drive assembly is operatively connected to the stripper member to selectively effect pivoting movement of the stripper member relative to the handle. The lost motion mechanism allows the stripper member to intermittently not be driven. The drive linkage assembly in one embodiment comprises a crank arm, a first link and a second link to provide lost motion connection. The crank is coupled to the drive assembly for rotation thereby.
[0009] In another aspect of the present invention, the drive linkage assembly provides a lost motion connection between a crank arm and a link arm. The crank arm is pivotally coupled to the drive assembly. The link arm has first and second end portions, and includes an elongated slot spaced from the second end portion. The crank arm is pivotally associated with the slot so as to provide lost motion connection. The second end portion of the link arm is operatively engaged with the stripper member.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a side view of a first embodiment of the present shingle removing apparatus constructed in accordance with the teachings of the present invention.
[0011] FIG. 2 is a perspective side view of the shingle removing apparatus of FIG. 1 .
[0012] FIG. 3 is a side view of the shingle removing apparatus of FIG. 1 .
[0013] FIG. 4 is an exploded perspective view of the drive link assembly in accordance with the teachings of the present invention.
[0014] FIG. 5 is a side view of the gear assembly of one housing portion of the shingle removing apparatus of FIG. 1 with portions broken away to show internal detail.
[0015] FIG. 6 is a perspective view of another embodiment of the stripper removing apparatus.
[0016] FIG. 7 is an exploded perspective view of a drive link assembly.
[0017] It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. Like numbers utilized throughout the various Figures designate like or similar parts or structure.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention involves the provisions of a shingle removing apparatus wherein the drive linkage assembly includes a lost motion mechanism that effects intermittent movement of the stripper member during continuous rotation of a crank arm so that an operator does not need to stop a motor to go forward for removing more shingles. The present shingle removing apparatus improves the overall efficiency of the shingle removing job as compared to the prior art apparatus with respect to time efficiency and worker efficiency in removing the shingles.
[0019] As best shown in FIGS. 2-4 , the shingle removing apparatus 10 comprises a drive system including a drive assembly 80 and a drive linkage assembly 40 . The apparatus 10 includes a stripper member 50 , such as a stripping blade, preferably having a toothed free end portion 52 for inserting under shingles. The shingle removing apparatus 10 is generally operated by using the drive assembly 80 , whereby the stripper member 50 lift nails out of a roofing substrate. As illustrated in FIG. 1 , the shingle removing apparatus 10 of the present invention is positioned on the surface from which material is to be removed such as a shingled roof. The operator positions himself or herself behind the shingle removing apparatus 10 . The operator grips the handle 20 and may advance the shingle removing apparatus 10 on wheels 53 . The shingle removing apparatus 10 is actuated by depressing a trigger 62 which will energize a motor 60 causing a drive shaft 25 to rotate. The drive assembly 80 will effect an oscillatory and reciprocal motion to the stripper member 50 through the drive linkage assembly 40 . The operator, by use of the grip 23 and/or handle 20 , advances the leading edge 51 of the stripper member 50 beneath the roofing material to be removed. As the leading edge 51 contacts the underside of the shingles 1 , the shingles 1 and any fasteners are lifted upwardly along with the fastener such as staples or nails. After the leading edge has lifted a section of shingles 1 from the surface, the operator proceeds forward so that the stripper member 50 is positioned between the next remaining layer of shingles 1 and removal is accomplished in a similar manner.
[0020] Referring to the drawings more particularly by reference numbers, the numeral 10 in FIGS. 1-3 identifies one embodiment of a shingle removing apparatus.
[0021] In one aspect of the present invention, the shingle removing apparatus 10 includes a handle 20 , a drive assembly 80 , a drive linkage assembly 40 and a stripper member 50 for forcibly removing shingles 1 as illustrated in FIGS. 1-7 . The handle 20 comprises an elongated tubular housing 22 , an on/off switch such as a trigger 62 disposed adjacent its distal end portion 24 , a transversely extending secondary handle 23 disposed on its intermediate portion and a mount member 54 disposed on its proximal end portion 26 . The handle 20 is hollow and can have an internal bearing (not shown) for supporting a drive shaft 25 . The stripper member 50 can be a shingle removing blade, which is operatively coupled to the drive assembly 80 for effecting movement of the stripper member 50 relative to the handle 20 through the drive linkage assembly 40 . The stripper member 50 is in the form of a plate with teeth 52 on the leading edge 51 . The stripper member 50 has a leading edge 51 which engages the shingles and fasteners to be removed. A stripper member 50 has a trailing edge portion and the beveled free end 51 .
[0022] The shingle removing apparatus 10 is powered by the motor 60 which may be hydraulic, pneumatic or electric with controls suitably located on the handle 20 . The motor 60 can be secured to the free end portion 24 of the handle 20 by a bolt 65 and a bracket 63 . Alternatively, the motor 60 can be bolted onto suitable motor mount in a motor casing with its controls preferably on the distal end portion of the handle 20 . (not shown)
[0023] Turning now to FIGS. 2-4 , it can be seen that rearwardly extending mounting brackets 57 are provided with an aperture disposed proximate the lower end of the trailing edge of the mounting bracket 57 . The mounting brackets 57 are positioned in spaced apart relationship and the proximal end portion 26 of the handle 20 is inserted between the two mounting brackets 57 . The mounting brackets 57 are secured to the proximal end portion 26 of the handle 20 by means of latch pins 58 , each extending through respective holes 59 . A plurality of holes 59 on each mounting bracket 57 permits adjustment of the vertical angular orientation of the handle 20 . The mounting brackets 57 include a plurality of aligned holes 59 which allow the operator to adjust angular relationship between the handle 20 and the mount member 54 . In one embodiment, the shingle removing apparatus 10 includes an optional wheel unit 53 positioned adjacent the proximal end portion 26 of the handle 20 . The wheel unit 53 can include a pair of wheels 53 mounted on an axle which extends through the apertures in the mounting bracket 57 for moving the apparatus 10 about a roof surface. The rearwardly tapered mount member 54 is attached to the mounting bracket 57 . In another embodiment, the mount member 54 can be directly connected to the handle 20 . The stripper member 50 is pivotally connected to the mount member 54 by means of outer and inner hinge sockets 55 respectively, mounted on a hinge pin 56 .
[0024] The stripper member 50 is driven by the motor 60 mounted to the handle 20 . The drive assembly 80 comprises the motor 60 operatively connected to the drive shaft 25 that can be enclosed by a tubular housing portion 22 of the handle 20 and which extends from the motor 60 to a worm gear 32 , as illustrated in FIG. 5 . The lower end of the drive shaft 25 connected to a gear assembly 30 including a ring gear 34 and worm gear 32 . Preferably, at least the lower portion of the drive shaft 25 is flexible to accommodate the angular adjustment between the handle 20 and the mount member 54 , for convenience of construction, the drive shaft 25 can be a flexible drive cable. The drive shaft 25 is operatively coupled to the worm gear 32 in a conventional manner as illustrated in FIG. 5 . The worm gear 32 is suitably mounted in a housing 31 and is operatively engaged with a ring gear 34 . The motor 60 is actuated by means of the trigger 62 . Preferably the motor 60 is a variable speed motor with speed being selected by the trigger 62 . In a preferred embodiment the motor 60 is a variable speed drill motor with a chuck coupling the motor 60 to the drive shaft 25 .
[0025] The drive assembly 80 includes a gear assembly 30 for coupling the drive shaft 25 to drive linkage assembly 40 , 70 to effect reciprocative movement of the stripper member 50 . The shingle removing apparatus 10 of the present invention includes a drive linkage assembly 40 that provides lost motion oscillating driving of the stripper member 50 . The motor 60 drives the drive shaft 25 to ultimately rotate a crank arm 42 as illustrated in FIGS. 4 and 7 . It will be understood that the driving mechanism used to translate rotational motion of the drive shaft 25 into rotating motion of the crank arm 42 is not critical, and any driving mechanism known in the art may be used to translate rotational rotation of the drive shaft 25 into rotating motion of the crank arm 42 or the crank arm 72 .
[0026] The present shingle removing apparatus 10 includes the drive linkage assembly 40 providing preferred lost motion mechanism as illustrated in FIGS. 2-4 . In one embodiment, the drive linkage assembly 40 includes the crank arm 42 , a first link 44 and a second link 48 . The crank arm 42 is positioned on the exterior of the housing 33 and is rotated by the drive assembly 80 . The crank arm 42 is adapted for moving the first link 44 which is pivotally connected to the crank arm 42 by means of a pivot pin 49 . The first link 44 includes an elongated slot 45 spaced apart from the pivotal connection of the crank arm 42 and the first link 44 . The second link 48 includes a follower 47 which is movably received in the elongate slot 45 to form a lost motion pivotal connection. The slot 45 receives the follower 47 for free movement of the follower 47 along the elongated slot 45 . The elongated slot 45 has a length sufficient to effect intermittent movement of the stripper member 50 during continuous rotation of the crank arm 42 . As a result, the lost motion mechanism delays movement of the stripper member 50 during a predetermined portion of the rotation of the crank arm 42 . In this regard, an operator can move the shingle removing apparatus 10 forward without manually stopping the motor due to effect a time delay in the movement of the stripper member to insert it under more shingles 1 . When the crank arm 42 is initially rotated by a gear assembly 30 , the stripper member 50 is permitted to rotate through a predetermined “lost motion” connection before establishing a direct-drive driving connection therewith to delay lifting or lowering the leading edge 51 of the stripper member 50 . Once the direct-drive driving connection is established, further rotation of the crank arm 42 will cause the stripper member 50 to lift or lower. This “lost motion” feature advantageously aids in going forward for removing next shingles. The operator can proceed rapidly and safely as slow return of the stripper member 50 to the set up position is accomplished by the lost motion mechanism. It is preferred that the drive assembly be constructed so that the direct drive portion of a crank arm rotation is preferably adjacent 3 o'clock and 9 o'clock portion of the crank arm 42 to provide mechanical advantage during the lifting movement of the stripper member 50 and less impact from the follower 47 following out at the each of the slot 45 .
[0027] An alternate embodiment of the shingle removing apparatus 10 of the present invention is shown in FIGS. 6 and 7 . The drive linkage assembly 70 includes a crank arm 72 and a link arm 76 . The crank arm 72 is pivotally connected to the gear assembly 30 and is rotated by the gear assembly 30 . The link arm 76 is pivotally coupled to the eccentric portion 71 of the crank arm 72 by means of a follower 79 . The link arm 76 has first end and second end portions, the second end portion being operatively engaged with a second link 77 , the first end portion being pivotally connected to the eccentric portion of the crank arm 72 . The second link is secured to the upper surface of the stripper member 50 . The link arm 76 includes an elongated slot 73 spaced apart from the pivotal connection of the link arm 76 to the second link 77 . The crank arm 72 includes the follower 79 which is mounted to and pivotally engaged with the elongated slot 73 through the lost motion connection. The elongated slot 73 receives the follower 79 for free movement of the follower 79 along the elongated slot 73 . The elongated slot 73 has a length sufficient to effect intermittent movement of the stripper member 50 during continuous rotation of the crank arm 72 . As a result, the lost motion mechanism delays movement of the stripper member 50 . The drive linkage assembly 70 further comprises two discs 78 which are positioned in spaced apart relationship with the lost motion connection between the discs to shield a pinch point.
[0028] In conclusion, the shingle removing machine greatly facilitates the removal of shingles from a roof. The time delay of the drive arm actuation oscillates and reciprocates the shingle removing blades in an efficient pattern.
[0029] Moreover, it will be understood that although the terms first, second and third are used herein to describe various features, elements, regions, layers and/or sections, these features, elements, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one feature, element, region, layer or section from another feature, element, region, layer or section. Thus, a first feature, element, region, layer or section discussed below could be termed a second feature, element, region, layer or section, without departing from the teachings of the present invention.
[0030] Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art.
[0031] Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. The scope of the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. | The present invention discloses a shingle removing apparatus which includes a handle, a stripper member, a drive assembly and a drive linkage assembly with lost motion mechanism. The stripper member is adapted for inserting under a shingle has a first end portion and a second end portion. The drive assembly drives at least a portion of the stripper member and the drive linkage assembly causes at least portion of the stripper member to reciprocally move up and down to thereby remove the shingle. The drive linkage assembly provides a lost motion mechanism which allows the stripper member to intermittently not be driven. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to measurement and logging of salinity of fluids in well bores.
2. Description of the Related Art
Salinity measurement of fluid in a well borehole is important to evaluate the formation fluid. Salinity measurement can help in delineating oil and water and to estimate the moveable oil in a reservoir. Measurement of salinity as a function of well depth helps in differentiating between fresh and saline water and can help in identifying invasion of salt water into a producing borehole.
The downhole fluid environment is complex with presence of multiple non-homogenous phases with variable velocities. Measurement of a particular fluid characteristic performed at a single point in the wellbore might not represent an accurate representation of actual borehole fluid salinity.
So far as is known, downhole salinity measurement methods have in the past primarily been based on acoustic wave propagation through the formation fluid. Examples are U.S. Pat. No. 4,754,839 and U.S. Published Patent Application No. 2011/0114385.
U.S. Pat. No. 7,129,704 related to electromagnetic detection of progression of salt water fronts headed through formations to a water well. The increase of salt water in the formation before intrusion into the well water was measured with widely spaced electrodes since a significant portion of the induced electromagnetic field was required to pass through formation water outside the well bore.
SUMMARY OF THE INVENTION
Briefly, the present invention provides a new and improved apparatus for measuring salinity of fluid in a well bore. The apparatus includes a sonde for moving in the well bore to a depth of interest to receive well bore fluid. The sonde has a fluid sample chamber with fluid ports formed in it for entry of a well bore fluid sample volume. The apparatus includes at least one fluid conductivity sensor measuring conductivity parameters of the fluid sample volume in the sample chamber, and a data processor mounted in the sonde to determine salinity of the sample volume of well bore fluid at the depth of interest based on the measured conductivity parameters of the fluid in the sample chamber.
The present invention further provides a new and improved method of measuring salinity of fluid in a well bore at a depth of interest. A sonde is moved in the well bore to a depth of interest, and a sample volume of fluid from the well bore is admitted into a sample chamber in the sonde. A measure of the conductivity of the fluid sample in the sample chamber, and the salinity of the fluid sample is determined based on the formed measure of conductivity of the fluid sample in the sample chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view taken partly in cross-section of a borehole fluid salinity measurement tool according to the present invention deployed on coiled tubing in a wellbore.
FIG. 2 is an enlarged vertical cross-sectional view of structure of the borehole fluid salinity measurement tool according to the present invention.
FIG. 3 is a horizontal cross-sectional view taken along the lines 3 - 3 of FIG. 2 .
FIG. 4 is a schematic electrical circuit diagram of the borehole fluid salinity measurement tool according to the present invention.
FIG. 5 is a schematic electrical circuit diagram of a conductivity measuring cell of the borehole fluid salinity measurement tool according to the present invention.
FIG. 6 is a functional block diagram of the procedure for measuring borehole fluid salinity according to the present invention.
FIG. 7 is a view taken partly in cross-section of a borehole fluid salinity measurement tool according to the present invention deployed on a wireline in a wellbore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, a downhole salinity measuring tool or apparatus T is shown ( FIG. 1 ) deployed in a wellbore or borehole 10 . The downhole salinity measuring tool T includes a plurality of conductivity cells C ( FIGS. 2 and 5 ) deployed in a sonde S which is deployed in the well bore 10 , which may be a wet production hydrocarbon well or a water well. The borehole 10 may be either an uncased open hole or cased hole with well casing installed. The sonde S may be deployed on a lower end of coiled tubing 12 as shown in FIG. 1 or on a signal conducting wireline or e-line 14 ( FIG. 7 ) as will be described.
The sonde S of FIG. 1 is suitably attached to a lower end 12 a of the coiled tubing 12 by clamping or other suitable connection arrangement. The coiled tubing 12 is injected into the borehole 10 from a storage reel 16 to lower the sonde S to selected depths of interest in the well bore 10 so that fluid salinity of fluid at those depths may be measured and recorded. The depth of the sonde in the well 10 is measured and recorded based on data readings of the length of coiled tubing 12 injected into the well.
As the sonde S is lowered in the well 10 , sample volumes of the well bore fluid at elected depths of interest are taken by the tool T in the conductivity cells C. As will be set forth, the salinity of the borehole fluid at a depth of interest is determined based on the conductivity measurements from the cells C, and the determined salinity value(s) of the borehole fluid at such depths measured and recorded or stored as data for analysis and evaluation. Measures of the temperature and pressure of the fluid samples are also obtained by instrumentation in the sonde S, as will be set forth. The fluid samples in the cells are then allowed to flow from the cells as the sonde S moves to a new well depth for another fluid sample.
By obtaining fluid samples and determining salinity, temperature and pressure at a number of selected depths of interest, a number of well fluid sampling and salinity measurements are obtained with a pre-programmed measurement schedule or plan over formations or depths of interest in the well 10 . Measured data obtained in the coiled tubing deployed sonde S of FIG. 1 is stored in on-system memory 18 of instrumentation components 20 contained in an instrumentation cartridge I ( FIGS. 1, 2 and 7 ) of the sonde S. Operating power for the instrumentation 20 of the sonde S is provided by an on-system battery 24 in the instrumentation cartridge I. The measured salinity, temperature and pressure data obtained at the various depths in the well 10 and stored in on-board memory 18 are transferred to a conventional computer for analysis, further processing and display after the tool T returns from the well 10 .
A salinity measurement performed based on a single measurement in a wellbore might not give an accurate value of fluid salinity because of the non-homogeneity of the wellbore fluid and the presence of multiphase flow regimes. Accordingly, with the present invention, to avoid the effect of possible wellbore fluid non-homogeneity and multiphase flow, as well as to improve accuracy of measurement, the tool T contains four conductivity cells C mounted at a common elevation on the instrumentation cartridge I within the sonde S as shown in FIGS. 2 and 3 . A suitable number of fluid passage ports 26 are formed in the body of sonde S to allow well bore fluid presence and containment with the interior of the sonde S.
The well bore fluid sample in each conductivity cell C is received in a fluid sample chamber F ( FIGS. 2 and 5 ). The shape, size and volume of the chamber F defines the geometry of the conductivity cell C. The sonde S also preferably includes a fluid temperature sensor 30 measuring temperature of the sample volume of well bore fluid in the fluid sample chamber, and a fluid pressure sensor P measuring pressure of the sample volume of well bore fluid in the fluid sample chamber.
FIG. 5 is a cross-sectional view of a single conductivity cell C along with a schematic view of associated electronics. Each cell C includes fluid receiving channel or chamber F located between a fluid inlet port 32 ( FIG. 2 ) and a fluid outlet port 34 for wellbore liquids for passage of wellbore fluid from the interior of the sonde S. As shown schematically in FIG. 5 , the chamber or channel F can be selectively opened and closed for entry and exit of well bore fluid by digitally controlled check valves 36 and 38 in inlet and outlet ports 32 and 34 , respectively to obtain sample volumes of the wellbore fluid. The valves 36 and 38 are preferably operated by solenoids or other suitable valve actuators.
Each conductivity cell C includes electrodes located within fluid chamber F. Two drive electrodes 40 and 42 apply alternating current (AC) to the wellbore fluid in the chamber F. Preferably a high frequency alternating current is applied between the drive electrodes 40 and 42 as indicated by the instrumentation 20 . The high frequency is used to avoid corrosion. In a preferred embodiment 10 KHz is used, although frequencies in a range of from 1 KHz to 100 KHz could be used.
Sense electrodes 44 and 46 form a measure of the voltage difference between spaced positions in the chamber F in response to the current between drive electrodes 40 and 42 . The electrodes 40 , 42 , 44 and 46 are preferably fabricated using platinum on a glass chip with an insulative plastic or synthetic resin used as the body of conductivity cell C housing the chamber F.
The conductivity of the wellbore fluid sample in the chamber F of each conductivity cell C is determined based on the product of the determined measure of liquid conductance (G) of the sample volume of well fluid in the cell, and cell constant (σ) which is a constant which is defined by the geometry and dimensions of the sample chamber. The conductance value G is the reciprocal of a measured fluid resistance (R) of the sample volume obtained based on the current and voltage measured with the drive electrodes 40 and 42 and the sense electrodes 44 and 46 . The fluid resistance R is determined using Ohm's law R=V/I relationship measured as indicated schematically at 45 of the voltage difference V between the sense electrodes 44 and 46 for an applied current level I applied by and flowing between the drive electrodes 40 and 42 .
The high frequency alternating current wave signal between drive electrodes is generated under control from microprocessor 50 ( FIG. 4 ) of the instrumentation 20 . The signal so generated is converted to a current signal in an operational amplifier 52 ( FIG. 5 ), and a resistor 54 . The amplitude of sine wave voltage signal from operational amplifier 52 is preferably limited to an acceptable low level such as 1V to avoid electrolysis and metal corrosion, as the borehole fluid sample could be brine with high saturation of salts. It should be understood that low voltage levels in the range of less than 2 volts may be used.
Based on the resistance R obtained from the conductance and the cell constant σ based on the physical geometry of cell C, resistivity of the borehole fluid sample is thus determined. The determined wellbore fluid sample resistivity is representative of the salinity of the borehole fluid sample in the each conductivity cell C. The conductivity measurements are obtained in each of the cells C and an average of these values is determined and stored as the representative salinity of the wellbore fluid at the sample depth of interest.
The temperature sensor 30 is usually a thermal resistive device with a linear resistance-to-temperature relationship for temperature measurement. Resistance (R) of a thermal resistive device depends on the material's resistivity (ρ), the structure's length (L) and cross section area (A):
R=ρL/A
The change in temperature can be calculated by measuring the change in resistance by the following formula using initial values of resistance and temperature, R o and T o and the temperature coefficient (α):
R=R o (1+α( T−T o ))
A platinum resistance thermometer (PRT) is preferably used as the temperature sensor 30 . Platinum has a higher temperature range, good stability and low tendency to react with surrounding material as required for downhole conditions. These unique properties of platinum enable PRT to operate in temperature range of −272.5° C. to 961.78° C. The platinum resistor of temperature sensor 30 is typically fabricated on a glass substrate.
The pressure sensor P which determines fluid pressure in the well is preferably a piezoresistive pressure sensor made using micro electro-mechanical systems (MEMS) fabrication techniques. The pressure sensor P thus preferably takes the form of a membrane over a cavity. In such a pressure sensor, the magnitude of membrane movement corresponds to the pressure level imposed by the wellbore fluid on the membrane. Changes in pressure on the membrane change the stress in membrane which can be measured by a change in resistance.
The conductivity cells C, the temperature sensor 30 , and the pressure sensor P each form analog signal measures indicative of the value of the boreholes fluid parameter measures sensed. The analog signals from the borehole sensors are converted in analog-to-digital converters 60 , 62 and 64 , respectively, into suitable digital format for data acquisition and storage in on-system memory 18 and for processing by the microprocessor 50 .
The salinity of the well bore fluid sample is determined in the on-board microprocessor 50 of the instrumentation 20 based on liquid conductivity, as described above, and stored in on-board memory 18 , along with measured temperature and pressure of the wellbore fluid. From the measured salinity, conductance, temperature and pressure obtained wit the tool T, other borehole fluid parameters can also be computed including resistivity, density, acoustic velocity, freezing point, specific heat and potential density.
The microprocessor 50 serves as the main processing unit in on-board instrumentation of the sonde S. The microprocessor 50 includes a main controller 70 , a power management unit 72 , a digital signal processer 74 , a timer 76 and the on-board memory 18 . The memory 18 serves as internal memory for the tool T. The amount of memory provided depends upon the wellbore fluid measurement interval, total measurement time and number of parameters to be stored for each measurement. If the measurement is to be done over a larger range of depths of interest or with small measurement intervals, an external random access memory can be included and interfaced with microprocessor 50 .
The digital signal processor 74 performs signal processing tasks including generation of signals for conductivity testing and computation of liquid conductance, resistivity and salinity in the manner described above. The timer 76 determines the time of occurrence of and the time interval between obtaining borehole fluid measurements, and thus defines the measurement frequency. The controller 70 controls the other subsystems of the microprocessor 50 and performs the required synchronization. An USB interface 78 is provided for connection of the controller 70 to an external computer at the surface for programming of operations in the wellbore and for transfer of data from the memory 18 .
Battery 24 which provides power for the microprocessor 50 and other electronics of the sonde S preferably is a rechargeable lithium ion battery. The power management unit 72 is implemented in the microprocessor 50 to efficiently manage the operating electrical power usage. A power optimized system architecture is utilized in the power management unit 72 in order to maximize the system service life. The functionality of the system is divided into different working states. The power management unit 72 activates modules required for the current working state and switches off the rest. Power saving strategies at both sensor level and system level are implemented to minimize power consumption of the system.
Detailed analysis and further measurements based on the borehole fluid data obtained S can be performed after the sonde S is moved out of the well bore to the surface. The contents of memory 18 are transferred by connecting the microprocessor 50 with a computer at the surface and retrieving the data.
FIG. 6 illustrates the operating sequence of measuring salinity of borehole fluid according to the present invention. The sonde S is deployed in the well bore with coiled tubing 12 . At a pre-programmed time to allow the sonde to reach a depth of interest, the valves of the conductivity cells C are activated to sample the wellbore fluid as indicated at step 100 . The sensors of the conductivity cells C are activated by the microprocessor 50 as indicated at step 102 so that borehole fluid salinity can be determined at the depth of interest.
During step 104 , the alternating current signal is applied to the borehole fluid samples in the conductivity cells C by current flow between the drive electrodes 40 and 42 . The resultant voltage is concurrently sensed by the sense electrodes 44 and 46 as indicated by step 106 . Pressure and temperature measures of the wellbore fluid are also obtained from pressure sensor P and temperature sensor 30 in step 106 . The measured borehole fluid data after collection is then collected and processed by the microprocessor 50 to determine borehole fluid salinity, as indicated by step 108 .
The computed salinity and other measurements of borehole fluid data are stored in the memory 18 during step 110 , along with a time stamp or record of the time the sample was taken. The sensors in the sonde S are then disabled during step 112 . Movement of the sonde S in the well bore continues and at the next pre-programmed time indicated by the timer 76 , the foregoing sequence is repeated.
The well bore fluid parameter sensors of the sonde S are preferably fabricated with micro electro-mechanical fabricated or MEMS microfabrication technologies which offer miniaturization as well as accurate measurement. The analog-to-digital converters 60 , 62 and 64 , the microprocessor 50 and other electronic components used as instrumentation 20 in the sonde S may be commercial, off the shelf harsh environment electronic components. A harsh environment commercial electronics component line is provided by Texas Instruments which can operate in the temperature range of −55° C. to 210° C.
Alternatively, a custom made application specific integrated chip or ASIC may be utilized, with multilayer thick film fabrication or silicon-on-insulator techniques and ceramic packaging. The board for the electronics of the sonde S is preferably a high temperature printed circuit board with an inorganic ceramic substrate. The board and electronics have ceramic packaging and are hermetically sealed to protect the circuits from well fluids.
As described above, the sonde S can also be deployed using the e-line or signal conducting wireline 14 ( FIG. 7 ). In this case, the wireline 14 is connected to a computer system 120 at the surface. The components of the sonde S in FIG. 7 to obtain measures of borehole fluid salinity, temperature and pressure are of like structure and functionality to those described for the coiled tubing deployed sonde S of FIG. 1 .
Borehole fluid data from the sonde S are received and recorded as functions of borehole depth in memory of uphole telemetry and preprocessing circuitry 122 . A surface processor computer 124 receives and processes the borehole fluid data of interest under control of stored program instructions stored as indicated at 126 . The results from processing by the processor computer 124 are available in real time during salinity measurement operations for analysis on a suitable display or plotter, such as display 128 . A depth measurement system (not shown) also is present as a component of the wireline 14 to also correlate or indicate downhole wellbore fluid sensor measurements and parameters of interest to their respective depths or true locations within the borehole 10 at which such measurements are made.
The surface computer 124 can be a mainframe server or computer of any conventional type of suitable processing capacity such as those available from any of several sources. Other digital computers or processors may also be used, such as a laptop or notebook computer, or any other suitable processing apparatus both at the well site and a central office or facility.
A power cable or conductor in the wireline 14 is used to charge the battery 24 and borehole fluid parameters of interest measured by the tool T can be accessed at the surface by computer system 120 in real-time. Conventional wireline telemetry and control circuitry are included in the tool T of FIG. 7 for transfer of data over the wireline 14 to the surface for processing by processor computer 124 and to receive control signals for the tool T from the computer system 120 . The controller 70 in the tool T can also be programmed while in the well by instruction signals sent by wireline to change the acquisition parameters including measurement frequency of sensors, total measurement time and other required parameters.
The invention has been sufficiently described so that a person with average knowledge in the matter may reproduce and obtain the results mentioned in the invention herein Nonetheless, any skilled person in the field of technique, subject of the invention herein, may carry out modifications not described in the request herein, to apply these modifications to a determined structure, or in the manufacturing process of the same, requires the claimed matter in the following claims; such structures shall be covered within the scope of the invention.
It should be noted and understood that there can be improvements and modifications made of the present invention described in detail above without departing from the spirit or scope of the invention as set forth in the accompanying claims. | A downhole salinity measurement and logging sensor system has multiple cells, each to measure conductivity, temperature and pressure of fluids at depths of interest in a wellbore. The multiple cells protect against effects of non-homogeneous wellbore fluids. The system also determines salinity of the liquid in the wellbore from conductance measurements, and stores the salinity data along with the temperature and pressure readings from the well. The sensors of conductivity, temperature and pressure are made using micro-fabrication technologies, and the system is packaged to comply with harsh downhole environments. The system may be deployed in the well with coiled tubing (CT), wireline or vehicles with a robotic system. The system can be deployed with an onboard memory, or with wireline surface access for real time access to measurement data or programming the device. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation application and claims priority under 35 U.S.C. §120 from U.S. patent application Ser. No. 08/841,271, filed Apr. 29, 1994, U.S. Pat. No. 6,138,313, which is in turn a continuation of U.S. patent application Ser. No. 08/513,273, filed Aug. 10, 1995 (abandoned), the full disclosures of which, in their entirety, are hereby incorporated by reference.
FIELD OF THE INVENTION
This invention relates generally to paint applicators, and specifically to paint brush handles, paint brushes and methods of manufacture thereof which result in a handle, and a paint brush, having an improved grip construction and other operational and manufacturing advantages.
BACKGROUND OF THE INVENTION
Currently available paint brushes are usually made with a rigid handle, often wood, but also plastic, to which a series of natural and/or synthetically formed brush filaments are secured, usually with a ferrule at the brush filament-handle junction area, using adhesives, fasteners, such as nails, crimping, or other means. Such brushes are extensively used by do-it-yourself painters who paint on an occasional basis as contrasted to a professional painter or decorator who paints day in and day out. The do-it-yourself painter is thus unaccustomed to the use of hand, wrist and forearm muscles that are called into play in painting with the result that painting becomes a difficult, and sometimes painful, task for such an occasional painter. The same difficulties may not be so pronounced with professional painters but they still are a factor, particularly near the end of a day of painting.
Brush makers have long been cognizant of this problem and attempts have been made to overcome it. The most common approach is to manufacture the brush handle in the form that experience tends to indicate is the most suitable for the specific use for which the brush is intended. Thus, for sash work a long straight handle has been preferred. For general painting purposes a semi-beaver tail contour has been widely used, and for large, wide surfaces, such as exterior siding, a full beaver tail contour has been preferred. Although these shapes do result in a rough match between the applicator and the painting task when such factors as flow and rate of spreadability are considered, nearly all styles include a handle made of a relatively hard, rigid material, such as varnished wood or hard plastic, and hence the problem of hand and forearm fatigue remains a significant drawback. Although attempts have been made to provide a brush having a less taxing operational characteristic, no system which is applicable to all handle contours and which combines sureness of grip, gentleness of contact with the user's hand and ease of use (in the sense of decreasing hand, wrist and forearm pain and stiffness in lengthy painting tasks) has come into widespread use.
Another general problem common to many if not the great majority of brushes currently in use is the degradation of the brush during use with consequent deleterious effects on both the brush, the user and the painting surface. For example, in many if not the great majority of current brushes the ferrule at the brush filament-handle junction area works loose and paint can enter the opened areas and solidify. And in use, water, solvent, or paint, or combinations thereof, which have entered the opened spaces, are able to re-emerge and run down the handle toward the user's hand, thus making a mess and possibly dripping an unwanted color onto a freshly painted surface.
A further annoying and dangerous problem occurs when portions of the end of the ferrule nearest the handle are dislodged from their normal lay-flat position, thus presenting an exposed sharp edge. This is particularly serious when the terminal exposed edge with its associated sharp upper corner is displaced away from a snug fitting relationship with the upper end of the brush filaments and/or the lower, concealed end of the brush handle. Such an exposed edge or sharp corner can easily cut the flesh of the user when in sliding contact with the user's hand.
And finally, it is well known that no system for providing the above described desirable attributes and avoiding the above described drawbacks which is adaptable to the mass production of brushes has been proposed, let alone entered the marketplace.
SUMMARY OF THE INVENTION
The invention is a paint brush, including a handle, and a handle per se, together with a method of manufacturing same, which results in a product which significantly reduces fatigue of the user during use, provides a sure grip with consequent excellent control over the head of the brush filaments during paint application, is applicable to brushes of all specialized uses and handle contours from sash to siding, and feels comfortable in the hand of the user, yet which can be produced at a very modest cost so that mass produced brushes may enjoy the aforesaid significant advantages. Said advantages result from the provision of a thin layer of material having the characteristics with respect to compressibility and flexibility of rubber-like material or soft plastic which is preferably formed as an independent molded product about a hard handle core. Preferably the thin layer is a thermoplastic elastomer and the core is a material compatible with the exterior layer in the sense that a good chemical and/or heat bond as well as a mechanical connection is formed between the thin resilient layer and the hard core. The handle is formed in a two stage injection process in which the core member formed in the first stage includes spacer means which fix the position of the core member in a subsequent molding cavity so that, upon injection of the resilient layer under the necessarily high injection pressures required in such operations to form the thin layer of resilient material, the core will remain perfectly spaced from the surface of the second mold cavity whereby the desired thickness is provided at all locations. The invention further includes application of the resilient layer at the junction area of the ferrule with the handle in such fashion that problems resulting from separation of the ferrule from the balance of the brush are eliminated during normal use to which the brush will be subjected.
Other objects and advantages of the invention will become apparent from the following description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:
FIG. 1 is a top plan view of a brush, here a sash brush having a straight handle, with parts broken away for clarity;
FIG. 2 is a right side view of the brush of FIG. 1;
FIG. 3 is a section taken substantially along the line 3 — 3 of FIG. 1;
FIG. 4 is a front end view of a brush handle of the invention, the ferrule and brush filaments having been omitted;
FIG. 5 is a top plan of an alternative form of a brush, here a semi-beaver tail general purpose brush, with a portion of the ferrule broken away for clarity;
FIG. 6 is a right side view of a handle assembly of the brush of FIG. 5; and
FIG. 7 is a section taken substantially along the line 7 — 7 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Like reference numerals will be referenced to like parts from Figure to Figure in the description of the drawing.
Referring first to FIG. 1, a brush, here a sash brush, is indicated generally at 10 . The brush 10 includes a handle, indicated generally at 11 , a brush head, indicated generally at 12 , at the distal end of the handle, and a means for securing the brush head to the handle in operative relationship, here a ferrule, indicated generally at 13 .
The handle 11 includes a core, indicated generally at 15 , see FIG. 3 particularly, and a thin covering layer, indicated generally at 16 , said covering layer having the characteristics, with respect to compressibility and resiliency, of rubber-like material or soft plastic. The core 15 is formed from a relatively hard material, preferably plastic, which provides strength and stiffness to the brush. The core includes a shank portion 17 which terminates at its upper end in hang portion 18 at the proximate end of the handle and, at its lower end, in a width expanded connecting portion 19 . Hang portion 18 has, in this instance, a key hole shaped hang slot 20 , the bottom of which is formed with inclined surfaces 21 , 22 , see FIG. 3, which form an apex at the center for easily assembly to a hang structure, such as a peg board hook or extended wire or Q-bic blade. The hang portion 18 is set off from shank portion 17 by a circular channel indicated generally at 23 , the bottom 24 of the channel 23 extending outwardly from the central axis of the handle a slightly greater distance than the upper end of the shank portion 17 of the handle for a purpose which will appear hereafter.
The lower expanded portion 19 of the handle terminates in a plug-in section of the ferrule cavity indicated generally at 26 which is received at the upper end of ferrule 13 in a conventional manner, the plug section including side prongs 27 , 28 .
The covering 16 is composed of a material having the characteristics with respect to compressibility, resiliency and flexibility of rubber-like material or soft plastic. As best seen in FIGS. 1 and 3 the covering 16 extends from the channel 23 downwardly over all the exposed surface area of the shank portion 17 and expanded portion 19 of the core, with one exception to be described hereafter, above the top of ferrule 13 . It will be noted from FIG. 1 that, in addition, the covering extends in a narrow band 31 along the upper end of the plug section 26 of the core, the narrow band 31 being located within the upper edge portion of the ferrule. It will be seen from FIG. 1 particularly that the width of the band 31 is slightly shorter than the width of the covering 16 at the lowest point of the expanded portion 19 of the core. Since the width dimension of the lower end of the covering on the expanded portion 19 of the core 15 is equal to or, preferably, slighter greater than the thickness of the ferrule 13 , the joining surfaces of the covering 16 and the narrow band 31 form a recess having a depth, in a width direction, at least as great as the thickness of the ferrule. Thus the narrow band 31 and the adjacent shoulder on the covering form a seal with the upper end of the ferrule, which seal precludes entry of fluids into the interior of the ferrule, or the leakage of paint or other applied coating, upwardly over the upper edge of the ferrule from its interior.
The covering 16 extends downwardly in a suitable recess in the center of the core as at 32 , loops under the bottom center of the core at 33 , see FIG. 3, and extends upwardly, as at 34 , in a suitable recess on the bottom side of the core, see FIG. 3, to form a loop connector between the covering on the top and bottom sides of the core which mechanically precludes separation of the covering from the core.
The upper edge of the covering 16 , indicated at 35 , partially abuts against a shoulder 29 formed just below channel 23 whereby slippage of the covering 16 toward the hang portion 18 is resisted.
A finger grip indentation is formed in the lower end of the handle in the junction area between the shank portion 17 and the expanded portion 19 of the core on both sides of the handle as best seen in FIG. 3 . Concave areas 37 , 38 , of covering 16 follow the contour of the finger grips 36 so that the user may place his thumb and forefinger into the two finger grips 37 , 38 during use. This placement of the finger grips 37 , 38 in the illustrated very close juxtaposition with the bottom of the handle and top of the ferrule provides near-maximum control of the brush head 12 by the user during coating application. The locations of the finger grips further ease the muscle strains which manipulation of a paint brush entails in that the grips provide a more natural, less stressful position for the hand to occupy during manipulation of the brush head 12 during coating; i.e.: as contrasted to the conventional wider spacing usually found on current brushes. By reference to a straight cylinder handle as the most disadvantageous grip construction, it will be appreciated that the herein disclosed configuration consisting of, firstly, a barrel section to accommodate the wrap of the last three fingers of the user's hand, in conjunction with, secondly, the finger grips 37 , 38 , provide the most natural and therefore the least tiring hand gripping configuration.
From FIGS. 2 and 3 it will be noted that the thickness 39 of the junction area between the shank portion 17 and the expanded portion 19 of the core is less than the thickness of the bottom portion 19 of the core. By providing a thickness 40 between the finger grips 37 , 38 , which is only thick enough to provide the minimum required rigidity and structural integrity to the brush, brush filament control is enhanced because of the relatively small distance between the thumb and forefinger of the user in operation as contrasted to the spacing between the thumb and forefinger in a conventional brush handle. It will be appreciated that the closer the two digits of the human hand are placed during a manipulating movement of the hand, the finer the degree of control the user has over the gripped object. The crescent shaped inclined surface 43 on the lower portion of the handle functions as an aesthetically pleasing transition section between the narrow dimension represented by the thickness 39 in the finger grip area and the substantially greater dimension 41 in the ferrule-handle joinder area. Other configurations, including a sharp right angle, could be used however. A plurality of grooves are indicated at 44 in the cover 16 . The grooves 44 provide a thumb rest for the user in the event the user finds it more comfortable during use to place his thumb on the bottom portion 19 of the handle than in a finger grip 37 , 38 . The grooves also function as a means for preventing slippage of the user's thumb, or other finger, which may rest thereon in preference to one of the grips 37 , 38 . Said grooves are aesthetically pleasing to the eye but, from a functional standpoint, they could be replaced by numerous other constructions, including dimpled depressions or a knurled configuration.
The ferrule 13 is of conventional construction and is applied in conventional fashion to the lower end of the handle, the exposed vertical edge of the ferrule being indicated at 45 . In this instance the ferrule has been secured by crimping to the brush head 12 and handle 11 , though nails could be used.
A particularly unique feature of the invention is illustrated in FIGS. 1 and 3 by the core projections 46 , 47 , 48 and 49 . As best seen in FIG. 3, projections 48 and 49 extend outwardly to the plane of the surface of cover layer 16 . The projections are preferably formed integrally with the core 15 during the core molding operation. The projections are here shown as diamond shaped, see FIG. 1, but it will be appreciated that virtually any contour is feasible, including a circle. The protrusions greatly facilitate the manufacturing process in that they make possible the production of a uniform product at a high rate of speed, and thus make the invention available at a price which the mass market consumer can afford. The protrusions, here diamond shaped, also function as a further mechanical interlock between the core 15 and the covering layer 16 to thereby prevent slippage between the core 15 and the cover layer 16 .
Specifically, after molding the core, including the projections 46 - 49 , the thus formed core is placed in a second mold cavity and the cover layer 16 injection molded about the core 15 . In view of the thinness of the cover layer 16 and the long distance the hot injection material must flow, and the resultant requisite high pressures encountered during the cover molding step, the core 15 must be braced away from the surface of the mold cavity to ensure that the cover layer material envelopes the core to the desired thickness at all locations. The projection 46 - 49 serve to locate the core 15 at the desired position within the second molding cavity, the projections thereby functioning in effect as spacers to maintain the core in a precise, predetermined position with respect to the second molding cavity. The projections are here configured so that the surfaces thereof, as indicated at 50 , see FIG. 3, abut the wall of the second molding cavity so that injected material may flow around the projections as indicated in FIGS. 1 and 3 but not between the surfaces of the projections and the surface of the mold cavity. As a consequence the surfaces of the projections are flush with the surface of cover layer 16 and provide an eye-pleasing, decorative appearance.
Referring now to the embodiment of FIGS. 5-7 it will be seen that a general purpose semi-beaver tail varnish or wall brush is there illustrated. Similar reference numerals have been used to refer to parts which are the same as or similar to the corresponding parts illustrated in FIGS. 1-4.
In this instance only a single pair of protrusions 52 , 53 , have been used for the reason that the core is sufficiently short that it may be maintained spaced from the wall of the second cavity with only said pair of protrusions.
In this instance also the lower edge of the exposed portion of cover 16 in its final condition projects outwardly beyond the thickness of the ferrule 13 a significant amount, as indicated in 54 . Thus even if the ferrule should work loose slightly at its upper edge, said upper edge will still be within, or aligned with, the exterior dimension of the cover 16 and thus the risk of injury to the user, or the ingress or egress of paint, solvent or other liquid between the cover 16 and the ferrule 13 will be decreased over the structure illustrated in FIGS. 1-4.
The thickness of the soft grip covering 16 will vary from a thickness of on the order of from about 0.030 inches to about 0.125 inches. Below 0.030 inches it will be difficult to push the material over the length of the core 15 through such a small space. If the cover material is thicker than about 0.125 inches the flow will be excellent, but the final structure may be too flexible for easy use, and the cost would increase considerably since the cover material is more costly than the material from which core 15 is made. More preferably, the thickness of the cover material 16 should be on the order of from about 0.050 inches to about 0.075 inches.
The core material is preferably polypropylene. The preferred over-grip or cover grip material is a thermoplastic elastomer (TPE). An example would be Santoprene, which is a polypropylene based TPE with vulcanized rubber dispersed in it. Since both materials are polypropylene based, there will be a better chemical and/or heat bond between both substrates than there would be with dissimilar materials. It will be understood that a bond may be formed by heat fusion or chemical reaction or both heat fusion and chemical reaction depending on the specific materials, times, temperatures and pressures utilized. Most preferably the cover 16 is secured to core 15 not only by the mechanical interlocks but also, to some degree, by a bond provided by heat and/or chemical means.
Other materials could be used for the core material, such as a polyethylene with the Santoprene TPE over-grip. Both materials are in the polyolefin family and would bond and work, but probably not as well as the same material based components. Other base materials such as blends of polypropylene and polyethylene could also be used.
Still other material combinations could be used. For example, Krayton is a styrene based TPE which could be used. It would not be as effective as Santoprene since the base material is styrene which does not have nearly as good solvent resistance to paint solvents as does Santoprene. It would be acceptable for latex or water based systems but not solvent based coatings. Polyvinylchloride (PVC) can also be used but like Krayton the PVC has limited resistance to non-water based solvents. A number of other core and over-grip materials could be used to make this type of brush handle but the materials described above both have a relatively high resistance to all paint solvents and a low manufacturing cost for an integrally molded handle.
As mentioned, the foregoing description pertains to a two-shot molded handle. Other handle designs could also be used such as sliding a premolded sleeve of a grip material over a core handle. A TPE, PVC, polyester or urethane foam or even a rubber material could be slid over a core handle. This slide on could be similar to a bicycle handgrip or it could be mechanically trapped in a recess but significant disadvantages to said alternative processes exist to the point where the illustrated and described construction is much preferred.
Although a preferred embodiment of the invention has been illustrated and described in the foregoing specification, it will at once be apparent to those skilled in the art that the modifications and improvements may be made. Accordingly it is intended that the scope of the invention be defined by the scope of the hereafter appended claims when interpreted in light of the relevant prior art, and not by the scope of the foregoing exemplary description. | A brush handle is disclosed having a core member which is surrounded by a layer of compressible and resilient gripping material of a non-slip nature, the layer of gripping material closely conforming to the contour of the brush handle and being mechanically interlocked to the handle by at least one projection which is integral with the core member and extend into the layer of gripping material, and also at least partially bonded one to the other by heat and or chemical processes. A brush having the above described handle sealingly secured to a brush head utilizing the layer of gripping material and a method of manufacturing a brush handle are also disclosed. | 8 |
FIELD OF THE INVENTION
[0001] The invention relates to a method and system for managing patient data. Specifically, the invention relates to an analytical instrument in direct communication with at least one other analytical instrument over a network for accessing patient data acquired by the other analytical instrument.
BACKGROUND OF THE INVENTION
[0002] Medical facilities such as hospitals and doctor's offices employ numerous medical devices to obtain and/or analyze samples from patients. These analytical instruments are often placed at different locations throughout the medical facility.
[0003] Typically, such instruments are connected to or communicate with a stand-alone computer to perform the data management functions relating to the processing of patient data. However, several problems exist with this arrangement. For example, the user must physically walk to the computer to see and/or manipulate the data from a particular device. In another example, the computer typically has a different user interface than the users interface of the instrument. Furthermore, in facilities using different instruments for different procedures, each instrument may have its own interface. These different user interfaces require the user to learn how to navigate through each user interface to perform the necessary tasks, and to quickly distinguish the differences between them. Moreover, if an analytical instrument is used outside of the facility in which it normally operates, the user would be unable to perform the data management functions without the stand-alone computer, or without having to return the instrument to the facility prior to performing any of these functions. This results in a cumbersome requirement to maintain the data management capabilities when the user travels with the instrument.
[0004] The medical facility may also employ a server computer for the storage of information associated with, for instance, the analytical data. The instruments (or other computers) traditionally communicate with the server to access the information. A user located at the server, however, cannot typically analyze a sample. Also, if many instruments request information from the server at approximately the same time, communications may be delayed. Moreover, if the server experiences a failure and has to be repaired, the retrieval of the data is delayed until the problem is fixed or until another server replaces the faulty server. Such server-centric arrangements can result in a chain reaction of inefficiencies such as data unavailability and inefficient medical treatment.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a method, system, and apparatus for managing patient data. In one aspect, the invention relates to a system for managing patient data having many instruments. The instruments have a sampling member for sampling a body fluid from a patient and directly communicate with each other.
[0006] The direct communication can include a first instrument controlling a second instrument. The control can include, for instance, the first instrument calibrating the second instrument, the first instrument processing a sample on the second instrument, the first instrument turning the second instrument off, and/or the first instrument turning the second instrument on. The direct communication can include one instrument being in direct communication with at least two other instruments, and the communication can be unidirectional or bidirectional.
[0007] In one embodiment, the direct communication includes one instrument accessing patient data acquired by another instrument. The accessing of patient data can include viewing status of another instrument, viewing one or more operations on another instrument, and searching patient results on at least one other instrument. In one embodiment, one instrument can operate as an agent for one or more of the other instruments, and thereby can transmit to and receive data from another instrument subsequent to the other instrument acquiring and/or accessing patient data.
[0008] In some embodiments, the system also includes a single user interface for managing the analysis of the body fluid sample and patient data. The data acquired or stored in each instrument can be displayed in a common format.
[0009] In another aspect, the invention relates to an instrument having an analytical module, a data management module, and a communications module. The analytical module analyzes a body fluid sample. The data management module within the instrument enables management of data associated with the body fluid sample. The communications module facilitates instrument-to-instrument communications. In some embodiments, the instrument also includes a user interface for receiving user instructions relating to the analytical module, the data management module, and the communications module. In one embodiment, the management of data includes generating a report, (which, in some cases may be generated automatically) managing security information, performing competency testing, determining a pattern associated with the instrument, performing inventory management, quality control, and/or determining the workload of the instrument.
[0010] The data can include patient data, which may be combined with the analytical data associated with the analysis of the body fluid sample. The report can include a quality control report, a regulation report, and a workload report. Moreover, the report can be automatically generated. In one embodiment, the performance of competency testing can be determining a pattern of occurrences to facilitate better training.
[0011] In yet another aspect, the invention relates to a method for accessing patient data. The method includes connecting the instruments to a network. Each instrument includes a sampling member for sampling a body fluid from a patient. The method also includes the steps of sampling, by the sampling member of a first instrument, a body fluid from a patient and accessing, and analyzing the sample. A second instrument then accesses the results of the analysis directly from the first instrument. In some embodiments, an instrument initiates a configuration process on one or more of the plurality of instruments according to predetermined acceptable ranges of the results of the analysis.
[0012] In another aspect, the invention relates to a system for managing patient information including a collection of instruments, each instrument including a sampling member for sampling a body fluid. The system also includes a collection of communications modules, each communication module being associated with an instrument, and directly exchanging patient information with other instruments without the patient information being permanently stored or processed on an apparatus other than one of the instruments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a block diagram of a system having a first, second, and third instrument communicating over a network according to an illustrative embodiment of the invention.
[0014] FIG. 2 is a block diagram of a system having a server communicating with a first and second instrument over a network according to an illustrative embodiment of the invention.
[0015] FIG. 3 is a block diagram of an instrument having a user interface and a data management module according to an illustrative embodiment of the invention.
[0016] FIG. 4 is a flow diagram of the steps performed for configuring the instruments of FIG. 1 according to an illustrative embodiment of the invention.
[0017] FIG. 5 is a flow diagram of the steps performed for using the instruments of FIG. 1 according to an illustrative embodiment of the invention.
DETAILED DESCRIPTION
[0018] FIG. 1 is a block diagram of a system 100 having a first instrument 104 , a second instrument 104 ′, and a third instrument 104 ″ (generally instrument 104 ) communicating over a network 116 according to an illustrative embodiment of the invention. Examples of instruments 104 include but are not limited to a GEM Intelligent Quality Management (iQM) 3000 analyzer, a GEM Intelligent Quality Management (iQM) 4000 analyzer (both from Instrumentation Laboratory, Lexington, Mass.), and a VITROS DT60 II Chemistry System (Johnson & Johnson, Piscataway, N.J.). Other instruments may be, for example, a hand-held instrument such as a handheld glucose sensor. The instruments 104 can be located in, for instance, a hospital, a doctor's office, a medical facility, a patient's home, an elderly care facility, an ambulance, public transportation vehicles, large public venues, or any other location in which medical analysis and/or patient data sampling occurs on either a routine or emergency basis. For example, one instrument of the system may be located in a hospital, and another one of the instruments may be located in a doctor's office. Alternatively, all of the instruments may be located in a hospital, but at remote locations throughout the hospital. In some cases, the instruments 104 travel throughout the facility, thereby introducing the possibility that any instrument 104 could be at any location at any time. Each instrument 104 , 104 ′, 104 ″ includes a respective sampling member 120 , 120 ′, 120 ″ (generally sampling member 120 ). An example of a sampling member 120 is a probe for contacting the sample, an inlet port for receiving a sample, a receptacle for receiving a sample cartridge, or a sample cuvette, for example. Each sampling member 120 , 120 ′, 120 ″ can sample a body fluid from a patient. Examples of a body fluid include blood, serum, plasma, urine, semen, saliva, tracheo-bronchial washing, cerebrospinal fluid, and the like. The sampling member 120 , 120 ′, 120 ″ can analyze a body fluid to determine qualitatively or quantitatively the amount or presence of one or more target analytes in the body fluid. Although described below with respect to the first instrument (“instrument 104 ”), the description applies to any or all of the instruments 104 , 104 ′, 104 ″. Similarly, although the description below is with respect to the first sampling member 120 (“sampling member 120 ”), the description applies to any or all of the sampling members 120 , 120 ′, 120 ″.
[0019] As used herein, accessing patient data means one instrument 104 directly accessing data on another instrument 104 ′, i.e., a central processing unit (CPU) or server positioned between the first and second instruments 104 , 104 ′, respectively, is not necessary for the first and second instruments to access data from each other. Acquiring patient data means when one instrument 104 analyzes a target component in a patient body fluid sample. In one embodiment, the acquiring of patient data includes using the sampling member 120 to obtain a patient sample. Patient data is patient personal data and patient clinical data. Personal data can include, for example, name, gender, residence, age, height, weight, sex, allergies, and/or health history. Clinical data can include a qualitative or quantitative determination of a target analyte in a patient body fluid sample.
[0020] As used herein, direct communication between two instruments 104 , 104 ′ means one instrument 104 communicating with another instrument 104 without the aid of a central CPU or computer that is incapable of sampling a body fluid from a patient (i.e., that is not an instrument 104 ) and that provides additional data processing functionality with respect to the analysis, storage, display, or manipulation of the data other than devices such as routers, repeaters, or switches that manage, direct, and/or amplify messages over the network 116 . Examples of direct communication among the instruments 104 includes, but is not limited to peer-to-peer communications, and communications over a mesh-type network whereby one or more of the instruments 104 can also assist with the transmission of a message from a first instrument 104 to a second instrument 104 ′.
[0021] To facilitate the direct communications among the instruments 104 , each instrument 104 contains or is connected to (either permanently or on an ad hoc basis) a communication module 124 . The communication module 124 maintains identification and routing information related to the plurality of instruments within the system, and packages instructions, data and other information as messages in such a manner that when broadcast, the message contains the routing information necessary to reach its intended destination (i.e., a second instrument 104 ′) without the aid of a central server. The communications module 124 also receives messages, and decodes, decrypts, and/or compiles the message into instructions for the second instrument 104 ′. In some embodiments, the communications module 124 also provides confirmation messages back to the first instrument 104 to confirm that a message has beep received, understood, and/or acted upon.
[0022] With continued reference to FIG. 1 , the direct communication between the first instrument 104 and second instrument 104 ′ is shown with a first communications channel 144 . Similarly, the direct communication between the first instrument 104 and third instrument 104 ″ is shown with a second communications channel 148 . Moreover, the direct communication between the second instrument 104 ′ and third instrument 104 ″ is shown with a third communications channel 152 .
[0023] The network 116 can be, for instance, an intranet. Example embodiments of the communication channels 144 , 148 , 152 include standard telephone lines, LAN or WAN links (e.g., T1, T3, 56 kb, X.25), broadband connections (ISDN, Frame Relay, ATM), and wireless connections (802.11).
[0024] With continued reference to FIG. 1 , the direct communication between, for instance, the first instrument 104 and the second instrument 104 ′ enables the first instrument 104 to access patient data acquired by the second instrument 104 ′. Likewise, the direct communication between the other instruments 104 enables one instrument (e.g., the second instrument 104 ′) to access patient data acquired by another instrument (e.g., the third instrument 104 ″) in direct communication with the instrument 104 (e.g., the second instrument 104 ′). In one embodiment, the direct communication between two or more instruments 104 is bidirectional. For example, when the first and second instruments 104 , 104 ′ are in direct communication, the first instrument 104 can communicate with and obtain information from the second instrument 104 ′ and the second instrument 104 ′ can likewise communicate with and obtain information from the first instrument 104 . In another embodiment, the direct communication is unidirectional such that the first instrument 104 can communicate with and obtain information from the second instrument 104 ′ but the second instrument 104 ′ cannot initiate communications with and obtain information from the first instrument 104 . Thus, independent of which instrument's sampling member 120 samples a patient's body fluid, any instrument 104 communicating over the network 116 can access data associated with the body fluid directly from the instrument 104 that sampled the body fluid.
[0025] FIG. 2 is a block diagram of a system operating in such a manner that an agent-instrument 204 communicates with the first instrument 104 and the second instrument 104 ′ over a network according to another illustrative embodiment of the invention. In one embodiment, the agent-instrument 204 acts as an agent for the first instrument 104 and the second instrument 104 ′, i.e., the agent-instrument 204 can perform the functions that can be performed on the first and second instruments 104 and 104 ′. For example, the agent-instrument 204 stores the clinical data associated with a sample obtained by a sampling member of one or more of the instruments 104 . Thus, in one embodiment, the agent-instrument 204 enables an instrument 104 to access patient data acquired by another instrument 104 by storing the patient data in a database and performing other centralized data processing functions. Thus, when a sampling member 120 samples a body fluid from a patient, the instrument 104 stores the patient data obtained from the sample. Additionally, the instrument 104 that acquired the sample also transmits the patient data to the agent-instrument 204 . The agent-instrument 204 enables the other instruments 104 to access all patient data from a single instrument (rather than having to access patient data at all instruments 104 that sampled a sample from the patient). Alternatively, instruments 104 can communicate with the instrument 104 that sampled the patient's body fluid to obtain data associated with the body fluid.
[0026] In one embodiment, the agent-instrument 204 also transmits the patient data to a hospital information system 208 . For example, the agent-instrument 204 transmits the patient data to the hospital information system 208 through a laboratory information system (LIS) interface. The hospital information system 208 can be, for example, another computer in the same (or different) hospital as the medical facility where the instruments 104 are located. The hospital information system 208 maintains a patient database for the hospital's patients. The agent-instrument 204 may also retrieve information from the hospital information system 208 .
[0027] In one embodiment, one instrument 104 (e.g., the first instrument 104 ) directly communicates with another instrument 104 (e.g., the second instrument 104 ′) to control the instrument (e.g., the second instrument 104 ′). If, for instance, the first instrument 104 is controlling the second instrument 104 ′, the first instrument 104 calibrates the second instrument 104 ′, initiates the processing of a patient sample on the second instrument 104 ′, turns the second instrument 104 ′ on, and/or turns the second instrument 104 ′ off. The first instrument 104 can also control the second instrument 104 ′ by initiating a specific measurement of an analyte in the patient sample.
[0028] Additionally, in one embodiment, the first instrument 104 controls a heterogeneous second instrument 104 ′, i.e., the second instrument 104 ′ is a different model or type compared with the first instrument 104 . For example, in one embodiment the first instrument 104 is a GEM Intelligent Quality Management (iQM) 4000 analyzer and the second instrument 104 ′ is a GEM Intelligent Quality Management (iQM) 3000 analyzer (both from Instrumentation Laboratory, Lexington, Massachusetts). Moreover, in one embodiment the first instrument 104 controls a second instrument 104 ′ that is manufactured by a different company altogether. For example, the first instrument 104 is a GEM iQM 4000 analyzer and the second instrument 104 ′ is a VITROS DT60 II Chemistry System (Johnson & Johnson, Piscataway, N.J.).
[0029] FIG. 3 is a block diagram of an instrument 104 having a user interface 316 and a data management module 320 according to an illustrative embodiment of the invention. In the illustrated embodiment, the sampling member 120 of the instrument 104 has an analytical module 304 for analyzing patient data. In particular, the analytical module 304 is a software module providing a programmed series of steps that analyzes a target analyte in a body fluid sample from a patient. For example, the target analyte is blood platelet concentration, white blood cell concentration, red blood cell concentration, blood urea nitrogen (BUN), blood gases, electrolytes, metabolites, and/or hematocrit.
[0030] The instrument 104 also includes a user interface 316 and a data management module 320 . The data management module 320 enables management of the patient data. The data management module 320 can manage patient data that is stored on the instrument 104 that the data management module 320 is executing on and/or can manage patient data stored on another instrument 104 . For example, the data management module 320 of the first instrument 104 can perform management functions on data associated with a particular patient that the first instrument 104 accesses from the second instrument 104 ′.
[0031] The user interface 316 enables a user of the instrument 104 to perform functions associated with the analytical module 304 and the data management module 320 . Specifically, the user interface 316 performs functions and displays patient data in a common format on the instruments 104 . Thus, the user interface 316 enables the user of the instrument 104 to experience a single “look and feel” when sampling a body fluid sample, analyzing the sample, and/or managing patient data regardless of the instrument. As an example, a common menu structure can be employed such that the messaging functions all appear under one menu option that is consistent across all instruments 104 , and operational functions such as processing a patient sample can be described using common terminology, with like screen coloring, command controls, and help text. The analytical module 304 , the user interface 316 , and the data management module 320 are software modules that can be written in any computer programming language, such as Java or C++. In some embodiments where the instruments 104 are manufactured by different vendors, a browser-like interface may be included as the user interface 316 , thus enabling the use of standard data rendering, data transmission, and data presentation technologies such as HTML, HTTP/HTTPS, XML, SOAP, Web Services, and the like. Examples of browser interfaces include, but are not limited to applications such as Internet Explorer, by MIRCOSOFT CORPORATION of Redmond, Wash., NETSCAPE NAVIGATOR, by AOL/TIME WARNER of Sunnyvale, Calif., and MOZILLA FIREFOX by the MOZILLA FOUNDATION of Mountain View, Calif.
[0032] The user interface 316 enables a user to, for example, view a snapshot of the instrument screen display, review patient data or quality control results, review the instrument's status, enable or disable analytes, enable or disable operator access, lock the instrument 104 , calibrate the instrument 104 , configure the instrument 104 according to predetermined acceptable ranges of the results of the analysis of the patient data, and/or post a message on the instrument 104 . Moreover, the user of an instrument 104 can use the user interface 316 to perform these functions on any other instrument (e.g., the second instrument 104 ′). Thus, a user can use the user interface 316 to view patient data acquired by the instrument 104 including the user interface 316 or another instrument 104 , view the status of this or another instrument 104 , view operations performed on this or another instrument 104 (e.g., analyze a patient sample, prepare a pie chart for all patient data for a particular patient, etc.), and/or search patient results on this or another instrument 104 . As described above, the instruments 104 may be heterogeneous types, e.g., instruments manufactured by different companies altogether.
[0033] Examples of data management functions that the data management module 320 can perform include generating a report, managing security information, performing competency testing, and determining the workload of the instrument 104 . For instance, the data management module 320 can automatically generate a table of the previous ten data points obtained for a target analyte of a patient's body sample. The data management module 320 can also generate a report (e.g., a table) on demand or periodically as based on a predetermined schedule. The user of the instrument 104 can also use the data management module 320 to search for patterns, such as a pattern in a patient's clinical data. Moreover, the user can additionally use the data management module 320 to discern data patterns associated with one or more instruments 104 . For example, the data management module 320 can determine that a particular instrument, such as the third instrument 104 ″, has the highest number of analytical failures.
[0034] Further; the data management module 320 can provide operator competency information. For example, the data management module 320 of the first instrument 104 may determine that the third instrument 104 ″ has the highest number of discarded samples. Such information may be useful in assessing operator performance. The operator using the third instrument 104 ″ may, in such cases, require additional training in the use of the instruments 104 .
[0035] Additionally, the data management module 320 can perform inventory management. For example, if the sampling member 120 employs cartridges to sample a patient's body fluid, the data management module 320 can determine the number of times the cartridge has been used and indicate when a user of the instrument 104 needs to replace the cartridge. Further, the data management module 320 of one instrument 104 (e.g., the first instrument 104 ) can determine when the cartridge supply of another instrument (e.g., the second instrument 104 ′) needs to be replaced.
[0036] As described above, the data management module 320 can also determine the workload of an instrument 104 . In one embodiment, the data management module 320 can determine the workload of the instrument 104 that the data management module 320 is executing on. The data management module 320 can also determine the workload of another instrument 104 communicating with the instrument 104 that the data management module 320 is executing on. For example, a user of the first instrument 104 can use the data management module 320 to determine the frequency that the third instrument 104 ″ is being used (e.g., once a day, ten times a day, etc.). The user can use this information to determine whether to remove an instrument 104 (e.g., the third instrument 104 ″) from the particular location (e.g., if the instrument 104 is not being used enough to warrant its positioning at the location), to add another instrument 104 to the same location (e.g., if the instrument 104 is being overworked) or to regulate the distribution and usage of the instruments 104 .
[0037] In a particular embodiment, a user can access the user interface 316 and the data management module 320 from a web browser (e.g., Internet Explorer developed by Microsoft Corporation, Redmond, Wash.). For instance, a user can use the web browser executing on a personal computer (e.g., in the user's office in the hospital) to access the data management module 320 and/or the user interface 316 . Moreover, the user interface and data management module displayed in the web browser have the same “look and feel” as the user interface 316 and data management module 320 executing on the instrument 104 . The web browser enables a remote user to perform the same functions that a user using the user interface 316 on the instrument 104 can perform. Thus, a remote user can, for instance, view a snapshot of the instrument screen display, review patient or quality control results, review the instrument's status, enable or disable analysis, enable or disable operator access, lock the instrument, calibrate the instrument 104 , and post a message on the instrument 104 .
[0038] Continuing to refer to FIG. 3 , and as described above with reference to FIG. 1 , each instrument 104 comprises a communications module 124 to facilitate inter-instrument communication. In some embodiments, the communications module 124 is an internal component of the instrument 104 that (i.e., an internal wireless network interface card, transponder, or other signal-generating device). In other embodiments the communications module 124 is an external device that, for example, can be periodically connected to the instruments 104 via an interface 328 .
[0039] FIG. 4 is a flow diagram of the steps performed for configuring the instruments 104 of FIG. 1 according to an illustrative embodiment of the invention. The instruments 104 in the illustrative embodiment are connected to the network 116 so that each instrument 104 is in direct communication with one or more of the other instruments 104 (step 410 ). The sampling member 120 of the first instrument 104 then samples a body fluid from a patient (step 415 ). The first instrument 104 then analyzes the body fluid sample (step 420 ) and obtains patient data. The second instrument 104 ′ (or any other instrument 104 ) then accesses, directly from the first instrument 104 , the patient data corresponding with the analysis of the sample (step 425 ). Alternatively, the second instrument 104 ′ instructs the first instrument 104 to sample a body fluid and steps 415 , 420 , 425 are then started. For example, upon receipt of the instruction, the first instrument 104 samples a body fluid (e.g., blood) from a patient, as shown in step 415 . Moreover, any number of the steps shown in FIG. 4 may occur. For instance, the first instrument 104 may only sample a body fluid (Step 415 ) and then analyze the body fluid sample (Step 420 ). Another instrument 104 may not access patient data associated with the analysis of the sample or may access the patient data after a long time delay (e.g., four days later).
[0040] With reference to FIG. 5 , and in one exemplary embodiment, a laboratory technician needing a particular test, analysis, or collection of a patient sample utilizes a first instrument 104 to initiate a request for a patient sample (STEP 510 ). A doctor, nurse, or other medical technician receives the request on a second instrument 104 ′ (STEP 515 ). The request may be in the form of a screen message, audible message, or other recognizable indication that a request has been received. The medical technician may then acknowledge receipt of the request and, if no sample was previously taken (STEP 520 ) draw the patient sample using the sampling member of the second instrument 104 ′ (STEP 525 ) after which the second instrument 104 ′ then performs the requested analysis (STEP 530 ). The second instrument 104 ′ then transmits the results of the analysis (STEP 535 ) where it is received by the first instrument 104 (STEP 540 ), thereby providing the laboratory technician with the necessary data. Such requests may be made in conjunction with scheduled rounds, patient care protocols, or on an as needed (i.e., random) basis.
[0041] In another embodiment a medical technician tending to a patient and using a first instrument 104 requests an analysis of a previously drawn sample of the patient. At another location, such as a laboratory where multiple patient samples are stored awaiting analysis, the second instrument 104 ′ receives the request from the first instrument 104 and introduces the sampling member of the second instrument 104 ′ into the patient sample (STEP 550 ). The analysis is conducted by the second instrument 104 ′ (STEP 530 ), and the results are transmitted from the second instrument 104 ′ (STEP 535 ) back to the first instrument 104 (STEP 540 ), where the results are displayed. Alternatively, or in conjunction with this approach, the patient samples are arranged in a tray such that an automated sampling member probe of the second instrument 104 ′ extends to and selects the desired patient sample and samples the patient sample (STEP 560 ) such that the appropriate analysis of the sample directed by the first instrument 104 is conducted by the second instrument 104 ′ (STEP 530 ).
[0042] In another example, the second instrument 104 ′ may be connected directly to a patient via an extracorporeal device such as a blood pump used during a cardio-bypass procedure. In such cases, the sampling member of the second instrument 104 ′ is in contact with the patient sample on a frequent, or in some cases continuous basis, and requests for sampling and analysis by the first instrument 104 directed by the second instrument 104 ′ can be serviced in real-time.
[0043] Having described certain embodiments of the invention, it will now become apparent to one of skill in the art that other embodiments incorporating the concepts of the invention may be used. | The present invention relates to a method and apparatus for managing patient data. In one aspect, the invention relates to a system for managing patient data having many instruments. The instruments have a sampling member for sampling a body fluid from a patient and are in direct communication with at least one other instrument. | 6 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the artificial illumination arts. It finds particular application in providing high ignition voltages for portable lamp ballasts and will be described with particular reference thereto. It is to be appreciated, however, that the present invention is also applicable to boosting voltages in fixed ballasts and other circuits, and is not limited to the aforementioned application.
[0002] Typical portable lamp ballasts utilize relatively low-cost, low-voltage sources to operate the lamp. For instance, certain types of popular fluorescent camping lanterns utilize four “D” cells. In other words, the lantern has a six volt source. Typically, much larger voltages are needed to ignite and sustain a lighted fluorescent lamp. Inexpensive fluorescent lamps, as are commonly found in such lanterns, require on the order of about 200 Volts to ignite. Consequently, when these systems initiate start-up, extremely high circulating currents are present in resonant tanks of the ballast, and relatively high-valued circuit components are required to meet the voltage demands for lamp ignition.
[0003] In addition to having high startup currents, typical portable ballasts are inefficient. As a result of limited voltage available from direct current sources, typical portable lamps utilize light sources that require less voltage to ignite, but are more inefficient, lessening light output and battery life.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In accordance with one aspect of the present invention, a lighting ballast is provided. A voltage source provides current that is converted by a switching portion, the switching portion including first and second transistors. A drive portion is included. A resonant load portion receives a lamp, and a transformer boosts the voltage from the switching portion to the resonant load portion.
[0005] In accordance with another aspect of the present invention, a method of igniting a lamp is included. A threshold voltage is supplied by boosting a signal significantly higher than its direct current source. The direct current is converted into alternating current by a switching portion, the switching portion including first and second transistors.
[0006] In accordance with another aspect of the present invention, a portable lamp ballast is provided. A direct current battery provides power to the ballast. A complementary pair of MOSFETs convert the direct current signal from the battery into an alternating current signal. A drive inductor taps power from a resonant inductor. A transformer including primary and secondary windings boosts the alternating current signal to the lamp.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention.
[0008] [0008]FIG. 1 is a circuit diagram of a ballast circuit, in accordance with the present invention;
[0009] [0009]FIG. 2 is a time-voltage graph showing start-up and steady-state voltages;
[0010] [0010]FIG. 3 is a graph showing circuit activity in select components in time.
DETAILED DESCRIPTION OF THE INVENTION
[0011] With reference to FIG. 1, a lamp 10 is operably connected between contacts 12 , 14 of a ballast housing circuit. In the preferred embodiment, the circuit is powered by a direct current (DC) battery 16 of 5 to 7 V. Preferably the bus voltage 16 is between 5.5 and 6 volts with 6 volts being ideal. The circuit is referenced at point 18 to ground. The lamp 10 is preferably a compact fluorescent lamp that operates at a particular frequency or range of frequencies. The ballast circuit provides AC power at the operational frequency of the lamp 10 .
[0012] In order to convert a DC signal into an AC signal, a first transistor 20 and a second transistor 22 alternate between periods of conductivity and periods of non-conductivity, out of phase with each other. That is, when the first transistor 20 is conductive, the second transistor 22 is non-conductive, and vice-versa. The action of alternating periods of conduction of the transistors provides an AC signal across the contacts 12 and 14 . In the preferred embodiment, the transistors are MOSFETs, but it is to be understood that bipolar junction transistors or other field effect transistors are also possible.
[0013] Each transistor 20 , 22 has a respective gate and source. The voltage from gate to source on either transistor defines the conduction state of that transistor. That is, the gate-to-source voltage of transistor 20 defines the conductivity of transistor 20 and the gate-to-source voltage of transistor 22 defines the conductivity of transistor 22 . As shown, the sources of the two transistors 20 , 22 are connected at a common node 24 . The gates of the transistors 20 , 22 are connected at a control node 26 . The single voltage between the control node 26 and the common node 24 determines the conductivity of both transistors 20 , 22 . The drains of the transistors 20 , 22 are connected to the bus voltage 16 and ground 18 , respectively.
[0014] A gate drive circuit, connected between the common node 24 and the control node 26 controls the conduction states of the transistors 20 , 22 . The gate drive circuit includes a serial capacitor 27 , and a drive inductor 28 that is connected to a resonant inductor 30 at the common node 24 . The other end of the drive inductor 28 is coupled to a phase inductor 32 . The phase inductor 32 is used to adjust the phase angle of the base-emitter voltage appearing between nodes 24 and 26 . The drive inductor 28 provides a driving energy for the operation of the drive circuit. The resonant inductor 30 along with a resonant capacitor 33 connected between nodes 12 and 14 determine the operating frequency of the lamp 10 . The serial capacitor 27 charges to provide sufficient voltage to turn the first transistor 20 conductive. During steady state operation of the ballast, the serial capacitor 27 aids in switching between the two transistors 20 , 22 .
[0015] As stated previously, the voltage source is preferably a 6 V battery, or its equivalent. The lamp 10 of the preferred embodiment has a threshold ignition voltage of 500 to 700 V, more preferably in the range of 550 to 650 V with 600 V being most preferred. A transformer 34 boosts the bus voltage of 6 V to a magnitude adequate to ignite the lamp 10 . Preferably, the transformer 34 boosts the voltage to between 1.0 and 1.4 kV during a period of time between when the ballast is activated and the lamp 10 ignites. The preferred ignition voltage is between 1.1 and 1.3 kV with 1.2 kV being ideal. After the lamp ignites, the ballast circuit settles to a steady state operation mode in which the transformer 34 boosts the bus voltage to a relatively small steady state value, relative to the ignition voltage. The steady state value of the preferred embodiment is on the order of 50 V.
[0016] The transformer 34 includes a primary winding 36 and a secondary winding 38 . Current that passes through the primary winding 36 induces a current in the secondary winding 38 . The secondary winding 38 is on operative connection with the lamp 10 . The number of coil turns of the secondary winding 38 exposed to current passing through the primary winding 36 is controllable. Thus, the magnitude of the voltage transform is controllable. In the preferred operation of the transformer, during lamp ignition, all of the windings of the secondary coil 38 are exposed to the primary coil 36 . This boosts the voltage to 1.2 kV, as discussed previously. Subsequent to lamp ignition, the number of secondary coil 38 windings exposed to the primary coil 36 is reduced, and the voltage across the lamp 10 drops to its steady state operating value. In an alternate embodiment, the transformer 34 is an auto transformer.
[0017] In the preferred embodiment, during periods of time when the lamp 10 is lit, a user can manipulate the windings ratio between the secondary and primary coils 38 , 36 to adjust an intensity of the lamp 10 . The user can select high medium and low settings, for instance, thereby changing the windings ratio, the voltage across the lamp 10 and ultimately the brightness of the lamp 10 . Possible windings ratios are, for high intensity, 24:1, for medium intensity, 12:1, and for low intensity, 6:1. Alternately, an analog dial may be used to select and de-select windings, giving the user a dimming control of the intensity of the lamp. Regardless of the method used to give the user intensity control, the lowest setting that the user may select still provides the lamp 10 with sufficient voltage to stay lit, unless, of course, if the user selects an off position, in which power is cut from the ballast circuit.
[0018] Additionally, the ballast circuit includes smoothing capacitors 40 , 42 between the bus voltage 16 and ground 18 to smooth abnormalities and noise in the bus voltage signal. Starting resistors 44 , 46 prevent current in the ballast circuit from exceeding tolerable levels during startup, before the capacitors and inductors are charged. Back to back Zener diodes 48 , 50 clamp the voltage across the transistors 20 , 22 .
[0019] During lamp ignition, and with reference to FIG. 2, the ballast circuit boosts the voltage across the lamp 52 to a temporary ignition voltage 54 . With a lamp having a steady state resistance of 400 Ω, the ballast achieves 1.2 kV with a battery voltage of 5.5 volts. This ensures sufficient voltage as the battery discharges. From the time the lamp is switched on (0 s) to lamp ignition at about 2 ms, the starting voltage of 1.2 kV is applied. After the lamp ignites, the voltage settles to a steady state voltage 56 between 40 and 60 volts, with 50 volts being preferred. The steady state voltage 56 is maintained while the lamp is in normal operation.
[0020] With reference to FIG. 3, waveforms across select circuit components are provided over a period of 20 μs. The curve 58 depicts a gate-source voltage of the first and second transistors 20 , 22 . Only one is shown, but the other transistor has a gate-source voltage preferably identical, but 180° out of phase. As is shown, the gate source voltage resembles a square wave, having transition periods of less than 2 μs, ranging from approximately 5V to −5V. The source drain voltage of the second transistor 60 is provided. This square wave function ranges from about 5.5 to 6 V (bus voltage) down to zero volts. The current across the phase inductor 62 is provided for comparison. The current 62 preferably alternates between approximately 5 A and −5 A. The curve 64 is the resultant voltage across the lamp 10 , which is an AC signal.
[0021] Exemplary component values for the circuit of FIG. 1 are as follows:
Part Description Part Number Nominal Value Lamp 10 23 watts DC Bus Voltage 16 6 Volts Circuit Reference 18 0 Volts Serial Capacitor 27 47 nanofarads First Transistor 20 IRLML2502 Second Transistor 22 IRLML6401 Drive Inductor 28 5.6 microhenries Resonant Inductor 30 560 microhenries Phase Inductor 32 220 microhenries Resonant Capacitor 33 2.2 nanofarads Primary Winding 36 13.9 microhenries Secondary Winding 38 8 millihenries Smoothing Capacitor 40 10 microfarads Smoothing Capacitor 42 10 microfarads Starting Resistor 44 100 k Ohms Starting Resistor 46 3 k Ohms Zener Diode 48 1N5227 Zener Diode 50 1N5227
[0022] The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A portable lighting ballast includes first and second transistors 20, 22 for converting direct current from a voltage source 16 into alternating current to operate a lamp 10 . The lamp has an ignition voltage that is significantly higher than the voltage that the source 16 produces. The battery is a typical 6 volt cell or a combined source of 4 “D” cells, also producing six volts. The ignition voltage of the lamp 10 is approximately 600 V. A transformer 34 boosts the alternating current signal from the transistors 20, 22 to an amplitude sufficient to ignite the lamp 10 . The transformer 34 boosts the signal to 1.2 kV. After lamp ignition, the transformer settles the voltage to a steady state value. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 08/506,169 filed on Jul. 25, 1995, now abandoned.
FIELD OF THE INVENTION
This invention relates to an in situ plastic consolidation method for constraining sand or gravel particles forming a subterranean reservoir.
BACKGROUND OF THE INVENTION
There are some hydrocarbon reservoirs that are referred to as unconsolidated sands. The sand grains are not cemented together or are only poorly cemented. When contained fluids are produced from the reservoir through a wellbore, there is some tendency for the sand grains to move with the flow and enter the wellbore. The sand can plug the wellbore or erode the producing equipment.
The problem is significant and as a result extensive research has been carried out to develop ways to alleviate it.
In situ plastic consolidation is one technique which has been applied for this purpose. In general, this technique involves emplacing a polymer oligomer in the flow channels of the near-wellbore region of the reservoir and then cross-linking or hardening the oligomer. (The "near-wellbore region" is a zone extending out radially from the wellbore a short distance--perhaps two or three feet.)
More particularly, a slug of a first solution, comprising the polymer oligomer dissolved in a viscosity-reducing solvent, is displaced down the wellbore and into the near-wellbore region. A liquid slug containing a curing agent is then pumped into the region to contact the first slug. The well is then temporarily shut in, to allow the polymer to harden.
The patent literature contains many examples of this general system. Typical polymers used are epoxy, furfuryl alcohol and phenol/formaldehyde.
Now, there are a number of difficulties that require consideration in connection with plastic consolidation. Many of the prior art patents are specifically directed at proposing solutions for these difficulties. The difficulties include:
Maintaining adequate residual permeability in the near-bore region. The hardened plastic can block the flow channels. Since the plastic is cross-linked, there is no effective way to remove it to restore permeability;
Developing a consolidated near-wellbore sand/polymer matrix that has good compressive strength, which is an indicator of good resistance to erosion by the flow of produced fluids;
Developing a plastic framework that has some residual structural strength in the event that sand grains are dissolved, which is a possibility in thermal projects where steam is being injected;
Wetting the sand so that the cross-linked polymer resin binds sand grains together; and
Developing a consolidated near-wellbore sand-polymer composite that does not shrink or disintegrate with time.
It is therefore desirable to develop a novel process which yields a consolidated sand/polymer matrix that is characterized by good residual permeability, good compressive strength, and a plastic framework that survives sand dissolution. In addition, it is desirable to use a plastic which can be reversibly dissolved in a solvent, so that, in the event of plugging, the plastic can be removed.
At this point, it is appropriate to refer to a prior art technology which has been developed in connection with the manufacture of microporous plastic membranes used for pressure driven filtration. This technology is described in the Handbook of Industrial Membrane Technology, published by Noyes Publications, Chapter 1. The technology involves contacting a first solution, comprising a polymer dissolved in a "good" organic solvent, with a second "poor" solvent in which the polymer is insoluble. The polymer will precipitate in the form of a porous, permeable solid. To applicants' knowledge, this technology has not been applied in situ in a subterranean reservoir. The technology is applied in a specific manner in connection with the present invention.
SUMMARY OF THE INVENTION
The present invention is based on combining the following:
emplacing, by displacement down a wellbore, a slug of polymer-carrying solution in the near-bore region of an unconsolidated sand or gravel reservoir, to locate the solution in the flow channels between the sand or gravel particles, the solution comprising a linear polymer dissolved in a first organic component that is a good solvent for the polymer, said good solvent preferably being miscible with water and substantially non-reactive with the polymer and, preferably, with the reservoir minerals and fluids;
then injecting a slug of a poor solvent for the polymer into the near-bore region to contact the first slug, said poor solvent being miscible with the good solvent, and precipitating solid linear polymer from solution to form a three-dimensional network of interconnected strands, said strands extending through the fluid flow channels, to consolidate the particles while retaining residual permeability.
The solvents and polymer need to "match" in order to achieve the required network. Stated otherwise, one needs to test combinations of polymer and good and poor solvents to determine if a combination yields the three-dimensional, fish net-like network. For example, in our best mode we have matched:
morpholine as the good solvent,
polysulfone as the polymer,
with a polymer loading of 5 to 20% by weight of the solution, and
water as the poor solvent
to achieve the network in a consolidated sand that is characterized by residual permeability that is typically about 50% of the original permeability and a level of unconfined compressive strength such that failure occurs between 100 kPa and 4000 kPa. The viscosity of the polymer solution varies between 20 and 3800 centipoise over the given concentration range.
In the product of this best mode embodiment, when tested in sand, one finds:
that the strands have a slight clearance from the surfaces of the sand particles, which clearances appear to be the main contributing factor to a desirable level of residual permeability;
that the network combines with the sand to create a compressively strong composite matrix, without bonding to the particles; and
that if fluid is flowed through the consolidated product, the sand remains affixed in the composite matrix.
It will be appreciated that it will be a difficult practical problem to sample a subterranean near-wellbore region to determine if the described network has been formed. The invention as claimed is therefore to be construed as being restricted with respect to reagents to those which perform, when applied to a sand sample to yield the network in a laboratory experiment carried out in accordance with a Standard Test Procedure set forth below. Also, it may be possible to collect downwell samples by a procedure known as side-track drilling.
Broadly stated, the invention is a process for consolidating the near-bore region of an unconsolidated subterranean reservoir containing reservoir fluid and being formed by discrete sand or gravel particles having communicating fluid flow channels extending therebetween to provide fluid flow permeability, comprising: (a) emplacing a liquid slug of a first solution in the near-bore region, said solution comprising a linear polymer dissolved in a good solvent for the polymer; (B) then injecting a liquid slug of a poor solvent for the polymer, said poor solvent being miscible in the good solvent, into the near-bore region to contact the first slug and precipitate linear polymer to consolidate the particles of the near-bore region while retaining sufficient residual permeability to enable production of the reservoir fluid; the solvents and polymer having been selected on the following basis: (i) the good solvent being substantially non-reactive with the polymer, (ii) the polymer being non-miscible with water and with petroleum and substantially non-reactive with the reservoir solids and fluids, (iii) the combination of solvents and polymer used being operative, if tested under laboratory conditions in accordance with the Standard Test Procedure set forth in the disclosure, to form a three-dimensional network of interconnected strands in a sand sample, said strands extending through fluid flow channels in the sample.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plot showing the increase in compressive strength of consolidated sand as the percentage of polymer (polysulfone) in the good solvent (morpholine) is increased;
FIG. 2 is a plot showing the variance of residual permeability in consolidated sand as the polymer content in the good solvent is varied;
FIG. 3 is a scanning electron micrograph showing a polymer network formed in sand using the polysulfone/morpholine system;
FIG. 4 is a scanning electron micrograph of a polymer network formed in sand using the polysulfone/morpholine system, the network being revealed after dissolving the sand grains in aqueous hydrofluoric acid; and
FIG. 5 is a photograph showing a consolidated sand "near-bore region" formed by injecting polysulfone/morpholine as a first slug and water as a second slug in a sand bed, after removal of the unconsolidated sand in the bed;
DESCRIPTION OF THE PREFERRED EMBODIMENT
Polymers which can be used with reservoir temperatures less than 100° C. include polysulfone, polystyrene, polyvinyl/chloride, polymethyl/methacrylate, polyethylene terephthalate, polyimide and polyphenylene oxide.
Good solvents which can be used which are miscible with water include acetone, acetonitrile, 2-butoxyethanol, dimethylformamide, dimethylsulfoxide, dioxane, ethylmethylketone, m-cresol, morpholine and tetrahydrafuran. Halogenated solvents may be used if they are miscible with water, provided that environmental problems are not an issue.
The good solvent preferably should be non-reactive with respect to reservoir minerals or fluids or the polymer.
The precipitating or poor solvent may be water or brine or a mixture of water with an alcohol such as 2-methanol.
Alternatively, the poor solvent may be organic, such as white oil, kerosene or petroleum ether (also called hexanes). In the case of an organic poor solvent, useful good solvents include acetone acetonitrile, cyclohexanone, diethylether, dimethylformamide, dimethylsulfoxide, dioxane, m-cresol, methyl t-butyl ether, nitrobenzene, phenol, tetrahydrofuran, toluene, or xylene.
Polymers which can be used for steam enhanced oil recover ("EOR") applications include such engineering plastics as polyethylene terephthalate and polyimides, such as those based on 1,4-phenylenediamine and 3,3', 4,4'-benzophenonetetracarboxylic acid. Good solvents which can be used with these polymers include dimethylformamide, trifluoracetic acid, m-cresol, phenol, resorcinol or a substituted phenol which is a liquid at reservoir conditions. In this case, the poor solvent may be a low carbon number alcohol such as 2-methanol or a mixture of the alcohol with water.
Table I sets forth a group of recommended matched combinations which yield the desired network consolidation:
TABLE I______________________________________Polymer Good Solvent Poor Solvent______________________________________Polyvinyl chloride dimethylformamide waterpolyvinyl chloride tetrahydrofuran waterPolystyrene morpholine waterPolymethylmethacrylate morpholine waterPolysulfone tetrahydrofuran waterPolysulfone morpholine waterPolyethyleneterephthalate phenol waterPolyethyleneterephthalate m-cresol 50% aq. methanolPolyimide dimethylsulfoxide 50% aq. methanol______________________________________
In principle, mixtures of solvents, as well as mixtures of polymers may also be used. For example, a mixture of polysulfone and polyvinyl chloride will dissolve in a mixture of tetrahydrofuran and morpholine. However, workers skilled in the craft will be aware that not all solvents are chemically compatible with each other, and that some polymers are not chemically compatible with some solvents.
We have found that the preferred polymer is a particular polysulfone based on bisphenol A and diphenylsulfone, (density=1.24 kg/L, molecular weight=50,000 Daltons; glass temperature=190° C.). We have found that the preferred solvent is morpholine, (NHC 4 H 8 O, density=0.999; m.p. -6° C.). The preferred poor solvent for this system is water or brine. The optimum concentration of polysulfone falls in the range 5-20% (wt/wt). The viscosity of the polysulfone solution varies between 20 and 3800 Cp over this concentration range. The exact best composition depends on the optimization for a particular application (based on compressive strength, final permeability, solution viscosity and cost).
We have found empirically that 200 mL of 20% (wt/wt) polysulfone in morpholine will consolidate 160 mL of fine sand. With well-packed sand in an isotropic stress field, the final distribution of polymer is uniform around the injection port and homogeneous throughout the consolidated zone. The transition between consolidated and unconsolidated sand is sharp, (1-5 mm) (see FIG. 5).
We have found that the specific gravities of the polymer solution and the poor solvent should be within 5% of each other. In experiments in which there was a significant difference in specific gravities, channelling of the polymer solution was observed. This resulted in the deposition of a dense polymer solid within a narrow zone, rather than evenly through the near-bore region of the sand bed.
It is anticipated that this polymer consolidation treatment can be used in many applications, such as vertical and horizontal wells. Packers may be used to block off that section to be treated. The treatment should be effective in consolidating reservoirs producing conventional crude oil, heavy oil, natural gas and water. The treatment may also be used to help extend the life of injection wells. If a polymer is selected with a sufficiently high softening point (or melting point), and sufficiently good resistance to hydrolysis, the treatment can be used in steam EOR operations, such as those involving cyclic steam and steam drive.
The invention is exemplified by the following examples:
EXAMPLE 1
Preparation of Samples for Strength Testing
Samples of consolidated sand were prepared by injecting into clean sand, solutions of polysulfone in morpholine at concentrations of 5, 7.5, 10, 15 and 20% (wt/wt). The apparatus consisted of a steel cylinder, fitted with threaded end caps, both of which were fitted with Swagelok fittings. An HPLC pump and metal tubing was used to pump the liquids through the sand bed. The sand used was quartz sand (F-125 Ottawa, 0.1 to 0.2 mm diameter). The pressure was monitored using a pressure transducer. In preparing the solution, it was found that the polymer dissolved more quickly when the solution was stirred and heated to 60° C. Injection was carried out at room temperature. The volume of polymer solution as 50 mL, and the injection rate was 1120 mL/hr. A spacer of neat morpholine was used to eliminate precipitation in the fluid lines. The polysulfone was precipitated using an aqueous solution of 0.1 m sodium chloride plus 0.01 m NaHCO 3 . The cores were easily removed from the core holder, and subjected to unconfined compressive strength tests. The results are shown in FIG. 1.
EXAMPLE 2
Preparation of Samples Containing Residual Oil for Strength Testing
Samples of consolidated sand were similarly prepared by injecting into oil-coated sand, solutions of polysulfone in morpholine at concentrations of 5, 7.5, 10, 15 and 20% (wt/wt). The sand was coated with Lloydminster crude by saturating the sand pack with the oil and then pumping water through the sand pack. The polysulfone was precipitated using dilute aqueous sodium chloride. The cores were removed from the core holder, and subjected to unconfined compressive strength tests. The results are shown in FIG. 1.
EXAMPLE 3
Sample Preparation for Determination of Changes in Permeability
Samples of consolidated sand were prepared by injecting into sand polysulfone in morpholine at concentrations of 5, 7.5, 10, 15 and 20% (wt/wt) as described above. The flow rate and the pressure drop across the core holder were measured, and these results were used to calculate sand permeabilities before and after consolidation. The results are shown in FIG. 2.
EXAMPLE 4
Preparation of Consolidated Sand Sample for Microscopic and Electron Microscopic Examination
Consolidated sand cores were prepared as in Example 1. A sub-sample was mounted on aluminum stubs and gold coated in preparation for scanning electron microscopic (SEM) examination. The results are shown in FIG. 3. Another sub-sample was treated with concentrated hydrofluoric acid at room temperature in a fume hood to completely dissolve the sand grains. The resulting spongy material was then thoroughly washed, dried, mounted and gold coated in preparation for SEM examination. The results are shown in FIG. 4. FIG. 3 shows that polymer forms solid strands around and between sand grains. There is little evidence of actually bonding of the polymer to the sand surfaces. FIG. 4 shows that the polymer network retained its integrity even though all the sand grains were dissolved.
EXAMPLE 5
Preparation of Unconfined Samples
A section of metal tubing was prepared with holes or perforations to provided in injection tube and imbedded in a sand bed packed into a 45 cm diameter pressure vessel (22.6 L capacity, containing 60 kg of F-125 Ottawa sand). Exit ports were installed some distance from the injection tube. The sand was pressurized using inflatable bladders located within the pressure cell. Then 200 mL of 20 wt % polysulfone in morpholine solutions were injected and precipitated using water. The pressure vessel was opened, and the unconsolidated sand was removed. The zone of consolidation was found to form uniformly around the injection tubing. See FIG. 5. Residual permeability of the consolidated sand core was confirmed by injecting water and observing the flow out of the consolidated section.
EXAMPLE 6
Testing of Consolidated Sand Beds for Breakdown During Fluid Flow
A core holder of 22 cm length and 7.6 cm internal diameter was fitted with slotted plates at one end, and filled with 1.5 Kg of sand. The lower 10% of the cylinder of sand, nearest the slotted end plate, was consolidated using polysulfone in morpholine solutions with concentrations of 5, 7.5, 10 and 15% (wt/wt). Following consolidation, water was pumped through the sand bed and out through the slotted end plate at various flow rates (see Table 2). Run times varied from 14 minutes to 186 minutes. Even at flow rates of 1600 mL/min., no sand was produced when the sand had been consolidated using a 10% polysulfone solution. Sand production was only observed when solutions containing 2.5% polysulfone or no polysulfone were used.
EXAMPLE 7
Samples of consolidated sand were prepared as in example 1. The cores were placed into stainless steel autoclave bombs, and heated with aqueous solutions of either 0.1% H 2 SO 4 or 0.5% NaOH for 5 days at 150° C. In all cases, the compressive strengths of the cores were the same as the untreated cores, respectively, depending on the polymer concentration.
EXAMPLE 8
Two samples of consolidated sand were prepared using a solution of 20% polysulfone in morpholine. One of the cores was prepared with clean sand, the other with oil-coated sand. The cores were placed into a stainless steel autoclave bombs with brine, and heated at 100 C. for six months. After the test, the compressive strengths of the two cores were 2500 and 2700 kPa, respectively. This compares with the strength of 3500 kPa of a core prepared with 20% polysulfone in morpholine, which had not been subjected to hydrothermal treatment.
EXAMPLE 9
Polyimide was dissolved in dimethylsulfoxide to form solutions containing 10 wt/wt % polymer and 15 wt/wt % polymer. These solutions were used to consolidate sand, by precipitating the polymer with 50% aqueous methanol. Scanning electron microscopy confirmed that the consolidated cores were bonded by a three dimensional network of polymer strands.
EXAMPLE 10
Polyethylene terephthalate was dissolved in m-cresol to form a solution containing 20 wt/wt % polymer. This solution was used to consolidate sand by precipitating the polymer with 50% aqueous methanol. Scanning electron microscopy confirmed that the consolidated core was bonded with a three dimensional network of polymer strands.
EXAMPLE 11
Cores prepared in examples 9 and 10 using polyimide and polylethylene terephthalate were placed into autoclaves containing brine and Lloydminister crude oil (10% oil homogenized with brine). The autoclave bombs were heated to 250° C. for 5 days. After that period, the cores were completely disintegrated, and no trace of solid polymer could be seen. When heated in air to 250° C., the polyimide is stable. This suggests that polyimide underwent hydrolysis under aqueous conditions.
TABLE II______________________________________Sand Production From Critical Slot ApparatusFor Various Consolidation ConditionsSlot Size Flow Rate (Max) Injection P Sand(mm) % Polysulfone (mL/min) (kPa) Prod'n?______________________________________0.30 0 450 82 N0.71 0 16 7 Y0.71 15 180 986 N0.71 15 980 230 N0.71 10 1600 360 N0.71 7.5 625 430 N0.71 5 1590 1810 N0.71 2.5 1480 220 Y______________________________________
A standard test procedure is now given to be used in establishing the solvents and polymers which are appropriate for the practice of the invention.
Standard Test Procedure in Sand Sample
Ottawa sand (or pure quartz sand) of specified particle size distribution is packed into a pressure vessel, fitted with an entrance port and as exit port. The sand is saturated with water. A solution of the linear polymer in solvent is injected such that the volume of the solution fully displaces the water from the sand core. A volume of neat solvent is injected to just displace the polymer solution contained within feed lines and pump. A sufficient quantity of an aqueous solution of 0.1% NaCl is injected to displace the good solvent and the spacer of neat solvent. The core is opened and the consolidated sand is removed.
The result should be that (1) at least part of the sand is consolidated into a self-supporting solid; (2) water or water/petroleum mixtures can be pumped through the core; (3) a sample removed from the consolidated sand and examined by microscopy (as in the scanning electron micrographs supplied with the disclosure) will show strands of solid plastic surrounding sand grains, without necessarily bonding to them, to form a three-dimensional network; (4) a sample removed from the consolidated sand and treated with concentrated aqueous hydrofluoric acid (HF) will yield a self-supporting, elastic sponge-like material containing no sand grains; (5) a sample removed from the consolidated sand when treated with a similar volume of hot (>50° C.) "good" solvent will cause the polymer to re-dissolve to yield the original unconsolidated sand. | A slug of solution, comprising a linear polymer such as polysulfone, polyethylene terephthalate or polyimide dissolved in a "good" solvent, such as morpholine, dimethylformamide m-cresol or dimethylsulfoxide, respectively, is emplaced in the near-wellbore region of an unconsolidated sand reservoir. A second slug comprising a poor solvent for the polymer, such as water or water+2-methanol is pumped into the region to contact the first slug. The linear polymer is precipitated and forms a three-dimensional network of interconnected strands extending through the fluid flow channels between the sand grains. The network functions to consolidate the sand without significantly damaging permeability. Petroleum and other fluids can then be produced without loose sand being entrained in the fluids. If necessary, this permeable network of plastic threads can be removed by re-injecting a slug of the good solvent to re-dissolve the plastic and reform the original linear polymer solution. | 2 |
This is a continuation, of application Ser. No. 215,806 filed Dec. 12, 1980 which is a continuation of application Ser. No. 44,355 filed May 31, 1979.
BACKGROUND OF THE INVENTION
From an energy-loss point of view, a window in a building is a mixed blessing. On the one hand, it allows light to enter the building and it provides in most cases an asethetically pleasing view. It even allows heat to enter the building by radiation, particularly when the sun is shining and is directed through the window. On the other hand, however, at nighttime heat radiates from the interior of the building through the window. Furthermore, when the wind is blowing strongly against the window there is a heat loss by convection. It has generally been recognized that many of these problems can be overcome by providing the window with an insert of insulated sheet material which would be removed by day and in place at night. The problem has always been that the insert must be stored in such a way as to be free of damage and so that is does not effect the appearance of the building aesthetically. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide an insulating structure for use in the reduction of loss of heat through a window by radiation and convection.
Another object of this invention is the provision of a window insulating structure, including a sheet of low thermal conductivity that can be moved quickly from operative to inoperative condition.
A further object of the present invention is the provision of an insulating structure in which storage does not cause deterioration of the aesthetic appearance of the building.
It is another object of the instant invention to provide an insulating system which can be installed in the building at the time that it is constructed.
A still further object of the invention is the provision of an insulating structure which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service with a minimum of maintenance.
Another object of the invention is the provision of an insulating panel that slides readily in and out of a recess in the wall because of a cushion of air that forms during the sliding action.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.
SUMMARY OF THE INVENTION
In general, the invention consists of an insulating system for use with the window of a building. A rigid rectangular envelope, having an opening along one side, is fastened in a wall with the opening located on the window frame. A sheet of insulating material is slidable in the envelope from an inoperative position within the envelope to an operative position substantially outside of the envelope and coextensive with the window.
More specifically, the envelope is made up of two rigid sheets held in spaced parallel relationship by spacing blocks extending around three sides, the opening existing on the side without a spacing block. The insulated sheet is provided with a rigid peripheral frame. The wall of the building is provided with large-size studding, except in the vicinity of the envelope where small-size studding is used that is smaller than the large size studding by an amount equal to the thickness of the envelope. The envelope and the sheet rest tightly enough that movement of the sheet in or out of the envelope causes a flow of air through the gap between them that acts as an air bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:
FIG. 1 is a perspective view of an insulating system incorporating the principles of the present invention shown in use with a window in a building,
FIG. 2 is a front elevational view of the interior of the window, and
FIG. 3 is a sectional view of the building taken on the line III--III of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, wherein is best shown the general features of the invention, the insulating structure, indicated generally by the reference numeral 10, is shown in use with a window 11 carried in a frame 12 which is mounted in a wall 15 of a building. The insulating structure includes an envelope 13 mounted in the wall, as will be further described hereinafter.
FIGS. 2 and 3 show the details of the invention, including the manner in which the envelope is mounted in the wall with an opening 14 exposed to the window opening 16 at a portion thereof located inwardly of the window. The envelope consists of a rigid rectangular container. The fixed sheet 17 of insulating material is slidable in and out of the envelope 13 from an inner position (as illustrated in FIG. 1,) to an operative position co-extensive with the window 11 and entirely filling the frame 12, (as illustrated in FIGS. 2 and 3. )
The envelope 13 consists of two rigid sheets 18 and 19 formed (in the preferred embodiment) of particle board. Both boards are rectangular in shape and are held in spaced parallel relationship by spacer blocks 21, 22, and 23 extending around three of the sides leaving the fourth side free for the opening 14. The sheet 17 is provided with a rigid peripheral frame 24 constructed preferably of wood. The vertical portion of the frame farthest from the opening 14 in the operative position is provided with a hand hold 25. The wall contains three narrow studs 26, 27, and 28 adjacent the window and supporting the envelope 14, while the remainder of the wall uses a wider stud 29. The difference between the width of the wide stud 29 and the narrow studs is exactly the same as the thickness of the envelope. In the preferred embodiment, the narrow studs 26, 27, and 28 are 2×4s, while the wider studs are 2×6s, so that the thickness of the envelope is 2 inches. The arrangement could also use a 2×4 for the stud 29 and a 2×4 on the side for the studs 26 and 28; the envelope 13 would still be 2 inches thick. A pair of beads extends entirely around the frame in the window opening 16 to embrace the edges of the main sheet 17 of insulating material. A bead 31 extends around the edge facing outwardly of the window and a bead 32 extends around the edge facing inwardly of the window. The bead spacing is selected to fit snugly around the edge of the sheet without, of course, inhibiting the sliding movement in or out of the envelope.
The operation and the advantages of the present invention will now be readily understood in view of the above description. When the sheet 17 of insulating material is in "stored" or inoperative position within the envelope 13, the operation and appearance of the window 11 is essentially the same as if the insulating system were not used. The light from the sun passes through the glazing of the window and serves not only to illuminate the room, but also to provide it with solar heat. On the other hand, at night radiation normally takes place from the interior of the room through the window to the outside, thus producing a cooling effect on the interior. In addition, there is a certain degree of leakage around the conventional double-hung window, causing a flow of cold air from the exterior to the interior. This leakage takes place both during the day and during the night and depends to a great extent on the velocity of the wind flowing against the exterior of the building. Nevertheless, since the temperature is usually lower at night, the cooling due to this type of convection leakage has a greater effect in the night time.
In order to render the insulating system operative, it is necessary to slide the sheet 17 out of the opening 14 in the envelope 13 and move it across the window until its peripheral frame 24 lies entirely between the beads 31 and 32. The tight fit of the sheet within the beads reduces the leakage of cold air into the building. More importantly, however, the sheet prevents radiation of heat from the interior of the room through the window to the exterior. In addition, it provides for an insulation of the portion of the building occupied by the window and prevents conduction of heat out of the building. In other words, the use of the present invention reduces the loss of heat due to conduction, convection, and radiation. It can be readily seen that the system is inexpensive in all respects, since it makes use of readily-available materials and is simple in construction. By selecting a suitable ornamentation on the interior and exterior surfaces of the main sheet, the sheet can even improve the interior or the exterior appearance of the house, rather than reduce its attractiveness. By a suitable selection of material and thickness of the main sheet, it is possible to provide a design suitable for any climate and desired effectiveness. As the sheet 17 moves out of the opening 14 in the envelope 13, air flows through the gaps between the sides, bottom edge, and top edge of the sheet and the corresponding surfaces of the opening into the envelope. This flow of air forms a cushion or bearing that allows the sheet to slide easily without the need for expensive rollers or the like. The same air bearing exists when the sheet is pushed into the envelope for storage. The provision for ease of sliding in this way takes advantage of the simplest, maintenance-free structure, which is also the least expensive.
It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed. | Energy saving apparatus for use with a window, including a sheet of insulating material slidable in and out of a rigid envelope built into the wall. | 4 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
The invention disclosed and claimed herein pertains to the field of neutron detection devices of the type which employ lithium-6, in a solid form, to respond to neutrons by radiating charged particles into an ionizable counting gas. More specifically, the invention pertains to detection devices of the above type wherein the lithium radiator is configured to provide one or more flat surfaces of lithium-6 foil in contact with ionizable gas, each surface being in spaced parallel relationship with an array of high voltage count wires which indirectly measure neutron activity by sensing pulses of gas ionization. Even more particularly, the invention pertains to detection devices of the above type wherein a plurality of flat lithium-6 foil surfaces may be stacked in parallel layers with one another, and with arrays of counting wires, in order to provide a neutron detector which is of very high sensitivity and which is yet capable of being contained in a package which is extremely portable, compact, and durable.
At present, most high-sensitivity neutron detectors of the radiator-ionizable gas type employ either 10 BF 3 or 3 He, in a gaseous state, as the radiator medium for the detector, i.e., for the detector component which receives neutrons and which radiates ionizing particles in response thereto. 3 He is always in a gaseous state at practical temperatures and pressures. 10 BF 3 must be employed in a gaseous state, since the principal ionizing particle which results from the reaction between a neutron and a boron nucleus of 10 BF 3 is an alpha particle, which is of extremely short range (e.g., 5×10 -3 mm). If a reaction generating an alpha particle were to take place within a solid material, the dimensions of the material would have to be extremely small, to prevent the alpha particles from being trapped therewithin.
Because of the low density of 10 BF 3 and 3 He at ordinary pressures, they must be contained in chambers of large volume in order to be used as the radiator component in a neutron detector. Consequently, such detectors tend to be comparatively large or bulky. While neutron detectors are available which have used a solid layer of 10 B as an alpha particle radiator, the layer must be kept very thin, as aforementioned, (e.g., 10 -2 mm) and it may still be necessary to supplement the 10 B radiator with one of the above gaseous radiator components.
In the past, solid lithium-6 ( 6 Li) has been used as the neutron sensitive component in a radiator-ionizable gas neutron detector, wherein the 6 L i is coated upon the curved inner surface of a cylinder. Note, for example, U.S. Pat. No. 2,721,944, issued Sept. 9, 1950, which discloses a neutron detector for use in geological exploration of oil fields. However, the Applicant has found that if, instead of such curved arrangement, a number of flat sheets of 6 L i are employed in a neutron detector, it becomes possible to provide a substantial reduction in detector size and to increase the ruggedness thereof, and yet provide high detection sensitivity. The Applicant uses flat sheets of 6 L i so that the sheets may be stacked in parallel layers within a thin, flat container. By enabling a number of sheets to be enclosed in the container, high sensitivity to neutron detection is provided since the probablility that a neutron entering the container will encounter a lithium-6 nucleus is optimized. By making the detector flat and thin, a neutron striking the detector from almost any angle will pass into at least one of the 6 L i sheets. Also, by stacking sheets in parallel relationship, the space between sheets, which is filled with ionizable counting gas, may be made so small that gamma rays generated within the detector can be prevented from being registered as neutron counts. High-sensitivity neutron detectors employing the principles of the present invention have been fabricated which are small enough to be held in an operator's hand, and to be carried in a coat pocket.
SUMMARY OF THE INVENTION
In the present invention, a neutron detection apparatus is provided which includes a selected number of flat surfaces of lithium-6 foil, and further includes a gas mixture in contact with each of the surfaces for selectively reacting to charged particles radiated from the lithium foil. A container means is provided for sealing the lithium foil and the reacting gas mixture within a volume from which water vapor and atmospheric gases are excluded, the container means having walls which are transmissive to neutrons. A monitoring means in contact with the gas mixture detects reactions in the gas mixture, and in response to detected reactions provides an output which represents the flux of neutrons passing through the detector volume.
Preferably, the lithium-6 foil comprises one or more flat sheets of lithium-6, the thickness of each sheet being substantially less than the range of a triton particle when such particle is traveling through lithium. The gas mixture comprises a counting gas which is readily ionized when charged particles pass through it, and the lithium foil and the counting gas are enclosed together within a flat, hermetically sealed container. Preferably also, the monitoring means includes an array of count wires which are maintained at a selected high voltage within the container, such array being in spaced parallel relationship with one of the sheets of lithium foil. An electronic processing means, located externally to the container, is coupled to the array of count wires.
It has been found that a flat sheet of lithium foil may be enclosed within the container by bonding it to a flat inner wall of the container, whereby one side of the lithium sheet is exposed to the counting gas and to the interior of the container. Alternatively, the sheet may be suspended within the interior of the container, so that both sides of the sheet are exposed to the counting gas. In a preferred embodiment of the invention, a neutron detector is formed by enclosing a plurality of flat lithium sheets within a flat container, some of the sheets being bonded to container walls and others being suspended. The sheets are stacked in spaced parallel relationship, an array of counting wires being positioned in spaced parallel relationship with each lithium surface which is exposed to counting gas. It has been found that by so configuring the lithium sheets and wire arrays, a neutron detector may be provided which has a very high neutron sensitivity and a low gamma-ray sensitivity, and which is yet enclosed in a container having a thickness of less than one inch.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a lighter, more compact neutron detector of high sensitivity.
Another object is to provide a neutron detector which employs one or more flat sheets of lithium-6 foil to radiate ionizing particles into a counting gas in response to neutrons received by the lithium sheets.
Another object is to provide a detecting device which is of high sensitivity to neutrons and low sensitivity to gamma rays which may be contained in a small, flat package having a thickness of less than one inch.
Another object is to provide a detecting device of the above type in which flat sheets of lithium-6 foil are spaced apart in parallel relationship so that the thickness of a layer of counting gas between them is very small, whereby there is substantially less ionization of the gas from gamma-ray passing therethrough than from a charged particle generated by a neutron.
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view showing an embodiment of the invention.
FIG. 2 is a schematic view for illustrating the principle of operation of the embodiment of FIG. 1.
FIG. 3 is an overhead view showing an array of count wires for the embodiment of FIG. 1.
FIG. 4 is a perspective view showing the embodiment of FIG. 1 fully assembled and coupled to monitoring electronics.
FIGS. 5 and 6 are schematic views which illustrate modifications of the embodiment of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there are shown various components which may be assembled to form three-layer lithium-6 neutron detector 10. Detector 10 includes flat top and bottom plates 12 and 14, respectively, which are usefully formed of brass or other material which is highly transmissive to neutrons n in proximity to detector 10. Detector 10 further includes upper and lower support frame sections 16a and 16b, respectively, which are likewise formed of brass, and which are provided with slots for respectively retaining ceramic strips 18a and 18b.
By means of a silk-screening and high-temperature firing process, for example, strips 18a and 18b are metallized. A number of count wires 20a (e.g., 44) are tensioned between and soft-soldered to metallized strips 18a in parallel relationship with one another, at a spacing which usefully is 1/8 inch. A like number of count wires 20b are similarly tensioned between and soft-soldered to ceramic strips 18b. Consequently, when detector 10 is assembled, upper and lower frame sections 16a and 16b support arrays of count wires 20a and 20b, respectively, in parallel relationship with one another and with top plate 12 and bottom plate 14.
In order to apply a selected high positive voltage (e.g. 1,000 V) to each count wire 20a, a cable 22a passes through frame section 16a, through a coupling 24a, and is connected to one of the metallized strips 18a. Similarly, a cable 22b passes through a coupling 24b to apply a high positive voltage to each count wire 20b.
Referring further to FIG. 1, there is shown a flat sheet or layer 26 of lithium-6 metal bonded to the under surface of top plate 12, and there is also shown a flat sheet 28 of lithium-6 bonded to the upper surface of bottom plate 14. Sheets 26 and 28 may be bonded to their respective plates by heating the plate to just below the melting point of lithium, and then rubbing lithium foil onto the surface of the plate with the aid of a large soldering iron. A quantity of 6 L i foil is applied to a plate which is sufficient to cover the surface of the plate to a depth of 50 microns (0.002 inches). By keeping the brass plate horizontal while a soldering iron is vigorously worked back and forth over the surface of the plate, it has been found that a lithium sheet of fairly uniform thickness may be bonded to the plate.
In addition to the array of count wires 20a, lower frame section 16b supports a grid of foil support wires 30 which are tensioned between and soft-soldered to opposing upper edges of lower frame section 16b. The grid formed by wires 30 is provided to support a layer or sheet of rolled 6 L i foil 32 of 50 microns thickness. A similar grid of wires (not shown) is attached to the lower edges of upper frame section 16a, so that if sections 16a and 16b are joined together along their respective lower and upper edges, for example, by means of epoxy glue, 6 L i foil layer 32 is immovably sandwiched therebetween.
Referring once more to FIG. 1, there is shown a counting gas mixture 34, which is sealed within an enclosed volume formed by hermetically joining sections 16a and b, top plate 12 and bottom plate 14. Counting gas 34 usefully comprises a mixture of 90% argon and 10% methane or 80% argon and 20% isobutane.
In order to assemble respective components of detector 10, all of the components are carefully cleaned and then placed into a glove box without being exposed to the atmosphere. As is well known, a glove box is a device which enables mechanical operations to be manually performed upon various work pieces or components while the components are isolated from both atmospheric gases and from water vapor. It is essential that lithium-6 be kept isolated therefrom because of its extremely reactive nature. The glove box may be filled with pure argon, an inert gas, to prevent any contact between lithium and elements or substances with which the lithium would react in such way that the lithium would be severely damaged.
It has been found that an epoxy glue may be employed to bond top plate 12 to the upper edges of frame section 16a and bottom plate 14 to the lower edges of frame section 16b, the count wires, 6 L i flat sheets, and counting gas being hermetically sealed in the chamber formed thereby. After assembly, purge tubes 36, which penetrate to the interior of detector 10, are employed to introduce counting gas 34 into the chamber, purge tubes 36 being provided with shutoff valves 38.
It has been found that frame sections 16a and 16b may each have a thickness of no more than one-quarter inch, so that detector 10 is very thin and flat. Most neutrons penetrating into detector 10 therefore pass into at least one of the lithium-6 foil sheets.
Referring to FIG. 2, there is shown a neutron n entering one of the sheets of 6 L i foil enclosed within detector 10. Because the foil is in a solid rather than a gaseous state, the density of lithium nuclei therein is very high and there is a very high probability that the neutron will react with, or be absorbed by, a 6 L i nucleus N. When a neutron reacts with a 6 L i nucleus, the following reaction occurs:
6 L i +n→ 3 H+ 4 He+4.78 Mev.
As is well known, 3 H is a triton particle. As is also well known, the range of a triton particle traveling through 6 L i is comparatively long (e.g. 0.135 millimeters). Consequently, in excess of 70% of the triton particles resulting from the reaction between a neutron and a 6 L i nucleus are able to escape from a layer of lithium of 50 microns thickness. By providing lithium foil layer 32, which is suspended within the chamber of detector 10, four lithium surfaces are provided from which triton particles T can be emitted into the chamber, and come into contact with counting gas 34.
Emitted tritons (or alpha particles which are able to escape the lithium) cause counting gas which they encounter to become ionized, generating electrons e. Since each of the count wires 20a and 20b of the count wire arrays is maintained at a high positive voltage, as aforementioned, released electrons are attracted thereto. When attracted electrons come within a range R of a count wire, they enter a region of avalanche multiplication, wherein they interact with counting gas to substantially increase the level of counting gas ionization. Sufficient electrons are released by counting gas in the avalanche multiplication regions of respective count wires to generate millivolt-size pulses thereupon. Such pulses may be readily detected and measured by electronic apparatus external to detector 10 to provide a quantitative indication of neutron activity.
While using detector 10 to monitor neutrons, it may be very important to prevent gamma rays occurring in the detector from being registered as neutron counts. By providing the aforementioned one-quarter inch spacing between lithium-6 sheets, the layer of counting gas 34 between adjacent sheets, or between a sheet and a wall, is too thin to enable significant ionization of the gas by a gamma-ray. The pulse generated by a gamma-ray is therefore detectably less than the pulse generated by a neutron in detector 10, and may therefore be readily distinguished from a neutron pulse.
Referring to FIG. 3, there is shown an overhead or plan view of upper frame section 16a, together with useful inner and outer dimensions therefor. Lower frame support section 16b is similar or identical thereto, so that frame sections 16a and 16b may be joined, as aforementioned, to form integrated sidewalls for the chamber of detector 10. If detector 10 is intended to be used in situations where small size and compactness are important, it may have an outer cross-section on the order of 61/2"×61/2". Its inner dimensions, the dimensions of the chamber which contains the counting gas, flat 6 L i sheets and count wires, may be 6"×51/4".
Referring to FIG. 4, there is shown detector 10 in a fully assembled form, conductors 22a and b being connected to monitoring electronics 40. Monitoring electronics 40 usefully includes a source of high voltage, a pulse height discriminator, and a scaler, the latter two devices being well known in the art of charged particle proportional counting systems. Low-level pulses coupled through conductors 22a and b, which are caused by noise or gamma-ray absorption, are rejected by the pulse height discriminator. Other pulses, which are sufficiently high that they may be presumed to result from the reaction between a neutron and a lithium nucleus included in one of the lithium-6 sheets of detector 10, are recorded by the scaler as neutron counts.
Referring to FIG. 5, there is shown a first modification of the invention, wherein only a single flat sheet of 6 L i foil 32 is provided to radiate charged particles in relation to adjacent neutron activity level. It will be noted that by suspending the sheet in the detector, tritons T may be radiated from either surface thereof into counting gas contained within the detector chamber. An array of parallel count wires 42 is maintained in spaced parallel relationship with each surface of the 6 L i foil.
Referring to FIG. 6, there is shown a second modification of the invention, wherein three flat sheets of 6 L i foil 32 are suspended within the chamber of a neutron detector, to provide maximum opportunity for a neutron entering the detector to collide with a lithium-6 nucleus. An array of parallel count wires 44 is maintained in spaced parallel relationship with each surface of each sheet of 6 L i foil.
Obviously, many other modifications and variations of the present invention are possible in the 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. | A neutron detection apparatus is provided which includes a selected numberf flat surfaces of lithium-6 foil, and which further includes a gas mixture in contact with each of the flat surfaces for selectively reacting to charged particles emitted by or radiated from the lithium foil. A container is provided to seal the lithium foil and the gas mixture in a volume from which water vapor and atmospheric gases are excluded, the container having one or more walls which are transmissive to neutrons. Monitoring equipment in contact with the gas mixture detects reactions taking place in the gas mixture, and, in response to such reactions, provides notice of the flux of neutrons passing through the volume of the detector. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to a sharply-edged medical cutting tool for incising a biological tissue with an improved piercing property.
BACKGROUND
[0002] At the time of an ophthalmic surgical operation, a knife or trocar is employed to pierce an eyeball or incise a cornea or sclera, and a suture needle for piercing or incising a muscle or a skin is employed to suture an affected area. A medical cutting tool such a knife, a trocar, or a suture needle includes a sharp tip, a sharp edge elongated from the sharp tip, a plane portion that forms the edge, and a body portion continuously elongated from the plane portion.
[0003] The edge and the plane portion have cross sections having a polygonal shape such as a triangle, a rectangle, or a pentagon. The shape of the cross section is set according to a type of a desired medical cutting tool, that is, according to whether the medical cutting tool is a knife, a trocar, or a suture needle. In addition, regardless of the cross-sectional shape of the medical cutting tool, two edges are formed by using the sharp tip as a starting point (for example, see Patent Literature 1).
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese Patent Laid-Open No. 06-077313
SUMMARY OF INVENTION
Technical Problem
[0005] In the medical cutting tool having the aforementioned configuration, it is necessary to reduce impalement resistance generated during the incision of the affected area. For example, if the impalement resistance is large, a doctor may feel fatigued, and may not accurately perform a surgical operation. For this reason, a manufacturer of a medical cutting tool has an important issue to improve a medical cutting tool including a knife, a trocar, and a suture needle having reduced impalement resistance.
[0006] The present invention provides an edged medical cutting tool having reduced impalement resistance.
Solution to Problem
[0007] In order to address the aforementioned problem, the inventors have made many development experiments. As a result, the inventors have found a fact that the impalement resistance is reduced by providing a sharp edge. In addition, the inventors have recognized that the sharp edge can be implemented by performing an electrolytic polishing process or a chemical polishing process within a short time after a polishing process.
[0008] The inventors have also recognized that a color of one plane portion along the edge is different from that of the other plane portion when the sharp edge is configured by performing an electrolytic polishing process or a chemical polishing process and the polishing process is performed within a short time. Furthermore, the inventors have also recognized that the chromium content of one plane portion along the edge is different from that of the other plane portion when a stainless steel is employed as a material.
[0009] According to an aspect of the present invention, there is provided a medical cutting tool including: a sharp edge for incising a biological tissue; and plane portions that form the edge, wherein a color of one plane portion along the edge is different from that of the other plane portion.
[0010] In the edged medical cutting tool described above, a color difference between one plane portion along the edge and the other plane portion is based on a thickness difference of an oxide film.
[0011] According to another aspect of the present invention, there is provided an edged medical cutting tool made of an austenitic stainless steel, including: a sharp edge for incising a biological tissue; and plane portions that form the edge, wherein a chromium content of one plane portion along the edge is larger than a chromium content of the other plane portion.
Advantageous Effects of Invention
[0012] In the edged medical cutting tool (hereinafter, simply referred to as a cutting tool) according to the present invention, it is possible to reduce impalement resistance by forming a sharp edge. Therefore, during an ophthalmic surgical operation or a general surgical operation, it is possible to alleviate fatigue of a doctor and accurately perform the incision.
[0013] Particularly, since the formation of the sharp edge can be recognized by checking a color difference between one plane portion along the edge and the other plane portion out of the flat portions that form the edge of the cutting tool, it is possible to perform accurate inspection at least when the cutting tool is manufactured.
[0014] In addition, in another cutting tool according to the present invention, by comparing the chromium content of one plane portion along the edge with the chromium content of the other plane portion, it is possible to check whether or not the sharp edge is formed.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a diagram illustrating a trocar as a cutting tool according to an embodiment.
[0016] FIG. 2 is a photographic image of the trocar illustrated in FIG. 1 .
[0017] FIG. 3 is a photographic image illustrating sampling positions when material components of a trocar are quantitatively analyzed.
[0018] FIG. 4 is a photographic image illustrating sampling positions when material components of a trocar as a comparative example are quantitatively analyzed.
REFERENCE SIGNS LIST
[0000]
A: TROCAR
1 : EDGE
2 , 2 a , 2 b : PLANE PORTION
3 : RIDGE
4 : SHARP TIP
5 : BODY PORTION
6 : BOUNDARY
7 : SMALL PLANE PORTION
10 : DASHED-DOTTED LINE (boundary between the plane portion 2 a and the other plane portion 2 b )
DESCRIPTION OF EMBODIMENTS
[0028] Hereinafter, a cutting tool according to the present invention will be described. According to the present invention, when a biological tissue is pierced and incised during a surgical operation using a knife, a trocar, an edged suture needle, and the like, impalement resistance is reduced, so that it is possible to alleviate fatigue of a doctor and accurately perform the surgical operation.
[0029] According to the present invention, a sharp edge for incising a biological tissue is configured by causing two planes to intersect each other. In addition, a color of one plane portion along the edge is different from that of the other plane portion. This color difference corresponds to a thickness difference of an oxide film, which is caused by reducing a processing time in an electrolytic polishing process or a chemical polishing process (electrolytic polishing or the like) performed during a cutting tool manufacturing procedure.
[0030] In other words, since burrs attached to the edge are large in the case of a medical cutting tool manufactured in the related art, it is necessary to perform an electrolytic polishing or the like for a long time in order to remove the burrs from the edge. In addition, due to the long-time electrolytic polishing or the like, elution also occurs in a portion along the edge when the burrs attached to the edge are removed. As a result, fine roundness is generated at a pointed end of the edge, so that sharpness of the edge disappears.
[0031] On the contrary, in a procedure of manufacturing a cutting tool according to the present invention, the burrs attached to the edge are removed by using short-time electrolytic polishing or the like, so that a sharp edge can be implemented. In addition, as a result of the short-time electrolytic polishing or the like, a thickness difference of an oxide film occurs between one plane portion along the edge and the other plane portion, and a color difference occurs due to the thickness difference of the oxide film.
[0032] In the cutting tool where a color difference occurs between one plane portion along the edge and the other plane portion as described above, a change in material component also occurs in addition to the color difference.
[0033] Therefore, the cutting tool according to the present invention can be recognized by the color difference between one plane portion along the edge and the other plane portion or by quantitatively analyzing the material components.
[0034] Furthermore, in the cutting tool according to the present invention, it is possible to sufficiently reduce the impalement resistance in comparison with that of the cutting tool typically used in the related art.
[0035] As a material for the cutting tool according to the present invention, a metal represented by a carbon steel or a martensitic stainless steel which can be expected to be hardened through thermal treatment or an austenitic stainless steel which cannot be expected to be hardened through thermal treatment can be selectively used. In addition, it is preferable that the cutting tool according to the present invention be configured by performing a shaping process and a hardening process for a desired cutting tool through processes optimized to the selected material.
[0036] Next, a trocar A according to the present embodiment will be described with reference to FIGS. 1 and 2 . The trocar A illustrated in FIGS. 1 and 2 is a cutting tool for piercing an eyeball and cutting a cornea or sclera in an ophthalmic surgical operation. As a material of the trocar A, SUS302 that is an austenitic stainless steel is employed. The trocar A is formed in a round bar shape having a fiber-like extending structure by performing a cold drawing process on an element wire with a predetermined area reduction rate and having a high strength through a fabrication and hardening process.
[0037] In addition, the trocar A is configured in a straight needle shape by performing a press process and then performing a grinding process on an end portion of the round-bar-shaped material fabricated as described above or by directly performing the grinding process on the end portion. Incidentally, as the cutting tool according to the present invention, in addition to the trocar A according to the present embodiment, there are an edged suture needle, a knife, and the like having a cutting functionality and any of them may be formed in the configuration of the trocar A described below.
[0038] In FIGS. 1 and 2 , the trocar A includes a pair of sharp edges 1 formed by causing two plane portions 2 including a plane portion 2 illustrated in FIG. 1 and a plane portion (not illustrated) on the rear side of the paper of FIG. 1 to intersect each other. Particularly, in the trocar A according to the embodiment, a cross section (a transverse cross section of a portion where the edge 1 of the trocar A exists) of a portion corresponding to the edge 1 is formed in a rhombus shape. The pair of edges 1 are formed on the two sides in the width direction (in the arrow direction X in FIG. 1 ), and the pair of ridges 3 having no incising function are formed on the two sides in the thickness direction (direction perpendicular to the paper plane of FIG. 1 ) perpendicular to the width direction. In addition, the rear surface side of the trocar A illustrated in FIG. 1 has the same shape as that illustrated in FIG. 1 .
[0039] The edge 1 and the plane portion 2 are formed to converge toward a sharp tip 4 . In other words, the edge 1 and the plane portion 2 are inclined by using the sharp tip 4 as a starting point. Therefore, the pair of edges 1 , the pair of ridges 3 , and the plane portions 2 that forms the edges 1 and the ridges 3 are separated from each other according to the respective inclination and are connected to the body portion 5 . The body portion 5 is formed in a round bar shape having a predetermined diameter, so that the trocar A is formed in a straight needle shape.
[0040] In the trocar A having the aforementioned configuration, as the plane portion 2 that forms the edge 1 is separated from the edge 1 and is connected to the body portion 5 , a boundary 6 is formed between the plane portion 2 and the body portion 5 . The boundary 6 forms an edge having an obtuse angle by causing the plane portion 2 and the outer circumferential surface of the body portion 5 to intersect each other.
[0041] In addition, in the trocar A according to the present embodiment, a small plane portion 7 is formed on the sharp tip 4 sides of the two plane portions 2 formed on one side in the thickness direction. By forming the small plane portion 7 , the sharp tip 4 is configured from three planes including the two plane portions 2 and the small plane portion 7 . Therefore, the sharp tip 4 is formed necessarily as one point, so that it is possible to improve positioning accuracy at the first time of impalement of a tissue and reduce the impalement resistance.
[0042] As illustrated in FIG. 2 , a part of the plane portions 2 along the edge 1 , that is, a plane portion 2 a (one plane portion 2 a ) formed between the dashed-dotted line 10 and the edge 1 illustrated in FIGS. 1 and 2 has a color different from that of the other plane portion 2 b . However, since it is difficult to clearly represent the color difference between the plane portions 2 a and 2 b by using a certain line as a boundary, the dashed-dotted line 10 indicates the boundary between the plane portion 2 a and the other plane portion 2 b for convenience purposes.
[0043] The inventors of the present invention have examined the cause of the color difference, and it have been determined that the color difference is generated due to a thickness difference of an oxide film between the plane portions 2 a and 2 b . In other words, since the oxide film in the plane portion 2 a is thin, the color is relatively close to a color of a metal material. Since the oxide film in the plane portion 2 b is thick, the color is close to gold. Incidentally, in the photographic image of FIG. 2 , the plane portion 2 a has a dark color, and the plane portion 2 b has a white color. However, these color components are caused from illumination during the photographing.
[0044] As illustrated in FIG. 2 , the plane portion 2 a having a different color is formed in a part of the plane portion 2 along the edge 1 , a portion along the boundary 6 , and a portion along the ridge 3 . In other words, the plane portion 2 a is formed over the substantially entire area in the vicinity of the plane 2 . However, in the case of the cutting tool, if the plane portion 2 a having a color different from that of the other plane portion 2 b is formed in a part of the plane portions 2 along the edge 1 , it is possible to sufficiently reduce the impalement resistance.
[0045] Next, a procedure of manufacturing a trocar A capable of removing burrs attached to the edge 1 by using a short-time electrolytic polishing or the like will be described in brief.
[0046] As described above, the trocar A is formed as a rod-like material by cutting a round bar material, which is made of an austenitic stainless steel having a predetermined strength through a cold drawing process, by a desired length. Then, by performing a press process on the end portion on the one side of the material, the cross section is formed in a rhombus shape. The formed portion is ground to form a plane portion 2 , so that an edge 1 is formed in an intersection between the two plane portions 2 . Furthermore, a ridge 3 is formed by an intersection portion between the two plane portions 2 or by a press-processed surface, and a boundary 6 is formed in an intersection between one plane portion 2 and the outer circumferential surface of the body portion 5 .
[0047] Similarly to the aforementioned case, when the material is ground, burrs are inevitably attached to the edge 1 , the ridge 3 , and the boundary 6 between the plane portion 2 and the body portion 5 . Therefore, by reducing at least the burrs attached to the edge 1 , it is possible to remove the burrs through a short-time electrolytic polishing process or the like. In this manner, in order to reduce the attached burrs, a processing rate during the grinding process is reduced.
[0048] The reduction of the processing rate can be implemented by decreasing a load to the material during the grinding process. For example, if a processing rate at the time of grinding is set to about 1/10 of the processing rate at the time of grinding of the trocar in the related art, the burrs attached to the edge 1 can be sufficiently reduced. However, the processing rate is not limited to a specific value, but it may be appropriately set depending on a target cutting tool.
[0049] When the burrs attached to the edge 1 are reduced by reducing the processing rate at the time of grinding, the burrs can be removed within a short time by performing a polishing process such as an electrolytic polishing. As a result, it is possible to reduce a processing time of the electrolytic polishing or the like. As the processing time of the electrolytic polishing or the like is reduced, the polishing is not uniformly performed on the plane portion 2 , but irregularity occurs in the polishing process. In other words, a difference is generated in a degree of polishing between the plane portion 2 a along the edge 1 and the other plane portion 2 b.
[0050] The partial difference in a degree of polishing in the plane portion 2 is caused from a thickness difference in an oxide film, a difference in a material component, and a difference in surface roughness. In other words, since the material is thin in the plane portion 2 a along the edge 1 , the electrolytic polishing or the like progresses at a high speed, so that the elution amount of iron increases and the chromium content increases. Therefore, the oxide film thereof becomes thin, and the surface roughness is reduced. On the contrary, in the other plane portion 2 b , since the material is thick in comparison with the plane portion 2 a , the electrolytic polishing or the like is performed at a low speed in comparison with the plane portion 2 a , so that the elution amount of iron decreases and the chromium content decreases. Therefore, the oxide film thereof becomes thick, and the surface roughness increases.
[0051] In this manner, the color of plane portion 2 a along the edge 1 is different from that of the other plane portion 2 b due to a thickness difference of an oxide film, so that the chromium content of the plane portion 2 a is larger than the chromium content of the plane portion 2 b.
[0052] Next, the description will be made for a result of the comparison between the trocar A according to the present embodiment and the trocar in the related art (comparative example). FIG. 3 is a diagram illustrating the trocar A according to the present embodiment and sampling positions for quantitative analysis of metal components. FIG. 4 is a diagram illustrating the trocar according to the comparative example and sampling positions for quantitative analysis of metal components. Spectra 1 to 5 are arranged on the flat portion along the edge, and spectra 6 to 10 are arranged on the other plane portion.
[0053] According to the present embodiment, an electrolytic polishing process was performed for the material subjected to the planar grinding. The electrolytic polishing was performed such that the entire length of the plane portion 2 was immersed for about 35 seconds, and then, the length portion corresponding to the edge 1 was immersed for about 5 seconds. Through the electrolytic polishing process, all the burrs attached to the edge 1 were removed. After the electrolytic polishing was completed, the quantitative analysis using X-ray analysis was performed for the spectra 1 to 10 .
[0054] As a result, in the spectrum 1 , the chromium content was 31.38%; the iron content was 60.08%; and the nickel content was 8.64%. In addition, in the spectrum 2 , the chromium content was 31.45%; the iron content was 59.36%; and the nickel content was 9.19%. In addition, in the spectrum 3 , the chromium content was 31.75%; the iron content was 60.10%; and the nickel content was 8.15%. In addition, in the spectrum 4 , the chromium content was 29.10%; the iron content was 61.33%; and the nickel content was 9.57%. In addition, in the spectrum 5 , the chromium content was 28.035%; the iron content was 63.41%; and the nickel content was 8.56%.
[0055] In the spectrum 6 , the chromium content was 26.55%; the iron content was 63.57%; and the nickel content was 9.88%. In addition, in the spectrum 7 , the chromium content was 26.47%; the iron content was 63.17%; and the nickel content was 10.36%. In addition, in the spectrum 8 , the chromium content was 28.49%; the iron content was 61.47%; and the nickel content was 10.04%. In addition, in the spectrum 9 , the chromium content was 27.40%; the iron content was 62.32%; and the nickel content was 10.28%. In addition, in the spectrum 10 , the chromium content was 25.07%; the iron content was 65.16%; and the nickel content was 9.77%.
[0056] From the result described above, it can be said that the chromium content of the plane portion 2 a along the edge 1 is larger that that of the other plane portion 2 b (the spectra 6 to 10 ). Particularly, it is conceived that, in the spectra 1 to 3 , since the thin edge 1 is formed only by the two plane portions 2 , the elution amount of iron increases, so that the chromium content increases (31.38%, 31.45%, and 31.75%). It is conceived that, in the spectra 4 and 5 , since the four plane portions approach each other, the relatively thick edge 1 is formed, so that the elution amount of iron is reduced and the chromium content is reduced (29.10% and 28.035%).
[0057] Here, out of the plane portion 2 a , the chromium content (31.38%) of the spectrum 1 as a portion where the thin edge 1 is formed only along the two plane portions 2 and the chromium content (26.55%, 26.47%, 28.49%, 27.40%, and 25.07%) of the spectra 6 to 10 were compared. As a result, there were differences of 4.83%, 4.91%, 2.89%, 3.98%, and 6.31%, respectively.
[0058] In summary, it can be concluded that the chromium content of the portion (positions of the spectra 1 to 3 , particularly, the width range within 40 μm in the vertical direction of the edge 1 ) where the thin edge 1 is formed only along the two plane portions 2 out of the plane portion 2 a is larger than the chromium content of the pointed end portion (positions of the spectra 4 and 5 ) where the four plane portions approach each other. In addition, it can be concluded that the chromium content of the portion (positions of the spectra 1 to 3 ) is obviously larger than the chromium content of plane portion 2 b (particularly, the portion separated by 100 μm or longer in the vertical direction of the edge 1 ).
[0059] Next, in the comparative example, the electrolytic polishing process was performed by immersing the entire length of the plane portion for about 50 seconds with an electric current density higher than that of the aforementioned embodiment. Through this electrolytic polishing process, overall burrs attached to the edge were removed. After the electrolytic polishing was completed, the quantitative analysis was performed as in the embodiment.
[0060] As a result, in the spectrum 1 , the chromium content was 27.70%; the iron content was 62.28%; and the nickel content was 9.02%. In addition, in the spectrum 2 , the chromium content was 27.55%; the iron content was 62.47%; and the nickel content was 8.98%. In addition, in the spectrum 3 , the chromium content was 26.55%; the iron content was 63.13%; and the nickel content was 9.32%. In addition, in the spectrum 4 , the chromium content was 25.86%; the iron content was 62.95%; and the nickel content was 10.19%. In addition, in the spectrum 5 , the chromium content was 25.22%; the iron content was 65.32%; and the nickel content was 9.46%.
[0061] In addition, in the spectrum 6 , the chromium content was 25.87%; the iron content was 64.42%; and the nickel content was 9.71%. In addition, in the spectrum 7 , the chromium content was 25.12%; the iron content was 65.00%; and the nickel content was 9.88%. In addition, in the spectrum 8 , the chromium content was 25.79%; the iron content was 64.53%; and the nickel content was 9.68%. In addition, in the spectrum 9 , the chromium content was 24.99%; the iron content was 65.16%; and the nickel content was 9.85%. In addition, in the spectrum 10 , the chromium content was 26.26%; the iron content was 63.89%; and the nickel content was 9.85%.
[0062] In the comparative example described above, the electrolytic treatment time was sufficiently long, and the electrolytic polishing was performed uniformly over the entire area of the plane portion. Therefore, the elution amount of iron was also substantially uniform, and the chromium content was also substantially uniform.
[0063] In addition, in the plane portion along the edge in the comparative example, the chromium content of the portions (positions of the spectra 4 , 5 and the like in the comparative example) where a thin edge is formed only along the two plane portions and the chromium content of the pointed end portions (positions of the spectra 1 , 2 and the like in the comparative example) where the four plane portions approach each other were compared. As a result, the former portions were 25.86% and 25.22%, and the latter portions were 27.70% and 27.55%. On the contrary to the present embodiment, the portions where a thin edge was formed only along the two plane portions tended to be slightly small.
[0064] In the trocar A according to the present embodiment, the surface roughness of the plane portion 2 a along the edge 1 and the surface roughness of the other plane portion 2 b were measured. As a result, the average surface roughness of the plane portion 2 a was Ra 2.38, and the average surface roughness of the plane portion 2 b was Ra 3.15. It can be said that this difference is a significant difference in a medial cutting tool.
[0065] Next, an experiment of comparing impalement resistance between the trocar A according to the embodiment and the trocar ( FIG. 4 ) according to the comparative example was performed. In this experiment, similar to a typical impalement experiment for a knife, a trocar, or a suture needle, a force for piercing a Porvair having a thickness of 0.45 mm was measured. Five samples of the trocar A and five samples of the trocar according to the comparative example were prepared. For each sample, the Porvair was pierced three times, and the average piercing force was obtained. In addition, the average value of overall piercing forces (that is, piercing of 15 times) was obtained, and comparison thereof was performed.
[0066] As a result, for the trocar A according to the present embodiment, the average impalement resistance was 96.6 mili-newton (mN), the maximum value of impalement resistance was 107.0 mN, and the minimum value of impalement resistance was 78.0 mN. On the contrary, for the trocar according to the comparative example, the average value of impalement resistance was 139.4 mN, the maximum value of impalement resistance was 158.3 mN, and the minimum value of impalement resistance was 118.3 mN.
[0067] In this manner, it can be said that the impalement performance of the trocar A according to the present embodiment is sufficiently improved in comparison with the impalement performance of the trocar in the related art or the trocar according to the comparative example.
INDUSTRIAL APPLICABILITY
[0068] The present invention can be usefully applied to a thinned knife, a trocar, or an edged suture needle used in an ophthalmic surgical operation or a neurosurgical operation. | [Problem] To provide a medical cutting tool with low impalement resistance. [Solution] The edged medical cutting tool comprising a knife, trocar or cutting suture needle has a sharp edge ( 1 ) for incising living tissue and a flat part ( 2 ) that configures the edge, and the color of the portion of the flat part ( 2 a ) along the edge ( 1 ) differs from the color of the rest of the flat part ( 2 b ). The difference in color results from a difference in the thickness of an oxide film. Another edged medical cutting tool is configured of austenite stainless steel and has a sharp edge ( 1 ) for incising living tissue and a flat part ( 2 ) that configures the edge. The chrome content of the portion of the flat part ( 2 a ) along the edge is higher than the chrome content of the rest of the flat part ( 2 b ). | 0 |
BACKGROUND OF THE INVENTION
[0001] This application is a continuation of application PCT/EP00/02278, filed Mar. 15, 2000. The invention relates to a safety device having at least one back seat airbag for a motor vehicle.
[0002] Safety devices for a motor vehicle, having airbag apparatus, are generally known in various embodiments. In particular, airbag apparatus with one or more airbags in the front, side and bead impact areas of front occupants and rear occupants are known. These airbags, in the event of a vehicle impact, are inflatable as a function of impact delay and impact direction, by means of an individually associated, activable gas generator, to cushion and attenuate an impact on an occupant.
[0003] U.S. Pat. No. 5,738,368 discloses a safety device having a back seat airbag for a motor vehicle, comprising at least one back seat for a rear occupant and a front seat assembly arranged in front of the back seat and consisting of a seat part and a backrest. The at least one back seat airbag is inflatable by means of at least one gas generator activable in event of a sensed vehicle impact. The at least one back seat airbag collapsed in neutral position and the at least one gas generator are arranged and fixed in the rear of a front seat backseat and adjustable together with the latter. The back seat airbag is so fashioned, and an airbag exit opening is so directed upon the back seat occupant that the fired back seat airbag is expandable towards the chest and head of the back seat occupant.
[0004] Concretely for this purpose, in a rearward region of the front seat backrest, an opening is provided into which a supporting plate is fitted, firmly connected to lateral backrest frame parts by way of a lateral attachment flange. On this supporting plate, the gas generator is arranged and held together with the airbag. The backrest frame parts are swingably articulated to the seat structure to make possible an adjustment of the inclination of the backrest. The swing articulations are designed and dimensioned so strong that forces can be absorbed and transmitted by them. In addition, a swinging flap is provided, swingably articulated to the supporting plate and, in neutral position with safety device not activated, closing the openings in the front seat backrest and accordingly covering the supporting plate, including gas generator and airbag. In event of activation of the safety device, the swinging flap is swung by the inflating airbag into an open position, so that the airbag can unfold towards the head and chest in front of the back seat occupant. The swinging flap is at the same time held in a certain swing position by retaining bands. A disadvantage of this construction is that seat comfort is considerably reduced by the arrangement of numerous hard parts in the backrest, because under load they will press through the backrest of the front seat. Besides, such a construction is evidently elaborate and hence expensive, so that in practical use, such a device is less adapted to the purpose upon the whole.
[0005] U.S. Pat. No. 5,324,071 discloses a safety device for a motor vehicle in which an airbag module comprising a gas generator is fixed, not to the vehicle seat but, independently of the vehicle seat, to a framework fixed to the floor. This framework is fixed to the floor by way of a slide rail stationary relative to the floor, the seat being adjustable relative to the framework and hence relative to the airbag module fixed to the framework. The airbag module is here configured as a bead-supporting airbag module, and can be accommodated in a receptacle at the back of the headrest in certain adjusted positions of the vehicle seat only. What this is supposed to accomplish is that the distance of the headrest airbag from the back seat occupant region behind it is always the same.
[0006] U.S. Pat. No. 5,782,529 discloses a safety device on a vehicle seat in which an inflatable airbag is integrated into the backrest, and upon activation of the safety device, it inflates inside the backrest and therefore can furnish an impact protection for the user of the seat in question. Part of this airbag may also be so constructed inside the backrest that it provides protection for the knee region of a rear occupant seated behind. A gas generator is here merely represented schematically in the seat portion. No inflatable back seat airbag inflatable towards the head and chest of a rear occupant sitting behind the front seat is provided.
[0007] French Patent 2,131,475 A discloses a vehicle seat around which a supporting framework is arranged for attachment of parts such as for example safety devices. Such a construction, especially in crash situations, constitutes a considerable potential hazard to the vehicle occupants, in particular those seated behind the vehicle seat in question, and is therefore impracticable. Besides, such a framework is not unattractive.
[0008] Japanese Patent Publication 04 166,455 discloses a construction of a safety device for a motor vehicle, in which an airbag module is arranged in an upper rear portion of a front seat backrest. By way of a control means, the inclination of the front seat backrest can be adjusted relative to the back seat occupant seated on the corresponding back seat.
[0009] Thus a problem underlying all of these arrangements consists in mounting the airbags, and particularly the gas generators, at locations in the vehicle where the requisite space is available, without poor appearance, and providing a favorable position of an airbag deployment opening from the point of safety engineering, together with a practicable airbag framework.
[0010] The object of the invention is to propose a suitable installation for a rear seat airbag device this is simple and inexpensive to produce.
SUMMARY OF THE INVENTION
[0011] In accordance with the invention, a rear seat airbag device includes an airbag arranged in an airbag housing which is mounted to the rear portion of a front seat. The housing has an airbag deployment opening directed to deploy the airbag toward the head and chest of a rear seat occupant.
[0012] Advantageously, the gas generator of the airbag apparatus may be connected to the seat underframe in an especially stable manner, without need to provide costly measures for this purpose. This means that the seat underframe may thus be employed in an advantageous twofold function for stable attachment of the at least one gas generator and at the same time of an airbag housing module as a whole. This contributes considerably to the functional dependability of the safety device over all. A rigid fixation by way of a carrier, or a direct fixation of the gas generator to the seat underframe in the rear area of the front seat part is further favorable in that the structural space there available is otherwise unused. In addition, seat comfort is not impaired by such an arrangement, since the rear area of the front seat regularly lies beneath the under side of the backrest and therefore is in any event not loaded by a front seat occupant.
[0013] With the back seat airbag arrangement in the rear area of the front seat, directly in front of a back seat occupant, a rapid and direct deployment of the back seat airbag in a region of potential impact on a back seat occupant can be achieved.
[0014] In one embodiment, the airbag module consists of a back seat airbag and the at least one gas generator is arranged in the rear area of the front seat, preferably in or on the underframe, and integrated with an airbag deployment opening directed obliquely to the rear and upward. The back seat airbag may include a flat and narrow lower portion that deploys in a first stage along the front seat backrest upward without colliding with the feet or knees of a back seat occupant. Then in a second phase, a voluminous upper portion of the back seat airbag unfolds in front of the back seat occupant in the chest and head direction. Thus, the filled back seat airbag has a flat and narrow configuration in the lower region and a voluminous configuration in the upper region. Such an embodiment, with good protective function, may be economically installed. The airbag deployment opening may alternatively be formed in the case of a crash only, in that the expanding airbag rips along a seam of a cover closing the airbag deployment opening and integrated in the front seat part, thus clearing the airbag deployment opening.
[0015] In another embodiment, a gas generator is integrated in the rear area of the front seat part, preferably in the seat underframe. The housing includes a cover behind the front seat backrest and resting in contact therewith, wherein the cover is capable of being forced away from the rear surface of the front seat backrest to form a passage. Between the rear surface of the front seat backrest and the cover is located a back seat airbag area in the uninflated condition, connected to the gas generator and partly unfolded. In the case of an activation of the back seat airbag due to a crash, the airbag forces the covering by pressure build-up in a first phase to form a cushion which also acts as passage. Through this passage, the upper portion of the back seat airbag is then deployed out in front of the back seat occupant in chest and head direction.
[0016] Preferably, the cover extends as a plate-like part from the front seat underframe upward about to a middle portion of the front seat backrest. Thus the cover in combination with the airbag part filled in the passage may advantageously configure a knee cushion as knee airbag for the remaining protective function of the back seat airbag.
[0017] In a preferred embodiment, the cover is swingably articulated to the front seat underframe and spring-loaded towards the rear surface of the front seat backrest. By such a swingable and spring-loaded arrangement, the cover advantageously moves in contact with the front seat backrest at its various adjustments of inclination. An accompanying motion of the cover is possible with a swingable mounting of the cover even if the cover is connected to the front seat backrest. Such a connection may for example be made by at least one tear strip, as a weak point intended to fail upon elevation of pressure in the back seat airbag to form the passage, in which case the cover is held by catch strips at a predetermined distance from the front seat backrest. Alternatively, the cover may be articulated to the front seat backrest only.
[0018] In another alternative embodiment, a stirrup is arranged behind the front seat backrest as carrier for the back seat airbag and the gas generator. The stirrup is of inverted U-shaped configuration, with the ends of the side legs of the stirrup being connected to the front seat underframe and/or to a seat rail. The cross-bar of the stirrup thus lies behind the front seat backrest surface, and higher than the front seat part. In the cross-bar of the stirrup, the back seat airbag is accommodated in its uninflated position. The airbag deployment opening is preferably arranged directed obliquely upward and rearward, so that upon activation of the back seat airbag due to a crash, it will be fillable in front of the back seat occupant to be protected in chest and head direction. The gas generator may be arranged in the cross-bar or in the seat underframe, in which case it will be connected to the airbag sack by way of a gas line.
[0019] In a preferred modification of this embodiment, the cross-bar of the stirrup is padded at least in the areas facing the knees of a back seat occupant, thus having the function of a knee cushion.
[0020] In this embodiment also, the stirrup may be swingably articulated to the front seat underframe, possibly with spring prestress, so that the stirrup will be carried along in various settings of the front seat backrest. Possibly also, the stirrup may be fixedly connected to the seat frame or the seat rails, and the backrest be adjusted within a limited region in front of the stirrup. This has the advantage that the stirrup will additionally reinforce the front seat, for example in a rear-end collision.
[0021] The function of the proposed airbag apparatus may be impaired if the front seat backrest is swung very far back in inclination, for example into a reclining position. To prevent such an impairment, it is proposed further that while the vehicle is being operated, an adjustment of the inclination of the front seat backrest be permitted only within a fixed comfort range, without extreme displacements to the rear. A swing of the front seat backrest into a reclining position may be released only when the vehicle is stationary. When starting a vehicle, with a front passenger seat backrest swung into reclining position, an acoustic or visual warning may be given, or the front seat backrest may be automatically erected from the reclining position by means of a mechanical drive. The swing of the front seat backrest may also be limited only in the event that there is an occupant sitting in the back seat. The back seat airbag may likewise, be arranged to deploy only if the corresponding rear seat is occupied.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 shows a schematic representation of a first embodiment of an airbag device for a motor vehicle, in which an airbag module is arranged in a rear area of a front seat.
[0023] [0023]FIG. 2 shows a schematic representation of a second embodiment of an airbag device for a motor vehicle, having a back seat airbag capable of being unfolded by way of a passage.
[0024] [0024]FIG. 3 shows a schematic representation of a third embodiment of an airbag device for a motor vehicle, having a stirrup as carrier for the back seat airbag and the gas generator.
DESCRIPTION OF THE INVENTION
[0025] [0025]FIG. 1 shows a rear seat airbag device 9 mounted on front seat assembly 1 . Front seat assembly 1 , shown in a normal sitting position in FIG. 1, comprises a front seat part 2 having a swingable front seat backrest 3 with headrest 4 . The front seat assembly 1 is arranged in front of a back seat for back seat occupants.
[0026] In the rear area of the front seat part 2 , outside of the sitting area of the front seat occupant, an airbag having 5 is integrated in the seat underframe. The airbag module 5 comprises a back seat airbag 6 in collapsed deflated condition and an associated gas generator 7 . An airbag deployment opening 8 is directed obliquely rearward and upward.
[0027] As shown dotted in FIG. 1, the back seat airbag 6 is so constructed that in the event of a crash, in a first phase, a lower portion 30 will unfold in an area behind and along the front seat backrest 3 upward. In a second phase, an upper portion 31 will deploy in chest and head direction in front of the back seat occupant. The back seat airbag 6 in filled condition is thus flat and narrow in the lower region 30 and voluminous in the upper region 31 .
[0028] [0028]FIG. 2 schematically shows a second embodiment of a rear seat airbag device 10 for a motor vehicle, on a front seat assembly 11 . In this airbag device 10 , a gas generator 12 is integrated in the rear area of a front seat 13 in the seat underframe.
[0029] Behind a backrest 14 of the front seat assembly 11 , a cover 15 is arranged, extending upward as a plate-like part of the front seat underframe, as far as the middle of the front seat backrest height. The cover 15 is swingably articulated to the front seat underframe, and in the deflated position indicated by solid lines in FIG. 2, the cover 15 follows the contour of the rear surface 16 of the front seat backrest.
[0030] Between the rear surface 16 of the front seat backrest and the cover 15 , in the uninflated condition, indicated by solid lines in FIG. 2, lies a partly deployed portion 17 of a back seat airbag 18 connected to the gas generator 12 .
[0031] Upon activation of the back seat airbag 18 due to a crash, in a first phase it controllably pushes the cover 15 rearward, forming a passage and a flat knee cushion as knee airbag 32 , as indicated by dotted lines in the representation of FIG. 2. In a second phase, the upper portion 33 of back seat airbag 18 unfolds in chest and head direction in front of a back seat occupant, as likewise indicated by dotted lines in FIG. 2.
[0032] [0032]FIG. 3 schematically shows a third embodiment of a rear seat airbag device 19 . In the case of this airbag device 19 , behind a backrest 20 of a front seat assembly 21 , a stirrup 22 is mounted as carrier for a back seat airbag 23 and a gas generator 24 connected to the back seat airbag 23 .
[0033] The stirrup 22 is of inverted U-shaped configuration, and connected by the ends of the lateral legs 25 , 26 of the stirrup to a front seat underframe. The stirrup 22 is swingably or fixedly articulated to the front seat underframe.
[0034] The stirrup 22 further comprises a stirrup cross-bar 27 extending more or less at the middle height of the front seat backrest 20 in the area of its rear surface 28 .
[0035] As may be seen further in the schematic representation of FIG. 3, the cross-bar 27 of the stirrup is finished to function as a knee cushion with a pad 29 facing the knees of a back seat occupant. The stirrup 22 and the cross-bar 27 are so arranged as to form an airbag deployment opening 30 directed obliquely upward and rearward.
[0036] Upon activation of the back seat airbag 23 due to a crash, it is unfolded in chest and head direction in front of a back seat occupant, as indicated by dotted lines 34 in the representation of FIG. 3.
[0037] To prevent the functioning of the safety devices 9 , 10 and 19 represented in FIGS. 1 to 3 from being impaired by a front seat backrest 3 , 14 and 20 in a reclined position, visual or acoustic warnings may be provided. Alternatively, inclination adjustment of the front seat backrest 3 , 14 , 20 may be limited to a fixed comfort range only when the vehicle is in operation or when the rear seat is unoccupied. Full reclining maybe permitted only when the vehicle is not being operated or when the rear seat is vacant.
[0038] While there have been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further changes can be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention. | A rear seat airbag device is arranged with an airbag housing mounted to a rear portion of a front seat of a vehicle. The housing has an airbag deployment opening which deploys the airbag upwardly and toward the head and chest portion of a rear seat occupant. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a neodymium-based (Nd-based) two-phase separation amorphous alloy, and more particularly, to a Nd-based two-phase separation amorphous alloy by adding an element having a big difference in heat of mixing in a Nd-based alloy with excellent glass forming ability through an inherent characteristic of compositional elements and consideration of thermodynamics, at the time of forming amorphous phase, to thereby obtain a two-phase separation amorphous alloy during solidification.
[0003] 2. Description of the Related Art
[0004] Amorphous metal can be defined as the atomic positions of the liquid phase are conceptually stopped in view of the structural analysis. Researches on the structural analysis of initial amorphous metal materials have been performed through Roentgen rays or electron diffraction based on a controversy whether the structure of the initial amorphous metal materials are amorphous or crystalline, but the research on the property of materials have not been performed. After 1970, Masumoto and Maddin have succeeded in manufacturing the uniform amorphous ribbon shape with a centrifugal quenching method. Accordingly, measurement about the property of the amorphous material has been facilitated. Since the different magnetic, electric, and mechanical properties are contained in the amorphous materials, in comparison with the conventional metal material, it has been reported that the amorphous materials are the dream metal, to thereby draw the attention of world wide metal and property researchers.
[0005] The most important one in the property of the amorphous alloy is the magnetism. The amorphous alloy has been currently developed as practical soft magnetic materials. The reasons why the amorphous alloy is suitable for the magnetic material are as follows.
[0006] 1) The smaller the crystal magnetic anisotropy constant (K) and magnetism negative constant (λ) may be, the better the magnetic material, may be. It is ideally best that they become all zero. In the case of crystalline materials, Sendust (one of Fe—Al—Si alloys), and Permalloy (one of Fe—Ni alloys) are famous since the values of the crystal magnetic anisotropy constant (K) and magnetism negative constant (λ) are small. However, the composition having the values of zero in these alloys exists as only a point. However, since the amorphous composition meets λ≈0, the group of the composition of λ≈0 has a high-permeability and low iron loss characteristic
[0007] 2) Since the amorphous material is intrinsically of a big electric resistance, the low iron loss can be easily obtained.
[0008] 3) Since the amorphous material can be made into thin ribbons of 20-30 μm, the low iron loss can be easily obtained.
[0009] Research and development on the amorphous materials proceed in the field of the following applications, due to the above-described magnetic property.
[0010] a. iron cores of a transformer using a high saturation magnetic flux density, and low iron loss (Fe—B—C or Fe—Si—B alloy)
[0011] b. Co-based amorphous alloy (Fe-95Co, Fe—Ni—Co, (Co, Fe)—B—Si) for making a magnetic head, and a magnetic portion for controlling a magnetic core of a switching power supply be near to zero (0)
[0012] c. Products including magnetic heads for video cassette recorders (VCR) having many advantages including a high-permeability, a less hysteresis loss, a high electric resistance to thereby cause a low overcurrent loss and an excellent high frequency property, and a high intensity to thereby cause an excellent abrasion resistance
[0013] One of the currently developed Nd-based amorphous alloys is a Nd—Fe—B material which is used as a hyper-strong magnet in 1980's. It is known that a very high coercive force can be obtained in a Nd—Fe alloy which has been rapidly cooled. The Nd—Fe alloy has the advantage having the magnetic property which is more excellent than a Sm—Co magnetic material in the room temperature and a price competitive power since the raw material is inexpensive. However, the general chemical composition is near to a Fe-rich composition of Nd 15 Fe 77 B 8 . Moreover, The Nd—Fe alloy has the disadvantage that the magnetic property is drastically lowered according to an increase in the temperature. Thereafter, the alloy of the Nd—Al-TM (TM=transition metal) has been reported. Nd—Al—Fe ternary alloys are under the active research on applications as the ferromagnetic materials (Materials Science and Engineering A Volumes 226-228, 15 Jun. 1997, Pages 393-396).
[0014] Particularly, in the case of the conventional Nd-based amorphous alloys as described above, there have been the efforts of controlling alloying elements or a cooling speed for the application of the magnetic material to thereby improve a magnetic property through nano-crystallizing of the whole or the part thereof (Journal of Magnetism and Magnetic Materials Volume 261, Issues 1-2, April 2003, Pages 122-130; Journal of Magnetism and Magnetic Materials Volumes 290-291, Part 2, April 2005, Pages 1214-1216; and Materials Science and Engineering A Volume 385, Issues 1-2, 15 Nov. 2004, Pages 38-43). Here, the nano-crystalline structure in the material suppresses movement of domain walls efficiently, to thereby increase a coercive force and magnetic susceptibility. Demagnetization has a positive effect on a magnetic property through a pinning effect that a corresponding external magnetic field is required. However, the form of precipitate is being limited to a crystal phase through crystallization of the material inside. So far, there have been no reports that the magnetic property can be improved by forming an amorphous phase of a second phase.
[0015] In the meantime, in the case of the currently developed two-phase separation amorphous alloys, there have been reports that a phase separation phenomenon is found only in the limited compositional range of Zr—La—Al—Cu—Ni, Y—Ti—Al—Co and Ni—Nb—Y based alloys through a rapid solidification process using a melt spinning process. As a result, while the two-phase separation amorphous alloy needs a higher cooling speed in comparison with a single-phase amorphous alloy. This means that the compositional range of alloy for obtaining amorphous microstructure is limited.
SUMMARY Of THE INVENTION
[0016] To solve the above problems, it is an object of the present invention to provide a Nd-based two-phase separation amorphous alloy in which elements having a big difference of heat of mixing are added in a Nd-based bulk amorphous alloy composition which has been reported to have an excellent glass forming ability through an inherent characteristic of compositional elements and consideration of thermodynamics, to thereby enable two-phase separation amorphous alloy during solidification, and the two-phase separated amorphous phase shows up a conspicuously separated crystallization behavior according to an inherent crystallization temperature difference of main elements, respectively, with a result that 1) manufacturing of the composite material is facilitated through nano-crystallization, 2) a multi-stage forming can be performed in a supercooled liquid region corresponding to the amorphous phase, respectively, and 3) a magnetic property can be improved by the amorphous phase of the second phase, or the nano-phase which can be easily formed through a thermal process.
