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BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a device for practicing the game of tennis, whereby a player may play or practice together with one or more other players or by playing alone.
The device is in the form of a tethered ball game. Numerous such apparatus have been developed heretofore, such as, for example, the devices shown in U.S. Pat. Nos. 2,772,882; 3,031,191; 2,747,873; 1,708,796; 1,528,909; 3,693,972; 3,776,551; 3,764,140; 3,601,398; 3,804,409; 3,809,406; 2,917,720; 2,307,905; 3,498,613; 1,655,599; British Pat. No. 813,002 and Australian Pat. No. 21,210. However, these devices have been generally developed for games other than tennis and they all primarily include complex tethering lines or cords.
Other various tennis trainers have been marketed heretofore by Tennis-For-One, of 100 Merrick Road, Rockville Centre, N.Y. 11570 and by Bancroft Sporting Goods Co., Woonsocket, R.I., the latter under the name of "Tretorn Tennis Trainer". These devices are essentially similar in concept consisting of a tennis ball attached by an elastic cord to an anchor base. However, neither of these tennis trainers, nor any of the above-noted patents, provides an adjustable elastic cord between the ball and a fixed base.
It is therefore an object of the invention to provide a novel self-workout device for tennis which is relatively simple in construction and one which enables a player to improve his tennis skills by controlling the speed and return of the tennis ball.
It is also another object of the invention to provide a device which is capable of being adjusted so that the ball return speed can be varied from generally fast to slow.
In accordance with an illustrative embodiment demonstrating objects and features of the present invention, there is provided a device which comprises a generally elastic cord having opposite ends and a ball secured to one end of the cord. Adjustment means is provided on said elastic cord for shortening or lengthening the cord, and anchoring means is provided for securely fastening the other end of the elastic cord to the ground or other flat surface. With such adjustment means, the ball return speed can be greatly varied to suit the skill of any player. Generally, a player initially sets the length of cord to a desired dimension and adjusts the length thereafter, as desired, depending upon his or her consistency in returning the ball by hitting it each time it rebounds back to the player.
BRIEF DESCRIPTION OF THE DRAWING
The above brief description as well as further objects, features and advantages of the present invention will be more fully understood by reference to the following description of the presently preferred but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawing, wherein:
FIG. 1 is a perspective view of the tennis self-workout device or variable speed tennis trainer of the present invention, as it would be stroked by a player upon the ball's return after being hit;
FIG. 2 is a greatly enlarged view of the adjustable means for varying the ball return speed;
FIG. 3 is a sectional view, taken along the line 3--3 of FIG. 1;
FIG. 4 is a side elevational view of three "typical string lengths" representing slow, medium and fast return speeds; and
FIG. 5 is an alternate connection means between the base and the cord or string.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While only the preferred forms of the invention are shown, it should be understood that various changes or modifications may be made within the scope of the claims attached hereto without departing from the spirit of the invention.
Referring now to the figures and more particularly to FIG. 1, there is shown an anchored ball game device 10 comprising a weighted base 12, a tethered ball 14, and a connecting elastic line or cord 16 having ajdusting means 18. The base 12 is positioned on the ground 20 or other suitable substrate, and as best shown in FIG. 3, it suitably comprises a hollow housing 22. The housing 22 is provided with a plurality of feet 24 and a removable plug 26. The plug 26 enables one to readily fill the housing 22 with any suitable heavy fluid material 23, such as sand, water or the like.
In FIG. 1, the player's hand 28 is shown holding a racket 30, and the player should generally stand in the vicinity of the base, for example, either in front or behind the base and generally along side thereof. Upon hitting the ball 14 with the racket 30, the ball travels for the length of the elastic cord 16 and then returns back to the player in a somewhat "whipping" manner. The return rebound or recoil given to the ball depends primarily on the length of the elastic cord 16. Thus, as shown in FIG. 4, the full length of the elastic cord 16 shown at the left of said figure provides the slowest return on the ball, while the right side of said figure illustrates a half length elastic cord having about twice the return speed as the former case. The middle view in said figure represents an intermediate or medium speed position as it shows the length of the elastic cord as being somewhere between the maximum length and half-length.
A Y-like element or yoke 32 is connected to said base 12 by means of a loop element 34. Such loop element 34 is somewhat like a cotter pin and is mounted in said base 12 so that it is free to rotate therein or swivel thereabout. The yoke 32 is positioned such that the pair of legs 36 and 38 of the fork section provide a spaced connection for an intermediate section of the elastic cord 16. With a spaced intermediate section of the elastic cord 16 connected to the base 12, there is less likelihood that the elastic cord 16 will become twisted about itself during extensive playing or practicing. Of course, the loop element 34 is in the form of a "swivel" in that it is free to rotate freely about the axis of the aperture in the base 12 to which it is rotatably secured.
A suitable connecting loop 40, as best shown in FIG. 2, preferably made of an elastic material is provided as a means for connecting the elastic cord 16 to the ball 14. Other loops 42 and 44 are provided respectively on the legs 36 and 38 of the yoke element 32. One end of the elastic cord 16 is generally connected to the elastic loop 40 and the other end 46 is connected to the adjusting means 18. Apertures 48 and 50 in the adjusting means 18 permit the elastic cord 16 to pass therethrough in a "weave-like" manner. With such an adjustment device, the apparatus of the invention is provided with the unique ability to adjust the speed of the ball's return or rebound. Thus, the snap-back or return speed of the ball can be varied by simply moving the adjusting device 18 up or down the length of the elastic cord 16. With the elastic cord 16 at maximum length, the ball returns at the slowest rate, whereas with the shortest possible length of the elastic cord 16 (doubled-up), the ball return speed is at its maximum speed. A player can therefore adjust and control the ball return speed to any desired result depending upon the skill of the player to consistently return the ball by constantly stroking it back into play. Generally, the game is best played when the ball is hit in such a manner as to have the ball return on a single bounce.
A player, of course, can stroke the ball in any desired manner, for example, forehand, backhand, smash shot, etc.
FIG. 5 simply illustrates an alternate connecting means between the base 22 and the elastic cord 16. Here another type of loop or a ring 52 is utilized, although any suitable connection means may be utilized. Even a swivel type connection may be employed, if desired, although the V-shaped device extending through the aperture in the base 22 permits the ring 52 and cord 16 to freely rotate about the axis of the aperture.
It may also be desired for purposes to provide the base 12 with a suitable depression or cavity 54. When the game is not being used, the ball 14 and, if desired, the cord may be stored in a cavity 54 provided in the bottom of the base 12. Alternatively, the elastic cord 16 may be suitably wrapped (not shown) about the base 12, in lieu of storing it in the cavity 54.
A suitable swivel joint device 56 may also be provided between the ball connecting loop 40 and one end of the elastic cord 16. Such swivel means 56 permits the ball 14 to rotate freely and also roll along the ground or floor without winding up the cord 16. A relatively short similar piece of elastic or inelastic cord 58 may be employed to simply connect one end of the swivel joint device 56 to the connecting loop 40, and the other end of the swivel device 56 is connected to the elastic cord 16. It is preferable where a cord 58 is employed to utilize a relatively short (as compared to the length of the elastic cord) inelastic or other like piece of cord, as such a cord lends itself to providing the ball with the duplication of an "actual bounce" and generally aids in controlling the "snap-back" and "hang-up" of the ball to a degree. With an all elastic cord, there is less control of the ball's snap-back and a greater likelihood of its hanging up.
The elastic cord 16 is suitably made from any generally elastic material, such as natural or synthetic rubber, or any other elastomeric material which is strong and capable of withstanding continuous flexing and stretching over literally hundreds of thousands of cycles. The ball may be a conventional tennis ball or other suitable ball, such as a resilient one capable of good rebounding qualities when bounced. The loop 40 is also likewise constructed of a flexible material as the elastic cord 16 and it is suitably securely fastened to the ball by any available means which is strong and yet does not interfere with the playing qualities of the ball. For example, the loop 40 can be secured by means of suitable adhesives to the ball.
It will be appreciated that with a single strand of elastic cord 16 (at its maximum length), the ball return speed is at its slowest since the tension of the elastic cord is at a minimum as it is a function of or based upon the elasticity of the cord. With the elastic cord at half the maximum length (cord is doubled up forming two equal lengths of elastic cord), then the ball return speed would be at its fastest as the tension of the elastic cord would be about double that of the single elastic cord length. Thus, as shown by the directional arrows near the adjusting means 18, moving the means 18 toward the ball increases the ball rebound speed, and moving the means 18 toward the base decreases the ball return speed. The length of the elastic cord 16 may be readily changed by simply holding the adjusting means 18 in one hand and pulling the elastic cord 16 through the apertures 48 and 50 in the desired direction, similarly as one would do in tightening or loosening a conventional belt buckle. One set, the length of the elastic cord is retained in place by the means 18 until it is further adjusted to suit a player's desires.
With just a single line of elastic cord, the shorter the section of cord, the faster the "snap-back". Here with the present invention, the "snap-back" or rebound is fastest with the elastic cord being doubled up as the "spring-tension" of the cord is at its strongest.
With the apparatus of the present invention, a player may practice his timing and stroking. When the ball is hit, it flies out to its farthest extension of the elastic cord and then flies back on a bounce as if hit by an unseen opponent. The player continues to play by hitting the ball again and again so as to keep his or her "rally" going for the longest possible time or period. In effect, the apparatus us almost like practicing against a wall or backboard, in contrast to hitting balls dispensed by a tennis ball throwing machine. The present invention is extremely versatile and by providing the apparatus with an adjustment means, the device can be made more lively by increasing or decreasing the speed of the ball's return. Such variation in the ball's speed can be used to increase one's skill in returning a ball to an opponent and also in improving and developing one's skills with the various tennis strokes used in playing the real game of tennis.
While the invention has been described, disclosed, illustrated and shown in terms of an embodiment or modification which it has assumed in practice, the scope of the invention should not be deemed to be limited by the precise embodiment or modification herein described, disclosed, illustrated or shown, such other embodiments or modifications as may be suggested to those having the benefit of the teachings herein being intended to be reserved especially as they fall within the scope and breadth of the claims here appended.
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A device for practicing tennis rebounds comprising an anchor or weighted base, a tennis ball and a generally elastic cord connected therebetween. The line or cord is provided with adjusting means for varying the length of the cord from a maximum length to one-half thereof, thereby enabling the ball return speed to be controlled by setting a desired or predetermined length for the elastic cord. The greater the length of the elastic cord, the slower the return of the tennis ball.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mechanisms for extracting water from a web of material, and more particularly from a fibrous web being processed into a paper product on a papermaking machine. Specifically, the present invention is an impermeable belt designed for use on a long nip press on a papermaking machine. The belt may also be used in other papermaking and paper-processing applications, such as calendering.
2. Description of the Prior Art
During the papermaking process, a fibrous web is formed on a forming wire by depositing a fibrous slurry thereon. A large amount of water is drained from the slurry during this process, after which the newly formed web proceeds to a press section. The press section includes a series of press nips, in which the fibrous web is subjected to compressive forces designed to remove water therefrom. The web finally proceeds to a drying section which includes heated dryer drums around which the web is directed. The heated dryer drums reduce the water content of the web to a desirable level through evaporation.
Rising energy costs have made it increasingly desirable to remove as much water as possible from the web prior to its entering the dryer section. The dryer drums are often heated from within by steam and related costs can be substantial especially when a large amount of water needs to be removed from the web.
Traditionally, press sections have included a series of nips formed by pairs of adjacent cylindrical press rolls. In recent years, the use of long press nips has been found to be advantageous over the use of nips formed by pairs of adjacent press rolls. The longer the time a web can be subjected to pressure in the nip, the more water can be removed there, and, consequently, the less water will remain behind in the web for removal through evaporation in the dryer section.
The present invention relates to long nip presses of the shoe type. In this variety of long nip press, the nip is formed between a cylindrical press roll and an arcuate pressure shoe. The latter has a cylindrically concave surface having a radius of curvature close to that of the cylindrical press roll. When the roll and shoe are brought into close physical proximity to one another, a nip is formed which can be five to ten times longer in the machine direction than one formed between two press rolls. This increases the so-called dwell time of the fibrous web in the long nip while maintaining the same level of pressure per square inch in pressing force used in a two-roll press. The result of this new long nip technology has been a dramatic increase in dewatering of the fibrous web in the long nip when compared to conventional nips on paper machines.
A long nip press of the shoe type requires a special belt, such as that shown in U.S. Pat. No. 5,238,537. This belt is designed to protect the press fabric supporting, carrying and dewatering the fibrous web from the accelerated wear that would result from direct, sliding contact over the stationary pressure shoe. Such a belt must be provided with a smooth, impervious surface that rides, or slides, over the stationary shoe on a lubricating film of oil. The belt moves through the nip at roughly the same speed as the press fabric, thereby subjecting the press fabric to minimal amounts of rubbing against the surface of the belt.
Belts of the variety shown in U.S. Pat. No. 5,238,537 are made by impregnating a woven base fabric, which takes the form of an endless loop, with a synthetic polymeric resin. Preferably, the resin forms a coating of some predetermined thickness at least on the inner surface of the belt, so that the yarns from which the base fabric is woven may be protected from direct contact with the arcuate pressure shoe component of the long nip press. It is specifically this coating which must have a smooth, impervious surface to slide readily over the lubricated shoe and to prevent any of the lubricating oil from penetrating the structure of the belt to contaminate the press fabric, or fabrics, and fibrous web.
The base fabric of the belt shown in U.S. Pat. No. 5,238,537 may be woven from monofilament yarns in a single- or multi-layer weave, and is woven so as to be sufficiently open to allow the impregnating material to totally impregnate the weave. This eliminates the possibility of any voids forming in the final belt. Such voids may allow the lubrication used between the belt and shoe to pass through the belt and contaminate the press fabric or fabrics and fibrous web.
When the impregnating material is cured to a solid condition, it is primarily bound to the base fabric by a mechanical interlock, wherein the cured impregnating material surrounds the yarns of the base fabric. In addition, there may be some chemical bonding or adhesion between the cured impregnating material and the material of the yarns of the base fabric.
While the belts shown in U.S. Pat. No. 5,238,537 have proved to be durable, reliable and long-lived on long nip presses, improvements both in the structure of such belts and in methods for their manufacture are continually being made. Some of the improvements are driven by the need to prevent the polymeric resin coating from delaminating from the base fabric and relate to means for improving the mechanical, and possibly chemical, interlock between the base fabric and the coating. Other improvements relate to the structure of the base fabrics themselves, and are designed to make the base fabrics stronger, more durable, or to the exact dimensional specifications required for a given application. Still other improvements relate to the coating processes themselves, and have as their object the complete impregnation of the base fabric and the provision of a uniformly thick coating of polymeric resin material on the inner surface of its endless configuration without the step of inverting (turning inside out) the belt during the manufacturing process.
The present invention relates to the base fabric of a long nip press belt. More specifically, the present invention is a long nip press belt having a base fabric in the form of an endless braided structure. In addition to being useful as a long nip press belt, the present invention may also be used in other papermaking and paper-processing applications, such as calendering.
SUMMARY OF THE INVENTION
Accordingly, the present invention is a resinimpregnated endless belt for a long nip press. The belt may also be used on a calender of the shoe type, as both a long nip press and a calender of that type comprise a cylindrical press roll and an arcuate pressure shoe which together define a nip therebetween. The resin-impregnated endless belt passes through the nip in direct sliding contact with the arcuate pressure shoe, and separates a fibrous web being treated there, and perhaps a press fabric or fabrics supporting the fibrous web, from the arcuate pressure shoe, thereby protecting the fibrous web, and the press fabric or fabrics, from damage by direct sliding contact with the arcuate pressure shoe and from contamination by any lubricant on the arcuate pressure shoe.
The resin-impregnated endless belt comprises a base fabric in the form of a braided structure having a plurality of braided layers of yarns. In each of the layers at least one yarn thereof extends into a contiguous layer to form an interlock therebetween. The layers are therefore interlocked with one another, and are unable to delaminate from one another. The base fabric is in the form of an endless loop having an inner surface, an outer surface, a longitudinal direction and a transverse direction, and is assembled according to the teachings of commonly assigned U.S. Pat. No. 5,501,133 to Brookstein et al. This patent was issued on Mar. 26, 1996 and is entitled "Apparatus for Making a Braid Structure".
At least the inner surface of the base fabric has a coating of a polymeric resin material, such as polyurethane. The coating impregnates the base fabric and renders it impermeable to liquids, such as oil and water, and is ground and buffed to provide it with smooth surface, and the belt with a uniform thickness.
The present invention will now be described in more complete detail with frequent reference being made to the figures, which are listed and identified as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side cross-sectional view of a long nip press;
FIG. 2 is a perspective view of a belt of the present invention;
FIG. 3 is a perspective view of an alternate embodiment of the belt;
FIG. 4 is a perspective view of another embodiment of the belt;
Figure 5 is a perspective view of the base fabric for the belt of the present invention;
FIG. 6 is a plan view of an area of the outer surface of the base fabric; and
FIG. 7 is a schematic cross-sectional view taken in the longitudinal, or machine, direction of the base fabric.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A long nip press for dewatering a fibrous web being processed into a paper product on a paper machine is shown in a side cross-sectional view in FIG. 1. The press nip 10 is defined by a smooth cylindrical press roll 12 and an arcuate pressure shoe 14. The arcuate pressure shoe 14 has about the same radius of curvature as the cylindrical press roll 12. The distance between the cylindrical press roll 12 and the arcuate pressure shoe 14 may be adjusted by hydraulic means operatively attached to arcuate pressure shoe 14 to control the loading of the nip 10. Smooth cylindrical press roll 12 may be a controlled crown roll matched to the arcuate pressure shoe 14 to obtain a level cross-machine nip profile.
Long nip press belt 16 extends in a closed loop through nip 10, separating cylindrical press roll 12 from arcuate pressure shoe 14. A wet press fabric 18 and a fibrous web 20 being processed into a paper sheet pass together through nip 10 as indicated by the arrows in FIG. 1. Fibrous web 20 is supported by wet press fabric 18 and comes into direct contact with smooth cylindrical press roll 12 in nip 10. Fibrous web 20 and wet press fabric 18 proceed through the nip 10 as indicated by the arrows. Long nip press belt 16, also moving through press nip 10 as indicated by the arrows, that is, counterclockwise as depicted in FIG. 1, protects wet press fabric 18 from direct sliding contact against arcuate pressure shoe 14, and slides thereover on a lubricating film of oil. Long nip press belt 16, accordingly, must be impermeable to oil, so that wet press fabric 18 and fibrous wet 20 will not be contaminated thereby.
A perspective view of the long nip press belt 16 is provided in FIG. 2. The belt 16 has an inner surface 28 and an outer surface 30. On the outer surface 30, the base fabric of the belt 16 may be visible.
FIG. 3 is a perspective view of an alternate embodiment of the belt 32. The belt 32 has an inner surface 34 and an outer surface 36. The outer surface 36 is provided with a plurality of grooves 38, for example, in the longitudinal direction around the belt 32 for the temporary storage of water pressed from fibrous web 20 in press nip 10.
Alternatively, the outer surface of the belt may be provided with a plurality of blind holes arranged in some desired geometric pattern for the temporary storage of water. FIG. 4 is a perspective view of such an alternate embodiment of the belt 40. The belt 40 has an inner surface 42 and an outer surface 44. The outer surface 44 is provided with a plurality of blind holes 46, so called because they do not extend completely through the belt 40.
The long nip press belts 16, 32, 40 of the present invention include a base fabric which is a braided structure. The braided structure comprises a plurality of braided layers of yarns in which the layers are laid down in a single pass of a braiding machine, with at least one yarn of each layer extending into a contiguous layer to form an interlock between the layers.
The braided structure of the base fabrics may be manufactured according to the teachings of commonly assigned U.S. Pat. No. 5,501,133 (the '133 patent) to Brookstein et al., entitled "Apparatus for Making a Braid Structure", the teachings of which are incorporated herein by reference. The '133 patent shows a multilayer braided structure in which the layers are interbraided. The interbraiding of the layers provides an interlock therebetween which prevents the delamination of multiple braided layers from one another.
The interlock between the layers may be a direct interlock in which the interlocking yarn passes from a first layer to a contiguous second layer, and passes around at least one yarn in the second layer.