[0017] To accomplish the above object of the present invention, there is provided a A Nd-based two-phase separation amorphous alloy which is represented as a general equation Nd 100-a-b (TM) a (D) b , wherein TM is transition metals which are one combination selected from A-B, A-C and B-C when an element group of A consists of Y, Ti, Zr, La, Pr, Gd and Hf, an element group of B consists of Fe and Mn, and an element group of C consists of Co, Ni, Cu and Ag, wherein the content of the element group which constitutes each combination is five atomic weight % or greater, and the element selected from each group is at least one, and wherein D is at least one selected from the group consisting of Al, B, Si and P, and a and b have the range of 20≦a≦80, and 5≦b≦30, respectively, in terms of atomic weight %.
[0018] In more detail, an equilibrium condition is generally determined by free energy calculation through thermodynamics consideration in the respective states of the metal materials. Particularly, mixing of two elements having a positive heat of mixing relationship forms an immiscibility gap which is an immiscible area between the two elements so that two solid solutions can be stabilized in a specific composition range.
[0019] Based on this fact, the present invention has made every effort in order to manufacture a neodymium (Nd)-based two-phase amorphous alloy. As a result, a Nd-TM group (TM is a transition element) is formed in which a base element is an element of Nd, a group of A consists of transition elements such as Y, Ti, Zr, La, Pr, Gd, and Hf having a positive heat of mixing relationship with respect to Nd, a group of B consists of transition elements such as Fe and Mn having an excellent glass forming ability together with a high crystallization temperature in a Nd-based amorphous alloy, and a group of C consists of transition elements such as Co, Ni, Cu, and Ag having a negative heat of mixing relationship with respect to Nd. Here, the two-phase separation amorphous alloy can be obtained during solidification by a positive heat of mixing relationship between Nd and the element of the A group in the TM, or between the element of B and the element of C group in the TM.
[0020] For this, the element of TM consists necessarily of any one selected from a combination of an element group among A-B, A-C and B-C, when a group of A consists of a group of elements such as Y, Ti, Zr, La, Pr, Gd and Hf having a positive heat of mixing relationship with respect to Nd, a group of B consists of transition elements such as Fe and Mn enhancing the glass forming ability and increasing the crystallization temperature in a Nd-based amorphous alloy, and a group of C consists of transition elements such as Co, Ni, Cu, and Ag having a negative heat of mixing relationship with respect to Nd, so as to match the purport of the present invention.
[0021] Furthermore, the semi-metal and non-metal elements which are known to contribute to improve the glass forming ability in the Nd-based amorphous alloy are classified as a group of D such as Al, B, Si, and P, to thereby have an excellent glass forming ability after the two-phase separation.
[0022] In the present invention, a heat of mixing relationship of an element pair which forms an immiscible area is as follows.
[0023] <Nd-A Group>
[0024] Nd—(Y or Gd): 0 KJ/mole, Nd—Ti: 17 KJ/mole, Nd—Zr: 10 KJ/mole, Nd—Hf: 13 KJ/mole, Nd—La: 0 KJ/mole, Nd—Pr: 0 KJ/mole
[0025] <B-C Group>
[0026] Fe—Co: −1 KJ/mole, Fe—Ni: −2 KJ/mole, Fe—Cu: 13 KJ/mole, Fe—Ag: 28 KJ/mole
[0027] Mn—Co: −2 KJ/mole, Mn—Ni: −4 KJ/mole, Mn—Cu: 4 KJ/mole, Mn—Ag: 13 KJ/mole
[0028] In the present invention, because TM gets to deviate from a eutectic composition with Nd in the case that TM is added to Nd by less than 20% or in excess of 80% in units of atomic weight %, the glass forming ability is decreased. Particularly, in the case that the elements of the A group, B group, and C group of TM are added by less than five atomic weight %, it is thermodynamically imperfect to form an miscibility gap which is an immiscible area between the element groups which have the positive heat of mixing relationship.
[0029] In order to perform the two-phase separation amorphous alloy, the glass forming ability becomes an important factor in addition to the two-phase separation of the main elements. Therefore, the elements of the D group have been selected considering the empirical formula for improving the glass forming ability (1) a multi-component system of a ternary component or greater, (2) a big difference of 12% or greater between compositional elements, (3) a composition of elements having a negative heat of mixing, and (4) the condition of the deep eutectic composition neighborhood. Here, in the case of the D group elements are added by less than five atomic weight %, this violates a confusion theory which is the glass forming ability improvement concept through the multi-component system of the empirical formula. In the case that the D group elements are added in excess of thirty atomic weight %, a big change is induced in the amorphous formation combination consisting of Nd-TM-D to rather drastically reduce the glass forming ability.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiment thereof in more detail with reference to the accompanying drawings in which:
[0031] FIGS. 1A and 1B are graphical views illustrating differential thermal analysis results and X-ray diffraction analysis results with respect to a two-phase separation amorphous alloy of Nd 25 Zr 35 Co 30 Al 10 according to the present invention, respectively;
[0032] FIG. 2 is a photographical view illustrating transmission electron microscope analysis results with respect to a two-phase separation amorphous alloy of Nd 25 Zr 35 Co 30 Al 10 according to the present invention;
[0033] FIG. 3 is a graphical view illustrating differential thermal analysis results with respect to alloys of Nd—Fe—X—Al according to the present invention;
[0034] FIG. 4 is a photographical view illustrating transmission electron microscope analysis results with respect to a two-phase separation amorphous alloy of Nd 30 Ti 30 Co 30 Al 10 after having undergone selective nano-crystallization through a thermal process according to the present invention;
[0035] FIG. 5 is a graphical view illustrating height variation measurement results of a specimen according to temperature using a thermo-mechanical analyzer (TMA) with respect to an alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention;
[0036] FIG. 6 is a graphical view illustrating results which is obtained by measuring a magnetic field versus magnetization behavior according to temperature using a vibrating sample magnetometer (VSM) with respect to an alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] A neodymium-based (Nd-based) two-phase separation amorphous alloy according to preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
[0038] (Manufacturing of a Specimen)
[0039] 1. Manufacturing of a Mother Alloy
[0040] In order to obtain a mother alloy of a desired alloy composition in the present invention, Nd which has a purity of 99.8%-99.99%, and elements selected from a group of A such as Y, Ti, Zr, La, Pr, Gd, and Hf, a group of B such as Fe and Mn, a group of C such as Co, Ni, Cu, and Ag, and a group of D such as Al, B, Si, and P elements have been arc-melted under a high purity argon gas atmosphere of 99.99%. Moreover, in order to remove any segregation of the alloy component during the arc-melting, a sample has been repeatedly melted three times while inverting.
[0041] 2. Manufacturing of a Specimen Using a Melt Spinning Method
[0042] The prepared mother alloy has been manufactured into a specimen of a ribbon-shape by using a melt spinning method whose cooling rate is 10 4 -10 6 K/s.
[0043] Concretely, the mother alloy has been firstly charged into a quartz tube. Then, the mother alloy has been melted to liquid state under the argon atmosphere of 7-9 KPa with a microwave induction heating after having maintained a degree of vacuum in a chamber into about 10 −4 Torr. Here, the molten metal is being maintained by a surface tension in the quartz tube. Then, the quartz tube has rapidly fallen before the reaction of the quartz tube has occurred after the mother alloy has been completely melted, and simultaneously the argon gas of about 50 KPa has been injected into the quartz tube. Accordingly, the molten metal is melt-spinned on the Cu roll surface (wheel surface velocity: about 40 m/s) which rotates at a high speed, to thereby manufacture a ribbon-shaped specimen of the thickness of about 30 μm and the width of about 2 mm.
[0044] 3. Manufacturing of a Specimen Using an Injection Casting Method
[0045] In the present invention, the mother alloy has been manufactured into a bulk specimen through an injection casting method while changing a cooling speed by using a copper mold of various diameters. The high purity argon gas is charged at the high vacuum state. The mother alloy has been melted with a high frequency induction under the argon atmosphere. Then, the melted mother alloy has been charged a water-cooled copper mold through a certain fixed injection pressure, to thereby manufacture a rod-shaped specimen of a fixed length of 50 mm.
[0046] The analysis of the amorphous alloy composition according to the present invention is as follows.
[0047] (Specimen Analysis)
[0048] 1. Transmission Electron Microscope Analysis
[0049] The transmission electron microscope (TEM) analysis has been conducted in order to observe the phase separation phenomenon of a bulk amorphous alloy. The specimen manufactured using an injection casting has been mechanically grinded and prepared by ion milling method. An angle between an ion beam and a specimen surface has been polished while changing into 4-8° by using the ion milling method.
[0050] Under the same condition as the above-described condition, a bright field image (BF image) and a limit viewing direction selected area diffraction pattern (SADP) has been obtained at the acceleration voltage of 200 kV using JEM 2000EX.
[0051] 2. Differential Thermal Analysis
[0052] In general, in order to estimate thermodynamic properties which relate to a glass transition temperature (Tg) of an amorphous phase, and a crystallization temperature (Tc), a differential scanning calorimetry (Perkin Elmer, DSC7) has been used.
[0053] In this experiment, a sample has been put into a copper fan, and then put in a platinum holder. Then, an empty pan has been put into a reference. The thermodynamic properties have been measured under the high purity argon atmosphere of 99.999% at the temperature range of 373-953 K in order to prevent the oxidation of the specimen. The DSC analysis has been performed under the 99.99% purity argon atmosphere after having charged a sample of about 20 mg at a constant temperature-up rate of 40 K/min(0.667 K/s).
[0054] 3. X-Ray Diffraction Analysis
[0055] In order to identify whether the manufactured specimen has an amorphous phase, an X-ray diffractometry (M18XHF 22 -SRA, monochromatic Cu K radiation) has been used to irradiate X-rays onto the specimen. The X-ray diffraction analysis has been performed with the condition of a tube voltage of 50 kV and current of 200 mA of a Cu target (λ=1.5406, Ka 1 ray). X-ray diffraction spectrum has been obtained within the range of a scanning range of 20°-80° with a sequential scanning method, at the speed of 4°/min while maintaining 0.02° interval.
[0056] In general, in the case of an amorphous specimen, a broad diffraction pattern with no crystalline picks has been obtained in the X-ray diffraction analysis. Differently from the general amorphous alloy, the diffraction patterns regarding the two amorphous phases have been overlapped in the two-phase amorphous alloy. As a result, it can be confirmed that the present invention has a relatively wider diffraction angle region.
[0057] 4. TMA Analysis
[0058] In a supercooled liquid region, TMA (TMA-7, Perkin-Elmer) has been used in order to measure viscosity of the amorphous alloy. By using a specimen of a rod-shape and a ribbon-shape, a certain compressive load is applied by a ceramic probe whose diameter is 3 mm at a compressed mode, and then a change in length of a specimen has been measured while increasing the temperature. Correction for temperature has been performed using In and Zn specimens before all the experiments. The experiment has been progressed under the Ar atmosphere.
[0059] 5. VSM (Vibrating Sample Magnetometer) Analysis
[0060] A macroscopic magnetism change has been measured according to temperature in the form of a ribbon or powder with respect to the two-phase amorphous alloy according to the invention using a VSM (Vibrating Sample Magnetometer). A change in a magnetic property (or magnetization) according to temperature has been measured with a magnetic force of 2 tesla at maximum and at the range of the temperature of 10 K to 300 K.
[0000]
TABLE 1
(Unit: Kelvin Temp.)
Manufacturing/
Items
Composition (at %)
T g 1
T x 1
T g 2
T x 2
form
Examples
1
Nd 25 Zr 35 Co 30 Al 10
468
488
671
719
M/DA
2
Nd 30 Zr 25 Hf 5 Co 30 Al 10
477
501
667
712
M/DA
3
Nd 50 Ti 10 Co 30 Al 10
496
519
562
587
M/DA
4
Nd 15 Y 40 Co 25 Al 20
598
646
810
848
M/DA
5
Nd 30 La 30 Co 30 Al 10
462
498
554
586
M/DA
6
Nd 30 Ti 30 Fe 30 Al 10
470
498
705
727
M/DA
7
Nd 30 Gd 30 Fe 30 Al 10
472
508
823
857
M/DA
8
Nd 50 Mn 20 Co 15 Al 15
534
562
682
715
M/DA
9
Nd 50 Fe 10 Co 25 Al 15
528
570
752
782
I/DA
10
Nd 50 Fe 5 Co 30 Al 12 B 3
527
560
769
789
I/DA
11
Nd 57 Fe 10 Co 15 Al 15 Si 3
478
507
688
727
M/DA
12
Nd 60 Fe 10 Ni 15 Al 15
471
499
717
762
I/DA
13
Nd 50 Fe 5 Ni 30 Al 12 P 3
530
561
752
766
M/DA
14
Nd 50 Fe 20 Ag 15 Al 15
492
522
716
784
I/DA
15
Nd 50 Fe 10 Ag 20 Cu 5 Al 15
499
524
735
758
M/DA
Comparative
1
Nd 60 Fe 30 Al 10
—
—
712
797
M/SA
Examples
2
Nd 70 Fe 10 Co 5 Al 15
—
—
—
734
M/Comp.
3
Nd 10 Fe 75 Co 7 B 8
—
—
—
870
M/Comp.
4
Nd 56 Zr 4 Co 30 Al 10
496
521
—
—
M/SA
5
Nd 30 V 30 Fe 30 Al 10
—
—
732
776
M/Comp.
6
Nd 30 Nb 30 Co 30 Al 10
—
—
—
—
M/Cryst.
7
Nd 60 Fe 15 Mn 15 Al 10
—
—
—
—
M/Cryst.
8
Nd 50 Ni 20 Cu 15 Al 15
503
542
—
—
M/SA
9
Nd 50 Fe 20 Zn 15 Al 15
—
—
—
—
M/Cryst.
10
Nd 65 Mn 17 Co 15 Si 3
—
—
—
—
M/Cryst.
11
Nd 40 Mn 15 Cu 10 Al 35
—
—
—
—
M/Cryst.
12
Nd 25 Zr 35 Co 30 C 10
—
—
—
—
M/Cryst.
[0061] Here, M=Melt spinning method, I.=Injection casting method, SA=single amorphous state, DA=two-phase amorphous state, Cryst.=crystallization, and Comp.=SA+Cryst.
[0062] As can be seen from Table 1, the alloys according to the present invention have two-phase separation amorphous microstructure (DA) during solidification. The glass forming ability of the two-phase separation amorphous alloy depends on cooling rates greater than that of the single amorphous alloy. However, in the case of the Nd—Fe—Co—Al group, the Nd—Fe—Ni—Al group, and the Nd—Fe—Ag—Al group amorphous alloy according to the present invention, the two-phase amorphous can be obtained through an injection casting method having a relatively small cooling rate of about 10-100 K/S.
[0063] In Comparative Example 1, only the element of the B group among the TM is selected. This violates the present invention requirement that at least two groups should be selected among the TM. The immiscible area is not formed due to the absence of the elements which has a positive heat of mixing. Thus, the Comparative Example 1 shows an example in which the amorphous alloy of the simple Nd-based single phase is formed.
[0064] In Comparative Example 2, the elements of TM are added by less than 20 wt %. In this case, the TM gets to deviate from a eutectic composition with Nd. Then, the glass forming ability of this alloy is reduced. As a result, a complete amorphous phase is not obtained even through a rapid solidification process.
[0065] In Comparative Example 3, the elements of TM are added in excess of 80 wt %. The TM element (Fe) becomes a main component in this composition. Accordingly, the TM gets to deviate from a eutectic composition in a combination of Nd-TM-(D group), to thereby greatly reduce the glass forming ability. As a result, a complete amorphous phase is not obtained even through a rapid solidification process.
[0066] In Comparative Example 4, the element of the A group among the TM is added by less than 5 wt % which is presented on the basis of a minimum standard. In this case, an element of the A group, Zr is insufficient in quantity to form an immiscible area together with the main element Nd. Thus, the Comparative Example 4 shows an example in which the amorphous alloy of the Nd-based single phase is formed.
[0067] In Comparative Examples 5 and 6, the other elements of V and Nb are added instead of the A group element according to the present invention. In these cases, although they have the positive heat of mixing value of 18 KJ/mole and 32 KJ/mole with respect to Nd, respectively, they have a relatively high melting temperature when the elements of V and Nb are combined with the other compositional elements. Accordingly, the Comparative Examples 5 and 6 violate the empirical formula for amorphous phase formation that they have to have the deep eutectic composition. Thus, the Comparative Examples 5 and 6 show an example that formation of amorphous phase is not facilitated even through a rapid solidification process, respectively.
[0068] In Comparative Example 7, only the element of the B group among the TM is selected. This violates the present invention requirement that at least two groups should be selected among the TM. Thus, the Comparative Example 7 shows an example in which two-phase separation of amorphous are not facilitated even through a rapid solidification process.
[0069] In Comparative Example 8, only the element of the C group among the TM is selected. This violates the present invention requirement that at least two groups should be selected among the TM. Thus, Comparative Example 8 shows an example that the Nd-based single phase of amorphous is made since it has a difficulty in forming an immiscible area.
[0070] In Comparative Example 9, zinc (Zn) which is an element other than those of the present invention is added as an element of TM. The Comparative Example 9 shows an example that amorphous is not achieved even through a rapid solidification since the glass forming ability is very reduced.
[0071] In Comparative Examples 10 and 11, the element of the D group is added by less than 5 wt % or in excess of 30 wt %. These show that the element of the D group which has been added by less than 5 wt % or in excess of 30 wt % plays a negative role in a correlation between the existing elements and thus amorphous is not achieved even through a rapid solidification since the glass forming ability is abruptly reduced.
[0072] In Comparative Example 12, a semi-metal or non-metal element different from the D group elements is added. Accordingly, when carbon (C) is added, the Comparative Example 12 violates the empirical formula for enhancing glass forming ability glass forming ability in the Nd-based alloy. Thus, the Comparative Example 12 shows an example that amorphous is not obtained even through a rapid solidification process.
[0073] Hereinbelow, a Nd-based two-phase separation amorphous alloy according to the present invention will be described in more detail with reference to the accompanying drawings.
[0074] FIGS. 1A and 1B are graphical views illustrating differential thermal analysis results and X-ray diffraction analysis results with respect to a two-phase separation amorphous alloy of Nd 25 Zr 35 Co 30 Al 10 according to the present invention, respectively. As can be seen from FIG. 1A , the two-phase separation amorphous alloy of the present invention shows a crystallization behavior conspicuously separated by the difference in the crystallization temperature range of main elements with a positive heat of mixing relationship. Moreover, as can be seen from FIG. 1B , the two-phase separation amorphous alloy of the present invention shows a typical amorphous halo pattern in an inherent two-theta (20) section which has been determined by the inherent atom radius of main elements whose two phases have been separated by a positive heat of mixing relationship from an X-ray diffraction analysis result. As a result, a diffraction pattern which two halo patterns have been overlapped can be obtained.
[0075] FIG. 2 is a photographical view illustrating transmission electron microscope analysis results with respect to a two-phase separation amorphous alloy of Nd 25 Zr 35 Co 30 Al 10 according to the present invention. As can be seen from FIG. 2 , in the case of a two-phase separation amorphous alloy of Nd 25 Zr 35 Co 30 Al 10 according to the present invention, two halo rings which are separated by the atom radius difference of a respectively separated amorphous main element are obtained similarly to the X-ray diffraction analysis results. The shape of amorphous phases obtained in this two-phase separation alloy of Nd 25 Zr 35 Co 30 Al 10 is indistinguishable through a Bright Field Image due to a similar density value of the separated amorphous phase, but definitively distinguishable through a Dark Field Image.
[0076] FIG. 3 is a graphical view illustrating differential thermal analysis results with respect to alloys of Nd—Fe—X—Al according to the present invention. As can be seen from FIG. 3 , it can be confirmed that a crystallization behavior for each separated ally occurs in two divided temperature ranges by a positive heat of mixing relationship. In this way, the alloy composition having the separated crystallization behavior has a supercooled liquid region of a certain temperature area showing a super plasticity behavior before the crystallization behavior, respectively.
[0077] FIG. 4 is a photographical view illustrating transmission electron microscope analysis results of a sample which has undergone a thermal process up to 600 K, with respect to a two-phase separation amorphous alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention. As can be seen from FIG. 4 , in the case that the two-phase separation alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention is thermally treated up to 600 K, it can be confirmed that nano-crystalline phase having particle size of several tens of nano-meters have partially appeared by a first crystallization behavior relating to a Nd-based amorphous phase, and an amorphous phase is maintained for the other regions. That is, it can be confirmed that the crystallized region and the amorphous region have a composite form of a nano-scale. As a result, it is possible to perform a selective crystallization due to the separated crystallization behavior of the two-phase separation amorphous alloy, to thereby manufacture nano-composite materials.
[0078] FIG. 5 is a graphical view illustrating height variation measurement results of a specimen according to temperature using a thermo-mechanical analyzer (TMA) with respect to an alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention. In the case of the alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention, it can be confirmed that a sudden height variation is undergone in a first supercooled liquid region (450-500 K) which relates to the Nd-based amorphous phase. This is the same result as that of the previously known super plastic deformation of the amorphous alloy. However, in the case of the two-phase separation amorphous alloy composition of the present invention, it can be confirmed that a step portion (a sudden height decreasing area according to the temperature increment) which has implied that a second variation is possible in a supercooled liquid region (680-740 K) relating to a second crystallization behavior relating to Zr differently from a single amorphous phase. In the vicinity of about 900 K (that is, at the solidus melting temperature (Ts), a sudden height reduction is initiated in connection with the melting of the Nd-based amorphous alloy.
[0079] FIG. 6 is a graphical view illustrating results which is obtained by measuring a magnetic field versus magnetization behavior according to temperature using a vibrating sample magnetometer (VSM) with respect to an alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention. In the case of the two-phase separation alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention, as shown in FIG. 6 , a spin reorientation temperature in which orientation of spins begins to be changed is about 30 K. That is, in the room temperature, the spins are oriented to an out-of-plane direction. If the temperature gets to fall down to 30 K or less, the spins rotate while forming a cone. As a result, an in-plane component of the spins is generated so that a magnetization value increases in an in-plane direction. This phenomenon is one of the general properties which show up in the magnetic materials. However, in the case of the two-phase separation alloy of the present invention, it can be confirmed that the magnetic property drastically changes from the soft magnetic characteristic to the hard magnetic characteristic, at the spin reorientation temperature due to the presence of a second amorphous phase. This phenomenon is taken into consideration that the two-phase separation alloy of Nd 30 Ti 30 Co 30 Al 10 according to the present invention can be used as a data storage medium etc., since spins are firstly oriented in an in-plane direction at the low temperature, a preference magnetization direction is changed according to a temperature, and a magnetism switching is possible at the time of applications with a little temperature change.
[0080] As described above, a Nd-based alloy which enables two-phase amorphous alloy according to the present invention has the following effects.
[0081] 1) An amorphous alloy composition can be manufactured in an in-situ manner through a thermodynamic access, in which a two-phase amorphous material having an excellent glass forming ability is phase-separated from the amorphous alloy composition and then phase-separated amorphous material exists.
[0082] 2) A phase separation mechanism applied in the amorphous alloy composition according to the present invention, presents standards designing an amorphous material in a new concept differing from previously proposed empirical formulas as well as opposing the general empirical formulas regarding the amorphous formation. Furthermore, two-phase bulk amorphous alloy compositions by the phase separation can be easily developed in the other alloy systems in the future.
[0083] 3) The two-phase separation amorphous alloy according to the present invention exhibits a phase separation having a quite fine connection structure of a nano-scale. Thus, a two-phase separated composition can be selectively nano-crystallized through a selective thermal process or a control of a cooling rate, to thereby easily manufacture an amorphous based nano-composite material.
[0084] 4) The two-phase separation amorphous alloy according to the present invention shows two supercooled liquid regions in respect of both of the two amorphous phases. Accordingly, a multi-stage deformational behavior is available in the supercooled liquid region. In more detail, a supercooled liquid region using the super-plasticity of the amorphous material for the existing micro electro mechanical systems (MEMS), including, the processing of the material through microforming etc., is mainly used, but the two amorphous phases of the invention have the supercooled liquid region separately with respect to the respective amorphous phase in the case of the alloy according to the present invention. It is possible to obtain an amorphous based composite material through a nano-crystallization process by appearance of the second supercooled liquid region, to accordingly be applicable as a new processing method for a nano-composite material.
[0085] 5) In the case of the Nd-based two-phase amorphous alloy according to the present invention, a magnetic property is improved by a nano-phase which can be easily formed through the second amorphous phase or a thermal process of the two-phase amorphous alloy. In this way, a neodymium-based amorphous alloy which enables a nano-structure control has a big potential in view of high value-added industry applications including electric and electronic industries etc., differently from the existing concept for enhancing the magnetic property through nano-crystallization relying upon various kinds of thermal treatments and processes.
[0086] As described above, the present invention has been described with respect to particularly preferred embodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. | Provided is a Nd-based two-phase separation amorphous alloy by adding an element having a big difference in heat of mixing in a Nd-based alloy with a superior amorphous formability through an inherent characteristic of compositional elements and consideration of thermodynamics, at the time of forming amorphous phase, to thereby enable two-phase separation amorphous alloy during solidification. The Nd-based two-phase separation amorphous alloy which is represented as a general equation Nd 100-a-b (TM) a (D) b wherein TM is a transition metal which is a combination of respective one selected from A-B, A-C and B-C when a group of A consists of Y, Ti, Zr, La, Pr, Gd, and Hf, a group of B consists of Fe, and Mn, and a group of C consists of Co, Ni, Cu, and Ag, wherein the content of the element group which constitutes each combination is 5 atomic weight % or greater, and the element selected from each element group is at least one, and wherein D is at least one selected from the group consisting of Al, B, Si and P, and a and b have the range of 20≦a≦80, and 5≦b≦30, respectively, in terms of atomic weight %. | 2 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Patent Application No. 62/233,733, filed on Sep. 28, 2015, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for producing a heating, ventilation, and air conditioning (HVAC) box for a vehicle, and more particularly, to producing a HVAC box for a vehicle using chemical foaming.
BACKGROUND
[0003] There is a continuing effort in the automotive industry to reduce vehicle weight in order to improve vehicle efficiency. Particularly, a trend exists to minimize weight of polymeric components of heating, ventilation, and air-conditioning (HVAC) systems through changes that reduce part thickness and densities.
[0004] One current solution for minimizing the weight of polymeric HVAC components is known as physical foaming. Physical foaming involves entraining a compressed gas, such as Nitrogen, into a molten flow of polymeric material to form a homogenous mixture within the barrel of a molding system. The homogenous mixture is then introduced to a molding chamber and pressure is reduced, thereby allowing the homogenous mixture to nucleate, wherein the compressed gas within the mixture expands to form a suspension of bubbles within the polymeric material.
[0005] However, physical foaming processes involve high capital investment, as specialty molding equipment is required to inject the gas into the polymeric material, and to maintain the molten polymeric material in a highly compressed state prior to introduction into the molding chamber. Once the polymeric material is cooled in the mold, inherent stresses may form within the molded component, leading to deformation and failure over the life cycle of the component.
[0006] Another method for forming foamed polymeric HVAC components involves the blending of hollow glass bubbles into a base resin. The hollow glass bubbles serve to displace the base resin, thereby forming hollow cavities within the material to reduce overall density of the material.
[0007] Unlike physical foaming, hollow glass bubble foaming does not require auxiliary equipment to inject a compressed gas. Thus, conventional molding systems may be utilized. However, the addition of hollow glass spheres to the polymeric material increases overall material costs. Additionally, hollow glass sphere-containing resins are not offered by many suppliers, making sourcing of suitable materials more difficult and costly.
[0008] Yet another known method for producing lighter weight HVAC components involves the blending of alternative filler materials and/or reinforcing agents, or to use less filler materials and/or reinforcing agents in the injection molding resins. For example, one common type of base resin used in injection molding is a polypropylene containing approximately 20% talc as a filler material. However, talc has a higher density than polypropylene, thereby increasing the overall weight of the material. Thus, it may be advantageous to reduce the concentration of talc within the base resin in an effort to minimize overall weight. Alternatively, at least a portion of the talc may be substituted with filler materials having a lower density.
[0009] However, the reduction of the concentration of talc may be undesirable for multiple reasons. Initially, the physical properties of the base resin may be negatively affected by removing or substituting the talc. Additionally, base resin blends having less than 20% talc are not commonly manufactured by suppliers, and costs to obtain these alternative base resins may be prohibitively high.
[0010] In addition to the aforementioned shortcomings in the art, part fit-and-finish and dimensional control is difficult to achieve due to increasingly complex part geometries combined with the desire for reduced wall thicknesses. For example, thinner wall sections make it progressively harder to inject molten material into a mold and achieve even pack pressure. There is also a desire in the art to minimize residual stresses created during cooling and re-crystallization of the thermoplastic, and to prevent the anisotropy of fillers and reinforcing agents.
[0011] Accordingly, there exists a need in the art for an improved means of forming polymeric components of a HVAC system, wherein the process utilizes conventional injection molding equipment, minimizes raw material costs, and minimizes inherent stresses.
SUMMARY OF THE INVENTION
[0012] In concordance with the instant disclosure, an improved process for forming polymeric components of a HVAC system, wherein the process utilizes conventional injection molding equipment, minimizes raw material costs, and minimizes inherent stress is surprisingly discovered.
[0013] In one embodiment, the foaming means involves the introduction of endothermic chemical foaming agent to an injection molding resin prior to molding. The introduction of chemical foaming agent results in molded articles having a reduced weight, reduced cycle times, reduced pressure and energy consumption, and improved dimensional control, thermal insulation, and noise and vibrational damping compared to those of the prior art.
[0014] A method of forming a component of a vehicle HVAC system from a polymeric material includes providing a molding system including at least one mold cavity, including a die configured to form a component of a vehicle HVAC system. A composition including a base resin and a chemical foaming agent is then provided to the mold cavity, wherein a pressure drop within the mold cavity is configured to initiate a nucleation of the foaming agent within the base resin. Nucleation of the chemical foaming agent forms a plurality of gas bubbles, creating a cellular structure within the composition and causing the composition to expand to fill the mold cavity.
[0015] A system for forming a component of a vehicle HVAC system from a polymeric material includes a mold and an injector. The mold includes a mold cavity having a definition corresponding to a profile of an HVAC component. The injector is in fluid communication with the mold cavity. The system further comprises a composition including a base resin and a chemical foaming agent. The injector is configured to heat the composition to a first temperature configured to initiate a decomposition of the chemical foaming agent, and a pressure of the mold cavity is configured to initiate a nucleation of the chemical foaming agent in the composition.
[0016] A component for a vehicle HVAC system includes at least one thin-walled section formed of a polymeric material. The polymeric material is formed of a composition including a base resin and a chemical foaming agent, wherein the thin-walled section of the component has a cellular core and a solidly formed surface layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The FIGURE is a schematic cross-sectional elevational view of an injection molding system for forming HVAC components according to an embodiment of the instant disclosure.
DETAILED DESCRIPTION
[0018] The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
[0019] As shown in the FIGURE, a molding system 2 for carrying out an embodiment of the disclosure is shown. The molding system 2 includes an injector 4 and a mold 6 in fluid communication with each other, wherein the injector 4 is configured to provide a flow of a composition 8 to the mold 6 .
[0020] The injector 4 includes a barrel 10 , a feed system 12 , and a head 14 . The barrel 10 of the injector 4 includes at least one inlet 16 in fluid communication with the feed system 12 , and an outlet 18 in communication with the head 14 . The barrel 10 further includes a screw 20 rotatably disposed therein and configured to convey the composition 8 from the feed system 12 to the head 14 .
[0021] The feed system 12 of the injector 4 is configured to provide the composition 8 to an interior of the barrel 10 through the inlet 16 . In the illustrated embodiment, the feed system 12 includes a plurality of hoppers 22 , 24 for containing a supply of various ingredients 26 , 28 of the composition 8 . As shown, the feed system 12 includes a first hopper 22 and a second hopper 24 , wherein the first hopper 22 contains a volume of a first ingredient 26 and the second hopper 24 contains a volume of a second ingredient 28 . As shown, the first hopper 22 and the second hopper 24 converge in a single mixing chamber 30 configured to blend the first ingredient 26 and the second ingredient 28 in a predetermined proportion to form the composition 8 . As discussed further below, the first ingredient 26 of the composition 8 may be a base resin, and the second ingredient 28 of the composition 8 may be a foaming agent. In alternate embodiments, the feed system 12 may include additional hoppers containing additional ingredients, such as nucleating agents and coloring agents, for example. Alternatively, the feed system 12 may include a single hopper, wherein the composition is mixed prior to provision to the feed system 12 .
[0022] The head 14 of the injector 4 is disposed adjacent the outlet 18 of the barrel 10 , and includes a nozzle 32 configured to convey the composition 8 from the barrel 10 to the mold 6 . The head 14 may further include a shut-off valve 34 disposed therein, and configured to control a flow of the composition 8 into the mold 6 . In one embodiment, the shut-off valve 34 may be a gate-valve system, wherein a plunger 36 is slidingly disposed within the nozzle 32 to selectively control a flow of the composition 8 into the mold 6 . Other types of shut-off valves will be appreciated by those skilled in the art.
[0023] The mold 6 of the molding system 2 is configured to form the composition 8 into one of a plurality of components 38 for a vehicle HVAC system. The mold 6 includes a mold cavity 40 defined by a pair of dies 42 , wherein each of the dies 42 is coupled to a respective platen 44 . As shown, a first one of the platens 44 may be stationary, while a second one of the platens 44 may be moveable between an open position and a closed position to selectively enclose the mold cavity 40 .
[0024] In the illustrated embodiment, a profile of the mold cavity 40 corresponds to a profile of a portion of a housing for a HVAC system. Particularly, the mold cavity includes a series of thin-walled legs corresponding to at least a first sidewall of the housing and a second sidewall of the housing. However, in alternate embodiments, the mold cavity 40 may define flow-control doors, vent panels and grills, actuating hardware, conduits, and other components commonly utilized in the assembly of vehicle HVAC systems.
[0025] The feed system 12 , the barrel 10 , and the dies 42 may each include at least one temperature control unit 46 for maintaining the composition 8 at a predetermined temperature. For example, heating temperature control units 46 may be included in at least one of the hoppers 22 , 24 and/or the mixing chamber 30 , wherein a temperature of the ingredients 26 , 28 of the composition 8 is elevated above a melting temperature of the base resin to facilitate blending of the ingredients 26 , 28 . As shown, the heating temperature control units 46 of the injector 4 are heater bands at least partially circumscribing the barrel 10 of the injector 4 . However, in alternate embodiments, the temperature control units 46 of the injector 4 may include both heating and cooling capabilities.
[0026] Additionally, at least one of the dies 42 of the mold 6 may include both heating temperature control units 46 and cooling temperature control units 46 , wherein the heating temperature control units 46 are used to control decomposition of a chemical foaming agent 28 , as described below, and the cooling temperature control units 46 are used solidify the base resin 26 and to further cool the HVAC component 38 after nucleation is complete, thereby expediting removal of the molded HVAC component 38 from the mold cavity 40 . In the illustrated embodiment, the temperature control units 46 of the mold 6 comprise a plurality of conduits formed integrally with the dies 42 of the mold 6 , wherein a heat transfer fluid is provided from an external source (not shown) to control a temperature of the mold cavity 40 . In one embodiment, a single circuit of conduits is formed in the mold 6 , wherein a single heat transfer fluid is used for heating and cooling of the dies 42 . In alternate embodiments, a first circuit of conduits may be used for a cooling heat transfer fluid and a second circuit of conduits may be used for a heating heat transfer fluid.
[0027] The base resin 26 may be a pelletized or a fluid form of an organic thermoplastic such as polyethylene; ethylene-vinylacetate copolymer; ethylene-ethyleneacrylate; ionomeric polyethylene; polypropylene; polybutene; polymethylpentene; polystyrene; impact-resistant polystyrene; styrene-acrylonitrile copolymer; acrylic-butadienestyrene copolymer; acrylonitrile styrene acrylate; polyvinylcarbazole; polyoxymethylene; polyester; polyamide; polyvinyl chloride; polytrifluoroethylene; polytetrafluoroethylene-perfluoropropylene; polyvinylidene fluoride; ethylene-tetrafluoroethylene copolymer; polymethylmethacrylate; chlorinated polyether; phenoxy resin; polyphenylene oxide; polysulphone; polyethersulphone; polyphenylenesulphide; polyurethane elastomer; cellulose acetate; cellulose propionate; cellulose-acetobutyrate, or a combination thereof. Other thermoplastics or elastomers will be appreciated by those of ordinary skill in the art.
[0028] A passive nucleating agent may also be blended with the base resin 26 to provide a starting point from which gas bubbles begin to grow during formation of foam cells. In one embodiment, the passive nucleating agent is a solid material blended with the base resin. For example, the base resin 26 may include about 20% talc blended therewith. In alternate embodiments an active nucleating agent, such as the chemical foaming agent 28 , may actively serve as the nucleating agent, thereby minimizing or eliminating the need for solid nucleating agents. Using the chemical foaming agent 28 has been discovered to be more efficient, and capable of providing a smaller and more uniform cellular structure than the use of solid nucleating agents.
[0029] The chemical foaming agent 28 , also referred to as a blowing agent, is blended with the base resin 26 . The chemical foaming agent 28 may be provided as an additive to the base resin 26 in powder form, wherein the chemical foaming agent 28 is contained within the second hopper 24 , and blended with the base resin 26 in the mixing chamber 30 of the feed system 12 immediately prior to introduction into the inlet 16 . The chemical foaming agent 28 may be mixed with the base resin 26 using a passive mixing means such as a gravity feed, or an active mixing means such as a screw, for example. Alternately, the base resin 26 may be provided as a master batch in a granular form, wherein the chemical foaming agent 28 is pre-blended with the base resin 26 in a desired proportion. In yet another embodiment, an operator may blend the base resin 26 and the chemical foaming agent 28 prior to provision of the composition 8 to the first hopper 22 .
[0030] The chemical foaming agent 28 is configured to produce a cellular structure within the composition 8 by decomposing within the base resin 26 at a predetermined processing temperature and pressure. The decomposition of the chemical foaming agent 28 brings about the development of a blowing gas within the composition 8 . In one example, the decomposition of the chemical foaming agent 28 may bring about the development of a CO 2 gas. The decomposition of the chemical foaming agent 28 , and subsequent formation of gas bubbles within the composition 8 is often referred to as nucleation.
[0031] The chemical foaming agent 28 may be an endothermic chemical foaming agent. The endothermic chemical foaming agent requires an input of energy to initiate and maintain decomposition. Examples of the endothermic chemical foaming agent include sodium bicarbonate and citric acid. In a particular embodiment, the endothermic chemical foaming agent is based on monoesters and diesters of citric acid. Particularly, it has been surprisingly discovered that a chemical foaming agent 28 formed of a monoester or diester of citric acid having up to 8 carbon atoms performs particularly well in the formation of thin-walled HVAC components. Those of ordinary skill in the art will appreciate that other endothermic chemical foaming agents may also be utilized.
[0032] Alternately, the chemical foaming agent 28 may be an exothermic chemical foaming agent. In contrast to the endothermic blowing agent, the exothermic chemical foaming agent requires an input of energy to initiate decomposition, but releases energy once decomposition has started. In exothermic reactions, decomposition continues spontaneously until all of the chemical foaming agent 28 is consumed. Examples of the exothermic chemical foaming agent include hydrazines and azo or diazo compounds.
[0033] The use of the endothermic chemical foaming agent in the manufacture of HVAC components provides several advantages over the use of a physical blowing agent and the exothermic chemical foaming agent. By requiring a continuous input of energy to maintain the decomposition process, the reaction rate can be controlled and reaction products can be retained in solution until nucleation can be initiated via the reduced pressures and temperatures present in the mold cavity 40 , thereby allowing a density and a volume of the composition 8 to be precisely controlled. Nucleation using the endothermic chemical foaming agent 28 also has the advantageous effect of consuming energy from the mold 6 during nucleation, which allows a temperature of the mold cavity 40 to be minimized. The minimized temperature of the mold cavity 40 is advantageous, as it allows the HVAC component 38 formed within the mold cavity 40 to be removed from the mold cavity 40 more quickly, thereby minimizing process times. The minimized temperature of the mold cavity 40 also provides the benefit of allowing outer surfaces of the HVAC component 38 to be rapidly cooled upon introduction to the mold cavity 40 , thereby minimizing surface nucleation to allow formation of a smooth outer “skin” on the part. A smooth outer skin is particularly beneficial in HVAC components 38 , as it eases manufacturing and assembly of individual HVAC components 38 by maximizing dimensional control, providing better aesthetic appearance, providing greater physical property retention, and maximizing aerodynamic performance of individual components 38 by minimizing surface drag.
[0034] Within the feed system 12 , the composition 8 is maintained at a first temperature range. The first temperature range is below a melting point of the base resin 26 and a decomposition temperature of the chemical foaming agent 28 , wherein the base resin 26 remains in a solid form. The composition 8 is then conveyed from the feed system 12 and into the barrel 10 under the action of gravity. Within the barrel 10 , energy is input into the composition 8 to transition the base resin 26 from a solid form to a molten form, and to initiate decomposition of the chemical foaming agent 28 within the composition 8 . Energy may be input to the composition 8 by at least one of the temperature control units 46 . Energy may also be input to the composition 8 by the screw 20 in the form of shear and pressure forces. Particularly, a temperature of the composition 8 within the barrel may be maintained at a temperature between 150° C. and 300° C. Optimal temperature ranges will depend on a type of base resin 26 and chemical foaming agent 28 included in the composition, wherein a selected temperature will be sufficient to initiate decomposition of the chemical foaming agent 28 at a desired rate, while maintaining the base resin 26 in a suitable physical state.
[0035] As the chemical foaming agent 28 decomposes, the composition 8 is maintained under pressure within the barrel 10 by the screw 20 . Accordingly, the blowing gas formed by the decomposed chemical foaming agent 28 within the composition 8 is maintained under pressure and remains entrained within the composition 8 , thereby minimizing nucleation.
[0036] The composition 8 is then introduced into the mold cavity 40 through the nozzle 32 of the injector 4 . A predetermined amount of the composition 8 is fed into the mold cavity 40 based on several factors including: final part volume and wall thicknesses, chemical foaming agent type, and chemical foaming agent concentration. The predetermined amount of the composition 8 may be an amount sufficient to partially fill the mold cavity 40 , thereby allowing space in the mold cavity 40 for expansion of the composition 8 . Introduction of the composition 8 into the mold cavity 40 may be metered in several ways. For example, a speed of the screw 20 may be controlled to effect a volumetric flow rate of the composition 8 into the mold cavity 40 . Alternately, the shut-off valve 34 may be relied upon to selectively control the volumetric flow rate of the composition 8 into the mold cavity 40 .
[0037] Upon introduction of the composition 8 into the mold cavity 40 , the reduced pressures within the mold cavity 40 allow the blowing gas to begin nucleation, wherein a suspension of gas bubbles is allowed to form and grow within the composition 8 , thereby forming a cellular structure within the composition 8 . Nucleation is controlled by a combination of a temperature of the mold cavity 40 , a pressure of the mold cavity 40 , and a thickness of a wall of the part, among other factors. The temperature of the mold cavity 40 may be maintained at an elevated state sufficient to sustain decomposition of the chemical foaming agent 28 within the composition 8 , as desired.
[0038] The use of chemical foaming agents in the manufacture of HVAC components offers several benefits over the prior art. For example, the use of chemical foaming agents provides a foam material having superior noise and vibrational damping and thermal insulation compared to HVAC components formed according to the prior art. By using the disclosed method of forming HVAC components, a weight of the component and energy consumption during formation of the component are minimized while a solid surface layer and cellular core are maintained.
[0039] The use of chemical foaming may also provide manufacturing benefits, such as allowing the foaming process to be implemented without the need for specialized injection molding equipment or increased raw material costs. Additionally, when an endothermic chemical foaming agent is used, process times are minimized by maintaining a relatively cool mold cavity 40 compared to physical foaming and exothermic chemical foaming. HVAC components formed using the disclosed method also exhibit improved dimensional accuracy through reduced differential shrinkage, increased speed of manufacture, and an ability to fill a mold cavity 40 quicker and with reduced resistance to material flow compared to physical foaming and hollow glass bubble foaming. Reduced shrink and therefore better contact with the mold surface will further add efficiency to the cooling.
[0040] The use of the disclosed method minimizes molding cycle times by minimizing the temperature of the mold through use of an endothermic chemical foaming agent. Additionally, the disclosed method minimizes energy consumption of the mold system 2 , as a viscosity of the composition 8 may be minimized by the inclusion of the chemical foaming agent 28 . Furthermore, the disclosed method may provide lower press clamp tonnage, improve dimensional control, and increase a flexural modulus of the material with minimal loss of strength or smooth surface appearance. The use of the disclosed method also provides improved HVAC component performance such as improved noise and vibration damping, and improved thermal insulation over the prior art, for example.
[0041] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions. | A method of forming a component of a vehicle heating, ventilation, and air-conditioning system from polymeric material includes providing a molding system including at least one mold cavity defining the component. A base resin is introduced to the mold system via an inlet. A chemical foaming agent is blended with the base resin to form a composition. The composition is then further heated and blended under pressure, wherein the chemical foaming agent decomposes within the composition. The composition is introduced to the mold cavity, wherein a reduced minimized pressure of the mold cavity facilitates initiation of a nucleation of the composition, wherein the composition expands to fill the mold cavity. | 1 |
The present invention is an operating button attachment for electronic devices. The present application claims the benefit of Provisional Patent Application 61/425,532 filed Dec. 21, 2010.
BACKGROUND OF THE INVENTION
Numerous electronic devices use designated input areas, often in the form of “buttons” to which finger pressure is applied and interpreted to enter a command, and as the supporting technology has expanded, the use to which a single input element can be put has expanded. For example, when Apple Inc.'s iPhone operating system was introduced in 2007, its input button, the “home” button, was simply used to exit an application and return to the home screen. Subsequent advancements, such as Apple's iOS 4 operating system, introduced to the public in 2010, provided for multi-tasking. Such increased functionality incorporated “double clicking” the home button to switch between applications. The home button thus has matured to the point where it is now a multi function/multi purpose input/control element, having functionality that has expanded far beyond its original single click purpose to return “home”. Other electronics devices of other manufacturers have or can be expected to adopt similar functionality, providing a single (or several) button(s) to perform a plurality of tasks and/or enter a variety of commands, particularly in portable devices in which available space for operating controls may be at a premium.
While use of such operating buttons has increased, they often have an upper contact surface which is recessed from the surrounding bezel or surface on which the button is mounted. While such a construction provides for a degree of security against inadvertent contact, it often hinders effective contact, and offers little in the way of tactile feedback.
Because of the multi-tasking feature of a home button or similar tactile input device, the button is used on a continuous basis, and it is important that the user have increased control and comfort in using the button. In addition, it would be advantageous to provide a button with means by which it can be easily tactilely identified. This can be of particular benefit when a group of buttons is present, whereby a particular button can be differentiated in a tactile manner to confirm its location and identity. Improving the tactile quality of operating buttons may also be of benefit to the visually impaired.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the forgoing and other benefits, the present invention allows for easier use of an operating button; such as in “double clicking” or applying a directed force to the button to control, for example, a displayed cursor when the button functions as a peripheral device. The invention is a disc shaped device with an adhesive backing, allowing the device to be affixed to the “home” or other designated control button on an electronics device. The device is intended to be applied to any electronic or mechanical device control button, and can be of a variety of shapes, although in a preferred form it is disc shaped.
When applied to a device's operating button, access to the button is enhanced, and the surface texture of the device can improve the reliability of the intended operation as well as the tactile response to the user.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a mobile electronics device with the invention in place thereon;
FIG. 2 is a top plan view of the device of FIG. 1 ;
FIG. 3 is an elevation view of the invention;
FIG. 4 is an illustration of how the invention may be ornamented; and
FIG. 5 is a cross-sectional view of a preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIGS. 1 and 2 , 10 is a representative mobile electronics device, such as a cell phone. In addition to the device's screen 12 , which may be touch-sensitive, a “home” button is provided towards the lower edge of the device's front face surface 22 . The button may be recessed from the surrounding surface and can be difficult to access. In the Figures the button is shown overlaid with the present invention 14 . It completely covers the button, providing a raised area that can be easily contacted and which transmits the applied finger pressure to the button which it overlies.
As depicted in the Figures, the device may preferably be in the form of a disc, the general construction of which may be seen in FIG. 3 , intended to generally conform to the outline shape of the button over which it is positioned. The disc has a top layer 16 , the top surface of which accepts the finger pressure of the user. The top layer may be formed of a variety of materials, including coarse fabrics, as well as materials with other textures, such as grooved rubber and foam. Depending on the nature of the top layer, a backing layer 18 may also be used to provide additional thickness to the device and/or to further control the tactile response of the device. For example, the backing layer may be of foam to provide further flexibility and cushioning. Alternatively, if the upper layer itself has sufficient flexibility, the backing layer may be a less resilient material, serving primarily to raise the top layer.
Bottom layer 20 is an adhesive that allows the device 14 to be affixed to the operating button which it overlies. Typically, the adhesive, as known in the art, is applied directly to the adjoining layer 18 (or 16 ). A removable liner 24 initially covers the bottom surface of the adhesive layer, and is removed by the user to expose the adhesive when the device is to be installed on the electronic device.
The diameter of the device 14 may be varied as appropriate to accommodate operating buttons of various sizes. A diameter of about 9.5 mm (⅜″), for example, may be appropriate for installation on the Apple Inc. iPhone product. As depicted in FIG. 4 , the top surface of the device may be imprinted with a logo or design to customize the device. In addition, the top layer 16 can be colored or otherwise decorated using any technique as known in the art. In addition to being round, the shape of the device may likewise be varied. Square, rectangular and hexagonal shapes in plan, for example, may be employed. So long as the operating button with which the device is to be used is adequately overlaid, the shape of the device may be varied as desired.
While as shown in FIG. 3 the adhesive layer 20 is coextensive with the area of the bottom surface of the layer upon which it lies, it need not be. The adhesive may be in the form of a ring or central spot. In addition, in conjunction with the size of the device 14 itself, which may be sized to overlie only the intended operating button or both the button and a portion of the surrounding surface 22 , the adhesive may be sized and located to adhere the device 14 to the button, the button's surrounding surface, or both.
FIG. 5 presents a cross-sectional view of a preferred embodiment, as may be used, for example on an Apple Inc. iPhone unit. The device 26 is circular in plan, constructed of silicone rubber, and may have a diameter of 13.2 mm and an overall thickness of 1.5 mm. The major portion of the upper surface is flat, with sloping peripheral edge 28 of about 1 mm in width. The intersection between the flat central portion and the edge 28 may bear a radius of 0.5 mm. The bottom surface of the device may be contoured to more readily accommodate a depressed operating button. Thus, the bottom central surface portion 30 is arcuate, with a contour that complements that of the upper surface of the button which it is to contact. The central portion is surrounded by planar peripheral rim 32 , 1 mm in width. In general the depth of the central portion below the rim is on the order of 0.5 mm.
The construction of FIG. 5 is intended to overlie both the corresponding button and a portion of the surrounding unit surface. Thus, the adhesive layer (not shown) may preferably be provided at the bottom rim 32 . It may, however, also extend onto the central portion 30 to allow device attachment directly to the overlaid button.
As set forth herein, the present invention adds functionality and design customization to the device upon which it is installed and with it is used, providing easier button location and more comfortable clicking. | A touch pad for an operating button of an electronics device provides a contact point for tactile input through the button. The button is adhesively mounted to the button, the surface of the electronics device surrounding the button, or both button and surrounding surface. The pad preferably fully overlies the button, and may have a lower surface that conforms to the shape of the top surface of the button. | 7 |
RELATED APPLICATION
The present invention claims priority to U.S. Provisional Patent Application No. 60/364,803 filed Mar. 15, 2002 entitled “Latching Micro-Regulator”, the contents of which are herein incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a micro-regulator and a bi-stable latching valve for regulating fluid flow on micro-scale dimensions.
BACKGROUND OF THE INVENTION
In the chemical, biomedical, bioscience and pharmaceutical industries, it has become increasingly desirable to perform large numbers of chemical operations, such as reactions, separations and subsequent detection steps, in a highly parallel fashion. The high throughput synthesis, screening and analysis of (bio)chemical compounds, enables the economic discovery of new drugs and drug candidates, and the implementation of sophisticated medical diagnostic equipment. Of key importance for the improvement of the chemical operations required in these applications are an increased speed, enhanced reproducibility, decreased consumption of expensive samples and reagents, and the reduction of waste materials.
Microfluidic devices and systems provide improved methods of performing chemical, biochemical and biological analysis and synthesis. Microfluidic devices and systems allow for the performance of multi-step, multi-species chemical operations in chip-based micro chemical analysis systems. Chip-based microfluidic systems generally comprise conventional ‘microfluidic’ elements, particularly capable of handling and analyzing chemical and biological specimens. Typically, the term microfluidic in the art refers to systems or devices having a network of processing nodes, chambers and reservoirs connected by channels, in which the channels have typical cross-sectional dimensions in the range between about 1.0 μm and about 500 μm. In the art, channels having these cross-sectional dimensions are referred to as ‘microchannels’.
By performing the chemical operations in a microfluidic system, potentially a number of the above-mentioned desirable improvements can be realized. Downscaling dimensions allows for diffusional processes, such as heating, cooling and passive transport of species (diffusional mass-transport), to proceed faster. One example is the thermal processing of liquids, which is typically a required step in chemical synthesis and analysis. In comparison with the heating and cooling of liquids in beakers as performed in a conventional laboratory setting, the thermal processing of liquids is accelerated in a microchannel due to reduced diffusional distances. Another example of the efficiency of microfluidic systems is the mixing of dissolved species in a liquid, a process that is also diffusion limited. Downscaling the typical dimensions of the mixing chamber thereby reduces the typical distance to be overcome by diffusional mass-transport, and consequently results in a reduction of mixing times. Like thermal processing, the mixing of dissolved chemical species, such as reagents, with a sample or precursors for a synthesis step, is an operation that is required in virtually all chemical synthesis and analysis processes. Therefore, the ability to reduce the time involved in mixing provides significant advantages to most chemical synthesis and analysis processes.
Another aspect of the reduction of dimensions is the reduction of required volumes of sample, reagents, precursors and other often very expensive chemical substances. Milliliter-sized systems typically require milliliter volumes of these substances, while microliter sized microfluidic systems only require microliter volumes. The ability to perform these processes using smaller volumes results in significant cost savings, allowing the economic operation of chemical synthesis and analysis operations. As a consequence of the reduced volume requirement, the amount of chemical waste produced during the chemical operations is correspondingly reduced.
In microfluidic systems, regulation of minute fluid flows through a microchannel is of prime importance, as the processes performed in these systems highly depend on the delivery and movement of various liquids such as sample and reagents. A flow control device may be used to regulate, allow or halt the flow of liquid through a microchannel, either manually or automatically. Regulation includes control of flow rate, impeding of flow, switching of flows between various input channels and output channels, as well as volumetric dosing. It is generally desirable that flow control devices, such as valves, precisely and accurately regulates fluid flow, while being economical to manufacture.
SUMMARY OF THE INVENTION
The present invention provides a latching micro-regulator for regulating liquid flow on micro-scale levels. The latching micro-regulator provides binary addressable flow control using digital latching. The latching micro-regulator includes a bi-stable latching valve comprising a substrate having an inlet port and an outlet port, a valve seat defining a valve chamber for opening and closing the inlet port, and an actuator assembly for actuating the valve element. The valve chamber is configured to contain a volume of fluid, and the inlet port and the outlet port are in fluid communication with the valve chamber to provide a liquid flow path through the chamber. The actuator assembly comprises a cantilever beam for moving the valve seat between an open position and a closed position, an actuator, such as a piezoelectric element, for moving the cantilever beam, and a latch, such as a permanent magnet, for securing the cantilever beam in the closed position.
According to a first aspect of the invention, a bi-stable latching valve for controlling fluid flow through a channel is provided. The bi-stable latching valve comprises a substrate defining an inlet port and an outlet port in communication with the channel, a valve seat, an actuator assembly for selectively moving the valve seat between the open position and the closed position and a latching mechanism. The valve seat defines a valve chamber in communication with the inlet port and the outlet port for containing a volume of fluid and the valve seat moves between a closed position wherein the valve seat blocks one of said inlet port and said outlet port and an open position to allow fluid flow through the valve chamber to regulate fluid flow through the chamber. The latching mechanism latches the valve seat in one of said open position and closed position.
According to another aspect, a flow regulating system is provided. The flow regulating system comprises a first flow channel for conveying liquids having a first flow resistance, a first bi-stable valve in communication with the first flow channel for selectively blocking liquid flow through the first flow channel, a second flow channel for conveying liquids having a second flow resistance and a second bi-stable valve in communication with the second flow channel for selectively blocking liquid flow through the second flow channel.
According to yet another aspect, a flow regulating system is provided. The flow regulating system comprises a first flow channel for conveying liquids having a first flow resistance, a first bi-stable latching valve in communication with the first flow channel for selectively blocking liquid flow through the first flow channel, a second flow channel for conveying liquids having a second flow resistance and a second bi-stable latching valve in communication with the second flow channel for selectively blocking liquid flow through the second flow channel. The first and second bi-stable latching valve each comprise a piezoelectric actuator for selectively opening and blocking the flow channel, and a magnetic latch for locking the valve in a closed position.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a cross-sectional side view of an embodiment of the bi-stable latching valve of the present invention.
FIG. 2 a is a detailed side view of the bi-stable latching valve of FIG. 1 in an open position.
FIG. 2 b is a top view of the bi-stable latching valve of FIG. 2 a.
FIGS. 3 a and 3 b illustrate the bi-stable latching valve switching from a closed position to an open position.
FIGS. 4 a and 4 b illustrate the bi-stable latching valve switching from an open position to a closed position.
FIG. 5 is a schematic diagram of a flow regulating system for a microfluidic system implementing a plurality of bi-stable latching valves according to an illustrative embodiment of the invention to provide variable control of fluid flow.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a digital latching micro-regulator including a bi-stable latching valve for accurately controlling fluid flow on demand. The present invention will be described below relative to an illustrative embodiment. Those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein.
The present invention provides a bi-stable latching valve for selectively blocking fluid flow through a channel. The valve is positioned in a channel to selectively block liquid flow through the channel. As shown in FIG. 1 , the bi-stable latching valve 10 of the present invention comprises a substrate 20 having an inlet port 22 and an outlet port 24 formed therein in fluid communication with a channel through which liquid flows. The substrate 20 is preferably formed of glass or plastic, though other materials may be used. The bi-stable latching valve 10 further includes a valve seat 30 cooperating with the substrate to define a valve chamber 26 in communication with the inlet port 22 and the outlet port 24 for containing a volume of fluid. The valve seat 30 selectively blocks the inlet port 22 to regulate the flow of fluid into the chamber 26 . The position of the valve seat 30 controls the fluid flow into the chamber 26 . The position of the valve seat 30 is controlled by an actuator assembly 50 . The actuator assembly can comprise any suitable structure for selectively operating or moving the valve seat 30 to block the inlet port 22 or the outlet port 24 . According to one embodiment, the actuator assembly includes a cantilever beam 40 hinged to the substrate 20 , an actuator 52 , and a latching mechanism 60 .
The position of the valve seat 30 is determined by the position of the cantilever beam 40 . The valve seat 30 is connected to the cantilever beam 40 , which is in turn connected to the actuator 52 . The actuator 52 can comprise any suitable structure for moving the valve seat 30 between an open position for allowing fluid to enter or exit the chamber, and a closed position. Examples of suitable actuators include mechanical, electrical, electromechanical, and magnetic devices. According to a preferred embodiment, the actuator 52 is a piezoelectric element. The cantilever beam 40 is hinged at a first end 41 to the glass substrate 20 and rotates about the fixed hinge under the control of the actuator 52 to move the valve seat 30 between the open and closed positions. When the cantilever beam 40 is lowered, the beam pushes the valve seat 30 into a closed position, thereby blocking the inlet port and preventing fluid flow into the chamber. When the cantilever beam 40 is raised, the valve 30 is moved to an open position to allow fluid flow through the chamber 26 . The cantilever beam 40 is driven by the piezoelectric element 52 , which selectively applies a driving force to the beam 40 .
The bi-stable latching valve 10 further includes a latching mechanism 60 for selectively latching or holding the beam 40 in a selected position. The latching mechanism can include any suitable mechanical, electrical, electromechanical or magnetic structure suitable for latching the beam 40 . The latching mechanism 60 , according to a preferred embodiment, comprises a permanent magnet 62 and a permalloy element 46 disposed on a free end 44 of the beam 40 . The permanent magnet 62 is attached to the glass substrate 20 opposite the permalloy element 46 and is configured to attract the permalloy element 46 . The magnetic attraction between the permanent magnet and the permalloy element is effective to latch, i.e. to retain, the valve element in a closed position to prevent fluid flow through the bistable latching valve 10 .
As shown in FIGS. 2 a and 2 b , the valve seat 30 is cylindrical in shape and includes a rim 38 about the circumference of the valve seat 30 , which defines the valve chamber 26 . The rim 38 cooperates with the glass substrate 20 to fluidly seal the valve chamber 26 . The valve chamber communicates with the inlet port 22 and the outlet port 24 . The valve seat 30 is preferably formed of a flexible material, such as silicone rubber, though one skilled the art will recognize that alternate materials may be used. The valve seat 30 further comprises a membrane portion 32 , a first protrusion 34 for contacting the cantilever beam 40 and second protrusion 36 for selectively blocking the inlet port 22 to prevent the flow of fluid through the valve chamber 26 , thereby blocking fluid flow through the associated channel. The second protrusion blocks the inlet port 22 when the cantilever beam depresses the valve seat 30 by pushing on the first protrusion 34 . One skilled in the art will recognize that the valve seat 30 is not limited to a cylindrical shape, and that any suitable shape may be utilized.
The operation of the bi-stable latching valve 10 is illustrated in FIGS. 3 a - 3 b and FIGS. 4 a - 4 b . The bi-stable latching valve 10 switches between two stable states: an ON state, which allows the flow of liquid through the valve chamber and an OFF state, which prevents the flow of liquid through the valve chamber. The state of the bi-stable latching valve 10 is controlled by the driving force on the cantilever beam 40 by the actuator 52 and the magnetic latching force created by the permanent magnet 62 on the beam free end. According to the illustrative embodiment, the bi-stable latching valve only requires power to switch between the two stable states and does not otherwise require power to operate.
FIG. 3 a illustrates the bi-stable latching valve 10 in an OFF state, where the second protrusion 36 of the valve seat 30 blocks the inlet port 22 so that fluid is prevented from flowing through the valve chamber 26 . In the OFF state, the latching mechanism 60 latches the cantilever beam 40 in the closed position by securing the permalloy element 46 to the permanent magnet 60 . As shown, when the attractive force of the magnet pulls the cantilever beam towards the magnet, causing the cantilever beam to push the valve into the closed position, such that the first protrusion blocks the inlet port. The valve maintains the closed position until activated.
To open the bi-stable latching valve and allow fluid flow, a voltage is applied to the piezoelectric element 52 using a controller (not shown). The applied voltage causes the piezoelectric element to compress, applying an opposite force on the cantilever beam in the direction away from the magnet. If the force generated is sufficient to overcome the magnetic attraction between the magnet and the permalloy, the magnet releases the permalloy element and the cantilever beam raises, pulling the valve seat 30 clear of the inlet port 22 . As shown in FIG. 3 b , fluid flows through unobstructed inlet port 22 into the valve chamber and out of the valve chamber via the outlet port.
The bi-stable latching valve 10 remains in the ON state, as shown in FIG. 4 a , until the controller subsequently actuates the piezoelectric element 52 by applying a second voltage. The second voltage causes the piezoelectric element to expand, which applies a driving force on the cantilever beam 40 , pushing the beam towards the magnet 60 . The lowered beam in turn applies a force to the valve seat 30 , which shifts into a closed position, blocking the inlet port. When the permalloy element 46 is brought close to the magnet 62 , a magnetic latching force generated by the magnet latches the beam 40 into the closed position until a subsequent actuation of the piezoelectric element 52 .
The bi-stable latching valve 10 may be employed in a valve architecture to provide binary addressable flow control using digital latching. As shown in FIG. 5 , multiple bistable latching valves may be connected to channels 550 of specific flow conductance that vary according to a pre-determined ratio to provide a micro-regulator 500 . Each bi-stable latching valve 10 can be set to an on or off state as described previously, allowing or blocking flow through its associated flow channel 550 . The bi-stable latching valves are selectively activated in various combinations to provide a number of discrete flow conductance states through the micro-regulator 500 . The net flow through the micro-regulator is therefore determined by the sum of the flows through the open bi-stable latching valves 10 . The number of discrete flow conductance states is determined by the number of bi-stable latching valves in the system and the flow conductance ratios between the channels.
A typical example of a 4-bit micro-regulator system is illustrated in FIG. 5 . The individual channels 550 a , 550 b , 550 c and 550 d in the system have flow conductance ratios of 1:2:4:8, thus providing 16 discrete net flow conductance states. For example, a first flow conductance state may be provided by opening all of the bi-stable latching valves 10 a - 10 d to allow flow through all of the channels 550 a , 550 b , 550 c and 550 d . A second flow conductance state is achieved by closing the first bi-stable latching valve 10 a , while leaving the remaining bi-stable latching valves 10 b , 10 c , 10 d open, allowing fluid flow through the channels 550 b , 550 c and 550 d only. A third conductance state is achieved by closing the first and second bi-stable latching valves 10 a , 10 b while leaving the remaining bi-stable latching valves 10 c , 10 d to allow flow through the associated channels 550 c and 550 d , and so on. This allows flow rates to be controlled to a 6.67% precision. Higher precision can be obtained by increasing the number of bits in the system—for example an 8-bit system has 128 discrete states, achieving less than 1% precision in the flow rate control.
One skilled in the art will recognize that any suitable bi-stable valve for selectively blocking liquid flow through a channel may be used in the flow regulating system 500 of FIG. 5 to provide variable flow resistance. The micro-regulator 500 may have any suitable number of channels arranged in any suitable configuration and having any suitable flow resistance to achieve a system having variable flow resistance, wherein the flow resistance depends on the state of the bi-stable valves.
The manufacturing process for the bi-stable latching valve 10 of an illustrative embodiment of the present invention is efficient, economical and simplified. The valve seat 30 may be formed by surface micromachining of a substrate, followed by deposition of silicone rubber, the permalloy element 46 and polysilicon. The substrate 20 is etched to form a channel and then drilled to form the inlet port 22 and the outlet port 24 . The cantilever beam 40 may be attached and hinged to the glass substrate through means known in the art. The permalloy element may be bonded to the beam and the permanent magnet 62 may be bonded to the substrate through means known in the art. The piezoelectric element 52 or other actuator for driving the cantilever beam 40 may be attached to the beam through any suitable means.
The present invention has been described relative to an illustrative embodiment. Since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are to cover all generic and specific features of the invention described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | A latching microregulator for regulating liquid flow on micro-scale levels comprises a substrate having an inlet port and an outlet port, a valve element defining a valve chamber for opening and closing the inlet port, and an actuator assembly for actuating the valve element. The valve chamber is configured to contain a volume of fluid, and the inlet port and the outlet port are in fluid communication with the valve chamber to provide a liquid flow path through the chamber. The actuator assembly comprises a cantilever beam for moving the valve element between an open position and a closed position, an actuator, such as a piezoelectric element, for moving the cantilever beam, and a latch, such as a permanent magnet, for securing the cantilever beam in the closed position. A flow regulation system comprises a plurality of fluid channels of varied flow conductance and a plurality of latching microregulators for selectively blocking or allowing flow through each of the fluid channels. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority to a provisional application that was filed on Feb. 5, 2004, Ser. No. 60/542,432, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates generally to monitoring systems and, more particularly, to a system for monitoring the status of a mini-bar.
[0003] Multi-unit buildings such as hotels, motels, inns, and the like, offer a variety of services and facilities for the convenience of their guests, such as a mini-bar. A mini-bar is a convenient store of goods within each room, usually within a refrigerator, that can be accessed by the occupant at his or her discretion. Typically, the mini-bar is re-stocked after the occupant checks out, and the occupant is billed for the items that he or she consumed. The mini-bar is also often checked on a daily basis, often while the room is occupied, for re-stocking. This can be annoying and inconvenient for the occupant.
[0004] Monitoring devices and systems for mini-bars are known. One such device is a door switch that detects an opening of the door of a mini-bar. Door switches only provide information that the mini-bar door has been opened. They fail to provide any indication that an item from the mini-bar has actually been removed. Accordingly, if the switch indicates that the mini-bar has been opened then housekeeping will check the mini-bar for re-stocking. However, as is often the case, no item has been removed from the mini-bar. Another such monitoring system not only indicates when a mini-bar has been accessed but also indicates that consumable items have been removed. Such mini-bars track items by, e.g., pressure sensitive switches or infrared light barriers. These product-sensor type mini-bars carry the disadvantage that they are unforgiving to the user—a removed and returned product is registered as consumed. These product sensors tend to be unreliable as the number of sensors per mini-bar can be very high. One example of a mini-bar monitoring system is commercially available from Bartech Systems Corporation of Millersville, Md. Further, removed and returned items can lead to awkward situations at the front desk during checkout to reconcile the actual consumption.
SUMMARY OF THE INVENTION
[0005] The above discussed and other drawbacks and deficiencies are overcome or alleviated by an exemplary system and method for viewing mini-bar status.
[0006] In one aspect of the invention, a mini-bar includes an imaging device disposed for acquiring an image of an interior of the mini-bar.
[0007] In another aspect of the invention, a system for monitoring activity of a mini-bar in a room of a multi-unit building, comprises an imaging device disposed for acquiring an image of an interior of the mini-bar, the imaging device configured to generate image data indicative of the image, and a display device receptive to the image data for displaying the image, the display device configured for viewing the image external to the mini-bar.
[0008] In still another aspect of the invention a method for monitoring activity of a mini-bar in a room of a multi-unit building comprises acquiring an image of an interior of the mini-bar, and displaying the image.
[0009] The above discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
[0011] FIG. 1 is a top sectional view of an exemplary room;
[0012] FIG. 2A is a perspective view of a mini-bar in accordance with the present invention;
[0013] FIG. 2B is an interior view of the door of the mini-bar of FIG. 2A ;
[0014] FIG. 3 is an interior view of the mini-bar without the door, in accordance with another embodiment of the invention;
[0015] FIG. 4 is a schematic block diagram of a controller for the mini-bar;
[0016] FIG. 5 is a schematic block diagram of a gateway module, in accordance with an embodiment of the present invention;
[0017] FIG. 6 is a front view of an IR transceiver plate assembly of FIG. 1 ;
[0018] FIG. 7 is a front view of a display plate assembly of FIG. 1 ; and
[0019] FIG. 8 is a centralized occupant room control system or network.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 shows an exemplary room 10 of a multi-unit building, the room including a number of devices enhancing the security and convenience of occupants, and the operating efficiency of the staff or the multi-unit building. One such device is a min-bar 12 . Multi-unit building includes hotels, motels, inns, dormitories, cooperatives, apartments, condominiums, and the like, that offer a variety of services and facilities for the convenience of their guests or residents (occupants).
[0021] Referring to FIGS. 2A and B, a conventional mini-bar 12 comprises a housing 14 (which is typically a refrigerated housing, but it is within the scope of the present invention that the housing is not refrigerated, as such is not required with many consumable items) and a door 16 . Items are stored within the housing, which typically includes at least one shelf 18 to maximize storage therein. Additional shelves 20 at the inside of the door 16 also provide storage. In the present invention, a door switch 22 is provided to detect the state, i.e., an open state or a closed state, of the door 16 . One example of a mini-bar door switch is model S 241 or S 541 door switch commercially available from Inncom International, Inc, and described in U.S. Pat. No. 6,832,072 which is herein incorporated by reference in its entirety. Cameras 24 are positioned on the inside of the door 16 to capture an image of the items at each level of the mini-bar and at the shelf to capture an image of the items on the door shelves 20 . A mechanical shutter may be employed over the lens of the camera to protect the lens from condensation and guest tampering.
[0022] It is within the scope of the present invention that any number of cameras may be used, including a single camera, and that such camera(s) may be arranged at any desired location(s) and disposition(s) (e.g., positioned on an interior side, back, top, or bottom surface of the mini-bar housing 14 ). Further, the cameras may employ a wide-angle lens or any other suitable lens to capture the images. What is important is that the camera(s) be positioned to capture one or more images of the items. It is preferred that the cameras be triggered to capture images upon closure of the door 16 , as detected by switch 22 . This may require a flash or in the case of mini-bars with an interior light, a delay in turning the light off to allow the cameras to capture images. The cameras may be triggered sequentially or simultaneously. The camera being controlled (and powered) by a controller 25 , which could be mounted at the exterior back of the mini-bar or any other suitable location. A still-picture camera may be preferred, as such is typically less expensive than a continuous camera (although use of a continuous camera is within the scope of the invention). Further, limiting imaging to when the door is closed will eliminate any concerns regarding privacy, as it may not be desirable to capture images of an occupied room.
[0023] Referring to FIG. 3 , camera 24 is mounted on a track 26 at an inside surface of the housing 14 or door 16 ( FIG. 2A, 2B ) to allow the camera 24 to move up and down to allow for imaging of all of the items in the mini-bar 12 . Additional tracks 28 may be provided, when mounted inside of the housing 14 , to allow track 26 (and thereby camera 24 ) to move backward and forward within the housing 14 . Use of tracks 28 will require further accommodations within the mini-bar 12 . More specifically, the shelf 18 may require shortening (as shown) to provide sufficient clearance, as will be readily apparent to one skilled in the art. The camera 24 is driven along track 26 and track 26 is driven along tracks 28 by miniature electric motors (continuous or step), with power being provided from a controller 25 ( FIG. 4 ). The camera is preferably driven to generate a series of sequential images.
[0024] Further, the camera 24 may be pivotally mounted, in any of the exemplary embodiments, with the position being controlled by a miniature electric motor (continuous or step), with power being provided from controller 25 .
[0025] Referring now to FIG. 4 , a schematic block diagram of the controller 25 is generally shown. Controller 25 includes a micro controller 30 having associated memory, i.e., random access memory (working memory) and non-volatile memory (boot-code and programming instructions) and an interface for providing data communication over a Local Area Network (LAN). Controller 25 communicates over the LAN in a suitable protocol (e.g., TCP/IP, UDP/IP, Inncom International, Inc's proprietary P5 Protocol, Wi-Fi, ZigBee, 802.15.4, Bluetooth, etc.) with a central floor switch 60 ( FIG. 8 ) for the floor or area where the room is located, which is in communication with a central server or processor 62 ( FIG. 8 ), or directly with the central server 62 . Controller 25 interfaces with the LAN by way of conventional wiring or wireless communication configurations. With wireless communications a wireless transceiver 32 is connected to micro controller 30 for providing wireless (e.g., IR (infrared), RF (radio frequency), U/S (ultrasonic), etc.) communication.
[0026] Wireless IR communication may utilize, for example, the protocol described in U.S. Pat. No. 5,128,792, which is incorporated herein by reference. Digital iterative gain control such as described in U.S. patent application Ser. No. 10/631,457, entitled Digital Iterative Gain Control, filed Jul. 30, 2003, which is incorporated herein by reference, may also be utilized. Further, the infrared communication protocol may be the IR5 infrared protocol described in the above-referenced applications. Other infrared communication protocols may include IrDA, or the like.
[0027] Wireless RF communication may utilize, for example, 802.11b radio frequency protocol, WI-FI, Bluetooth, ZigBee, 802.15.4, or any other suitable protocol.
[0028] Wired communication may comprise any conventional wiring, (e.g., twisted-pair not shown). Alternatively, the controller 25 could be connected to electrical or telephone wiring for providing communication over such, as communication configurations and protocols on such wiring are known.
[0029] Controller 25 is powered by a power regulator or supply 34 connected to line power, although controller 25 may be directly powered from an appropriate low voltage line (whereby the power regulator 34 could be eliminated). Low voltage DC power could be obtained from a low voltage DC electric bus commonly found in such multi-unit buildings or could be generated by a AC-to-DC converter located within a wall or ceiling of the building. The converter would be powered directly from electrical wiring of the multi-unit building. While a micro controller is described as having integrated elements, it will be appreciated that the memory and interface could be discrete elements, as is well known in the art. Also, the micro controller may alternatively comprise a microprocessor, a programmable logic device (PLD), a programmable logic array (PLA), a programmable logic controller (PLC) or other suitable device, generically referred to herein as a processor, each being well known in the art and the configuration of each being readily apparent to one skilled in the art.
[0030] Micro controller 30 of controller 25 , upon detection by door switch 22 of opening and closing of the mini-bar door, initiates a picture(s). This may be a single picture or a series of pictures when the camera is mounted for scanning on the aforementioned tracks or multiple cameras are employed. The data for the picture(s) is then transmitted to the central server 62 ( FIG. 8 ) for processing. Controller 25 may also control a light in the mini-bar to be on while images are being acquired. This light may be the light internal to the mini-bar (as are commonly found in conventional mini-bars) or a light mounted at the interior of the mini-bar (which would be powered by the controller).
[0031] Referring to FIGS. 1 and 5 , a gateway module 38 may be employed within the room 10 . Gateway module 38 includes a micro controller 40 having associated memory, i.e., random access memory (working memory) and non-volatile memory (boot-code and programming instructions) and an interface for providing data communication with a central floor switch 60 ( FIG. 8 ). A wireless transceiver 42 is connected to micro controller 40 for providing wireless (IR or RF) communication. Gateway module 38 is powered by a power regulator or supply 44 connected to line power, although gateway module 38 may be directly powered from an appropriate low voltage line (whereby the power regulator 44 could be eliminated). While a micro controller is described as having integrated elements, it will be appreciated that the memory and interface could be discrete elements, as is well known in the art. Also, micro controller may alternatively comprise a microprocessor, a programmable logic device (PLD), a programmable logic array (PLA), a programmable logic controller (PLC) or other suitable device, generically referred to herein as a processor, each being well known in the art and the configuration of each being readily apparent to one skilled in the art.
[0032] Gateway module 38 communicates over the LAN in a suitable protocol (e.g., TCP/IP or UDP/IP, Inncom International, Inc's proprietary P5 Protocol, Wi-Fi, ZigBee, 802.15.4, Bluetooth, etc.) that is compatible with the central floor switch 60 ( FIG. 8 ), or directly or wirelessly via wireless mesh-net backbone and/or over an aforesaid suitable protocol to the central server 62 . Gateway module 38 interfaces with the LAN by way of conventional wiring or wireless communication configurations in a suitable protocol. Gateway module 38 communicates with the controller 25 via wired or wireless communication in a suitable protocol.
[0033] Wireless IR communication may utilize, for example, the protocol described in U.S. Pat. No. 5,128,792, which is incorporated herein by reference. Digital iterative gain control such as described in U.S. patent application Ser. No. 10/631,457, entitled Digital Iterative Gain Control, filed Jul. 30, 2003, which is incorporated herein by reference, may also be utilized. Further, the infrared communication protocol may be the IR5 infrared protocol described in the above-referenced applications. Other infrared communication protocols may include IrDA, or the like.
[0034] Wireless RF communication may utilize, for example, 802.11b radio frequency protocol, WI-FI, Bluetooth, ZigBee, 802.15.4 or any other suitable protocol.
[0035] Wired communication may comprise any conventional wiring, (e.g., twisted-pair not shown). Alternatively, the gateway could be connected to electrical or telephone wiring for providing communication over such, as communication configurations and protocols on such wiring are known.
[0036] Typically, the mini-bar is re-stocked after the occupant checks out, and the occupant is billed for the items that he or she consumed. Server 62 ( FIG. 8 ) processes the image data for review by staff, with each image being time and date stamped. These images may displayed at any computer terminal or display 76 configured to receive the images. Server 62 ( FIG. 8 ) executes programming instructions to determine if restocking of the mini-bar is required, e.g., the mini-bar door has been opened and the collected images indicate that items may have been removed. Thereby providing staff with a current ‘slide-show’ of the mini-bars, i.e., a virtual walk-through.
[0037] Known image enhancement/processing techniques may be employed to add a visual-difference picture, highlighting the picture areas where actual changes are recognizable (for ease of picture interpretation). Also, a second set of images can be obtained in the IR domain for enhanced evaluation/tamper checks. For example, temperature changes may indicate that an item has been removed and replaced or that a liquid has been refilled to avoid a charge.
[0038] Displaying a sequence of pictures at a front desk terminal may assist the front desk clerk at time of checkout to reconcile consumption disputes. For example, the image at 9:00 a.m. shows a particular item in the mini-bar and an image at 10:00 a.m. shows that the particular item is no longer in the mini-bar, whereby it must have been removed when the mini-bar was opened causing the latter picture to be taken.
[0039] In an alternate embodiment, the server 62 ( FIG. 8 ) executes programming instructions to process the image data with a heuristic image interpretation for automated tracking of items in the mini-bar. From this heuristic image interpretation the server can generate a report of items in a mini-bar and/or items removed from the mini-bar. This report can be printed, displayed, and/or archived. Once the server determines that an item has been removed it can also generate a charge on the guest's account for the item through an interface between the central server 62 and a point-of-sale system. This would eliminate any staff member review of images to determine mini-bar status, as the process would be fully automated. The staff member would only have to review images in the event of a detected anomaly or dispute with a guest, as to which item(s) were consumed/removed from the mini-bar.
[0040] With RF wireless communications, images can be transmitted and received by a personal digital assistant (PDA) or other portable communication device, which supports RF communication, carried by a staff member. This allows the staff member to visually inspect the mini-bar without entering the room, by viewing images or a report. More specifically, the staff member sends a command from the PDA to the controller 25 to collect image data and/or reporting data (which may be acquired at that time or previously stored). This data is collected and sent to the PDA, where the inquiring staff member views images and/or a report. Images are preferably only acquired when the mini-bar door is closed, in order to protect the privacy of the occupants/guests.
[0041] With IR wireless communication a transceiver is used. Referring to FIGS. 1 and 6 , an IR transceiver plate assembly 46 is generally shown, which includes an IR transceiver 48 and may also include a room number thereon. The IR transceiver is of the type described hereinbefore with respect to the controller 25 and the gateway module 38 for wireless IR communication. This would allow for wireless IR communication between the IR transceiver 48 and a PDA or other portable communication device carried by a staff member. The IR transceiver 48 may be hard wired or wirelessly connected to the controller 25 or the gateway module 38 for communication as described hereinbefore. This allows the staff member to visually inspect the mini-bar without entering the room, by viewing images or a report. More specifically, the staff member sends a command from the PDA to the IR transceiver 48 , thereby to the controller 25 to collect image data and/or reporting data (which may be acquired at that time or previously stored). This data is collected and sent through the IR transceiver 48 to the PDA, where the inquiring staff member views images and/or a report. Again, images are preferably only acquired when the mini-bar door is closed, in order to protect the privacy of the occupants/guests.
[0042] Referring to FIGS. 1 and 7 , a display plate assembly 50 is generally shown, which includes a flat panel display 52 and may also include a room number thereon. Display plate assembly 50 includes a hidden switch 54 , which may be either mechanically, magnetically, or wireless (RF or optically, e.g., IR) triggered or queried, for activating the display 52 . Hidden switch 54 is mechanically activated when a staff member activates hidden switch 54 by depressing it. Hidden switch 54 can also be magnetically activated when the staff member activates the hidden switch 54 by placing a small, handheld magnet (not shown) near the hidden switch. This allows the staff member to visually inspect the mini-bar without entering the room, by viewing images or a report. More specifically, the staff member activates the switch causing a command to be sent to the controller 25 to collect image data and/or reporting data (which may be acquired at that time or previously stored). This data is collected and sent to the display 52 , where the inquiring staff member views images and/or a report. Again, images are preferably only acquired when the mini-bar door is closed, in order to protect the privacy of the occupants/guests.
[0043] Display plate assembly 50 may be hardwired to the controller 25 or the gateway module 38 for communication, as described hereinbefore, for receiving the image data and/or reporting data for display. Display plate assembly 50 may alternatively include a micro controller and a wireless transceiver (as described hereinbefore with respect to the controller 25 and the gateway module 38 ) for RF wireless communication. This would allow for RF wireless communication between the display plate assembly 50 and the controller 25 , directly or through the gateway module 38 . The display plate assembly 50 is typically mounted at the wall in close proximity to the door of the room.
[0044] The system of the invention may additionally or alternatively include a display device disposed within the room 10 by which an occupant of the room may access images of the interior of the mini-bar provided by the camera 24 and/or data or information relating to the images. The occupant display device may be any device which is suitable for displaying images, text, graphics, etc., such as a CRT monitor, an LED panel, etc. For example, the occupant display device may be a device such as the Guestroom Digital Assistant (GDA-700) commercially available from Inncom International, Inc. Alternatively, the occupant display device may comprise a television disposed in the room. Further alternatively, the occupant display device may comprise a monitor, display panel, or the like disposed on the mini-bar. The occupant display device is disposed communicatively within the system 70 ( FIG. 8 ) so as to receive the images and/or image information and image data from the micro controller 25 , the gateway 38 , the central server 62 , or the internet 78 by way of any wired or wireless modes described herein. In an exemplary embodiment, the occupant display device may be configured to display information concerning items removed from or remaining in the mini-bar. Such information may comprise an itemized listing of removed items and/or a monetary amount(s) corresponding to the removed items and/or an itemized listing of items remaining in the mini-bar and/or a monetary amount(s) corresponding to the remaining items and/or any other information pertaining to the status of the mini-bar.
[0045] It is within the scope of the present invention, that micro controller 30 of controller 25 perform much of the processing described herein as being performed at the server 62 . In such an embodiment micro controller 30 has sufficient processing power to accomplish the desired tasks. For example, micro controller 30 may process the image data with a heuristic image interpretation for automated tracking of items in the mini-bar, as described hereinbefore. Further, from this heuristic image interpretation the micro controller would generate a report of items in a mini-bar and/or items removed from the mini-bar. Again, this report can be printed, displayed, and/or archived.
[0046] A log of the images could be generated and stored at the central server. This log would be useful for analyzing anomalies or resolving disputes with guests at a later time. Further, the log could be useful to a mini-bar service company or a lodging corporation for data mining purposes and/or consumption interpretation and folio posting (ASP model). The log could be sent directly to a mini-bar service company or a lodging corporation over the Internet, as described herein.
[0047] If pictures/images are scheduled to be collected periodically, then such could be suspended when the room is not occupied. The central server has data as to the occupancy/rental status of a room, whereby it would send a command to the controller 25 to suspend collecting images. Controller 25 may be configured to provide an event message in response to some event. An event message may include the opening of a door to a mini-bar or that images have been obtained and are available, for example. Further, in a refrigerated mini-bar the level of cooling or the times the unit is run for cooling could be set, thereby providing energy savings. Such could be substantial in the larger multi-unit buildings.
[0048] FIG. 8 depicts a centralized room control system or network 70 . System 70 may be of the type described in one or more of the following: International Application Serial No. PCT/US02/02354, filed on Jan. 24, 2002; International Patent Application Serial No. PCT/US02/02264 filed on Jan. 24, 2002; U.S. patent application Ser. No. 10/470,111 filed on Jul. 23, 2003; U.S. patent application Ser. No. 10/470,109 filed on Jul. 23, 2003; U.S. Provisional Patent Application No. 60/263,940 filed on Jan. 24, 2001; U.S. Provisional Patent Application No. 60/323,872 filed on Sep. 21, 2001; all of which said applications are incorporated herein by reference. Building-level services such as, but not limited to, central electronic lock control, energy management, room control, and Internet access services may be provided to one or more rooms 10 throughout one or more hotels 72 (or other multi-unit building) over the same network. While the present example is directed to one or more hotels 72 , it will be recognized that the system 70 has application in a wide range of multi-unit buildings including, but not limited to, universities, health care, multi-dwelling units (MDUs), office, resort, and residential.
[0049] As depicted in FIG. 8 , the server 62 may be in communication with the Internet 78 by way of a modem 80 , as is well known, or by wireless means, as is also well known, whereby the server 62 may be accessed remotely.
[0050] While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof 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 the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best modes contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. | A mini-bar and a system and a method of monitoring activity of a mini-bar where the mini-bar includes an imaging device disposed for acquiring an image of an interior of the mini-bar. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid discharge recording head for recording on a recording sheet by discharging liquid used for recording from an orifice (discharge port). The invention also relates to a method of manufacture therefor, as well as to a liquid discharge recording apparatus. The present invention is applicable to a copying machine, a facsimile equipment provided with communication systems, and an apparatus such as a word processor provided with a printing unit, besides a general printing apparatus.
[0003] In the specification hereof, the term “print” (which may be referred to as “record” in some cases) is understood to indicate not only the case where characters, graphics, or some other meaningful information is formed, but also, indicate the case where images, designs, patterns, or others are formed on a print medium irrespective of being meaningful or meaningless broadly or whether or not those are made apparent so as to be observable by human eyesight, or to indicate such a case that a medium is processed. Here, the term “print medium” means not only paper used for a printing apparatus in general, but also, means broadly cloths, plastics films, metallic plate, glass, ceramics, woods, leathers, or the like which is made capable of receiving ink. Further, the term “ink” (which may be referred to as “liquid” in some cases) should also be interpreted broadly as in the definition of “print” described above, and means the liquid with which to form images, designs, patterns or the like when it is provided for a print medium or for the medium that may be used for processing a print medium or processing ink (such as to coagulate colorant or make it insoluble in ink to be used for a print medium).
[0004] 2. Related Background Art
[0005] The liquid discharge recording head comprises an element substrate having a plurality of discharge energy generating elements, such as electrothermal converting devices formed thereon, and a ceiling plate having on it a plurality of fine discharge ports and a plurality of liquid flow paths communicated therewith. The liquid discharge recording head is manufactured by assembling the element substrate and the ceiling plate in the state where each of the discharge energy generating elements and each of the liquid flow paths are positioned exactly. Then, the structure is arranged so that with electric energy applied to each of discharge energy generating elements, the change of states, which is followed by abrupt voluminal changes (creation of bubbles), is caused to occur on the liquid which is supplied from the outside and in contact with each of discharge energy generating elements, thus discharging liquid by the exertion of active force on the basis of such change of states of liquid for forming images on a recording medium by the adhesion of liquid thus discharged to it.
[0006] By adoption of the recording method that uses the liquid discharge recording head thus structured, images can be recorded in high quality at high speed with a lesser amount of noises, and at the same time, the discharge ports for discharging liquid can be arranged in high density with respect to the liquid discharge recording head that records using this recording method. Therefore, it has many advantages such as to obtain recorded images in high resolution even by use of a smaller apparatus, and also, obtain color images with ease, among some others. Thus, in recent years, this recording method is widely utilized for a printer, a copying machine, a facsimile device, and many other office equipment, and further, it is utilized even for textile printing systems, and others for industrial use.
[0007] However, the conventional grooved ceiling plate is formed by resin such as polysulfone on one hand, and the element substrate is formed by silicon on the other. Therefore, even if discharge energy generating elements and the grooves of liquid flow paths are positioned exactly at the time of manufacture, there are some cases where the positions of discharge energy generating elements and the grooves of liquid flow paths are caused to deviate later due to the difference in thermal expansion ratios influenced by the temperature changes under the environments of various uses, simply because materials used for both of them are different.
[0008] In order to avoid the positional deviation between the discharge energy generating elements and the grooves of liquid flow paths owing to the different materials used for the grooved ceiling plate and the element substrate, it is conceivable to form the grooved ceiling plate and the element substrate by use of the same material. In this case, the material of grooved ceiling plate should be arranged to be identical to that of element substrate. However, it is expected that this arrangement makes the integrated formation difficult for the orifice plate and the grooved ceiling plate in some cases. In other words, the orifice plate should be made in the form of thin and long plate without any warping, which should be provided with fine discharge ports formed thereon. It is not easy to produce a plate of the kind using silicon material. Here, therefore, it is conceivable to arrange the structure in which the orifice plate is prepared separately from the grooved ceiling plate, and after the grooved ceiling plate and element substrate, both of which are formed with the same material, are bonded together, the orifice plate individually formed by the material suitable for the formation of orifice plate is bonded to the already bonded face of the grooved ceiling plate and element substrate on liquid discharging side.
[0009] Conceivably, however, the liquid discharge recording head thus structured as described above makes it extremely difficult to effectuate sealing after having positioned each of plural discharge ports formed on the orifice plate and each of liquid flow paths with respect to those liquid flow paths formed by bonding the element substrate and the grooved ceiling plate. In other words, filler should be injected as sealant between the orifice plate and the bonding face of the orifice plate having liquid flow paths formed therefor, but only around the discharge ports. For example, therefore, if sealing is not made sufficient due to a smaller amount of sealant thus filled, it is expected that liquid is allowed to leak from the bonded faces even to disable liquid discharges or, on the contrary, if filling agent is too much, a problem may be encountered that the discharge ports are clogged.
SUMMARY OF THE INVENTION
[0010] The main object of the present invention is to provide a liquid discharge recording head capable of sealing the circumference of discharge ports without clogging the discharge ports or liquid flow paths, and also to provide a method of manufacture therefor, as well as a liquid discharge recording apparatus.
[0011] The liquid discharge recording head of the present invention comprises an orifice plate having discharge ports formed therefor to discharge liquid, and the main body portion having liquid flow paths formed therein to be communicated with an opening arranged at the edge portion thereof, the discharge ports and the opening being bonded to communicate with each other. For this liquid discharge recording head, a sealing groove is arranged on the circumference of the opening along the bonded face, and filler is filled in the sealing groove. Also, the method of the present invention for manufacturing a liquid discharge recording head comprises the steps of bonding an orifice plate having discharge ports to discharge liquid formed therefor to the main body portion having liquid flow paths therein to be communicated with opening arranged on the edge portion and provided with a sealing groove on the circumference of the opening, so as to enable the discharge ports and the opening to be bonded and communicated with each other; and filling filler into the sealing groove. Further, the liquid discharge recording apparatus of the present invention comprises a liquid discharge recording head of the invention described above, and a member for mounting the liquid discharge recording head.
[0012] For such typical embodiments of the present invention, the sealing groove is formed to surround the element substrate and the grooved ceiling plate, that is, to surround the face having the opening of liquid flow paths formed therefor. The face other than the one having the sealing groove formed therefor is provided with the injecting groove for use of filling filler formed to be communicated with the sealing groove. As a result, it becomes possible to pour filler into the sealing groove from the injecting groove after the orifice plate is bonded to the face having the opening formed therefor to communicate the opening with the discharge ports of orifice plate so as to eliminate any gaps from which filler leaks between the orifice plate and the face having opening formed therefor. Thus, it is made possible to carry out sealing by distributing filler over the entire area of sealing groove in an amount required for sealing appropriately without clogging the circumference of openings or discharge ports.
[0013] Here, it may be possible to form the edge portion of injecting groove in a position on the face other than the one where the sealing groove is arranged, but not covered by the fixing margin of orifice plate which is used for fixing it to the main body portion. In this case, the edge portion of injecting groove, that is, the injecting port of injecting groove for injecting filler, is not concealed even if the fixing margin of orifice plate is fixed to the main body portion. Therefore, it becomes possible to execute the filling of filler after the fixing margin of orifice plate is fixed to the main body portion.
[0014] The face where the opening is formed may be extruded from the face of liquid supply member on the side where the sealing groove is formed. In this case, the orifice plate is pressed to the face having the opening is formed therefor, thus making it possible to prevent further any gap from being formed to allow filler to leak between the orifice plate and the face having the opening formed therefor.
[0015] The dimension of sealing groove may be the one that makes filler flowable by means of capillary force. In this case, the filler can be poured into the sealing groove without any external force exerted to enable the filler to flow after it has been injected from the injecting groove, and distribute it over the entire area in the sealing groove.
[0016] In accordance with the present invention, it becomes possible to provide a liquid discharge recording head capable of sealing the circumference of discharge ports reliably without allowing filler to clog discharge ports or liquid flow paths, and also, to provide the method of manufacture therefor, and liquid discharge recording apparatus as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a partially broken perspective view which shows the liquid discharge recording head in accordance with one embodiment of the present invention before the orifice plate is bonded.
[0018] [0018]FIG. 2 is a perspective view which illustrates the positional relations between the edge portion of the orifice plate, and the injection part where filler is injected.
[0019] [0019]FIGS. 3A, 3B, 3 C, and 3 D are side views which illustrate bonding of the orifice plate to the chip tank, and filling of filler.
[0020] [0020]FIGS. 4A, 4B, 4 C, and 4 D are side views which illustrate bonding of the orifice plate to the chip tank, and filling of filler.
[0021] [0021]FIG. 5 is a perspective view which shows the outer appearance of the liquid discharge recording apparatus in accordance with the present invention.
[0022] [0022]FIG. 6 is a perspective view which shows the principal part of the liquid discharge recording apparatus in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Hereinafter, with reference to the accompanying drawings, the description will be made of the embodiment in accordance with the present invention.
[0024] [0024]FIG. 1 is a partially broken perspective view which shows the liquid discharge recording head in accordance with one embodiment of the present invention before the orifice plate is bonded. Also, FIG. 2 is a perspective view which illustrates the positional relations between the edge portion of the orifice plate, and the injection part where filler is injected.
[0025] The liquid discharge recording head 15 comprises the element substrate 1 formed by silicon base plate where the base plate 4 and a plurality of energy generating elements la arranged on the base plate 4 ; the grooved ceiling plate 5 of the same material as the element substrate 1 , for which a plurality of grooves 7 are formed to become the liquid flow paths each of which corresponds to each of the energy generating elements 1 a ; the main body portion 20 provided with the chip tank 11 having the liquid supply path 11 a communicated with the liquid supply hole 9 of the grooved ceiling plate 5 , and the sealing groove 11 b where filler is filled; and the orifice plate 6 having a plurality of discharge ports 6 a formed for discharging liquid.
[0026] In this respect, the orifice plate 6 is not only configured as shown in FIG. 1, but may be configured as shown in FIG. 2 to be folded to provide fixing margins 6 c whereby to fix the orifice plate on the upper ace 11 f of chip tank 11 and the lower face 4 a of base plate 4 .
[0027] Each energy generating element la formed on the element substrate 1 is an electrothermal converting device, and heated with the provision of electric signals from control circuits (not shown) through a flexible cable (not shown). Also, the element substrate 1 is bonded and fixed onto the base plate 4 using bonding agent or the like.
[0028] The liquid supply hole 9 , the common liquid chamber 8 , and each of grooves 7 , which are formed on the grooved ceiling plate 5 by the photolithographic process or the like, are communicated, and the grooved ceiling plate 5 is bonded to the element substrate 1 so that each of grooves 7 and each of the energy generating elements 1 a are bonded, thus forming liquid flow paths having energy generating elements 1 a correspondingly. The flow path opening edge 2 of each flow path is formed on the flow path edge face 3 that faces the orifice plate 6 .
[0029] For the chip tank 11 , there is formed the liquid supply passage 11 a through which liquid is supplied from the ink tank (not shown) that contains liquid, such as ink, in the interior thereof to the liquid supply hole 9 of grooved ceiling plate 5 . The liquid supply portion 11 c of the chip tank 11 where the liquid supply passage 11 a is formed presses down the element substrate 1 and the grooved ceiling plate 5 and fix them to the base plate 4 . This pressure may be exerted by arranging a structure in the form of cantilever having the portion where the liquid supply portion 11 c abuts against the element substrate 1 and the groove ceiling plate 5 as functioning point or may be exerted by use of elastic member such as spring. In this respect, for the front face 11 h , the opening 11 g is formed to enable the liquid flow edge face 3 to be exposed. The flow path edge face 3 may be extruded from the front face 11 h . In this case, the orifice plate 6 is pressed to the flow path edge face 3 . Therefore, it becomes possible to prevent more the formation of any gap between the orifice plate 6 and the flow path edge face 3 from which filler is allowed to leak.
[0030] Also, for the upper face 11 f of chip tank 11 , the first slit lid and second slit 11 e (see FIG. 2), which are grooves for use of filler injection, are formed for injecting filler after the orifice plate 6 is bonded to the flow path edge face 3 to be described later. Also, for the front face 11 h , a sealing groove 11 b is formed to be communicated with the first and second slits 11 d and 11 e , and to surround all the flow paths, that is, to surround the opening 11 g . The first and second slits 11 d and 11 e , and the sealing groove 11 b are formed each by a dimension so as to allow filler to be filled by the flow that occurs due to capillary force. Also, as shown in FIG. 2, the injecting sections 21 of the first and second silts 11 d and 11 e , through which filler is injected, is formed on the location where the edge portion 6 b of fixing margin 6 c of orifice plate 6 is exposed even if this edge portion is positioned at the place indicated by two-dot chain line in FIG. 2 when the orifice plate 6 of such a type as being folded for fixation is fixed to the chip tank 11 .
[0031] The orifice plate 6 is bonded and fixed to the flow path edge face 3 by use of bonding agent or the like so that each of discharge ports 6 a faces each of the flow path opening 2 , respectively. If the shape of the orifice plate 6 is such that it has fixing margins 6 c as shown in FIG. 2, the other faces of the orifice plate 6 than the one that faces the front face 11 h are folded to the upper face 11 f side of chip tank 11 , and the lower face 4 a side of base plate 4 , and then, fixed to each of these faces. The fixing margin 6 c of orifice plate 6 may be fixed to the chip tank 11 mechanically, not necessarily by means of bonding agent or the like.
[0032] Now, the description will be made of the liquid discharges of the liquid discharge recording head 15 structured as described above. Liquid, such as ink, supplied from the ink tank is supplied to the common liquid chamber 8 by way of the liquid supply hole 9 through the liquid supply passage 11 a . After that, liquid flows into each of the flow paths. Then, in this condition, each of the energy generating elements 1 a is heated when electric signals are given by use of the control circuits. Thus, thermal energy is given to liquid, and liquid is discharged from discharge ports 6 a as droplets by utilization of the bubbling pressure of bubbles created in liquid by change of phases (film boiling) of liquid at that time.
[0033] Next, with reference to FIGS. 3A to 3 D and FIGS. 4A to 4 D, the description will be made of bonding of the orifice plate to the chip tank, as well as filling of the filler, in particular, among the manufacturing processes of the liquid discharge recording head. In this respect, FIGS. 3A to 3 D and FIGS. 4A to 4 D schematically illustrate the chip tank 11 , the element substrate 1 , the grooved ceiling plate 5 , and the base plate 4 as the main body portion 20 . Also, regarding slits, only the first slit 11 is shown and the second slit 11 e is not represented in them.
[0034] As shown in FIG. 3A, the orifice plate 6 is arranged at first to face the front face 11 h of chip tank 11 .
[0035] Then, as shown in FIG. 3B, each flow path opening 2 represented in FIG. 1 and each discharge port 6 of orifice plate are positioned to face each other, and the orifice plate 6 is bonded to the flow path edge face 3 . In this manner, the orifice plate 6 and the flow path edge face 3 are conditioned to present no gap between them.
[0036] Next, as shown in FIG. 3C, filler is injected through the first slit 11 d . At this juncture, the location of injection may be the injecting portion 21 , but the location is not necessarily limited thereto. Any location on the first slit 11 d will do if only filler can be injected. Here, filler may be injected through the second slit 11 e or may be injected through both first and second slits 11 d and 11 e simultaneously. After flowing into the sealing groove 11 b , the filler thus filled is distributed by capillary force to the entire area in the sealing groove 11 b which is formed to surround the circumference of flow path opening 2 . Here, the depth of sealing groove 11 b is 1 mm and the width is 1 mm. As the material of filler, it is preferable to use the one the sealing performance of which is not lowered for a long time even if it is in contact with liquid such as ink or can hardly be lowered. For such material, there is silicon sealant, for example.
[0037] Next, as shown in FIG. 3D, the fixing margins 6 c of orifice plate 6 are folded to the upper face 11 f side of chip tank 11 , and to the lower face 4 a side of base plate 4 , and fixed to them, respectively. Here, now that the leakage of liquid from the gap between the front face 11 h of chip tank 11 and the orifice plate 6 is prevented by the filler which is filled into the sealing groove 11 b , it may be possible to effectuate the fixation mechanically as described above, but not using bonding agent or the like. In this case, the orifice plate 6 may be fixed while being tensioned in the direction indicated by an arrow B.
[0038] So far, in conjunction with FIGS. 3A to 3 D, the description has been made of bonding the orifice plate 6 to the chip tank 11 , and also, of filling the filler for such a method of manufacture that the filling of filler is executed before the orifice plate 6 is folded. However, as shown in FIGS. 4A to 4 D, it may be possible to fill the filler after the orifice plate 6 is folded.
[0039] In other words, as shown in FIG. 4A, the orifice plate 6 is at first arranged to face the front face 11 h of chip tank 11 , and as shown in FIG. 4B, the orifice plate 6 is bonded to the flow path edge face 3 .
[0040] Then, as shown in FIG. 4C, the orifice plate 6 is bonded to fix the fixing margins 6 c to the upper face 11 f of chip tank 11 and the lower face 4 a of base plate 4 , respectively. In this state, the injecting portion 21 of the first silt 11 d and the second slit 11 e are not covered by the folded orifice plate 6 , but exposed.
[0041] Next, as shown in FIG. 4D, filler is injected through the exposed injecting portion 21 . In this manner, the filler is distributed by capillary force to the entire area of sealing portion 11 b , and seals the gap between the orifice plate 6 and the front face 11 h of chip tank 11 .
[0042] As described above, in accordance with the liquid discharge recording head of the present embodiment, each of the flow path openings 2 and each of the discharge ports 6 a of orifice plate 6 are positioned exactly, and the filler which is used for preventing liquid leakage is filled from the gap between the orifice plate 6 and the front face 11 h after the orifice plate 6 is bonded to the flow path edge face 3 . In other words, the filler is poured into the sealing groove 6 b after it is arranged not to form any gap where the filler is allowed to flow between the orifice plate 6 and the flow path openings 2 by bonding the orifice plate 6 to the flow path edge face 3 . As a result, there is no possibility that the filler which is poured into the sealing groove 6 b is allowed to overflow into the flow path edge face 3 , and clog any one of the flow path openings 2 . Also, it becomes possible to fill a desired amount of filler needed to seal so as not to cause any leakage of liquid that may take place if the filling amount of filler is made smaller with the anxiety that the clogging of the flow path openings 2 should be avoided.
[0043] [0043]FIG. 5 and FIG. 6 are views which schematically illustrate the printer that used ink jet recording method.
[0044] In FIG. 5, the apparatus main body M 1000 that forms the outer frame of printer of the present embodiment comprises a lower case M 1001 ; an upper case M 1002 ; an access cover M 1003 ; and the external member of outlet tray M 1004 and the chassis M 3019 (see FIG. 6) housed in the external member thereof.
[0045] The chassis M 3019 is structured by a plurality of metallic plate members having a designated robustness, and forms the skeleton of the recording apparatus so as to hold each of recording operation mechanisms to be described later.
[0046] Also, the lower case M 1001 forms substantially the lower half of the apparatus main body M 1000 , and the upper case M 1002 forms substantially the upper half of the apparatus main body M 1000 , respectively, and when both cases are assembled, a hollow structure formed with a housing space to contain therein each mechanism to be described later. On the upper face portion and front face portion thereof, each of the openings is formed, respectively.
[0047] Further, On end of outlet tray M 1004 is rotatively held by the lower case M 1001 , and by the rotation thereof, it is made possible to rotate the opening formed on the front face portion of lower case M 1001 to be opened or closed. Therefore, when recording operation is carried out, the outlet tray M 1004 is rotated toward the front face side so as to make the opening portion ready to serve. Then, each of the recorded sheets is expelled from that portion, and at the same time, each recording sheet P thus expelled is stacked one after another. Also, In the outlet tray M 1004 , two auxiliary trays M 1004 a and M 1004 b are housed, and each tray is drawn out forwardly as needed to enlarge or reduce the supporting area in three steps for each of the recording sheets accordingly.
[0048] One end of the access cover M 1003 is rotatively supported by the upper case M 1002 to make it possible to open or close the opening portion formed on the upper face. With the access cover M 1003 being open, it becomes possible to exchange recording cartridges H 1000 or ink tanks H 1900 housed in the interior of main body. In this respect, although not particularly shown, it is arranged so that when the access cover M 1003 is opened or closed, the extrusion formed on the reverse side thereof enables the cover open and close lever to be rotated, and that the rotated position of the lever is sensed by a microswitch in order to detect the open or closed condition of access cover.
[0049] Also, on the rear upper face of the upper case M 1002 , the power-supply key E 0018 and the resume key E 0019 are arranged to be depressible, and at the same time, an LED E 0020 is arranged. When the power-supply key is depressed, the LED E 0020 is illuminated to inform the operator that recording is ready. Also, the LED E 0020 is provided with various functions of indication, such as to inform the operation of printer trouble or the like by changing the way of illumination or illuminated colors or a buzzer E 0021 is sounded. In this respect, the structure is arranged so that when trouble or the like is resolved, recording can be resumed by depressing the resume key E 0019 .
[0050] Now, the description will be made of the mechanisms of recording operation provided for and held in the aforesaid printing apparatus main body M 1000 . As the mechanisms of the present embodiment, there are provided the automatic sheet feeding unit M 3022 that automatically feeds a recording sheet P into the apparatus main body; the carrier unit M 3029 that carries the recording sheet P which is fed out from the automatic feeding unit one by one to the desired recording position, and at the same time, carries the recording sheet P to the sheet expelling unit M 3030 from the recording position; and the recording unit to perform a desired recording on the recording sheet P carried to the carrier unit M 3029 , and the recovery unit (M 5000 ) that performs recovery process for the aforesaid recording unit or the like. The recording unit comprises the carriage M 4001 movably supported by a carriage shaft M 4021 ; and the recording head cartridge H 1000 which is detachably mounted on the carriage M 4001 . | A liquid discharge recording head comprises an orifice plate having discharge port formed therefor to discharge liquid, and the main body portion having liquid flow paths formed therein to be communicated with the opening arranged at the edge portion thereof, the discharge port and the opening being bonded to communicate with each other. For this liquid discharge recording head, a sealing groove is arranged on the circumference of the opening along the bonded face, and filler is filled in the sealing groove, hence making it possible to pour filler into the sealing groove from the injecting groove after the orifice plate is bonded to the face having the opening formed therefor to communicate the opening with the discharge port of orifice plate so as to eliminate any gaps from which filler leaks between the orifice plate and the face having opening formed therefor, and carry out sealing by distributing filler over the entire area of sealing groove in an amount required for sealing appropriately without clogging the circumference of opening or discharge port. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application, under 35 U.S.C. §371, of PCT/EP2007/060279, filed Sep. 27, 2007, which claims benefit of European Patent Application No. 07108932.0, filed May 25, 2007, and European Patent Application No. 06121563.8, filed Sep. 29, 2006.
BACKGROUND OF THE INVENTION
Filter aids are taken to mean additives which are used in solid-liquid separation processes in order, by formation of a porous precoat layer on the actual filter medium and/or by incorporation into the filter cake framework, to ensure separation of the solids with simultaneously sufficient permeability of the resultant filter cake.
As filter aids, use is made of both inorganic substances such as, for example, kieselguhr or aluminum oxides, or else synthetic polymers. Which individual filter aids are used depends on the field of application. In the filtration of beer, kieselguhr is one of the filter aids principally used.
For economic reasons it is advantageous when the filter aid can be regenerated. A regeneration over a plurality of cycles is particularly advantageous.
WO 02/32544 describes coextrudates of polystyrene and water−insoluble polyvinylpyrrolidone and use thereof as regenerable filter aids, but the regenerability is only mentioned quite in general.
WO 03/084639 describes coextrudates of thermoplastic polymers, apart from polystyrene, and water-insoluble polyvinylpyrrolidone and use thereof as regenerable filter aids, but the regenerability is only mentioned quite in general.
WO 92/11085 describes filter aids based on agglomerates of crosslinked polyvinylpyrrolidone and fibrous thermoplastic polymers such as, for example, polyethylenes or polyamides, and use thereof as filter aids. It is noted quite in general terms that the filter aids are regenerable.
EP-A 611249 describes a process for regenerating a filter aid by addition of enzymes. Only the treatment of kieselguhr is described specifically.
EP-A 253 233 describes the regeneration of kieselguhr by means of sodium hydroxide solution.
DE 19625481 describes the regeneration of kieselguhr in the presence of a mixture of nonionic surfactants.
DE 196 52 499 describes the regeneration of filter aids of kieselguhr, the filter aids first being treated with enzyme solutions and thereafter first with weak alkalis, then with weak acids, and finally with an oxidizing agent.
WO 03/008067 describes the regeneration of filter aids, first flushing with hydroxide solution on the intact filter cake and subsequently, also on the intact filter cake, a neutralization of the pH by flushing with acid being performed. WO 96/35497 discloses regeneration of filter aids made of synthetic polymers by washing with sodium hydroxide solution and washing with an enzymatic compound, the treatment being performed in situ in the filter unit on the intact filter cake. What is described is especially the regeneration of a polyamide filter aid.
However, it has been found that the previously known processes for the filter aids to be treated according to the invention do not give satisfactory results. Using these processes, satisfactory regeneration of the coextrudate over a plurality of cycles is not possible, and the good filtration properties of the fresh filter aid with respect to pressure rise during filtration and also the filter and wash resistances in the regenerated material are not retained.
Customarily, filter resistances and washing resistances which exceed a certain value, depending on technical field of application and filter aid, are not considered acceptable in practice, since otherwise they provoke excessively high rates of pressure increase during the beer filtration, which results in uneconomically short filtration times. In the case of beer filtration, for example the filter resistances and washing resistances for the filter aid to be treated according to the invention should as far as possible not exceed a value of 10×10 12 mPas/m 2 .
Filter resistance is the product of fluid viscosity and resistance to flow during the buildup of filter cake, and washing resistance is the product of fluid viscosity and resistance to flow on flow through the filter cake which is already built up. Determination of the corresponding measured values is known to those skilled in the art and is extensively described in VDI Guideline 2762.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a process for regenerating a filter aid which is a co-extrudate of a water-insoluble polyvinylpyrrolidone and a thermoplastic polymer by treatment with aqueous alkali and with the use of enzymes. The invention further relates to regenerated materials which are obtained with the aid of the process according to the invention, and also use thereof in the filtration of beer.
It was an object of the invention to find a process for regenerating the abovementioned filter aid, which process enables repeated use of the filter aid at economical values of filtrate throughput and filter life and also sufficient clarification action, and also the provision of a corresponding regenerated material. In addition there was the problem of finding a process in which breakdown of the polymeric components does not occur.
Accordingly, a process was found for regenerating a filter aid which is a coextrudate of a water-insoluble polyvinylpyrrolidone and of a thermoplastic polymer by treatment with aqueous alkali and enzymes, which comprises first subjecting the filter aid to a treatment with aqueous alkali and subsequently performing a treatment with an enzyme solution, subsequently thereto carrying out a further treatment with aqueous alkali and if appropriate a treatment with a surfactant.
The process is preferably carried out in such a manner that the enzyme treatment is not carried out in situ on the intact filter cake, but that the filter cake is removed whilst destroying the particle composite and is treated outside the filter unit.
According to the invention, the pressure-resistant vessel and the filter element situated therein in which the filtration takes place are termed the filter unit. As filter elements, all known devices therefor such as, for example, filter candles or disk filters can be present.
The regeneration process according to the invention is suitable as described for filter aids which are obtained as coextrudates of water-insoluble polyvinylpyrrolidone and a thermoplastic polymer.
DETAILED DESCRIPTION OF THE INVENTION
Mixtures of chemically different polymers which are obtained by joint processing of the individual components in the extruder are termed coextrudates, with the coextrudates not being able to be fractionated into the individual components by physical methods. In the case of the present invention, the coextrudates preferably comprise a thermoplastic polystyrene component and a non-thermoplastic water-insoluble crosslinked polyvinylpyrrolidone. In the co-extrusion, the polyvinylpyrrolidone component is dispersed in the molten thermoplastic. In addition to polystyrene, suitable thermoplastics are, for example, polyethylene, polypropylene or polyamides.
As polystyrene component, all current polystyrene types come into consideration, such as standard polystyrene, impact-modified polystyrene (SB types) such as copolymers of styrene and butadiene, or high impact-modified polystyrene (HIPS types), for example polystyrene modified by polybutadiene rubber or styrene-butadiene rubber. Such polystyrenes are commercially available, for example as PS 158 k, PS 486 M or Styrolux® (BASF) or Empera 153F (Nova Innovene) or Edistir® N2987, Edistir® N1782 (Polimeri Europa). In addition, anionically polymerized polystyrene can be used.
According to the invention, the coextrudates, in addition to the polystyrene component, as second polymer component comprise water-insoluble crosslinked polyvinylpyrrolidone polymers which are not gel-forming on water absorption and are also termed in the literature popcorn polymers (cf. J. W. Breitenbach, Chimia, Vol. 21, pp. 449-488, 1976). In pharmacopeias such as USP or Ph. Eur., such polymers are called crospovidones. Such polymers have a porous structure and are rich in cavities. The polymers are also, as stated, not gel-forming on water absorption. The swelling volume of such polymers in water at 20° C. is customarily in the range from 2 to 10 l/kg, preferably 4 to 8 l/kg.
Such crospovidones are commercially available, for example as Divergan® types from BASF or as Polyplasdone® types, from ISP.
The coextrudates can comprise 95 to 20% by weight, preferably 75 to 60% by weight, polystyrene and 5 to 80% by weight, preferably 25 to 40% by weight, crospovidone, based on the total weight of the coextrudate.
Production of the coextrudates to be treated according to the invention is known per se and is described, for example in WO 02/32544 or WO 03/084639.
The coextrudates, for use as filter aids, are customarily adjusted by milling processes to mean particle sizes of 20 to 100 μm. Mixtures of milled coextrudates having different particle size distributions can also be used.
As water-insoluble polyvinylpyrrolidone, in particular a crosslinked homopolymer of N-vinylpyrrolidone comes into consideration, which is also called crospovidone. Such products are commercially available.
Suitable thermoplastic polymers are, for example, polystyrene types, polyamides, polyolefins such as polyethylene or polypropylene. Preferably, as thermoplastic polymers, use is made of polystyrene.
The process according to the invention is carried out in such a manner that the filter aid loaded with impurities is first subjected to a treatment with an aqueous alkali. Suitable aqueous alkalis are, especially sodium hydroxide solution or potassium hydroxide solution, particularly preferably sodium hydroxide solution. The concentration is customarily 0.5 to 5% by weight solid base/l in particular 1 to 5% by weight, particularly preferably 2 to 3.5% by weight The treatment time depends on the amount of the filter aid to be treated. The treatment time Is customarily from 15 to 180 minutes, preferably from 45 to 120 minutes
The treatment with an aqueous alkali is followed by an enzymatic treatment of the filter aid. It can also be advisable, between the first treatment step with an alkali and the enzymatic treatment, to perform a washing step using cold or hot water or a suitable acid. Suitable acids are mineral acids such as, for example, hydrochloric acid, nitric acid or phosphoric acid or else organic acids such as citric acid, lactic acid and carbonic acid. According to a preferred embodiment of the invention, a washing step is compulsory.
Before the treatment with an enzyme, the pH is customarily adjusted to values<pH 7, preferably to pH 3.5 to 5.5.
The pH can be adjusted, for example using mineral acids such as phosphoric acid, nitric acid, sulfuric acid or, in the case of glass apparatuses, also with hydrochloric acid. In addition, citric acid or lactic acid is suitable.
Suitable enzymes are in principle proteases, glucosidases, amylases or pectinases and all other enzymes which are able to lyse yeast cells, or else mixtures of enzymes. Such enzymes or enzyme mixtures are commercially available.
Suitable enzymes are preferably glucanases, particularly preferably β-1,3-glucanases. In addition to a B-glucanase activity, further enzyme activities may also be present in the enzyme solution used in accordance with the invention.
Use is customarily made of the enzymes in the form of aqueous solutions.
The suitable amount of enzyme depends on the activity of the respective enzyme and the loading of the unfiltered slurry and the filter cake with impurities.
The activity can be determined by those skilled in the art by a few simple experiments by studying what amount of enzyme is required in order to lyse a defined number of yeast cells. Then, the dosage can proceed as a function of the haze or loading with yeast cells and of the volume of unfiltered slurry to be filtered.
The enzyme treatment can be performed at 25-80° C., preferably 35-60° C., most preferably 40-50° C. The time depends on the amount of filter aid and loading with yeast cells. The time is customarily from 30 to 300 minutes, preferably from 100 to 180 minutes.
The active units can be determined as described below:
One active unit U is defined according to the invention as the decrease in extinction at 800 nm by 0.04/min in an enzyme assay at pH 4.0 and 45° C. within the first 10 min. As substrate in this assay, use can be made of brewer's yeast having 1-3×10 7 cells/ml which has been treated in advance with sodium hydroxide solution.
Based on the EBC value of the unfiltered slurry at 25° C. and also the filtered volume and with consideration of the above described active units, a recommended dosage is of 0.2 U/(EBC×hL) to 12 U/(EBC×hL), preferably 1 to 5 U/(EBC×hL).
(EBC: European Brewery Convention; standard test for determination of haze values.)
With respect to the yeast cell count in the filter cake to be regenerated, a dosage of 3 to 170 U/10 10 yeast cells is advisable, preferably 5 to 85 U/10 10 yeast cells, In particular 5 to 20 U/10 10 yeast cells.
Subsequently to the enzymatic treatment, a second treatment step with an aqueous alkali proceeds under the conditions described for the first treatment step with an alkali. Between the enzymatic treatment and the alkali treatment, if desired, again a washing step with cold or hot water can proceed.
If desired, the filter aid can also be treated with an aqueous surfactant solution or surfactant dispersion. The concentration of surfactant, based on the total weight of the solution, can be 0.01 to 4% by weight, preferably 0.01 to 1.5% by weight, most preferably 0.1 to 0.75% by weight. Suitable surfactants are both anionic and nonionic surfactants. Mixtures of surfactants can also be used.
Suitable ionic surfactants can be the following: fatty alcohol sulfates such as sodium dodecyl sulfate or ammonium dodecyl sulfate, fatty alcohol ether sulfates, alkyl sulfoacetates, fatty alcohol esters of phosphoric acid, fatty alcohol ether phosphates, alcohol esters of phosphoric acid such as trisobutyl phosphate, monoalkyl or dialkyl esters of sulfosuccinic acid such as dioctyl sodium sulfosuccinate, alkyl sulfonates, alkylbenzenesulfonates such as dodecylbenzenesulfonic acid.
Nonionic surfactants which come into consideration are:
fatty alcohol ethoxylates such as, for example, a C 13 -fatty alcohol having 6 EO units, alkylphenolethoxylates, polyoxyethylene esters of fatty acids, polypropylene glycol ethoxylates, fatty acid mono- and di-glycerides and also the corresponding ethoxylates, partial glycol esters of fatty acids, sorbitan esters of fatty acids or polyoxyethylene-sorbitan esters of fatty acids.
The treatment with the surfactant can be performed simultaneously with the second treatment step with aqueous alkali, or In a downstream treatment step. The surfactant treatment can also be performed before the second treatment step with aqueous alkali.
The treatment with aqueous surfactant Is a preferred process variant.
This treatment step can be followed by a further washing step with cold or hot water.
The process according to the invention is carried out, according to one embodiment, in such a manner that the enzymatic treatment step is not performed on an intact filter cake or a precoat layer, but In a separate device. This separate device can be, for example, a kettle or other suitable vessel, and is preferably fitted with an agitator device. However, the treatment may also be performed on the filter, if appropriate.
The first treatment step with aqueous alkali, according to a process variant, can proceed on the intact filter cake. Before the enzymatic treatment, the filter aid is then removed from the filter element with dispersion of the particle composite in the filter cake, removed from the filtration unit and treated in a separate device. The enzymatic treatment is performed on an aqueous suspension or slurry of the filter aid which customarily has a solids content of 5 to 25% by weight.
According to another process variant, the first treatment with aqueous alkali can also be performed on a filter cake removed from the filter unit whose particle composite has been disintegrated and which is an aqueous slurry or suspension.
After the enzymatic treatment, the second treatment step with aqueous alkali can likewise be performed, if appropriate, in the presence of surfactants, on the aqueous slurry or suspension of the filter aid. According to a process variant, the filter aid, however, is applied as precoat in a suitable filter and the newly formed filter cake is subjected to the further treatment steps.
The regeneration steps which are performed by flowing through the intact filter cake can be carried out at all pressure differences between the feed side and the filtrate side of the filter which, on the one hand, allow flow through the filter cake and, on the other hand, do not exceed the pressure resistance of the filter housing. This pressure difference is customarily between 1 kPA and 800 kPa.
The enzymatic treatment, and also if appropriate the first and/or the second treatment step with an alkali, and also the surfactant treatment in the separate device, are customarily performed at atmospheric pressure. It is also conceivable for at least one of the steps to be carried out at overpressure.
The temperature of the aqueous alkalis used for the regeneration can be 5 to 95° C., preferably 45 to 95° C. just like the aqueous surfactants.
The completely regenerated filter aid can remain in the filter unit and be used immediately for filtration. The regenerated filter aid, however, can alternatively be removed from the unit, dried and stored.
By means of the process according to the invention, successful regeneration of the coextrudate over a plurality of cycles is possible, the good filtration properties of the fresh filter aid with respect to pressure rise during filtration and also the filtration and washing resistances in the regenerate being very largely retained.
Those skilled in the art, depending on beer type and yeast load, can add fresh filter aid to the initial precoat or continuous metered addition.
The process according to the invention is suitable for regenerating filter aids for any type of precoat filters having a precoat layer deposited on filter elements.
The regeneration process according to the invention is suitable, in particular, for use in beer filtration.
The main assessment feature of the regeneration is the pressure rise with time. (pressure difference between feed side and filtrate side of the filter) in beer filtration following regeneration. An excessive pressure rise or an increase in the pressure rise rate from experiment to experiment indicates incomplete regeneration of the filter aid.
An approximately constant pressure rise rate from experiment to experiment, which is in the range of that of the fresh product, indicates complete regeneration. The haze load in the unfiltered slurry customarily fluctuates and has a considerable effect on the pressure rise rate. This effect can be virtually eliminated by normalizing the pressure difference using the respective (likewise normalized to a standard value) unfiltered haze (25°-EBC). The haze normalized pressure can be calculated in this case by dividing the measured pressure by the quotient of the actual unfiltered haze and a standard haze of 30 EBC (25°-EBC).
A further criterion for evaluating the successful regeneration is the filter resistance or washing resistance of the regenerated material. If these values are significantly increased compared with the fresh product and demonstrate an increase from cycle to cycle, likewise incomplete regeneration must be assumed.
EXAMPLES
In the examples hereinafter, as filter aid, use was made of a coextrudate of 70% by weight polystyrene PS 158K and 30% by weight crospovidone, based on the total amount of coextrudate. It was a mixture of two milling fractions having mean particle sizes D [0.5] 54 μm (45% by weight) and D [0.5] 28 μm (55% by weight).
For the enzyme treatment, an aqueous solution of a 1,3-β-glucanase (Trenolin Filtro DF, Erbslöh) was used.
Beer filtration was performed, using hazy beer, as precoat filtration by means of a pilot candle filter (gap width 70 μm, filter area 0.032 m 2 , throughput 15 l/h).
The filter resistances were determined as specified in VDI Guideline 2762.
Example 1 (Comparative Example)
Series Experiment Using 4 Filtration-Regeneration Cycles; Example of an Incomplete Regeneration
Regeneration Conditions
First the residual volume of beer in the unit was removed using cold drinking water.
Regeneration was performed by flushing for 15 min with hot water (85° C.), followed by flushing for 15 min with 3% strength by weight aqueous NaOH (85° C.), and renewed flushing with hot water (15 min, 85° C.). All flushing was carried out on the still-intact. filter cake.
Pressure-rise Curves: (see FIG. 1 )
FIG. 1 : Haze-normalized pressure difference as a function of the filtration time (normalization to 30 EBC (25° C.)); cycle numbers: ♦-1, ▪-2, x-3, ▴-4
It may be seen that the gradient of the pressure curves increases from cycle to cycle and significantly higher pressure differences are measured than in the case of the fresh product.
Filter Resistances of the Regenerated Material: (see FIG. 2 )
FIG. 2 : Filter resistances as a function of the number of regenerations
The filter resistance of the regenerated material increases after each regeneration, which indicates the accumulation of biomass in the regenerated material.
Example 2
Series Experiment Using 10 Filtration-Regeneration Cycles, Example of a Successful Regeneration
Regeneration Conditions
After the end of the beer filtration, the volume of residual beer in the unit was flushed out with cold drinking water. Subsequently, hot water flushing was performed by flushing the filter cake which was still intact and situated on the filter with drinking water (85° C.) for a period of 15 min, at a throughput of 30 l/h. Subsequently, the filter cake was flushed with aqueous 2% strength by weight NaOH (85° C.) for a period of 10 min with the flushing liquid being discarded, subsequently 50 min, likewise with aqueous NaOH in a recirculation procedure, in both cases at a throughput of 15 l/h. Thereafter, cold water flushing was performed to remove the residual volume of NaOH solution in the unit and cooling by flushing with cold drinking water (5-10° C) for 15 min at 30 /h. Subsequently thereto, an enzyme treatment was performed, with the filter cake being removed before the treatment and transferred Into a stirred tank situated outside the filter unit. There a treatment with an aqueous solution of a β-1,3-glucanase was performed at pH 5 and 47° C. for 120 min. The enzyme quantity was 10.9 U/EBC×hL. After the enzyme treatment was ended, the filter aid was again applied as precoat to the filter candle via a metering device at a throughput of 30 l/h. Thereafter the resultant filter cake was flushed with an aqueous solution comprising NaOH and Na-dodecyl sulfate (SDS) (1% strength by weight NaOH, 2% strength by weight SDS) at a flushing solution temperature of 85° C., for 15 min with the flushing liquid being discarded, 10 min in recirculation procedure, at a throughput of 15 l/h. This was followed by hot water flushing of the filter cake with drinking water at 85° C. for 15 min at a throughput of 30 l/h, and thereafter a flushing with cold drinking water (5-10° C.) for 15 min at 30 l/h.
The pressure rise curves may be seen in FIG. 3 .
FIG. 3 : Haze-normalized pressure difference as a function of the filtration time (normalization to 30 EBC (25° C.)); cycle numbers: ♦-1, ▪-2, x-3, ▴-4, Δ-5, □-6, ⋄-7, +-8, ∘-9, ●-10
The individual pressure rise curves lie in a band around that of the starting filtration using fresh product and show no systematic rise of the gradient.
Filter and washing resistances of the regenerated material:
Although the filter and washing resistances (see FIG. 4 ) show experiment-specific variations, they do not show a continuous rise.
FIG. 4 : Filter resistances (grey) and washing resistances (hatched) as a function of the number of regenerations
Example 3
Series Experiment Using 11 Filtration-Regeneration Cycles, Second Example of a Successful Regeneration
Regeneration Conditions
The regeneration was performed in a similar manner to example 2, but the enzyme concentration was, depending on cycle 1.1-2.5 U/EBC×hL.
The pressure rise curves may be seen in FIG. 5 .
FIG. 5 : Haze-normalized pressure difference as a function of the filtration time (normalization to 30 EBC (25° C.));
cycle numbers: ♦-1 , ▪-2, x-3, ▴-4, Δ-5, □-6, ⋄-7, +-8, ∘-9, ●-10, −-11
Again it may be seen that there was no systematic rise with respect to the gradient of the pressure rise curves. The scattering of the experimental data is firstly caused by the differing haze of the unfiltered slurry (the normalization attenuates this only in part) and secondly by the different enzyme quantities used.
Filter and washing resistances of the regenerated material
The filter and washing resistances (see FIG. 6 ) show some increases compared with the fresh product, but no continuous rise as in example 1.
FIG. 6 : Filter resistances (grey) and washing resistances (hatched) as a function of the number of regenerations
Example 4
The experimental procedure was performed substantially similarly to example 2, but with the following differences:
At the start of the regeneration, flushing was performed using aqueous sodium hydroxide solution for a time of 60 min, then 15 min with the flushing liquid being discarded, 45 min in a recirculation procedure.
The amount of enzyme used was 1.4 U/(EBC×hL).
The treatment (duration: 25 min) with an aqueous solution comprising 1% by weight NaOH and 0.5% by weight Na dodecyl sulfate, was carried out directly after the enzyme treatment outside the filter unit in a stirred tank. After this treatment the material was applied to the filter as a precoat and hot water (85° C.) flowed through the filter cake for 15 min, and subsequently cold water (5-10° C.) for 15 min at a throughput of 30 l/h.
The pressure course of the filtration is shown in FIG. 7 , the filter and washing resistances are shown in FIG. 8 .
FIG. 7 : Haze-normalized pressure difference as a function of filtration time (normalization to 30 EBC (25° C.)); cycle numbers: ♦-1, ▪-2, x-3, ▴-4, Δ-5, □-6, ⋄-7, +-8 FIG. 8 : Filter resistances (gray) and washing resistances (hatched) as a function of the number of regenerations
There is no monotonic increase in filter and washing resistances as a function of number of cycles, which means that the regeneration had been successful. | Processes comprising: (i) providing a filter aid comprising a co-extrudate of a water-insoluble polyvinylpyrrolidone and a thermoplastic polymer, (ii) treating the filter aid with aqueous alkali; (iii) subsequently treating the filter aid with an enzyme; and (iv) subsequently thereto carrying out a second treatment with aqueous alkali, to provide a regenerated filter aid, and uses therefor. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a circuit for monitoring temperatures of electrical switching devices, and in particular the temperature of the contacts in circuit breakers.
As with most equipment used in the electrical field, temperature is a limiting factor in the life expectancy of circuit breakers. If temperatures in excess of those for which the circuit breakers have been designed are reached, the insulation used in the circuit breaker degrades, and deterioration of the contacting members (i.e. contacts) occurs. By monitoring the temperature of a circuit breaker, appropriate action can be taken to ensure that the temperature of the circuit breaker does not exceed the design (or rated) limits.
Direct measurement of the temperature of the contacts of a circuit breaker is not always possible, particularly when high voltages are involved and the integrity of the circuit breaker insulation must be maintained. Accordingly, some type of indirect temperature monitoring must be devised to handle situations of this type. It is an object of the present invention to provide means for indirectly monitoring the temperature of electrical switching devices.
SUMMARY OF THE INVENTION
A circuit for monitoring the temperature of the contacts of an electrical switching device, according to this invention, comprises an electrical analogue circuit of the thermal characteristics of the switching device to be monitored. The analogue circuit comprises electrical resistance and capacitance, interconnected so as to form an electrical model of the heat flow paths and capacitances, respectively, in the circuit breaker. In the preferred embodiment of this invention, there is also provided a temperature sensing device to sense the temperature of the exterior of the switching device and introduce to the analogue circuit a voltage signal, the magnitude of which is proportional to the exterior temperature. The analogue circuit is connected in a series circuit relationship with a current controller. The current controller, as the name implies, controls the amount of current flowing through the analogue circuit. The current controller is in turn controlled by a voltage control signal the magnitude of which is proportional to the amount of current being carried by the circuit breaker. The current controller is operated in such a fashion that the current it lets flow through the analogue circuit is proportional to the square of the voltage control signal.
Expressed in another way, the present invention is a circuit for monitoring the temperature of the contacts of an electrical switching device, the circuit comprising: an electrical, resistance-capacitance analogue circuit of the thermal system of the switching device; at least one switch for modifying the analogue circuit to account for different methods of cooling the switching device; a current controller in series circuit relationship with the analogue circuit for controlling the flow of current through the analogue circuit; a load sensing means, both for obtaining a control signal that is proportional to the magnitude of the current conducted by the switching device, and for applying the signal to the controller for controlling the current conduction thereof; and at least one voltage level detector connected across the capacitance of the analogue circuit for measuring the voltage level thereof, the voltage level being representative of the temperature of the contacts of the switching device.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiment of this invention will be described in more detail with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of the invention in simplified form;
FIG. 2 is a simplified schematic diagram of one possible circuit to be used as the resistance-capacitance analogue in FIG. 1;
FIG. 3 is a simplified schematic of the preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a simplified block diagram of the invention comprising a resistance-capacitance analogue circuit 10 connected in a series circuit relationship with current controller 11. Load sensing means 12 is connected to controller 11, and voltage level detector 13 is connected to analogue circuit 10.
Resistance-capacitance analogue circuit 10 is essentially an electrical network comprising capacitance and resistance, and is designed to duplicate electrically the thermal capacitance and resistance, respectively, of the circuit breaker to be monitored. Analogue circuit 10 will be described in more detail in reference to FIGS. 2 and 3.
Current controller 11 (FIG. 1) varies the amount of current that flows through analogue circuit 10. A DC voltage supply (common bus 50 and negative voltage supply 51) is connected across the series connection of analogue circuit 10 and controller 11 to enable a current to flow therethrough. Load sensing means 12 monitors the current (3 phase in this embodiment) flowing through the three-phase circuit breaker (not shown) and produces a negative DC voltage, the magnitude of which is proportional to the highest AC current (i.e. the largest current of the 3 phases). This negative DC voltage is then fed to controller 11 to provide a control signal 40 for controller 11. Current controller 11 is made such that it allows current to pass through itself (and also through analogue circuit 10 since they are in series) at a rate which is proportional to the square of control signal 40 (which, in turn, is proportional to the highest current in the circuit breaker).
Resistance-capacitance analogue circuit 10 is an electrical analogue of the thermal characteristics of the circuit breaker. The current I which passes through analogue circuit 10 (i.e. from terminal 24 to terminal 25) via controller 11, simulates the heating effect of the circuit breaker due to current passing through the breaker. In very simplistic terms, analogue circuit 10 comprises a capacitance to store current and thus represent the heat stored in the circuit breaker, and a resistance in parallel with the capacitance to represent heat loss due to cooling of the circuit breaker. Voltage level detector 13 measures the voltage level (or magnitude) across the capacitance in analogue circuit 10 and gives an indication when the voltage level across the capacitance exceeds a predetermined limit.
FIG. 2 depicts a simplified schematic of one possible capacitance analogue circuit 10, according to this invention, but not the preferred circuit. The circuit 10a of FIG. 2 is simpler than the preferred circuit for analogue circuit 10, so FIG. 2 will be discussed first (note: the numeral 10 is used to refer to the resistance-capacitance analogue circuit in general; numeral 10a is used to refer to one specific embodiment of circuit 10 as shown in FIG. 2; and numeral 10b is used to refer to a second and preferred embodiment of circuit 10 as shown in FIG. 3).
The circuit 10a of FIG. 2 comprises a capacitor 14 connected in series with a pulsed switch 15, a diode 16 and a resistor 17; resistor 18 is in parallel with the series connection of diode 16 and resistor 17. The series circuit connection of switch 19 and resistor 20 is connected in parallel to resistor 18. Resistor 21 is connected in parallel to the series circuit connection of capacitor 14, switch 15, diode 16 and resistor 17. The series circuit of switch 22 and resistor 23 is connected in parallel to resistor 21. Terminal 24 is connected to zero voltage potential (i.e. common bus 50), and terminal 25 is connected to current controller 11.
The effect of circuit 10a is to attempt to duplicate, electrically, the thermal characteristics of a circuit breaker. In this regard, capacitor 14 represents the thermal capacity of the circuit breaker. Since the thermal capacity of the circuit breaker is large, capacitor 14 should also be made large. This is not always convenient to do. In FIG. 2 a smaller capacitor 14 is employed, but its effective capacitance is made much larger by the use of pulsed switch 15. Switch 15 is turned "on" and "off" by a pulse generator (not shown) such that the "off" time is very much greater than the "on" time (e.g. 1000:1). The time constant of circuit 10a is multiplied by this factor (i.e. 1000) and the effective time contant of circuit 10a is thus one thousand times what it would otherwise be without switch 15. The use of a pulsed switch in this manner is known and Canadian Pat. No. 958,082 issued Nov. 19, 1975 by James S. Mark describes this general concept.
The purpose of diode 16 and resistor 17 is to provide for different time constants between heating and cooling of the circuit breaker. When the circuit breaker is heating, a current Ia is flowing through circuit 10a as shown, and diode 16 is biased on and thus conducting with current flowing through resistor 17. During cooling of the circuit breaker, current Ia does not flow, diode 16 is biased off and resistor 17 has no effect on circuit 10a, and thus the effective resistance and the time constant of the circuit increases.
Switches 19 and 22 are used to modify circuit 10a and thereby account for different methods of cooling the circuit breaker. When the circuit breaker is cooled by radiation and natural convection (i.e. not fan cooled) switch 19 is normally open (marked N.O. in FIG. 2) and switch 22 is normally closed (marked N.C. in FIG. 2). When the fan is turned on (which is the case once the circuit breaker reaches a predetermined upper temperature limit) switch 19 closes, and switch 22 opens. Accordingly, both the time constant and the steady state level of circuit 10a are thus adjusted to match the thermal characteristics for both the fan cooling and the non-fan cooling mode of operation.
FIG. 3 is a simplified schematic showing the preferred embodiment of the present invention. FIG. 3 shows the preferred form of resistance-capacitance analogue circuit 10 (the preferred analogue is indicated by the numeral 10b in FIG. 3) connected in a series circuit relationship with current controller 11. The suffix "b" is used in FIG. 3 to refer to those items which have essentially the same function in FIG. 3 as do the same numbered items, less the suffix, in FIG. 2. Load sensing means 12 is shown connected to controller 11 and voltage level detector 13 is shown connected to analogue circuit 10b. Additionally, a Resistance Temperature Detector (RTD) 26, in a series circuit relationship with RTD measurement circuit 27 is connected between the common bus 50 (zero voltage potential) and analogue circuit 10b, as shown in FIG. 3. It can be seen that analogue circuit 10b of FIG. 3 is similar to analogue circuit 10a of FIG. 2. In analogue circuit 10b, capacitor 14b, switch 15b, diode 16b and resistor 17b are all connected in a series circuit relationship. Resistor 18b is parallel to the series connection of diode 16b and resistor 17b. Switch 19b and resistor 20b are connected in a series circuit relationship and are in parallel with resistor 18b. However, resistor 21b is connected to RTD measurement circuit 27, unlike resistor 21 (FIG. 2) which was connected directly to the common bus 50. The series circuit connection of resistor 23b and 22b is in parallel with resistor 21b and a diode 28 is connected from the junction of switch 15b and diode 16b to RTD measurement circuit 27, with the polarity as indicated in FIG. 3.
Analogue circuit 10b functions in much the same manner as did analogue circuit 10a is that now switch 22b and resistor 21b are connected to RTD measurement circuit 27 rather than to the common bus 50. Additionally, diode 28 has been inserted. Diode 28 is used so that when power is applied to analogue 10b, capacitor 14b rapidly charges to the voltage at the output of RTD measurement circuit 27. This provides an "instant on" feature.
The operation of RTD 26 and RTD measurement circuit 27 is known in the art, so that they will not be discussed in much detail. Canadian Pat. No. 962,088 issued Feb. 4, 1975 to D. R. Boothman and D. W. Nutt shows temperature measurement circuits of this general type. RTD 26 is basically a resistance, such as a bar of copper, which changes its resistance, approximately linearly, with temperature. RTD measurement circuit 27 acts as a current "sink" to allow current to flow from the common bus 50 via RTD 26 to circuit 27 and eventually to the negative voltage supply 51. Additionally, circuit 27 measures the voltage drop across RTD 26 to get a measurement of the resistance of RTD 26 and consequently an indication of the temperature of RTD 26. The output of circuit 27 is a negative DC voltage (relative to the common bus 50) the magnitude of which is proportional to the temperature of RTD 26. For the circuit of FIG. 3, the output of circuit 27 was designed so that zero volts corresponds to 0° C., -1 volt corresponds to + 20° C and the voltage output of circuit 27 is approximately linear with respect to temperature.
Attention will now be directed to current controller 11 which is connected in series with resistance-capacitance analogue circuit 10b between the common bus 50 and the negative voltage supply 51. As has been stated previously, current controller 11 regulates the current I b flowing through itself, from the common bus 50, via analogue circuit 10b to the negative voltage supply 51. Controller 11 regulates the current I b such that current I b is proportional to the square of the largest current sensed by load sensing means 12.
As can be seen from FIG. 3, controller 11 comprises three operational amplifiers 29, 30 and 31. The outputs of these amplifiers are connected to the bases of transistors 32, 33 and 34 respectively, as shown in the Figure. The collectors of transistors 32, 33 and 34 are joined together and are connected to terminal 25 which is in turn connected to resistor 18b of analogue circuit 10b. The emitter of transistor 32 is connected to the negative voltage supply 51 via resistor 35. Also, the emitter of transistor 32 is connected to the inverting (-) input of amplifier 29.
The emitter of transistor 33 is connected to the negative voltage supply 51 via resistor 36. The emitter of transistor 33 is also connected to the inverting (-) input of amplifier 30. The inverting (-) input of amplifier 30 is additionally connected, via resistor 37, to the common bus 50. The emitter of transistor 34 is connected to the negative voltage supply 51 via resistor 38. The emitter of transistor 34 is also connected to the inverting (-) input of amplifier 31. The inverting (-) input of amplifier 31 is also connected, via resistor 39, to the common bus 50. The non-inverting (+) inputs of each amplifier 39, 30 and 31 are connected together and are connected to load sensing means 12 so as to receive a control signal 40 indicative of the maximum current flowing through any phase of the circuit breaker.
Current controller 11 responds to signal 40 in such a fashion that initially only transistor 32 is conducting current, and transistors 33 and 34 are biased into the "off" state and are not conducting current. Transistor 32 remains the only transistor in controller 11 to conduct current until signal 40 reaches a level indicative of the circuit breaker carrying 0.7 times its rated capacity (rated capacity is 2500 amp., non-fan cooled, for this embodiment). At that point, transistor 33 also begins to conduct and both transistors 32 and 33 are conducting, while transistor 34 remains biased "off" and non-conducting. When signal 40 reaches a level indicative of the circuit breaker carrying 1.2 times its rated capacity, transistor 34 also begins to conduct and all three transistors (i.e. transistors 32, 33 and 34) of controller 11 are conducting current. As stated previously, the effect thus produced by controller 11 is to have current I b approximately proportional to the square of control signal 40. Control signal 40 is in turn approximately proportional to the largest current carried by any one phase of the circuit breaker. Such approximations are reasonably accurate up to approximately 3 times the circuit breaker's rated current capacity.
Load sensing means 12 monitors the current through each phase of the three phase circuit breaker and produces a single output, control signal 40, approximately proportional to the largest current carried by any one of the three phases of the circuit breaker. Terminal 41 is connected to a current transformer (not shown) which provides a negative voltage signal proportional to the current flowing through one phase of the circuit breaker. Terminals 42 and 43 are similarly each connected to current transformers (not shown) which provide negative voltage signals proportional to the current flowing through each of the remaining two phases of the circuit breaker.
Terminals 41, 42 and 43 are connected to the cathodes of diodes 44, 45 and 46 respectively. The anodes of diodes 44, 45 and 46 are connected together and are connected to one end of resistor 47. The other end of resistor 47 is connected to the anode of zener diode 48; the cathode of zener diode 48 is connected to the negative voltage supply 51. Electrolytic capacitor 49 is connected in a parallel circuit relationship to diode 48 with the polarities as indicated in the Figure. The series connection of resistor 52 and potentiometer 53 is connected in parallel to capacitor 49. The moveable contact 54 of potentiometer 53 carries connectrol signal 40 to current controller 11.
Briefly stated, diodes 44, 45 and 46 maintain capacitor 49 with a voltage proportional to the largest current flowing through any one of the phases of the circuit breaker. Diode 48 serves as a means of protecting the electronic circuitry from high voltage transients which may be present in an industrial environment. Zener diode 48 limits the maximum magnitude of the voltage input to current controller 11. The series circuit of resistor 52 and potentiometer 53 serves as a voltage divider and contact 54 can be varied so as to provide an adjustment to set the magnitude of control signal 40.
Turning now to voltage level detector 13, it can be seen that detector 13 comprises an operational amplifier 55, level detector 56 and level detector 57. Operational amplifier 55 has its non-inverting (+) input connected to the junction of capacitor 14b and switch 15b. The output of amplifier 55 is connected back to its inverting (-) input. The purpose of amplifier 55 is to act as a "buffer" with a very high input impedance so that the voltage across capacitor 14b can be monitored with a negligible influence. The output amplifier 55 is also connected both to level detector 56 and to level detector 57. Level detector 56 monitors the voltage level (or magnitude) across capacitor 14b, via amplifier 55, and produces an output signal 58 when the magnitude of the voltage across capacitor 14b reaches a predetermined first level, and accordingly, the temperature of the contacts of the circuit breaker has reached a first predetermined level. In the present embodiment, signal 58 is used to commence the operation of a fan to cool the circuit breaker. As can be seen from the figure, output signal 58 is also connected to switches 19b and 22b. This is done so that resistance-capacitance analogue circuit 10b can be modified so as to account for the fan cooling. When signal 58 causes the fan to start, it also causes switch 19b to close and switch 22b to open, and thereby modify analogue circuit 10b to account for fan cooling.
Level detector 57 operates in a similar fashion to detector 56, but detector 57 is set to produce an output signal 59 when the magnitude of the voltage across capacitor 14b reaches a predetermined second level which is greater in magnitude than the first level detected by detector 56. This second level indicates that the contacts of the circuit breaker are at a temperature in excess of their rated maximum and corrective action should be taken.
The foregoing has been a description of the preferred embodiment of the present invention, as envisioned by the inventors, for the application of the invention to a circuit breaker. It is to be understood that the component values as given in this specification are for one specific application of the invention only, and different values can be employed depending upon the particular application. Accordingly, the component values given herein should not be considered as a limitation of the invention in any manner whatsoever, but rather, considered solely as examples for illustrative purposes. | A circuit for monitoring the temperature of the contacts of an electrical switching device (such as a circuit breaker), comprises an electrical analogue circuit of the thermal characteristics of the switching device. The analogue circuit comprises electrical resistance and capacitance, interconnected so as to form an electrical model of the heat flow paths and capacitances respectively, in the switching device. The preferred embodiment also provides a temperature sensing device to introduce to the analogue circuit a voltage signal the magnitude of which is proportional to the exterior temperature of the switching device. The analogue circuit is connected in a series circuit relationship with a current controller. The current controller controls the amount of current flowing through the analogue circuit. The current controller is in turn controlled by a voltage control signal proportional to the amount of current being carried by the switching device. The current controller is operated in such a fashion that the current it lets flow through the analogue circuit is proportional to the square of the voltage control signal. | 7 |
BACKGROUND
1. Field of the Invention
The present invention generally relates to a mold releasing device, and particularly to a mold releasing method.
2. Description of Related Art
Injection molding processes are widely used for manufacturing workpieces, for example, optical articles such as lenses, light guide plates or other. The injection molding method has advantages such as high production rate and efficiency, and cost of optical elements thereby can be reduced.
In an injection molding process of the related art, a mold is utilized for forming the workpiece. The mold typically includes a first mold part and a second mold part. Each of the first and second mold parts has a core member. Both of the core members have a molding surface conforming to a surface of the workpiece. When the first and second mold parts are brought together, a mold chamber according to a size of the workpiece is defined between the two molding surfaces of the core members. Generally, when the size, such as a thickness of the workpiece requires an adjustment, the core members of the mold need to be pulled apart from the mold to be replaced, or to be disassembled and then modified. However, pulling apart the core members directly may lead to problems for the mold such as abrasion and loss of concentricity, as a result, a service life of the mold is shortened and quality of the workpiece formed using such a mold is reduced also.
Therefore, a mold releasing method is desired for overcoming the described limitations.
SUMMARY
In accordance with the present embodiment, a mold releasing method for releasing a core member from a mold includes steps of: a) providing a supporting member and arranging the supporting member on the mold, the supporting member comprising a base and a number of sidewalls extending from the base to the mold, a through hole being defined in the substrate and co-axially aligned with the core member; b) providing a bolt, the bolt comprising a threaded rod extending through the through hole of the substrate and threadedly engaged with the core member; and c) rotating the bolt to move the core member to disengage from the mold.
Other advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a mold releasing device arranged on a mold.
FIG. 2 shows the mold releasing device engaging with the mold core of the mold.
FIG. 3 shows the mold releasing device releasing a mold core of the mold.
DETAILED DESCRIPTION OF THE INVENTION
A detailed explanation of a mold releasing device according to an exemplary embodiment will now be made with reference to the drawings attached hereto. The mold releasing device is configured for releasing a core member of a mold.
As shown in FIG. 1 , the mold includes a mold base 4 and a core member 5 . The mold base 4 defines a mounting hole 41 therein. The mounting hole 41 extends through the mold base 4 , and includes an upper portion 42 and a lower portion 43 . The upper portion 42 of the mounting hole 41 has a diameter greater than that of the lower portion 43 , i.e., the mold base 4 has a relatively large inner diameter at an upper portion, and a relatively small inner diameter at a lower portion thereof. Thus a step (not labeled) is formed at an inner surface of the mold base 4 . The core member 5 , which can be a member such as an insert, is received in the mounting hole 41 of the mold base 4 . The core member 5 includes an upper portion 51 arranged on the step of the mold base 4 with a diameter being approximately the same as the diameter of the upper portion 42 of the mounting hole 41 , and a lower portion 53 with a diameter being approximately the same as the diameter of the lower portion 43 of the mounting hole 41 . The lower portion 53 of the core member 5 forms a molding surface 55 at a distal end thereof. A tapped blind hole 52 is defined in a center of the upper portion 51 of the core member 5 with inner thread 54 formed therein. The tapped blind hole 52 is co-axially aligned with the mounting hole 41 of the mold base 4 . A depth of the tapped blind hole 52 of the core member 5 is less than a height of the core member 5 , and is greater than a height of the lower portion 53 of the core member 5 .
The mold releasing device includes a supporting member 1 , a bolt 2 and a washer 3 . The supporting member 1 includes a substrate 11 and a pair of sidewalls 13 . The substrate 11 is elongated and rectangular. A through hole 12 is defined in a center of the substrate 1 . The sidewalls 13 extend downwardly from two opposite sides of the substrate 11 , respectively. A distance between the sidewalls 13 of the supporting member 1 is greater than the diameter of the upper portion 51 of the core member 5 , and the supporting member 1 is arranged on a top surface (not labeled) of the mold base 4 with the sidewalls 13 thereof located at two opposite sides of the core member 5 of the mold. A height of the sidewalls 13 is greater than the height of the lower portion 53 of the core member 5 . The through hole 12 is co-axially aligned with the tapped blind hole 52 of the core member 5 .
The bolt 2 includes a threaded rod 21 with outer thread 23 formed on an outer surface thereof, and a head 22 formed on a top end of the threaded rod 21 . The head 22 has a diameter lager than that of the threaded rod 21 . The washer 3 is ring-shaped with a central hole (not labeled) defined therein. The washer 3 is arranged on the substrate 11 of the supporting member 1 and surrounds the threaded rod 21 of the bolt 2 . An inner diameter of the washer 3 is greater than a diameter of the threaded rod 21 of the bolt 2 and less than a diameter of the head 22 of the bolt 2 . An outer diameter of the washer 3 is greater than the diameter of the head 22 of the bolt 2 . The threaded rod 21 has a height greater than a sum of a height of the washer 3 and the height of sidewalls 13 of the supporting member 1 , and less than a sum of a depth of the tapped blind hole 52 , the height of the sidewalls 13 and the height of the washer 3 . A height of the outer thread 23 of the threaded rod 21 of the bolt 2 is not less than the depth of the tapped blind hole 52 of the core member 5 . In this embodiment, the height of the outer thread 23 is greater than the depth of the tapped blind hole 52 .
Referring to FIG. 2 , when the core member 5 of the mold needs to be replaced, the mold releasing device is mounted on the mold for releasing the core member 5 of the mold. The threaded rod 21 of the bolt 2 extends through the washer 3 and the through hole 12 of the substrate 11 of the supporting member 1 to the core member 5 . Since the height of the bolt 2 is greater than the sum of the supporting member 1 and the washer 3 , the bottom end of the bolt 2 extends into the tapped blind hole 54 of the core member 5 . The threaded rod 21 of the bolt 2 and the core member 5 cooperatively form a helical pair. Then rotates the head 22 of the bolts 2 , the threaded rod 21 of the bolt 2 rotates and moves downwardly along an axial direction thereof and threadedly engages into the tapped blind hole 52 of the core member 5 . When the head 22 of the bolt 2 contacts to the washer 3 , the bolt 2 cannot move downwardly. A bottom end of the threaded rod 21 of the bolt 22 is received in a top end of the tapped blind hole 54 of the core member 5 . A distance between the bottom end of the threaded rod 21 and a bottom end of the tapped blind hole 54 is a little greater than the height of the lower portion 53 of the core member 5 .
Referring to FIG. 3 , then rotates the bolt 2 continually, the rotation of the bolt 2 turns to an axial movement of the core member through the action between the outer thread 23 of the threaded rod 21 and the inner thread 54 of the tapped blind hole 52 . For the distance between the threaded rod 21 and the tapped blind hole 54 is a little greater than the height of the lower portion 53 , the lower portion of the core member 5 can move upwardly and axially to a position a little higher than the step of the mold base 4 . For the height of the sidewalls 13 of the supporting member 1 is higher than that of the lower portion 53 of the core member 5 , when the lower portion 53 of the core member is a little higher than the step of the mold base 4 , the upper portion 51 of the core member is lower than the substrate 11 of the supporting member 1 . The core member 5 thus is conveniently and accurately released from the mold base 4 as the rotation of the bolt 2 . The washer 3 arranged between the supporting member 1 and the bolt 2 prevents friction occurring between the head 22 and the substrate 11 during rotation of the bolt 2 . Alternatively, the washer 3 can be omitted, and the head 22 of the bolt 2 abuts against the substrate 11 of the supporting member 1 . In this situation, rotation of the bolt 2 can be turned to the axial movement of the core member 5 through the action of the outer thread 23 of the bolt 2 and the inner thread 54 of the core member 5 .
As stated above, the mold releasing device and the mold releasing method employ a bolt 2 threadedly engaging into the core member 5 to form a helical pair, therefore, during mold releasing processes, the core member 5 moves axially and outwardly during rotation of the bolt 2 . The movement of the core member 5 is accurate and thus problems such as abrasion generated by pulling the core member 5 can be avoided. A service life of the mold is elongated and a quality of the workpiece formed using such a mold is improved. Alternatively, the supporting member 1 can define a thread in the through hole 12 thereof, and the bolt 2 can be threadedly engaged with the thread of the supporting member 1 and preassembled to the supporting member 1 . As a result, transportation or mounting of the mold releasing device is convenient.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A mold releasing method for releasing a core member from a mold includes steps of: a) providing a supporting member and arranging the supporting member on the mold, the supporting member comprising a base and a number of sidewalls extending from the base to the mold, a through hole being defined in the substrate and co-axially aligned with the core member; b) providing a bolt, the bolt comprising a threaded rod extending through the through hole of the substrate and threadedly engaged with the core member; and c) rotating the bolt to move the core member to disengage from the mold. | 8 |
[0001] This is a 371 of PCT/EP2016/053746 filed 23 Feb. 2016, which claims priority benefit of Provisional Patent Application 62/119,525 filed 23 Feb., 2015, the entire contents of which are incorporated herein by reference.
[0002] The present invention pertains to a bridge tape and the use of the bridge tape for permanently sealing openings, such as holes, especially in metal sheets or plastic parts of automobile bodies, before or after the so-called e-coating of such metal sheets or plastic parts.
[0003] In the present state of the art, OEM (Original Equipment Manufacturers) of automobile vehicles need to seal openings, such as holes and seams in the vehicles against entry into the opening of a variety of environmental elements, such as water, dirt, and the like, in order to help avoid corrosion and noise. For most applications putty, a pumpable material, plugs, Butyl or other types of sealing patches are used. However, most of these materials must be applied after e-coat in order to allow the inner cavities to be coated before sealing the cavities off as desired.
[0004] Some of the materials used for this purpose will shrink when the e.g. automobile body is passed through a paint drying oven as part of the final finish of the automobile body, and such shrinkage can create a leak into the previously-sealed opening.
[0005] Furthermore, some of the openings that need to be sealed are in areas that are not accessible after the vehicle has been welded together.
[0006] It is an object of the present invention to overcome the foregoing difficulties, by providing a sealant tape that can be applied to such openings either before or after e-coating, which will allow e-coating of the cavities inside the openings even after the sealant tape has been applied over the openings, and subsequently provide an effective seal for such openings.
[0007] In accordance with the present invention, there is provided a bridge tape which can be die cut to form patches of appropriate sizes to cover such openings, and which, if applied prior to e-coating of the sheet metal or plastic part, allows for the passing of e-coat fluid through the patch and into the cavities, and also through which excess e-coating fluids can drain out of said cavities.
[0008] The bridge tape of the present invention is constructed of a fabric backing having an adhesive coating, or followed by a two-sided adhesive tape, i.e., a “transfer tape”, a layer of a foamable composition with a layer of adhesive or adhesive promoter. The tape is perforated with a plurality of holes, if it is to be applied prior to e-coating, to allow for passing of the e-coat fluid through the holes.
[0009] When a patch of the bridge tape is applied over an opening in the sheet metal or plastic part, e-coating fluid can pass through the holes in the patch and into the cavity under the opening.
[0010] When the thus treated sheet metal or plastic part is subjected to heat treatment, such as occurs during the oven drying of the e-coat or paint, the foamable composition foams and expands to close off all of the holes in the patch, if present, as well as expands over all of the edges of the tape/patch to seal the edges and bond the die-cut patch to the body of the sheet metal substrate or plastic part.
[0011] In a similar manner, the tape patch can be applied to a gap in a sheet metal or plastic substrate, and then heat treated to expand the foam and seal the gap.
BRIEF DISCUSSION OF THE DRAWINGS
[0012] The construction of several embodiments of the bridge tape of the present invention is illustrated in the following figures, in which
[0013] FIG. 1 illustrates a side view of a section of the bridge tape of the present invention having the following layers:
[0014] Layer 1 is a layer of a foam foamable composition,
[0015] Layer 2 is a layer of an adhesion promoter,
[0016] Layer 3 is a two-sided tape,
[0017] Layer 4 is an adhesive coated fabric liner, and
[0018] Layer 5 is a release liner on the adhesive coated fabric liner.
[0019] FIG. 2 illustrates an alternative embodiment of the bridge tape of the invention, in which:
[0020] Layer 6 is a layer of a foamable composition,
[0021] Layer 7 is a layer of backing material, such as an adhesive coated fabric liner, and
[0022] Layer 8 is a release liner on the adhesive coated side of the fabric liner.
[0023] FIG. 3 illustrates the top view of the bridge tape patch of FIG. 2 , after holes ( 9 ) have been punched into it,
[0024] FIG. 4 illustrates the bridge tape patch of FIG. 3 , after it has been subjected to heat treatment to cause the foamable composition to foam and expand the foam to seal the holes, the sealed holes being illustrated in outline ( 10 ).
DETAILED DESCRIPTION
[0025] As shown in FIG. 1 , the bridge tape is formed of a layer of a foamable composition adhered to a backing material, such as a cloth liner having an adhesive coating or layer of a transfer tape, and a release liner over the adhesive coating or transfer tape.
[0026] As backing material for the bridge tape of the present invention it is possible to use all known textile backings, such as wovens, knits or nonwoven webs; the term “nonwoven web” embraces at least textile sheetlike structures as well as stitchbonded nonwovens and similar systems. It is likewise possible to use spacer fabrics, including wovens and knits, with lamination.
[0027] A preferred backing material comprises woven cotton fabric, typically having a mesh count in the range of 140 to 160, preferably 148 (implying a warp thread count of 74 and a weft thread count of 74).
[0028] With further preference the weft count is 70 to 80 and/or the warp count is 70 to 80.
[0029] As adhesives on the backing it is possible in principle to choose a variety of polymer systems, with natural-rubber or synthetic-rubber and also acrylate systems having proven particularly advantageous if their adhesive properties and temperature stabilities are in accordance with the requirements. With further preference the bond strength to steel is at least 5 N/25 mm.
[0030] A suitable adhesive is one based on acrylate hotmelt which has a K value of at least 20, in particular more than 30 (measured in each case in 1% strength by weight solution in toluene, 25.degree. C.), obtainable by concentrating a solution of such an adhesive to give a system which can be processed as a hotmelt.