Alternatively, the interlock between the layers may be an indirect interlock in which an interlocking yarn passes from the first layer through the second layer to another, not necessarily contiguous, layer in the structure, and passes around a strand in the other layer to serve to bind the first layer and the other layer together and at the same time to bind the layers therebetween.
To manufacture a base fabric for a long nip press belt, the braided structure may be of a hollow, tubular form. In view of the fact that long nip press belts, depending on the size requirements of the long nip presses on which they are installed, have lengths from roughly 10 to 40 feet (approximately 3 to 12 meters), measured longitudinally around their endless-loop forms, and widths from roughly 100 to 450 inches (approximately 250 to 1125 centimeters), measured transversely across those forms, the production of the base fabric may require a cylindrical braiding mandrel having a diameter from roughly 3 to 12 feet (approximately 1 to 4 meters) and a length from roughly 100 to 450 inches (approximately 250 to 1125 centimeters).
The multilayer braided structure of the base fabric is made by feeding a plurality of yarns from a first set of movable package carriers to a braid-forming area to form a braid layer thereat in which each movable package carrier traverses a predetermined first serpentine path, and by feeding a plurality of yarns from a second set of movable package carriers to the braid-forming area to form a braid layer thereat in which each movable package carrier of the second set traverses a predetermined second serpentine path, wherein each of the serpentine paths is arranged so that at least one package carrier of each set can carry a yarn from its respective layer into the other layer to interlock with the other layer.
As noted above, the second layer may be contiguous to the first layer. Alternatively, the second layer may be spaced from the first layer and have a number of intermediate layers interposed therebetween. In such circumstances, a yarn associated with the package carrier moving between the first and second layers is used to pass through all the intermediate layers prior to forming a positive interlock with the second layer.
Yarns from static package carriers may also be fed to the braid-forming area between two or more layers for interbraiding with the yarns from the respective movable package carriers. The yarns fed from static package carriers maintain a longitudinal or axial orientation with respect to the cylindrical braiding mandrel. In this way, the base fabric may be provided with reinforcement yarns lying in the transverse, or cross-machine, direction of the belt. Such reinforcement is useful where the belt is of the "press jacket" variety held by clamping rings on the widthwise edges of the press.
The cylindrical braiding mandrel may be positioned in the braid-forming area in order to form the requisite hollow braid structure. The first layer of the braid is then formed on the mandrel and second, and subsequent, layers are formed over the first layer. The mandrel may be moved through the braidforming area as braiding takes place so that a continuous hollow braided structure is built up thereon. All of the layers of the multilayer braided structure are laid down in one pass of the mandrel through the braiding machine.
The plurality of package carriers and serpentine paths are arranged on the internal surface of a tubular braiding machine, the internal surface having a plurality of serpentine paths formed therein. Movable package carriers traverse the serpentine paths; static package carriers are fixed on the internal surface of the tubular braiding machine.
The braid-forming area is preferably situated at the longitudinal axis of the tubular braiding machine and, as the braided structure is formed, it, or, more specifically, the cylindrical braiding mandrel is moved through the tubular braiding machine along the longitudinal axis thereof.
For use as the base fabric for a long nip press belt, the braided structure preferably consists of yarns which make an angle of 85° or more to the longitudinal axis of the cylindrical braiding mandrel. In other words, the yarns of the base fabric will define left-handed and right-handed intertwined spirals each making an angle of 5° or less with respect to the machine direction of the long nip press belt. This will make it less likely that the long nip press belt will distort in response to tension applied in the machine direction, and can be accomplished by minimizing the number of movable package carriers used to make the braided structure.
Figure 5 is a perspective view of the base fabric 50 for the belts of the present invention. The base fabric 50 is in the form of an endless loop and has an inner surface 52 and an outer surface 54. The longitudinal, or machine, direction is indicated as "MD" in FIG. 5, while the transverse, or cross-machine, direction is indicated as "CD".
FIG. 6 is a plan view of an area of the outer surface 54 of the base fabric 50. Some of the yarns 56 define right-handed spirals; other yarns 58 define left-handed spirals. Yarns 56,58 spiral continuously about the base fabric 50 at a small angle relative to the longitudinal, or machine, direction (MD) thereof, and preferably make an angle θ less than 5° relative to the longitudinal direction. Accordingly, at crossing points 60, yarns 56,58 make an angle of 10° or less relative to each other. Reinforcing yarns 62, which lie in the transverse, or cross-machine, direction (CD) are interbraided with the spiralling yarns 56,58.
FIG. 7 is a schematic cross-sectional view of the base fabric 50 taken in the longitudinal, or machine, direction (MD) thereof. Referring to the preceding discussion, base fabric 50, as shown in FIG. 7, comprises two braided layers of yarns defined by yarns 58 which define left-handed spirals about the base fabric 50. Yarns 56, which define right-handed spirals about the base fabric 50, pass back and forth between the two braided layers to interlock them together. Reinforcing yarns 62 are directed transversely across the base fabric 50 within its braided structure.
The base fabric may be produced from any of the yarn varieties used by those of ordinary skill in the art to produce papermachine clothing. Monofilament yarns are preferred, although plied monofilament, multifilament and plied multifilament yarns may also be used. The yarns may be of any of the polymeric resins from which yarns for papermachine clothing are commonly extruded, such as polyamide, polyester, polyetheretherketone (PEEK), polyaramid and polyolefin resins.
The braided structure of the base fabric must be of an openness sufficient to ensure its complete impregnation by the polymeric resin material with which it is to be coated. Complete impregnation eliminates the possibility of undesirable voids forming in the finished belt. Voids are particularly undesirable because they may allow the lubricating oil used between the belt and the arcuate pressure shoe to pass through the belt and contaminate the press fabric 18, or press fabrics, and fibrous wet 20 being processed into paper.
When the braiding of the base fabric has been completed, it may be removed from the cylindrical braiding mandrel and coated with a polymeric resin material using techniques well-known in the art. Alternatively, the coating may be carried out, at least in part, while the base fabric is still on the cylindrical braiding mandrel.
The polymeric resin material is applied to at least one surface of the base fabric, that surface being the one which will ultimately be the inner surface of the belt. As the inner surface slides across the lubricated arcuate pressure shoe 14, the coating of polymeric resin material protects the base fabric from such sliding contact and the wear by abrasion that would otherwise result. The polymeric resin material also impregnates the base fabric and renders the belt impermeable to oil and water. The polymeric resin material may be polyurethane, and, if so, is preferably a 100% solids composition thereof to avoid the formation of bubbles during the curing process through which the polymeric resin proceeds following its application onto the base fabric. After curing, the coating of polymeric resin material is ground and buffed to provide the belt with a smooth surface and a uniform thickness.
Alternatively, both surfaces of the base fabric may be coated with a polymeric resin material. Following the curing of the polymeric resin material, both the inner surface and the outer surface of the belt may be ground and buffed to provide the belt with smooth surfaces and a uniform thickness. Finally, the outer surface may be provided, by cutting, scoring, graving or drilling, with a plurality of grooves, for example, in the longitudinal direction around the belt, or blind holes for the temporary storage of water press from fibrous web 20 in the press nip 10.
It will be recognized that modifications to the above would be obvious to anyone of ordinary skill in the art without departing from the scope of the claims appended hereinbelow.
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A resin-impregnated endless belt for a long nip press or calender of the shoe type has a base fabric in the form of a multilayer braided structure wherein each of the constituent layers are connected to those adjacent thereto by at least one interlocking yarn to inhibit interlayer delamination. The base fabric is in the form of an endless loop, at least the inner surface of which is coated with a polymeric resin material, such as polyurethane. The polymeric resin material impregnates the structure of the base fabric, rendering it impermeable to oil and water.
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FIELD OF THE INVENTION
The present invention relates to a grease composition for rolling bearing. More particularly, the present invention relates to a grease composition for rolling bearing having an improved peeling resistance suitable for rolling bearings mounted in automobile electrical parts or engine auxiliary machinery such as alternator, solenoid clutch for car air conditioner, interpulley, electric fan motor and water pump.
BACKGROUND OF THE INVENTION
In general, the rotary portion of various power plants of automobile engine such as automobile electrical parts and engine auxiliary machinery, e.g., alternator, solenoid clutch for car air conditioner, interpulley, electric fan motor and water pump is provided with a rolling bearing which is lubricated mostly with a grease.
Due to the spread of FF cars, i.e., front wheel drive cars with the engine in the front which are intended for the reduction of size and weight, and the requirement for the enlargement of room, automobiles have been compelled to reduce the space of engine room. Thus, the reduction of the size and weight of electrical parts and engine auxiliary machinery as mentioned above has been accelerated. In addition, the foregoing various parts have been further required of higher performance and higher output.
However, the reduction of size unavoidably causes an output drop. For example, alternator or solenoid clutch for car air conditioner has been designed to operate at a higher speed to compensate for output loss. At the same time, interpulley has been designed to operate at a higher speed. Further, the requirement for reduction of noise has promoted the design of closed engine room accompanied by the rise in the temperature in the engine room. Thus, the foregoing various parts must withstand high temperatures more than ever.
On the other hand, the grease for use in rolling bearing for automobile has heretofore been given requirements mainly concerning lubricity such as prolonged life of bearing lubrication, little grease leakage, excellent low temperature performance, excellent rust-proofing properties and excellent bearing acoustic properties. However, the foregoing trend towards higher speed operation or higher performance has caused new problems. In some detail, a high load is periodically applied to the bearing surface of a rolling bearing, causing premature peeling on the running surface of the bearing. The development of a grease for preventing such a problem has been under way. As a long-lived grease for high speed rolling bearing intended for the prevention of premature peeling there is disclosed a grease composition comprising as an extender (i.e., a thickening agent) a diurea compound mainly terminated by an aromatic hydrocarbon group in JP-A-5-98280 (The term “JP-A” as used herein means an “unexamined published Japanese patent application”), JP-A-5-194979 and JP-A-5-263091.
As mentioned above, the prior art grease composition has comprised a properly selected extender (i.e., a thickening agent) to exhibit an improved peel resistance. However, there is a limit in the improvement of peel resistance attained by the selection of extender alone. Thus, the prior art grease composition cannot meet the demand for further improvement of peel resistance.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a grease composition which is excellent in peel resistance, not to mention lubricity, as compared with the prior art products.