[0031] It is also possible to use an adhesive comprised of natural rubbers or synthetic rubbers or of any desired blend of natural rubbers and/or synthetic rubbers, it being possible to select the natural rubber or the natural rubbers in principle from all available grades, such as, for example, crepe, RSS, ADS, TSR or CV grades, depending on the required purity and viscosity level, and to select the synthetic rubber or synthetic rubbers from the group of randomly copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), synthetic polyisoprenes (IR), butyl rubbers (IIR), halogenated butyl rubbers (XIIR), acrylate rubbers (ACM), ethylene-vinyl acetate (EVA) copolymers and polyurethanes and/or blends thereof.
[0032] With further preference it is possible to add thermoplastic elastomers to the rubbers, in order to improve the processing properties, with a weight fraction of from 10% to 50% by weight, based on the total elastomer fraction.
[0033] As representatives mention may be made at this point in particular of the especially compatible styrene-isoprene-styrene (SIS) and styrene-butadiene-styrene (SBS) products.
[0034] Tackifying resins which can be used include without exception all tackifier resins which are already known and have been described in the literature. As representatives mention may be made of the rosins, their disproportionated, hydrogenated, polymerized, and esterified derivatives and salts, the aliphatic and aromatic hydrocarbon resins, terpene resins and terpene-phenolic resins. Any desired combinations of these and further resins may be used in order to adjust the properties of the resultant adhesive in accordance with requirements. Express reference may be made to the depiction of the state of the art in the “Handbook of Pressure Sensitive Adhesive Technology” by Donatas Satas (van Nostrand, 1989).
[0035] Heat-activatable adhesive sheets may be used for the adhesive layer on the backing layer. Such heat-activatable adhesive sheets preferably have the following composition: i) a polymer, with a fraction of at least 30% by weight, a first section of the heat-activatable adhesive sheet being based with particular preference on reactive polyurethane, polyamide, nitrile rubber with reactive phenolic resins or reactive epoxy resins, and/or a second section being based on thermoplastic, non-reactive polyamides or epoxides, ii) one or more tackifying resins, with a fraction of 5% to 50% by weight, and/or iii) epoxy resins with hardeners, and accelerators, if desired, with a fraction of 5% to 40% by weight.
[0036] The adhesive sheets preferably have a thickness of from 10 to 500 μm.
[0037] The compositions for the adhesive sheet can be widely varied by changing the type and proportion of raw materials. It is also possible to obtain further product properties such as, for example, color, thermal conductivity or electrical conductivity, by means of selective additions of dyes, mineral and/or organic fillers, silicon dioxide for example, and/or powders of carbon and/or of metal.
[0038] The foamable layer is preferably formed of a foamable polyurethane composition or of an EVA (ethylene vinyl acetate), with a blowing agent, having a layer thickness prior to expansion of from about 1.5 to about 4 mm and comprising a foaming agent. A particularly preferred expandable foam is that formed of ethylene copolymers and available from ND Industries, Inc. under the product name NB169P041.
[0039] These materials are laminated together to form the bridge tape of the present invention. Once formed, the bridge tape is die cut to the size required for the particular use, and, if necessary, holes punched through it.
[0040] FIG. 2 illustrates a further embodiment of the bridge tape of the present invention, in which the foamable composition ( 6 ) has been extruded directly onto the backing layer ( 7 ), such as an adhesive coated fabric with a release liner ( 8 ). | Bridge tape comprised of thermally foamable composition, useful for applying coating material through holes in the tape to a substrate beneath the tape, after which the holes can be sealed by heating to cause the foamable composition to foam and expand the foam to seal the holes. | 2 |
TECHNICAL FIELD
[0001] The present invention relates to systems for processing sewage; more particularly, to such systems for handling biologically digestible materials in sewage; and most particularly to methods and apparatus for separating biologically-digestible materials from an influent sewage stream.
BACKGROUND OF THE INVENTION
[0002] The primary historical objective of waste water treatment operations has been to neutralize and otherwise render sewage effluence in compliance with regulatory limits based on environmental and health standards. An important and growing objective of modern waste water treatments is the generation of energy from biologically-digestible organic materials present in the waste water. To achieve this objective, during the treatment of waste water influent streams containing biologically-digestible materials, as part of selectively classifying and separating grits, solids, hair and fibers, particulates, and solvated materials, it is particularly desirable to separate the digestible materials in the influent stream from non-digestible materials such that digestion of the digestible materials can be optimized. For systems that produce sludge in processes downstream from primary clarification (i.e., secondary sludge), it is desirable to extract the remaining biologically-digestible materials present in that sludge. Optimization can include increasing and capturing the bio-gas producing materials; production of energy bearing bio-gasses such as methane, produced by the decomposition of the digestible materials; reducing the frequency with which digesters used to digest the digestible materials need to be taken off line and cleaned; automation of the process for separating the digestible materials in the influent stream for digestion to reduce operating costs; reducing energy consumption-related operating costs; reducing the particle size of organic materials to allow rapid biodegradation and to capture organics prior to conversion to carbon-dioxide and biomass; and reducing the capital costs to build a treatment facility to separate and digest biologically-digestible materials in an influent stream.
[0003] In the prior art, the separation of grit from waste water influent is a long standing problem. Grit adversely impacts equipment reliability and lifespan, and increases operating costs of downstream treatment processes. Consequently, grit separators traditionally are used to remove grit from the influent stream as early in the treatment sequence as possible, preferably prior to primary clarification, or in cases where no primary clarification exists, then prior to secondary treatment. In practice, these devices often perform poorly because they are designed for a specific flow range which often is based on peak flows based on projected increases in population or a specific maximum flow based on storm events or future expansion of flows from new industries, etc. The projected flow range frequently is not reached for a number of reasons, such as unanticipated changes in population; changes in economic conditions of a region causing industries to leave or never develop; increased inflow and infiltration (“I and I”) of water into the treatment system from deteriorating collection systems; and the increase in storm intensities.
[0004] In many treatment plants, in an attempt to provide flow equalization at the head of the plant, variable frequency drives have been added to control the pumps delivering influent to the treatment plants from wet wells used as buffers. The variable frequency drives enable operation of the pumps over a range of pump speeds rather than a single speed with the only control option being to turn them off and on. In practice, these variable frequency drives create large fluctuations in influent velocity that can hinder the performance of the highly velocity-sensitive hydrocyclone grit separators. Due to their poor performance, these velocity sensitive grit separators often fail and/or are left in disrepair, requiring grit to be removed from the influent stream as a component of the sludge formed during the primary-treatment process. Typically, the grit slowly fills the secondary treatment process tanks, contributing to reduced energy content of the primary sludge, increasing the frequency with which digesters and secondary process tanks must be cleaned, and causing wear and tear on the plant equipment.
[0005] Current typical waste water plants capture only thirty to thirty-five percent of the biologically-digestible materials during primary clarification. The remainder of the biologically-digestible materials are typically digested during secondary treatment in an activated sludge process that permits the greenhouse gas (CO 2 ) to escape into the atmosphere.
SUMMARY OF THE INVENTION
[0006] Briefly described, a system in accordance with the present application comprises a method and apparatus for separating biologically digestible materials from an influent sewage stream.
[0007] In one aspect of the present application, a primary clarification tank is used to capture sixty percent or more of the total solids from an influent stream.
[0008] In another aspect of the present application, a sludge classifying press (SCP) is used to isolate and concentrate biologically-digestible materials from sludge formed in a primary clarification tank, releasing valuable organics, such as are found in corn kernels, by fracturing the protective casings.
[0009] In another aspect of the present application, grit is captured in a chamber within the primary clarification tank and isolated from the bulk of the sludge-containing biologically-degradable materials.
[0010] In another aspect of the present application, a grit trap or hydrocyclone is used to remove grit from the sludge prior to classifying the sludge with the SCP.
[0011] In another aspect of the present application, the sludge is thickened after classification and prior to digestion.
[0012] In another aspect of the present application, one or more elements of the process for separating and digesting the biologically-digestible materials in an influent stream is automated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0014] FIG. 1 is a schematic drawing of an embodiment of a water treatment plant in accordance with the present application;
[0015] FIG. 2 is a schematic drawing and elevational side view of an Influent Feed System (IFS) used in the embodiment shown in FIG. 1 ;
[0016] FIG. 3 is a detailed plan view of one IFS shown in FIG. 1 ;
[0017] FIG. 4 is a schematic drawing of a prior art primary treatment system suitable for use as a first stage in the present application to collect suspended and solvated BOD;
[0018] FIG. 5 is a schematic drawing and elevational end view of one embodiment of a clarification tank and IFS in fluid communication with apparatus to treat grit and sludge settled in the clarification tank and IFS in accordance with the present application;
[0019] FIG. 6 is a schematic elevational drawing of a grit separator in accordance with the present application;
[0020] FIG. 7 is a schematic drawing and plan view of an alternative embodiment of a clarification tank and IFS in fluid communication with apparatus to treat grit and sludge settled in the clarification tank and IFS in accordance with the present application;
[0021] FIG. 8 is a schematic drawing and plan view of another alternative embodiment of a clarification tank and IFS in fluid communication with apparatus to treat grit and sludge settled in the clarification tank and IFS in accordance with the present application;
[0022] FIG. 9 is a schematic drawing and plan view of another alternative embodiment of a clarification tank and IFS in fluid communication with apparatus to treat grit and sludge settled in the clarification tank and IFS in accordance with the present application;
[0023] FIG. 10 is an alternative embodiment of an IFS with separate discharge pipes for removing materials from the IFS troughs and grit box;
[0024] FIG. 11 is a schematic drawing and side elevational view of an IFS arranged to discharge grit and sludge in accordance with the present application; and
[0025] FIG. 12 is a schematic drawing and plan view of an adapative system for treatment of sludge and grit in accordance with the present application.
[0026] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate currently preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] U.S. Pat. No. 7,972,505, PRIMARY EQUALIZATION SETTLING TANK, to Wright; U.S. Pat. No. 8,225,942 to Wright, SELF-CLEANING INFLUENT FEED SYSTEM FOR A WASTEWATER TREATMENT PLANT; U.S. Pat. No. 8,398,864 SCREENED DECANTER ASSEMBLY FOR A SETTLING TANK to Wright; co-pending U.S. patent application Ser. No. 14/142,197 METHOD AND APPARATUS FOR A VERTICAL LIFT DECANTER SYSTEM IN A WATER TREATMENT SYSTEM by Wright; co-pending U.S. patent application Ser. No. 14/142,099 FLOATABLES AND SCUM REMOVAL APPARATUS FOR A WASTE WATER TREATMENT SYSTEM by Wright, and co-pending U.S. patent application Ser. No. 14/325,421 IFS AND GRIT BOX FOR WATER CLARIFICATION SYSTEMS by Wright (the '421 application), all of which are incorporated by reference in their entirety for all purposes, disclose systems and processes for primary clarification that remove substantially all grit, solids, and particulates larger than 50 microns during primary clarification.
[0000] Separation of Biologically Digestible Materials from the Influent Stream
[0028] FIG. 1 shows a block diagram of one exemplary embodiment of a clarification system 1 configured to separate biologically-digestible materials from an influent stream. In one embodiment, the influent enters the clarification system 1 via pipes 11 where it is stored in wet well 12 . A settling tank 30 is in fluid communication with eight IFS's, 100 - 107 . Pump 13 pumps influent from wet well 12 to IFS's 100 - 107 at a substantially constant flow rate via piping 14 , 15 and 15 ′. In one embodiment, pump 13 operates under the control of a supervisory control and data acquisition system (SCADA) 900 in communication with pump 13 via communication channel 901 . In one embodiment, the SCADA 900 turns pump 13 in response to an indication of wet well 12 fluid level reaching an upper limit, the indication provided by sensor 18 in communication with SCADA 900 via communication channel 907 . In one embodiment, SCADA 900 turns pump 13 off in response to an indication of wet well 12 fluid level reaching a lower limit, the indication provided by sensor 19 in communication with SCADA 900 via communication channel 908 . In an alternative embodiment, SCADA 900 turns pump 13 off after a pre-determined period of time. In an alternate embodiment, SCADA 900 turns pump 13 off after a predetermined volume of fluid has been pumped as indicated by measuring the flow via signals provided by flow meter 25 in communication with SCADA 900 via communication channel 909 . Flow meters and sensors to measure fluid level are well known in the art.
[0029] As is well known in the art, pipes 14 , 15 and 15 ′ are configured to deliver substantially the same flow rate of influent to each IFS 100 - 107 . Flow balancing valves and/or flow splitting may be used. The influent enters the IFS's 100 - 107 where grits, solids, and optionally solvated materials, are selectively classified and separated from the influent via settling and optionally flocculation. Materials settled in the IFS's 100 - 107 are removed via discharge pipes 570 - 577 as described in more detail with reference to FIG. 5 . The influent traverses IFS's 100 - 107 to enter clarification settling tank 30 . As described in the '505 and '864 patents and '197 application, solids remaining in the influent traversing to the clarification settling tank 30 are further classified and separated from the influent via settling. Upon completion of the separation of the solids from the influent, the influent is discharged from the settling tank 30 using screen box assemblies (SBX's) 50 - 54 as described in the '197 application.
[0030] In the embodiment of FIG. 1 , flocculents are optionally added to the influent stream by flocculent delivery systems 40 , 41 . The use of flocculents, for the removal of solids and solvated materials in the treatment of waste water and designs to add flocculents to an influent waste water stream, is well known in the art.
[0031] FIG. 2 shows a side view of an exemplary IFS 100 with IFS troughs and grit box 500 and FIG. 3 shows a top view of the IFS of FIG. 2 , as further described and disclosed in the '421 application. As described in more detail in the '421 application, a mixing zone 504 is created within a grit box 500 at the location where deposition of the floc is desired. With reference to FIG. 2 and FIG. 3 , IFS 100 is configured with a grit box 500 and two IFS troughs 201 , 202 having trough walls 207 , 208 . IFS troughs 201 , 202 are in fluid communication with the grit box 500 . Influent is delivered to IFS 100 via pipe 501 and is split into two streams which enter grit box 500 via pipes 502 , 503 . The streams exit opposing pipes 502 , 503 and collide under pressure to create turbulent mixing zone 504 . A deflector plate 505 is positioned above mixing zone 504 to confine the volume of the mixing zone and return the upward velocities of the streams existing pipes 502 , 503 back into mixing zone 504 . Grit, dense solids, and flocs are deposited in grit box hopper 506 .
[0032] To limit disturbance of solids settling in the lower portion of IFS troughs 201 , 202 in proximity to the grit box 500 , the length of pipes 502 , 503 is arranged to position mixing zone 504 below the lowest portion of IFS troughs 201 , 202 in proximity to and in fluid communication with grit box 500 . Mixing zone 504 and grit box hopper 506 are positioned below the lowest portion 150 , 150 ′ of IFS troughs 201 , 202 in proximity to and in fluid communication with grit box 500 . Solids with a lower settling rate than the designed influent rise velocity in the grit box hopper 506 move into IFS troughs 201 , 202 . Additionally, prior to entering IFS troughs 201 , 202 , solids moving upward under the influence of the rising influent undergo a 90 degree change in direction, turning from vertical to horizontal thus losing inertia and lessening the fluid forces on the suspended grits, solids, and flocs. In one embodiment, as explained in more detail below, grits settle preferentially in grit box 500 .
[0033] Materials that settle in grit box 500 and clarification, tank 30 may be removed as part of periodic scouring of grit box 500 and clarification tank 30 or as part of the ongoing operation of clarification system 1 to selectively classify and separate grits, solids, particulates, and solvated materials from an influent stream.
[0034] Other methods may be used to separate and capture large quantities of biologically digestible material from an influent stream. By way of example and not limitation, with reference to FIG. 4 , large quantities of solids, suspended materials, and solvated materials can be rapidly settled from an influent stream by a prior art system such as CLARI-FLOCCULATOR packaged sewage treatment 1100 for primary treatment manufactured by Waterneer, a company with offices in Lidkoping Sweden. In the Waterneer primary treatment system, inlet feed pump 1102 is in fluid communication with influent stream 1101 and mixing chamber 1103 . Flocculent source 1106 is in fluid communication with mixing chamber 1103 . Mixing chamber 1103 is in fluid communication with turbulence redirection apparatus 1104 which is in fluid communication with sedimentation chamber 1105 . Sedimentation chamber 1105 further comprises a sludge discharge pipe 1111 , a sensor 1108 in communication with programmable controller 1107 , and valve 1109 under control of and in communication with programmable controller 1107 . Valve 1109 is positioned in sludge discharge pipe to control fluid communication of materials from sedimentation chamber 1109 through sludge discharge pipe 1111 .
[0035] In the Waterneer primary treatment system, inlet feed pump 1102 pumps water from influent stream 1101 into a mixing chamber 1103 where it is mixed with flocculents added to the influent stream by flocculent source 1106 . The influent and flocculent mix is delivered to turbulence redirection apparatus 1104 to slow the velocity of the fluid after which it is delivered to sedimentation chamber 1105 where flocs, grits and other materials settle. Effluent 1110 , free of the settled materials, is evacuated from primary treatment system 1100 . Programmable controller 1106 opens and closes valve 1109 responsive to signals from sensor 1108 indicating that the thickness of the sludge settled in sedimentation chamber 1105 has exceeded a predetermined threshold. Sludge from sedimentation chamber 1105 is evacuated via discharge pipe 1111 .
[0000] Treatment of Materials Separated from the Influent Stream to Concentrate Biologically-Digestible Materials
[0036] With reference to FIGS. 2 and 5 , grit box 500 of IFS 100 is in fluid communication with discharge pipe 570 . Fluid communication via discharge pipe 570 is controlled by valve 580 . Valve 580 may be a manually-operated valve. In an alternate embodiment, valve 580 is electronically controlled by a supervisory control and data acquisition SCADA system 900 which provides a signal via communication channel 919 to open and close valve 580 . SCADA systems and electronically controlled valves are well known in the art.
[0037] With reference to FIG. 5 in one embodiment, IFS 100 , 104 discharge pipes 570 , 574 and clarification tank 30 discharge pipe 70 are in fluid communication with sludge and grit intake pipe 20 which is in fluid communication with sludge pump 50 . Sludge pump 50 is in fluid communication with grit separator 51 via pipe 20 a. Grit separator 51 is in fluid communication with sludge classification press 52 via pipe 20 b. Sludge classification press 52 is in fluid communication with optional sludge thickener 53 via pipe 20 c. Sludge thickener 53 is in fluid communication with pipe 20 d. Optionally, a flocculent source 55 a is arranged to communicate flocculents to sludge prior to treatment by sludge classification press 52 . Optionally, a flocculent source 55 b is arranged to communicate flocculents to the sludge discharged by sludge classification press 52 . In one embodiment, sludge pump 50 is in communication with and controlled by SCADA 900 via communication channel 926 . In one embodiment, classification press 52 is in communication with and controlled by SCADA 900 via communication channel 927 . In one embodiment, flocculent sources 55 a, 55 b are in communication with and controlled by SCADA 900 via communication channels 929 a, 929 b. In one embodiment, sludge thickener 53 is in communication with and controlled by SCADA 900 via communication channel 928 .
[0038] In one embodiment, one or more optional flowmeters are incorporated in the system: flow meter 5701 to measure the flow in discharge pipe 570 ; flow meter 5741 to measure the flow in discharge pipe 574 ; flow meter 7001 to measure the flow in discharge pipe 70 ; flow meter 2001 to measure the flow in pipe 20 a; flow meter 2003 to measure the flow in discharge pipe 20 b; flow meter 2005 to measure the flow in pipe 20 c; and flow meter 2007 to measure the flow in pipe 20 d.
[0039] In one embodiment, flow meter 5701 is in communication with SCADA 900 via communication channel 917 . In one embodiment, flow meter 5741 is in communication with SCADA 900 via communication channel 920 . In one embodiment flow meter 7001 is in communication with SCADA 900 via communication channel 923 . In one embodiment, flow meter 2001 is in communication with SCADA 900 via communication channel 936 . In one embodiment, flow meter 2003 is in communication with SCADA 900 via communication channel 938 . In one embodiment, flow meter 2005 is in communication with SCADA 900 via communication channel 940 . In one embodiment, flow meter 2007 is in communication with SCADA 900 via communication channel 942 .
[0040] In one embodiment, one or more optional sensors are incorporated in the system: sensor 5702 to measure the characteristics of materials in discharge pipe 570 ; sensor 5742 to measure the characteristics of materials in discharge pipe 574 ; sensor 7002 to measure the characteristics of materials in discharge pipe 70 ; sensor 2002 to measure the characteristics of materials in discharge pipe 20 a; sensor 2004 to measure the characteristics of materials in discharge pipe 20 b; sensor 2006 to measure the characteristics of materials in discharge pipe 20 c; and, sensor 2008 to measure the characteristics of materials in discharge pipe 20 d. The optional sensors are in communication with SCADA 900 : sensor 5702 via communication channel 918 ; sensor 5742 via communication channel 921 ; sensor 7002 via communication channel 924 ; sensor 2002 via communication channel 937 ; sensor 2004 via communication channel 939 ; sensor 2006 via communication channel 941 ; and sensor 2008 via communication channel 943 .
[0041] Sensors 5702 5742 , 7002 , 2004 , 2006 , and 2008 may be a UVAS sensor, turbidity sensor, pH sensor, or any other type of sensor consistent with measuring the physical and/or chemical characteristics of sludge and grits undergoing treatment.
[0042] With reference to FIG. 5 , sludge 1000 settled in grit box 500 of IFS 100 can be removed via discharge pipe 70 . With reference to the exemplary embodiment of FIG. 2 , in one embodiment valve 580 is opened and fluid is pumped or gravity fed through pipes 410 , 415 to scour the IFS troughs and grit box. In an alternative method for evacuating and scouring the IFS, valve 580 is opened and IFS troughs 201 , 202 are scoured with liquid to evacuate solids from the entirety of the IFS. In one embodiment, as part of the ongoing operation of the clarification system 1 of FIG. 1 , to selectively classify and separate grits, solids, particulates, and solvated materials from an influent stream, valve 580 is opened to remove the settled materials without concurrent scouring of the IFS.
[0043] With reference to FIG. 5 , sludge 1000 settled in grit box 500 may have viscosity low enough to flow from the grit box under the influence of gravity. The solids content of the sludge is dependent on the type of solids, the depth of the tank, the methodology of extraction, and how long the sludge is resident in the tank prior to extraction. A representative range for the solids content of materials 1010 is from less than one-tenth of a percent to five percent or more. The head pressure from the influent in IFS 100 may be used to assist in moving sludge 1000 in grit box 500 through discharge pipe 570 . In one embodiment, sludge pump 50 is used to assist in the evacuation of materials 1000 settled in grit box 500 . In one embodiment, sludge pump 50 is electronically controlled by a supervisory control and data acquisition system SCADA 900 which provides a signal via communication channel 926 to start and stop pumping.
[0044] With reference to FIG. 5 , sludge 1010 settled in clarification tank 30 can be removed via discharge pipe 70 in liquid communication with the clarification tank 30 . Fluid communication via discharge pipe 70 is controlled by valve 80 . Sludge 1010 settled in clarification tank 30 can be removed by scouring and cleaning with a fluid as described for example in the '864 patent. In one embodiment, as part of the ongoing operation of clarification system 1 of FIG. 1 , to selectively classify and separate grits, solids, particulates, and solvated materials from an influent stream, valve 80 is opened to remove the settled materials.
[0045] Sludge 1010 , settled in clarification tank 30 may have viscosity low enough to flow from clarification tank 30 under the influence of gravity. The solids content of the sludge is dependent on the type of solids, the depth of the tank, the methodology of extraction, and how long the sludge is resident in the tank prior to extraction. A representative range for the solids content of materials 1010 is from less than one-tenth of a percent to five percent or more. The head pressure from the influent in clarification tank 30 may be used to assist in moving sludge 1010 in the clarification tank 30 through discharge pipe 70 . In one embodiment, a sludge pump 50 is used to assist in the evacuation of sludge 1010 settled in clarification tank 30 .
[0046] Sludge from IFS 100 , 104 and clarification tank 30 enters grit separator 51 which separates and removes coarse, dense solids, referred to herein as “grit” or “grits”, that are not biologically digestible from the sludge. Grit separator 51 may be a gravity separator as shown with reference to FIG. 6 or a hydro-cyclone as is well known in the art. The removal of grits from the sludge removed from clarification tank 30 and IFS' 100 - 107 rather than from the influent stream prior to primary clarification provides for improved operation of the grit separator and overall plant reliability.
[0047] With reference to FIG. 6 , there is shown one embodiment of a grit separator 51 that is a gravity separator 1200 in accordance with the current invention. Gravity separator 1200 has an influent pipe 1201 in fluid communication with a gravity separation chamber 1202 . Gravity separation chamber 1202 is in fluid communication with grit discharge pipe 1203 and sludge discharge pipe 1204 . Valve 1205 is positioned on grit discharge pipe 1203 and controls fluid communication through pipe 1203 . Influent pipe 1201 is arranged to have dimensions perpendicular to the flow of influent sludge substantially larger than the dimensions perpendicular to the flow of influent sludge of pipes providing a source of sludge to be treated for removal of grit. Influent pipe 1201 is arranged to provide a downward direction to the flow of fluids and materials as they enter gravity separation chamber 1202 giving dense solids inertia downward to gently agitate settled solids and to re-suspend any low density organic materials. The bottom of gravity separation chamber 1202 is designed to slope down to grit discharge pipe 1203 to facilitate discharge of grit under the influence of gravity.
[0048] In operation, sludge enters gravity separator 1200 from a source such as clarification tank 30 of FIG. 5 via pipe 20 a as shown with respect to FIG. 5 . The substantially larger dimensions of influent pipe 1201 relative to source pipe 20 a in the direction perpendicular to the direction of sludge flow results in a rapid and substantial decrease in sludge flow velocity. The dimensions of gravity chamber 1202 are arranged to provide time for grit to settle in the gravity chamber prior to discharge of the sludge. Periodically valve 1205 is opened to remove accumulated grit from gravity separation chamber 1202 . Preferably, valve 1205 is a pinch valve to avoid fouling and failure associated with grit becoming lodged in a valve seat.
[0049] With reference to FIG. 5 , sludge substantially free from grit exits the grit separator and is fluidly communicated to sludge classification press via pipe 20 b. The sludge classification press 52 may be a rotary screw press such as the Strainpress® Sludgecleaner SP manufactured by Huber Technology. In one embodiment, sludge classification press 52 removes all solids larger than 1.6 mm from the sludge. In alternate embodiments, the sludge classification press 52 removes solids with dimensions that range from 0.15 mm to 10 mm. In one embodiment the compression and sheering of the sludge by the sludge classification press 51 releases biologically-digestible material from items such as corn kernels while removing the indigestible or less rapidly digestible materials such as the outer layer of a corn kernel.
[0050] After treatment with sludge classification press 52 , the solids content of the sludge consists primarily of biologically-digestible materials that can be digested in a digester to produce energy-rich bio-gases such as methane. The removal of materials that are not biologically digestible increases the rate of digestion of the remaining materials, enabling greater throughput and processing of sludge by a digester. The removal of non-digestible materials reduces the frequency with which digesters need to be taken off line and cleaned.
[0051] In some applications, it may be desirable to increase the concentration of biologically-digestible material in the sludge after treatment by the sludge classification press 52 and prior to digestion to improve the efficiency of digestion, maintain a low hydraulic retention rate (HRT), and increase the volume of production of bio-gases, such as, by way of example and not limitation, methane. Optionally, a flocculent may be added to the sludge via flocculent source 55 after treatment of the sludge by sludge classification press 52 . The flocculent is added to the sludge to create flocs from dissolved and suspended biologically-digestible materials, thereby increasing the concentration of biologically-digestible materials to improve performance of the digesters that digest the resultant sludge. By way of example, in a municipal waste water treatment plant a representative range for the total solids content the sludge after treatment by sludge classification press 52 is between two and three percent, whereas a digester may operate more efficiently with a total solids content of five to seven percent, and some as much as ten percent or more, depending upon the type of digester. Current systems use total solids as a surrogate measure for the concentration of biologically-digestible organic material in sludge. Gas production comes from volatile solids (VS) which are approximately 70-80% percent of the total solids. In one embodiment of the system, the treated sludge from the sludge classification press is fluidly communicated to solids concentrator 53 via pipe 20 c. Devices to increase solids content of sludge are well known in the art. By way of example and not limitation, solids concentrator 53 may comprise a gravity deck thickener, rotary drum thickener, or a rotary screw press. Sludge thickener 53 increases the solids content of the sludge treated by sludge classification press 52 .
[0052] With reference to FIG. 7 , in one embodiment IFS 100 - 107 discharge pipes 570 - 577 and clarification tank 30 discharge pipe 70 are in fluid communication with sludge and grit intake pipe 20 which is in fluid communication with sludge pump 50 . Sludge Pump 50 is in fluid communication with grit separator 51 via pipe 20 a. Grit separator 51 is in fluid communication with sludge classification press 52 via pipe 20 b. In one embodiment, sludge classification press 52 is in fluid communication with optional sludge thickener 53 via pipe 20 c. Optionally, a flocculent source 55 is arranged to communicate flocculents to sludge traversing pipe 20 c. Optional sludge thickener 53 is in fluid communication with digester 54 via pipe 20 d and wet well 12 of FIG. 1 via pipe 22 . In one embodiment, sludge pump 50 is in communication with and controlled by SCADA 900 via communication channel 926 . In one embodiment, sludge pump 52 is in communication with and controlled by SCADA 900 via communication channel 926 . In one embodiment, flocculent source 55 is in communication with and controlled by SCADA 900 via communication channel 929 . In one embodiment, sludge thickener 53 is in communication with and controlled by SCADA 55 via communication channel 928 .
[0053] In one embodiment, sludge classification press (SCP) 52 is in fluid communication with digester 54 via pipe 20 c.
[0054] In one embodiment, digester 54 is an anaerobic digester. Sensor 64 is arranged to measure aspects of the operation of digester 54 . Sensor 64 is in communication with SCADA 900 via communication channel 944 . Sensor 64 may be one or more of temperature sensors, carbon-dioxide sensors, oxygen sensor, pH sensor, methane sensor, or any other sensor suitable for measuring the physical condition and characteristics, and chemical properties of the materials undergoing digestion.
[0055] To optimize overall operations of the system and to detect indications of existing or imminent component or system failure, in one embodiment the characteristics of the sludge are measured by sensor 64 as the sludge is treated. Bacteria in an anaerobic digester thrive best when supplied with food at constant concentration and flow rate. If the rate of organics of solid being supplied to the digester 54 goes outside of the desired ranges as measured by one or more sensors 60 , 61 , 62 , SCADA 900 adjusts the throughput of the sludge classification press 52 as needed. If the organics/solids ratios are too low, as measured by one or more sensors 60 , 61 , 62 , SCADA 900 increases the dosage supplied by flocculent source 55 . If the organics/solids ratios are too high, as measured by one or more sensors 60 , 61 , 62 , SCADA 900 decreases or stops the dosage supplied by flocculent source 55 . In one embodiment, as single sampling well and set of sensors are used to minimize cost associated with sensors and simplify issues of cross-sensor calibration and correlation across multiple sensors deployed throughout the system.
[0056] Sampling pump 56 is in fluid communication with pipes 20 a - 20 d via pipe 21 . Sampling pump 56 is preferably a positive displacement pump such as a diaphragm pump or progressive cavity pump in order to prevent fouling. Valves 7 a - 7 d control fluid communication between pipes 20 a - 20 d and pipe 21 . In one embodiment, valves 20 a - 20 d are manually operated. In one embodiment, valves 20 a - 20 d are controlled by and in communication with SCADA 900 via communication channels 935 a - 935 d. In one embodiment, sampling pump 56 is controlled by and in communication with SCADA via communication channel 931 . Sampling pump 56 is in fluid communication with sampling well 57 via pipe 21 . One or more sensors 60 , 61 , 62 are arranged in sampling well 57 to measure various characteristics of materials in sampling well 57 . The one or more sensors are controlled by and in communication with SCADA 900 via communication channels 932 , 933 , 934 . Sampling well 23 is in fluid communication with wet well 12 of FIG. 1 via pipe 23 .
[0057] Sludge from IFS 100 - 107 and clarification tank 30 is treated in a substantially similar manner by sludge pump 50 , sludge classification press 52 , solids concentrator 53 , and flocculent source 55 as described hereinabove with respect to FIG. 5 . Upon final treatment of the sludge by sludge classification press 52 , or optional sludge thickener 53 , as applicable, the sludge is fluidly communicated to digester 54 .
[0058] Sludge removed from IFS 100 - 107 and clarification tank 30 is sampled as it is discharged from sludge pump 50 via pipe 20 a. In one embodiment, SCADA 900 closes valves 7 b, 7 c, 7 d, opens valve 7 a and turns sampling pump 56 on to withdraw sludge via pipe 21 . Sludge is pumped via sampling pump 21 to sampling well 57 where one or more sludge characteristics are measured via one or more sensor 60 , 61 , 62 . Upon completion of the measurements, the sludge sample is discharged via discharge pipe 23 . In a similar manner, one or more characteristics of grit-free sludge are sampled as the sludge is discharged from grit separator 51 via pipe 20 b. In one embodiment, SCADA 900 closes valves 7 a, 7 c, 7 d, opens valve 7 b, and turns sampling pump 56 on to withdraw sludge via pipe 21 . Sludge is pumped via sampling pump 21 to sampling well 57 where sludge characteristics are measured via one or more sensors 60 , 61 , 62 . Upon completion of the measurements, the sludge sample is discharged via discharge pipe 23 . One or more characteristics of classified sludge are measured as the sludge is discharged from sludge classification press 52 via pipe 20 c. In one embodiment, SCADA 900 closes valves 7 a , 7 b , 7 d, opens valve 7 c and turns sampling pump 56 on to withdraw sludge via pipe 21 . Sludge is pumped via sampling pump 21 to sampling well 57 where one or more sludge characteristics are measured via one or more sensors 60 , 61 , 62 . Upon completion of the measurements, the sludge sample is discharged via discharge pipe 23 . One or more characteristics of concentrated sludge are measured as the sludge is discharged from solids concentrator 53 via pipe 20 d. In one embodiment SCADA 900 closes valves 7 a , 7 b , 7 c, opens valve 7 d, and turns sampling pump 56 on to withdraw sludge via pipe 21 . Sludge is pumped via sampling pump 21 to sampling well 57 where one or more sludge characteristics are measured via one or more sensor 60 , 61 , 62 . Upon completion of the measurements, the sludge sample is discharged via discharge pipe 23 .
[0059] In an alternate embodiment, and with reference to FIG. 8 , only the sludge from IFS' 100 - 107 is treated by a grit separator as the sludge in clarification tank 30 is substantially free of grits and other dense solids. IFS 100 - 107 discharge pipes 570 - 577 are in fluid communication with sludge processing intake pipe 20 ′ and sludge pump 50 ′. Sludge pump 50 ′ is in fluid communication with grit separator 51 via pipe 20 f. Grit separator 51 is in fluid communication with sludge classification press 52 via pipe 20 g. Clarification tank 30 discharge pipe 70 is in fluid communication with sludge pump 50 . Sludge pump 50 is in fluid communication with grit separator 51 via pipe 20 e.
[0060] In an alternate embodiment and with reference to FIG. 9 , the content of biologically-digestible materials in sludge from the IFS' 100 - 107 is insignificant relative to the cost of extraction from the sludge. IFS 100 - 107 discharge pipes 570 - 577 are in fluid communication with sludge processing intake pipe 20 ′ and sludge pump 50 ′. Sludge pump 50 ′ is in fluid communication with grit separator 51 via pipe 20 f. Grit separator 51 separates the grits and particulates from the liquid. Liquid and non-particulate, non-grit sludge extracted from the sludge by grit separator 51 are returned to wet well 12 of FIG. 1 via discharge pipe 26 , and grit is disposed of in a landfill or by other means.
[0061] In another alternate embodiment, and with reference to FIG. 10 where substantive biologically-degradable material settles in IFS 100 IFS troughs 201 , 202 , but not in IFS 100 grit box 500 , IFS trough 201 , 202 discharge pipes 271 , 272 may be arranged to be in fluid communication with sludge process intake pipe 20 in communication with sludge pump 50 while grit box discharge pipe 570 is arrange to be in fluid communication with sludge processing intake pipe 20 ′ in fluid communication with sludge pump 51 ′ for further treatment, as shown by way of example and not limitation in FIG. 8 and FIG. 9 .
[0062] In a waste water treatment plant, the composition of the sludge settled in the IFS troughs, grit box, and clarification tank can change over time as a result of variations in the composition of the influent, changes in plant operating conditions, and other factors such as temperature and relative humidity. With reference to FIG. 11 , to provide flexibility in the treatment of sludge from clarification tank 30 , if the sludge has substantially no grit, discharge pipe 70 may be placed in fluid communication with sludge pump 50 by opening valve 36 and closing valve 35 , resulting in the sludge bypassing grit separator 51 . Check valve 47 prevents the sludge in discharge pipe 70 from entering sludge and grit intake pipe 20 ′ via pipe 20 i. Alternatively, if there is a need to separate grit from sludge in clarification tank 30 , discharge pipe 70 is placed in fluid communication with sludge pump 50 ′ by opening valve 35 and closing valve 36 . Check valve 49 prevents sludge from clarification tank 30 flowing into IFS' 100 - 107 via sludge and grit intake pipe 20 ′. Similarly, to provide flexibility in the treatment of sludge from IFS' 100 - 107 , if the sludge has substantially no grit, sludge and grit intake pipe 20 ′ may be placed in fluid communication with sludge pump 50 by opening valve 37 and closing valve 38 , resulting in the sludge bypassing grit separator 51 . Check valve 46 prevents the sludge from IFS′ 100 - 107 flowing back into clarification tank 30 via discharge pipe 70 . Alternatively, if there is a need to separate grit from sludge in the IFS' 100 - 107 , sludge and intake pipe 20 ′ is placed in fluid communication with sludge pump 50 ′ by opening valve 38 and closing valve 37 . Check valve 48 prevents sludge from IFS' 100 - 107 flowing into clarification tank 30 via discharge pipe 70 .
[0063] Similarly, in a waste water treatment plant the amount of biologically-degradable material associated with sludge processed by grit separator 51 may change over time as a result of variations in the composition of the influent, changes in plant operating conditions and other factors such as flows from precipitation, snow melt, industrial discharges, and significant public events such as a surge in the use of toilets during Super Bowl halftime.
[0064] With reference to FIG. 9 , IFS 100 - 107 discharge pipes 570 - 577 are in fluid communication with sludge and sludge intake pipe 20 ′ which is in fluid communication with sludge pump 50 ′. IFS 100 - 107 discharge pipes 570 - 577 are in fluid communication sludge pump 50 via sludge and intake pipe 20 ′ which is in fluid communication with pipe 20 i which is in fluid communication with clarification tank 30 discharge pipe 70 which is in direct fluid communication with sludge pump 50 . Valve 38 is positioned in pipe 20 ′ to control the flow of materials from discharge pipes 570 - 577 to sludge pump 50 ′ and not to affect the fluid communication of materials between discharge pipes 570 - 577 and sludge pump 50 and between clarification tank 30 discharge pipe 70 and sludge pump 50 as described hereinbelow. Valve 37 is positioned in pipe 20 i to control the flow of materials from IFS 100 - 107 discharge pipes 570 - 577 to sludge pump 50 . Valve 37 and pipe 20 i are arrange to have no effect on the fluid communication between clarification tank 30 ′ discharge pipe 70 and sludge pump 50 and between clarification tank 30 discharge pipe 70 and sludge pump 50 ′.
[0065] Valve 36 is positioned to control the flow of materials in discharge pipe 70 to sludge pump 50 and to have no effect on the fluid communication of materials between pipe 20 ′ and sludge pump 50 ′ or on the fluid communication of materials between discharge pipe 70 and sludge pump 50 .
[0066] Clarification tank 30 discharge pipe 70 is in fluid communication with sludge pump 50 . Clarification tank 30 discharge pipe 70 is in fluid communication with sludge pump 50 ′ via pipe 20 h which is communication with pipe 20 ′. Valve 36 is positioned in discharge pipe 70 to control the fluid communication of materials in discharge pipe 70 with sludge pump 50 and to have no effect on the fluid communication between materials in discharge pipe 70 and sludge pump 50 ′ and to have no effect on fluid communication of materials in discharge pipes 570 - 577 and sludge pump 50 . Valve 35 is positioned in pipe 20 h to control the fluid communication of materials in discharge pipe 70 to sludge pump 50 ′ and to have no effect on the fluid communication of materials between discharge pipe 70 and sludge pump 50 . Valve 35 and pipe 20 h are positioned so as to have no effect on the fluid communication between materials in discharge pipes 570 - 577 and sludge pump 50 ′ via pipe 20 ′.
[0067] Flap valve 46 is positioned in discharge pipe 70 between clarification tank and valves 35 , 36 to prevent the reverse flow of materials in discharge pipe 70 when valves 35 or 36 are opened, preventing the fluid communication of materials between clarification tank 30 and IFS 100 - 107 . Flap valve 47 is positioned in pipe 20 i to prevent the reverse flow of materials through pipe 20 i when valve 37 is opened, preventing the fluid communication of materials from clarification 30 discharge pipe 70 with sludge pump 50 ′ and IFS troughs 100 - 107 via pipe 20 i. Flap valve 48 is positioned in pipe 20 h to prevent the reverse flow of materials through pipe 20 h when valve 35 is opened, preventing the fluid communication of materials from IFS troughs 100 - 107 with clarification tank 30 and sludge pump 50 via pipe 20 h. Flap valve 49 is positioned in grit and sludge intake valve 20 ′ to prevent the reverse flow of materials in sludge and intake pipe 20 ′, preventing fluid communication of materials from clarification tank 30 and IFS troughs 100 - 107 .
[0068] Sludge pump 50 is in fluid communication with sludge classification press 52 via pipe 20 e. Sludge pump 50 ′ is in communication with grit separator 51 via pipe 20 f. Grit separator 51 discharges grit-free sludge via pipe 20 g and is in communication with sludge classification press 52 via pipe 20 g. Alternatively grit separator 51 discharges grit-free pipe via pipe 26 and is in fluid communication with wet well 12 of FIG. 1 via pipe 26 . Grit Separator 51 discharges grit via discharge pipe 24 . Valve 39 is positioned on pipe 20 g to control fluid communication between grit separator 51 and sludge classification press 52 . Valve 43 is positioned on pipe 26 to control fluid communication between grit separator 51 and wet well 12 of FIG. 1 .
[0069] Sludge classification press 52 is in fluid communication with optional sludge thickener 53 via pipe 20 c. Optional solids concentrator 53 is in fluid communication with digester 54 via pipe 20 d. In one embodiment, sludge thickener is in direct fluid communication with digester 54 via pipe 20 c.
[0070] Valves 35 - 39 may be manually operated valves. In one embodiment, valves 35 - 39 are electronically-controlled valves under control of and in communication with SCADA 900 via communication channels 945 - 949 respectively. Valves 43 may be a manually operated valve. In one embodiment, valve 43 is an electronically-controlled valve under control of and in communication with SCADA 900 via communication channel 950 .
[0071] With reference to FIG.11 , to provide flexibility in the treatment of sludge processed by grit separator 51 , if the sludge has substantially no biologically-degradable materials, valve 39 providing fluid communication between grit separator 51 and sludge classification press 52 remains closed. Valve 43 is opened and liquid and non-particulate, non-grit sludge extracted from the sludge by the grit separator 51 is returned to wet well 12 of FIG. 1 via discharge pipe 26 and grit is disposed of in a landfill or by other means. If the sludge has substantive biologically-degradable materials, valve 39 providing fluid communication between grit separator 51 and sludge classification press 52 is opened and valve 43 is closed. Liquid and non-particulate, non-grit sludge extracted from the sludge by the grit separator 51 is then treated by sludge classification press 52 and grit is disposed of in a landfill or by other means.
[0072] In one embodiment of the current application, sludge and grit that has not otherwise been separated into components by a primary treatment system is treated to remove grits and other undesirable materials and to separate and concentrate biologically digestible materials. With reference to FIG. 4 , discharge pipe 1111 of primary treatment system 1100 is in fluid communication with sludge and grit intake pipe 20 of FIG. 12 . In one embodiment, a sludge pump 50 is used to assist in the evacuation of the primary treatment system 1100 sludge. In one embodiment, sludge pump 50 is electronically controlled by a supervisory control and data acquisition system SCADA 900 which provides a signal via communication channel 926 to start and stop pumping.
[0073] A sludge treatment system may receive sludge with varying characteristics during its operation. In a waste water treatment system, the characteristics of the sludge may vary due to seasonal and diurnal variations in the characteristics of the influent as well as from periodic and/or isolated events. A storm may result in flushing of grit and particulates from a sewer system connected to the waste water treatment system. An industrial emitter may periodically discharge low grit materials rich in biologically-digestible materials into a sanitary sewer system connected to a waste water treatment plant. Clarification systems such as the prior art CLARI-FLOCCULATOR® system of FIG. 4 may be used to treat sites containing waste water that are remote or otherwise not directly connected to a waste water treatment system. In these circumstances, the sludge produced by treatment of the waste water may need to be transported to a sludge treatment system. It may be desirable to regularly or periodically treat secondary sludge to remove biologically-digestible materials as well as primary sludge. A waste treatment plant may accept food and other wastes with an exceptionally high proportion of biologically-digestible material trucked or otherwise transported directly to the plant. For these and other reasons, it is desirable to have an adaptive, configurable sludge treatment system.
[0074] With reference to FIG. 12 , in one embodiment of the current application, sludge enters grit intake pipe 20 which is in fluid communication with sludge pump 50 . Sludge pump 50 is in fluid communication with grit separator 51 via pipe 20 a. Valve 66 is arranged in line with pipe 20 a to control fluid communication to grit separator 51 . Grit separator 51 is in fluid communication with sludge classification press 52 via pipe 20 b. Valve 84 is arranged in line with pipe 20 b to control fluid communication to sludge classification press 52 . Sludge classification press 52 is in fluid communication with sludge thickener 53 via pipe 20 c. Valve 86 is arranged in line with pipe 20 c to control fluid communication to sludge thickener 53 . Sludge thickener 53 is in fluid communication with digester 54 via pipe 20 d. A flocculent source 55 is arranged to communicate flocculents to sludge prior to being treated by sludge classification press 52 via pipe 27 a or alternatively to sludge discharged from sludge classification press 52 via pipe 27 b. In one embodiment, sludge pump 50 is in communication with and controlled by SCADA 900 via communication channel 926 . In one embodiment, sludge classification press 52 is in communication with and controlled by SCADA 900 via communication channel 927 . In one embodiment, flocculent source 55 is in communication with and controlled by SCADA 900 via communication channel 929 . In one embodiment, sludge thickener 53 is in communication with and controlled by SCADA 900 via communication channel 928 .
[0075] In one embodiment, one or more optional flowmeters are incorporated in the system: flow meter 2009 to measure the flow in discharge pipe 20 ; flow meter 2001 to measure the flow in pipe 20 a, flow meter 2003 to measure the flow in discharge pipe 20 b; flow meter 2005 to measure the flow in pipe 20 c; and flow meter 2007 to measure the flow in pipe 20 d. In one embodiment, flow meter 2009 is in communication with SCADA 900 via communication channel 951 . In one embodiment, flow meter 2001 is in communication with SCADA 900 via communication channel 936 . In one embodiment, flow meter 2003 is in communication with SCADA 900 via communication channel 938 . In one embodiment, flow meter 2005 is in communication with SCADA 900 via communication channel 940 . In one embodiment, flow meter 2007 is in communication with SCADA 900 via communication channel 942 .
[0076] In one embodiment, one or more optional sensors are incorporated in the system: sensor 2010 to measure the characteristics of materials in sludge and grit intake pipe 20 ; sensor 2002 to measure the characteristics of materials in discharge pipe 20 a; sensor 2004 to measure the characteristics of materials in discharge pipe 20 b; sensor 2006 to measure the characteristics of materials in discharge pipe 20 c; and, sensor 2008 to measure the characteristics of materials in discharge pipe 20 d. The optional sensors are in communication with SCADA 900 : sensor 2010 via communication channel 952 ; sensor 2002 via communication channel 937 ; sensor 2004 via communication channel 939 ; sensor 2006 via communication channel 941 ; and sensor 2008 via communication channel 943 .
[0077] Sensors 2010 , 2004 , 2006 , and 2008 may be a UVAS sensor, turbidity sensor, pH sensor or solids sensor or any other sensor consistent with measuring the physical and/or chemical characteristics of sludge and grits undergoing treatment.
[0078] Pipe 20 a is in direct fluid communication with pipes 20 a, 20 b, 20 c, and pipe 20 d via pipe 20 j. Valve 64 controls fluid communication between pipe 20 a and pipe 20 j. Valve 65 controls fluid communication between pipe 20 j and pipe 20 b. Valve 85 controls fluid communication between pipe 20 j and pipe 20 c. Valve 87 controls fluid communication between pipe 20 j and pipe 20 d. Valve 69 controls the communication of grit discharged through grit separator 51 grit discharge pipe 24 . In one embodiment, valves 64 , 65 , 66 , 69 , 84 , 85 , 86 , 87 are manually controlled. In one embodiment, valves 64 , 65 , 66 , 69 , 84 , 85 , 86 , 87 are under the control of and in communication with SCADA 900 : valve 64 via communication channel 953 , valve 65 via communication channel 955 ; valve 66 via communication channel 954 ; valve 69 via communication channel 957 ; valve 84 via communication channel 958 ; valve 85 via communication channel 959 ; valve 86 via communication channel 960 ; and, valve 87 via communication channel 961 .
[0079] Check valve 68 is arranged in line with pipe 20 b to permit flow of fluid from grit separator 51 to sludge classification press 52 and to pipe 20 j where pipe 20 j is in fluid communication with pipe 20 b and while preventing the reverse flow of fluid to grit separator 51 . Check valve 88 is arranged in line with pipe 20 c to permit flow of fluid from sludge classification press 52 to solids concentrator 53 and to pipe 20 j where pipe 20 j is in fluid communication with pipe 20 c while preventing the reverse flow of fluid to sludge classification press 52 . Check valve 89 is arranged in line with pipe 20 d to permit flow of fluid from sludge thickener 53 to digester 54 and to pipe 20 j where pipe 20 j is in fluid communication with pipe 20 d while preventing the reverse flow of fluid to sludge thickener 53 .
[0080] The system of FIG. 12 operates in substantially the same manner as the corresponding elements of FIG. 5 when valves 64 , 65 , 85 and 87 are closed and valves 66 , 84 , 86 and 87 are opened. The system is dynamically configured to optimally and most efficiently separator biological materials from the incoming sludge by a combination of continuous monitoring of the sludge characteristics undergoing treatment and a priori knowledge of the sludge characteristics. By way of example, upon receiving sludge from an industrial beverage or food processing source known to have little grit and high solids content, the sludge treatment system of FIG. 12 may be configured to route material past the grit separator and sludge thickener by closing valves 66 and 84 and opening valves 64 , 65 , 84 , 86 and 87 . Upon receiving sludge known to have a great deal of grit, but little biologically-digestible materials, the sludge treatment system of FIG. 12 may be configured to separate grit from the fluid and discharge both by closing valves 64 , 65 and 84 and opening valve 69 .
[0081] While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims. | A system comprising method and apparatus for separating biologically-digestible materials from an influent sewage stream. The system may comprise a primary clarification tank to capture sixty percent or more of the total solids from an influent stream; a sludge classifying press (SCP) to isolate and concentrate biologically digestible materials from sludge formed in the primary clarification tank, releasing valuable organics, such as are found in corn kernels, by fracturing the protective casings; a grit capture mechanism in a chamber within the primary clarification tank and isolated from the bulk of the sludge containing biologically-degradable materials; a grit trap to remove grit from the sludge prior to classifying the sludge with the SCP; apparatus for adding thickener to the sludge after classification and prior to digestion; and automation of one or more elements of the process for separating and digesting the biologically digestible materials in an influent stream. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 61/936,142 entitled Physical And Academic Game and filed on Feb. 5, 2014, which is incorporated by reference in its entirety.
BACKGROUND
[0002] Many elementary age children take physical education as part of their academic curriculum. In this regard, throughout a typical school day of a child he/she has a physical education (also referred to as “PE”) class intermixed with his/her academic classes.
[0003] Typical PE classes focus entirely on physical activities that help a child learn the skills to be active in life. For example, PE classes teach fundamental locomotor skills, such as walking, running, hopping, jumping and skipping. In addition PE classes may also focus on nonlocomotor skills such as turning, twisting, swinging, balancing and bending. Addition physical activities in PE class may focus on teaching manipulative skills, such as catching, dribbling, throwing, or kicking. Other types of activities may include those directed toward improving gross/fine motor skills, eye hand coordination, spatial awareness, and agility/balance.
SUMMARY
[0004] The present disclosure is a game that has a mixer positioned at a location on a gaming area and a plurality of balls randomly dispersed throughout the gaming area. In response to a command, a player on a team collects one or more of the plurality of balls, the score is incremented based upon the balls collected, the player throws the collected ball(s) into the mixer, and the mixer disperses the ball(s) back into the gaming area.
DESCRIPTION OF THE DRAWINGS
[0005] The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the several views.
[0006] FIG. 1 is an isometric view of an exemplary mixer in accordance with an embodiment of the present disclosure.
[0007] FIG. 2 is a side isometric view of the mixer depicted in FIG. 1 .
[0008] FIG. 3 is an isometric view of another exemplary mixer in accordance with an embodiment of the present disclosure.
[0009] FIG. 4 is an isometric view of an exemplary basket of lettered balls in accordance with an embodiment of the present disclosure used in playing a game incorporating the mixers of FIG. 1 or FIG. 3 .
[0010] FIG. 5 is an isometric view of an exemplary builder tray in accordance with an embodiment of the present disclosure used in playing a game incorporating the mixers of FIG. 1 or FIG. 3 .
[0011] FIG. 6 depicts an exemplary set of task cards that may be used in playing a game incorporating the mixers of FIG. 1 or FIG. 3 .
[0012] FIG. 7 depicts an exemplary set of point indicator pieces used to keep score in a game incorporating the mixers of FIG. 1 or FIG. 3 .
[0013] FIG. 8 depicts exemplary wrist bands for identifying players in a game incorporating the mixers of FIG. 1 or FIG. 3 .
[0014] FIG. 9 depicts another exemplary task card that may be used in a game incorporating the mixers of FIG. 1 or FIG. 3 .
DESCRIPTION
[0015] The present disclosure related to a physical and academic game that effectively integrates academic skills, e.g., reading and spelling, into basic physical skills. In this regard, the physical and academic game comprises a mixer goal that is placed in the middle of a playing area, e.g., a gym, a school yard, or other indoor or outdoor physical education arenas. Balls inscribed with letters of the alphabet are placed in proximity to the mixer goal. Children playing the game are tasked with building words from balls inscribed with letters of the alphabet. In order to perpetuate the game, once a child (or group of children, e.g., a team) have built the tasked word, the children throw the balls making up the word into the mixer goal, and the mixer goal disperses the balls back into the playing area.
[0016] FIG. 1 depicts a mixer goal 100 in accordance with an embodiment of the present disclosure. The mixer goal 100 comprises a floor mat 107 , four flexible poles 103 a - 103 d, a ball receiver and disperser 104 , and ball dispersion ramps 101 a - 101 b.
[0017] In the embodiment shown, the floor mat 107 is a substantially square piece of fabric. However, the floor mat 107 may be other shapes and made of other types of materials in other embodiments. The floor mat 107 rests upon a gaming area 113 , which can be, for example, a gym floor or a playground yard.
[0018] In the embodiment depicted, the four flexible poles 103 a - 103 d are flexibly and removeably coupled to the floor mat 107 . In this regard, the floor mat 107 may have openings and/or stops integrated therein to retain the poles 103 a - 103 d with respect to the floor mat 107 . Note that the floor mat 107 may not be used in other embodiments of the present disclosure. In this regard, the ends of each pole 103 a - 103 d may comprise feet (not shown) coupled thereto that retain the poles in the positions shown in FIG. 1 .
[0019] The poles 103 a - 103 d are inserted through casings 108 a - 108 d, respectively. Each of the casings 108 a - 108 d is a fabric channel of the ball receiver and disperser 104 through which the poles 103 a - 103 d may be inserted. Note that when the poles 103 a - 103 d are inserted within the casings 108 a - 108 d, the poles 103 a - 103 d bend such that the mixer 100 stands upright. Further, in bending the poles 103 a - 103 d create a point 110 of the ball receiver and disperser 104 .
[0020] In the embodiment depicted, the ball receiver and disperser 104 is a pyramidal shape having four faces 111 a - 111 d. Note that the ball receiver and disperser 104 may be other shapes in other embodiments. For example, the ball receiver and disperser 104 may be rectangular or square.
[0021] The ball receiver and disperser 104 further comprises openings 106 a and 106 b, respectively. In the embodiment depicted, the openings 106 a and 106 b are triangular. However, the openings 106 a and 106 b may be other shapes in other embodiments, e.g., circular, square, etc. Further, the ball receiver and disperser 104 is coupled to flaps 102 a and 102 b. In one embodiment, the flaps 102 a and 102 b are sewn to the seams 112 a, 112 b and 112 c, 112 d , respectively. The flaps 102 a and 102 b are positioned such that a portion of each flap hangs below the ball receiver and disperser 104 .
[0022] Further, the mixer 104 comprises the ball dispersion ramps 101 a and 101 b. Note that in the embodiment depicted in FIG. 1 , the ball dispersion ramps 101 a and 101 b are made of an open-meshed material, i.e., netting. However, the dispersion ramps 101 a and 101 b may be made of other types of materials in other embodiments.
[0023] The mixer 100 is used in a game, the rules and details for which are described further herein. Notably, during the game, a ball (not shown) is thrown into one of the openings 106 a or 106 b. The ball then falls through the force of gravity toward the ramps 101 a and 101 b. The flaps 102 a and 102 b create a barrier for the ball. In this regard, the flaps 102 a and 102 b ensure that the ball thrown is directed toward either ramp 101 a or ramp 101 b such that the ball thrown is dispersed into the gaming area 113 . In this embodiment, the ball rolls downward on one of the ramps 101 a or 101 b and is launched from the mixer 100 to the gaming area 113 .
[0024] FIG. 2 is a side view of the mixer 100 to further show an exemplary structure of the mixer 100 . The side view of the mixer 100 of FIG. 2 shows a ball being received in the opening 106 a and being dispersed onto the gaming area 113 .
[0025] In this regard, the ball receiver and disperser 104 receives a ball 201 through the opening 106 a. The ball 201 falls through the force of gravity, and the flap 102 a or 102 b directs the ball 201 down the respective ramp 101 a or 101 b, which in FIG. 1 shows the ball being directed by 102 a down ramp 101 a. The ball 201 rolls down the ramp 101 a and is launched by the ramp 101 a onto the gaming area 113 .
[0026] FIG. 3 depicts another embodiment of the mixer 100 . In the embodiment, the mixer 100 comprises the floor mat 107 , four flexible poles 103 a - 103 d, a ball receiver and disperser 301 , and a dispersion ball 302 .
[0027] In the embodiment shown, the floor mat 107 and the poles exhibit the same structure and function as the embodiment depicted in FIG. 1 ; however, coupled to the floor mat 107 is a dispersion ball 302 , which is described further herein. The dispersion ball 302 may be coupled to the mat 107 via Velcro® or some type of adhesive.
[0028] In the embodiment depicted, the ball receiver and disperser 306 is a pyramidal shape having the four faces 111 a - 111 d. Note that the ball receiver and disperser 301 may be other shapes in other embodiments. For example, the ball receiver and disperser 301 may be rectangular or square.
[0029] The ball receiver and disperser 301 further comprises the openings 106 a and 106 b, respectively. In the embodiment depicted, the openings 106 a and 106 b are triangular. However, the openings 106 a and 106 b may be other shapes in other embodiments, e.g., circular, square, etc. Further, the ball receiver and disperser 301 is coupled to a funnel 309 . In one embodiment, the funnel 309 is sewn to the seams 308 a - 308 d. The funnel 309 is further coupled to a tube 310 .
[0030] The mixer 100 is used in a game, the rules and details for which are described further herein. Notably, during the game, a ball 304 is thrown into one of the openings 106 a or 106 b . The ball then falls through the force of gravity toward the funnel 309 . The ball 304 rolls along the inside surface 312 of the funnel 309 , which directs the ball 304 to the tube 310 .
[0031] The ball 304 falls through the tube through the force of gravity, and lands on the dispersion ball 302 . The ball 304 bounces off the dispersion ball 302 , and the ball 304 is dispersed to the gaming area 113 . The dispersion of the ball 304 to the gaming area 113 is random and is based on the position at which the ball 304 strikes the dispersion ball 302 .
[0032] FIG. 4 depicts a basket 400 in accordance with an embodiment of the present disclosure. The basket 400 comprises a set of balls 401 . Each ball 401 is inscribed with a particular letter. Note that the balls are removeable from the basket 400 . As will be described further herein, a subset of the balls may be used to form words.
[0033] FIG. 5 is an isometric view of an exemplary builder tray 500 in accordance with an embodiment of the present disclosure. The builder tray 500 comprises a plurality of openings 501 that comprise a circumferential edge 502 . A letter ball 401 is placed upon the circumferential edge 502 of the opening 501 , and the ball 401 is retained by the builder tray 500 . In this regard, a plurality of balls 401 may be placed on the circumferential edges 502 of adjacent openings 501 to form a word. In the example shown in FIG. 5 , the word is “happy.”
[0034] FIG. 6 depicts a set of task cards 600 . With reference to FIG. 5 , balls 401 corresponding to the letters of a word exhibited on one of the set of cards 600 may formed on the builder tray 500 ( FIG. 5 ).
[0035] FIG. 7 depicts point indicators 700 and 703 . The exemplary point indicators 700 and 703 shown are circular-shaped and representative of a pie. The point indicator 700 comprises four pieces 701 , and the point indicator 701 comprises eight pieces 703 . Each of the pieces has indicium thereon. In the exemplary pieces shown, the indicia comprise the word “pie” and a graphical heart. Note that as will be described herein, the pieces 701 or 703 are collected by players of a game of the present disclosure to indicate scoring.
[0036] FIG. 8 depicts a set of wristbands 801 - 804 . The wristbands 801 - 804 may be word by players of an exemplary game of the present disclosure to indicate the respective players' functions in the game. In this regard, the wristbands 801 - 804 may be colored, e.g., red and yellow to identify a team and/or the role of the player wearing the wristband 801 - 804 in the game.
[0037] FIG. 9 depicts another embodiment of a task card 900 in accordance with the present disclosure. The task card 900 may comprise and indicator 901 that identifies the grade level for the particular card. In addition, the card may comprise indicium 902 that provides instructions to a team of a game of the present disclosure. In the example, the task card 900 instructs the team to spell the word “cooks.”
[0038] With reference to the previous described figures, an exemplary game in accordance with the present disclosure will now be described. The game description following shall assume only two teams for ease of explanation and discussion. However, any number of teams may play the game of the present disclosure in other embodiments.
[0039] During set up of the game, a player or instructor (i.e., a teacher) places a mixer 100 ( FIG. 1 ) in a central location (not shown) of the gaming area 113 ( FIG. 1 ). Additionally, balls 401 ( FIG. 4 ) are scattered and dispersed manually throughout the gaming area.
[0040] Further, the point the point indicator pieces 701 ( FIG. 7 ) and the task cards 600 ( FIG. 6 ) or 900 ( FIG. 9 ) are placed in a designated area. Note that for a game having two teams, if the point indicator 700 is used, there is available eight pieces 701 (or 16 pieces if the point indicator 703 ( FIG. 7 ) is used). Eight pieces total ensures that there are in game play enough pieces for each team to form a complete point indicator 700 . In the example provided herein, the pieces 701 form a complete circle, as described with reference to FIG. 7 .
[0041] Further note that the task cards 600 ( FIG. 6 ) or task cards 900 ( FIG. 9 ) may be placed at a particular position in the gaming area. Each set of task cards 600 or 900 placed in the gaming area may identify a particular, e.g., with a number identifier card may correlate a team playing the game with a particular number.
[0042] Additionally, builder trays 500 ( FIG. 5 ) are placed at separate and distinct positions on the gaming area 113 . Note that in playing the game, each identified team has a designated builder tray 500 .
[0043] A plurality of players (not shown) is divided into teams. In the embodiment described herein, the game is described using two teams wherein each team comprises six players. However, each team may consist of any number of players in other embodiments, and there may be more than two teams in other embodiments. Thus, for the two teams created there are eight point indicator pieces available for retrieval and two sets of task cards (each set having an identifier that identifies the team associated with the set) in the gaming area.
[0044] Further, the wristbands 801 - 804 are worn by a subset of the players. In this regard, each team has a captain player and a point guard player, and each captain/point guard wears identifying wristband, e.g., the captain may wear a red wristband whereas the point guard may wear a yellow wristband. The other players on each team are referred to as “letter ninjas” herein.
[0045] When the game begins, the captain retrieves a task card 600 or 900 from the set of task cards identified for his/her team. The captain places the retrieved task card 600 or 900 next to the builder tray placed for his/her team. The task card 600 or 900 , as described herein, identifies a word that the team is to spell in its builder tray 500 .
[0046] The letter ninjas travel around the gaming area 113 looking for one or more balls 401 (FIG.
[0047] 4 ) inscribed with letters contained in the word identified on the task card 600 and 900 . In one embodiment, the captain may give instructions to each of the letter ninjas instructing him/her to find and retrieve a ball inscribed with a particular letter.
[0048] As the letter ninjas bring the balls 401 to the builder tray, he/she places the retrieved letter on the opening 501 associated with the letter position in the work. In another embodiment, the letter ninja may give the ball 401 to the captain, and the captain builds the word in the builder tray 500 .
[0049] Once the letter ninjas have retrieved all letters in the word indicated by the task card 600 or 900 retrieved, the point guard travels to the point indicator pieces and retrieves one piece 701 ( FIG. 7 ). The team then begins to build his/her point indicator shape, e.g., a circular shape that may be designated as a “pie.”
[0050] Once the word is spelled on the builder tray 500 the point indicator piece 701 , the letter ninjas retrieve the balls 401 from the builder tray 500 . The letter ninjas travel to the mixer 100 ( FIG. 1 ), and each letter ninja throws his/her ball into the mixer 100 . The mixer 100 receives and disperses the balls 401 back into the gaming area 113 .
[0051] The teams race against one another to build its complete point indicator 700 , e.g., retrieve and position four pieces of the circular shaped point indicator to form a complete circle. In this regard, each team continues to build words identified by the task cards 600 or 900 until the team has a complete point indicator 700 .
[0052] The mixer and game components may further be used for players who are non-readers, e.g., prekindergarten. In this regard, the instructor may instruct each player to find all the balls identifying his/her favorite color, and throw such balls 401 into the mixer.
[0053] For nonreaders, an instructor may also instruct each player to retrieve balls 401 having a particular color, e.g., red balls. Once the class has collected all the red balls, the students may throw the balls in the mixer. | The present disclosure is a game that has a mixer positioned at a first location on a gaming area and a plurality of balls randomly dispersed throughout the gaming area. In response to a command, a player on a team collects one or more of the plurality of balls, the score is incremented based upon the balls collected, the player throws the collected ball(s) into the mixer, and the mixer disperses the ball(s) back into the gaming area. | 0 |
BACKGROUND OF THE INVENTION
The trend in the circuit protection industry is currently toward complete circuit protection which is accomplished by the addition of supplemental protection apparatus to standard overcurrent protective devices, such as molded case circuit breakers. U.S. Pat. No. 4,622,444 entitled "Circuit Breaker Housing and Attachment Box" describes an accessory that can be field-in-stalled within a circuit breaker without interfering with the integrity of the circuit breaker internal components. This is accomplished by mounting the accessories within a recess formed in the circuit breaker enclosure cover.
An electronic trip actuator which is mounted within the circuit breaker enclosure is described within U.S. Pat. No. 4,679,019 entitled "Trip Actuator for Molded Case Circuit Breakers". The circuit breaker actuator responds to trip signals generated by an electronic trip unit completely contained within a semi-conductor chip such as that described within U.S. Pat. No. 4,589,052. The development of a combined trip actuator for both overcurrent protection as well as accessory function is found within U.S. Pat. No. 4,700,161 entitled "Combined Trip Unit and Accessory Module for Electronic Trip Circuit Breakers". The aforementioned U.S. Patents which represent the advanced state of the art of circuit protection devices are incorporated herein for reference purposes.
A shunt trip accessory unit allows the circuit breaker operating mechanism to be articulated from a remote location to separate the circuit breaker contacts, usually to perform a tripping function for electrical system control and protection. One such shunt trip accessory unit is described within U.S. patent application Ser. No. 133,867 filed Dec. 16, 1987 entitled "Molded Case Circuit Breaker Shunt Trip Unit". An auxiliary switch accessory unit allows an operator to determine the "ON" or "OFF" conditions of a molded case circuit breaker contacts at a remote location by means of an audible alarm or visible display. One such auxiliary switch unit is described within U.S. patent application Ser. No. 133,868 filed Dec. 16, 1987 entitled "Molded Case Circuit Breaker Auxiliary Switch Unit". Both of the aforementioned U.S. Patent Applications are incorporated herein for purposes of reference.
A more recent example of a combined overcurrent trip actuator and multiple accessory unit is described within U.S. patent application Ser. No. 133,869 filed Dec. 16, 1987 entitled "Molded Case Circuit Breaker Multiple Accessory Unit" which combined overcurrent trip actuator and multiple accessory unit requires a separate mounting recess within the circuit breaker cover to house the printed wire board that carries the accessory control circuit. U.S. patent application Ser. No. 163,589 entitled "Molded Case Circuit Breaker Actuator-Accessory Unit" describes one such combined overcurrent trip actuator and multiple accessory unit wherein the printed wire board and actuator-accessory unit are both contained within the same mounting recess within the circuit breaker cover. U.S. patent application Ser. No. 176,589 describes an actuator-accessory module wherein the electromagnetic actuator and electronic control circuits are self-contained within a single unitary module. U.S. patent application Ser. No. 185,723 entitled "Molded Case Circuit Breaker Actuator-Accessory Module" describes an arrangement whereby a separate actuator-accessory module is selected for different combinations of accessory functions. All of the aforementioned U.S. Patent Applications are incorporated herein for reference purposes.
SUMMARY OF THE INVENTION
An integrated protection module which includes overcurrent protection along with auxiliary accessory function within a common enclosure contains an accessory cover for access to the selected accessory modules to allow field installation of the accessory modules within an integrated protection unit. One combined actuator-accessory module provides overcurrent protection along with shunt trip function and ground fault protection. The electromagnetic actuator includes a first coil for overcurrent operation and a second coil for shunt trip operation. The overcurrent electronic control is provided by the electronic trip circuit contained within the circuit breaker portion of the integrated protection unit or by means of a thermal-magnetic trip unit whereas the shunt trip control and ground fault protection is provided by an electronic circuit contained within the accessory module.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of an integrated molded case circuit breaker containing an overcurrent, shunt trip and ground fault actuator-accessory module according to the invention;
FIG. 2 is an exploded top perspective view of the integrated circuit breaker of FIG. 1 prior to assembly of the overcurrent, shunt trip and ground fault actuator-accessory module according to the invention;
FIG. 3 is a plan view of the integrated molded case circuit breaker with part of the cover removed to show the interaction between the circuit breaker operation mechanism and the combined overcurrent, shunt trip and ground fault actuator-accessory module of Fig. 2; and
FIG. 4 is a circuit diagram of the shunt trip and ground fault electrical circuit contained within the printed wire board for the overcurrent, shunt trip and ground fault actuator-accessory module of Fig. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An integrated circuit breaker 10 consisting of a molded plastic case 11 with a molded plastic cover 12 is shown in FIG. 1 with the accessory cover 13 attached to the circuit breaker cover by means of screws 14. The case includes a wiring slot 18 formed therein for allowing external connection with a remote switch by means of conductors 34. The circuit breaker operating handle 19 extends up from an access slot 20 formed in the cover escutcheon 9. A rating plug 15 such as described in U.S. Pat. No. 4,728,914 entitled "Rating Plug Enclosure for Molded Case Circuit Breakers", which Patent is incorporated herein for reference purposes is shown assembled within the accessory cover. A pair of accessory doors 16, 17 are formed in the accessory cover for providing access to the overcurrent and shunt trip actuator and accessory module 31, hereafter "actuator-accessory module" contained within the recess 40, shown in Fig. 2. Still referring to FIG. 2, the rating plug 15 is fitted within a recess 23 formed in the accessory cover 13 and the accessory cover is fastened to the circuit breaker cover by means of screws 14, thru-holes 24 and threaded openings 25. Access to the rating plug interior for calibration purposes is made by means of the rating plug access hole 21.
The trip unit for the integrated circuit breaker 10 is contained within a printed wire board 27 which is positioned in the trip unit recess 26. The rating plug 15 when inserted within the rating plug recess interconnects with the printed wire board by means of pins 28 upstanding from the printed wire board and sockets 29 formed on the bottom of the rating plug. The trip unit in turn electrically connects with the current transformers 47, 48 (Fig. 3) by means described within U.S. Pat. No. 4,652,975 entitled "Mounting Arrangement for Circuit Breaker Current Sensing Transformers" which Patent is incorporated herein for reference purposes. When the trip unit printed wire board has been assembled within its recess, the actuator-accessory module 31 is then installed within recess 40. In some applications the printed wire board and rating plug are omitted and a thermal-magnetic trip unit is used for overcurrent protection while the accessory functions are separately provided by the actuator-accessory module per se. One example of one such thermal-magnetic trip unit is found in U.S. Pat. No. 4,706,054. The actuator-accessory module includes a housing 32 within which the dual actuator-accessory coil 35 is enclosed and which further contains a plunger 36 and a plunger spring 41 which projects the plunger in a forward trip position when the dual actuator-accessory coil 35 becomes energized. The actuator-accessory module is similar to the actuator-accessory unit described within aforementioned U.S. patent application Ser. No. 163,589 wherein a trip actuator latch 37 is pivotally attached to the housing 32. A hook 38 formed at one end of the trip actuator latch cooperates with the circuit breaker operating mechanism shown in aforementioned U.S. Pat. No. 4,700,161 in the manner to be described below in greater detail. The operation of the actuator-accessory module is similar to that described within U.S. Pat. Nos. 4,641,117 and 4,679,019 which Patents are incorporated herein for purposes of reference. The dual actuator-accessory coil 35 differs from that described within some of the referenced Patents by including a separate flux shift coil 22 for overcurrent trip operation and a separate shunt trip coil 60 for remote shunt trip operation. A permanent magnet 59 is provided at the end of both coils to hold the plunger 36 against the bias exerted on the plunger by the charged plunger spring 41. A similar combined accessory and trip actuator unit is described within U.S. Pat. No. 4,641,117 entitled "Combined Accessory and Trip Actuator Unit for Electronic Circuit Breakers" which Patent is incorporated herein for purposes of reference. The actuator-accessory module includes a printed wire board 33 which contains the components required for operating the shunt trip coil 60 and is connected with the shunt trip coil by means of a pair of wire conductors 67, 68. A pair of wire conductors 34 connect the actuator-accessory module with an external voltage source and switch for shunt trip operation. The flux shift coil 22 connects with the trip unit 27 by means of a pair of wire conductors 69 attached to the coil and by means of edge connectors 61 arranged within the housing for receiving a pair of pins 30 upstanding on the trip unit 27.
The actuator-accessory module 31 is depicted in Fig. 3 within the recess 40 in the integrated circuit breaker 10 with part of the actuator-accessory module printed wire board 33, actuator-accessory module housing 32 and accessory cover 13 removed to show the interaction between the actuator-accessory module 31 and the mechanical actuator 50 which sits in the integrated circuit breaker case 11. The integrated circuit breaker operating mechanism shown generally at 53 includes an operating cradle 54 having a hook 55 formed at one end thereof which is retained by means of a primary latch 56. The secondary latch assembly 57 prevents the primary latch from releasing the operating cradle until the secondary latch is displaced. A tab 58 extending from the secondary latch is contacted by the operation of the mechanical actuator 50 to displace the secondary latch and thereby articulate the circuit breaker operating mechanism and separate the circuit breaker contacts in response to a trip command in the following manner. Electric current flow is sensed by the current transformers 47, 48 which are located ahead of load lugs 51, 52 and is acted upon by the trip unit 27 described earlier with reference to FIG. 2. The operating lever 46 sits within the case 11 and connects with the latch support arm 44 in the actuator-accessory module recess 40 by means of a connecting arm 45. The latch pin 43 is retained by the trip actuator latch 37 which is in turn controlled by the position of the trip actuator arm 39 which extends through a side wall 42 of the actuator-accessory module housing 32. The trip actuator arm 39 interfaces with the plunger 36 in the following manner. When the circuit current exceeds a predetermined value, current is applied to the flux shift coil 22 thereby allowing the plunger 36 to be propelled by the urgence of the plunger spring (Fig. 2) to thereby rotate the trip actuator latch 37 in the clockwise direction to release the trip actuator latch 37 from the latch pin 43.
The shunt trip function is provided by means of the accessory circuit 90 which includes the input circuit 62, shunt trip circuit 82 and ground fault circuit 83 seen by now referring to both FIG. 2 and FIG. 4. It is noted that an auxiliary switch, such as described within the referenced actuator-accessory Patents is no longer required to interrupt the external voltage signal applied to the shunt trip coil 60. In operation, the remote shunt trip signal voltage is applied to wire conductors 34 and terminals T1, T2 connected to the shunt trip circuit 82 through a bridge rectifier 63 consisting of diodes D 9 -D 12 and current limiting resistor R 14 via conductors 86, 87. External power is supplied to the accessory circuit over external wire conductors 80 and input terminals T5, T6. Transient voltage protection is provided to the input circuit by the combination of the series resistor R 1 and zener diode Z 1 which are connected across the input terminals. Resistor R 2 is a current limiting resistor connected in series with one of the inputs to the diode bridge rectifier 49 consisting of diodes D 1 -D 4 . The output of the bridge rectifier connects respectively with the positive and negative rails, 70, 71. A charging circuit 64 consisting essentially of a storage capacitor C 1 connects across the positive and negative rails through an FET and resistors R 3 , R 4 . The function of the charging circuit is to provide first and second charging rates to the storage capacitor C 1 . The first charging rate charges the capacitor in less than 10 milliseconds and is provided by the charging circuit consisting of the FET, resistors R 3 , R 5 , R 6 , a signal diode D 5 and a zener diode Z 2 . When voltage is applied over conductors 80 to terminals T5, T6 base drive is applied to transistor Q 5 through resistor R 13 turning on Q 5 . This clamps the gate of the FET to less than 2 volts and disables the fast charge circuit to the storage capacitor C 1 through the FET. To institute a shunt trip operation, a voltage is applied to terminals T 1 , T 2 over conductor 34 through the bridge rectifier 63 including diodes D 9 -D 12 and current limited resistor R 14 onto conductors 86, 87. This executes the photo diode D 16 within the opto-isolator 84 and turns on the photo transistor Q 6 causing the base drive to Q 5 to become diverted to the ground rail 71 through diodes D 7 , D 15 turning off Q 5 . The voltage on the gate of the FET exceeds 2 volts thereby charging C 1 , which becomes completely charged in a period of time less than 10 milliseconds. The voltage across C 1 is applied across resistor R 7 , silicon switch Q 1 and zener diode Z 3 within the switching circuit 65. When the silicon switch trigger voltage is exceeded, the switch becomes conductive thereby discharging capacitor C 1 through the shunt trip coil 60 which is connected between the charging circuit 64 and the electronic switch 74 by means of conductors 67, 68 and terminals T3, T4 described earlier. The shunt trip coil immediately responds by providing an electromagnetic field in opposition to the permanent magnet 59 within the actuator-accessory module 31 of FIG. 2 and allows the plunger 36 to interact with the trip actuator latch 37 and thereby articulate the circuit breaker operating mechanism 53 shown in Fig. 3 and described earlier. The fly-back diode D 6 is connected across the shunt trip coil to prevent the occurrence of a transient voltage when the circuit turns off. Once the circuit breaker operating mechanism has responded, and the external voltage signal remains applied to the terminals T1, T2, some means is usually required to insure that the circuit breaker operating mechanism cannot be reset until the remote switch is deactivated. In the prior art arrangement, described earlier, an auxiliary switch interacted with the circuit breaker operating mechanism to interrupt the current applied to the shunt trip coil and to prevent the coil from becoming overheated. The auxiliary switch mechanically interacted with the circuit breaker operating mechanism to insure that the circuit breaker operating mechanism could not be reset without first resetting the auxiliary switch. Since the actuator-accessory module of the instant invention does not include nor require an auxiliary switch, the circuits, per se, insure that the circuit breaker operating mechanism cannot be reset manually while a voltage signal remains impressed across the terminals T1, T2. This is provided by the second capacitor charging circuit through resistor R 4 which by-passes the FET in its "OFF" states. The charging current applied to the storage capacitor fully charges the storage capacitor within one to two seconds. The silicon switch responds in the manner described earlier to continuously provide a current pulse to the shunt trip coil 60 every second or so to insure that the circuit breaker operating mechanism remains in a "TRIPPED" condition while the terminals T1, T2 remain energized. The switching function is provided by means of an electronic switch 74 consisting of the silicon switch Q 1 , zener diode Z 3 , resistors R 7 , R 8 and transistor switches Q 2 , Q 3 . The electronic switch operates in the manner described in the aforementioned U.S. patent application Ser. No. 176,589. The repeated ON and OFF operation of the electronic switch insures that the required trip current is applied to the shunt trip coil 60 without causing the coil to become overheated. Once the electronic switch is turned off, the storage capacitor begins to recharge. With the silicon switch Q 1 conductive, current flows through resistor R 7 and the emitter-base junction of the transistor switch Q 2 causing Q 2 to become conductive. Current then flows through resistor R 8 and the emitter-base junction of transistor switch Q 3 causing Q 3 to become conductive. With Q 3 conductive, current is shunted away from the silicon switch Q 1 turning off the silicon switch and drawing more current through transistor switch Q 2 which thereby provides a regenerative latching action that insures that the electronic switch remains on until the discharge current from the storage capacitor decreases to a predetermined value set by the resistor R 8 . When the trip current through the shunt trip coil drops below the predetermined value, the electronic switch becomes non-conductive and thereby allows the storage capacitor to charge to a voltage sufficient to exceed the trigger voltage to the silicon switch Q 1 causing the ON-OFF cycle to repeat itself. The timing circuit 66 for controlling the "ON"-"OFF" states of the FET connects with the positive rail 70 through resistor R 9 and operates in the following manner. When terminals T5, T6 are energized, the timing capacitor C 2 charges to a voltage determined by zener diode Z 5 , R 12 and the capacitor C 2 . Resistor R 11 , connected across the base-emitter junction of transistor switch Q 4 , insures that Q 4 remains non-conductive. When the timing capacitor C 2 exceeds the voltage of Z 4 , current flows through resistors R 9 , R 10 , zener diode Z 4 and resistor R 11 to turn on Q 4 . With Q 4 conductive, the gate terminal of the FET is clamped to the negative rail 71 through resistor R 6 turning off the FET. This, in turn, initiates the second charging circuit through resistor R 4 as described earlier.
Still referring to FIGS. 2 and 4, the ground fault trip function is provided in the following manner. The three-phase currents through line terminal buses 75-77 is sensed within a zero sequence current transformer 78 shown in phantom in FIG. 2 which connects with the actuator-accessory printed wire board 33 over wire conductors 81. Although the zero sequence current transformer is described as arranged around the line terminal buses, this is by way of example only. It is to be clearly understood that the zero sequence current transformer can be arranged around the load terminal buses, if desired. The zero sequence current transformer operates in the manner described within U.S. Pat. No. 4,121,269 entitled "Ground Fault Signal Circuit for Circuit Breaker Trip Unit" to sense the occurrence of a ground fault current appearing within the protected circuit to which the terminal buses are connected. This Patent is incorporated herein for reference purposes. When a ground fault signal is accordingly applied to terminals T7, T8 over the wire conductors 81, the signal appearing on conductors 88, 89 is clamped to approximately one volt by means of the back-to-back diodes D 13 , D 14 and burden resistor R 20 . An averaging circuit including resistors R 18 , R 19 and capacitor C 4 produces an average ground fault voltage value onto the negative input terminal to the comparator 85. Operating voltage to the comparator is applied to pin 1 which connects with the positive rails 70 through resistor R 15 and through pin 2 which connects with the negative rail. Power to the comparator is filtered and regulated by the zener diode Z 6 and capacitor C 3 . The reference voltage is supplied to the positive input terminal to the comparator by the midpoint of the voltage divider consisting of resistors R 16 , R 17 . When the ground fault signal exceeds the reference voltage an output signal from the comparator is applied through diode D 8 to the base of Q 5 thereby clamping the base of Q 5 to a low level and causing Q 5 to become non-conducting. This will activate the shunt trip coil 60 in the manner described earlier and thereby institute a circuit interruption.
It has thus been shown that an actuator-accessory module containing a flux shift coil for direct operations by means of the circuit breaker trip unit for overcurrent protection and a shunt trip coil connected with a self-contained shunt trip and ground fault circuit for shunt trip operations via a remote voltage source switch and upon the occurrence of a ground fault condition can be provided within a single actuator-accessory module. The shunt trip circuit initiates a continuous series of trip current pulses to the shunt trip coil, without overheating to insure that the circuit breaker operating mechanism remains tripped as long as an external signal voltage is applied to the shunt trip circuit within the actuator-accessory module. | An integrated protection unit is a circuit breaker which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unit cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and multiple accessory module is either field-installed or factory-installed within the integrated protection unit. A separate actuator-accessory module is selected for different combinations of accessory functions. One such actuator-accessory module provides ground fault protection along with remote trip facility. | 7 |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention is directed to air vents and ducts, methods of venting and directing air or exhaust, and construction methods and apparatus related thereto. The present invention more particularly concerns a clothes drier vent box and method for through-the-wall, ceiling and/or floor venting of clothes dryer exhaust from the interior of a home, apartment, building, and the like, an outside dryer vent box and method, and an outside or exterior exhaust box and method.
As shown in FIG. 1 of the drawings, conventional residential home construction, clothes dryer venting duct work includes a large diameter polyvinyl chloride (PVC) 90° elbow 10, a vertical section of large diameter PVC pipe 12, another 90° elbow 14, and an elongate section of large diameter PVC pipe 16 which extends from the elbow 14 to the exterior of the slab or foundation. The slab 18 is covered with plywood decking 20, and hardwood flooring 22. The dryer 24 is conventional and shown to be resting about six inches away from a conventional 2×4 studded wall 25 having drywall wallboard 28 and 30 attached to vertical 2×4 studs 26 in a conventional fashion. Drywall wallboard 28 includes a large circular opening 32 which accommodates one end of PVC elbow 10. Drywall wallboard 30 includes a slower protruding or broken portion 34 which extends beyond the normal dimension of the 2×4 studded wall 25 to accommodate the remainder of PVC elbow 10 and the upper end of PVC pipe or riser 12. Baseboards or trim 36 are added to the base of drywall wallboards 28 and 30 adjacent hardwood flooring 22. Clothes drier 24 includes an exhaust gas or air outlet pipe 38 which is operatively connected to the open end of elbow 10 by a flexible plastic or metal conduit 40. Typically, one end of the flexible conduit 40 is simply placed into the open end of elbow 10 while the other end is placed over the drier outlet 38 and held in position either by friction or a removable clip or clamp.
This conventional dryer venting arrangement (FIG. 1) suffers from several drawbacks. First, the wall 26 has to be partially modified, destroyed, or broken to accommodate the elbow 10 and upper end of pipe 12. Second, the large opening 32 in drywall section 28 and open end of elbow 10 are unsightly and usually misplaced with respect to the outlet 38 of dryer 24. Third, flexible conduit 40 provides for fluid communication between outlet 38 and elbow 10, but tends to buckle and bow and in so doing prevents the full flow of exhaust gas or air from dryer 24 to reach elbow 10. This blockage tends to reduce the efficiency of the dryer 24, increase energy consumption, and may cause dust collection within the conduit 40, and thereby further prevent the passage of exhaust air or gases therethrough. Fourth, the end of flexible conduit 40 may become dislodged from the opening in elbow 10 and require the dryer to be moved away from the wall and the conduit placed back into the elbow. Fifth, the broken or bowed out lower portion 34 of drywall wallboard 30 is unsightly and causes bowing in the baseboard 36. This protruding portion 34 of the wall may obstruct the placement of items up against drywall wallboard 30 and reduce the aesthetic quality as well as the usefulness of that portion of the wall and room.
Also, if one attempts to avoid the protrusion of the lower portion 34 of drywall 30 by moving the elbow 10 to the right, this causes the open end of the elbow 10 to extend through the drywall wallboard 28 which is not only unsightly, and detracts from the aesthetic quality of the wall, but also may cause the dryer to have to be moved further out into the room thereby reducing the remaining useful room space.
Similar undesirable venting assemblies are found in conventional multi-unit residential units as well as commercial and industrial buildings and plants. In some instances, a clothes dryer or similar device is vented to the outside of the building by simply knocking a large opening through the outer wall and placing a length of large diameter PVC pipe therein to serve as a vent. This produces unsightly openings in the interior and exterior of the wall, may not provide for proper placement or location of the vent opening relative to the dryer outlet, and may leave a large outer opening which allows the entrance of rain, insects, rodents, etc.
Thus, there exists a need for an improved venting assembly and method for the venting of exhaust gases or air.
SUMMARY OF THE INVENTION
In accordance with the present invention, a dryer vent box and method is provided which addresses the problems inherent in conventional dryer vent assemblies. In accordance with an exemplary embodiment of the present invention, a dryer vent box includes upper and lower mating substantially rectangular housings which are dimensioned so as to be received within the confines of a conventional 2×4 studded wall. Each of the upper and lower rectangular housings have a protruding cylindrical flange with an opening into the housing to provide for the intake and exhaust of dryer exhaust gases or air. The upper housing section includes at least one tab or wing extending from one of the sides thereof to provide for the attachment of the upper housing to the wall. The lower housing includes cutoff markings or indicators which provide for the correct placement of the cylindrical flange of the upper housing relative to the dryer outlet. Thus, the dryer vent box of the present invention provides an aesthetically pleasing, effective, efficient and improved dryer venting assembly.
In accordance with a particular example of the present invention, the dryer vent box housings are molded PVC and the lower housing includes elongate notches which facilitate the sawing off of the lower housing by hacksaw or other device capable of cleanly sawing through PVC to provide for the adjustment of the upper housing relative to the dryer outlet. Further, the cylindrical flanges protruding from the upper and lower housings can be shortened by being sawed off or shortened with a hacksaw or other instrument, such as a pipe cutter, to the desired length to provide for the best fit of the vent box for its particular application. By having the dryer vent box housings molded of PVC, the dryer vent box of the present invention meets building code requirements which mandate that only certain materials including PVC may be located in the concrete slab or foundation.
The dryer vent box of the present invention provides the advantages of eliminating unsightly or crude conventional dryer vent wall openings, provides for the close placement of the dryer up against a wall so as to increase the useful room area and reduce or eliminate the happenstance dropping of clothing or other items behind the dryer. In at least some circumstances and if used properly, the present dryer vent box eliminates the need for a flexible conduit for providing fluid communication between the dryer outlet and the dryer vent box inlet. Also, the dryer vent box is adapted for use in through the wall, through the wall and floor, through the wall and ceiling, slab or peer and beam construction, stacked washer and dryer units, and multi-unit dwellings using upper and lower housings, PVC pipe, and elongate rectangular extensions as necessary.
In accordance with another exemplary embodiment of the present invention, an outside or exterior vent box includes rectangular upper and lower housings with cylindrical flanges extending from opposite faces of the assembled item. Additionally, a nozzle, flap, or displaceable louver is placed over the cylindrical flange extending from the upper housing to provide an aesthetically pleasing appearance, and reduce or eliminate the possibility of the inadvertent entrance of animals, bugs, or water into the vent box.
In accordance with yet another exemplary embodiment of the present invention, a rectangular housing having opposing cylindrical flanges is used as an exterior exhaust vent box. For example, the rectangular housing includes a large diameter cylindrical flange on one face and a smaller diameter cylindrical flange on the opposite face for attachment to and venting exhaust gases from a small diameter PVC pipe which serves as a vent tube for exhaust gases from bathroom plumbing.
The principal object of the present invention is the provision of an improved dryer vent box and method.
Another object of the present invention is the provision of an improved exterior dryer vent box.
Yet another object of the present invention is the provision of an improved exterior exhaust vent box.
A still further object of the present invention is the provision of a relatively inexpensive, easily installed, extremely adaptable dryer vent box system and method which finds utility in a variety of applications.
Yet another object of the present invention is the provision of the dryer vent box which is shaped and dimensioned so as to be received within the confines of a conventional 2×4 studded wall.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view partial cross-section illustration of a conventional through-the-wall and floor dryer vent assembly made up of cylindrical PVC pipe and elbows;
FIG. 2 is an exemplary perspective view representation of a dryer vent box of the present invention;
FIG. 3 is a schematic side view partial cross-section illustration of the dryer vent box of FIG. 2 in use in an interior wall of a home with pier and beam construction;
FIG. 4 is a perspective view illustration of an elongate rectangular extension adapted for use with the dryer vent box of FIG. 2;
FIG. 5 is a schematic side view partial cross section representation of an exterior dryer vent box in accordance with the present invention;
FIG. 6 is a schematic side view partial cross-section representation of an exterior exhaust box in accordance with another embodiment of the present invention; and
FIG. 7 is a perspective view illustration of the exterior exhaust box of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with an exemplary embodiment of the present invention as shown in FIGS. 2 and 3 of the drawings, a dryer vent box generally designated by the reference numeral 50 includes upper and lower substantially rectangular housings 52 and 54. Upper housing 52 has front, back, right, left, top and bottom planar surfaces 56, 58, 60 62, 64 and 66 defining a substantially rectangular internal cavity or chamber. Upper housing 52 also includes a circular inlet opening 68 defined by the inner surface of a cylindrical flange 70 and a rectangular outlet opening 72 defined by the inner surface of a rectangular flange 74 which extends from bottom wall 66. Rectangular outlet 74 includes a protruding exterior nub or ridge 76 which facilitates a friction fit of the outlet 74 within the rectangular inlet of lower housing 54. Right and left hand mounting brackets, tabs, or wings 78 and 80 are attached to and extend from respective side walls 60 and 62. The front face of each of the brackets 78 and 80 is flush with the front face of front wall 56.
The top wall 64 of upper housing 52 includes a rectangular groove or notch 82 defining a central rectangular portion which can be knocked out or removed by sawing to produce an opening which matches the rectangular inlet of lower housing 54 and is adapted to receive the rectangular outlet 74 of another upper housing 52 or the rectangular outlet of a rectangular extension (FIG. 4) as will be described in greater detail below.
Lower rectangular housing 54 includes front, back, right, and left side and bottom walls 84, 86, 88, 90, and 92 defining a substantially rectangular internal chamber or cavity. Bottom housing 54 also includes an upper rectangular inlet or opening 94 and a rectangular frame-like upper face or surface 96. Lower housing 54 further includes a circular outlet opening 98 defined by the inner surface of a circular flange 100 which extends from the front face of front wall 84. Front and back walls 84 and 86 include a plurality of spaced grooves or saw marks 102 which facilitate the shortening of the lower housing to provide for the proper placement of the upper housing inlet 68 relative to the clothes dryer outlet 38. Typically, this is 51/2 inches above the floor so that the dryer outlet 38 is received within the cylindrical flange 70 of upper housing 52 merely by pushing the dryer back towards the wall so that the dryer outlet 38 is telescopically received within the cylindrical flange 70 as shown in FIG. 3 of the drawings. Although the inner surface of flange 70 is shown smooth in FIG. 2, it is contemplated that circumferential nubs or protrusions can be added therein to provide a substantially airtight pressure fit with outlet 38.
With reference again to FIG. 1 of the drawings, the dryer vent box 50 of the present invention replaces not only the PVC elbows 10 and 14 and vertical pipe section or riser 12 of the conventional dryer vent assembly, but also, the flexible conduit 40. Since the upper housing 52 can be located in the proper position to mate with the dryer outlet 38, the flexible conduit 40 can be eliminated.
Although the dryer 24 is shown a couple of inches away from the wall 28, in FIG. 3 of the drawings it is to be understood that the dryer can be pushed back against cylindrical flange 70 and dryer outlet 38 is fully received within the cylindrical flange so that the dryer can be placed within an inch or less of the wall 28. This provides for maximum usage of the remaining room space and eliminates unnecessary waste of space due to dryer 24. Also, by reducing the gap between the dryer and the wall, one reduces the chance that items are mistakenly dropped behind the dryer 24. This gap can be further reduced by cutting off or removing a selected length of the front of cylindrical flange 70 using a pipe cutter or hacksaw to shorten the flange 70 to its minimum length.
If for some reason it is desirable to move the drier a certain distance away from the wall to, for example, be in a position flush with an adjacent clothes washing machine which has behind it, water hoses and an electrical cord, the flange 70 can be left at its full length and/or an adapter can be used between cylindrical flange 70 and dryer outlet 38 with the adapter being a rigid short length of PVC pipe having one end with an outer diameter which corresponds to the outer diameter of the outlet 38 so that it fits within cylindrical flange 70 and the other end having an inner diameter which corresponds to the inner diameter of cylindrical flange 70 so as to fit around dryer outlet 38.
Since the dryer vent box 50 replaces the PVC elbows 10 and 14, and the pipe length 12 of FIG. 1, and the dryer vent box 50 includes upper housing 52 and lower housing 54 dimensioned to fit within the confines of a standard 2×4 studded wall between the drywall, panelling, or other wall covering that is used, and also between adjacent studs, the wall protrusion 34 of FIG. 1 is eliminated. Typically, walls are studded at 12, 14, 16, 18, or 24 inches, and the dryer vent box 50 is dimensioned accordingly. In accordance with a particular example of the dryer vent box 50, the upper housing 52 has a front to back dimension of about three inches, a side to side dimension of about ten inches, an overall vertical height of about ten inches, a cylindrical flange protruding about three inches and having an inner diameter just greater than four inches. Also in accordance with this particular example, the lower housing 54 has an overall height of about three feet, a front to back dimension of about two inches, a side to side dimension of about nine inches, and has a cylindrical flange with an outer diameter of about 51/2 inches, and a length of about six inches. Also, the upper housing 52 has a rectangular outlet with a front to back dimension of about 11/2 inches, and a side to side dimension of about 81/2 inches, and a vertical length of about two inches.
In the pier and beam construction shown in FIG. 3 of the drawings, the plywood decking 20 is supported on floor joists or beams 104. The lower surface 92 of lower housing 54 is shown supported on concrete blocks 106 which space the lower housing 54 from the ground surface 108. It is to be understood that the lower housing 54 can be rested upon a layer of gravel or on the ground itself depending upon the distance between the flooring 20 and 22 and the ground surface 108. Also, it is contemplated that the lower housing 54 and/or the PVC pipe 16 may be suspended from the floor joists 104 by appropriate brackets or strapping.
The dryer vent box 50 of the present invention has equal utility in home or building construction, wherein the flooring is either a slab or concrete foundation type construction (FIG. 1), or pier and beam with a crawl space (FIG. 3). The dryer vent box 50 of the present invention is adaptable to both residential and commercial construction, prefab housing, mobile homes, and the like.
Moreover, the dryer vent box 50 is utilized in situations where the upper housing 52 is spaced from lower housing 54 using one or more of the rectangular extension 110 shown in FIG. 4 of the drawings. The rectangular extension 110 has front, back, right, left, side, and bottom surfaces 112, 114, 116,118, and 120, an upper rectangular inlet opening 122, and a rectangular frame-like upper surface 124. Extension 110 also has a rectangular outlet opening 126 defined by a rectangular flange 128 extending from bottom surface 120. Flange 128 has a protruding nub or bur 130 around the exterior thereof. Front and back surfaces 112 and 114 include saw marks, notches or grooves 132 which facilitate the sawing off or shortening of the extension as necessary for a particular application. Note that the rectangular inlet 122 has the same dimensions as rectangular inlet 94 of lower housing 54. Also, rectangular outlet flange 128 has the same dimensions as rectangular outlet flange 74 of upper housing 52. Thus, one or more extensions 110 can be inserted between the housings 52 and 54. A variety of combinations of upper housings, lower housings, and extensions can be used to provide for through-the-wall, through- the-floor, and/or through-the-ceiling venting of one or more clothes dryers.
In accordance with a particular example of the present invention, the extension 110 is an overall height of about three feet, a front to back dimension of about two inches, a side to side dimension of about nine inches and is used to raise the upper housing 52 so that the cylindrical flange 70 mates with the dryer outlet of a dryer in a stacked dryer over washer appliance arrangement.
In accordance with another exemplary embodiment of the present invention, the housing 52, housing 54, and extension 110 are used for a through-the-wall-and-ceiling venting by inverting the housings 52 and 54, and extension 110 and running the pipe 16 through the ceiling.
Although it is preferred to use PVC materials in constructing the dryer vent box of the present invention, other resins, plastics, polycarbonates, galvanized metals, stainless steel, and the like may be used given the particular application, and which will meet local, state and federal building codes.
With reference to FIG. 5 of the drawings, in accordance with another exemplary embodiment of the present invention, an outside or exterior clothes dryer vent box is generally designated by the reference numeral 150 and shown to include an upper rectangular housing 152, a lower rectangular housing 154, and an outlet hood or down spout 156. The upper and lower housings 152 and 154 are substantially identical to the housings 52 and 54 of dryer vent box 50 (FIGS. 2 and 3) except that the tabs 78 and 80 have been removed. The lower housing 154 includes a cylindrical flange 158 which serves as a fluid gas or air inlet to the vent box 150. Upper housing 152 includes a cylindrical flange 160 which serves as a fluid outlet, and which is adapted to receive the spout 156 which directs the air or exhaust downwardly. Clothes dryer exhaust passes through dryer vent box 50 (FIG. 3), PVC pipe 16, inlet 158, housing 154, housing 152, outlet 160, and out spout 156. The spent 156 has a substantially rectangular outlet opening 162 which directs these gases in a downward direction. Spout 156 is designed to have a rectangular outlet which is substantially the same in total cross-sectional area as the cylindrical opening thereof which fits over flange 160.
The PVC pipe 16 serves to direct air exhaust from a clothes dryer vented through an interior wall down under the foundation of the house out through the foundation or footer 164 in a location beneath the surface of the soil 166. With the housing 152 and 154 formed of PVC or similar materials, it is possible to join the PVC pipe 16 and housing 154 with a PVC solvent or fixative which provides a water-tight seal between the exterior of flange 158 and the interior of pipe 16.
In accordance with another exemplary embodiment of the present invention, as illustrated in FIG. 6 of the drawings, an exterior exhaust vent box is generally designated by the reference numeral 170, and shown to include a rectangular housing 172, a small diameter circular flange 174, and a large diameter circular flange 176. The small diameter cylindrical flange 174 serves as a gas, fluid, or exhaust inlet to a substantially rectangular cavity or chamber within housing 172. The larger cylindrical flange 176 serves as a gas, fluid, or exhaust outlet of the housing 172. A downturned hood or spout 156 is attached to outlet flange 176 so as to direct the vented gases downwardly away from the eaves 178 of a roof 180.
The inlet flange 174 is received within the open end of a length of PVC pipe 182 which passes through exterior wall 184 and siding 186. Pipe 182 is connected to a vertical exhaust pipe 188 via an elbow 190. Exhaust pipe 188 serves to exhaust gases, vapors, and fumes from plumbing, sewer, and the like. Typically, such gases are either vented through an open ended section of pipe directly into the attic of a house or building, through the roof with a six or eight inch section of pipe extending upwardly from the shingles of the roof, or vented out of the side of a building near the roof. This typical venting of the exhaust gases is unsightly and may allow debris or insects to enter into the exhaust pipe 188. In accordance with the present invention, the exhaust box 170 is employed to provide an outside venting of these exhaust gases, an aesthetically pleasing arrangement, and the utilization of an attachment which prevents debris, insects, rain, and the like from entering the exhaust pipe.
It is preferred that the vent box 170, down spout 156, and pipe section 182 be formed of compatible PVC or other sturdy molded plastic material which allow then to be joined together with conventional PVC or pipe fitting solvents and form a water-tight, permanent assembly.
Thus, it will be appreciated that as a result of the present invention, a highly effective improved dryer vent box and method, dryer venting system and method, outside vent box and method, and exhaust vent box and method are provided by which the principle objective, among others, is completely fulfilled. It is contemplated and will be apparent to those skilled in the art from the preceding description and accompanying drawings, that modifications and/or changes may be made in the illustrated embodiments without departure from the present invention. Accordingly, it is expressly intended that the foregoing description and accompanying drawings are illustrative of preferred embodiments only, not limiting, and that the true spirit and scope of the present invention be determined by reference to the appended claims. | A dryer vent box and method is provided which addresses the problems inherent in conventional dryer vent assemblies. The dryer vent box includes upper and lower mating substantially rectangular housings which are dimensioned to be received within the confines of a conventional 2×4 studded wall. Each of the upper and lower rectangular housings have a protruding cylindrical flange with an opening into the housing to provide for the intake and exhaust of dryer exhaust gasses. The upper housing section includes at least one tab extending from one of the sides thereof to provide for the attachment of the upper housing to the wall. The lower housing includes cutoff markings or indicators which provide for the correct placement of the cylindrical flange of the upper housing relative to the dryer outlet. Thus, the dryer vent box of the present invention provides an aesthetically pleasing, effective, efficient and improved dryer venting assembly. An outside or exterior vent box includes rectangular upper and lower housings with cylindrical flanges extending from opposite faces of the assembled item. Additionally, a nozzle, flap, or displaceable louver is placed over the cylindrical flange extending from the upper housing. A rectangular housing having opposing cylindrical flanges is used as an exterior exhaust vent box. | 3 |
BACKGROUND
[0001] The present disclosure generally relates to parallel computing, and particularly to methods of relaxing synchronization of data access during parallel computing, and systems for implementing the same, and machine readable storage media encoding a program for implementing the same.
[0002] Emerging applications in computing, particularly in the area of data analytics, predominantly use iterative convergence techniques to arrive at the desired solution. Typically, the computation consists of a set of iterations, each of which can be spawned as an individual thread which computes largely using data private to that thread, and globally synchronizing to contribute to the overall solution at a later step. In such scenarios, the application scales with the number of processors employed in parallel computing by utilizing multi-threaded concurrent execution of the iterations. However, one of the scalability challenges is the synchronization overhead which, in the worst case, can be the dominant portion of the program execution time.
[0003] One method for addressing the scalability problem in parallel computing is the privatization method. In the privatization method, multiple copies of the data are made so that each of the executing threads performs all the updates in the local copy. When all the iterations are complete, the master thread coordinates to merge all the updates from the other threads, and determines the convergence criteria for the overall solution. As the size of the data increases, it becomes difficult to scale to a large number of threads using this approach because the copying results in data bloat, and puts a strain on the memory bandwidth.
[0004] Another method for addressing the scalability problem in parallel computing is the lock-free synchronization method. The lock-free synchronization method employs atomic instructions (such as compare-and-swap) so that the overhead of synchronization is reducible. However, the method is limited to atomic operations on word-size data objects. For updating larger quantities of data, this method cannot be used directly, and hence the significant synchronization overhead remains.
[0005] Yet another method for addressing the scalability problem in parallel computing is the transaction-based synchronization method. In the transaction-based synchronization method, transactions can be considered as coarse-grain synchronization, and they offer reduction in synchronization overhead using speculation. However, not all application domains are amenable to this synchronization method. Furthermore, it is possible that the speculation, if incorrect, could lead to expensive rollback and recovery. Thus, the transaction-based synchronization method, if employed by itself, provides only a limited solution to the scalability problem.
BRIEF SUMMARY
[0006] Systems and methods are disclosed that allow atomic updates to global data to be at least partially eliminated to reduce synchronization overhead in parallel computing. A compiler analyzes the data to be processed to selectively permit unsynchronized data access for at least one type of data. A programmer may provide a hint to expressly identify the type of data that are candidates for unsynchronized data transfer. In one embodiment, the synchronization overhead is reducible by generating an application program that selectively substitutes codes for unsynchronized data access for a subset of codes for synchronized data access. In another embodiment, the synchronization overhead is reducible by employing a combination of software and hardware by using relaxation data registers and decoders that collectively convert a subset of commands for synchronized data access into commands for unsynchronized data access.
[0007] Reduction of atomic updates can be applied either at the fine-grain level or at a coarse-grain “transaction” level. Synchronization overhead reduction can be effected independent of the size of the atomic data update. Programmer specified hints can allow the application to run either with full synchronization, or with reduced synchronization based on the contents of the hints. The scalability challenges of synchronization can be overcome by exploiting the nature of iterative convergence used by the application to arrive at the desired solution. These methods can also be applied to transaction-based synchronization.
[0008] According to an aspect of the present disclosure, a method of relaxing synchronization in parallel computing is provided. The method includes: providing a system including a plurality of processors, the plurality of processors including at least one processor containing relaxation data registers and a decoder; generating an application program from a source program, wherein the application program includes an instruction for storing data representing a mode of synchronization relaxation in one of the relaxation data registers; and running the application program in the system to store the data in the relaxation data registers, wherein the system decodes at least one command in the application program for synchronized data access between processors in the system as at least one command for unsynchronized data access based on the stored data in the relaxation data registers. A loader in a processor can load the relaxation data registers for each iterative convergent computation based on command line arguments.
[0009] According to another aspect of the present disclosure, another method of relaxing synchronization in a parallel computing system is provided. The method includes: providing a system including a plurality of processors, the plurality of processors including at least one processor containing relaxation data registers and decoders; providing an application program and a set of parameters, wherein the set of parameters include values for storing data representing a mode of synchronization relaxation in one of the relaxation data registers; and running the application program in the system to store the data in the relaxation data registers, wherein the system decodes at least one command in the application program for synchronized data access between processors in the system as at least one command for unsynchronized data access based on the stored data. The set of parameters can be provided to a system running the application program as a direct input, which can be provided manually or by an automated system configured to provide a direct input to the system running the application program.
[0010] According to even another aspect of the present disclosure, another method of relaxing synchronization in parallel computing is provided. The method includes: providing a compiler module that enables recognition of a compiler directive for selective relaxation of synchronization during compilation; providing a source program for an application, the source program including at least one instance of the compiler directive; generating, by employing a complier program that runs in at least one computing means, an application program from the source program by compiling the source program, wherein at least one command for synchronized data access in the source program is compiled as at least one command for unsynchronized data access in the application program; and running the application program in a system including a plurality of processors and configured for parallel computing.
[0011] According to yet another aspect of the present disclosure, a system for parallel computing is provided. The system includes: a plurality of processors configured to run an application in a parallel computing mode, wherein at least one of the plurality of processors includes relaxation data registers and a decoder that is configured to either convert a command for synchronized data access in an application program into a command for unsynchronized data access or transmit the command for synchronized data access unmodified based on contents of data stored in the relaxation data registers.
[0012] According to still another aspect of the present disclosure, at least one non-transitory machine readable data storage medium embodying a plurality of programs is provided. The plurality of programs includes: a compiler module for enabling recognition of a compiler directive for selective relaxation of synchronization during compilation; and a compiler configured to use the compiler module to recognize the compiler directive and to compile at least one command for synchronized data access in a source program as at least one command for unsynchronized data access in an application program upon detection of the compiler directive for selective relaxation of synchronization.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] FIG. 1 is a first flow chart illustrating a first method for selectively relaxing synchronization according to a first embodiment of the present disclosure
[0014] FIG. 2 is an assembly of processors including relaxation data registers and an inter-processor communication hardware according to the first embodiment of the present disclosure.
[0015] FIG. 3 is a schematic flow diagram that can be employed by each of the processors in an assembly of processors according to the first embodiment of the present disclosure.
[0016] FIG. 4 is a schematic flow diagram that can be employed by a processor to allow relaxation of synchronization during run-time according to the first embodiment of the present disclosure.
[0017] FIG. 5 is a second flow chart illustrating a second method for selectively relaxing synchronization according to a second embodiment of the present disclosure
[0018] FIG. 6 is a schematic flow diagram that can be employed by a compiler to perform the step of 330 in FIG. 5 according to the second embodiment of the present disclosure.
[0019] FIG. 7 is a first exemplary system configured to implement the methods of the embodiments of the present disclosure.
[0020] FIG. 8 is a second exemplary system configured to implement the methods of the embodiments of the present disclosure.
DETAILED DESCRIPTION
[0021] As stated above, the present disclosure relates to methods of relaxing synchronization of data access during parallel computing, and systems for implementing the same, and machine readable storage media encoding a program for implementing the same, which are now described in detail with accompanying figures. Like and corresponding elements mentioned herein and illustrated in the drawings are referred to by like reference numerals. The drawings are not necessarily drawn to scale.
[0022] As used herein, a “synchronized data access” is an operation in parallel computing that employs exclusive access to the data that is transferred between a unit from which data is transferred and a unit to which the data is transferred.
[0023] As used herein, an “unsynchronized data access” is an operation in parallel computing that employs non-exclusive access to the data that is transferred between a unit from which data is transferred and a unit to which the data is transferred.
[0024] As used herein, an “atomic instruction” is an instruction that requires synchronized data access.
[0025] As used herein, a “non-atomic instruction” is an instruction that does not require synchronized data access, i.e., allows unsynchronized data access.
[0026] As used herein, “synchronization relaxation” is substitution, either fully or partially, of atomic instructions with non-atomic instruction(s).
[0027] As used herein, “selective synchronization relaxation” is a conditional substitution, based on a set of predefined criteria, of atomic instructions with non-atomic instructions.
[0028] As used herein, a “hint” is a code in a source program indicating permissibility of selective synchronization relaxation.
[0029] As used herein, a “frequency of synchronization relaxation” is the ratio of the number of substitutions of atomic instructions with non-atomic instructions to the occurrences of all atomic instructions in a source code.
[0030] As used herein, a “frequency of selective synchronization relaxation” is the ratio of the number of conditional substitutions of atomic instructions with non-atomic instructions based on a set of predefined criteria to the occurrences of all atomic instructions in a source code.
[0031] As used herein, a “compiler module” is a software program that is used as a part of the compiler to enable the recognition, processing and related optimization of the synchronization relaxation compiler directives.
[0032] As used herein, a “synchronized data access” or “unsynchronized data access” refers to exclusive or non-exclusive, respectively, access of data via a plurality of mechanisms that includes: memory access, communication via messages, and disk access.
[0033] As used herein, a “loader” or a “loader module” refers to executable program that is used by a compiler or independently to prepare any program for execution.
[0034] As used herein, a “quality condition” refers to a set of instructions provided in a source code for determining whether a solution to be generated from an application program derived from the source program is an acceptable solution. A quality condition typically examines a convergence property of a solution to be generated from the application program.
[0035] In broad terms, the methods and systems of the present disclosure can be employed to reduce the synchronization overhead for a class of parallel programs identified as Iterative Convergent Computations (ICC), which refer to programs that consists of iterations (loops) with a convergence test as criterion for completion of execution. Thus, computations are repeatedly performed until the convergence criteria are met in the ICC. The parallel execution of these iterations by threads normally involves synchronization points to exchange data among parallel computational threads.
[0036] The methods of the present disclosure take advantage of the observation that there are cases in which meaningful performance improvement can be obtained in parallel computing by relaxing the data access synchronization requirement to be carried out only for some iterations instead of for each iteration. While this benefit could be achieved by modifying the source code of the program, but this approach is not attractive due to the associated complexity and makes the program non-deterministic. Instead, the methods of the present disclosure employ a compiler that generates the relaxation condition. The resulting application program can be executed in a deterministic manner without performance improvements, or in a relaxed synchronization manner with the associated benefits. Further, the programmer or the compiler can control the degree of synchronization.
[0037] Referring to FIG. 1 , a first flow chart 100 illustrates a first method for selectively relaxing synchronization according to a first embodiment of the present disclosure. The first method can be employed to relax synchronization in parallel computing. The first method can be implemented in a system including a plurality of processors and configured for parallel computing and including hardware adapted to provide selective relaxation of synchronization in at least one of the plurality of processors.
[0038] Referring to step 110 , a compiler module that enables use of relaxation data registers in a processor is provided. The compiler module enables a compiler, i.e., a compiler program, to recognize a compiler directive in the form of a code. The compiler directive communicates to a compiler that additional information is to be added during compilation of a source program in order to generate a compiled program, i.e., an application program that can be executed in a computing means configured for parallel computing.
[0039] Referring to step 120 , a source program for an application is provided by a programmer. The source program includes at least one instance of the compiler directive that the compiler module enables. The compiler directive, after compilation into an application program, enables use of relaxation data registers in at least one processor to subsequently run the application program generated from the source program. If the relaxation of synchronization is provided in the source program code by the programmer, such relaxation of synchronization can be referred to as “programmer directed relaxation.” In one embodiment, at least one quality condition for a solution (to be generated by running an application program) can be specified in a code in the source program.
[0040] For illustrative purposes, the method of the first embodiment is described using Open Multi-processing (“OpenMP,” or “Open specifications for Multi-Processing developed via collaborative work between interested parties from the hardware and software industry, government and academia”) parallelization as a method of implementing parallel programs. It will be clear to those skilled in the art that the disclosure can be practiced for other parallelization methods as well including pthreads (POSIX threads) methods, message passing interface (MPI) method, and transactions.
[0041] Concurrent parallel threads can be generated by providing a source code. An exemplary source code for generating concurrent parallel threads may, for example, be:
[0000]
while (converged( ) == false) {
#pragma omp parallel for private(...) shared(shared_var) schedule(..)
for(....){
do-independent-work( )
#pragma omp atomic {
update shared_var
}
do-independent-work( )
} // implicit barrier( )
} // end while( ).
[0042] In the above example, the “shared_var” variable refers to a shared variable, and the “do-independent-work” refers to a set of commands to do an independent work. Concurrent parallel threads execute the independent work with no data dependencies, and the computation to update the “shared_var” is done atomically. The execution time of the above code is determined by the execution time of slowest iteration (i.e., slowest thread). Hence, to improve the execution time of the algorithm, it is important to improve the run time of each iteration (including the slowest iteration). One of the key bottlenecks in the iteration execution is the synchronization required for the atomic update of the “shared_var.”
[0043] A programmer can provide hints in the source program to relax the synchronization so that at least one iteration can be speeded up by not requiring atomic updates to a shared variable, such as “shared_var” in the above example, to be synchronized during execution of an application program. Since each thread could actually execute a chunk of iterations before reaching the implicit barrier, it is possible to skip synchronization for some (or all) iterations executed by each thread.
[0044] For example, the above exemplary source code can be modified to include a user provided hint, which can have a syntax such as “#pragma relax ICC,” for possible synchronization relaxation. The modified exemplary source code can be:
[0000]
#pragma relax ICC
while (converged( ) == false) {
#pragma omp parallel for private(...) shared(shared_var) schedule(..)
for(....){
do-independent-work( )
#pragma omp atomic {
update shared_var
}
do-independent-work( )
} // implicit barrier( )
} // end while( )
[0045] In the above exemplary source code, “#pragma relax ICC” is a hint, which is also a construct by which the programmer directs the compiler to relax synchronization. The hint is a directive communicating additional information to the compiler. The compiler module enables the compiler to recognize these types of hints so that the compiled program, i.e., the application program, which the compiler generates, includes instructions for relaxing synchronization.
[0046] Referring to step 130 , an application program is generated from the source program by compiling the source program employing the compiler module and a compiler. The compiler can run in at least one computing means which includes at least one processing unit such as a processor. The at least one computing means can be any computing device configured to run a compiler employing the compiler module. For example, the at least one computing means can include at least one computer. The application program includes a code for storing data representing a mode for relaxing synchronization in the relaxation data registers. The selective relaxation is implemented by expressly specifying allowability of synchronization relaxation during subsequent execution of the compiled program, i.e., the application program.
[0047] In one embodiment, the compiler can profile (i.e., iteratively compile, execute and observe the behavior of the application program) combinations of synchronization commands and data structure classes to be synchronized according to the source program to determine whether selective relaxation of synchronization can effectively accomplish the purpose of the source program. At least one combination of a data structure class and a synchronization command, in which a frequency of synchronization is reducible to a level less than 100% of occurrences specified in the source program without projected violation of a quality condition for a solution for the application program, is identified during the profiling. The projection of violation of the quality condition for the solution for the application program at a reduced level of synchronization frequency can be performed, for example, by running a portion of the source program that is intended to produce iterative convergence and by monitoring the rate of convergence.
[0048] Compiler makes a choice of which ICCs to relax and for each relaxed ICC which data structures to relax and by how much. In one embodiment, a plurality of ICCs can be marked by the programmer as candidates for relaxed synchronization. In this case, the compiler can choose one or more ICCs in which the commands for synchronized data access are converted to commands for unsynchronized data access.
[0049] In another embodiment, the programmer provides command line parameter for the selected set of ICCs for which synchronization relaxation can be enabled. In this embodiment, the application program is not changed, and hence the original application program binary can be used for execution. The parameters provided by the programmer take effect only before the execution of the selected ICCs, and are used to set the corresponding relaxation registers. This hardware-only embodiment allows relaxing synchronization even for pre-compiled libraries—libraries that are available only in binary format—because this embodiment does not require changing the application program.
[0050] In yet another embodiment, the application programmer can provide compiler directives in the source code of the application near the function with the ICC to enable relaxing the synchronization. These compiler directives provide the values of the relaxation registers, and these values are subsequently loaded in the hardware relaxation registers prior to the execution of the ICC. This embodiment again does not change the application binary. However, the compiler directives are used at run-time to load the necessary relaxation registers. In the embodiment as well, the application programmer provides the values for the relaxation registers. The application binary is generated by the compiler with an reduction in the frequency of synchronization. The parameter for the reduced frequency of synchronization is transmitted from the compiler directive at run-time, and subsequently stored as data in, the relaxation data registers ( 930 , 932 ) in the system for parallel computing.
[0051] The selective relaxation of synchronization and consequent reduction of synchronization overhead during parallel computing can be implemented employing hardware specifically configured for this purpose. A system configured for parallel computing with selective relaxation of synchronization can be employed. The system for parallel computing includes a plurality of processors configured to run an application in a parallel computing mode. At least one of the plurality of processors includes relaxation data registers and a decoder. The decoder is configured to either convert a command for synchronized data access in an application program into a command for unsynchronized data access or transmit the command for synchronized data access unmodified based on contents of data stored in the relaxation data registers.
[0052] Referring to FIG. 2 , an assembly 914 of processors 912 including relaxation data registers ( 930 , 932 ) and inter-processor communication hardware 913 is illustrated. Each processor 912 can include a first relaxation data register 930 configured to store data indicating activation of selective synchronization relaxation and a second relaxation data register 932 configured to store data indicating frequency of selective synchronization relaxation. The inter-processor communication hardware 913 provides signal communication paths for synchronization data to travel through between processors 912 . For example, the inter-processor communication hardware 913 can be a packaging substrate including built-in signal paths and configured to mount a plurality of processors 912 . Alternately, the inter-processor communication hardware 913 can be a circuit board on which a plurality of processors 912 is mounted. Yet alternately, the inter-processor communication hardware 913 can be a collection of at least one router and signal cables configured to enable transmission of data among the plurality of processors 912 .
[0053] Referring to step 140 , the selective relaxation of synchronization can be implemented at run time, i.e., during running of the application program. At the time of execution of the application, the programmer can specify parameters to the loader module. These parameters can be of the form of the name of the ICC in the application program, and the relaxation factor for that ICC. Thus, run-time parameters can be provided to a loader module so as to load the relaxation data registers ( 930 , 932 ) at relevant points during running of the application. At the time of execution of the application program, prior to the execution of the selected ICC, the loader module stores the programmer specified parameters in a set of special registers, i.e., the first relaxation data register 930 and the second relaxation data register 932 . Prior to the execution of the ICC, the loader module can set the first relaxation data register 930 , for example, from a default value of “0” representing absence of selective relaxation of synchronization to a value of “1” representing enablement of selective relaxation of synchronization. The first relaxation data register 930 , which is also referred to as a “relax register,” remains set until an implicit barrier is seen by the loader module. The implicit barrier refers to the end of the ICC.
[0054] The second relaxation data register 932 , which is also referred to as a “relax factor register,” tracks the granularity of synchronization relaxation. For example, the second relaxation data register 932 stores data for integer k (greater than 1), which can be employed to relax synchronization once for every k iterations.
[0055] Each processor 912 includes an opcode mapper table 950 . Optionally, each processor 912 may include a memory 952 for loading a thread or is in communication with a memory unit (not shown) that stores at least one thread to be run on the processor 912 .
[0056] Referring back to step 130 , the data stored in the relaxation data registers ( 930 , 932 ) can enable for a given ICC, the frequency of synchronization to be reduced to a level less than 100% of occurrences specified in the source program without projected violation of a quality condition for a solution for the application program. During running of the application program, at least one command for synchronized data access among the at least one combination in the application program is decoded as at least one command for unsynchronized data access.
[0057] In one embodiment, a fraction of commands for synchronized data access corresponding to each combination in the source program can be executed as commands for unsynchronized data access during the running of the application program. This fraction is greater than a ratio between the reduced frequency of synchronization to the corresponding frequency of synchronization and is less than 1. The at least one parameter for the reduced frequency of synchronization can include information representing this fraction.
[0058] The at least one command for unsynchronized data access in the application program can include, for example, at least one of an unsynchronized read command and an unsynchronized write command.
[0059] Referring to step 150 , the application program is run, i.e., executed, in the system for parallel computing while the data representing the mode of selective relaxation of synchronization are stored in the relaxation data registers ( 930 , 932 ). Thus, at least one command for synchronized data access in the application program is decoded as at least one command for unsynchronized data access based on the data stored in the relaxation data registers ( 930 , 932 ).
[0060] In one embodiment, data indicating enablement of selective synchronization relaxation can be stored in the first relaxation data register 930 among the relaxation data registers ( 930 , 932 ) before running the selected ICC of the application program. See FIG. 2 . Further, data indicating frequency of selective synchronization relaxation can be stored in the second relaxation data register 932 among the relaxation data registers ( 930 , 932 ) before running the selected ICC of the application program.
[0061] While the first relaxation data register 930 is set at a value indicating enablement of selective relaxation of synchronization, a “relax” mode is turned on. Any atomic update instructions (such as synchronized read instructions and synchronized store instructions) seen by the decoder is interpreted (decoded) differently from the usual manner during the relax mode. For example, a Content Addressable Memory (CAM) lookup of a special opcode mapper table, such as the opcode mapper table 950 in FIG. 2 , can be employed in the hardware. The opcode mapper table 950 maps the atomic instructions seen in the code to the appropriate opcodes to be used in the “relaxed” mode. For example, the mapper could return a regular load word instruction for a command for a synchronized load word instruction, and a regular store word instruction for a synchronized store word instruction.
[0062] The new instructions, i.e., the unsynchronized instructions or “regular” instructions, are now executed as if they were present in the application's binary code, i.e., in the application program. The advantages of using a hardware implementation include the absence of any change to the application binary code, and the ability to turn on or off the user provided hint to switch from normal synchronization mode (that requires 100% of synchronized commands to be performed during run time) to the relaxed synchronization mode (that requires less than 100% of synchronized commands to be performed during run time, while allowing the rest to be replaced with unsynchronized commands). The hardware embodiment does not require any changes to the Instruction Set Architecture (ISA)s, or the application binary. This embodiment incurs the additional overhead of a change to the processor's decode stage of the pipeline. Additional mapper tables can be used to determine the equivalent instructions to use in the relaxed mode.
[0063] Referring to FIG. 3 , a schematic flow diagram that can be employed by each of the processors 912 is shown. A thread of an application program is stored in a memory 952 within a processor 912 or a memory unit that is shared among processors 912 within an assembly 914 of processors 912 . Referring to steps 201 and 210 , upon commencement of running of the thread of the application program code on the processor 912 , the first code line from a thread of the application code that is assigned to the processor is fetched from a memory 952 attached to the processor 912 or a memory unit shared among the processors 912 . At step 215 , if the corresponding relaxation registers in the hardware are set, then the relaxation of synchronization is enabled.
[0064] To make this determination, the value stored at the first relaxation data register 930 is checked. If the selective relaxation mode is not turned on, the opcode mapper table 950 returns corresponding instructions without any relaxation at step 220 , i.e., all codes for atomic instructions are performed as atomic instructions during run time.
[0065] If the selective relaxation mode is turned on, the code is examined by the processor to determine if the current code line is a code for an atomic instruction at step 225 . If the code is not a code for an atomic instruction, the opcode mapper returns a corresponding instruction at step 220 . If the code is a code for an atomic instruction, the opcode mapper checks the second relaxation data register 932 and the iteration count within the thread. The determination as to whether the code mapper should return an instruction for a synchronized command or an instruction for an unsynchronized command is made based on the data stored in the second relaxation data register 932 and the iteration count.
[0066] For example, the opcode mapper may be programmed to return an unsynchronized command for an atomic instruction only when the iteration count (with or without any offset value to the actual number of iterations performed so far) within the thread is an integer multiple of the value stored within the second relaxation data register 932 , or may be programmed to return an unsynchronized command for an atomic instruction only when the iteration count within the thread is not an integer multiple of the value stored within the second relaxation data register 932 . The value stored in the second relaxation data register may be a positive integer greater than 1 . Thus, the opcode mapper table 950 returns an instruction for an unsynchronized command for a code for an atomic instruction (an instruction for a synchronized command) in step 250 , or an instruction for a synchronized command for a code for an atomic instruction in step 240 .
[0067] Referring to step 260 , the current instruction is performed in the processor 912 . At step 265 , a determination is made as to whether the end of the execution has been reached. If the end of the execution is reached, the thread ends at step 299 . Otherwise, step 270 is performed, at which the next code line in the thread is fetched from the memory.
[0068] In one embodiment, at least one of the one set of compiler directives is present to allow selective relaxation of synchronization on a combination of a data class and a synchronization command, and at run-time these directives are used to store the parameters to the relaxation data registers as data.
[0069] In one embodiment, at least one of the plurality of processors can be configured to convert every k-th command for synchronized data access within a combination of a data class and a synchronization command in the application program into the command for unsynchronized data access, and transmit unmodified other commands for synchronized data access within the combination. The integer k is greater than 1.
[0070] In another embodiment, at least one of the plurality of processors is configured to transmit unmodified every k-th command for synchronized data access within a combination of a data class and a synchronization command in the application program, and convert other commands for synchronized data access within the combination into the command for unsynchronized data access. The integer k is greater than 1.
[0071] An application program may have a format as illustrated in the following exemplary application program:
[0000]
#if RELAX
<directive to set relax register>
<directive to set relax_factor>
#endif
Loop1 :
# parallel computation
# lock acquisition and atomic update
Loop2: lwarx r5,0,r3 # Load and reserve
CAM lookup to load
word
stwcx. r4,0,r3 # Store new value if reserved
CAM lookup to
store word
bne- Loop2 # Loop if lost reservation
CAM to nop
bc Loop1 # if did not converge, go to Loop1
[0072] Referring to FIG. 4 , a flow chart 190 illustrates exemplary steps that can be employed to enable relaxation of synchronization at a processor according to the method of the first embodiment. The steps in the flow chart 190 correspond to steps 140 and 150 in the first flow chart 100 .
[0073] The starting step 141 corresponds to the beginning of step 140 in the first flow chart 100 . At step 403 , the application program is examined to determine whether a compiler directive for relaxation of synchronization is present. If a compiler directive or relaxation of synchronization is present in the application program, the process flow proceeds to step 148 to load the corresponding values provided by the application programmer in the set of relaxation data registers ( 930 , 932 ) in a processor during execution of the application program.
[0074] If a compiler directive or relaxation of synchronization is not present in the application program, the application program is examined to determine whether loader run-time parameters are present for relaxation of synchronization of iterative convergent computation (ICC) at step 145 . If loader run-time parameters are present in the application program, the process flow proceeds to step 148 .
[0075] If loader run-time parameters are not present in the application program, the process flow proceeds from step 145 to step 152 so that the application program is run without relaxation of synchronization.
[0076] Upon loading the corresponding values provided by the application programmer in the set of relaxation data registers ( 930 , 932 ) at step 148 , the process flow proceeds to step 151 so that the application program is run with selective relaxation of synchronization as described above. Steps 151 and 152 collectively correspond to step 150 in the first flow chart 150 .
[0077] Referring to FIG. 5 , a second flow chart 300 illustrates a second method for selectively relaxing synchronization according to a second embodiment of the present disclosure. The second method can be employed to relax synchronization in parallel computing. The second method can be implemented in any system including a plurality of processors and configured for parallel computing as known in the art.
[0078] Referring to step 310 , a compiler module is provided that enables recognition of a compiler directive for selective relaxation of synchronization during compilation. The compiler module enables the compiler to recognize a compiler directive in the form of a code. The compiler directive communicates to a compiler that additional information is to be added during compilation of a source program in order to generate a compiled program, i.e., an application program that can be executed in a computing means configured for parallel computing.
[0079] Referring to step 320 , a source program for an application is provided by a programmer. The source program includes at least one instance of the compiler directive that the compiler module enables. The compiler directive, after compilation into an application program, enables use of relaxation data registers in at least one processor to subsequently run the application program generated from the source program. If the relaxation of synchronization is provided by a code provided by the programmer, such relaxation of synchronization can be referred to as “programmer directed relaxation.” In one embodiment, at least one quality condition for a solution (to be generated by running an application program) can be specified in a code in the source program.
[0080] Referring to step 330 , a complier program can be run in at least one computing means to generate an application program, i.e., a compiled program, from the source program. The compiler compiles the source program employing the compiler module.
[0081] The application program that allows selective relaxation of synchronization. The selective relaxation is implemented by expressly specifying synchronized data access and unsynchronized data access in the application program. At least one command for synchronized data access in the source program is compiled as at least one command for unsynchronized data access in the application program.
[0082] The compiler is enhanced to insert relaxation code for some iterations for each thread within the parallel loop. The compiler determines using profiling if the algorithm converges to a desired solution in a reasonable time. For example, the compiler's relaxation can be effected by employing a source code, i.e., a code in a source program, such as:
[0000] #pragma relax ICC while (converged( ) == false) { #pragma omp parallel for private(...) shared(shared_var) schedule(..) for(....){ do-independent-work( ) if (iteration % relax_factor == 0) { update shared_var } else { #pragma omp atomic { update shared_var } } do-independent-work( ) } // implicit barrier( ) } // end while( )
In the above code, “relax_factor” determines the degree of relaxation, i.e., how many iterations per thread will relax atomic updates.
[0083] In one embodiment, a plurality of synchronization points in the source program can be marked with a hint. In the above exemplary code, the hint is provided by the compiler directive of “#pragma relax ICC.” The plurality of synchronization points can be contained in an iterative loop as in the above exemplary code. The compiler can assign priority for compilation as commands for unsynchronized data access to commands for synchronized data access in the marked plurality of synchronization points over commands for synchronized data access in unmarked synchronization points.
[0084] Referring to FIG. 6 , a schematic flow diagram that can be employed by a compiler to perform the step of 330 is shown. The source program is loaded into a memory within a processor or a memory unit shared by multiple processors. Referring to steps 401 and 410 , upon commencement of compilation of the source code on a processor (or a set of processors), the first code line from the source code is fetched from a memory attached to the processor or a memory unit in communication with the processor, which can be a processor 912 or an assembly 914 of processors 912 illustrated in FIG. 3 or any other processor(s). At step 215 , the code line is examined to determine if the code line includes an atomic instruction.
[0085] If the code line does not include an atomic instruction, the compiler encodes a corresponding instruction in a compiled program, i.e., in the application program, at step 420 .
[0086] If the code line does not include an atomic instruction, at step 425 , the compiler examines the code to determine if the code line is marked with a hint. The compiler may examine adjacent code lines to determine whether the current code line is marked with a hint that authorizes the use of selective relaxation of synchronization during compilation (and run time as a consequence). If no hint is present for the current code line in the source code, the compiler encodes a corresponding instruction (which is an atomic instruction) at step 220 . If a hint is present for the current code line in the source code, the compiler program proceeds to step 435 . The determination as to whether the compiler should employ relaxed synchronization for this portion of the code is made preliminary evaluation of the nature of iterative computation employed within this portion of the source code and data stability as assessed by the compiler at step 435 .
[0087] In one embodiment, the compiler profiles combinations of synchronization commands and data structure classes to be synchronized according to a code in the source program to determine whether selective relaxation of synchronization can effectively accomplish the purpose of the source program at step 435 . During the compilation, at least one combination of a data structure class and a synchronization command is identified in which a frequency of synchronization is reducible to a level less than 100 % of the occurrences specified in the source program without projected violation of a quality condition for a solution for the application program.
[0088] In one embodiment, the compiler can generate, for each of the at least one combination, a reduced frequency of synchronization at step 435 . The reduced frequency of synchronization is selected to be not less than a minimum frequency of synchronization that avoids projected violation of the quality condition, and to be less than corresponding frequency of synchronization specified in the code in the source program.
[0089] The compiler encodes an instruction for an unsynchronized command (for an atomic instruction) only when the compiler determines that such relaxation does not result in projected violation of a quality condition for a solution to be solved by a compiled program (application program) to be generated from the source program. Thus, the compiler may encode a non-atomic instruction (an instruction for an unsynchronized command) for a code line for an atomic instruction within the source code in step 450 , or an atomic instruction (an instruction for a synchronized command) for a code for an atomic instruction within the source code in step 440 .
[0090] Referring to step 465 , a determination is made as to whether the end of the source code has been reached. If the end of the source code is reached, the compilation process is completed at step 499 . Otherwise, step 470 is performed, at which the next code line in the source code is fetched from the memory.
[0091] Thus, a fraction of commands for synchronized data access corresponding to a combination in the source program can be compiled as commands for unsynchronized data access in the application program. The fraction is greater than a ratio between the reduced frequency of synchronization to the corresponding frequency of synchronization and is less than 1.
[0092] In one embodiment, a command for unsynchronized data access in the application program can include at least one of an unsynchronized read command and an unsynchronized write command.
[0093] The programs for implementing the second method can be embodied, i.e., stored, in a non-transitory machine readable data storage medium. Non-transitory machine readable data storage media include any non-transitory media (excluding signals in electromagnetic radiation or other types traveling waveform in free non-confined media) known in the art. For example, non-transitory machine readable data storage media can be a DVD ROM, a CD ROM, a hard disk, a magnetic tape, a portable USB drive, or any other data storage device configured to store electronic data.
[0094] The programs can include a compiler module, which includes a code for enabling recognition of a compiler directive for selective relaxation of synchronization during compilation. Further, the program can include a compiler, i.e., a compiler program, configured to recognize the compiler input program and to compile at least one command for synchronized data access in a source program as at least one command for unsynchronized data access in an application program upon detection of the compiler directive for selective relaxation of synchronization.
[0095] The compiler can be configured to perform the steps of profiling combinations of synchronization commands and data structure classes to be synchronized according to a code in the source program, and identifying at least one combination of a data class and a synchronization command so that a frequency of synchronization is reducible to a level less than 100% of the occurrences specified in the source program without projected violation of a quality condition for a solution for the application program in the at least one combination.
[0096] Further, the compiler can be configured to perform a step of generating, for an identified combination, a reduced frequency of synchronization that is not less than a minimum frequency of synchronization that avoids projected violation of the quality condition and less than corresponding frequency of synchronization specified in the code in the source program.
[0097] The at least one non-transitory machine readable data storage medium can also be employed to store the source program that includes at least one of the compiler directive.
[0098] Referring to step 340 , the application program can be run in a system including a plurality of processors and configured for parallel computing. Synchronization is selectively relaxed during the run as expressly coded in the application program.
[0099] The at least one non-transitory machine readable data storage medium can also be employed to store the application program. The application program includes at least one command for unsynchronized data access corresponding to at least one command for synchronized data access within a combination of a data class and a synchronization command in the source program, and at least another command for synchronized data access corresponding to at least another command for synchronized data access within the combination.
[0100] Referring to FIG. 7 , a first exemplary system configured to implement the methods of the embodiments of the present disclosure is shown. The first exemplary system includes a computing means 910 , which includes an assembly 914 of processors 912 therein. The processors 912 can include relaxation data registers ( 930 , 932 ) and inter-processor communication hardware 913 as illustrated in FIG. 2 for implementation of the first embodiment, or can be any type of multiple processors connected through inter-processor communication hardware for implementation of the second embodiment.
[0101] The at least one non-transitory machine readable data storage medium employed to store programs of any of the above embodiments can be located within the computing means 910 , for example, as a hard disk, outside the computing means 910 , for example, as a database, or as a portable non-transitory machine-readable data storage medium 942 such as a CD ROM or a DVD ROM. A data-writing device 940 may be provided in the computing means 910 to enable encoding of any program employed in this disclosure.
[0102] The at least one non-transitory machine readable data storage medium is a computer program product, which may comprise all the respective features enabling the implementation of the inventive method described herein, and which—when loaded in a computer system—is able to carry out the method. Computer program, software program, program, or software, in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: (a) conversion to another language, code or notation; and/or (b) reproduction in a different material form.
[0103] The computer program product may be stored on hard disk drives within processing unit, as mentioned, or may be located on a remote system such as a server (not shown), coupled to the processing unit, via a network interface such as an Ethernet interface. A monitor, a mouse, a keyboard, and any other human interface device can be coupled to the processing unit, to provide user interaction. A scanner (not shown) and/or a printer (not shown) may be provided for document input and output.
[0104] Referring to FIG. 8 , a second exemplary system configured to implement the methods of the embodiments of the present disclosure is shown. The second exemplary system includes a plurality of computing means 910 , each of which includes a processor or an assembly of processors as illustrated in FIG. 7 . The processor or the assembly of processors can include relaxation data registers and inter-processor communication hardware as illustrated in FIG. 2 for implementation of the first embodiment, or can be any type of multiple processors connected through inter-processor communication hardware for implementation of the second embodiment.
[0105] The plurality of computing means 910 are interconnected among one another through an inter-processor communication device 960 , which can be a router or any other routing device, and data cables 963 . One or more of the plurality of computing means 910 can be provided with a monitor and/or a data-writing device 940 .
[0106] The above embodiments are chosen for illustrative purposes only, and it will be clear to those skilled in the art to practice the disclosure using modifications to other stages of the pipeline as well. For example, a pre-decode stage may be employed to store the pre-decoded instructions in the instruction cache. Therefore, subsequent execution of these instructions will not have to be decoded in the above manner, and this could further improve the overall execution time.
[0107] The methods for relaxing synchronization can be employed in a parallel computing system employing distributed shared memory. Distributed programs do not use locks, but use communication primitives such as blocking send/receives (as in MPI) or blocking communication queues or message buffers, to synchronize. To relax such communication based synchronization, communicators (sender or receiver) are allowed to use stale values. This can be realized by allowing the receiver to operate using stale data, and to synchronize with the sender once every few iterations. The frequency of the reduced synchronization can be determined by a parameter employed during the run time, such as “relax_factor” in the exemplary code. It is also possible to enhance the MPI library to support synchronization relaxation transparently employing the methods of the present disclosure. Thus, the synchronization relaxation of the present disclosure can be implemented in a distributed shared memory system as well.
[0108] While the disclosure has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the disclosure is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the disclosure and the following claims. | Systems and methods are disclosed that allow atomic updates to global data to be at least partially eliminated to reduce synchronization overhead in parallel computing. A compiler analyzes the data to be processed to selectively permit unsynchronized data transfer for at least one type of data. A programmer may provide a hint to expressly identify the type of data that are candidates for unsynchronized data transfer. In one embodiment, the synchronization overhead is reducible by generating an application program that selectively substitutes codes for unsynchronized data transfer for a subset of codes for synchronized data transfer. In another embodiment, the synchronization overhead is reducible by employing a combination of software and hardware by using relaxation data registers and decoders that collectively convert a subset of commands for synchronized data transfer into commands for unsynchronized data transfer. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Application No. 61/093,714 filed Sep. 2, 2008.
FIELD OF THE INVENTION
[0002] This invention relates generally to novel packaging for shipped objects and more particularly to packaging for chimney pipe.
BACKGROUND OF THE INVENTION
[0003] Manufactured products are generally shipped or mailed to their final destination. One such product is chimney pipe. In many applications, chimney pipe is installed outside and visible to the public. As such, modern chimney pipes are plated or coated to make them aesthetically pleasing.
[0004] It is not uncommon for chimney pipe to be scratched, dented or otherwise damaged during shipping, requiring the installer to ship the item back for replacement. This can cause project delays with resultant cost overruns, wasted time, effort and resources.
[0005] Known packaging uses rectangular boxes in which the chimney pipe is placed. There may or may not be padding surrounding the chimney pipe. Most often the packaging is in direct contact with the pipe with no crush zones so that, for example, if a pointed object pierces the box, the chimney pipe is easily scratched or dented.
[0006] Formed plastic has been used to encase and protect shipped items. However, this packaging method greatly the increases the packaging costs, is not environmentally sound, and is too expensive to be cost effective for lower priced items such as chimney pipe.
[0007] Accordingly, there is still a continuing need for an economical, light weight, environmentally-friendly packaging which more effectively protects shipped products than does known packaging. The present invention fulfills this need and further provides related advantages.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides an improved package design for protecting a product during shipment.
[0009] In a first embodiment, the present invention comprises:
a) an outer box comprising four sidewalls, a first end and a second end; b) a rat box comprising a crush zone, the rate box positioned at at least one end of the outer box; c) a half moon support fitting against the inner wall of the outer box comprising a surface in contact with a product surface and angled slots diverging interiorly from an outer edge of the half moon support; d) torpedo shield panels positioned inside of the outer box having a center panel and two side panels diverging at an angle with respect to the center panel, the side panels at least partially fitting into the slots of the half moon support; and e) an inner support having a plurality of contact points for contacting an inner product surface, the inner support extending beyond each end of the product and received by the rat box, thereby suspending the product within the outer box.
[0015] In a second embodiment, the at least one half moon support and the torpedo shields are omitted.
[0016] It is an object of the present invention to provide packaging which protects shipped products from scratches.
[0017] It is an object of the present invention to provide packaging which protects shipped products from dents.
[0018] It is an object of the present invention to provide protective packaging which is economical.
[0019] It is an object of the present invention to provide protective packaging which is environmentally-friendly.
[0020] It is an object of the present invention to provide protective packaging which has reduced waste.
[0021] It is an object of the present invention to provide protective packaging which is light weight.
[0022] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings are included to provide a further understanding of the present invention. These drawings are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.
[0024] FIG. 1 is a perspective view of the novel packaging according to the present invention.
[0025] FIG. 2 is a side elevational view of the novel packaging according to the present invention.
[0026] FIG. 3 is a cross-sectional plan view of the novel packaging according to the present invention shown in FIG. 2 .
[0027] FIG. 4 is a plan view of the cardboard cut outs which are folded into a rat box of the packaging according to a first embodiment of the present invention.
[0028] FIG. 5 is a plan view of the cardboard cut outs which are folded into the inner support of the packaging according to the present invention.
[0029] FIG. 6 is a plan view of the cardboard cut outs which are folded into the torpedo shield of the novel packaging according to the present invention.
[0030] FIG. 7 is a cut out of several half moon supports.
[0031] FIG. 8 shows a cross sectional view of a support according to the prior art.
[0032] FIG. 9 shows a cross sectional view of a half moon support interlocked with the torpedo shield.
[0033] FIG. 10 is a plan view of the cardboard cut outs which are folded into a rat box of the packaging according to a second embodiment of the present invention.
[0034] FIG. 11 is a cross-sectional plan view of the novel packaging according to a second embodiment of the present invention.
[0035] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] As required, detailed embodiments of the present invention are disclosed; however, it should be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. The figures are not necessary to scale, and some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0037] In the following exemplars, the present invention is fabricated of cardboard. Cardboard is economical, rigid, lightweight, offers protection against scratching and denting and is environmentally-friendly. However, the invention is not limited to cardboard.
[0038] Turning now to the Figures, FIG. 1 is a perspective view of the novel packaging according to a first embodiment of the present invention. An outer box 1100 shown with its front face removed, encloses a product 1 being shipped. In this embodiment, product 1 has an elongated cylinder shape, for example, a chimney pipe. However, the packaging is not limited to an elongated cylinder shape and may be used with slight modifications to package objects having various shapes and cross sections.
[0039] An elongated package, such as packaging used to ship chimney pipe, is most prone to damage when it falls on an end, due to the substantial force concentrated on a relatively small surface area. To protect the ends of the product 1 , a ‘rat box’ 1200 is constructed and used at either end of the package 1000 , each rat box 1200 having end crush zones 1210 .
[0040] Two half moon supports 1500 hold product 1 in the center of the box 1100 . Each half moon support 1500 includes a product interface surface shaped to mate with the product 1 . Each half moon support 1500 has a corresponding half moon support 1500 on the opposite side of the product 1 thereby creating support around the perimeter of the product 1 .
[0041] Each half moon support 1500 has an angled slot 1510 which receives an edge of a torpedo shield 1400 . Torpedo shields 1400 are shown in phantom for clarity. There are torpedo shields 1400 on opposite sides of product 1 . These torpedo shields 1400 are designed to provide additional protection to the product 1 should an object break the integrity of outer box 1100 . The elongated torpedo shield 1400 fits within the angled slots 1510 of the half moon supports 1500 .
[0042] Preferably, each torpedo shield 1400 is comprised of a single piece having a center panel and two side panels diverging at an angle with respect to the center panel, the side panels at least partially fitting into the slots 1510 of the half moon support 1500 . The geometry of the torpedo shield 1400 serves to transfer/redirect an impact force away from the product 1 into the half moon support 1500 . This transfer/redirection of impact force is novel from the prior art which uses geometry that serves only to act as a physical block to an impact. Without the novel force redirection capability of the present invention, the prior art can suffer deformation of the product when receiving an impact, even if the prior art geometry prevents direct impact contact to the product.
[0043] FIG. 2 is a side elevational view of the novel packaging according to the present invention. In this view, outer box 1100 is shown enclosing product 1 . Rat boxes 1200 containing crush zones 1210 are shown at either end of package 1000 . The two half moon supports 1500 are shown in cross section. Rigidity is achieved by, for example, several folded cardboard layers. Torpedo shield 1400 is shown in phantom for clarity. The torpedo shield on the opposite side of product 1 is not visible from this view.
[0044] FIG. 3 is a cross-sectional plan view of the novel packaging according to the present invention shown in FIG. 2 .
[0045] Viewing FIGS. 2 and 3 , the outer box 1100 is visible enclosing shipped product 1 . The rat box 1200 is shown at either end of the package 1000 each having end crush zones 1210 . The two half moon supports 1500 have a product interface surface shaped to hold product 1 in the center of the box 1100 . A torpedo shield 1400 is shown in phantom ( FIG. 2 ) over product 1 . The elongated torpedo shield 1400 fits within the half moon support 1500 .
[0046] It is possible that an impact striking at an angle to the end of package 1000 could collapse the ends of a hollow product 1 , for example, a chimney pipe. In order to protect such hollow products 1 , an inner support 1600 is provided. Inner support 1600 has, for example a triangular cross sectional shape which fits snugly inside of the open ends of product 1 . Optionally, other cross sectional shapes that provide interior support to a hollow product may be used, for example, an octagonal cross sectional shape or any other geometric cross sectional shape that provides supporting contact points within the product 1 .
[0047] Although inner support 1600 may span the entire length of product 1 , in a preferred embodiment, inner support 1600 comprises two separate end pieces. Regardless of whether inner support comprises two separate pieces or a single piece, inner support 1600 extends beyond the product 1 to engage a mating cutout in the rat boxes 1200 . In this manner, product 1 is suspended within package 1000 .
[0048] FIG. 4 is a plan view of a cardboard cut-out pattern which is folded into a rat box 1200 of the novel packaging according to the present invention. The mating cutout, for example, triangular cut out 1211 in panel 1201 , 1213 in panel 1203 , 1251 in panel 1231 and 1253 in panel 1233 is provided. A panel 1202 connects panels 1201 and 1203 . Similarly, a panel 1232 connects panels 1231 and 1233 .
[0049] Fold lines 1271 , 1273 and 1275 , 1279 indicate where panels 1201 and 1203 fold over each other making a box shape with the triangular cut outs 1211 and 1213 overlapping each other to make a single triangular hole.
[0050] A portion 1285 between fold lines 1271 and 1273 becomes a side of the folded rat box 1200 . Similarly, a portion 1287 between fold lines 1275 , 1279 becomes the other side of rat box 1200 . Notches 1281 overlap notches 1283 of panels 1202 and 1232 to create a recess to receive the top and bottom edges of torpedo shields 1400 . Tabs 1260 fold to make the other sides of the rat box 1200 . Rat box 1200 is now ready to receive and hold the inner support 1600 .
[0051] FIG. 5 is a plan view of the cardboard cut-out which folds into the exemplar triangular shaped inner support 1600 of the novel packaging according to the present invention.
[0052] Surface 1610 is one of the faces of the inner support 1600 . By folding on the fold lines 1651 , 1610 becomes one of the triangular faces, panels 1620 become two of the other faces. Sections 1640 allow space for folding and provide a flattened apex of the triangular shape. Panels 1630 overlap each other.
[0053] FIG. 6 is a plan view of the cardboard cut outs which are folded into the torpedo shield 1400 of the novel packaging according to the present invention. By folding torpedo shield 1400 cut out on center line 1423 , a double layer thickness with panels 1410 overlapping each other is formed. Panels 1420 each overlap as do panels 1430 . Notches 1433 overlap notches 1431 on one side and notches 1421 on the other side. These notches fit into slots 1510 of half moon support 1500 shown in FIG. 7 . By partially folding panels 1420 and 1430 , the torpedo shield 1400 takes on its characteristic shape as shown in FIG. 1 .
[0054] Panels 1430 are partially folded on line 1411 . Panels 1420 are also partially folded at line 1413 to create the characteristic shape of torpedo shield 1400 . The upper and lower corners of the partially folded torpedo shield 1400 fit into the recesses created from notches 1281 and 1283 of FIG. 4 .
[0055] FIG. 7 is a cut out of several half moon supports 1500 . The cutout is cut on line 1515 to result in two identical mirror images. Each is folded into a half-moon support 1500 .
[0056] For ease of reading, only one panel side 1520 of the cut out is described. Other sides are similarly formed. Panels 1517 , 1519 , 1521 and 1523 are connected to each other at fold lines 1511 . Depending upon the thickness of the materials used and the desired strength, the left set of panels 1520 may be folded into 1, 2 or 4 half moon supports 1500 . Panels 1517 may be folded onto panel 1519 . They may additionally be folded onto panels 1521 and 1523 .
[0057] The panels are scored, or partially cut on line 1513 to allow easier folding. The panels are then folded on line 1513 to create the half moon shape. The inner surface 1517 is designed to fit against and support the product 1 ( FIG. 1 ). Optionally this inner surface may be covered with a material to further prevent scratching of the product.
[0058] In this manner, the structure of the half moon supports 1500 and the torpedo shield 1400 fit together to make a structure which surrounds the product 1 perimeter, holds itself together without connectors, is rigid, and resists torsional forces. Due to the geometry of the half moon supports 1500 , the angled slots 1510 and the torpedo shield 1400 , a rigid structure is formed.
[0059] FIG. 8 shows a cross sectional view of a support according to the prior art. A flat elongated piece 11 is shown with it folded at 90 degree angles to create side panels 13 . The slots 15 are perpendicular to the front edge 17 allowing the side panels 13 to slide into them. This allows for easy construction. Problematically, the side panels 13 slide out just as easily as they slide into slots 15 .
[0060] Twisting elongated piece 11 causes the left edge 13 to move in the direction of arrow A into slot 15 . If left side panel 13 is fully inserted into slot 15 , then it does not move. However, the right edge panel 13 is forced to move in the direction marked by arrow B out of slot 15 causing it to partially disassemble. With the prior art design, if a force contacts elongated piece 11 in a direction marked by arrow “C”, the entire elongated piece 11 may be pulled out of slots 15 . These may progressively ‘creep’; moving further and further out until it is disassembled. Furthermore, as discussed above, the prior art does not allow for transfer/redirection of the impact force away from the product.
[0061] FIG. 9 shows a cross sectional view of a half moon support 1500 interlocked with the torpedo shield 1400 . Due to the geometry of the present device, it is harder to disassemble. Center panel 1410 must be bowed to allow side panels 1420 , 1430 to be inserted into slots 1510 . However, when a force is applied in the direction marked by arrow “D”, side panels 1420 , 1430 resist being pulled out of slots 1510 and return to their original positions after the force is removed. This geometry only disassembles when force D is great enough to pull side panel 1430 entirely out of slots 1510 . In this manner, the present invention employs a more rigid internal structure, which is more resilient and better protects the product than does the prior art.
[0062] The above embodiment of the present invention is envisioned for use with spans of product 1 , where without such rigidity, package 1000 could fold upon receiving a side impact thereby causing damage to product 1 .
[0063] When shorter spans of product 1 are packaged, for example, spans of about twenty four inches or less, the added rigidity provided by half moon supports 1500 and torpedo shields 1400 become optional. Packages 1000 of such lengths have been found to be sufficiently rigid so a to not fold during a side impact. However, to better protect such shorter spans of product 1 , when half moon supports 1500 and torpedo shield 1400 are omitted, inner support 2600 ( FIG. 11 ) ideally comprises more contact points than a triangular cross-sectional geometric shape provides. Preferably, an octagonal cross-sectional geometric shape is utilized, although inner support 2600 is not limited to an octagonal cross-sectional geometric shape.
[0064] FIG. 10 is a plan view of a cardboard cut-out pattern which is folded into a rat box 1200 of the novel packaging according to a second embodiment. The mating cutout, for example, octagonal cut out 2211 in panel 2201 and 2213 in panel 2203 is provided. A panel 2202 connects panels 2201 and 2203 .
[0065] Fold lines 2271 , 2273 and 2275 , 2279 indicate where panels 2201 and 2203 fold over each other making a box shape with the octagonal cut outs 2211 and 2213 overlapping each other to make a single octagonal hole.
[0066] A portion 2285 between fold lines 2271 and 2273 becomes a side of the folded rat box 1200 . Similarly, a portion 2287 between fold lines 2275 , 2279 becomes the other side of rat box 1200 . Notches 2281 overlap notches 2283 of panel 2202 to create a recess to receive the top and bottom edges of optional torpedo shields 1400 , should they be utilized. Tabs 2260 fold to make the other sides of the rat box 1200 . Rat box 1200 is now ready to receive and hold the inner support 2600 .
[0067] FIG. 11 is a cross-sectional plan view according to the second embodiment. The optional two half moon supports 2500 have a product interface surface shaped to hold product 1 in the center of the box. An optional torpedo shield 2400 is shown over product 1 . The optional elongated torpedo shield 2400 fits within the optional half moon support 2500 , received by slots 2510 of optional half moon support 2500 . Inner support 2600 fits snugly inside of the open ends of product 1 .
[0068] Although the present invention has been described in connection with specific examples and embodiments, those skilled in the art will recognize that the present invention is capable of other variations and modifications within its scope. These examples and embodiments are intended as typical of, rather than in any way limiting on, the scope of the present invention as presented in the appended claims. | The present invention comprises an outer box comprising four sidewalls, a first end and a second end; a rat box comprising a crush zone, the rate box positioned at at least one end of the outer box; a half moon support fitting against the walls of the outer box comprising a surface in contact with a product surface and angled slots diverging interiorly from an outer edge of the half moon support; torpedo shield panels positioned inside of the outer box having a center panel and two side panels diverging at an angle with respect to the center panel, the side panels at least partially fitting into the slots of the half moon support; and an inner support having a plurality of contact points for contacting an inner product surface, the inner support extending beyond each end of the product and received by the rat box, thereby suspending the product within the outer box. | 1 |
TECHNICAL FIELD
[0001] This disclosure relates to weighing and display systems relevant to the drilling and well servicing industry. In particular, the disclosure relates to weighing and display systems for well drilling and service rigs which provide for temperature and load compensation, eliminate the need for multiple weight indicator systems, can be used in parallel with existing weight indicator systems and can collect data regarding the drilling and servicing processes.
BACKGROUND
[0002] Mobile service and drilling rigs have been commonplace for many years and are primarily used to drill boreholes and to perform various other downhole operations. In a great number of applications, the total weight of the shaft and the rigging equipment can far exceed the desirable weight at the drill head for optimal drilling and other operations. As shaft equipment extends deeper into a downhole, additional shaft or tubular sections must added to increase the length of the apparatus. As such a process continues, the gross weight of the shaft and rigging equipment increases and naturally exerts additional force on the drill head. In some applications, this weight may increase by an average of over six pounds for every vertical foot of shaft. If the total weight of the shaft and rigging equipment is continuously allowed to be placed on the shaft head, undesirable results may occur. For example, excessive weight on a drill bit during drilling can result in a bore hole which is not straight.
[0003] To eliminate problems due to excessive shaft weight, weight indicators have been developed and used since the early 20 th Century. By using a weight indicator, a rig operator can observe the relative weight of the drilling equipment that is being supported by the equipment rather than at the shaft head. Using this information, the operator can either increase or decrease the tension in the rigging to vary the net weight placed on the drill head. Because of their usefulness, weight indicators have become an essential tool for many downhole operations and have become ubiquitous in the downhole drilling and servicing industry.
[0004] There are generally two types of weight indicators which have become the most prevalent in the industry: the diaphragm type weight indicator and the pad type weight indicator. Both types use hydraulic fluid in a closed loop system in conjunction with analog bourdon tube type dial gages to indicate a change in pressure in the system. Each type also has changeable load dials having varying scales to correspond to different pad diameters or rigging systems which may be used in a given application. Another similarity is that both types of indicators require that the fluid pressure be manually dampened prior to engaging in certain operations which can lead to sharp changes in system pressure. This is required to protect the bourdon tube type gauges that are typically used for these indicators. Even though these and other similarities exist, the indicators are very different with respect to the location on the rig where the measurements are being taken and the type of sensing equipment utilized. A discussion of each type of weight indicator follows.
[0005] The diaphragm type weight indicator generally has a diaphragm unit, a gauge and a hose connecting the diaphragm unit to the gauge. This type of system is generally pre-filled with fluid and the fluid level is not readily changeable by the end user. In practice, the diaphragm unit is clamped onto the static deadline of a rig. When installed, the diaphragm forces a one inch deflection in the line. As the tension in the deadline increases from additional loads on the rigging, the deadline tends to straighten against the diaphragm. As this straightening force increases, the diaphragm is compressed thereby causing an increase in fluid pressure which is reflected at the gauge. The hook load, which is generally supported by a 2, 4 or 6 line tackle system, is directly proportional to the tension in the deadline. To accommodate the varying tackle arrangements and line numbers, differently scaled load dials are used to indicate an actual weight measurement. In general, the fluid pressure will range from 0 pounds per square inch at no load to 100 pounds per square inch at full load for this type of system.
[0006] The diaphragm weight indicator performs well at sensing differences in the hook load, but is generally not capable of providing a measurement for absolute hook load. Several factors contribute to this condition. First, because the hydraulic fluid is in a closed system, the pressure in the system is dependent on the fluid temperature. Thus, large ambient temperature changes will result in different readings for the same hook load. Second, the fluid level in the system is not easily checked or serviced by the user. Thus, it is not always known if the fluid levels are at the appropriate level. Third, excessive frictional forces in the rigging tackle system can cause readings to become distorted. Fourth, and lastly, the connection of the diaphragm to the deadline and the resulting contact points are not always consistent. This is especially true if system components become worn over time. Although all of these factors do present problems with determining an absolute load, the system does provide generally reliable information for changes in hook load. Further, only knowing load changes is generally sufficient for most service and drilling operations. As a result, the diaphragm type weight indicator has become very popular over a long period of time as a rugged and reliable tool for downhole operations.
[0007] The pad type weight indicator relies upon a very different method of operation and can be used to obtain an absolute weight value for the hook load. It should be noted that when a pad type indicator is being used, an operator would not also use a diaphragm type weight indicator at the same time. Rather, the operator would choose one type of indicator or another based on the particular application at hand. The pad type indicator relies upon two load cells, each of which is located under the service rig's jack screws or mast legs. The load cells are generally 6, 7 or 8 inches in diameter and are connected via hoses to individual bourdon type pressure indicating gauges and also to a pressure integrator or summarizer configured to add the two pressures together. The pressure integrator has a tube connected to a third gauge which indicates the total system weight. The fluid operating pressure in this type of system is typically ranges from 0 to 2,000 pounds per square inch (psi) and potentially up to 3,000 psi. Additionally, the load dials for this type of system are differently scaled based on the pad diameter and are generally able to rotate such that the load can be zeroed or tared. This feature allows the user to compensate for the weight of the mast itself, forces exerted by the guy wires stabilizing the mast and potential temperature effects on the closed system. Because the pads are directly under the mast legs, the indicated load is not skewed by frictional forces in the rigging system. There is not a concern with inaccuracies due to fluid level for this system because the user can readily monitor and ensure proper fluid levels. As such, the pad type weight indicator provides a reliable and rugged option to the diaphragm type indicator and is also capable of providing a good indication of absolute hook load.
[0008] Even though the diaphragm and pad type weight indicators have gained wide acceptance in the well service industry and are considered vital tools, improvements are possible and desired. This is especially true in light of the many technological advances that have recently occurred with respect to the electronics industry.
SUMMARY OF THE DISCLOSURE
[0009] One aspect of the invention constitutes an improvement in diaphragm type weight indicators for well drilling and service rigs. The improvement is a rotating load dial which can be rotated about a central pivot point to provide a taring function. No such rotatable dial exists to date for use in deadline type weight indicators for well drilling and service rigs. This rotatable load dial allows for the compensation of ambient temperature changes and the weight of the blocking system that supports the downhole equipment. The blocking system for some service rigs can be as much as 4,500 pounds. Although the resulting indication, after taring the rotating load dial, may still not be the absolute weight of the downhole equipment, a much closer value is obtained than currently possible. Further, the rotating load dial enables the user to more easily track changes in load because no subtraction is required, as is normally the case, once the dial is tared. Thus, a rotatable load dial for a diaphragm type weight indicator represents a considerable improvement over existing prior art indicators of this type.
[0010] Another aspect of the invention is a system for monitoring hook loads in well service and well drilling applications. This is accomplished through the use of pressure transducers that are in electronic communication with a digital user interface module and in fluid communication with a hydraulic diaphragm or hydraulic load cells. Additionally, the system is capable of monitoring, tracking and controlling the output torque of a power tong which is typically used for assembling and disassembling threaded oil field tubular goods such as sucker rods, tubing, casing, downhole tools and other equipment. The system is also capable of acting as a controller of brake systems by functioning as a safety override of manual braking operations when hoisting loads and performing other operations. Lastly, the digital user interface module is optionally mounted onto an interface box which houses the piping for the transducers, the wiring for the transducers and the 12 volt power supply for the user interface. The user interface and the interface box can be constructed such that the assembled unit is mobile and readily moved from one service or drilling rig to another. The following paragraphs provide a more detailed description of the system and the benefits it represents over the prior art.
[0011] In one embodiment, the system comprises four pressure transducers located in the interface box and configured to produce a 4-20 milliamp output signal to the user interface module based on the sensed fluid pressure. One of the transducers is designed for use with a diaphragm type pressure indicator diaphragm and can accept a 0-100 psi range in fluid pressure. Two of the transducers are designed for use with a pad type pressure indicator load cells and can accept a 0-3000 psi range in fluid pressure. The fourth pressure transducer is designed for use with a power tong and can accept a 0-3000 psi range in fluid pressure. As should be appreciated, the fact that these transducers are all in electronic communication with the user interface module enables the user interface module to simultaneously monitor multiple hydraulic systems. These functions have not been combined into a single user interface module of this type to date. This functionality is unique in the mobile downhole service and drilling industry and represents a significant advantage over the current practice of using individual devices for each activity.
[0012] Each pressure transducer is in fluid communication with a first quick connect coupling. The quick connect couplings allow for easy connection to hydraulic hoses which are in fluid communication with the diaphragm, load cells or power tong hydraulic system. Optionally, each pressure transducer is in fluid communication with a second quick connect coupling also in fluid communication with the first quick connect coupling. This feature enables the standard type of weight indicator to also be in fluid communication with the diaphragm or load cells or power tong pressure indicator through the use of additional hoses. As can be appreciated, the second quick connect couplings allow for the user interface module to be in simultaneous and parallel use with the traditional indicating equipment meaning that an operator would not have to forego their use in order to gain the advantages of the invention. As both pad type and diaphragm type indicators are in heavy use, it is anticipated that an operator would be potentially reluctant to replace his or her trusted analog system with an electronic device before seeing the electronic device function well in actual use. Because the invention does not require that any existing equipment be removed, this issue is resolved with the invention and represents a significant advancement over the art.
[0013] The user interface module, in electronic communication with the pressure transducers, is optionally mounted to the interface box. The user interface module comprises a housing, an LCD interface screen, multiple knobs and buttons, a dip switch station, a transducer input station, an LED alarm light, a speaker and a flash card memory module. The user interface module is generally powered by a 12 volt power source which can come from the vehicle itself. Also, the user interface module can be optionally constructed to operate in temperatures as low as −30 degrees Fahrenheit. Even though the user interface module is described and shown in conjunction with pressure transducers, it should be appreciated that the module can also be configured for use with other types of non-hydraulic load sensing devices such as strain gages. The user interface module is described in further detail in the following paragraphs.
[0014] The user interface module housing is typically constructed of a plastic suitable for use in a harsh environment such as oilfield operations. However, it should be appreciated that the housing can be constructed of many different materials and can be configured such that it has an explosion proof rating or be located in a housing having such a rating.
[0015] The user interface module LCD screen is configured to display multiple screen views based on the position of mode selector knob. The mode selector knob allows for a user to choose among a deadline screen view, a pad type screen view and a torque screen view. Each of these views corresponds to a specific transducer input(s) based on the type of measuring equipment currently being used. The screen views are described in further detail later in the description.
[0016] The alarm level knob allows the operator to set an alarm limit in each of the screen views. The selected alarm level in each view is shown graphically and numerically. When the alarm threshold is exceeded, the user interface module is configured with an alarm speaker and an LED alarm light to notify the user that an alarm condition has been reached. Such a feature is not present in current diaphragm and pad type weight indicators and can greatly enhance the safety of drilling and servicing operations.
[0017] A tare button on the user interface module allows an operator to zero out the indicated load on the system. This feature replaces the rotating load dials of the pad type weight indicators and further enables the user to tare a deadline load even when using a diaphragm type unit. The latter function is not a feature present on prior art diaphragm type weight indicators.
[0018] A data logging button is also present on the user interface module. Through the use of a flash card module, measured and calculated data based on the pressure transducer inputs can be logged, stored and extracted. The module can be optionally configured to store seven days worth of measured load data. This information can provide the operator with very useful information regarding the downhole operations and the use of the servicing and drilling equipment. As typical weight indicators are purely analog devices, historical, digitized data from the described user interface module has not been available to date.
[0019] A dip switch station is also available on the user interface module allowing for software configuration of different types of pressure transducers and measuring devices which may be interfaced with the module. Because there are a number of different types of rigging configurations and load cell diameters, the user interface software is especially valuable in that multiple configurations can be stored and selected for a particular application. Currently, pad type and diaphragm type weight indicators use a multitude of load dials scaled for a particular application. The software configurations in the user interface module are capable of replicating each of these scales in a digital environment thereby eliminating the traditional step of acquiring, selecting and installing the appropriate load dial. Further, the user interface module is also capable of having software configurations created and/or uploaded such that any new devices can be integrated for use in the future. This will allow for the invention to be used with any manufacture of load cells, diaphragm units and other types of hydraulic or electronic load sensors. Lastly, it should be appreciated that the user interface module can be adapted such that different configurations can be created through the use of screen views and without the use of dip switches.
[0020] The user interface module also has a torque level knob which is used to view the torque screen view. This allows for the user to select the range of torque load that is displayed on the screen view. For example, during low load conditions, the user may wish to view a smaller range in order to see the graphical load displayed more clearly. Conversely, in high torque load conditions, the user may wish to display the entire range of loads. This feature is also available with all the other views as well such that the operator is always able to increase or decrease the graphical scale to obtain the best view possible of the load. Additionally, the software allows for the user, in all of the aforementioned situations, to increase or decrease the sensitivity of the measurement such that a more or less stable output reading and graph is displayed. These features represent a significant advancement over existing analog based weight indicators in that the load dials cannot be changed in such a manner and that the sensitivity adjustment is a manual operation. As might also be appreciated, the analog weight indicators must also be dampened during certain operations to prevent the gauge from being harmed from sharp spikes in fluid pressure. With the digital user interface, this is not a concern as bourdon tube type gauges are not present. As such, the invention not only eliminates the usual steps of manually dampening and undampening the gauge, it also is more reliable because the operator cannot accidentally harm the system by forgetting to dampen the system as is the case with the analog gauges.
[0021] When the user interface module mode selector knob is rotated to “deadline,” the deadline screen view is displayed on the LCD screen. The deadline screen view shows the calculated present load based on the fluid pressure sensed at a corresponding pressure transducer. This pressure is induced by a diaphragm unit typically used in conjunction with a diaphragm weight indicator. The load value is shown both numerically and in the form of a bar graph. In addition to the load information, an alarm limit set point can be adjusted via the alarm knob and displayed numerically and on the bar graph. The bar graph can be configured to be color coded to represent whether the calculated load is below or above the selected alarm limit set point. The deadline screen view can also display trend log data of the calculated load at various intervals. For example, the trend log can show the calculated load at 1 second intervals for the past 30 seconds.
[0022] When the user interface module mode selector knob is rotated to “pad type,” the pad type screen view is displayed on the display screen. This screen displays the individual and combined loads of load cells of the kind usually used with a pad type weight indicator. For one option, the pad type screen shows the individual calculated present loads for two load cells in graphical and numerical forms. The combined total load is displayed as well in graphical and numerical forms. As with the deadline view, the alarm features are the same with respect to the total calculated load. For the individually measured loads, the alarm limit value can be divided in half and displayed in the same fashion on each bar graph. Additionally, the bar graph can be color coded to show when the individual calculated loads are within 90% of the limit set point. Under a second option, the two load cell values are shown on the same bar graph which graphically shows the difference in load between the two load cells. When the loads are equal, a horizontal bar graph would show no value. However, as the loads become imbalanced, a bar appears on the more heavily loaded side of the graph and represents the disparity between the loads. This information is important to ensure that the drilling or servicing operation remains safe and that no dangerous conditions develop due to load imbalances. Graphically representing the load imbalance in this way provides an operator with easily recognizable information tied to an alarm that it typically only obtained by manually subtracting the reading on two analog gauges in a pad type weight indicator. As such, this type of display represents an improvement over such prior art devices.
[0023] When the user interface module mode selector knob is rotated to “torque,” the pad type screen view is displayed on the display screen. In one embodiment, the torque from a power tong can be shown graphically on a bar graph and in numerical form. In addition to the load information, the alarm limit is also displayed numerically and on the bar graph. The bar graph is configured to be color coded to represent whether the calculated load is below or above the selected alarm limit set point. Optionally, the bar graph maximum value can be adjusted by the torque level knob thereby enabling the user to view a given value at different resolutions.
[0024] With all of the above described display screens, it should be appreciated that many different configurations are possible which integrate the various described features of the user interface module. This includes, but is not limited to: the ability to display, store and extract trend log data; the enabling and adjustment of visual and audible alarms; adjustment features which allow changes to the resolution of the graphs; color coding of graphs with respect to alarm set points and calculated load; and the creation and use of software configurations for different models and types of diaphragms, load cells and power tongs.
[0025] With respect to the invention, it should also be appreciated that the screen views can be modified to display information which may be present on the other screens. For example, the deadline screen view can be configured to display the numerical value of the power tong torque load. Further, additional screen views can be created which show different combinations of data other than that described above.
[0026] A variety of advantages of the invention will be set forth in part in the following description, and in part will be apparent from the description, or may be learned by practicing the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 shows a front view of an exemplary deadline type weight indicator.
[0028] FIG. 2 shows a front view of an exemplary pad type weight indicator.
[0029] FIG. 3 shows a rear view of an exemplary pad type weight indicator.
[0030] FIG. 4 shows a front view of a deadline type weight indicator configured with a rotating load dial.
[0031] FIG. 5 shows a back view of the weight indicator of FIG. 4 .
[0032] FIG. 6 shows a typical diaphragm unit used in conjunction with a deadline weight indicator.
[0033] FIG. 7 shows a front view of the user interface module
[0034] FIG. 8 shows the user interface model with the mode selector knob in the “deadline” position and showing the deadline screen view.
[0035] FIG. 9 shows the user interface model with the mode selector knob in the “pad type” position and showing a first option for the pad type screen view.
[0036] FIG. 10 shows the user interface model with the mode selector knob in the “pad type” position and showing a second option for the pad type screen view.
[0037] FIG. 11 shows the user interface model with the mode selector knob in the “torque” position and showing the torque screen view.
[0038] FIGS. 12-13 show optional screen views for displaying information for pad type load cells and a power tong torque output in various states of operation.
[0039] FIG. 14 shows optional screen views for displaying information for a diaphragm used on a deadline and a power tong torque output in various states of operation.
[0040] FIG. 15 shows optional screen views for displaying information for a power tong torque output shown in various states of operation.
[0041] FIGS. 16-18 show a prototype version of the user interface module.
DETAILED DESCRIPTION
[0042] Reference will now be made in detail to exemplary aspects of the present invention that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
[0043] As shown in FIG. 1 , an exemplary deadline weight indicator 10 used in the drilling industry includes a housing 20 , a main gauge 30 having a main gauge body 70 , an indicator needle 40 and a load dial 50 having a number scale 60 . As can be seen, the load dial 50 is not able to be rotated to zero or tare the load because of the shape of the gauge and load dial. The indicator needle 40 represents the equivalent load based on the change in fluid pressure caused by a diaphragm unit (not shown) which is connected to a deadline (not shown).
[0044] As shown in FIGS. 2 and 3 , an exemplary pad type weight indicator 100 for the drilling industry is shown. The pad type indicator 100 comprises a housing 110 which has a first side 111 , a second side 112 , a top 113 , a bottom 114 , a handle 115 and a mounting panel 116 . On the mounting panel 116 , a main gauge 120 , a first pad gauge 130 and a second pad gauge 131 are mounted. The first pad gauge 130 shows the equivalent load based on fluid pressure changes caused by the first pad (not shown). The second pad gauge 131 shows the equivalent load based on fluid pressure changes caused by the second pad (not shown). The main gauge 120 shows the sum of the loads displayed on the first pad gauge 130 and the second pad gauge 131 .
[0045] On FIG. 2 the rear side of the pad type indicator 100 and the associated hydraulic components are shown. The first pad hydraulic hose (not shown) is connected to the first inlet line coupling 140 which is also connected to a first tee connection 141 . From the first tee connection 141 , a first pad gauge inlet line 142 is connected to the first pad gauge 130 . The second pad hydraulic hose (not shown) is connected to the second inlet line coupling 140 which is also connected to a second tee connection 151 . From the second tee connection 151 , a second pad gauge inlet line 152 is connected to the second pad gauge 131 .
[0046] The pad type indicator 100 also has a pressure integrator 160 which functions to add the pressures indicated at the first pad gauge 130 and the second pad gauge 131 . From the first tee connection 141 , a first inlet line 161 is connected to the integrator 160 . From the second tee connection 151 , a second inlet line 162 is connected to the integrator 160 . From the pressure integrator 160 , an outlet line 163 is routed to the main gauge 120 .
[0047] As shown in FIGS. 4 and 5 , a new diaphragm type weight indicator 200 is shown having a housing 210 and a main gauge 220 . The main gauge 220 is fitted with a rotating load dial 226 which has a rotation knob 227 for rotating the load dial 226 . The rotating load dial 226 also has a numbered scale 228 . The load dial 226 is secured to the main gauge 220 by a retaining ring 221 . The retaining ring 221 is secured to the housing 210 by set screws 222 located near the top of the retaining ring 221 and a first knob 223 located at the bottom of the retaining ring 221 . To lock the load dial 226 from rotating, the first knob 223 is tightened fully. To allow the load dial 226 to be rotated manually by the rotation knob 227 , the first knob 223 is manually loosened. To remove the load dial 226 , the first knob 223 and the set screws 222 are removed which allows the retaining ring 221 to be removed as well. Also shown in FIG. 2 is the main gauge needle 224 which indicates the load based on the pressure sensed from the diaphragm 300 . The rotating load dial 226 allows the operator to zero out or tare the existing load on the system and to compensate for any changes in temperature. This is a function not present on existing deadline type weight indicators and represents and advancement over the prior art. FIG. 5 shows the back side of the diaphragm type weight indicator 200 .
[0048] On FIG. 6 , a diaphragm unit 300 is shown clamped onto a support bar 310 . Normally, the diaphragm unit would be clamped onto a deadline (not shown) instead of the support bar 310 . The diaphragm unit 300 has a deflection plug 320 which imparts a deflection on the deadline when the diaphragm unit 300 is installed. As the deadline tension increases, it imparts a force against a diaphragm within the unit 300 . The diaphragm inside the unit 320 is in hydraulic fluid communication with the main gauge 220 of the weight indicator.
[0049] FIGS. 7 through 18 show various embodiments and views of a digital user interface module 400 and its associated functions and components. As shown on FIG. 7 , the user interface module 400 has an interface housing 410 , an interface display screen 411 , a mode selector knob 412 , an alarm level knob 413 , a torque level knob 414 , a tare button 415 , a data logging button 416 , an LED alarm light 417 , a dip switch station 418 and a speaker 419 . Additionally, the user interface module 400 has an input station 420 with a first pressure transducer input 421 , a second pressure transducer input 422 , a third pressure transducer 423 and a fourth pressure transducer 424 . Not shown are four pressure transducers which are mounted to either the housing 410 or a separate housing and are in electrical communication with the individual transducer inputs.
[0050] FIG. 8 shows the user interface module 400 with the mode selector knob 412 in the “deadline” position and displaying the deadline screen view 430 on the interface display screen 411 . Deadline screen view 430 shows a numerical value 431 for the third pressure transducer input 423 in addition to a bar graph 432 . The third pressure transducer input is a 4-20 milliamp signal derived from a 0-100 psi hydraulic pressure change. With this screen view, a diaphragm unit normally used in conjunction with a deadline type weight indicator is in fluid communication with the transducer. Also displayed is a trend log graph 433 which shows a graph of historical load data. The bar graph 432 can be color coded to represent whether the load has exceeded an alarm set point as defined by the alarm level knob. The bar graph also shows the alarm set point numerically. The user interface module 400 is configurable such that the LED alarm light 417 and the speaker 419 are activated if the load exceeds the alarm set point 434 . The tare button 415 can be pressed at any point during the operation to zero out the current load value reading.
[0051] FIG. 9 shows the user interface module 400 with the mode selector knob 412 in the “pad type” position and displaying a first option screen view 440 on the interface display screen 411 . This screen displays the individual and combined loads of load cells that are usually used with a pad type weight indicator. The first pad load cell is in fluid communication with the first pressure transducer which is in electrical communication with the user interface module via the input station 420 . The second pad load cell is in fluid communication with the second pressure transducer which is also in electrical communication with the user interface module via the input station 420 . Based on the load cell pressures, the interface module 400 calculates and displays a load for each load cell pad. The calculated load value for the first load cell pad is based upon the first pressure transducer input 421 and displayed in a first bar chart 441 and as a first numerical value 442 . The calculated load value for the second load cell pad is based upon the second pressure transducer input 422 and displayed in a second bar chart 443 and as a second numerical value 444 . The total calculated load based on the first and second transducer inputs is displayed as a third bar chart 445 and as a third numerical value 446 . An alarm set point numerical value 447 is also displayed along the third bar chart 445 . Additionally, an alarm condition is calculated for the first and second transducer loads by dividing the set point in half. As with the deadline screen view, this view also allows for the color coding of the bar charts such that the user can easily tell if any of the parameters are in an alarm condition.
[0052] FIG. 10 shows the user interface module 400 with the mode selector knob 412 in the “pad type” position and displaying a second option screen view 450 on the interface display screen 411 . This screen is based upon all of the same inputs and calculations which are performed on the screen shown in FIG. 9 . However, the individual load cell information is shown in a much different manner in a combined bar chart 451 and with a first load cell numerical value 452 and a second load cell numerical value 453 . In this screen view, bar chart 451 graphically shows the difference in load between the two load cells instead of the load value for each load cell. When the loads are equal, a horizontal bar graph would show no value. However, as the loads become disparate, a bar appears on the more heavily loaded side of the graph and represents the disparity between the loads. This screen also shows a color coding option wherein a separate color is provided when the loads are within 90% of the alarm limit set point.
[0053] FIG. 11 shows the user interface module 400 with the mode selector knob 412 in the “torque” position and displaying the torque screen view 460 on the interface display screen 411 . In one embodiment, the torque from a power tong can be shown graphically on a bar graph 461 and in numerical form 462 . This data is based upon the fourth pressure transducer input 424 which is in electrical communication with a fourth pressure transducer which is in fluid communication with the hydraulic pressure in a power tong. The bar chart 461 is configured to be color coded to represent whether the calculated load is below or above the selected alarm limit set point. Additionally, the bar chart 461 maximum value 464 can be adjusted by the torque level knob 414 which enables the user to view a given value at different resolutions.
[0054] FIGS. 12-13 show optional screen views 500 - 506 for displaying information for pad type load cells and a power tong torque output in various states of operation. Screen view 500 shows a pad type indicator screen wherein the first load cell has a load 21,000 pounds and second first load cell has a load of 10,000 pounds and wherein the total combined load is 31,000 pounds. Screen view 500 also shows that the user interface has been configured for 8″ Totco™ brand load cells. Screen view 500 also shows a combined bar chart for the individual load cells which displays that the first load cell is more loaded than the second load cell. Also shown on screen view 500 is a torque load output of 2,200 ft-lbs. Screen views 501 and 502 are the same as screen view 500 , but with other load values which show the total load in a near alarm condition. Screen views 503 and 504 on FIG. 14 show a deadline type display wherein the load is in a near alarm condition. Screen views 503 and 504 also display a measured torque value and a trend log graph of load data. FIG. 15 includes screen views 505 and 506 which show the display in the torque screen view. Screen view 505 shows the torque value numerically and graphically in a normal operating state while screen view 506 shows data which produces an alarm condition.
[0055] FIGS. 16-18 show a FIGS. 16-18 show a prototype version of the user interface module. FIG. 16 shows a user interface module with the front cover removed, but with the interface display screen visible and secured to a first mounting panel. FIG. 17 shows the user interface module with only four pressure transducers mounted within the bottom of the module. FIG. 18 shows a second mounting panel to which the wiring and electronics components of the invention are mounted. This mounting panel is located between the transducers and the first mounting panel for the display screen.
[0056] With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of the parts without departing from the scope of the present invention. It is intended that the specification and depicted aspects be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the following claims. | A system for monitoring loads at well drilling and service operations includes a digital user interface. The digital interface is in electronic communication with a first pressure transducer in fluid communication with a first pad type hydraulic load sensor, a second pressure transducer in fluid communication with a second pad type hydraulic load sensor, and a third pressure transducer in fluid communication with a hydraulic diaphragm type deadline load sensor. The digital user interface module functions to monitor the hydraulic pressures experienced at each pressure transducer and functions to calculate and display a corresponding weight load in numerical and graphical form for each pressure transducer. The digital user interface is also in electronic communication with a fourth transducer in fluid communication with a hydraulic power tong unit. The digital user interface module also functions to monitor the hydraulic pressure experienced at the pressure transducer and functions to calculate and display a corresponding torque load produced by the power tongs in numerical and graphical form. | 4 |
RELATED APPLICATION
This is a continuation-in-part application of Ser. No. 07/989,648, filed Dec. 11, 1992, now abandoned, which is a divisional of Ser. No. 07/825,982, filed Jan. 27, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with an improved fire retardant mastic composition particularly adapted for application to roofing decks, and which includes an additive therein causing the mastic to char and form a barrier to inhibit passage of flowable material therethrough, when the solidified mastic is subjected to temperatures of at least about 150° C. In another aspect of the invention, complete roof constructions are provided including a metal deck, a layer of expanded synthetic resin foam atop the deck, with the fire retardant mastic of the invention applied to the deck and adhering the foam layer thereto. Also, a mastic material extruding apparatus for evenly spreading a flowable roof mastic is provided. Use of the invention permits fabrication of low cost replacement roofs which give a minimum of added dead load to an existing roof structure, while also imparting a high degree of thermal insulation and the ability to form a barrier resistant to passage of melted resin foam or other materials through the deck, in the event of a fire.
In yet another aspect of the invention, an integrated roofing section system is provided which employs a solvent-free, water-based emulsion that can be substituted for solvent-based mastic and roofing asphalt in the construction and installation of metal deck roofing. In particular, the emulsion is useful to bind an unfaced roof board to a foam layer for forming the integrated roofing section. The emulsion can also be used to adhere the integrated roofing sections to the metal roof deck, as well as for forming a layer of fire retardant over the outer surface of all roofing boards once the integrated sections are installed.
2. Description of the Prior Art
Many industrial-type buildings constructed during the last 30 to 40 years were roofed with metallic decking panels. Such panels were normally secured by screws, bolts, or rivets penetrating the metal decking, these penetrations being sealed. Metal roofs of this type suffer from a number of disadvantages, including a tendency to leak, and poor thermal insulation qualities. Over the years, as these metal roofs have begun to wear out, the building owners are faced with the task of providing a replacement roof. Generally speaking, it is a very expensive proposition to remove the original metal decking, and replace it with new decking. A replacement would typically cost approximately two times that of the modified insulated roof system concerned in this patent. Another alternative is to simply place a new metal deck atop the original deck. This is a problem inasmuch as the new metal roof imposes a significant dead load upon the structure of the building, which is particularly troublesome in the case of older buildings.
It has also been suggested in the past to provide a replacement built-up roof using the worn metal roof as a substrate. In such systems, preformed panels of expanded polystyrene, adapted to be placed over the contour of the original deck are employed. Such panels have rigid boards secured to the upper surfaces thereof, and are generally provided in 4'×4' or 4'×8' sections. With such built-up roofs, hot asphalt is initially applied to the decking, whereupon the preformed insulation panels are applied. At this point, a roofing membrane may be secured to the upper surface of the foam panels sections, followed by conventional lap joint sealing and finishing. In some of these prior built-up constructions, hot asphalt or existing mastics have been employed which include asphalt, mineral spirits, fibers and fillers. A problem with these roofs is that, in the event of a fire, the polystyrene foam readily melts and becomes flowable, and then drips into the building below with the asphalt. This can cause severe damage to the building and its contents, and indeed the fire insurance rates for a building having a built-up roof of this character are increased because of this hazard if insurable at all.
Another problem with these roofs is that the use of such solvent-based mastics can create an adverse environmental impact. There is presently pending legislation introduced by the Environmental Protection Agency, which, if enacted, will restrict and phase out the use of solvent-based mastics for use in roofing construction. Already in states such as California (Orange County, Dade County) and Florida, the use of mastics with traditional solvent-based carriers has been restricted. In addition, the use of hot asphalt in connection with roofing installations is already considered dangerous to public safety stemming from the hazard posed by the transportation of hot asphalt (typically between 450-500 degrees F.) over public roads and highways.
There is accordingly a real and unsatisfied need in the art for a new roofing system which can be used to form a safe built-up roof on an existing metal deck, while overcoming the problem of leak-through in the event of fire.
SUMMARY OF THE INVENTION
The present invention overcomes the problems outlined above, and provides a modified roof construction including the original metal deck, together with a layer of expanded synthetic resin foam situated atop the deck and having a roof membrane affixed to the outer surface of the foam layer. A layer of fire retardant mastic is applied to the deck and as solidified adheres perlite layer thereto. The mastic comprises respective quantities of asphalt, mineral spirits and a fire retardant additive for causing the mastic to char and form a barrier to inhibit passage of flowable materials such as melted resin foam through the deck, when the mastic is subjected to a temperature of at least about 150° C.
In preferred forms, the foam layer is made up of expanded polystyrene foam, with a rigid insulative roofing board interposed between the outer surface of the foam and the roofing membrane. Furthermore, it is desirable to use the fire retardant mastic in three locations, i.e., between the deck and foam layer, between the outer surface of the foam layer and the 1/2" perlite board (U.S. Pat. No. 4,766,024), and between the roofing board and final modified roofing membrane.
Advantageously, the roofing mastic of the invention includes from about 30-60% by weight asphalt and from about 8-30% by weight mineral spirits, with from about 3-50% by weight of fire retardant additive. Other minor ingredients includes fibers (0.5-5% by weight), surfactant (0.1-1.5% by weight), filler (10-35% by weight) clay (1-7% by weight). The fire retardant additive is preferably selected from the class of intumescent glasses, most especially amorphous sodium/calcium borosilicate glass.
The invention also comprehends a new device which greatly facilitates application of roof mastic to a metal deck. Such apparatus comprises an elongated, hollow mastic delivery bar adapted to be transversely pulled across a roofing surface and having structure defining a plurality of mastic delivery openings therethrough along the length of the bar. Means is also provided for evenly spreading mastic delivered from the openings of the bar, including a plurality of chains operatively disposed relative to the delivery bar and oriented to contact and spread mastic delivered therefrom as the bar is pulled across a roof surface.
An alternative embodiment of the present invention overcomes those problems, outlined above, which are directed to the use of solvent-based mastics and high temperature asphalt. The alternative embodiment provides integrated roofing sections for placement atop metal roof decks constructed and installed without the use of either solvent-based mastics or high temperature asphalts. Each such roofing section is similar in many respects to the modified construction discussed above and includes a layer of expanded-synthetic resin foam having an inner and outer surface and a layer of rigid, weather-resistant roofing cap board also having inner and outer unfaced surfaces. The foam layer and cap board layer are bound together by means of a commercially available, solvent-free, water-based emulsion.
In the preferred form of the alternative embodiment, the integrated roofing sections are manufactured by means of a method which applies a plurality of elongated beads of clay-based emulsion to one side of the unfaced cap board. The emulsion beads are configured in such a way so that at least two of said elongated beads are separated and define a quick-bond glue receiving surface area located centrally on the roof board. A bead of quick-bonding, hot-melt glue is applied to the glue-receiving surface. The beads of emulsion and glue are next exposed to a heat source that partially cures the beads and renders them tacky. The foam layer is situated atop the cap sheet so that the emulsion beads spread out to form a layer of emulsion therebetween. The quick-bonding glue bead offers sufficient binding to substantial eliminate shifting between the layers as the roofing sections are palletized and transferred to the construction site. The binding effect of the quick-bond glue is further sufficient to generally maintain the orientation of the layers comprising the integrated roofing section in a period during which emulsion drying and curing occurs.
Advantageously, the integrated roofing sections of the alternative embodiment are adhered to the roofing deck by means of the same clay-based, solvent-free emulsion used to construct the integrated roofing sections. The emulsion can also be used as a fire retardant layer applied over the outer surfaces of the roofing boards of the installed integrated roofing sections.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic, side elevational view of the preferred mastic spreading apparatus of the invention, shown operatively coupled to a reservoir of flowable mastic;
FIG. 2 is an enlarged, fragmentary, vertical sectional view depicting the construction of the spreading apparatus;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2, and further illustrating the structure of the mastic delivery bar;
FIG. 4 is a fragmentary top view illustrating the spreading operation of the apparatus of the invention;
FIG. 5 is a rear elevational view of the delivery bar of the apparatus shown in FIGS. 1-3 illustrating the mastic delivery apertures;
FIG. 6 is a plan view of another type of delivery apparatus in accordance with the invention, wherein the mastic deliver bar has a generally U-shaped header secured thereto;
FIG. 7 is a rear elevational view of the apparatus shown in FIG. 6, and illustrating the header construction and the mastic delivery apertures;
FIG. 8 is an enlarged fragmentary sectional view illustrating a modified form of the invention wherein certain of the mastic delivery apertures are oriented obliquely relative to the longitudinal axis of the delivery bar, in order to properly coat an upstanding decking rib;
FIG. 9 is an exploded view illustrating an underlying metal deck together with a preformed polystyrene foam/roofing/board panel designed to overlie the deck;
FIG. 10 is a fragmentary vertical sectional view illustrating the instruction of a built-up roof in accordance with the present invention;
FIG. 11 is a side elevational view of an assembly line used to manufacture integrated roofing sections of the alternative embodiment improved by the provision of clay-based emulsion used in place of solvent-based mastic;
FIG. 12 is an enlarged, cross-sectional, side elevational view of an integrated roofing section of the alternative embodiment; and
FIG. 13 is an enlarged, side elevational, cross-sectional view of the cap board showing a single bead of instant bonding, hot-melt glue applied along the centrally located surface area of the inner surface 16b;
FIG. 14 is an enlarged, front elevational view of a header used to apply solvent-free emulsion to the inner surface of the cap board layer as it moves down the assembly line.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fire retardant roofing mastic of the invention is made up of a combination of asphalt and mineral spirits, together with a fire retardant additive for causing the mastic to char and form a barrier to inhibit passage of flowable material therethrough, when the mastic is solidified and subjected to temperatures of at least about 150° C. As indicated previously, the mastic may contain other conventional ingredients, such as fibers, surfactant, filler, clay and the like.
The following table sets forth the ingredients of the preferred fire retardant mastic, as well as approximate broad and preferred ranges of use thereof.
TABLE______________________________________ Most Broad Range Preferred Range PreferredIngredient (% by wt.) (% by wt.) (% by wt.)______________________________________Asphalt 30-60 35-55 48.60Mineral Spirits 8-30 12-20 16.20Fibers 0.5-5 1-2 1.33Surfactant 0.1-1.5 0.3-0.8 0.63Filler 10-35 15-25 19.92Clay 1-7 2-5 3.32Fire Retardant 3-50 5-15 10.00Additive______________________________________
In preferred practice, the asphalt and mineral spirits fractions of the mastic are provided as a 75%/25% mixture of asphalt and mineral spirits. Such a mixture is referred to as a "cut-back" asphalt. The specific product found useful in the context of the invention is AC 20 cutback asphalt having a softening point of about 115° F. This product is commercialized by Koch Industries of Wichita, Kans. It is somewhat important in this respect that the spirits fraction of the cut-back asphalt not be highly aromatic and therefore flammable. Generally, the mineral spirits fractions should therefor have a flash point of at least about 100° F., and most preferably about 104° F.
The preferred fibers are non-asbestos cellulose fibers (CAS No. 65996-61-4), which are insoluble but dispersable in water, and have a specific gravity of 1.58. Other physical properties include oil absorption of 500-600% and moisture content of about 13.2%, and a pH in water of about 6.9. Fibers of this character are commercialized by Custom Fibers Central of Wellsville, Kans. While such cellulose fibers are preferred, other possibilities exist, such as rock wool fibers.
A number of fillers can also be used in the mastics of the invention. The most preferred filler is limestone. In actual practice, Hubercarb limestone commercialized by J. N. Huber Corporation of Quincy, Ill. has been used to good effect. This product is principally made up of calcium carbonate, with minor amounts of magnesium, carbonate and silica therein.
The clay and surfactant materials present in the compositions of the invention to provide a homogeneous gel-like consistency, and to maintain the filler in suspension. The preferred surfactant is isodecyloxypropyl amine acetate (CAS No. 28701-67-9), sold by Exxon Chemical Company of Milton, Wis. This surfactant is known for use in roof coating formulations, and has a total amine value of 185-205, an acid value of 185-205, a neutralization of 95-105% and a water content of about 0.75%. Of course, other types of alkyl amine salt surfactants can also be employed in the invention.
The clay fraction of the mastic is preferably selected from the atapulgite clays, which can be obtained from a number of commercial sources, e.g. Oil-Dri Corporation of Chicago, Ill. The most preferred atapulgite is commercialized as the "Select 520" clay of Oil-Dri Corporation. This product includes a number of inorganic oxides such as SiO 2 , Al 2 O 3 , CaO, MgO, Na 2 O, K 2 O, Fe 2 O 3 , MnO, TiO 2 and P 2 O 5 . The product has a free moisture content of from about 10-15% and a pH from about 8.5-10.0. Again, other types of clays and clay/surfactant combinations can be used.
In preparing the mastic, the cut-back adhesive is first warmed (e.g., 140° F.,) and the clay and surfactant added thereto, with sufficient moisture to assure homogeneity. At this point, the remaining ingredients are added in any desired order, with further mixing.
Attention is next directed to FIG. 10 which shows a final built-up roof 10 in accordance with the invention. Broadly speaking, the roof structure 10 includes an underlying metal deck 12, a layer 14 of synthetic resin foam situated atop the deck 12, rigid roofing board 16 applied over the layer 14, and finally, a final roofing membrane 18 (preferably formed of modified bitumen) presenting the weather surface for the roof construction.
In more detail, the metal deck 12 is completely conventional and is in the form of a series of co-planar main panels 20 with elongated, upstanding ribs 22 between adjacent main panels.
The foam layer 14 and roofing board 16 are preformed as integrated sections 24 (see FIG. 9). That is to say, each of the sections 24 a layer of expanded polystyrene foam whose underside is configured to closely conform with the configuration of deck 12. To this end, the depicted foam layer underside has a plurality of main planar surfaces 25 with elongated, concave, rib-receiving recesses 26 between the surfaces 24. Generally speaking, the sections 24 are provided in 4'×4' or 4'×8' sizes. A variety of polystyrene foams can be used, e.g., the Fostafoam styrenes commercialized by American Hoechst Company of Leominster, Mass.
The roofing board 16 may be of any conventional material, and is preferably formed of the well known "Perlite". This board is rigid and weather resistant, and can be readily bonded to the foam layer 14. In the later regard, although not specifically shown in the drawings, it is preferred that the fire retardant adhesive of the invention be used to secure the roofing board 16 to the underlying foam layer 14.
The modified bitumen membrane 18 is itself entirely conventional, and can be UL Class A, and is laid as elongated strips, using any desired roofing mastic, but preferably the fire retardant mastic of the invention.
In constructing the modified roof 10, the fire retardant mastic of the invention is first applied over the upper surface of deck 12 of a thickness to form, once the mastic has solidified, a layer 27 of perhaps 25 mm in thickness. After the mastic is applied, and is still in the heated, flowable condition, the preformed roofing sections 24 are applied, simply by laying the panels in place and applying moderate downward pressure thereto in order to ensure that the mastic properly adheres the sections to the deck 12.
In the next step, an additional layer 28 of the fire retardant mastic is applied over the upper surfaces of the roofing boards 16. Here again, the thickness of the mastic layer 28 is not critical, but would generally give a solidified thickness of perhaps 25 mm. At this point, the membrane 18 is applied in the entirely conventional fashion over the flowable mastic, and the necessary lap joints 29 (see FIG. 10) are created and sealed using a 25 pound lap roller. This completes the roofing structure 10.
The complete roof structure 10 exhibits a number of very desirable advantages. First, a considerable degree of thermal insulation is provided, usually on the order of R-12. This is of course is a decided improvement over a conventional raised rib metal deck roof, which provides little if any thermal insulation. Furthermore, the modified roof concerned in this invention adds very little dead load. The new modified roof can also be installed at a price approximately 50% of a conventional metal re-roof, owing to the use of relatively low cost materials, but also because of the fact that the system of the invention can be installed with a minimum of labor. Specifically, the modified roof hereof can be applied at a rate of 1-11/2 roofing squares per man hour, whereas typical roofs using hot asphalt or metal fasteners and BUR require something on the order of 2 1/2 man hours per roofing square. In this same vein, it has been found that perfectly acceptable applications can be produced using from 11/2-2 gallons of the fire retardant mastic per roofing square. This compares with applications of perhaps three gallons per roofing square using conventional asphalts.
The construction of built-up roofs in accordance with the invention is greatly facilitated by the mastic applicator devices illustrated in FIGS. 1-8. Turning first to FIGS. 1-5, it will be seen that the applicator apparatus 30 includes an elongated, hollow mastic delivery bar 32 adapted to be transversely pulled across a roofing surface and having structure defining a plurality of mastic delivery openings 34 along the length thereof. As shown, the bar 32 is coupled to a handle 36 which extends upwardly from the bar and includes manipulation end 38. The handle 36 is tubular in construction, and is adapted to be connected to a reservoir 40 of hot, flowable mastic, by means of line 42 and pump 44. In this way, hot mastic is delivered via line 42 and handle 36 to bar 32, whereupon it flows out of the openings 34 during the application process.
The overall apparatus 30 further includes means 46 for evenly spreading mastic from the openings 34. The spreading means 46 includes a plurality of elongated, lightweight chain sections 48 which are operatively disposed in trailing relationship to the bar 32 and are oriented to contact and spread mastic as the bar is pulled across the roofing surface. As best seen in FIGS. 2 and 4, an elongated chain draw bar 50 mounted generally parallel with and spaced from delivery bar 32 is provided, with the chains 48 being secured to the draw bar 50 in spaced relationship along the length thereof. Attachment between the delivery bar 32 and draw bar 50 is provided by means of a plurality of spaced apart eyes 52 welded to bar 32 with trailing swivels 54 serving to interconnect the draw bar 50 and eyes 52. It will thus be appreciated that as bar 32 is pulled across a roofing surface, the chain draw bar 50 and spreading chains 48 are likewise drawn across the surface of the roof.
Attention is specifically drawn to FIG. 4, which illustrates the spreading operation of the chains 48. That is to say, flowable mastic is delivered from the openings 32 in respective streams 56 which slightly spread of their own accord; however, the effect of the chains 48 is to evenly merge and spread the individual streams 48 in order to completely cover the roofing surface.
In those instances where a metal deck such as the previously described deck 12 is to be covered with mastic, it may be advantageous to specifically orient certain of the openings 34 of delivery bar 32 to ensure that the upstanding ribs of the deck are covered with mastic. Referring specifically to FIG. 8, it will be seen that delivery bar 32 includes a plurality of apertures 34 having their longitudinal axis transverse to the longitudinal axis of the delivery bar; however, in this embodiment, others of the openings 34a are obliquely oriented relative to the longitudinal axis of bar 32, so that the streams of mastic 56a therefrom converge towards each other and thereby more readily cover the sloping sidewalls of a rib 22. It will be observed in this respect that the rib-coating apertures 34a are separated by a central aperture 34 properly coats the planar top wall of the rib.
Another embodiment of the invention is illustrated in FIGS. 6-7. In this case, a somewhat longer mastic delivery bar 58 having spaced delivery aperture 60 is provided, along with a trailing, multiple-chain spreading device 62. In order to feed the elongated bar 58 and ensure that all the apertures 60 thereof receive an adequate supply of mastic, the bar 58 is provided with a generally U-shaped tubular header 64 having the ends thereof in communication with bar 58. A handle 66, again of tubular design, extends upwardly from header 64 and is adapted, as in the case of handle 36, to be coupled with a supply of mastic from a remote location.
It has been found that use of a chain-type spreader/applicator in accordance with the invention, gives complete coverage of a metal deck with a single pass. This is to be contrasted with traditional mopping operations, wherein adequate coverage is obtained only by multiple passes and is labor-intensive. Moreover, the applicator device hereof readily covers roofing surfaces of all normal configurations, including any upstanding bolt or rivet heads which may be present.
Although a variety of reservoirs may be used for preparing and storing mastic, a heated mobile, 500-1,000 gallon tank rig has proved completely workable. The lengths of the spreading chains described previously are also variable, and it has been found that chains should range from about 5-12 inches in length. This permits ready manipulation of the complete spreader assembly, and also gives the proper degree of mastic spreading and coverage.
It has been found that the roofing systems of the invention have a very decided advantage in the event of a fire. That is to say, the fire retardant material present in the adhesives of the invention begins to char at about 150° C. and form a solid barrier. This inhibits the passage of flowable material through the metal decking of the roof, as is common with the conventional built-up roofs including an insulative synthetic resin foam layer. As a consequence of this characteristic, building owners having the built-up roofs hereof are subject to lower fire insurance rates, than those having conventional built-up roofs.
FIGS. 11-14 illustrate an alternative embodiment of the invention showing a manufacturing process used to construct integrated roofing sections 24a including structure which is similar in many respects to the embodiment in FIGS. 9 and 10; accordingly, like reference numerals, differentiated by the letters "a", will be used in the description of this embodiment, as compared with the FIGS. 9-10.
Referring to FIG. 12, there is shown a fully assembled integrated roof section 24a which includes foam layer 14a and roof board 16a are preformed as described above. Foam layer 14a is obtainable from AFM Corp., Excelsior, Minn. In the alternative embodiment, however, roof board 16a is preferably formed of fiberglass or rock wool and is unfaced on both inner and outer surfaces 16b and 16c, respectively (available from Owens-Corning, Kansas City, Kans.). In addition, in the construction of the integrated roofing section 24a, a solvent-free, water-based emulsion 68 is used as a means to bind roof board 16a to foam layer 14a.
Emulsion 68 is solvent-free and water-based and can be obtained from Vance Bros., Kansas City, Mo. (Other sources include Nordcoat manufactured by Nord Bitumi, and a generic formulation from Grundy Industries, Chicago, Ill.) Emulsion 68 is preferably clay-based. Water-based additives, such as latex polymers (operating as weak elastomers) may be mixed into the emulsion 68 to effect desired properties and results. Emulsion 68, further, is of a type which can be applied to materials of construction at room temperatures and may be so applied with any conventional means such as a chain mop. Roof board 16a is constructed of such material so that when emulsion 68 is applied to it, moisture from emulsion 68 can be advantageously absorbed and dissipated into the cellular space between the fibers (not shown) which make up roof board 16b. In this way, emulsion 68 begins to cure and bind with the fibers. In the latter respect, when fiberglass or rock wool is preferentially used as a material of construction for roof board 16a, inner and outer surfaces 16b and 16c respectively, are unfaced to permit the curing and binding effect of emulsion 68 as previously discussed.
Turning now to the construction method of the integrated roofing section 24a in FIG. 11, there is shown an assembly line comprising a first conveyor assembly 70, a second conveyor assembly 72, a waste collection basin 74, a heat source 76, an emulsion delivery and application header 78, and a quick-bonding glue delivery and application header 80. Integrated roofing sections 24a are manufactured by first placing a roof board 16a on first conveyor assembly 70 (of conventional design and construction) as indicated by the letter "A". First conveyor assembly 70 moves roof board 16a into a region beneath emulsion header 78 and quick-bond glue header 80 as indicated by the letter "B". As first conveyor assembly 70 carries roof board 16a beneath quick-bond header 80, a single bead 82 of quick-bond glue is applied to inner surface 16b as shown in FIG. 13. Preferably, quick-bond glue bead 82 is applied along an imaginary center line dividing the inner surface 16b of roof board 16a. The quick-bond glue used is of the hot-melt, translucent type obtainable from Western Adhesives, Kansas City, Mo. As conveyor assembly 70 carries roof board 16a along the conveyor path, a plurality of elongated beads 88 of emulsion 68 are next applied to the roof board 16a inner surface 16b by means of applicator 84 associated with the emulsion delivery and application header 78. The applicator 84, shown in FIG. 14, is a hollow delivery bar and includes a plurality of openings on its bottom side (not shown) through which emulsion 68 flows to form beads 88. Applicator 84 is disposed above and oriented generally transversely to conveyor assembly 70 so that the formation of emulsion beads 88 are generally parallel to quick-bond glue bead 82, as shown in FIG. 14. Emulsion 68 is supplied to applicator 84 through piping 86 by means of pump 87 from reservoir 90 and is controlled by valve 92, all of which components are of conventional design. Applicator 84 is also configured with a water cleanup header 94 and water control valve 96 used to direct water through applicator 84 and flush valve 98 and is collected in waste collection basin 74 for cleanup purposes after completion of use.
As roof board 16a continues to be moved from first conveyor assembly 70 to second conveyor assembly 72 (also of conventional design and construction), it passes over the waste collection basin 74 (as indicated by the letter "C"). Thereafter, roof board 16a is moved by second conveyor assembly 72 into a region, indicated by the letter "D" in which foam layer 14a is situated on roof board 16a such that outer surface 14b comes into contact with the emulsion beads 88 and glue bead 82. Sufficient force is applied to foam layer 14a so that emulsion beads 88 form a substantially continuous layer between foam layer 14a and roof board 16a, as shown in FIG. 12. In this way, foam layer 14a and roof board 16a are bound together forming an integrated roofing section 24a.
Quick-bond glue bead 82 is sufficiently quick drying and possesses sufficient binding properties so that inter-layer shifting is substantially eliminated between roof board 16a and foam layer 14a during the time required for emulsion 68 to dry and cure. The quick-drying and binding properties of glue bead 82 are particularly important to minimize inter-layer shifting within the integrated roofing section 24a as it is palletized (after being assembled) and in the time period during which it is stored on the pallet and while being transported to a construction site. Integrated roofing sections 24a are preferably stored in a horizontal position while on the pallet if the drying and curing process has not been fully completed. Uncured integrated roofing sections 24a may, however, be stored vertically provided that inter-layer shifting is physically restricted. When stored vertically, the roofing sections 24a are preferably oriented such that glue bead 82 is vertical to permit the draining of moisture from the emulsion during the drying and curing process.
The integrated roofing sections 24a are so configured so that once installed on a metal deck, radiant energy from the sun will assist in the emulsion drying and curing process described above. Once the emulsion 68 is completely dried and cured (typically requiring about 3 days), it provides a harder surface than that which might otherwise develop with the use of, for example, craft paper and hot asphalt as the final layer applied to roof board outer surfaces.
The integrated roofing section 24a exhibits a number of desirable advantages. First, it avoids the use of solvent-based mastics, which mastics may in the future be considered to be a hazard, by the substitution of a water-based solvent-free emulsion. Use of the emulsion offers the additional advantage of avoiding personal exposure to hazardous, high-temperature asphalt. | A built-up roofing structure (10) is provided which is characterized by low dead weight, enhanced fire retardancy, and ease of construction. The structure (10) includes a lowermost deck (12) with integrated, insulative sections (24) applied thereover and adhered in place by a novel fire retardant mastic (27); the sections (24) each include a preformed expanded foam layer (14) covered by a roofing board (16). A modified bitumen membrane (18) is applied over and completes the roofing structure (10). The improved mastic includes asphalt, low volatility mineral spirits and a fire retardant additive such as an intumescent glass, and particularly a borosilicate glass. The mastic is advantageously applied using a spreader apparatus (30) having an elongated, tubular, apertured mastic delivery bar (32, 58) and spreading means (46, 62) with a plurality of separate, spaced apart, lightweight trailing spreader chains (48). An alternative embodiment is provided in the form of an integrated roofing section (24a) which is constructed with a solvent-free, water-based emulsion (68) used to bind an unfaced roof board (16a) to a foam layer (14a). The emulsion (68) can also be used as a substitute for hot asphalt in the construction of roofing upon metal decks. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent No. 62/331,962 entitled GuardSpark Covers and filed on May 4, 2016, which is specifically incorporated by reference herein for all that it discloses and teaches.
TECHNICAL FIELD
[0002] The invention relates generally to the field of commercial and residential electrical construction; and more particularly, to the field of preparing electrical wiring components prior to painting/texturing or otherwise finishing surrounding surfaces; and more particularly still, to electrical covers designed to fit over one or more electrical recessed light fixtures to protect said component during painting/texturing/finishing processes.
BACKGROUND
[0003] There are many products designed to cover and/or protect recessed light fixtures (hereinafter, “electrical components”) from receiving paint, texture, or other finishing materials (collectively, “finish materials”) during finishing projects. This is important as such materials can enter electrical components and cause malfunctions, be unsightly, reduce functionality, or even create electrical wiring hazards. In such situations, removing materials from electrical components can be time consuming and difficult; it is a much better approach to keep such materials from entering the electrical components in the first place. One common partial solution is to tape over the electrical components before commencing finish work. However, this is a laborious and time consuming process that ultimately yields unimpressive results as the gaps between rows or columns of tape allow materials to enter the electrical components. Furthermore, during the taping process, it is easy to accidentally make contact with the interior of the electrical components leading to potential electrical shock hazards. Tape is not reusable and often lets loose or fails when touched, vibrated, or otherwise moved—simple exposure to sunlight can also cause tape to fail. Not to mention the unsightly residue that tape often leaves behind. The prior art has seen the shortcomings of tape and attempted to address them with plastic paint shields. However, most such shields utilize prongs that either project into the outlets or into the electrical boxes. Many modern outlets have safety tabs that defeat insertion of such prongs causing such paint shields to be unusable. Further, depending on the installation of electrical components, there may be no room for insertion prongs to fit into an electrical box to the side of switches or outlets. Again, failure of such paint shields results. Additional problems with prior art paint shields is that they are flat, flimsy and prone to cracking, so they often gap or buckle, leaving spaces through which finish materials can enter. Thicker, more rigid shields fail to account for variations in manufacturing tolerances between electrical components, so may not fit all electrical components. What is needed is an electrical cover that is able to be pressure-fit so that no insertion prongs are necessary, and is easy to quickly add or remove in order to save labor during finishing projects.
SUMMARY
[0004] The electrical cover comprises a friction-held recessed light fixture cover. Embodiments of the electrical cover described herein provide flexible finish material covers that guard recessed “can” light fixtures from paint, spackling, and other foreign materials. The frictionally-held finish material covers utilize specifically shaped features on the surfaces, such as negative draft, that contact the electrical components to increase the hold on the electrical device. Some of the shaped features of the frictionally-held covers also help minimize stress in the cover. Features are also molded into the parts to assist and strengthen the cover once installed, and thus protect against the intrusion of finish material behind the cover.
[0005] The above summary provides a basic understanding of some aspects of the specification. This summary is not an extensive overview of the specification. It is intended to neither identify key or critical elements of the specification nor delineate any scope of particular embodiments of the specification, or any scope of the claims. Its sole purpose is to present some initial concepts in a simplified form as a prelude to the more detailed description that is presented later.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following descriptions of a preferred embodiment and other embodiments taken in conjunction with the accompanying drawings, wherein:
[0007] FIG. 1 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover in place on a recessed light fixture;
[0008] FIG. 2 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover being emplaced within a recessed light fixture;
[0009] FIG. 3 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover;
[0010] FIG. 4 illustrates a bottom plan view of an exemplary embodiment of an electrical cover; and
[0011] FIG. 5 illustrates a side elevation view of an exemplary embodiment of an electrical cover.
DETAILED DESCRIPTION
[0012] In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, those skilled in the art will appreciate that embodiments may be practiced without such specific details. Furthermore, lists and/or examples are often provided and should be interpreted as exemplary only and in no way limiting embodiments to only those examples. Similarly, in this disclosure, language such as “could, should, may, might, must, have to, can, would, need to, is, is not”, etc. and all such similar language shall be considered interchangeable whenever possible such that the scope of the invention is not unduly limited. For example, a comment such as: “item X is used” can be interpreted to read “item X can be used”.
[0013] Exemplary embodiments are described below in the accompanying Figures. The following detailed description provides a review of the drawing Figures in order to provide an understanding of, and an enabling description for, these embodiments. One having ordinary skill in the art will understand that in some cases well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. Further, examples described herein are intended to aid in understanding the principles of the embodiments, and are to be construed as being without limitation to such specifically recited examples and conditions. As a result, the inventive concepts are not limited to the specific embodiments or examples.
[0014] Referring now to the drawings, FIG. 1 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover 310 in place on a recessed light fixture 390 . The recessed light fixture 390 includes a recessed light fixture assembly 394 in the illustration in FIG. 1 . The electrical cover 310 in this embodiment is illustrated as being transparent, other embodiments may utilize translucent and/or opaque components.
[0015] In the embodiment illustrated in FIG. 1 , a electrical cover 310 comprises a main body having a series of concentric annular fittings that allow the electrical cover 310 to mate to various sized openings of the various sizes of recessed light fixtures 390 . Note the plurality of scored cut-lines 320 and 322 shown in later figures; these provide cut-lines for removal of larger diameter concentric annular fittings when the small or medium size recessed light fixture is encountered. When using the electrical cover 310 with the large size, no cutting or removal is needed as the excess smaller concentric annular fittings simply fit inside the larger recessed light fixture.
[0016] Unlike the plurality of fasteners holding the electrical box cover in place, the electrical cover utilizes a pressure-fit inside the opening of the recessed light fixture. In order to adjust for slight differences in manufacturing tolerances, the concentric annular fittings incorporate a plurality of alignment features (see later FIGS.) that allow the fittings to match the various diameters of recessed light fixtures.
[0017] Note that as the electrical cover 310 is pressed into the recessed light fixture, the outer rim of the electrical cover is pressed approximately flat against the mounting surface so that no gaps are available through which finish materials can enter the recessed light fixture. The electrical covers protect not only the recessed light fixture itself, but associated wiring, wiring connections, and the walling materials (e.g., drywall) that surround the perimeter of the recessed light fixture. The electrical covers shield the electrical components from paint and/or other surface finishing materials such as plastering or spackling that is sprayed and/or rolled onto a wall surface or surface finishing treatments such as grouting tiles. The electrical covers may be reused, and may be washable or disposable. The electrical covers can be fabricated from a low-cost thermally formed polymer plastic. The covers can utilize negatively drafted contact surfaces to improve the overlapping friction holding force while minimizing material stress.
[0018] An arched surface formed into the center of the recessed light fixture grip handle 330 improves the strength of the recessed light fixture grip handle 330 while improving the flexibility thereof as well. Rounded surfaces are designed into the covers to minimize the risk of cracking, make the electrical covers easier to form during fabrication, and improve the electrical covers' life-cycle for reusability.
[0019] FIG. 2 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover 310 being emplaced within a recessed light fixture. Note that this view helps to show the electrical cover in relation to the electrical components it is protecting.
[0020] FIG. 3 illustrates a bottom perspective view of an exemplary embodiment of an electrical cover 310 . The cover comprises a series of concentric annular fittings 340 , 350 , and 360 which allow the electrical cover 310 to mate to various sized openings of the various sizes of recessed light fixtures 390 . Each of the fittings 340 , 350 and 360 have an outer rim 341 , 351 , and 361 (respectively), and a sidewall 342 , 352 , and 362 . Additionally, each fitting has a plurality of alignment features 343 , 353 , and 363 that align the sidewall with the interior of the recessed light fixture and provide for spacing/room to accommodate various size differences in the recessed light fixture openings due to manufacturing tolerances, etc. Additional slight angling of the sidewalls 342 , 352 , and 362 works in concert with the alignment features to ensure that the electrical cover 310 can fit almost any recessed light fixture.
[0021] Note that as the electrical cover 310 is pressed into the recessed light fixture, the outer rim of the electrical cover is pressed approximately flat against the mounting surface so that no gaps are available through which finish materials can enter the recessed light fixture. This is true regardless of whether the small, medium, or large concentric annular fittings 340 , 350 , and 360 are used. In the embodiment illustrated in FIG. 3 , three sizes of fittings are illustrated. In other embodiments, the number can be one, two, three, four, or more.
[0022] On the rear wall 380 of the electrical cover 310 is a grip handle 330 . It can incorporate an arched surface 375 that strengthens resistance against grasping and deforming the interior walls of the grip handle 330 while providing flexibility as well. It is preferable that the grip handle 330 extends outwards/forwards from the rear wall, but in alternate embodiments, the grip handle 330 can be inset/rear extending.
[0023] A plurality of support ridges 390 can strengthen and keep the electrical cover rigid.
[0024] FIG. 4 illustrates a bottom plan view of an exemplary embodiment of an electrical cover 310 . In addition to all the subcomponents discussed above, FIG. 4 highlights the plurality of scored cut-lines 322 and 320 extending around beyond the perimeters of the small concentric annular fitting rim 361 and the medium concentric annular fitting rim 351 . The cut-lines 320 and 322 provide a simple guide for the user to cut away excess materials when using the electrical covers 310 on small and medium recessed light fixtures. In other embodiments, the scored cut-lines 320 and 322 can be deep enough that a user can simply snap off the excess rather than requiring cutting.
[0025] The electrical cover 310 is designed with pressure points that allow the user to grasp and easily engage/disengage the electrical cover from a recessed light fixture. In FIG. 4 , these pressure points comprise the plurality of finger holds within the grip handle 330 . By squeezing at these points, the user can easily grasp and hold the electrical cover without covering his or her fingers with paint or other finish material that may have been inadvertently applied to the rims of the cover. Squeezing the grip handle 330 pulls the can cover 310 towards the center and relieves some of the pressure fit tension between the cover and the can in which the cover is mated. As noted above, the cover may utilize surfaces that are negatively drafted relative to other drafted features on the surfaces that contact the electrical device to increase the overlap and help minimize stress in the cover.
[0026] FIG. 5 illustrates a side elevation view of an exemplary embodiment of an electrical cover 310 . Note the slight angle to each of the sidewalls 340 , 350 , and 360 that help the cover fit into the various sized recessed light fixtures. The relatively small size of the rims 341 , 351 , and 361 is also apparent in FIG. 5 . The perimeter of the electrical cover rim is approximately flattened against the installation surface (wall, recessed light fixture assembly, box, etc.) once installed, thereby minimizing gaps between the rim and the installation surfaces.
[0027] While particular embodiments have been described and disclosed in the present application, it is clear that any number of permutations, modifications, or embodiments may be made without departing from the spirit and the scope of this disclosure. Particular terminology used when describing certain features or aspects of the embodiments should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects with which that terminology is associated. In general, the application should not be construed to be limited to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the inventions encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the claimed subject matter.
[0028] The above detailed description of the embodiments is not intended to be exhaustive or to limit the disclosure to the precise embodiment or form disclosed herein or to the particular fields of usage mentioned above. While specific embodiments and examples are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. Also, the teachings of the embodiments provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
[0029] Any patents, applications and other references that may be listed in accompanying or subsequent filing papers, are incorporated herein by reference. Aspects of embodiments can be modified, if necessary, to employ the systems, functions, and concepts of the various references to provide yet further embodiments.
[0030] In light of the above “Detailed Description,” the Inventors may make changes to the disclosure. While the detailed description outlines possible embodiments and discloses the best mode contemplated, no matter how detailed the above appears in text, embodiments may be practiced in a myriad of ways. Thus, implementation details may vary considerably while still being encompassed by the spirit of the embodiments as disclosed by the inventor. As discussed herein, specific terminology used when describing certain features or aspects should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the embodiments with which that terminology is associated.
[0031] The above specification, examples and data provide a description of the structure and use of exemplary implementations of the described systems, articles of manufacture and methods. It is important to note that many implementations can be made without departing from the spirit and scope of the disclosure. | The electrical cover comprises a friction-held electrical cover for a recessed light fixture. Embodiments of the electrical cover described herein provide flexible finish material covers that guard recessed “can” light fixtures from paint, spackling, and other foreign materials. The frictionally-held finish material covers utilize specifically shaped features on the surfaces, such as negative draft, that contact the electrical components to increase the hold on the electrical device. Some of the shaped features of the frictionally-held covers also help minimize stress in the cover. Features are also molded into the parts to assist and strengthen the cover once installed, and thus protect against the intrusion of finish material behind the cover. | 5 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to materials for acoustic absorption. More particularly it relates to thermoformable acoustic sheets.
[0002] Sounds absorption is required in a wide variety of industrial and domestic applications. In many of these applications it is desirable that the acoustic material conforms to the shape of a surface for example or otherwise retains a particular shape. In such applications it is desirable that the acoustic sheet can be heat moulded to the required shape to provide relative ease and speed of production. Sound absorption can be a function of depth of air space, air flow resistance, mass, stiffness and the acoustic impedance of any porous media behind the acoustic sheet. Therefore, adding a third dimension for example by moulding to a required shape increases stiffness and can add practical and aesthetic value. Importantly a three dimensionally shaped material provides its own air space. The shape therefore has a major influence on sound absorption and stiffness. One particular application for heat mouldable or thermoformable acoustic sheets is in the automotive industry, in particular, in under bonnet insulators for motor vehicles. Existing under bonnet insulators use moulded fibreglass insulators for sound absorption. In these products resinated fibreglass, or felt is sandwiched between two layers of non-woven tissue and subsequently heat molded to form a so called “biscuit” with sealed edges. The difficulties associated with this product include the fact that the moulding process is relatively slow taking up to 2½ minutes per moulded part. Additionally, the use of resinated fibreglass is undesirable because of its inherent undesirable handling problems while the resins can release toxic gases during the moulding process.
[0003] Other examples of applications for thermoformable sheets in the automotive industry include wheel arch linings, head linings and boot linings.
[0004] Attempts to produce a suitable thermoformable material from thermoplastic textile for underbonnet insulator have been unsuccessful due to one or more of the failure of the materials to meet requirements of low sag modulus typically encountered at operating temperatures, unsuitable moulding performance, and lack of uniformity of air flow resistance required for acoustic absorption performance.
[0005] It is an object of this invention to provide a thermoformable acoustic sheet and a method of producing such a sheet that will at least provide a useful alternative.
SUMMARY OF THE INVENTION
[0006] In one aspect this invention provides a thermoformable acoustic sheet formed by a compressed fibrous web including high melt and adhesive thermoplastic fibres. During forming the adhesive fibres are at least partially melted so that in the compressed web the adhesive fibres at least partially coat the high melt fibres and reduce the interstitial space in the fibre matrix.
[0007] In one form of the invention, the thermoplastic fibres are treated with an adhesive coating to increase the airflow resistance.
[0008] In another form of the invention, the thermoplastic fibres are treated with a coating formed by one or more further webs of thermoplastic fibres to increase the air flow resistance.
[0009] Preferably the further web contains a substantial amount of adhesive fibre.
[0010] In another aspect this invention provides a method of producing a thermoformable acoustic sheet including the steps of heating a fibre web including high melt and adhesive thermoplastic fibres to at least partially melt the adhesive fibres and compressing the web to form a sheet. In the compressed sheet the adhesive fibres at least partially coating the high melt fibre to reduce the interstitial space in the fibre matrix.
[0011] In one form of the method of the present invention, the sheet is treated with an adhesive coating to increase the air flow resistance.
[0012] In another form of the method of the present invention, the thermoplastic fibres are treated with a coating formed by one or more further webs of thermoplastic fibres to increase the air flow resistance.
[0013] The compression of the fibrous material under heat and pressure results in the at least partial melting of the adhesive fibre which acts as a heat activatable binder to at least partially coat and join to the high melting fibre thus reducing interstitial space in the fibre matrix and creating a labyrinthine structure that forms a tortuous path for air flow through the fibre matrix. The high melting fibre remains substantially intact, although some softening is acceptable and can act as a reinforcement in the acoustic sheet.
[0014] Preferably, the acoustic sheet has a total air flow resistance of between 275 and 1100 mks Rayl, more preferably 600-1100 mks Rayl and even more preferably 900-1000 mks Rayl. Such air flow resistance values of the acoustic sheet result in effective absorption of sound for applications such as hood or under bonnet insulation. In this regard the acoustic sheet produced in accordance with the present invention exhibit the acoustic behaviour of a porous limp sheet. Porous limp sheets display superior sound absorption at low frequencies.
[0015] Preferably, the thermoformable acoustic sheet has a low sag modulus at temperatures up to about 150° C.
[0016] The fibrous material can be a combination of fibres of various denier. The high melt fibres are 12 denier or below, 6 denier or below and/or 4 denier or below. The adhesive fibres are 8 denier or below, 6 denier or below, 4 denier or below and/or at about 2 denier.
[0017] The fibrous material can be selected from, but not limited to, polyester, polyethylene terephthalate (PET), polyethylene butylphthalate (PBT), polyethylene 1,4-cyclohexanedimethanol (PCT), polylactic acid (PLA) and/or polypropylene (PP). Fibre with special characteristics such as high strength or very high melting point can also be used. Examples include Kevlar™, Nomex™ and Basofil™. Alternatively, the high melting point fibres may be substituted by natural fibre such as wool, hemp, kanet etc.
[0018] The web of fibrous material used to produce the acoustic sheet of this invention can be produced from a non-woven vertically aligned high loft thermally bonded material formed by the STRUTO™ process under Patent WO 99/61693. Suitable low and high melt materials can be used to provide the respective fibres.
[0019] The web of fibrous material used to produce the acoustic sheet of this invention can also be produced by cross-lapping and thermal bonding. The web can also be produced by carding fibres and consolidation by needle punching. According to another option the web can be produced by other non-woven textile manufacturing methods such as melt blown, spun bond etc.
[0020] Adhesive fibres are also known as low melt, bonding or binding fibres. Various materials can be used for the high melt and adhesive fibres so long as the adhesive fibre can be partially melted without substantially melting the high melt fibre. Some softening of the high melt fibre is acceptable. The high melt fibre preferably has a melting point above about 220° C. The adhesive fibre preferably has a melting point between 100 and 160° C., more preferably 120-150° C. and even more preferably 135-145° C. It will be appreciated that thermoplastic fibres are available in mono and bi component form. A bicomponent fibre can be formed of discrete low and high melting point portions. Heating such a bicomponent fibre (“adhesive bicomponent fibre”) results in at least partial melting of the low melting point portion leaving the higher melting point portion intact. Therefore in the method of the present invention, heating a fibre web results in at least partial melting of the adhesive fibres and/or the low melting point portion of any adhesive bicomponent fibres present in the web to at least partially coat and join to the high melting fibre. The higher melting point fibres and high melting point portions of any adhesive bicomponent fibre remain intact after the compaction process.
[0021] The web of fibrous material used to produce the acoustic sheet preferably has a web weight 1000 g/m 2 or below, more preferably 800 g/m 2 or below, even more preferably 600 g/m 2 or below and even further preferably 400 g/m 2 or below. The web is typically compressed by between 15 and 25 times.
[0022] The compression step of the method of the present invention can be undertaken in any suitable known manner, for example in any flat bed laminator or calender.
[0023] In one embodiment, the fibrous material is produced as a single layer with a high proportion, preferably greater than 50% of adhesive and/or adhesive bicomponent fibre. This may be compacted in a Meyer™ flat bed laminator at 180-220° C., preferably at 190-200° C., for a period of 1-3 minutes, preferably 1.5-2 minutes. The processing conditions can be varied to alter the thickness and/or other characteristics and the subsequent air flow resistance of the acoustic sheet.
[0024] In one form of the invention, the thermoplastic fibres are treated with an adhesive coating. The coating treatment can be effected in any suitable known manner, for example by the application of an adhesive film or an adhesive powder and subsequent heating. The amount of adhesive treatment can be adjusted to control the total air flow resistance of the thermoformable acoustic sheet. The adhesive can be a cross-linking adhesive powder. The application rate of powder is dependent on particle size, melting point, melt flow properties and polymer type. These types of adhesive have an initial curing temperature that can be exceeded after curing and cooling without remelting of the adhesive. Suitable adhesives include the product SURLYN™ manufactured by DuPont. Typical polymers for the adhesive film and/or powder are co-polyester, polyethylene and/or polypropylene.
[0025] In one form of the invention, where the adhesive coating is an adhesive powder, a layer of non-woven fabric or other material may be laminated to the compressed thermoplastic sheet using the adhesive powder.
[0026] Preferably the compression and coating treatment steps are performed in a single process. That is, heating required prior to the compression and for adhesive melting (to form the coating) can be a single step before compression.
[0027] In another form of the invention, the compression of the thermoplastic fibre and the lamination to the non-woven fabric are achieved in a single process. Preferably a compression and adhesive melting temperature of about 200° C. is used.
[0028] In another form of the invention, the coating by use of a web of thermoplastic fibres may be effected by the application of multiple webs of fibrous material which are introduced in parallel into the compaction process, and compacted concurrently. Alternatively, the web(s) can be introduced in one or more further compacting steps after the first web of fibrous material including adhesive and high melt thermoplastic fibres has been compacted. The further web(s) of fibrous material can include adhesive fibre, adhesive bicomponent fibre and/or high melt fibre. The amount and type of additional fibrous material can be adjusted to control the total air flow resistance of the thermoformable acoustic sheet.
[0029] In one form of the invention the thermoformable acoustic sheet can be formed from a first web preferably comprising 10-40%, further preferably 20% high melting point fibre and a second web of fibrous material, preferably comprising 60-100% further preferably more than 70%, even further preferably 100% adhesive or adhesive melt bicomponent fibre. The two webs can be compacted concurrently and adhere to each other without the need for an adhesive layer.
[0030] In another form of the invention the thermoformable acoustic sheet may be formed from two webs in which one of the webs may have a relatively low proportion of adhesive or adhesive bicomponent fibre, such as 10-60% preferably 20-25%. The webs can be compacted as described above. However, in this embodiment, a thermoplastic adhesive layer may be required to be introduced between the two webs, in the form of a powder. The addition rate of the powder is preferably within the range 10 and 80 g/m 2 , more preferably 40-60 g/m 2 . If a film is used rather than a powder it must be thin enough to become permeable during the compaction process, preferably from 15-25 microns thick. The adhesive may be required if the compressed webs exhibit recovery after compaction, or if they do not compact sufficiently for adequate sound absorption.
[0031] The mouldable acoustic sheet according to this invention has been found to be particularly suitable for use in automotive applications and in particular as an under bonnet acoustic liner. The thermoformable acoustic sheet can be readily formed using a moulding temperature of between 150° and 180° C. and may require use of flame retardant fibres or an additional flame retardant treatment. Suitable additives as flame retardants are deca-bromodiphenyloxide as supplied by Great Lake Chemicals. High melt fibres having improved inherent flame retardant characteristics may be used, for example a grafted polyester such as Trevira™ CS. The moulded sheet substantially retains the air flow resistance of the unmoulded sheet and thus its acoustic properties. Moreover, the sheet has a low sag modulus at temperatures up to about 150° C. and is suitable for use as an under bonnet insulator or liner.
[0032] For hood insulator applications, the appearance must be consistent and low gloss. Appearance can be influenced by the fibre properties and binder fibres tend to develop gloss during compaction and subsequent molding. To minimise gloss, the option of using an additional layer of fibrous material as the coating with each layer having significantly different fibre blend ratios is preferred. A face web should have a relatively low proportion of binder fibre, preferably 10-20% and a back web should have a very high binder ration, from 60-100%, preferably 80%. The back web will significantly contribute to flow resistance to assure excellent sound absorption, whilst the facing web assists in resisting marring during the process.
[0033] The thermoformable material of this invention is also suitable for use in wheel arch linings, head linings and boot linings. In most applications the selected air flow resistance of the moulded sheet can be used in combination with an acoustic cavity or space behind the sheet to achieve desired acoustic absorption.
[0034] In another form of the invention the uniform air flow resistance can be at least partially achieved by laminating a textile layer with selected air flow resistance to the compressed sheet. The layer can for example be a slit or perforated thermoplastic film or textile layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The invention will now be described by way of example only with reference to the accompanying drawings and examples, in which:
[0036] FIG. 1 is a schematic diagram of a flat bed laminating machine;
[0037] FIG. 2 is a plot of normal incidence sound absorption coefficient against frequency for tested samples of this invention;
[0038] FIG. 3 is a plot of flow resistance versus fibre formulation for samples having a high melt/adhesive fibre ratio of 1:1 and web weight of 600 g/m 2 ;
[0039] FIG. 4 is a plot of flow resistance versus powder additive weight for samples having a high melt (6 denier)/adhesive (4 denier) fibre ratio of 1:1, and a web weight of 600 g/m 2 ;
[0040] FIG. 5 is a plot of sound absorption versus flow resistance for a range of samples with a web weight of 600 g/m 2 at a frequency of 1000 Hz and a 50 mm air gap; and
[0041] FIG. 6 is a plot of sound absorption versus product weight for a range of samples with an air flow resistance of 600 mks Rayls at a frequency of 500 Hz and an air gap 50 mm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The present invention can be implemented using a known laminating machine such as a Meyer laminating machine schematically illustrated in FIG. 1 . As shown in the drawing the laminating machine 1 includes a web supply roll 2 .
[0043] The web 3 is fed to a heat contact system 9 which is readily known to those in the art as including heaters 10 positioned on either side of two opposed parallel belts 11 and 12 . The belts 11 , 12 are thus heated and in turn heat the web 3 to about 200°. A pair of adjustable pressure rollers 13 , 14 bear against the respective belts 11 , 12 to compress the web 3 . A subsequent cooling system 15 is provided to cool the compressed product.
[0044] In the case of a product made using a thermoplastic adhesive powder, the web 3 is fed from the supply roller through a scatter head 4 which applies the thermoplastic adhesive powder to the surface of the web 3 . A winding system 5 for thermoplastic adhesive film 6 is also provided in the machine 1 . It will be apparent to those skilled in the art one or other of the scatter head system 4 or unwinding system 5 for thermoplastic adhesive film 6 is to place adhesive in contact with web 3 . As described above, the web 3 then continues through heat contact system 9 where the thermoplastic adhesive powder is melted under the action of heated belts 11 , 12 as the web 3 is simultaneously compressed under the action of pressure rollers 13 , 14 . Cooling system 15 cools the final product as described above.
[0045] Where a further fabric layer or web is to be provided, a supply of fabric or web 7 is stored on a roll 8 prior to entry into the heat contact system 9 so that the fabric web 7 is fed to the heat contact system 9 simultaneously with web 3 . Where a thermoplastic adhesive has been deposited on web 3 by scatter head system 4 or unwinding system 5 , the heated belts 11 , 12 heat the fabric 7 and web 3 to melt the adhesive. Pressure rollers 13 , 14 bear against the respective belts 11 , 12 to force fabric 7 into contact with web 3 and the melted adhesive. Again, as described above, the web 3 is compressed and the cooling system 15 cools the compressed and laminated product.
[0000] Test Results
Example 1
[0046] A sample was prepared using the above described machine and tested using an impedance tube with a 50 mm air gap to ASTME E 1050-90. The properties of the sample were:
carrier formulation 30% polypropylene (adhesive fibre) and 70% polyester (high melt); web material was a needle punched mixture in roll form; carrier web weight 450 g/m 2 ; and polyester non-woven fabric facing web weight 50 g/m 2 adhered with a small (15-20 g) of polypropylene powder.
[0051] The average air flow resistance of the sample was 300-400 mks Rayls.
[0052] FIG. 2 is a plot of average incident sound absorption versus frequency for six randomly selected samples prepared according to this example.
Example 2
[0053] A sample was prepared and tested in the same manner as in Example 1 with the following specifications;
50% high melt fibre of 6 denier; 50% adhesive fibre of 4 denier; and web weight 700 g/m 2 .
[0057] The air flow resistance of the sample was in the range of 300-400 mks Rayls.
Example 3
[0058] A sample was prepared and tested in the same manner as in Example 1 with the following specifications:
30% high melt polyester fibre of 6 denier; 70% adhesive polyester fibre of 4 denier; web weight 600 g/m 2 .
[0062] The air flow resistance of the sample was in the range of 700-850 mks Rayls.
Example 4
[0063] A sample was prepared and tested in the same manner as in Example 1 with the following specifications:
50% high melt polyester fibre of 6 denier; 50% adhesive bicomponent polyester fibre of 4 denier; and web weight 600 g/m 2 .
[0067] As shown in FIG. 3 , the air flow resistance of the sample was in the range of 275-375 mks Rayls.
Example 5
[0068] A sample was prepared and tested in the same manner as in Example 1 with the following specifications:
50% staple high melt polyester fibre of 6 denier; 50% adhesive bicomponent polyester fibre of 2 denier; and web weight 600 g/m 2 .
[0072] As shown in FIG. 3 , the air flow resistance of the sample was in the range of 450-600 mks Rayls.
Example 6
[0073] A sample was prepared and tested in the same manner as in Example 1 with the following specifications:
50% high melt polyester fibre of 3 denier; 50% adhesive polyester fibre of 2 denier; and web weight 600 g/m 2 .
[0077] As shown in FIG. 3 , the air flow resistance of the sample was in the range of 550-750 mks Rayls.
Example 7
[0078] A sample was prepared and tested in the same manner as in Example 1 with the following specifications:
30% high melt polyester fibre of 4 denier; 70% adhesive bicomponent polyester fibre of 2 denier; web weight 250 g/m 2 ; spun bonded non-woven fabric polyester with a web weight of 100 g/m 2 , polyethylene thermoplastic powder at an application rate of 20 g/m 2 ; and dibromophenyloxide flame retardant additive at an application of 25 g/m 2 .
[0085] The air flow resistance of the sample was in the range of 700-900 mks Rayls.
Example 8
[0086] A sample was prepared and tested in the same manner as in Example 1 using two webs of fibrous material with the following specifications:
180 g/m 2 30% bicomponent polyester fibre of 2 denier and 70% high melt black 4 denier polyester fibre; and 300 g/m 2 100% 2 denier bicomponent fibre.
[0089] The two webs of the above specification were introduced to a Meyer laminator at the following settings.
pressure 15 KPa; distance between top and bottom belt 1 mm; first bank of heaters temperature 175° C.; and second bank of heaters temperature 190° C.
[0094] This resulted in a flow resistance of 900-1100 mks Rayls.
Example 9
[0095] A sample was prepared and tested in the same manner as in Example 8:
[0000] Web 1
[0000]
85% high melt polyester fibre with 4 denier;
15% adhesive bicomponent polyester fibre of 2 denier; and
web weight 180 g/m 2 .
Web 2
30% staple high melt polyester fibre of 4 denier;
70% adhesive bicomponent polyester fibre of 2 denier; and
web weight 250 g/m 2 .
[0102] The air flow resistance of the sample was in the range of 700-900 mks Rayls.
Example 10
[0103] Samples were prepared and tested in the same manner as in Example 1 with the following specifications:
50% high melt polyester fibre of 6 denier, 50% adhesive polyester fibre of 4 denier; web weight 600 g/m 2 ; and varying application rates of LDPE adhesive powder.
[0108] Eight samples were made, each with the application rate of the adhesive powder varying from 10 g/m 2 to 80 g/m 2 in 10 g/m 2 intervals. A plot of the resulting air flow resistance of each sample is shown in FIG. 4 .
[0109] Test results for a range of acoustic sheets made in accordance with the invention are illustrated in FIGS. 5 and 6 . In FIG. 5 , a range of samples with a web weight 600 g/m 2 were tested at a frequency of 1000 Hz with a 50 mm air gap between the sample and a solid surface for their sound absorption coefficient against the air flow resistance. FIG. 6 illustrates the sound absorption coefficient against product weight (g/m 2 ) for a range of samples having an air flow resistance of 600 mks Rayls. The sound absorption coefficients were measured at a frequency of 500 Hz with a 50 mm air gap between the samples and a solid surface.
[0110] The air flow resistance is dependent on the ratio of binder matrix to high melt fibre. If a low air flow resistance is required, then a smaller amount of binder is required. For a high air flow resistance, the binder ratio is significantly higher.
[0111] Air flow resistance can vary with fibre size and geometry. Larger diameter fibres result in lower air flow resistance through a higher porosity.
[0112] The foregoing describes a limited number of embodiments of the invention and modifications can be made without departing from the scope of the invention. | A thermoformable acoustic sheet formed by a compressed fibrous web includes high melt fibres and adhesive thermoplastic fibres in which the adhesive fibres are at least partially melted so that in the compressed web the adhesive fibres at least partially coat the high melt fibres and reduce the interstitial space in the fibre matrix. Also included are methods of producing a thermoformable acoustic sheet which includes heating a fibre web including high melt and adhesive thermoplastic fibres to at least partially melt the adhesive fibres and compressing the web to form a sheet so that the adhesive fibres at least partially coat the high melt fibres to reduce the interstitial space in the fibre matrix. | 3 |
BACKGROUND AND OBJECTS OF THE INVENTION
This invention relates generally to a breathing device which is particularly suited to preheat incoming breath air through the mouth when the weather is cold. The device is also particularly suited to limit the volume of air entering the user's lungs through the oral cavity. As such, the device has utility for those working outside in cold weather as well as runners, joggers, and the like including serious athletes dependent on the manner in which the device is used.
It is well known that the inhalation of cold and particularly cold, dry air can be both uncomfortable and a source of irritation to the upper respiratory track. This is particularly true when exercising such as running, jogging and the like in temperatures which are particularly cold, i.e., at 0° F. or below. The effect of breathing such cold air at -20° F. can result in lung function impairment, overexertion of the heart and other detrimental effects such as those referred to by Dr. O. Schaefer in his article entitled "Respiratory Function Impairment and Cario-pulminary Consequences in Long-time Residents of the Canadian Arctic" CMA Journal, Nov. 22, 1980 Volume, page 123,997. A copy of such article is attached to this specification and is incorporated herein by a specific reference as an indication of the type of physical consequences from breathing cold air which can be avoided by the use of the present invention.
The present invention utilizes the concept of preheating the user's incoming breath by the residual heat and humidity supplied by the previous exhaled breath imparted to an open mesh element positioned in the device. Although such general concept has been known for some time, prior devices utilizing such concept have either been too cumbersome or complicated for simple use. Thus, the need remains for a device of an uncomplicated, simple, low cost nature which can be used by both amateur and serious athletes as an assist in their running or jogging efforts. Examples of previously known devices include those described in U.S. Pat. No. 3,326,214 issued June 20, 1967; U.S. Pat. No. 4,196,723 issued Apr. 8, 1980; and U.S. Pat. No. 4,201,206 issued May 6, 1980.
In addition to preheating the incoming breath, it is desirable that a device of this general nature may be able to additionally or separately limit the volume of air entering the user's oral cavity. By so limiting air volume, work level or heart rate which a user such as a middle-aged jogger is functioning may be regulated. Also as in the case of gold medal athletes, an anerobic overload state of exhaustion necessary in some types of training activity may be created. The device of the present invention accomplishes these desirable features by the provision of an air trap breathing device adapted to be held in the user's mouth with a portion thereof protruding therefrom and including an elongated hollow body open at both ends thereof in which an open mesh element is disposed in the hollow interior such that air entering the device through the breathing process is preheated and/or limited in volume thereby.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawing.
DESCRIPTION OF THE DRAWING
In the drawing which illustrates the best mode presently contemplated for carrying out the present invention:
FIG. 1 is a perspective view of a user utilizing the device of the present invention, that is, gripping the base portion thereof in his or her teeth while permitting the remainder thereof to project through the lips;
FIG. 2 is a top plan view of the device;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is an end view thereof taken from the left-hand side of FIG. 2; and
FIG. 5 is a sectional view similar to FIG. 3 but showing a modified form of the invention.
DESCRIPTION OF THE INVENTION
Turning now to the drawing, it may be apparent particularly from FIG. 1 thereof that the device 10 of the present invention may be conveniently held in the user's mouth. Such is in part facilitated by constructing the inner end 14 of the body 12 of the device of a heavier walled construction and in part by the flattened shape of such inner end. The body is normally constructed of a plastic material formed by conventional techniques such as blow molding. Suitable plastic materials include polyetylene and polypropylene which along with other polymeric materials provide a generally moderate insulative characteristic desirable in producing a satisfactory comfort level for devices of this type which are held in one's mouth.
The body of the device 10 is provided with a hollow continuous passageway 16 which opens at the inner end 14 in an open slot 18 and at the outer end 20 in a downwardly directed opening 22. The outer end 20 may be of less substantial construction, that is, a thinner walled construction and generally of lesser width and terminating in a downturned terminal portion such that the opening 22 when in the "use" position depicted is downwardly directed. An open mesh element generally formed from expanded aluminum and relatively closely packed together but permitting air to freely pass therethrough is positioned in the passage 16 generally within inner end 14. Such positioning serves the function that it enables the element 24 to maintain constant mouth cavity temperature, thus preventing water particles on the element from freezing in cold weather.
Thus it may be apparent that the device 10 of the present invention not only may heat the incoming air to the user's oral cavity by means of the heat residing in the element 24 by the previous exhaled breath but also that such element and the walls of the device 10 itself may be heated by conduction by its position in the mouth cavity. In other words, the user may run with the major portion of the device projecting from his or her lips or alternatively if a greater heating effect is desired, position the device such that only a small portion including the opening 22 projects from the user's lips.
In any event, the shape of the inner end 14 is such that the device can be comfortably held in the mouth, i.e., gripped by the teeth and positioned such that the outer end 10 projects therefrom. It is also desirable that the outer end project downwardly outwardly, that is, be of a curved nature such that moisture from the runner's mouth and nose may move along the outside of this portion of the device and drip off the end thereof. Also, it is advantageous that the opening 22 be cut or otherwise formed on a slant or bias such that a larger area opening is provided such that air may be brought in through the device and restricted only by the design, length, and openness of the element 24. When it is necessary to clear the element of excess moisture, the crook or curve in the outer end 20 thereof may naturally prevent the element 24 from being forced out the opening 22 when the user blows through the passageway 16 via the opening 18. The element may also be retained by stops (not shown) projecting into the passageway. It is also desirable that the inner end of the body be of a heavier weight construction so that it can be easily gripped in one's teeth and won't flatten so as to reduce the cross-sectional area of the passageway in that portion. Also, the inner end is preferably imperforate such that the user's saliva will not pass into the passageway except possibly through slot 18. When it is desired to clear the mouth saliva when utilizing the device, one's tongue can be forced into the slot 18 prior to the swallowing action and in this way a residual amount of saliva from the mouth cavity does not accummulate on the element thus undesirably restricting air flow through the element.
Specific provision for the prevention of swallowing the device may be provided. Turning now to FIG. 3, one such means is illustrated in the form of a safety line 32 threaded through an opening or bore 30 provided through the outer end 20 of the device. The line 32 is looped and adjustable in length so as to be worn around the user's neck. Another provision for the prevention of swallowing the device is shown in FIG. 5 in the form of a pin or rod 28 extending through the body.
Cleaning of the device so as to prevent odors, contamination, and the like may be provided by rinsing the device in cold running water before and after use. Also when not in use, the device may be stored in a container under a water solution of hypochlorite (approximately 1 part per 100 water). Also since water ph levels vary geographically, normal oxidation of the element may take place quicker in some regions than others. Therefore if the element loses its gloss or shine, it may be desirable to replace it. It may also be desirable to utilize disposable or at least easily replaceable elements and/or provide elements which vary the air intake limit through the device or which absorb less or greater amounts of heat depending on climatic and use conditions.
It may be thus seen that the device 10 of the present invention has maximum utility for a wide variety of uses. Thus the device has the potential to significantly preheat cold air masses inhaled through the mouth by athletes during cold weather training sessions so as to avoid upper respiratory irritation as previously described. In addition, the device has the potential to control the volume of air inhaled by weekend or middle-aged joggers so as to ensure that a runner keeps his or her heartbeat per minute during a workout at a level just below the recommended heartbeat rate. This allows a new or problem runner to read his or her body more carefully and minimize the chance of over-stressing his or her heart. The device also has use with professional or gold medal type athletes in that it allows such competitors to create anerobic overload states of exhaustion that surpass normal fatigue levels at sea level training conditions such that this overload conditioning process predisposes the body to adapt at higher stages of development both physiologically and psychologically. This overload concept of conditioning may be continued in warmer weather by elite athletes by simply removing the element from the passageway thus restricting the air flow by the passageway itself.
While there is thus shown and described herein certain specific structure embodying this invention, it will be clear to those skilled in the art that various modifications and rearrangements may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except to the extent indicated by the scope of the appended claims. | A device for use by runners, joggers and the like for preheating and/or limiting the volume of air entering the user's lungs through the mouth. The device is constructed such that it is retained at least partially in the user's oral cavity and preferably may be substantially completely held therein. The device includes a body of elongated construction formed of suitable materials such as plastic and the like and having a hollow interior open at both ends thereof. The hollow interior houses an open mesh element. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation application of non-provisional patent application Ser. No. 14/185,057, titled “TENT HAVING RETRACTABLE ROOF”, filed on Feb. 20, 2014 in the United States Patent and Trademark Office, which claims the priority of Chinese Patent Application No. 2013305988911, filed on Dec. 4, 2013 before the Chinese State Intellectual Property Office.
The specifications of the above referenced applications are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The present invention relates to a tent, and more particularly, a tent having a retractable roof.
BACKGROUND
Tents have been widely used in nowadays, and as outdoor tents, tents having a retractable roof have been developed increasingly. But a conventional tent having a retractable roof has long non-foldable poles, which makes the package of the tent is big in size and thus is inconvenient to be transported.
SUMMARY
Accordingly, an objective of the present invention is to at least partially overcome the shortcomings of the prior art and to provide a tent having a retractable roof that can be easily folded so as to decrease the size of the package, thereby facilitating transportation of the tent.
To achieve at least some of the objectives, the present invention provides a tent having a retractable roof, comprising a plurality of poles extending substantially perpendicular to the ground, a roof frame fastened to the plurality of poles and a tarpaulin attached on the roof frame. At least one of the plurality of poles comprises an upper pole and a lower pole, and the tent further comprises a connection mechanism detachably connecting the upper pole and the lower pole.
Preferably, the connection mechanism comprises a connection plate, a plurality of bolts and a plurality of second through holes disposed on a lower end of the upper pole, a lower end of the connection plate is received in and fastened to an upper end of the lower pole, an upper end of the connection plate is received in the lower end of the upper pole, the connection plate has a plurality of first through holes, the plurality of bolts are inserted into the second through holes and the corresponding first through holes respectively so that the connection plate and the upper pole are fixedly connected.
Preferably, the upper pole and the lower pole are formed in a shape of a hollow rectangular tube, and the connection plate is formed in a shape of a beam channel. The connection plate has a wall with a thickness being greater than a thickness of walls of the upper pole and a thickness of walls of the lower pole.
Preferably, a sleeve is further disposed on the lower end of the upper pole, and the sleeve is formed in a shape of a tube adapted to slide along the upper pole. An inner diameter of an upper part of the sleeve is substantially the same as an outer diameter of the upper pole, and an inner diameter of a lower end of the sleeve is greater than an outer diameter of the upper pole.
Preferably, a collar is further fixedly disposed on the upper end of the lower pole, the sleeve comprises a concave portion recessed inward at a lower end of an inner wall of the sleeve, the collar comprises a convex portion adapted to engage with the concave portion of the sleeve on an outer wall of the collar.
Preferably, the collar further comprises a retainer ring on an inner wall of the collar, the retainer ring is protruded toward the center axis of the collar, a bottom surface of the retainer ring abuts a top surface of the lower pole, and a top surface of the retainer ring contacts and supports a bottom surface of the upper pole. Both of the sleeve and the collar are made of rubber or plastic material.
Preferably, the lower end of the connection plate is fastened to the upper end of the lower pole through welding. The connection plate is made of metal.
Alternatively, the connection mechanism comprises a plurality of first connection holes disposed on a lower end of the upper pole, a plurality of second connection holes disposed on an upper end of the lower pole and a plurality of bolts which are inserted into the first connection holes and the corresponding second connection holes respectively so that the upper pole and the lower pole are fixedly connected.
Preferably, the roof frame comprises a front supporting rod, a rear supporting rod and a plurality of guiding rods, the number of the plurality of poles is four and each of the plurality of poles comprises an upper pole and a lower pole. The front supporting rod and the rear supporting rod are disposed to be extended along a first direction which is substantially parallel to the ground, both ends of the front supporting rod and both ends of the rear supporting rod are fixed to upper ends of the upper poles respectively, the plurality of guiding rods are disposed to be extended along a second direction which is substantially parallel to the ground and perpendicular to the first direction.
Preferably, the number of the plurality of guiding rods is three, both ends of the outmost two guiding rods are fastened to the upper ends of the upper poles respectively, and both ends of the middle guiding rod is fastened to the front supporting rod and the rear supporting rod respectively. The middle guiding rod has the same interval to each of the outmost two guiding rods.
Preferably, the roof frame further comprises a plurality of reinforcement rods extended along the second direction. The number of the plurality of reinforcement rods is two, each of the two reinforcement rods is disposed between adjacent guiding rods, with a same interval to the adjacent guiding rods.
Preferably, the roof frame further comprises a plurality of sliding rods on which the tarpaulin is attached, wherein the plurality of sliding rods are disposed to be extended along the first direction. A plurality of sliding blocks may be further disposed on the plurality of sliding rods, and the guiding rods may have a plurality of sliding grooves extended in the second direction, the plurality of sliding blocks may be slidably received in the plurality of sliding grooves.
Preferably, a plurality of feet attached on lower ends of the plurality of poles is further provided.
According to the present invention, since at least one of the poles has two parts and a connection mechanism is provided between the two parts, the pole can be folded and thus the package is relatively small in size compared with the conventional tents having a retractable roof. Therefore, the tents according to the present invention are convenient to be transported.
In addition, a sleeve and a collar may be further provided, so that the connection mechanism may be hidden in the sleeve, which makes the poles have a beautiful appearance.
Further and other features of the invention will be apparent to those skilled in the art from the following detailed description of the embodiments thereof.
BRIEF DESCRIPTION OF DRAWINGS
Reference may now be made to the following detailed description taken together with the accompanying drawings in which:
FIG. 1 is a schematic perspective view illustrating a tent according to a first embodiment of the present invention;
FIG. 2 is a schematic partial cross-sectional view illustrating a pole of the tent according to the first embodiment of the present invention;
FIG. 3 is an enlarged view of Part A shown in FIG. 2 ;
FIG. 4 is an enlarged view of Part B shown in FIG. 2 ;
FIG. 5 is a schematic partial perspective view illustrating a pole and a connection plate of the tent according to the first embodiment of the present invention;
FIG. 6 is a schematic perspective view illustrating a collar and a sleeve of the tent according to the first embodiment of the present invention;
FIG. 7 is a schematic partial perspective view illustrating a guiding rod of the tent according to the first embodiment of the present invention; and
FIG. 8 is a schematic partial cross-sectional view illustrating a pole of the tent according to a second embodiment of the present invention.
DETAILED DESCRIPTION
Various embodiments of the present invention will be described hereinafter. The following description provides specific details for a thorough understanding and enabling description of these embodiments. Those skilled in the art will understand, however, that the present invention may be practiced without many of these details. Likewise, those skilled in the art will also understand that the present invention can include many other obvious features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below, so as to avoid unnecessarily obscuring the relevant description.
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. Among other things, the present invention may be embodied as systems, methods or devices. The following detailed description should not to be taken in a limiting sense.
Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrase “in one embodiment” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.
In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on”. Further reference may be made to an embodiment where a component is implemented and multiple like or identical components are implemented.
While the embodiments make reference to certain events this is not intended to be a limitation of the embodiments of the present invention and such is equally applicable to any event where goods or services are offered to a consumer. The detail structures will be described to provide a thorough understanding of the present invention. Apparently, the implementation of the present invention is not limited by the specific details well known by those skilled in the art. A preferred embodiment will be described as follows; however, there are many other embodiments.
The terminology used below is to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain embodiments of the present invention. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overly and specifically defined as such in this Detailed Description section.
FIG. 1 is a schematic perspective view illustrating a tent according to a first embodiment of the present invention. Referring to FIG. 1 , a tent according to the first embodiment of the present invention includes a plurality of poles 2 extending substantially perpendicular to the ground, a roof frame 3 fastened to the upper ends of the poles 2 and a tarpaulin 1 attached on the roof frame 3 . In this embodiment, the number of the poles 2 is four, but the prevent invention is not limited thereto. In addition, a plurality of feet 10 attached on lower ends of the poles 2 may be further provided to increase contact area with the ground.
At least one of the poles 2 includes an upper pole 21 and a lower pole 22 . Preferably, each of the poles 2 includes an upper pole 21 and a lower pole 22 . The lower pole 22 is supported on the ground, for example, via the foot 10 .
The roof frame 3 includes a front supporting rod 31 , a rear supporting rod 32 and a plurality of guiding rods 33 . In this embodiment, the number of the guiding rods 33 is three, but the present invention is not limited thereto. The front supporting rod 31 and the rear supporting rod 32 are disposed to be extended along a first direction which is substantially parallel to the ground, i.e., perpendicular to the direction in which the poles 2 are extended. Both ends of the front supporting rod 31 and both ends of the rear supporting rod 32 are fixed to the upper ends of the four upper poles 21 , respectively. The guiding rods 33 are disposed to be extended along a second direction which is substantially parallel to the ground and perpendicular to the first direction. Both ends of the outmost two guiding rods 33 are fastened to the upper ends of the upper poles 21 respectively, and both ends of the middle guiding rod 33 is fastened to the front supporting rod 31 and the rear supporting rod 32 respectively. Preferably, the middle guiding rod 33 has the same interval to each of the outmost two guiding rods 33 .
The roof frame 3 may further include a plurality of reinforcement rods 34 extended along the second direction. The number of the reinforcement rods 34 may be two and each of the two reinforcement rods 34 may be disposed between adjacent guiding rods 33 , preferably with the same interval to the adjacent guiding rods 33 .
The roof frame 3 may further include a plurality of sliding rods 4 on which the tarpaulin 1 is attached. The plurality of sliding rods 4 are disposed to be extended along the first direction. The guiding rods 33 have a plurality of sliding grooves 33 a (referring to FIG. 7 ) extended in the second direction, the plurality of sliding blocks 9 are slidably received in the plurality of sliding grooves 33 a so that the sliding rods 4 is adapted to slide along the guiding rods 33 .
When lighting is needed, all of the sliding rods 4 can be slid to be together, thus the tarpaulin 1 is shrunk, so that the roof frame 3 is opened and light can go into the tent. If an edge of the tarpaulin 1 is dragged to expand the tarpaulin 1 , the sliding rods 4 can be slid along the guiding rods 33 and can be stopped at any position, so that the area shaded by the tarpaulin 1 can be adjusted. When the tarpaulin 1 is fully expanded, the inside space of the tent is fully shaded.
FIG. 2 is a schematic partial cross-sectional view illustrating a pole of the tent according to the first embodiment of the present invention. FIG. 5 is a schematic partial perspective view illustrating a pole and a connection plate of the tent according to the first embodiment of the present invention. FIG. 6 is a schematic perspective view illustrating a collar and a sleeve of the tent according to the first embodiment of the present invention. Referring to FIGS. 1, 2, 5 and 6 , the upper ends of the upper poles 21 are fastened to the roof frame 3 . For example, the upper ends of the upper holes 21 are fastened to the intersection points of the front supporting rods 31 and the guiding rods 33 and the intersection points of the rear supporting rods 32 and the guiding rods 33 respectively, but the present invention is not limited thereto.
Hereinafter, one upper pole 21 and one corresponding lower pole 22 are taken as example. In this embodiment, the upper pole 21 and the lower pole 22 are formed in a shape of a hollow rectangular tube. The tent according to the first embodiment further includes a connection mechanism comprising a connection plate 5 , a plurality of bolts 6 and a plurality of second through holes 21 a disposed on lower end of the upper pole 21 . The connection plate 5 formed in a shape of a beam channel is disposed between the upper pole 21 and the lower pole 22 . The connection plate 5 extended vertically is disposed inside the upper pole 21 and the lower pole 22 . In detail, a lower end of the connection plate 5 is received in and fastened to, for example, through welding, an upper end of the lower pole 22 . An upper end of the connection plate 5 is received in a lower end of the upper pole 21 . The connection plate 5 has a plurality of first through holes 51 with the same number as the second through holes 21 a . The plurality of bolts 6 are inserted into the second through holes 21 a and the corresponding first through holes 51 respectively, so that the connection plate 5 and the upper pole 21 are fixedly connected.
The connection plate 5 may be formed of metal and thus has a good strength, and may have a wall with a thickness being greater than a thickness of walls of the upper poles 21 and a thickness of walls of the lower poles 22 . Since the connection plate 5 is disposed between the upper pole 21 and the lower pole 22 , the robustness of the connection of the upper pole 21 and the lower pole 22 can be improved.
FIG. 3 is an enlarged view of Part A shown in FIG. 2 . FIG. 4 is an enlarged view of Part B shown in FIG. 2 . Referring to FIGS. 2, 3, 4 and 6 , a sleeve 7 for covering the bolts 6 is disposed on the lower end of the upper pole 21 . The sleeve 7 is formed in a shape of a tube adapted to slide along the upper pole 21 . An inner diameter of an upper part of the sleeve 7 is substantially the same as an outer diameter of the upper pole 21 so that the sleeve 7 is radially supported by the upper pole 21 , and an inner diameter of a lower end of the sleeve 7 is greater than an outer diameter of the upper pole 21 so that a gap is formed there between. The sleeve 7 includes a concave portion 71 recessed inward at a lower end of an inner wall of the sleeve 7 .
A collar 8 is fixedly disposed on the upper end of the lower pole 22 . The collar 8 includes a convex portion 81 which is adapted to engage with the concave portion 71 of the sleeve 7 on an outer wall of the collar 8 . In operation, the sleeve 7 can be slid in the first direction, and be stopped when the concave portion 71 of the sleeve 7 engages with the convex portion 81 of the collar 8 .
The collar 8 may further include a retainer ring 82 on an inner wall of the collar 8 . The retainer ring 82 is protruded toward the center axis of the collar 8 . A bottom surface of the retainer ring 82 abuts a top surface of the lower pole 22 , and a top surface of the retainer ring 82 contacts and supports a bottom surface of the upper pole 21 . Both of the sleeve 7 and the collar 8 may be made of rubber or plastic material.
In addition, since there is a gap between the lower end of the inner wall of the sleeve 7 and the outer wall of the upper pole 21 , the sliding of the sleeve 7 is not interfered by the heads of the bolts 6 . Such design enables the bolts 6 be hidden inside the sleeve 7 and makes the pole 2 have a beautiful appearance.
In order to assemble the upper pole 21 and the lower pole 22 , the sleeve 7 is firstly mounted on the upper pole 21 , then the collar 8 is mounted to the connection plate 5 so that the bottom surface of the retainer ring 82 abuts the top surface of the lower pole 22 and the positions of the second through holes 21 a of the upper pole 21 correspond to those of the first through holes 51 . Next, the bolts 6 are inserted into the second through holes 21 a and the first through holes 51 respectively to fixedly connect the connection plate 5 and the upper pole 21 . At this point, the connection of the upper pole 21 and the lower pole 22 is completed.
In an embodiment of the present invention, after the connection of the upper pole 21 and the lower pole 22 is completed, the sleeve 7 is further moved downward so that the concave portion 71 of the sleeve 7 engages with the convex portion 81 of the collar 8 . At this point, the sleeve 7 is fixed and the bolts 6 are hidden inside the sleeve 7 .
FIG. 8 is a schematic partial cross-sectional view illustrating a pole of the tent according to a second embodiment of the present invention. The second embodiment is similar to the first embodiment and only different parts will be described hereinafter.
Referring to FIG. 8 , unlike the connection plate 5 according to the first embodiment, the connection mechanism according to the second embodiment includes a plurality of first connection holes 11 , a plurality of second connection holes 12 and a plurality of bolts. In detail, the first connection holes 11 are disposed on a lower end of the upper pole 21 and the second connection holes 12 are disposed on an upper end of the lower pole 22 . And the positions of the first connection holes 11 correspond to those of the second connection holes 12 . The plurality of bolts are inserted into the first connection holes 11 and the corresponding second connection holes 12 respectively, so that the upper pole 21 and the lower pole 22 are fixedly connected.
The connection manner of the front supporting rod 31 , the rear supporting rod 32 , the guiding rods 33 and the reinforcement rods 34 may be similar as that of the poles 2 . That is, each of the front supporting rod 31 , the rear supporting rod 32 , the guiding rods 33 and the reinforcement rods 34 may include two parts which may be connected by a connection mechanism according to the first embodiment or the second embodiment. The repeated description thereof will be omitted herein.
Those skilled in the art can understand that even though there are a lot of terms, such as tarpaulin 1 , pole 2 , upper pole 21 , second through holes 21 a , lower pole 22 , a roof frame 3 , front supporting rod 31 , rear supporting rod 32 , guiding rod 33 , sliding grooves 33 a , reinforcement rods 34 , sliding rods 4 , connection plate 5 , first through holes 51 , bolt 6 , sleeve 7 , concave portion 71 , collar 8 , convex portion 81 , retainer ring 82 , sliding block 9 , feet 10 etc., other terms may also be used, and those terms are only used to describe and explain the nature of the invention, and should be used to limit the scope of the present invention.
It should be understood that the above description just displays preferred embodiments of the present invention and is in no way intended to limit the scope of the present invention. Any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be encompassed in the scope of the present invention. | The present invention provides a tent having a retractable roof. A plurality of poles extend substantially perpendicular to the ground. A roof frame is fastened to the plurality of poles and a tarpaulin is attached on the roof frame. At least one of the plurality of poles is divided into an upper pole and a lower pole, and a connection mechanism detachably connects the upper pole and the lower pole. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field Of The Invention
[0002] The present invention relates to fluid dispensing apparatus and, more particularly, to a robust, relatively simple, low-cost, and easily actuatable dispensing valve for dispensing fluid from a source of such fluid, which valve is configured so as to reduce the tendency for residual fluid to collect on and ultimately drip from the valve following a dispensing operation, and to minimize the risk of contamination of the valve and the fluid that is to be dispensed.
[0003] 2. Description Of The Background
[0004] Dispensing valves for dispensing fluid from fluid containers, systems, or other sources of such fluid are shown by U.S. Pat. Nos. 3,187,965; 3,263,875; 3,493,146; 3,620,425; 4,440,316; 4,687,123; 5,918,779; 6,491,189; and 6,742,680. Such valves can be used, for example, in a system for dispensing beverages or other liquids used by consumers in the home. Low cost, trouble-free, and reliable valve action are significant considerations in these applications. Low cost is particularly important if the valve is to be sold as a disposable item as, for example, where the valve is provided attached to a filled fluid container and discarded along with the container when the fluid has been consumed.
[0005] Unfortunately, many of the dispensing valve mechanisms available fail to provide a dispensing outlet that does not avoid the collection of liquid on its surfaces, thereby resulting in the unwanted release of liquid from the dispensing outlet after it has been shut off. For instance, during a dispensing operation, fluid from a storage container typically contacts the inside surfaces of a dispensing outlet on a dispensing valve. These inner surfaces can tend to collect liquid during use of the dispensing valve, such that after fluid is dispensed and the user has removed the cup, glass, or other receptacle for receiving the liquid and released the actuation mechanism of the dispensing valve, the collected liquid on the inner surface remains. Thus, not all of the liquid is caught in the receptacle; rather, some accumulates on such inner surfaces and may drip off such surfaces after the dispensing operation.
[0006] Still further, many of the currently employed dispensing valves promote the development of unsanitary conditions in and around the dispensing outlet. This may be due to the configuration of the dispensing outlet, which allows direct contact between the outlet and the user or the receptacle employed by the user. Through such direct contact with the dispensing outlet, various bacteria, pathogens, and the like may be transmitted to the surfaces of the dispensing outlet. Many such pathogens and the like may not be readily ascertainable through visual inspection and may survive cleaning of the dispensing outlet. This may lead to such unwanted organisms traveling further into the dispensing valve, and likewise into a container to which the dispensing valve is attached and contaminating the liquid within.
[0007] In U.S. Pat. No. 3,187,965 to Bourget, a dispensing valve for a milk container is shown having a generally integral valve body connected at one end to the milk container. The valve body has an L-shaped passage formed therein defining an inlet opening at one end in communication with the milk container and a discharge outlet at the opposite end for discharging the milk to the exterior of the container when the valve is opened using a push-button actuator. The discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet.
[0008] Another valve, shown in U.S. Pat. No. 3,263,875 to Lofdahl, has a similarly configured dispensing outlet and a push-button actuator, and once again lacks any provision to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet, and fully exposes the discharge outlet to the outside environment, thus promoting contact with potentially contaminated surfaces.
[0009] Likewise, commercial attempts have been made to provide low-cost dispensing valves for use with disposable containers, but such efforts have met with limited success. For example, Waddington & Duval Ltd. provide a press tap for use with disposable containers (such as wine boxes, water bottles, and liquid laundry detergent containers) under model designations COM 4452 and COM 4458, both of which provide a depressible button actuator operatively connected to a valve closure for moving the valve closure away from a valve seat to dispense fluid through a discharge outlet. As with the examples provided above, the discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet.
[0010] Similarly, the Jefferson Smurfit Group provides a similar tap for use with disposable containers under the model designation VITOP. Once again, the Jefferson Smurfit Group tap construction is configured such that the discharge outlet is fully exposed to the outside environment, thus promoting contact with potentially contaminated surfaces, and no provision is made to prevent residual undispensed fluid from collecting in and/or dripping from the discharge outlet.
[0011] Moreover, such valve constructions are configured such that undispensed fluid will remain in the valve behind the valve seat after use in a significant portion of the valve body and away from the container to which such valve is attached (and likewise away from any refrigerated environment in which such container is stored). This increases the risk of spoilage of such volume of fluid resting within the valve body after each use. Still further, such valve constructions lack the physical integrity to withstand vigorous sterilization procedures required of many fluid dispensing applications, including irradiation at exposures of up to as high as 5.0 MRAD and high temperature steam and chemical sterilization procedures.
[0012] Thus, although substantial effort has been devoted in the art towards development of low-cost valves of this general type, there remains an unmet need for a disposable valve having a discharge outlet that reduces the tendency for residual fluid to collect in and drip from the dispensing outlet while maintaining a simple construction for ease of manufacture, and that exhibits a configuration that tends to prevent, or at least minimize the risk of, contact between potentially contaminating external surfaces with the surfaces of the discharge outlet. Likewise, there remains an unmet need for a dripless valve that is easier to use than prior known valves and that does not require that the user exert large forces to hold the valve open. This problem is complicated by the fact that the tendency of a spring or other resilient member to maintain the valve in a closed position should provide the force necessary to assure leak-free seating of the valve seal when in such closed position Likewise, there remains an unmet need for a disposable valve that is sufficiently robust so as to be able to withstand vigorous sterilization procedures, that reduces heat transfer through the valve between the interior and exterior of the fluid container, and that does not trap a significant amount of fluid outside of the intended storage vessel between dispensing cycles.
SUMMARY OF THE INVENTION
[0013] It is, therefore, an object of the present invention to provide a fluid dispensing valve that avoids the disadvantages of the prior art.
[0014] Accordingly, the present invention provides a drip resistant dispensing valve including a discharge mechanism having decreased liquid retention properties. Further, the discharge mechanism of the drip resistant dispensing valve provides an outer shell that promotes the avoidance of direct contact between a user and/or receptacle and the dispensing outlet.
[0015] It is another object of the present invention to provide a fluid dispensing valve that is drip resistant and avoids the unwanted accumulation of liquids outside of the liquid container to which the valve is attached.
[0016] It is a further object of the present invention to provide a fluid dispensing valve that promotes the avoidance of contaminants contacting and/or inhabiting the dispensing outlet, other interior surfaces of the dispensing valve, and/or the liquid container.
[0017] Disclosed herein is a drip resistant dispensing valve for fluids that provides for ease of use by requiring only a minimal force exerted on the valve actuator to maintain the valve in an open position, and that offers a simple, ergonomic design and robust functionality capable of dispensing a wide variety of products.
[0018] With regard to a first aspect of a particularly preferred embodiment, a valve includes a discharge mechanism having properties that reduce or eliminate the propensity for residual fluid to remain on such discharge mechanism following a discharge or dispensing operation. The discharge mechanism provides an outer shell that promotes the avoidance of direct contact between a user, a receptacle, and/or other potentially contaminating surfaces and the dispensing outlet of the discharge mechanism.
[0019] With regard to another aspect of a particularly preferred embodiment, the valve body and actuator are formed of a polypropylene copolymer with an average wall thickness of approximately 0.06 inches, and the valve seal is formed of a thermoplastic rubber having an average thickness of about 0.03 inches. Such dimensional characteristics and materials allow the drip resistant dispensing valve to withstand the highest aseptic sterilization regimen as outlined by the Food & Drug Administration (FDA) and maintain the sterility of a product as specified by the National Sanitation Foundation (NSF) guidelines. More specifically, the dispensing apparatus is able to withstand either gamma or cobalt irradiation at the maximum dose of 5.0 MRAD (50 Kilogray) in the sterilization process. The dispensing apparatus is able to withstand the high temperatures associated with the steam and chemical sterilization processes required in the filling process. The dispensing apparatus is capable of withstanding these combined sterilization regimens without degrading the valve structure or operation. Thus, the valve of the instant invention may be used to dispense products ranging from aseptic products such as dairy, 100% juice and soy products, to commercially sterile products such as preserved juice and coffee products, to non-sterile fluids such as chemical solvents.
[0020] In order to allow a minimal force for holding the valve in an open position, a resilient valve actuator having the characteristics of a nonlinear spring is provided at an actuator end of the valve body and operatively connected to a plunger, with the opposite end of the plunger having mounted thereon a resilient valve seal. An intermediate discharge outlet is positioned between the actuator end and the valve seal, such discharge outlet being placed in fluid communication with the interior of a fluid container to which the valve is attached when the valve is in an open position. A valve port wall is positioned between the valve seal and the dispensing chamber providing a plurality of ports for controlling the flow of fluid through the valve body when the valve is in an open position. The valve and the valve port wall are positioned such that when the valve is installed on a liquid container, virtually no liquid will be trapped by the valve structure outside of the insulated container, thus preventing the spoilage of a dose of liquid resting in the valve after each dispensing cycle. A push-button is provided for actuating the drip resistant dispensing valve and is exposed to the exterior of a fluid container to which the drip resistant dispensing valve is attached. In one embodiment of the instant invention, the push-button is concentrically mounted within a breakaway circular rim. Upon first using the drip resistant dispensing valve, a user depresses the push-button, dislodging the circular rim from the button, and thereby providing evidence that the valve had been opened, thus providing a tamper-evident actuator.
[0021] Such valve is also preferably configured so as to withstand sterilization procedures including irradiation up to 5.0 MRAD and high temperature steam and chemical sterilization processes without degradation of the integrity of the valve structure or operation, and thus may be used for dispensing a wide variety of products ranging from aseptic products (free from microorganisms) to non-sterile products.
[0022] The simplicity and functionality of the drip resistant dispensing valve of the instant invention enables its manufacture and automatic assembly with multiple cavity tools, which in turn reduce manufacturing costs, and offers the market a low cost dispensing solution. The simplicity and functionality of the design also enables the dispensing apparatus to be easily customized in the manufacturing process to fit a wide range of dispensing packages such as a flexible pouch, flexible bag, or semi-rigid plastic container. The drip resistant dispensing valve of the instant invention is also configured to adapt easily to a wide range of filling machines and filling conditions worldwide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which:
[0024] FIG. 1 is an exploded view of a drip resistant dispensing valve in accordance with an exemplary embodiment of the present invention;
[0025] FIG. 2 is an expanded partial cut-away view illustrating the drip resistant dispensing valve shown in FIG. 1 ;
[0026] FIG. 3 is a side view illustrating the dispensing outlet of the drip resistant dispensing valve shown in FIG. 1 ;
[0027] FIG. 4 is a cut-away view of the drip resistant dispensing valve taken along line ‘A-A’ of FIG. 3 ;
[0028] FIG. 5 is an enlarged view of FIG. 4 , showing the valve plunger, actuator, and seal;
[0029] FIG. 6 is a side view illustrating a sanitary cover for the dispensing outlet of the drip resistant dispensing valve shown in FIG. 1 ;
[0030] FIG. 7 is a top view illustrating the actuation end of the drip resistant dispensing valve shown in FIG. 1 ;
[0031] FIG. 8 is a cut-away view of the drip resistant dispensing valve taken along line ‘B-B’ of FIG. 7 ;
[0032] FIG. 9 is a bottom view illustrating the fluid inlet end of the drip resistant dispensing valve shown in FIG. 1 ;
[0033] FIG. 10 is a plan view of the valve seal shown in FIGS. 1 , 2 , and 5 ;
[0034] FIG. 11 is a cross-section of the valve seal taken along line ‘C-C’ of FIG. 10 ; and
[0035] FIG. 12 is a side cross-sectional view of an actuator for use with the drip resistant dispensing valve shown in FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] The invention summarized above and defined by the enumerated claims may be understood by referring to the following description, which should be read in conjunction with the accompanying drawings in which like reference numbers are used for like parts. This description of an embodiment, set out below to enable one to build and use an implementation of the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
[0037] Referring to the drawings, FIG. 1 shows a drip resistant dispensing valve 12 in accordance with one embodiment of the present invention. As will be described in greater detail below, valve 12 is configured for attachment to a fluid container (not shown), which may be a rigid container (such as a thermos or plastic bottle), a flexible bag or pouch, or any other fluid container. The drip resistant dispensing valve 12 may be so situated on a fluid container so as to allow dispensing of fluid under gravity flow, or alternately, where the source of fluid is under a head of pressure, provided by a source other than gravity.
[0038] As is shown in the Figures, drip resistant dispensing valve 12 has a generally tubular valve body 13 having an outer wall 13 a and an inner wall 13 b . The valve body has an inner or inlet end 7 , and an opposite outer or actuation end 9 , and an axial direction extending between these ends. Although the valve body 13 is shown generally in the form of a round cylindrical tube, the valve body may be round, square, octagonal or other shape adapted for the application to which the drip resistant dispensing valve 12 will be applied. Alternately, only a portion of the valve body 13 may have such alternate shape, with the remainder of the valve body maintaining a generally cylindrical shape. For instance, inlet end 7 may have an oblong configuration where it connects to a fluid container, while the remainder of the valve body may maintain a generally cylindrical configuration. Valve body 13 is provided with features 14 for connecting the valve body 13 to a fluid container or other source of fluid to be dispensed so as to bring the inlet opening 15 ( FIG. 2 ) formed in the valve body 13 in communication with the fluid to be dispensed. The particular connecting features 14 depicted in the drawings include ribs encircling the exterior of the valve body near the inlet end 7 . These ribs are arranged to form a fluid-tight, press-fit connection between the exterior of the valve body and the interior of an outlet provided in the container. Other suitable connecting and sealing features may be used in addition to or in lieu of ribs. For example, the valve body 13 can be provided with threads or bayonet-type locking features that can be mated with features of the container. In addition, auxiliary sealing elements such as resilient O-rings or other gaskets can be provided on the container or on the valve body for engagement between the valve body and the container.
[0039] In a preferred embodiment, a discharge mechanism for the drip resistant dispensing valve 12 includes a shell 100 at least partially encompassing a discharge outlet 121 . In a preferred embodiment, the shell 100 and discharge outlet 121 are integrally connected with or formed in the valve body 13 at a position between the inlet end 7 and actuator end 9 . It is to be understood that shell 100 may be connected with valve body 13 through the use of various connection mechanisms, such as a threaded connection, compression lock connection, snap fit connection, friction fit connection, and the like. The shell 100 and discharge outlet 121 are disposed outside of the container or other source of fluid when the valve body 13 is engaged with the container. The shell 100 and discharge outlet 121 are generally in the form of a short tubular member extending in the direction perpendicular to the axial direction of the valve body. Discharge outlet 121 provides communication between an outside environment and the interior of the valve body 13 .
[0040] Discharge outlet 121 is configured so as to prohibit fluid being dispensed from outlet 121 from coming into contact with and/or collecting on the interior of shell 100 . More particularly, discharge outlet 121 includes a wall 125 that forms a projecting surface extending from outer wall 13 a of valve body 13 so as to direct all flow through an outlet channel 134 . Discharge outlet 121 is configured to substantially prevent fluid from collecting on the interior surfaces of the outlet and remaining there following a dispensing operation. Fluid flowing through the outlet channel 134 may run along the interior of wall 125 of discharge outlet 121 , but when it reaches the outer edge 139 of such discharge outlet 121 , it has no path but to remain on the edge of the discharge outlet 121 or fall from the valve into a container into which the fluid is being dispensed. The wall 125 of discharge outlet 121 extends away from outer wall 13 a , thus creating a distal separation between the open face 140 of discharge outlet 121 and the interior, back wall of shell 100 (formed by the outer wall 13 a of the body). As shown in FIGS. 2-5 , wall 125 of discharge outlet 121 forms a small rectangular opening at the open face 140 of the outlet channel 134 . In the current embodiment, the rectangular opening is approximately 0.23 inches on each side. To promote a dripless feature, the wall 125 of the discharge outlet 121 should be as thin as possible (consistent with good molding practices), and should extend outward from the outer wall 13 a of valve body 13 a distance that is at least three times the thickness of the outer edge 139 of the wall 125 , and will preferably extend outward from the outer wall 13 a a distance greater than three times the thickness of the outer edge 139 of the wall 125 . The distal separation between the outer edge 139 at the open face 140 of the outlet channel 134 and the outer wall 13 a of the valve body 13 prevents fluid being dispensed through discharge outlet 121 from contacting the inner surfaces of shell 100 , as the fluid is unable, on its own, to traverse the 180 degree turn that would be necessary in order to migrate to those interior surfaces of shell 100 . In this manner, residual undispensed fluid cannot pool on the inner surfaces of shell 100 and later drip off those surfaces at an undesirable time. Therefore, contamination of the interior of shell 100 (and establishment of sites on those surfaces at which biological contaminates might grow) is minimized, if not prevented altogether.
[0041] In the current embodiment, shell 100 is configured in a flat, generally cylindrical shape having an inner surface 105 . Alternative configurations for shell 100 may be employed, such as in the shape of a square, rectangle, other polygonal shapes, or as a cylinder, oval, oblong, and other shapes as contemplated by those of ordinary skill the art, without departing from the scope and spirit of the present invention.
[0042] Shell 100 further includes a shell channel 114 that provides an open passage through the interior of shell 100 . The boundaries of the shell channel 114 are defined by the shell inner surface 105 . In a preferred embodiment, the shell channel 114 defines the open passage through shell 100 that surrounds the discharge outlet 121 . Shell channel 114 , similar to shell 100 , extends in a perpendicular direction from the axial direction of the valve body 13 .
[0043] The length that the shell 100 extends from the outer wall 13 a of valve body 13 may increase the ease with which a user may proximally locate a receptacle next to the shell 100 for receiving the dispensed liquid. Further, the size of shell channel 114 may promote the use of the drip resistant dispensing valve 12 with variously sized receptacles, such as cups, water bottles, and the like. For instance, the generally cylindrical shape of the shell 100 may allow for its insertion into the mouth of a water bottle. This may promote a decrease in the amount of “lost” liquid or spillage during operation of the drip resistant dispensing valve 12 .
[0044] An outer edge 116 , which is formed at the opposite end of shell 100 from its connection with the outer wall 13 a of the valve body 13 , preferably provides a generally flat surface. In some embodiments, the outer edge 116 may provide a concave surface. A removable cover 119 , as best seen in FIG. 6 , may be temporarily attached to the outer edge 116 during shipment of an unused, new valve 12 . The cover 119 should be removed and disposed prior to use of the valve 12 .
[0045] Further, shell 100 is configured to decrease the risk of contamination of the discharge outlet 121 and possibly a liquid within a container to which the drip resistant dispensing valve 12 may be attached. For instance, sufficient distance is provided between the outer edge 116 of shell 100 and the outer edge 139 at the open face 140 of the outlet channel 134 and laterally between the wall 125 of the discharge outlet 121 and the shell inner surface 105 to reduce the risk of contaminates on the outer edge 116 of the shell 100 traveling or migrating to the outer edge 139 of discharge outlet 121 . Furthermore, the opening 143 at the end of shell channel 114 is substantially larger than the open face 140 of discharge outlet 121 . Thus, the shell 100 provides a guard against the contamination of the discharge outlet 121 through its dimensional structure.
[0046] In operation, when a user activates the valve to dispense the liquid from within the container, fluid is discharged through channel 134 of the discharge outlet 121 in a manner that substantially prevents the liquid from contacting the inner surface 105 of the shell 100 . Thus, while the shell 100 may promote the efficient use of the drip resistant dispensing valve 12 by providing an indicator to the user of where to locate a receptacle to receive the liquid during dispensing, it is generally not directly involved with the dispensing of the liquid itself. This may promote an environment on the inner surface 105 of the shell 100 capable of remaining substantially free from contaminates and/or as previously mentioned, assist in avoiding the travel of contaminates onto or into the discharge outlet 121 and outlet channel 134 .
[0047] The thickness of the walls provided for the shell 100 and discharge outlet 121 may vary to accommodate the needs of various liquids and/or materials to be dispensed through drip resistant valve 12 connected to a container of the liquids/materials, so long as the construction maintains sufficient integrity to undergo the above-described sterilization and irradiation processes. In a preferred embodiment, the outer shell 100 and discharge outlet 121 have wall thicknesses of approximately 0.06 inches. The thickness of the walls assists in promoting the ease of operation and cleaning of the drip resistant valve 12 and the ability of the valve to be subjected to sterilization processes while maintaining its functionality.
[0048] As shown more particularly in FIGS. 4 , 5 , 8 and 9 , a valve port wall 17 extends across the interior of body 13 between inlet opening 15 and discharge outlet 121 . The valve port wall 17 defines a at least one hole or valve port 80 , as well as a valve seat 18 encircling the valve port 80 and facing toward the inlet opening 15 . Preferably, the valve port 80 is located off the centerline of the valve port wall 17 , toward the side of the valve body 13 from which the discharge outlet 121 extends. The fluid flow resistance of the valve 12 in the open position is controlled in large measure by the flow resistance of p valve port 80 . Thus, the fluid flow resistance of the valve can be selected to fit the application by selecting the size of the valve port 80 . The size of valve port 80 can be varied through only slight modification of injection molding apparatus (such as by varying movable pin positions within such a mold structure). This allows the manufacturer to make valves for almost any application with minimal tooling costs. Limited only by the size of discharge outlet 121 , the valve port 80 need not be round or oval; other shapes, including an arcuate port extending partially around the center of the valve body and partially around plunger guide opening 33 , can be made with appropriate interchangeable injection molding components.
[0049] The valve port wall 17 also defines a plunger guide opening 33 adjacent the central axis of the valve body 13 . A tubular plunger guide 20 extends outwardly from the valve port wall 17 toward the actuator end 9 of the valve body 13 . The plunger guide 20 is aligned with the plunger guide opening 33 of the valve port wall 17 . As best seen in FIGS. 5 and 8 , a plunger guide support wall 5 extends across the valve body 13 just outward of discharge outlet 121 , so that the plunger guide support wall 5 lies between the discharge outlet channel 134 and the actuator end 9 of the valve body 13 . In the embodiment described herein, a portion of the plunger guide 20 combines with portions of the valve port wall 17 and the plunger guide support wall 5 to form boundaries for the discharge outlet channel 134 .
[0050] The valve body 13 may also have a pair of grip wings 30 and 31 projecting outwardly from the remainder of the valve body 13 at actuator end 9 . Grip wings 30 and 31 extend generally in directions perpendicular to the axial direction of the valve body and parallel to the direction of discharge outlet 121 . Valve body 13 desirably is formed from a polymeric material compatible with the fluid to be dispensed as, for example, a thermoplastic such as polypropylene or other polyolefin. In a preferred embodiment, valve body 13 is formed from a polypropylene copolymer.
[0051] A plunger member 21 is slidably mounted in plunger guide 20 . Plunger member 21 desirably is also made of polypropylene or other plastic material. In a preferred embodiment, plunger member 21 is likewise formed from a polypropylene copolymer.
[0052] Plunger member 21 has an inner end 22 that extends through the plunger guide 20 and through the plunger guide opening 33 of valve port wall 17 into the inlet opening 15 . The plunger guide 20 also serves to separate the plunger member 21 from the discharge outlet 121 .
[0053] Referring to FIGS. 10 , 11 , and 12 , a resilient valve seal 19 in the form of a shallow conical member is fixedly connected to the inner end 22 of the plunger member, as by a coupling element 22 a that can be force fitted into engagement with a sized opening 19 a in the valve seal 19 because of the resilient nature of the materials from which the valve seal 19 and plunger 21 are fabricated. Valve seal 19 can be formed from essentially any resilient material that will not react with or contaminate the fluid being dispensed, and that will not melt or degrade under the conditions encountered in service. For example, a thermoplastic or thermosetting elastomer or other flexible material, typically in the range of about 30 to about 80 Shore A durometer, and more preferably, about 50 to about 80 Shore A durometer, can be employed in typical beverage dispensing applications. In a preferred embodiment, valve seal 19 is formed from a thermoplastic rubber. The periphery of valve seal 19 overlies valve seat 18 and seals against the valve seat when the valve is in the closed position depicted in FIGS. 2 and 5 .
[0054] The thickness of the valve seal 19 will depend on the material and operating conditions. Merely by way of example, in a valve for dispensing beverages under gravity head (e.g., on the order of 0.5 to 1 pound per square inch pressure), the valve seal is about 1 inch in diameter and about 0.020 to 0.040 inches thick, most preferably about 0.032 inches thick, at its periphery.
[0055] A cylindrical stop member 28 and actuator 24 are formed integrally with the plunger member 21 at the outer end 23 of plunger member 21 remote from the inner end 22 . Actuator 24 has a dome-shaped resilient section 25 , so sized that the perimeter 26 of this dome-shaped section 25 can be mounted or held from escaping by a ledge or groove 27 disposed on the inner wall 13 b of the valve body 13 , just inward of the actuator end 9 of the valve body 13 . The dimensions of the actuator 24 are selected to provide desired resilient action and force/deflection characteristics as described in U.S. Pat. No. 6,491,189, the specification of which is incorporated herein by reference in its entirety. In one exemplary embodiment, the plunger 21 , stop member 28 , and actuator 24 , including resilient section 25 , are molded as a unit from polycarbonate or similar material. The resilient section 25 is generally conical and about 1 inch in diameter, with an included angle of about 160°. That is, the wall of the conical resilient section lies at an angle Z ( FIG. 12 ) of 10° to the plane perpendicular to the axial direction of the plunger member 21 . The resilient section 25 is about 0.012 inches thick at its perimeter, and about 0.018 inches thick at its juncture with stop member 28 . Stop member 28 is about 0.292 inches in diameter. Thus, the ratio between the axial extent x of the conical resilient section and the average thickness of the resilient section is about 4:1.
[0056] Stop member 28 coacts with a stop shoulder 29 formed by the outer end of the plunger guide 20 . Thus, the distance that the plunger 21 can be moved when force is exerted on the plunger 21 at actuator 24 will be determined by the distance the stop member 28 can travel before contact is made with the stop shoulder 29 (see FIG. 5 ).
[0057] A positioning flange 10 is preferably provided circumscribing the valve body 13 just above connecting features 14 . When the drip resistant dispensing valve 12 is installed on a fluid container, positioning flange 10 abuts the exterior wall of the container. In its closed position (seated against the port wall 17 ), the valve seal 19 is positioned a short axial distance from positioning flange 10 , preferably not more than about 0.25 inches, so as to limit the amount of fluid contained within the portion of the valve outside of the fluid container to the volume within the inlet end of the valve between positioning flange 10 and the valve seal 19 . By limiting the amount of fluid that may be contained within the valve structure after a dispensing cycle, the risk of subjecting a dose of liquid held within the valve after a dispensing cycle to temperature fluctuations is reduced, in turn reducing the risk of dispensing a dose of spoiled liquid at the start of the following dispensing cycle.
[0058] In operation, the valve 12 is preferably mounted to a fluid container (not shown). The discharge opening preferably points downwardly outside of the container, whereas finger grip wings 30 and 31 project horizontally. The valve 12 normally remains in the fully closed position. In this position, the resilience of actuator 24 urges the plunger 21 outwardly, toward the actuator end 9 of the valve body 13 , and holds the valve seal 19 in engagement with seat 18 , so that the valve seal 19 blocks flow from the inlet opening 15 to port 80 and discharge outlet 121 . In this condition, the pressure of the liquid in the container tends to force the valve seal 19 against seat 18 , thereby closing the valve.
[0059] In the embodiment of the instant invention shown in FIGS. 2 and 5 , a separate push button element 60 is provided for manual engagement by a user to operate the drip resistant dispensing valve 12 . Push button element 60 is preferably formed as a disk having a generally planar top surface 61 and a bottom surface 62 on the opposite side from the top surface 61 . Extending downward from and centrally located on bottom surface 62 is an engagement pin 63 . In the embodiment of the instant invention depicted in FIGS. 2 and 12 , the dome-shaped resilient section 25 of actuator 24 is provided with a central opening 64 sized to receive engagement pin 63 therein and to hold the engagement pin 63 in place via a friction fit. Thus, depressing push button element 60 downward likewise causes plunger member 21 and valve seal 19 to move in an opening direction aligned with the central axis of the valve body and transverse to valve port wall 17 . Preferably, engagement pin 63 is provided a circumferential ledge 65 around pin 63 generally parallel to bottom surface 62 . When inserted into actuator 24 , pin 63 thus fits snugly within central opening 64 in actuator 24 , while ledge 65 lies flush against the top face of actuator 24 . Thus, when push button element 60 is pushed downward, only ledge 65 comes in contact with actuator 24 , thus ensuring that the dome-shaped resilient section does not lose its shape or its spring characteristic when the button is actuated.
[0060] In an alternate embodiment of the instant invention, push button element 60 further comprises a detachable tamper indicating ring 70 circumscribing push button element 60 . Tamper indicating ring 70 includes a flat surface sized and configured to seat against the actuation end 9 of the valve body 13 surrounding actuator 24 . The tamper indicating ring 70 is provided with a plurality of tabs 74 extending towards the interior of the tamper indicating ring 70 , each tab 74 having a narrow terminal section attached to the upper and outer edge of push button element 60 . Tabs 74 are preferably configured so as to position push button element 60 substantially below the plane defined by the uppermost extent 72 of the tamper indicating ring 70 , such that when push button element 60 is assembled with actuator 24 within the drip resistant dispensing valve 12 , the outermost point of the actuation end 9 is the uppermost extent 72 of the tamper indicating ring 70 . Thus, by recessing push button 60 into the structure of drip resistant dispensing valve 12 and below the uppermost extent 72 of the tamper indicating ring 70 , inadvertent or accidental actuation of the valve (through bumping against a surface, etc.) may be averted.
[0061] In use, a new drip resistant dispensing valve 12 is provided on an unused container with push button element 60 installed in actuator 24 with tamper indicating ring 70 intact. Upon the first actuation of the valve through depression of push button 60 , movement of tamper indicating ring 70 is blocked by the upper edge of valve body 13 , such that movement of push button element 60 into valve body 13 results in breaking of tabs 74 and tamper indicating ring 70 separating from push button element 60 . Thus, previous actuation of valve 12 may be readily apparent to a user based upon either the presence or absence of tamper indicating ring 70 from push button element 60 .
[0062] The user can open the valve by grasping the finger grip wings 30 and 31 with his or her fingers and pressing his or her thumb against the center section of the push button element 60 so as to intentionally move actuator 24 , plunger member 21 , and valve seal 19 in an opening direction aligned with the central axis of the valve body and transverse to valve port wall 17 . Such movement takes the plunger member 21 and valve seal 19 from the normally closed position towards an open position, in which stop member 28 on the plunger member 21 engages stop shoulder 29 on the plunger guide 20 of the valve body 13 . In this open position, the valve seal 19 is remote from valve port wall 17 and remote from seat 18 , so that the valve seal 19 does not occlude port 80 and hence fluid can flow from a container to outlet channel 134 .
[0063] Because the finger gripping members 30 and 31 extend generally transverse to the discharge outlet 121 , and extend generally horizontally during use of the valve, the user's fingers will be supported above the bottom end of the discharge outlet 121 , out of the stream of fluid discharged from the opening. Thus, if a hot fluid is being dispensed, it will not harm the user.
[0064] By constructing each of the valve elements as discussed above, namely, forming the valve body from a polypropylene copolymer having a minimum average wall thickness of approximately 0.06 inches, and forming the valve seal from a thermoplastic rubber having an average thickness of about 0.03 inches, the valve structure may be subjected to the vigorous sterilization processes necessary for using the valve in food applications, including irradiating the structure at up to 5.0 MRAD and subjecting the structure to high temperature chemical and steam sterilization processes, without causing the valve structure to become brittle or otherwise jeopardizing the integrity of the valve's structure or operation.
[0065] Since the drip resistant dispensing valve 12 as above described is made with only a few parts formed by conventional, simple molding techniques, it is relatively simple in operation and inexpensive to manufacture. It is inherently reliable, and does not require extreme precision in manufacture.
[0066] Those skilled in the art of spring design will readily recognize that the resilient element 25 of the actuator 24 may be disposed at the exposed or actuator end 23 of the plunger 21 , so that the resilient section acts as part of the push button and closes the actuator end of the valve body 13 . However, this is not essential, and the resilient element 24 can be disposed within the valve body 13 , at a location inaccessible to the user, as explained in detail above through use of push button element 60 . In addition, although it is highly advantageous to form the resilient element integrally with the plunger member, this is not essential.
[0067] The invention has been described with references to a preferred embodiment. While specific values, relationships, materials and steps have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with such underlying concept. It is intended to include all such modifications, alternatives and other embodiments insofar as they come within the scope of the appended claims or equivalents thereof. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive. | A drip resistant dispensing valve for fluids is disclosed, which provides a dispensing outlet configured to minimize the tendency for residual fluid to collect in and drip from the dispensing outlet while maintaining a simple construction for ease of manufacture. The dispensing outlet face is situated a distance away from the valve body, which tends to prevent, or at least minimize the risk of, contact between potentially contaminating external surfaces with the surfaces of the discharge outlet. Such construction assists in minimizing the retention of fluid on the surfaces of the dispensing outlet, and migration of the fluid to surfaces outside of the dispensing outlet that could tend to promote growth of biological contaminates and/or provide additional surfaces that could pool fluid following a dispensing operation and thereafter drip from the valve. A shell is provided around the dispensing outlet to assist in avoiding contamination of the valve and of the fluid being dispensed through the valve, and to aid in positioning a receptacle for receiving fluid from the dispensing valve. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application relates to co-pending United States patent application Ser. No. 08/881,925, attorney docket number SP-2078 US, filed on even date herewith, entitled Broadly Distributed Termination For Buses Using Switched Terminator Logic and naming Jonathan E. Starr as inventor, the application being incorporated herein by reference in its entirety.
This application relates to co-pending United States patent application Ser. No. 08/881,157, attorney docket number SP-2128 US, filed on even date herewith, entitled Differential Receiver and naming Michael A. Ang, Alexander D. Taylor, and Jonathan E. Starr as inventors, the application being incorporated herein by reference in its entirety.
This application relates to co-pending United States patent application Ser. No. 08/883,723, attorney docket number SP-2489 US, filed on even date herewith, entitled Method for Resolving Differential Signals and naming Michael A. Ang, Alexander D. Taylor and Jonathan E. Starr as inventors, the application being incorporated herein by reference in its entirety.
This application relates to co-pending United States patent application Ser. No. 08/881,929, attorney docket number SP-2086 US, filed on even date herewith, entitled Impedance Control Circuit and naming Sai V. Vishwanthaiah, Alexander S. Taylor and Jonathan E. Starr as inventors, the application being incorporated herein by reference in its entirety.
This application relates to co-pending United States patent application Ser. No. 08/881,940, attorney docket number SP-2486 US, filed on even date herewith, entitled Method for Controlling the Impedance of a Driver Circuit and naming Sai V. Vishwanthaiah, Alexander S. Taylor and Jonathan E. Starr as inventors, the application being incorporated herein by reference in its entirety.
This application relates to co-pending United States patent application Ser. No. 08/881,938, attorney docket number SP-2547 US, filed on even date herewith, entitled Method for Determining Bit Element Values for Driver Impedance Control and naming Sai V. Vishwanthaiah, Alexander S. Taylor and Jonathan E. Starr as inventors, the application being incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to buses and more particularly to termination of buses for use in information processing systems.
2. Description of the Related Art
In computer and information processing systems, various integrated circuit chips communicate digitally with each other over a common bus. The signal frequency at which this communication occurs can limit the performance of the overall system. Thus, the higher the communication frequency, the better. The maximum frequency at which a system communicates is a function not only of the time that it takes for the electromagnetic wavefronts to propagate on the bus from one chip to another, but also of the time required for the signals to settle to levels than can be recognized reliably at the receiving bus nodes as being high or low, referred to as the settling time.
The length of the settling time is a function of the amount of reflection and ringing that occurs on the signal bus. The more effective the termination of a bus system, the smaller the effects of reflection and ringing in the system and the shorter the overall settling time of the signal.
SUMMARY OF THE INVENTION
It has been discovered that a bus may be provided with broadly distributed signal termination by using switched termination logic where the pull up resistance of the driver corresponds to the characteristic impedance of the line and the pull down resistance of the driver corresponds to the number of drivers coupled to the line. Accordingly, signals being transmitted over the bus suffer relatively few reflections thus advantageously producing a shortened signal settling time, thereby increasing the attainable signaling frequency.
In a preferred embodiment, the invention relates to a method for terminating a line having a number of drivers coupled thereto, the line having a characteristic impedance. The method includes the steps of pulling up a signal on the line with a pull up resistance substantially corresponding to the characteristic impedance of the line; and pulling down a signal on the line with a pull down resistance substantially corresponding to the number of drivers coupled to the line.
Additionally, in a preferred embodiment, the invention relates to a method for terminating a line having a plurality of ends, the line having a characteristic impedance. The method includes the steps of coupling a plurality of drivers to the plurality of ends, each driver including a pull up circuit, and a pull down circuit, the plurality of drivers being divided into a driving driver and a plurality of receiving drivers, pulling up a signal on the line with the pull up circuit of the driving driver, the pull up circuit of the driving driver having a pull up resistance corresponding to the impedance of the line, the receiving drivers having a resistance corresponding to the impedance of the line when the driving driver is pulling up the signal; pulling down a signal on the line with the pull down circuit of the driving driver, the pull down circuit having a pull down resistance corresponding to the number of drivers coupled to the line, the receiving drivers having a resistance corresponding to the impedance of the line when the driving driver is pulling down the signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
FIG. 1 shows a block diagram of an information handling system having a bus as well as driver circuits in accordance with the present invention.
FIG. 2 shows a block diagram of broadly distributed termination using switched termination logic of the information handling system of FIG. 1.
FIGS. 3A, 3B, 3C and 3D show schematic block diagrams of a variety of bit elements of the driver circuits having switched termination logic in accordance with the present invention.
The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
Referring to FIG. 1, information handling system 100 includes a plurality of components 102 such as processor 102a, memory controller 102b, and I/O controller 102c. It will be appreciated that these components 102 may be any type of component commonly found in an information handling system. Each of these components 102 is generally configured as an individual integrated circuit chip. However, it is known to combine various components into a single integrated circuit chip. Components 102 are coupled via bus 104. Bus 104 includes a plurality of parallel lines which are coupled to individual signal outputs of each of the components 102. Components 102 are also coupled to a common reference voltage (REF)
Each component 102 includes a plurality of input/output circuits 108 which are coupled to individual signal paths of bus 104. Each input/output circuit 108 includes a receiver circuit 109 and a driver circuit 110. Each receiver circuit 109 is also coupled to the common reference voltage. Component 102 also includes impedance control circuit 112 which is coupled to each driver circuit 110. Impedance control circuit 112 controls driver circuits 110 so that the impedance of each pull up driver circuit is matched to that of the bus 104 and the impedance of each pull down driver circuit is equal to the impedance of the bus 104 divided by the difference of the number of drivers coupled to the bus minus one.
In operation, driver circuits 110 include switchable termination logic for controlling whether each driver circuit 110 is driving or terminating and thus each driver circuit includes circuitry which controls the pull up and pull down termination resistance of the driver circuit.
Referring to FIG. 2, each driver circuit 110 of information handling system 100 includes a plurality of signal nodes coupled to bus 104 having a characteristic impedance of Z O . Attached to each signal node at the end of a transmission line trace or stub is a the push-pull driver 110. Driver 110 includes a pull up driver circuit 202 and a pull down driver circuit 204. Pull up driver circuit 202 includes a pull up resistance that is substantially equal to (i.e., within 5% of) the characteristic impedance Z O of the transmission line. Pull down driver circuit 204 includes a pull down resistance that is substantially equal to(i.e., within 5% of) ##EQU1## where n is the number of nodes in the information handling system 100. The receiver, if any, functions as a small capacitive load; however, no DC current flows between the receiver and the transmission line. Accordingly, the receiver does not contribute to the output impedance of the driver.
When a node is driving signals onto line 104, the driver 110 of the node either pulls the signal up or pulls the signal down, as appropriate to send the desired digital signal. When a node is receiving, the pull up portion of the driver remains active continuously, thereby functioning as a terminating resistance which is matched to the impedance of the transmission line.
However, because the pull down resistance at the driving node is equal to the net resistance of the parallel combination of the pull up portions of all of the receiving nodes, the signal swing on the bus 104 is from VDD to VDD/2. Accordingly, the receivers are capable of resolving a swing of VDD/2.
Because the impedance at each receiving node is matched to the impedance of the transmission line, signals arriving at the receiving node terminate without reflection. The impedance at the driving node is also matched to the line when driving high. However, the impedance at the driving node is mismatched when driving the signal low because the impedance is equal to Z O /(n-1) instead of Z O . Accordingly, the only stub on which reflections are created is the stub with the driver when the driver pulls the signal low. Because there is an impedance mismatch at the intersection of this stub with the rest of the bus, only a fraction of these reflections, which fraction is already a fraction of the initial signal, are transmitted to the receiving nodes. This condition is preferable because the settling time of the receiving node is the crucial parameter to bus performance. The net effect of the absence of reflections from the stub ends can be a reduced overall settling time when compared to systems without termination at each receiving node.
In this configuration, the pull down resistance is Z O /(n-1) because, by having the pull up resistors on chip, the pull up resistance at the driving node is switched off when the driver is pulling low. Accordingly, this system advantageously consumes less overall current and power than a system that has an off chip pull up resistor that is always drawing current.
Additionally, providing the termination within each component 102 improves signal integrity when compared to having a termination resistor that is not within component 102. When the termination resistor is not within component 102, the terminator is actually separated from the receiving node by some distance along a transmission line and thus parasitics are introduced in the connection to the termination resistor. Also, because of the separation such a system can have reflections from the intersection of the stubs of the transmission line. However, when the termination is within each component, the termination resistance is placed right at the receiver, thereby reducing reflections and ringing.
Referring to FIGS. 3A, 3B, 3C and 3D, the pull up and pull down elements of driver circuit 110 may be of a variety of configurations. For example, as shown in FIG. 3A, the driver element may be a PMOS transistor. Also for example, as shown in FIG. 3B, the driver element may be the parallel combination of a PMOS transistor and an NMOS transistor. With this parallel combination, it is the resistance of the parallel combination that would be equal to the desired bit element resistance. Also for example, as shown in FIG. 3C, the driver element may be an NMOS transistor. Also for example, as shown in FIG. 3D, the driver element may be the parallel combination of two NMOS transistors. In a preferred embodiment, the pull up driver element includes the parallel combination of the PMOS transistor and the NMOS transistor and the pull down element includes the parallel combination of two NMOS transistors. It will be appreciated that a driver circuit may have other circuitry that contributes to the overall pull up and pull down resistance of the driver.
Other Embodiments
Other embodiments are within the following claims.
For example, while a variety of configurations are disclosed for the pull up and pull down driver elements, it will be appreciated that other driver configurations may be used so long as the appropriate driver and termination resistances are maintained.
Also, in the present invention, a MOS transistor may be conceptualized as having a control terminal which controls the flow of current between a first current handling terminal and a second current handling terminal. Although MOS transistors are frequently discussed as having a drain, a gate, and a source, in most such devices the drain is interchangeable with the source. This is because the layout and semiconductor processing of the transistor is symmetrical (which is typically not the case for bipolar transistors). For an N-channel MOS transistor, the current handling terminal normally residing at the higher voltage is customarily called the drain. The current handling terminal normally residing at the lower voltage is customarily called the source. A sufficient voltage on the gate causes a current to therefore flow from the drain to the source. The gate to source voltage referred to in an N-channel MOS device equations merely refers to whichever diffusion (drain or source) has the lower voltage at any given time. For example, the "source" of an N-channel device of a bi-directional CMOS transfer gate depends on which side of the transfer gate is at a lower voltage. To reflect the symmetry of most N channel MOS transistors, the control terminal is the gate, the first current handling terminal may be termed the "drain/source", and the second current handling terminal may be termed the "source/drain". Such a description is equally valid for a P channel MOS transistor, since the polarity between drain and source voltages, and the direction of current flow between drain and source, is not implied by such terminology. Alternatively, one current handling terminal may be arbitrarily deemed the "drain" and the other deemed the "source", with an implicit understanding that the two are not distinct, but interchangeable. | A bus line is provided with broadly distributed signal termination by using switched termination logic where the pull up resistance of a driver corresponds to the characteristic impedance of the line and the pull down resistance of the driver corresponds to the number of drivers coupled to the line. Accordingly, signals being transmitted over the bus suffer relatively few reflections thus advantageously producing a shortened signal settling time, thereby increasing the attainable signaling frequency. | 6 |
STATEMENT OF RELATED APPLICATION
[0001] This application is related to U.S. patent application Ser. No. ______ (attorney docket no. GS 217), filed on even date herewith and entitled “Subassembly That Includes A Power Semiconductor Die And A Heat Sink Having An Exposed Surface Portion Thereof”, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to mounting assemblies and packages for semiconductor devices used in electronic equipment, and more particularly to mounting assemblies and packages power semiconductor devices.
BACKGROUND OF THE INVENTION
[0003] The electronics industry has been progressing with the miniaturization of electronic devices. This trend influences semiconductor packaging technology, which enables the connection between bare IC chips and other components, and enables the connection between bare IC chips and other components. Typically, a semiconductor package has a footprint much larger than that of the chip. To adapt to the miniaturization trend, the size difference between the package and the chip has been reduced, producing a new package type called a Chip scale package (CSP). A chip scale package is loosely defined as a package that takes no more than about 20% additional area (length and width) than the bare silicon die. The solder balls of chip scale packages are smaller than ball grid array (BGA) that had arranged according to international standard of Joint Electron Device Engineering Council (JEDEC). When it comes to personal and portable electronic devices, smaller is better, and various products need different chip scale package types, a wide array of which are currently available.
[0004] Certain semiconductor devices are designed to handle relatively high voltages in a compact space. For example, semiconductor devices that are exposed to RMS voltages greater than 100 VAC, such as 265 VAC or 415 VAC, are often mounted in electronic power supplies and the like. These devices may dissipate relatively large amounts of power, and are accordingly often mounted to heat sinks or like devices as well as being electrically connected to electronic equipment of various types.
[0005] Many such semiconductor devices for power applications are commonly available in the JEDEC standard TO-220 and DO-218 packages (www.jedec.org). An illustrative TO-220 package 110 is shown in FIG. 1 . The TO-220 package 110 includes a pressure clamp 140 , retainer 130 , heat sink 120 , a spacer 150 interposed between the package 110 and the heat sink 120 , and a semiconductor die (not visible in FIG. 1 ) with leads 114 exiting the package 110 on one side. High-voltage semiconductor devices may also be available in various other packages similar to the TO-220 package.
[0006] The continued emphasis on faster, smaller, lighter, and lower cost electronics systems is making component, board and system packaging more complex each year. The increase in complexity is due to wider use of finer pitch and thinner array surface mount packages, which are the key to miniaturization of electronics products. Most of the components on a typical systems motherboard for desk top computer systems remain at 1.27 and 1.00 mm pitch surface mount components with increasing use of finer pitch (0.80, 0.65, 0.50 & 0.40 mm) array styled packages. Portable systems are moving to the finer pitches at a faster rate. The component pitch and overall profile height plays a critical role in the complexity of manufacturing process. The use of finer pitch, low profile components demands assembly equipment and processes that operate with tighter specification limits. The assembly processes that demand a higher precision include: pick-and-place, solder paste-printing applications, reflow, inspection, and rework. The use of finer pitch low profile components increases the complexity, which could negatively effect yield and rework making assemblies more difficult and costly.
[0007] One aspect of the packaging process that can reduce yield is the accuracy with which the semiconductor die can be mounted to the heat sink or slug. The accuracy of this process relies primarily on the pick and place machine that is employed. In addition, another packaging aspect of the packaging process that can also reduce yield is the accuracy with which the solder thickness can be controlled.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, a semiconductor assembly is provided. The assembly includes a first subassembly comprising a heat sink and a first patterned polymer layer disposed on a surface of the heat sink to define an exposed portion of the first surface. The exposed portion of the first surface extends radially inward along the heat sink surface from the first layer. The subassembly also includes a second patterned polymer layer disposed on a radially outer portion of the first patterned polymer layer. The first and second layers define a cell for accommodating a power semiconductor die. Solder material is disposed on the exposed portion of the heat sink surface and in the cell. A power semiconductor die is located within the cell on a radially inward portion of the first layer and thermally coupled to the heat sink by the solder material.
[0009] In accordance with one aspect of the invention, the semiconductor assembly may also include a semiconductor package in which the first subassembly, solder and die are located.
[0010] In accordance with another aspect of the invention, the semiconductor package may be is a chip scale package.
[0011] In accordance with another aspect of the invention, at least one of the first and second patterned polymer layers may include polyimide.
[0012] In accordance with another aspect of the invention, the power semiconductor die may have a footprint with a given shape and the first patterned polymer layer conforms to the given shape.
[0013] In accordance with another aspect of the invention, the semiconductor assembly may also include a second subassembly. The second subassembly may include a second heat sink and a third first patterned polymer layer disposed on a surface of the heat sink to define an exposed portion of the surface. The exposed portion of the surface extends radially inward along the second heat sink surface from the third layer. The second subassembly also includes a fourth patterned polymer layer disposed on a radially outer portion of the third patterned polymer layer The third and fourth layers define a cell for accommodating a power semiconductor die. A second solder material is disposed on the exposed portion of the second heat sink surface. The he power semiconductor die is further located within the cell on a radially inward portion of the third layer and thermally coupled to the second heat sink by the second solder material.
[0014] In accordance with another aspect of the invention, a semiconductor assembly is provided that includes a heat sink and a first patterned polymer layer disposed on a surface of the heat sink to define an exposed portion of the first surface. The exposed portion of the first surface extends radially inward along the heat sink surface from the first layer. Solder material is disposed on the exposed portion of the heat sink surface and a power semiconductor die is located on the first patterned layer and thermally coupled to the heat sink by the solder material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows an illustrative package for a power semiconductor die.
[0016] FIGS. 2( a ) and 2 ( b ) show cross-sectional and top views, respectively, of a first heat sink that is to be mounted to a semiconductor die and a first patterned polymer layer formed on the heat sink.
[0017] FIGS. 3( a ) and 3 ( b ) show cross-sectional and top views, respectively, of the patterned polymer layers formed on the first heat sink.
[0018] FIGS. 4( a ) and 4 ( b ) show cross-sectional and top views, respectively, of a solder material located on the surface of the first heat sink.
[0019] FIGS. 5( a ) and 5 ( b ) show cross-sectional and top views, respectively, of a power semiconductor die positioned on the first heat sink and contacting one of the patterned polymer layers.
[0020] FIGS. 6( a ) and 6 ( b ) show cross-sectional and top views, respectively, of solder material applied to the exposed surface of the semiconductor die.
[0021] FIGS. 7( a ) and 7 ( b ) show cross-sectional and top views, respectively, of the final semiconductor assembly that includes the semiconductor die mounted to two heat sinks.
[0022] FIGS. 8( a ) and 8 ( b ) show cross-sectional and top views, respectively, of a first heat sink that is to be mounted to a semiconductor die and a first patterned polymer layer formed on the heat sink when only the x-y position of the die is to be constrained by the polymer.
[0023] FIGS. 9( a ) and 9 ( b ) show cross-sectional and top views, respectively, of a solder material located on the surface of the first heat sink depicted in FIGS. 8( a ) and 8 ( b ).
[0024] FIGS. 10( a ) and 10 ( b ) show cross-sectional and top views, respectively, of a power semiconductor die positioned on the first heat sink depicted in FIGS. 9( a ) and 9 ( b )
[0025] FIGS. 11( a ) and 11 ( b ) show cross-sectional and top views, respectively, of solder material applied to the exposed surface of the semiconductor die depicted in FIGS. 10( a ) and 10 ( b )
[0026] FIGS. 12( a ) and 12 ( b ) show cross-sectional and top views, respectively, of the final semiconductor assembly that includes the semiconductor die mounted to the two heat sinks referred to in connection with FIGS. 8-11 .
[0027] FIGS. 13( a ) and 13 ( b ) show cross-sectional and top views, respectively, of a first heat sink that is to be mounted to a semiconductor die and a first patterned polymer layer formed on the heat sink when only the solder thickness is to be controlled by the polymer.
[0028] FIGS. 14( a ) and 14 ( b ) show cross-sectional and top views, respectively, of a solder material located on the surface of the first heat sink depicted in FIGS. 13( a ) and 13 ( b ).
[0029] FIGS. 15( a ) and 15 ( b ) show cross-sectional and top views, respectively, of a power semiconductor die positioned on the first heat sink depicted in FIGS. 14( a ) and 14 ( b )
[0030] FIGS. 16( a ) and 16 ( b ) show cross-sectional and top views, respectively, of solder material applied to the exposed surface of the semiconductor die depicted in FIGS. 15( a ) and 15 ( b )
[0031] FIGS. 17( a ) and 17 ( b ) show cross-sectional and top views, respectively, of the final semiconductor assembly that includes the semiconductor die mounted to the two heat sinks referred to in connection with FIGS. 13-16 .
DETAILED DESCRIPTION
[0032] The present invention provides a mounting system for a semiconductor device that overcomes the aforementioned limitations of prior-art mounting systems. The mounting system is particularly suitable for use with discrete power semiconductor devices such as those employed for power linear and switching applications. Examples of such devices include, without limitation, resistors, rectifiers, transistors and the like. The mounting system discussed herein may be used in connection with surface mount technology packages such as chip scale packages, for example. Examples of standardized packages that may be suitable include, without limitation, JEDEC TO-220 and DO-218 packages. In the detailed description that follows, like element numerals are used to identify like elements appearing in one or more of the figures.
[0033] FIGS. 2( a ) and 2 ( b ) show cross-sectional and top views, respectively, of a first heat sink 210 that is to be mounted to a semiconductor die. The heat sink 210 may be formed from any suitable thermally conductive material such a, but not limited to, Cu, Al and alloys thereof. In accordance with the present invention, a curable polymer is applied to an upper surface of the first heat sink 210 and patterned using well-known stenciling and screening techniques to form a first patterned polymer layer 212 . Suitable polymers include, without limitation, polymide, silicon rubber, and fluoroelastomer. The first patterned polymer layer 212 defines sidewalls of a cell 211 in which the solder can be placed. Next, in FIGS. 3( a ) and 3 ( b ), a second patterned polymer layer 214 is formed over the first polymer layer 212 , again using well-known stenciling and screening techniques. The second patterned polymer layer 214 defines a border within which the die is to be situated. Exposed portions 213 of the first patterned layer 212 (i.e., those portions not covered by the second patterned layer 214 ) define surfaces on which the die ultimately can be mounted. As shown in FIGS. 4( a ) and 4 ( b ), after formation of the first and second patterned polymer layers, solder 216 is dispensed in a conventional manner using a syringe, for example, onto the heat sink 210 into the cell 211 that is defined by the first patterned layer 212 . In FIGS. 5( a ) and 5 ( b ) a pick and place assembly machine or robot is used to position the semiconductor die 218 onto the exposed portion 213 of the first patterned layer 212 . The border of the second patterned layer 214 facilitates accurate placement and alignment of the die on the heat sink 210 .
[0034] The process depicted in FIGS. 2-5 may be repeated for a second heat sink that is to contact the side of the die 218 opposing the first heat sink 210 . In this case a second heat sink 220 first undergoes the process steps depicted in FIGS. 2-4 to form first and second patterned layers 212 and 214 on a second heat sink 220 . Next, as shown in FIGS. 6( a ) and 6 ( b ), solder 222 is dispensed onto the exposed surface of the die 218 . The second heat sink subassembly (i.e., heat sink 220 with patterned layers 212 and 214 located thereon) is then positioned over the die 218 so that the die 218 contacts the exposed surface portion of the second patterned layer 212 of the second heat sink subassembly. FIGS. 7( a ) and 7 ( b ) show cross-sectional and top views, respectively, of the final semiconductor assembly that includes the semiconductor die mounted to two heat sinks.