The foregoing object of the present invention will become more apparent from the following detailed description and examples.
The inventors made extensive studies of the mechanism of occurrence of peeling. As a result, it was considered that peeling occurs due to a synergistic effect of rise in the load caused by resonance of bearing, etc. and bending stress developed by the deformation of outer ring while the prolongation of the life of bearing against peeling by the use of a grease is attributed to a damping effect exerted by a grease film sufficiently retained on the rolling body and bearing surface resulting in the reduction of the vibration level during resonance or the maximum load on the rolling body (see “NSK Technical Journal”, No. 656, page 1, 1993). The inventors then made further studies paying their attention to the fact that the effect of preventing peeling can be improved by enhancing the damping effect of grease film. As a result, it was found effective to strengthen the gel structure formed by an extender in order to enhance the grease-forming capacity of a grease film and hence enhance the damping effect against impact load. It was further found that as a means for strengthening the gel structure there is effectively employed a method involving the combined use of an inorganic compound filer and a specific organic zinc compound.
The present invention has been worked out on the basis of the foregoing knowledge. In other words, the foregoing object of the present invention is accomplished with a grease composition for rolling bearing comprising a base oil, an extender (i.e., a thickening agent), an inorganic compound-based filler and zinc dithiocarbamate wherein said inorganic compound-based filler has an average particle diameter of not more than 2 μm and comprises at least one material selected from the group consisting of particulate materials made of metal oxides, metal hydroxides, metal carbonates, hydrates thereof, metal nitrides, metal carbides, (synthetic) clay minerals, diamond, and solid lubricants.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example and to make the description more clear, reference is made to the accompanying drawings in which:
FIG. 1 is a graph illustrating the relationship between the concentration of zinc dithiocarbamate and the added amount of inorganic compound filler wherein a zone effective for the prevention of peeling and prolongation of seizing life is shown; and
FIG. 2 is a graph illustrating the relationship between the amount of extender and the ratio of the number of R 5 in the total number of R 5 and R 7 of diurea wherein a zone effective for the prevention of peeling and prolongation of seizing life is shown.
DETAILED DESCRIPTION OF THE INVENTION
The grease composition for rolling bearing of the present invention will be further described hereinafter.
[Inorganic Compound Filler]
(Kind)
As mentioned above, the inorganic compound filler may be any material which can strengthen the gel structure formed by an extender and thus is not specifically limited. In practice, however, a compound which exerts an extending effect itself is preferably used to exert an enhanced strengthening effect.
Specific examples of such an inorganic compound filler include particulate materials made of metal oxides such as SiO 2 , Al 2 O 3 , MgO, TiO 2 , PZT and ZnO, metal hydroxides such as Mg(OH) 2 , Al(OH) 3 and Ca(OH) 2 , metal carbonates such as MgCO 3 and CaCO 3 , hydrates thereof, metal nitrides such as Si 3 N 4 , ZrN, CrN and TiAlN, metal carbides such as SiC, TiC and WC, (synthetic) clay minerals such as bentonite, scmetite and mica, diamond, etc. Further examples of such an inorganic compound filler include particulate materials made of solid lubricants such as MOS 2 , graphite, BN and WS 2 .
In order to improve the affinity for the base oil or extender described later, the surface of the inorganic compound filler to be used herein may be modified hydrophilic. Preferred among the foregoing inorganic compounds are particulate materials made of metal oxides or clay minerals which exert an extending effect themselves.
(Particle Diameter)
The foregoing inorganic compound filler to be used herein has a particle diameter such that no troubles occur even when used and enclosed in a rolling bearing. In a rolling bearing, particles having a size of greater than 2 μm normally act as foreign matters (foreign particles), and hard particles accelerate the abrasion of the bearing surface or rolling body surface, causing premature damage of the bearing. These particles may occasionally deteriorate the bearing acoustic characteristics. Thus, if the average particle diameter of the inorganic compound filler exceeds 2 μm, the proportion of particles having a diameter of greater than 2 μm is raised to disadvantage. Further, taking into account the lubrication life of bearing, the particle diameter of the inorganic compound filler to be used herein is preferably smaller than the thickness of the film of base oil. Since the thickness of the oil film under practical working conditions is about 0.2 μm, the particle diameter of the inorganic compound filler is more preferably not more than 0.2 μm.
Accordingly, the inorganic compound filler to be incorporated in the grease composition for rolling bearing of the present invention preferably has an average particle diameter of not more than 2 μm, particularly not more than 0.2 μm.
The shape of the particulate inorganic compound filler is preferably close to sphere. In practice, however, the particulate inorganic compound filler may be in the form of polyhedron (cube or pallallelopidron) or needle in an extreme case if it has an average particle diameter falling within the above defined range.
(Concentration)
The content of the foregoing inorganic compound filler is preferably from 0.001% by weight (1 ppm) to 10% by weight based on the total weight of the grease used. If the content of the foregoing inorganic compound filler falls below the above defined range, the resulting effect of strengthening the gel structure formed by an extender is not sufficient. On the contrary, if the content of the foregoing inorganic compound filler exceeds the above defined range, the number of the foregoing filler particles is excessive, causing an increased abrasion that possibly has an adverse effect on the life against seizing.
In order to further secure the strengthening effect and take an adverse effect on the life against seizing into account, the content of the foregoing inorganic compound filler is preferably from 0.005 to 1% by weight.
[Zinc Dithiocarbamate]
(Kind)
The zinc dithiocarbamate to be used herein may be any material which further enhances the effect of preventing peeling and thus is not specifically limited. In practice, however, a compound represented by the following formula (1) may be used:
wherein R 1 to R 4 , each represents a C 1-18 , preferably C 1-13 , more preferably C 3-8 hydrocarbon group. Examples of the hydrocarbon group represented by R 1 to R 4 include alkyl group, alkenyl group, aryl group, alkaryl group, and aralkyl group. In particular, the alkyl group can provide an excellent effect of preventing premature peeling.
Specific examples of zinc dithiocarbamates which can be preferably used include zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dipropyldithiocarbamate, zinc dibutyldithiocarbamate, zinc dipentyldithiocarbamate, zinc dihexyldithiocarbamate, zinc diheptyldithiocarbamate, zinc dioctyldithiocarbamate, zinc dinonyldithiocarbamate, zinc didecyldithiocarbamate, zinc diundecyldithiocarbamate, zinc didodecyldithiocarbamate, zinc ditridecyldithiocarbamate, and mixtures thereof.
(Concentration)
The content of the foregoing zinc dithiocarbamate is preferably from 0.05 to 10% by weight based on the total weight of the grease used. Zinc dithiocarbamates are occasionally available commercially in a form diluted with a mineral oil or kerosine. In this case, the content of the foregoing zinc dithiocarbamate indicates the content of the effective component thereof. If the content of the foregoing zinc dithiocarbamate falls below the above defined range, the resulting effect of preventing peeling is not sufficient, possibly causing premature peeling. On the contrary, even if the content of the foregoing zinc dithiocarbamate exceeds the above defined range, it no longer enhances the effect of preventing peeling and thus is not economical.
In order to assure prolonged life against peeling and take lubrication life into account, the content of the zinc dithiocarbamate is preferably from 0.25 to 5% by weight based on the total weight of the grease used.
[Extender]
The extender to be used herein is not specifically limited so far as it can form a gel structure in which the base oil can be retained. For example, the extender to be used herein may be properly selected from the group consisting of metallic soaps such as metallic soap made of Li, Na, etc. and composite metallic soap made of materials selected from Li, Na, Ba, Ca, etc., and non-soap compounds such as bentone, silica gel, urea compound, urea-urethane compound and urethane compound. Taking into account the heat resistance of the grease used, urea compound, urea-urethane compound, urethane compound or mixtures thereof are preferred. Specific examples of the urea compound, urea-urethane compound and urethane compound include diurea compound, triurea compound, tetraurea compound, polyurea compound, urea-urethane compound, diurethane compound, and mixtures thereof. Preferred among these compounds are diurea compound, urea-urethane compound, diurethane compound, and mixtures thereof. More preferably, diurea compounds represented by the following formulae (2) to (4) are blended:
wherein R 5 represents a C 6-12 aromatic ring-containing hydrocarbon group; R 6 represents a C 6-15 divalent aromatic ring-containing hydrocarbon group; and R 7 represents a cyclohexyl group or C 7-12 alkylcyclohexyl group.
The foregoing diurea compound can be obtained by reacting 1 mol of diisocyanate as R 6 component with a total of 2 mols of monoamine as R 5 or R 7 component. In this manner, the diurea compound is obtained in the form of mixture of compounds represented by the foregoing general formulae (2) to (4). In the mixture of diurea compounds, the proportion of the number of R 5 in the total number of R 5 and R 7 , i.e., (mols of R 5 /(mols of R 5 +mols of R 7 ) ) is preferably from 0.10 to 0.95, more preferably from 0.20 to 0.85. If this value falls below 0.10, the resulting grease leakage resistance is not sufficient. On the contrary, if this value exceeds 0.95, the resulting compound exhibits a deteriorated fluidity that possibly causes seizing.
Specific examples of the group represented by R 5 include toluil group, xylyl group, β-fenchyl group, t-butylphenyl group, dodecylphenyl group, benzyl group, and methylbenzyl group.
Specific examples of the group represented by R 6 which can be preferably used will be given below.
Specific examples of the group represented by R 7 include cyclohexyl group, methylcyclohexyl group, dimethyl cyclohexyl group, ethylcyclohexyl group, diethylcyclohexyl group, propylcyclohexyl group, isopropylcyclohexyl group, 1-methyl-3-propylcyclohexyl group, butylcyclohexyl group, pentylcyclohexyl group, pentylmethylcyclohexyl group, and hexylcyclohexyl group. Particularly preferred among these groups are cylohexyl group and C 7-8 alkylcyclohexyl group such as methylcylohexyl group and ethylcyclohexyl group.
Specific examples of the diurea compounds represented by the foregoing formulae (2) to (4) which can be preferably used will be given below:
(Concentration)
The content of the foregoing extender is from 9 to 38% by weight, preferably from 13 to 30% by weight based on the total weight of the grease used. If the content of the extender falls below 9% by weight, the resulting gel-forming capacity is not sufficient, making it impossible to obtain a sufficient hardness or increasing the occurrence of grease leakage. On the contrary, if the content of the extender exceeds 38% by weight, the resulting grease exhibits a remarkably deteriorated durability life at high temperatures and high speed.
[Base Oil]
The base oil to be used herein is not specifically limited. Any oils which are commonly used as base oil for lubricant may be used. In order to avoid the generation of noise during actuation at low temperatures due to lack of low temperature fluidity or the occurrence of seizing due to difficulty in formation of oil film at high temperatures, it is preferred to use a base oil having a 40° C. dynamic viscosity of preferably from 10 to 400 mm 2 /sec, more preferably from 20 to 250 mm 2 /sec, even more preferably from 40 to 150 mm 2 /sec.
Specific examples of the base oil employable herein include mineral oil-based lubricant, synthetic oil-based lubricant, and natural oil-based lubricant. Examples of the foregoing mineral oil-based lubricant include those obtained by subjecting mineral oil to purification by distillation under reduced pressure, lubricant deasphalting, solvent extraction, decomposition by hydration, solvent dewaxing, washing with sulfuric acid, purification with clay, purification by hydrogenation, etc. in proper combination.
Examples of the foregoing synthetic oil-based lubricant include aliphatic hydrocarbon oil, aromatic hydrocarbon oil, ester oil, and ether oil. Examples of the foregoing aliphatic hydrocarbon oil include normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, poly-α-olefin obtained by polymerization of 1-decene with ethylene oligomer, and hydrogenation products thereof.
Examples of the foregoing aromatic hydrocarbon oil include alkylbenzenes such as monoalkylbenzene and dialkylbenzene, and alkylnaphthalenes such as monoalkylnaphthalene, dialkylnaphthalene and polyalkylnapthalene. Examples of the foregoing ester oil include diester oils such as dibutyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl glutarate and methyl acetyl cinnolate, aromatic ester oils such as trioctyl trimellitate, tridecyl trimellitate and tetraoctyl pyromellitate, polyol ester oils such as trimethylol propane caprylate, trimethylol propane pelargonate, pentaerythritol-2-ethyl hexanoate and pentaerythritol pelargonate, and complex ester oils as oligo ester of polyvalent alcohol with a mixed fatty acid of dibasic acid and monobasic acid.
Examples of the foregoing ether oil include polyglycols such as polyethylene glycol, polypropylene glycol, polyethylene glycol monoether and polypropylene glycol monoether, and phenyl ether oils such as monoalkyl triphenyl ether, alkyl diphehyl ether, dialkyl diphenyl ether, pentaphenyl ether, tetraphenyl ether, monoalkyl tetraphenyl ether, and dialkyl tetraphenyl ether.
Other examples of the synthetic lubricant-based base oil include tricresyl phosphate, silicone oil, and perfluoroalkyl ether.
Examples of the foregoing natural oil-based lubricant include fats and fatty oils such as beef tallow, lard, soybean oil, rape seed oil, rice bran oil, coconut oil, palm oil and palm seed oil, and hydrogenation products thereof.
These base oils may be used singly or in admixture. These base oils may be adjusted to the foregoing desired dynamic viscosity.
[Other additives]
The grease composition for rolling bearing of the present invention may comprise know additives incorporated therein as necessary to further improve its properties.
Examples of these additives include gelatinizing agents such as metallic soap, bentone and silica gel, oxidation inhibitors such as amine compound, phenol compound, sulfur-based compound and zinc dithiophosphate, extreme-pressure additives such as chlorine-based compound, sulfur based compound, phosphor-based compound, zinc dithiophosphate and organic molybdenum compound, oily agents such as aliphatic acid, animal oil and vegetable oil, rust preventives such as petroleum sulfonate, dinonylnaphthalenesulfonate and sorbitan ester, metal inactivating agents such as benzotriazole and sodium nitrite, and viscosity index improvers such as polymethacrylate, polyisobutylene and polystyrene. These additives may be used singly or in combination. The added amount of these additives is not specifically limited so far as the desired object of the present invention can be accomplished. In practice, however, it is preferably not more than 20% by weight based on the total weight of the grease used.
[Preparation Process]
The process for the preparation of the grease composition for rolling bearing of the present invention is not specifically limited. In practice, however, the grease composition for rolling bearing of the present invention can be obtained by reacting an extender in a base oil. The inorganic compound filler and the zinc dithiocarbamate are preferably blended in a predetermined amount during the foregoing reaction. Alternatively, a grease composition which has been previously prepared from an extender may then be mixed with the inorganic compound filler and the zinc dithiocarbamate. However, the mixture of the grease composition with the inorganic compound filler and the zinc dithiocarbamate thus prepared needs to be thoroughly stirred by means of a kneader, roll mill or the like to obtain a uniform dispersion. This processing may be effected under heating.
In the foregoing preparation process, additives other than the inorganic compound filler and zinc dithiocarbamate are preferably added at the same time with the inorganic compound filler and zinc dithiocarbamate from the standpoint of process efficiency.
EXAMPLE
The present invention will be further described in the following examples, but the present invention should not be construed as being limited thereto.
(Preparation of Grease)
The formulation of the extender, base oil, inorganic compound filler and zinc dithiocarbamate used in the examples of the present invention and the comparative examples are shown in Tables 1 to 4 below. In Table 1, TDI stands for tolylene diisocyanate, and MDI stands for 4,4′-diphenylmethane diisocyanate. The urea compound is obtained by reacting diisocyanate shown in Table 1 in an amount of 1 mol with monoamines shown in Table 1 in a total amount of 2 mols. In Table 3, the average particle diameters of the inorganic compound filler of the kind 1 (MgO), the inorganic compound filler of the kind 2 (MgO) and the inorganic compound filler of the kind 3 (Al 2 O 3 ) are 50 nm, 200 nm and 13 nm, respectively.
These extenders, inorganic compound fillers, zinc dithiocarbamates and base oils were then used in various formulations shown in Table 5 to prepare various grease compositions. In some detail, the total blended amount of the extender, inorganic compound filler, zinc dithiocarbamate and base oil was 920 g. To the blend were added 50 g of an amine oxidation inhibitor and 30 g of a sulfonate-based rust preventive to prepare a grease composition having a total weight of 1,000 g. The preparation process will be further described hereinafter.
In some detail, a base oil mixed with diisocyanate and a base oil mixed with monoamine were reacted, and then heated with stirring to obtain a semisolid matter. To the semisolid matter was then added an amine-based oxidation inhibitor which had previously been dissolved in a base oil. The mixture was thoroughly stirred, and then allowed to cool. To the mixture was then added a sulfonate-based rust preventive. The mixture was then passed through a roll mill to obtain a base grease. To the base grease thus obtained were then added an inorganic compound filler and a zinc dithiocarbamate in a predetermined amount as shown in Table 5. The mixture was then thoroughly kneaded to obtain a grease composition.
(Rapid Acceleration and Deceleration Test)
The grease compositions thus obtained were then subjected to the following test to evaluate their peeling resistance. The results are shown in Table 5.
In some detail, a single row deep groove ball bearing (inner diameter: 17 mmφ; outer diameter: 47 mmφ; width: 14 mm) having 2.36 of each of the foregoing grease composition specimens enclosed therein was mounted into an alternator. In this arrangement, the bearing was then continuously operated at an engine rotary speed ranging from 1,000 to 6,000 rpm (bearing rotary speed: 2,400 to 13,300 rpm) at room temperature and a pulley load of 160 kgf. When the bearing surface of the outer ring underwent peeling that caused vibration, the test was then terminated. The testing time which had passed so far was measured. The maximum allowable operating time of the grease compositions of the various examples and other comparative examples were then evaluated relative to that of the grease composition of Comparative Example 1 as 1.
TABLE 1
Extender
Formulation
Formulation of extender
1
2
3
4
5
6
7
8
Diisocyanate
TDI
1.0
1.0
1.0
MDI
1.0
1.0
1.0
1.0
1.0
Monoamine
p-Toluidine
1.0
1.7
1.9
0.2
2.0
Aniline
0.4
Cyclohexylamine
1.0
0.3
1.6
0.1
1.8
2.0
1.0
Stearylamine
1.0
TABLE 2
Kind of base oil
Dynamic viscosity of
Kind
Composition
base oil (mm 2 /sec, 40° C.
Kind 1
Poly-α-olefin
50
Kind 2
Dialkyl diphenyl ether
100
TABLE 3
Inorganic compound filler
Kind
Composition
Trade name
Maker
Kind 1
MgO
Type 500A high purity
Ube Materials Co.,
ultraparticulate magnesia
Ltd.
Kind 2
MgO
Type 2000A high purity
Ube Materials Co.,
ultraparticulate magnesia
Ltd.
Kind 3
Al 2 O 3
Aluminum oxide C
Nippon Aerosil Co.,
Ltd.
TABLE 4
Zinc dithiocarbamate
Kind
Component
Structure
Proportion
Kind 1
Zinc dithiocarbamate
50% by weight
Diluted oil
Mineral oil-based lubricant
50% by weight
TABLE 5
Example No.
1
2
3
4
5
6
7
8
Extender
Formulation
Formulation
Formulation
Formulation
Formulation
Formulation
Formulation
Formulation
composition
1
2
3
4
5
6
7
8
Amount of
20
30
13
9
38
20
29
15
extender (wt %)
Kind of base oil
Kind 1
Kind 2
Kind 1
Kind 2
Kind 1
Kind 2
Kind 1
Kind 1
Inorganic
Kind 2
Kind 1
Kind 1
Kind 3
Kind 1
Kind 1
Kind 2
Kind 1
compound filler
Amount in-
3
0.005
1
10
0.001
3
0.005
3
organic compound
filler (wt %)
Amount of zinc
1
0.25
5
10
0.05
1
0.05
2
dithiocarbamate
(wt %)
Mixture
No. 2
No. 2
No. 2
No. 2
No. 2
No. 2
No. 2
No. 2
consistency
Rapid
25
20
22
16
18*
14
13*
12
acceleration and
deceleration test
(Comparative
Example 1 = 1)
Comparative Example No.