[0035] A number of advantages arise from the use of the mounting process depicted in FIGS. 2-7 . For example, the use of a second patterned layer (e.g., second patterned layer 214 ) to constrain the position of the die on the heat sink limits rotational and out-of plane misalignments of the die. In this way the second patterned layer actively cooperates with the pick and place assembly machine to assist in the placement process and, as a result, the pick and place assembly machine is not solely responsible for placement of the die. In addition, the use of a first patterned layer (e.g., first patterned layer 212 ) that directly contacts the heat sink allows precise control of the overall solder thickness and thickness uniformity. For instance, in some cases the solder thickness in the final package can be maintained within a tolerance of about 0.25 mil to 3 mil. In addition, because the polymer that forms the first and second patterned layers is generally relatively soft and pliable, the level of stress exerted upon the die can be reduced.
[0036] To illustrate the advantages of the present invention, three samples were manufactured in accordance with the technique discussed above. The solder thickness of the samples were selected to be 55 microns, 65 microns and 75 microns, respectively. The 55 micron sample was found to vary in thickness between about 52.8 microns and 54.6 microns. The 65 micron sample was found to vary in thickness between about 64.5 microns and 69.2 microns. The 75 micron sample was found to vary in thickness between about 74.4 microns and 79.2 microns.
[0037] The size and shape of the cells 211 defined by the first and second patterned layers is not limited to those depicted in FIGS. 2-7 . Rather, the size and shape of the cells can be selected as desired for different die geometries or footprints (e.g., square, hexagonal, round). The cell configuration may also be selected to comply with other factors such as flux overflow, the prevention of shorts and the like. Moreover, the sidewalls of the patterned layers 212 and 214 are not limited to the four linear segments of polymer for each of the two patterned layers that are depicted in FIGS. 2-7 . Rather, any suitable configuration and number of polymer segments may be employed. For example, a square, rectangular or circular cell can be defined by a single continuous segment of polymer that has a shape defining a square, rectangle or circle, respectively. Alternatively, multiple continuous or non-continuous polymer segments may be employed in any number that is desired.
[0038] In the embodiments of the invention presented above one patterned polymer layer (e.g., patterned layer 214 ) is employed to constrain or control the x-y position of the die on the surface of the heat sink 210 and a second patterned polymer layer (patterned layer 212 ) is used to control the thickness of the solder in the z-direction. In other embodiments of the invention only one polymer layer is employed to control either the x-y position of the die or the thickness of the solder in the z-direction.
[0039] FIGS. 8-10 show an embodiment of the invention in which only a single polymer layer is employed to constrain or control the x-y position of the die on the surface of the heat sink. As shown in FIGS. 8( a ) and 8 ( b ), which once again show cross-sectional and top views, respectively, of the heat sink 210 , a curable polymer is applied to an upper surface of the first heat sink 210 and patterned using well-known stenciling and screening techniques to form an orienting patterned polymer layer 214 that is used to constrain or control the x-y position of the die. The orienting layer 214 defines sidewalls of a cell 211 in which the solder can be placed. Next, in FIGS. 9( a ) and 9 ( b ), solder 216 is dispensed in a conventional manner using a syringe, for example, onto the heat sink 210 into the cell 211 that is defined by the orienting patterned layer 214 . In FIGS. 10( a ) and 10 ( b ), a pick and place assembly machine or robot is used to position the semiconductor die 218 into the cell 211 so that it contacts the solder 216 . The border of the orienting patterned layer 214 facilitates accurate placement and alignment of the die 218 on the heat sink 210 .
[0040] The process depicted in FIGS. 8-10 may be repeated for a second heat sink that is to contact the side of the die 218 opposing the first heat sink 210 . In this case a second heat sink 220 first undergoes the process steps depicted in FIGS. 8-9 to form the orienting patterned layer 214 on a second heat sink 220 . Next, as shown in FIGS. 11( a ) and 11 ( b ), solder 222 is dispensed onto the exposed surface of the die 218 . The second heat sink subassembly (i.e., heat sink 220 with orienting patterned layer 214 located thereon) is then positioned over the die 218 so that the die 218 is located within the cell defined by the orienting patterned layer 214 of the second heat sink subassembly. The die 218 contacts the solder 222 of the second heat sink assembly to form the complete semiconductor assembly depicted in FIG. 12 .
[0041] FIGS. 13-15 show an embodiment of the invention in which only a single polymer layer is employed to control the overall thickness and thickness uniformity of the solder in the z-direction. As shown in FIGS. 13( a ) and 13 ( b ), which once again show cross-sectional and top views, respectively, of the heat sink 210 , a curable polymer is applied to an upper surface of the first heat sink 210 and patterned using well-known stenciling and screening techniques to form a thickness-controlling patterned polymer layer 212 that is used to control the thickness of the solder in the z direction. Next, in FIGS. 14( a ) and 14 ( b ), solder 216 is dispensed in a conventional manner using a syringe, for example, onto the heat sink 210 into the cell 211 that is defined by the thickness-controlling patterned layer 212 . In FIGS. 15( a ) and 15 ( b ) a pick and place assembly machine or robot is used to position the semiconductor die 218 onto the thickness-controlling layer 212 .
[0042] The process depicted in FIGS. 13-15 may be repeated for a second heat sink that is to contact the side of the die 218 opposing the first heat sink 210 . In this case a second heat sink 220 first undergoes the process steps depicted in FIGS. 13-14 to form the thickness-controlling patterned layer 212 on a second heat sink 220 . Next, as shown in FIGS. 16( a ) and 16 ( b ), solder 222 is dispensed onto the exposed surface of the die 218 . The second heat sink subassembly (i.e., heat sink 220 with thickness-controlling patterned layer 212 located thereon) is then positioned over the die 218 so that the die 218 is located on the thickness-controlling patterned layer 212 of the second heat sink subassembly. The die 218 contacts the solder 222 of the second heat sink assembly to form the complete assembly depicted in FIGS. 17( a ) and 17 ( b ). | A semiconductor assembly includes a first subassembly comprising a heat sink and a first patterned polymer layer disposed on a surface of the heat sink to define an exposed portion of the first surface. The exposed portion of the first surface extends radially inward along the heat sink surface from the first layer. The subassembly also includes a second patterned polymer layer disposed on a radially outer portion of the first patterned polymer layer. The first and second layers define a cell for accommodating a power semiconductor die. Solder material is disposed on the exposed portion of the heat sink surface and in the cell. A power semiconductor die is located within the cell on a radially inward portion of the first layer and thermally coupled to the heat sink by the solder material. | 7 |
BACKGROUND OF THE INVENTION
Plastic bags containing an integral zipper or fastener with opposing male and female elements, such as illustrated by U.S. Pat. No. Re. 28,969, have been on the market place for a number of years. While bags with the integral zipper have many advantageous features, one of their difficulties has been in aligning and pressing together the zipper elements for closing of the bags by the average consumer. For this reason, attempts have been made to add closing devices or tools to the bags to permit ready closing of the zipper. Illustrations of such devices are shown in U.S. Pat. Nos. 3,122,807; 3,360,875; 3,790,992 and 3,806,998, for example. However these devices have not been particularly economical, not normally reusable, nor very successful in the market place. The need for an economical, reusable closing device which merely acts as a simple extension of the thumb and finger remained until the present invention was achieved.
SUMMARY OF THE INVENTION
The present invention comprises a device or tool for aligning and closing integral fastening or zipper elements for plastic bags. The closing device is separable from the bag so that it can be used many times to totally and simply close the zipper elements. The device includes an inverted U-shaped channel with flexible opposing legs having a means for guiding the legs onto the zipper elements and aligning these elements, aided by additional means whereby the sensitivity of the fingers and thumb to the proper location of the zipper elements within the closing device is included to permit ready and accurate closing of the bag. The guide means can include an embossed pressure means for further accentuating the closing function.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front elevational view of a closing device constructed according to the principles of the present invention, the rear elevational view being the same;
FIG. 2 is a side elevational view of the closing device of FIG. 1, the other side elevational view being the same;
FIG. 3 is a cross-sectional view of the closing device of FIG. 1 taken along with the line 3--3 thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a fragmentary isometric view schematically showing how the closing device can align and close the integral zipper elements of a bag;
FIG. 6 is an enlarged fragmentary sectional view of the closing device of FIG. 5 showing the zipper elements pressed together;
FIG. 7 is a front elevational view of a modified form of a closing device according to the present invention;
FIG. 8 is a side elevational view of the closing device of FIG. 7, the other side elevational view being the same;
FIG. 9 is a cross-sectional view of the closing device of FIG. 7 taken along the reference line 9--9 thereof; and
FIG. 10 is a bottom view of the closing device of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the exemplary embodiment of the invention disclosed in FIGS. 1 to 4 of the drawing, a closing device 10 includes a pair of resilient legs 12 and 14 in a generally inverted U-shaped disposition presenting a gap or channel 36 between the leg ends. The legs are joined at a bite or yoke portion 16 so that the entire device, legs and yoke portion, presents a generally inverted Y-shaped configuration. The legs of the closing device can be formed of a relatively resilient but tough, semi-rigid synthetic resin such as cellulose acetate butyrate, polypropylene, polyethylene, nylon, polycarbonate, impact polystyrene and various copolymers and blends thereof, and the like, suitable forms of which resins are well known in the trade.
The structure of the closing device is one which allows the use of finger or equivalent pressure to flex and close the legs 12 and 14 against one another yet retains sufficient resilience to open again with release of the finger pressure. The legs 12 and 14 can be rigidly attached to bite section 16 through solvent welding, sonic or other thermal welding, by the use of adhesives or can be mechanically fastened together. The closing device 10 can also be integrally formed of one piece by injection molding, if desired. The bite portion can be made of the same materials as the legs or can be of a different, perhaps more rigid material, such as an acrylic resin. In one actual sample of the invention the legs were formed of cellulose acetate butyrate and the bite portion was formed of an acrylic resin. However, it would function properly if it were instead formed entirely by injection molding of polypropylene resin material. In the sample, the legs were about 1"×1/2" having a material thickness of about 1/32". The gap 36 between the legs was about 1/16". The device readily closed a Ziploc® storage bag manufactured by The Dow Chemical Company.
The edges 18 and 20 of the legs 12 and 14 are preferably flared outwardly along the length of the legs as shown most clearly in FIG. 4. The flared edges present a channel 21 which acts as a guide for finger alignment on the device as described more particularly hereinafter. The corners and edges of the device 10 are preferably rounded or tapered to avoid catching of the bag thereon.
The lower ends of legs 18 and 20 have formed in their interior surfaces guides or grooves 22 and 24 adapted to receive the mating profiles of the bag zipper elements or fasteners. Preferably, the guides 22 and 24 are chamfered at sections 26 and 28 to funnel the mating zipper elements more readily into main central sections 30 of the guides 22 and 24 when the zipper elements are being secured together. Provided in the main sections 30 of the guides are finger sensing ridges 32 extending from channel surfaces 21 on each of the legs 12 and 14, respectively, to help locate the proper finger position for applying pressure directly against the mating profiles located within the guides 22 and 24. A raised pressure bump 37 can also be included on the inside of a section 30 to add to the closing pressure.
FIG. 5 represents the operation of closing zipper or fastening elements 40 and 42 of a bag 38 by use of the closing device 10. Bag 38 includes bag lips 44 and 46 which normally are used for pulling the bag zipper elements apart once the fastening elements 40 and 42 are secured together. Slot 48 of the closing device 10 has enough height so that it can take the extent of the lips 44 and 46 above the fastening members 40 and 42 which fit within the guides 22 and 24 of the closing device 10. Gap or slot 36 between the legs 12 and 14 is sufficient to take the width of the bag body although the gap can be more or less than that width.
In operation, left end 43 of the bag shown in FIG. 5 can be fed into the gap 36 at the left end 45 of closing device 10 with the zipper elements 40 and 42 entering the funnel-shaped zipper receiving section 28 (FIG. 1) of closing device 10 so that the zipper elements 40 and 42 are aligned within the section 30. This closing could alternately be done from the right end of the bag and either end of the closing device can be used as the device is the same on both sides and ends, except for the optional pressure bump 37.
Should the gap 36 be wide enough or resilient enough, then it is possible for the closing device to be inserted directly downwardly over the lips 44 and 46 and zipper elements 40 and 42 for accomplishing the closing operation rather than sliding the device over the same from the left end of the bag. However, the purpose of the funnel-shaped sections 26 and 28 is to facilitate feeding or entry of the zipper elements from the end of the closing device to accomplish the closing function in one preferred manner. Once the closing device is properly located over zipper elements 40 and 42, the user simply needs to locate his thumb and opposite index finger over the sensing ridges 32 which are exactly opposite fastening elements 40 and 42 and press the legs 12 and 14 together which causes mating of the zipper elements 40 and 42 together, and then slide closing device 10 along the open part of the zipper to close the zipper elements progressively from one end to the other, as illustrated in FIG. 5 from the left end to the right end of the bag. This results in a complete closing of the zipper elements 40 and 42 to secure any contents therein. FIG. 6 illustrates in enlarged detail the zipper elements 40 and 42 being pressed together so that the guides' main sections 30 are pressing against back side ridges 34 of the zipper elements 40 and 42 to interlock the same.
As the closing device proceeds from the left end of the bag across to the right end of the bag, it merely slips off the bag and is ready for use in sealing another bag, (or the same bag again) on the next occasion by following the same procedure as with the first bag. Where the closing device 10 is placed over the top of the bag rather than feeding an end of the bag into the closing device, caution should be taken that the closing device is placed over the zipper elements close to one end of the bag, or be sure the device is run laterally back and forth over the zipper elements so that the bag is sealingly closed. Thus, a closing device permitting repeated usage and which is simple to understand and use, and is entirely effective in sealing tongue and groove type closing elements, has been achieved.
Yet another preferred embodiment of the present invention is illustrated in FIGS. 7 to 10. Here a closing device 50 comprises opposing legs 52 and 54 and a bite portion 56 together presenting an inverted Y-shaped configuration to the device. Closing device 50 can be made of a one-piece construction which is basically flat with a hinge line 58 so that leg 52, as shown in dotted lines in FIG. 9, is directly above leg 54 but can be folded about hinge line 58 to come directly opposite from leg 54 in U-shaped fashion to form the closing device as illustrated by solid lines. To hold the two legs together, the right section can include a barb 60 on one of the legs, such as leg 52, and an aperture 62 to which the barb 60 penetrates in order to fasten the two halves together. With certain thermoplastic materials, hinging is possible because of the resilient nature of the material itself as, for example, with a nylon or polypropylene resin material.
Besides the foldability of the legs 52 and 54 upon one another as above-described, another principle difference between the embodiment shown in FIGS. 7 to 10 and that shown in FIGS. 1 to 4 is that lower portions 64 and 66 of legs 52 and 54 are canted outwardly from upper portions 68 and 70 of the legs 52 and 54 to provide an extra large gap 72 at the ends 74 and 76 of the legs 52 and 54. This gap is generally greater than the combined thickness of the zipper elements 40 and 42 of the bag 38 to be closed so that it is easily placed over the top of the bag for closing in the event this is preferred. The side flanges 18' and 20' are continued around the bottom of each leg as at 57 so that the channel 21' is cup-like. The flange portion 57 will limit the lower extent to which the thumb and finger can easily extend, thereby more accurately locating them over the sensing ridges 32'. The cup-like channel 21' together with the extra large gap 72 combine to permit easy locating of the closing device 50 over the zipper elements. The yoke 56 has also been narrowed somewhat to save material. The other characteristics of the closing device 50 are all fundamentally the same as those of the closing device 10 and are identified by like reference characters with primes supplied. An actual sample of this embodiment was made of materials and had dimensions similar to those of the sample of FIGS. 1 to 4 only the gap 72 between the legs was about 1/8".
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and applications can be made therein without departing from the spirit and scope of the invention. For example, the closing device can be made and designed of various sizes depending on the particular size of the bag or other container to be closed and particular shape and size of the zipper elements of the bag, and can take different aesthetic appearances and still be comprehended by the basic invention claimed herein. | A device for closing zippers on plastic bags, the device being separable from the bags to enable repeated usage. The closing device is adapted to function as an extension of the finger-thumb action. It comprises a generally inverted U-shaped channel for receiving the interlocking elements of the zipper with the opposing legs of the device being resilient and engageable toward one another to press the interlocking zipper elements together. A guide is formed in the legs to align the zipper elements. Projections opposite the guide aid in giving a sense to the user of aligning of the guide with the zipper elements. | 8 |
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2010/060767, filed on Jul. 26, 2010, which claims the benefit of priority to Serial No. DE 10 2009 028 249.1, filed on Aug. 5, 2009 in Germany, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
The disclosure relates to flap drives such as for example luggage compartment flaps and vehicle doors of a motor vehicle which can be operated electrically.
Flap systems for electric opening and closing are used in motor vehicles in luggage compartment systems or vehicle doors. Triggered by the actuation of an operating element, such as for example a switch, in the passenger compartment of the motor vehicle or by a remote control element, an electric motor is activated so as to open the flap. The electric motor is connected to the respective flap (vehicle door, luggage compartment flap and the like) via a spindle gearing or the like, so as to provide a corresponding speed and force for the opening process.
A closing process can likewise be triggered by means of a corresponding operating element or remote control element or else by pushing the flap in the closing direction. It may furthermore be provided that, in the case of the flap being pushed in the closing direction, the movement of the flap via the corresponding causes a rotation of the electric motor, which thereby produces a generator current. It may be provided that the generator current produced triggers the closing process, such that the electric motor is activated so as to close the flap, and the flap is correspondingly closed.
In general, the exertion of a force on the closing element causes a rotation of the electric motor. If, when a force is exerted on the closing element, a threshold value is exceeded, for example if a user imparts a large force for opening or closing the flap or the flap abuts against an obstruction during a movement driven by the electric motor, a clutch, in particular a slipping clutch, is provided between the electric motor and the gearing which is coupled to the flap, which clutch, when a force greater than a certain magnitude acts (above a disengagement threshold value), is disengaged. The disengagement of the clutch causes the movement of the flap to be decoupled from the movement of the electric motor. In other words, when the clutch in a flap drive is disengaged, the previously positively locking connection between the flap and the electric motor is eliminated.
In the case of electrically driven flap systems, a function is normally realized by means of which a maximum open position of the flap can be programmed by a user. To ensure that the position of the maximum open position is not exceeded, the position of the flap must be known at all times in the control unit which drives the flap system. This is generally possible by detecting the absolute rotor position of the electric motor and assigning this to a flap position. A disengagement of the clutch may however have the result that, in a flap system in which the position of the flap is determined not directly but rather only from the position of the rotor of the electric motor, the position information for the flap is lost. It is therefore necessary to detect the time of the disengagement of the clutch in order to identify when the position information can no longer be used for determining the flap position.
It is an object of the present disclosure to provide a method and a device for detecting a disengagement of a clutch in a flap system.
SUMMARY
Said object is achieved by means of the method as claimed in claim 1 and the device as claimed in the further independent claim.
The dependent claims relate to further advantageous refinements.
According to a first aspect, a method is provided for detecting a disengagement of a clutch in a flap drive. Here, the clutch couples a drive motor to an adjustable flap such that the flap can be adjusted by means of the drive motor, and wherein the coupling action between the drive motor and the flap is eliminated if a force or a torque acting on the flap exceeds a maximum value. The method comprises the following steps:
detecting data regarding an adjustment speed, in particular a rotational speed of the drive motor; determining a gradient of the adjustment speed, in particular a rotational speed gradient, by means of the data regarding the adjustment speed; detecting a disengagement of the clutch by determining whether the predetermined gradient exceeds or undershoots a predetermined gradient threshold value.
One concept of the disclosure consists in identifying when the clutch disengages, and the transmission of force to the flap thereby eliminated, by merely monitoring the adjustment speed of the drive motor, for example a rotational speed of an electric motor. If a force is exerted on the flap, for example as a result of manual actuation or as a result of the flap abutting against an obstruction, the clutch is disengaged after static friction has been overcome, and the transmission of force via the clutch is eliminated or considerably reduced. Upon the disengagement of the clutch, the adjustment speed of the drive motor, in particular the rotational speed of an electric motor, generally changes, because there is a resulting significant, fast change in the load moment. This is generally independent of whether or not the rotational speed of the electric motor is regulated. If a gradient of the adjustment speed is detected which lies above a gradient threshold value, this can be inferred as a disengagement of the clutch. In this case, it is for example possible for a function of the flap system for moving to a maximum, user-defined opening height to be deactivated.
It may furthermore be provided that, if a disengagement of the clutch is detected, an actuation of the drive motor is permitted only in the direction for closing the flap.
It may be provided that, if a disengagement of the clutch is not present, the position of the flap is detected from a position of a rotor of the drive motor.
According to one embodiment, during the movement of the flap, the position of the flap may be limited to a maximum open position.
It may be provided in particular that, if a disengagement of the clutch is detected, the flap is moved in the closing direction until an end position is reached, wherein when the flap has reached the end position, the position of the flap is assigned to a rotor position of the drive motor.
According to a further aspect, a device may be provided for detecting a disengagement of a clutch in a flap drive, in particular in a motor vehicle. The device comprises:
a drive motor; a clutch which is designed to couple the drive motor to an adjustable flap such that the flap can be adjusted by means of the drive motor, and wherein the clutch is designed to eliminate the coupling action between the drive motor of the flap if a force or a torque acting on the flap exceeds a maximum value, having a control unit which is designed to detect data regarding an adjustment speed, in particular a rotational speed of the drive motor; to determine a gradient of the adjustment speed, in particular a rotational speed gradient, by means of the data regarding the adjustment speed; to detect a disengagement of the clutch by determining whether the determined gradient exceeds or undershoots a predetermined gradient threshold value.
According to a further aspect, a computer program product is provided which comprises program code which, when executed on a data processing unit, carries out the above method.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the disclosure will be explained in more detail below on the basis of the appended drawings, in which:
FIG. 1 is a schematic illustration of a flap system;
FIG. 2 is a schematic illustration of the rotational speed profile upon a disengagement of the clutch as a result of the action of an external force on the flap.
DETAILED DESCRIPTION
FIG. 1 shows a rear part of a motor vehicle 1 having a luggage compartment 2 which can be closed off by a luggage compartment flap 3 . The luggage compartment flap 3 can be opened and closed by means of an electric drive system 4 .
The drive system 4 comprises an electric motor 5 which is mechanically coupled to a gearing 6 . In the present exemplary embodiment, a rotational movement of a drive output shaft 11 of the electric motor 5 is converted, in the gearing 6 , into a translatory movement of a linkage 7 which engages on the luggage compartment flap 3 . Here, a spindle 10 slides in a cylinder 9 of a gearing 6 , such that the overall length of the linkage 7 changes. As a result of the translatory sliding of the linkage 7 or of the spindle 10 , it is thereby possible for the luggage compartment flap 3 , which is suspended in a pivotably movable manner, to be opened and closed.
Furthermore, there is arranged between the electric motor 5 and the gearing 6 a clutch 8 , in particular a slipping clutch. The clutch 8 is designed in the form of a conventional clutch, for example with two clutch plates 12 which are pressed against one another with a force in order to attain a coupling action for the transmission of a torque by means of a static friction force. If the difference between the torques acting on the clutch plates via the drive input and drive output shafts is exceeded, the clutch disengages and the clutch plates slip relative to one another, such that the rotational speeds of the drive input and drive output shafts differ. The clutch 8 is dimensioned so as to disengage in the event of the action of an adequately high disengagement force in the movement direction of the linkage 7 , that is to say a force acting on the linkage 7 , or in the event of the action of an adequately high disengagement torque on clutch plates.
In alternative embodiments, the clutch may also be provided between the gearing 6 and the linkage 7 . In this case, the clutch may be for example a plate clutch in which two plates are pressed against one another, such that if the static friction caused thereby is exceeded, the plates move relative to one another, and the length of the linkage 7 is thereby varied.
The drive system 4 is electrically actuated by a control unit 15 via corresponding supply lines 16 . The control unit 15 is connected to operating elements (not shown) by means of which the user can indicate whether the luggage compartment flap 3 should be opened or closed. Furthermore, via a corresponding signal line from the electric motor 5 , the control unit 15 detects a position signal PS which indicates the absolute position of a rotor of the electric motor 5 . The position signal PS may be provided by a position sensor (not shown) arranged on the electric motor 5 . The position signal PS serves for the detection of the present position of the luggage compartment flap 3 . This is realized by means of a defined assignment of the present position of the rotor of the electric motor 5 to a position of the luggage compartment flap 3 . To be able to carry this out, defined fixed coupling is required between the rotor of the electric motor 5 and the position of the luggage compartment flap 3 .
In the control unit 15 there is often realized a function for ensuring that the luggage compartment flap 3 , when it opens, moves only to a certain maximum position which is predefined by a user. In this way, it is possible to prevent situations in which the luggage compartment flap 3 abuts against an obstruction, for example the roof of a garage. In the case of an electrically driven opening process, the electric motor is correspondingly stopped at the maximum position.
However, if the clutch 8 disengages and said clutch is positioned between the rotor of the electric motor 5 , the absolute position of which is detected, and the luggage compartment flap 3 , the information regarding the position of the luggage compartment flap 3 is lost. As a result, the above function for limiting an opening process to a maximum position would no longer be implementable because, when it has been detected that the clutch 8 has disengaged, the position information PS can no longer be assigned to a position of the luggage compartment flap 3 .
For the renewed calibration of the luggage compartment flap 3 , the latter must be moved into a defined position, or fully closed. The defined position must be detectable, that is to say for example the fully closed state of the luggage compartment flap 3 must be detectable, for example from an increase in the current through the electric motor 5 when the luggage compartment flap 3 is blocked by an end stop. Furthermore, the end stop may also be signaled to the control unit 9 by a corresponding sensor.
For comfort reasons, the calibration process should not be carried out often. Provision is now made to detect when the clutch has disengaged, and to carry out a calibration preferably only when the clutch has disengaged. For this purpose, the rotational speed of the electric motor 5 is monitored for example by evaluating the position signal PS, and a disengagement of the clutch 8 is inferred for example on the basis of a change in the rotational speed signal. Data regarding the rotational speed may be derived for example from detected position information, by determining a change in position over a defined time period. By means of a derivation of the rotational speed data with respect to time, it is thereby possible to detect a change in rotational speed.
Owing to the inertia of the overall system, that is to say the mass of the luggage compartment flap 3 with the moment of inertia of the electric motor 5 and of the gearing 6 and also the inertia of the linkage 7 , changes in rotational speed take place during the electromotive operation of the luggage compartment flap 3 which however do not exceed a certain rotational speed gradient value. In the event of an abutment of the luggage compartment flap 3 against an obstruction or as a result of a force being exerted on the luggage compartment flap which exceeds that during a manual actuation of the luggage compartment flap 3 , generally as a result of the exertion of a large force, the clutch 8 can be disengaged if static friction is overcome. To permit manual adjustment of the luggage compartment flap 3 , a disengagement limit value at which the clutch 8 disengages is selected to be so high that a manual actuation of the luggage compartment flap 3 does not automatically lead to a disengagement of the clutch 8 . Only when an even higher force arises, such as for example in the event of the abutment of the luggage compartment flap 3 against an obstruction, does the clutch 8 disengage for safety reasons.
A disengagement results in a rapid change in the rotational speed of the electric motor 5 . If the force acts on the luggage compartment flap 3 in the direction of an actuating movement of the electric motor 5 , the electric motor 5 initially speeds up as a result of the action of the force on the luggage compartment flap 3 ; upon the disengagement of the clutch 8 , the coupling action between the movement of the luggage compartment flap 3 and the rotational movement of the electric motor 5 is however significantly reduced, such that the torque exerted by the gearing falls and, as a result, the rotational speed suddenly decreases. The magnitude of the gradient of the rotational speed change then exceeds a certain rotational speed gradient threshold valve, and it can be inferred that the clutch 8 has disengaged.
If, in another situation, a force is exerted on the luggage compartment flap 3 which counteracts the drive movement of the electric motor 5 , the electric motor 5 initially slows down until the clutch 8 disengages. After the disengagement of the clutch 8 , the rotational speed suddenly increases, wherein the rotational speed gradient which is then present exceeds the rotational speed gradient threshold valve.
FIG. 2 shows the rotational speed profile before and after a disengagement of such a clutch 8 , if the rotational speed of the electric motor 5 is regulated by means of a regulator. Owing to the high magnitude of the rotational speed gradient after the clutch 8 has disengaged, an intense intervention into the regulation takes place, which leads to an oscillation of the regulator. This can be clearly seen from FIG. 2 .
It may furthermore be provided that, after the detection of a disengagement of the clutch 8 , a movement of the luggage compartment flap 3 by means of the drive system 4 is permitted only in the direction of the closed position, in order to prevent a user-defined maximum position, that is to say open position of the luggage compartment flap 3 , from being exceeded. Possible damage to the luggage compartment flap 3 can be prevented in this way.
The method described above may basically be applied to all electrically operable opening mechanisms in which a flap can be moved over an opening in order to open up or close off the opening. | A method is disclosed for detecting the activation of a coupling in a damper actuator, the coupling engaging a drive motor and an adjustable damper with each other, so that the damper can be adjusted by means of the drive motor, and the engagement between the drive motor and the damper being disengaged if a force or a momentum acting on the damper exceeds a maximum value. The method comprises the following steps: detecting the indication of an adjustment rate, in particular a rotary speed of the drive motor; determining a gradient of the adjustment rate, in particular a rotary speed gradient, by the indication of the adjustment rate; determining the activation of the coupling by determining whether the determined gradient exceeds or falls below a predetermined threshold value of the gradient. | 4 |
ORIGIN OF THE INVENTION
[0001] The invention described herein was made in the performance of work under a NASA contract and is subject to Public Law 96-517 (35 U.S.C. §200 et seq.). The contractor has not elected to retain title to the invention.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to solar power control systems, and in particular, to an efficient system and method for applying solar-generated power to refrigeration.
[0004] 2. Description of the Related Art
[0005] Two billion people live without electricity. They represent a market for various solar powered systems such as stand-alone power systems and small capacity solar refrigerators. Efforts have been made to develop stand-alone photovoltaic (PV) power systems that provide lighting and power for small devices such as radios and small televisions. For example, such systems may include a solar panel, a battery, and a low wattage fluorescent light. Solar refrigerators, however, represent a bigger challenge,
[0006] Previous attempts to produce a marketable solar refrigerator have been largely unsuccessful. For example, consider the following patents:
[0007] In U.S. Pat. No. 4,126,014, Thomas Kay discloses an absorption refrigeration system powered by a heated fluid from a solar panel.
[0008] In U.S. Pat. No. 5,501,083, Tae Kim discloses an AC-powered air conditioner having a solar panel for backup electrical power.
[0009] In U.S. Pat. No. 5,497,629, Alexander Rafalovich discloses the use of solar power in an air conditioning system to pump heat from an indoor space to a thermal store.
[0010] In U.S. Pat. No. 5,685,152, Jeffrey Sterling discloses using a heated medium from solar collectors to produce a cold thermal store and mechanical energy to pump heat from an indoor space to the cold thermal store.
[0011] Kay's refrigeration system provides no means to maintain refrigerator operation in the absence of sunlight (e.g. at nighttime or on overcast days). As the air conditioning systems are largely unsuited for even small capacity refrigerators or freezers, no attempt has been made to scale these systems to produce a commercializable solar refrigerator.
[0012] Accordingly, it is desirable to provide an efficient, inexpensive, commercializable small capacity solar refrigerator which can operate for several days in the absence of sunlight. As batteries are often expensive and require regular maintenance, it would further be desirable to provide such a solar refrigerator which does not require batteries.
SUMMARY OF THE INVENTION
[0013] A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a capacitor, a compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power, some of which is stored in the capacitor. The capacitor provides additional current during compressor start-up, and thereafter acts to smooth out variations in the power voltage. The power from the PV panel and capacitor drives the compressor to circulate refrigerant through a vapor compression refrigeration loop, thereby extracting heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen. Thereafter the thermal reservoir is able to act as a heat sink to maintain the temperature of the insulated enclosure for an extended period in the absence of sunlight.
[0014] This conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the maximum available power, and adjusts the compressor speed accordingly. In this manner, the compressor operation is continuously adjusted to convert substantially all available solar power into stored thermal energy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A better understanding of the present invention can be obtained when the following detailed description of preferred embodiments is considered in conjunction with the following drawings, in which:
[0016] [0016]FIG. 1 is a block diagram of a first solar refrigeration system embodiment;
[0017] [0017]FIG. 2 is a block diagram of a second solar refrigeration system embodiment;
[0018] [0018]FIG. 3 is a graph of an exemplary I-V curve for a photovoltaic panel;
[0019] [0019]FIG. 4 is a graph of an exemplary I-V curve for a photovoltaic panel in reduced light;
[0020] [0020]FIG. 5 is a flowchart of a first compressor speed control method; and
[0021] [0021]FIG. 6 is a flowchart of a second compressor speed control method.
[0022] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] Turning now to the figures, FIG. 1 shows a first embodiment of a solar refrigeration system which includes a solar panel 102 connected to a power bus 103 . Although a wide variety of solar panel types and styles may be employed, one suitable example is a 12 volt nominal PV panel that is capable of a peak power output of approximately 120 watts at approximately 15 volts under full solar insolation.
[0024] A capacitor 104 is connected to power bus 103 in parallel with solar panel 102 . Capacitor 104 operates to provide temporary storage of electrical charge in order to smooth any voltage variations on power bus 103 and to provide extra current during demand periods. The voltage variations may be caused by a variety of sources including changes in light intensity on the solar panel and changes in the electrical load driven by the solar panel 102 . The capacitor 104 may be varied in size and type, but a preferred example is a 0.2 Farad electrolytic capacitor.
[0025] A variable speed compressor 108 with a load controller 106 is directly coupled to the solar panel 102 by power bus 103 . In this context, “directly coupled” is defined to mean that no power converters are provided between the compressor 108 and solar panel 102 . Although other embodiments are also contemplated, this embodiment advantageously exhibits relatively high efficiency due to the direct powering of the compressor 108 by a PV panel. It is noted that systems which use batteries typically force the solar panel to operate below its peak power point to match the battery charging voltage. Powering the compressor directly from the solar panel allows the solar panel to be operated at the maximum power point.
[0026] The variable speed compressor 108 is preferably a direct current compressor such as a Danfoss® BD35F direct current compressor with refrigerant 134 a . Persons of skill in the art will recognize that other suitable compressors and refrigerants can be employed. The BD35F includes a “brushless” DC (direct current) motor in that provides permanent magnets on the rotor. Electronics in the BD35F switch the DC input to provide a 3-phase input to fixed coils that drive the rotor. The electronics improve the motor's efficiency by sensing the back-EMF in the coils to determine the rotor position. This compressor implementation is believed to exhibit efficiency and longevity advantages over typical DC compressors. As discussed in further detail below, load controller 106 senses the voltage on power bus 103 and regulates the speed of compressor 108 in response to variations in this voltage.
[0027] Compressor 108 circulates refrigerant through a vapor compression refrigeration loop that preferably includes a first heat exchanger (a.k.a. a condenser) 110 , a capillary tube 112 , a second heat exchanger (a.k.a an evaporator) 114 internal to an insulated enclosure 120 , and a third heat exchanger (sometimes referred to as SLLL HX, or the suction line/liquid line heat exchanger) 116 associated with the capillary tube 112 . As refrigerant is circulated through the loop, it is compressed by compressor 108 , cooled to a liquid state by ambient air in condenser 110 , flash-cooled by heat exchanger 116 in capillary tube 112 , evaporated to a gaseous state in evaporator 114 , warmed by heat exchanger 116 , and recompressed and re-circulated by compressor 108 . This circulation results in a net transfer of heat from the evaporator 114 to the condenser 110 , thereby cooling the interior of the insulated enclosure 120 by heating ambient air. One of skill in the art will readily recognize that this refrigerant loop may be constructed in various suitable manners, and that other refrigerant loops may also be employed to achieve a net transfer of heat energy away from the insulated enclosure 120 without departing from the scope of the invention. For example, one specific alternate implementation uses an expansion valve in place of the capillary tube 112 .
[0028] Similarly, many types of insulated enclosures are well known and may be employed, but a preferred construction for the insulated enclosure 120 uses fiberglass-reinforced plastic shells for the cabinet with vacuum panels between the inner and outer shells for insulation. A bezel interface is preferably provided between the cabinet and the door to minimize thermal conductance and convection through the seal. With this preferred construction, a cabinet having a composite R value (thermal resistance in units of hr·ft 2 ·° F./BTU) of 26 has been achieved. (Most conventional refrigerators have a composite R value of 5.)
[0029] Referring still to FIG. 1, the load controller 106 senses the voltage on power bus 103 and provides a speed control signal 107 to variable speed compressor 108 . By controlling the compressor speed, the load controller 106 effectively maximizes the power extracted from the solar panel. It inexpensively implements an advantageous optimization method as described in further detail below. While it can take various forms, the load controller 106 is preferably implemented in the form of a microcontroller that implements a software algorithm. The microcontroller may also be designed to perform other system functions such as: monitoring internal temperature of the insulated enclosure, monitoring the compressor for error conditions, and initiating compressor start-ups and shut-downs in a manner designed to extend the life of the compressor. In alternate embodiments, the load controller 106 may also control power source switching to access alternate power sources, if available and when necessary, or to provide redundancy (in the case of multiple solar panels).
[0030] A thermal reservoir 118 is preferably provided in the insulated enclosure 120 . Thermal reservoir 118 preferably comprises a phase-change material that has a phase-change temperature at or slightly below the target interior temperature for the insulated enclosure. Particularly desirable phase-change materials are those having a solid-liquid phase change with a high heat of fusion, and which are inexpensive and relatively non-toxic. Water and water solutions are examples of suitable phase change materials. A water solution of approximately 3-5% propylene glycol may be particularly desirable, as it exhibits a reduced tendency to rupture closed containers when freezing. The size and phase change material of the thermal reservoir is preferably chosen to maintain the target interior temperature for several days in the absence of solar power (or at least 36 hours). One of skill in the art will recognize that thermal reservoir 118 may be implemented in a variety of suitable configurations.
[0031] In the embodiment of FIG. 1, the thermal reservoir 118 is contemplated as being adjacent to evaporator 114 , and/or as being a part of evaporator 114 . As refrigerant circulates through the evaporator 114 to cool the interior of the insulated enclosure 120 , a direct transfer of heat energy occurs to evaporator 114 from thermal reservoir 118 to cool the thermal reservoir and induce a phase change of the phase-change material. In other words, if the phase-change material is water, the flow of refrigerant through the evaporator cools and freezes the water.
[0032] In operation, the solar panel 102 delivers power to power bus 103 during the day when the sun is shining. The load controller 106 runs the compressor 108 at a speed that maximizes the power extracted from the solar panel. The compressor 108 circulates refrigerant through a refrigerant loop to cool the insulated enclosure and to cool and induce a phase change of the material in the thermal reservoir. At night and during adverse weather conditions, no power is delivered to the power bus 103 , and the compressor 108 is inactive. The temperature in the insulated enclosure is maintained by the thawing of the material in the thermal reservoir. Advantageously, no fluid circulation or active heat pumping is required to maintain the enclosure temperature during these inactive time periods.
[0033] Referring now to FIG. 2, a second solar refrigeration system embodiment is shown. In this embodiment, an alternate power source 205 is coupled to power bus 103 . The alternate power source 205 may take many forms including, e.g. a supplemental battery, a fuel cell, a generator, or an AC/DC converter connected to a commercial AC power grid. The load controller 106 turns the alternate power source 205 on or off by means of an enable signal 206 . The load controller 106 preferably minimizes the use of alternate power source 206 to the greatest extent possible, using it only when solar power is unavailable and the temperature of the insulated enclosure exceeds a predetermined threshold. The load controller 106 monitors the interior temperature of insulated enclosure 120 by means of a temperature signal 207 from a temperature sensor (not shown) in insulated enclosure 120 .
[0034] The solar refrigeration system embodiment of FIG. 2 also employs an alternate configuration for the evaporator 114 and thermal reservoir 118 . In this configuration, the refrigerant passing through evaporator 114 cools a second fluid that is pumped through the evaporator 114 by a pump 209 . Many fluids may be used, but currently a propylene glycol and water mixture is preferred. The cooled second fluid is then circulated through a heat exchanger in the thermal reservoir 118 to cool and induce a phase change in the phase change material. The load controller 208 may be configured to turn pump 209 on and off by means of a signal 208 . Pump 209 is preferably activated only when compressor 108 is operating. A fan may be provided to improve air circulation, and may also be controlled by signal 208 .
[0035] In one particular implementation of the alternate configuration shown by FIG. 2, the cooling of the insulated enclosure 120 is accomplished primarily by the thermal reservoir 118 and the heat exchanger therein. This implementation may prove advantageous relative to the configuration shown in FIG. 1 for several reasons. A first feature of this implementation is that the refrigerant volume is reduced, which may provide reduced cost and increased system longevity. A second feature of this implementation is that thermal leakage to the interior of the insulated enclosure during and after compressor shut-down is reduced. A third feature is that mechanical design of the thermal reservoir may be simplified due to a larger and more favorably distributed heat exchange area with the phase change material. It is noted that the solar refrigeration system embodiment of FIG. 1 may be modified to use this thermal reservoir configuration.
[0036] The load controller 106 may be designed to monitor the temperature of the insulated enclosure and respond to temperature excursions above or below predetermined thresholds. As mentioned previously, the load controller 106 may activate alternate power source 205 in response to a detected temperature above an upper temperature limit. Also, the load controller 106 may halt the variable speed compressor 108 in response to a detected temperature below a lower temperature limit. Once the temperature returns to the desired range, the load controller 106 may then resume normal solar-powered operation. One of skill in the art will recognize the desirability of providing some hysteresis in any such temperature regulation strategy. It is noted that the upper temperature limit is preferably slightly above the phase change temperature, and the lower temperature limit is preferably is slightly below the phase change temperature.
[0037] As previously mentioned, load controller 106 operates to maximize the power drawn from the solar panel 102 . Various methods which may be implemented by the load controller are now described with reference to FIGS. 3 and 4. FIG. 3 shows an I-V curve 302 representing the voltage V provided by solar panel 102 as a function of current I drawn from the solar panel, assuming maximum insolation (sunlight intensity). The voltage varies from V OC when no current is drawn to 0 when the short circuit current I SC is drawn. A typical example of an open circuit voltage V OC for a nominal 12 volt panel is 20 volts, and a typical example of a short circuit current is 8 amperes. On the curve between these two points is a maximum power point (I MP ,V MP ) where the maximum power is extracted from the solar panel. This point occurs where the slope of the curve is dV/dI=−V/I.
[0038] The load controller 106 preferably locates this maximum power point by an iterative search process. At an initial time t=0, the compressor 108 is not running, and no current is drawn. The load controller determines that a sufficient start-up voltage exists and starts the compressor at a minimum startup speed. Note that the current drawn by the compressor increases as the speed of the compressor increases. At a subsequent time t=1, the compressor is drawing a current and the voltage provided by the solar panel has been slightly reduced. The load controller 106 then begins gradually increasing the speed of the compressor 108 , detecting the power bus voltage at regular intervals and adjusting the speed of the compressor in response to some criterion based on the detected voltage. The time progression of operating points has been exaggerated for illustration. In a preferred embodiment, the increments in speed are digital and are much smaller, so that 255 or more operating points on the curve are possible.
[0039] Various adjustment criteria may be used. For example, referring momentarily to FIG. 4, a second I-V curve 402 is shown for reduced insolation. The maximum power point on curve 402 has shifted relative to the maximum power point on curve 302 . It is noted that while the current I MP at the maximum power point is particularly sensitive to the amount of insolation, the voltage V MP at the maximum power point is relatively insensitive to the amount of insolation. Consequently, the load controller 106 may increase or decrease the compressor speed as needed to maintain the power bus voltage close to a predetermined voltage target, e.g. the maximum power voltage for full solar insolation.
[0040] While simple, this criterion is suboptimal since the maximum power voltage varies with temperature, and in any case, this criterion does not provide for full power extraction during reduced insolation. Referring again to FIG. 3, it is noted that at all operating point voltages on curve 302 above the maximum power point voltage, the power provided by the solar panel increases as the current increases, whereas for all operating point voltages on the curve below the maximum power point voltage, the power provided by the solar panel DECREASES as the current increases. When this observation is combined with the observation that the power required by the compressor always increases as the speed increases, an improved control method can be developed for the load controller 106 .
[0041] Referring simultaneously to FIGS. 1 and 3, it is noted that when the compressor 108 is run at a speed requiring less power than the solar panel 102 can provide, an increase in compressor speed will result in a matching increase in power extracted from the solar panel. Due to the capacitor 104 , the power bus voltage will decrease smoothly and stabilize. In other words, the magnitude of the time derivative of the voltage decreases as a function of time. When the compressor 108 is run at a speed requiring more power than the solar panel 102 can provide, the charge on capacitor 104 provides the extra power required. Since only a limited amount of charge exists on capacitor 104 , the capacitor 104 is increasingly depleted as time goes on, and the compressor attempts to draw more current from solar panel 102 . This in turn causes the solar panel to provide less power as the voltage drops, causing further depletion of the capacitor and even more current draw from the solar panel 102 . The power bus voltage rapidly decays, and in fact, the rate of voltage decay increases as a function of time. Expressed in calculus terms, when the second derivative of the voltage with respect to time is greater than or equal to zero, the system is operating on the curve above the maximum power point voltage. When the second derivative of the voltage with respect to time is less than zero, the system is operating on the curve below the maximum power point voltage.
[0042] [0042]FIG. 5 shows a first improved control method which may be implemented by load controller 106 . After the load controller has started the compressor and allowed some small amount of time for the voltage on the power bus to settle into a steady state, the load controller begins sampling the voltage at regularly spaced time intervals. One of skill in the art will recognize that the sampling intervals may be allowed to vary if this is determined to be desirable, and appropriate adjustments can be made to the method. Additionally, the power bus voltage signal may be mildly conditioned to remove high frequency noise before being sampled by the load controller.
[0043] In step 502 an initial voltage sample is taken before the load controller enters a loop consisting of steps 504 - 516 . For each iteration of the loop, two additional voltage samples are taken. In step 504 , a first voltage sample is taken, and in step 506 a first change in the voltage is calculated by subtracting the previous voltage sample from the first voltage sample. In step 508 , a second voltage sample is taken, and in step 510 a second voltage change is calculated by subtracting the first voltage sample from the second voltage sample.
[0044] In step 512 , the two calculated voltage changes are compared. If the magnitude of the second voltage change is less than or equal to the magnitude of the first voltage change, then in step 514 , the loop controller increments the speed of the compressor by one step. On the other hand, if the magnitude of the second voltage change is larger than the magnitude of the second voltage change, then in step 516 , the loop controller decrements the speed of the compressor by two or more steps. While various implementations of decrement step 516 are contemplated, it is currently preferred to make the number of decrement steps a predetermined constant based on the system embodiment. It is further contemplated to make the increment step sizes adaptive in nature. The adaptation may be based on the size of the calculated first voltage change, so that smaller voltage changes result in smaller step sizes. In this manner, the load controller may more quickly and accurately locate the maximum power point. The nature of the adaptation may be changed after the first time the speed is decremented to provide for a smaller range of variation about the optimal operating point. For example, the step size may become based proportionally on the size of the second calculated voltage change, so that larger voltage changes result in larger step sizes.
[0045] [0045]FIG. 6 shows a second improved control method which may be implemented by load controller 106 . When the system is operating on the portion of the solar panel curve below the maximum power point, the calculated voltage changes continually grow if the compressor speed is not adjusted. Hence the method of FIG. 5 may be simplified by eliminating steps 508 and 510 , and replacing step 512 with step 612 , in which the calculated voltage change is compared with a predetermined threshold. No matter where the system is operating on the lower part of the curve, eventually the calculated voltage change will exceed the threshold, and the compressor speed will be reduced accordingly. When the voltage change is less than the threshold, the system is assumed to be on the upper part of the curve, and the compressor speed is increased. The threshold is preferably adjusted to allow for only a small range of variation around the maximum power point.
[0046] It is noted that the disclosed refrigeration systems and power control methods may have many varied embodiments. For example, one refrigeration system embodiment may employ an insulated enclosure with divided compartments that are maintained at different temperatures such as might be suitable for storing fresh and frozen foods. Another embodiment may employ the structure and stored contents of the insulated enclosure as the thermal reservoir. This latter approach may prove particularly suitable for refrigeration systems that are configured to produce the stored contents, such as would be the case for an ice maker. Some embodiments may include alternate energy sources such as batteries, a generator, or a commercial power grid, the use of which is may be minimized by using the solar panel as much as possible. These embodiments could use a smaller thermal reservoir due to availability of an alternate power source to maintain the temperature. In some embodiments, the refrigeration system may be applied to cool poorly insulated enclosures that are often exposed to substantial amounts of sunlight. In this vein, one refrigeration embodiment is an air conditioning system for vehicles that cools the interior when the vehicle is exposed to the sun. Such a system may or may not include some form of phase change material as a thermal reservoir.
[0047] Numerous such variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy. | 8 |
BACKGROUND
The present invention relates generally to an integrated circuit (IC) design, and more particularly to a laterally diffused metal-oxide-semiconductor (LDMOS) device with improved electrostatic discharge (ESD) performance.
As semiconductor devices continue to shrink in size, their susceptibility to ESD damage becomes an increasingly important reliability concern. An ESD event occurs when electrostatic charge is transferred between one or more pins of an IC and another object in a short period of time. The rapid charge transfer often generates voltages large enough to break down insulating films of semiconductor devices, thereby causing permanent damages. In order to protect the semiconductor devices from ESD damages, various protection circuits can be implemented at the input and output pins of the IC to shunt ESD currents away from sensitive internal structures.
The LDMOS transistor is one kind of the semiconductor devices that are particularly susceptible to damages caused by the ESD event. The LDMOS device, featured by its extended source or drain doped region, is often found in circuits operating in high voltages, such as 5, 12, 40, 100 and 1000 volts. Conventionally, the LDMOS transistor requires some additional devices or circuit modules to protect it from ESD damages. These ESD protection devices and circuit modules typically require a separate set of fabrication process steps different from those for the LDMOS transistors. Thus, the addition of these ESD protection devices and circuit modules increases the costs of manufacturing ICs that have LDMOS transistors implemented thereon.
As such, it is desirable to have a LDMOS transistor with improved ESD protection performance, thereby eliminating the need for other additional ESD protection devices and circuit modules.
SUMMARY
The present invention discloses a semiconductor device with improved ESD protection performance. In one embodiment of the invention, the semiconductor device includes a first doped region disposed on a first well in a semiconductor substrate; a second doped region disposed on a second well adjacent to the first well in the semiconductor substrate, the second doped region having a dopant density higher than that of the second well; and a gate structure overlying parts of the first and second wells for controlling a current flowing between the first and second doped regions. A first spacing distance from an interface between the second doped region and the second well to its closest edge of the gate structure is greater than 200 percent of a second spacing distance from a center point of second doped region to the edge of the gate structure, thereby increasing impedance against an electrostatic discharge (ESD) current flowing between the first and second doped regions during an ESD event.
The construction and method of operation of the invention, however, together with additional objectives 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. 1A illustrates a cross-sectional diagram of a conventional LDMOS device set.
FIG. 1B illustrates a layout diagram of the conventional LDMOS device set shown in FIG. 1A .
FIG. 2A illustrates a cross-sectional diagram of a LDMOS device set in accordance with one embodiment of the present invention.
FIG. 2B illustrates a layout diagram of the LDMOS device set shown in FIG. 2A in accordance with one embodiment of the present invention.
DESCRIPTION
FIG. 1A illustrates a cross-sectional diagram 100 of a conventional LDMOS device set, which includes two transistors 102 and 104 . The transistors 102 and 104 can be used as ESD protection devices or normally functioned devices. Both the transistors 102 and 104 are implanted on an N-tub 106 above a P-type substrate 108 . Each of the transistors 102 and 104 includes a gate structure 110 , an N+ doped source region 112 , and a shared N+ doped drain region 114 .
The N+ doped source regions 112 for both the transistors 102 and 104 are formed on P-type wells 119 . A P+ doped region 115 is also formed on one of the P-type wells 119 to provide a substrate contact. The N+ doped drain region 114 is formed on an N-type well 117 having a dopant density lower than that of the region 114 . The gate structures 110 for both transistors 102 and 104 are formed on the surface that overlies parts of the P-type wells 119 , the N-tub 106 and the N-type well 117 . A set of source contacts 116 and 118 are implemented respectively at the N+ doped source regions of the transistors 102 and 104 , while a drain contact 120 is implemented at the N+ doped drain region 114 .
FIG. 1B illustrates a layout diagram 122 of the conventional LDMOS device set shown in FIG. 1A . The layout diagram 122 shows the two LDMOS transistors 102 and 104 constructed by the gate structures 110 , the N+ doped source regions 112 , and the shared N+ doped drain region 114 , within a P+ guard ring 124 . The layout diagram 122 further illustrates the small spacing distances 121 between the N+ doped drain region 114 and the gate structures 110 , which are critical for the transistors 102 and 104 to withstand ESD currents.
Referring simultaneously to both FIGS. 1A and 1B , the spacing distances 121 are not long enough to provide sufficient impedance against an electrical current flowing between the N+ doped drain region 114 and the N+ doped source regions 112 when the transistors 102 and 104 are at the off state. During an ESD event occurring at the contact 120 , there is a high possibility that the ESD current would break down the transistors 102 and 104 and flow from the N+ doped drain region 114 to the N+ doped source regions 112 . As a result, the LDMOS transistors 102 and 104 are very susceptible to ESD damages. Additional ESD protection devices or circuit modules may be needed to protect the transistors 102 and 104 , thereby increasing manufacturing costs.
FIG. 2A illustrates a cross-sectional diagram 200 of a LDMOS device set in accordance with one embodiment of the present invention. The LDMOS device includes two transistors 202 and 204 , which are implanted on an N-tub 206 above a P-type substrate 208 . Each of the transistors 202 and 204 includes a gate structure 210 , an N+ doped source region 212 , and a shared N+ doped drain region 214 . The gate structure 210 can be constructed by a dielectric layer such as silicon oxide or nitride, and a conductive layer such as polysilicon or other metal materials. The P-type substrate 208 can be made of, for example, silicon, germanium, silicon-germanium alloys, or silicon on insulation (SOI) structures.
The N+ doped source regions 212 for both the transistors 202 and 204 are formed on P-type wells 230 . A P+ doped region 215 is also formed on one of the P-type wells 230 to provide a substrate contact. The N+ doped drain region 214 is formed on an N-type well 232 having a dopant density lower than that of the region 214 . In this embodiment, the dopant density of the N+ doped drain region 214 ranges approximately from 1×10 14 (1/cm 2 ) to 1×10 17 (1/cm 2 ), while the dopant density of the N-type well 232 ranges approximately from 1×10 11 (1/cm 2 ) to 1×10 14 (1/cm 2 ). The gate structures 210 for both transistors 202 and 204 are formed on the surface that overlies parts of the P-type wells 230 , the N-tub 206 and the N-type well 232 . A set of source contacts 216 and 218 are implemented respectively at the N+ doped source regions 212 of the transistors 202 and 204 , while a drain contact 220 is implemented at the N+ doped drain region 214 .
FIG. 2B illustrates a layout diagram 222 of the LDMOS device set shown in FIG. 2A in accordance with the embodiment of the present invention. The layout diagram 222 shows the two LDMOS transistors 202 and 204 constructed by the gate structures 210 , the N+ doped source regions 212 , and the shared N+ doped drain region 214 , within a P+ guard ring 224 . The layout diagram 222 further illustrates the small spacing distances 221 between the N+ doped drain region 214 and the gate structures 210 , which are critical for the transistors 202 and 204 to withstand ESD currents.
Referring to FIGS. 2A and 2B simultaneously, unlike the conventional LDMOS device shown in FIG. 1A , the N+ doped drain region 214 is designed to be much smaller in physical size, thereby allowing the spacing distances 221 between the gate structures 210 and the N+ implanted drain 214 to be increased. This, in turn, increases the impedance between the N+ doped drain region 214 and the N+ doped source regions 212 . When an ESD event occurs at the contact 220 , it would be more difficult for the ESD current to pass from the N+ doped drain region 214 to the N+ doped source region 212 . Thus, the transistors 202 and 204 can withstand ESD better than their conventional counterparts. As such, the need for ESD protection devices or circuit modules that are particularly designed for the LDMOS device can be eliminated, thereby significantly reducing the manufacturing costs.
The determination of the value of spacing distance 221 is a matter of optimization, depending on, for example, the device dimensions. As a general rule the spacing distance 221 measured from an interface between the N+ doped drain region 214 and the N-type well 232 to its closest edge of the gate structure 210 should be greater than 200 percent of a reference spacing distance 234 from a center point of N+ doped drain region 214 to the edge of the gate structure. In a specific embodiment, the spacing distance 221 should be greater than 1.5 μm. The LDMOS transistors 202 and 204 can be dedicated ESD protection devices as opposed to other normally functioned LDMOS transistors. The LDMOS transistors that function as ESD protection devices should have a longer spacing distance than that of the normally functioned LDMOS transistors.
While the above-mentioned embodiment uses N-type LDMOS transistors for descriptive purposes, it is understood by those skilled in the art that they can also be P-type LDMOS transistors. Specifically, the doped regions 212 and 214 , and the well 232 should be doped with the same type of dopant, while the well 230 should be doped with a different type of dopant. It is noted that silicide layers interfacing the contacts 216 and 220 and the doped regions 212 and 214 can be alternatively formed in another embodiment of the present invention.
Table I below provides a set of test data demonstrating how ESD performance of a LDMOS device can be improved by increasing the spacing between its doped drain region and gate structure.
TABLE I
De-
Total
+HBM/
vice
PO—N+
N+—CO
Width
IT
Vss
+MM/Vss
A
0.4 μm
0.25 μm
360 μm
0.2 A
0.5 kV
Below 50
V
B
1.0 μm
0.25 μm
360 μm
0.6 A
2.0 kV
100
V
C
1.5 μm
0.25 μm
360 μm
5.1 A
3.0 kV
350
V
D
2.0 μm
0.25 μm
360 μm
5.2 A
7.5 kV
500
V
Specifically, Table I shows specifications and test results of four different LDMOS devices: A, B, C, and D. All four LDMOS devices A, B, C, and D are designed to have a total width of 360 μm and a spacing of 0.25 μm between the edges of the drain region and the drain contact. The LDMOS device A is designed to the specifications of the conventional LDMOS device shown in FIG. 1A . More specifically, the LDMOS device A has a small spacing of 0.4 μm between the drain region and the gate structure. The LDMOS devices B, C, and D are designed to the specifications of the LDMOS device shown in FIG. 2A . More specifically, the LDMOS devices B, C, and D have corresponding spacing distances of 1.0, 1.5, and 2.0 μm between the drain region and the gate structures. From the results of the test, it can be shown that by setting the spacing between the gate structures and doped drain region higher, ESD performance of the LDMOS device can be improved.
The above illustration provides many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims.
Although the invention is illustrated and described herein as embodied in one or more specific examples, 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. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims. | A semiconductor device includes a first doped region disposed on a first well in a semiconductor substrate; a second doped region disposed on a second well adjacent to the first well in the semiconductor substrate, the second doped region having a dopant density higher than that of the second well; and a gate structure overlying parts of the first and second wells for controlling a current flowing between the first and second doped regions. A first spacing distance from an interface between the second doped region and the second well to its closest edge of the gate structure is greater than 200 percent of a second spacing distance from a center point of second doped region to the edge of the gate structure, thereby increasing impedance against an electrostatic discharge (ESD) current flowing between the first and second doped regions during an ESD event. | 7 |
FIELD OF THE INVENTION
The present invention relates to a nonvolatile memory apparatus and a method of using a thin film transistor (TFT) as a nonvolatile memory by storing carriers (including electrons and holes) in a body of the TFT, which operates a general TFT as a memory cell of a nonvolatile memory by manipulating the electrical characteristics of the TFT.
BACKGROUND OF THE INVENTION
As a result of the flat panel display widely used in the electrical devices, such as computers, televisions and communication devices, in recent years, the requirements of the flat panel display with high performance have raised. To achieve the purpose of system on panel, the peripheral circuits of the flat panel display have been integrated on the Low Temperature PolySilicon (LTPS) TFT-LCD panel, and using TFTs as the nonvolatile memory is very critical to such purpose.
Currently, most of techniques about integrating the nonvolatile memory on the panel change the structure of a general TFT in order to storage carriers (including electrons and holes). Please refer to U.S. Pub. No. 2004/0206957 “SEMICONDUCTOR DEVICE AND METHOD OF MAINUFACTURE” and U.S. Pat. No. 6,005,270 “SEMICONDUCTOR NONVOLATILE MEMORY DEVICE AND METHOD OF PRODUCTION OF SAME” for related arts regarding using TFT as nonvolatile memory. U.S. Pub. No. 2004/0206957 discloses a plurality of silicon particles for trapping the charge of injected carriers are placed between two gate oxide films; U.S. Pat. No. 6,005,270 discloses a charge storing layer formed between the gate and the gate oxide film.
However, manufacturing processes of the methods for adding the mentioned floating gate or tunneling oxide are more complicated than the general process of TFTs, thus increasing the cost. Moreover, when the electrical components become further miniaturized, the tunneling oxide is formed thinner and prohibits the data retention of the memory. Therefore, there are problems to be solved in the conventional methods for using general thin film transistors as nonvolatile memory.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide a method for using a thin film transistor (TFT) as a nonvolatile memory by storing carriers in a body of the TFT, which operates by manipulating the electrical characteristics of the TFT. When the TFT is turned on to cause the self-heating effect and generate electron-hole pairs, the vertical electric field on the gate separates the electron-hole pairs and injects the carriers to the body of the TFT in order to make the carriers store in the body and complete the writing operation. The method can be used for nonvolatile memory and takes advantage of integrating with other electrical components formed by TFTs, such as logic circuit or TFT-LCD pixel transistor, on the LCD panel without additional semiconductor manufacturing processes.
Another objective of the present invention is to provide a nonvolatile memory apparatus by using thin film transistors as memory units, which integrates with other TFT components on a same substrate without additional semiconductor manufacturing processes.
In order to achieve the foregoing objectives of the invention, a method of storing carriers in a body of a thin film transistor according to the present invention is provided, which comprises a thin film transistor including a semiconductor layer formed over a substrate having a insulating surface, a gate insulating film formed over the semiconductor layer and a gate formed over the gate insulating film, wherein the semiconductor layer includes a body formed between a source and a drain, the method includes providing a first drain voltage to the drain, a gate voltage to the gate and grounding the source at the same time, wherein when a Joule Heat resulted by the gate voltage and the first drain voltage is enough to cause the self-heating effect, majority carriers (holes with N-channel) of the thin film transistor are induced to be stored in the body of the thin film transistor, and the threshold voltage of the thin film transistor is changed to complete the writing operation; providing a second drain voltage to the drain, a source voltage to the source and grounding the gate at the same time, wherein when a potential difference between the second drain voltage and the source voltage is enough to make the majority carriers stored in the body overcome the energy barrier in grain boundary of the body, the bias of the drain, and the source removes the majority carriers from the body of the semiconductor layer of the thin film transistor to complete the erasing operation.
A further embodiment of the present invention is to provide a nonvolatile memory apparatus by using the TFTs as memory units providing a writing operation and an erasing operation, which comprises a memory for data access, including a plurality of memory units arranged in a matrix form, each of said memory units including a semiconductor layer formed over a substrate having a insulating surface, a gate insulating film formed over the semiconductor layer and a gate formed over the gate insulating film; a logic circuit for data control, wherein the semiconductor layer of the memory units includes a body formed between a source and a drain, and the memory units are general TFTs integrated with the logic circuit on the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a TFT memory according to the first embodiment of the invention;
FIG. 2 is a diagram showing voltages in the writing operation according to the first embodiment of the invention;
FIG. 3 is a diagram showing voltages in the erasing operation according to the first embodiment of the invention;
FIG. 4 is a sectional view showing a nonvolatile memory apparatus according to the second embodiment of the present invention;
FIG. 5 is a diagram showing memory units in a matrix form according to the second embodiment of the present invention;
FIG. 6 is a sectional view showing one of memory units according to the second embodiment of the present invention; and
FIG. 7 is a sectional view showing integration of a nonvolatile memory device according to the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The techniques employed by the present invention to achieve the foregoing objectives and the effects thereof are described hereinafter by way of examples with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a TFT memory according to the first embodiment of the invention. Referring to FIG. 1 the present invention uses a thin film transistor ( 10 ) comprising a semiconductor layer ( 20 ) which includes a body ( 21 ) formed between a drain ( 22 ) and a source ( 23 ) and is formed over a substrate ( 30 ) having a insulating surface ( 31 ), a gate insulating film ( 41 ) formed over the semiconductor layer ( 20 ) and a gate ( 40 ) formed over the gate insulating film ( 41 ). A method for storing carriers in a body of a thin film transistor according to the invention comprises a writing operation and an erasing operation.
FIG. 2 is a diagram showing voltages in the writing operation according to the first embodiment of the invention. The writing operation provides a first drain voltage, 15V in this embodiment, to the drain ( 22 ) of the thin film transistor ( 10 ), a gate voltage, 25V in this embodiment, to the gate ( 40 ) and grounds the source ( 23 ) of the thin film transistor ( 19 ) at the same time, wherein when a Joule Heat (the product of drain current and drain voltage) resulted by the gate voltage and the first drain voltage is enough to cause the self-heating effect, under the electric field effects of the gate ( 40 ), the electrons are emitted from the valence band to the conduction band of the semiconductor layer ( 20 ). The electron-hole pairs are generated and separated by the vertical electric filed on the gate ( 40 ), and the majority carriers (holes with N-channel) stores in the body ( 20 ) of the thin film transistor ( 10 ). The threshold voltage of the thin film transistor ( 10 ) is changed to complete the writing operation. According to the data in this embodiment with N-channel, the time of writing operation takes 3 milliseconds and the memory window is 3V.
FIG. 3 is a diagram showing voltages in the erasing operation according to the first embodiment of the invention. The erasing operation provides a second drain voltage, −5V in this embodiment, to the drain ( 22 ) of the thin film transistor ( 10 ), a source voltage, 10V in this embodiment, to the source ( 23 ) and grounds the gate ( 40 ) at the same time, wherein when a potential difference between the second drain voltage and the source voltage is enough to make the majority carriers stored in the body ( 21 ) overcome the energy barrier in grain boundary of the body ( 21 ), the bias of the drain, and the source removes the majority carriers from the body ( 21 ) of the semiconductor layer ( 20 ) of the thin film transistor ( 10 ) to complete the erasing operation. According to the data in this embodiment with N-channel, the time of erasing operation takes 100 milliseconds.
FIG. 4 is a sectional view showing a nonvolatile memory apparatus according to the second embodiment of the present invention, and FIG. 5 is a diagram showing memory units in a matrix form according to the second embodiment of the present invention. Referring to FIG. 4 , the present invention uses thin film transistors as memory units of a nonvolatile memory apparatus comprising a memory ( 110 ) for data access and a logic circuit ( 60 ) for data control, wherein the logic circuit ( 60 ) comprise at least one thin film transistor (TFT) and is integrated with the memory ( 110 ) on a substrate ( 30 ). Referring to FIG. 5 , the memory ( 110 ) includes a plurality of memory units ( 100 ) arranged in a matrix form providing a writing operation and an erasing operation.
FIG. 6 is a sectional view showing one of memory units according to the second embodiment of the present invention. Referring to FIG. 6 , each of the memory units ( 100 ) includes a semiconductor layer ( 20 ) formed over a substrate ( 30 ) having a insulating surface ( 31 ), a gate insulating film ( 41 ) formed over the semiconductor layer ( 20 ) and a gate ( 40 ) formed over the gate insulating film ( 41 ), wherein the semiconductor layer ( 20 ) of the memory units ( 100 ) includes a body formed between a source ( 23 ) and a drain ( 22 ), and the memory units ( 100 ) are general TFTs covered by a interlayer insulating film ( 50 ) and connected to peripheral circuits by the metal layer ( 51 ).
During the writing operation, the drain ( 22 ) is provided a first drain voltage, the gate ( 40 ) is provided a gate voltage and the source ( 23 ) is grounded, wherein when a Joule Heat (the product of drain current and drain voltage) resulted by the gate voltage and the first drain voltage is enough to cause the self-heating effect, under the electric field effects of the gate ( 40 ), the electrons are emitted from the valence band to the conduction band of the semiconductor layer ( 20 ). The electron-hole pairs are generated and separated by the vertical electric filed on the gate ( 40 ), and the majority carriers (holes with N-channel) stores in the body ( 20 ) of the memory units ( 100 ). The threshold voltage of the thin film transistor ( 10 ) is changed to complete the writing operation.
During the erasing operation, the drain ( 22 ) is provided a second drain voltage, the source ( 23 ) is provided a source voltage, and the gate ( 40 ) is grounded at the same time, wherein when a potential difference between the second drain voltage and the source voltage is enough to make the majority carriers stored in the body ( 21 ) overcome the energy barrier in grain boundary of the body ( 21 ), the bias of the drain, and the source removes the majority carriers from the body ( 21 ) of the semiconductor layer ( 20 ) of memory units ( 100 ) to complete the erasing operation.
Referring to FIG. 7 , a sectional view showing integration of a nonvolatile memory device according to the second embodiment of the present invention, the nonvolatile memory device according to the present invention can further be integrated with general TFT-LCD's pixel units ( 70 ) on the substrate ( 30 ), a Low Temperature PolySilicon (LTPS) substrate.
Hence the nonvolatile memory apparatus and the method of using a thin film transistor (TFT) as a nonvolatile memory by storing carriers in a body of the TFT according to the present invention, which makes the nonvolatile memory integrated with the TFT-LCD on a panel by using general TFTs storing carriers without additional floating gate or tunneling oxide, would decrease steps in the semiconductor manufacturing process of memory and reduce the manufacturing cost.
The preferred embodiments of the present invention have been disclosed in the examples. However the examples should not be construed as a limitation on the actual applicable scope of the invention, and as such, all modifications and alterations without departing from the spirits of the invention and appended claims shall remain within the protected scope and claims of the invention. | The present invention relates to a nonvolatile memory apparatus and a method of using a thin film transistor (TFT) as a nonvolatile memory by storing carriers in a body of the TFT, which operates a general TFT as a memory cell of a nonvolatile memory by manipulating the electrical characteristics of the TFT in order to integrate with other electrical components formed by TFTs, such as logic circuit or TFT-LCD pixel transistor, on the LCD panel without additional semiconductor manufacturing processes. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit and priority of U.S. Provisional Patent Application 61/925,451 titled “Cone Grip for Handgun” and filed on Jan. 9, 2014 and is a continuation of U.S. patent application Ser. No. 29/478,902 titled “Firearm Grip” and filed on Jan. 9, 2014 both of which are herein incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] Embodiments relate to the fields of small arms, handguns, and handgun grips.
BACKGROUND
[0003] Standard handgun grips, particularly revolver grips, must be held in a manner that often leads to discomfort and higher sensitivity to recoil. This is particularly true when the operators hand is large in comparison to the grip size. Systems and methods for providing a more ergonomic grip are needed.
BRIEF SUMMARY
[0004] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0005] Systems and methods are needed for providing a more ergonomic revolver grip. The needed grip can be obtained by use of a cone grip that mounts on a revolver frame in place of a standard revolver grip.
[0006] It is therefore an aspect of the embodiments to provide a grip for a revolver. The revolver has a frame with a trigger guard and a grip area. The grip area includes the frames base, palm strap, and typical finger interface. The grip includes a left overmold, left substrate, right substrate, and right overmold. The left substrate fits into the left substrate to form the left half of the grip. The right substrate fits into the right overmold to form the right half of the grip. The left half and the right half can be fastened together with the grip area between them to thereby install the grip on the revolver.
[0007] It is another aspect of the embodiments that the grip fills the large gap between the typical finger interface and the trigger guard. To accomplish this, the grip can contact the trigger guard or the finger interface forward edge can lie underneath at least some portion of the trigger guard.
[0008] It is yet another aspect of certain embodiments to have a finger interface with finger grooves. A possible side effect of filling the large gap is that one or more of the finger groves can be located within or under the large gap.
[0009] It is a further aspect of the embodiments that the palm interface and the finger interface are closer together at the bottom of the grip than the top of the grip such that the grip has a substantially conical cross-section. Certain embodiments can have the finger interlace and the palm interface intersecting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying figures, in which like names (reference numerals in utility) refer to identical or functionally similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the background of the invention, brief summary of the invention, and detailed description of the invention, serve to explain the principles of the present invention.
[0011] FIG. 1 illustrates a right side front view of a cone grip mounted on a revolver frame form in accordance with aspects of the embodiments;
[0012] FIG. 2 illustrates a top view of a cone grip mounted on a revolver frame form in accordance with aspects of the embodiments;
[0013] FIG. 3 illustrates a bottom view of a cone grip mounted on a revolver frame form in accordance with aspects of the embodiments;
[0014] FIG. 4 illustrates a left side view of a cone grip mounted on a revolver frame form in accordance with aspects of the embodiments;
[0015] FIG. 5 illustrates a back left exploded view of a cone grip and a revolver frame form in accordance with aspects of the embodiments;
[0016] FIG. 6 illustrates another back left exploded view of a cone grip and a revolver frame form in accordance with aspects of the embodiments;
[0017] FIG. 7 , which shows prior art, illustrates a machine screw and brass insert;
[0018] FIG. 8 , which shows prior art, illustrates a right front view of a revolver frame form;
[0019] FIG. 9 , which shows prior art, illustrates a left front view of a revolver frame form;
[0020] FIG. 10 , which shows prior art, illustrates a right back view of a revolver frame form;
[0021] FIG. 11 , which shows prior art, lustrates a left back view of a revolver frame form;
[0022] FIG. 12 , which shows prior art, illustrates a right side view of a revolver frame form;
[0023] FIG. 13 , which shows prior art, illustrates a left side view of a revolver frame form;
[0024] FIG. 14 , which shows prior art, illustrates a bottom view of a revolver frame form;
[0025] FIG. 15 , which shows prior art, lustrates a top view of a revolver frame form;
[0026] FIG. 16 illustrates a left side view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0027] FIG. 17 illustrates a right side view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0028] FIG. 18 illustrates a front left view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0029] FIG. 19 illustrates a right front view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0030] FIG. 20 illustrates a bottom left view left overmold for a cone grip in accordance with aspects of the embodiments;
[0031] FIG. 21 illustrates a bottom right view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0032] FIG. 22 illustrates a back right view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0033] FIG. 23 illustrates a back left view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0034] FIG. 24 illustrates a top right view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0035] FIG. 25 illustrates a top left view of a left overmold for a cone grip in accordance with aspects of the embodiments;
[0036] FIG. 26 illustrates a right side view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0037] FIG. 27 illustrates a left side view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0038] FIG. 28 illustrates a back left view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0039] FIG. 29 illustrates a back right view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0040] FIG. 30 illustrates a front left view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0041] FIG. 31 illustrates a right front view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0042] FIG. 32 illustrates a top left view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0043] FIG. 33 illustrates a bottom left view of a left e for a cone grip in accordance with aspects of the embodiments;
[0044] FIG. 34 illustrates a top right view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0045] FIG. 35 illustrates a bottom right view of a left substrate for a cone grip in accordance with aspects of the embodiments;
[0046] FIG. 36 illustrates a left side view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0047] FIG. 37 illustrates a right side view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0048] FIG. 38 illustrates a top right view of a right substrate or a cone grip in accordance with aspects of the embodiments;
[0049] FIG. 39 illustrates a top left view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0050] FIG. 40 illustrates a front left view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0051] FIG. 41 illustrates a front right view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0052] FIG. 42 illustrates a bottom left view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0053] FIG. 43 illustrates a bottom right view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0054] FIG. 44 illustrates a back left view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0055] FIG. 45 illustrates a back right view of a right substrate for a cone grip in accordance with aspects of the embodiments;
[0056] FIG. 46 illustrates a left side view of a right overmold for a cone g p n accordance with aspects of the embodiments;
[0057] FIG. 47 illustrates a right side view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0058] FIG. 48 illustrates a top left view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0059] FIG. 49 illustrates a top right view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0060] FIG. 50 illustrates a front left view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0061] FIG. 51 illustrates a front right view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0062] FIG. 52 illustrates a bottom right view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0063] FIG. 53 illustrates a bottom left view of a right overmold for a cone grip in accordance with aspects of the embodiments;
[0064] FIG. 54 illustrates a back right view of a right overmold for a cone grip in accordance with aspects of the embodiments; and
[0065] FIG. 55 illustrates a back left view of a right overmold for a cone grip in accordance with aspects of the embodiments.
DETAILED DESCRIPTION
[0066] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof. In general, the figures are not to scale.
[0067] A handgun grip 102 having a left side and a right side and that provides finger grooves 104 and a somewhat conical shape can provide a more ergonomic and controllable grip for a revolver. Each grip half has a substrate and an overmold with the substrate being a rigid plastic that provides structural rigidity and the overmold being a softer plastic that provides an ergonomic gripping surface and form. The two halves can be positioned over a firearm frame and secured there with fasteners such as a machine screw 105 and a threaded insert.
[0068] FIG. 1 illustrates a right side front view of a cone grip 102 mounted on a revolver frame form 101 in accordance with aspects of the embodiments. The right overmold 103 can be seen with a machine screw 105 attaching the right side of the grip to the left side. The generally conical shape of the grip 102 can be seen as can the finger grooves 104 .
[0069] The frame form 101 is used in the illustrations as a stand in for a revolver frame 101 , which are herein treated as equivalents. It is understood that the frame form 101 is dimensioned the same as a revolver frame 101 . A frame form 101 is typically used for ease of presentation and shipping because the frame form 101 is not a firearm and therefor requires no special licensing or handling. The cone grip 102 is designed to fit on a firearm.
[0070] FIG. 2 illustrates a top view of a cone grip 102 mounted on a revolver frame form 101 in accordance with aspects of the embodiments. The left overmold 201 and the right overmold 103 can be seen with the revolver frame 101 between them, The palm interface 202 is the back side area where the palm of the operators hand lies while operating the firearm.
[0071] FIG. 3 illustrates a bottom view of a cone grip 102 mounted on a revolves frame form 101 in accordance with aspects of the embodiments. The left overmold 201 and the right overmold 103 can be seen with the firearm frame 101 between them. The finger grooves help position the operators fingers while gripping the firearm. The finger interface 301 is the front side area where the operator's fingers, other than the index finger, grip the firearm.
[0072] FIG. 4 illustrates a left side view of a cone grip 102 mounted on a revolver frame form 101 in accordance with aspects of the embodiments. The left overmold 201 , which includes the left portion of the palm interface 202 and finger interface 301 , can be seen. The grip 102 can be seen to fill the area directly behind the trigger guard and therefor extends much further forward than other styles of grip. In fact, certain embodiments can have the forward edge 402 of the finger interface 301 lying directly under the firearm trigger or even slightly in front of the firearm trigger. Another aspect is that the finger interface 301 and the palm interface 202 extend downward in smooth curves to nearly meet each other near the bottom of the grip 102 . It is therefore an aspect of the cone grip 102 to have no base but instead have a transition between the finger interface 301 and palm interface 202 . Other styles of revolver grip can have a large and essentially flat base area at the bottom.
[0073] FIG. 5 illustrates a back left exploded view of a cone grip 102 and a revolver frame form 101 in accordance with aspects of the embodiments. The illustrated grip embodiments have six parts that fit together and onto a revolver frame 101 . Those parts include a left overmold 201 , a left substrate 501 , a right substrate 502 , and a right overmold 103 . A machine screw 105 and brass insert 503 can attach the grip 102 to a firearm.
[0074] FIG. 6 illustrates another back left exploded view of a cone grip 102 and a revolver frame form 101 in accordance with aspects of the embodiments. The difference between FIG. 5 and FIG. 6 is that the viewing angle has shifted further to the left and the machine screw 105 and brass insert 503 are not shown.
[0075] FIG. 7 , which shows prior art, illustrates a machine screw 105 and brass insert 503 . A brass insert 503 that is threaded to receive the machine screw 105 is taught here because it reduces the likelihood of galling or seizing with the non-brass, typically steel or iron, machine screw 105 . In practice, other materials can be used including plastic. The brass insert 503 can be pressed into a proper receptacle in one grip half. The machine screw 105 , after passing through the other grip half and the firearm, can be threaded in the brass insert 503 to fasten the grip 102 to the firearm. Other alternatives include molding or tapping threads directly into one of the substrates to thereby remove the need for an insert.
[0076] FIGS. 8-15 , which show prior art, illustrate views of a revolver frame form 101 . The trigger guard area 401 is clearly indicated. Another aspect of the illustrated frame form 101 is that there are two frame studs 801 on either side of the lower frame. The illustrated frame studs 801 mimic the frame studs 801 in certain well known revolvers and are used to help fasten and align firearm grips.
[0077] FIG. 12 , which shows prior art, illustrates a right side view of a revolver frame form 101 . The silhouette of the frame form 101 provides an indication of the normal grip profile. While using a typical prior art firearm grip, an operator's palm rests against the palm strap 1201 and the fingers wrap around the grip encompass the typical finger interface 1202 . The palm strap 1201 and the typical finger interface 1202 do not curve smoothly to meet each other, but instead meet the essentially flat base 1203 at the bottom. In addition, the large gap 1204 between the typical finger interface 1202 and the trigger guard 401 is readily apparent. The cone grip 102 occupies the large gap 1204 to provide a finger interface 301 that begins much further forward than otherwise possible.
[0078] Also with respect to FIG. 12 , the revolver frame 101 represented by the frame form 101 clearly shows the large gap 1204 between the finger interface 301 and the trigger guard 401 . Many semi-automatic handguns also exhibit a similar large gap. As such, a modification of the illustrated cone grip design would be appropriate for semi-automatic handguns to thereby move the forward edge 402 of the finger interface 301 forward and to fill the large gap 1204 . The operator of a semi-automatic handgun would thereby enjoy the ergonomic benefits of the cone grip design.
[0079] FIGS. 16-25 illustrate views of a left overmold 201 for a cone grip 102 in accordance with aspects of the embodiments.
[0080] FIG. 17 illustrates a right side view of a left overmold 201 for a cone grip 102 in accordance with aspects of the embodiments. The left overmold 201 , as with the right overmold 103 , is typically thermoformed or thereto-set to provide a firm but not hard or stiff gripping surface. More specifically, the durometer of the left and right overmolds 103 , 201 can have Shore Hardness A 55 or thereabout. In general, Shore Hardness A 55 works very well with the cone grip 102 although values between 40 and 65 have produced good grip. Manufacturing process has repeatably produced durometers within plus or minus 2% of the desired value.
[0081] The illustrated overmold embodiments can be produced by an over-molding process with a substrate placed in a mold, the mold sealed, and then the overmold material introduced into the mold. Given an overmold material that melts at 375 degrees, the substrate must not melt at 375 degrees.
[0082] The left side overmold 201 has pins 1701 that interface with pin holes 4601 in the right side overmold 103 . Certain of the structures are the result of material flowing into and around the left substrate 501 . Those structures include the formed plugs 1703 , the formed indent 1704 , the insert hole 1705 , and the rib grooves 1702 , Notice that the formed plugs 1703 are shaped like disks atop cylinders. The formed plugs 1703 get their shape from the overmold material flowing through a hole and filling a cavity on the other side of the hole. The insert hole 1705 is often a blind hole.
[0083] FIGS. 26-35 illustrate views of a left substrate 501 for a cone grip 102 in accordance with aspects of the embodiments.
[0084] FIG. 26 illustrates a right side view of a left substrate 501 for a cone grip 102 in accordance with aspects of the embodiments. The overmold material flowing into the plug forms 2602 produces the formed plugs 1703 . The stud hole 2603 matches the frame stud 801 in the revolver frame 101 or frame form 101 . The insert holder 2601 is a hole into which the brass insert 503 can be pressed. Note that other embodiments could provide a threaded hole instead of an insert holder 2601 . Also note that the substrate can be smaller such that the stud hole 2603 is molded into the overmold material instead of the substrate material.
[0085] FIG. 27 illustrates a left side view of a left substrate 501 for a cone grip 102 in accordance with aspects of the embodiments. The overmold material flows through the plug holes 2702 to thereby produce the formed plugs 1703 . The overmold material flows around the insert hole form 2704 , indent form 2703 , and ribbing 2701 to thereby produce the insert hole 1705 , formed indent 1704 , and plug hole grooves 1702 , respectively.
[0086] FIGS. 36-45 illustrate views of a right substrate 502 for a cone grip 102 in accordance with aspects of the embodiments.
[0087] FIG. 36 illustrates a left side view of a right substrate 502 for a cone grip 102 in accordance with aspects of the embodiments. The right substrate 502 is very similar to the left substrate 501 with the exception of providing a screw hole 3601 for the machine screw. Otherwise, similar structures perform similar functions.
[0088] FIG. 37 illustrates a right side view of a right substrate 502 for a cone grip 102 in accordance with aspects of the embodiments. The hole support 3701 around the screw hole 3601 can be seen.
[0089] FIGS. 46-55 illustrate views of a right overmold 103 for a cone grip 102 in accordance with aspects of the embodiments.
[0090] FIG. 46 illustrates a left side view of a right overmold 103 for a cone grip 102 in accordance with aspects of the embodiments. Most of the illustrated elements and structures are similar to those of the left overmold 201 . The right overmold 103 has pin holes 4601 to interface with the left overmold's pins 1701 . The right overmold 103 also has a support indent 4602 and a screw hole 3601 . The support indent 4602 is formed by overmold material flowing around the hole support 3701 of the right substrate 502 . The screw hole 3601 can be molded in a cut later.
[0091] FIG. 47 illustrates a right side view of a right overmold 103 for a cone grip 102 in accordance with aspects of the embodiments. The head of the machine screw 105 fits fully into the recess 5101 in the right overmold 103 to protect the operator's hand.
[0092] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, that 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 claims. | An ergonomic grip for a revolver can be better suited to people's hands by extending the forward edge of the finger interface forward to near the lower portion of the trigger guard. The palm interface and the finger interface can intersect or nearly intersect at the bottom of the grip. The grip has a substantially cone shaped cross-section. | 5 |
This is a Continuation Division of application Ser. No. 127,054 filed March 4, 1980, now abandoned.
FIELD OF THE INVENTION
This invention relates generally to food processing and packaging and more particularly to a process for producing semiprocessed fried potato in packaged state suitable for marketing (storing and distribution) at room temperature.
BACKGROUND OF THE INVENTION
Fried potatoes prepared by cutting potatoes into pieces of suitable size and frying these pieces in deep fat or oil, particularly so-called French-fried potatoes, are widely consumed as a snack food and as an accompanying food for meat, fowl, and fish courses and are greatly relished because of their unique aroma, flavor, and pleasant feel in the mouth.
This fried potato can be directly prepared from the raw potato through the process steps of washing in water, peeling, cutting, draining and frying in deep fat or oil (hereinafter referred to collectively as "oil") in any ordinary kitchen such as that in a home or in a restaurant. However, in order to simplify the cooking process, it is becoming a widespread practice to produce and market semiprocessed fried potatoes so that only a short, final deep-oil frying step need be carried out in the kitchen.
Heretofore, a typical process for producing this semiprocessed fried potato has comprised washing raw potatoes in water, peeling the same, cutting the same into pieces, immersing these pieces in an aqueous solution containing an antioxidant and a texture enhancing agent, draining off water from the pieces, pre-frying the pieces in deep oil, freezing the fried pieces, and packaging the same. In this process, the freezing is carried out for the purpose of preserving the quality of the semiprocessed product and for its preservation and stable supply throughout the year. The pre-frying in deep oil is carried out for improving the quality and efficiency of the product in use. The semiprocessed fried potato thus produced is distributed and marketed in the frozen state and preserved in freeze preservation facilities owned by the consumers until the final step of frying in deep oil.
The production and distribution of the semiprocessed products produced by the above described process, however, are accompanied by difficult problems. More specifically, the semiprocessed product produced in a frozen state requires freezing facilities respectively prior to, during, and after distribution, and the cost for procuring and maintaining these facilities is considerable. Furthermore, another problem is unintentional thawing of the once-frozen semiprocessed product caused by failures in facilities such as the freezing equipment and giving rise to a serious deterioration of the product quality.
In order to avoid these problems of distribution and preservation accompanying semiprocessed products in frozen state, the production of semiprocessed fried potato for preservation at room temperature is being considered in some quarters, but has not been reduced to practice in the present state of the art. One production process proposed for this purpose is that for so-called retort foods which, after the steps of washing in water, peeling, cutting, and treating in an aqueous solution containing a texture enhancing agent and an antioxidant of the potatoes, contemplates the steps of draining, packaging the potato pieces directly as they are into retort bags, tightly sealing the bags, and retort sterilizing the bag contents by applying pressure and heat thereto.
However, the storing and distributing at room temperature of semiprocessed fried potato produced merely by such a process are accompanied by several other problems. More specifically, when the semiprocessed potato which has been packaged in a sealed bag is sterilized by heating under pressure in the final stage, moisture is driven out from the ruptured tissues of the potato by heating, and this moisture collects in the bag because of its sealed construction. Consequently, this water soaks into the semiprocessed potato, which then becomes soggy and may even assume the state of a gruel, whereby the texture of the semiprocessed potato becomes poor. Furthermore, a large quantity of excess moisture adheres also to the surfaces of the potato pieces and causes an extremely violent spattering of oil in the final cooking step of frying in deep oil, whereby this cooking step is made difficult and unpleasant.
These problems can be avoided by sufficiently drying the potato pieces prior to packaging. However, the unique aroma and flavor of fried potato arise from the direct frying in deep oil of the raw potato, and the deliciousness of eating fried potato is enhanced also by the combination of the crisp outer surface and the resilient, mealy interior part thereof. All of these desirable characteristics of fried potato cannot be obtained by frying dried potato pieces in deep oil.
While the procedure of storage and distribution of semiprocessed fried potato in this manner can be theoretically conceived in principle, it has not been reduced to actual practice.
As a result of my research, however, I have found that the deterioration of the semiprocessed fried potato represented by the above mentioned oozing out or exudation of moisture from the potato pieces is not due solely to the heating for retort sterilization but progresses with elapse of time as a consequence of overlapping of the effects of other factors. A representative factor among these is the effect of oxygen and light on the semiprocessed fried potato pieces. I have found further that, while a large quantity of moisture has a substantial effect on the deterioration of the potato pieces as described above, this difficulty can be remarkably overcome, not only by completely removing the moisture from the potato pieces in their natural state, but also by partially lowering the moisture content.
More specifically, since the solid content and the water content within a raw potato piece exist in a state of equilibrium, this equilibrium is disrupted by a variation in an external influence such as the retort sterilization treatment, whereby oozing out of water occurs. Accordingly, by causing beforehand the water content in the potato to be somewhat lower than that for the equilibrium state, the oozing out of water due to a variation in an external influence can be prevented. I have found also that when potato pieces which are in a partially dried state, and not in a completely dried state, are fried in deep oil, the above mentioned desirable characteristics of fried potato are retained and preserved.
This desirable result may be attributed to ample heating even to the innermost part of each potato piece when the final step of frying in deep oil is carried out, whereby moisture saturation occurs with a relatively low absolute water content. In the case where raw potato pieces are fried directly in deep oil, the surplus water under the heating condition is driven out of the potato pieces.
As a result of my further study conducted on the basis of the above described findings, I have found further that when potato pieces are partially dried prior to packaging and, moreover, are then packaged with an enveloping packaging material which has a gas-impervious or gas-barrier property and lightproofness, deterioration of the semiprocessed fried potato pieces during storage and distribution at room temperature can be prevented, and, at the same time, the above mentioned desirable characteristics of fried potato can be substantially preserved until the potato pieces are finally fried and eaten.
SUMMARY OF THE INVENTION
It is an object of this invention to provide, on the basis of the above described findings, a process for producing semiprocessed fried potato slices, strips, shoe-string strips, short bars, and the like (herein referred to collectively as "pieces") in a packaged state suitable for storing and distribution at room temperature, during which the desirable unique characteristics of fried potato are preserved to be fully exhibited when the potato pieces are finally fried and consumed.
According to this invention in one aspect thereof, briefly summarized, there is provided a process for producing semiprocessed potato for preservation at room temperature which comprises: partially predrying potato pieces which have been prepared by washing, peeling, and cutting raw potatoes; placing the pieces thus predried into a packaging bag made of a sheet material having a gas-barrier property and lightproofness; gas-tightly sealing the bag to package the pieces; and sterilizing by heating the potato pieces thus packaged.
According to another aspect of this invention, there are provided semiprocessed potato pieces processed and packaged for preservation at room temperature during storage and marketing to be ultimately finish-fried in deep oil and consumed, which potato pieces are produced by the above summarized process.
The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with this invention, raw potatoes are first washed with water, peeled, and cut into pieces of suitable size. These steps are carried out according to the ordinary method in the prior art and are not especially novel. If desired, the potato pieces thus prepared are treated by immersion thereof in an aqueous solution containing a texture enhancing agent and an antioxidant. Examples of suitable texture enhancing agents are calcium chloride, potassium alum, and calcium phosphate. The concentration of the texture enhancing agent is 0.5 to 1.5 percent, preferably 0.5 to 1.0 percent (throughout this disclosure, quantities expressed in percent being by weight). The antioxidant, an example of which is ascorbic acid, is used in a concentration of 0.5 to 2.0 percent.
After the above described immersion treatment, the potato pieces are subjected to blanching for 5 to 10 minutes with a medium such as steam, according to necessity, to deactivate the enzyme activity of the potato and are then drained.
The potato pieces thus obtained are partially predried according to this invention. This predrying is carried out until the moisture content is reduced by 10.0 to 20 percent, preferably 15.0 to 17.0 percent. This degree of drying is especially critical. If this degree of drying is less than 10 percent, the oozing out of water in the subsequent sterilization treatment or during storage cannot be sufficiently prevented. On the other hand, if 20 percent is exceeded, the aroma and flavor of the fried potato product will be impaired. Furthermore, the weight of the potato will be excessively reduced, whereby the loss will be great. Since a potato ordinarily has a water content of from 78.0 to 82.0 percent, the water content in the potato pieces after predrying becomes from 61.0 to 72.0 percent, preferably from 63.0 to 67.0 percent.
The predrying can be carried out by a variety of methods, including frying in oil, exposure to a stream of hot air, or heating by means of an infrared heater or a far-infrared heater. However, frying in oil is an effective and conveniently simple method. More specifically, one desirable feature of this predrying method is that it is substantially the same as the final cooking step of frying in oil, whereby a process step of a different nature is not introduced into the entire process of producing fried potato pieces.
Another desirable feature of this predrying method is that it fulfills the following condition. Since the aforementioned oozing out of water from the potato pieces occurs from the outer surfaces thereof, it is desirable that the predrying operation be of a mode by which the moisture is removed with priority from the surfaces of the potato pieces, and the desired water content is retained in the interior of the pieces. Frying in oil is one of the methods which most ideally satisfy this condition. Still another desirable feature of this predrying method is that a thin shell into which the oil has permeated is formed around the outer surface of each potato piece by the frying in oil. This shell functions to effectively prevent oozing out of moisture from the interior of the piece.
While this frying in oil can be carried out with any edible oil, light oils such as shortening oils and salad oils are preferable. I have found that the best results are obtained by frying the potato pieces at a relatively high temperature such as, for example, 140° to 190° C., preferably 170° to 190° C., for a short time such as 15 to 60 seconds. These conditions are selected for the purpose of removing water with priority from the surfaces of the potato pieces. After this frying in oil, surplus oil is drained off.
A specific quantity of the potato pieces thus predried is then charged into a bag, a pouch, a sealable tray or cup or the like (herein referred to collectively as "a bag") made of a packaging material having a gas-barrier property and lightproofness, and the bag is then sealed in a gastight manner. A most desirable packaging material for this purpose which simultaneously possesses the above mentioned properties comprises a laminated sheet of a thermoplastic resin film and aluminum foil for retort use.
This packaging and sealing is preferably carried out by a vacuum packaging process, i.e., by sealing the predried potato pieces in the packaging bag under vacuum. One reason for this is that vacuum packaging removes oxygen from the package bag interior. Another reason for this is that vacuum packaging greatly reduces the deformability of the package. More specifically, one cause of promoting deterioration of the potato pieces during storage at room temperature is physical damage of the potato pieces. This damaging of the potato pieces in many instances arises from stacking of the packaged semiprocessed product during storage or from the application of external forces locally to certain parts of the packaged potato pieces during handling in the market distribution. When vacuum packaging is resorted to, however, the structurally integral or unitary nature of the package bag and the potato pieces contained therein is improved, whereby the combined structure is not readily subject to external forces acting locally thereon, and the resistance to deformation of the entire semiprocessed fried potato product is increased.
Finally, the potato pieces sealed in the packaging bag are subjected to sterilization treatment until they can withstand storage at room temperature. The simplest sterilization treatment is heat treatment.
While the sterilization conditions cannot be generally stated since they differ with factors such as the shape of the package and the size (thickness) of the potato pieces, the sterilization temperature may be effected at a temperature of, e.g., 115° to 120° C. The sterilization time is appropriately determined with the sterilization value (Fo value) as a criterion so as to impart the desired preservability to the semiprocessed fried potato product.
While this sterilization can be carried out by any suitable heating method such as heating with hot air, a treatment wherein pressure and heat are applied by means of a retort sterilizer using steam or hot water is particularly suitable.
A semiprocessed fried potato product produced in the above described manner has a preservability of the order of six months at room temperature. After storage and distribution at room temperature, the package is opened when necessary within this period, and the contents are fried in deep edible oil, for example, at a temperature of 170° to 180° C. for a time of the order of 2.0 to 5.0 minutes, whereupon the final fried potato product is obtained for consumption.
In order to indicate more fully the nature and utility of this invention, the following specific examples of practice constituting preferred embodiments of the invention are set forth, it being understood that these examples are presented as illustrative only and are not intended to limit the scope of the invention.
EXAMPLE 1
Raw potatoes ("Danshaku" Species, produce of Hokkaido, Japan) were washed, peeled, and cut into pieces measuring 10×10×30 mm. These pieces were treated by immersion for 60 minutes in an aqueous solution containing 1.0 percent of calcium chloride and 1.0 percent of L-ascorbic acid.
Thereafter, the pieces were washed with water, drained, and fried for 30 seconds in deep salad oil heated to 180° C. thereby to reduce the water content of the potato by 17 percent from that of the raw potato.
The potato pieces thus predried were cooled, and then 1 kg. of these pieces were placed in a retort bag measuring 320×250 mm. and made of a laminated sheet material comprising a 12-micron polyester film, a 9-micron Al foil, and a 60-micron polypropylene film. 100-percent vacuum sealing of the bag containing the potato pieces was then carried out by means of a vacuum packaging machine.
Sterilization of the potato pieces thus packaged and sealed was carried out at 120° C. for 20 minutes in a pressurized hot-water rotary type retort sterilizer. The packaged potato pieces were then promptly cooled.
After preservation for one month at 25° C., the package of the product manufactured in the above described manner was opened, and the semiprocessed fried potato pieces were fried for approximately 5 minutes in deep salad oil heated to 180° C., during which there was little spattering of the oil due to surplus water content. As a result, French-fried potatoes of firm texture and good taste and flavor were obtained.
Separately, the same procedure was followed except for the use of a retort bag of a laminated sheet comprising a 12-micron polyester film, a 9-micron Al foil, and a 60-micron high-density polyethylene film, whereupon results similar to those set forth above were obtained.
EXAMPLE 2
Raw potatoes ("Yukijiro" species, produce of Hokkaido, Japan) were washed, peeled, and cut into pieces measuring 10×10×30 mm. by means of a potato cutter. These pieces were washed well in water, thereby to wash off excess starch and other substances, and were then treated by immersion for 60 minutes in an aqueous solution containing 1.5 percent of calcium chloride and 1.0 percent of L-ascorbic acid.
Thereafter, the potato pieces were washed in water and were then drained and fried for 60 seconds in deep lard oil heated to 140° C. By this predrying, the water content in the potato was lowered by 12 percent relative to that of the raw potato. Then the pieces were cooled by using dry aseptic air.
One kg. of the potato pieces thus cooled were placed in a retort bag measuring 320×250 mm. and made of a laminated sheet material comprising a 12-micron polyester film, a 9-micron Al foil, and a 60 -micron polypropylene film. 100-percent vacuum sealing of the packaged potato pieces was then carried out by means of a vacuum packaging machine.
Sterilization of the potato pieces thus packaged and sealed was carried out at 130° C. for 7.5 minutes in a pressurized hot-water rotary type retort sterilizer, after which the potato pieces were immediately cooled.
After preservation for three months at 20° C., the package of the product manufactured in the above described manner was opened, and the semiprocessed fried potato pieces were fried for approximately 2 minutes in salad oil heated to 180° C., during which there was little spattering of the oil since there was almost no water adhering to the surfaces of the potato pieces. The finally fried potatoes thus obtained were crispy and had good taste and flavor. | Potato pieces or strips prepared by washing, peeling, and cutting raw potatoes are immersed in an aqueous solution of an antioxidant and a texture enhancing agent, washed, drained, prefried for partial drying in deep edible oil thereby to reduce their water content by 10 to 20 percent by weight, packaged, gas-tightly sealed under vacuum in a bag made of a laminated sheet comprising a thermoplastic resin film and an aluminum foil, and then sterilized by heating under pressure. The preprocessed potato pieces thus produced can be preserved for a number of months while being stored and distributed at room temperature and require only a few minutes of final frying in deep oil or fat for consumption. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is related to copending application serial no. (Attorney Docket YOR920050131US1), filed herewith, for “Injection Molded Microlenses For Optical Interconnects,” the disclosure of which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a highly efficient wafer-scale microelectronic process for the fabrication of spectral filters, microoptics, optical waveguide arrays and their aligned attachment to optoelectronic semiconductor imaging devices, integrated photonic devices, image displays, optical fiber interconnection, optical backplanes, memory devices, and spectrochemical or biomedical analysis devices.
[0004] 2. Background Art
[0005] Synthetic reconstruction of color images in solid-state analog or digital video cameras is conventionally performed through a combination of an array of optical microlens and spectral filter structures and integrated circuit amplifier automatic gain control operations following a prescribed sequence of calibrations in an algorithm. Fabrication of a planar array of microlenses is conventionally performed by application of a photoresist on a topmost layer of planarized film formed over red, green, blue color filters. By successive processing steps of patterning, developing, etching, followed by thermal reflow, the resist forms approximate plano-convex or hemispherical microlenses. The rheologic properties of the resist will determine the radius of curvature of the microlens elements in the planar array. Coupled with the resist's index of refraction, the resulting microlens array will have a focal length and light-collection properties which may depart from desired optimum performance, including poor control of the fill-factor of the photodiodes in an array comprising the pixel plane. Optical design of the lens shape and refractive index is extremely limited by the necessity to use photoimageable materials with restricted thermal reflow characteristics.
[0006] It is difficult to achieve long focal length high radius of curvature and high refractive index microlens arrays in a single array-plane using conventional microlens forming and fabrication processes. U.S. Pat. No. 6,482,669 B1 summarizes a number of the drawbacks of known solutions in the Prior Art. It is further noted and particularly pointed out that the present invention enables high-volume manufacturing of aspheric microlens arrays. In addition to the foregoing description of fabricating semiconductor color imagers for digital cameras, microlens arrays are also widely employed for high-resolution display monitors and for the coupling of optical waveguides in optical backplanes and optical fibers used in optical communications networks. Electrically addressable lens elements made of various liquid crystal materials are also used in lens assemblies with variable focal length and variable depth of field, or to adjust the image position to accommodate different viewing conditions. These active lens elements are on the order of tens of microns in thickness and can be switched at speeds greater than 85 MHz, enabling full spectrum color imaging without noticeable flicker.
[0007] FIG. 1A exhibits the Prior Art process 100 for the formation of a microlens array: a planar film of a photoimageable material such as a photoresist is photolithographically patterned such that exposure to actinic radiation and subsequent development of the photoresist forms a two-dimensional array of mesas which can be thermally reflowed (melted) into planoconvex microlenses under surface tension forces. An exploded assembly view is shown in 110 , indicating the relative position and alignment of the microlens array elements to an underlying array of red, green, blue color filters and further underlying array of semiconductor photodetectors. By electronically amplifying and combining the outputs of the red, green and blue signals to comprise a unit of image or a picture element termed a pixel, color image formation is achieved. FIG. 1B is an isometric view showing the detailed semiconductor cross-section of the mesa-patterned photoresist 120 before reflow and the resulting planoconvex lens 130 after reflow. Topographical variations caused by the process of integrating color filters into the semiconductor, as shown in FIG. 1B , are a common problem in the Prior Art and typically require additional processing steps for adding a planarizing layer. The focal length required of the microlens elements is the vertical distance projected down to the photodetector array plane.
[0008] As the diameter of the approximately hemispherical microlens is reduced to accommodate increasing imager resolution and pixel density, the precursor photoresist film thickness scales down and the thermal reflow process of the prior art microlens formation process becomes limiting; the radius of curvature and refractive index of the reflowed lens cannot achieve the focal length requirement without significant cross-sectional thinning of the semiconductor device structure. FIG. 1C illustrates the case of collimated incident light 140 collected by planoconvex lens 150 converging a cone of light 170 passing through color filter 160 to focal plane 180 at photodetector 190 . Optically generated cross-talk may result for off-axis incident image light, in spite of measures incorporating metal light shields formed between the color filters, when the optical properties of the microlens are limited by the thermal reflow process of the Prior Art, as demonstrated in FIG. 1D .
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to teach an apparatus for high-volume wafer-scale manufacturing by injection molding of microoptic elements and microspectral filtering devices.
[0010] The conventional definition of a microlens is a lens with a diameter less than one millimeter. Generalizing this definition to the functional elements of optical systems designs, such as refractive or diffractive lenses, mirror/reflectors, Bragg gratings, interferometric devices like Mach-Zender interferometers, mode transformers for waveguide or fiber-optic couplers, variable or fixed optical attenuators, polarizers, compensators, rotators, splitters, combiners, and other devices, it is in accord with the above-mentioned object of the present invention to teach the extension of injection-molding technology down to the order of a micron.
[0011] Another object of the present invention is to provide processes for the wafer-scale fabrication of microoptic devices, which can be integrated into semiconductor structures, such as a color-imaging device for digital cameras. A further object of this invention is to extend this fabrication process to include liquid crystal materials which may be formed into active lens arrays with electronically variable focal length and depth of focus. In accord with another object of the present invention, there is provided a manufacturing method and microelectronic fabrication process sequence which minimizes the number and task-times of the operational unit-process steps required in the reduces of semiconductor arrays for color imaging devices. Production cost minimization is consistent with this latter object of the present invention.
[0012] A further object of the present invention is to teach the manufacturing of aspheric microlenses and lensfilter integration that are not possible with Prior Art technologies. A still further object of the present invention is to provide an apparatus and method for the lithographically precise alignment of arrays of microoptic elements to semiconductor structures, such as integrated color filter arrays and photodiode arrays, and, the attachment thereto.
[0013] Attachment of semiconductor chips to carriers, modules or packages using controlled collapse chip connection (“C4”) technology has proven to provide superior electrical performance parameters, such as minimizing parasitics, mutual inductance, controlled impedance, and noise reduction. It is an object of the present invention to enable the concurrent use of the injection-molding apparatus for the hybrid use of solders for C4 joining of chips to substrates and for optical polymers or glasses for forming and attaching microoptic elements.
[0014] Additional molding features and additional uses for molded microoptic devices are described in copending patent application no. (Attorney Docket YOR920050267US1) for “Injection Molded Microlenses For Parallel Optical Interconnects,” filed herewith, the disclosure of which is hereby incorporated herein by reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1A illustrates a conventional semiconductor color imager device cross-section.
[0016] FIG. 1B depicts the Prior Art thermal reflow process of forming resist into microlenses.
[0017] FIG. 1C pictures the light cone for image formation by microlenses onto the photodiodes.
[0018] FIG. 1D exhibits the optics for color pixel formation with microlenses and color filters.
[0019] FIG. 2 is a simplified process flow chart describing the sequence and principal features of a preferred injection molded microoptics procedure.
[0020] FIG. 3 indicates the process description for mold plate fill.
[0021] FIG. 4 is a side view of the mold plate fill tool scanning injection process.
[0022] FIG. 5 depicts the process sequence for alignment, clamp, transfer, and attachment of microlenses.
[0023] FIG. 6 provides a side view of the fixture frame for mold to wafer alignment and transfer.
[0024] FIG. 7 illustrates the optional post-transfer thermal adjustment of a microlens array.
[0025] FIG. 8 indicates the wafer preparation process description for a microlens interface layer.
[0026] FIG. 9 is a prior art imager cross-section showing alignment of lens, filter and photodiode.
[0027] FIG. 10 shows the integrated red, green and blue color lensfilters of the present invention.
[0028] FIG. 11 illustrates an optical assembly for parallel waveguides or fiber-optic interconnects.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The present invention teaches an apparatus and method for the formation of planar arrays of microlenses and/or optical waveguides and photonic devices which may comprise, inter alia, optical bus I/O and memory structures in advanced future computer backplanes, image-formation layers on CMOS or CCD solid-state color imagers, matrix arrays of lenses on flat panel displays, and other fields of applications for microoptic elements.
[0030] Unlike conventional art, aspherics, anamorphics, cylindrical lenticular and ellipsoidal microoptic surface designs may be realized with the present invention to provide the long focal lengths required for semiconductor color imaging devices or for VCSEL (vertical cavity surface emitting laser) couplers, particularly those used in parallel optical links including applications such as InfiniBand channels for computers and storage devices. Employment of high refractive index materials, such as polymers, or glasses, or liquid crystal materials, with non-spherical shapes are enabled by the present invention. It is recognized and particularly pointed out that anisotropic etching processes to form cavities in mold plates, including reactive ion etching (RIE) or plasma etching, may be harnessed to create designed microoptics geometries by virtue of differential etch-rates along selected spatial directions, or, by virtue of preferential etching along crystallographic planes. Hence ellipsoidal or aspheric microlens shapes are generated through the controlled ratio of forward to lateral etch-rates in plasma or RIE chambers with defined gas components at specified partial pressures producing designed cavity shapes in a carrier mold plate or template.
[0031] Cavities with desired geometry can be created in a glass plate or other suitable carrier mold material such as polyimide to meet the requirement of various applications. Both wet etching and dry etching techniques have been widely used to etch cavities. The resolution of the wet etching technique is relatively poor due to its isotropic etching characteristics and the undercut it generates. In contrast, reactive ion etching (RIE) has the advantage of controlling the directionality and sidewall profile of the etched cavities. RIE offers good selectivity, little undercut, and high throughput. The process starts by first applying a blanket layer of etch mask material on the glass surface, then patterns it to have the mirror image of the device array on the wafer to which it will subsequently be transferred and attached. The etch mask can be a metal mask, polymer or combination of both. The glass plate is loaded in the RIE tool which generally consists of parallel plate electrodes and an rf power supply. The glass plate is placed on the electrode to which rf power is applied. The plasma of ionized gas is generated between the electrodes. A gas inlet introduces reactive gases, and a pumping system is used to maintain a constant pressure in the etching chamber. The pressures used in RIE are 1 to 20 Pa. Suitable etching gases, such as CF4, CF3, C2F6, CHF3, C3F6, − CF4+O2, Cl2F2, CCl4, etc. can be selected so as to produce ionic species which react chemically with glass to form volatile products which spontaneously desorb from the etched glass surface and are removed by the vacuum pump system in the RIE tool. The sidewall profile can be controlled and optimized by parameters such as pressure and flow rate, rf power density (W/cm2), electrode design and the chemical nature of the discharge species.
[0032] Moldplates can also be fabricated by direct laser etching of the cavities. This process is particularly suitable for polyimides or polyimide-on-glass substrates.
[0033] A carrier mold plate with alignment marks and patterned, shaped cavities is designed to generate the microoptic array. Molten polymer or glass is injected to fill the mold plate. A conformal liner of PTFE or other release-film coats the surface of the mold cavities to enable detachment from the mold during transfer and attachment to various devices. Alternatively, plasma etch conditions may be controlled to effect a surface state on the injection mold's cavity walls which is hydrophobic or hydrophilic, thereby aiding the release of the molded microoptic elements. The mold plate coefficient of thermal expansion (CTE) is matched to the target wafer to which the injection molded optical components are bonded. An alternative embodiment employs a layer of polyimide which may either be laser ablated or photoexposed and developed into the array of cavities.
[0034] In order to facilitate release of the microlens material from the mold cavities, well known release agents can be used, including waxes and poly(tetrafluoroethylene) (PTFE) coatings. In addition, a class of materials is well known to form dense, highly ordered monolayer films on silica glass surfaces. These self-assembled monolayers, or SAM's, form because of the tendency of trisilanols to form a tight silyl ether network with silanol groups on the glass surface and with silanol groups on neighboring molecules. The self-ordering films come about from the close packing of long chain alkyl groups attached to the trisilanols. For example, when a wet glass surface is dipped into a dilute solution of octadecyltriethoxysilane or octadecyltrichlorosilane, a well ordered monolayer film assembles on the glass surface. Subsequent baking of the film makes a permanent bond of the film to the surface. Because the end group on the long chain alkyl can have a large number of different functional groups, SAM's allow tuning the surface energy of the glass mold to promote release of the microlenses to the wafer to which they are to be transferred. The SAM's are robust and will survive multiple reuses; and, moreover, when fouled they can easily be removed completely by oxygen ashing and a fresh SAM applied.
[0035] FIG. 2 provides a process flow-chart description of one embodiment of the present invention. In FIG. 2 , two parallel process sequences are shown, one for the filling and inspection of the cavities in a prepared mold plate, and, a second for the preparation of the wafer to be receiving the transferred elements from the cavities of the mold plate. The details of the apparatus design, alignment, transfer, optional reflow, and mold reuse cleaning processes are described in the set of FIGS. 2 through 7 .
[0036] In FIG. 2 , a wafer-scale mold plate 220 with photolithographically formed and etched optical alignment keys 254 and etched cavity array with cavity sidewalls coated with a release layer such as wax, PTFE, a SAM, or other suitable material or plasma process, is injected with a molten lens material 240 . Wafer 210 with etched conjugate optical alignment keys 252 and an optional applied planarizing optical adhesive and refractive index matching layer 230 is brought into alignment by centering alignment key 254 inside key 252 as shown in the aligned state 256 . The alignment process is performed by a conventional photoaligner tool 250 . The microoptic elements formed in the cavities of the mold plate are transferred as shown in 260 to the interface layer 230 . The wafer proceeds to dice, sort and pick 280 for final packaging of the finished device chip, while the mold plate is cleaned and prepared for multiple reuse 270 .
[0037] The process flow details for the mold preparation and injection filling sequence are provided in FIG. 3 steps A, B, C, D. As previously described herein, a patterned array of cavities of designed shape are etched into mold plate 300 by one of the isotropic or anisotropic etch processes taught by the present invention. A conformal release layer 310 is applied to the array of cavities, the preferred composition of which may be selected from the group consisting of fluoropolymers such as PTFE (polytetrafluoroethylene), spray release agents based on wax or zinc oxide, a sacrificial laser ablatable layer or thermally decomposable layer using cavity heaters, self-assembled monolayers or SAMs, trichlorosilane, or other antistiction agents. A fill-tool, described in FIG. 4 , injects dispensed liquid from the fill-head crucible into the array of cavities which will be solidified into microoptic or microspectral filter elements.
[0038] The preferred liquid materials for microlens arrays may be selected from the group consisting of polymers, photopolymers, glasses, sol-gels, UV-curable epoxies, resins, acrylics, cyclolefins, polycarbonates, PMMA (polymethyl methacrylate), polyimide, glass semiconductors such as Ge x Sel 1-x , and, combinations using photoinitiators and/or photoreactive agents. Two optional process sequences may next be followed: a first sequence, illustrated in FIG. 3 step C as transmissive microlenses 320 , or a second sequence shown in FIG. 3 step C as spectrally absorptive microlenses which are defined in the present invention by the new term color filterlenses 330 , or simply filterlenses 330 . The filterlenses 330 are taught in the present invention to be the integration of the microlens array with the appropriate red, green and blue array of color filters. The lensfilter represents the combination of a red, green or blue dye-loaded or other color absorbing filter device into the optical polymer or glass comprising the microlens.
[0039] It is recognized and particularly pointed out that extrapolation of the lensfilter concept to other microoptic combinations of image-formation and spectral selection characteristics is subsumed in the present invention, and, that the apparatus and methods taught enable advances in the integration and wafer-scale manufacturing of microoptic products.
[0040] The advantage of parallel processing injection mold microoptics in carrier mold plates concurrently with that of other substrates, such as semiconductor device fabrication (e.g., image sensors or VCSEL wafers), is an important distinction from Prior Art. In particular, microoptics for VCSEL applications require unique characteristics which can more easily be fabricated using injection molding; these include fabrication of interconnected lens arrays which compensate for VCSEL array tolerance runout, compensation for the mismatch between a VCSEL divergence angle (typically 15-20 degrees) and the numerical aperture of an optical fiber or waveguide (which can be as low as 6 degrees) without violating international laser eye safety conditions (such as IEC 825). Accurate formation of the microlens surface is crucial, since due to their size, microlens elements cannot be optically polished using conventional means; the injection molding technique greatly facilitates this aspect of microlens fabrication.
[0041] A further important distinction is the independent inspection and characterization 340 made possible, as shown in FIG. 3 step D, wherein such spectral measurements as transmission spectrophotometry may be utilized for process and product Quality Control against color filter specifications or microlens focal length. The nature of the transparent glass mold enables blank subtraction of the glass transmission spectrum and optimization of dye-loading, film-thickness, microlens cavity depth and shape, and, determines whether rework is required before the microlens array and/or color filter array is committed to the product wafer. In a similar manner, microlens arrays used for VCSEL applications may enable wafer-scale alignment and test of the microlens/VCSEL combinations, wherein the characterization of VCSEL spectral measurements, optical power, and other features may be utilized for product quality control against the VCSEL specifications. If rework is needed, the mold plate is cleaned and prepared as detailed in the process flow chart provided in FIG. 2 . It is also noteworthy that the mold plates can be prepared, filled and characterized against product engineering specifications to build to stock an inventory of parallel processed components, and, concurrently, wafers may similarly be prepared to stock devices which can be finished in manufacturing in a make-to-order operations management model. Consequently, product engineering changes and upgrades at minimum cost are enabled by the present invention.
[0042] FIG. 4 is a schematic representation of the mold plate Fill Tool 400 , comprised of a crucible containing either transmissive molten microlens material 420 for case A, or absorptive color lensfilter material for case B. Either the platen on which the mold plate resides or the dispensing, injection head may be translated relative to the other. Illustrated in FIG. 4 , the Fill-Tool head is selected to be scanned as in 410 relative to the mold plate. A small positive pressure 430 drives fluid flow injection through fill blade 405 to fill a mold plate with cavities 220 ; unfilled cavities 440 ahead of the scan head, and, filled cavities 450 behind the scan head are shown. For the integration of microlens and color filter arrays, lensfilters of green, blue and red are fabricated using fill blade 455 which teaches a configuration for the single-step transfer of lensfilters to a receiving substrate. For CMOS or CCD color imagers the substrate is silicon, and for flat panel displays the substrate may be a glass or polymer plate. For VCSELs, the substrate will be a III-V based semiconductor Wafer. The color fill blade 455 is seen to be comprised of a unique configuration of 3 rows, a first blue inject row 460 , a second green inject row 470 , and a third red inject row 480 .
[0043] An alternative embodiment employing the standard fill blade 405 is as follows. Dye-loaded photocurable prepolymers are prepared as red, green and blue fluids and placed in separate crucibles. In a first scan of the fill head, all mold plate cavities are filled by dispensing and injecting the green fluid. A map of the red, green and blue color filter positions in a color imager array is used to selectively expose and photocure the corresponding mold plate cavities for green lensfilters. The remaining cavities are emptied and flushed. All green color filter positions remain in the form of green lensfilters. Again using the design map of color imager filter positions, a second scan dispenses and injects blue fluid into all unfilled cavity positions in the mold plate. Selective exposure cross-links and hardens the blue lensfilters in their cavities, and, all remaining uncured cavities are emptied and flushed. A third scan of the fill head dispenses and injects red fluid in the empty cavities and is cured. Spectrophotometric characterization of the filled template at appropriate stages assures in-spec manufacturing of the color lensfilters, unlike Prior Art processes which are testable only when the product has been completed. The color lensfilters are therefore known good lensfilters before committing them to the transfer to a product substrate; lensfilters are transferred to a color image sensor wafer only when the template is perfect. Significant increase in final product yield and cost reduction results.
[0044] While the process for injection molding of microlenses and of color filters has been taught for the independent cases of fabricating microlenses or integrating color filters with microlenses, it is recognized and particularly pointed out that the independent fabrication of color filters alone is also enabled by the present invention.
[0045] Advantages for molding microlenses include superior shape control, since the microlens elements are shaped by cavities not by surface tension. Laser etching to optical design specifications can be used to augment RIE, plasma or acid wet etched templates. Since the templates are transparent, lenses and spectral filters can be optically characterized in situ in the template. High multiples of reuse of the templates correlate well with lower cost than photolithographic on-wafer processing, resulting in yield improvements by inspection prior to transfer. Single layer arrays of aspheric microlenses provide the equivalence of compound spherical lenses requiring multilayering, with the attendant advantage of a thinner image sensor cross-sectional stack. Thinner image sensors are in turn very desirable for reducing product packaging dimensions. The current industry trend to higher resolution color imagers will similarly benefit from chromatic aberration corrections and color filter compensation for wavelength-dependent index of refraction variations inherent in the red, green, blue color filters of Prior Art.
[0046] The transfer process sequence for injection molded microoptics is given in FIG. 5 . An Alignment-Tool using conventional photolithographic alignment keys aligns the filled template to a substrate such as a silicon CMOS color imager, as shown at 500 . The aligned pair is clamped at 510 , the cavity contents transferred, optionally assisted by an ultrasonic or gas pressure agent, and, separated at 530 .
[0047] FIG. 6 is a sideview of the mold-to-wafer transfer apparatus 600 . Alignment key 254 on mold plate 220 is centered in alignment key 252 on wafer 210 supported on base 630 and contact points 620 inside fixture frame 610 . Molded microlenses 640 are shown in alignment and in contact with the interface layer 800 shown in FIG. 8 .
[0048] After the injection molded microoptic array has been transferred to the receiving device surface, an optional thermal reflow adjustment is shown in FIG. 7 to provide a process for modifying the lens shape and spacing as molded and transferred 700 to a configuration in which the lenses are contiguous 710 , touching at their edges to eliminate gaps. An additional optional step can be added to provide a post-transfer irradiation for index of refraction tuning of the microlenses or an absorbance tuning of the color filters.
[0049] FIG. 8 illustrates the wafer preparation for the interface layer 800 which provides planarization, refractive-index matching to minimize interfacial reflection loss, and adhesion of the transferred microoptic array. Also shown is the alignment of color filter layer 820 to photodetector array 830 integrated in the silicon wafer 810 .
[0050] A semiconductor color imager cross-section is given in FIG. 9 , depicting the aligned positions of the microlens array elements 900 above the color filters 910 and pn photodiodes. The advanced integration of the color filters and microlenses into the color lensfilters 1000 on interface layer 1010 is taught in the present invention as shown in FIG. 10 .
[0051] While one application for microoptic injection molding has been illustrated for solid-state color imaging devices, FIG. 11 exhibits the utility of molding optical assemblies for laser transmitters and receivers in parallel optical interconnects with waveguides or optical fibers, and shows two examples, one for hemicylindrical fibers or waveguides 1110 and square or rectangular fibers or waveguides 1100 .
[0052] Most applications for microlenses or other optical coupling elements will also require electrical interconnects as well, if only for connecting power. Procedures are known for the injection molding of solder bumps onto silicon wafers, and it will be advantageous to have a hybrid process to use injection molding for both optical coupling elements as well as solder electrical interconnects. In this process, the microlenses are fabricated on the wafer as already described. Then a second mold is aligned to the wafer. This second mold has two different sets of cavities. The lower set of cavities is slightly larger than the microlenses to allow the mold to be placed in close contact with the wafer without contacting or damaging the microlenses. The second set of cavities is cylindrical through-holes in the glass mold to allow molten solder to be dispensed through the mold onto the wafers. After cooling, the second mold is separated from the wafer; leaving solder interconnects at the appropriate sites for making electrical contacts when the chips are assembled to the packaging substrates.
[0053] Additional molding features and additional uses for molded microoptic devices are described in copending patent application no. (Attorney Docket YOR920050267US1) for “Injection Molded Microlenses For Parallel Optical Interconnects,” filed herewith, the disclosure of which is hereby incorporated herein by reference in its entirety.
[0054] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention. | A wafer-scale apparatus and method is described for the automation of forming, aligning and attaching two-dimensional arrays of microoptic elements on semiconductor and other image display devices, backplanes, optoelectronic boards, and integrated optical systems. In an ordered fabrication sequence, a mold plate comprised of optically designed cavities is formed by reactive ion etching or alternative processes, optionally coated with a release material layer and filled with optically specified materials by an automated fluid-injection and defect-inspection subsystem. Optical alignment fiducials guide the disclosed transfer and attachment processes to achieve specified tolerances between the microoptic elements and corresponding optoelectronic devices and circuits. The present invention applies to spectral filters, waveguides, fiber-optic mode-transformers, diffraction gratings, refractive lenses, diffractive lens/Fresnel zone plates, reflectors, and to combinations of elements and devices, including microelectromechanical systems (MEMS) and liquid crystal device (LCD) matrices for adaptive, tunable elements. Preparation of interfacial layer properties and attachment process embodiments are taught. | 6 |
This is a division of application Ser. No. 794,240 filed May 5, 1977 now U.S. Pat. No. 4,104,114.
FIELD OF INVENTION
This invention relates to a pulp mill bleach plant, and in particular, relates to a bleach plant construction and operation for use in a liquid effluent free bleached pulp mill.
BACKGROUND TO THE INVENTION
In a liquid effluent free bleached pulp mill, in which bleached pulp is formed by digesting cellulosic fibrous material and bleaching and purifying the pulp and in which spent pulping liquors are subjected to recovery and regeneration to form fresh pulping liquor, liquid effluents from the bleaching and purification operations (bleach plant effluent) are discharged into the recovery and regeneration operation.
The organic materials content of the bleach plant effluent is burned off in the recovery furnace of the recovery and regeneration operation and the aqueous phase is evaporated in the recovery and regeneration operation.
Owing to the high cost of evaporating water in a pulp mill, in the interests of minimizing operating costs, it is desirable to decrease the total volume of bleach plant effluent which must be discharged into the pulp mill recovery and regeneration operation and hence minimize the total evaporation load. It is also desirable that any bleach plant effluent volume decrease not significantly adversely affect the pulp quality obtained.
SUMMARY AND GENERAL DESCRIPTION OF INVENTION
In accordance with the present invention, there is provided a bleach plant operation in which water conservation is practised by controlling the use of wash water in the bleach plant, controlling the design and operation of washers, deckers and other mechanical devices used in the bleach plant, and controlling the inflow of water with chemicals.
The invention is particularly applicable to a bleach plant operation using a D/CEDED sequence, in which D/C means bleaching with an aqueous solution of chlorine dioxide and chlorine wherein the chlorine dioxide provides the majority of the available chlorine of the solution, D means bleaching with an aqueous solution of chlorine dioxide and E means caustic extraction with aqueous sodium hydroxide solution.
The bleach plant operation of the invention produces two liquid effluents from the bleach plant, one acid and the other alkaline. These effluents then pass to the recovery operation, preferably in accordance with the teachings of copending U.S. application Ser. No. 665,240 filed Mar. 9, 1976, entitled "Bleach Plant Filtrate Recovery", Douglas W. Reeve, et al., (J32) and assigned to the assignee of this application.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic flow sheet of a liquid effluent free pulp mill;
FIG. 2 is a schematic flow sheet of a bleach plant in accordance with one embodiment of the invention; and
FIG. 3 is a schematic flow sheet of a pulp mill recovery and regeneration operation for use in this invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, wood chips are digested in pulping liquor in a digester 1 and pass to a brown stock washer 2 wherein the pulp is freed from entrained pulping liquor. The pulp then passes to the bleach plant 3 for bleaching and purification with intermediate washing operations, using chlorine dioxide and chlorine, chlorine dioxide and sodium hydroxide solutions and water, and bleached pulp is recovered by line 4.
Spent pulping liquor from the brown stock washer 2 in line 5 and two aqueous effluents from the bleach plant 3 in line 6 pass to a recovery and regeneration operation 7 wherein combustible organic materials are combusted, pulping liquor is regenerated and sodium chloride, arising from the sodium atoms and the chlorine atoms in the bleach plant effluents, is removed by line 8 to prevent its build up in the system. Regenerated pulping liquor is recycled to the digester 1 by line 9.
In the aqueous effluent-free pulp mill as illustrated in FIG. 1, noxious aqueous effluents from the pulp mill are eliminated by discharge of the bleach plant effluents into the recovery and regeneration operation 7. The organic materials content of the bleach plant effluent is burned off in the recovery furnace of the recovery and regeneration operation 7 while the aqueous phase is evaporated.
In FIG. 2, there is illustrated a detailed flow sheet which includes a bleach plant 3 constructed and operated in accordance with the present invention for use in the effluent-free pulp mill illustrated in FIG. 1.
Referring to FIG. 2, a pulp treatment operation 10, incorporating a bleach plant designed to use a D/CEDED bleaching and caustic extraction sequence, includes a D/C bleaching tower 12, an E 1 caustic extraction tower 14, a D 1 bleaching tower 16, an E 2 caustic extraction tower 18 and a D 2 bleaching tower 20.
Drum washers are provided for each bleaching and caustic extraction stage including a D/C washer 22, a E 1 washer 24, a D 1 washer 26, an E 2 washer 28 and D 2 washer 30. Seal tanks are associated with each of the washers, including a D/C seal tank 32, an E 1 seal tank 34, a D 1 seal tank 36, an E 2 seal tank 38 and a D 2 seal tank 40.
An unbleached decker 42 in the form of a displacement washer is provided along with an associated seal tank 44. A similar bleached decker 46 is provided with an associated seal tank 48. Unbleached pulp and bleached pulp storage towers 50 and 52 respectively are provided. Screens and cleaners 54 and 56 are provided for unbleached pulp and bleached pulp respectively.
Unbleached pulp from the brown stock washing is passed by line 58 through the screens and cleaners 54 and via line 60 to the unbleached decker 42 and thence by line 62 to the storage tank 50. The pulp is passed from the storage tank 50 by line 64 to a sensor 66 which senses chlorine dioxide and chlorine required by the pulp. From the sensor the pulp passes by line 68 to the D/C bleaching tower 12.
After D/C bleaching, the pulp passes by line 70 to the D/C washer 22. From the D/C washer the pulp passes by line 72 through an E 1 mixer 73 and by line 74 to the E 1 extraction tower 14. The pulp passes from the E 1 tower 14 by line 76 to the E 1 washer 24 and thence by line 78 to a D 1 mixer 80 and by line 82 to the D 1 bleaching tower 16.
Following D 1 bleaching, the pulp next passes by line 84 to the D 1 washer 26 and by line 86 to the E 2 extraction tower 18. From E 2 extraction, the pulp passes by line 88 to the E 2 washer 28, by line 90 to a D 2 mixer 92 and by line 94 to the D 2 bleaching tower 20.
The pulp next passes by line 96 to the D 2 washer 30 before passage by line 98 to the screens and cleaners 56, by line 100 to the bleached decker 46 and by line 102 to bleached pulp storage 52. From the bleached pulp storage 52 the pulp is passed forward by line 104, such as, to a pulp drying machine, not shown.
Each of the washers 22, 24, 26, 28 and 30 and each of the deckers 42 and 46 is a rotating foraminous drum type having wash water shower bars 106 arranged adjacent the periphery thereof for the application of wash water to the pulp mat as it is transported on the drum surface, the water displaced from or passing through the mat passing to the appropriate seal tank by lines 108, 110, 112, 114, 116, 118 and 120 respectively. Wire cleaners 122 also are provided for each of the washers and deckers.
A complete countercurrent flow wash water system is utilized. Thus, fresh water passes to the pulp drying machine and pulp drying machine white water or other relatively fresh water is passed by line 124 to the showers 106 on the bleached decker 46 to displacement wash the pulp mat on the bleached decker. Part of the displaced liquor collected in the seal tank 48 is passed by lines 126 and 128 to the showers 106 of the D 2 washer 30, with the remainder passing by lines 126 and 130 for dilution of the pulp in line 98 before passage of the diluted pulp to the screens and cleaners 56.
Part of the liquor collected in the D 2 seal tank 40 passes by lines 132 and 134 to the washing showers 106 on the E 2 washer 28. Part of this liquor passes by lines 132 and 136 to pulp passing from the D 2 bleaching tower 20 to the D 2 washer 30 in line 96. Part of the collected liquor passes from the seal tank 40 by line 138 to the D 2 bleaching tower 20.
The liquor collected in the E 2 seal tank 38 partially passes by lines 140, 142 and 144 to the washing shower 106 of the D 1 washer 26. Another portion of this liquor passes by lines 140 and 146 to the pulp passing in line 88 from the E 2 extraction tower 18 to the E 2 washer 28. Further quantities of the collected liquor pass by line 148 to the E 2 extraction tower 18.
A small quantity of the liquor collected in the E 2 seal tank is used to dilute caustic extraction chemical and is passed to the caustic extraction chemical inlet feed line for this purpose by lines 140, 142 and 150.
The D 1 seal tank liquor is partially passed by line 152 to the D 1 bleaching tower 16. A portion of the liquor passes by lines 154, 156 and 158 to the showers 106 on the E 1 washer 24, while another portion of the liquor passes by lines 154, 156 and 160 to the first showers 106 on the D/C washer 22. Part of the D 1 seal tank liquor passes by lines 154 and 162 to the pulp in line 84 passing from the D 1 bleaching tower to the D 1 washer 26.
From the E 1 seal tank 34, part of the liquor passes by lines 163, 164 and 166 to the last showers 106 on the D/C washer 22 while another part passes by lines 163, 164 and 168 to the pulp passing in line 76 from the E 1 extraction tower 14 to the E 1 washer 24. Another part passes by line 170 to the E 1 extraction tower 14 while the remainder is discharged from the bleach plant by lines 163 and 172 for passage to the pulp mill recovery system.
Liquor from the D/C seal tank 32 partly passes by lines 174 and 176 to dilute the pulp passing by line 64 from the storage 50 to the sensor 66 with another part passing by lines 174 and 178 to the pulp passing by line 70 from the D/C bleaching tower 12 to the D/C washer 22. Another part of the liquor is passed by lines 180, 182 and 184 to the showers 106 of the unbleached decker 42. The liquor passing in this way to the showers 106 of the unbleached decker 42 is neutralized by sodium hydroxide solution fed by line 186. The remainder of the liquor passes out of the bleach plant 10 by line 188 for passage to the pulp mill recovery system.
The bleach plant effluents in lines 172 and 188 and the unbleached decker seal tank liquor in line 190 may be utilized as described in the aforementioned copending U.S. application Ser. No. 665,240 filed Mar. 9, 1976. (now U.S. Pat. No. 4,039,372).
From the unbleached decker seal tank 44 liquor passes by line 190 for use as wash water in the brown stock washer of the pulp mill and liquor passes by line 192 to the unbleached pulp entering the unbleached screens and cleaners 54 by line 58.
It will be seen, therefore, that there is a general countercurrent flow of wash water and pulp through the pulp treatment operation 10.
Each of the cleaner showers 122 on the washers and deckers is fed by hot water. An inlet feed in line 194 feeds the cleaner 122 on the decker 42 by line 196, the cleaner 122 on the D/C washer 22 by lines 198 and 200, the cleaner 122 on the E 1 washer 24 by lines 198, 202 and 204, the cleaner 122 on the D 1 washer 26 by lines 198, 202, 206 and 208 the cleaner 122 on the E 2 washer by lines 198, 202, 206, 210 and 212, the cleaner 122 on the D 2 washer 30 by lines 198, 202, 206, 210, 214 and 216 and the cleaner 122 on the bleached decker 46 by lines 198, 202, 206, 210 214 and 218.
Steam for heating purposes also is used. Thus, steam is fed by lines 220 and 222 to the E 1 mixer 72, by lines 220, 224 and 226 to the D 1 mixer 80, by lines 220, 224, 228 and 230 to an injection ring 232, and by lines 220, 224, 228 and 234 to the D 2 mixer 92.
To accommodate emergency overflow conditions, the seal tanks are connected in a countercurrent flow overflow arrangement. Thus, overflow from the bleached decker seal tank 48 passes by line 236 to the D 2 seal tank 40, the overflow from the D 2 seal tank 40 passes by line 238 to the E 2 seal tank 38, the overflow from the E 2 seal tank 38 passes by line 240 to the D 1 seal tank 36 and the overflow from the D 1 seal tank 36 passes by line 242 to the E 1 seal tank 34.
From the E 1 seal tank 34, the overflow passes by line 244 to a first spill storage tank 246 while overflow from the D/C seal tank 32 and the unbleached decker seal tank 44 pass to a second spill tank 248 by lines 249 and 250 and lines 252 and 250 respectively.
The overflow collected in the second spill tank 248 under emergency conditions may be returned to the system, after neutralization with sodium hydroxide solution, at a convenient time by lines 254, 256 and 258 while the overflow collected in the first spill tank 246 passes to the recovery system for use in brown stock washing or white liquor dilution.
With this seal tank overflow arrangement, when there is a temporary discharge of a pulp mat of lower than normal consistency from one washer to another, the excess water is returned to the preceding stage by seal tank overflow.
High density pumps are used for pumping the pulp through the bleach plant and such pumps use water-fed seal glands. Hot water fed from line 194 is used for such seal glands. Thus, seal glands of a pump 260 conveying the pulp by line 74 are fed by hot water in line 262, seal glands of a pump 264 conveying the pulp by line 82 are fed by hot water in line 266, seal glands of a pump 268 conveying the pulp by line 86 are fed by hot water in line 270, and seal glands of a pump 272 conveying the pulp by line 94 are fed by hot water in line 274. The pressure on the pump glands is controlled to minimize the flow of fresh water into the pulp passing through the pump.
Chemical feed for the bleaching and caustic extraction operations is provided by dilute sodium hydroxide solution, aqueous solutions of chlorine dioxide and chlorine and sodium hypochlorite solution. Sodium hydroxide solution in concentrated form (typically 50% by wt.) is fed by line 276 to the system and is diluted by the E 2 seal tank liquor in line 140 to the concentration required. The diluted sodium hydroxide solution then is passed by lines 278 and 280 to the pulp leaving the D/C washer 22. Sodium hydroxide solution also is passed by lines 278, 282 and 284 to the pulp leaving the E 1 washer 24 by lines 278, 282, 286 and 288 to the pulp leaving the D 1 washer 26, lines 278, 282, 286, 290 and 291 to the pulp leaving the E 2 washer 28. Dilute sodium hydroxide solution also passes by line 292 to the sodium hydroxide neutralization feed 186, provision also being made for emergency flow to the second spill tank 248 in line 293.
An aqueous solution of chlorine dioxide and chlorine is fed by line 294 to the pulp passing by line 64 from the pulp to storage 50 to the sensor 66. Sodium hypochlorite solution is fed by line 296 to the pulp in line 64.
An aqueous chlorine dioxide solution is fed by lines 298 and 300 to the pulp in line 82 before passage thereof into the D 1 bleaching tower 16. A mixer, not shown, is located immediately after the injection point of the chlorine dioxide solution to ensure even mixing of the solution with the pulp.
Chlorine dioxide solution is also fed by lines 298 and 302 to the pulp in line 94 before passage thereof into the D 2 bleaching tower 20. A mixer, not shown, is located immediately after the injection point of the chlorine dioxide solution to ensure even mixing of the solution with the pulp.
The chlorine dioxide solution fed by line 298 is one having a low concentration of dissolved chlorine whereby over 90% of the available chlorine content of the chlorine dioxide solution is provided by chlorine dioxide. A typical solution is one having a chlorine dioxide concentration of 10 gpl and chlorine concentration of 2 gpl.
The chlorine dioxide and chlorine solution fed by line 294 is one having a higher dissolved chlorine concentration than the chlorine dioxide solution in line 298, whereby about 70% of the available chlorine content of the solution is provided by chlorine dioxide and the remainder of the available chlorine is provided by the chlorine. A suitable solution contains about 10 gpl ClO 2 and about 6 gpl Cl 2 .
The sodium hypochlorite solution in line 296 breaks down under the acid condition of the pulp in line 64 to produce chlorine for the bleaching of the pulp in the D/C bleaching tower 12.
The chlorine dioxide solution in line 298, the chlorine dioxide and chlorine solution in line 294 and the sodium hypochlorite solution in line 296 all may be produced from a single chlorine dioxide and chlorine generator, for example, using the procedure outlined in U.S. Pat. No. 4,010,112. By the use of the latter chlorine dioxide generation system, the most efficient use of bleaching chemicals is obtained while the volume of water entering the bleach plant with chlorine dioxide and chlorine is minimized.
OPERATION
In operating the pulp mill system described above, steps are taken to ensure optimum bleaching, caustic extraction and washing, minimal consumption of water, energy and chemicals and the discharge of a minimal volume of liquid effluent, in the region of about 4000 U.S. gallons/air dried ton (USG/ADT) of pulp, as compared with the liquid effluent discharge from a conventional bleach plant operation of up to about 25,000 USG/ADT while the bleached pulp produced has properties at least comparable to those of pulp produced in conventional operations.
The fresh water consumption in the bleach plant is very small, with the principal inputs of fresh water to the bleach plant being pulp machine white water, chlorine dioxide solutions and the water in the unbleached pulp. Thus, not only does this bleach plant operation decrease the effluent volume to a level which is suitable for feed to the recovery system, but also decreases fresh water and hot water use from typically 20,000 USG/ADT to a negligible value.
Steam consumption is also decreased considerably from the conventional 5,000 to 7000 lbs/ADT to less than 1000 lbs/ADT, a considerable saving.
In the bleach plant operation, the pulp leaving line 64 is diluted with D/C seal tank filtrate in line 176 to the required consistency, typically about 4%, before mixing with the chlorine dioxide and chlorine solution in line 294, with additional chlorine being supplied by the sodium hypochlorite solution in line 296. In this way, the necessity for conventional chlorine gas injection is eliminated. While the use of sodium hypochlorite solution to provide part of the first stage chlorine requirement raises the pH of the D/C bleaching, it has been found that efficient bleaching chemical utilization is maintained even up to 1% of sodium hypochlorite (determined as available Cl 2 on the pulp).
Owing to the heat in the filtrate used in the dilution and arising from the elimination of conventional discharge of unbleached decker filtrate, the pulp fed to the bleaching tower 12 has a temperature of about 120° to 140° F. (50° to 60° C.). As is well known, pulp chlorination is usually carried out at temperatures less than 90° F. (30° C. ) and higher temperatures increase the rate of reaction of the chlorine with the pulp. To control against overchlorination of the pulp with consequent strength losses, the chlorine dosage to the pulp is controlled in accordance with the sensor 66 which senses the kappa number of the pulp passing therethrough. This control, which may be by an optical or oxidation-reduction potential sensor, also results in no residual chlorine values and effective chemical usage.
The D/C bleaching tower 12 may be a conventional upflow tower having about 30 to 60 minutes retention time or a two-stage upflow-downflow tower with a retention time of about 20 minutes in the upflow and 0 to 25 minutes in the downflow. The variation in retention time achieved by an upflow-downflow tower allows ready compensation for variations in temperature and %ClO 2 substitution.
The substitution of chlorine dioxide for about seventy percent of the chlorine in the first stage bleaching operation is an important feature of the bleach plant operation. Since all the sodium and chlorine atoms in the recovered effluent must be matched, providing part of the oxidizing power with chlorine dioxide decreases the total chlorine atoms and hence the required matching sodium atoms, enabling the overall quantity of sodium hydroxide required to be decreased.
It follows, therefore, that the use of 70/30 D/C bleaching decreases the total quantity of sodium chloride discharged to the recovery system as compared with 100% C. Hence, any detrimental effects which may result from the discharge of sodium chloride containing liquors into the recovery system are decreased.
The use of 70/30 D/C first stage bleaching also produces brighter, stronger pulp with greater stability to yellowing with age as compared with 100% C first stage bleaching and results in an improved yield of bleached pulp.
In each of the other stages, conventional towers are used, operating at conventional temperatures of about 160° F. (70° C.), while the consistency is about 13%, which is higher than the conventionally achieved value of 10 to 12%.
The use of the E 2 seal tank filtrate to dilute the 50% NaOH solution for use in the system results in water and steam savings, the resulting solution being hotter than is usually used. It is also preferred to use a concentration of about 10 to 13% NaOH, which is more concentrated than conventionally used.
In the countercurrent washing operation, the wash water for a given stage is obtained from the seal tank of the following stage. Good washing is required on the E 1 washer to minimize the carry over of E 1 stage solids which would result in increased chlorine dioxide consumption in the D 1 stage. Hence a dilution factor of at least three is used in the E 1 washer and on all other washers a dilution factor of at least 2 is used.
The showers 106 on each of the washers are placed and oriented for optimum wash water distribution on the pulp mat and hence most efficient washing on each of the washers. The washer size is such as to provide a consistency of at least 13% on each washer for greatest washing efficiency.
The washing on the D/C washer is split between first D 1 filtrate and then E 1 filtrate with the E 1 filtrate application being controlled to about 75% of the water contained in the pulp mat in order to prevent passage of E 1 filtrate through the mat and into the D/C filtrate. The presence of E 1 filtrate in the D/C filtrate increases chemical consumption in the D/C stage and operation in the described manner avoids this problem.
On each of the washers an air doctor is used in place of a conventional external water-fed hydraulic doctor to remove the pulp mat from the screen after washing, although it may be possible to use a hydraulic doctor which uses filtrate recycled within the particular stage.
The wire cleaning showers 122 which are used in place of conventional hydraulic doctors which also remove the pulp mat from the washer screen are high pressure low volume wire cleaning showers. Each of the wire cleaning showers 122 is timer controlled so that they operate for only a small percentage of the time in order to decrease fresh hot water usage, typically to an overall volume of about 10 USG/min on the D/C and E 1 washers and to an overall volume of about 5 USG/min on the D 1 , E 2 and D 2 and bleached decker washers. Conventional hydraulic doctors use about 100 USG/min.
The use of hot water on the showers 122 decreases the thermal shock of conventional cold water hydraulic doctors, thereby improving the effective washer life and decreasing the overall steam heating requirement.
The liquid level in the bleached decker seal tank 48 is controlled by the addition of pulp machine white water in line 304 while the levels in the seal tanks 32, 34, 36, 38 and 40 are controlled by level control valves which feed the shower water to the preceding stage providing a positive control on these levels, in place of the conventional overflow system. The seal tanks only overflow under emergency conditions.
The seal tanks have a tangential drop leg entry. The use of tangential entry releases entrained air and minimizes foaming tendencies. A parallel tangential entry of overflow from the following seal tank may be used to prevent reverse overflow.
The seal tanks are sized to allow sufficient time for entrained air separation, the sizing typically being such as to provide a filtrate retention time of about 120 seconds for the unbleached decker, D/C and E 1 seal tanks and of about 60 seconds for the D 1 , E 2 , D 2 and bleached decker seal tanks. A large freeboard space also is provided in each seal tank to allow for air separation, typically about 8 feet.
Turning now to consideration of FIG. 3, there is illustrated a bleached kraft pulp mill operation in which the overall material flow within an effluent-free pulp mill is illustrated. With the elimination of the toxic effect of bleach plant effluent by introducing the same to the pulp mill recovery operation, black liquor condensates become the potential dominant effluent. While the total BOD of the black liquor condensates is moderate, typically about 20 lbs of methanol ADT of pulp, when compared with that of bleach plant effluent, within the context of an "effluent-free" pulp mill, the value is quite high.
In the pulp mill operation illustrated in FIG. 3, the BOD level of the black liquor condensates is decreased to a very low level acceptable for discharge from the mill in the "effluent-free" environment. This is achieved by combining the most contaminated condensates and them steam stripping methanol from this mixture. The methanol removed in this way then may be used for its fuel value or otherwise. The stripped condensate then may be used in various locations in the mill.
As seen in FIG. 3, wood chips are fed by line 510 to a digester 512 to which white liquor is fed by line 514 and steaming vessel steam is fed by line 516. Pulp wash water also is fed to the digester 512 by line 518. The brown stock pulp is fed from the digester 512 by line 520 to a brown stock washer 522 to which wash water is fed by line 524. The washed pulp passes by line 526 through cleaners and screens 528 and line 530 to a bleach plant 532, such as that described above in connection with FIG. 2 and including the unbleached decker 42.
Wash water from the bleach plant 532 passes by line 534 to the cleaners and screens 528 and E 1 stage effluent from the bleach plant 532 passes by line 536 to join the wash water in line 524 passing to the brown stock washer 522. Wire cleaning water also passes to the cleaners and screens 528 by line 538.
Chlorine chemical preparation 540 provides chlorine dioxide and chlorine solutions to the bleach plant 532 by line 542 and sodium hypochlorite solution by line 544. The chemical preparation is fed by water in line 545 and is typically in accordance with the aforementioned procedure of U.S. Pat. No. 4,010,112.
Sodium hydroxide for the bleach plant 532 is fed by line 546 while wash water in the form of pulp machine dryer white water is fed by line 548 to the bleach plant. Other inputs for the bleach plant 532 are heating steam by line 550 and washer screen cleaner water by line 552.
The bleached pulp passing out of the bleach plant 532 passes by line 554 to the pulp machine dryer 556. Bleached pulp exits the dryer by line 558 while any excess white water not required in line 546 is passed to sewer by line 560, while some moisture passes to atmosphere through the dryer stack 562. Water for a variety of purposes enters to pulp machine dryer 556 by line 563, including vacuum pump seal water, condensate cooler water, trim jet water and steam shower steam.
The dilute black liquor and flash steam from the digester 512 pass by lines 564 and 566 to black liquor evaporators 568. Additional heating steam is fed to the evaporators 568 by line 570. The black liquor evaporators takes the form of sextuple effect evaporators which produce concentrated black liquor which passes by line 572 to the recovery furnace 574. Various other liquid effluents are produced and these will be described further below. Moisture is lost through weak black liquor oxidation stack 576.
In the recovery furnace 574 all the organic materials are burned and there is formed a smelt in line 578 containing sodium carbonate, sodium sulphide, sodium chloride and sodium sulphate. Stack gases are vented by line 580. Steam is generated in the furnace and the blow down is passed by line 582 to the evaporators 568.
The smelt in line 578 then is passed to liquor prepartion 584 wherein white liquor is regenerated. D/C effluent from the bleach plant 532 passes by line 586 to liquor preparation 584 for kiln scrubbing therein. Smelt spray water is fed to the liquor preparation 584 by line 588. Solid green liquor dregs are removed from the liquor preparation 584 by line 590 as are dregs from the causticization by line 592.
The white liquor resulting from chemical preparation passes to a salt recovery process 594 by line 596. In the salt recovery process, which typically may be that outlined in U.S. Pat. No. b 3,950,217, solid sodium chloride is removed from the white liquor by an evaporative procedure and recovered by line 598. The concentrated white liquor is diluted by E 1 filtrate from the bleach plant 532 fed by line 600 to the desired concentration to the digester 512 by line 514, as described in our copending application Ser. No. 665,240 mentioned above (J32).
Burkeite also deposited in the salt recovery process 594 passes by line 602 to the liquor preparation 584, while excess condensate from the salt recovery process 594 is passed to sewer by line 604. Water for salt leaching in the salt recovery process 594 is fed by line 605.
The only liquid effluents being sewered from the system are excess white water in line 560 and excess condensate from the salt recovery process in line 604. Both of these liquors are pure water and hence their discharge is not harmful.
As mentioned above, there are a number of condensates from the black liquor evaporators 568. Those most contaminated with methanol from the black liquor, the hotwell condensate, the flash heat double evaporator condensate and the sextuple surface condenser condensate pass by line 606, 608 and 610 respectively to a methanol stripper 612 along with turpentine underflow from the digester 512 in line 614. In the methanol stripper 612, steam, fed by line 616, strips methanol from the contaminated condensate. The methanol is recovered by line 618 while the purified condensate passes by line 620 to the brown stock washer 522 for use as wash water therein.
Part or all of the purified condensate may be used in a variety of other locations within the mill, for example, in wire cleaning in the cleaners and screens 528, for chlorine dioxide adsorption in chemical preparation 540, or as wash water in the bleach plant, in the bleach plant of FIG. 2.
The condensate from the fifth and sixth effect evaporators in the black liquor evaporators 568 is passed by line 622 to liquor preparation 584, while condensate from the second, third and fourth effect evaporators being relatively free of contaminants may be discharged or may join with the purified condensate in line 620 by line 624.
SUMMARY
The present invention, therefore, provides a bleach plant process which results in a low efficient volume and yet produces good pulp quality. The present invention also provides a bleached kraft mill water utilization system which eliminates noxious aqueous effluents. Modifications are possible within the scope of the invention. | A pulp mill bleach plant operation having a low effluent volume, a low consumption of water, energy and chemicals, and yet provides efficient bleaching, caustic extraction and washing is described. Water conservation is practised by controlling the use of wash water in the bleach plant, controlling the design and operation of washers, deckers and other mechanical devices used in the bleach plant and controlling the inflow of water with chemicals. An aqueous polluting effluent-free pulp mill water utilization system is also described. | 3 |
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/703,941, filed Jul. 29, 2005.
TECHNICAL FIELD
[0002] The present invention relates to unsaturated polyester resin compositions having improved weatherability. In a more specific aspect, this invention relates to durable unsaturated polyester resin compositions for applications requiring hydrolytic stability and ultraviolet light resistance. Some applications include coatings, panels, engineered stone, and any composite parts intended for use outdoors or in harsh environments. This invention also relates to a process for the manufacture of these unsaturated polyester resin compositions.
BACKGROUND OF THE INVENTION
[0003] Thermoset resins, including unsaturated polyesters, are commonly employed in a variety of fabrications, such as casting materials, fiber reinforced materials and gel coats. Many of the composite articles fabricated from thermoset resins are used in environments exposing them to ultraviolet light, solvents or water. Prolonged UV and water exposure of composite articles derived from conventional unsaturated polyester resins often results in degradation of the article, which can be evidenced by blister formation, fiber prominence, loss of color and yellowing.
[0004] Many technologies have been disclosed in patents and general literature for improvements in weatherability of composite articles derived from unsaturated polyester resins. Available technologies have either claimed improved UV resistance or improved hydrolytic stability over conventional systems.
[0005] Therefore, a need exists for high performance UV and water resistant unsaturated polyester resin compositions which will also meet the U.S. EPA limits for MACT compliance for hazardous air pollutants (HAPs).
SUMMARY OF THE INVENTION
[0006] Briefly described, the present invention provides curable, low-HAP unsaturated polyester resin compositions which exhibit improved hydrolytic stability and enhanced UV light resistance as compared to conventional unsaturated polyesters. The resin compositions of this invention may be employed in demanding environments where there is exposure to water and sunlight, such as composite articles used in marine, bathtub/shower, panel, automotive, farm equipment, synthetic stone, engineered stone, gel coat applications and articles intended for outdoor use in general. The present invention also provides a process for the manufacture of these unsaturated polyester resin compositions.
[0007] Accordingly, an object of this invention is to provide unsaturated polyester resin compositions.
[0008] Another object of this invention is to provide low HAP unsaturated polyester resin compositions.
[0009] Another object of this invention is to provide low HAP unsaturated polyester resin compositions having mechanical and physical properties that are equivalent to conventional unsaturated polyesters.
[0010] Another object of this invention is to provide low HAP unsaturated polyester resin compositions having improved weathering characteristics as demonstrated by ultraviolet light stability and blister resistance in aqueous environments.
[0011] Still another object of this invention is to provide a process for the manufacture of unsaturated polyester resin compositions.
[0012] Still another object of this invention is to provide a process for the manufacture of low HAP unsaturated polyester resin compositions having mechanical and physical properties that are equivalent to conventional unsaturated polyesters.
[0013] Still another object of this invention is to provide a process for the manufacture of low HAP unsaturated polyester resin compositions having improved weathering characteristics as demonstrated by ultraviolet light stability and blister resistance in aqueous environments.
[0014] These and other objects, features and advantages of this invention will become apparent from the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention provides new and unique low HAP unsaturated polyester resin compositions, one embodiment of which comprises the following five components: (1) an unsaturated polyester comprised of less than 10% by weight aromatic character; (2) a reactive diluent which is styrene, a styrene analogue, an acrylate, or methacrylate or any combination thereof, less than or equal to about 45 percent by weight of the resin composition; (3) a benzophenone; (4) a benzotriazole; and (5) a hindered amine light stabilizer. In another embodiment, the benzophenone and benzotriazole components are replaced with a triazine UV absorber. In addition to the above components, various additives enable the formulation of the curable composition to a gel coat, laminating resin, non-reinforced resin or molding compound. Additionally, more than one of each component can be used in the resin compositions of this invention.
[0016] Whenever used in this application the term “(meth)acrylate” will be understood to include both “acrylate” and “methacrylate”, and the term “molecular weight” will be understood to mean weight average molecular weight.
Polyester Composition
[0017] The procedure for the synthesis of unsaturated polyesters is well known to those skilled in the art. Typically, these polymers are the condensation products of multifunctional carboxylic acids and/or their corresponding anhydrides with multifunctional alcohols. Less common, but still utilized in the polyester industry, are monofunctional carboxylic acids, alcohols and epoxies. In the present invention, the preferred concentration of the first essential component, an unsaturated polyester, is from about 20 to about 70 percent by weight in the curable resin composition.
[0018] Suitable unsaturated multifunctional acids or anhydrides used in the synthesis of polyester resins include maleic anhydride, maleic acid, fumaric acid, itaconic acid and related derivatives. These are preferably charged in at least 10 mole percent of the total carboxylic acid and anhydride content.
[0019] Saturated multifunctional carboxylic acids or anhydrides that may be used include phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, cyclohexane dicarboxylic acid, adipic acid, succinic acid, malonic acid, nadic acid, trimellitic acid, pyromellitic acid, the related derivatives of such compounds and their corresponding anhydrides. The nadic ester of nadic anhydride is commonly synthesized in situ by reaction of cyclopentadiene with the fumarate and maleate moieties in the polyester backbone. In this application, the term “saturated” refers to compounds that are relatively unreactive towards traditional methods of free radical polymerization. The preferred concentration of the total saturated multifunctional carboxylic acid and anhydride equals about 10 to about 90 mole percent of the total carboxylic acid and anhydride content.
[0020] Preferably, saturated multifunctional carboxylic acids or anhydrides that lack carbon-carbon double bonds are used. Examples of these include adipic acid, succinic acid, malonic acid, glutaric acid, oxalic acid, cyclohexane dicarboxylic acid, hexahydrophthalic acid, the related derivatives of such compounds and their corresponding anhydrides. The preferred concentration of these saturated multifunctional carboxylic acids and anhydrides is from about 10 to about 90 mole percent of the total carboxylic acid and anhydride content.
[0021] The acids, anhydrides and related derivatives described above may be reacted with any combination of multifunctional alcohols. Examples of suitable multifunctional alcohols used in this process are ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol (NPG), butane diol, butyl ethyl propane diol, trimethyl pentane diol, trimethylol propane, hexane diol, cyclohexane dimethanol, glycerol, pentaerythritol and related derivatives including polyether polyols and other polymeric analogs. The amount of total multifunctional alcohol charged in the preferred unsaturated polyester composition is from about 70 to about 130 mole percent relative to the total carboxylic acid and anhydride content.
[0022] Monofunctional acids, alcohols and epoxies can be used in the synthesis of the unsaturated polyester. Some saturated monofunctional carboxylic acids used in polyester synthesis include benzoic acid, 2-ethylhexanoic acid and lauric acid. Examples of monofunctional alcohols that may be used are benzyl alcohol, 2-ethyl hexanol, lauryl alcohol and cyclohexanol. Monofunctional epoxy compounds such as allyl glycidyl ether, glycidyl methacrylate or related derivatives may also be utilized. One or more of these compounds may be used. The preferred concentration of these monofunctional compounds is from about 1 to about 30 percent by weight of the reactor charge in the polyester synthesis.
Polyester Synthesis
[0023] The unsaturated polyester in the present invention may be prepared by a single or multi-stage procedure. Suitable reaction temperatures are from about 150 to about 240° C., preferably from about 180 to about 220° C. This procedure may optionally include catalysts for esterification and isomerization. The catalysts for esterification are well known to those skilled in the art and include a variety of acids, transition metal catalysts and tin compounds. These esterification catalysts are preferably used at levels of up to about 1 percent by weight of the polyester synthesis charge. Examples of suitable isomerization catalysts are acids, nitrogen containing compounds, amines and amides. These are typically used at levels of up to about 1 percent by weight of the polyester synthesis charge.
[0024] The resulting unsaturated polyester in the present invention has a weight average molecular weight of from about 1000 to about 12000, preferably from about 1500 to about 8000.
[0025] Following the synthesis, the unsaturated polyester of the present invention is dissolved in an unsaturated reactive diluent. Styrene and related analogues of styrene may be utilized as a reactive diluent. Some analogues of styrene include vinyl toluene, alpha methyl styrene, divinyl benzene and t-butyl styrene. The concentration of styrene or related analogues of styrene in the unsaturated polyester resin solution can be up to about 45 percent by weight. In a preferred embodiment, the styrene concentration is less than about 30 percent by weight. (Meth)acrylates may also be utilized as a reactive diluent up to about 45 percent by weight. The preferred concentration of (meth)acrylates in the unsaturated polyester resin solution can be up to about 30 percent by weight.
Formulation
[0026] Additives may be used in formulating the curable resin composition of the present invention. The additives and their functions are well known in the industry, examples of which are thixotropic additives, pigments, suppressants, air release agents, fillers, adhesion promoters, inhibitors, leveling agents, wetting agents, adhesion promoters, UV absorbers and light stabilizers.
[0027] Thixotropic agents that are useful in this invention include fumed silica, organoclays, inorganic clays and precipitated silica. Multifunctional alcohols are commonly used to enhance thixotropic properties. If used, the preferred level of thixotropic agent is up to about 10 percent by weight. The thixotropic enhancer is often used at levels of up to about 2 percent by weight.
[0028] Pigments that may be used with this invention may be organic or inorganic, such as titanium dioxide, carbon black, iron oxides, phthalocyanine blue and quinacridone red. These pigments are often dispersed in a vehicle resin, and the level of pigment in this invention may range up to about 40 percent by weight.
[0029] Suppressants to reduce emissions and enhance cure time include waxes, polyethers, polysiloxanes and various block copolymers, and these may be used at levels of up to about 5 percent by weight. Air release agents are commonly available and may be used at levels of up to about 1 percent by weight.
[0030] The present invention may also contain fillers such as talc, alumina trihydrate, calcium sulfate, calcium carbonate, magnesium sulfate, magnesium carbonate, barium sulfate and the like. These fillers may be present at levels of up to about 40 percent by weight.
[0031] Leveling agents such as acrylic resins, fluorocarbons, fluoropolymers and silicones may be added at levels of up to about 2 percent by weight.
[0032] Wetting agents may also be used, such as boric acid esters, phosphate esters, fatty acid salts, polyethers and others. These agents may be used at levels of up to about 2 percent by weight.
[0033] Adhesion promoters such as silanes may be used in amounts of up to about 2 percent by weight in the formulated resin.
[0034] UV stability is improved with the addition of light stabilizers and UV absorbers. Many commercially available light stabilizers are classified as hindered amine light stabilizers (HALS) that oxidize and scavenge radicals. UV absorbers classified as triazines, benzotriazoles, benzophenones, and micronized titanium dioxide, shield the polymer or additives by absorbing UV and dissipating the energy as heat. Combinations of these classes of compounds may be formulated in this invention at levels of up to about 5 percent by weight. Preferably, two or more classes of these compounds of UV absorbers and/or hindered amine light stabilizers are utilized in the resin formulation. It is more preferred the resin composition contains at least one benzotriazole, one benzophenone and one hindered amine light stabilizer.
[0035] The resin compositions of this invention may be cured by a number of free-radical initiators, such as organic peroxide and azo-type initiators. Peroxide initiators include diacylperoxides, hydroperoxides, ketone peroxides, peroxyesters, peroxyketals, dialkyl peroxides, alkyl peresters, percarbonates and peroxydicarbonates. Azo-type initiators include azobisisobutyronitrile (AIBN) and related compounds. These initiators are preferably used in the range of from about 0.3 to about 3 percent by weight.
[0036] The resin compositions of this invention may optionally be cured by UV or electron beam.
[0037] Metal carboxylates, such as cobalt naphthenate or cobalt octoate are often employed to catalyze the free-radical reaction. Zinc, iron, vanadium, manganese, zirconium, calcium and other transition metal compounds are also commonly used for this process. Nitrogen-containing compounds including derivatives of aniline, various amides, quaternary ammonium salts, aromatic and aliphatic amines are also used to promote the free radical reaction. These metal carboxylates and nitrogen-containing compounds and combinations thereof can be added to the resin composition at levels of up to about 5 percent by weight.
[0038] Inhibitors such as hydroquinone, parabenzoquinone, toluhydroquinone, 4-tert butylcatechol, butylated hydroxytoluene and related derivatives may be added to increase shelf stability and adjust gel time. Copper naphthenate may also be used for the same function. Such compounds and combinations thereof are added to the resin composition at levels of from about 0.0002 to about 1 percent by weight.
[0039] Fire retardance may be introduced by adding phosphorus-containing compounds, hydrated fillers, clays, silicon compounds, halogenated materials or combinations thereof up to about 60 percent by weight. More preferably to maintain acceptable weatherability, phosphorus-containing compounds may be added up to about 40 percent by weight.
[0040] The resin compositions of this invention can be formulated and cured with a variety of fillers, additives and initiators commonly used in conventional polyester pultrusion formulations. Fillers such as ATH, clay or calcium carbonate can be used to improve processing and reduce cost. Additives such as pigments, internal lubricants and wetting agents can be part of the final formulation.
Testing
[0041] The mechanical properties of the cured products obtained from this invention are comparable to that of conventional unsaturated polyester resins. The resin compositions of this invention may be useful in any application where articles fabricated from these resins are exposed to UV and/or water. Some applications include resins to be used in gel coats, cast polymers, filled and unfilled glass or carbon fiber reinforced laminating resins, compression molding, pultrusion and resin transfer molding.
[0042] The present invention is further illustrated by the following examples which are illustrative of certain embodiments designed to teach those of ordinary skill in the art how to practice the invention and to represent the best mode contemplated for practicing the invention.
[0043] In the following examples, the term “parts” indicates parts by weight. Several of the examples were evaluated for performance with UV exposure and hydrolytic stability. Resins were also evaluated as ⅛-inch clear cast samples for mechanical properties, which were cured with 1.25% MEKP, followed by a post cure for five hours at 100° C. The results of mechanical testing demonstrate acceptable properties.
[0044] Gloss and color retention of several examples formulated as gel coats were evaluated and compared to conventional gel coats in accelerated weather testing using a Q-UV weather-o-meter. Test specimens were constructed by applying a 20-mil thickness cured film of the examples on a glass plate. After thin film cure was achieved, two plies of 1½ ounce fiberglass mat and a commonly available marine-grade polyester resin were used to construct the reinforcing laminate. After cure, the specimens were de-molded with initial color and gloss readings taken. The specimens were exposed in the weather-o-meter using UV-A 340 nm bulbs and UV-B 313 nm bulbs. Gloss and color readings were taken periodically during the exposure period.
[0045] The hydrolytic stability of several formulated gel coat examples was evaluated and compared to conventional gel coats by water resistance testing. Test specimens were constructed by applying a 20-mil thickness cured film of the examples on a glass plate. After thin film cure was achieved, two plies of 1½ ounce fiberglass mat and a commonly available marine-grade polyester resin were used to construct the reinforcing laminate. After cure, the specimens were de-molded and exposed to boiling water for a period of 100 hours. The specimens were then rated for resistance to blistering, cracking, fiber prominence, color change and loss of gloss.
[0046] Pultrusion test samples for QUV weather testing were constructed by first mixing the formulations in Examples 1-4. While any size shape or thickness can be pultruded with this technology, this example pultruded samples that were 0.050 inches thick by 2.5 inches wide. The samples were fabricated using 48 ends of 250 yield glass roving and two layers of polyester veil. The veil covered the outside of the sample with the majority of the sample substantially comprised of glass roving. The glass roving was wet with the resin formulation by pulling them through a bath containing the resin formulation. Excess resin was squeezed off the glass, and the polyester veil was introduced as the glass entered the die. The resin/glass/veil packaged was pulled through the heated die and cured within the die. Upon exiting the die, the sample was pulled on a continuous basis by the pultruder pullers until the sample reaches an inline saw that cuts samples to length. The samples were tested in QUV weathering equipment with the results given in FIG. 1. The specimens were exposed in the weather-o-meter using UV-A 340 nm bulbs and UV-B 313 nm bulbs. Gloss and color readings were taken periodically during the exposure period.
[0047] The invention described herein encompasses the preparation and use of a curable resin. Tinuvin UV stabilizers were obtained from Ciba Specialty Chemicals. Lowilite UV stabilizers were obtained from Great Lakes.
EXAMPLE 1
[0048] To a stainless steel reactor was charged 30 parts of neopentyl glycol, 4 parts of propylene glycol, 22 parts of hexahydrophthalic anhydride, 3 parts trimethylol propane, 0.004 parts hydroquinone, 0.25 parts piperidine, 25 parts maleic anhydride and 8 parts 2-ethyl hexanol. The mixture was heated at 210° C. with removal of water until an acid number of 15 was obtained with a weight average molecular weight of 4,500. The molten unsaturated polyester product was delivered to styrene containing 50 ppm predissolved toluhydroquinone. The unsaturated polyester was dissolved in styrene solution with agitation at a concentration of 70 percent resin solids and 30 percent styrene. The base resin was then formulated to pultrusion resin as described in Table 1.
TABLE 1 Material Parts Base resin of Example 1 98 TINUVIN 400 (Triazine UVA) 1 TINUVIN 123 (HALS) 1 INT Pul-24 Lubricant 1 70% Titanium dioxide pigment dispersion 3 Calcium Carbonate 14 Wilklay SA-1 (Clay filler) 14 Butylated hydroxyl toluene 0.05
[0049] The unsaturated polyester was cured by pultrusion as described above and evaluated by QUV weathering. The invention showed superior results compared to the conventional resin systems (FIG. 1).
EXAMPLE 2
[0050] To a stainless steel reactor was charged 30 parts of neopentyl glycol, 4 parts of propylene glycol, 22 parts of hexahydrophthalic anhydride, 3 parts trimethylol propane, 0.004 parts hydroquinone, 0.25 parts piperidine, 25 parts maleic anhydride and 8 parts 2-ethyl hexanol. The mixture was heated at 210° C. with removal of water until an acid number of 15 was obtained with a weight average molecular weight of 4,500. The molten unsaturated polyester product was delivered to styrene containing 50 ppm predissolved toluhydroquinone. The unsaturated polyester was dissolved in styrene solution with agitation at a concentration of 70 percent resin solids and 30 percent styrene. The base resin was then formulated to pultrusion resin as described in Table 2.
TABLE 2 Material Parts Base resin of Example 2 99 Lowilite 20 (Benzophenone) 0.4 Lowilite 27 (Benzotriazole) 0.4 Lowilite 92 (HALS) 0.6 Pul-24 Lubricant 1 70% Titanium Dioxide pigment dispersion 3 Calcium Carbonate 14 Wilklay SA-1 (Clay filler) 14 Butylated hydroxyl toluene 0.05
The unsaturated polyester was cured by pultrusion as described above and evaluated by QUV weathering. The invention showed superior results compared to the conventional resin systems (FIG. 1).
EXAMPLE 3
[0051] To a stainless steel reactor was charged 22 parts of neopentyl glycol, 16 parts of propylene glycol, 3 parts trimethylol propane, 12 parts of adipic acid, 0.0025 parts hydroquinone, 0.09 parts piperidine, 37 parts maleic anhydride and 9 parts 2-ethyl hexanol. The mixture was heated at 210° C. with removal of water until an acid number of 15 was obtained with a weight average molecular weight of 8,000. The molten unsaturated polyester product was delivered to styrene containing 30 ppm predissolved toluhydroquinone and 10 ppm 8% copper naphthenate in mineral spirits. The unsaturated polyester was dissolved in styrene solution with agitation at a concentration of 70 percent resin solids and 30 percent styrene. The base resin was then formulated to pultrusion resin as described in Table 3.
TABLE 3 Material Parts Base resin of Example 3 99 Lowilite 20 (Benzophenone) 0.4 Lowilite 27 (Benzotriazole) 0.4 Lowilite 92 (HALS) 0.6 Pul-24 Lubricant 1 70% Titanium Dioxide pigment dispersion 3 Calcium Carbonate 14 Wilklay SA-1 (Clay filler) 14 Butylated hydroxyl toluene 0.05
The unsaturated polyester was cured by pultrusion as described above and evaluated by QUV weathering. The invention showed superior results compared to the conventional resin systems (FIG. 1).
EXAMPLE 4
[0052] To a stainless steel reactor was charged 22 parts of neopentyl glycol, 16 parts of propylene glycol, 3 parts trimethylol propane, 12 parts of adipic acid, 0.0025 parts hydroquinone, 0.09 parts piperidine, 37 parts maleic anhydride and 9 parts 2-ethyl hexanol. The mixture was heated at 210° C. with removal of water until an acid number of 15 was obtained with a weight average molecular weight of 8,000. The molten unsaturated polyester product was delivered to styrene containing 30 ppm predissolved toluhydroquinone and 10 ppm 8% copper. naphthenate in mineral spirits. The unsaturated polyester was dissolved in styrene solution with agitation at a concentration of 70 percent resin solids and 30 percent styrene. The base resin was then formulated to pultrusion resin as described in Table 4.
TABLE 4 Material Parts Base resin of Example 4 98 TINUVIN 400 (Triazine UVA) 1 TINUVIN 123 (HALS) 1 Pul-24 Lubricant 1 70% Titanium dioxidepigment dispersion 3 Calcium Carbonate 14 Wilklay SA-1 (Clay filler) 14 Butylated hydroxyl toluene 0.05
The unsaturated polyester was cured by pultrusion as described above and evaluated by QUV weathering. The invention showed superior results compared to the conventional resin systems (FIG. 1).
EXAMPLE 5
[0053] To a stainless steel reactor was charged 30 parts of neopentyl glycol, 4 parts of propylene glycol, 22 parts of hexahydrophthalic anhydride, 3 parts trimethylol propane, 0.004 parts hydroquinone, 0.25 parts piperidine, 25 parts maleic anhydride and 8 parts 2-ethyl hexanol. The mixture was heated at 210° C. with removal of water until an acid number of 15 was obtained with a weight average molecular weight of 4,500. The molten unsaturated polyester product was delivered to styrene containing 50 ppm predissolved toluhydroquinone. The unsaturated polyester was dissolved in styrene solution with agitation at a concentration of 70 percent resin solids and 30 percent styrene. The base resin was then formulated to gel coat as described in Table 5.
TABLE 5 Material Parts Base resin of Example 5 55 Air release agent 0.3 TINUVIN 123 (HALS) 0.5 TINUVIN 400 (Triazine UVA) 1 Titanium Dioxide 19 Fumed Silica 1.8 Talc 3.3 Cobalt Hex-Cem 0.2 Tertiarybutyl catechol 0.02 Methyl methacrylate 10 Thixotropic synergist 0.25 Styrene 9
The unsaturated polyester was cured as described above and evaluated by QUV weathering and hydrolytic stability. The invention showed superior results after QUV exposure in gloss retention compared to the conventional resin systems (FIG. 2). The product was also evaluated in hydrolytic stability tests (Table 6).
[0054] FIG. 1. QUV weathering analysis (total color change DE*, CIE L*a*b*) of the examples of the invention compared to conventional unsaturated polyester resins and conventional unsaturated polyester resin with UV stabilizers. All samples were cured by pultrusion with a combination of intiators as follows: Percadox 16 (0.55 parts per hundred resin), Trigonox 121-BB-75 (0.4 parts per hundred resin), and Trigonox C (0.3 parts per hundred resin). The conventional unsaturated polyester resin is a DCPD-based polyester with a weight average molecular weight of 7500 without any additives to prevent UV degradation. Also included for comparative purposes is the same conventional DCPD-based unsaturated polyester resin formulated to a UV stabilized resin as in the formulation from Table 1.
[0055] FIG. 2. QUV weathering analysis (gloss retention) of invention example 5 compared to conventional isophthalic-NPG based gel coat and a low HAP isophthalic-NPG based gel coat. The conventional isophthalic-NPG (M W =5500) based gel coat was formulated to a gel coat as Example 5 with UV stabilizers (Tinuvin 123 and Tinuvin 400) at concentrations equal to Example 5. The low HAP isophthalic-NPG (M W =4200) based gel coat was also formulated to a gel coat as Example 5 with UV stabilizers (Tinuvin 123 and Tinuvin 400) at concentrations equal to Example 5.
TABLE 6 Comparative hydrolytic stability exposure tests of Gel Coats. The Example 5 gel coat is compared to conventional isophthalic-NPG based gel coat and a low HAP isophthalic-NPG based gel coat. The conventional isophthalic-NPG (M w = 5500) based gel coat was formulated to a gel coat as Example 5. The low HAP isophthalic-NPG (M w = 4200) based gel coat was also formulated to a gel coat as Example 5. Exposure Hours Blisters Color Fibres Cracks Gloss Conventional Isophthalic-NPG 250 0 1 2 0 1 500 0 2 3 0 1 750 0 2 3 0 1 1000 2 3 3 0 2 1250 2 3 3 0 3 Low HAP Isophthalic-NPG 250 0 1 1 0 1 500 0 1 2 0 1 750 0 1 2 0 1 1000 0 1 2.5 0 1 1250 0 1 3 0 2 Example 5 250 0 1 0 0 1 500 0 1 1 0 1 750 0 1 0 0 1 1000 0 1 1 0 1 1250 0 1 1 0 1 Ratings: 0 = No Change, 5 = Failure
[0056] This invention has been described in detail with particular reference to certain embodiments, but variations and modifications can be made without departing from the spirit and scope of this invention. | Unsaturated polyester resin compositions with improved weathering characteristics are presented. Further, the manufacture of these unsaturated polyester resin compositions and their potential applications are presented. | 2 |
The present invention relates to rescue apparatus and comprises a projectile, one end of the projectile having grappling hook members projecting therefrom the opposite end of the projectile having fins thereon for stabilizing the projectile in flight. A pulley is mounted on the projectile intermediate the ends thereof, a first rope storage member and a second rope storage member being provided for paying out rope to the projectile while the projectile is in flight. A rope is secured in and leads from said storage member over the pulley into and secured to the second storage container, the length of the rope being at least twice the distance to be traversed by the projectile. The first and second rope storage containers are separated for a distance sufficient to keep the rope away from the fin of the projectile when the projectile is in flight.
The pulley is rotatably mounted on an axle secured to the projectile the axle being transverse to and passes through the longitudinal axis of the projectile, the axle being rotatable about in a plane passing through longitudinal axis on pivot members for allowing the axle to move through an arc of up to about 45° .
A ladder is provided which is securable to one end of the rope, a winch also being provided which is also connectable to the rope.
In a further embodiment, the pulley is mounted on an axle passing through the center of gravity of the projectile, the pulley diameter also being greater than the span of the fins to further prevent the rope from becoming entangled in the fins when the projectile is in flight.
The projectile may be launched from a launching member such as a launching tube or cannon by a propellant charge placed in the launcher or a propellant charge mounted on the projectile such as in the case of using a rocket propellant to launch the projectile.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a side elevation illustrating the projectile mounted in a launcher which is affixed to a vehicle according to one embodiment of the present invention.
FIG. 2 is a side elevation in section illustrating in greater detail the projectile and launching tube of the rescue apparatus according to one embodiment of the present invention.
FIG. 3 is a side elevation taken in section along the line 3--3 from FIG. 2 illustrating the axle for mounting a pulley intermediate the ends of the projectile according to one embodiment of the present invention.
FIG. 4 is a plan view of a ladder container used for paying out a ladder which may be secured to one end of the rope which passes through the projectile according to another embodiment of the present invention.
FIG. 5 is a side elevation in section taken along the line 5--5 from FIG. 4.
DETAILED DESCRIPTION
Rescue devices are known in the prior art which comprise projectiles that are fired from launching tubes and which have a rope secured thereto which is payed out while the projectile is in flight. Some of the projectiles of the prior art carry a pulley so that a strand of rope may be run therethrough, both ends of the rope being secured at some point on ground level so that when the projectile is fixed onto an object to which the rope is to be strung, rescue apparatus such as a cage or a ladder may be pulled up to the projectile by means of the rope. The positioning of the pulley in the projectile has presented some difficulty in the prior art since if placed in the tail, the explosive force of a launching charge has a tendency either to jam the pulley or scorch the rope of both. The problem of positioning the pulley to avoid these difficulties has been obviated to some degree in the prior art by putting the pulley on an arm which extends forward from a pivot secured to the tail of the projectile whereby the pulley is positionable outside the muzzle of a launching gun thereby avoiding damage to the pulley or the rope by the discharge of the explosive propellant. When in flight, the pivot allows the pulley on the end of the arm to fold backwards and trail behind the projectile. The problem is not entirely obviated by the apparatus since the pivot which is secured to the tail of the projectile also receives an explosive charge and would have a tendency to jam before the arm can be swung backwards to allow the rope to trail behind the projectile. The latter device is disclosed in U.S. Pat. No. 276,090 Sperry.
U.S. Pat. No. 569,810 Carey discloses a projectile having a pulley mounted in the tail; however, the positioning of the pulley in this manner again exposes it to an explosive charge when the projectile is launched from a mortar or cannon as employed in the Carey reference.
Other apparatus employed in the prior art for securing a line to an object by means of a projectile include U.S. Pat. Nos. 1,069,088 Taylor; 598,110 Petersen; 530,525 Hoekstra; 495,505 Martin; 424,460 Burt; and 291,441 Watts.
It is therefore an object of the present invention to overcome these and other difficulties encountered in the prior art.
It is a further object of the present invention to provide rescue apparatus comprising a projectile for securing a line or a rope to a distant object such as the upper floors of a building or similar structure.
It is also an object of the present invention to provide a projectile having grappling hooks thereon and a pulley for receiving a line, both ends of the line being secured to the launching area of the projectile so that the line and the pulley, once the grappling hook on the end of the projectile is set into an object, may be employed to bring objects up to the point where the projectile is secured by means of the grappling hooks.
It is a further object of the present invention to provide a pulley in a projectile which is not exposed to the launching charge used to propel the projectile.
These and other objects have been achieved according to the present invention and will become apparent from the disclosure and claims that follow as well as the appended drawing.
Referring to the drawing and FIGS. 1 through 5, rescue apparatus 10 is illustrated comprising a projectile body 12 having grappling hook members 14, 16 and 18 projecting from the nose thereof and fins 20, 22 and 24 secured to the opposite end or tail of the projectile 12, the fins providing stability for the projectile in flight, i.e., fins 20, 22 and 24 stabilize the projectile against pitch, roll and yaw. A pulley 26 is mounted intermediate the ends of projectile 12 on axle 28 which is mounted in arcuate slots 52 and 54 in a plane passing through the longitudinal axis of the projectile, the axle 28 being biased by resilient members 56 and 68 such as springs 56 and 58 so that axle 28 is substantially normal to the longitudinal axis of projectile 12.
The diameter of pulley 26 is the same as or greater than the span of tail fins 20 and 24 in order to further assure that line 30 passing around pulley 26 will not become entangled in the fins when the projectile 12 is in flight. Pulley 26 is movable in slots 52 and 54 through an arc up to about a 45 degrees to further prevent projectile 12 from veering off target while in flight because of rope drag.
Guide members 37 and 39 are provided inside of the launching tube 36 from which projectile 12 is launched, guide members 37 and 39 being provided so that fins 20 and 24 may slidingly engage these members as the projectile is launched out of tube 36.
Line 30 is payed out from a first container 34 and a second container 32 which are positoned or separated for a distance sufficient to keep rope 30 from the fins on the tail of projectile 12 when the projectile is in flight.
Tube 36 from which projectile 12 is launched is mounted on support members 40 and 42 through pivots 38 and 40, support members 42 and 44 in turn being secured to a base 46 which is rotatable about pivot 48 mounted on base 50, the rotation of the tube or launcher 36 being such that the muzzle thereof may be swung through an arc of up to about 180°, base 46 being rotatable through an arc of up to about 360° so that the tube 36 may be aimed in a number of directions.
Rope 30, when payed out after projectile 12 is launched and secured to an object may be fastened to a ladder 64 mounted in a container 60 having an opening 62 therethrough, ladder 64 being accessible for storage by means of lid 66 and hinge 68 secured thereto and the wall of container 60.
Winch 70 having pulley 72 thereon may be secured to one end of the rope 30 in order to assist in pulling an object to the projectile 12 when the projectile is secured by means of the grappling hooks thereon to an object. The winch 70 is operated off of a variable speed reversible motor so that the rate and direction of rotation of the pulley 72 may be changed. A vehicle 72 may be employed to transport the rescue apparatus of the present invention, vehicle 72 having lights 74 thereon for night operations.
Rope 30 may be made of any lightweight fire-resistant or heat-resistant material or any material having a high tensile strength such as wire rope e.g., stainless steel wire rope, or a fiber rope made from synthetic polymers or natural materials such as nylon, Dacron (trademark) and the art known equivalents thereof or sisal, hemp and the lile. Stainless steel and synthetic polymer fiber ropes are preferred. An irridescent or phosphorescent coating may be applied to the line 30 or an irridescent or phosphorescent synthetic polymer coated or dyed with such irridescent or phosphorescent material is employed so that the line 30 is better seen, especially at night when lights 74 are aimed at the rope. Ladder 64 may be made of the same material as rope 30.
A propellant charge is used to launch projectile 12, the propellant being either in the base of the projectile 12 such as in the case of a rocket or may be an explosive charge positioned in the bottom of launching tube 36.
In use, the launching tube 36 is aimed at an object by means of sight 70 and the propellant charge discharged whereupon line 30 is payed out from containers 34 and 32 until grappling hooks 14, 16 and 18 are secured to the object to which line 30 is to be attached. The charge used to launch projectile 12 when the projectile is fired as a cannon shot may be varied according to the range to be traversed. Various charges can be loaded into launching tube 36 and can be color coded for different ranges, the different colors representing different distances and propellant charges. Line 30 is then wrapped about pulley 72 on winch 70 and ladder 64 attached to the other side of rope 30 so that it may be positioned or brought up to the object on which grappling hooks 14, 16 and 18 are secured such as the upper story of a building.
Thus, by providing a pulley mounted intermediate the ends of the projectile 12 and sufficiently away from the end of the projectile which receives an explosive force or which has a propellant charge therein, the difficulties of the prior art are obviated wherein the explosive charge is far enough removed from the pulley so that the rope 30 will not be scorched or the charge will not adversely affect the pulley, pulley 26 in the above-described embodiment being sufficiently far away from the end of the projectile so that it is out of the muzzle of the launching tube and away from the hazards of a propellant charge when it is discharged. In one embodiment, the axle of pulley 26 is placed at the substantial center of gravity of the projectile 12 so that the drag force on pulley 26 from lines 30 while the projectile 12 is in flight is less likely to cause the projectile to be thrown off course. Any pitch or yaw of the projectile in flight may be compensated for by the movement of pulley 26 in slots 52 and 54. Containers 34 and 32 are separated for a distance sufficient to keep the rope 30 from entangling in the fins of projectile 12 when the projectile is in flight.
Although the invention has been described by reference to some embodiment, it is not intended that the novel rescue apparatus be limited thereby but that modifications thereof are intended to be included as falling within the broad scope and spirit of the foregoing disclosure, the following claims and the appended drawings. | Rescue apparatus is disclosed comprising a projectile launched from a launching tube, one end of the projectile having grappling hook members projecting therefrom, the opposite end of the projectile having fins for stabilizing the projectile in flight and a pully mounted intermediate the ends for receiving a rope which is payed out from two storage containers separated a sufficient distance so that the rope does not entangle with the fins of the projectile when the projectile is in flight. Once the grappling hook is set in an area where a rescue is to be attempted such as the roof of a building, the rope may be employed to raise a ladder to that point where the grappling hook is secured. A winch is also provided for assisting in either raising the rope or other apparatus needed in the rescue operation. | 5 |
The United States of America may have certain rights to this invention under Management and Operating Contract No. DE-AC05-84ER 40150 from the Department of Energy.
FIELD OF THE INVENTION
The present invention relates to a composition of concrete, and a method of making same, incorporating polyethylene terephthalate to be used in neutron shielding applications.
BACKGROUND OF THE INVENTION
Neutron radiation may be generated as a result of a variety of nuclear reactions or interactions. More specifically, devices such as particle accelerators and nuclear reactors may emit neutrons during operation. Neutrons have a deleterious effect on both living matter and inanimate objects. Neutrons may also participate in neutron activation, thereby inducing radioactivity in environmental materials, equipment, and structures.
It is of vital importance, therefore, to provide adequate shielding from any sources of neutron radiation. Various methods and devices are known to be capable of providing such shielding. One such method involves the use of materials having a high hydrogen content. It is desirable to convert fast neutrons to thermal neutrons for purposes of shielding, as the thermal neutrons can be further attenuated by other shielding materials or methods. Materials with embedded hydrogen are known to effectively thermalize fast neutrons to thermal neutrons.
Hydrogen-enhanced concrete, therefore, can be used to assist in neutron radiation shielding in a variety of applications. Concrete shielding can be incorporated into the structure of a building, room, or any portion thereof. When utilizing such material in construction, the concrete must be of sufficient strength to satisfy the structural requirements of the building elements. Further, such material needs to have the same pourability and workability characteristics as found in traditional concrete formulations.
Accordingly, it is desirable to have a lightweight and structurally sound concrete which is enriched with hydrogen and is able to provide effective neutron shielding, either independently or as part of an advanced neutron shielding system.
OBJECT OF THE INVENTION
It is an object of the invention to provide a concrete composition and a method of making same which can be used as an effective but low-cost neutron shield, and, further, possess sufficient compressive strength and other such characteristics for a variety of building and construction applications.
SUMMARY OF THE INVENTION
The present invention describes a concrete composition incorporating plastic which can be used as a thermal neutron shield. Plastic, in the form of polyethylene terephthalate, is added to the concrete mixture in place of a portion of the traditional ingredient of sand. In a preferred embodiment of the invention, the hydrogen content of the concrete mix is four percent (4%) hydrogen by volume. The concrete composition and method for making same provides efficient and inexpensive shielding for neutrons that also serves as an excellent structural building material.
DETAILED DESCRIPTION
Various types and methods of neutron radiation shielding are known in the art. It is recognized that materials with a high hydrogen content are able to provide effective neutron attenuation.
The mass of the nucleus of a hydrogen atom is essentially the same as that of a neutron. Therefore, neutrons will progressively lose speed and, commensurately, energy after repeated collisions with hydrogen atoms in a shielding substance. This characteristic of hydrogen to effectively thermalize neutrons via scattering makes it ideal for applications involving neutron shielding. A cost-effective method of shielding thermal neutrons can therefore be realized by making hydrogen-enriched concrete.
As set forth herein, plastic can be substituted for a portion of the sand found in ordinary concrete in order to make a hydrogen-rich concrete suitable for shielding thermal neutrons. The enriched concrete mixture includes a high hydrogen content while still maintaining high strength. Further, such concrete possesses excellent workability properties.
Plastic, in the form of polyethylene terephthalate is added to the concrete mixture in place of sand. In a preferred embodiment, recycled PET plastic is used. This type of plastic is generally hard, making it more structurally sound in the finished concrete. The size of the plastic pieces in the mixture may vary but the pieces are generally rough with jagged edges. A 4 mesh screen is used to insure that the size of any particular plastic piece does not exceed 0.187 inches (4.75 mm). In a preferred embodiment, the lightweight concrete is composed of essentially twenty percent (20%) PET plastic by volume.
It will be noted that the concrete may be prepared by using plastic other than recycled PET plastic, such as fresh, extruded plastic. The preferred embodiment, however, relies upon recycled PET plastic as that type provides sufficient structural strength while significantly reducing the overall cost of the mixture.
Gravel is a staple component of ordinary concrete. In order to further reduce the weight of the finished concrete, shale may be used in place of gravel in the instant composition. It is recognized in the art that the replacement of gravel with shale will reduce the final weight of concrete. Nonetheless, the replacement of both gravel and sand, with plastic and shale, as disclosed herein, yields an even lighter weight finished concrete.
Table A illustrates the mix quantities to produce one cubic yard of the preferred embodiment of the concrete disclosed herein:
TABLE A
Quantity to Produce One
Material
Cubic Yard of Concrete
Volume
Portland cement (lbs)
564
2.869
Fly ash (lbs)
141
0.922
Micron3 (oz)
50
0.315
Plastic (lbs)
290
5.404
¾″ course aggregate (e.g.,
492
5.222
Solite)(lbs)
Fine aggregate (sand)(lbs)
1179
7.187
Water (gallons)
33
4.405
Plastocrete (oz)
5.0 per 100 lbs of concrete
Viscocrete (oz)
2.5 per 100 lbs of concrete
Total Cementitious Material (lbs)
7.55
Water/Cementitious Ratio
0.36
Air Content (percent)
0
Aside from the addition and/or removal of specific components, as detailed herein, the lightweight concrete is produced by combining, mixing, pouring, and curing as one would with traditional large batch concrete compositions: (1) combine approximately 60% of the water with the viscosity additives, (2) add the various aggregates, including plastic, and mix thoroughly, and (3) introduce the cement and continue to mix while adding the balance of the water.
The structural strength of the concrete composition is comparable to ordinary concrete while being essentially seventy percent (70%) of the weight of ordinary concrete. Specifically, the structural strength of the instant concrete is equal to 4,000 psi or greater while the instant concrete has a unit weight in the range of 110-115 pounds per cubic foot, compared to 150 pounds per cubic foot for ordinary concrete.
The instant concrete is further composed of essentially four percent (4%) hydrogen by volume as compared to one percent (1%) by volume for ordinary concrete. This hydrogen enhancement makes it three times more efficient at thermalizing neutrons than ordinary concrete.
The lightweight, hydrogen-enriched concrete has potential shielding applications in the nuclear power industry, in high-energy particle and nuclear physics labs, and any industry or location where neutrons are present. The fact that this type of shielding can be integrated into the building structure further serves to reduce overall costs and the necessary footprint for adequate levels of neutron shielding.
While the invention has been described in reference to certain preferred embodiments, it will be readily apparent to one of ordinary skill in the art that certain modifications or variations may be made to the composition and method without departing from the scope of invention described in the foregoing specification. | A lightweight concrete containing polyethylene terephthalate in an amount of 20% by total volume. The concrete is enriched with hydrogen and is therefore highly effective at thermalizing neutrons. The concrete can be used independently or as a component of an advanced neutron radiation shielding system. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application 61/577,241 filed Dec. 19, 2011, and the complete contents of that application is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention pertains to electrospinning for the production of nanofibers and nanofiber webs, and, more particularly, the invention is focused on producing nanofibers and nanofiber webs from a polymer melt.
BACKGROUND
[0003] Electrospinning is a process that is used to produce nanofibers and nanofiber webs. The nanofibers and nanofiber webs have been evaluated for use in a wide range of applications including without limitation in filtration, protective clothing, drug delivery, tissue engineering, and nanocomposites. Although there is significant research interest in nanofiber development, most of the current work is focused on electrospinning from solutions. Solution electrospinning can pose a significant safety problem during manufacture since most solvents used for synthetic polymers are highly flammable, as well as toxic or carcinogenic. The solvents employed in solution based electrospinning also pose additional concerns such as solvent cost, solvent recovery, low production rates, and limiting limited biomedical applications due to residual toxic solvent. Hence, there is a strong interest in developing solvent-free processes such as melt processes for the manufacture of nanofibers.
SUMMARY
[0004] In an embodiment of the invention, co-extrusion technology is combined with electroprocessing technology to produce nanofibers containing multiple layers of materials.
[0005] In another embodiment of the invention, multilayered nanofibers produced by electroprocessing are effectively “delaminated” (i.e., the layers within the fibers are separated) by sonication or other suitable energy application techniques.
[0006] According to an embodiment of the invention, a “solvent-free” process is used to create fibrous materials that have significantly higher surface areas than currently manufactured nanofibers. Specifically, the process combines co-extrusion where two polymer resins in the molten state are arranged to give alternating layers via feed blocks or layer multipliers, with melt electrospinning (or other suitable electroprocessing). By combining the two technologies, nonwoven webs that have hundreds to over a thousand layers within each microfiber can be created. These webs can be subsequently exposed to ultrasonication to create delamination of the layers which result in nanolayer melt electrospun (NME) fibrous webs.
[0007] The multilayer electrospun fibers have been evaluated using electron microscopy both before and after sonication. Experiments have demonstrated that melt electrospun fibers produced according to the invention with 257 alternating layers can be successfully produced and delaminated by ultrasonication.
[0008] The invention includes melt electrospun fibers and matrices, such as non-woven webs, of fibers that contain alternating layers, and their method of production. In addition, the invention includes nanolayer thick fibers (e.g., fiber ribbons) created by delamination of melt electrospun fibers having alternating layers of polymers. Also, the invention includes matrices of these nanolayer thick fibers, in laminated or delaminated form. In some applications, the inventive matrices can have substances of interest deposited on them (e.g., bioactive agents, catalytic agents, fire retardant chemicals, etc.).
[0009] In any exemplary embodiment, two extruders deliver different polymers to a 3 layer feedblock where layering of the melt occurs and this 3 layer melt stream is fed to a single orifice die. A high voltage is applied to a flat plate collector placed at a suitable distance from the die and electrospun fibers are formed and collected on the flat plate. In another exemplary embodiment of this invention, the 3 layer melt stream is fed to a layer multiplying unit where the melt layers are multiplied (multiplying depends on the number of multipliers used). A melt stream with 257 layers, when 7 multipliers are used, is fed to the single orifice die. A high voltage is applied to a flat plate collector placed at a suitable distance and electrospun fibers are collected on the flat plate. In yet another embodiment of the invention, melt electrospun webs that have about 257 alternating layer fibers are exposed to ultrasonication (or other energy application or chemical application) to create nanolayer thick fibers due to delamination of the layers. Delamination can be achieved by other mechanisms such as exposure to chemicals such as chloroform.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1( a ) is a schematic of the layer multiplying process that occurs when using two layers as input to the layer multiplying process.
[0011] FIG. 1( b ) is a schematic of the cross-section of a fiber with multiple layers of two different polymers.
[0012] FIGS. 2A-C are, respectively, schematic drawings of a system for producing multilayer electrospun fibers according to the invention with a flat plate collector ( FIG. 2A ), a rotary drum collector ( FIG. 2B ), and a wide width die in combination with a rotary drum collector ( FIG. 2C ).
[0013] FIG. 3 illustrates a simplified process for delaminating fibers in a fibrous mat formed by melt electroprocessing multiple polymers according to the invention.
[0014] FIG. 4 is a scanning electron micrograph (SEM) of a melt electrospun fiber described in Example 1 that has 257 alternating layers of polycaopactone (PCL) and polyethylene (PE).
[0015] FIG. 5 is a SEM image of a melt electrospun fiber described in Example 2 that has 257 alternating layers of PCL and PE.
[0016] FIG. 6 is a SEM image of a melt electrospun fiber web described in Example 7 that has 257 alternating layers of PCL and PE after ultarsonication which shows delamination of the layers after sonication.
[0017] FIG. 7 is an SEM image of a melt electrospun fiber web described in Example 8 where PCL and PP layers in the fibers are delaminated by exposure to chloroform with slight agitation.
[0018] FIG. 8 is an SEM image of a melt electrospun fiber web described in Example 9 where PCL and PE layers in the fibers are delaminated by exposure to chloroform with slight agitation.
DETAILED DESCRIPTION
[0019] “Co-extrusion” in the context of the present invention is a process by which two polymer resins in the molten state are arranged via feed blocks or layer multipliers to give alternating layers. The number of layers in the final extruded form (e.g., film or microfiber) can be as low as two or in the hundreds (up to and exceeding a thousand). While feedblock technology is typically used to produce films with approximately 3 to 7 layers, layer-multiplying technology is used to produce hundreds to thousands of layers within 25-50 micron thick films. The layer multiplying process is shown schematically in FIGS. 1 a and 1 b.
[0020] With reference to FIG. 1 a there is shown a two component (AB) co-extrusion system which could include, for example, two single screw extruders each connected by a melt pump to a co-extrusion feedblock. The feedblock combines polymeric material (a) and polymeric material (h) in an (AB) layer configuration (see leftmost portion of FIG. 1 a ). Melt pumps (not shown) control the two melt streams that are combined in the feedblock as two parallel layers. By adjusting the melt pump speed, the relative layer thickness, that is, the ratio of A to B can be varied (as shown, the ratio of the top layer to the bottom layer). From the feedblock, the melt goes through a series of multiplying elements. As shown in FIG. 1 a a multiplying element first slices the AB structure vertically, and subsequently spreads the melt horizontally. The flowing streams recombine, doubling the number of layers. An assembly of n multiplier elements produces an extrudate with the layer sequence (AB), where x is equal to (2) n and n is the number of multiplying elements to form a multilayer stack (as depicted in the right most portion of FIG. 1 a ). FIG. 1 b is a cross-sectional view of a fiber with multiple layers produced by co-extrusion (it being recognized that the layers in a co-extruded fiber may not be flat as depicted in FIG. 1 b; rather, the individual layers may be curved or have other configurations, but will form distinct regions in the fiber).
[0021] Co-extrusion with the use of feedblocks and multipliers is a well understood technique in chemical engineering (see, for example, U.S. Pat. No. 7,936,802, U.S. Pat. No. 7,141,297, U.S. Pat. No. 7,255,928, U.S. Pat. No. 7,052,762, U.S. Pat. No. 3,565,985, and U.S. Pat. No. 3,051,453, each of which are herein incorporated by reference). Layered melt blown fibers made using feed block technology are described in U.S. Pat. No. 5,176,952 and U.S. Pat. No. 5,207,970, both of which are herein incorporated by reference.
[0022] The Examples below show the combination of polyethylene (PE) and polycaprolactone (PCL) being combined as multiple layers in electroprocessed fibers according to the present invention. However, many different polymers can be employed in the practice of the invention including without limitation polyolefins (e.g., polyethylene, polypropylene, etc.), poly(urethanes), poly(siloxanes), poly(vinyl pyrolidone), poly(-hydroxy ethyl methacrylate), poly(N-vinyl pyrrolidone), poly(methyl methacrylate), poly(vinyl alcohol), poly(acrylic acid), polyacrylamide, poly(ethylene-co-vinyl acetate), poly(ethylene glycol), poly(methacrylic acid), polylactides (PLA), polyplycolides (PGA), poly(lactide-co-glycolides) (PLGA), polyanhydrides, polyorthoesters, styrene-diene block copolymers, and block copolymers with tackifiers. In addition, thermally stable and melt processable natural polymers (e.g., those occurring naturally in a plant or animal) can be employed in the practice of the invention including without limitation plasticized cellulose acetate.
[0023] In the context of the present invention, “electroprocessing” or “electrodeposition” broadly include all methods of electrospinning, electrospraying, electroaerosoling, and electrosputtering of materials, including combinations of two or more of such methods, as well as any other method wherein materials are streamed, sprayed, sputtered, or dripped across an electric field toward a target. A material can be electroprocessed from one or more grounded reservoirs in the direction of a charged substrate or from charged reservoirs toward a grounded target. Electroprocessing can be performed using one or a plurality of nozzles, and, in the case of using multiple nozzles, each nozzle can be connected to a single reservoir or each can be connected to a different reservoir where each reservoir contains the same or a different melt. The size of the nozzles can be varied to provide for increased or decreased flow out of the nozzles, and a pump or a plurality of pumps can be used to control flow from the reservoir(s). Electrospinning is generally defined as a process by which fibers are formed from melt by streaming the melt through an orifice. In an embodiment of this invention, elecrospinning is achieved by applying a voltage to a collector and the melt is streamed from through the orifice to the collector. Other configurations are possible. Electroaerosoling is generally defined as a process by which droplets are formed from a melt by streaming an electrically charged solution or melt through an orifice.
[0024] Electroprocessing techniques are well known in the art. See, for example, U.S. Pat. No. 7,759,082, U.S. Pat. No. 7,615,373, U.S. Pat. No. 7,374,774, U.S. Pat. No. 6,787,357, U.S. Pat. No. 8,282,712, U.S. Pat. No. 6,592,623, U.S. Pat. No. 8,282,712, U.S. Pat. No. 8,277,712, U.S. Pat. No. 8,277,711, U.S. Pat. No. 8,277,706, U.S. Pat. No. 8,262,958, U.S. Pat. No. 8,257,628, U.S. Pat. No. 8,247,335, U.S. Pat. No. 8,246,730, U.S. Pat. No. 8,241,729, U.S. Pat. No. 8,178,199, U.S. Pat. No. 8,240,174, U.S. Pat. No. 8,206,484, U.S. Pat. No. 8,178,199, U.S. Pat. No. 8,178,029, U.S. Pat. No. 8,173,559, U.S. Pat. No. 8,172,092, U.S. Pat. No. 8,168,550, U.S. Pat. No. 8,163,350, U.S. Pat. No. 8,052,407, U.S. Pat. No. 7,757,811, U.S. Pat. 7,754,123, U.S. Pat. No. 7,717,975, U.S. Pat. No. 7,691,168, U.S. Pat. No. 7,662,332, U.S. Pat. No. 7,628,941, U.S. Pat. No. 7,618,579, U.S. Pat. No. 7,601,262, U.S. Pat. No. 7,452,835, U.S. Pat. No. 7,291,300, U.S. Pat. No. 7,134,857, U.S. Pat. No. 7,070,640, and U.S. Pat. No. 6,838,005, each of which are herein incorporated by reference. As discussed in these patents, natural fibers (e.g., collagen, fibrin, etc.), and synthetic fibers, and combinations thereof can be produced from solutions by electroprocessing.
[0025] The invention contemplates a co-extruded stream of two or more polymer melts (e.g., polymer blend streams), which can be multiplied or not multiplied, being subject to electroprocessing to produce fibers with a plurality of layers therein. The fibers will have at least two layers (Examples below show co-extruded, electroprocessed fibers with three layers, and show the order of the layers does not impact the ability to form fibers), and possibly 50 to 100 or more layers (Examples below show co-extruded, electroprocessed fibers with 247 layers).
[0026] The fibers produced by co-extrusion and electroprocessing according to the invention are multilayered and have a diameter of 100 μm or less. As shown in the Examples below, fibers of 50 μm or less have been produced, and some multilayer fibers having diameters as small as 5-10 μm have been produced. Furthermore, on delamination of the multilayer fibers, ribbon shaped fibers which have thicknesses on the order of nanometers have been produced.
[0027] In a preferred embodiment, the electroprocessed materials form a “matrix”. Matrices are comprised of multilayer fibers, or blends of multilayer fibers and droplets of any size or shape. Matrices can be single structures or groups of structures, and can be formed through one or more electroprocessing methods using a plurality of materials. Matrices can be engineered to possess specific porosities.
[0028] Substances of interest can be deposited within, anchored to, or placed on matrices. Exemplary substances of interest can include bioactive agents (e.g., proteins, nucleic acids, antibodies, anesthetics, hypnotics, sedatives, sleep inducers, antipsychotics, antidepressants, antiallergics, antianginals, antiarthritics, anti asthmatics, antidiabetics, antidiarrheal drugs, anticonvulsants, antigout drugs, antihistamines, antipruritics, emetics, antiemetics, antispasmondics, appetite suppressants, neuroactive substances, neurotransmitter agonists, antagonists, receptor blockers, reuptake modulators, beta-adrenergic blockers, calcium channel blockers, disulfarim, muscle relaxants, analgesics, antipyretics, stimulants, anticholinesterase agents, parasympathomimetic agents, hormones, anticoagulants, antithrombotics, thrombolytics, immunoglobulins, immunosuppressants, hormone agonists, hormone antagonists, vitamins, antimicrobial agents, antineoplastics, antacids, digestants, laxatives, cathartics, antiseptics, diuretics, disinfectants, fungicides, ectoparasiticides, antiparasitics, heavy metals, heavy metal antagonists, chelating agents, alkaloids, salts, ions, autacoids, digitalis, cardiac glycosides, antiarrhythmics, antihypertensives, vasodilators, vasoconstrictors, antimuscarinics, ganglionic stimulating agents, ganglionic blocking agents, neuromuscular blocking agents, adrenergic nerve inhibitors, anti-oxidants, anti-inflammatories, wound care products, antithrombogenic agents, antitumoral agents, antithrombogenic agents, antiangiogenic agents, antigenic agents, wound healing agents, plant extracts, growth factors, growth hormones, cytokines, immunoglobulins, osteoblasts, myoblasts, neuroblasts, fibroblasts, glioblasts; germ cells, hepatocytes, chondrocytes, keratinocytes, smooth muscle cells, cardiac muscle cells, connective tissue cells, epithelial cells, endothelial cells, hormone-secreting cells, neurons, emollients, humectants, anti-rejection drugs, spermicides, conditioners, antibacterial agents, antifungal agents, antiviral agents, antibiotics, tranquilizers, cholesterol-reducing drugs, antitussives, histamine-blocking drugs and monoamine oxidase inhibitors), catalysts (e.g., metals and metal alloys, such as platinum, gold, ruthenium, rhodium, iridium, transition metals and transition metal complexes, nanomaterial catalysts, zeolites, alumina etc.), flame retarding agents, and carbon black
[0029] FIGS. 2A-C shows schematic drawings of an exemplary electroprocessing configuration where a voltage controller 10 is used to charge a target 12 or 12 ′. In FIG. 2A , the target 12 is a flat panel. In FIGS. 2B and 2C , the target 12 ′ is a mandrel or rotary drum. In FIGS. 2B and 2C , the target 12 may be rotated during electroprocessing in order to take up thicker non-woven mats of multilayer fibers. The Target 12 or 12 ′ can be of many different shapes and sizes to suit the needs of the application.
[0030] Each of FIGS. 2A-2C , show a source 13 having a feedblock 14 and multiplier section 15 that allow combining a plurality of polymers from polymer sources 16 a - 16 n. The multiplier section 15 can have zero to a plurality of multipliers (e.g., 2, 3, 7, 10, 20, etc.) depending on the application. With zero multipliers, the feedblock 14 will be used to introduce a layered polymer melt for electroprocessing. However, in some applications, it will be advantageous to have 50 or 100 or more layers in each fiber (the Examples below show formation of fibers with 247 layers). In the present invention, the fibers produced will have at least two different layers of two different polymers (the Examples below show some fibers produced with three different layers having two different polymers, wherein in one Example the outer layers are PE and the inner layer is PCL and in another Example the inner layer is PE and the outer layer is PCL). While the Examples below show combining two polymers into one multilayered fiber, it will be recognized that a plurality of the polymers can be combined by co-extrusion. Thus, fibers having layers of three different polymers, four different polymers, five different polymers, etc. can be made according to the present invention. Thus, FIGS. 2A-C are depicted with polymer sources 16 A- 16 N, where N equals the number of polymers being combined. Further, the polymers in the polymer sources 16 A- 16 N may themselves be polymer blends.
[0031] For simplicity, FIGS. 2A-2C show a single source 13 . However, it should be recognized that in the practice of the present invention there can be a plurality of sources interacting with a single target 12 or 12 ′ during electroprocessing, and that the polymers provided by each of the sources can be the same or different. Furthermore, different operational designs can be used for each of the sources to achieve the formation of multilayer fibers of different diameter as well as mixtures of multilayer fibers and multilayer droplets. In the context of the invention, what is required is that the polymers provided by source 13 have at least two different layers of two different polymers. The thickness of each of the layers of polymers in the fiber can be varied by a variety of means including by control of pumps (not shown) from the polymer sources 16 A- 16 N.
[0032] In FIGS. 2A-2C , the stream of polymer 18 emanating from the nozzles or “tips” 20 or 20 ′ directed towards the target 12 or 12 ′ can be controlled. For example, source 13 could supply a stream 18 of multilayer fibers or a mixture of multilayer fibers and droplets towards target 12 , or source 13 could supply a stream 22 of multilayer fiber which may include branching. Control of the streams can be achieved by a variety of mechanisms including controlling polymer supply pumps, regulating the nozzle 20 or 20 ′ sizes in the sources 13 , regulating the charge on the polymer and/or target 12 or 12 ′, etc. Ultimately, the target 12 or 12 ′ will receive a mass of multilayer fibers generally configured as a non-woven mat. The multilayer fibers can have some crosslinking with the polymers in adjacent fibers, and can contain multilayer droplets interspersed with the multilayer fibers. The bottom of FIG. 2C shows a plan view of the tip 20 ′ where there are multiple orifices for emitting multiple streams of polymer during electroprocessing. With this design a thick mat can be created over a wide area in a short term.
[0033] FIG. 3 illustrates the process of converting the multilayer fibers created by coextrusion/electroprocessing to ribbon shaped fibers, as shown by Example 7 below. The fibrous mat 50 from the electrospinning target is placed in a delaminating device 52 such as a sonicating bath. The sonicating bath 50 can contain any suitable fluid (e.g., water, solvents, etc.) for permitting ultrasonic energy to interact with the fibers such as, for example, a mixture of isopropanol and water. Alternatively, delamination may be achieved chemically by, for example, exposure to chloroform, ethyl acetate, or other solvent. Further, chemical and physical techniques may be used in combination, for example, by exposure to chloroform or ethyl acetate which promotes delamination (e.g., by a rinse) in combination with exposure to energy (e.g., sonication). Delamination can be achieved fairly quickly. For example, sonication of a multilayered polyethylene/polycaprolactone fiber of less than 100 μm in diameter achieved delamination in approximately 30 seconds. FIG. 3 shows the delaminated fibers 54 can be retrieved as a mat from the delaminator (sonicating bath) 52 . The delaminated fibers 54 are comprised of a plurality of ribbon shaped fibers, typically on the order of nanometers in thickness where each individual ribbon is of one distinct material. FIG. 3 also shows that active agents 56 (such as biological active agents, catalytic agents, etc.) can be deposited on the delaminated fibers 54 . This can be accomplished by spraying the active agent onto the mat, dipping the mat into a pool of active agents, electroplating the active agent onto the mat, and by many other means recognized by those of skill in the art. In addition, while FIG. 3 shows application of the active agent 56 to the delaminated fibers 54 , in some applications, active agents could simply be applied to the mat of multilayer fibers 50 .
[0034] The fibrous mats produced according to the invention can be used in a wide variety of applications including without limitation filtration, protective clothing, drug delivery, tissue engineering, and nanocomposites. The fibrous materials have significantly higher surface areas than currently manufactured nanofibers, which can provide superior properties in many applications. In addition, the fibrous materials are manufactured in a “solvent free” manner which avoids many of the manufacturing risks and costs encountered in current electrospinning processes.
EXAMPLES
[0035] In the Examples below, the polymeric components are melted in a single screw extruder and transported via gear pumps to a 3 layer feedblock, where the two polymers are formed into a single flow stream of 3 alternating layers. This 3 layer melt stream is delivered to a layer multiplier that has seven multipliers where the 3 layer stream is cut and stacked seven times to have final melt stream that has 257 alternating layers. This melt stream is delivered to a single orifice die and electrospun into fibers by the application of a high voltage to a flat plate collector which is positioned at a suitable distance across from the die.
[0036] The size and structure of the electrospun fibers were obtained using a LEO (Zeiss) 1550 field emission scanning electron microscope (FE-SEM) in the secondary electron mode. Scanning electron microscopy images were obtained at different magnifications and the fiber diameters were measured using image analysis software.
[0037] For delamination, the melt electrospun fibers and webs were immersed in a water/isopropanol (w/w 80/20) mix and exposed to sonication using a Tekmar Sonic Disruptor at different intensities and time periods. These materials were viewed in the SEM to determine if delamination of the layers occurred and to what extent it occurred.
Example 1
[0038] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL PE ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 1 revolution per minute (RPM). The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7× and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 58 kV was applied to a flat plate collector placed 6 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 258 alternating PCL/PE layers.
[0039] A scanning electron micrograph (SEM) of the electrospun fiber produced according to this Example 1 is presented in FIG. 4 . The diameter of the fiber is approximately 5-10 μm.
Example 2
[0040] A melt electrospun fiber and web, comprising 257 layer fibers was prepared according to the procedure described in Example 1, except the voltage applied was 42 kV.
[0041] An SEM of the electrospun fibers is presented in FIG. 5 . The fiber diameters are approximately in the 25 to 30 μm range.
Example 3
[0042] A melt electrospun fiber and web, comprising 257 layer fibers was prepared according to the procedure described in Example 1, except the flow rate of both gear pumps were maintained at 2 RPM's, the voltage was 60 kV and the flat plate collector was placed 4 inches away from the die.
Example 4
[0043] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 320° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PE ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 RPM's. This stream with 3 alternating layers was fed to a single orifice die which was maintained at about 320° F., and a voltage of 60 kV was applied to a flat plate collector placed 4 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 3 alternating PCL/PE layers.
Example 5
[0044] A melt electrospun fiber and web of the present invention was made using polyethylene (Epolene C-10 available from Westlake Chemical Corporation) and polypropylene (PP) resin (PP 3746G available from Exxon-Mobile Corporation). The polymer pellets and granules were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 392° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PE. The PE:PP ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 RPM. This stream with 3 alternating layers was fed to a single orifice die which was maintained at about 392° F., and a voltage of 60 kV was applied to a flat plate collector placed 3 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 3 alternating PE/PP layers.
Example 6
[0045] A melt electrospun fiber and web, comprising 3 layer fibers was prepared according to the procedure described in Example 5, except that PCL was substituted for PE, the PCL extruder temperature was maintained at 356° F., the PP extruder and feedblock temperatures were maintained at 428° F., the die temperature was maintained at 536° F., the voltage was 62 kV and the flat plate collector was placed 10 inches away from the die.
Example 7
[0046] A melt electrospun fiber web described in Example 1 was immersed in a water/isopropanol (w/w 90/10) mix and exposed to sonication using a Tekmar Sonic Disruptor at a setting of 3 for 30 minutes. FIG. 6 shows an SEM of the resulting material. Thick, ribbon shaped fibers are observed due to delamination of the layers.
Example 8
[0047] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polypropylene (PP) resin (PP 3746G available from Exxon-Mobile Corporation). The polymer pellets and granules were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PP ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 1 revolution per minute (RPM). The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7× and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 63 kV was applied to a flat plate collector placed 10 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 257 alternating PCL/PP layers.
[0048] A melt electrospun fiber web described in this Example 8 was immersed in a beaker of chloroform with a magnetic stirrer and exposed to gentle agitation for 30 minutes. FIG. 7 shows an SEM of the fibrous material where at least a portion of the layers of the multilayer melt electrospun fibers have been delaiminated.
Example 9
[0049] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PE ratio was maintained at a 1:2 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 and 1.0 revolution per minute (RPM) respectively. The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7× and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 65 kV was applied to a flat plate collector placed 10 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 257 alternating PCL/PE layers.
[0050] A melt electrospun fiber web produced as described in this Example 9 was immersed in a beaker of chloroform with a magnetic stirrer and exposed to gentle agitation for 30 minutes. FIG. 8 shows an SEM of the fibrous material with delamination of at least a portion of the layers. | Fibers having two or more alternating polymer layers are formed by co-extrusion followed by electroprocessing. The fibers can be used as a non-woven mat or other substrate for a variety of applications. Delamination of the fibers using ultrasonication yields separated, micro and nanolayer, fiber ribbons which may also be used a non-woven mat or other substrate. | 3 |
This application is a continuation in part of Ser. No. 118,663 filed Nov. 9, 1987, abandoned.
FIELD OF THE INVENTION
The invention is directed to polycarbonate molding compositions and more particularly, to thermoplastic compositions resistant to gamma radiation.
SUMMARY OF THE INVENTION
The invention relates to thermoplastic polycarbonate molding compositions which are rendered resistant to gamma-radiation by incorporating therewith about 0.05 to about 10 percent by weight of a stabilizing agent selected from the group consisting of ##STR3## wherein R is a hydrogen or a halogen atom or a C 1 -C 10 -alkyl, C 6 -C 10 aryl, C 6 -C 18 arylalkyl or a C 4 - 10 cycloalkyl radical, m is 1 or 3 to 6, n is an integer of 20 to 70 and Y is a radical conforming to ##STR4## wherein R, R' and R" independently one of the others are selected from C 1 -C 10 alkyl and C 6 -C 12 aryl radicals preferably C 1 -C 4 alkyl radical.
BACKGROUND OF THE INVENTION
Because of its physical and mechanical properties polycarbonate resin was found to be eminently suitable for a variety of applications in the medical field. Applications which require sterilization by exposure to gamma radiation present a problem since polycarbonate tends to yellow and show increased haze. The art is noted to include U.S. Pat. No. 4,624,972 which disclosed polycarbonate compositions resistant to gamma radiation containing an ester of an aromatic polycarboxylic acid. European Patent Application No. 152,012 disclosed a method for increasing the ionizing radiation resistance of polycarbonate by including in the composition a non-polymeric compound which is characterized by a strong oxidizing action and/or reaction at high reaction rate with active species such as E or OH radicals or hydrated electrons formed by ionizing radiation. U.S. Pat. No. 4,451,641 disclosed a container prepared from a copolyester which has been modified with either a dimer acid or a dimer glycol. The copolyester is said to have an improved resistance to gamma radiation. Radiation stable polyolefin compositions have been disclosed in U.S. Pat. No. 4,460,445. European Patent Application No. 228,525 discloses polycarbonate compositions which are rendered gamma ray resistant by the incorporation of a polyether polyol therewith. End capping of the polyol, by a methyl or an ethyl radical is also disclosed. Also relevant in this connection is U.S. patent application Ser. No. 067,670 filed June 26, 1987 which discloses a particular end-capped polyether which is useful in stabilizing polycarbonate resins against the adverse effects of gamma rays.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the invention comprises a polycarbonate resin and a stabilizing agent in an amount sufficient to enhance the resistance of the resin to yellowness and to the formation of haze upon exposure to gamma radiation. Preferably, the composition contains about 0.05 to 10.0 percent of the stabilizing agent.
The polycarbonate resins useful in the practice of the invention are homopolycarbonates, copolycarbonates and terpolycarbonates or mixtures thereof. The polycarbonates generally have a weight average molecular weight of 10,000-200,000, preferably 20,000-80,000 and their melt flow rate, per ASTM D-1238 at 300° C., is about 1 to about 65 g/10 min., preferably about 2-24 g/10 min. They may be prepared, for example, by the known diphasic interface process from a carbonic acid derivative such as phosgene and dihydroxy compounds by polycondensation (see German Offenlegungsschriften Nos. 2,063,050; 2,063,052; 1,570,703; 2,211,956; 2,211,957 and 2,248,817; French Pat. No. 1,561,518: and the monograph H. Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, New York, 1964, all incorporated herein by reference).
In the present context, dihydroxy compounds suitable for the preparation of the polycarbonates of the invention conform to the structural formulae (1) or ##STR5## wherein A denotes an alkylene group with 1 to 8 carbon atoms, an alkylidene group with 2 to 8 carbon atoms, a cycloalkylene group with 5 to 15 carbon atoms, a cycloalkylidene group with 5 to 15 carbon atoms, a carbonyl group, an oxygen atom, a sulfur atom, --SO-- or --SO 2 -- or a radical conforming to ##STR6## e and g both denote the number 0 to 1; Z denotes F, Cl, Br or C 1 -C 4 -alkyl and if several Z radical are substituents in one aryl radical, they may be identical or different one from the other; d denotes an integer of from 0 to 4; and f denotes an integer of from 0 to 3.
Among the dihydroxy compounds useful in the practice of the invention are hydroquinone, resorcinol, bis-(hydroxyphenyl) alkanes, bis-(hydroxyphenyl) ethers, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)sulfoxides, bis-(hydroxyphenyl)-sulfides, bis-(hydroxyphenyl)-sulfones, and α,α'-bis-(hydroxyphenyl)-diisopropyl-benzenes, as well as their nuclear-alkylated compounds. These and further suitable aromatic dihydroxy compounds are described, for example, in U.S. Pat. Nos. 3,028,356; 2,999,835: 3,148,172; 2,991,273: 3,271,367: and 2,999,846, all incorporated herein by reference. Further examples of suitable bisphenols are 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A), 2,4-bis-(4-hydroxyphenyl)-2-methyl-butane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, α,α'-bis-(4-hydroxyphenyl)-p- diisopropylbenzene, 2,2-bis-(3-methyl-4-hydroxypropane phenyl)-propane, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfide, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfoxide, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfone, hydroxybenzophenone, 2,4-bis-(3,5-dimethyl-4-hydroxyphenyl)-cyclohexane, α,α'-bis-(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene and 4,4'-sulfonyl diphenyl.
Examples of particularly preferred aromatic bisphenols are 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane and 1,1-bis-(4-hydroxyphenyl)-cyclohexane.
The most preferred bisphenol is 2,2-bis-(4-hydroxyphenol)-propane (bisphenol A).
The polycarbonates of the invention may entail in their structure units derived from one or more of the suitable bisphenols.
Among the resins suitable in the practice of the invention are included phenolphthalein-based polycarbonate, copolycarbonates and terpolycarbonates such as are described in U.S. Pat. Nos. 3,036,036 and 4,210,741, both incorporated by reference herein.
The polycarbonates of the invention may also be branched by condensing therein small quantities, e.g., 0.05-2.0 mol % (relative to the bisphenols) of polyhydroxyl compound. Polycarbonates of this type have been described, for example, in German Offenlegungsschriften Nos. 1,570,533; 2,116,974 and 2,113,374; British Pat. Nos. 885,442 and 1,079,821 and U.S. Pat. No. 3,544,514. The following are some examples of polyhydroxyl compounds which may be used for this purpose: phloroglucinol: 4,6-diethyl-2,4,6-tri-(4-hydroxyphenyl)heptane; 1,3,5-tri-(4-hydroxyphenyl)-benzene: 1,1,1-tri-(4-hydroxyphenyl)-ethane: tri-(4-hydroxyphenyl)phenylmethane: 2,2-bis-[4,4-(4,4'-dihydroxydiphenyl)cyclohexylpropane; 2,4-bis-(4-hydroxy-1-isopropylidene)phenol; 2,6-bis-(2'-dihydroxy-5'-methylbenzyl)-4-methylphenol; 2,4-dihydroxy-benzoic acid; 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane and 1,4-bis-(4,4'-dihydroxytriphenylmethyl)-benzene. Some of the other polyfunctional compounds are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis-(4-hydroxyphenyl)-2-oxo-2,3-dihydroindole.
Monohydric aromatic hydroxy compounds are commonly used for regulating the molecular weight of polycarbonate resins. These are well known in the art and include monophenols, such as m- and p-methylphenol, m- and p-isopropylphenol, m- and p-ethylphenol, m- and p-propylphenol, p-bromophenol, m- and p-butylphenol. Para-tert.-octylphenol is preferred.
In addition to the polycondensation process mentioned above, other processes for the preparation of the polycarbonates of the invention are polycondensation in a homogeneous phase and transesterification. The suitable processes are disclosed in the incorporated herein by references U.S. Pat. Nos. 3,028,365: 2,999,846; 3,153,008; and 2,991,273.
The preferred process for the preparation of polycarbonates is the interfacial polycondensation process.
Other methods of synthesis in forming the polycarbonates of the invention such as disclosed in U.S. Pat. No. 3,912,688, incorporated herein by reference, may be used.
Suitable polycarbonate resins are available in commerce, for instance, under the tradenames Makrolon FCR, Makrolon 2600, Makrolon 2800 and Makrolon 3100, all of which are bisphenol A based homopolycarbonate resins differing in terms of their respective molecular weights and characterized in that their melt flow indices (MFR) per ASTM D-1238 are about 16.5-24, 13-16, 7.5-13.0 and 3.5-6.5 g/10 min., respectively. These are products of Mobay Corporation of Pittsburgh, Pa.
The stabilization agent in accordance with the present invention is a monomeric or a polymeric compound conforming structurally to ##STR7## wherein R is a hydrogen or a halogen atom or a C 1 -C 10 alkyl, a C 6 -C 10 aryl, C 6 -C 18 arylalkyl or a C 4 -C 10 cycloalkyl radical, m is 1 or 3 to 6, n is an integer of about 20 to 70 and preferably 30 to 50 and Y conforms to ##STR8## wherein R, R' and R" independently one from the other denote a C 1 -C 10 alkyl, preferably C 1 -C 4 alkyl radical or a C 6 -C 12 aryl radical.
Excellent stabilization effects were obtained by incorporating in a polycarbonate resin (a bisphenol-A based homopolymer) having a molecular weight of about 25,000, 0.5 or 1.0% of a stabilizer conforming structurally to ##STR9## where n was about 35.
The stabilizer of the invention may be prepared by reacting the corresponding silane-compound with a suitable polyether polyol having a molecular weight of up to about 100,000 in the presence of an acid scavenger. Illustrative of the preparation is the process where chlorotrimethyl silane was reacted with a polyether polyol of the formula ##STR10## in the presence of triethyl amine as the acid scavenger.
While the polyether polyol itself, without the silane-derived end groups is a fair stabilizer of polycarbonates against gamma radiation, the stabilizer in accordance with the invention offers distinct advantages thereover. In particular, the stabilizer of the present invention yields splay-free molded articles even at high processing temperatures.
The invention is further illustrated but is not intended to be limited by the following examples in which all parts and percentages are by weight unless otherwise specified.
EXAMPLES
EXAMPLE 1
300 grams of a polyether polyol conforming to formula IV above were added to 500 ml of hexane in a 2000 ml, three-necked flask. To this were added 30.3 g of triethyl amine. 65.18 g of chlorotrimethylsilane were then added in a dropwise fashion to the flask through an addition funnel. The reaction was stirred for 5 hours. The reaction solution was then filtered and washed with hexane several times. The product is a clear to slightly yellow liquid. The IR spectrum of the polyether shows that there are no remaining hydroxyl groups from the starting polyol and new peaks at 11.8 nm and 7.8 nm.
EXAMPLE 1A
The same stabilizer was prepared as follows: Into a 1000 ml three-necked flask there were added 200 grams of hexamethyldisilazane and 300 grams of the polyether polyol of formula IV in 250 ml of THF. The temperature was raised to about 70° C. for about 6 hours and the solution was allowed to reflux. The solvent, ammonia and unreacted compounds were distilled off.
EXAMPLE 2
Polycarbonate molding compositions of the invention containing the end-blocked stabilizers prepared in accordance with Example 1 above were evaluated as to their optical properties both before and after exposure to gamma radiation. The Table below summarizes the results of the evaluation and includes a comparison between a composition containing no stabilizer and compositions containing 0.5% and 1% of the stabilizer. In the compositions the polycarbonate was Makrolon FCR - 2400 resin which is a bisphenol-A based homopolymer having a melt flow index of about 16.5-21.0 g/10 min.
TABLE I__________________________________________________________________________ % Melt Radiation Light.sup.(2) Temp. Dose Trans-Composition (°F.) (MegaRads) mission Haze %.sup.(4) YI.sup.(2) YI.sup.(3)__________________________________________________________________________Polycarbonate.sup.(1) 550° 0.0 88.0 2.31 4.07 -- 2.5 86.4 2.54 12.10 8.03 5.0 85.3 2.12 16.89 12.82 650° 0.0 86.87 2.56 4.17 -- 2.5 85.28 2.63 10.35 6.18 5.0 84.65 2.32 13.98 9.810.5% Additive of 550° 0.0 91.0 0.70 2.83 --the stabilizer 2.5 90.0 0.81 6.00 3.16in 5.0 89.6 0.73 8.85 6.02polycarbonate 650° 0.0 90.8 0.67 2.91 -- 2.5 90.3 1.02 5.44 2.53 5.0 89.7 0.63 8.03 5.121.0% Additive of 550° 0.0 89.9 0.64 2.34 --the stabilizer 2.5 89.4 0.71 5.61 3.27in polycarbonate 5.0 88.4 0.76 8.31 5.97 650° 0.0 90.3 0.70 2.83 -- 2.5 89.9 0.86 4.98 2.15 5.0 89.6 0.86 7.13 4.30__________________________________________________________________________ .sup.(1) A homopolycarbonate based on bisphenol A characterized in that its melt flow index is about 16.5-21.0 g/10 min. .sup.(2) Per ASTM D1925. .sup.(3) Difference in yellowness index in comparsion with the unradiated sample. .sup.(4) Per ASTM D1003.
The compositions of the invention may be prepared by following conventional procedures for the preparation of polycarbonate molding compositions. The stabilizing agent may be introduced by directly mixing it with the polycarbonate. Alternatively, concentrates containing a high amount of the stabilizer of the invention may be prepared and later diluted with a polycarbonate resin to any desired concentration. Other conventional additives may also be incorporated in the composition for their art-recognized utility. These include release agents, plasticizers, stabilizers, antioxidants, fillers, reinforcements and the like.
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims. | The invention relates to thermoplastic polycarbonate molding compositions which are rendered resistant to gamma-radiation by incorporating therewith about 0.05 to about 10 percent by weight of a stabilizing agent selected from the group consisting of ##STR1## wherein R is a hydrogen or a halogen atom or a C 1 -C 10 alkyl, a C 6 -C 10 aryl, C 1 -C 22 acyl, C 6 -C 18 alkylaryl or a C 4 -C 10 cycloalkyl radical, m is 1 or 3 to 6, n is an integer of about 20 to 70 and Y is a radical conforming to ##STR2## wherein R, R' and R" independently one of the others are selected from C 1 -C 10 alkyl and C 6 -C 12 aryl radicals preferably C 1 -C 4 alkyl radical. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a process for the preparation of 4-hydroxyisophorone through the oxidation of beta-isophorone.
2. Discussion of the Background
3,5,5-Trimethyl-4-hydroxy-2-cyclohexen-1-one (4-hydroxyisophorone) is described in the literature as a fragrance for tobacco products (JP-OS 81 35 990; CH-PS 549 961; DE-OS 22 02 066), as a flavor and fragrance in foods (CH-PS 549 956; M. Ishihara et al., J. Org. Chem. 1986, 51, 491-5), and as a base material for the synthesis of various pharmaceuticals (N. S. Zarghami et al., Phytochemistry 1971, 10, 2755-61; J. N. Marx and F. Sondheimer, Tetrahedron, Suppl. No. 8, Pt 1, 1-7, 1966). It is generally synthesized by the oxidation of beta-isophorone (3,5,5-trimethyl-3-cyclohexen-1-one) by various methods. ##STR1##
However, a severe limitation existed until recently because no practical procedure was known for preparing beta-isophorone and no further synthetic possibilities were studied. In accordance with DE-OS 37 35 211, however, beta-isophorone can now be prepared conveniently from alpha-isophorone (3,5,5-trimethyl-2-cyclohexen-1-one) by catalytic isomerization, so that at least this problem has been eliminated.
Oxidation in the para-position relative to the carbonyl group in these compounds produces a reactive substituent that permits further syntheses to obtain odorants and flavors identical to natural products, and to prepare Vitamin A derivatives. For this reason, the least expensive and chemically most economical method for carrying out this oxidation step was sought. It must be considered here that beta-isophorone rearranges (back-isomerizes) readily to alpha-isophorone, which does not undergo the desired reaction and is thus unavailable for producing 4-hydroxyisophorone. A need exists, therefore, for a method to keep back-isomerization within limits in addition to the other requirements mentioned.
It is well known that beta-isophorone can be oxidized by air using noble metal catalysts (FR-A 2 335 486). In addition to 4-ketoisophorone and alpha-isophorone, the desired 4-hydroxyisophorone is obtained in this reaction as a byproduct also. 4-Hydroxyisophorone can also be obtained directly from alpha-isophorone in small yields using a biochemical method with Aspergillus niger (JP-OS 81 35 990; Y. Mikami et al., Agric. Biol. Chem. 1981, 45, 791-3). A. Heymes and P. Teisseire obtained 4-hydroxyisophorone in 34% yield by oxidation with monoperphthalic acid (Recherches 1971, 18, 104-8), while N. S. Zarghami and D. E. Heinz (Phytochemistry 1971, 10, 2755-61) disclosed no yield information for the reaction with peracetic acid. J. N. Marx and F. Sondheimer report a yield of 87% from the treatment of beta-isophorone with m-chloroperbenzoic acid, but the recalculation of the results they reported shows only a yield of 56%, which is also in agreement with other information in the literature (Tetrahedron, Suppl. No. 8, Pt. 1, 1-7, 1966; see also O. Isler et al., Helv. Chim. Acta 39, 2041, 1956).
All of the methods published so far have serious deficiencies. On the one hand, the yields are poor, the chemicals used are costly, and it is difficult and expensive to isolate the end product; on the other hand, the processes have large amounts of waste. A technical process based on the available literature can thus be rather surely excluded.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a process for the preparation of 4-hydroxyisophorone which may be carried out easily and uses inexpensive reagents.
This and other objects which will become apparent from the following specification have been achieved by the present process for producing 4-hydroxyisophorone in which beta-isophorone is oxidized in the presence of hydrogen peroxide and a weak organic acid at a temperature in the range from 0-100° C.
BRIEF DESCRIPTION OF THE DRAWING
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing, wherein:
FIG. 1, illustrates the reformation of alpha-isophorone with time from an initial mixture of beta-isophorone and formic acid at room temperature.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It was found surprisingly that the oxidation of beta-isophorone to 4-hydroxyisophorone succeeds in the presence of hydrogen peroxide and even commercial hydrogen peroxide solution. The hydrogen peroxide concentration can be from about 25 to 45%, preferably about 30%. ##STR2##
To prevent oxirane (epoxide) formation, which is known with this reaction, it is preferable to carry out the oxidation in acidic medium. An especially preferred acidic medium is prepared using a weak organic acid, for example formic acid. Other acids, especially inorganic acids, catalyze the back-isomerization of beta-isophorone to alpha-isophorone to a large extent. On the other hand, sufficient time remains for the oxidation of most of the beta-isophorone to 4-hydroxyisophorone when using the weaker formic acid. The diagram shown in FIG. 1 shows the time curve for the reformation of alpha-isophorone in an initial mixture of molar quantities of beta-isophorone and formic acid at room temperature.
Furthermore, weak organic acids, such as formic acid, have the advantage of better solubility for all of the reactants. Another benefit of the use of weak acids such as formic acid, is based on the fact that the excess hydrogen peroxide is positively destroyed, as shown in the equation below, in the subsequent processing and there is no risk of spontaneous peroxide decomposition.
H.sub.2 O.sub.2 +HCOOH →CO.sub.2 +2 H.sub.2 O
The reaction is controlled so that the conditions for reliable destruction of excess hydrogen peroxide are reached toward the end of the reaction. The reaction product can be separated after neutralization as an organic phase, and can be distilled.
The process of the present invention is relatively simple technically. Inexpensive commercial chemicals are used as reagents. For example, formic acid and 30% hydrogen peroxide solution are placed in a stirred apparatus in a molar ratio of from about 1:1 to about 5:1 in a temperature range between 0° C. and 100° C., and about 0.5 to 2.5 moles, preferably 1 mole of beta-isophorone is added slowly. The formic acid/hydrogen peroxide mixture may also be added to the beta-isophorone. Gentle cooling may be used to remove the heat of reaction, depending on the selected temperature conditions and batch size. After completing the reaction and allowing the reaction to stand, the batch, which has become homogeneous, is neutralized with a suitable base, such as for example an alkali or alkaline earth metal hydroxide, oxide, carbonate or bicarbonate. A preferred base is sodium bicarbonate. The upper phase that forms is separated, dried, and distilled under vacuum. After the separation of back-isomerized alpha-isophorone, 4-hydroxyisophorone is obtained as a distillate. The alpha-isophorone distilled off in the forerun can be recycled to the process after reisomerization according to DE-OS 37 35 211.
Other features of the invention will become apparent in the course of the following descriptions of the exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
Example 1
120 g (2 moles) of 30% hydrogen peroxide solution is mixed with 48 g (1 mole) of formic acid, and 138 g (1 mole) of beta-isophorone is added over a period of 1/2 hour with stirring at 40° C. The reaction is allowed to continue at 40° C. (gentle external cooling and stirring), and after being allowed to stand for 12 hours, the mixture is heated for a short time (1/2 hour) at 80° C. The mixture is then neutralized with sodium bicarbonate, and the upper layer that forms is separated, dried with sodium sulfate, and distilled under vacuum.
The fractions obtained from the distillation are:
______________________________________Bp(4 mm Hg) = 68-92° C. 44 g corresponding to 32% alpha-isophorone, andBp(0.2 mm Hg) = 124° C. 72 g corresponding to 47% 4-hydroxyisophorone with n.sub.D.sup.20 = 1.5010.______________________________________
Considering the conversion and the recovered alpha-isophorone, the yield is 69% of product.
EXAMPLES 2 AND 3
Examples 2 and 3 are carried out similarly to Example 1, but at a reaction temperature 60° C. (Example 2) or 80° C. (Example 3).
The amounts of product obtained are:
Example 2:
42 g corresponding to 31% alpha-isophorone, and
59 g corresponding to 39% 4-hydroxyisophorone.
The yield based on conversion is 66%.
Example 3:
46 g corresponding to 34% alpha-isophorone, and
63 g corresponding to 42% 4-hydroxyisophorone.
The yield based on conversion is 70%.
EXAMPLE 4
The procedure is similar to Example 1, but the amount of hydrogen peroxide solution used was increased to a molar ratio of hydrogen peroxide to beta-isophorone of 3:1. The amounts of product produced are then:
27 g corresponding to 20% alpha-isophorone, and
85 g corresponding to 56% 4-hydroxyisophorone.
The yield based on the conversion is calculated to be 82%.
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. | A process for preparing 3,5,5-trimethyl-4-hydroxy-2-cyclohexen-1-one, comprising:
oxidizing beta-isophorone in the presence of hydrogen peroxide and a weak organic acid at a temperature in the range of 0°-100° C. | 2 |
This is a division of application Ser. No. 100,651, filed Sept. 24, 1987, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention relates to latent catalysts for heat curable thermosetting resins. More particularly, the subject invention relates to a new class of catalysts which have improved latency at ambient temperatures and which are oxidation and hydrolysis resistant. These catalysts are useful in catalyzing a variety of resin systems, particularly epoxy and bismaleimide resins.
2. Description of the Related Art
Latent catalysts are necessary for the cure of several important categories of resins. The cure of epoxy resins, for example, is generally catalyzed even when "curing agents" such as acid anhydrides or organic diamines are present. Bismaleimide resins may be cured by heat along, but the properties of the cured products are not as good as those achieved when the same resin system is cured catalytically.
Latent catalysts may be divided into two principle groups: those which are activated photochemically, and those which are activated thermally. Photo-activated catalysts are extensively used in the electronics industry in formulating resins useful in processing integrated circuits and circuit boards. In the structural materials area, however, where part sizes are generally much larger and often of complex shape, thermally-activated catalysts are the norm. The discussion which follows relates to this type of latent catalyst.
An ideal latent catalyst will have little or no catalytic activity below a certain threshold temperature, above which the catalyst becomes active. This threshold temperature must be high enough above ambient to facilitate long term storage of the uncured, catalyzed resins and products containing them, but must be low enough to be convenient for the cure of the particular resin system with which the catalyst is used.
When the catalyst has a latency threshold which is too high, several deleterious effects may occur, including thermal decomposition of the resin components; volatilization of low molecular weight resin components or solvents; and extensive thermal curing in conjunction with catalytic cure of the resin. Additionally, subjecting assemblies such as structural composites to wide temperature ranges during processing may cause distortion due to uneven expansion and contraction.
In U.S. Pat. No. 3,562,215, for example, are disclosed substituted urea and guanidine compounds which are used in conjunction with a glycol and with organic lead or mercury derivatives to form a latent catalyst system for epoxy resins. However the catalyst must be used in amounts of approximately ten percent by weight relative to the epoxy resins. Furthermore it is well known that the decomposition of ureas can produce a number of volatile products. Finally, organolead and organomercury compounds are highly poisonous, difficult to handle safely, and may cause environmental problems.
The use of phosphonium halides in conjunction with alkali metal hydroxides or halides are disclosed as latent catalysts for use in epoxy resins in U.S. Pat. No. 4,320,222. However the presence of alkali metal salts may be deleterious to the long term stability of the cured resin. Moreover, the decomposition of the phosphonium halide involves the formation of an organic halide which, in most cases, is relatively volatile. Finally, the phosphonium halides are water soluble and possess strong biocidal properties, thus presenting safety and environmental concerns.
The use of organophosphines and organophosponium salt as latent catalysts for bismaleimide resin systems is disclosed in U.S. Pat. No. 4,644,039. However, organophosphines, particularly the aliphatic phosphines, are volatile compounds of high toxicity and thus also present handling problems. Moreover, many organophosphines, again particularly the aliphatic organophosphines, are readily oxidizable to phosphine oxides which possess little or no catalytic activity. Thus formulation of systems containing these catalysts preferably takes place in inert atmospheres, and subsequent oxidation in situ is possible, causing gradual loss of catalytic activity.
In U.S. Pat. No. 4,131,633 are disclosed latent catalysts prepared by the reaction of maleic anhydride and tris-substituted phosphines. However, the latency threshold of these compounds is rather low, and the products are additionally highly water sensitive, being subject to complete hydrolysis.
It would be desirable to prepare a latent catalyst which is oxidatively and hydrolytically stable under ordinary conditions; which presents a minimum of handling problems; which has a latency threshold which allows for long term storage of uncured products; which is active at a temperature suitable for use with advanced resin systems; and which produces low levels of volatiles upon cure.
SUMMARY OF THE INVENTION
It has now been discovered that catalysts prepared through the reaction of organophosphines with maleimide-group-containing compounds are solids which exhibit excellent storage stabilities with respect to both oxidation and hydrolysis; have latency thresholds which provide for excellent storage stability of catalyzed but uncured resins systems; which produce either no volatiles or very low levels of volatiles upon activation; and which exhibit catalytic activity at temperature suitable for the elevated temperature cure of modern, high strength resin systems. The catalysts are effective in a variety of resin systems, particularly in epoxy resins and bismaleimide resins, and contain the N-[3-phosphoranylidenyl-1-azacyclopenta-2,5-dione] radical having the formula: ##STR1##
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The latent catalysts of the subject invention are prepared by reacting a tris-substituted organophosphine with a maleimide-group-containing compound. The reaction takes place readily at low temperature, i.e. from about 0° C. to 25° C., preferably in an inert soluent such as dichloromethane.
The tris-substituted phosphines suitable for the preparation of the latent catalysts of the subject invention have the formula R 3 P, wherein each R may be individually selected from the group consisting of substituted or unsubstituted hydrocarbon groups, in particular alkyl, cycloalkyl, and aryl groups. The term "alkyl group" as used herein and in the claims includes alkyl groups which are substituted by cycloalkyl or aryl groups or by other inert substituents.
Among the many tris-[alkyl] phosphines useful for the practice of the invention are trimethyl-, triethyl-, tris[n-propyl]-, tris[2-propyl]-, tris[n-butyl]-, tris[i-butyl]-, tris [t-butyl]-, tris[n-octyl]-, tris[2-ethylhexyl]-, tridecyl-, tridodecyl-, tribenzyl, and 1,1,1,-tris[2-phenylethyl]phosphines, as well as mixed alkyl phosphines such as methyldiethylphosphine, dibutyloctylphosphine, and the like.
Among the cycloaliphatic phosphines useful are tris-cyclopentyl]-and tris[cyclohexyl]phosphine, tris[2-, and 4-methylcyclohexyl]phosphines, and mixed phosphines such as dibutylcyclohexylphosphine. The cycloaliphatic substituents generally have 5-6 carbons in the ring structure proper.
Among the aryl phosphines which are useful are triphenylphosphine, tris[4-chlorophenyl]phosphine, tritolylphosphine, and mixed phosphines such as cyclohexyldiphenylphosphine and diethylphenylphosphine.
Thus many tris-substituted phosphines are useful. Preferred tris-substituted phosphines, because of their availability and lower cost, are those wherein each R is the same. However mixed phosphines may occasionally be quite useful, as the characteristics of the latent catalysts vary with the nature of the substituents. Most preferred are tributylphosphine and triphenylphosphine.
The maleimide-group-containing compound has the formula ##STR2## wherein X may be a substituted or unsubstituted hydrocarbon group having a valence, n, of from 1 to about 4, and a formula CY 3 , wherein Y may be hydrogen, an alkyl, cycloalkyl, or aromatic group which is optionally substituted with a maleimide group having the formula ##STR3## or wherein Y may represent a polyoxyalkylene group such as polyoxyethylene, polyoxypropylene, or polyoxybutylene, or other suitable organic group such as those described in the text which follows, and wherein R 1 is hydrogen, substituted or unsubstituted alkyl, cycloaklyl, or aryl, but preferably hydrogen.
The maleimide-group-containing compounds useful in preparing latent catalysts are themselves generally prepared by reacting the corresponding amine with maleic anhydride. The synthesis of such maleimides is well known to those skilled in the art. Suitable maleimides are, for example, the maleimides of aromatic amines such as aniline; o-,m-,and p-toluidine; 2,4-and 2,6-toluene diamines; aromatic diamines having the formula ##STR4## wherein A may be ##STR5## wherein R 2 and R 3 may be hydrogen, C 1 -C 6 lower alkyl, or aryl; ##STR6## alkylene; oxyalkylene, and polyoxyalkylene; aromatic polyamines, particularly those prepared through the condensation of aniline or substituted anilines with formaldehyde (e.g. polymeric MDA); aliphatic amines such as the various C 1 -C 20 alkyl monoamines; the alkylene diamines, particularly ethylenediamine; the polyalkylene polyamines such as diethylenetriamine and amine terminated polyoxyalkylene polyethers. Cycloalklamines such as 1,4-cyclohexanediamine and 1,4-bis[aminomethyl]cyclohexane are also useful.
The maleimide-group-containing compounds may also be substituted with other organic groups such as hydroxyl, halo, acyloxy, carbonamide, alkoxy, and cyano groups. The maleimide of p-aminophenol is an example of such a compound. Additional maleimides are those of amines having the following structures: ##STR7## particularly preferred are the maleimides of 1,4-phenylenediamine, p-aminophenol, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone. As can be seen, the bismaleimides which may work in the present invention are exceptionally numerous and varied. As the properties of the latent catalysts depend upon the nature of both the phosphine and the maleimide, the latent catalysts of the subject invention may be varied to suit many applications.
The latent catalysts of at the subject invention are especially useful in epoxy systems, particularly those containing phenolic or carboxylic anhydride curing agents. The latent catalysts also find use in maleimide systems, especially those containing alkenylphenols as comonomers.
In preparing the catalyzed resins, the necessary quantity of catalyst, which is generally from about 0.01 percent to about 5 percent by weight based upon the curable resin components, more preferably from about 0.5 percent to 4 percent by weight, and most preferably about 1-3 percent by weight, is mixed with the resin components to form a homogenous mixture. Mixing generally takes place at a modestly elevated temperature, for example from 70° C. to 120° C., preferably from about 80° C. to about 100° C. If a curing agent is used, as is generally the case with epoxy resins, the catalyzed resin absent the curing agent is generally allowed to cool somewhat, for example to about 70° C. before the curing agent is added.
The catalysts of the subject invention are generally useful whenever a phosphine or phosphonium salt catalyst would be effective. In addition to epoxy resin compositions and maleimide resin compositions, these include resins whose reactive monomers may be cyanates, isocyanates, acrylates, and alkenyl and alkynyl resins. This list is not exhaustive. In the claims which follow the example, the term "heat-curable resin" should be taken to mean any resin system the thermal cure of which can be accelerated through the use of the latent catalysts of the subject invention.
To evaluate a resin system with respect to its catalysis with the latent catalysts of the subject invention, a simple test is to prepare a resin system both with and without from about 1-5 percent by weight of the latent catalyst. The gel times of the catalyzed and non-catalyzed systems are then compared at a temperature sufficient to activate the catalyst. If the latent catalyst is effective in causing a decrease in gel time of the resin system, then the heat-curable resin is one which is within the scope of the claims.
The examples which follow illustrates the preparation of several catalysts and their use in catalyzing a variety of heat-curable, thermosetting resins. The examples are not limiting, but are illustrative only.
EXAMPLE 1
Reaction of Triphenylphosphine with the Bismaleimide of 4,4'-Diaminodiphenylmethane.
The bismaleimide (7.16, 0.02 mole) is dissolved in CH 2 Cl 2 (30 ml) in a 250 ml glass reactor cooled by means of an ice-water bath. To the solution, triphenylphosphine (11.0 g, 0.042 mole) in 20 ml CH 2 Cl 2 is slowly added under N 2 flow while stirring. The resulting red solution is stirred overnight at room temperature. Addition of ethyl acetate gives an orange precipitate which is separated by filtration, washed with cold ethylacetate, and dried under vacuum.
Yield of catalyst (m.p.>200° C.) was 15.3 g. Analytical results are consistent with a compound corresponding to the structure Ia. ##STR8##
EXAMPLE 2
Reaction of Tributylphosphine with the Bismaleimide of 4,4'-Diaminodiphenylmethane
Tributylphosphine (8.50 g, 0.042 mole) and CH 2 Cl 2 (50 ml) are charged to a 250 ml glass reactor under N 2 flow then cooled with an ice-water bath. To the solution, the bismaleimide (7.16 g, 0.02 mole) in CH 2 Cl 2 (50 ml) is slowly added while stirring. The resulting red solution is stirred at room temperature overnight. Addition of ethyl acetate causes the precipitation of the product which is separated by filtration and washed with cold ethyl acetate. Drying under vacuum gives 14.0 g of orange solid (m.p.>200° C.). Analytical results are consistent with a compound corresponding to the structure Ib. ##STR9##
EXAMPLE 3
Reaction of Triphenylphosphine with the Maleimide of p-aminophenol.
A mixture of the maleimide (4.73 g, 0.025 mole) and 50 ml of CH 2 Cl 2 is slowly added to a solution of triphenylphosphine (6.80 g, 0.026 mole) in 50 ml of CH 2 Cl 2 at 15° C. under N 2 while stirring. The resulting mixture is stirred overnight at room temperature. Filtration, followed by washing with cold ethyl acetate gives a colorless solid (yield 11.0 g, m.p. 180° C. with decomposition). Analytical results are consistent with a compound corresponding to the structure II. ##STR10##
EXAMPLES 4-7
Heat-Cure of Bismaleimide Resins
Heat-Curable Bismaleimide resin systems are prepared in the following manner:
The bismaleimide of 4,4'-diaminodiphenylmethane (6.7g) and o,o'-diallylbisphenol A (3.3g) are stirred at 140° C. to give a uniform mixture. The mixture is cooled to 80° C. and catalyst (0.05g) is added while stirring. Gel times are measure din aliquots of each of the catalyzed mixtures at both 177° C. and 120° C. Results are shown in Table I.
TABLE I______________________________________ Gel Time (Minutes) atExample Latent Catalyst of 177° C. 120° C.______________________________________4 Example 1 10 605 Example 2 10 --6 Example 3 10 807 No Catalyst 23 --______________________________________
Uncured, catalyzed samples are allowed to stand at room temperature for four weeks. No loss of tack is observed.
EXAMPLE 8
Preparation of Precatalyzed Epoxy Resins
Precatalyzed epoxy resins are prepared by mixing a diglycidylether of bisphenol A (DER 332® available from the Dow Chemical Co., Midland, MI., epoxy equivalent weight=172, 10.00 g) and the catalysts (0.88 g) from Examples 1-3, at 80° C. The mixtures are stored at room temperature for four weeks. No change in EEW is observed, illustrating the storage stability of the catalyzed systems.
EXAMPLE 9
Preparation of Linear Epoxy Resins
A 100 ml glass reactor equipped with a mechanical stirrer is charged with the diglylcidyl ether of bisphenol A (DER 332®, EEW 172, 15.2 g), bisphenol A (4.8 g), and the catalyst (0.09 g) from Example 1 dissolved in DER® (1.0 g). The stirred reaction mixture is heated to 150° C. for 10 hours to yield a viscous oil which solidified at room temperature. EEW of the resulting mixture is 444 (theoretical EEW=406). Further mixing at 150° C. does not alter the EEW value.
EXAMPLES 10-13
Samples are prepared in the following manner: An expoxy novolac (DEN® 438, available from the Dow Chemical Co., Midland, MI., EEW=176, 38.0 g) and bisphenol A (12.0 g) are mixed at 100° C. to give a clear mixture. At 70° C., the above mixture (10.0 g) and the precatalyzed epoxy (1.09 g) from Example 8 are mixed in an aluminum dish to give a uniform mixture. Gel times are measured in aliquots of each of the catalyzed mixtures at both 177° C. and 120° C. Results are shown in Table II. A sample (Example 12) was also prepared from DEN 438 (17.6 g), bisphenol A (3.4 g), and triphenylphosphine (0.052 g).
TABLE II______________________________________ Gel Time (Minutes) atExample Latent Catalyst of 177° C. 120° C.______________________________________10 Example 1 4.0 4011 Example 3 1.5 1212 Triphenylphosphine 1.3 913 No Catalyst >60 --______________________________________
Uncured samples are allowed to stand at room temperature. The triphenylphosphine catalyzed sample (Example 12) shows the loss of tack after three days, whereas the samples from Example 10, 11, and 13 show no loss of tack even after two weeks.
EXAMPLE 14
Heat-Cure of Epoxy Resin
Nadic anhydride (4.0 g) is dissolved in a novolac epoxy (DEN® 438, 5.0 g) at 100° C. At 70° C., the catalyst (0.5 g) from Example 3 dissolved in DER 332 (0.5 g) is added while stirring.
The resulting resin system is cured at 120° C. Gel time is 21 minutes. | The subject invention relates to N-[3-phosphoranylidenyl-1-azacyclopenta-2,4-dione] radical-containing-compounds which are effective, storage stable latent catalysts for a variety of high performance resin systems. | 2 |
FIELD OF THE INVENTION
This invention relates generally to bookmarks and, more particularly, to bookmarks that do not easily dislodge from their position in a book and which are adjustable to fit all sizes and shapes of books.
BACKGROUND OF THE INVENTION
To an avid reader with a busy life, bookmarks are indispensable. Since it is difficult for most people to finish a book in one sitting, the pages where the reader has left off must be marked and remarked as the reader progresses through the book. Frequently, in this manner, the reading of a single text is accomplished in multiple sittings, requiring the reader to interrupt the process and resume reading the book when convenient.
A single book may also be read in multiple locations, whereby it is carried by the reader from place to place until it is finished. For example, a single book may be read while in bed, at the doctor's office while waiting for an appointment, in a park over a lunch hour or even while exercising on a stationary bike at the local gymnasium. Consequently, an unfinished book may frequently need to be carried from one location to another as the author progresses through the book. This necessitates marking and remarking the stopping points in the book in a secure manner so that the proper stopping point is designated regardless of the physical movement of the book from one location to another.
Sometimes it is also desirable to use bookmarks to facilitate the ready location of a particular page in a book that the reader may use frequently. For example, it may be desirable to mark a particular recipe in a cookbook or a favorite poem in a poetry book so that the excerpt can be located and referred to quickly.
A book containing a bookmark may be stored in various places while being read, including purses or briefcases. It may be stored in a flat position on its back cover when placed on a bedside table, in an upright position when stored in a bookcase, or in various other positions while being transported.
The known bookmarks of the prior art tend to be in the nature of paper or plastic coated paper strips, string or cloth which are intended to be inserted between the pages of a book after the page last read. By inserting such devices so that they project beyond the upper edge of the book and placing the book on its back cover, the place where the reader left off may be quickly and easily found again when desired. This avoids the necessity of searching through pages of text to find the reader's place or pick up the story.
This method may be sufficient if the book is placed in a horizontal position and lies undisturbed on a bedside table, to be picked up again the next night at the same location. This is because the weight of the finished pages of the book and the force of gravity will hold the bookmark in its place when the book is lying horizontally.
However, such bookmarks have certain disadvantages and limitations. For example, these bookmarks are not particularly useful if the book is placed vertically on end, as may be the case if the book is carried from place to place in a purse, knapsack or briefcase, or if the book is inadvertently dropped. Under such circumstances, the force of gravity and the lack of weight holding the bookmark in place often results in the bookmark falling loosely to the center of the book and could result in its becoming dislodged from the book altogether. At that point, the reader must then examine the book closely to determine where the reader left off--a process that can be frustrating and time consuming and which negates the value of using a bookmark at all.
Other devices in the prior art that have been used as bookmarks are in the nature of clips which can be fastened or clipped to a particular page in the book. Such devices have the disadvantage of potentially causing a permanent mark on, or permanent damage to, the book pages. Such devices can cause permanent marking, bending or tearing of the paper pages due to the weight of the marker on a particular page, making such devices undesirable.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a bookmark which will stay in the desired position in a book regardless of the position of the book.
A further object of the invention is to provide a bookmark that will stay in place in the book even when the book is transported from one location to another.
Another object of the invention is to provide a bookmark that is inexpensive to manufacture.
A further object of the invention is to provide a bookmark that can be adjusted to fit a broad range of sizes and thicknesses of books.
Yet another object of the invention is to provide a bookmark that can be easily manufactured out of many different types of materials and in many different shapes and sizes.
Another object of the invention is to provide a bookmark which easily marks a page in a book without any damage to the book or its pages.
Still another object of the invention is to provide a bookmark that is readily removed from the book and easily reinserted in the same or another book.
A further object of the invention is to provide a bookmark which can be easily and inexpensively decorated in the manner desired.
How these and other objects are accomplished will become more apparent from the following descriptions and from the drawings.
SUMMARY OF THE INVENTION
The invention involves a device used to mark pages in a book or other reading material. In the improvement, the device has a base having a base front, a base back, a base top and a base bottom, as well as a marking means. The marking means has a first end and a second end. The first end of the marking means and the second end of the marking means are attached to the base.
In one embodiment of the device, the second end of the marking means is removably attached to the base. The second end of the marking means may be removably attached to the base front by means of hook and eye fasteners such as Velcro. Alternatively, the second end of the marking means may be removably attached to the base front by means of snaps.
In another embodiment of the invention, the base has a first hole on the base top and a second hole on the base bottom. The first end of the marking means is attached to the base in the first hole and the second end of the marking means is attached to the base in the second hole. The base may be elastic, rigid or flexible. Likewise, the marking means may be elastic, rigid or flexible.
Another aspect of the invention is a book, in combination with a device used to mark pages in a book or other reading material. This device has a base which has a base front, a base back, a base top and a base bottom. It also has a marking means with a first end and a second end, wherein the first end of the marking means and the second end of the marking means are attached to the base. In this aspect, the base back may be affixed to the book.
In another preferred embodiment, the invention is a device used to mark pages in a book or other reading material, the device having a base, with a base front, a base back, a base top and a base bottom; a marking means, having a first end, a second end and a marking means length measured by the distance between the first end and the second end; a marking means adjusted second point along the marking means length, between the marking means first end and the marking means second end, and an adjusted marking means length measured by the distance between the marking means first end and the marking means adjusted second point; means to hold the marking means in fixed position relative to the base at the marking means adjusted second point; and means to increase or reduce the adjusted marking means length by adjusting the marking means adjusted second point, wherein the marking means first end is connected to the base and the marking means second end is connected to the length adjustment means.
In this embodiment, the length adjustment means may be a wheel having a wheel diameter attached to the base front, whereby a portion of the marking means length may be wound around such wheel to thereby increase or reduce the adjusted marking means length. A crank may also be attached to the wheel to allow easy turning of the wheel.
In another aspect of the device, a faceplate may be removably attached to the base, thereby allowing access to the wheel when adjustment of the marking means is desired. Or, the device may include a rotatable faceplate attached to the base top, wherein said faceplate may be rotated away from the base to access the wheel when adjustment of the marking means is desired or rotated toward the base to cover at least a portion of the wheel and a portion of the base when adjustment is completed.
Another alternative is for the device to have a faceplate, having lateral edges and a width, which is attached to the base and covers at least a portion of the wheel. In this embodiment, the wheel has a diameter greater than the width of the faceplate, whereby the wheel extends beyond the lateral edges of the faceplate.
In still another preferred embodiment, the device is used to mark pages in a book or other reading material and the device has a base with a base front, a base back, a base top and a base bottom; a marking means, having a first end, a second end and a marking means length measured by the distance between the first end and the second end; a marking means adjusted first point and a marking means adjusted second point along the marking means length between the marking means first end and the marking means second end, and an adjusted marking means length measured by the distance between the marking means adjusted first point and the marking means adjusted second point; means to hold the marking means in fixed position relative to the base at the marking means adjusted first point; means to hold the marking means in fixed position relative to the base at the marking means adjusted second point; means to increase or reduce the adjusted marking means length by adjusting the marking means adjusted first point and the marking means adjusted second point.
In this embodiment of the device, the length adjustment means may be two wheels attached to the base front whereby a portion of the marking means length may be wound around each such wheel to thereby increase or reduce the adjusted marking means length.
Other aspects of the invention are set forth in the following detailed description and in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the device attached to a book.
FIG. 2 is a front view of the device showing the second end of the marker unattached to the base.
FIG. 3 is a top view of the device shown in FIG. 2.
FIG. 4 is a side view of the device showing the second end of the marker removably attached to the base.
FIG. 5 is a side view of an embodiment of the device showing the first end of the marker and the second end of the marker permanently attached to the base.
FIG. 6 is a perspective view of the device attached to a book showing the use of a crank to tighten the marker at one end.
FIG. 7 is a perspective view of an embodiment of the device showing a faceplate on top of the base having a marker adjusting means of a wheel situated between the faceplate and the base.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a perspective view of the new inventive device 10 when in use on a book 12. The device 10 consists of a base 14, having a base front 16, a base back 18, a base top 20 and a base bottom 22. Also shown in FIG. 1 is a marking means 24. The marking means 24 is designed to be inserted between the pages of the book 12 or other reading material just after the last page read so that the reader, upon resuming his reading of the book 12, can immediately locate where he left off in the book 12 by turning to the marking means 24. The device 10 must therefore be capable of being easily removed from the book 12 and easily replaced therein at another location in the book. Preferably, the device 10 is capable of use on a wide variety of books 12 in terms of size and shape.
The base 14 can be manufactured from various types of materials, depending upon the objectives of the user. It can be configured from rigid materials, such as metal, plastic, ceramic, glass, wood, or even cardboard strengthened by a plastic coating. Such materials have the advantage of long-term durability and can be easily engraved or decorated. Alternatively, the base 14 can be made from a flexible, soft material such as fabric, which is relatively inexpensive, easy to decorate or personalize, and easy to fold and store when not in use. Because the device 10 may often be carried, it is preferable for the material used to be lightweight.
It also could be advantageous in some embodiments of the invention to use a width of elasticized fabric for the base, so that the length of the base 14 is expandable. Under such circumstances, the marking means 24 could be rigid and the marking means length 26 fixed, since the use of elastic material on the base 14 would allow the device 10 to be removed and replaced on a book 12, although it may limit the variations of books 12 on which such a device 10 could be used.
As shown in FIGS. 2, 4 and 5, the marking means 24 has a first end 28 and a second end 30. In order to effectively retain a fixed location in the book 12, the marking means 24, in a preferred embodiment, is attached at the first end 28 and at the second end 30 to the base 14.
The marking means 24 can also be manufactured from a wide variety of materials, including rigid materials such as wire, or flexible materials such as ribbon, fabric, yarn or string. The marking means 24 could also be made of elastic fabric, which would allow the marking means length 26 to expand for removal and replacement purposes in the book 12, thereby allowing fixed attachment at the first end 28 and at the second end 30 to the base 14. Such an example can be seen in FIG. 5.
FIGS. 1, 2, 3, and 4 show a preferred embodiment of the device 10, having a fixed attachment to the base 14 at the first end 28 and a removable attachment to the base 14 at the second end 30. In this embodiment, the base 14 is generally rectangular and flat in shape. This shape accommodates placement on either the book spine 32 (as shown in FIG. 1) or the book cover 34 (as shown in FIG. 6) and is attractive in appearance without excess bulk.
However, the base 14 could be manufactured in a wide variety of shapes and sizes, thereby accommodating different design preferences or book sizes. The base 14 could also be designed to provide an eraserable surface on the base front 16 or a note pad for those in book groups or those generally interested in jotting down thoughts or recollections as reading through the book 12.
The removable attachment of the second end 30 of the marking means 24 can be achieved in various ways. For example, a portion of the marking means length 26 near and at the marking means second end 30 could be covered by a hook-and-eye, or Velcro-type, marking means fastening material 36 (see FIGS. 2 and 3), which could then be removably joined at various points along its length with a length of the base mating material 38 (see FIGS. 1 and 2) affixed to the base front 16, as shown in FIGS. 1, 2 and 4. Such a design affords some adjustability in the size of books 12 it will accommodate, depending upon the marking means length 26, the length of the marking means fastening material 36, and the size and placement of the base mating material 38.
The device 10, as shown in FIGS. 1, 2 and 4, is used by placing the base 14 on the book spine 32 or book cover 34, inserting the marking means 24 from the fixed first end 28 between the pages to be marked (as shown in FIG. 1) and folding the marking means fastening material 36 affixed to the second end 30 over the base mating material 38. With this device 10, the desired place in the book 12 will be secure even if the pages of the book 12 open up or the book 12 is inadvertently dropped. When reading is resumed, the marking means fastening material 36 is simply pulled away from the base mating material 38 by the user. In this manner, pages in the book 12 can be marked and remarked in secure fashion without damage to the book 12.
Placing the device 10 on the book spine 32 has the advantage of allowing one reader of a book 12 to mark his or her place while still allowing the book 12 to be read by a second reader, since pages may be turned without dislodging the device 10. Conceivably, two people could each use a separate device 10 concurrently on the same book 12 by placing the base back 18 of one on top of the base front 16 of the other on the book spine 32, or, alternatively, placing one device 10 on the book spine 32 and a second device 10 on the book cover 34. Different indicia, designs or coloration on each device 10 could be used to clearly indicate which device 10 belonged to which reader.
Alternative methods of securing the marking means second end 30 to the base front 16 could also be employed in different embodiments of the device 10. For example, the device 10 could be fastened by the use of snaps, potentially fixed in series on the base front 16 or on the marking means 24 to afford some adjustability.
Likewise, clips could be employed as a closure option.
FIG. 5 shows an embodiment of the device 10 which provides for a marking means 24 that is attached to the base 14 in fixed position at the first end 28 and at the second end 30. In this embodiment, the marking means 24 is preferably elastic or adjustable along some portion of the marking means length 26.
In this preferred embodiment, the base 14 must be rigid and have sufficient thickness to accommodate the boring of a first hole 40 on the base top 20 and a second hole 42 on the base bottom 22. The marking means first end 28 is attached to the base 14 in the first hole 40 and the marking means second end 30 is attached to the base 14 in the second hole 42. Alternative embodiments can be manufactured by combining a marking means first end 28 attached to the base 14 in the foregoing manner with an adjustable marking means second end 30 as previously described.
In another embodiment, the invention is a book 12 in combination with the device 10 described previously in its varying embodiments. In this combined embodiment, the device 10 may be permanently affixed at the base back 18 to the book 12 by glue, or removably affixed by velcro attachment.
Another preferred embodiment of the device 10 combines the base 14, the marking means 24 and a marking means adjusted second point 44 along the marking means length 26. This embodiment provides for an adjusted marking means length 46, which is measured by the distance between the marking means first end 28 and the marking means adjusted second point 44. The embodiment provides for the means to increase or reduce the adjusted marking means length 46, as desired, by adjusting the marking means adjusted second point 44. This is accomplished by attaching the marking means first end 28 to the base 14 and the marking means second end 30 to the length adjustment means 48.
Alternatively, the marking means first end 28 may be attached to the length adjustment means 48 and the marking means second end 30 may be affixed to the base 14 (as shown in both FIGS. 6 and 7), whereby the means to increase or reduce the adjusted marking means length 46 is accomplished by adjusting the marking means adjusted first point 50. Another alternative embodiment could provide for length adjustment means 48 at both the marking means first end 28 and the marking means second end 30, thereby providing for both a marking means adjusted first point 50 and a marking means adjusted second point 44, and thereby provide for adjustment at both ends of the marking means 24. Under these circumstances, the adjusted marking means length 46 is measured by the distance between the marking means adjusted first point 50 and the marking means adjusted second point 44. Yet another alternative could provide for a marking means first end 28 fixed to the base 14, a marking means second end 30 fixed to the base 14, and length adjustment means 48 affixed solely to the marking means 24.
Examples of alternative length adjustment means 48 are shown in FIGS. 6 and 7. FIG. 6 shows the use of a crank 52 attached to a wheel 54 affixed in its center 56 to the base front 16 in such a manner as to allow free rotation of the wheel 54. In the embodiment shown in FIG. 6, the marking means second end 30 is affixed to the base 14 in the second hole 42. The marking means first end 28 may be attached to the wheel 52 by any of a number of methods, including fixed attachment. Alternatively, it may be held in place by the weight of the length of marking means 24 wrapped around the wheel 52 over the marking means first end 28, similar to the manner in which thread is held in place on a bobbin.
The device 10 is used to mark the appropriate page in the book 12 by inserting the lengthened marking means 24 between the appropriate pages and tightening the marking means 24 on the book 12 by reducing the adjusted marking means length 46. The adjusted marking means length 46 is reduced by rotating the wheel 54 in the direction in which the marking means 24 is wound around the wheel 54. As the wheel 54 is turned, the marking means 24 wraps around the wheel 54 until the device 10 is held tightly in place on the book 12. The crank 52, as an attachment to the wheel 54, while not necessary to its function, makes it easier for the user to turn the wheel 54 since it is easier to grasp the crank 52 than the wheel 54 directly.
In this embodiment, the wheel 54 is easily turned by rotating the crank 52 around the center axis A--A of the wheel 54. The adjusted marking means length 46 achieved can then be held in fixed position by temporarily locking it in position at the marking means adjusted first point 50 and/or the marking means adjusted second point 44 depending upon the embodiment and the location of the length adjustment means 48. This objective may be accomplished by any number of various locking means, including a locking tab that allows the marking means 24 to travel in reverse direction around the wheel 54 only when in an "up" position, or a clip on the crank 52.
As an alternative embodiment, the fixed marking means second end 30 shown in FIG. 6 may also terminate on a wheel 54 identical in appearance and function to the wheel 54 to which the first end 28 is attached to provide further adjustability of adjusted marking means length 46. Such a wheel 54 may also have a crank 52 attached to its center 56 for easier use.
Any of the foregoing alternative embodiments can also include a rotatable face plate 58 (as shown in FIG. 7). This faceplate 58 preferably approximates the size and shape of the base 14, but could vary in size to create an alternative appearance or to save on material expenditures. The faceplate is attached to the base 14 by hinges or a similar method to the base front 16 in such a manner that it can readily be rotated in an upwardly direction away from the base 14 by the user if access to the length adjustment means 48 is desired. The faceplate 58 may then be rotated downwardly to cover the base 14 or a portion thereof when adjustment is completed. The faceplate 58, since it covers the wheel 54 or other length adjustment means 48, has the advantage of providing a "clean" surface for easy decoration as desired.
A preferred embodiment of the device 10 incorporating a faceplate 58 would provide for the faceplate 58 to lock in position on the base 14 when adjustment was not required. Alternative possibilities of fastening the faceplate 58 to the base 14 also exist, including the possibility of a completely removably faceplate 58 which could engage the base 14 and thereby lock onto the device 10, or a hinged connection at any other location along the base 14. Obviously, the faceplate 58 must have sufficient depth and size to accommodate any length adjustment means 48 attached to the base front 16, including any wheel 54 or crank 52 thereon.
In another embodiment of the device 10, as shown in FIG. 7, the device has a wheel 54 attached at the wheel center 56 to the base 14 and a faceplate 58. However, in this embodiment, the diameter of the wheel 54 is greater than the width of the base 14 and the faceplate attachment means 60 between the base 14 and the faceplate 58 is configured in such a way as to provide a slots 62 along the length of the device 10 through which the wheel 54 extends. In this way, the user has access to the wheel 54 in order to rotate it to tighten or loosen the marking means 24 around the book 12.
While the principles of the invention have been described in connection with exemplary embodiments, it should be understood clearly that such descriptions are by way of example and are not limiting. | The disclosure involves an improved bookmark which will mark the reader's place in the book without becoming inadvertently dislodged and without damaging the book. The device is easily removable for reuse at an alternative location in the book. The device may also be manufactured inexpensively out of a wide range of materials. Various embodiments provide for alternative adjustment possibilities to enhance ease of use. | 1 |
FIELD OF THE INVENTION
[0001] The field of the invention is collapsible chairs.
BACKGROUND OF THE INVENTION
[0002] Numerous collapsible chairs are known in the art, and many of those include a plurality of X-shaped braces that cooperate together to form a collapsible brace. Examples for such chairs are found in FR 2,532,535, and U.S. Pat. No. 3,124,387, U.S. Pat. No. 5,718,473, U.S. Pat. No. 5,499,857, U.S. Pat. No. 4,836,601, U.S. Pat. No. 4,685,725, or U.S. Pat. No. 4,652,047. While such chairs provide collapsibility, various disadvantages remain. Among other things, some of the known chairs require disassembly for folding, removal of one or more components before folding, or by virtue of their arrangement, a relatively low seat height. Moreover, not all of such chairs are comfortable over a prolonged period of time, especially for a relatively tall person. Thus, while there are numerous collapsible chairs known in the art, various problems remain with such chairs. Consequently, there is still a need to provide improved collapsible chairs.
SUMMARY OF THE INVENTION
[0003] The present invention is directed to a collapsible chair that has (a) a front brace having a first and a second front rod rotatably coupled to each other, (b) a left side brace having a first and a second left side rod rotatably coupled to each other, (c) a right side brace having a first and a second right side rod rotatably coupled to each other, (d) a back brace having a first and a second back rod rotatably coupled to each other, wherein the front brace, the left side brace, the right side brace, and the back brace are coupled to each other to form a collapsible frame. In especially contemplated chairs, a seat is slidably coupled to the front brace and the back brace, and the seat is further contiguous with a back rest that is coupled to the back brace.
[0004] Most typically, an armrest is coupled to the front brace and the back brace, and the first and second rods of the back brace are angled to a degree such that the chair has a seat height of at least about 17 inches at a maximum backrest width of about 30 inches. Viewed from a different perspective, the first and second rods of the back brace are angled to a degree such that the chair has a backrest width to seat height ratio of between 1.4 to 1.8.
[0005] While not limiting to the inventive subject matter, the collapsible chair has a maximum backrest height of about 30 inches, and the first and second rods of front brace are angled to a degree such that the armrests have a maximum distance from each other of about 20 inches. Moreover, it is generally preferred that the armrest is coupled to the angled portion of the first and second rods of front brace, and/or that the armrest is slidably coupled to a rod of the back brace. A stopper is preferably coupled to the first and second rods of the front and back brace, respectively, at a position effective to maintain the seat height at a height of at least about 17 inches, and/or the upper portion of the backrest is fixedly coupled to the ends of the first and second rods of the back brace, while the lower portion of the back rest is slidably coupled to the first and second rods of the back brace. In such chairs, it is generally preferred that the backrest is coupled to the angled portion of the first and second rods of the back brace.
[0006] Particularly preferred backrest width to seat height ratios are between 1.4 and 1.6 and between 1.6 and 1.8, and the seat height is at least 16 inches. Alternatively, or additionally, it is preferred that the backrest width is less than 30 inches, and more typically less than 28 inches. In still further preferred chairs, the first and second rods of the front brace are angled such that the arm rest distance is less than 22 inches, and more typically less than 20 inches.
[0007] Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0008] FIG. 1 is a perspective view of a collapsible chair according to the inventive subject matter.
DETAILED DESCRIPTION
[0009] The inventors have discovered that a collapsible chair can be manufactured from a frame that has a quad configuration to which the seat, the armrests and the back are coupled without use of backrest support rods and/or armrest support rods.
[0010] In one especially preferred aspect of the inventive subject matter as depicted in FIG. 1 , a collapsible chair 100 has a front brace 110 having a first and a second front rod 112 and 114 , respectively, rotatably coupled to each other. A left side brace 120 has a first and a second left side rod 122 and 124 , respectively, rotatably coupled to each other. A right side brace 130 has a first and a second right side rod 132 and 134 , respectively, rotatably coupled to each other, and a back brace 140 has a first and a second back rod 142 and 144 , respectively, rotatably coupled to each other. In such chairs, it is especially preferred that the front brace, the left side brace, the right side brace, and the back brace are movably coupled (typically via the ends of the rods in the side braces) to each other to form a collapsible quad frame. The seat 150 is slidably coupled to the front brace 110 (e.g., via an opening in the seat; not shown) and the back brace 140 (e.g., via a tab T with an opening that is coupled to the seat and back). The seat is further contiguous with the back rest 152 that is coupled to the back brace 140 . The armrests 160 (optionally with cup holder 162 ) are coupled to the front brace 110 and (preferably slidable via opening) to the back brace 140 .
[0011] It is especially preferred that the upper ends of the first and second rods of the back brace 140 are angled to a degree such that the chair has a seat height of at least about 17 inches at a maximum backrest width of about 30 inches. Most typically, for a chair for an adult person, the angle α1 will be between about 10 and 35 degrees. To accommodate the armrests in a position that is particularly comfortable to a person sitting in the chair, it is also preferred that the upper ends of the front rods are angled at an angle α2, typically between about 15 and 45 degrees. While not limiting to the inventive subject matter, it is generally preferred that α1 and α2 are identical. Moreover, another angled portion may be included in the front rods that will receive part of the armrest 160 (typically in a horizontal position), wherein the that angle α3 will be between about 40 and 100 degrees. It should further be noted that the angles are preferably positioned at a height above the seat to allow for maximum seat width at minimum backrest width. The term “about” as used herein in conjunction with a numeral refers to a range of ±10% of that numeral, inclusive. For example, the term “about 15” inches refers to any numeral between 13.5 inches to 16.5 inches, inclusive.
[0012] It should especially be appreciated that using such angled rods, collapsible chairs can be manufactured without a separate backrest support rod as commonly found in many other known collapsible chairs. Indeed, quad chairs without a separate backrest support rod and without the angled back (and front) rods would either be excessively wide to achieve an acceptable seat height, or have an unacceptably low and/or narrow seat at an acceptable backrest width. Thus, using angled rods for the back brace (and front brace) will advantageously allow construction of a chair having a backrest width to seat height ratio of between 1.4 to 1.8.
[0013] Most typically, contemplated seat heights (as measured from the front edge of the unfolded seat to the ground on which the chair stands) will be between about 10 inches (e.g., for kid's chairs) to about 24 inches (e.g., for a barstool type seat), or even higher. However, it is generally preferred that the seat height will be between about 16-17 inches, 17-18 inches, or 18-19 inches (in certain embodiments, it may be preferred that the seat height is at least 16 inches).
[0014] Similarly, the seat width may vary considerably and will typically be between about 15 inches to about 28 inches. However, more preferably, the seat width will be between about 18 and 20 inches, or between 20 and 22 inches, or between 22 and 24 inches. With respect to the back rest width, it is generally preferred that suitable widths may be between 20 and 35 inches, and more preferably between about 24 to 26 inches, between 26 and 28 inches, or between 28 and 30 inches. In some aspects of the inventive subject matter, the maximum backrest width is less than 30 inches, and even more preferably less than 28 inches, while preferred backrest heights will not exceed about 30 inches. Consequently, and among other ratios, particularly preferred backrest width to seat height ratios are between about 1.4 and 1.6, or between about 1.6 and 1.8.
[0015] It is still further preferred that the first and second rods of the front brace are angled to a degree such that the armrests have a distance from each other of between about 16 inches to about 25 inches (with the distance being measured between the armrest edges facing each other when the chair is in the unfolded configuration). However, in especially preferred aspects of the inventive subject matter, the angle α2 will be such as to provide a maximum armrest distance of about 18-20 inches, or 20 to 22 inches. Furthermore, and in most typical embodiments, the first and second rods of the front brace are angled such that the arm rest distance is less than 22 inches, and more preferably less than 20 inches. Where implemented, it is preferred that angle α3 will be selected to provide a horizontal support for the armrest. Most preferably, the angles and rod positions are also selected such that the maximum width of the backrest is equal or less than the maximum width of the chair, and most typically equal or less than the distance of the outer edges or the armrests of the chair.
[0016] With respect to the seat it is generally preferred that the seat is made from a material that sufficiently flexible to allow folding of the seat. Therefore, numerous materials are deemed suitable and exemplary materials include natural and synthetic fibers, which are typically woven into a cloth or other generally sheet-like form. The seat preferably has a rectangular shape (as observed from the top of the chair) and is dimensioned such that the width is substantially wider than the depth as measured from the front to the back. For example, a typical chair according to the inventive subject matter will have a width of between about 18 to 25 inches, while having a depth of between about 12 to 18 inches.
[0017] Similarly, it is generally contemplated that the back rest and arm rests are fabricated from the same material as the seat. Most typically (but not necessarily so), the seat and the backrest are contiguous and coupled to the front and back rods. In especially preferred aspects, the upper portion of the backrest is fixedly coupled to the ends of the first and second rods of the back brace, and the lower portion of the backrest is slidably coupled to the first and second rods of the back brace. Such slidable coupling may be done via a tab that is coupled to the backrest as depicted in FIG. 1 or indirectly, by coupling the backrest to the seat and by coupling the seat slidably to the back rods. There are numerous manners of slidably coupling seats and backrests to rods known in the art, and all of those are contemplated herein. Similarly, all known manners of fixedly coupling the seat, armrest, and/or backrest are known in the art, and all of such manners are deemed suitable for use herein. However, it is generally preferred that the fixed coupling includes an anchor to which the fabric or other material is sewn, wherein that anchor is then affixed to the rod (e.g., by sliding and bolting). Most typically, and using such coupling, the backrest is in substantially vertical (±10 degrees) and/or the seat is substantially horizontal (±10 degrees) when the chair is in the unfolded configuration.
[0018] Thus, it should be recognized that the upper portion of the backrest is preferably fixedly coupled to the angled portion of the first and second rods of the back brace and that the lower portion of the backrest is preferably fixedly coupled to the angled portion of the first and second rods of the back brace. In contrast, both sides (front and back) of the seat are preferably slidably coupled to the angled portion of the first and second rods of the back brace and front brace. To maintain a desired distance of the seat from the ground, it is generally preferred that a stopper (schematically depicted as S in FIG. 1 , other stoppers on remaining rods not shown) or other element is coupled to the first and second rods of the front and back brace, respectively, at a position effective to maintain the seat height (e.g., at a height of at least about 17 inches). Such elements may be disks, sleeves, pins, etc, or may be even integral with the rods. In still further contemplated aspects, it is generally preferred that each of the front and back rods has a foot element preferably coupled to the front and back rods. Most typically, such foot elements are fixedly coupled to the front and back rods and are not coupled to the side rods. Therefore, in such configurations the foot elements will not need rotating and/or pivoting points to accommodate for the folding motion.
[0019] With respect to the armrest, it is typically preferred that the armrest is on one end coupled to the angled portion of the first and second rods of front brace, and on the other end slidably coupled to a rod of the back brace. Contemplated rods for the braces may be made from numerous materials known in the art and it should be appreciated that all known materials for collapsible chairs are deemed suitable for use herein. However, especially preferred materials include metals, metal alloys, synthetic polymers, and all reasonable combinations thereof. Furthermore, it should be appreciated that the rods are movably coupled to each other such as to allow a collapsing motion in which the frame folds in a side-to-side motion as the frame folds in a front-to-back motion. Thus, movable couplings between the rods may have at least one, and more typically at least two degrees of rotational freedom. However, and where desired, rotating couplings may also be replaced with sliding couplings.
[0020] Thus, specific embodiments and applications of collapsible quad chairs with integrated back and armrest have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. | Particularly preferred collapsible chairs have a minimum configuration in which the back and front rods in a quad arrangement are extended to support the arm rests, the backrest, and the seat, and wherein the back and front rods are angled such that the backrest width to seat height has a ratio of between 1.4 to 1.8. Such chairs are not only esthetically pleasing, but also relatively comfortable for users of average and above-average height. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a three-dimensional high frequency inductor, its module and fabrication method of the same; the passive components, such as miniaturized high frequency inductors, filters, resistors, capacitors are associated with active components or power components to form an integrated circuit, then it is packaged by using the technology of flip chip or wafer level packaging, so as to upgrade the properties of high frequency modules and reduce the packaging and measurement costs by minimizing the modular size.
2. Description of the Prior Art
Rapid growth in technological development of mobile communication has stimulated need of high frequency radio devices a great deal. The prosperity of radio communication products depends a lot on the size of their component parts and durability of batteries used. Accordingly, the component manufacturers have been doing their efforts in developing components which are more effective yet smaller in size and cheaper in cost than ever. The ultimate goal of minimizing these components is to combine them with an integrated circuit (IC) to form a system-on-chip (SOC). However, there is a big problem in forming SOCs by combining varieties of function provided by different suppliers, since a considerably long time is required for transferring techniques pertaining to particular intellectual property and combining products and fabricating processes which are individually developed by different manufacturers. To cope with the above depicted situation, it is absolutely necessary to establish a systematic technology of combining varieties of wafers, dies provided by different manufacturers and instrumentation processes of dies in advance so as to improve yield rate and to save packaging cost. At the same time, through establishment of perfect customization, intellectual property can be surely protected. In order to minimize product size, power consumption and electro-magnetic interference, to decrease complexity of fabrication process and to improve portability of the products in a relatively low cost way, the combination of active components made of wafers with different fabrication processes and materials with IC circuit modules of high density passive components to form high density IC SOC by packaging process is preferably feasible.
At present, there are two series of high frequency module products composed of combined passive components having competitive force in fabrication technique and product cost. The first one is a thin film high frequency module compatible with IC manufacturing process, the second one is a low temperature co-fired ceramic (LTCC) module with a very high durability for high frequency power as its greatest advantage, but there are a lot of outstanding problems still have to be resolved, for examples, insufficient line width, difficulty in measurement, difficulty in obtaining the ceramic powder, and occurrence of ceramic shrinkage during fabrication process etc. Therefore, severe deviation between fabrication process and simulation result is occurred and which is difficult to rectify. As for fabrication cost, it appears no significant difference between two series of products mentioned above, but the thin film combined high frequency module has a tangible superiority of its smaller product size, and is able to combine active circuit components to realize systematic simulation so as to be benefited by saving, research cost and shortening research time.
A high frequency module requires many passive components in it, and occupies a considerably large space. These passive components are composed of resistors, capacitors, inductors, conductors, coupling wire or transducers. In the passive components, resistors and capacitors which can be easily figured out with simple formula with fewer problems for performance. While the inductor, which being a magnetic element, is relatively tedious procedure. The most commonly used inductor at present is one formed in a planar spiral configuration which can be easily manufactured with advantages of low noise and very small power consumption, but on the contrary, it is disadvantageous because of a bulky size and an unstable inductance value influenced by fabrication process and a low quality factor. Especially, in a planar spiral inductor used in IC, mutual induction between its magnetic line of force with the IC substrate further exacerbates degrading the Q (quality factor) value of device and resulting in a low efficiency of the device.
For achieving the object of improving the property of the inductors in a high frequency module, it is a commonly adopted method to lower the loss of the substrate and minimize the resistance of the metal layer. Means for lowering the substrate loss includes using a high impedance substrate, etching the part of the substrate beneath the inductor, interlarding a thin isolation layer (SGS or PGS), or a porous silicon oxide layer (OPS) between the inductor and the substrate. While the means for minimizing the resistance of the metal layer includes using a thick metal layer, connecting a plurality of metal layers in parallel, or adopting electroplating process etc. Besides, an elaborate circuital layout is another feasible solution.
In the past decade, benefited by rapid growth of the technology for fabricating micro-electromechanical elements, a three-dimensional spiral inductor becomes compatible in an IC so as to replace a conventional planar spiral inductor. As for representative fabrication methods for this new type of inductor are: applying three-dimensional laser molding or surface micro electro-mechanical technology so as to keep the area required for an inductor as small as possible, and at the same time allowing the effect of substrate parasitic capacitance.
FIG. 1 a through FIG. 1 f are schematic views of structure for a planar spiral inductor and fabrication process of same in U.S. Pat. No. 5,844,299 pertaining to American National Semiconductor Co. The conventional silicon substrate of a suspended inductor is removed by etching, but herein the inductor is suspended on the silicon substrate by means of micro-electro-mechanical technique. As shown in FIGS. 1 a and 1 b , using photo-lithographic method, a predetermined etching region 12 is defined on a substrate 10 by photo resistance 11 , next, etching is carried out by an etchant so as to form a cavity 13 ; then, as shown in FIGS. 1 c and 1 d , forming a sacrificial layer 14 on the cavity 13 by coating and polishing the surface thereof smooth (as shown in FIG. 1 e ); after that, as shown in FIG. 1 f , forming a supporting layer 15 and an inductance metallic pattern 1 b on the smoothed sacrificial layer 14 ; finally, removing the sacrificial layer 14 so as to complete a suspended inductor.
FIGS. 2 a and 2 b are schematic views of structure for a three-dimensional solenoid inductor in U.S. Pat. No. 6,008,102 pertaining to Motorola Co. As shown in these two drawings, a buffer layer 26 and a seed layer 25 are grown on a substrate 20 , then the three-dimensional solenoid inductor 21 is constructed by means of a first photo-resistive layer 22 , a second photo-resistive layer 23 , and a third photo-resistive layer 24 wherein the metal for forming the inductor 21 is essentially made by electroplating, the seed layer 25 is necessary to be included between the metal layers for stacking up the inductor 21 . This type of inductor are quite different from a planar spiral inductor in that its inductance varies in proportional to the number of turns. This is a very important and valuable feature in designing a three-dimensional solenoid inductor. On the contrary, the inductance of a planar spiral inductor can not maintain a linear relationship with its number of turns but is influenced by the parasitic and coupling capacitances between the silicon substrate and the metal layer. Accordingly, it is difficult to estimate an accurate value of inductance. Furthermore, the spacing between spiral turn also affect the quality factor of the inductor. If the spacing is too small, the inductance will decrease notwithstanding the quality factor is improved by increasing density of magnetic fluxes there between. There are several advantages concerning the solenoid inductor: a good inductor on the silicone substrate, an inductance in linear relationship with number of turns, the shorten distance between adjacent coils thereby minimizing the size of the inductor, and the provision of thicker metal layer so as to improve ability for withstanding high current. But instead of its high quality, stability of the three dimensional structure is apt to be influenced by bonding force between layers provided by the seed layer 25 for the reason that the inductor is electroplated. Especially, the final fabrication processes, i.e. packaging, and application in mobile communication, the unpreventable shock or vibration will definitely affect its property. Besides, the three-dimension solenoid inductor is able to shorten the distance between coils to decrease its size, but it is difficult to avoid resonance arising from the inductance and the capacitance distributing between the inductor windings. As a result, inductance of the inductor varies as the frequency is changed, and from worse to worst, the inductor's behavior deviates far apart from an inductor and approaches a capacitor. Accordingly, minimizing above mentioned distributing capacitance as low as possible is important for widening applicable frequency range for this high frequency module.
SUMMARY OF THE INVENTION
It is an object of the present invention to resolve aforesaid disadvantages of conventional techniques.
It is another object of the present invention to provide a fabrication method for combining a high quality inductor in a high frequency module thereby upgrading the quality of the same.
It is further object of the present invention to provide an inductor whose inductance varies linearly with its number of turns so as to upgrade the quality of the high frequency module.
It is one more object of the present invention to combine active and passive circuits formed of different wafer fabrication processes to realize systematic simulation so as to decrease the research cost and shorten the research time required.
For achieving these and other objects, the fabrication method of high frequency module according to the present invention provides a three-dimensional S-type high frequency inductor with an improved Q value for obtaining a high frequency module with good properties.
The method of the present invention further provides an arrayed coplanar jointed pads, it provides the selectivity and facilitating trimming of the high frequency inductor.
The method of the present invention further provides packaging technology of flip-chip and wafer level chip scale package (WLCSP) to combine active and passive circuits formed of different processes for realizing the systematic simulation so as to reduce research cost and shorten research time required for communication high frequency module.
The method of the present invention provides a combined CMOS circuit, a chip for treating base band signal, chips for system control, and a memory chip all combined together to form an unit package and attains the aim of isolation and protection between high frequency and low frequency regions.
A more complete understanding of these and other features and advantages of the present invention will become apparent from a careful consideration of the following detailed description of certain embodiments illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 a ˜ 1 f are schematic views of a conventional planar suspended high frequency inductor.
FIG. 2 a and FIG. 2 b are schematic views of a conventional three-dimensional solenoid high frequency inductor.
FIG. 3 a is a schematic view of a double layered adjustable toroidal-meander type high frequency inductor which is a combination of planar S type and spiral type high frequency inductor of the first embodiment of the present invention.
FIG. 3 b is a cross sectional view of each layer of the toroidal-meander type high frequency inductor shown in FIG. 3 a.
FIGS. 4 a ˜ 4 c are illustrative views showing fabrication process of the adjustable toroidal-meander type high frequency inductor in a first embodiment of the present invention.
FIGS. 5 a ˜ 5 o are the cross sectional views of combined circuit of the toroidal-meander type high frequency inductor and the passive components of a second embodiment of the present invention.
FIG. 6 is a cross sectional view of a module composed of combination of passive components, active components, and other basic frequency circuits and containing the toroidal-meander type high frequency inductor of a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 a to FIG. 2 b are schematic views of two types of conventional high frequency inductors which have been fully described in foregoing context and will not be repeated.
FIG. 3 a shows a schematic view of a double layered adjustable toroidal-meander type high frequency inductor which is a combined planar S-type and toroidal-meander high frequency inductor in a first embodiment. As shown in FIG. 3 a , 30 - 1 to 30 - 7 are jointed pads for trimming inductance value which can be jointed in any number according to the inductance required, it should be noted in this case the value of inductance is in a linear relationship with number of turns of the inductor. Meanwhile, a plurality of jointed pads 30 - 1 to 30 - 7 fixed on a substrate is not only used to trim value of inductance but also for sustaining entire structure of three dimensional inductor stably. The pads 30 - 1 to 30 - 7 can either be arrayed in single side, or staggeringly disposed along two sides as long as structural stability is concerned. Besides, the entire three dimensional structure of inductor is recessively mounted between two adjacent walls so as to avoid damage from inadvertent impact. The cross sectional views per layer of the toroidal-meander type high frequency inductor are shown in FIG. 3 b , wherein the upper drawing includes a metallic pattern 31 of an upper layer inductor and a plurality of jointed pads 30 - 1 to 30 - 7 , while the lower drawing includes a metallic pattern 33 of an lower layer inductor. The upper and the lower metallic patterns 31 and 33 are interconnected with each other by an intermediate metallic part 32 .
FIG. 4 a through FIG. 4 c illustrate fabrication process of the adjustable toroidal-meander type high frequency inductor of the first embodiment of the present invention, wherein FIG. 4 a illustrates fabrication process using an insulated aluminum oxide or a glass substrate, and FIG. 4 b and FIG. 4 c illustrate respectively the fabrication processes wherein a backside etching and a front side etching are applied to remove the substrate formed of semiconductor silicone.
As shown in FIG. 4 a , a first metallic pattern 41 is formed on a substrate 40 [as shown in FIG. 4 a (1)]. Next, forming a first dielectric layer 42 by coating on the first metallic pattern 41 [as shown in FIG. 4 a (2)]. Then defining the first dielectric layer 42 by means of masked photo-lithographic technique to form an empty hole. Then filling the empty hole to define a second dielectric layer 43 , and forming a second metallic layer 44 by deposition to interconnect the upper and the lower metallic patterns [as shown in FIG. 4 a (3)]. Then forming a third metallic pattern 45 on the entire structure so as to construct an upper metallic pattern of the high frequency inductor for electrically connecting with other circuitry components. This third metallic pattern 45 can be formed into a metallic layer with metal deposition process, and then defining the third metallic pattern 45 by etching [as shown in FIG. 4 a (4)], or finishing it by electroplating. Finally removing the second dielectric layer 43 by etching using, an etchant thereby completing the fabrication process for this structure [as shown in FIG. 4 a (5)].
In case the substrate effect is to be eliminated or to the semiconductor substrate is to be used, the substrate under the inductor can be removed by etching after the inductor is fabricated on the substrate. There are two ways may be performed in etching the substrates, FIG. 4 b shows a way that the substrate under the inductor structure is removed from the backside of the substrate. FIG. 4 c shows the other way that the substrate under the inductor structure is removed from the front side of the substrate.
A double layered adjustable toroidal-meander type high frequency inductor with the method of removing from the backside is shown in FIG. 4 b , firstly, a sustaining layer 47 is formed on the substrate 40 and then a first metallic pattern 41 is formed [as shown in FIG. 4 b (1)]. Afterwards, forming the first dielectric layer 42 on the first metallic pattern 41 by coating so as to form an empty hole [as shown in FIG. 4 b (2)]. Then defining the second dielectric layer 43 by filling up the empty hole. Then forming the second metallic layer 44 by deposition [as shown in FIG. 4 b (3)] to interconnect the upper and the lower metallic patterns. Afterwards, forming the third metallic pattern 45 on the entire structure so as to construct the upper metallic pattern of the high frequency inductor for electrically connecting with other circuital components [as shown in FIG. 4 b (4)]. This third metallic pattern 45 can be defined by etching a metallic layer formed with metal deposition, or can be formed by electroplating. Finally, the second dielectric layer 43 is removed by wet etching so as to complete the fabrication processes of the inductor [as shown in FIG. 4 b (5)]. Afterward, a cavity 48 is formed using the backside etching to remove substrate.
The double layered adjustable toroidal-meander type high frequency inductor can eliminate substrate effect by etching the substrate from the front side. Referring to FIG. 4 c , it comprises the steps of forming a sustaining layer 47 on the substrate 40 , and using masked photolithography to form an etching window for etching the substrate to be followed; and forming a pattern for the sustaining layer 47 ; and then forming the first metallic pattern 41 [as shown in FIG. 4 c (1)]; then forming the first dielectric layer 42 on the first metallic pattern 41 by coating [as shown in FIG. 4 c (2)]; afterwards filling the empty hole with the second dielectric layer 43 after defining the empty hole, and forming the second metallic layer 44 by deposition to interconnect the upper and the lower metallic patterns [as shown in FIG. 4 c (3)]; then forming the third metallic pattern 45 on the entire structure so as to construct an upper metallic pattern for the high frequency inductor for electrically connecting with other circuital components [as shown in FIG. 4 c (4)]; forming a metallic layer with this third metallic pattern 45 by etching, or by common electroplating; and finally, removing the second dielectric layer 43 with an etchant thereby completing fabrication of the inductor component. After that, removing the substrate by etching, the etching process may begin from an etching window exposed on the front surface of the substrate after removing the second dielectric layer 43 using either an isotropic or an anisotropic etching. After forming a blank cavity 49 after removal of the substrate, a double layered adjustable toroidal-meander type high frequency inductor is suspended on the substrate [as shown in FIG. 4 c (5)].
FIGS. 5 a ˜ 5 o are cross sectional views of combined circuit of the toroidal-meander type high frequency inductor and the passive components of the second embodiment of present invention. As shown in FIGS. 5 a ˜ 5 e , at first, resistor layers 501 and 502 are formed and defined on a substrate 500 by deposition (as shown in FIG. 5 a ). Two first metallic patterns 503 , 504 are defined by etching or lift-off method after deposition (as shown in FIG. 5 b ). These two first metallic patterns 503 , 504 simultaneously serve as two electrode terminals of a resistor R 1 and the lower electrode of a capacitor C 1 . Then successively depositing and defining a first dielectric layer 505 (as shown in FIG. 5 c ), and a second metallic pattern 506 , the first dielectric layer 505 interlarded between the first and the second metallic patterns 503 and 506 forms the capacitor C 1 there between (as shown in FIG. 5 d ). Then a second dielectric layer 507 is formed on the resistor R 1 and the capacitor C 1 by coating an insulation layer uniformly with a sufficient thickness. Then as shown in FIGS. 5 f ˜ 5 k , a three-dimensional high frequency inductor over the passive components with above described structure is constructed so as to obtain an effective and space saving, minor interference, high frequency module through combining the three dimensional high frequency inductor and passive component circuits. As shown in FIG. 5 f , at first, a third metallic pattern 508 is formed on a second dielectric layer 507 ; then as shown in FIG. 5 g , a third dielectric layer 509 is formed on the third metallic pattern 508 with coating; then as shown in FIGS. 5 h ˜ 5 i , after removing the third dielectric layer 509 in the defined region, and after that, filling and defining a fourth dielectric layer 510 and forming a fourth metallic pattern 511 interconnecting the upper and the lower metallic patterns; then as shown in FIGS. 5 j ˜ 5 k by forming a fifth metallic pattern 512 on the entire structure so as to form an upper metallic pattern layer of the high frequency inductor thereby electrically connecting with other circuital components; then forming a blank cavity 513 by removing the lower third dielectric layer 509 ; meanwhile, the high frequency inductor may be formed in the position apart from other passive components like resistor and capacitors as shown in FIGS. 5 i ˜ 5 o.
besides, it has become a tendency that more and more components of high frequency radio communication apparatus are constructed in differential and systematical ways to eliminate noises that the active components such as amplifier are disposed in pairs, and the coupled inductors are disposed in pairs accordingly resulting in exaggeratedly increasing the area occupied by inductor. The three dimensional S type high frequency inductor of the present invention provides an timely remedy for eliminating this disadvantage effectively.
FIG. 6 shows the cross sectional view in a third embodiment of the present invention. As shown in FIG. 6 a (left view), there are components C 1 , R 1 and L 1 mentioned in foregoing embodiment; a first and a second dielectric layer 605 , 607 for isolating C 1 , R 1 and L 1 ; and a sustaining layer 606 for sustaining L 1 on a blank cavity 609 . By crystal stabilized or wafer level packaging, a high frequency module including C 1 , R 1 , and L 1 can be completed through metal conductors 602 and joint nodes 608 , where a circuit unit 603 on a substrate can be combined therein, the circuit unit 603 can be an active component or a power unit, or other base frequency circuit.
Although the present invention has been described with a certain degree of particularity by six examples, the present disclosure has been made by way of example and changes in details of structure may be made without departing from the spirit thereof. | A three dimensional adjustable high frequency inductor, its module and fabrication method of the same. The high frequency module includes micro high frequency inductors, filters, resistors, capacitors and associated with active components or power components to form a hybrid circuit, then it is packaged by using the technology of flip chip or wafer level packaging, so as to upgrade properties of high frequency modules and reduce the packaging and instrumentation costs by minimizing the modular size. | 8 |
CLAIM OF PRIORITY
[0001] This application claims the priority of U.S. Ser. No. 61/555,707 filed on Nov. 4, 2011, the contents of which are fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a composition useful in treating baldness, in particular to a composition of natural ingredients and a method of using the composition.
BACKGROUND OF THE INVENTION
[0003] The invention relates to a composition, a method of making the composition, and a method of using the composition to slow hair loss and to aid in hair re-growth. Anecdotal evidence indicates that the invention is effective in both men and women.
[0004] Alopecia, or hair loss, is a common cosmetic problem that can also cause serious negative psychological effects. Hair growth is cyclical, occurring in three stages: anagen, the active growth phase; catagen, the degenerative phase; and telogen, the resting phase. After telogen, the old hair fiber is shed and a new hair is generated as part of the repeating cycle. Alopecia, or hair loss, occurs in both men and women, and is attributed to numerous causes including aging, hormone levels, stress, and chemotherapy. In these circumstances, more and more hair follicles remain in the telogen stage, resulting in a gradual decrease of the hair fiber length and diameter, finally reaching a stage of partial or complete baldness.
[0005] Various types of hair loss are known, including alopecia areata, androgenetic alopecia, anagen effluvium, self-induced hair loss, telogen effluvium, and scarring alopecia. Alopecia areata, thought to be an auto-immune disorder, begins with hair loss in a rounded patch on the scalp. Alopecia areata includes mild patchy hair loss on the scalp, as well the loss of all scalp hair, known as alopecia totalis, and the loss of all scalp and body hair, known as alopecia universalis. Androgenetic alopecia, including male and female pattern baldness, is thought to be caused by a combination of genetic predisposition, aging, and androgen hormone levels.
[0006] Androgenetic alopecia is associated with increased androgen stimulation, which adversely affects the hair follicles. Increased androgen stimulation can be produced, among other mechanisms, by elevated levels of 5-alpha-reductase, an enzyme that converts testosterone to dihydrotestosterone. Anagen effluvium is hair loss due to chemicals or radiation, such as chemotherapy or radiation treatment for cancer. Self-induced hair loss includes hair loss caused by conscious or unconscious self-inflicted damage to the hair. Two common types of self-induced hair loss are trichotillomania, or hair loss that results when someone continually pulls or plucks out his own hair, and traction alopecia, which is caused by hairstyles such as ponytails or braids that continually pull at the hair. Telogen effluvium is stress-related hair loss caused by events such as, for example, surgery, child birth, or pregnancy termination. Further causes of telogen effluvium include the use of oral contraceptives or other prescription drugs, thyroid abnormality, diabetes, lupus, and emotional stress. Scarring alopecia includes hair loss caused by infection and inflammation of the hair follicles, and hair loss caused by burns or other trauma.
[0007] Because hair loss is a widespread problem that is considered cosmetically unappealing and often causes emotional distress, there is great demand for alopecia treatments. Many compositions have been tested for their ability to stimulate hair growth, for example, by promoting or prolonging anagen. Examples of such compositions include potassium channel openers, such as minoxidil (Rogaine®, Pharmacia Corp.) and diazoxide; 5-alpha-reductase inhibitors, such as finasteride (Propecia®, Merck & Co.); and the immunosuppressant cyclosporin A. However, known treatments for stimulating hair growth exhibit limited effectiveness and cause unwanted side effects. For example, among other undesirable side effects, potassium channel openers cause cardiovascular effects, finasteride is unsafe for women who are pregnant or may become pregnant, and cyclosporin A suppresses the immune system. Further, even when applied topically to areas in which hair growth is desired, known treatments for alopecia often cause hair growth in undesired areas of the body, such as facial hair on women. Such disadvantages of known compositions for treating alopecia lead many individuals experiencing hair loss to rely on wigs and toupees. Other individuals seek hair transplant surgery, which is expensive, is not fully effective, and sometimes is not possible, for example, for chemotherapy patients. Accordingly, there is a need for new agents for treating alopecia that are safe and effective and stimulate hair growth only in desired areas.
[0008] Various treatments are known in the art, but fail to address all of the problems solved by the invention described herein.
SUMMARY OF THE INVENTION
[0009] The present invention is a composition comprising 5-90% by weight Aloe vera slurry liquid portion and 1-90% by weight honey. The composition may also comprise any or all of the extracts from the parent constituents of chamomile, rosemary, horse tail, and sage. The composition is applied to the skin in a place in which a person wants to grow hair. It has been shown effective in non-clinical testing to re-grow hair and to stop hair loss when used as directed.
[0010] Therefore, the present invention succeeds in conferring the following, and others not mentioned, desirable and useful benefits and objectives.
[0011] It is an object of the present invention to provide a treatment for preventing hair loss.
[0012] It is another object of the present invention to provide a treatment for re-growing hair.
[0013] Yet another object of the present invention is to provide a natural treatment for treating hair loss.
[0014] It is an object of the present invention to prevent dandruff.
[0015] It is another object of the present invention to provide a treatment for animals.
[0016] It is another object of the present invention to provide a shampoo.
[0017] It is another object of the present invention to provide a treatment for acne.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Reference will now be made in detail to embodiment of the present invention. Such embodiments are provided by way of explanation of the present invention, which is not intended to be limited thereto. In fact, those of ordinary skill in the art may appreciate upon reading the present specification and viewing the present drawings that various modifications and variations can be made thereto.
[0019] The present invention is a composition of components. The components are, with the exception of honey, extracts of their parent constituents. The extraction process will be described in detail with regard to the examples that are cited after the description of the parent constituents below. The parent constituents may be ground up, used whole, crushed, or prepared in any other way for the extraction process. The entire constituent plant may be used, or a part or parts of the constituent plant may be used. For example, only the leaves of the sage plant may be used, only the stems may be used, a combination of leaves and stems may be used, or the entire plant may be used. The components may be extracted from parent constituents prepared in any way, including but not limited to, fresh (no special preparation) or dried.
[0020] Aloe vera is a species of succulent plant in the genus Aloe. Aloe vera is about 95% water. The rest contains active ingredients including essential oil, amino acids, minerals, vitamins, enzymes and glycoproteins. Some positive effects of treatment with aloe vera are thought to be due to the presence of compounds such as polysaccharides, mannans, anthraquinones, and lectins.
[0021] Other compounds, such as tannins, polysaccharides, organic acids, enzymes, vitamins, and steroids, have been identified. Aloe vera contains bradykininase, which relieves pain and decreases swelling and redness. Magnesium lactate may contribute to the antipruritic effect of aloe by blocking histamine production. An antiprostaglandin that reduces inflammation has also been isolated. Anthraquinones are local irritants in the GI tract but have been used in treating certain skin diseases, such as psoriasis.
[0022] Aloe vera has been used externally to treat various skin conditions, such as cuts, burns, and eczema, as well as sunburn, dermatitis, insect stings, poison ivy, abrasions, and other dermatological conditions. It is alleged that sap from Aloe vera eases pain and reduces inflammation. It is held that components such as several glycoproteins and salicylates are anti-inflammatory, and there are substances that stimulate growth of skin and connective tissue, as well as various vitamins and minerals (vitamin C, vitamin E, and zinc) and antifungal and antibacterial components (Longe 2005). Aloe vera 's activity is also attributed to moisturizing and pain relieving properties (Longe 2005).
[0023] Anecdotal evidence also has indicated that Aloe vera can help in keeping the skin flexible, and it has been used in the control of acne and eczema. The healing power is believed to be due to Aloe vera 's action in increasing the availability of oxygen to the skin, and by increasing the strength of skin tissue. The herb has a moisturizing effect on the skin and is a common therapy for sunburn and skin irritation.
[0024] Honey is a naturally occurring food made by bees using nectar from flowers. Honey is primarily a saturated mixture of two monosaccharides, dextrose and levulose, with a low water activity. When honey is used topically hydrogen peroxide is produced by dilution of the honey with body fluids and/or water. As a result, hydrogen peroxide is released slowly and acts as an antiseptic.
[0025] A review in the Cochrane Library suggests honey could reduce the time it takes for a burn to heal—up to four days sooner in some cases. The review included 19 studies with 2,554 participants.
[0026] Chamomile is a plant belonging to the sunflower or daisy family, Asteraceae. The common name Chamomile includes more than one species. Although any species may be used, the preferred species is Matricaria. The flowers of chamomile contain 0.4-2% (v/w) essential oil. The pharmacopoeial standard of essential oil contains no less than 4 mg/kg of blue oil. Its main components are (−)-alpha-bisabolol (up to 50%) and chamazulene (1-15%). The chief constituents of Roman chamomile oil are n-butyl angelate and isoamyl angelate. The flower heads have been shown to contain approximately 0.6% bitter sesquiterpene lactones (germacranolides), including nobilin and its derivatives. Other constituents may include (−)-alphabisabolol oxide A, B and C, (−)-alpha-bisabolone oxide A, 1,8-cineole, en-yn-dicycloether, alpha-pinene, amyl and isobutyl alcohols, angelic acid esters, anthemol, anthemic acid, apigenin, choline, coumarins, farnesol, germacranolide, heniarin, inositol, lueteolin, nerolidol, nobilin, patuletin, phenolic and fatty acids, phytosterol, quercetin, scopoletin-7-glucoside, spiroethers (e.g., cis- and trans-en-yn-dicycloether), sesquiterpenes (e.g., anthecotulid), tricontane, cadinene, farnesene, furfural, spanthulenol, tiglic acid esters, flavonoids (e.g., apigenin and luteolin), proazulenes (e.g., matricarin and matricin), and umbelliferone. 29 Chamazulene is formed from matricin during steam distillation of the oil. It varies in yield depending on the origin and age of the flowers.
[0027] Up to 50% of essential oil of chamomile contains alpha-bisabolol (terpenoid) and is reported to have anti-inflammatory, antibacterial, antimycotic, (anti-fungal) and ulcer-protective properties. The precise mechanism of action remains unclear, but it has been theorized that azulenes activate the pituitary-adrenal system to release cortisone and prevent the discharge of histamine.
[0028] Rosemary is a plant belonging to the mint family, Lamiaceae. Its scientific name is Rosmarinus officinalis . The leaves contain 0.5% to 2.5% of volatile oil. The major components of the oil include monoterpene hydrocarbons (alpha and beta-pinene), camphene, limonene, camphor (10% to 20%), borneol, cineole, linalool, and verbinol. Rosemary contains a wide variety of volatile and aromatic components. Flavonoids in the plant include diosmetin, diosmin, genkwanin, luteolin, hispidulin, and apigenin. One analysis reports new flavonoid glucuronides, also found in the leaves. Other terpenoid constituents in rosemary include triterpenes oleanolic and ursolic acids and diterpene carnosol. The concentration of phenolic diterpenes in certain commercial rosemary extracts has been determined by HPLC. Phenols in rosemary include caffeic, chlorogenic, labiatic, neochlorogenic, and rosmarinic acids. Rosemary contains high amounts of salicylates.
[0029] Rosemary extracts are commonly found as cosmetic ingredients and a lotion of the plant is said to stimulate hair growth and prevent baldness. The plant has been used in traditional medicine for its astringent, tonic, carminative, antispasmodic, and diaphoretic properties.
[0030] Horsetail is a plant of the family Equisetum. In the context of this application the term “Horsetail” means the various species of the family Equisetum, including but not limited to Equisetum arvense, E. palustris, E. sylvaticum and E. pratense . The stems of horsetail contain 5% to 8% of silica and silicic acids. The plant contains about 5% of a saponin called equisetonin, in addition to the flavone glycosides isoquercitrin, equisetrin, and galuteolin. The sterol fraction of E. arvense contains beta-sitosterol, campestrol, isofucosterol, and trace amounts of cholesterol. The alkaloid nicotine is present in minute amounts (less than 1 ppm) but may account for a portion of the pharmacologic activity of the plant. The plant contains more than 15 types of bioflavonoids, as well as manganese, potassium, sulfur, and magnesium. The cytokinin isopentenyladenosine has been identified in fertile fronds.
[0031] Horsetail has been traditionally used for a variety of complaints and conditions, including baldness, tuberculosis, kidney and bladder infections, kidney stones, excessive menstrual flow, gastrointestinal bleeding, gout, skin wounds and ulcers, fractures, frostbite, brittle fingernails, fluid retention, and arthritis. Horsetail is a popular herbal remedy for a variety of conditions, but it has found the most use among people who want to take advantage of its silicon content for improving hair, skin and nail quality.
[0032] The genus Salvia includes a number of species that are traditionally used as herbs and called “sage”. The scientific name of the common sage is Salvia officinalis In the context of this invention the term “Sage” includes various Salvia species, including but not limited to Salvia officinalis and Salvia lavandulaefolia . The species Salvia officinalis contains 1% to 2.8% essential oil, along with flavones, phenolic acids, phenylpropanoid glycosides (eg, martynoside), triterpenoids, and diterpenes, including phenolic, quinoidal, and rearranged abietane and apianane derivatives. The plant's compounds include salvigenin, lupeol, beta-sitosterol, stigmasterol, physcion, carnosol, rosmadial, rosmanol, epirosmanol, isorosmanol, columbaridione, atuntzensin A, miltirone, carnosic acid, and 12-O-methyl carnosic acid.
[0033] Monoturpenes have been identified using gas chromatography and other techniques, with alpha- and beta-thujones accounting for about one-half of the oil's composition. Capillary electrophoresis has been used to identify the polyphenols, while high performance liquid chromatography and nuclear magnetic resonance techniques have been applied to cold water extracts in identifying polysaccharides.
[0034] Salvia lavandulaefolia (Spanish sage) and Salvia officinalis have similar compositions except that Salvia officinalis has a much higher concentration of thujone, which is toxic in large doses. Salvia lavandulaefolia also contains variable amounts of camphor, cineol, limonene, camphene, and pinene. Sage oil is often adulterated by the addition of thujone derived from the leaves of Juniperus virginiana (red cedar).
[0035] The plant has been used topically as an antiseptic and astringent and to manage excessive sweating. Sage tea has been ingested for the treatment of dysmenorrhea, diarrhea, gastritis, tonsillitis, and sore throat. The dried leaves have been smoked to treat asthma.
[0036] Examples of the compositions made from the components are described below:
Example 1
[0037] Example 1 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion and 1-80% by weight honey.
[0038] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0039] 2) Pass the slurry of 1) through a separator to separate the liquids from the solids to yield approximately 510 grams of liquid portion.
[0040] 3) Add approximately 60 grams of honey to the liquid portion obtained from 2) to yield approximately 570 grams of the composition.
[0041] 4) Mix the components of 3) together until well blended.
Example 2
[0042] Example 2 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-80% by weight honey, and 0.0001-50% by weight chamomile extract, extracted from chamomile, a parent constituent.
[0043] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0044] 2) Add approximately 1 gram of chamomile to approximately 140 grams of the slurry obtained in 1) and mix well.
[0045] 3) Add the remaining approximately 430 grams of slurry from 1) through a separator and retain the liquid.
[0046] 4) Allow the mixture of 2) to mull for approximately 24 hours at 35-40° C. (95-104° F.).
[0047] 5) Pass the mulled mixture of 4) through a separator to separate the liquid from the solids.
[0048] 6) Combine the liquids of steps 3) and 5).
[0049] 7) Add approximately 60 grams of honey to the liquid obtained from 6).
[0050] 8) Mix the components of 7).
Example 3
[0051] Example 3 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-80% by weight honey, and 0.0001-50% by weight rosemary extract, extracted from rosemary, a parent constituent.
[0052] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0053] 2) Add approximately 0.5 grams of rosemary to approximately 140 grams of the slurry obtained in 1) and mix well.
[0054] 3) Add the remaining approximately 430 grams of slurry from 1) through a separator and retain the liquid.
[0055] 4) Allow the mixture of 2) to mull for approximately 24 hours at 35-40° C. (95-104° F.).
[0056] 5) Pass the mulled mixture of 4) through a separator to separate the liquid from the solids.
[0057] 6) Combine the liquids of steps 3) and 5).
[0058] 7) Add approximately 60 grams of honey to the liquid obtained from 6).
[0059] 8) Mix the components of 7).
Example 4
[0060] Example 4 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-80% by weight honey, and 0.0001-50% by weight horsetail extract, extracted from horsetail, a parent constituent.
[0061] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0062] 2) Add approximately 1 gram of horsetail to approximately 140 grams of the slurry obtained in 1) and mix well.
[0063] 3) Add the remaining approximately 430 grams of slurry from 1) through a separator and retain the liquid.
[0064] 4) Allow the mixture of 2) to mull for approximately 24 hours at 35-40° C. (95-104° F.).
[0065] 5) Pass the mulled mixture of 4) through a separator to separate the liquid from the solids.
[0066] 6) Combine the liquids of steps 3) and 5).
[0067] 7) Add approximately 60 grams of honey to the liquid obtained from 6).
[0068] 8) Mix the components of 7).
Example 5
[0069] Example 5 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-98% by weight honey, and 0.0001-50% by weight sage extract, extracted from sage, a parent constituent.
[0070] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0071] 2) Add approximately 0.5 grams of sage to approximately 140 grams of the slurry obtained in 1) and mix well.
[0072] 3) Add the remaining approximately 430 grams of slurry from 1) through a separator and retain the liquid.
[0073] 4) Allow the mixture of 2) to mull for approximately 24 hours at 35-40° C. (95-104° F.).
[0074] 5) Pass the mulled mixture of 4) through a separator to separate the liquid from the solids.
[0075] 6) Combine the liquids of steps 3) and 5).
[0076] 7) Add approximately 60 grams of honey to the liquid obtained from 6).
[0077] 8) Mix the components of 7).
Example 6
[0078] Example 6 results in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-80% by weight honey, 0.0001-50% by weight chamomile extract, 0.0001-50% by weight rosemary extract, 0.0001-50% by weight horse tail extract, and 0.0001-50% by weight sage extract.
[0079] Example 6 may also result in a composition that is 5-98% by weight Aloe vera slurry liquid portion, 1-80% by weight honey, 0.0001-5% by weight chamomile extract, 0.0001-5% by weight rosemary extract, 0.0001-5% by weight horse tail extract, and 0.0001-5% by weight sage extract.
[0080] Example 6 may also result in a composition that is 50-95% by weight Aloe vera slurry liquid portion, 1-50% by weight honey, 0.0001-5% by weight chamomile extract, 0.0001-5% by weight rosemary extract, 0.0001-5% by weight horse tail extract, and 0.0001-5% by weight sage extract.
[0081] 1) Puree entire fresh Aloe vera leaves in a blender on high speed for approximately 3 minutes such that approximately 570 grams of a slurry is obtained.
[0082] 2) Divide the slurry from 1) into four portions of approximately 140 grams each.
[0083] 3) Add 0.1 to 10 grams, preferably approximately 1.0 grams of chamomile to one portion of the slurry from 1).
[0084] 4) Add 0.1 to 10 grams, preferably approximately 0.5 grams of rosemary to a second portion of the slurry from 1).
[0085] 5) Add 0.1 to 10 grams, preferably approximately 1 gram of horsetail to a third portion of the slurry from 1).
[0086] 6) Add 0.1 to 10 grams, preferably approximately 0.5 grams of sage to the fourth portion of the slurry from 1).
[0087] 7) Allow the slurry mixtures of 3-6 to mull separately for 24 hours at 35-40° C. (95-104° F.).
[0088] 8) Place the slurry mixtures of 7) in a blender and mix them together.
[0089] 9) Pass the mixture of 8) through a separator to separate the liquids from the solids to yield approximately 510 grams of liquid.
[0090] 10) Add 1-90% by weight, preferably approximately 60 grams of honey to the liquid obtained from 9).
[0091] 10) Mix the components of 11) together until well blended.
[0092] As per Claim 2 , other examples not detailed here include combining the slurry mixtures of two, three, or all four of the parent constituents in various combinations.
[0093] Although example 6 details an order for adding the four parent constituents to the Aloe vera slurry portions, and examples 2-6 detail a specific period for mulling, the parent constituents may be added to their respective slurry portions in any order, and the mulling periods may be any length, preferably from 30 minutes to 30 days, and most preferably approximately 24 hours. The mulling periods for each parent constituent need not be the same, although that is preferred.
[0094] As stated earlier, the components with the exception of honey are extracted from their parent constituents. The fresh Aloe vera plant is pureed into a slurry; the slurry extracts the components from their parent constituents through diffusion and/or a solvent effect. As can be seen in examples 2-6 above, the parent constituents are mixed with the Aloe vera slurry and are subsequently allowed to mull for 24 hours after each addition; diffusion occurs, allowing molecules to move from the parent constituents into the Aloe vera slurry. The mulling temperature may be any temperature, but is preferably from 20° C. to 60° C. In the examples above, the mulling occurs at the preferred elevated temperature of 35-40° C. (95-104° F.); this speeds the extraction process, but the mulling could also occur at a lower temperature. In this case, the mulling time may be adjusted to compensate for a lower extraction rate. In the preferred embodiment, the parent constituents are all mulled at approximately the same temperature, but different temperatures or times may be used for different components or parent constituents.