1
2
3
4
5
Extender composition
Formulation
Formulation
Formulation
Formulation
Formulation
8
1
2
3
8
Amount ot extender (wt %)
15
20
30
13
15
Kind ot base oil
Kind 1
Kind 1
Kind 2
Kind 1
Kind 1
Inorganic compound filler
—
—
Kind 1
—
Kind 1
Amount of inorganic compound
—
—
0.005
—
1
filler (wt %)
Amount of zinc
—
—
—
0.25
—
dithiocarbamate (wt %)
Mixture consistency*
No. 2
No. 2
No. 2
No. 2
No. 2
Rapid acceleration and
1
3
4
3
deceleration test
(Comparative Example 1 = 1)
*Some of the samples of Examples 5 and 7 underwent seizing before peeling and thus was no longer subjected to testing.
*No. 2 in the Mixture consistency is defined in the item “Penetration No.” in JIS K 2220.
As is apparent from the results of Table 5, the grease compositions of the examples of the present invention, which comprises an inorganic compound filler and a zinc dithiocarbamate incorporated therein, take far much time to reach peeling as compared with the grease compositions which contain no these components or contain either of these components incorporated therein and hence exhibit an excellent peeling resistance.
FIG. 1 illustrates the zone effective for the prevention of peeling and the zone where seizing life is reached, determined from the relationship between the concentration of zinc dithiocarbamate required for the prevention of peeling in the present invention determined by the foregoing rapid acceleration and deceleration test and the amount of an inorganic compound filler (MgO having an average particle diameter of 1 μm is used) added to strengthen the gel structure formed by an extender.
In accordance with FIG. 1, the zone surrounded by the added amount of zinc dithiocarbamate ranging from 0.05 to 10% by weight and the amount of inorganic compound filler ranging from 0.001 to 10% by weight is a zone where neither peeling nor seizing occurs (according to comparison of life). This zone contains an even more desirable zone surrounded by the added amount of zinc dithiocarbamate ranging from 0.25 to 5% by weight and the amount of inorganic compound filler ranging from 0.005 to 1% by weight.
Similarly, the relationship between peeling and seizing of bearing was determined from the desired composition and added amount of extender (diurea) in the foregoing rapid acceleration and deceleration test. The data are shown in FIG. 2 . In FIG. 2, the numbers on the ordinate indicate the ratio of the number of R 5 in the total number of R 5 and R 7 (R 5 / (R 5 +R 7 )) as an example of extender made of diurea compound. This ratio means the fluidity of grease. The greater this value is, the lower is the fluidity of grease and the more easily can occur seizing. On the contrary, the smaller this value is, the higher is the fluidity of grease and the more easily can occur grease leakage. The numbers on the abscissa indicate the amount of an extender (e.g., urea) used to form a gel structure.
As is apparent from the results of Table 2, the zone surrounded by the amount of extender ranging from 9 to 38% by weight and the ratio of R 5 /(R 5 +R 7 ) ranging from 0.1 to 0.95 is a zone suitable for the elimination of disadvantages such as peeling and seizing. In particular, the zone surrounded by the amount of extender ranging from 13 to 30% by weight and the ratio of R 5 /(R 5 +R 7 ) ranging from 0.2 to 0.85 is a zone where the durability life of bearing can be prolonged because of proper gelation and fluidity.
EFFECT OF THE INVENTION
As mentioned above, in accordance with the present invention, a grease composition for rolling bearing extremely excellent in peeling resistance can be obtained. The grease composition for rolling bearing according to the present invention is suitable particularly for rolling bearings mounted in automobile electrical parts or engine auxiliary machinery such as alternator, car air conditioner solenoid clutch, interpulley, electric fan motor and water pump.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
|
The present invention provides a grease composition which is excellent in peel resistance, not to mention lubricity, as compared with the prior art products. A novel grease composition for rolling bearing is provided, comprising a base oil, an extender, an inorganic compound-based filler having an average particle diameter of not more than 2 μm and zinc dithiocarbamate.
| 2
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BACKGROUND OF THE INVENTION
The present invention relates to a temperature-compensating device of digitally temperature compensated oscillator. Further, the present invention relates to a calibration device of a digitally compensated oscillator and more specifically, the to the input operation of calibration data effective to calibrate the oscillator by means of the calibration device.
According to the prior art, the oscillating frequency of an oscillator is regulated according to the information obtained from a temperature-detecting portion and corresponding compensation data stored in a memory portion. The temperature-detecting portion needs to have its own source of a reference signal and the reference signal requires a certain accuracy.
Further, according to the prior art, temperature characteristics of individual oscillators are measured and then written in the memory portion to carry out the calibration. However, the individual temperature characteristics of the oscillators are not identical. Therefore, it is necessary to measure oscillators individually. Further, calibration error of the temperature-detecting portion can not be eliminated.
SUMMARY OF THE INVENTION
In order to solve the above described first drawback of the prior art, according to the present invention, the output frequency of the oscillator is utilized for the reference signal of the temperature-detecting portion. By such a construction, the output of the temperature-detecting portion changes in response to the ambient temperature change, the output of the temperature-detecting portion is counted with reference to the output of the oscillator, and the output frequency of the main oscillator is regulated based on the counted output of the temperature-detecting portion according to the preset content of the memory portion. Then the regulated output of the oscillator is again utilized as the reference signal of the temperature-detecting portion so that the output frequency of the oscillator is more accurately controlled to obtain a stable oscillation with respect to the temperature change.
According to the present invention, the digitally temperature-compensated oscillator has a main oscillator and another oscillator for detecting a temperature. The frequency change of the detecting oscillator is measured with reference to a frequency generated in the main oscillator. A frequency-regulating portion is controlled according to a content preset in a memory portion and the measured frequency change so as to regulate the frequency of the main oscillator. The regulated frequency is used for the measurement of the frequency change of the detecting oscillator once again. The above described operation is repeated such that the frequency of the main oscillator is adjusted to a predetermined frequency so that the main oscillator produces a stable oscillating signal with respect to the temperature change.
According to the present invention, in order to solve the second drawback of the prior art, it is an object to accurately calibrate the oscillator as a whole under different temperatures without separately measuring the oscillating portion and temperature-detecting portion.
In order to solve the second drawback, according to the present invention, the oscillator has an oscillating portion, a comparing portion for comparing the frequency of the oscillating portion with the frequency of a calibration input, means for adjusting the frequency o the oscillating portion according to data from the comparing portion to equalize the frequency of the oscillating portion with the calibration input, and a memory portion for storing data from the temperature-detecting portion and data effective to regulate the frequency when the frequency of the oscillating portion coincides with the frequency of the calibration input. By such a construction, the oscillator can be accurately calibrated as a whole without separately measuring temperature characteristics of the oscillating portion and the detecting portion.
The digitally temperature-compensated oscillator is held at a given temperature and a calibration signal is applied to a calibration input terminal of the oscillator. The comparing portion compares the frequencies of the oscillating portion and calibration input with each other, and the regulating portion is controlled according to the compared result to equalize the frequency of the oscillating portion with that of the calibration input. At the same time, the control data and the data from the temperature detecting portion are memorized. By repeating such an operation at different temperatures, the oscillator can be calibrated to various temperature conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit block of a digitally temperature-compensated oscillator according to the present invention;
FIG. 2 is a flow chart showing operation of the oscillator of FIG. 1.
FIG. 3 is a circuit block of another embodiment according to the present invention;
FIG. 4 is a flow chart showing control steps of the oscillator of FIG. 3; and
FIG. 5 is a detailed circuit diagram of the oscillator shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention in which quartz oscillators are utilized as a main oscillating portion and a temperature detecting portion will be described in conjunction with the drawings. As shown in FIG. 1, a frequency regulating portion 2 regulates on oscillating frequency of a main oscillating portion 1. An output of a temperature-detecting portion 3 is counted by a counting portion 4 with reference to the output of the main oscillating portion 1. The output of the counting portion 4 is inputted to a controlling portion 5, and the controlling portion 5 controls the frequency regulating portion 2 based on the output of the counting portion 4 according to preset content of a memory portion 6. The thus regulated output frequency of the main oscillating portion 1 is again utilized as a reference in the counting portion 4 for counting the output frequency of the temperature-detecting portion 3 so that the accuracy of the temperature-detection is increased. By repeating the above described operation, the frequency of the main oscillating portion 1 can be regulated to a desired frequency.
FIG. 2 shows a flow chart for executing the above described operation. In FIG. 2, P1-P4 denote respective steps of the flow chart. Firstly, in the step P2, the temperature information from the temperature-detecting portion is counted in the counting portion with reference to the frequency of the main oscillating portion, and the counted temperature information is inputted into the controlling portion. Next, in the step P3, the preset control data is retrieved from the memory portion according to the inputted temperature information. In the step P4, the frequency of the main oscillating portion is regulated by means of the frequency-regulating portion according to the control data selectively retrieved in the step P3. By repeating the steps P1-P4, the main oscillating portion oscillates accurately at a predetermined desired frequency under the fluctuating ambient temperature.
The main oscillating portion 1 oscillates at a variable frequency in response to ambient temperature. The temperature-detecting portion 3 detects the ambient temperature and produces a temperature-dependent frequency signal representative of the ambient temperature. The counting portion 4 counts the frequency signal with reference to the variable frequency of the main oscillating portion 1 to produce temperature data. However, the temperature data does not accurately represent the ambient temperature because the reference frequency is variable, but approximately indicates the ambient temperature. The controlling portion 5 retrieves corresponding compensation data from the memory portion 6 according to the approximate temperature data, the compensation data representing the amount of regulation needed to equalize the frequency of the frequency signal to that of a predetermined frequency. Therefore, the retrieved compensation data is also approximate. The controlling portion 5 controls the frequency-regulating portion 2 according to the approximate compensation data to regulate the frequency of the main oscillating portion 1. Thus the frequency of the main oscillating portion is approximately or coarsely regulated to a predetermined desired constant oscillating frequency. Then, the coarsely regulated frequency is utilized as the reference signal in the counting portion 4. At this time, the counted temperature data is more accurate because the reference signal is regulated close to the constant frequency. The controlling portion 5 retrieves more accurate compensation data according to the more accurate temperature data and controls the frequency-regulating portion 2 according to the more accurate compensation data to finely regulate the frequency of the main oscillating portion 1. By repeating the above operation, the variable frequency is finally regulated to the desired constant frequency.