[0095] The blender used to make the slurry and to mix the separate slurries may be any kind of blender. It preferably is an electric blender such as but not limited to, blenders for home use such as Waring, Hamilton Beach, or Oster, or industrial or commercial blenders by those manufacturers or others. The blender may also be manual, and may be any type of blending instrument, including but not limited to, a hand mixer, a mortar and pestle, a pastry blender, a cement mixer, an industrial mixer, or others.
[0096] The separator used may be any type of device that can separate solids from liquids. It is preferably a mesh sieve with sieve size 0.020 mm to 11.2 mm. The separator may also be, but is not limited to, a centrifuge, a filter, a membrane, a cyclone separator, a pressure driven separator, a vacuum separator, or a funnel.
[0097] Although the extraction process described in the examples above is the preferred method for obtaining the extracts, the extracts may be obtained through other methods. For instance, other methods of extraction may include, but are not limited to, using different meld times, different temperatures, using varying methods to grind up the parent constituents, using solvents to aid in extraction, using an agitator to facilitate extraction, or they may be purchased from a supplier who uses his own method of extraction.
[0098] A composition made using from any of the examples above is applied to the skin in the following manner. First, a user identifies where he or she wants to grow or retain hair. The spot (or spots) is cleaned, then the composition is applied in a thin layer on the skin. The composition is allowed to dry on the user's skin, and is left on for approximately 8 hours or until the skin is again cleaned. The skin is then cleaned again, and the composition is re-applied as above. This process continues as long as the user desires.
[0099] The present invention has been used on humans and dogs both, and has been shown anecdotally to reduce dandruff in both species and to reduce skin itching in dogs. It has also been shown to slow hair loss and to re-grow hair in humans. The invention may be used on other species as well to improve skin health.
[0100] Other components that may be used to formulate the base for the compositions described above include, but are not limited to, water, vp/va copolymer (polyvinylpyrrolidone/vinyl acetate copolymer), pvp (polyvinyl pyrrolidone), polysorbate 20, ginseng root extract, sage leaf extract, allatoin, panthenol, acrylates, c10-30 alkyl acrylate crosspolymer, propylene glycol, triethanolamine, tetrasodium edta, tetrasodium pyrophosphate, salicylate, limonene, linalool, phenoxyethanol, and diazolidinyl urea.
[0101] Additional components may include, but are not limited to, toronjil (scientific name Melissa Officinalis ); fragrance, including but not limited to bubble gum fragance; avocado oil; and lemon grass.
[0102] An alternate embodiment is a shampoo using any or all of the same components described above or in subsequent paragraphs. The method of preparing the compositions would be the same or similar, but other compounds may be added to formulate the shampoo. These compounds include, but are not limited to, water, decyl glucoside, coco betaine, lauramide dea, lauryl glucoside, edta, methylchloroisothiazolinone, methylisothiazolone, citric acid, sodium chloride, vitamin A, vitamin D, vitamin C, hemp oil, avocado oil, and coconut oil. Another embodiment is a conditioner using any or all of the same components described above or in subsequent paragraphs. Other components of the conditioner may be, but are not limited to, glycerin, emulsifying wax nf, mineral oil, quanternium-7, pvp (polyvinyl pyrrolidone), glycerilstearate se, stearalkonium chloride, ethoxydiglycol, propylene glycol, butylene glycol, extract of matricaria, extract of nettle, extract of birch sap, extract of arnica, extract of cinchona, extract of birch leaf, potassium sorbate, sodium benzoate, and imidasolidinyl urea.
[0103] Vitamin C crystals and debittered brewer's yeast powder may be also be added to any of the compositions described above.
[0104] Any and/or all of the components described above may be used to formulate a shampoo or skin wash for dogs or other animals.
[0105] The present invention has also been shown through use to improve skin health when used as a face wash, particularly in the reduction of acne. It may also be used as a general body wash. It may be combined with other compounds to make these formulations.
[0106] Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention. | An all natural formulation for the treatment of baldness in men and women is described. Also described is a method of making the formulation and a method of using it. | 0 |
RELATED APPLICATIONS
The present invention was first described in Disclosure Document Number 539,592 filed on Oct. 7, 2003 under 35 U.S.C. §122 and 37 C.F.R. §1.14. There are no previously filed, nor currently any co-pending applications, anywhere in the world.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to deicing systems, and, more particularly, to a deicing material dispensing system for gutters.
2. Description of the Related Art
Those of us who live in areas where the winter climate brings snow, sleet, high winds and ice know all too well of the harshness and hazards associated with such weather. Such conditions are not only hard on people, but buildings as well. Perhaps the biggest threat to homes in such climates is the ice that builds up in roof gutters. The massive ice damns that buildup with repeated thawing and freezing cycles not only risk damaging the gutter, but the roof and possibly the structural frame of the home as well in severe situations. Such severe weather conditions make it impossible to climb onto the roof to work on the ice damns. Ladders are hardly any safer when snow and ice builds up on the steps, exposing the user to severe and nasty falls.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related:
U.S. Pat. No.
Inventor
Issue Date
5,391,858
Tourangeau et al.
Feb. 21, 1995
5,878,533
Swanfeld, Jr.
Mar. 9, 1999
5,786,563
Tiburzi
Jul. 28, 1998
6,314,685
Sullivan
Nov. 13, 2001
6,348,673
Winters
Feb. 19, 2002
6,489,594
Jones
Dec. 3, 2002
4,769,526
Taouil
Sep. 6, 1988
Consequently, a need has been felt for providing a means by which ice buildup in roof gutters can be safely eliminated without the disadvantages listed above.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved deicing system.
It is a feature of the present invention to provide an improved deicing material dispensing system for gutters.
Briefly described according to one embodiment of the present invention, the de-icing dispenser for gutters is an apparatus for dispensing ice melting chemicals directly into roof gutters, while allowing the user to remain safe on ground level. The dispenser includes a long handle which will allow a user of average height to reach the gutters while safely standing on the ground. The angle of the handle with respect to the ground will be approximately 45°. The handle is provided with two cushioned grips for comfortable holding. At the upper end of the invention, a guide hook is provided which hooks over the edge of the gutter, and properly positions a container filled with calcium chloride or other safe ice-melting chemical directly over the gutter. A trigger release mechanism at the bottom handle opens a release gate on the chemical container allowing a small amount of the chemical to be released into the gutter. Should the chemical clog and not be released, a separate “thumping” mechanism will be activated by a lower handle and tap the chemical container to aid in the chemical release. The user would release approximately eight to twelve ounces of chemical every four to five feet along the gutter to aid in ice melting.
The use of the De-Icing Dispenser for Gutters allows homeowners to keep their gutters clear of ice in the winter time thus preventing possible costly roof and structural damage.
An advantage of the present invention is that it dispenses ice-melting chemical directly into roof gutters, thereby helping eliminate ice dams and blockage in roof gutters in the winter time.
Further, the present invention allows user of typical height to reach the gutters while safely standing on the ground.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is an overall pictorial diagram depicting the deicing material dispensing system for gutters 10 in a state of being utilized, according to a preferred embodiment of the present invention;
FIG. 2 is a side view of the deicing material dispensing system for gutters 10 ;
FIG. 3 is a front view of the deicing material dispensing system for gutters 10 ;
FIG. 4 , is a detailed isometric of the aligning hook 90 ;
FIG. 5 , is a detailed plan view of the lower end of the deicing material dispensing system for gutters 10 ; and,
FIG. 6 is a detailed side view of the deicing material dispensing system for gutters 10 .
DESCRIPTIVE KEY
10
deicing material dispensing system for gutters
15
user
20
building
25
roof gutters
30
grade level
35
deicing material
40
interval distance “d”
45
roof valley locations
50
down spout locations
55
pole
60
upper cushioned hand grip
65
lower cushioned hand grip
70
deicing material release lever
72
internal cable
73
pulleys
75
deicing material slide gate
80
deicing material reservoir
85
reservoir lid
90
aligning hook
95
support brace
100
outward edge of roof gutter
105
support arms
110
thumping mechanism
115
thumping lever
120
pivot point
125
control cable
130
return spring
135
hole array
140
connecting harness
145
connecting cable
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within the FIGS. 1–6 .
1. Detailed Description of the Figures
Referring now to FIG. 1 , an overall pictorial diagram of the deicing material dispensing system or apparatus for gutters 10 , in a state of utilization, is disclosed according to a preferred embodiment of the present invention. A user 15 stands along a building 20 such as a residential home or other single story structure equipped with roof gutters 25 . It should be noted that while the current FIG. depicts a single story structure building 20 , it is envisioned that the deicing material dispensing system for gutters 10 could be used with multiple story structures by the use of a longer deicing material dispensing system for gutters 10 , and as such should not be interpreted as a limiting factor of the current invention. The user 15 is standing safely upon a grade level 30 as normally provided on the exterior of a building 20 . As such, the user 15 is capable of walking along the grade level 30 for the length and travel path of the roof gutters 25 . As will be described in greater detail herein below, the user 15 uses the deicing material dispensing system for gutters 10 to deposit a small amount of deicing material 35 in or on the roof gutters 25 proper at an interval defined by an interval distance “d” 40 . It is envisioned that the amount of deicing material 35 dispensed would be approximately eight to twelve ounces and the interval distance “d” 40 would be approximately four to five feet, though amounts and distances could vary depending on the amount of ice buildup on the roof gutters, current weather conditions, type of deicing material 35 being used and the like. It is also envisioned that a continuous stream or path of deicing material 35 could be dispensed by the deicing material dispensing system for gutters 10 along the entire route of the roof gutters 25 . Additional amounts of deicing material 35 could be dispensed in troublesome ice buildup locations such as roof valley locations 45 , down spout locations 50 , and the like.
Referring next to FIG. 2 , a side view of the deicing material dispensing system for gutters 10 is shown. The central component of the deicing material dispensing system for gutters 10 is a pole 55 , which would vary in length depending on the distance of the roof gutters 25 (as shown in FIG. 1 ) above the grade level 30 (as shown in FIG. 1 ). The pole 55 is equipped with an upper cushioned hand grip 60 and a lower cushioned hand grip 65 . The upper cushioned hand grip 60 would be held in the left hand and the lower cushioned hand grip 65 would be held in the right hand in the case of a right-handed user and vice-versa in the case of a left-handed user. The lower cushioned hand grip 65 is provided with a deicing material release lever 70 which when operated, activates an internal cable 72 (shown as dashed line for illustrative purposes) inside the pole 55 which opens a deicing material slide gate 75 at the top of the pole 55 under a deicing material reservoir 80 via the use of two pulleys 73 . The deicing material reservoir 80 is of a sufficient size to contain approximately three to five pounds of deicing material 35 (as shown in FIG. 1 ). The deicing material reservoir 80 is equipped with a reservoir lid 85 to allow the user 15 (as shown in FIG. 1 ) to fill the deicing material reservoir 80 . An aligning hook 90 supported by a support brace 95 allows for the proper and automatic positioning of the deicing material slide gate 75 over the roof gutters 25 . The aligning hook 90 will be shown in greater detail herein below. The aligning hook 90 will rest upon the outward edge of roof gutter 100 , thus assuring proper positioning. Such positioning is important to avoid dispensing deicing material 35 above or beyond the roof gutters 25 on the roof of the structure, or below the roof gutters 25 where it may fall upon the grade level 30 (as shown in FIG. 1 ) or possibly upon the user 15 (as shown in FIG. 1 ). The deicing material reservoir 80 is attached to the pole 55 by the use of two support arms 105 , one of which is shown here for purposes of illustration. A thumping mechanism or hammer 110 is provided which is capable of tapping or “thumping” the side of the deicing material reservoir 80 should the deicing material 35 inside clump or stick together. Such a feature is important in the event that any moisture in the deicing material 35 is present, and environmental conditions such as temperature and humidity may cause it to clump or stick together. The thumping mechanism or hammer 110 is activated by a thumping or hammer lever 115 located by the lower cushioned hand grip The thumping mechanism or arm 110 pivots about a pivot point 120 as activated by a control cable 125 that runs the length of the pole 55 on its exterior. A return spring 130 is located at the upper end of the pole 55 to automatically retract or withdraw the thumping mechanism 110 , thus aiding the user 15 (as shown in FIG. 1 ) when performing the “thumping” action.
Referring now to FIG. 3 , a front view of the deicing material dispensing system for gutters 10 is depicted. This view more clearly depicts the nature of the pole 55 and its relationship to the upper cushioned hand grip 60 , the lower cushioned hand grip 65 and the deicing material reservoir 80 . The thumping mechanism or hammer 110 hits or “thumps” the deicing material reservoir 80 directly in the center right below the reservoir lid 85 , as pivoted around the pivot point 120 , and operated around the thumping or hammer lever 115 , the control cable 125 and the return spring 130 . Such action is also directly over the deicing material slide gate 75 (as shown in FIG. 2 ) and as will be described in greater detail herein below, thus aiding in the removal of the deicing material 35 from the deicing material reservoir 80 . The support arms 105 , both visible in this FIG. are in physical contact with the deicing material reservoir 80 . It is envisioned that the deicing material reservoir 80 would be made of plastic thus offering protection from the corroding effects of the deicing material 35 . Other components of the deicing material dispensing system for gutters 10 such as the pole 55 , the support arms 105 and the like would be made of rolled or stamped carbon steel for strength and painted for corrosion protection.
Referring next to FIG. 4 , a detailed isometric of the aligning hook 90 is disclosed. This FIG. clearly depicts the dual nature of the aligning hook 90 . Additionally, the support brace 95 and its relationship and interconnection to the pole 55 is shown.
Referring now to FIG. 5 , a detailed plan view of the lower end of the deicing material dispensing system for gutters 10 is shown. This FIG. clearly shows the relationship between the upper cushioned hand grip 60 and the lower cushioned hand grip 65 . Additionally, the relationship between the deicing material release lever 70 and the thumping or hammer lever 115 is depicted as well. Finally, a cutaway view inside the pole 55 shows the control cable 125 .
Referring finally to FIG. 6 , a detailed side view of the deicing material dispensing system for gutters 10 , as seen along a line I—I in FIG. 2 is disclosed. This FIG. shows the deicing material slide gate 75 in a partially retracted state on the bottom of the deicing material reservoir 80 . Such retraction depicts a hole array or plurality of holes 135 on the bottom of the deicing material reservoir 80 , through which the deicing material 35 (not shown in this FIG.) will emerge, in much the same manner as a salt shaker. This FIG. also clarifies the use of the support arms 105 in securing the deicing material reservoir 80 . The deicing material slide gate 75 is retracted with the aid of a connecting harness 140 and a connecting cable 145 which are located on the interior of the deicing material dispensing system for gutters 10 , and thus depicted with hidden lines. The connecting cable 145 then connects to the deicing material release lever 70 as shown in FIG. 1 .
It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
2. Operation of the Preferred Embodiment
The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After purchase or procurement of the deicing material dispensing system for gutters 10 , it would be filled with deicing material 35 , such as calcium chloride, rock salt, a fluid with a non-toxic an anti-freezing agent, or other common material that would not damage the roof or roof gutters 25 of the building 20 . The user 15 would then begin at one end of the building 20 and hook the aligning hook 90 over the outward edge of roof gutter 100 to properly position it while holding the deicing material dispensing system for gutters 10 with the upper cushioned hand grip 60 and lower cushioned hand grip 65 . Next, the user 15 would actuate the deicing material release lever 70 , causing the deicing material slide gate 75 to open on the bottom of the deicing material reservoir 80 thus exposing the hole array 135 . Gravity then would cause approximately eight to twelve ounces of the deicing material 35 to drop out onto the roof gutters 25 . The user 15 would then release the deicing material release lever 70 , ceasing the flow of deicing material 35 and move the deicing material dispensing system for gutters 10 to the next spot on the roof gutters 25 which would be approximately four to five feet.
In the event that the deicing material 35 clumps inside of the deicing material reservoir 80 , the user 15 may activate the thumping or hammer lever 115 causing the thumping or hammer mechanism 110 to tap or “thump” the side of the deicing material reservoir 80 causing the deicing material 35 to dislodge. The thumping or hammer lever 115 accomplishes this with the aid of the pivot point 120 , the control cable 125 and the return spring 130 .
When finished, the user would rinse out the deicing material reservoir 80 with water, allowing it to air dry thus preparing it for use the next time it may be required.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. Therefore, the scope of the invention is to be limited only by the following claims. | An apparatus for dispensing ice melting chemicals directly into roof gutters comprises a linearly elongated pole having two cushioned grips for comfortable holding. At the upper end of the pole, a guide hook is provided which hooks over the edge of the gutter, and properly positions a container filled with calcium chloride or other safe ice-melting chemical directly over the gutter. A lever at the bottom handle opens a release gate on the chemical container allowing a small amount of the chemical to be released into the gutter. Should the chemical clog and not be released, a separate hammer may be activated by a hammer lever to tap the chemical container and aid in the chemical release. The user would release approximately eight to twelve ounces of chemical every four to five feet along the gutter to aid in ice melting. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a heat and oxidation resistive high strength material used in structural body pans subject to bleaching in high temperature/oxidative atmosphere, the body structure of an orbital space plane, a combustor, the combustor for a gas turbine, a blade, and a nozzle; the present invention also relates to a method for producing the heat and oxidation resistive high strength material.
Concerning the fields in energy, material production process, and spacecraft, developments in the heat resistive materials having thermal insulation, heat resistance, and excellent resistance to environmentally induced damages are cited as important technical topics for materials used under extreme environmental circumstances.
As heat resistive materials there are metallic materials, composite materials, and ceramics to name a few. As far as heat resistive alloy is concerned, there is a super alloy which has Ni, Co, and Fe as the constituent bases. However, Ni, the main constituent of a Ni-based super alloy, has a melting point of 1455° C., and therefore, this alloy cannot be used in an environment with temperature range that goes beyond this point. For this reason, an environmentally induced damage insulation layer is formed on the surface of this alloy. As one of the representative examples, a thermal barrier coating (TBC) method is presented which involves spraying melted ceramics of ZrO 2 and Y 2 O 3 into the middle layer of a super alloy, produced with the purposes of relaxing thermal stress, improving adhesion, enhancing oxidation resistance, and improving anti-corrosion at the surface. Furthermore, JPA62-156938 describes a functionally gradient material (FGM) which relaxes thermal stress by having the composition ratio of ZrO 2 and Y 2 O 3 change continuously at the middle layer between the substrate and the ceramics.
There are others such as an intermetallic compound and a high melting point metal. Some of the intermetallic compounds as a heat resistive structure are Al compounds of iron family (Fe, Ni, Co) and Ti, but these compounds leave some room for improvement in terms of hardness, workability, and resistive to oxidation. On the other hand, the high melting point metals of W, Mo, Nb, Ta etc., have high thermal conduction and has good resistance against heat but has a weakness of being abraded easily by oxidation; and therefore, there is a need to develop an alloy having strength and resistance to oxidation or a surface process which imparts these characteristics.
Moreover, there are composite materials which have heat resistancy and high strength. Composite materials having high strength fibers at a high temperature range improve the strength of matrix materials at a high temperature range. In terms of matrix types there are fiber reinforced plastics (FRP), fiber reinforced metals (FRM), fiber reinforced ceramics (FRC), and carbon fiber reinforced carbons (CFRC). Limit on the highest usable temperature depends on the type of matrix used. For the plastic type, the temperature is 300° C.; for the metal type, 1300° C.; for the ceramic type, 1800° C.; and for the carbon type, 3000° C. approximately. Specifically, the density of the CFRC is less than 2.0 and the strength of this material does not deteriorate until over 300° C.; the material is known as a super heat resistive material for retaining excellent strength and excellent hardness at high temperatures. However, since the CFRC is made of carbon only, in the oxidative atmosphere of around 500° C., oxidative abrasion becomes noticeable. Therefore, this material cannot be used at temperatures above 500° C. in an environment of oxidative atmosphere. Therefore, in order to use the CFRC even in such an environment, an anti-oxidation treatment becomes necessary. That is, the determining factor of the usable heat resistive temperature of the CFRC in the oxidative atmosphere is the durability of the anti-oxidation treatment. An example of the anti-oxidation treatment is an anti-oxidation coating formed on the substrate surface.
One of the main coating elements of the anti-oxidation coating is SiC. For forming SiC, there are a chemical vapor reaction (CVR) method or a chemical vapor deposition (CVD) method. The CVR method involves diffusing metallic silicon vapor into the substrate and reacting with the carbons in the substrate to form SiC. Passages are required for producing this reaction, and because holes are very difficult to get rid of, the coating is left with many holes. In the oxidative atmosphere, oxygen enter into the substrate through these holes and cause damages, and therefore, there is the oxidation problem. Since the CVD method involves forming a coating by depositing a coating at the atomic level, SiC with very high purity and a very fine crystal structure can be formed. However, since the expansion coefficient of the CFRC is small (0 to 1×10 -6 /°C.), microcracks form across the thickness of the coating by thermal stress caused by the differences in thermal expansion. Through these microcracks, oxygen of the oxidative atmosphere enter to cause damages to the substrate. Therefore, microcracks must be sealed, and this is done by tetraethyl orthosilicate (TEOS), for example, which impregnates into the microcracks of SiC to seal it; this process is described in Spacecraft Technical Research Report TR-946, "Trial Product Test of Carbon Composite Combustor for Low Thrust Storage Propulsion Chemical Engine" (October, 1987), or The Third Symposium for the Advances in Environmentally Induced Damage Super Resistant Materials, "Petroleum Pitch Type C/C Composite Material Composite Formation and Anti-Oxidation Technology" (October, 1987).
For an anti-oxidation coating of greater temperature range (2000° C.), two layer coatings of Ir and Al 2 O 3 , placed on top of Ir, are formed on the C/C material surface by a sputtering deposition instrument. However, this coating is subject to cracks when the temperature is made to rise to and fall from the high temperature range, and therefore, a sealing process is required (described in The Third Symposium for the Advances in Environmentally Induced Damage Super Resistant Materials, "Petroleum Pitch Type C/C Composite Material Composite Formation and Anti-Oxidation Technology" (October, 1987)). Therefore, it is necessary to examine the sealing materials and the process methods for maintaining anti-oxidation property in the 2000° C. range.
On the other hand, as a method of other formation of the anti-oxidation surface of the C/C material, a material of metallic layers consisting of a hafnium, tantalum or zirconium foil between the rhenium or silicon carbite layers is described in JPA1-23048 No. 7 of "Heat and Oxidation Resistive Reinforced Material and its Production Method." The anti-oxidation coating layer of this materials reacts, in the oxidative atmosphere at 2000° C., under certain combination of materials to produce products that possibly lower the anti-oxidation property. Also, high temperature anti-resistive carbon materials having a silicon carbite film formed on top of the carbon substrate, and Hf and Zr metal films formed on top of the silicon carbite film, and an Ir film formed on top of this is disclosed in JPA4-149083.
According to the known technologies of the above, it would be difficult to obtain light and strong materials in the 2000° C. range. That is, it became evident that a carbon fiber reinforced carbon as a highly strong material does not have adequate heat and oxidation resistivity in the oxidative atmosphere at the 2000° C. range. SiC, which is used often as a heat and oxidation resistive coating layer formed on the substrate surface, is oxidized to SiO 2 in the high temperature range, and higher the temperature, more of this product forms. Additionally, as heating and cooling is repeated, the oxidized coating of SiO 2 is subject to peeling and therefore, durability cannot be achieved. Furthermore, if the temperature goes above 1700° C., SiO 2 melts, and in the case of materials on the body of a spacecraft which receives bombardment on the surface, the melted material scatters and the abrasion becomes noticeable. Therefore, the limit on the usable temperature of SiC as a heat and oxidation resistive coating layer is 1700° C.
Additionally, as an easily accessible technology, there is a plasma flame coating method for forming high melting point ceramics. By this method, even if a high melting point ceramics layer or a metal layer is formed on the carbon fiber reinforced carbon substrate, there are cases in which cracks or peeling occurs after the formation of the layer or when the layer receives thermal shocks because of the differences in the expansion coefficients between the layer and the substrate or a lack of good adhesion between the two. In these kinds of situation, the substrate oxidizes and is subject to abrasion, and the layer ceases to function as a good heat and oxidation resistive coating layer.
The purpose of the present invention is to solve the aforementioned problems of the prior arts by presenting, first, a heat and oxidation resistive high strength material having a heat and oxidation resistive coating layer that has anti-thermal shock, anti-corrosion, and anti-oxidation properties along with excellent adhesive property to the surface of a heat resistive high strength substrate made of carbon and, second, a production method thereof.
SUMMARY OF THE INVENTION
In order to carry out the purpose mentioned above, the first feature of the present invention relates to a heat and oxidation resistive high strength material having a heat and oxidation resistive coating layer on a carbon substrate, comprising a SiC type coating on top of the carbon substrate, a ZrO 2 type ceramic coating on top of the SiC type coating, and an Ir type coating on top of the ZrO 2 type ceramic coating. In the SiC type coating, either the carbon concentration decreases continuously from the carbon substrate to the ZrO 2 type ceramic coating or a mixture layer of a SiC type coating material and a substrate material is formed between a part of the ZrO 2 type ceramic coating side and the carbon substrate.
The second feature of the present invention relates to a mixture layer of a SiC type coating material and a ZrO 2 type ceramic coating material formed between the SiC type coating and the ZrO 2 type ceramic coating of the first feature of the present invention.
The third feature of the present invention relates to the mixture layer of the SiC type coating material and the ZrO 2 type ceramic coating material of the second feature of the present invention in which the mixture ratio continuously changes from the SiC type coating towards the ZrO 2 type ceramic coating.
The fourth feature of the present invention relates to a mixture layer of a ZrO 2 type ceramic coating material and an Ir type coating material formed between the ZrO 2 type ceramic coating and the Ir type coating of the first feature of the present invention.
The fifth feature of the present invention relates to the mixture layer of the ZrO 2 type ceramic coating material and the Ir type coating material of the fourth feature of the present invention in which the mixture ratio continuously changes from the ZrO 2 type ceramic coating towards the Ir type coating.
The sixth feature of the present invention relates to the SiC type coating of the first, second, third, fourth, or fifth feature of the present invention comprising SiC as the main constituent with a part or a whole of the vacant space filled with Al 2 O 3 , ZrO 2 , Y 2 O 3 , or SiO 2 , or combinations thereof.
The seventh feature of the present invention relates to the ZrO 2 type ceramic coating of the first, second, third, fourth, fifth, or sixth feature of the present invention comprising ZrO 2 as the main constituent along with more than one from the group consisting of Y 2 O 3 , MgO, and CaO.
The eighth feature of the present invention relates to the carbon substrate of the first, second, third, fourth, fifth, sixth, or seventh feature of the present invention being made from a carbon fiber reinforced carbon.
The ninth feature of the present invention relates to a heat and oxidation resistive high strength material comprising a carbon substrate layered with a heat and oxidation resistive coating layer, which has a SiC type coating formed by a chemical vapor reaction method, and has a ZrC or a HfC coating formed by a chemical vapor deposition method, and has a ZrO 2 type ceramic coating layered on top of the ZrC or the HfC coating, and has an Ir type coating layered on top of the ZrO 2 type ceramic coating.
The tenth feature of the present invention relates to a method for producing a heat and oxidation resistive high strength material, which has a carbon substrate layered with a heat and oxidation resistive coating layer on the surface, comprising the steps of forming a SiC type coating on the surface of the carbon substrate, forming a ZrO 2 type ceramic coating on top of the SiC type coating, and forming an Ir type coating on top of the ZrO 2 type ceramic coating by an electron beam vapor deposition method.
The eleventh feature of the present invention relates to a method for producing a heat and oxidation resistive high strength material, which has a carbon substrate layered with a heat and oxidation resistive coating layer on the surface, comprising the steps of forming a SiC type coating on the surface of the carbon substrate, forming a ZrO 2 type ceramic coating on top of the SiC type coating, and forming an Ir type coating on top of the ZrO 2 type ceramic coating by using a method that uses simultaneously an electron beam vapor deposition method and ion beam irradiation.
The twelfth feature of the present invention relates to a method of the eleventh feature of the present invention, wherein the acceleration voltage of ion beam is within 1 to 50 kV and the main element that comprises the ion beam is either oxygen or argon.
The structure and the effect of the present invention will be described. In regard to the substrate of the super heat resistive composite material of the present invention, a carbon fiber reinforced carbon material is utilized, which is made of a matrix of carbons where carbon fibers fill the interstices. In placing this carbon fiber reinforced carbon material in the oxidative atmosphere at 2000° C. as an environmental induced damage and heat resistive material, reliability of the coating layer against environmental induced damage becomes a very important consideration. Important factors for this consideration are the heat resistivity, anti-oxidation ability, structural design, and adhesion. The following describes the coating layer of the present invention.
On top of the substrate of the carbon fiber reinforced carbon, a coating layer structure of the present invention form a heat resistive ceramic coating with excellent adhesion to the substrate and also a high melting point metallic coating with an oxygen barrier function on the surface layer exposed to the oxidative atmosphere. In this instance, a middle level layer ceramic coating has a reaction suppressing function on the heat resistive ceramic coating and the high melting point metallic coating.
SiC is a good choice in regard to the heat resistive ceramic coating formed on top of the substrate of the carbon fiber reinforced carbon, having excellent mechanical characteristics and chemical stability at high temperatures. This SiC coating is formed by the chemical vapor reaction method and the chemical vapor deposition method, depending on the function of purpose. That is, as SiC, which is formed on top of the substrate directly, needs to have a high adhesion force, the chemical vapor reaction method is used such that the metallic silicon vapor is reacted with and bonded to the carbon substrate, and this process produces SiC; thereby adhesion to the substrate can be promoted; and because the coating is a multiporous body, it is effective in relaxing thermal shocks. And by forming SiC above this layer by depositing SiC at the atomic level by the chemical vapor deposition method, fine and good crystal structures of high purity result, having excellent heat resistive characteristics. Moreover, this coating can be ZrC or HfC. Especially, in the case of forming a ZrO 2 coating on top of the ZrC coating, ZrC is desirable because it is compatible with the ZrO 2 coating. In this instance, it is desirable to form a SiC coating, which is compatible with the substrate of the carbon fiber reinforced carbon, by the chemical vapor reaction method and form ZrC or HfC on top of this coating by the chemical vapor deposition method. However, microcracks form across the thickness of the SiC coating, which is formed by the chemical vapor reaction method and the chemical vapor deposition method, because of thermal stress caused by the differences in thermal expansion between the substrate and the coating. Therefore, there is a possibility of oxygen penetrating into the substrate through these microcracks and damaging the substrate. For this reason, sealing the microcracks is effective in preventing penetration. Concerning the materials for this purpose, Al 2 O 3 , ZrO 2 , Y 2 O 3 , or SiO 2 or combinations thereof, having heat resistivity, can be used. The filling process of these materials involves a sol/gel method; that is, it involves filling or painting TEOS, MAP, butoxyl zirconium, tetra-n-butoxyl zirconium, or tris-n-butoxyl yttrium into the cracks and firing the product. In this way, the SiC type coating can be produced which has excellent heat resistivity and great adhesion to the substrate of the carbon fiber reinforced carbon.
Next, for the surface of the high melting point metallic coating, in the case it is subjected to the oxidative atmosphere, Ir is desirable, in addition to being a high melting point metal that has excellent heat and oxidation resistivity at 2000° C., as it has the oxygen barrier function that prevents the impregnation of oxygen into the internal parts of the heat resistive ceramics coating or the carbon fiber reinforced carbon. That is, within the platinum metal VIII family, Os, Ir, and Ru have heat resistivity at 2000° C., but Ir has the highest melting point temperature among this group at 2447° C. and has the least amount of evaporative abrasion in the oxidative atmosphere. On the other hand, the other high melting point metals such as Ta, W, and Zr are subject to abrasion in the oxidative atmosphere or oxidative reaction, and hence, they are not desirable for the stated purpose of the present invention. From these, high melting point metal coating can be had, which has excellent heat and oxidation resistivity.
However, a coating structure, in which Ir of a high melting point metallic coating is directly placed on the SiC of a high heat resistive ceramic coating on top of the substrate, reacts to form IrSi, which has a low melting point of 1380° C., and therefore, the purpose of the present invention cannot be realized. For this reason, it is necessary to place a ceramic coating middle layer between SiC and Ir that does not react with either of these coatings at 2000° C. and that still has excellent heat and oxidative resistivity. In the present invention the purpose is accomplished by having a middle layer ceramic coating. That is, ZrO 2 , which has a non-reactive function with either SiC or Ir and has heat resistivity, anti-thermal shock property, anti-oxidation property, and low thermal conduction as a ceramic, is selected. Additionally, it is effective to add Y 2 O 3 , MgO, or CaO as stabilizers in preventing phase change of ZrO 2 .
On the other hand, Al 2 O 3 , the other representative ceramics, is extremely bad in terms of anti-thermal shock because of the phase change, α⃡γ. Furthermore, it is not appropriate for the purpose of the present invention because of its reaction with Ir. From these, the ZrO 2 type coating is found appropriate for its heat resistivity in conjunction with the SiC high heat resistivity ceramic coating and Ir high melting point metallic coating and for its non-reactive function.
Next, the method for producing the ZrO 2 type ceramic coating and the Ir type coating becomes an important consideration. That is, in consideration of violent thermal shocks and history of heating/cooling that can be received by the ZrO 2 type ceramic coating formed on top of the SiC type coating and by the Ir type coating formed on top of the ZrO 2 type ceramic coating, a coat forming technology of the present invention producing excellent adhesion at the interface of each coating is presented. Another feature of the coat forming technology of the present invention, in order to control thermal stress and the characteristics of each coating, is the excellent control of the elements in coating whereby various constituents are continuously changed easily from the surface to the inner surface and are not uniformly distributed within the coating.
As far as the coat forming technology is concerned, a method involving irradiating energy at the same time forming coating has been considered. After experimenting with various different energy sources for the vaporization process and for consistency, ion beam was determined to be best suited for the purpose. The method involves irradiating the substrate with an ion beam and vaporizing the ZrO 2 type or Ir type materials by the electron beam vapor deposition method, which is suitable for melting high melting point heat resistant ceramics. An ion beam is a high density energy source, but this energy must be applied only on the outermost surface. Therefore, by applying both an ion beam irradiation and deposition, even if the coating is formed at a low substrate temperature, in the case the energy of ion beam is adequately greater than the energy of the chemical compound production, the coating layer that is formed becomes a chemical compound. This is because the energy imparted by the irradiation of ion beam has the same effect as the preheating of the substrate to a high temperature for the instance of deposition. Furthermore, there is a feature that the constituents of this compound can be freely selected by controlling the quantity of deposition and the quantity of energy of the ion beam irradiation. Furthermore, extremely good adhesion can be obtained because of the formation of a mixing layer (a mixed layer of the formed layer compound and the elements of the substrate) by the injection of ions at the interface of the substrate or because of the formation of a single ion injection layer (few hundred Å).
Moreover, by controlling the acceleration voltage of the dynamic ion beam mixing, it becomes possible to produce a sputtering phenomenon associated with ion irradiation. Through this, sputtering cleaning can be conducted. Therefore, after cleaning the surface of the SiC type coating, if the ZrO 2 type coating is formed on top of it, the adhesion of the ZrO 2 type coating can be improved because there are no impurity at the interface.
As stated above, in regard to the production method of the present method invention, on top of the C/C substrate having a SiC type coating of several tens of microns to several hundreds of microns thick formed by the chemical vapor reaction method and the chemical vapor deposition method, first, an ion beam irradiation and a ZrO 2 type material deposition are conducted simultaneously to form a mixing layer. Second, the energy of ion beam is made small or reduced to zero and the ZrO 2 type material is deposited to form a fine ZrO 2 type ceramic coating.
After this, ion beam irradiation and Ir type material deposition are conducted simultaneously to form the mixing layer. Following this, the energy of ion beam is made small or reduced to zero and the Ir type material is deposited to form a fine Ir type coating.
By this production method of the present method invention, a mixing layer is formed between the SiC type coating and the ZrO 2 type ceramic coating, or between the ZrO 2 type ceramic coating and the Ir type coating, and an extremely good adhesion can be obtained even when the product is heated to a high temperature range.
The heat and oxidation resistive coating layer produced by the production method of the present method invention has a high reliability in terms of materials near the origin of destruction induced by thermal stress, and hence peeling associated with destruction is made difficult. Concerning the production method of the present method invention, it is desirable to have oxygen ions for ion beam. The reason for this is that, when the coating is heated to a high temperature and melted by the electron beam in the case for the ZrO 2 type material deposition, oxygen is released to form ZrO 2-x , and hence it is desirable to have an oxygen ion beam that can resupply the oxygen under the condition of obtaining ZrO 2 in as close to stoichiometric value as possible. Furthermore, as a reason for having the ion beam, in controlling the constituent of the ZrO 2 type ceramic coating and the Ir type coating, the speed of the response of the energy associated with the irradiation of ion beam can be noted. That is, when the ion beam is turned on, the energy becomes immediately suitable for coat forming, and when the ion beam is turned off or reduced, the energy is immediately extinguished. This type of rapid response is extremely difficult to achieve by the vacuum internal heating of a large structural product.
By the structure above, an environmentally induced damage resistant coating layer having excellent heat resistivity and adhesive property on the substrate of the carbon fiber reinforced carbon can be obtained.
For a better understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments of the invention and to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a cross-sectional view of the heat and oxidation resistive high strength material of the present invention.
FIG. 2 illustrates a cross-sectional view of the heat and oxidation resistive high strength material of the present invention.
FIG. 3 illustrates a cross-sectional view of the heat and oxidation resistive high strength material of the present invention.
FIG. 4 shows a graph which indicates the constituent density of the heat and oxidation resistive high strength material of the present invention.
FIG. 5 is a schematic of a high frequency thermal plasma irradiation instrument for the oxidation experiment.
FIG. 6 indicates a cross-sectional view of the structure of a gas turbine.
FIG. 7 is an expanded view of a part of the turbine blade of FIG. 6.
FIG. 8 is an expanded view of a part of the turbine blade of FIG. 6.
FIG. 9 is an expanded view of a part of the combustor of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following describes the embodiments of the present invention in concrete terms.
EMBODIMENT 1
With a long fiber reinforced cross type carbon fiber reinforced type as a substrate, an environmentally induced damage resistant coating layer that is heat and oxidation resistant is formed as shown in FIG. 1. This environmentally induced damage resistant coating layer is made up of three coatings which are a SiC type coating 2, a ZrO 2 type coating 4, and an Ir coating 6. The dimension of the substrate 1 is 25 mm on the side and 5 mm in thickness, and the environmentally induced damage resistant coating layer is formed on the entire surface of this substrate 1.
First of all, the SiC type coating is formed after washing and drying the substrate 1. A SiC type coating 2A of 60 microns in thickness is formed by the chemical vapor reaction method with coke power at the processing temperature of 2000° C. and the surface residue is cleaned by honing. After washing and drying this substrate 1, 120 microns in average of a SiC type coating 2B is formed on top of the SiC type coating 2A by the plasma chemical vapor deposition method. The process requirements are that the processing gases, SiCl 4 , CH 4 , and H 2 , be used at the processing temperature of 1400° C., the processing pressure be 4 Torr, the applied voltage be 1200 V, and the applied current be 10 A (discharge area approximately 3600 cm 2 .
Following this, the ZrO 2 type coating 4 is formed on the surface of the substrate having the SiC type coating 2 by the ion beam mixing method comprising the ion beam source and the deposition source. The deposition source is the electron beam with the 10 kW output power. The material for the deposition source is ZrO 2 -6% Y 2 O 3 and the material for the ion beam source is oxygen ions. The coat formation involves irradiating the surface of the SiC type coating 2 with an Ar ion beam (acceleration voltage 10 kV) and sputter cleaning the surface associated with the Ar ions. The pressure in the formation chamber in this case is 2×10 -5 Torr, and the temperature is set to 75° C. Following this, the passage of the gas of the ion beam source is closed and ZrO 2 -6% Y 2 O 3 is deposited. In this state, the thickness of the coating was brought to 70 microns by controlling the coating formation monitor. At this juncture, the pressure in the formation chamber is controlled to 5×10 -5 Torr and the substrate temperature is controlled to 1000° C. By this, a fine ZrO 2 type coating without pores or holes is made.
Following this, the Ir coating 6 is formed in the same process as described above on the surface of the substrate having the ZrO 2 type coating 4 and the SiC type coating 2. The coat formation involves irradiating the surface of the ZrO 2 type coating 4 with the oxygen ion beam (acceleration voltage 10 kV) and sputter cleaning the surface associated with the oxygen ions. The pressure in the formation chamber is 2×10 -5 Torr, and the temperature is set to 75° C. After this, the irradiation of the oxygen ions is stopped and Ir is deposited. In this state, the thickness is brought to 30 microns while monitoring with the coating formation monitor. At this juncture, the pressure in the formation chamber is controlled to 2×10 -5 Torr and the substrate temperature is controlled to 1000° C. By this, a fine Ir type coating 4 without pores is achieved.
An experiment was conducted involving heat and oxidation resistivity on the experimental substrate having the environmentally induced damage resistant coating layer, as described above. The experiment was conducted in the atmospheric heat chamber and the temperature was raised to 2000° C. for 25 minutes and then cooled naturally. The result was evaluated by a weight change after the experiment. The result showed that there was no apparent peeling upon visual inspection of the substrate with the environmentally induced damage resistant coating layer. The weight change was determined to be approximately 2 mg/cm 2 , a very small amount. An experiment without the coating layer reduced the surface of the substrate to ash-like white.
The experiment indicated that the heat and oxidation resistive high strength material of the carbon fiber reinforced carbon having the environmentally induced damage resistant coating layer is extremely durable.
EMBODIMENT 2
A SiC coating 2A and a SiC coating 2B is formed by the same method with the same specifications as in the embodiment 1. A visual inspection of this surface reveals several microcracks of 5 microns at maximum. Hence, these microcracks are sealed after the SiC coating is formed. The sealing involves using TEOS and MAP; the product is submerged into these liquids, and after about 100 mg of weight increase is incorporated, it is heated at a low temperature of 400° C. in air, and following this, it is heated at a high temperature of 1000° C. From these processes, a SiC type coating 2 comprising the SiC coating 2A, the SiC coating 2B, and the microcrack seal 2C is made, as shown in FIG. 2.
Then, on top of the SiC type coating 2, a ZrO 2 type coating 4 and an Ir coating 6 are formed by the same method with the same specifications as in the embodiment 1. This test product was tested for durability, as in the embodiment 1, and the result was the same as in the embodiment 1. This experiment indicated that the heat and oxidation resistive high strength material of the carbon fiber reinforced carbon having the environmentally induced damage resistant coating layer is extremely durable.
EMBODIMENT 3
An environmentally induced damage resistant coating layer having resistance to heat and oxidation is formed as shown in FIG. 3. A SiC type coating 2 is formed by the same method with the same specifications as in the embodiment 2. After this, this test product is irradiated by an Ar ion beam (acceleration voltage 10 kV) and the surface according to the Ar ion is sputter cleaned. The pressure inside the coating chamber is 2×10 -5 Torr at this point and the substrate temperature is 75° C. After this, the source for the ion beam is changed to oxygen, an oxygen ion beam (acceleration voltage 10 kV) is irradiated on the test product while depositing ZrO 2 -6%Y 2 O 2 . At this situation, the deposition and the irradiation are conducted and by monitoring the coating thickness, the thickness is made to 70 microns. At this stage, the internal pressure of the coat forming chamber is 8×10 -5 Tort and the temperature is controlled to 1000° C. By this, a mixing layer 3 having a mixture of SiC of the SiC type coating surface and ZrO 2 -6%Y 2 O 3 of the deposition material is formed, and the thickness of this layer is measured to be 0.1 micron. On top of this layer, 70 microns of a ZrO 2 -6%Y 2 O 3 layer is formed. In this way a fine ZrO 2 type coating 4 that does not have pores is constructed.
Then, an Ir coating 6 is formed on the surface of the product that has the SiC type coating 2 and the ZrO 2 type coating 4. First of all, an oxygen ion beam (acceleration voltage 10 kV) is irradiated on the surface of the ZrO 2 type coating 4, and the surface according to the oxygen ions is sputter cleaned. At this point, the pressure inside the coating chamber is 2×10 -5 Torr and the substrate temperature is 75° C. Following this, Ir is deposited while irradiating the surface with the oxygen ions. The coating thickness is monitored to a thickness of about 0.5 micron by irradiating and depositing. After this, the gas passage for the ion beam source is shut off, and only the Ir deposition is conducted. In this situation, the thickness was increased to 30 microns by monitoring the thickness formation. At this stage, the internal pressure of the coat forming chamber is 3×10 -5 Torr and the temperature is controlled to 1000° C. By this, a mixing layer 5 of a mixture of ZrO 2 and Ir of the deposition material is formed on top of the ZrO 2 type coating surface, and the thickness of this particular layer is made to about 0.1 micron. On top of this, an Ir coating of 30 microns is formed, and a fine Ir type coating 4 without pores is achieved.
An experiment was performed on this test product to test for its durability by using the high frequency induced thermal plasma irradiation instrument shown in FIG. 5. Concerning FIG. 5, the test product 14 is fixed on a holding fixture 15, and this is placed inside a closed vessel 16 which is evacuated by a vacuum pump 17. By a high frequency electricity source 11 and a high frequency coil 10, the atmospheric gas supplied by a gas supply control system 12 is excited to generate a thermal plasma 13, and this is irradiated on the test product 14. The number 18 designates a shutter. This instrument has a high frequency electricity source of 50 kW output, and supplies oxygen to produce oxygen plasma, and inside this instrument the test product 14 is placed and is heated for 20 minutes at a temperature between 1300° C. and 2000° C. The result was evaluated by the change in weight. The result showed that there was no apparent peeling upon visual inspection of the substrate covered with the environmentally induced damage resistant coating layer even when the test product was subjected to a temperature between 1300° C. and 2000° C. On the other hand, a test product covered with a SiC coating (SiO 2 seal) of the prior art remained protected up to the temperature of 1700° C., but at 2000° C., holes started to form and there were damages to the substrate of the carbon fiber reinforced carbon. Furthermore, there were weight reductions by 3 mg/cm 2 at 1300° C. and by 15 mg/cm 2 at 2000° C.
This indicates that the heat and oxidation resistive high strength material of the carbon fiber reinforced carbon having the environmentally induced damage resistant coating layer is extremely durable at high temperatures.
EMBODIMENT 4
As shown in FIG. 4, an environmentally induced damage resistant coating layer of heat and oxidation resistivity is formed. A SiC type coating 2 is formed by the same method with the same specifications as in the embodiment 2. After this, this test product is irradiated by an Ar ion beam (acceleration voltage 10 kV) and the surface according to the Ar ion is sputter cleaned. The pressure inside the coating formation chamber is 2×10 -5 Torr at this point and the substrate temperature is 75° C. After this, the source for the ion beam is changed to methane, and a carbon ion beam (acceleration voltage 10 kV) is irradiated on the test product while depositing SiC. In this situation, the deposition and the irradiation are simultaneously conducted and by monitoring the coating thickness, the thickness is made to 5 microns. Following this, as the deposition quantity of SiC is continuously decreased, and as the deposition quantity of ZrO 2 -6%Y 2 O 3 is continuously increased, the beam scanning of electron beam is controlled to form a gradient element coating of 10 microns having the quantity of SiC and ZrO 2 -6%Y 2 O 3 continuously changing inversely over the thickness. Furthermore, only the deposition of ZrO 2 -6%Y 2 O 3 and the irradiation of the oxygen ion beam are simultaneously conducted to build up a ZrO 2 coating of 50 microns. At this stage, the internal pressure of the coat forming chamber is 8×10 -5 Torr and the temperature is controlled to 1000° C. By this, the gradient element coating, which has a continuous changing mixture of ZrO 2 -6%Y 2 O 3 of the deposition material and SiC of the SiC type coating surface, and the ZrO 2 -6%Y 2 O 3 only layer are formed. And these fine layers are devoid of holes or pores.
After this, as the deposition quantity of ZrO 2 -6%Y 2 O 3 is continuously decreased, and as the deposition quantity of Ir is continuously increased, the beam scanning of electron beam is controlled to form a gradient element coating of 10 microns having the quantity of ZrO 2 -6%Y 2 O 3 and the quantity of Ir continuously changing inversely over the thickness. Following this, only Ir is deposited to build up an Ir coating of 30 microns. At this stage, the internal pressure of the coat forming chamber is 3×10 -5 Torr and the temperature is controlled to 1000° C. By this, the gradient element coating, which has a continuous changing mixture of ZrO 2 -6%Y 2 O 3 of the deposition material and the Ir only coating are formed. And these fine layers are devoid of holes or pores.
The durability of this test product was tested in a similar manner as in the embodiment 3. In this instance, the thermal plasma 13 shut off by the shutter 18 is opened to rapidly raise the temperature of the test product 14 for imparting thermal shock to the coating layer. The surface temperature was raised to 2000° C. in 30 seconds. The result of the experiment revealed no peeling of the coating layer. And the weight change in this instance was the same as in the embodiment 3.
In this way, the heat and oxidation resistive high strength material of the carbon fiber reinforced carbon having the environmentally induced damage resistant coating layer is shown to be extremely durable at high temperatures.
EMBODIMENT 5
FIG. 6 shows an example of the land machine composite material of the present invention utilized in a rotational part and the surrounding parts of a gas turbine shown in a cross-sectional view. The numeral 21 indicates a turbine disc, 22 a turbine blade, 23 a turbine stocking, 24 a turbine spacer, 25 a distant piece, 26 a compressor disc, 27 a compressor blade, 28 a compressor stocking bolt, 29 a compressor stub shaft, 30 a turbine disc, 31 a central hole, 32 a turbine nozzle, 33 a combustor, 34 a compressor nozzle, 35 a liner, 36 a diaphragm, and 37 a shroud.
FIG. 7 shows the detail of the turbine blade 22 of FIG. 6, and in the present embodiment, this turbine blade is made of the heat and oxidation resistive high strength material of the embodiment 1 of the present invention.
Because the turbine blade is abraded by the burning gas, the surface of the blade is raised to an extremely high temperature. The turbine of the prior art is made of metallic material or metallic material coated with ceramic; and to reduce the temperature of the blade, it is cooled by compressed air.
The cooling method involves suspending the inner structure of the turbine and cooling the inner structure, and after this, directing a cooled air from the end of the blade to the burning gas, and furthermore, cooling in a film like manner the outer surface of the gas turbine that is abraded by the burning gas blowing out from the small holes on the surface of the turbine blade. Because these procedures necessitate a large amount of compressed air, they invite inefficiency of the turbine.
Moreover, because the cooling means is directed toward the burning gas, this lowers the temperature of the burning gas. In the case of the turbine blade of the present embodiment, the outer surface of the turbine blade that is subject to abrasion by the burning gas is made from the carbon fiber reinforced carbon which has high heat strength as well as excellent durability. That is, the carbon fiber reinforced carbon of the substrate of the turbine blade is a long fiber chain structure (three dimensional structure) of determined construction that is a matrix of long carbon fiber chains; and on this surface, the part indicated by the slanted line in FIG. 7, the heat and oxidation resistive coating layer of the present invention is placed. The result of burning the turbine model based on this gas turbine blade 22 for 100 hours (at the burning gas temperature of 1200° C.) showed no damages on the environmentally induced damage resistant coating layer, and hence, no damages were detected on the carbon fiber reinforced carbon of the substrate.
In this way, cooling like in a film manner of the material surface torched with the burning gas is not necessary because the gas turbine blade of the heat and oxidation resistive high strength material has excellent thermal resistivity.
Therefore, in comparison with the turbine blade of the prior art, the turbine blade of the present embodiment causes no reduction of the burning gas temperature, and because the usage of the amount of compressed air can be reduced, efficiency of the turbine is not sacrificed.
EMBODIMENT 6
FIG. 8 shows the detail of the turbine nozzle 32 of FIG. 6. In this present embodiment, this turbine nozzle is made with the heat and oxidation resistive high strength material of the present invention featured in the embodiment 2. The carbon fiber reinforced carbon that is to be the basis for the turbine nozzle is a long fiber chain structure (three dimensional structure) of determined construction that is a mesh of long carbon fiber chains, and the heat and oxidation resistive coating layer of the present invention is placed on the blade surface 38 indicated by the mesh part in FIG. 8 and the gas pass parts 39 and 40. The result of burning the turbine model based on this gas turbine nozzle for 100 hours (at the burning gas temperature of 1200° C.) showed no damages on the environmentally induced damage resistant coating layer, and hence, no damages were detected on the carbon fiber reinforced carbon of the substrate.
EMBODIMENT 7
FIG. 9 shows a cross-sectional view of a combustor part of the combustor 33 shown in FIG. 6, which is constructed with the heat and oxidation resistive high strength material of the present invention. Burning occurs inside the cylindrical structure of the combustor part. Therefore, the inside of the combustor part is subject to high temperature abrasion. The combustor part of the prior art, having metallic structure, is cooled by compressed air to reduce the high temperature. However, this invites cooling of the burning gas because this method introduces cooling means into the burning gas. However, in the case of the combustor part structure of the present embodiment, it is not necessary to employ cooling in a film like manner of the surface torched by the burning gas because the surface is coated by the heat and oxidation resistive high strength material, which has excellent thermal and oxidation resistivity. Furthermore, by blowing in compressed air into the space 42 between the structure 41 of Ni based thermal resistant alloy and the heat and oxidation resistive high strength material 43, the constructed structure can be more effectively cooled, and there is no need to mix compressed air with the burning gas.
Therefore, in comparison with the turbine blade of the prior art, the turbine blade of the present embodiment causes no substantial reduction of the burning gas temperature.
CONCLUSION
The heat and oxidation resistive high strength material of the present invention does not crack or peel even in the high temperature/oxidative atmosphere since it is made in the manner as described above. Also, in accordance with the present method invention, the production of the heat and oxidation resistive high strength material of special characteristics can be facilitated.
Furthermore, according to the heat and oxidation resistive high strength material and the light weight heat resistive material under thereof, the product coated with these materials are extremely strong against high temperatures.
Moreover, according to the light weight heat and oxidation resistive high strength product of the present invention which has an open space for cooling, since it is possible to flow in cooling means into the open space in the high temperature/oxidation atmosphere, a reduction of the temperature of the structure can be achieved and durability can be increased. | A heat and oxidation resistive high strength material utilized in structural body parts subject to bleaching in high temperature/oxidative atmosphere, the body structure of a space vehicle, a combustor, the combustor for a gas turbine, a turbine blade, and a turbine nozzle, is presented. A method for producing this heat and oxidation resistive high strength material is also explained. | 2 |
FIELD OF THE INVENTION
The invention pertains to improved methods and compositions adapted to aid in control of the dissemination of fugitive dust particles into the atmosphere.
BACKGROUND
Dust dissemination poses safety, health and environmental problems in many commercial environments. For instance, dust suppression is of particular concern in the coal mining industry wherein coal dust dissemination caused by wind or transit motion may lead to black lung disease if inhaled over lengthy periods or, in other cases, to possible spontaneous combustion of the small dust particles. Similar concerns are raised when other materials such as sulfur, phosphates, clays, or other finely divided ores and minerals generate dust in handling operations during mining, transportation, storage or use.
In addition to the mining industry, many other commercial activities also provide potential for dust control problems. For instance, fertilizer dust has raised health concerns due to human and animal inhalation thereof and it also poses the problem of spontaneous combustion. The cement industry also is concerned with fugitive dust dissemination during the manufacture, transport and storage steps.
Industrial sources of fugitive dust include open operations, leaks and spills, storage, disposal, transit or poor housekeeping of sundry finely divided solids particulates. The iron and steel industries are replete with examples of the above enumerated categories. Problems associated with disposal and storage of the source of fugitive dust may be exemplified by, for instance, operation of a steel mill open hearth precipitator of the type having an electrostatic precipitator to control dust emissions. The dust removed by the electrostatic precipitator is typically collected in hoppers and periodically dumped into essentially closed containers known as "collecting pans." Despite the fact that connecting hoses are extended between the hopper and collecting pan, considerable fugitive dust emissions occur during material transfer. If the electrostatically removed particulate matter is to be used as landfill, severe fugitive dust emissions can occur during the dumping thereof. Natural winds have been reported as creating great dust clouds at such landfill sites. The transportation of particulates along conveyor belts and the dumping of the particulates therefrom also create fugitive dust emission problems of the "transportation and disposal" source type.
SUMMARY OF THE INVENTION
The present invention provides improvement over the conventional use of sprayed or foamed oil containing dust control treatments in that a small amount of a water insoluble elastomeric polymer is included with the oil and applied to the dust. Inclusion of the elastomer significantly improves the dust control performance and provides economies in that less dust control agent can be used.
PRIOR ART
Oil and oil-based emulsions have been previously used for dust control purposes. For instance, in 1977, Frick suggested that petroleum based products be used to control fugitive dust emanating from agricultural fertilizer granules, See "Petroleum Based DCA's to Control Fugitive Dust", Frick, Proceedings of the Annual Meeting of the Fertilizer Industry, Round Table, Series 27, pages 94-96. Similarly, U.S. Pat. No. 4,417,992 (Bhattacharyya) discloses, inter alia, use of oil containing emulsions comprising light paraffinic solvents, water, and sundry cross-linked polymers for dust control.
Oil additives have been used to control grain dust as per an article appearing in Agricultural Engineering, September 1985, pages 9-12. Kittle Patent, U.S. Pat. No. 4,561,905, reports the use of foamed oil/water emulsions to control coal dust dissemination. In U.S. Pat. No. 4,571,116 (Patil et al.), aqueous emulsions comprising asphalt, petroleum extender oils, protective colloids, and surfactants are sprayed onto dusty substrates such as on dirt or gravel roads.
The use of water insoluble elastomeric substances including natural rubbers and synthetic polymers to prevent erosion of finely divided ores, coal, etc. is taught by Booth et al. in U.S. Pat. No. 2,854,347. U.S. Pat. No. 4,551,261 (Salihar) teaches that the Booth et al. elastomeric substances can be incorporated into an aqueous foam comprising water and foaming agents (surfactants) and used to suppress dust generation.
DETAILED DESCRIPTION
The present invention provides improvement over the known use of oil containing treatments for dust control purposes. It has been discovered that the addition of a small amount of a water insoluble elastomeric polymer to an oil-based treatment results in improved dust control efficacy compared to oil alone. This is believed to be due to the fact that the elastomeric polymer imparts a tackiness to the oil, thereby enhancing the adhesional properties desired for effective dust control. While tacky-type oils have been formulated for "no-drip" and "anti-spatter" lubricant applications, the use of oils containing a tackiness agent for dust control purposes is believed to be novel and an improvement in the prior art.
As to the tackiness imparting water insoluble elastomers that can be used, these are described in aforementioned U.S. Pat. Nos. 4,551,261 (Salihar) and Booth et al., 2,854,347. These generally may be described as being synthetic rubber-like polymers which encompass copolymers of butadiene with a monoolefinic monomer such as styrene, methylstyrene, dimethylstyrene and acrylonitrile. Copolymers of methyl, ethyl and butyl acrylates with acrylonitrile or with styrene may also be mentioned. Plasticized polyvinyl acetate, plasticized polyvinyl chloride, plasticized polystyrene, plasticized substituted polystyrenes, and plasticized polyolefins such as polyethylenes and polyisobutylenes are suitable. At present, it is preferred to utilize a polyisobutylene elastomer having a molecular weight within the range of about 500,000 to about 2 million, with a particular polyisobutylene of around 1 million molecular weight being especially preferred. It is essential that the elastomer be water insoluble so that it is carried by the oil phase of the sprayed or foamed treatment. In this manner, it is though that the elastomer serves to increase the tackiness of the oil, thereby extending or enhancing the oil's dust control efficacy. As used broadly herein, the term oil includes mineral (petroleum or petroleum derived), vegetable and animal oils.
The oil and the elastomer may be applied to the dusty material separately or concurrently. Concurrent addition is preferred. The oil/elastomer combination is preferably provided in the form of an O/W or W/O emulsion, but it is to be noted that a neat oil/elastomer mixture or solution may also be used.
Any oil material capable of being sprayed or applied via foam may be used. Especially pereferred are oils that are capable of being emulsified in an O/W or W/O emulsion. For example, asphalts, extender oils of the types noted in U.S. Pat. No. 4,571,116, heavy process oils, and light process oils may be mentioned. The heavy process oils are of the type specified by Kittle, U.S. Pat. No. 4,561,905. That is, they include asphalt "cut-backs", i.e., asphalt dissolved in a moderately heavy oil such as No. 3 fuel oil, residual fuel oils of relatively high viscosity such as No. 6 fuel oil, etc. The heavy process oils may be further defined as having viscosities in the range of about 600-7,000 SUS. One exemplary heavy process oil is "Hydrolene 90" sold by Sun Oil Company. This particular product is a low volatile aromatic oil having an SUS viscosity of about 3500 at 38° C.
Preferred oils are classified as "light viscosity process oils." These have SUS viscosities of about 60-600 measured at 38° C. Highly preferred are those having an SUS viscosity of from about 200-400. The latter are commercially available under the "Shellflex", "Tellura" and "Tufflo" trademarks.
Surfactants are used to emulsify the oil/water mixture. For this purpose, well-known and commercially available anionic and/or nonionic surfactants suffice. For instance, acceptable anionic surfactants include alkyl aryl sulfonic acids, alkyl sulfonic acids, alkenyl sulfonic acids, sulfonated alkyls, sulfonated alkenyls, sulfated monoglycerides and sulfated fatty esters. Also, long chain alpha olefin sulfonates, water soluble salts of alkenyl sulfonic acid, water soluble alkyl aryl sulfonic acid salts, water soluble salts of sodium lauryl sulfate, etc. may be mentioned.
Nonionic surfactants which may be used include ethylene oxide condensates of alkylphenols, ethylene oxide condensates of straight chain alcohols, fatty acid amides, etc.
The oil/water insoluble elastomer may be applied to the dust in neat or emulsified form. The treatment may be sprayed onto the dust or applied in the form of a foam. Based upon preliminary studies, it is preferred to apply an emulsion comprising oil/elastomer/water in the foam form.
When the emulsion is to be sprayed, acceptable oil containing solutions may be provided in one drum. Exemplary compositions are:
______________________________________ 1-25 wt % Anionic and/or nonionic surfactants.01-0.3 wt % Water insoluble elastomeric polymer (Note that commercially available prod- ucts comprise water insoluble elasto- meric polymers in solution with an oil solvent)Remainder Oil______________________________________
The oil solution is mixed with water at the job site to form an emulsion and is then sprayed onto the desired dust. Generally, enough water and oil solution is mixed and sprayed so that from about 0.01 gallon of the oil/elastomer mixture to about 5.0 gallons per ton of treated dust is supplied. The specific amount of oil/elastomer mixture to be applied depends, of course, upon dust type, wind and weather factors, spray location, etc.
At present, a preferred oil solution adapted for application via spray technique is
______________________________________5.0 wt % Isopropylamine dodecylbenzene sulfonate4.0 wt % Oleic acid.06 wt % Polyisobutylene, Mw 1 × 10.sup.6Remainder Light process oil, 275 SUS @ 100° F.______________________________________
It is preferred to form an oil/water insoluble elastomer/water emulsion and then apply it to the dust in form of a foam. For this type of application, the oil-elastomer combination can be provided as a solution. The oil/elastomer solution is mixed with a water/surfactant solution upstream from or at a foaming nozzle wherein additional water and air will be provided to result in an acceptable foamed emulsion.
______________________________________Exemplary Compositions for FoamingOil Solution (OS) Surfactant Solution (SS)______________________________________.01-0.3 wt % 10-50% anionic and/orwater insoluble elastomer nonionic surfactantRemainder oil Remainder waterlight process oil275 SUS @ 100° F.______________________________________
______________________________________Preferred Compositions for FoamingOil Solution (OS) Surfactant Solution (SS)______________________________________.06 wt % water insoluble 6 wt % sodium alphaelastomer olefin sulfonateRemainder 5.5% sodium alkyl etherlight process oil sulfate275 SUS @ 100° F. Remainder water______________________________________
The oil solution (OS), surfactant solution (SS) and additional water are mixed at a foaming nozzle or upstream from one within the following component mixing ranges (all percentages adding up to 100 wt%):
______________________________________OS SS Makeup Water______________________________________1-20 0.5-5.0 75-98.5______________________________________
Air is preferred for use as the foam forming gas. Details of the foam forming process are not critical to the invention. Generally, foam may be produced as stated in U.S. Pat. No. 4,400,200 (Cole). Typically, the OS, SS, and makeup water will be mixed with air at a ratio of about 1 gallon liquid (OS, SS and makeup water) to 1.0 to 10.0 scf air. The air and liquid may combine at a point immediately upstream from the mixing chamber. The mixing chamber may be a packed column, venturi, or static mixer. The purpose of the mixing chamber is to induce the air in liquid dispersion defined as foam. It is important that from about 0.01 gallon to 5.0 gallons of the OS product be applied via the foam carrier per ton of treated dust. Acceptable foam properties include expansion ratios (volume foam:volume of OS, SS, and makeup water) of about 10-100. Desirable foam bubble diameters are on the order of about 0.005 to 0.015 inch.
DRAWINGS
FIG. 1 is a graphical depiction of the data gathered in the "comparative testing" portion of the ensuing examples.
EXAMPLES
The following examples are illustrative of the invention:
In order to demonstrate the efficacy of the elastomeric dust control enhancers of the present invention, a series of laboratory tests were undertaken. A lab scale dust chamber was created. The particulate, dusty material treated was 1/4 in XO, hot (275° F.) calcined coke dust. Oil, as the dust control additive, was tested by itself and in combination with varying amounts of a polyisobutylene extender. All of the treatments were applied as O/W emulsions in spray form (10% oil or oil plus extender, 0.5% nonionic surfactant-alkyl phenol ethoxylate, 0.5% polyethylene glycol, remainder water). The emulsions were sprayed onto the dust via a hand held trigger-type sprayer. Treatment rates were 0.5 gallon oil or oil plus extender per ton of coke dust.
Relative dustiness testing was performed after the samples had been treated and stored for 24 hours at 225° F., and again after 24 hours' storage at 70° F. Percent dust suppression was calculated based on the relative dustiness index (R.D.I.) of treated and untreated samples. ##EQU1##
Results are reported in Tables I and II.
TABLE I______________________________________ RelativeTreatment % Dustiness % DustElastomer Index (RDI) SuppressionOil A A (actives) 70° F. 225° F. 70° F. 225° F.______________________________________-- -- (control) 16.4 20.5 -- --100 0 8.1 10.7 51 4899.94% 0.06% 4.6 7.6 72 6399.88% 0.12% 6.5 10.7 60 4899.79% 0.21% 4.3 7.6 74 6399.70 0.30% 5.0 8.9 70 57______________________________________
TABLE II______________________________________ RelativeTreatment % Dustiness % DustElastomer Index (RDI) SuppressionOil A A (actives) 70° F. 225° F. 70° F. 225° F.______________________________________-- -- (control) 18.4 24.1 -- --100% 0 7.7 11.0 58.2 54.499.7% 0.03% 7.7 10.6 58.2 56.099.94% 0.06% 5.5 8.4 70.1 65.199.88% 0.12% 5.6 7.9 69.6 67.2______________________________________ Oil A = Naphthenic process oil, 275 SUS @ 100° F. Elastomer A = polyisobutylene, Mw ≈ 1,000,000.
As Tables I and II indicate, the addition of as little as 0.03% polyisobutylene elastomer to the oil significantly enhances the dust control efficacy compared to oil alone. The 0.12% polyisobutylene data of Table I are apparently in error due to the substantial improvement shown by the Table II data at the same elastomer addition level.
It is noted that, although the oil/elastomer blends were applied as sprayed emulsions for the Table I and II examples, it is thought that the optimum method for applying the oil/elastomer dust control treatments will be as foamed, O/W emulsions containing the elastomeric extender.
COMPARATIVE TESTING
Comparative tests were performed on coal dust samples. A graphical depiction of the test results may be seen in FIG. 1. The x-axis of the graph is given in terms of feedrate % equals % product fed based on the weight of coal tested.
Comparative Product A=lignosulfonate based product
Comparative Product B=an acrylic latex based product
Comparative Product C=a cationic polymer solution
The present invention, Composition "A", is:
______________________________________0.06% polyisobutylene, Mw ≈ 1,000,000Remainder mostly light naphthenic process oil having 275 SUS @ 100° F.______________________________________
FIG. 1 shows the significantly enhanced dust control results of Composition "A" in comparison to use of commercially available dust control treatments.
The oil/elastomer dust control treatment may be applied to any dust particles which present a problem of undesired air-borne dissemination. For example, coal dust, green or calcined petroleum coke dust, steel mill sinter dust, metallurgical coke dust, fertilizer dusts including raw materials process and product dusts, cement raw materials and clinker, and basic oxygen furnace dust may be mentioned.
While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention. | Minor amounts of water insoluble elastomeric polymers are combined with oil. The combination is sprayed or applied in a foam carrier to dust particles to inhibit dissemination thereof which would otherwise occur by windage or transit motion and the like. | 2 |
This application is a continuation of application Ser. No. 328,387 filed Mar. 24, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for producing bean curd of the type termed "momen tofu" which is bean curd conventionally prepared with use of "momen" or cotton cloth.
Conventionally, bean curd of the type mentioned is prepared by adding a coagulant to soybean milk at about 80° C. with stirring to coagulate the milk and by dewatering the coagulated milk for forming. The coagulant used is bittern, calcium sulfate, glucono delta lactone or the like.
The coagulated soybean milk is dewatered and formed by wrapping the coagulated milk with cotton cloth laid inside a mold box, placing a closure over the coagulated milk as wrapped with the cotton cloth and applying pressure to the closure with a heavy stone placed thereon.
The single mass of bean curd thus obtained corresponds to tens of unit blocks and is cut into blocks of unit size.
When bittern is used as the coagulant in the above process, there arises the problem that bean curd having good water retentivity can not be obtained since soybean milk rapidly coagulates at a high temperature. The problem as to water retentivity can be overcome if calcium sulfate or glucono delta lactone is used as the coagulant, whereas another problem is then encountered in that the bean curd prepared tastes somewhat sour, hence has an impaired flavor.
Furthermore, the conventional process essentially requires the use of cotton cloth, which involves the following problems. First, the cotton cloth is not sanitary. Second, it is difficult to automatically lay the cotton cloth inside the mold box and remove the cloth from the bean curd formed.
SUMMARY OF THE INVENTION
The main object of the present invention is to provide a process and apparatus for producing bean curd of the type stated free of the foregoing problems.
The process of the invention for producing bean curd comprises the steps of cooling soybean milk and bittern individually to below the coagulating temperature of the milk, mixing the cooled soybean milk and bittern together and filling the mixture into buckets, coagulating the mixture in the buckets by heating, and withdrawing the coagulated soybean milk from the buckets and dewatering the coagulated milk to obtain formed bean curd.
Preferably, the mixture is filled into each of the buckets in an amount required for preparing a block of bean curd. Subsequently, the blocks of soybean milk coagulated in the respective buckets are individually dewatered and thereby formed.
The coagulated soybean milk is dewatered and formed with use of a mold box and a pressing closure, each of which has in a required portion a multiplicity of holes not passing the coagulated milk therethrough but permitting the water contained in the coagulated milk to pass therethrough. For this step, the coagulated milk withdrawn from the bucket is placed into the mold box, the mold box is closed with the pressing closure, and pressure is applied to the closure for a required period of time.
The present invention further provides an apparatus for producing bean curd which comprises a mold box, and a pressing closure upwardly and downwardly movable into and out of the mold box, each of the mold box and the pressing closure having in a required portion a multiplicity of holes not passing therethrough the coagulated soybean milk placed in the mold box but permitting the water contained in the milk to pass therethrough.
With the above process, soybean milk and bittern are cooled to below the coagulating temperature, then mixed together and thereafter heated, so that the milk coagulates at a relatively moderate velocity. Accordingly, the process affords bean curd having good water retentivity despite the use of bittern.
The milk is coagulated and dewatered for forming in amounts each required for preparing one block of bean curd. This eliminates the need to cut the resulting bean curd into blocks. The cutting step can therefore be omitted from the bean curd production process, which in turn is simplified.
Because the water contained in the coagulated soybean milk is removed through the holes in the mold box and the pressing closure, there is no need to use cotton cloth, consequently obviating the sanitation problem due to the use of cotton cloth and the problem encountered in practicing the process automatically.
Bean curd can be prepared by the apparatus of the invention without using cotton cloth.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the overall construction of an apparatus embodying the invention; and
FIG. 2 is a perspective view of a mold box and a pressing closure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the invention will be described below with reference to the drawings.
FIG. 1 shows an apparatus for producing bean curd which comprises a filling device 52 having a downwardly directed delivery opening 51, an intermittently driven bucket conveyor 62 having buckets 61 so arranged as to stop one after another at a position immediately below the delivery opening 51, a steam chamber 71 enclosing the delivery opening 51 of the filling device 52 and the entire bucket conveyor 62, a forming conveyor 81 disposed outside the steam chamber 71, and an aseptic chamber 90 enclosing the entire forming conveyor 81.
The filling device 52 has a vertical nozzle 53 positioned close to the rear end of the top wall 72 of the steam chamber 71, extending through the top wall 72 and having the delivery opening 51 at its lower end. The mixture of soybean milk and bittern to be described in detail later is fed to the filling device 52 through a supply pipe 54.
The bucket conveyor 62 comprises a pair of front and rear vertical sprockets 63, 64, and an endless chain 65 reeved around the sprockets and having attached thereto the buckets 61 as arranged at a specified spacing. Each bucket 61 is pivotally movable about a horizontal line intersecting the chain 65 at right angles therewith.
The steam chamber 71 is in the form of a rectangular parallelepipidal box elongated longitudinally of the apparatus. The interior of the chamber 71 is maintained at a high temperature of about 98° C. A breaker 91 provided near the front end of the steam chamber top wall 72 is positioned immediately above the upper path of travel of the buckets. The breaker 91 has a breaking member 92 in the form of a lattice and vertically movable. The steam chamber 71 has a bottom wall 73 which is formed in a portion close to its front end with a communication opening 74 positioned immediately below the lower path of travel of the buckets 61. A slanting chute 75 has its upper end connected to the wall edge defining the opening 74.
The forming conveyor 81 comprises a pair of vertical front and rear sprockets 82, 83, an endless chain 84 reeved around the sprockets, and a multiplicity of mold boxes 11 equidistantly spaced apart and attached to the chain 84.
The rear sprocket 83 is disposed below the lower end of the chute 75. The front sprocket 82 is positioned to the front of the sprocket 83. The two sprockets 82, 83 are intermittently driven as timed with the bucket conveyor 62 such that the mold boxes 11 stop one after another at the position immediately below the lower end of the chute 75.
Each of the mold boxes 11 is provided with a pressing closure 12 supported by unillustrated means through a spring 85, etc. and movable with the mold box 11. The closure 12 is movable into and out of the mold box 11 and rotatable about a horizontal axis perpendicular to the direction in which the closure 12 moves with the box 11.
The aseptic chamber 90 in the form of a box like the steam chamber 71 communicates with the steam chamber 71 through the communication opening 74 and has a bottom wall formed with an outlet 90a. The outlet 90a is covered with the wall of an outside air blocking chamber 100.
Next, the mold box 11 and the pressing closure 12 will be described in detail with reference to FIG. 2.
The mold box 11 is in the form of a vertically elongated rectangular parallelepipedal box having an opening at its upper end and comprises a side wall 21 and a bottom wall 22. Each of the side wall 21 and the bottom wall 22 is made of stainless steel and has a thickness of 0.6 mm. The upper end of the side wall 21 defining the opening is provided with an upwardly flared portion 23. Approximately the lower half of the side wall 21 except for its corner portions has holes 24, 0.8 mm in diameter, at a pitch of 4 mm. The bottom wall 22 except for its peripheral portion is formed with holes 25, 0.8 mm in diameter, at a pitch of 2.5 mm.
The pressing closure 12 is in the form of a flat rectangular plate positionable inside the side wall 21 with a small clearance formed therebetween, made of stainless steel and having a thickness of 0.5 mm. The closure 12 is provided at its four side midportions with large and small recinforcing ribs 31, 32 which extend upward. The closure is formed generally over the entire area thereof with holes 33 of 0.8 mm in diameter as arranged at a pitch of 1.2 mm.
The pressing closure 12 has secured to its upper side a saddle-shaped holder 41 extending upward from its four corners. A vertical shank 42 is fixed to the top of the holder 41 and inserted in a socket of unillustrated lifting means.
The holes 24, 25, 33, if up to 0.5 mm in diameter, make the box and the closure difficult to clean and are liable to clog up, whereas if the diameter is not smaller than 1.0 mm, coagulated soybean milk will leak through the holes. To be suitable, the diameter is 0.6 to 0.9 mm.
The pitch of the holes 24 in the side wall 21 of the mold box 11 is larger than the pitch of the holes 25 in the bottom wall 22 of the box 11. If the former pitch is approximately equal to the latter pitch, the side portion of the formed block of bean curd becomes rough-surfaced because when the coagulated soybean milk in the mold mox 11 is gradually diminished in volume, the portion of the milk forming the side surface of the bean curd is rubbed by the inner surface of the side wall 21 and defaced by the irregularities in the wall inner suface to due the presence of holes.
Aseptic bean curd is produced by the following process. A mixture of soybean milk and bittern is fed to the filling device 52. The bittern is magnesium chloride having a purity of at least 99.5%. The mixture is prepared by sterilizing soybean milk and bittern by heating, cooling the milk by a heat exchanger to such a temperature that becomes about 15° C. when the milk is to be filled into the bucket, cooling the bittern to about 20° C. by like means and thereafter mixing the milk and bittern together by an unillustrated mixer.
The delivery opening 51 of the filling device 52 is provided with a damper (not shown) for closing the opening. The mixture is filling into each bucket 61 in an amount corresponding to one block of bean curd by opening the damper. For example, when one block of bean curd to be formed has a volume of 400 c.c., it is suitable that the amount of the mixture be about 750 c.c.
While the bucket 61 filled with the mixture travels to above the communication opening 74 in the chamber 71, the mixture coagulates. This requires about 30 minutes.
About 2 minutes before the bucket 61 reaches the position above the opening 74, the bucket 61 comes to a position immediately below the breaker 91, which operates to break the soybean milk immediately before coagulation to lumps about 20 mm cube in size.
When the bucket 61 is brought to the position above the communication opening 74, the bucket 61 which has been in an erect position is turned upside down by unillustrated means, whereby the milk coagulated in the bucket 61 is discharged from the chamber 71 through the chute 75.
The coagulated milk falling through the chute 75 is received by the mold box waiting below the chute, whereupon the pressing closure 12 advances into the mold box 11. Pressure is applied to the pressing closure 12 while the closure 12 travels with the mold mox 11, whereby the coagulated milk is dewatered and formed to obtain bean curd. The pressure to be applied to the closure 12 in this step is progressively increased stepwise with time.
When the mold box 11 advances into the lower path of its travel, the mold box 11 is turned upside down. By the time the box 11 in this position reaches the midportion of the path, the bean curd is completely dewatered and formed. The pressing closure 12 then descends to retract from inside the mold box 11, and the bean curd as placed on the closure 12 is withdrawn from the mold box 11. The closure 12 in this state continues to descend, whereby the bean curd is discharged from the aseptic chamber 90 through the outlet 90a and the air blocking chamber 100. By unillustrated means, the pressing closure 12 is returned to the initial position where it advanced into the mold box 11.
A container C in an inverted state is placed over the withdrawn bean curd by an unillustrated capping device. The container C with the bean curd placed therein is then brought to an erect position by turning the closure 12 through 180 degrees and is delivered onto a discharge conveyor 86.
An unillustrated lid is placed over the bean curd containing container C, which is thereafter cooled to about 100° C., whereby a finished product is obtained. | A process for producing bean curd comprising the steps of cooling soybean milk and bittern individually to below the coagulating temperature of the milk, mixing the cooled milk and bittern together and filling the mixture into buckets, coagulating the mixture in the buckets by heating, and withdrawing the coagulated milk from the buckets and detwatering the coagulated milk to obtain formed bean curd. An apparatus for practicing the process comprises a mold box and a pressing closure each having in a required portion a multiplicity of holes not passing the coagulated milk therethrough but permitting the water contained in the coagulated milk to pass therethrough. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to an arrangement for producing selvage in woven fabrics. The arrangement is advantageously arranged in front of the weave shaft.
The selvage threads are, because of their irregular interweaving paths, advantageously taken of separate spools and are operatively moved by the arrangement, whereas the warp threads are moved by the regular weaving shafts and are in most cases guided by the healds suspended from the frames, which serve for producing the woven material.
There are already known arrangements (German Pat. No. 1,814,269) in which pairs of rigidly connected needles are arranged one above the other. It is possible to produce with such an arrangement oppositely running setting twist selvages. However, due to the rigid connection between the needles of each pair of needles, the adjustability and variability of such an arrangement is very limited.
There is, furthermore, known an arrangement disclosed in German Pat. No. 1,246,619 wherein needles which are adjustably arranged in pairs can produce twist selvages. Here too, the arrangement of pairs of levers provide only a very limited range for setting of the selvage threads for the woven material.
SUMMARY OF THE INVENTION
It is an object of this invention to obtain, by means of selvage threads and regular warp threads a selvage weave pattern.
The arrangement of this invention includes a frame on which a plurality of needles are mutually independently mounted. Each needle guides a selvage thread and can be independently positively controlled.
Such an arrangement makes it possible that the movement of the individual selvage threads is adjusted separately and is adapted to the movement of one or more warp threads in order to provide one or more corresponding selvage patterns.
Such an arrangement makes it possible to control the movement of the individual selvage threads separately and to adapt this movement to one or more warp threads to obtain one or more selvage patterns in accordance with the adjustment of the needles guiding the selvage thread.
BRIEF DESCRIPTION OF THE DRAWING
The invention is further set forth in the following detailed decription taken in conjunction with the appended drawing, in which:
FIG. 1 illustrates two arrangements in accordance with this invention mounted on one weaving shaft frame;
FIG. 2 illustrates a front view of the arrangement of the invention;
FIG. 3 illustrates a side view of the arrangement of the invention partially in section along line II--II in FIG. 2;
FIG. 4 is a cross-sectional view through a needle along line III--III of FIG. 3;
FIG. 5 is a schematic side view of the arrangement of the invention in its lower operative position illustrating also the coacting healds with eyes;
FIG. 6 is a schematic side view corresponding to FIG. 5, wherein the arrangement of the invention is shown in its upper operative position;
FIG. 7 is a schematic view of a woven fabric having a selvage pattern which has been provided by means of the arrangement of this invention;
FIG. 8 is a schematic view of a woven material having two selvage patterns produced with an arrangement of this invention;
FIG. 9 is a schematic view of an alternate version of a woven material having alternate versions of selvage patterns produced with an arrangement of this invention;
FIG. 10 is a schematic view of a woven material having four selvage patterns produced with an arrangement of this invention; and
FIG. 11 is a side view of an alternate embodiment of the arrangement of this invention, said view corresponding otherwise to FIG. 2.
DETAILED DESCRIPTION
The arrangements 1, in accordance with this invention, can advantageously be arranged on the forward weaving shaft frame 2. As can be noted from FIG. 1 there are mounted the required number of arrangements 1 (illustratively 2 in FIG. 1) on the weaving shaft frame 2. These arrangements 1 can be laterally adjusted on the weaving shaft frame 2 by means not illustrated in detail.
As can be noted from FIG. 2 there are secured onto the frame 1 bolts 3', 3". Levers 4', 4", 4'" and 4"" are respectively pivotally mounted on the aforementioned bolts 3' and 3". The levers 4', 4", 4'" and 4"" have respectively mounted thereon the needles 5', 5", 5'" and 5"" for guiding the selvage thread. The ends of the aforementioned needles are bent as is illustrated in FIG. 4 and have eyes 6 on their bend ends. Selvage threads 7', 7", 7'" and 7"" are guided through the needle eyes 6. These threads are shown by dashed lines FIGS. 2, 3, 5 and 6 of the drawing. The selvage threads run from the needle eyes 6 into the woven material 8 as can be noted from FIGS. 5 and 6. These selvage threads are guided respectively through eyelets 8',8", arranged on the frame 1 (see FIG. 2) and are fed from non-illustrated spools of selvage thead into the frame 1.
The movement of the needles 5' - 5"", and thereby the movement of the selvage threads 7' - 7"", is controlled via rods 9', 9", 9'" and 9"" and the aforementioned levers 4' - 4"". The rods 9' - 9"" are respectively controlled by electromagnets 10', 10", 10'" and 10"" mounted on opposite sides of the frame 1 as shown in FIG. 2. These electromagnets 10' - 10"" are controlled, according to need, either by the weaving shaft movement itself, or by the operating mechanism for the weaving shafts, or by separately driven means.
The needle 5' is, as is conventional, somewhat longer than the needle 5" in order to permit an outward swinging of the selvage threads 7',7" without mutual interference. The selvage needels 5'" and 5"" are of different lengths for equivalent reasons.
The warp threads which are required for the production of the selvage, for example the warp threads 11', 11", 11"" (see FIGS. 5 and 6) can be obtained from the healds 12', 12" mounted on their respective weaving shafts in the border region thereof. These warp threads are guided through the frame 1 in the region of the needles 5', 5", 5'" and 5"" and define a field 13.
There is schematically illustrated in FIG. 7 a selvage weave which has been produced by an arrangement in accordance with this invention. This weave includes four selvage threads 7', 7", 7'", and 7"" and three warp threads 11', 11" and 11'". The last-mentioned warp threads are woven in a linen weave pattern and are interwoven with the illustrated selvage threads. Two selvage threads (7'", 7"") always alternate their position when the weave frame 1 is in its lower operative position (see FIG. 5) by virtue of a corresponding motion of their guiding needles 5'", 5"". These selvage threads 7'" and 7"" are respectively controlled via their needles and levers by means of the electromagnets 10'" and 10"". The two other selvage theads 7' and 7" change their position via their guiding needles when the frame 1 is in its upper operative position (see FIG. 6). The needles 5', 5" and the appurtenant electromagnets 10', 10" operate in such a case simultaneously. It is also possible to use only one electromagnet for two needles, that is when both rods 9' and 9" are constructed as one unit. Similarly, the rods 9'" and 9"" can be constructed as one unit in the lower portion of frame 1.
The illustrated example of a selvage for a woven fabric, in accordance with FIG. 7, includes seven weft threads. It is possible to make a more simple selvage weave by omitting two warp threads 11", 11'" and/or the selvage threads 7" and/or 7'" and/or 7"". Thus, it is possible to interweave a large number of combinations of selvage and warp threads without radically changing the frame 1 and its operative motion.
Thus, with the same basic operative motion of the selvage threads 7', 7", 7'" and 7"" as is shown in FIG. 7 in which one selvage cord is formed, there can be produced two selvage cords 13', 13" as is illustrated in FIG. 8. In such a weave there are present, in lieu of the three linen-weave pattern warp threads 11', 11", 11'", two warp threads 14', 14", of which one warp threads 14' is held continuously in the upper operative position and the other warp thread 14" is held continuously in the lower operative position of the weaving mechanism. The selvage thread 7" in such a case is originally positioned by means of the needle 5" in a path as illustrated in dashed lines (see FIG. 8), but slides due to its tension over the deeply bound warp thread 14" and those selvage threads 7" and 7'" which also are positioned in their lower bound positions until it reaches the position 7" illustrated in full lines in FIG. 8.
The selvage thread 7"" moves in the same sense. This thread is originally positioned by means of the needle 5"" onto the position 7"" (illustrated in dash lines in FIG. 8) and slides under the high-bound warp thread 14' and those selvage threads 7' and 7" which are just positioned in the upper bound position, into the position shown in full lines for the selvage thread 7"". These two selvage cords can be used for serving as borders for cutting the woven material along the lines 15', 15".
Frequently it is desirable to provide a selvage in a woven material that is not too thick by producing a selvage cord as is illustrated in FIG. 9. Such a selvage cord has less threads than the selvage cords of FIG. 8. Such a selvage cord can be obtained, without changing the motion of the weaving shafts and the other elements of the arrangement, by omitting one selvage thread 7" respectively 7"".
If, for example, four or more selvage cords are desired in lieu of the aforementioned two selvage cords, a weave such as is illustrated in FIG. 10 can be produced with the arrangement of this invention wherein the cutting line 15a, 15b can be used for cutting the woven material. In order to produce a selvage cord pattern as is illustrated in FIG. 10, there are, of course, required two or more frames 1 which are mounted side by side on the weave shaft frame 2. Such an arrangement has, however, the drawback that it requires a lot of space.
It is also possible, according to the basic concept of the invention, to arm each lever 4' . . . , with more than one needle (in lieu of just one needle 5'0 . . . as is illustrated in FIG. 2). For example, it is possible to have modified types of levers 4a, 4b from each of which there extend a pair of needles 5a, 5b (see FIG. 11). In this embodiment there is also illustrated, as has been mentioned hereinabove, that in order to obtain a simultaneous motion of, for example, the levers 4a, 4b, the appurtenant rods 9a, 9b can be constructed so as to form one unit and the motion of this unit can be controlled by a common electromagnet 10a.
There is mouted on the lower portion of frame 1a the unit consisting of rods 9c, 9d which is controlled by a rod 9e which extends from the upper portion of frame 1a and the motion of which is controlled by an electromagnet 10b mounted on the upper portion of the weave shaft. This makes for a more simple construction and eliminates the necessity of having electromagnets mounted on the lower portion of the weave shaft frame as is necessary with the embodiment of FIG. 2.
Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims. | In a weaving machine an arrangement for producing selvages in woven fabrics. The arrangement includes a frame which is mounted between the healds and the woven fabric. A plurality of guide needles are pivotally mounted in the frame and are controlled by electromagnets mounted on the frame. The guide needles have eyes through which selvage threads fed from spools are passed. Each guide needle is adapted to independently guide a selvage thread during the weaving process. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application of International Application No. PCT/DE2004/001972 filed Sep. 1, 2004, which designates the United States of America, and claims priority to German application number DE 10345020.3 filed Sep. 23, 2003, the contents of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention relates to an apparatus for adjustment of the impedance of a high-voltage line which carries an alternating current and comprises a plurality of phases, having at least one control coil which can be inserted into the high-voltage line connected in series, and having at least one switching device which is in each case associated with one of the control coils, with a control unit being provided in order to control each switching device in such a manner that the effective reactance of the control coil in the apparatus can be adjusted by the switching of the switching device.
[0003] The invention also relates to a method and a control unit for adjustment of the impedance of a high-voltage line which carries alternating current.
BACKGROUND
[0004] An apparatus such as this, a method such as this and a control unit such as this are known, for example, from DE 37 87 355 T2. The apparatus disclosed there is also illustrated in FIG. 1 of the attached drawing. The already known apparatus 1 has a control coil 2 and an uncontrolled coil 6 which can be inserted in series into a high-voltage line, which carries alternating current, by means of expedient connections or switches which are not shown in FIG. 1 . In order to control the effective impedance of the control coil 2 in the apparatus 8 , a switching device 3 is provided, and is formed by two thyristors which are connected in opposite senses. The thyristors are connected to a control unit 4 , whose control signals allow the current flow through the thyristors to be interrupted or permitted. The effective impedance of the control coil 2 in the apparatus, and thus the impedance of the entire apparatus, can be adjusted by expedient choice of the triggering time of the thyristors as a function of the phase of an alternating current in the high-voltage line. This response time of the thyristors, which is dependent on the phase of the alternating current, is referred to in the following text as the trigger angle. The use of the thyristors in the control path 5 for solid-state interruption of the alternating current also results in higher-order harmonic of the fundamental frequency of the alternating current, that is to say integer multiples of the fundamental frequency of the alternating current. For this reason, a filter unit 7 is provided in parallel with the control path 5 and is designed to suppress one or more of these harmonic oscillation components. Furthermore, the filter unit and the filter coil 6 are used to maintain the current path through the apparatus when the switching device 3 is in a position in which the current flow is interrupted. However, the already known apparatus occupies a large amount of space and is costly because of these additional components. Furthermore, the control capabilities of the already known apparatus are restricted, since its impedance cannot be reduced to zero, but only to the impedance of the parallel-connected coils 2 and 6 .
SUMMARY
[0005] One object of the present invention is thus to provide an apparatus of the type mentioned initially which is compact and cost-effective, as well as a method as mentioned initially, and a control unit, by means of which the impedance of a high-voltage line can be controlled in a simple manner.
[0006] With regard to the apparatus, this object can be achieved by arranging each switching device in a parallel path in parallel with the control coil associated with it.
[0007] Furthermore, this object can also be achieved by a method in which the control coil is bridged as a function of the phase of the alternating current by triggering a switching device which is arranged in a parallel path in parallel with a control coil which can be inserted in series into the high-voltage line, with the impedance of the high-voltage line being adjusted in this way.
[0008] Furthermore, this object can also be achieved by a control unit for adjustment of the impedance of a high-voltage line which carries alternating current, having a phase sensor for production of a zero-crossing signal on verification of a zero crossing of the alternating current, and having at least one trigger unit, which is connected to a phase measurement device and to a trigger angle transmitter for production of a trigger angle for the trigger unit, and which produces a trigger signal after a delay time corresponding to the trigger signal, on receiving a zero-crossing signal, which trigger signal is used to control the impedance of the high-voltage line by using a switching device to bridge a control coil, which is inserted in series into the high-voltage line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further expedient refinements and advantages of the invention are the subject matter of the following description of the exemplary embodiments of the invention with reference to the figures of the drawing, in which components which have the same effect are provided with the same reference symbols, and in which:
[0010] FIG. 1 shows an apparatus of this generic type according to the prior art,
[0011] FIG. 2 shows one exemplary embodiment of the apparatus according to the invention,
[0012] FIG. 3 shows the method of operation of the apparatus shown in FIG. 2 on the basis of current or voltage curves, resolved on a time basis, and illustrated schematically,
[0013] FIG. 4 shows the reactance of the apparatus shown in FIG. 2 with respect to the reactance of the control coil, as a function of the trigger angle,
[0014] FIG. 5 shows the fundamental frequency component of the voltage which is dropped across the apparatus at various trigger angles,
[0015] FIG. 6 shows a digital simulation of the change in power flow in the high-voltage line when the trigger angle of the circuit device of the apparatus shown in FIG. 2 is varied,
[0016] FIG. 7 shows the components of the fundamental frequency and of the higher harmonic oscillations of the voltage which is dropped across the apparatus as shown in FIG. 2 when the alternating current is constant, as a function of the trigger angle,
[0017] FIG. 8 shows an illustration showing the control unit of the apparatus illustrated in FIG. 2 ,
[0018] FIG. 9 shows a more detailed illustration of the control unit shown in FIG. 8 ,
[0019] FIG. 10 and FIG. 11 show characteristics of the control unit as shown in FIG. 9 ,
[0020] FIG. 12 shows a further exemplary embodiment of the apparatus according to the invention,
[0021] FIG. 13 shows the control means for an apparatus as shown in FIG. 12 ,
[0022] FIG. 14 shows calculated voltage profiles of the fundamental and harmonic voltage components as a function of the trigger angle of the apparatus shown in FIG. 13 ,
[0023] FIG. 15 shows characteristics of the control unit as shown in FIG. 13 ,
[0024] FIGS. 16 and 17 show characteristics which differ from FIG. 15 for a control unit for an apparatus as shown in FIG. 13 ,
[0025] FIG. 18 shows a further exemplary embodiment of the apparatus according to the invention,
[0026] FIG. 19 shows a further exemplary embodiment of the apparatus according to the invention,
[0027] FIG. 20 shows an illustration showing how the apparatus illustrated in FIG. 19 is controlled,
[0028] FIGS. 21 to 23 show characteristics of the control unit as illustrated in FIG. 20 , and
[0029] FIG. 24 shows a further exemplary embodiment of the apparatus according to the invention.
DETAILED DESCRIPTION
[0030] According to an embodiment, the control coil is no longer arranged connected in series with the switching device, as in the prior art. In fact, the control coil can be bridged by the switching device, by which means a control method according to the invention, which differs from the prior art, is linked. The switching arrangement according to an embodiment also makes it possible to dispense virtually completely with additional uncontrolled coils or filter units. It should be noted that a control coil need not be in the form of a single component for the purposes of the invention. In fact, according to an embodiment, it is also possible to connect a plurality of coils in series in the respective parallel path. In this case, the expression “control coil” should be understood as meaning the sum of all of the coils in the parallel path.
[0031] The method according to an embodiment is used to control the apparatus according to an embodiment. In this case, the method according to an embodiment is preferably carried out by means of the control unit according to an embodiment.
[0032] The apparatus according to an embodiment advantageously has a parallel path which has no inductive components such as coils or the like even when these are provided only to suppress transient effects, and have no influence on the control characteristic.
[0033] According to an embodiment, the switching unit may be a high-speed mechanical switch. However, at least one switching device expediently comprises thyristors which are connected in opposite senses. The use of thyristors improves the capabilities for controlling the impedance by means of the control unit. According to an embodiment, by way of example, the thyristors are used as high-speed switches. Their switching response can be matched to the respectively required circumstances by means of so-called electrical or optical trigger signals, and thus in a particularly simple manner. All semiconductor components which are already known and are compatible with high voltages, and which are based on silicon or else carbide, are suitable for use as thyristors. Examples of suitable silicon thyristors include electrically triggered thrysitors, optically triggered thyristors, so-called GTOs or else IGBTs.
[0034] The control unit advantageously has a zero-crossing unit, which is connected to current sensors, in order to verify a zero crossing of the alternating current, and at least one trigger unit, which is connected to a trigger angle transmitter. According to an embodiment, the current sensor can thus be a current sensor which emits digital current values and has a current transformer in order to produce a secondary current that is proportional to the alternating current, a sampling device for sampling the secondary current at a sampling clock rate in order to obtain current values, and an analog/digital converter in order to convert the sampled current values to digital current values. A change in the mathematical sign is identified, for example, by conventional software for this purpose in the zero crossing unit, which then sends a zero crossing signal to the trigger unit which is connected to it. The trigger unit is supplied with a trigger angle via the trigger angle transmitter. This trigger angle corresponds to a time period after which the trigger unit sends a trigger signal to trigger the thyristors, to these thyristors, following a zero crossing of the alternating current. This therefore allows any desired phase shift between the zero crossing of the alternating current and the current bridging by the thyristors by the choice of the trigger angle.
[0035] According to an embodiment which differs from this, the control unit can be in the form of an analog control unit with the normal components relating to this that are known to those skilled in the art.
[0036] According to a further embodiment, the trigger angle transmitter is connected to a current sensor in order to measure the alternating current, and is connected to a voltage sensor in order to measure the voltage on the high-voltage line with respect to the ground potential or with respect to the voltages between the phases, with the control unit having a read only memory element which is provided for storage of control parameters, with at least one matching unit being provided in order to detect discrepancies between the control parameters and the measured values from the current sensor and/or the voltage sensor, or between the control parameters and measurement variables which are calculated from the measured values from the current sensor and/or voltage sensor. In other words, each matching unit is provided with one or more nominal values which, for example, correspond to a nominal current value, to a nominal voltage value or, for example, to a nominal value of a real power or wattless component calculated from these two electrical variables. If the respective matching unit detects a difference which exceeds the tolerance range between the respectively measured actual and nominal values or between the actual values as calculated from the measured variables and the nominal values, it shifts the trigger angle in the direction such that the discrepancy between the actual value and the nominal value is once again shifted into the tolerance range. The tolerance range is dependent on the respective application of the apparatus, and is typically 1 % of the respective nominal parameter.
[0037] According to a further embodiment, the apparatus can be provided with two control coils arranged in series which each have a switching device arranged in a parallel path connected in parallel. According to this further embodiment, it is possible to design the overall apparatus using high-voltage components which occupy less space than apparatuses with a control coil which can be bridged. Furthermore, the harmonic component of the voltage which is dropped across the apparatus is less than that of an apparatus with only one controllable reactance.
[0038] According to a further embodiment, the control unit has two trigger units which each interact with a switching device. The control unit is also connected to two different trigger angle transmitters, so that the timing of the trigger of the switching devices can be controlled independently of one another.
[0039] In the case of this refinement, a further embodiment is possible in which only one of the switching devices has thyristors which are connected in opposite senses, with the other switching device being in the form of a mechanical switch. This admittedly reduces the control capabilities of the apparatus. However, a variant such as this is cost-effective, and its control capability is simplified.
[0040] According to an embodiment, a capacitor can be advantageously provided, which is connected in series with the control coil and can be bridged by means of a capacitor switching unit which is arranged in parallel with the capacitor in a capacitor parallel path. The addition of a capacitor connected in series considerably widens the impedance range which can be controlled by the apparatus. According to this further embodiment, two controllable reactance ranges are provided, although only one common controller is required to control the overall impedance. The series arrangement of controllable reactances can, of course, also be added to by further modules of this type arranged connected in series.
[0041] According to a further embodiment, a filter unit is provided and is arranged in parallel with a series path in which the control coil and the capacitor are connected in series. The filter units can be used only when a capacitor or a coil is also provided in the bridged series circuit, in addition to at least one control coil.
[0042] According to a further embodiment of the control unit, at least one of the switching devices is formed by thyristors which are connected in opposite senses. All of the switching devices may, of course, also comprise thyristors which are connected in opposite senses.
[0043] FIG. 2 shows an exemplary embodiment of the apparatus 8 which can be inserted into a high-voltage line 9 via switches which cannot be seen in FIG. 2 , with the high-voltage line 9 being provided in order to transmit power between two nodes of an electrical power distribution network. In this case, the apparatus 8 is arranged in series with the high-voltage line 9 in such a way that all of the alternating current which is carried by the high-voltage line 9 flows via the apparatus 8 . In the normal way, the high-voltage line comprises three phases, that is to say three high-voltage conductors which are routed alongside one another, and of which only one phase is illustrated in the figures of the drawing, for clarity reasons. The other phases, which are not shown, of the high-voltage line 9 are connected to the apparatus 8 in the same way as the phase which is illustrated in the figures of the drawing. The device 8 may, of course, be connected in a corresponding manner to a high-voltage line which has more than three phases or less than three phases.
[0044] The apparatus 8 has a control coil 2 and a switching device 3 , which in this case is formed by two thyristors 10 which are connected in opposite senses. In this case, the switching device 3 is arranged in the parallel path 5 , in parallel with the control coil 2 .
[0045] The thyristors 10 are each connected via expedient control lines 11 to a control unit 4 , which is designed to produce a trigger signal as a function of the phase of the alternating current in the high-voltage line 9 .
[0046] FIG. 3 illustrates the method of operation of the apparatus 8 according to an embodiment as shown in FIG. 2 on the basis of time-resolved schematic current and voltage curves. FIG. 3 a shows two oscillation periods of an idealized sinusoidal alternating current I on in the high-voltage line 9 , with the alternating current amplitude being 1.5 kA. At the time t 0 , the thyristors 10 in the switching device 3 are in an off position, so that the current passed via the control coil 2 and illustrated in FIG. 3 b essentially corresponds to that of the alternating current in the high-voltage line 9 . The current passed via the parallel path 5 is illustrated in FIG. 3 c. In consequence, this is equal to zero at the time t 0 .
[0047] When the time indicated by α in FIG. 3 is reached, the thyristors 10 in the switching device 3 are triggered by the control unit 4 . Because of the self-induction in the coil, the coil current shown in FIG. 3 b remains essentially constant. The current which is carried via the parallel path 5 and is shown in FIG. 3 c likewise reaches a relative minimum at the vertex point of the alternating current. At the time which is indicated by β, the current carried via the parallel path and thus via the switching device 3 with the thyristors 10 is equal to zero, so that the thyristors 10 are once again changed to the off position. After this time, the current carried via the control coil 2 once again corresponds to the alternating current in the high-voltage line 9 . This process is then repeated, but this time in the positive region of the alternating current, that is to say with the alternating current having the opposite mathematical sign.
[0048] FIG. 3 d shows the voltage which is dropped across the switching device 3 . Its magnitude is a maximum at the time to, and corresponds to a magnitude of about −40 kV. The thyristors 10 are triggered at the time α, following which the voltage falls to a zero value in order to rise to +28 kV at the time β.
[0049] FIG. 3 e shows the results of the calculation of the fundamental frequency component of the voltage which is dropped in total across the apparatus 8 . As can be seen, the fundamental frequency component of the voltage is phase-shifted through +90 degrees with respect to the current shown in FIG. 3 a. As will be described in the following text, the amplitude of the fundamental frequency component is dependent on the trigger angle α. For this reason, the apparatus 8 acts as a controllable reactance.
[0050] The voltage which is dropped across the triggering apparatus 8 in the time period between the first triggering of the thyristors α and the subsequent interruption of the current by the thyristors π−α, that is to say β, is equal to zero, as can be seen in FIG. 3d . When the thyristors 10 are switched off, the voltage V(t) which is dropped depends on the change in the current as well as the inductance of the control coil. In this case:
V ( t )=0 for α<ω t <(π−α)
V ( t ) = L RSP ⅆ ( I on ) ⅆ t ,
for (π−α)<ω t <(π+α),
where I on corresponds to the alternating current in the high-voltage line 9 and L RSP corresponds to the inductance of the control coil. The trigger angle is α in radians, and ω—likewise in radians—represents the angular velocity. On the basis that I on =I 0 sin(ωt),
V ( t )= L RSP ωI 0 cos(ω t ) for (π−α)<ω t <(π+α)
[0051] The fundamental frequency component of V(t) can be calculated using Fourier techniques. This is based on the approximate assumption that the resistance of the apparatus is equal to zero. The only voltage component of the voltage which is dropped across the apparatus 8 that is of interest is thus that which is in phase with cos(ωt). As shown in FIG. 3 , the positive and negative half cycles of the voltage which is dropped across the apparatus are symmetrical. The magnitude of the component of the fundamental frequency of the voltage V SUM which is dropped across the apparatus 8 is thus given by:
V SUM = 2 π · ∫ π - α π + α V ( t ) · cos ( ω · t ) · ⅆ ( ω · t ) = 2 π · I 0 · ω · L RSP · ∫ π - α π + α cos 2 ( ω · t ) · ⅆ ( ω · t ) = 2 π · I 0 · ω · L RSP · ( α + sin ( 2 · α ) 2 )
for α between 0 and 90 degrees.
[0052] The reactance at the fundamental frequency is thus:
X SUM X RSP = 2 π · ( α + sin ( 2 · α ) 2 )
[0053] FIG. 4 shows the reactance of the apparatus 8 X SUM , normalized with respect to the reactance of the control coil 2 X RSP , as a function of various trigger angles α, as is indicated in FIG. 4 , with the units being radians. As can be seen, the impedance of the apparatus 8 according to an embodiment is negligible at trigger angles in the region of 0 degrees, while it approaches the maximum value asymptotically at trigger angles greater than 70 degrees, with this maximum value being determined by the reactance of the control coil X RSP .
[0054] FIG. 5 shows the total voltage V SUM which is dropped across the apparatus 8 , with the functional profile being identified by quadrilateral points. Furthermore, FIG. 5 shows the fundamental frequency component of the voltage, calculated on the basis of a simplified model, in the form of a curve V G , which is identified by round points. The calculation was based on the assumption of an ideal sinusoidal alternating current with an amplitude of 1.5 kA, with the control coil 2 having an inductance of 80 MilliHenrys. FIG. 5 a shows the voltage profiles for a trigger angle α of 10°. This means that a control pulse for the thyristors 10 is triggered after just a short time period following a zero crossing of the alternating current in the high-voltage line 9 , as a result of which the control coil 9 is bridged, and the voltage is dissipated.
[0055] The trigger angles a in FIGS. 5 b, 5 c, 5 d and 5 e were 20, 30, 45 and 60°, respectively. As can be seen, the amplitude of the fundamental frequency rises as the trigger angle becomes larger, and, in FIG. 5 e, the profile of the fundamental frequency corresponds essentially to the voltage drop across the apparatus 8 .
[0056] FIG. 6 shows a digital simulation based on the same simplified model that was also used as the basis for FIG. 5 . The illustrated results are based on the assumption of a high-voltage line having a reactance of 45 Ohms at 50 Hz, with the apparatus 8 being fitted with a control coil 2 of 80 MilliHenrys. The respective trigger angle α in radians, chosen for the calculation, is plotted in FIG. 6 a as a function of the time in seconds, with α still being zero after 0.2 s, and with α having risen to 90 degrees after 0.8 s. FIG. 6 b also shows the voltage of V SUMm dropped across the apparatus as a function of the time, whose profile approaches a sinusoidal profile to an ever greater extent as the trigger angle increases. The alternating current in the high-voltage line is plotted in FIG. 6 c, and its amplitude decreases as the trigger angle increases. FIG. 6 d shows the real power P w which is transported through the high-voltage line and whose magnitude, as expected, decreases as the trigger angles α become greater.
[0057] FIG. 7 shows the amplitudes of the fundamental frequency and of the higher harmonic oscillation components of the voltage which is dropped across the apparatus 8 up to the 13th harmonic V x with respect to the amplitude of the total voltage V SUM , as a function of the trigger angle α. As can be seen, the amplitude Y of the higher harmonics decreases as the trigger angles become greater, and the fundamental frequency component of the total voltage is virtually 100% at trigger angles of 90 degrees.
[0058] FIG. 8 shows the apparatus 8 as shown in FIG. 2 , but with the control unit 4 being illustrated in more detail. As can be seen in FIG. 8 , the control unit 4 comprises a zero crossing sensor 12 as well as a trigger unit 13 , with the zero crossing sensor 12 being connected to a current sensor 14 . For its part, the current sensor 14 comprises, for example, a current transformer, which is not shown but produces a secondary current which is proportional to the alternating current in the high-voltage line 9 , is sampled by a sampling unit (which is likewise not shown) in the current sensor 14 in order to obtain sample values, with the sample values then being converted by an analog/digital converter (which is not shown) to digital current values I on , and being supplied to the zero crossing sensor 12 via a connecting line 15 . When the zero crossing sensor 12 detects a change in the mathematical sign of the digital current values I on , it sends zero crossing pulses 16 to the trigger unit 13 . Receiving the zero crossing pulses 16 , the trigger unit 13 sends trigger pulses 17 , after a delay time α, to the thyristors 10 in the switching device 3 , which are then switched from an off position, in which the current carried via the parallel path 10 is interrupted, to an on position, in which current can flow via the parallel path 5 . The delay time by which the trigger unit 13 delays the emission of the trigger pulses 17 after receiving the zero crossing pulses 16 corresponds to the trigger angle α, which is supplied to the trigger unit 13 via a signal line 18 . The impedance can thus be controlled and thus the real power transmitted via the high-voltage line 9 can be regulated, by varying the trigger angle parameter α via the signal line 18 .
[0059] FIG. 9 shows a more detailed illustration of the control unit 4 of the apparatus 8 as shown in FIG. 8 and, in particular, the components of a trigger angle transmitter 19 for production of a trigger angle α which is suitable for controlling the apparatus 8 . The trigger angle transmitter 19 has a real-current sensor 20 and a real-power sensor 21 . In this case, the real-current sensor 20 is connected to the current sensor 14 and is designed to receive the digital current values 19 which are produced by the current sensor, as described above.
[0060] The real-power sensor 21 is connected both to the current sensor 14 and to the voltage divider 22 , whose output signal V on is proportional to the voltage on the high-voltage line 9 with respect to ground potential. The analog signals which are emitted from the voltage divider 22 are sampled and digitized by the real-power sensor 21 , and are converted with the digital current values of the voltage standard 14 to digital power values, which correspond to the power transmitted through the high-voltage line 9 .
[0061] The trigger angle transmitter 19 can also be supplied via a nominal current line 23 and via a nominal power line 24 with control parameters, with the control parameters in each case being supplied to a matching unit 25 and 26 . The nominal current line 23 or the nominal power lines 24 is or are connected, for example, to a computer (which is not shown) or to a control console (which is not shown), so that a user is able to supply expedient control parameters to the control unit 4 . The matching units 25 and 26 are each connected to a proportional/integral regulator 27 or 28 , respectively, which is followed by a selection unit 29 . The selection unit 29 is used to select the measurement variable which will be monitored by comparison with a control parameter and will be used to control the apparatus 8 . In order to select the respective control parameter, the selection unit 29 is connected via a selection line 30 to, for example, the computer or the control console.
[0062] The selection unit 29 is also connected to a nominal trigger angle line 31 . The trigger angle transmitter can thus be supplied directly with a nominal trigger angle, which can then be used to control the apparatus 8 , by expedient adjustment of the selection unit 29 via the selection line 30 .
[0063] Furthermore, additional control signals can be introduced via further control lines 32 into the trigger angle transmitter 19 from the exterior, for example via the control computer. The additional control signals 32 can also be supplied to the open-loop and closed-loop control measures described above, and can be used for open-loop control purposes. By way of example a matching unit 33 which is connected downstream from the selection unit 29 is used for closed-loop control purposes. Further control signals in this sense are, for example, known control variables to increase the transient stability of the power supply network. Furthermore, it is possible to use the apparatus 8 to damp sub-synchronous resonances.
[0064] At this point, it should be noted that FIGS. 8 and 9 illustrate the control process only in a schematic form, and any limiters, signal filters and the like which are used however, covered by the scope of the invention, although they are not expressively mentioned.
[0065] The output signal SIN from the matching unit 33 is supplied to a linearization unit 34 , which is provided in order to compensate for any non-linear behavior of the impedance of the apparatus 8 with respect to said output signal S IN .
[0066] FIGS. 10 and 11 show the method of operation of the linearization unit 34 . In FIG. 10 , the output signal α from the linearization unit 34 is plotted on the ordinate as a function of the output signal from the selection unit 29 or from the matching unit 33 , that is to say the input signal SIN to the linearization unit 34 . As can be seen, there is a non-linear relationship between these signals. In FIG. 11 , the reactance of the apparatus 8 X SUM , normalized with respect to the maximum value X MAX , is plotted on the ordinate between 0 and 1, as a function of the input signal SIN to the linearization unit 34 , that is to say of the output signal from the selection unit 29 . As can be seen, the linearization unit 34 produces the desired proportionality between these two variables.
[0067] FIG. 12 shows a further exemplary embodiment of an apparatus which has two control coils 2 , which are arranged connected in series and can each be bridged by a separate parallel path 5 . In this case, each parallel path is provided with a switching device 3 , whose thyristors 10 , which are connected in opposite senses, are controlled by a common control unit 4 . The common control of two switching devices 3 is illustrated in FIG. 13 . As can be seen, the control unit 4 now has two trigger units 13 a and 13 b, which are each associated with a switching device 3 a or 3 b, respectively. In this case, the trigger units 13 a and 13 b are supplied with different trigger angles α a and α b . For this purpose, the output signal from the selection unit 29 or from the matching unit 33 is split into two signals, and is respectively supplied to a linearization unit 34 a, which is connected to the trigger unit 13 a, and to a linearization unit 34 b, which is provided in order to cause the trigger unit 13 b to respond.
[0068] FIG. 15 a shows the characteristic of the linearization unit 34 a, with the characteristic of the linearization unit 34 b being plotted in FIG. 15 b. In this case, the trigger angles α a and α b which are emitted from the respective linearization unit 34 a or 34 b are plotted as a function of the output signal S IN from the matching unit 33 .
[0069] FIG. 14 shows an illustration, corresponding to FIG. 7 , of the calculated amplitudes of the fundamental frequency and of the higher harmonic frequencies of the voltage V x which is dropped across the apparatus 8 , normalized with respect to the total voltage V SUM dropped in total across the apparatus 8 , as a function of the output signal S IN from the matching unit 33 of a control unit 4 as shown in FIG. 9 . As can be seen, there is a particularly advantageous linear relationship between the output signal S IN from the matching unit 33 and the amplitude of the fundamental frequency.
[0070] FIGS. 16 and 17 show a configuration, which is different to this, of the linearization units 34 a and 34 b as shown in FIG. 13 . As can be seen in this case, the first switching device 3 a, whose switching behavior is controlled by the linearization unit 34 a, is operated as a high-speed switch. In the case of normalized output signals S IN from the matching unit 33 below 0.5, the switching device 3 a remains in an on position, in which the thyristors 10 which are connected in opposite senses in the switching device 3 allow current to flow through the parallel path 10 a. In the case of output signals S IN from the matching unit 33 of more than 0.5, the switching device 3 a is switched to an off position, so that no current can flow via the parallel path 5 a. This control process makes it possible to achieve a profile of the voltage amplitudes of the fundamental frequency components corresponding essentially to FIG. 14 .
[0071] According to one different exemplary embodiment, which is not illustrated, the switching device annotated 3 a in FIG. 12 is not formed by two thyristors which are connected in opposite senses but by a mechanical switch which interacts with the linearization unit 34 a, whose characteristic corresponds to the characteristic shown in FIG. 16 . The use of a mechanical switch instead of thyristors 10 results in cost advantages.
[0072] FIG. 18 shows a further exemplary embodiment of the apparatus 8 . As can be seen, the apparatus 8 according to an embodiment, which is surrounded by a dashed line, comprises an inducted unit 35 , which is surrounded by a further dashed line, and a capacitive unit 36 , which is surrounded by a dashed line, which units 35 and 36 can be connected in series with one another by means of mechanical switches 37 . The inductive unit 35 corresponds very largely to the exemplary embodiment of the apparatus as shown in FIG. 2 , but with a bridging path 38 being provided in order to bridge the inductive unit 35 . The capacitive unit 36 can likewise be bridged by means of a bridging path 38 .
[0073] The capacitive unit 36 also has a capacitor 40 and a parallel path 41 in which a mechanical switch 42 is arranged. In addition, a varistor 43 and a spark discharge gap 44 are connected in parallel with the capacitor 40 and with the switch 42 . The capacitive unit 36 thus corresponds to a solution which is already known per se in order to compensate for the impedance of a high-voltage line 9 , with the exception that the switch 42 is opened and closed in order to bridge the capacitor 40 by means of the same control unit 4 which is also used to control the switching device 3 of the inductive unit 35 . Connection of the inductive unit 35 and capacitive unit 36 in series in these ways widens the control range of the apparatus 8 .
[0074] FIG. 19 shows an exemplary embodiment of the apparatus 8 which largely corresponds to the exemplary embodiment shown in FIG. 18 . In the exemplary embodiment shown in FIG. 19 , the control unit 4 in the inductive unit 36 causes a switching device 3 which is arranged in series with the control coil 2 to respond, however. In this case, the switching device 3 is once again formed by two thyristors 10 which are connected in opposite senses. The reactance of the control coil 2 of the apparatus is connected by triggering of the thyristors 10 .
[0075] The capacitive unit 36 as shown in FIG. 19 correspond to an apparatus which is already known per se but which is used in this case, by means of the illustrated combination, to extend the application range of the apparatus 8 according to an embodiment, and at the same time to control the impedance of the high-voltage line 9 .
[0076] FIG. 20 shows, schematically, the control unit 4 of the apparatus 8 shown in FIG. 19 . As can be seen, in this case as well, two trigger units 13 a and 13 b are provided, and are connected to a respective switching device 3 a and 3 b. The trigger units 13 a and 13 b are once again connected to respectively associated linearization units 34 a and 34 b, which each have a different but expedient characteristic.
[0077] One example of this circuitry for production of an apparatus 8 which operates continuously and linearly with respect to S IN is shown in FIGS. 21, 22 and 23 . This is based on the assumption that the reactance of the apparatus 8 is symmetrical, with positive values plotted on the abscissa representing inductive reactances, while negative abscissa values, in contrast, represent capacitive reactances. FIG. 21 shows the reactance of the capacitive unit 36 X ASC as a function of the output signal S IN from the matching unit 33 . FIG. 22 shows the reactance of the inductive unit 35 X TRIC as a function of the output signal S IN of the matching unit 33 . The resultant reactance X SUM of the apparatus 8 , which comprises the total reactance of the series-connected inductive unit 35 and capacitive unit 36 , is illustrated in FIG. 23 as a function of the output signal S IN from the matching unit 33 . As can be seen, the relationship is linear.
[0078] FIG. 24 shows a further exemplary embodiment of an apparatus 8 with an inductive unit 35 and a capacitive unit 36 , which are connected in series, with a filter unit 45 being connected in parallel with this series circuit. The filter unit 45 represents a so-called single-tuned filter which is designed, for example, to trigger a specific harmonic frequency component of the voltage which is dropped across the apparatus 8 .
[0079] Finally, it should be noted once again that a filter unit 45 can be connected in parallel with the apparatus 8 according to an embodiment only when a capacitive unit 36 is also provided, in addition to an inductive unit 35 . In the case of one exemplary embodiment, which differs from this, an uncontrollable inductive unit, that is to say a coil, is provided instead of the capacitive unit 36 , connected in series with the control coil 2 , for this purpose, that is to say for connection of the filter unit 45 . | A device ( 8 ), for adjusting the impedance of a high voltage line ( 9 ), supplying an alternating current, has at least one control coil ( 2 ), which may be inserted in series in the high voltage line ( 9 ) and at least one switching device ( 3,10 ), provided for each control coil ( 2 ). The device is compact and economical. A control unit ( 4 ) for controlling each switching device ( 3,10 ) is also provided, such that the reactance of the control coil ( 2 ), acting in the device may be adjusted by the switching of the switching device ( 3,10 ), whereby each switching device ( 3,10 ) is arranged parallel to the corresponding control coil ( 2 ) in a parallel branch ( 5 ). | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to engines driven by pistons most usually and more particularly to internal combustion engines. These mechanisms are particularly useful for converting the reciprocating notion of a powered piston to a rotating output movement.
Most conventional engines included at multiple cylinders in which a piston reciprocates. The piston is then connected to an output crank by an elongated connecting rod pivoted at the upper end to the piston at the lower end to the crank. It is conventional that the output of the powers for such an engine and, in particular, for internal combustion engines, is the crankshaft rotary output. It is the unique configuration of the present invention to provide an energy efficient easily maintained functional replacement for that design.
2. Description of the Prior Art
Many patents have been granted to internal combustion designs utilizing gearing mechanisms for drives such as U.S. Pat. No. 1,316,437 patented Sep. 16, 1919 to H. L. Flood on a "Rack And Pinion Mechanism For Engines"; and U.S. Pat. No. 1,399,900 patented Dec. 13, 1921 to C. G. Sprado and assigned to Allis-Chalmers Manufacturing Company on a "Method Of And Apparatus For Manipulating Internal-Combustion Engines"; and U.S. Pat. No. 1,434,146 patented Oct. 31, 1922 to A. L. Powell and assigned to A. L. Powell Power Co. on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,496,490 patented Jun. 3, 1924 to A. L. Powell and assigned to A. L. Powell Power Co. on a "Transmission For Engines"; and U.S. Pat. No. 1,567,172 patented Dec. 29, 1925 to A. L. Powell and assigned to A. L. Powell Power Co., Inc. on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,569,582 patented Jan. 12, 1926 to C. W. Scott on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,583,368 patented May 4, 1926 to A. L. Powell and assigned to A. L. Powell Power Company Incorporated on a "Transmission For Engines"; and U.S. Pat. No. 1,636,612 patented Jul. 19, 1927 to L. H. Noah on an "Internal-Combustion Engine"; and U.S. Pat. No. 1,687,744 patented Oct. 16, 1928 to F. M. Webb on a "Reciprocating Engine"; and U.S. Pat. No. 1,705,930 patented Mar. 19, 1929 to R. E. Leonard and assignment of one-half to David G. Lorraine on a "Long-Stroke Pump-Operating Mechanism"; and U.S. Pat. No. 1,708,888 patented Apr. 9, 1929 to I. N. Keeling and assignment of one-fourth to Andrew J. parks on a "Mechanical Movement"; and U.S. Pat. No. 1,735,543 patented Nov. 12, 1929 to V. H. Palm on an "Internal Combustion Engine"; and U.S. Pat. No. 1,885,298 patented Nov. 1, 1932 to A. A. Schell on an "Internal Combustion Engine"; and U.S. Pat. No. 2,088,504 patented Jul. 27, 1937 to E. Brzezinski on a "Crankless Motor"; and U.S. Pat. No. 2,155,497 patented Apr. 25, 1939 to A. Latil on a "Transforming Alternating Rectilinear Movement Into Continuous Rotary Movement"; and U.S. Pat. No. 2,334,684 patented Nov. 16, 1943 to A. T. Zappia and assigned to Fairmount Glass Works, Inc. on an "Intermittent Drive Mechanism"; and U.S. Pat. No. 2,337,330 patented Dec. 21, 1943 to Z. J. Julin on a "Driving Mechanism"; and U.S. Pat. No. 2,482,136 patented Sep. 20, 1949 to W. N. Wright on an "Engine"; and U.S. Pat. No. 3,528,319 patented Sep. 15, 1970 to Kenjiro Ishida and assigned to President Shizuoka University on a "Perfectly Balanced Vibrationless Rotation-Reciprocation Device Of Crankshaft Planetary Motion System"; and U.S. Pat. No. 3,604,204 patented Sep. 14, 1971 to H. Conrad et al and assigned to Fried Krupp Gesellschaft mit beschrankter Haftung on a "Counterpiston Machine, Especially Counterpiston Motor"; and U.S. Pat. No. 3,895,620 patented Jul. 22, 1975 to B. Foster on an "Engine And Gas Generator"; and U.S. Pat. No. 3,916,866 patented Nov. 4, 1975 to J. M. Rossi on an "Engine Having Reciprocating Piston And Rotary Piston"; and U.S. Pat. No. 3,991,736 patented Nov. 16, 1976 to R. C. Spellman and assigned to Raymond Lee Organization, Inc. on a "Ratchet Driving Internal Combustion Engine"; and U.S. Pat. No. 4,135,409 patented Jan. 23, 1979 to R. Ishimaru on a "Device For Converting Rocking Motion Into Reciprocating Rotary Motion"; and U.S. Pat. No. 4,411,165 patented Oct. 25, 1983 to L. Evans on a "Power Transmission Unit With Infinite Speeds"; and U.S. Pat. No. 4,465,042 patented Aug. 14, 1984 to R. Bristol on a "Crankless Internal Combustion Engine"; and U.S. Pat. No. 4,803,964 patented Feb. 14, 1989 to W. Kurek et al on an "Internal Combustion Engine"; and U.S. Pat. No. 4,890,589 patented Jan. 2, 1990 to H. Miyate and assigned to Nissan Shatai Company, Limited on a "Variable Capacity Type Reciprocating Piston Device"; and U.S. Pat. No. 4,938,186 patented Jul. 3, 1990 to L. Pal et al on an "Internal Combustion Engine Variable Stroke Mechanism"; and U.S. Pat. No. 4,951,615 patented Aug. 28, 1990 to N. Pahis on a "Motion-Conversion Mechanism For A Four Stroke Oscillating Piston Internal Combustion Engine".
SUMMARY OF THE INVENTION
The present invention provides an improved drive mechanism used for a reciprocating piston engine which includes a housing block defining multiple cylinders therein and preferably four such cylinders. A crankshaft is rotatably mounted within the housing block and includes a plurality of piston journals defined thereon. Preferably the crankshaft where mounted within the housing block includes crankshaft support journals therein to facilitate rotational movement of the crankshaft with respect to the housing block.
A piston member is included positioned within each of the cylinders defined by the housing block such as to be movably axially therewithin. Each of the pistons preferably includes a piston head drive surface and a piston leg extending therefrom preferably downwardly. The piston leg is preferably fixedly secured with respect to the piston and is oriented perpendicularly with respect to the piston head drive surface. In this manner each of the pistons and the piston legs will be adapted to move axially within the cylinder without any component of movement thereof whatsoever laterally with respect to the axis of the particular cylinder. As such, conventional wobble of a piston head resulting from off-axis movement of a conventional connecting rod is avoided.
A piston link arm apparatus is included pivotally attached with respect to each of the piston legs and pivotally attached with respect to the piston journal. The piston link arm preferably includes a first link arm end pivotally secured to the piston leg. Also the piston link arm preferably includes a second link arm end pivotally secured with respect to one of the piston journals. This second link arm also is positioned to be spatially disposed on the piston link arm remotely from the location of the first link arm in such a manner as to mechanically create pivotal linkage interconnecting the piston with respect to the crankshaft. A piston pin may also be included extending through the first link arm end and the piston leg in order to maintain the pivotal engagement therebetween.
A power driveshaft is also included rotatably mounted within the housing block adjacent the path of movement of each of the piston legs. An idler driveshaft may also be included rotatably mounted within the housing block at a location opposite from the position of the power driveshaft. This idler driveshaft is preferably positioned extending generally parallel with respect to the power driveshaft and opposite therefrom with the path of movement of the piston leg positioned therebetween.
A plurality of power clutch bearings are fixedly secured on each of the power driveshafts adjacent each of the piston legs. Each of these power clutch bearings include a power inner race fixedly secured to the power driveshaft and a power outer race. The power clutch bearings are adapted to provide the power inner race in fixed securement with respect to the power outer race only responsive to rotation thereof in a first power direction which is preferably clockwise. They are adapted to provide freewheeling relative rotatable attachment therebetween responsive to rotation thereof in a second power direction normally being counterclockwise.
A plurality of power drive gears are each mounted securely to the power outer race of the one of the power clutch bearings. A plurality of power rack gears are preferably fixedly secured to the piston legs and are movable therewith adjacent the power driveshaft means. They are also preferably in engagement with the power driving gear mounted on the power driveshaft thereadjacent. The power rack gear also is preferably reciprocally movable with the piston leg and is maintained in continuous engagement with the power driving gear located thereadjacent. A power timing gear is preferably fixedly secured to the power driveshaft adjacent the output end thereof.
A plurality of idler clutch bearings are fixedly secured onto the idler driveshaft adjacent each of the piston legs. Each of these idler clutch bearings include an idler inner race fixedly secured to the idler driveshaft and an idler outer race. The idler clutch bearing is adapted to provide the idler inner race in fixed securement with respect to the idler outer race responsive to rotation thereof in a first idler direction being preferably counterclockwise. It is also adapted to provide freewheeling rotatable attachment therebetween responsive to rotation thereof in a second idler direction which preferably is clockwise.
A plurality of idler drive gears are included each mounted directly to the idler outer race of one of the idler clutch bearings. Also multiple idler rack gears are included each being fixedly secured to the piston leg and movable therewith adjacent the idler driveshaft. Each idler rack gear is in engagement with the idler driving gear mounted on the idler driveshaft thereadjacent. The idler rack gear is preferably reciprocally movable with the piston leg and maintained in continuous engagement with the idler driving gear located thereadjacent. Each of these idler rack gears are preferably oppositely positioned on the piston leg from the power rack gear located thereon.
An idler timing gear is preferably fixedly secured to the idler driveshaft adjacent to the power timing gear and in operative engagement therewith in order to facilitate driving of the power driveshaft by the idler driveshaft at certain points in the cycle of reciprocating motion of this engine. A power output shaft may preferably be fixedly secured with respect to the power driveshaft in such a manner as to be axially coincident therewith in order to provide access to power for delivery as desired.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein maintenance requirements are minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein initial capital cost outlay for producing the assembly is minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein down time is minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein output power is provided at an output shaft other than the crankshaft.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein rocking of pistons moving through the cylindrical cylinders is minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein oil consumption is minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein cylinder wear is minimized.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein less heat is generated in the engine generally and within the cylinders specifically.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with diesel and/or gasoline powered or other powered engine configurations is possible.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein the cost of production of the crankshaft can be greatly minimized since it requires less weight because it does not provide the source of drive output from the motor.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with a conventional internal combustion engine is possible.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any fluid powered piston engine is possible including both pneumatic and hydraulic power piston systems.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein the unique combination and positioning of clutch bearings provide continuous power to the output shaft, which provides frictional power to the crankshaft.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any number of multiple cylinders is possible.
It is an object of the present invention to provide an improved drive mechanism for a reciprocating piston engine assembly wherein usage with any conventional valve configurations is made possible.
BRIEF DESCRIPTION OF THE DRAWINGS
While the invention is particularly pointed out and distinctly claimed in the concluding portions herein, a preferred embodiment is set forth in the following detailed description which may be best understood when read in connection with the accompanying drawings, in which:
FIG. 1 is a perspective illustration of an embodiment of the improved drive mechanism for a reciprocating piston engine of the present invention;
FIG. 2 is an end plan view of the embodiment shown in FIG. 1 as viewed from the left;
FIG. 3 is a rear plan view of the embodiment shown in FIG. 1 as viewed from the right;
FIG. 4 is a side plan view of the embodiment shown in FIG. 1 with the outer pistons in the uppermost position and the inner pistons in the lowermost position;
FIG. 5 is the same view shown in FIG. 4 with the inner pistons in the uppermost position and the outermost pistons in the lowermost position;
FIG. 6 is a front plan view of an embodiment of a power clutch bearing made in accordance with the present invention; and
FIG. 7 is front plan view of the an embodiment of an idler clutch bearing made in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The improved drive mechanism for a reciprocating piston engine of the present invention includes a housing block 10 defining a plurality of individual cylinders 12 thereon. Preferably cylinders 12 are of a cylindrical cross section. A crankshaft 14 is rotatably mounted within the housing block 10 to facilitate rotation of crankshaft 14. It can include a plurality of crankshaft journals 18 thereon which are designed to be mounted within bearings in the housing block 10 in the conventional manner. The crankshaft 14 preferably also defines a plurality of piston journals 16 adjacent to each of the cylinders 12 to facilitate interconnection of the crankshaft with respect to the pistons located therewithin.
A piston means 20 is preferably movably positioned within each of the cylinders 12. Each piston 20 includes a piston leg 24 fixedly secured thereto and extending downwardly therefrom. Each piston 20 also includes a piston head drive surface 22 facing the interior portion of the cylinder 12 to receive power transmitted therefrom. In the preferred orientation of the pistons 20 of the present invention the individual piston leg 24 will be oriented perpendicularly with respect to the piston head drive surface 22.
The pistons 20 are designed to move as shown in FIG. 2 vertically along a cylindrical axis 26 within the cylinder 12. One of the important aspects of the present invention is that the piston 20 only has a vertical component of movement and has no lateral movement component 28 as shown in FIG. 3. The vertical movement component shown by arrow 23 is designed to smoothly slide along the interior wall surfaces of cylinder 12. Since there is no lateral movement component 28 in the apparatus of the present invention a distinct improvement over prior art internal combustion engines is achieved. The elimination of such lateral movement or wobble significantly reduces wear on the interior walls of the cylinder which enhances performance, efficiency and significantly reduces oil consumption thereof.
In order to maintain this vertical orientation during movement of the piston, a piston link arm 30 is preferably positioned interconnecting the piston leg 24 with the piston journal 16. This piston link arm 30 preferably includes a first link arm end 32 and a second link arm end 36 spatially disposed with respect to one another preferably at opposite ends at the piston link arm 30. The first link arm means 32 is preferably secured to the piston leg 24 by a piston pin 34. The use of this piston pin 34 enhances the pivotal yet secure interconnection between the first link arm end 32 of piston link arm 30 and the piston leg 24. The opposite end of the piston link arm 30 which is defined as the second link arm end 36 is preferably pivotally secured with respect to piston journal 16 on the crankshaft 14.
A very important aspect of the present invention is the inclusion of a power driveshaft 38 rotatably mounted within the housing block 10 preferably at a position above the crankshaft and running along one side of the cylinders 12. Power driveshaft 38 is preferably mounted in a plurality of power driveshaft journals 40 defined within housing block 10. On the opposite side of the cylinders 12 from the power driveshaft 38 is preferably located an idler driveshaft 42. Preferably idler driveshaft 42 is rotatably mounted within a plurality of idler driveshaft journals 44 defined within the housing block 10.
The power driveshaft 38 and the idler driveshaft 42 are preferably spaced apart from one another and extend parallel with respect to one another and provides a means for withdrawing power from the apparatus of the present invention and for maintaining the piston 20 in vertical orientation during movement thereof.
A plurality of power clutch bearings 46 are mounted on the power driveshaft 38 at each location thereof immediately adjacent to one of the cylinders 12. Power clutch bearing 46 includes a power inner race 48 as well as a power outer race 50 movably oriented with respect to one another. A power drive gear 56 is positioned fixedly secured to the power outer race 50 at each location of positioning of the power clutch bearing 46 adjacent each of the pistons 20.
A power rack gear 58 is positioned fixedly secured with respect to the piston leg 24 and extending vertically at a position immediately adjacent to the power drive gear 56. Power timing gear 60 and idler timing gear 76 are positioned with the gear teeth thereof in engagement with respect to one another at all times. The configuration of the power clutch bearing 46 is such that rotation of the outer race 50 in a clockwise direction as shown in FIG. 2 causes similar clockwise rotation of the power inner race 48. However, as also shown in FIG. 2, rotation of the power outer race 50 counterclockwise with respect to the power inner race 48 will be freewheeling as controlled by the power clutch bearing 46. Clutch bearing 46, thus, is designed such that whenever power outer race 50 is rotated clockwise during movement of the piston 20 toward the crankshaft 14 a similar rotational movement will occur of the power inner race 48 and consequently the power driveshaft 38 resulting from powered engagement of the teeth of the power rack gear 58 in engagement with the power drive gear 56. This configuration is included for each of the cylinders 12.
In a similar manner the power clutch bearing 46 is designed to disengage the power inner race 48 from the power outer race 50 and allows freewheeling thereof whenever, as shown in FIG. 2, the power outer race 50 is rotated in the counterclockwise direction 54. During that portion of the stroke one of the other cylinders will be in the drive mode causing rotation of its associated gearing mechanism for maintaining continuous drive powering of the engine of the present apparatus. With respect to the configuration shown in FIG. 2, whenever the piston 20 is moved toward the crankshaft 14 the power clutch bearing 46 will be in the drive mode firmly interconnecting the power inner race 48 with respect to the power outer race 50 causing driving movement. This results from movement in the first power direction 52 which is clockwise as shown in FIG. 2. The second power direction 54 is as described above, however, there is no connection within the clutch bearing during movement in that counterclockwise direction. This results in a freewheeling relationship between the power inner race 48 and the power outer race 50.
The power driveshaft 38 so driven by the above described configuration will provide power output through a power output shaft 78 which is preferably axially coincident thereto and extending outwardly from the housing block 10.
To provide continuous power to the output shaft 78 the present invention includes a supplementary power driving shaft. This is defined as the idler driveshaft 42. Outer driveshaft 42 is of a similar configuration to the power driveshaft 38 but is oppositely positioned with respect to the piston legs 24. The idler driveshaft 42 is driven and includes an idler timing gear 76 in engagement with a power timing gear 60 fixedly secured to the power driveshaft 38 adjacent the power output shaft 78 thereof. Powering of the idler driveshaft 42 thus will achieve powering of the power output shaft 78 due the engagement between the idler timing gear 76 and the power timing gear 60.
The idler driveshaft 42 is crafted to a similar configuration as is the power driveshaft 38. Idler driveshaft 42 includes a plurality of idler clutch bearings 62 positioned thereon at each location immediately adjacent to a cylinder 12. Each idler clutch bearing 62 includes an idler inner race 64 and an idler outer race 66 which have controlled movement with respect to one another as controlled by the idler clutch bearing 62. Whenever the idler outer race 66 is moved as shown in FIG. 2 in the first idler direction 68, which in this configuration is the counterclockwise direction, then the idler inner race 64 and the idler outer race 66 are firmly secured with respect to one another causing driving of the idler inner race. Since the idler inner race is fixedly secured with respect to the idler driveshaft 42, power driving thereof is caused by rotation of the idler outer race 66 in the counterclockwise direction. The idler outer race 66 is adapted to receive an idler drive gear 72 mounted thereon. This idler drive gear 72 is adapted to engage the teeth of an idler rack gear 74 which is fixedly secured with respect to a piston leg 24. Normally such a piston leg 24 will include an idler rack gear 74 on one side thereof and a similarly configured power rack gear 58 on the opposite side thereof.
The idler rack gear 74 being in engagement with respect to the idler drive gear 72 will cause rotation thereof. Whenever the piston 20 is moved toward the crankshaft 14 the idler rack gear 74 will cause rotation of the idler drive gear 72 as shown in FIG. 2 in the counterclockwise direction which is the drive direction for the idler clutch bearing 62. Thus, the idler inner race 64 will be rotating in a counterclockwise direction and cause drive rotation of the idler driveshaft 42.
Whenever the piston 20 is moving in a direction away from the crankshaft 14 the idler rack gear 74 will cause clockwise rotation of the drive gear 72 and the idler outer race 66 secured thereto. This clockwise rotation is defined as the second idler direction 70 as shown in FIG. 2 which is freewheeling. The idler clutch bearing 62 defines such clockwise movement to be freewheeling and, as such, is the directional movement for non-power or non-driving driving of the idler driveshaft 42.
By positioning of the idler rack gear 74 and the power rack gear 58 on opposite vertically extending sides of the piston leg 24, it will be wedged between the idler drive gear 72 and the power drive gear 56 within each cylinder configuration 12. As such, the piston 20 and the piston leg 24 will be always maintained in a vertical orientation to allow vertical movement 23 and to prevent any lateral movement component 28.
The use of both the power driveshaft 38 and the idler driveshaft 42 provides an overall balance configuration which enhances the stability and strength and efficiency of operation of the drive mechanism for the reciprocating piston engine of the present invention.
Thus we see that each of the pistons will alternately drive the idler drive gear 72 and the power drive gear 56 associated therewith depending on whether the piston is in power stroke moving downwardly. When moving downwardly in power stroke, the power is applied to the two power shaft, namely, the power driveshaft 38 and the idler driveshaft 42. Movement upward in the non-powered movement direction of the piston will result in freewheeling as controlled by the idler clutch bearing 62 and power clutch bearing 46.
Fixed interconnection of the power driveshaft 38 with respect to the idler driveshaft 42 is achieved through the full and continuous engagement of the idler timing gear 76 with respect to the power timing gear 60. Coordinated movement of these parts provides power output to the power output shaft 78 axially coincident with the power driveshaft 38. Normally this power output shaft would be connected with respect to a flywheel or torque converter or other device that can be powered by a rotating driveshaft. This power output shaft 78 provides the power takeoff for the improved drive mechanism of the engine of the present invention.
One of the important aspects of the present invention is that the crankshaft is not used as the means for transmitting power output. As a result the crankshaft of the present invention can be with much smaller parts since strength is not required. Thus, the cost of manufacturing and the weight of the crankshaft can be significantly reduced. The power is applied through the combination of the power driveshaft 38 and the idler driveshaft 42 which pinches the piston legs 24 between the drive gears mounted thereon for maintaining vertical orientation of the pistons within the cylinders and for receiving balanced coordinated power. The use of two powering shafts eliminates the necessity for a single extremely heavy duty power output shaft such as the crankshaft of a conventional internal combustion engine. Such parts tend to provide the weak link in regard to maintenance and construction of such engine assemblies.
By avoiding the wobble or rocking of the individual pistons wear of the interior portion of the cylinders 12 is minimized. Less heat is also generated at this location and less oil is used.
It should be appreciated that the apparatus of the present invention can be utilized with any type of piston powering system such as conventional internal combustion utilizing diesel or gasoline for power or any other fluid system such as hydraulic or pneumatic powering systems.
The configuration of the driveshafts of the present invention is made possible by the clutch bearings which provide full drive in one direction and full freewheeling in the opposite direction. Such clutch bearings are readily available. Often movement in the freewheeling direction is also defined in such clutch bearings to be the overrun mode and movement in the drive direction is defined to be movement in the lock mode.
It should be appreciated that a single clutch bearing component can comprise both the power clutch bearings 46 and the idler clutch bearings 62 of the present invention. Although we have included two separate figures to show these two bearings, actually the two bearing configurations can be provided by a single clutch bearing part merely by reversing the direction of the bearing axis to provide a clutch bearing which drives in the opposite direction on one side and in the freewheeling direction also oppositely. Thus, a single part can be used for the clutch bearing of the present invention wherein drive is achieved in one direction and freewheeling is created in the opposite direction.
While particular embodiments of this invention have been shown in the drawings and described above, it will be apparent, that many changes may be made in the form, arrangement and positioning of the various elements of the combination. In consideration thereof it should be understood that preferred embodiments of this invention disclosed herein are intended to be illustrative only and not intended to limit the scope of the invention. | The present invention provides an improved drive mechanism for reciprocating engines primary adapted for converting reciprocating motion of a piston within a cylinder to rotary motion which includes a piston and piston leg assembly which moves solely axially within the piston chamber with two rack gear members secured to the sides of the piston leg. A power driveshaft and an idler driveshaft are positioned on opposite sides of the movable piston leg and include a plurality of gears thereon positioned adjacent to each piston chamber for receiving driving movement therefrom. This longitudinal movement of the piston is converted to rotational movement of the shaft through the rack gears and power and idler gears which are connected to the power driveshaft and the idler driveshaft through a unique configuration including clutch bearings adapted to convey power driving movement responsive to movement of the pistons toward the crankshaft and to be freewheeling during movement of the pistons away from the crankshaft. The power driveshaft and idler driveshaft are mounted parallel with respect to one another and are interconnected by drive gears. Power output is provided at the power driveshaft rather than at the crankshaft in a more conventional reciprocating piston engine configuration. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a portable small-sized washing machine adapted to wash small articles such as dishcloths.
2. Description of the Prior Art
For cleaning the dishcloths, it has been a common practice to wash them by hand with a detergent and a sterilizer. It has also been a common practice to wear rubber gloves so as to prevent the hands from being chapped by the detergent and the sterilizer. However, the rubber gloves render it difficult for the dishcloths to be sufficiently cleaned. Moreover, there is the possibility that the dishcloths may be smudged stains with which the rubber gloves may have covered.
On the other hand, it is not economical to wash the dishcloths in a washing machine allotted for washing very soiled clothes.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a portable small-sized washing machine handy to carry and adapted to wash a small quantity of articles such as dishcloths.
The washing machine in accordance with the present invention is provided with a washing tub which has a capacity of washing about ten dishcloths at the most, each of these dishcloths being about 30 cm square. It is small-sized and handy to carry so as to be usable even in a kitchen. The washing tub is made of a transparent or semitransparent material so that one can tell how dirty the washing water contained therein has become. Thus the washing machine in accordance with the present invention is adapted for the substantially exclusive use of washing dishcloths, to which cleanliness is essential in view of their use as cloths for drying dishes.
With the above-described object in view and as will become apparent from the following detailed description, the present invention will be more clearly understood in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the present invention; and
FIG. 2 is a vertical sectional view thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, a washing machine in accordance with the present invention includes a main body 1 and a transparent or semitransparent washing tub 2 mounted on the main body 1. A drainage opening 3 and a pulsator 5 are provided in and near the center of the bottom of the washing tub 2, respectively. The pulsator 5 is adapted to be driven by a motor 4 which is secured to the main body 1. An overflow opening 6 is provided in the upper part of a side wall of the washing tube 2. A wringer 7 is provided in the opposite side wall and at a higher position than the lower edge of the overflow opening 6. Two rollers 7 constituting the wringer can be revolved on their axes by manipulating a handle 8 connected to one of the two rollers. Preferably, the washing tub 2 has a capacity of washing ten dishcloths at the most, each of these dishcloths being about 30 cm square. As the case may be, however, it is enough for the washing tub 2 to have a capacity of washing five or six dishcloths.
The drainage opening 3 and the overflow opening 6 communicate with a drain hose 10 through a valve 9. The end portion 10a of the drain hose 10 is detachably supported by a hose clip 11 which is provided on the external surface of the washing tub 2. The overflow opening 6 is always in communication with the drain hose 10, while the communication between the drainage opening 3 and the drain hose 10 can be controlled by the valve 9 which is actuated by a drainage blocking switch 12. The switch 12 is provided adjacently to a motor switch 13 on the main body 1. When the switch 12 is pushed on, the communication between the drainage opening 3 and the drain hose 10 is intercepted by the valve 9 so as to prevent the water from draining out of the washing tub 2 through the drainage opening 3. When the switch 12 is turned off, the drainage opening 3 and the drain hose 10 are allowed to communicate with each other by the valve 9 so as to allow the water to drain out of the washing tub 2 through the drainage opening 3. The motor 4 is switched on and off by the motor switch 13.
The rollers 7 remove excess moisture from the wash by wringing it therebetween and deliver the wash into a basket 14 which is detachably supported on a hook 15. The hook 15 is provided under the rollers 7 on the external surface of the washing tub 2. The washing tub 2 is covered with a detachable lid 16. A handle 17 is hingedly attached to the main body 1.
The handle 17 may be of a fixed type. The washing tub 2 may be covered with a casing made of a transparent or semitransparent material and extending upwardly from the main body 1. It is preferable to provide a timer for automatically stopping the machine at a given time, e.g. 10 minutes after starting the motor 4 by the switch 13, so that one may not be endangered by a failure to switch off the motor 4 at a proper time. Another timer for setting the operating interval may also be provided in the main body 1.
Preferably, the embodiment shown in the drawings, exclusive of the handle 17, is about 30 cm in height and about 30 cm in maximum breadth. These dimensions are enough for allowing the machine to wash a small quantity of articles such as dishcloths. | A portable small-sized washing machine is proposed. The washing tub of this machine has a capacity of washing about ten dishcloths at the most, each of these dishcloths being about 30 cm square. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Ser. No. 60/488,857 filed Jul. 18, 2003.
FIELD OF THE INVENTION
This invention is generally in the field of compositions and methods for electrically stimulating the dorsal horn and other regions of the spinal cord to interfere with or otherwise block transmission of neural signals concerned with pain. The technique involves placement of electrodes directly into the spinal cord in order to activate selectively the target region. This technique improves delivery of electrical stimuli to the desired portion of the spinal cord and serves to decrease power requirements.
BACKGROUND OF THE INVENTION
Spinal Cord Injury. Pain resulting from trauma or other diseases of the nervous system is termed neuropathic pain. The abnormal pain includes ongoing (spontaneous or stimulus independent pain) and heightened pain to stimuli (hyperalgesia). Spinal cord injury (SCI), one cause of neuropathic pain, can result from a variety of causes including (among others) trauma, tumor, infection, congenital malformations, multiple sclerosis, and vascular lesions. Pain after SCI is a frequent occurrence. The development of pain can have devastating effects on the patients and even be of greater concern than the coincident loss of neurological function (paralysis). An important factor in the pathogenesis of SCI pain is the development of hyperexcitable cells near the site of injury (Christensen et al, J Neurotrauma 1997; 14:517-37). This hyperexcitability occurs in cells, activity in which is ordinarily concerned with pain. The abnormal spontaneous discharge leads to ongoing pain and accounts also for heightened pain (hyperalgesia) to natural stimuli (touch, heat, cold) at the border zone of the SCI. Patients feel pain at the level of spinal injury (“at level pain”) and at regions below the injury (“below level pain”). The distal pain is typically stimulus independent and in a sense represents a “phantom” pain, since the patient may have no feeling in this area. There are many factors that cause this change in neuronal excitability at the region of injury. One factor could include changes in receptor expression in neurons in the dorsal horn (Mills et al, Exp. Neurol. 2001; 170:244-257; Chen et al, Neuroscience 2002; 111:761-773; Eide et. al, J Neurol Neurosurg Psychiatry 1996; 60:411-415.)
Numerous therapies have been attempted to treat SCI pain. Drug trials even with high doses of opioids are generally ineffective. (Burcheil and Hsu, Spine 2001 26:S161; Sjolund, Brain Res Rev 2002 40:250-6). Antidepressant, and anticonvulsant medications are also ineffective. Interventional approaches have largely proved ineffective as well. These have included neuro-destructive procedures, implantation of drug pumps into the lumbar intrathecal space, and various forms of electrical stimulation of the nervous system. For example, clinicians have tried implantation of catheters into the spinal fluid for purposes of targeted drug delivery. Though different drugs have been implanted, the results have proven disappointing.
Neuro-destructive procedures have been largely unsuccessful (Sjolund, Brain Res Rev 2002 40:250-6). Some clinicians have advocated lesions of the dorsal root entry zone in the region of SCI (DREZ operation), but whether this surgery is successful is controversial. It has been suggested that the success rates can be improved if dorsal horn recordings are used. (Falci et al. J Neurosurg 2002, 97(2 Suppl):193-200). However this approach contributes to the damaged state and pain may recur or even become worse in the long term. In any case further spinal cord destruction leads to further permanent loss of spinal cord function and therefore is an unsavory choice for a patient with SCI (Denkers et al, Spine 2002 27:E177-84; Sjolund, Brain Res Rev 2002 40:250-6; Burcheil and Hsu, Spine 2001 26:S161).
Electrical stimulation of the spinal cord with electrodes placed in the epidural space (or within the dura) is commonly used to treat a variety of pain problems. It has been scientifically tested and approved by the United States Food and Drug Administration (FDA) as a safe and effective treatment for certain types of chronic pain associated with the trunk and/or limbs. This technique, sometimes termed dorsal column stimulation (but distinct from the present invention which involves intramedullary spinal cord stimulation in the dorsal horn and other spinal cord structures), has proven ineffective for pain from SCI (Kumar et al; Surg Neurol 1996; 46:363-369). Subdural spinal stimulation has also been tried as a technique to stimulate the surface of the spinal cord (Hunt et al 1975 Surg Neurol 4:153-156), but this technique became obsolete with the development of better epidural electrodes.
There remains a need for better pain control in patients with chronic pain.
It is therefore an object of the present invention to provide a device and methods for use thereof for alleviation of chronic pain.
SUMMARY OF THE INVENTION
Electrodes placed directly into the spinal cord (in contradistinction to surface stimulation as is provided by epidural stimulation) are used to provide spinal cord stimulation for pain control. Electrodes are placed directly into the dorsal horn, dorsal column, spinothalamic tract, nucleus cuneatus, nucleus gracilis, spinal tract of V, or spinal nucleus of V (nucleus caudalis) depending on the source of pain. This “intramedullary” stimulation “jams” or otherwise prevents the pain signal from being transmitted. The placement of the electrodes is accomplished through an open surgical procedure in which the dura is opened to allow the surgeon direct access to the spinal cord. In the case of SCI (or disease), the electrodes are positioned in the dorsal horn of the spinal cord within several dermatomal segments of the lesioned site. Direct stimulation of the dorsal horn should be effective to relieve pain arising from diseases and/or injury of the peripheral nervous system as well, and thus represents an alternative to dorsal column stimulation with epidural electrodes. Stimulation with intramedullary electrodes may be used to treat other types of pain where stable stimulation of the dorsal columns (and the analogous structures for the face), or their nuclear counterparts (nucleus cuneatus, nucleus gracilis, nucleus caudalis) should relieve pain. Stimulation of the spinothalamic tract may also be achieved by intramedullary placement of electrodes. The method provides a means to stimulate the targeted area directly, creating a stable means of stimulating the desired area, and decreasing stimulation of other structures.
Each intramedullary electrode lead may be composed of one of more contact points. There may be one or more electrodes. The multiple leads and contact points provide a number of potential stimulus permutations. The ideal stimulus configuration can be determined after electrode implantation. The electrodes can be stably anchored in the spinal cord dorsal horn to prevent electrode migration. The electrodes are positioned in the spinal cord with electrode leads of sufficient length to prevent movement of the electrode from its fixed position during movements of the neck and torso. In some cases affixing the electrodes to the dentate ligament or dura or other extradural structures may be of use to prevent further the problem of electrode migration.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic of how the dorsal horn in the region of SCI develops the capacity to signal pain in body regions at and below the level of SCI. Data indicate that increased discharges occur in the dorsal horn area subjacent to the site of SCI (e.g., Falci S, Best L, Bayles R, Lammertse D, Starnes C. J Neurosurg. 2002 September;97(2 Suppl):193-200. Dorsal root entry zone microcoagulation for SCI-related central pain: operative intramedullary electrophysiological guidance and clinical outcome). Cells in the thalamus that have lost inputs from distal regions (as a result of the SCI) recruit inputs from the abnormal dorsal horn cells near the SCI. Thus, the inputs from this spinal cord region acquire the capacity to signal pain in the distal regions of the body. The electrodes provide a means to block the inputs from these abnormal cells to the brain and thus control pain felt by the patient at and below the level of SCI.
FIG. 2 is a perspective drawing showing that one or more electrodes are placed into the dorsal horn immediately adjacent to the region of SCI. Multiple contacts permit various stimulation paradigms to be employed to maximize effectiveness and minimize untoward side effects. In cases of bilateral pain, the electrodes are placed bilaterally.
FIG. 3 is a perspective drawing showing electrodes placed into the portion of the dorsal column that serves the painful region. If pain is bilateral the electrodes are placed bilaterally.
DETAILED DESCRIPTION OF THE INVENTION
I. Devices
A. Electrodes
Electrodes can be obtained from a variety of commercial sources. These are typically characterized by small size and flexibility.
Flexible electrodes are described by U.S. Pat. Nos. 6,024,702 and 5,012,810 incorporated by reference herein. Flexible conductive materials can also be used in making the electrodes as described in U.S. Pat. No. 6,495,020. For example, an electrode member can comprise a strip of material having a thickness of about 10-20 micrometers, such as IMPERIAL® lapping film No. 15 MIC LF S/C (3M Co®, St. Paul, Minn.), having a coating of silver/silver chloride of about 0.3-0.7, and preferably about 0.5, micrometers thick thereon.
The electrodes must be small enough to be implanted into the dorsal horn and other areas of the spinal cord. One such device is, for example, the MEDTRONIC® Model 3387 quadripolar lead, which has been approved by the FDA for several years for unilateral deep brain stimulation for treating tremor. There are four platinum-iridium contacts that are 1.5 mm in length and separated by 1.5 mm. Stimulus parameters such as amplitude, duration, and frequency can all be adjusted externally.
In a preferred embodiment, multi-contact electrodes are used with an array placed in a target area. The electrode leads are several millimeters in length with open contacts along the electrode. These electrodes are very similar to the deep brain stimulation electrodes that have open contacts. Each contact can be post-hoc programmed to be anodal or cathodal. For example, if three separate electrodes are implanted into the spinal cord, and each electrode has three open contacts, it is possible to program many thousands of potential combinations (each electrode may be anodal, cathodal, or inactive). One or more electrodes are placed into the spinal cord in the appropriate position (e.g., in the dorsal horn immediately adjacent and rostral to the region of SCI). Multiple contacts permit various stimulation paradigms to be employed to maximize effectiveness and minimize untoward side effects. In cases of bilateral pain, the electrodes are placed bilaterally.
B. Stimulators
Spinal cord and brain stimulators represent a large group of electrical stimulators that are implanted for a wide variety of indications. Existing spinal and brain stimulators can affect dorsal roots, dorsal columns, and other sites within the brain. The technical and surgical aspects have been reviewed by Simpson ( Brit J Neurosurg 1997; 11:5-11).
The method is designed to work with existing spinal cord and brain stimulation devices. These stimulators typically consist of three components: the power source, an implanted receiver, and electrodes. An external controller allows the device to be custom programmed to idealize the electrical stimulation parameters. Stimulators delivering charge-balanced pulses, either by constant-current or constant-voltage, are preferred. These devices can also be either microprocessor-controlled impedance-sensitive pulse generators, or piezo-electric current devices.
Appropriate stimulators and electrodes for this method include, but are not limited to, those made by MEDTRONICS® (Minneapolis, Minn.) and ADVANCED NEUROMODULATION SYSTEMS, INC® (Plano, Tex.), NEUROMED® (Ft. Lauderdale, Fla.) and EXONIX™ (Miami, Fla.). Examples of these are described in U.S. Pat. Nos. 4,044,774, 5,501,703, 6,027,456, 6,314,325 and PCT application WO 99/56818.
II. Methods of Use
A. Patients to be Treated
1. Spinal Cord Injury. Pain occurs frequently as a complication of SCI. SCI may result from congenital anomalies (e.g., syringomyelia), tumor, trauma, infection, disc herniation, degenerative disease (e.g., spinal stenosis), vascular disease, and demyelinating diseases (multiple sclerosis), and other autoimmune disorders. The damaged site is also called a lesion. Patients describe pain in areas that have lost afferent input to the brain as well as at the border zone of the spinal cord lesion. The pain can vary in intensity, frequency of episodes, duration of episodes, and quality of pain experienced.
Chronic pain problems can occur in individuals with neurologically complete or incomplete injuries. Two types of pain may develop after SCI: 1) segmentally distributed pain (“at level pain”), and 2) pain in the body below the lesion (“below level pain”). In cases of complete spinal cord lesions this second type of pain by definition is stimulus-independent.
2. Other pain conditions affecting the arms and legs. Dorsal column stimulation is accomplished currently with electrodes placed into the epidural space. This technique is useful for treatment of many pain conditions, including lumbar radiculopathy. A requirement for this technology to work is that there has to be “coverage.” This means that the patient must feel paresthesias in the area felt to be painful. Electrodes must be positioned precisely to achieve this coverage. In certain instances coverage is difficult or impossible to obtain. One reason for this problem is that electrodes may migrate with spinal movements. The problem is especially apparent in regards to spinal cord stimulation for treatment of neck and upper extremity pain conditions. Neck motion changes the contact with the epidural space such that in one position the stimulation may be too strong, and in another the stimulation may be too weak. The result is that clinical efficacy is lost. Even if the electrodes are fixed to the dura, the spinal cord distance from the dura also varies with bodily movement. This leads to variations in delivery of electrical stimulation of the spinal cord.
These problems are overcome by placing the electrodes directly into the dorsal columns or their nuclear equivalents (nuclei cuneatus and gracilis). Evoked potential measurements help establish the ideal locations for electrode placement in patients that are under general anesthesia for the surgery required to place the electrodes.
3. Facial pain. The pain processing pathways for the face involve the nucleus caudalis and descending tract of V, both located in the upper part of the cervical spinal cord. Patients with facial pain can not be treated with conventional “dorsal column” epidural stimulation because these targets are not accessible. The electrodes can be implanted directly into the pain processing pathways for the face in the upper cervical spinal cord. This provides a direct means of stimulating the appropriate target without over stimulating other targets. Evoked potential monitoring can provide a physiological means intraoperatively to guide placement of the electrodes into the appropriate target.
B. Targets for Electrode Implantation
The method of treatment of pain involves: (a) targeting areas of the spinal cord that generate signals that lead to pain; and (b) ways to apply direct stimulation to the spinal cord of targets that are involved in pain inhibition (such as the dorsal columns) in situations where epidural activation of these targets is technically not feasible or is associated with untoward side effects.
1. Targeting the dorsal horn with electrical stimulation at the level of injury in cases of SCI.
Whereas stimulation of the dorsal columns (with epidural electrodes) has proved efficacious in treating a variety of pain disorders, this technique has failed to help with pain from SCI. A major region for this is that the region of the dorsal column that conducts signals from the painful region has been disconnected. Thus stimulation fails to provide coverage given that the appropriate targets have undergone Wallerian degeneration. It is clear that a radically different approach must be considered to treat pain from SCI.
The region responsible for initiating the neural signals responsible for pain must be rostral to the transection site of the spinal cord, since involvement of the brain is ultimately necessary to have pain, and because signals below the level of injury have no way of reaching the brain ( 18 ). One consideration is that the pain signals arise in the brain itself The following lines of evidence suggest that this conclusion is incorrect. (a) If the pain signals arise in the supraspinal region independent of the injured spinal cord then spinal anesthesia should have no effect on the pain. The opposite, however, is true. Loubser and Donovan (Loubser and Donovan; Paraplegia. 1991 January 29(1):25-36) noted that application of spinal anesthesia often relieved distal pain. Intrathecal lidocaine was delivered to paraplegic and quadriplegic patients in concentrations such that the highest effect of the anesthesia would be T4. In this blinded protocol, the anesthetic had a significant pain relieving effect. Thus, the pain signaling neurons must be in the region of the spinal cord transection. (b) Other investigators have found that spinal cord ablative procedures may correct pain from SCL Of particular interest is the finding that thermal destruction of the dorsal horn near the region of spinal injury may relieve pain in distal regions (Falci et al; J Neurosurg 2002 September; 97:193-200). This can be explained if the dorsal horn region at the level of SCI has developed the capacity to signal pain in the distal regions.
Dorsal horn neurons in the region of the SCI are known to become abnormally active ( 14 ). The dorsal horn is the primary relay center in the spinal cord for painful stimuli to the brain. The nociceptors synapse on neurons in the marginal zone, substantia gelatinosa and deeper layers and from these regions information ascends to the brain. Normally the spinothalamic tract transmits the nociceptive information with nerve fibers ascending in the contralateral ventrolateral spinal cord to the brainstem and ventroposterolateral thalamus.