FIG. 3 shows another embodiment of the present invention. As shown in FIG. 3, a controlling portion 5 controls a frequency-regulating portion 2. A counting portion 4 receives the frequency output of a main oscillating portion 1 and frequency output of a temperature-detecting portion 3 and counts the frequency output of the temperature-detecting portion 3 with reference to the frequency output of the main oscillating portion 1 to apply the counted result to the controlling portion 5. Further, the output of the main oscillating portion 1 is fed to a frequency-comparing portion 7 to compare the same with the frequency of a calibration input signal. The controlling portion 5 controls the frequency-regulating portion 2 according to the compared result between the calibration input signal and the output of the main oscillating portion 1 to thereby equalize the frequency of the main oscillating portion 1 with that of the calibration input signal. When the frequency of the main oscillating portion 1 coincides with that of the calibration input, data from the temperature-detecting portion 3 is counted with reference to the equalized frequency and is stored as temperature data in a memory portion 6. At the same time, the compensation data representative of the amount of regulation needed to enable the frequency-regulating portion 2 to equalize the frequency of the main oscillating portion 1 is stored in the memory portion 6. By such a construction, the calibration data effective to compensate the frequency of the main oscillating portion 1 for the temperature change is obtained.
FIG. 4 shows a flow chart to execute the above described control. In FIG. 4, P1-P10 denote respective steps of the flow chart. Memorization of the compensation data is carried out only when the calibration input is applied.
Firstly, in the step P2, when the calibration input is not applied, the digitally temperature-compensated oscillator effects the oscillation operation in the step P9. When the calibration input is applied in the step P2, on the other hand, the calibration input and the frequency of the main oscillating portion are compared with each other to determine whether these signals coincide with each other in the step P4. If the frequency of the main oscillating portion does not coincide with that of the calibration input, the frequency-regulating portion is controlled to change the frequency of the main oscillating portion in the step P10 to repeat the steps P3, P4 and P10 sequentially to thereby equalize the frequency of the main oscillating portion with that of the calibration input. If the frequency of the main oscillating portion coincides with that of the calibration input, the temperature data is applied from the temperature-detecting portion to the counting portion and is counted with reference to the equalized frequency of the main oscillating portion. The stability of the temperature data is checked through the steps P2-P6. If the stability of the temperature data is assured, the data from the temperature-detecting portion and the corresponding compensation data effective to regulate the frequency of the main oscillating portion are stored in the memory portion 6 in the step P7. The calibration at a given temperature is completed at this step. Then a step complete signal is produced in the step P8 to carry out another calibration at a different temperature. The calibration is repeated within the required temperature range so that the calibration data (the data from the temperature-detecting portion and the data effective to regulate the frequency of the main oscillating portion) are automatically stored in the memory portion.
As described above, the digitally temperature-compensated oscillator is provided with the calibration function so that a plurality of oscillators are calibrated at the same time, and that all variable elements of the oscillator are calibrated as a whole.
FIG. 5 shows a detailed circuit structure of the digitally temperature-compensated oscillator with the automatic calibration. The frequency-regulating portion 2 is comprised of switched capacitors selectively turned on and off to regulate the frequency of the main oscillating portion 1. The main oscillating portion 1 is comprised of a quartz oscillator 11. The temperature-detecting portion 3 is comprised of a temperature-sensitive quartz oscillator 31. The counting portion 4 is comprised of a frequency counter 41, gate circuit 42 and a frequency divider 43 for dividing the frequency of the main oscillating portion 1 by a factor N. The frequency-comparing portion 7 is comprised of a frequency counter 71, a gate circuit 72 and a frequency divider 73 for dividing the calibration signal by a factor M.
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A digitally temperature-compensated oscillator has an oscillator for producing a frequency signal, a regulator for regulating the frequency of the frequency signal, and a detector for detecting ambient temperature and producing a corresponding temperature signal. A processor processes the temperature signal with reference to the frequency signal to produce processed temperature data. A memory stores compensation data effective to regulate the frequency of the frequency signal. A controller operates according to the temperature data to retrieve corresponding compensation data from the memory for controlling the regulator according to the retrieved compensation data to regulate the frequency of the frequency signal.
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BACKGROUND OF THE INVENTION
This invention relates to a process for preparing substituted 2-thioxopenams which are useful in the preparation of known penem antibiotics (7). The process may be conducted enantiospecifically to produce the latter in their correct enantiomeric state necessary for full antibacterial activity. ##STR5## wherein: R 6 and R 7 are independently selected from: hydrogen; R 9 NH--(R 9 is acyl or H); substituted and unsubstituted: alkyl, alkenyl, alkynyl, having 1-6 carbon atoms; aryl, such as phenyl; heterocyclyl, heteroaryl, having 1-4 heteroatoms selected from O,N,S; cycloalkyl, and cycloalkenyl; wherein said substituent or substituents are selected from: halo (chloro, bromo, fluoro, iodo), hydroxyl, cyano, carboxyl, amino, and the above-recited values for R 6 /R 7 . R 6 and R 7 are described in detail below; however, it should be noted now that the term "acyl" in the foregoing definition means those acyls known to be effective in the related bicyclic β-lactam antibiotic art, such as the penicillins and cephalosporins. In this regard the definition of acyl recited in U.S. Pat. No. 4,226,866 (issued 10-7-80) is incorporated herein by reference. Also, with respect to R 6 and R 7 , it should be noted that reactive functional groups carried by R 6 /R 7 , such as, amino, hydroxyl, or carboxyl, for example, may be covered by conventional blocking groups, such as p-nitrobenzyloxycarbonyl, 2,2,2-trichloroethoxycarbonyl and triorganosilyl, wherein the organo moiety is selected from alkyl having 1-6 carbon atoms, phenyl, and phenylalkyl.
R 2 , in functional terms, is a group which potentially forms a stable carbonium ion, for example: trityl; (--C(C 6 H 5 ) 3 );
bis(methoxyphenyl)methyl, ##STR6## 2-(diphenyl)isopropyl, ##STR7## 2,4-dimethoxybenzyl, ##STR8## and the like. M is a thiophilic metal such as silver, thallium, mercury, or the like.
R 1 is a removable protecting group such as allyl, p-nitrobenzyl, or a biologically removable group, for example: pivaloyloxymethyl, pivoloyloxyethyl, ethoxycarbonyloxymethyl, phthalidyl, or the like; in short, R 1 is selected from any of the conventionally employed protecting groups, or pharmaceutically acceptable ester moieties known in the classical (penicillins, and cephalosporins) and nonclassical (e.g., carbapenems, and penems) β-lactam antibiotic art (see for example, U.S. Pat. No. 4,226,866, which is incorporated herein by reference to the extent that it discloses such ester moieties).
X is a leaving group such as substituted or unsubstituted: phenoxy, alkoxy, phenylthio, or alkylthio having 2 to 7 carbon atoms; halo (chloro or bromo), and the like, wherein, for example, such substituents are: chloro, nitro, methyl, and the like.
R 8 , representatively defined below, is, inter alia, substituted and unsubstituted: alkyl, aryl, heteroaryl, heterocyclyl, and the like; wherein the substituent or substituents are selected from: amino, cyano, amidino, carbamoyl, hydroxyl, acyl, acyloxy, carboxy, and the like.
The ultimate penem antibiotics 7, including the foregoing definitions for R 1 , R 6 , R 7 and R 8 , are representatively disclosed in the following publications and pending U.S. Patent applications, all of which are incorporated herein by reference for the purpose of defining 7 and its utility as an antibiotic: U.S. Pat. No. 4,260,618 (4/7/81); U.S. Pat. No. 4,215,124 (7/29/80); U.K. Patent Application G.B. No. 2013674A (8/15/79); U.K. Patent Application G.B. No. 2042520A (9/24/80); and U.S. patent application Ser. Nos. 353,451, filed Mar. 1, 1982; 353,450, filed Mar. 1, 1982; 353,454, filed Mar. 1, 1982; 353,453, filed Mar. 1, 1982; and 373,008, filed Apr. 29, 1982.
The conversion process of appropriately substituted 2-thioxopenams 5 to the corresponding antibiotic 2-SR 8 -pen-2-em-3-carboxylic acids 6 is known; as is the final deblocking step 6 to 7: ##STR9## wherein R 8 X° is an alkylating agent; X° is bromo or iodo, for example; and R 8 is as defined above, for example, cyanomethyl, cyanoethyl, or the like. R 8 is additionally defined below. With respect to the formation of 5 and its conversion to 6, see U.K. Patent Application GB No. B 2074563A; or J. Chem. Soc. Chem. Cummun. No. 13, pp 713-714 (1982), which are fully incorporated herein by reference.
In the previous process referred to above (wherein R 6 is hydrogen and R 7 is protected hydroxyethyl) the thioxopenams are prepared by a distinctly different process where the C 5 -C 6 positions have the cis configuration. This is a result of two factors. First, the 3-substituted-4-alkylthioazetidinone intermediates are obtained with the C 3 -C 4 trans configuration and, second, the ring closure step involves displacement at the C 4 carbon atom causing an inversion at this position. Thus the known alkylation of the cis-thioxopenams produces the undescribed and antibacterially inferior 5,6-cis-2-alkylthiopenems which are converted to a mixture containing the 5,6-trans-penems by a thermal equilibration. The present invention maintains the stereochemical integrity of the substituent on the intermediate azetidinone throughout the conversion to thioxopenams and alkylthiopenems. Thus it provides the preferred 5R,6S-6(1-R-hydroxyethyl)penems from the azetidinone nucleus derived from 6-aminopenicillanic acid.
DETAILED DESCRIPTION OF THE INVENTION
The following diagram conveniently summarizes the process of the present invention: ##STR10##
In words relative to the above diagram, the azetidinone starting material 1 is known, or can readily be prepared by known methods. Representative, and representatively preferred values for R 6 and R 7 are given below. R 2 in starting material 1 must be a group which allows the formation of a carbonium ion. Preferred values for R 2 include, trityl, bis(p-methoxyphenyl)methyl, 2,4-dimethoxybenzyl, and the like. The most preferred value for R 2 is trityl. As defined above, the most preferred values for R 1 include allyl, p-nitrobenzyl, and the like. The conversion 1 to 2 is accomplished by treating 1 in a solvent such as benzene, toluene, xylene, DMF, or the like, in the presence of powdered fused potassium hydroxide, sodium hydride, potassium t-butoxide, Triton B or the like, and 18-crown-6 or a tetraalkylammonium salt, or the like with a bromoacetic ester such as allylbromoacetate, p-nitrobenzylbromo acetate, or the like, for from 0.5 to 4 hours at a temperature of from 0° to 80° C.