Since these dorsal horn cells normally signal pain at the respective segmental level, it is clear that these cells likely generate the “at level” pain ( 10 ). In that the dorsal horn region just above the SCI may also still have connections with peripheral nerve inputs, this hyperexcitability also accounts for why hyperalgesia (including allodynia) is also present at the level of injury. The reasons why pain develops in distal body regions (viz., legs, feet, and sacral region) after spinal cord transection may be understood by considering two interrelated mechanisms: (1) abnormal spontaneous activity in pain generating neurons in the dorsal horn of the spinal cord at (and near) the level of injury ( 14 ); and (2) acquired capacity of these cells to activate neurons in the brainstem/thalamus/cortex that signal sensation in the body regions that have lost input to the brain as a result of the SCI ( 16 ).
FIG. 1 illustrates these concepts. The neurons in the dorsal horn near the area of injury develop abnormal spontaneous activity ( 14 ). This spontaneous activity accounts for the so called “at level” pain ( 10 ). Normally these neurons signal pain confined to their segmental inputs. The areas in the brain, such as the thalamus, that receive inputs from the spinal cord caudal to the region of SCI ( 18 ) demonstrate plasticity such that they now receive inputs from the cells of the dorsal horn at the level of injury ( 16 ). The inputs from the segmental dorsal horn neurons near the area of SCI acquire the capacity to activate the neurons that signal pain in the caudal areas of the body by way of synaptic sprouting and/or physiological changes in synaptic efficacy ( 16 ). This concept of SCI pain accounts for the findings of Falci et al (2002) that destruction of the dorsal horn near the transection site may eliminate “at level” as well as “below level” pain. Additionally this concept explains why spinal anesthesia may eliminate below level pain. For example, the T7 level of the dorsal horn provides pain and temperature sensation at the T7dermatome. If the cord is severed just below the T7 region, the T7 dorsal horn cells become hyperexcitable. Ordinarily these cells would simply signal pain at the T7 (mid-thoracic) regions. It is the border zone at the lesion site, or immediately proximal to the lesion, that is the site of aberrant neuronal activity ( 14 ). The abnormal activity in the dorsal horn cells is relayed not only to the regions in the thalamus that normally receive the T7 input but also regions of the thalamus that ordinarily serve the distal regions. This rearrangement (from sprouting and/or changes in synaptic efficacy) in the thalamus occurs because the thalamic area that serves the distal region has been denervated ( 20 ). The changes might also occur in other areas such as the cortex. Thus the abnormal activity at T7 leads to abnormal pain at in the T7 dermatome but also the regions distal to the SCI.
Given that the culprit in SCI pain is the dorsal horn, a potential therapy is to block that abnormal neural activity in the dorsal horn. This might be achieved by lesioning the dorsal horn as advocated by Falci et al (2002). The disadvantages of this approach are that this technique extends the level of SCI, is irreversible, and potentially establishes a new zone of SCI that could create new sources of pain. Stimulation of the generator site in the dorsal horn provides a non-destructive means of blocking the pain signaling.
In the field of movement disorders, (e.g., Parkinson's disease) certain brain targets can be stimulated at high frequency (>100 Hz) with an implanted microstimulator and achieve a therapeutic effect (Starr et al Neurosurg. Clin. N. Am. (1998) 9(2):381-402). It is important to note that the targets for stimulation are the same as the targets for ablation. As described herein, the target for stimulation (dorsal horn) is also the same as the target for lesioning in treatment of pain from SCI. Although not critical to the method of treatment, possible mechanisms that would account for how stimulation relieves pain include: (1) activation of nearby inhibitory cells, and (2) a jamming mechanism in which the rate of stimulation leads to loss of conductive capacity in the neurons (Magarinos-Ascone C, Pazo J H, Macadar O, Buno W. Neuroscience. 2002;115(4):1109-17 High-frequency stimulation of the subthalamic nucleus silences subthalamic neurons: a possible cellular mechanism in Parkinson's disease; Beurrier C, Bioulac B, Audin J, Hammond C.); J Neurophysiol. 2001 April;85(4):1351-6. High-frequency stimulation produces a transient blockade of voltage-gated currents in subthalamic neurons); (3) an alteration of the pattern of discharge such that the rostrally conducted impulses no longer activate brain areas concerned with pain signalling. Thus, implantation of an electrode and stimulation offers an alternative to ablation and avoids destruction of spinal cord tissue. This reversible intervention can be removed or stop being used at a later time if other therapies emerge. The stimulation parameters can also be adjusted so that the therapy can be graded to a certain level as opposed to the all-or-none action of surgical ablation. Multiple implant sites can be used and post-hoc programming can be used to determine the ideal electrode configuration.
2. Technique for Dorsal Horn Stimulation.
Dorsal horn stimulation preserves the hyperexcitable neurons at the level of the lesion while inactivating their function or capacity to transmit signals to the brain. As shown in FIG. 2 , the electrodes ( 24 ) are inserted into the gray matter of the spinal cord, preferably at the level of the lesion ( 22 ). Since the border zone is the target site for dorsal horn stimulation, it is most preferable that the electrodes ( 24 a, 24 b, 24 c ) be positioned at and within 2-3 spinal segments rostral to the lesion ( 22 ). Placement of the electrodes must be done precisely and requires surgical exposure of the dorsal horn through a laminectomy. Anatomical landmarks are used to guide placement of the electrodes. It is possible that electrophysiological monitoring can be used as well to guide placement as described by Falci et al (2002). Programming of the electrical stimulation paradigm post-operatively with the patient awake will determine the ideal configuration of stimulation. The variety of electrode placements intraoperatively allows the best electrical stimulation paradigm to be used in order to maximize pain relief and minimize side effects.
3. Use of Intramedullary Electrodes to Stimulate Targets in the Spinal Cord Other than the Dorsal Horn.
Spinal cord stimulation is a frequent therapeutic tool to treat a variety of pain states. Electrodes are placed into the epidural space and positioned so that the patient feels parethesias in the region of pain. The patient indicates whether there is pain relief and the decision is made to do a permanent implant. Electrodes have been placed in the subdural space and intradural compartment, but because of ease of use epidural stimulation is the prevailing technique presently utilized. This technique, though effective, suffers from problems with obtaining stable stimulation. The electrodes may move or the electrical connectivity with the desired target may be such that excessive stimulation has to be applied to unwanted regions of the spinal cord in order to stimulate the desired target (Barolat Arch Med Res 2000 31:258-262; Holsheimer et, al., Neurosurg 1998 42:541-547). While somewhat a problem for the lower extremities, this problem with inadequate stimulation of the desired targets in the dorsal column is especially limiting for the upper extremities. Neck motion changes the conduction properties in patients such that the patient experiences sags and surges in the intensity of the stimulation with normal neck motion. Several attempts have been tried to circumvent these technical problems. For example, suturing of the electrode to the adjacent soft tissue or bone is one method. Another method provides a lead anchor (LA) and/or suture sleeve (SS) that may be used after insertion of the electrode array into the spinal canal in order to secure and maintain the position of the electrode and prevent its dislodgement due to axial loads that are placed upon the lead (described in U.S. Pat. No. 6,516,227). A paddle lead has also been used with a variety of electrode contact configurations or arrays so that a combination can be used if the first stimulus combination becomes inactive (U.S. Pat. No. 6,308,103). These techniques are still insufficient because other factors affect the stimulation efficacy. The conduction to the dorsal columns is also affected by the distance between the dura and the spinal cord. It is well known that with different head position or trunk positions that the space between the dura and the spinal cord varies. This is a further factor that gives rise to sags and surges in the stimulation afforded by durally based electrodes.
Therefore, the method described herein involves placement of intramedullary electrodes into the desired target. Intramedullary refers to the substance of the spinal cord.
Potential targets include the dorsal columns, the nucleus cuneatus (arm), nucleus gracilis (leg and sacral regions), nucleus caudalis and spinal tract of V (face and neck), and the spinal-thalamic tract. The dorsal horn may also be included as a target for stimulation in cases other than SCI. As shown in FIG. 3 , electrodes ( 30 ) can be inserted directly into the spinal cord white matter ( 36 ) comprising the dorsal column projection pathway. The lead ( 34 ) is connected to a stimulator. The cuneate fascicle ( 38 ) is one of the nerve pathways relaying sensory information from the spinal cord to the brain. This provides more stable stimulation.
Fibers in the dorsal column pathway normally relay touch and position sense information and ascend to the medulla where they synapse onto neurons in the nucleus cuneatus and nucleus gracilis. Neurons in these two nuclei project along the medical lemniscus and synapse on cells in the ventroposterolateral (VPL) thalamus. The VPL thalamus is the central receiving area for sensory information before transmission to the cortex.
The position of cathodes and anodes, and configuration of the stimulation are the major determinants of whether the patient will experience “coverage.” Coverage refers to the desired goal of having the patient feel paresthesias in the painful area in the case of dorsal column stimulation (including here stimulation of nuclear areas, nuclues cuneatus, and nucleus gracilis).
Stimulation of the nuclues cuneatus and nucleus gracilis provides a way to obtain results similar to dorsal column stimulation. These nuclei receive inputs from the dorsal columns. In particular, stimulation in these areas would be expected to provide widespread coverage with less power requirements if the patient has widespread pain.
A further use of the intramedullary spinal cord stimulating electrodes is to stimulate the nucleus caudalis and spinal trigeminal tract. These structures are immediately lateral to the cuneate fasciculus below the level of the medulla, and are the facial analogs of the dorsal horn. Implantation of electrodes in these structures should relieve facial pain in a similar fashion to how pain is relieved by dorsal horn stimulation.
Stimulation with implanted electrodes for treatment of facial pain is presently unsatisfactory. The dorsal column equivalent for the face region is sufficiently far from the epidural space that epidural electrodes would not be expected to provide selective stimulation of the relevant target. Recently neurosurgeons working with implantation of epidural electrodes over motor cortex observed some promising results. There are potential liabilities for stimulation of the cortex of the brain, however, including the possibility, for example, of inducing epilepsy. Moreover, the mechanism by which motor cortex stimulation works is unknown. The types of patients helped with this technique may be completely different from the patients who should derive benefit from intramedullary stimulation of the spinal cord.
C. Electrode Implantation
The electrodes are inserted by the surgeon directly into the spinal cord tissue with direct visual control. Electrophysiological recordings may be made as well to ensure that the electrode positioning is accurate. Typically, the leads are implanted in a procedure called a bilateral laminectomy. This procedure is considered major surgery and entails removing two or three spinous processes and one or more full set of lamina. The dura is opened and the surgeon visualizes the spinal cord directly. The anatomic target is selected and the electrodes are placed (this may require use of the operating microscope).
The electrodes will be placed directly by the surgeon into the appropriate region of the spinal cord. The surgeon can be aided by electrophysiological data. The nerve that serves the painful area can be stimulated intraoperatively and the evoked potentials associated with this stimulation can be used to place the electrodes into the ideal regions of the dorsal columns as well as other targets. Such methods are known in the art and are described in U.S. Pat. No. 6,027,456. Electrophysiological recordings are used in cases of SCI to guide spinal cord lesioning (Falci, 2002). Similar guidance should be useful for electrode positioning.
In a preferred embodiment, the electrodes are implanted at and just above the SCI site in the dorsal horn. Recent advances in electrode arrays with multiple contacts have allowed for optimal combinations of contacts to be stimulated after implantation.
D. Connection to and Use of the Stimulator
The stimulator is hermetically sealed from the external environment except for the electrode leads and is sterile packaged to minimize potential for infection after implantation. The electrodes may be connected to existing stimulator systems in one of two ways. One version consists of an external (to the body) radio frequency transmitter and antenna, with an implanted radiofrequency receiver and stimulation leads. In an alternative version the transmitter is implanted and thus an external antenna is not needed.
The electrodes are connected to an implanted receiver via conductive leads. The stimulation at a range of potential frequencies and voltages is provided in similar fashion as what is provided with conventional dorsal column and deep brain stimulation devices. Multiple contacts permit various stimulation paradigms to be employed to maximize effectiveness and untoward side effects. In cases of bilateral pain, the electrodes are placed bilaterally. The dorsal horn stimulation will lead to relief of pain.
The intensity of the stimulation must be in an amount effective to provide coverage of the areas where the patient describes feeling pain. For example, if the patient is experiencing pain in the right arm, but stimulation evokes sensation in the right leg, coverage is not adequate. Paresthesia coverage can be altered by proper positioning of the anodes and cathodes and by programming the electrical stimulation configuration. In a preferred embodiment, multiple electrode leads and contacts permit a “stimulation array” wherein effective coverage is obtained to relieve pain by stimulating different contacts.
Stimulus parameters can be adjusted to manipulate the strength, duration and frequency of stimulation. The parameters (electrode or electrodes used, number of pulses, amplitude, pulse to pulse interval, duration of pulses, etc.) of the stimulation may be set or varied as a result of the detection of signals from the patient's body including the nervous system or set by a physician. Typical stimulus parameters include pulse duration between 60-120 microseconds, pulse amplitude between 0.1-7V, and stimulus frequency between 10-300 Hz. Observations in the treatment of movement disorders have shown that on a behavioral level, a stimulation of >100 Hz gives the same results as lesioning the area (Starr et al. 1998 Neurosurg Clin N Am 9(2):381-402).
A stimulation regimen can be determined empirically to give a certain amount of “on time,” and “off time” to give optimal balance between analgesia, prolonged battery life and patient satisfaction. An external programming device can be used to adjust all stimulus parameters and also determine which electrodes are activated, and furthermore which electrodes serve as cathodes and anodes.
In summary, the method typically includes the steps of implanting the electrodes, attaching the electrode leads to the receiver and power source and applying a stimulus in an effective amount to decrease pain due to the disease or injury. In one embodiment, different electrodes are positioned rostral to, and at the level of spinal cord disease or injury. In another embodiment, the electrodes are positioned in the dorsal column, to treat pain from the neck down. In still another embodiment, the electrodes are positioned in the nucleus cuneatus for treatment of pain in the arm. In additional embodiments, the electrodes are positioned in the nucleus gracilis for treatment of pain in the leg and sacral regions or in the nucleus caudalis and spinal tract of V for treatment of pain in the face and neck. In other embodiments, the electrodes are positioned in the spinal-thalamic tract or into the spinothalamic tract to treat pain in the contralateral arm, trunk, leg, or sacral area. In yet another embodiment, the electrodes are positioned in the dorsal horn of the spinal cord within several dermatomal segments of the lesion site.
In the preferred method, the electrodes directly stimulate the dorsal horn in an amount effective to relieve pain, usually by a pulse duration between 60 and 120 microseconds, a pulse amplitude up to 7 volts, and a stimulation frequency greater than 20 Hz.
There are drawbacks to caring for a chronically implanted device, but these are known in the art. There is always the risk of infection and migration of the electrodes with any implanted foreign object. If a power supply is worn externally and if batteries are used, they must be changed regularly. A single stimulator may also be limited to a particular effective field. Operative risks including spinal cord injury are associated with implantation of the electrodes. Despite these drawbacks, intramedullary stimulation may provide pain relief where other alternatives are ineffective.
Modifications and variations of the present invention will be obvious to those skilled in the art from the foregoing detailed description. Such modifications and variations are intended to come within the scope of the following claims. | The method disclosed herein entails spinal cord stimulation via electrodes placed directly into the dorsal horn, dorsal column, spinothalamic tract, nucleus cuneatus, nucleus gracilis, spinal tract of V, or spinal nucleus of V (nucleus caudalis) depending on the source of pain. This “intramedullary” stimulation “jams” or otherwise prevents the pain signal from being transmitted. The method provides a means to stimulate the targeted area directly, creating a stable means of stimulating the desired area, and decreasing stimulation of other structures. | 0 |
REFERENCE TO EARLIER FILED APPLICATION
This application claims the benefit of earlier filed provisional patent application 60/559,423 filed Apr. 6, 2004 by the applicant herein.
BACKGROUND OF THE INVENTION
The present invention relates generally to road or pavement sweeping machines and, more particularly, to such machines having debris-intake hoods of the type designed to pickup or remove dust, particulates, and other debris from a road or pavement surface.
Various types of vehicles have been developed to sweep or vacuum debris from pavements, roadways, and streets. In general, these vehicles use a motor-driven fan to create a high-velocity air flow to effectively vacuum or aspirate the debris from the pavement or street surface. In a typical recirculating air-flow system, a motor-driven fan develops a high-volume, high-velocity air-flow through a debris-intake hood that is mounted closely adjacent the pavement surface. As the high-velocity air flow moves from an air-inflow portion of the debris-intake hood to an air-outflow portion, debris is aspirated by or entrained into the air flow. The debris-carrying air flow is then carried by ducting into and through a debris-collecting hopper or container. A gutter broom is often mounted adjacent to one or both lateral sides of the debris-intake hood to brush debris into the path of the debris-intake hood, and, additionally, a laterally extending cylindrical brush roll can be used to further dislodge debris from the surface being swept.
It is oftentimes desirable not to collect debris from the road or pavement surface but to blow the debris off the surface; for example, when cleaning an airport runway or waterfront pier of new-fallen snow, it may be more convenient to merely blow the snow onto ground surfaces adjacent the runway or into the water surrounding the pier.
SUMMARY OF THE INVENTION
A road/pavement sweeper is provided with a pickup head or debris-intake hood that operates in a conventional manner to entrain or aspirate particles and/or debris from the pavement surface. The air-inlet structure of the debris-intake hood is provided with an air-flow control member that selectively directs the air flow through the debris-intake hood or through an opening in the air-inlet structure to create an air blast useful to blow debris from the pavement or roadway surface. In one form of the invention, fixed-position air-flow vanes direct the air blast in a preferred direction, and, in other forms of the invention, one or more variable or controllable-position air-flow vanes allow the operator to selectively and variable direct the air-blast direction.
The full scope of applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings, in which like parts are designated by like reference characters.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial side elevational view of a representative pavement/street sweeper having a debris-intake hood with a side or lateral air blast/blower system in accordance with the present invention;
FIGS. 2 and 3 are side-to-side lengthwise views of a debris-intake hood showing air flow arrows for a first pickup mode in FIG. 2 and for a second air blast mode in FIG. 3 ;
FIG. 4 is a top view of the debris-intake hood of FIGS. 2 and 3 ;
FIGS. 4A and 4B illustrate an alternate variant of the structure shown in FIG. 4 ;
FIGS. 4C and 4D illustrate further alternate variants of the structure shown in FIG. 4 ;
FIG. 5 is a detailed side elevational view, in partial cross-section, of the inlet structure of the debris-intake hood of FIGS. 2 and 3 showing an air flow control structure in an “air blast” mode;
FIG. 6 is another side elevational view of the inlet structure of FIG. 5 , taken along line 6 - 6 of FIG. 5 , showing an air-blast outlet opening;
FIG. 7 is a detailed side elevational view, in partial cross-section, of the inlet structure of the debris-intake hood of FIG. 5 showing the air flow control structure in an intermediate position;
FIG. 8 is a detailed side elevational view, in partial cross-section, of the inlet structure of the debris-intake hood of FIG. 5 showing the air flow control structure in a “pickup” mode;
FIG. 9 is a side elevational view of the air flow control structure;
FIG. 10 is a front elevational view of the air flow control structure of FIG. 9 ;
FIG. 11 illustrates the manner by which the air flow control structure of FIG. 10 is fabricated;
FIG. 12 is a front elevational view of a support panel for the air flow control structure of FIG. 9 ; and
FIGS. 13 and 14 are an idealized view of a curvilinear air flow control structure.
DESCRIPTION OF THE INVENTION
An exemplary pavement/street sweeper upon which a debris-intake hood in accordance with the preferred embodiment can be mounted is shown in representative form in a truck-mounted sweeper 20 in side view in FIG. 1 ; the particular sweeper shown is exemplary and representative of sweepers manufactured by Schwarze Industries, Inc. of Huntsville, Ala. 35811.
As shown in FIG. 1 , the truck-mounted sweeper 20 , which can be fabricated from a commercial truck chassis, includes a pickup head or debris-intake hood 22 carried beneath the truck frame 24 , a conventional gutter broom 26 that is mounted forwardly of the debris-intake hood 22 on one or both sides thereof, and a power unit 28 that includes (not specifically shown) a high-volume, high-velocity radial flow fan, an internal combustion engine for driving the fan and associated hydraulic pumps and various accessory and related equipment as is known in the art.
A debris container 30 is mounted rearwardly of the power unit 28 and is designed to receive and accumulate debris that is aspirated or swept from the roadway surface. The debris container 30 typically includes an inlet (not shown) into which the debris-laden air is conducted into the container 30 and an outlet 30 a through which the air flow is returned in an air flow recirculation loop as is known in the art. Air handling flexhoses (of which flexhose 30 b is shown in FIG. 1 ) interconnect the debris intake hood 22 with the debris container 30 as is also known in the art. The debris-laden air, as it enters the internal volume of the debris container 30 , experiences a decrease in its air velocity so that the entrained particles “drop-out” of the air flow and are collected in the debris container 30 . The air flow within and through the debris container 30 can be directed through various baffles and/or screens to maximize the probability the debris will be collected in the debris container 30 . A more detailed description of the vehicle shown in FIG. 1 is provided in commonly assigned U.S. Pat. No. 6,371,565 issued Apr. 16, 2002 to A. Libhart, the disclosure of which is incorporated herein.
FIGS. 2 and 3 are a side-to-side lateral elevational view of the debris-intake hood 22 of FIG. 1 illustrating the air-flow pattern for the conventional pickup mode ( FIG. 2 ) and the air blast mode ( FIG. 3 ). As shown, the debris-intake hood 22 includes a housing 32 that is typically open on the side thereof facing the ground surface to be swept. An air-flow inlet structure 34 is provided on the right side of the housing 32 into which a high-volume, high-velocity flow of air enters the housing 32 . In a similar manner, an air-flow outlet 36 structure is provided on the opposite end thereof from which the air-flow exits the housing 32 . As is known in the art, the air-flow inlet and outlet structures connect to the vehicle air-flow recirculation system via flexible ducting (of which flexhose 30 b of FIG. 1 is representative).
A pivotally mounted control arm 38 is provided on the right side of the housing 32 and is designed to be pivoted about an axis A x between a first position, as shown in FIG. 2 , and a second position, as shown in FIG. 3 . The control arm 38 is selectively moveable to and from its first and second position by an actuator 40 connected between the remote end of the control arm 38 and a suitable anchor point 42 . The actuator 40 can take any suitable form including a hydraulic, electric, or pneumatic actuator. While the actuator 40 has been shown as a linear actuator, a rotary actuator is equally suitable. If desired, the control arm 38 can function as a manually controlled handle by which an operator moves the control arm 38 to a selected position or, optionally, the control arm 38 can be operated remotely by a “Bowden” type cable or other mechanical linkage.
When the control arm 38 is in its first position as shown in FIG. 2 , the debris-intake hood 22 is configured in its normal debris removal mode in which a high-volume, high-velocity flow of air enters the air-inlet structure 34 and moves laterally from the right to the left in FIG. 2 to exit the debris-intake hood 22 through the air-flow outlet 36 as shown by the solid and dotted-line arrows.
When the control arm 38 is in its second position as shown in FIG. 3 , the debris-intake hood 22 is configured in its air blast/blower mode in which a high-volume, high-velocity flow of air enters the air-inlet structure 34 and is directed laterally outward of the debris-intake hood 22 to the right in FIG. 3 . The high-volume, high-velocity flow of air through the debris-intake hood 22 entrains or otherwise picks-up debris from the roadway surface as is known in the art.
FIG. 4 is a top view of the debris-intake hood 22 and illustrates the air-flow inlet structure 34 and the air-flow outlet 36 of FIGS. 2 and 3 from the top. As shown on the right in FIG. 4 , one or more air-directing vanes 44 can be optionally provided to direct the air blast in the direction shown. In the preferred embodiment, the air-directing vanes 44 are fixed to the air-flow inlet structure 34 and direct the air blast laterally and fowardly from the vehicle. As can be appreciated and as shown in FIG. 4 in dotted-line illustration, the air-directing vanes 44 can be pivotally mounted on appropriate hinges (or similar structure) and connected together by a link (not shown) so that they move together. A bi-directional actuator 46 is attached to one or the other of the vanes 44 and selectively controlled to point the air blast in a desired direction. If desired, the actuator 46 can be controlled in a cyclic or oscillatory manner by an appropriate controller to cause the air blast to sweep in a recurring manner to and from its angular limits. As in the case of the actuator 40 , the actuator 46 can take any suitable form including a linear or rotary hydraulic, electric, or pneumatic actuator or mechanical actuator such as a “Bowden” cable or other suitable linkage.
FIGS. 4A-4D represent further alternate variants of the present invention including independent control of the air-directing vanes 44 and further air-directing vanes that allow an up/down control of the air blast.
In FIG. 4A , each air-directing vane 44 is under independent control of a respective actuator 46 so that each air-directing vane 44 can be independently moved. As shown in FIG. 4A , the air-directing vanes 44 can be pivoted toward one another to “narrow” the air flow or, as a shown in FIG. 4B , the air-directing vanes 44 can be pivoted away from one another to “widen” the air flow. While FIGS. 4A and 4B show their respective air flows as laterally directed, the air-directing vanes 44 can be controlled to direct the appropriately “narrowed” or “widened” air flow in a forward or aft direction as desired and in a manner consistent with that shown in FIG. 4 .
FIG. 4C shows an embodiment in which the air-control vanes 44 described above are removed and replaced by spaced-apart air-control vanes 44 ′ that are pivoted or hinged along axes that are 90° relative to those of the air-control vanes 44 of FIG. 4 . The air-control vanes 44 ′ are connected by a link (not shown) so that they move together under the control of an actuator 46 so that the air flow can be directed down toward the ground surface, horizontally relative to the ground surface, or upwardly. As in the case of the embodiments of FIGS. 4A and 4B , the air-control vanes 44 ′ can be independently controlled by separate actuators 46 to “narrow” or “widen” the air flow as desired while also allowing for up/down directional control.
The embodiment of FIG. 4D represents a combination of controllable vanes 44 for forward/aft direction control and vanes 44 ′ for up/down direction control. In FIG. 4D , the air-control vanes 44 are shown as rectangular panels and are mounted in the same manner as in FIG. 4 and FIG. 4A or FIG. 4B with one or more actuators providing directional control. Baffle plates 62 are affixed to the air-inlet structure 34 and extend outwardly therefrom with sufficient clearance so that the air-control vanes 44 are free to move to control the forward/aft direction of the air blast. In addition, air-control vanes 44 ′ are pivoted to or hinged to the remote ends of the baffle plates 62 and are controlled by one or more actuators to provide up/down directional control. As can be appreciated, the embodiment of FIG. 4D provides the operator with the ability to control the forward/aft and the up/down direction of an appropriately “narrowed” or “widened” air blast to effect the desired debris removal or movement solution.
FIGS. 5-9 illustrate the operation of an air-flow controller 48 located in the air-flow inlet structure 34 . In FIG. 5 , an air-flow controller 48 is shown in its air-blast position corresponding to FIG. 3 in which a high-volume, high-velocity air flow enters the air-flow inlet structure 34 and is directed by the air-flow controller 48 through an opening 50 ( FIG. 6 ) with the air-flow directing vanes 44 assisting in the control of the resulting air blast. In FIG. 7 , the air-flow controller 48 is shown in an intermediate position as it is moved to its first position corresponding to FIG. 2 . In FIG. 8 , the air-flow controller 48 is shown in its first position in which the air flow entering the air-flow inlet structure 34 is directed by interval vanes (not shown) into the debris-intake hood 24 as shown in FIG. 2 while the opening 50 is concurrently and substantially blocked or occluded.
The structure of the air-flow controller 48 is shown in FIGS. 9-12 ; as shown in the side view of FIG. 9 and the elevational view of FIG. 10 , the air-flow controller 48 includes the above-mentioned control arm 38 attached at its one end to a shaft 52 mounted for limited rotation about the axis A x . A multi-plate assembly that includes first, second, and third sub-plates 54 , 56 , and 58 and a brace 60 are mounted to the shaft 52 (e.g., by welding) for rotation therewith in response to movement of the control arm 38 .
As shown in FIG. 11 , the sub-plates 54 and 56 are assembled as a tab-and-slot weldment; more specifically, tabs A 1 , A 2 , and A 3 in the sub-plate 54 are received in appropriately sized and positioned slots B 1 , B 2 , and B 3 in the sub-plate 56 and secured together with the sub-plates 54 and 56 aligned at an angle α (i.e., about 150°) as shown in FIG. 9 . The sub-plate 58 includes tabs A 4 and A 5 that interengage with slots B 4 and B 5 in the sub-plate 56 as shown in FIG. 9 . Preferably, the sub-plate 58 is formed along a curved line that corresponds to internal flow vanes (not shown) in the housing 32 of the debris-intake hood 22 to smoothly transition the high-velocity, high-volume air flow into and through the debris-intake hood 22 . For the preferred embodiment shown, the general angular separation between the sub-plate 54 and that of the sub-plate 58 can be in the general vicinity of about 70° or so.
When the control arm 38 is in its first position as shown in FIG. 2 , the sub-plate 56 substantially blocks or occludes the opening 50 ( FIG. 6 ) with the various margins of the sub-plate 56 engaging with or otherwise pressing against margins of the opening 50 to form an adequate seal therebetween. In this configuration, the high-velocity, high-volume air flow entering the air-inlet structure 34 is guided, in part, by the appropriately curved sub-plate 58 into the interior of the housing 32 and moves laterally from the right to the left in FIG. 2 to exit the debris-intake hood 22 through the air-flow outlet 36 as shown by the solid and dotted-line arrows in FIG. 2 .
When the control arm 38 is in its second position as shown in FIG. 3 , the debris-intake hood 22 is configured in its air blast/blower mode in which a high-volume, high-velocity flow of air enters the air-inlet structure 34 and is directed laterally outward of the debris-intake hood 22 through the opening 50 to the right in FIG. 3 . In this air blast mode, the sub-plates 54 and 56 engage or otherwise press against interior surfaces of the air-inlet structure 34 to direct the high-volume, high velocity air flow through the opening 50 with the air-directing vanes 44 directing or guiding the air blast. In the case of the preferred embodiment, the air-inlet structure 34 is located on the driver side of the vehicle 20 and the air-directing vanes 44 (and/or 44 ′) are oriented or aligned to direct the air blast laterally of the vehicle. As can be appreciated and as mentioned above, the air-directing vanes 44 can be made adjustable as desired.
In the exemplary embodiment above, the air-flow controller 48 has been shown as a multi-plate weldment; as can be appreciated, other embodiments are possible. For example and as shown diagrammatically in FIGS. 13 and 14 , another air-flow controller 48 ′ is shown as an appropriately shaped single curvilinear plate or as a multi-plate weldment that is appropriately shaped to provide the desire operation. As can be appreciated, the air-inlet structure 34 is appropriately modified to accommodated the air-flow controller 48 ′. In yet another variation, a single sub-plate can be welded to the shaft 52 to function as a simple ‘flap’ valve in which the shaft 52 is rotated to substantially block the opening 50 or counter-rotated to substantially block the interior cross-section of the air-inlet structure 34 while unblocking the opening 50 .
While the controllers 40 and 46 have been described as any type of linear or rotary hydraulic, electric, or pneumatic actuators, suitable control can also be achieved by manually operable links or linkages, flexible cables, Bowden-type push/pull wires, or combinations thereof. Additionally, the CTRL function shown in FIG. 4 can be a pre-programmable or otherwise programmable electronic or mechanical/electrical device that controls the actuator 46 to move the various air-control vanes 44 and/or 44 ′ in accordance with a desire back-and-forth and/or up/down motion or any other desired sweep pattern.
As will be apparent to those skilled in the art, various changes and modifications may be made to the illustrated embodiment of the present invention without departing from the spirit and scope of the invention as determined in the appended claims and their legal equivalent. | A road/pavement sweeper is provided with a pickup head or debris-intake hood that operates in a conventional manner to entrain or aspirate particles and/or debris from the pavement surface. The air-inlet structure of the debris-intake hood is provided with an air-flow control member that selectively directs the air flow through the debris-intake hood in order to conventionally entrain debris or particles from the surface being swept or through an opening in the side of the air-inlet structure to create an air blast useful to blow debris from the pavement or roadway surface. One or more fixed-position or controlled-position air flow vanes can be provided to selectively direct the air blast. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates to a fan, especially for the conveyance of the combustion air in the case of a motor vehicle heater.
Fans of this type, which frequently are ring-duct fans, supply high pressures at relatively low efficiency. Their characteristic curves are steep. Mainly, in the case of higher rotational speed, they are considerably noisy during operation.
Fans of this type are known, for example, from German Pat. No. 902 074 and German Published Patent Application No. 24 09 184. In the case of the known ring-duct fans or lateral-duct compressors, an opening is provided in the area of the impeller between the intake connection and the pressure connection, through which gas can exit, which otherwise would be pulled along from the pressure connection to the intake connection. This measure has the purpose of increasing the efficiency of such known fans. In this case, the gas exiting through the opening may either, by means of a return pipe, be directed to an intermediate point of the lateral-duct (DE-AS No. 24 09 184) or it may also be directed to the intake connection of the compressor of the fan (DE-PS No. 902 074).
The present invention has for a principal object the creation of a fan of the initially mentioned type that has a mechanism for the adjustment of its capacity, which enables the adjustment of the fan output to be performed in a manner that as little noise as possible is developed and an efficiency is achieved that is as high as possible.
According to the present invention, this object is achieved, in accordance with preferred embodiments, by provision of a by-pass duct that is connected with the conveying outlet of the fan and has an adjustable throttling member.
In contrast to the conventional output control, where a throttling member is disposed in the intake duct of the fan, the measure according to the present invention results in the following advantages: The power input of the fan rises with an increasing pressure ratio. In the case of an output by means of the throttling of the intake air, the pressure ratio is increases and, therefore, also the power input. Because of the features of the present invention, however, the pressure ratio is not increased during the reduction of the fan output, because an equalization of pressure takes place through the by-pass duct. Thus, the power input is reduced in comparison to the output control by means of the throttling of the intake air. The development of noise also increases with the pressure ratio. Since, as explained, the pressure ratio is not increased when the output of the fan of the present invention is reduced, the development of noise is also decreased in comparison to the conventional solutions.
When the fan is used in a combustion fan in heaters, the fan according to the present invention also results in the following advantage: When the point in the by-pass duct, where the throttling member is located, is clogged by dirt, this only results in an increase of the fan output. However, an increase of the fan output is harmless in regard to the production of harmful substances (CO 2 and CO). In the case of the conventional solution, on the other hand, where the output control takes place by means of the throttling of the intake air, dirt accumulation at the throttling point would result in a decrease of the combustion air conveyance and, thus, in an increase in the unburned, partially toxic fuel components.
Furthermore, in the case of the damming of the combustion-air intake opening of a heater according to the solution of the state of the art, where the supply of intake air is throttled, the maximally possible fan pressure accumulates at all seals and, in the case of possible small leaks, results in emissions of harmful substances. In the case of the by-pass solution according to the present invention, however, the fan pressure can reach no more than the flow resistance of the by-pass duct (which is significantly lower than the maximal fan pressure).
According to a particularly advantageous aspect of the invention, the efficiency of the fan can be further increased if the air expanding in the by-pass duct is used for admission to the fan impeller. For this purpose, it is provided that the by-pass duct leads into the intake duct of the fan.
Especially in combination with ring-duct fans, the invention is advantageous because ring-duct fans have steep characteristic curves and the adjustment of the output is, therefore, especially critical.
According to an advantageous embodiment, the throttling member in the by-pass duct consists of an adjusting screw. It is especially advantageous to use a setscrew for this purpose.
According to another advantageous embodiment of the invention, this adjusting screw may be disposed so that it also projects into both the intake duct and the by-pass duct so that, to the extent that adjustment of the screw frees the cross section of the by-pass duct, it reduces the cross section of the intake duct. Consequently, the adjustment is especially effective because the two mentioned effects are added to one another.
The efficiency of this control is greater, the closer the by-pass opening is disposed to the lateral duct of the fan, and the more directly the by-pass opening connects the pressure side with the suction of the duct. Accordingly, it is an advantageous feature of the invention to make the by-pass duct between the intake duct and the conveying outlet of the fan as short as possible.
In another development of the preferred embodiment, it is provided that the by-pass duct extends in the proximity of the lateral duct of the ring-duct fan.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a fan according to the invention installed in a motor vehicle heating system;
FIG. 2 shows a detail from FIG. 1 at a larger scale;
FIG. 3 shows another embodiment of a fan according to the invention in the form of an axial section; and
FIG. 4 shows the embodiment shown in FIG. 3 in plan view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an axial section of a heating-air fan. At the opening 1, fresh air enters into the heater, by action of the heating-air fan 5, with the heated air leaving through opening 2. The air required for the combustion is drawn in by a ring-duct fan 6 via connection pipe 3 and is directed to the burner through connection 30. By means of a fuel line 8 extending in the connection 3, the fuel is directed to the burner by means of a fuel pump 9. By means of a rotary vaporizer 11, the fuel is vaporized and ignited by a spark plug 13, whereupon it burns in a combustion chamber 12. The resulting heat, by means of the heat exchanger 14, is transmitted to the air flowing through the heater. The exhaust gases resulting from the combustion are drawn off through a connection 4. For reasons of safety, a combustion-monitoring thermostat 15, a temperature control 16, as well as a solenoid valve 10 are provided. The heating-air fan 5, the ring-duct 6, the fuel pump 9 and the rotary vaporizer 11 are driven by an electric motor 7. The ring-duct fan 6 consists of a lateral duct 20 and an impeller part 21. An air-intake duct 19, communicating with air connection pipe 3, leads into the lateral duct 20. Separately from the air-intake duct 19, the pressure connection 30 leads from the lateral duct 20. The pressure connection 30 is connected with a by-pass duct 18 leading into the intake duct 19. A setscrew 17 is provided in the by-pass duct 18 for changing the flow cross section of the by-pass duct 18.
The ring-duct fan 6 operates as follows: Driven by the motor 7, the impeller part 21 rotates around its axle, whereby the air contained in the lateral duct 20 is taken along, so that an underpressure is generated at the intake connection 19 and air is conveyed there by means of the connection 3. Compressed air exits at the pressure connection 30 of the ring-duct fan 6 and is directed to the combustion chamber 12. Depending on how far the setscrew 17 is screwed into its threaded receiving bore 22, a part of the compressed air flows back to the suction side of the ring-duct fan 6 through the by-pass duct 18, and there is, again, drawn in through the intake duct 19. By turning the setscrew 17, the total output of the fan can, therefore, be adjusted. In addition, the setscrew 17 projects into the intake duct 19. The result is that, by screwing the setscrew 17 into place, the by-pass duct 18 is, at the same time, opened increasingly, and the intake duct 19 is closed, both of which contributes to a decrease of the output of the fan 6. An unscrewing of the setscrew 17 results in an increase of the output of the fan since the intake duct is freed and the by-pass duct 18 is closed.
FIG. 2 shows that part of FIG. 1 that is significant for the output adjustment of the fan 6 at a larger scale. Again, the setscrew 17 can be recognized which, by means of a slot or a hexagonal recess at its top, can be screwed into a threaded bore 22. The by-pass duct 18 coming from the pressure connection of the fan 6, as well as the intake duct 19 leading to the suction connection of the fan 6, lead into the threaded bore 22. When the setscrew 17, as shown, is in a center position in the threaded bore 22, air from the pressure connection of the fan 6, by means of the by-pass duct 18, can enter the cylindrical threaded bore 22 and can leave the threaded bore again at the front side thereof (at the top of the figure), and can combine with the intake air. The intake air enters through a borehole 23 into the lower part of the bore 22 (indicated in the figure on the opposite side of the setscrew 17) and exits at the mouth point 24 into the intake duct 19. As shown clearly in FIG. 2, the screwing-into-place of the setscrew 17 opens the by-pass duct 18 increasingly, while the intake duct 19 is closed to the same extent. Thus, by the screwing-in of the setscrew 17, it moves into the intake duct 19, so that the output of the fan 6 is reduced, while, by screwing of setscrew 17 in the opposite direction, i.e., in the direction of the by-pass duct 18, the output is increased up to the maximal output.
FIGS. 3 and 4 show another embodiment of the fan 6. The fan consists of a housing 25 which is closed by a lid 26 having a central borehole for the reception of a drive shaft 27. An impeller part having blades 21 is disposed on the shaft 27. The blades disposed in an annular groove that faces opposite a groove 20, that is semicircular in its cross section and is disposed in the floor 25 of the housing. The groove 20 is a so-called lateral duct. As shown in FIG. 4, the lateral duct 20 has a pressure connection 28 and a suction connection 29, which are separated by a barrier. The pressure connection 28 is connected by the shortest distance with the suction connection 29 through a by-pass duct 18' in the barrier. A tapped hole extends normally with respect to the by-pass duct 18' and radially with respect to shaft 27. A setscrew 17' is adjustably screwed into the tapped hole, and by the screwing-in or unscrewing of the setscrew 17', the cross section of the by-pass duct 18' is progressively changed.
While we have shown and described various embodiments in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and we, therefore, do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims. | A fan, especially for the conveyance of the combustion air in a motor vehicle heating system, provides for adjusting of its output, with an efficiency that is as high as possible, and little operating noise. The fan, which preferably is a ring-duct fan, has a by-pass duct connected in by-passing relationship to the exit of the fan, with the by-pass duct containing an adjustable throttling member. In accordance with a preferred embodiment, the by-pass duct leads back into the intake duct of the fan. | 5 |
FIELD OF THE INVENTION
This invention is concerned with improved uniformity of patterns etched in copper sheets in the process of fabricating multilayer printed circuit boards.
BACKGROUND OF THE INVENTION
Copper etching is a crucial step in the processing of multilayer printed circuit boards (MLPCB). Copper sheets, laminated to glass fiber reinforced epoxy board substrates and destined to become inner layer circuitry, are imaged and then etched typically using acid CuCl 2 -based etchant solutions to produce the inner layer circuitry on the substrate. Two or more individual substrates are then bonded with inner layer circuitry being inside of the MLPCB. An example of an intermediate stage of a MLPCB, denoted as 1, is shown in FIG. 1. The intermediate stage comprises boards, 2, of a C stage glass fiber reinforced material, metal conductors, 3, and bonding layers, 4, which may be of a prepreg or B stage material. The intermediate stage may also include metallizations, 5, on the outer surfaces of the boards, which eventually shall be patterned into the outer circuitry of the MLPCB. Typically, alkaline copper etchants are being used for this etching.
The acid cupric chloride etchant is used to produce about 80% of inner layer boards, 85% of the print-and-etch boards, and 90% of the flexible circuit boards manufactured in the United States. The presently used etchant and associated equipment are adequate for relatively simple circuits. However, significant non-uniformities in the etch rate across the boards are observed, with variations in the etch rate across the board ranging typically from 5 to 10% and in some instances up to 30%. This suggests that the processing of these boards requires more stringent control of the copper etching process. In addition, the multilayer boards developed for computer applications are more complex and use smaller conducting lines. Improving the etch uniformity should improve the fine line etching capability.
Numerous attempts were made to improve the uniformity of the copper etching process with CuCl 2 etchant. For example, Isaev and coworkers indicate that addition of metal chlorides increases the etching rate. See V. V. Isaev et al., Zasch, Met., Vol. 13, No. 4, July 1977, pp. 444-445. Improvement in the etching of metals using solutions containing both ferric and cupric chloride by varying the pH, temperature, and salt concentration has also been reported by A. F. Bogenschuetz et al., Chemical Abstracts, Vol. 90, No. 161138z, 1979. It has also been reported that undercutting effects may be reduced by the addition of a mixture of an anionic surfactant with a structure RO(CH 2 CH 2 ═O) n SO 3 R' and a nonionic surfactant of N-alkanolmonocarboxamide, where R' represents either H or an alkali metal and R is a (C 6-15 ) alkyl group. See A. Tanaka, Chemical Abstracts, Vol. 105, No. 105-106957u, 1986.
However, while some progress was made in improving the etch rate, the need for more stringent control of the etching process and more uniform etching of copper is still present.
SUMMARY OF THE INVENTION
This invention is a process for etching copper sheets on insulating boards for use in fabricating multilayer printed circuit boards. The improvement resides in adding to a typical copper etching solution certain alkyltrimethyl ammonium chlorides with alkyl chain lengths ranging from 6 to 20 carbon atoms in amounts sufficient to yield intermediate kinetics behavior. Of special interest are dodecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride and octadecyltrimethyl ammonium chloride present in an amount of from 0.01 to 1 wt %. A silicon-based antifoaming agent may be added in amounts of from 0.05 to 2.0 wt. % to prevent an unacceptably large amount of foam occurring during etching. With this formulation, the rate is mass transport controlled at low rates and almost independent of mass transport at high rates due to the inhibition of the surface reaction rate. As a result, non-uniformities in etch rates due to variations in mass transport conditions in processing equipment may be eliminated. This unique formulation could significantly improve the yields presently obtained in manufacturing as well as allow the processing of fine-line multilayer as well a dual-sided circuit boards.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an intermediate stage in MLPCB production, with inner metallization being inward of the MLPCB.
FIG. 2 is a representation of a variation of an etching rate with square root of disk rotation speed for mass transport controlled kinetics as well as for intermediate kinetics;
FIG. 3 is a schematic representation of a design of a rotating disk assembly for use in testing mass transport characteristics of the etchant solutions;
FIG. 4 is a diagram of a variation of etch rate with ω 1/2 for the modified cupric chloride etch containing 0.12 and 0.22% dodecyltrimethyl ammonium chloride (DTAC) plus 0.26% (by weight) Dow Corning 544 (DC-544) antifoaming agent, 87.5 g/l Cu +2 as cupric chloride, 3N HCl, 55° C.; the upper solid curve marked KCl contains additional 1.0M KCl;
FIG. 5 is a schematic representation of a configuration of spray chamber/reservoir used for stability experiments;
FIG. 6 is a diagram of a stability of cupric chloride etchant containing 2M HCl, 0.1% DTAC and 0.1% DC-544;
FIG. 7 is a diagram of stability of cupric chloride etchant nominal solution containing 2M HCl, 1M NaCl, 0.1% DTAC and 0.1% DC-544.
DETAILED DESCRIPTION
This invention is a process and chemistry for improviing the uniformity of etching process and, thus, of etched circuitry on copper-clad fiberglass reinforced substrates in the process of fabricating printed circuit boards. Applicants have realized that the non-uniformity of the etching process may be attributed to certain characteristics of the processing equipment. In operation, boards with copper sheets thereon pass horizontally between two nozzle matrices which spray the etchant onto the boards. On the top surface of the board, the solution puddles in the middle of the board, while on the edges and the bottom surface of the board, the solution is continuously swept off by the spray. Therefore, the etch rate is smaller in the middle of the top surface of the board. These observations imply that mass transport, the process by which reactants reach the surface and products are removed from the surface by convective diffusion, plays a significant role in the reaction kinetics and that the uniformity of the etching process may be improved.
Theoretical analysis of mass transport conditions at the surface of a rotating disk indicates that the rate of transport of solution species is linearly proportional to the square root of the rotation speed, ω. See Veniamin G. Levich, Physiochemical Hydrodynamics 1962, Prentice-Hall, Inc., pp. 93-102. This characteristic of the rotating disk has been verified by numerous workers in the field. For example, see John S. Newman, Electrochemical Systems 1973, Prentice-Hall, Inc., pp. 307-310. For the case of intermediate kinetics, at low rotation speeds, the rate of solution transport varies as ω 1/2 , see V. G. Levich, supra., but eventually the surface reaction limits the observed reaction rate and the reaction rate becomes independent of the rotation speed. This generalized behavior is illustrated in FIG. 2. Applicants have concluded, regarding a standard or conventional cupric chloride etchant, that: 1) the etch rate is mass transport controlled over the range of conditions used, 2) the etch rate increases significantly with Cl - concentration, 3) the etch rate is not limited by Cu +2 for concentrated solutions ( >87.5 g/l copper), 4) the etch rate decreases with Cu + concentration, but to a smaller extent than the increase due to chloride ion, and 5) cations used in combination with Cl - affect the rate, with the rate increasing in the order of NH 4 + >K + >Na + >H + .
In view of this, the applicants have realized that the uniformity of etching across the board cannot be improved by varying the concentrations of the standard etchant. Since the etch rate for the standard CuCl 2 etchant is limited by mass transport under all of the conditions indicated, improvements in the uniformity of the mass transport conditions for the processing equipment could lead to the improvements in the etching uniformity; however, there are limits to improvements in the processing equipment including the reluctance on the part of the user to modify an existing etching line. Therefore, if modifications to the chemistry of the CuCl 2 etchant would yield the intermediate kinetics condition indicated in FIG. 1, the cupric chloride etching process would be less sensitive to the characteristics of the processing equipment.
Etch rate experiments were performed using 2 oz. (2.8 mils thick) copper clad glass-fiber reinforced epoxy board substrates which corresponded to the material used in the manufacture. To facilitate the use of controlled mass transport conditions for a study of the standard cupric chloride etchant, using this material, a rotating disk assembly, 10, shown in FIG. 3 was used in the tests. The assembly includes a rotator shaft, 11, with an enlarged end surface, 12, on which is positioned a copper clad disk, 13, secured to the rotator shaft by an etch-resistant screw, 14. The copper clad disk of 1.2 cm diameter has a 0.6 cm (0.24 in.) hole in the center to mount the disk to the rotator shaft. The disk was clad with 2 oz (2.8 mils thick) copper layer on 60 mil thick glass-fiber reinforced epoxy board substrate. The rotation speed was varied within a range of from 100 to 2000 rpm using a Pine Instruments Analytical Rotator Model ASR2. A 250 ml volume of the etchant was prepared for each run and experiments were performed on freshly cleaned copper disks in a thermostat controlled cell. The copper surface was cleaned, prior to the etching, using an alkaline cleaner of the following composition: sodium hydroxide (5 oz/gal), sodium carbonate (10 oz/gal), trisodium phosphate (8 oz/gal), dodecyl benzene sulfonate (0.1 oz/gal), and the cleaner bath temperature was maintained at 60° C. The copper disks were soaked in the cleaner for 1 minute, rinsed in warm tap water for 30 seconds, rinsed twice with deionized water, dipped in 10% sulfuric acid for 1 minute, rinsed in deionized water, dried with methanol-air, and weighed on an analytical balance to determine the starting weight of the disk. The disks were then mounted on the rotator shaft. and etched for varying intervals of time. The etched disks were removed from the shaft, washed, dried, and weighed. The etch rate was subsequently calculated using the weight loss.
Typical operating parameters for the standard cupric chloride etchant in use on copper etching processing lines are: 1). 150 to 203 g/l (20-27 oz/gal) total copper, 2). 1.6 to 2.4N HCl, 3). 31° to 35° Be, and 4). 115°-130° F. (46°-55.4° C.). Regeneration of the etchant involves bubbling chlorine gas to maintain an oxidation-reduction potential (ORP) value of 520 mV on Pt vs Ag/AgCl. The specific gravity is maintained by a bleed and feed procedure, adding a 2.0N HCl solution to replace the removed etchant.
Etching experiments were conducted under conditions including 87.5 g/l Cu as cupric chloride, temperature of the etchant of 55° C., and 3 or 4N HCl. Several etchant properties were analyzed for each experiment. The normality of H + was determined by titration with a standard NaOH solution to a pH of 2.3 using a Mettler Autotitrator Model DL25. Titratable chloride (Cl - ) was determined by titrating a known sample volume, acidified with dilute nitric acid, with a 0.1N silver nitrate solution to a first derivative end point. The concentration of cuprous ion was determined by first oxidizing Cu + with excess ferric sulfate. The equivalent ferrous ions formed was titrated with a 0.1N Ce(IV) standard using ferroin as an indicator. The density of the solution (degrees Baume) was measured with a hydrometer and the oxidation-reduction potential (ORP) measured using a reference Pt-Ag/AgCl couple.
Applicants have discovered that addition to the CuCl 2 solution of certain alkyltrimethyl ammonium chlorides in amounts of from 0.01 to 1.0 wt. %, with further addition in some instances of silicone-based antifoaming agents in amounts of from 0.05 to 2.0 wt. % led to the improvement of the mass transport. The alkyltrimethyl ammonium chlorides, selected from those having alkyl chain lengths ranging from 6 to 20, preferably from 10 to 18, carbon atoms, yield the desired intermediate kinetics behavior and etch rate which is very uniform across the disk.
Significant foaming occurred with 0.1 wt. % dodecyltrimethyl ammonium chloride (DTAC) at 2000 rpm; however, the use of 0.26 wt. % of Dow Corning 544 (DC-544) antifoaming agent, resolved this problem. Two additional members of the homologous series represented by DTAC were hexadecyltrimethyl ammonium chloride (HTAC) and octadecyltrimethyl ammonium chloride (OTAC). Table I (See Appendix) illustrates the etch rate at 2000 rpm for the modified etch containing DTAC, HTAC, and OTAC. Potential solubility problems may exist for the use of OTAC. The reduction of the surface reaction rate increases with chain length; therefore, such monovalent alkaline metal chlorides as KCl and NaCl may be added to the etchant to yield a higher etch rate.
The preferred additive for the modified etch chemistry is dodecyltrimethyl ammonium chloride with a nominal concentration of 0.1 wt. %. When used in combination with 0.1 wt. % DC-544 antifoaming agent, intermediate kinetics are obtained in which the etch rate is independent of mass transport conditions at approximately >1500 rpm. The decrease in etch rate (without additives) at 2000 rpm is from 1.2 mil/min to 0.7 mil/min. KCl or NaCl may be added to the etchant to yield a higher etch rate, still exhibiting intermediate kinetics. FIG. 4 represents the etch rate versus ω 1/2 with the addition of DTAC and DC-544 (lower solid line) and also of KCl (upper solid line).
To investigate the stability of these additives, a pilot scale experiment was conducted to age the etchant by etching copper sheets in a spray chamber. The configuration of the apparatus, 20, used for stability tests is shown in FIG. 5, wherein etchant, 21, is being sprayed from nozzles, 22, onto a 2 oz (2.8 mils thick) copper sheet, 23. Regeneration of the etchant was performed using hydrogen peroxide-HCl additions, with a bleed-and-feed operation. A recipe for regeneration of cupric chloride etchants involves the addition of 40 ml of stabilized 35% H 2 O 2 or 46.7 ml of stabilized 30% H 2 O 2 and 94.5 ml of 12M HCl for each ounce of copper etched. See R. E. Markle, Processing and Economic Aspects of Etchant Regeneration, Plating and Surface Finishing, January 1983, pp. 59-62, which is incorporated herein by reference.
Two nominal compositions of the modified etchant were investigated for stability. Both compositions contained 90-130 g/l Cu and 2N H + . The first solution was diluted with a diluent containing 0.1 wt. % DTAC and 0.1 wt. % DC-544. The second solution composition contained 1M NaCl at make-up, and was diluted with a solution containing 0.1 wt. % DTAC, 0.1 wt. % DC-544, and 1M NaCl. The etching experiments were conducted at 55° C. Normal operation involved oxidation of cuprous ions after every two hours of etching operation. After four hours of operation, the etchant was diluted to yield a composition of 90 g/l Cu and 2N H + . The normal operation was then repeated for a total of 90 hours, corresponding to about 5 turnovers of the etching bath.
The rotating disk behavior shown in FIGS. 6 and 7 indicates that intermediate kinetics were maintained for both solution compositions after 5 turnovers of operation. No degradation of performance has occurred. The high etch rate for the initial solution in FIG. 6 is due to a higher-than normal concentration of H + . The solution properties for both compositions are given in Tables II and III (See Appendix).
For comparison purposes several other modifications to the bath chemistry were investigated: 1): the use of metal chlorides at significant concentrations, and 2): the use of other additives including surfactants at small concentrations. To investigate the effect of metal chlorides on the etch rate, standard conditions of 87.5 g/l Cu +2 as cupric chloride, 55° C., and 4N additional Cl - were used. Rotation speeds of 100 and 2000 rpm were used to test for dependency on mass transport conditions. Cations investigated were NH 4 + , K + , Na + , Li + , Ca +2 , Mg +2 , Ba +2 , Mn +2 , La +3 and Al +3 . Different cations significantly affect the etch rate, but the rate remained mass transport limited. Monovalent cations have the greatest influence on the rate with relative etch rates being NH 4 + >K + >Na + >Li + . Divalent cations yield etch rates smaller than those obtained with monovalent cations, including H + . The relative rates are Ca +2 >Mg +2 >Ba +2 >Mn +2 . For the trivalent cations, La +3 yields a larger etch rate than Al +3 .
To investigate the effect of other additives on the intermediate kinetics and on the etch rate, standard conditions of 87.5 g/l Cu +2 as cupric chloride, 55° C., and 3N HCl were used. Rotation speeds of 1500 and 2000 rpm were chosen as being characteristic of the plateau region for intermediate kinetics (FIG. 2). Several organic ammonium chlorides and hydrochlorides were investigated for their effects on the intermediate kinetics. Tetrabutyl ammonium chloride gives intermediate kinetics without the need for an antifoaming agent. However, this additive tends to break down with use as the etch rate for successive experiments increases. The etch is also uneven, giving spotted etching over the millimeter scale. Tetrapentyl ammonium chloride, tetrahexyl ammonium chloride, and tetraoctyl ammonium chloride are all insoluble and as a result do not inhibit the etching reaction. Cetyl pyridinium chloride has a limited solubility and gives a spotty, non-uniform etch. Dodecylamine hydrochloride and octadecylamine hydrochloride are also insoluble.
It is to be understood that the above-described improvements and tests described with reference to acid cupric chloride etchant are applicable to the alkaline copper etchants as well. For example, the uniformity of copper etching with an alkaline etchant having 150 to 203 g/l (20-27 oz/gal) of total copper, 18° to 26.50° Be (1.145-1.225 specific gravity) 5-5.8M HCl, pH=8.2-8.8, useable at a temperature of 115°-130° F. (46°-55° C.), may be improved by the addition of the specified alkyltrimethyl ammonium chlorides and silicone-based antifoaming agents, as needed.
TABLE I______________________________________APPENDIXUseful Additives for the Cupric Chloride Etchant(87.5 g/l Cu.sup.++, 55° C., 3 N HCl, 2000 RPM) H.sup.+ Cl.sup.- ORP ρ R RAdditive N N mV g/cc Be° mg/s mil/min______________________________________ 2.66 5.35 461 1.190 23.0 0.436 1.1900.057% DB-31 2.54 5.54 483 1.190 23.4 0.405 1.1050.1% Dodecyl- 2.49 5.55 519 1.190 23.4 0.265 0.723trimethylammoniumchloride0.1% Hexade- 2.44 5.53 388 1.200 24.0 0.214 0.585cyltrimethylammoniumchloride0.1% Octade- 2.50 5.66 0.135 0.368cyltrimethylammoniumchloride______________________________________ Note; All three trimethyl ammonium chloride solutions also contain 0.1% DC544 antifoaming agent. The octadecyltrimethyl ammonium chloride is insoluble at room temp.
TABLE II__________________________________________________________________________Results of Modified Etch Stability ExperimentTime Total Cu Cu.sup.+ Cl.sup.- H.sup.+ γ η ρ Etch Rate DTAChours Turnover g/l g/l N N dynes/cm centipoise g/cc mil/min (2000 rpm) g/l__________________________________________________________________________ 0 0.0 91.3 1.6 5.85 2.72 32.4 0.942 26.0 0.97 0.9452 1.16 117.2 1.6 6.55 1.80 33.8 0.954 28.6 0.80 0.3460 1.96 114.2 2.4 5.69 1.81 31.9 0.954 28.4 0.77 0.4970 2.75 125.9 1.6 6.70 2.04 31.2 0.989 29.6 0.87 0.5174 3.40 129.6 3.2 6.33 1.95 34.0 0.973 29.1 0.86 0.3690 5.10 132.1 3.0 6.83 1.85 32.0 1.020 30.8 0.84 0.50__________________________________________________________________________ Diluent used2 N HCl + 0.1% DTAC + 0.1% DC544
TABLE III__________________________________________________________________________APPENDIXResults of Modified Etch Stability ExperimentTime Total Cu Cu.sup.+ Cl.sup.- H.sup.+ γ η ρ Etch Rate DTAChours Turnover g/l g/l N N dynes/cm centipoise g/cc mil/min (2000 rpm) g/l__________________________________________________________________________ 8 1.11 111.7 7.9 7.27 1.64 34.4 1.016 30.2 0.98 0.2516 2.22 130.8 0.6 7.27 1.55 32.0 1.092 32.2 0.3124 3.32 106.1 1.1 6.92 1.71 30.4 1.018 30.3 0.95 0.4632 4.45 108.0 0.3 6.76 1.50 31.0 1.013 29.5 0.5438 5.18 99.9 1.4 6.71 1.78 30.5 0.989 28.6 0.93 0.61__________________________________________________________________________ Diluent used2 N HCl + 1M NaCl + 0.1% DTAC + 0.1% DC544 | This invention is a process for etching copper sheets on insulating boards for use in fabricating multilayer printed circuit boards. The improvement resides in adding to a standard copper etching solution certain alkyltrimethyl ammonium chlorides with alkyl chain lengths ranging from 6 to 20 carbon atoms in amounts sufficient to yield intermediate kinetics behavior. Of special interest are dodecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride and octadecyltrimethyl ammonium chloride present in an amount of from 0.01 to 1.0 wt %. A silicon-based antiforming agent may be added in amounts of from 0.05 to 2.0 wt. % to prevent an unacceptably large amount of foam from occurring during etching. With this formulation, the rate is mass transport controlled at low rates and almost independent of mass transport at high rates due to the inhibition of the surface reaction rate. As a result, non-uniformities in etch rates due to variations in mass transport conditions in processing equipment may be eliminated. This unique formulation could significantly improve the yields presently obtained in manufacturing as well as allow the processing of fine-line multilayer circuit boards. | 2 |
BACKGROUND OF THE INVENTION
This is a continuation-in-part of a formal application filed Dec. 9, 1996, Ser. No. 08/762,345, based on the specification and drawings submitted as a provisional application filed Feb. 29, 1996, Ser. No. 60/012,494.
This invention relates to a system for creation of chemical termite barrier around the exterior of a building above ground level, between exterior surfacing materials and the outside walls. The invention is adapted for both new and existing construction.
Although it is now common practice in the construction of new buildings to pre-treat the fill or soil area which is to underlie the foundation with a termiticide, the initial termite barrier does not last indefinitely, and there is a need to supplement this barrier during the life of the building by efficient and inexpensive means at the points where termites can gain access to wooden structural members. Termites do not bore holes through concrete. However they can gain entry into the areas where wood is used in the construction of the building by forming earthen tunnels from ground level over the surfaces of concrete foundations, slabs and walls. A common problem in buildings clad with exterior surfacing materials such as stucco, brick facing, or wood siding, is the ability of termites to build tunnels in the tiny spaces between the walls and the surfacing material, the tunneling activity going undetected because it is behind the surfacing material. The various surfacing materials used to clad the exterior walls are necessarily impenetrable to liquids used as solvents for termiticide substances, and there is rarely a good seal between the walls and the surfacing material that can keep out termites, which can enter tiny spaces as narrow as one sixty-fourth of an inch. In buildings having exterior cladding, the surfacing material frequently extends to or below ground level. Although wood siding would not be extended to ground level by a professional builder, frequently post-construction mulching and other landscaping activities may raise the soil level to the point where the wood siding is in contact or close proximity thereto. Thus is possible for termites to form their tunnels from below grade up the edges of a foundation slab and between the walls and the exterior coating material without being detected until after severe damage has been done to wooden structural members of the building. Accordingly, there is a continuing need for access to the surface of exterior walls beneath their exterior coating, so that termiticide can be applied to these surfaces.
It has been a widespread practice in the pest control industry, when termite infestation occurs between the exterior walls and the exterior surfacing, to remove a strip of the surfacing material around the building perimeter, extending from below grade to a height of six to nine inches above grade, thereby exposing the foundation and its junction with other structural features so that they may be easily inspected. This detracts from the aesthetic appearance of the structure.
Prior methods approved by the National Pest Control Association of preventing termites from entering between the exterior walls and the surfacing material involve saturating the soil with termiticide at the point of termite entry. This is accomplished by trenching or rodding. In the first of these methods, a trench is dug around the perimeter and filled with four gallons of termiticide per linear foot of trench. In the other method, termiticide is injected through a hollow rod jammed into the soil and against the foundation about every six inches or so. Usually the soil adjacent the foundation is relatively dry. Since dry soil does not absorb liquids easily, much of the termiticide is likely to drain of it very quickly, much like most of the water added to a dry flower pot. Thus much of the termiticide will be dispersed into areas where it is not effective at the point of termite entry, and where it likely creates an environmental detriment to beneficial creatures inhabiting the soil. Also, these methods being labor intensive, they entail substantial cost. Therefore, there is a need for an efficient, labor-saving termiticide delivery system for providing an effective termite barrier between the exterior cladding of a building and its foundation and exterior structural walls, whereby termiticide saturates the surfaces thereof down into the soil.
A recent development in the construction industry intended to conserve energy has been the use of rigid styrofoam or closed cell foamboard as insulation material installed on the exterior walls and foundation of a building and extending down the footing below grade to insulate the exteriors of basements or cellars. This rigid insulation material also aids in reducing relatives humidity within to fifty percent. Typically the foamboard is then covered above grade with galvanized lath and about seven-eighths of an inch of stucco or other facing material. In some construction, the foamboard is mounted directly on the framing studs, there being no exterior wall material or sheathing other than the foamboard, the lath, and the exterior coating. If the exterior cladding is not wood, it will extend below grade to cover the foam board.
Another recent development in the construction industry is the use of interlocking hollow rigid foam forms for poured concrete. These forms are typical by modules four feet long, four feet high, and sixteen inches wide. Each module usually has four interconnecting cells for concrete, metallic mesh connectors holding the opposing sides together, and other metal parts for the attachment of interior wall materials and exterior lath. The forms are assembled into the desired shape and are not removed after the concrete is poured, one reason therefor being that the foam is excellent insulation.
The federal government has been providing a tax credit to encourage use of energy-efficient construction systems such as these, and in order to qualify for a credit, rigid insulation board has been required to extend as much as a foot or more below grade. In some parts of the country, local building codes require that the foundation be insulated with rigid foam board below grade. Only recently has it been discovered that although termites cannot digest the foam, they have no trouble chewing their way through it. Once penetrated, moisture which termites need can enter the foam. As a consequence, these new developments in construction have made it much easier for termites to tunnel up to the wood structural members of buildings, undetectable within the foam. Huge new colonies of termites have been built within foamboard and foam concrete forms above ground, there being no longer a need for the termites to return to the soil because everything they need, including a controlled temperature, can be found inside the foam material. Thus there is a need for a termite barrier within these foam construction materials that are accessible to termites.
Heretofore there have been a number of fluid distribution systems for insecticides, comprised of conduit capable of emitting pesticide through apertures or valves, for incorporation in or under a building foundation. Many of these systems are elaborate in construction, requiring extensive modification of traditional and conventional building methods, expensive pumps and reservoirs, and resulting in substantial increases in building costs, as has been previously noted in U.S. Pat. No. 3,513,586 to Meyer et al. Meyer discloses and teaches a distribution system comprising tube means disposed within a building footer constructed of conventional concrete building blocks, requiring additional support members and plate members, among other things, that but for the distribution system, would not be required as part of the footer.
U.S. Pat. No. 3,209,485 to Griffin discloses a pesticide distribution system comprised of multiple, independent, branched circuits, to be installed within and under a foundation. The system comprises many parts and installation requires multiple steps at different stages of construction of the building.
U.S. Pat. No. 3,602,248 to Peacock discloses a distribution system comprised of a plurality of parallel connected pipe branches, each branch thereof short enough so that fluid pressure is maintained along the entire piping, and at least two inlets into each branch. Each branch requires a closure fitting at the end opposite the inlet end. Multiple pumps are required to maintain uniform pressure in the branch lines.
There are a number of related systems for distributing pesticide within the walls of buildings. In the Ramsey U.S. Pat. No. 3,676,949, pipes with emitter nozzles pass through the studs of the walls, with a nozzle disposed between each set of studs. In U.S. Pat. to Bridges et al., U.S. Pat. No. 3,782,026, pipes extend within the walls or alternatively, beneath baseboard moldings on the interior walls, permitting injection of insecticide gas within the walls. In Lundwall, U.S. Pat. No. 4,0228,841, an insecticide storage and pressurizing system is installed in the attic and perforated pipes carry pest control fluid into the building walls. In U.S. Pat. No. 4,742,641 to Cretti, a built-in reservoir is installed in within a building wall and pesticide is distributed whenever the pump is operated, which can be done by a timing device for injecting predetermined amounts at predetermined spaced intervals. U.S. Pat. No. 3,330,062 to Carter is another pest control system utilizing pipes installed through holes drilled through the wall studs of a building. The pipes require threaded caps at the distal ends thereof. U.S. Pat. No. 4,944,110 to Sims is for method of applying pesticide to the concealed areas of a building, utilizing injection of pressurized chemicals into perforated tubing. A divisional application for a related apparatus was filed by Sims.
U.S. Pat. No. 5,347,749 to Chitwood et al. discloses a system for reapplication of termiticide to the fill dirt underlying the foundation slab of a building at potential termite entry points: junction of foundation block with slab, and openings in the slab for penetration of bundles of utility connections. None of the foregoing patents teaches or discloses a system adapted to deliver a termiticide barrier to the exterior walls of a building underneath its surface coating or siding materials, or to foam board used as insulation or foam concrete forms.
Hence it is an object of this invention to provide a delivery system for application of termiticide to form a chemical termite barrier between the exterior coating on the one hand, and the exterior walls and foundation of a building, to prevent termites from building their above-ground tunnels up the exterior walls or through styrofoam forms or board insulation to access wood materials such as sole plates, studs, etc.
SUMMARY OF THE INVENTION
In accordance with the present invention, a peripheral termiticide delivery system of flexible apertured tubing is provided for injection under pressure of termiticide into the space between the outside walls of a building and its exterior surfacing, where it may spread by capillary action over the adjacent surfaces and down into the soil, thereby creating a termite barrier. The tubing preferably has flanges extending therefrom which prevent clogging of the apertures and also facilitate fastening the tubing to the walls around the building slightly above the junction of foundation with the exterior walls. There are several configurations of the flanged tubing, and several ways of installing it, depending on whether it is installed prior to application of the exterior surfacing material or in existing finished construction, and whether the building has rigid foam insulation around the foundation, or is constructed of concrete poured into styrofoam forms. Injection ports for injection of termiticide into the tubing are disposed at intervals along the tubing, which ports are adapted to extend outside the exterior surfacing materials. Termiticide may then be injected under pressure at the various ports until the tubing is filled to overflowing and termiticide exits the apertures and saturates the adjacent wall surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial perspective view of the invention installed on the walls of a building prior to application of an exterior surfacing material.
FIG. 2 is a vertical sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a partial, exploded top plan view of the invention together with a cross-sectional view of a building wall taken along lines 3--3 of FIG. 1.
FIG. 4 is a partial back elevational view of the invention.
FIG. 2A is like FIG. 2 except that the configuration of the back surface of the tubular member is different.
FIG. 5 is a vertical sectional view of the invention installed in a horizontal channel through foam board insulation surrounding a foundation.
FIG. 6 is a partial perspective view of another embodiment of the invention installed on the walls of a concrete building with pre-existing stucco surface.
FIG. 7 is a partial perspective view of the invention installed on a wood-framed building with pre-existing stucco surface.
FIG. 8 is a detail of an elbow connector used to connect lengths of the tubing of the embodiment of FIG. 6 at inside and outside corners of a building.
FIG. 9 is a detail view of a combination tubing connector and injection port.
FIG. 10 is a vertical sectional view taken along line 10--10 of FIG. 6.
FIG. 11 is a perspective detail view of a portion of the perforated tubing of this invention, showing the back surface.
FIG. 12 is a perspective view of a rigid foam concrete form with a horizontal slot in the exterior vertical surface and the tubing means of this invention installed therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 through 12 of the drawings, the invention 10 shows a peripheral termiticide delivery system comprised of lengths of ribbon-like tubing means 12 having a central bore 14 co-extensive with each length of tubing means 12, flanges on either side thereof 15, a front surface 16, and a back surface 18. As shown in FIG. 2 bore 14 has the circumferential shape of a small piece of a circle sliced off by a chord, thus having a curved side connected at the ends thereof to the ends of a flat side. The bore could be some other shape, such as oval or round, without changing its function. FIG. 4 shows small apertures 20, through the back surface 18 only, to the central bore 14. FIG. 1 shows tubing 12 affixed to the exterior side of a building at the junction 34 of its foundation slab 30 with exterior walls 32; back surface 18 is adjacent the building, as more particularly shown in FIG. 2. Although walls in the drawings are illustrated as being made of concrete blocks, the invention is appropriate on buildings whose exterior walls are made of other structural materials, such as wood sheathing. The ribbon-like feature of tubing means 12 facilitates attachment and orientation thereof so that the long axes of apertures 16 will be more or less horizontally perpendicular to the walls 32. The flat extensions or flanges serve to prevent stucco material or other or other particulate matter from reaching the apertures and clogging them. This embodiment of the invention may be installed prior to application of exterior facing material, such as stucco, siding, shingles, half-bricks, or stone, to the exterior walls. Horizontal ridges 22 on front surface 16 facilitate adhesion of cement-like materials that will be used to apply facing over the walls 32 after installation of the invention. Double-sided adhesive tape is one of the most convenient means of attaching tubing 12 to a building, but cement staples through the side extensions 15, or other attaching or adhesive means, could also be used. An appropriate site of attachment of tubing means 12 would be at junction 34, but there are situations where it would be more desirable to install the tubing at a level above junction 34, such as in an existing structure where soil has been mounded above the original grade.
As shown in FIG. 3, approximately every fifteen feet, injection ports 25 are disposed between lengths of tubing means 12. Injections ports 25 are comprised of T-shaped tubular three-way connectors 26, each of which interconnects three adapter means 28a, 28b, and 28c, comprised of short lengths of conventional round unperforated flexible tubing, the outside circumference of which matches the circumference of bore 14. The plastic material out of which adapter means 28 are made permits them to deform to fit the shape of bore 14. The two adapter means 28a and 28b connected to the "arms" of the T of connecter 26 are in turn connected to lengths of tubing 12 by insertion into bore 14, and adapter means 28c connected to the "stem" of the T of connector 26 protrudes horizontally outward from and perpendicular to the plane of wall 32. Adapter means 28c is intended to extend outside the finishing facing to be applied to exterior walls 32, and is provided with a removable cap or stopper 29 to prevent entry of matter that would clog any of the tubing elements of this invention.
At outside corners of buildings, the T-shaped connectors 26 are optional but unnecessary. Adapter means 28d are inserted directly into the ends of tubing means 12; likewise they are also of a length to extend outside the finishing facing of walls 32, and are provided with removable stoppers or caps 29. FIGS. 1 and 3 show stoppers, but caps into which the protruding ends of adapters 28c are insertable would serve equally well.
An alternative to the form of tubing 12 is shown in FIG. 2A as ribbon tubing means 50. The front surface 52 is approximately the same as outer surface 16 of tubing 12. However the back surface 56 of tubing means 50 is indented to form a round circumference for bore 54, instead of the shape of the circumference of bore 14. Back surface 56 also forms pockets 58 extending the length of tubing means 50. Apertures 59 through back surface 56 to bore 54 are comparable to apertures 16 in tubing 12, are disposed at approximately six-inch intervals. Side extensions 60 of tubing means 50 are comparable to side extensions 15 so that when back surface 56 is affixed along junction 34 of walls 32 with slab 30, the long axes of apertures 59 will be horizontally perpendicular to junction 34. One advantage of using tubing means 50 rather than tubing means 12 is that adapters 28a and 28b are unnecessary at the injection ports 25. T-shaped connectors can directly interconnect two lengths of tubing means 50 with adapter means 28c.
The advantage of the shape of alternate tubing means 50 is that the pockets 58 form reservoirs with the building walls for additional termiticide.
In FIG. 6, foam board insulation 40 is sandwiched between the exterior walls 32 and a surface coating 42. An horizontal slot 44 is cut all the way around the building preferably at about three inches above grade through the coating 42 and the foam board 40 all the way to the wall 32 and the tubing 12 is inserted into the slot 44 with the apertures 20 opening downward. Foam board insulation 40 comes in different thicknesses; tubing 12 should extend over the entire thickness of the foam board in order for it to create an effective barrier. The portion of the slot 44 through coating 42 not filled by tubing 12 should then be refilled with additional coating material.
FIG. 12 depicts a modular concrete form 140 sold by Cope, Inc. of Toccoa, Ga., using the tradename "Polysteel Forms". Form 140 has tubing means 50 installed in a horizontal slot 142 cut into the foam. Slot 142 is of sufficient depth to permit creation of an effective chemical barrier within the foam. Form 140 is shown without any concrete to simplify the drawing for better understanding, but normally the conrete would have been poured into the assembled forms prior to cutting the slot.
Referring to FIGS. 6 through 11 of the drawings, a variant 70 of invention 10 is shown installed around the walls 102 of a building 100 with a pre-existing exterior stucco coating 104. The installation is done by first cutting a more or less U-shaped groove 114 in the exterior coating 110 approximately three inches above grade for a concrete block structure, or three inches above the junction 106 of foundation slab 108 with the wooden sill plate of a wood-framed structure. Groove 114 should extend all the way through the coating which is customarily about five-eighths (0.625) of an inch thick. This embodiment is comprised of sections of tubing means 80 having a back surface 82 and a front surface 84, an internal central bore 86 and at least two integral external flanges 88 co-extensive with each section of tubing means 80, spaced from one another on said front surface 84. Flanges 88, preferably with toothed surfaces, extend from said front surface 84 divergently from each other, terminating at distal edges 89, the distance between said distal edges 89 being greater than the external diameter of a cross-section 81 of tubing sections 80, thereby creating in cross-section a wide-bottomed V shape. The sections 80 are ideally around fifteen feet long, for reasons that will be set forth hereinbelow. Each section 80 of tubing also has small apertures 92 at preferably three-and-three-quarter (3.75) inch intervals spaced in alignment along each section, through back surface 82 only, to the central bore 86. The sections 80 are interconnected end-to-end in much the same manner as tube sections 12 by three-way T-shaped tubular connectors 26, except that adapters 28a and 28b are not required with this configuration of tubing. This is because the shapes of its internal bore is better adapted for sealing engagement of the ends of the connectors 26 than is tubing means 12. Injection port 28 extends outward beyond the vertical plane of the external stucco coating 104. At corners of a building, an L-shaped connector 90 without an arm for an injection port is used in place of a T-connector 26 to connect tubing sections 80.
The tubing sections 80 may be inserted into groove 114 with a splining tool. The outside diameter of the tubing sections 80, not including the flanges, is approximately one-quarter inch, so that when they are installed in accordance with the teachings of this invention, there is a void space 116 behind back surface 62 and the deepest area or nadir 118 of groove 114.
Tubing sections 80 are oriented in groove 114 so that apertures 92 open to space 116. The width of groove 116 is approximately the same as the outside diameter of tubing sections 80, and less than the distance between distal edges 89 of flanges 88 when undeformed, so that when tubing sections 80 are forced into groove 114, flanges 88 are pressed into a more or less parallel alignment with each other, biased against the sides of groove 114, thereby sealing the void space 116 and holding sections 80 securely in place. Once the system is installed, stucco coating 104a can then be applied over it to recreate the original continuous finish, as shown in FIG. 10, making sure that injection ports 26 protrude beyond the outer surface.
When installing the invention on a wood-framed structure with a pre-existing coating, groove 114 is cut through the metal lath 110 used to provide adherence for the stucco.
To service the delivery system, a pressurized injection means, not shown, of any commercially available type, is provided with a delivery tip, not shown, adapted to inject fluid termiticide into the invention 10 at injection ports 27. Injection of termiticide at one port continues until the fluid is observed squirting out of a nearest-in-line port for several seconds, which phenomenon indicates that a length of tubing means 12, is full, and termiticide is exiting apertures 20. The lengths of tubing means 12 being ideally fifteen feet, the injection ports 27 are accordingly spaced at fifteen foot intervals, which has been found experimentally to be desirable in order to ensure that termiticide will be distributed effectively through all the apertures 22 into the entire length of the void space 116 served by each section of tubing means 12. Because cement and wood are porous, capillary action and porosity will ensure that the termiticide will spread to soak the area between the apertures emitting it. The sealed void space 116 thus forms a reservoir for termiticide. The person injecting the termiticide then proceeds to inject a next-in-line port 26 until all ports have received sufficient termiticide to fill each length of tubing means 12 and to exit the apertures 22 in sufficient quantity to fill the void space 116. Thus a continuous strip of termiticide material extends around the periphery of the building foundation above its juncture with the exterior walls, and behind the exterior facing material, wherever the invention has been installed.
The various embodiments of the invention 10, 50, or 80 as the case may be, are designed to provide a termiticide delivery system for saturation of the surfaces of exterior walls 32 or 102 and foundation 30 or 108 down into the soil. A pressurized injection means, not shown, of any commercially available type, is provided with a delivery tip, not shown, adapted to inject fluid termiticide into tubing means 12, 50 or 80 at injection ports 25. Injection of termiticide at one port continues until the fluid is observed squirting out of a nearest-in-line port for a pre-determined period of time, which phenomenon indicates that a length of tubing means 12, 50 or 82 as the case may be, is full, termiticide is exiting apertures 20, 59, or 92 as the case may be, and running down the adjacent surfaces into the soil. Since cement and wood are somewhat porous, capillary action and porosity will ensure that the termiticide will spread to soak the surface areas between the apertures emitting it. Tubing means 50 and 82 provide additionally a continuous reservoir of termiticide up against the walls 32 or 102 The person injecting the termiticide then proceeds to inject a next-in-line port until all ports have received sufficient termiticide to fill each length of tubing means and to exit the apertures 20, 59, or 92 in sufficient quantity to soak the adjacent surfaces and run down into the soil. Thus a continuous strip of chemical termite barrier extends around the periphery of the building foundation beneath or behind the exterior cladding and down into the soil, wherever the invention has been installed.
Various changes and departures may be made to the invention without departing from the spirit and scope thereof. Thus it is not intended that the invention be limited to what is described in the specification and illustrated in the drawings, rather only as set forth in the claims. | A peripheral termiticide delivery system of flexible apertured tubing is provided for injection under pressure of termiticide between the exterior walls of a building and its exterior coating. The tubing preferably has flanges extending therefrom whereby it is affixed to the walls around the building above ground level, and the apertures are protected from clogging by coating material. Injection ports for injection of termiticide into the tubing are disposed at intervals along the tubing, which ports are adapted to extend outside the exterior surfacing materials. Termiticide is injected under pressure into each port until all sections of tubing are filled to overflowing and termiticide exiting the apertures soaks the adjacent wall surfaces and runs down into the adjacent soil, creating a termite barrier. The system may be installed after construction by cutting a channel through the exterior coating, inserting the tubing into the channel and then reapplying exterior coating. Where foam material is sandwiched between the exterior framing and the exterior coating, whether as insulation, or as a form for poured concrete, the channel extends into the foam to a depth sufficient to introduce an effective chemical termite barrier within the foam. | 4 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to an improved data processing system and, in particular, to a method and apparatus for managing audit logs in a data processing system. Still more particularly, the present invention provides a method and apparatus for creating and verifying audit logs in a relational database without compromising the ability to detect data tampering in a data processing system.
2. Description of Related Art
Audit logs have long been used to keep permanent records of events. The audit log can be used at some future date to reconstruct events that happened in the past. This reconstruction might be required for legal, accounting, or security purposes or for recovery after a disaster.
Audit logs are more useful if the entries can be authenticated in some way. In paper systems, the physical log itself enforces this authentication. However, modern audit logs are often kept in digital files within a computer system. Such computer audit logs differ from paper documents in that they can be more easily modified undetectably. For example, it is easy to add, delete, or modify individual entries within an audit log in a computer system in such a way that the changes will go undetected. In fact, many computer hackers who break into computer systems take specific actions to modify the audit logs to erase all traces of their actions.
Computer security manufacturers have responded to this threat in several ways. One is to force the audit log to be continuously printed out on paper. Variants of this technique involve writing the audit log to a non-erasable medium, such as a CD-ROM. Another approach uses conventional computer security techniques to guard the audit log files. Such techniques include hiding and encrypting the log files or requiring special permissions to write to them. These techniques work well in some applications—most notably when the audit log is stored on a shared computer and the malicious person trying to modify the audit log does not have full permissions on that computer—but are not without their disadvantages. For example, clever hackers can often figure out ways around the computer security techniques and make changes to the audit log.
A common implementation approach for audit subsystems is to store audit records in a flat file. Such solutions are limited in terms of scalability, transaction support, sophisticated query capabilities, and recovery. Furthermore, they are not amenable to supporting on-line integrity checking or on-line archiving.
Therefore, it would be advantageous to have an improved method and apparatus for protecting against data tampering of audit logs.
SUMMARY OF THE INVENTION
The present invention solves the problems associated with the prior art by storing audit records in a relational database comprising a primary audit log table, auxiliary tables, and a system table. Audit record level protection is achieved by including an integrity column in every audit record and by assigning a unique identifier, such as a serial number, to each audit record. System level protection is achieved by maintaining serial number range and integrity information in the system table. The present invention provides for detection of unauthorized row modification, deletion, or insertion, and incorporates extra measures to protect against administrator attacks. Using the serial number range in the system table, a snapshot may be taken of the audit log to enable integrity checking and audit log archiving without having to suspend or bring down the audit subsystem.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 depicts a pictorial representation of a distributed data processing system in which the present invention may be implemented;
FIG. 2 is a block diagram of a data processing system that may be implemented as a server in accordance with a preferred embodiment of the present invention;
FIG. 3 is a block diagram illustrating a data processing system in which the present invention may be implemented;
FIG. 4 is a client/server view of an exemplary audit subsystem of the present invention;
FIG. 5 illustrates a database schema in accordance with a preferred embodiment of the present invention;
FIG. 6 is a flowchart, which illustrates an audit server or audit tool startup process in accordance with a preferred embodiment of the present invention;
FIG. 7 is a flowchart, which illustrates an audit record creation process in accordance with a preferred embodiment of the present invention;
FIG. 8 is a flowchart, which illustrates an integrity check utility in accordance with a preferred embodiment of the present invention;
FIG. 9 is an audit record checking utility in accordance with a preferred embodiment of the present invention; and
FIG. 10 is an extraneous record checking utility in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the figures, FIG. 1 depicts a pictorial representation of a distributed data processing system in which the present invention may be implemented. Distributed data processing system 100 is a network of computers in which the present invention may be implemented. Distributed data processing system 100 contains a network 102 , which is the medium used to provide communications links between various devices and computers connected together within distributed data processing system 100 . Network 102 may include permanent connections, such as wire or fiber optic cables, or temporary connections made through telephone connections.
In the depicted example, a server 104 is connected to network 102 along with storage unit 106 . In addition, clients 108 , 110 , and 112 also are connected to network 102 . These clients 108 , 110 , and 112 may be, for example, personal computers or network computers. For purposes of this application, a network computer is any computer, coupled to a network, which receives a program or other application from another computer coupled to the network. In the depicted example, server 104 provides data, such as boot files, operating system images, and applications to clients 108 - 112 . Clients 108 , 110 , and 112 are clients to server 104 . The example illustrated in FIG. 1 also includes a server 114 connected to network 102 and a storage unit 116 connected to server 114 .
Distributed data processing system 100 may include additional servers, clients, and other devices not shown. In the depicted example, distributed data processing system 100 is the Internet with network 102 representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational and other computer systems that route data and messages. Of course, distributed data processing system 100 also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIG. 1 is intended as an example, and not as an architectural limitation for the present invention.
Referring to FIG. 2, a block diagram of a data processing system that may be implemented as a server, such as server 104 in FIG. 1, is depicted in accordance with a preferred embodiment of the present invention. Data processing system 200 may be a symmetric multiprocessor (SMP) system including a plurality of processors 202 and 204 connected to system bus 206 . Alternatively, a single processor system may be employed. Also connected to system bus 206 is memory controller/cache 208 , which provides an interface to local memory 209 . I/O bus bridge 210 is connected to system bus 206 and provides an interface to I/O bus 212 . Memory controller/cache 208 and I/O bus bridge 210 may be integrated as depicted.
Peripheral component interconnect (PCI) bus bridge 214 connected to I/O bus 212 provides an interface to PCI local bus 216 . A number of modems may be connected to PCI bus 216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to network computers 108 - 112 in FIG. 1 may be provided through modem 218 and network adapter 220 connected to PCI local bus 216 through add-in boards.
Additional PCI bus bridges 222 and 224 provide interfaces for additional PCI buses 226 and 228 , from which additional modems or network adapters may be supported. In this manner, data processing system 200 allows connections to multiple network computers. A memory-mapped graphics adapter 230 and hard disk 232 may also be connected to I/O bus 212 as depicted, either directly or indirectly.
Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other peripheral devices, such as optical disk drives and the like, also may be used in addition to or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention.
The data processing system depicted in FIG. 2 may be, for example, an IBM RISC/System 6000 system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system.
An operating system runs on processor 202 and is used to coordinate and provide control of various components within data processing system 200 in FIG. 2 .
The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 200 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs are located on storage devices, such as hard disk drive 232 , and may be loaded into main memory 209 for execution by processor 202 .
With reference now to FIG. 3, a block diagram illustrating a data processing system in which the present invention may be implemented. Data processing system 300 is an example of a client computer. Data processing system 300 employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor 302 and main memory 304 are connected to PCI local bus 306 through PCI bridge 308 . PCI bridge 308 also may include an integrated memory controller and cache memory for processor 302 . Additional connections to PCI local bus 306 may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter 310 , SCSI host bus adapter 312 , and expansion bus interface 314 are connected to PCI local bus 306 by direct component connection. In contrast, audio adapter 316 , graphics adapter 318 , and audio/video adapter 319 are connected to PCI local bus 306 by add-in boards inserted into expansion slots. Expansion bus interface 314 provides a connection for a keyboard and mouse adapter 320 , modem 322 , and additional memory 324 . Small computer system interface (SCSI) host bus adapter 312 provides a connection for hard disk drive 326 , tape drive 328 , and CD-ROM drive 330 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors.
An operating system runs on processor 302 and is used to coordinate and provide control of various components within data processing system 300 in FIG. 3 . The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provides calls to the operating system from Java programs or applications executing on data processing system 300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs are located on storage devices, such as hard disk drive 326 , and may be loaded into main memory 304 for execution by processor 302 .
Those of ordinary skill in the art will appreciate that the hardware in FIG. 3 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 3 . Also, the processes of the present invention may be applied to a multiprocessor data processing system.
For example, data processing system 300 , if optionally configured as a network computer, may not include SCSI host bus adapter 312 , hard disk drive 326 , tape drive 328 , and CD-ROM 330 , as noted by dotted line 332 in FIG. 3 denoting optional inclusion. In that case, the computer, to be properly called a client computer, must include some type of network communication interface, such as LAN adapter 310 , modem 322 , or the like. As another example, data processing system 300 may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system 300 comprises some type of network communication interface. As a further example, data processing system 300 may be a Personal Digital Assistant (PDA) device, which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data.
The depicted example in FIG. 3 and above-described examples are not meant to imply architectural limitations. For example, data processing system 300 also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system 300 also may be a kiosk or a Web appliance.
With reference now to FIG. 4, a client/server view of an audit subsystem is shown in accordance with a preferred embodiment of the present invention. The audit subsystem 400 includes audit clients 402 , 404 connected to audit servers 406 , 412 . Audit clients 402 , 404 are controlled by audit client software and audit servers 406 , 412 are controlled by audit server software. In a preferred embodiment, the audit client software and audit server software is written in an objected-oriented programming language, such as Java. However, the software may be written in any known programming language.
Audit server 406 is connected to keystore 408 and database 410 . Similarly, audit server 412 is connected to keystore 414 and database 416 . A keystore represents a collection of keys and certificates.
Audit clients 402 , 404 may be embodied on client computers within a network, such as clients 108 - 112 in FIG. 1 . Audit servers 406 , 412 may each be embodied on a network server, such as server 104 in FIG. 1 . It will be understood that audit subsystem 400 may comprise any number of audit clients and any number of audit servers. Each client 402 , 404 and each server 406 , 412 may reside in a separate computer. Alternatively, a client and server, such as client 402 and server 406 , may reside in a single computer. It will also be understood that the connectivity between clients and servers may be modified within the scope of the present invention. For example, audit client 404 may only be connected to audit server 412 .
Audit clients 402 , 404 monitor for events and send the events to audit servers 406 , 412 . The audit servers collect the events into the audit database. The audit servers also include utilities for ensuring the integrity of the audit database, as will be described below.
Audit database 410 includes a primary audit log table 420 , a system table 422 , and auxiliary tables 424 . According to a preferred embodiment of the present invention, audit database 410 is a relational database, such as Database 2 (DB 2 ) from IBM Corporation. A relational database is a database in which relationships between files are created by comparing data and by using indexes, which are built and maintained on key fields used for matching.
Each record in the audit log table has an integrity column, which is computed as the message authentication code (MAC) over the rest of the columns. A MAC is an authentication tag or checksum derived by application of an authentication scheme, together with a secret key, to a message. MACs are computed and verified with the same key. MACs can be categorized as (1) unconditionally secure, (2) hash function-based, (3) stream cipher-based, or (4) block cipher-based. Audit record modifications are detected by comparing the integrity column with a recomputed MAC over the remaining columns.
A keystore 414 is provided to store integrity information, such as keys or passwords, including the MAC key and any other keys or passwords related to integrity, and MAC values. Only the audit server and audit tools are able to compute MAC values, since they are the only code modules that have access to the keystore. The keystore checks that the calling code is trusted code and denies access to the contents of the keystore if the calling code is not trusted.
Examples of commonly used MACs include cipher block chaining message authentication code (CBC-MAC) and HMAC (short for “keyed-Hashing for Message Authentication”). CBC-MAC is a widely used U.S. and international standard. In CBC-MAC, the message blocks are encrypted using DES cipher block chaining and the final block in the ciphertext is output as the checksum. HMAC uses a key or keys in conjunction with a hash function to produce a checksum that is appended to the message.
Each record also has a unique serial number that increases monotonically with each new audit record. The serial number is used in aiding detection of row deletions and additions. After invoking a query to scan the audit records, a row deletion may be detected when a gap is encountered in the serial number sequence. Since the records are queried in ascending order and the serial numbers increase monotonically, a hole would occur if the serial number of the current audit record and the previous serial number plus one are not equal.
The system table 422 maintains the serial number of the first record in the audit log table (First_SN) and the serial number that will be assigned to the next audit record (Next_SN). When an audit record is inserted into the audit log table, the Next_SN value in the system table is updated and the audit record is inserted in the same transaction, so that the serial number range in the system table is always consistent with the set of current audit records. Any row whose serial number is outside the range of First_SN to Next_SN minus one is considered to be an extraneous record. A query of the audit log table for records outside the range may be invoked to isolate extraneous records for recording in an error log.
The system table also contains the integrity value of the auxiliary tables in the audit database. Similar to an audit record in the audit log table, the system table contains its own integrity column, which is computed as a MAC over the other columns. The integrity of the system table may be verified by recomputing the system table MAC and comparing it with the integrity column of the system table. The integrity of all the auxiliary tables may be verified by recomputing their respective MACs and comparing them with their corresponding values in the system table.
If all data were maintained in the database, a database administrator who is not authorized as an auditor could make modifications to the audit database without such changes being detectable. Such an attack may occur if (1) the database administrator gains access to the MAC key or (2) the database administrator mounts a database restore attack in which a restore operation is performed after some set of records have been inserted in the audit log.
To protect against the first type of attack, the MAC key is protected in a keystore, such as keystores 408 , 414 . The MAC key is triple data encryption standard (triple-DES) encrypted under a DES key derived from a password known by an individual acting as an auditor. This password is required to log into the keystore and subsequently gain access to any of the content of the keystore.
In addition, when a program attempts to access the contents of the keystore via the keystore application program interfaces (APIs), the keystore API logic authenticates the calling code. If the calling code is not trusted code, the APIs return failure codes and no access to data is granted. These techniques make it very difficult for an administrator, or any user for that matter, to gain access to the contents of the keystore.
To protect against the second type of attack, the first serial number, next serial number, and integrity columns from the system table are written to the keystore. Before verifying the integrity of the system table, the system table's integrity value, the first serial number, and the last serial number are compared with the corresponding values in the keystore file. If the next serial number in the system table is less than that in the keystore, then it is assumed that a database restore has been completed.
The above described technique for protection against DBA restore attacks is effective assuming that the DBA and the owner of the keystore file, typically an auditor, are not the same individual. If an enterprise defines a DBA role that is distinct from the auditor role, undetected tampering of the audit log via a restore attack is only possible if an individual acting as a DBA were to collude with an individual acting as an auditor.
With reference now to FIG. 5, a database schema is depicted in accordance with a preferred embodiment of the present invention. Database Schema 500 includes system table 510 , audit log table 530 , and auxiliary tables, particularly event type table 540 and authorized entity table 550 . The system table 510 maintains the serial number of the first record in the audit log table (First_SN) and the serial number that will be assigned to the next audit record (Next_SN). The system table also contains the integrity value of other auxiliary tables in the audit database, particularly the event type table MAC and the authorized entity table MAC. The system table also contains its own integrity column, the system table MAC, which is computed as a MAC over the other columns. System table 510 may be embodied as system table 422 in FIG. 4 .
The system table MAC is stored in keystore 520 . The keystore also contains the MAC key to protect against a DBA attack. The first serial number (First_SN) and the next serial number (Next_SN) in the audit log table are also stored in the keystore. The keystore also stores database credentials. Keystore 520 may be embodied as one of keystores 408 , 414 in FIG. 4 .
Audit log table 530 includes a row for each event. The columns of audit log table 530 include serial number (SN), event type (ET), and authorized entity (AE). Each record in the audit log table also has an integrity column, which is computed as the MAC over the rest of the columns. The serial number column is populated with the Next_SN value from the system table when the audit record is created. The event type column is populated with an event type identification (ID) and the authorized entity column is populated with an authorized entity ID. In the example shown in FIG. 5, the audit record with SN equal to ten has an event type of ET 1 and an authorized entity of AE 2 . The event type ID and the authorized entity ID are associated with an event type and distinguished name of the authorized entity, respectively, using lookup tables 540 , 550 , as discussed further below. Audit log table 530 may be embodied as audit log table 420 in FIG. 4 .
Event type table 540 and authorized entity table 550 are examples of auxiliary tables that may be embodied in auxiliary tables 424 in FIG. 4 . Each record in event type table 540 associates an event type ID with an event type. In the example shown in FIG. 5, event type ID ET 1 is associated with a “Certificate Generation” event. Event type ID ET 2 is associated with a “Certificate Revoke” event. Each record in authorized entity table 550 associates an authorized entity ID with distinguished name of an authorized entity. In the example shown in FIG. 5, authorized entity ID AE 1 is associated with distinguished name DN 1 . Authorized entity ID AE 2 is associated with distinguished name DN 2 . Therefore, the audit record in audit log table 530 with a SN equal to ten is a “Certificate Generation” event and the authorized entity is DN 2 .
The database schema shown in FIG. 5 illustrates the advantages of the present invention discussed above. The audit log table 530 in conjunction with system table 510 protects against record insertion, deletion, and modification by use of the serial numbers and integrity column. The system table maintains the integrity of the auxiliary tables and stores the range of serial numbers of the audit records to allow an integrity check to be performed on-line. The keystore 520 protects against DBA attacks by storing the system table integrity value, the MAC key, and database credentials needed to access the audit database.
Those of ordinary skill in the art will appreciate that the structure of database schema 500 may vary depending on the implementation. The database may include fewer or, more likely, more tables and columns within the tables. For example, audit log table 530 may include additional columns each of which has an associated auxiliary table.
With reference now to FIG. 6, a flowchart of an audit server or audit tool startup process is depicted in accordance with a preferred embodiment of the present invention. The process begins and reads a password from a startup command (step 602 ). The process allows the user to log into the keystore (step 604 ) and a determination is made as to whether authorization is successful (step 606 ). If authorization is not successful, the process exits with a failure ( 608 ) and the process ends.
If authorization is successful in step 606 , the process proceeds to read database credentials from the keystore (step 610 ), record the MAC key from the keystore (step 612 ), and obfuscate the MAC key in memory (step 614 ). The process then attempts to connect to the database using the database credentials (step 616 ) and a determination is made as to whether the connection is successful (step 618 ). If connection is not successful, the process exits (step 620 ) and ends. If connection is successful in step 618 , the process continues normal processing (step 622 ).
With reference now to FIG. 7, a flowchart of an audit record creation process is depicted in accordance with a preferred embodiment of the present invention. The audit record creation process begins following the startup sequence as shown in FIG. 6, gets the next audit event (step 702 ), and makes a determination as to whether the event is valid (step 704 ). If the event is a not a valid event, the client is notified and the process returns to step 702 to get the next record.
If the event is a valid event in step 704 , the process creates an audit record structure in memory (step 706 ) and gets the Next_SN value from the system table (step 708 ). This locks the system table because of the database isolation level (COMMIT_READ) and blocks the archive utility. Thereafter, the process assigns Next_SN (step 710 ) and other required information (step 712 ) to the audit record in memory. Next, the process computes the audit record MAC (step 714 ), inserts the audit record into the database, and makes a determination as to whether the insertion is successful (step 718 ). If the insertion is not successful, the transaction is rolled back to the state before the process received the event (step 720 ) and the process returns to step 702 to get the next audit event and the audit client is notified of the failure.
If the insertion is successful in step 718 , the system table is updated so that (1) Next_SN=Next_SN+1, and (2) the system MAC is recomputed (step 722 ). A determination is made as to whether the system table update is successful (step 724 ). If the system table update is not successful, the transaction is rolled back (step 720 ) and the process returns to step 702 to get the next audit event and the audit client is notified of the failure.
If the system table update is successful in step 724 , the keystore is updated with First_SN, Next_SN, and system MAC values from the system table (step 726 ). A determination is made as to whether the keystore update is successful (step 728 ). If the keystore update is not successful, the transaction is rolled back (step 720 ) and the process returns to step 702 to get the next audit event and the audit client is notified of the failure. If the keystore update is successful, the process commits the transaction (step 730 ) and returns to step 702 to get the next audit event.
With reference now to FIG. 8, an integrity check utility process is depicted in accordance with a preferred embodiment of the present invention. The process begins following the startup sequence shown in FIG. 6, sets database isolation level to committed read (step 802 ) and reads the system table into memory (step 804 ). The row is locked because of database isolation level and inserts are blocked. The process then reads keystore information (step 806 ) and performs a rollback to unlock the system table (step 808 ). The rollback to unlock the system table unblocks inserts.
Thereafter, the process compares First_SN, Next_SN, and system MAC values of the system table in memory with the keystore information in memory (step 810 ). A determination is made as to whether the values are equal (step 812 ). If the values are not equal, the process logs the error (step 814 ) and verifies the system MAC in memory (step 816 ). If the values are equal in step 812 , the process proceeds directly to step 816 to verify the system MAC in memory.
A determination is made as to whether the system MAC in memory is verified (step 818 ) by recomputing the MAC using the MAC key and comparing the recomputed value with the value read from the system table. If the system MAC is not verified, the process logs the error (step 820 ) and verifies the MACs of all auxiliary tables (step 822 ). If the system MAC is verified in step 818 , the process proceeds directly to step 822 to verify the MACs of all auxiliary tables.
A determination is made as to whether the MACs of all the auxiliary tables are verified (step 824 ) by recomputing the auxiliary table MACs using the MAC key and comparing the recomputed value with the values read from the system table. If the MAC of any of the auxiliary tables is not verified, the process logs the error (step 826 ) and executes an audit record check process (step 828 ). If the MACs of all the auxiliary tables are verified in step 824 , the process proceeds directly to step 828 to execute the audit record check process. The detailed operation of the audit record check process according to a preferred embodiment of the present invention will be described in more detail below with respect to FIG. 9 . After the process executes the audit record check process, results are printed (step 830 ) and the process ends.
With reference now to FIG. 9, an audit record checking utility process is shown in accordance with a preferred embodiment of the present invention. The process begins, sets database isolation level to TRANSACTION_READ_COMMITTED (step 902 ). This isolation level releases the shared lock on the current row when the next record is read, so that a large number of records is not locked. Next, the process queries the audit log table for records between First_SN and Next_SN−1 (step 904 ). The process then sets a variable Current_SN to be equal to First_SN and Previous_SN to be equal to First_SN−1 (step 906 ). Thereafter, the process fetches the next record from the query results (step 908 ). A determination is made as to whether the record is available ( 910 ).
If the record is available, the value of Current_SN is set to be equal to the serial number from the fetched record. The process verifies the MAC for the record (step 912 ). A determination is made as to whether the MAC is verified (step 914 ) by recomputing the MAC using the MAC key and comparing the recomputed value with the value read from the integrity column. If the MAC is not verified, the process determines that the record has been modified and logs an error for corrupted record (step 916 ) and then determines whether Current_SN is equal to Previous_SN+1 (step 918 ). If the MAC is verified in step 914 , the process proceeds directly to step 918 .
If Current_SN is not equal to Previous_SN+1 in step 918 , the process has found a gap in the serial numbers and logs an error for deleted records (step 920 ). The process then sets Previous_SN to be equal to Current_SN (step 922 ) and returns to step 908 to fetch the next record. If Current_SN is equal to Previous_SN+1, then no gap is found and the process sets Previous_SN to be equal to Current_SN (step 922 ) and returns to step 908 to fetch the next record.
With reference again to step 910 , if the record is not available, a determination is made as to whether Current_SN is less than Next_SN−1 (step 924 ). If Current_SN is less than Next_SN−1, then the process determines that the record to be fetched is in the range of event records that are supposed to be in the audit log table. Therefore, since the record is not available, the record is missing and the process logs an error for missing records at the end of the log (step 926 ), executes a check extraneous records process (step 928 ), and ends.
If records have been deleted, the audit record checking utility will detect this because of gaps in the audit record serial numbers. The issue is that the audit record checking utility will detect this every time without a capability whereby an auditor running the tool can “patch” the audit log so that previously reported deleted records will not be reported again. In a preferred embodiment, the auditor may insert dummy records using the audit record checking utility. The inserted dummy records would be MAC'd liked other records and would have appropriate content to enable the auditor to get a later report on deleted records. At the same time, since the serial number gaps would be closed, the audit record checking utility would only report recent deletions or those for which the auditor has not patched in dummy records.
If Current_SN is not less than Next_SN−1 in step 924 , then the process determines that the end of the log has been reached. Thus, the process proceeds directly to step 928 to execute a check extraneous records process and ends. The detailed operation of the check extraneous records process according to a preferred embodiment of the present invention will be described in more detail below with respect to FIG. 10 .
The above described design for system level protection exploits the fact that each audit record has a unique serial number that increases monotonically. The first serial number and the next serial number are maintained in the system table. By maintaining these values in a separate table, it is possible to take a snapshot of the audit database at any given time.
The integrity check utility takes a snapshot of the audit log based upon the serial number range in the system table and performs an integrity check on the records using the previously described process. The system table is locked in shared mode for the duration of the read and released immediately. This allows the audit subsystem to continue inserting rows while the integrity check utility is executing.
With reference now to FIG. 10, an extraneous record checking utility process is shown in accordance with a preferred embodiment of the present invention. The process begins and queries the audit log table for records outside the First_SN to Next_SN−1 range (step 1002 ). A determination is made as to whether records outside the range are available (step 1004 ). If records outside the range are available, the process fetches each record and logs the serial number as an extraneous record (step 1006 ). Next, the process ends. If records outside the range are not available in step 1004 , the process ends.
If the integrity check fails due to row modification, deletion, or insertion, the offending rows must be reported and an authorized administrator, typically an auditor, must be given an opportunity to inspect these rows. Once an administrator has taken action on the offending rows, they must be marked as having been inspected; otherwise, the integrity check utility will continue to report integrity failures. In a preferred embodiment of the present invention, the set of offending serial number ranges is stored in a separate table. The MAC of this table is stored in the system table. This MAC is protected under the system level MAC, so that data tampering of the “inspected” serial number ranges will be detected. In an alternate embodiment, the serial number ranges may be stored in the keystore.
Since the audit records are never deleted by any application, the audit log table can grow significantly over time. Audit records generated five years ago may no longer be required to be online. For this purpose, the audit subsystem provides a mechanism to archive and purge audit records. The records are archived to files and signed using an audit signing key. Archived records can be brought online for viewing purposes. Online archiving is accomplished using the snapshot mechanism described above allowing archival of records to be done at the same time new audit records are being inserted into the audit log.
The present invention provides an improved method and apparatus for protecting against data tampering of audit logs. Audit records are stored in a table in a relational database. Each record is assigned a unique serial number, which increases monotonically. The serial number is used in aiding the detection of row deletions and additions. Record modification is detected by computing a message authentication code over each record to verify the integrity of the record. The present invention protects against database administrator attacks by the use of a keystore.
It will be apparent to those of ordinary skill in the art that modifications may be made to the above described embodiments within the scope of the present invention. For example, while the audit records are described as being stored in a database table and having a unique, monotonically increasing serial number, the audit records may be stored in another data structure. The audit records may also be assigned some other identifier that maintains the order of the records. For instance, each record may be assigned a pointer to the next audit record in sequence. As another example of modifications that may be made to the embodiments described herein, the MAC value for each audit record may be computed over a smaller subset of columns (e.g., every other column), rather than the remaining columns in each record.
It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media such a floppy disc, a hard disk drive, a RAM, and CD-ROMs and transmission-type media such as digital and analog communications links.
The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A data processing system and method stores a relational database in which audit records are stored without compromising the ability to detect data tampering. The technique provides for detection of unauthorized row modification, row deletion, and row insertion. Extra measures are incorporated to protect from administrator attacks. In addition, the technique enables integrity checking and audit log archiving without having to suspend or bring down the audit subsystem. These on-line capabilities are especially important in mission critical applications which must satisfy the requirement that the application be disabled if the audit subsystem is not functioning properly. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/771,982, filed on Dec. 23, 1996. This application also claims priority from the following provisional applications: Helical Drive Wheelchair, Lawnmower, and Golf Cart, filed Jun. 9, 1997; In-Line Multi-Gear System for Bicycles and Other Applications, Multiple Multi-Gear Systems, and Shifting Devices, filed, Jun. 20, 1997; Multi-Gear Hub, In-Line Multi-Gear System, and Vehicles, filed Jun. 9, 1997; Helical Drive and Motors, filed Apr. 7, 1997; Helical Drive Vehicles, filed Apr. 8, 1997; Improved Helical Drives, filed Apr. 16, 1997; Helical Fishing Reels, filed Apr. 7, 1997; Multiple Ratio Slotted Helix, filed May 1, 1997; Polycycle filed Apr. 7, 1997; Polycycle II, filed Apr. 17, 1997; Improved Slider and Helical Drives, filed Jun. 9, 1997; and Helical Drive Fitness Equipment, Wench, Contained Mono-Helix Drive, filed Jun. 9, 1997.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to wheelchairs.
2. Description of the Related Art
In a conventional non-motorized wheelchair, when powered by the user, the user must grab a large wheel or a hand rail disposed around the large wheel and push in a forward direction for forward movement. To move straight ahead, the user must simultaneously push the two large wheels, one on either side of the user. To cause the wheelchair to turn right, the user must push only on the large wheel or associated hand rail on a left side of the chair. To make a left turn, the user must push only on the wheel or associated hand rail on the right side of the wheelchair.
The motion of pushing the chair requires a certain level of manual dexterity and upper body strength not found in all wheelchair users. Those wheelchair users who lack the required manual dexterity and upper body strength must either have someone push their wheelchair or they must use a more expensive motorized wheelchair. Any speeds, except for very slow speeds, are awkward to obtain.
SUMMARY OF THE INVENTION
The present invention addresses the above problems in the related art and has as its object to provide a wheel chair which can be operated by wheelchair users having less upper body strength and manual dexterity than is required to operate a conventional non-motorized wheelchair.
It is further an object of the invention to provide add-on component parts for converting a conventional non-motorized wheelchair to one which requires less upper body strength and manual dexterity to operate than a conventional non-motorized wheelchair.
A first embodiment of the invention is a wheel chair having two large wheels. One large wheel is disposed on the left side of the wheelchair and another large wheel is disposed on the right side of the wheel chair. Both large wheels are disposed toward a front portion of the wheelchair. A single smaller pivoting wheel is disposed in a central position of a rear portion of the wheelchair. A helical drive is associated with each of the two large wheels. Each helical drive is powered by a rectilinear motion. Such a motion requires less manual dexterity and upper body strength than that which is required to power a non-motorized conventional wheelchair.
A second embodiment is identical to the first embodiment, but instead has two smaller wheels disposed at a rear portion of the wheelchair, one on the left and another on the right. This embodiment has the same advantages as the first embodiment.
A third embodiment has four wheels of equal size. The two front wheels are powered by two parallel mounted helical drives.
A fourth embodiment provides two helical drives for powering the two large rear wheels of a wheelchair. The two front wheels are small and are not powered.
A helical drive is provided which includes a helical member which is a twisted flat bar and a slider. The slider has an opening having the twisted flat bar disposed therethrough. A sliding motion of the slider causes the twisted flat bar to rotate.
Two helical drives for powering the wheelchair are on each wheelchair. Each helical drive includes a pinion gear which engages a crown gear. The crown gears are fixed to the drive wheels of the wheelchair, such that rotation of each of the crown gears causes rotation of the respective wheel.
Add-on components for converting a conventional wheelchair to one which is powered by a helical drive are provided, thereby gaining the advantages described in the embodiments described above.
Other objects and features of the invention will appear in the course of the description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a first embodiment of a helical drive wheelchair having a single small pivoting wheel disposed in a rear portion of the wheelchair.
FIG. 2 is a side plan view of the wheel chair shown in FIG. 1 .
FIG. 3 is a top plan view of a second embodiment of the helical drive wheelchair having two small pivoting wheels disposed in a rear portion of the wheelchair.
FIG. 4 is a side plan view of the wheelchair shown in FIG. 3 .
FIG. 5 is a top plan view of a third embodiment of a wheelchair having four wheels of equal size.
FIG. 6 is a side plan view of the wheelchair shown in FIG. 5 .
FIG. 7 is a top plan view of a fourth embodiment of a wheelchair having two large wheels driven by helical drives and two small front wheels.
FIG. 8 is a side plan view of the wheelchair shown in FIG. 7 .
FIG. 9 is a side plan view of the components of an embodiment of a helical drive, as used in FIGS. 1, 2 , 3 , 4 , 7 , and 8 .
FIG. 10 is a top plan view of an embodiment of two helical drives including a synchronizing gear and a single crown gear having an axle disposed therethrough, as used in FIG. 5 and FIG. 6 .
FIG. 11 is a top plan view of two helical drives including a separate crown gear being engaged by a pinion gear of each helical drive, as used in FIGS. 1, 2 , 3 , 4 , 7 , and 8 .
FIG. 12 shows another embodiment.
FIGS. 13-16 show other helical drive configurations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a first embodiment of the present invention, a helical drive wheelchair. As shown in the figures, two large wheels 10 are each attached to ends of their respective axles such that the two large wheels 10 protrude from a right and left side of a wheelchair frame 20 close to the front of the wheelchair. A single small pivoting wheel 25 is mounted in a central position of the rear of the wheel chair.
A helical drive is disposed on the right and left sides of the wheel chair. Each helical drive 30 is attached to the frame 20 via a rod 40 extending outward from the frame 20 on the left and right sides of the wheelchair, such that each helical drive 30 is disposed on an outer side of a corresponding large wheel 10 . An annular crown gear 50 protrudes outwardly from a hub of each large wheel 10 . The hub is fixedly attached to elongated sections or spokes 52 which extend from the hub to the annular rim of the wheel 10 . Each helical drive 30 has a pinion gear 55 protruding from an end of the helical drive. The pinion gear 55 is disposed in contact with the crown gear 50 , such that rotation of the pinion gear 55 causes the crown gear to rotate, thereby rotating the large wheel. The helical drive 30 has an input device including a handle 60 . Sliding the handle 60 along a slot formed in an outer casing 70 of the helical drive 30 in one direction causes a helical member within the outer casing 70 to rotate, thereby causing the pinion gear 55 to rotate. Moving the handle 60 in the other direction causes the helical drive to free wheel and resets the handle 60 .
FIGS. 3 and 4 show a second embodiment of the present invention. As shown in the figures, two large wheels 10 are each attached to ends of their respective axles such that the two large wheels 10 protrude from a right and left side of a wheelchair frame 120 close to the front of the wheelchair. Two small pivoting wheels 125 are mounted on left rear and right rear portions of the frame 120 . Two helical drives 30 are disposed on the right and left sides of the wheel chair. Each helical drive 30 is attached to the frame 120 via a rod 140 extending outward from the frame 120 on the left and right sides of the wheelchair, such that each helical drive 30 is disposed on an inner side of a corresponding large wheel 10 . An annular crown gear 150 protrudes inwardly from a hub portion of each large wheel 10 . Each helical drive has a pinion gear 55 protruding from an end of the helical drive. The pinion gear 55 is disposed in contact with the crown gear 150 , such that rotation of the pinion gear 55 causes the wheel driving gear to rotate, thereby rotating the large wheel 10 . The helical drive 30 has an input device including a handle 60 . Sliding the handle 60 in one direction along a slot formed in an outer casing 70 of the helical drive 30 causes a helical member within the outer casing 70 to rotate, thereby causing the pinion gear 55 to rotate. Moving the handle 60 in the other direction causes the helical drive to free wheel and resets the handle 60 .
The first two embodiments show a wheelchair having large wheels disposed toward the front of the wheelchair. However, the large wheels could be disposed toward the rear of the wheelchair and pivoting small wheels disposed toward the front of the wheelchair, as in FIGS. 7 and 8.
The embodiments in FIGS. 1, 2 , 3 , 4 , 7 , and 8 , show helical drives directly connected to the drive wheels, and oriented radial to the wheels. However, other orientations are possible, with a linkage connecting the pinion gear of the helical drive with the crown gear on the wheel. The linkage could be, for example, a belt drive, a chain drive, or a drive shaft. For example, the helical drive may be horizontal, parallel to the ground, with a drive shaft connecting the pinion gear on the helical drive to the crown gear on the drive wheel. See for example, in FIG. 12, drive wheel 1201 , and front wheel 1202 are attached to the frame 1203 . Helical drive 1204 , with handle 1205 and pinion gear 1206 , drives wheel 1201 , through drive shaft 1207 . Shaft 1207 connects pinion gear 1206 to annular crown gear 1208 fixed to wheel 1201 . This drive shaft arrangement can also be used in the front wheel drive wheelchair in FIGS. 1 and 2. The helical drive can be installed at any angle.
FIGS. 5 and 6 show the next embodiment of the helical drive wheelchair. This embodiment comprises four wheels 200 of approximately the same size. Each wheel has a hub 202 fixedly attached to an end of an axle 204 or 202 . Each hub 202 is disposed in the center of an area defined by an annular rim of the wheel 200 . The hub is fixedly attached to elongated sections or spokes 206 which extend from the hub to the annular rim of the wheel 200 . The front axle 204 is received in an opening formed in two axle receiving sections 208 which are aligned such that the axle 204 passes through the opening formed in both axle receiving sections 208 . An annular crown gear 210 is disposed on a portion of the axle 204 such that the axle 204 is fixedly attached to and disposed through the center of the crown gear. Two parallel helical drives 212 , each having a slidable disposed handle 214 , are disposed such that a pinion gear 216 extending from an end of each helical drive 212 engages the crown gear 210 . The two helical drives 212 include a connecting section 217 which extends between the two helical drives 212 and integrally connects the helical drives 212 . A frame 218 extends from the axle receiving sections 208 toward the rear of the wheelchair. The rear of the frame 218 includes an opening forming a rear axle receiving section (not shown) through which the rear axle 202 passes. Like the front wheels 200 , a hub of each of the rear wheels 200 is attached to an end of the rear axle 202 . A seat 220 is disposed over a rear section of the frame 218 extending to the rear wheels 200 . A seat back 222 extends upward from an end of the seat 220 closest to the rear of the wheelchair such that the seat back 222 forms an angle with the seat 220 which is more than 90 degrees.
A seated user of the wheelchair operates the wheelchair by sliding the handles 214 of the helical drives 212 . The sliding motion causes a helical member in each helical drive to rotate. When viewed from a perspective of a person seated in the wheelchair, the right helical drive 212 causes the corresponding pinion gear 216 to rotate in a clockwise direction and the left helical drive 212 causes the corresponding pinion gear 216 to rotate in a counterclockwise direction. The pinion gears 216 engage the crown gear 210 thereby forcing the crown gear 210 to rotate in a forward direction.
FIGS. 7 and 8 show the next embodiment of the wheelchair. This embodiment includes two large wheels 224 disposed toward the rear of the wheel chair and two small wheels 226 disposed toward the front of the wheel chair. Each of the wheels has a hub 202 and spokes 206 . Each hub is attached to an axle. The front axle is disposed through openings formed in the frame. Extending outward from the hub of each of the rear wheels 202 is a crown gear 228 . A pinion gear 216 extending from an end of the helical drive 212 is engages the crown gear 228 such that when the pinion gear 216 rotates, the crown gear 228 rotates.
FIGS. 7 and 8 show the helical drives 212 and crown gears 228 being disposed on an outside portion of each large wheel 202 . However, the helical drives and crown gears 228 may be disposed on an inner portion of each large wheel 202 , as is the case for the embodiments in FIGS. 1, 2 , 3 , and 4 .
A seated user of the wheelchair slides the handle 214 of each helical drive 212 in an up and down direction causing the helical member in each helical drive 212 to rotate. The rotation of the helical drive shaft thereby causes the corresponding pinion gear 216 to rotate. Each pinion gear 216 rotates in a manner such that the crown gear is engaged to rotate in a forward direction. As a result, the two large wheels 202 are thereby forced to rotate in a forward direction causing the wheel chair to move forward.
FIG. 9 illustrates a helical member 230 disposed within the helical drive. The helical member 230 comprises a twisted flat bar. A slider 232 forming a thin rectangular opening has the helical member 230 disposed therethrough. One end of the helical member 230 is disposed within a mounting bracket 234 . The other end of the helical member 230 is disposed within a roller clutch 236 . An rod extends from another end of the roller clutch 236 and is disposed within a center of a pinion gear 216 . An outer rim of the pinion gear engages the crown gear 238 such that rotation of the pinion gear 216 causes rotation of the crown gear 238 . Thus, sliding of the slider 232 along a length of the helical member 230 causes the helical member 230 to rotate, thereby rotating the pinion gear 216 and the crown gear 238 .
FIG. 10 shows an embodiment of a helical drive arrangement suitable for use with a helical drive wheelchair embodiment in FIGS. 5 and 6. Two helical drives are shown. Each helical drive 212 includes the helical member 230 , a roller clutch 236 , a mounting bracket 234 , and a slider 232 disposed in the manner shown in FIG. 9 and previously discussed. A handle 240 is attached to the slider 232 . An end of each of the helical drives 212 have a pinion gear. Disposed between the two pinion gears 216 is a single crown gear 238 such that each pinion gear 216 is engages the crown gear 238 . An axle is disposed through an opening in the crown gear 238 and is fixedly attached to the crown gear 238 . Extending from each mounting bracket 234 is a rod 242 . The rod 242 extends through a center of an output gear 244 . A synchronizing gear 246 is disposed between the two output gears 244 . A rod 248 is disposed through the center of the synchronizing gear 246 . A flange 250 is formed near each of the two ends of the rod 248 . A pull cable is attached to one end of the rod facing away from the crown gear 238 . A spring 254 is disposed around a section of the rod between the synchronizing gear 246 and the flange 250 closer to the pull cable 252 .
The helical drive 212 operates in the same manner as discussed previously. The synchronizing gear serves to preserve a relationship between the movement of a handle 240 of one helical drive with the movement of another handle 240 of the other helical drive 212 . By pulling on the pull cable 252 , readjusting the position of the handles 240 , and releasing the pull cable 252 , the relationship between the handles 240 can be altered.
FIG. 11 shows two helical drives 212 which are similar to the helical drives shown in FIG. 10 . The pinion gear 216 of each helical drive 212 is engages a separate crown gear 256 . An axle 258 is disposed between the two crown gears 256 . This is the same helical drive used in the helical drive wheelchair shown in FIGS. 7 and 8.
Sliding the handles 258 cause corresponding helical members 230 to rotate. The rotation of the helical members 230 cause the corresponding pinion gears 256 to rotate engaging the corresponding crown gears 256 , thereby causing the crown gears 256 to rotate.
The helical drive provides a constant torque to the wheels of the wheelchair. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention is not limited to the specific details and representative devices shown and described herein. Accordingly, various modifications to the embodiments of the invention may be made without departing from the spirit or scope of the invention as defined by the appended claims and their equivalents.
Also any embodiment may use other configurations of helical drives, such as, for example, a compound helix, or a concentric helix, or a contained helix. Also, motorized helical drives may be used.
Transmissions may be provided in the wheel chairs. Multi-gear hubs on the drive wheels may be used, or currently found on some bicycles. Or helical drive mechanisms can be used with in-line transmissions.
The wheel chairs of the present invention can be operated in reverse in the conventional manner, by the user manually grabbing the drive wheels and rotating them backwards manually, allowing the helical drive mechanisms to free-wheel. Alternatively, reverse gears can be installed in the helical drive mechanisms to allow helical driven reverse movement.
The helical drives shown herein deliver power only when the handle is used in one direction, and free-wheel when the handle is moved to reset in the other direction. However, other helical drives can be used, that give power in the same direction, when the handle is moved in both directions, such as the concentric helical drive and compound helical drive.
FIG. 13 shows a compound helix drive for powering a helical wheelchair. A first cylindrical screw 200 is disposed closer to an output gear 220 and a second cylindrical screw 210 is disposed further from the output gear 220 . In this embodiment, each cylindrical screw 200 , 210 is a cylindrical tube with a groove 230 extending in a spiral around the cylindrical tube and along a length of the cylindrical tube. The groove 230 on the first cylindrical screw 200 extends in a direction opposite to the direction of the groove 230 on the second cylindrical screw 210 . Extending through the first and the second cylindrical screws 200 , 210 is an axle 240 . Two roller clutches 245 are mounted on the axle 240 such that the axle 240 passes through the center of each of the two roller clutches and an outer rim of a respective roller clutch is in contact with an inside surface of a corresponding one of the cylindrical screws 200 , 210 . A sleeve 255 of an input device is slidable disposed along the outer surface of the cylindrical screws 200 , 210 . Two input shafts 248 extend from an inside surface of the sleeve 255 facing toward a respective one of the cylindrical screws 200 , 210 . An end of each input shaft 248 is slidable disposed within a respective groove 230 of a corresponding cylindrical screw 200 , 210 . An input device handle 260 extends outward from an outside surface of the sleeve 255 and passes through a slot (not shown) formed on the outer casing (not shown). The slot extends along a side of the outer casing in a direction parallel to the lengthwise direction of the two cylindrical screws 200 , 210 . A bearing 275 is disposed around a first end of the axle 240 close to the output gear 220 . The outer surface of the bearing is in contact with an inner surface of the first cylindrical screw 200 . The first end of the axle 240 is disposed within a hole formed in the center of output gear 220 . A second bearing 275 is disposed around the axle 240 , such that the outer surface of the second bearing is in contact with an inner surface of the second cylindrical screw 210 close to an end of the second cylindrical screw 210 opposite to an end closer to the output gear 220 . The second bearing 275 is attached to an end cap (not shown), which, in turn, is attached to an inside end of the outer casing (not shown). A third bearing 275 is disposed around the axle 240 , such that the outer surface of the third bearing is in contact with an inner surface of the first cylindrical screw 200 close to an end of the first cylindrical screw 200 opposite to an end closer to the output gear 220 . A fourth bearing 275 is disposed around the axle 240 , such that the outer surface of the fourth bearing is in contact with the inner surface of the second cylindrical screw 210 near an end of the second cylindrical screw 210 closer to the output gear 220 .
Moving the handle 260 of the input device from a position within the slot in the outer casing further from the output gear 220 to a position within the slot of the outer casing near the output gear causes the input shafts 248 attached to the inner surface of the sleeve 55 to move along the grooves 230 of the first and second cylindrical screws, thereby forcing the second cylindrical screw 210 to move in a clockwise (when viewed from a direction of the output gear 220 ) and the first cylindrical screw 200 to move in a counterclockwise direction. Moving the input device across the slot of the outer casing in an opposite direction forces the first and second cylindrical screws 200 , 210 to rotate in an opposite direction. When each of the two cylindrical screw rotates in the clockwise direction, the roller clutch 245 , which is in contact with a corresponding cylindrical screw 200 , 210 will cause the axle 240 to remain stationary. Thus, the corresponding cylindrical screw 200 , 210 is said to be free-wheeling and not producing any torque. When each of the two cylindrical screws 200 , 210 rotates in a counterclockwise direction, the roller clutch 245 , which is in contact with a corresponding cylindrical screw 200 , 210 , will cause the axle 240 to rotate in the counterclockwise direction. The rotation of the axle 240 in the counterclockwise direction causes the output gear 220 to rotate in a counterclockwise direction.
FIGS. 14, 15 , and 16 illustrate a concentric helix drive for a wheelchair. Only the differences from the previous embodiment of a helical drive, shown in FIG. 13, shall be discussed.
Instead of two cylindrical screws as shown in FIG. 13, this embodiment includes a left-handed (or “LH”) slotted helix cylinder 330 and a right-handed (or “RH”) slotted helix cylinder 335 , both disposed within an outer casing 325 . The RH slotted helix cylinder 335 is disposed within the LH slotted helix cylinder 330 . A stationary shaft 340 is disposed through a longitudinal hole formed through the RH slotted helix cylinder 335 and protrudes from two ends of the RH slotted helix cylinder 335 . An annular carrier 77 is disposed around a portion of the stationary shaft 340 extending beyond an end of the RH slotted cylinder 335 . A bearing 375 is disposed around another portion of the stationary shaft 340 protruding beyond another end of the RH slotted cylinder 335 . The bearing 375 has an annular portion disposed in contact with an inner surface of the LH slotted cylinder 330 . A roller clutch 345 has an outer surface disposed in contact with the inner surface of the LH slotted helix cylinder 330 . The roller clutch 345 is disposed around the carrier 377 . A bearing 375 is disposed around the stationary shaft 340 near an end of the RH slotted helix cylinder 335 further from the output gear 320 and contacts an inner surface of the RH slotted helix cylinder 335 . A roller clutch 345 is disposed around the stationary shaft 340 near another end of the RH slotted helix cylinder 335 closer to the output gear 320 and contacts an inner surface of the RH slotted helix cylinder 335 . An input device comprises a cylindrically-shaped sleeve 350 having a hole formed in a longitudinal direction. The stationary shaft 340 is disposed through the hole formed in the sleeve 350 , such that the sleeve 350 is slidable disposed along the stationary shaft 340 . An input shaft 355 of the input device extends from an outside surface of the sleeve 350 such that the input shaft 355 is disposed at an angle substantially perpendicular to the stationary shaft 340 and passes through a slot 365 formed in the outer casing 325 and extends in a lengthwise direction along a length of the outer casing 325 . A shaft roller 357 is disposed on the input shaft 355 such that the shaft roller 357 is slidable disposed in contact with the RH slotted helix cylinder 335 , Another shaft roller 357 is disposed on the input shaft 355 such that the shaft roller is slidable disposed in contact with the LH slotted helix cylinder 330 . An output sleeve 379 , with two ends, has one end disposed through an opening in a central portion of a bearing 375 which is attached to a central portion of an output gear 320 . The output sleeve 379 extends from the end near the output gear 320 through a central portion of the roller clutch 345 disposed within a central portion of the carrier 377 .
Moving the input shaft 355 in a direction toward output gear 320 causes the LH slotted helix cylinder 330 to rotate in a clockwise direction, when viewed from an end of the helical drive having the output gear 320 , and causes the RH slotted helix cylinder 335 to rotate in a counterclockwise direction. Moving the input shaft 355 in a direction away from the output gear 320 causes the LH slotted helix cylinder 330 to rotate in a counterclockwise direction and the RH slotted helix cylinder 335 to rotate in a clockwise direction. When either the LH slotted helix cylinder 330 or the RH slotted helix cylinder 335 is rotated in the clockwise direction, the respective roller clutch 345 causes the output sleeve 379 to rotate in the clockwise direction. When the output sleeve 379 rotates in the clockwise direction, the outer rim of the output gear 320 rotates in the clockwise direction. | A wheelchair is provided with a helical drive mechanism. A rectilinear input to the helical drive causes an output gear to rotate, thus providing power to rotate the driving wheels of a wheelchair. The helical drive may include, for example, a compound helix, a drive with a twisted flat bar, or a concentric helix drive. Add-on components may be provided to convert a conventional wheelchair to a wheelchair powered by a helical drive mechanism. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 12/416,641, filed Apr. 1, 2009, which is a divisional of U.S. application Ser. No. 10/694,730, filed Oct. 29, 2003, which claims the benefit of U.S. Provisional Application No. 60/421,780, filed Oct. 29, 2002, the contents of all of which are herein incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to serializer/deserializer integrated circuits with multiple high-speed data ports, and more particularly to a serializer and deserializer chip that includes the functionality to switch between multiple high-speed data ports.
[0004] 2. Related Art
[0005] High-speed data links transmit data from one location to another over transmission lines. These data links can include serializer data links (i.e., SERDES) that receive data in a parallel format and convert the data to a serial format for high-speed transmission, and deserializer data links (i.e., SERDES) that receive data in a serial format and convert the data to a parallel format. SERDES data links can be used for communicating data through a backplane in a communications system (e.g., Tyco Backplane 16 or 30-inch trace).
[0006] In a high-speed back plane configuration, it is often desirable to switch between multiple SERDES links. In other words, it is often desirable to switch between any one of multiple SERDES links to another SERDES link, and to do so in a low power configuration on a single integrated circuit.
SUMMARY OF THE INVENTION
[0007] A multi-port SERDES transceiver includes multiple parallel ports and serial ports, and includes the flexibility to connect any one of the parallel ports to another parallel port or to a serial port, or both. Furthermore, the multi-port transceiver chip can connect any one of the serial ports to another serial port or to one of the parallel ports. Each parallel port and each serial port includes a plurality of input-output (IO) pads. According to embodiments of the present invention, the pads are programmable to support multiple different electrical specifications, data protocols, timing protocols, input-output functions, and the like.
[0008] The IO pads for the parallel ports are programmable to support different data protocols, including, but not limited to, the XGMII protocol, the Ten Bit Interface (TBI) protocol, the Reduced TBI (RTBI) protocol, and the like. The IO pads are also programmable to support different electrical specifications, including, but not limited to, the High Speed Transistor Logic (HSTL) electrical specification, the Solid State Track Link (SSTL) electrical specification, the Low Voltage Transistor—Transistor Logic (LVTTL) specification, and the like.
[0009] The multi-port transceiver of the present invention is also programmable to support multiple electrical specifications. The transceiver includes a plurality of management data input/output (MDIO) pads. Each MDIO pad is programmable to configure itself and its associated IO pads to comply with the appropriate electrical requirements and data protocols. The electrical specifications and data protocols include IEEE 802.3™ clause 45, IEEE 802.3™ clause 22, or the like.
[0010] Depending on the specified electrical specification and the specified data protocol, the transceiver may be required to support different electrical requirements at the MDIO pad and the adjacent IO pads. Therefore, the MDIO pad is configured to have a separate power connection from the power connection to associated IO pads. In an embodiment, a split-voltage bus structure is provided to connect the pads for the transceiver to a bus. The structure breaks the power bus VDDO I/O supply, which allows the MDIO pads and the IO pads to operate at different voltage at a given time.
[0011] The multi-port SERDES transceiver also includes a packet bit error rate tester (BERT). The packet BERT generates and processes packet test data that can be transmitted over any of the serial ports to perform bit error testing. The packet BERT can monitor (or “snoop”) between the serial ports. In other words, if data is being transmitted from one serial port to another serial port, the packet BERT can capture and store a portion of this data for bit error testing.
[0012] The substrate layout of the multi-port SERDES transceiver chip is configured so that the parallel ports and the serial ports are on the outer perimeter of the substrate. A logic core is at the center of the substrate, where the logic core operates the serial and parallel data ports, and a bus that connects the data ports. The bus can be described as a “ring” structure (or donut “structure”) around the logic core, and is configured between the logic core and the data ports. The ring structure of the bus provides efficient communication between the logic core and the various data ports.
[0013] Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0014] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art(s) to make and use the invention. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears.
[0015] FIG. 1 illustrates a multi-port SERDES transceiver chip according to an embodiment of the present invention.
[0016] FIG. 2 illustrates a substrate layout of a multi-port SERDES transceiver chip according to an embodiment of the present invention.
[0017] FIG. 3 illustrates sections of a bus on a multi-port SERDES transceiver chip according to an embodiment of the present invention.
[0018] FIG. 4 illustrates path lengths of wires in a bus on a transceiver chip according to an embodiment of the present invention.
[0019] FIG. 5 illustrates path lengths of wires in a bus on a transceiver chip according to another embodiment of the present invention.
[0020] FIG. 6 illustrates a substrate layout of the multi-port SERDES transceiver chip according to another embodiment of the present invention.
[0021] FIG. 7 illustrates a control system for programming a transceiver pad according to an embodiment of the present invention.
[0022] FIG. 8 illustrates a pad timing controller according to an embodiment of the present invention.
[0023] FIG. 9 illustrates a power bus connection for a multi-port SERDES transceiver chip according to an embodiment of the present invention.
[0024] FIG. 10 illustrates an operational flow for configuring a transceiver pad to support a specified data protocol according to an embodiment of the present invention.
[0025] FIG. 11 illustrates an operational flow for reconfiguring an output transceiver pad to function as an input according to an embodiment of the present invention.
[0026] FIG. 12 illustrates an operational flow for programming a transceiver pad to perform Iddq testing according to an embodiment of the present invention.
[0027] FIG. 13 illustrates an operational flow for changing a timing protocol for a transceiver pad according to an embodiment of the present invention.
[0028] FIG. 14 illustrates an operational flow for configuring a transceiver pad to comply with a specified electrical specification according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] FIG. 1 illustrates a multi-port SERDES transceiver 100 according to embodiments of the present invention. The SERDES transceiver 100 includes multiple parallel ports and serial ports, and includes the flexibility to connect any one of the parallel ports to another parallel port or to a serial port, or both. Furthermore, the multi-port transceiver chip 100 can connect any one of the serial ports to another serial port or to one of the parallel ports.
[0030] More specifically, the SERDES transceiver chip 100 includes two parallel transceiver ports 102 a - 102 b and four serial transceiver ports 104 a - 104 d. Other configurations having a different number of ports could be used. The parallel transceiver ports 102 a - 102 b transmit and receive data in a parallel format. The parallel transceiver ports 102 a - 102 b can be XGMII parallel ports, for example, where the XGMII transceiver protocol is known to those skilled in the relevant art(s). Each XGMII port 102 can includes 72 pins, for example, operating at 1/10 the data rate of the serial ports 104 .
[0031] The four serial ports 104 a - d can be XAUI serial ports, and transmit and receive data in a serial format. Each serial port 104 can be a quad serial port having four serial data lines using the XAUI protocol that is known to those skilled in the relevant art(s). In embodiments of the invention, the serial ports 104 can operate at data rates of 3.125 GHz, 2.5 GHz, and 1.25 GHz. In other words, transceiver chip 100 is a multi-rate device. However, the XAUI data rates above are effectively quadrupled since there are four serial data lines in each serial port 104 . The serial ports 104 can be further described as a 10-Gigabit extension sub-layer (XGXS). In embodiments, the serial data ports 104 are differential.
[0032] The parallel ports 102 and the serial ports 104 are linked together by a bus 106 . The bus 106 enables data to travel between all the ports 102 and 104 . More specifically, the bus 106 enables data to travel from one parallel port 102 to another parallel port 102 , and to travel from one parallel port 102 to a serial port 104 . Multiplexes 108 connect the bus 106 to the parallel ports 102 and to the serial ports 104 . The serial port 104 performs a parallel to serial conversion when receiving parallel data that is to be sent out serial. Likewise, the bus 106 enables data to travel from one serial port 104 to another serial port 104 , and to travel between a serial port 104 and a parallel port 102 . The parallel port 102 performs a serial-to-parallel conversion when receiving serial data that is to be sent out in parallel. The multi-port SERDES transceiver 100 is highly flexible in being able to connect multiple parallel ports 102 to multiple serial ports 104 , and vice versa.
[0033] In embodiments, the SERDES transceiver chip 100 can be implemented on a single CMOS substrate. For example, the SERDES transceiver chip 100 can be implemented using a low power 0.13-micron CMOS process technology, which lends itself to higher levels of integration and application.
[0034] The transceiver 100 enables dual unit operation, where one parallel port 102 is paired up with two of the serial ports 104 , and the other parallel port 102 is paired up with the other two serial ports 104 . For example, parallel port 102 a can be paired with serial ports 104 a and 104 b. Likewise, the parallel port 102 b can be paired with serial ports 104 c and 104 d. However, there is complete selectivity of the ports that are grouped together for dual unit operation. For example, parallel port 102 a can be paired with either serial ports 104 a and 104 b, or serial ports 104 c and 104 d. In a backplane configuration, this provides flexibility to connect a parallel port to one or more serial ports for redundancy.
[0035] The transceiver 100 also includes a packet bit error rate tester (BERT) 112 . The packet BERT 112 generates and processes packet test data that can be transmitted over any of the serial ports 104 or parallel ports 102 to perform bit error testing. Any type of packet data can be generated to perform the testing and at different data rates. For example, the packet BERT 112 can generate packet data that can be used to test the SERDES data link. As such, the packet BERT 112 provides a built-in self test for the SERDES data link. The packet BERT 112 generates test data that is sent over one or more of the serial ports 104 using the bus 106 to perform the bit error rate testing of the SERDES data link. Likewise, the packet BERT 112 can capture test data received over any one of the serial ports 104 or parallel ports 102 using the bus 106 for comparison with test data that was sent out. A bit error rate can then be determined based on this comparison.
[0036] In one embodiment, the packet BERT 112 is RAM-based so that the test data is stored and compared in a RAM memory to perform the bit error rate test. In another embodiment, the packet BERT 112 is logic-based so that the test data is generated by a logic function, and transmitted across a SERDES link. Upon receipt back, the test data is re-generated by the logic packet BERT 112 , for comparison with the original test data that was sent over the SERDES data link. A RAM packet BERT 112 is more flexible than a logic packet BERT 112 because there is no limitation on the data that can be stored in the RAM packet BERT 112 . However, a logic packet BERT 112 is more efficient in terms of substrate area because a RAM occupies more area than a logic circuit.
[0037] Since the packet BERT 112 shares the same bus 106 with the serial ports 104 , the packet BERT 112 can monitor (or “snoop”) between the serial ports 104 . In other words, if data is being transmitted from one serial port 104 to another serial port 104 , the packet BERT can capture and store a portion of this data for bit error testing. In one embodiment, the packet BERT 112 “blindly” captures data being sent from one serial port 104 to another serial port 104 . In another embodiment, the packet BERT 112 starts capturing data after a particular byte of data is transmitted. In another embodiment, the packet BERT 112 starts capturing data after an error event occurs.
[0038] The SERDES transceiver chip 100 also includes the ability to include other optional logic blocks 114 that are not necessary for the operation of the SERDES transceiver. In other words, these could be customer-driven logic blocks or some other type of logic block. These optional logic blocks 114 can transmit and receive data over the serial ports 104 or parallel ports 102 using the bus 106 . The packet BERT 112 and the optional blocks 114 connect to the bus 106 using the multiplexers 110 .
[0039] The SERDES transceiver chip 100 also includes a management interface 116 that enables the configuration of the portions (parallel ports 102 , serial port 104 , packet BERT 112 , and optional logic blocks 114 ) of the transceiver chip 100 . In an embodiment, the management interface 116 is configured to be compatible with both IEEE 802.3™ clause 45 and the IEEE 802.3™ clause 22 management standards. The management interface 116 includes two pads 117 that enable two different management chips to program and control the portions of the transceiver chip 100 . For example, one management chip connected to pad 117 a could control the parallel port 102 a and the serial ports 104 a and 104 b, and another management chip connected to pad 117 b could control the parallel port 102 b and the serial ports 104 c and 104 d. The quantity of pads 117 and management chips are provided for illustrative purposes. A greater or smaller quantity of pads 117 and management chips can be included as determined by the system designer.
[0040] FIG. 2 illustrates the substrate layout 200 for the SERDES transceiver 100 according to embodiments of the present invention. The substrate layout 200 is configured to minimize the substrate area of the transceiver 100 , and efficiently provide the port interconnections described above.
[0041] The substrate layout 200 is configured so that the parallel ports 102 a - 102 b and the serial ports 104 a - 104 d are on the outer perimeter of the substrate layout 200 , as shown. A logic core 202 is at the center of the substrate layout 200 , where the logic core 202 operates the bus 106 , serial ports 104 , and parallel 102 ports. The management interface 116 , the packet BERT 112 , and the optional logic blocks 114 a - 114 c are adjacent to the logic core 202 as shown. The bus 106 can be described as a “ring” structure (or donut “structure”) around the logic core 202 , and placed in between the logic core 202 and the parallel ports 102 and serial ports 104 that occupy the parameter of the substrate layout 200 . Furthermore, the ring structure of the bus 106 also provides efficient communication between the logic core 202 and the various ports 102 and 104 . Furthermore, the ring structure of the bus 106 also provides efficient communication between the management interface 116 , the packet BERT 112 , the optional logic blocks 114 , and the various ports 102 and 104 .
[0042] The bus 106 is illustrated as eight sections 106 a - 106 g for ease of illustration. Each section provides an interlace to the respective ports 102 or 104 that are adjacent to the respective sections.
[0043] FIG. 3 represents one of the eight sections 106 a - 106 g of the bus 106 according to embodiments of the present invention. Each section of the bus 106 can be represented as two paths 308 and 310 . Data enters the bus 106 through a buffer 302 and proceeds to its destination along the path 308 and through the buffers 304 . Once on the bus 106 , data passes from one section to another section of the bus 106 using the path 310 and passing through the buffers 312 . The mux 306 represents data passing from the bus 106 to a functional block, such as a parallel port 102 , serial port 104 , or packet BERT 112 . The actual wires and buffers on the bus 106 are matched to minimize signal distortion.
[0044] In embodiments, the data wires in the bus 106 are deposited on the substrate for substrate layout 200 in a particular fashion. Namely, a power or ground is placed between adjacent (or near by) data wires. Furthermore, adjacent data wires on the bus 106 are placed on two separate layers. Therefore, a power or ground will be above or below a data wire, and adjacent to a data wire. Therefore, two nearby data wires will not be located directly adjacent to one another, but instead will be positioned diagonally to each other, thereby reducing cross-talk.
[0045] FIG. 4 further illustrates an example layout of the bus 106 . The wires 402 between parallel ports 102 and serial ports 104 are configured to have the same path lengths. In other words, wires 402 a - d are deposited so as to have the same path length so as to reduce signal distortion.
[0046] FIG. 5 illustrates another embodiment of the bus 106 in the substrate layout 200 . Whereas FIG. 4 depicted only four wires 402 a - 402 d for connecting one port ( 102 or 104 ) to an adjacent port ( 102 or 104 ), FIG. 5 depicts a plurality of wires 402 a - 402 n for connecting two adjacent ports ( 102 and 104 ). The total number of wires 402 a - 402 n is determined by the design of the chip 100 .
[0047] In an embodiment, multi-port SERDES transceiver 100 is programmable to support different data protocols, including, but not limited to, the XGMII protocol, the Ten Bit Interface (TBI) protocol, the Reduced TBI (RTBI) protocol, and the like. Transceiver 100 is also programmable to support different electrical specifications, including, but not limited to, the High Speed Transistor Logic (HSTL) electrical specification, the Solid State Track Link (SSTL) electrical specification, the Low Voltage Transistor—Transistor Logic (LVTTL) electrical specification, and the like. The present invention includes methodologies or techniques for sending control signals to configure the parallel ports 102 a - 102 b to support a designated data protocol. This can be explained with reference to FIG. 6 , which illustrates a substrate layout 600 for the SERDES transceiver 100 according to another embodiment of the present invention. Substrate layout 600 includes a plurality of pads 604 a - 604 d that are part of the four serial ports 104 a - 104 d. In other words, each serial port 104 includes a plurality of pads 604 . As shown, serial port 104 a includes a plurality of pads 604 a. Serial port 104 b includes a plurality of pads 604 b. Serial port 104 c includes a plurality of pads 604 c. Serial port 104 d includes a plurality of pads 604 d.
[0048] Substrate layout 600 also includes a plurality of pads 602 a - 602 d representing two parallel ports 102 a - 102 b. Pads 602 a - 602 b are part of parallel port 102 a, and pads 602 c - 602 d are part of parallel port 102 b. Pads 602 a and pads 602 d are input pads. As such, transceiver 100 receives data and control signals at input pads 602 a and input pads 602 d. Pads 602 b and 602 c are output pads that enable transceiver 100 to transmit data and control signals. In an embodiment, each group of pads 602 includes forty-four individual pads. Forty of the pads are dedicated to sending or receiving data signals, and four of the pads are dedicated to sending or receiving control signals (e.g., clock signals). The total quantity of pads can be increased or decreased as determined by the system designer. Likewise, the ratio of data-to-control pads can also be increased or decreased to meet system requirements as determined by the designer.
[0049] Substrate layout 600 also includes a plurality of management data input/output (MDIO) pads 606 a - 606 d. MDIO pads 606 a - 606 d represent another embodiment of pads 117 a - 117 b, which are described above with reference to FIG. 1 . MDIO pads 606 a - 606 d are programmable to configure pads 602 a - 602 d and 604 a - 604 d for compliance with a designated electrical specification and/or data protocol. The electrical specification and/or data protocol is configured via an external pull-up or pull-down resistor(s) at the designated control pad. The electrical specifications include IEEE 802.3™ clause 45, IEEE 802.3™ clause 22, or the like. As shown MDIO pads 606 a control pads 602 a - 602 b, MDIO pads 606 b control pads 604 c - 604 d, MDIO pads 606 c control pads 602 c - 602 d, and MDIO pads 606 d control pads 604 a 604 b. As discussed above with reference to FIG. 1 , in an embodiment, MDIO pads 606 receive instructions from one or more management chips. These instructions are executed by the MDIO pads 606 to configure transceiver 100 and parallel ports 102 a - 102 b to be compatible with the designated electrical specification. As discussed, in an embodiment, one management chip is provided to instruct all MDIO pads 606 and their associated IO pads 602 and/or 604 . In another embodiment, a distinct management chip is provided to instruct each MDIO pad 606 and its associated IO pads 602 and/or 604 . In another embodiment, a separate management chip is provided to instruct a subset of MDIO pads 606 and their associated IO pads 602 and/or 604 .
[0050] The serial IO pads 604 a - 604 d, parallel IO pads 602 a - 602 d, and MDIO pads 606 a - 606 d are positioned to provide rotational symmetry for substrate layout 600 . Therefore, if the transceiver 100 is rotated 180 degrees, the serial and parallel ports can be connected to another communications device without impeding the performance of transceiver 100 , or having to reconfigure either device. The symmetrical layout of the components also allows efficiencies to be gained when the transceiver is being connected. For instance, while wire-bonding the pads (i.e., 604 a - 604 d, 602 a - 602 d, and 606 a - 606 d ), a technician only needs to design or configure equipment to wire-bond half of the transceiver 100 since the other half would have identical dimensions.
[0051] As discussed, the pads 602 a - 602 d for the parallel ports 102 a - 102 b are programmable to support multiple different standards, protocols, and/or functions. FIG. 7 illustrates a block diagram for logic or circuitry for a control system 700 for programming each pad 602 according to an embodiment of the present invention. Control system 700 includes one or more programmable control registers 702 , a pad timing controller 704 , input controller 706 , output controller 708 , and configuration control logic 710 . Configuration control logic 710 is responsive to various control signals, which are executed to program pad 602 such that it is capable of supporting a designated protocol. Input controller 706 sends an input control signal 722 to configuration control logic 710 to program pad 602 to receive input. Output controller 708 sends an output control signal 724 to configuration control logic 710 to program pad 602 to send output.
[0052] Control registers 702 includes five types of control signals for programming pad 602 . A system operator inputs these control signals, but in an embodiment, the control signals are supplied by a computer system (not shown). The five control signals include a reset message 712 , an Iddq message 714 , a power down message 716 , a pad type message 718 , and a delay select message 720 .
[0053] A reset message 712 is released to instruct pad 602 to change its originally designated function (i.e., input or output). For example, if pad 602 is originally designated as an output pad, the pad 602 is reconfigured to operate as an input pad upon receipt of a reset message 712 . In FIG. 7 , pad 602 is an output pad. Therefore, reset message 712 is only delivered to input controller 706 to enable pad 602 to switch to receiving input.
[0054] An Iddq message 714 is released to implement Iddq testing to measure the quiescent supply current of transceiver 100 . When executed, Iddq message 714 places the path across a pad 602 in a quiescent state to measure the leakage current. As shown, Iddq message 714 is sent to input controller 706 , output controller 708 , and/or configuration control logic 710 for implementation.
[0055] A power down message 714 is released to suspend the operations of portions of pad 602 . If power down message 714 is delivered to input controller 706 , pad 602 no longer receives input. If power down message is delivered to output controller 708 , pad 602 no longer outputs data or control messages. If power down message 714 is delivered to configuration control logic 710 , the muxing and timing operations of the control logic 710 are suspended.
[0056] PAD type message 718 specifies the data protocol and electrical specification, and instructs configuration control logic 710 to implement the specified data protocol and electrical specification. As discussed, the data protocol includes the XGMII, TBI, RTBI protocols, and the like. The electrical specification includes HSTL, SSTL, and LVTTL electrical specifications, and the like.
[0057] Delay select message 720 specifies the path delay for input and output. The parameter specified in the delay select message 720 enables the system operator, or the like, to adjust the delay between input and output at each pad 602 for better system performance.
[0058] As discussed above, the present invention allows transceiver 100 to be programmed to support different data protocols. Referring to FIG. 10 , flowchart 1000 represents the general operational flow for configuring a programmable pad 602 to support a designated data protocol, according to an embodiment of the present invention.
[0059] The control flow of flowchart 1000 begins at step 1001 and passes immediately to step 1003 . At step 1003 , protocol instructions for a designated data protocol are specified. Referring back to FIG. 7 , the specified protocol instructions are placed in programmable control registers 702 .
[0060] At step 1006 , a control signal carrying the protocol instructions are released to program a pad 602 . Referring back to FIG. 7 , the control signal is shown as PAD type message 718 , which is received by configuration control logic 710 .
[0061] At step 1009 , the control signal (i.e., PAD type message 718 ) is executed to implement the specified data protocol. At step 1012 , an output control signal 724 or input control signal 722 is sent to configuration control logic 710 to instruct the programmable pad 602 to function as an output or input. At step 1015 , pad 602 transmits or receives in accordance with the specified data protocol. Afterwards, the control flow ends as indicated at step 1095 .
[0062] Referring back to FIG. 7 , pad 602 is programmed to function as an output. However, pad 602 can be reconfigured to function as an input. Referring to FIG. 11 , flowchart 1100 provides an example of a general operational flow for reconfiguring an output programmable pad 602 to function as an input.
[0063] The control flow of flowchart 1100 begins at step 1101 and passes immediately to step 1103 . At step 1103 , pad 602 is instructed to cease functioning as an output. Referring back to FIG. 7 , power down message 716 is sent to output controller 708 , which as a result, stops sending output control signal 724 .
[0064] At step 1106 , input operations are initiated at pad 602 . Referring back to FIG. 7 , reset message 712 is sent to input controller 706 to initiate the operations. At step 1109 , input control signal 722 is sent to configuration control logic 710 . At step 1112 , configuration control logic 710 executes the input control signal 722 to configure pad 602 to start receiving input. Afterwards, the control flow ends as indicated at step 1195 .
[0065] As discussed above, programmable control registers 702 also release an Iddq message 714 to implement Iddq testing. Referring to FIG. 12 , flowchart 1200 provides an example of a general operational flow for programming pad 602 to perform Iddq testing.
[0066] The control flow of flowchart 1200 begins at step 1201 and passes immediately to step 1203 . At step 1203 , Iddq message 714 is released to either input controller 706 or output controller 708 , depending on the I/O operations currently designated for pad 602 . At step 1206 , Iddq message 714 is also released to configuration control logic 710 , which programs pad 602 to measure leakage as previously discussed. Afterwards, the control flow ends as indicated at step 1295 .
[0067] As shown, if pad 602 is operating as an input pad, pad timing controller 704 receives pad data 726 from pad 602 . The delay select message 720 instructs pad timing controller 704 to buffer the pad data 726 for a prescribed time period before sending the data to its destination as internal data 728 . The prescribed time period is substantially the same as the path delay at other pads 602 .
[0068] Conversely, if pad 602 is operating as an output pad, pad timing controller 704 receives internal data 728 and buffers the data for a prescribed time period before enabling it to be output as pad data 726 .
[0069] FIG. 8 represents the buffering process for implementing path delay according to an embodiment of the present invention. As shown, pad timing controller 704 includes a plurality of buffers 802 a - 802 n and a multiplexer 804 . Data enters pad timing controller 704 and is delayed in one or more buffers 802 a - 802 n for a prescribed time period. The incoming data can be pad data 726 received by pad 602 , or internal data 728 received from another portion of transceiver 100 .
[0070] Each buffer 802 a - 802 n delays the incoming data a fixed delay time. The delay time is fixed internally. In other words, the system designer specifies the delay time for the buffers during fabrication of transceiver 100 , and this value is not changed by the control registers 702 or a system operator. The data is sent to the next buffer 802 a - 802 n unless multiplexer 804 opens the communications path to receive the data. The delay select message 720 determines when multiplexer 804 opens the communications path. The communications path can be opened prior to the data entering one of the buffers 802 a - 802 n, or at any point after the data is released from one of the buffers 802 a - 802 n. Therefore, the delay select message 720 enables the path delay to be increased or decreased by specifying the number of buffers 802 a - 802 n, if any, that the data should traverse. Once the data is received by multiplexer 804 , the data is sent to its destination as pad data 726 or internal data 728 .
[0071] Hence, the multi-port SERDES transceiver 100 includes the ability to change the timing of parallel ports 102 and serial ports 104 . This includes the ability to change the timing between the data and clock signals. In other words, the registers in the parallel ports 102 and serial ports 104 can be re-programmed to operate at different timing protocols. Referring to FIG. 13 , flowchart 1300 provides an example of a general operational flow for changing the timing protocol for a pad 602 .
[0072] The control flow of flowchart 1300 begins at step 1301 and passes immediately to step 1303 . At step 1303 , one or more parameters are input to adjust the path delay. Referring back to FIG. 7 , the parameters are entered at programmable control registers 702 .
[0073] At step 1306 , the delay parameters are communicated to PAD timing controller 704 . Referring back to FIG. 7 , the delay parameters are encoded in delay select message 720 .
[0074] At step 1309 , the delay parameters (i.e., delay select message 720 ) are executed to specify the total delay period for the path delay. As discussed with reference to FIG. 8 , the total delay period is measured by the quantity of buffers 802 a - 802 n that data must traverse before being received by multiplexer 804 .
[0075] At step 1312 , data (i.e., PAD data 726 or internal data 728 ) is received, and at step 1315 , the data is delayed the specified total delay period. At step 1318 , the data is sent to its destination. Afterwards, the control flow ends as indicated at step 1395 .
[0076] As discussed with reference to FIG. 6 , each MDIO pad 606 a - 606 d is programmable to configure itself to comply with a designated electrical standard, such as IEEE 802.3™ clause 22, IEEE 802.3™ clause 45, or the like. For instance, IEEE 802.3™ clause 22 specifies the access to management scheme, including data protocol and electrical requirements.
[0077] Pads 602 a - 602 d are programmable to support any combination of data protocols (e.g., XGMII, TBI, RTBI, etc.) and electrical specifications (e.g., HSTL, SSTL, LVTTL, etc.), and the electrical requirements are determined by the designated electrical specification. For example, the SSTL electrical specification requires pads 602 a - 602 d to operate at 2.5 volts. The HSTL electrical specification requires pads 602 a - 602 d to operate at 1.5 volts or 1.8 volts. The LVTTL electrical specification requires pads 602 a - 602 d to operate at 2.5 volts or 3.3 volts.
[0078] Notwithstanding the electrical requirements for pads 602 a - 602 d, MDIO pads 606 a - 606 d must operate at 1.2 volts to comply with IEEE 802.3™ clause 45. To comply with IEEE 802.3™ clause 22, MDIO pads 606 a - 606 d must operate at 2.5 volts. Accordingly, MDIO pads 606 a - 606 d are programmable to configure themselves and their associated pads 602 a - 602 d to comply with the appropriate electrical requirements. For example, to comply with IEEE 802.3™ clause 45, the power connection to the MDIO pads (e.g., pads 606 c ) and their corresponding input and output pads (e.g., 602 d and 602 c ) must be broken to allow the MDIO pads to operate at 1.2 volts and the input/output pads to operate at 2.5 volts. To enable the split voltage requirement to be implemented, a split-voltage bus structure is provided to connect the pads for transceiver 100 to a bus. An embodiment of a split-voltage bus structure is illustrated in FIG. 9 .
[0079] FIG. 9 illustrates power supply connections for MDIO pads 606 c - 606 d and output pads 602 c, according to an embodiment of the present invention. The power supply connections include VDDO I/O supply 912 , VSSO I/O supply 914 , VSSC core supply 916 , and VDDC core supply 918 . MDIO pads 606 c - 606 d are separated from output pads 602 c by split voltage structure 902 a - 902 b. Structure 902 a - 902 b breaks the power bus VDDO I/O supply 912 , which allows different electrical requirements to be provided for MDIO pads 606 c - 606 d and the adjacent output pads 602 c. Hence, the power signals 904 , data signals 906 , clock signals 908 , and ground signals 910 for MDIO pads 606 c - 606 d will not interfere with the electrical and data signals communicated from output pads 602 c. The connection for the VSSO I/O supply 914 , VSSC core supply 916 , and VDDC core supply 918 is not broken by the structure 902 a - 902 b.
[0080] Referring to FIG. 14 , flowchart 1400 provides an example of a general operational flow for configuring a programmable pad (i.e., serial IO pads 604 a - 604 d, parallel IO pads 602 a - 602 d, and MDIO pads 606 a - 606 d ) to comply with a specified electrical standard, such as IEEE 802.3™ clause 22, IEEE 802.3™ clause 45, or the like.
[0081] The control flow of flowchart 1400 begins at step 1401 and passes immediately to step 1403 . At step 1403 , MDIO instructions are accessed to identify the specified electrical specification (e.g., HHTL, SSTL, LVTTL, etc.). As discussed, the MDIO pad 606 must operate at a certain voltage, depending on the specified electrical specification.
[0082] At step 1406 , the MDIO instructions are executed to configure the electrical requirements for the associated IO pads 602 and/or 604 . As discussed, the IO pads 602 and/or 604 may be required to operate at a different voltage than the MDIO pad 606 .
[0083] Once the electrical requirements have been configured, the control passes to step 1409 . At step 1409 , data and control signals are sent or received at the MDIO pad 606 and IO pads 602 and/or 604 in accordance with the specified electrical specification. Afterwards, the control flow ends as indicated at step 1495 .
CONCLUSION
[0084] Example embodiments of the methods, systems, and components of the present invention have been described herein. As noted elsewhere, these example embodiments have been described for illustrative purposes only, and are not limiting. Other embodiments are possible and are covered by the invention. Such other embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | A method for performing Iddq testing including receiving an Iddq message and executing the Iddq message to measure current leakage. | 8 |
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