The conversion 2 to 3 is accomplished by treating 2 in a solvent such as methanol, ethanol, butanol, or solvent mixtures such as methanolmethylene chloride, or the like, in the presence of pyridine, picoline, lutidine, 4-dimethylaminopyridone, or the like, with a thiophilic metal salt reagent such as silver, mercury, thallium, nitrate, triflate, acetate, or the like, for from 0.1 to 3 hours at a temperature of from 0° to 60° C. The most preferred thiophilic metal is silver, and the most preferred silver reagent is silver nitrate.
The conversion 3 to 4 is accomplished by treating 3 in a solvent such as methylene chloride, benzene, tetrahydrofuran, or the like, with a halothiocarbonate ester of the formula: ##STR11## wherein: X'=chloro, bromo, and X is an aryloxy, arylthio, alkylthio, alkoxy or halo group, for example, in the presence of pyridine, picoline, lutidine, 4-dimethylaminopyridine, or the like, at a temperature of 0° to 30° C. for from 0.5 to 2 hours. [In the foregoing, alkyl is 1-6 carbon atoms; and aryl is phenyl.]
In general, the cyclization 4 to 5 is accomplished in the presence of base. For example, cyclization 4 to 5 may be accomplished by treating 4 in a solvent such as tetrahydrofuran, toluene, ether, dioxane, or the like, or mixtures thereof in the presence of lithium hexamethyldisilazide, lithium 2,2,6,6-tetramethyl piperidide, lithium triethyl methoxide, sodium hydride, potassium t-butoxide, or the like, in the presence of hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone (DMF) or the like, at a temperature of from -78° to 23° C. for from 0.1 to 8 hours. Alternatively, the conversion of 4 to 5 is accomplished by treating 4 in a solvent such as, methylene chloride, chloroform, tetrahydrofuran, benzene, or the like, in the presence of 1,8-diazabicyclo[5.40] undec-7-ene, diisopropylethylamine, 1,5-diazabicyclo[4.3.0]non-5-ene; 1,8-bis(dimethylamino)naphthalene, or the like, at a temperature of from 20° to 80° C. for from 1 to 18 hours.
The conversion 5 to 6 is accomplished by treating the 2-thioxopenam in a solvent such as methylenechloride, dimethoxyethane, dimethylformamide, or the like, at a temperature of from -25° to 100° C. with an alkylating agent R 8 X°; wherein R 8 is alkyl, alkenyl, aralkyl, heteroaralkyl, alkynyl, or heterocyclyl; and X° is a leaving group such as halo, arylsulfonate, trifluoromethyl sulfonate, or the like, or with an alkanol, diethylazodicarboxylate, and triphenyl phosphene, and the like.
The final deblocking step 6 to 7 is accomplished by conventional procedures such as hydolysis or hydrogenation. Typically 6 when R 1 is p-nitrobenzyl in a solvent such as dioxane-water-ethanol, tetrahydrofuran-aqueous dipotassium hydrogen phosphate-isopropanol, or the like, is treated under a hydrogen pressure of from 1 to 4 atmosphere in the presence of a hydrogenation catalyst such as palladium on charcoal, palladium hydroxide, or the like at a temperature of from 0° to 50° C. for from 0.5 to 4 hours to provide 7.
When R 1 is allyl, the ester is removed by the method of Jeffrey and McCombie, J. Org. Chem. 43, 587 (1982). Typically the penem allyl ester is stirred in a solvent such as methylene chloride, ethylacetate or tetrahydrofuran with potassium or sodium 2-ethylhexanoate and a catalytic amount of tetrabistriphenylphosphine palladium (O) at ambient temperature for from 15 minutes to 1 hour. The potassium salt of the penem usually precipitates from solution or may be precipitated by the addition of Et 2 O and is recovered by filtration. When R 7 is a protected hydroxyalkyl group the hydroxy protecting group may be removed prior to or simultaneously with the removal of the ester blocking group. Typically when the protecting group is tert-butyldimethylsilyl it is removed prior to deesterification by treatment with 3 eq. of tetrabutylammonium fluoride buffered with 10 eq. of glacial acetic acid in tetrahydrofuran solution at 23° for 24-72 hours. When the hydroxy protecting group is p-nitrobenzyloxycarbonyl and the ester group is p-nitrobenzyl they are removed simultaneously by hydrogenation (above).
PREPARATION OF STARTING MATERIAL ##STR12## Starting materials 1 are known, or are prepared according to known methods. The most preferred situation finds R 6 =H and R 7 as defined above, such as, alkyl having 1-6 carbon atoms and hydroxyl-substituted alkyl, for example, CH 3 CH(OH); wherein the hydroxyl function is typically protected by a triorganosilyl group, such as, t-butyldimethylsilyl (TBDMS), or the like. The racemic tritylthioazetidinone 1 may be prepared according to U.K. Pat. No. 2,042,514 (1980), which is incorporated herein by reference; the preferred chiral azetidinone 1 (R 6 =H, R 7 =protected hydroxyethyl) can be prepared from 6-APA by the method of A. Yoshida, T. Hayoshi, N. Takeda, S. Ohda and E. Olki Chem. Pharm. Bull. 29, 2899 (1981), citing the procedure of F. Di Ninno, U.S. Pat. No. 4,168,314 (1979) and J. Org. Chem. 42, 2960 (1977) who used a p-nitrobenzyl (PNB) blocking group on the OH instead of TBDMS. These publications are all incorporated herein by reference. Other, representative values of R 6 and R 7 are listed below.
DEFINITION OF R 6 and R 7 ##STR13##
DEFINITION OF R 8
Representative values for R 8 include:
CH 3 , --CH 2 CH 3 , --CH 2 CONH 2 , CH 2 CN, CH 2 CH 2 OH, CH 2 CH 2 CN, CH(Me)CH 2 CONH 2 , CH(Me)CH 2 CN, CH 2 (CH 3 )CHCN, ##STR14## CH 2 COCH 3 , ##STR15## CH 2 CO 2 R, where R=Me, Et, allyl or pharmaceutically acceptable ester.
The most preferred 2-thioxopenams bear at ring position number 6 the 1-hydroxyethyl substituent. The most preferred configuration of these thioxopenams is 8R, 6S, 5R. ##STR16##
With regard to the preparation of the preferred 2-thioxopenams of the present invention, the following diagram specifically recites their synthesis. ##STR17## R=t-butyldimethylsilyl φ=phenyl
R 1 =CH 2 CH═CH 2 or p-nitrobenzyl (PNB)
Step I
In the preferred process (3R,4R)-4-acetoxy-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-azetidinone (1) is stirred with sodium triphenylmethylmercaptide in DMF solvent at 0° C. for 45 minutes to produce after workup and isolation (3S,4R)-4-triphenylmethylthio-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-azetidinone (2). Alternatively intermediate (2) can be produced by exposure of 1 to tritylmercaptan in methanolic soidum methoxide.
Step II
The tritylthioazetidinone 2 is treated with 1.5 equivalents of allyl bromoacetate and powdered potassium hydroxide in benzene solvent at ambient temperature in the presence of dicyclohexyl-18-crown-6 for 4 hours. The resulting (3S,4R)-1-(allyloxycarbonyl)methyl-3-[(R)-1-(tert-butyldimethylsiloxy)-ethyl]-4-triphenylmethylthio-2-acetidinone (3) is isolated by conventional means. Alternatively p-nitro-benzylbromoacetate may be substituted for allylbromoacetate.
Step III
The azetidinone 3 is treated with a methanolic solution of silver nitrate in the presence of pyridine in methanol solvent at 0° C. for 0.5 hours. After removal of the water-soluble salts the crude mixture containing the silver thiolate 4 is preferably carried into the next step but may be purified by conventional techniques, such as preparative thin layer chromatography. The solvent methanol employed herein serves a dual purpose in that it reacts with the incipient trityl carbonium ion to form trityl methyl ether, which need not be separated from the silver thiolate, as it is inert to the reagents used in Step IV and may be conveniently separated later. The process of forming silver thiolates from 4-tritylthioazetidinone and their acylation has been described in the U.K. Pat. No. 2,042,520A, which is incorporated above. This invention adopts that process to specifically form a 4-dithiocarbonate ester of an azetidinon-1-yl acetic ester giving the critical intermediate 4 for the hitherto unknown cyclization reaction in Step V.
Step IV
The crude silver thiolate obtained from Step III is thioacylated with phenoxythiocarbonyl chloride in methylene chloride solvent in the presence of pyridine at 0° C. for 20 minutes. The chlorothiocarbonate ester employed herein is not critical, however, the leaving group X should not be so reactive that is undergoes elimination under the conditions of the thioacylation reaction, leading to side reactions; nor so wealkyl reactive that it is displaced with difficulty during Step V. Phenoxy acid substituted phenoxy are preferred for group X, although alkoxy, alkylthio and arylthio may be used. From 0.1 to 1.0 equivalents of pyridine or a similar organic base is used to catalyze the reaction. In the preferred case it is not necessary to purify the resulting phenoxythiocarbonyl derivative 5 for use in the next step, particularly if purified silver thiolate is used in the reaction.
Step V
Purified (3S,4R)-1-(allyloxycarbonyl)methyl-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-phenoxy(thiocarbonyl)thio-2-azetidinone (5) is treated with 2.75 equivalents of the preferred base lithium hexamethyldisilazide at -78° C. in anhydrous tetrahydrofuran containing some 1,3-dimethyl-2-imidazolidinone (DMI), which appears to make the reaction proceed more uniformly, under an atmosphere of nitrogen. After 5-15 minutes, the mixture is neutralized with dilute hydrochloric acid, although other organic acids such as acetic, trifluoroacetic, and p-toluenesulfonic acids, as well as aqueous buffers, may be used, and worked up to give the desired 2-thioxopenams 7. Since the initial product of the reaction is the thiolate anion 6, it may be treated in situ if desired with the alkylating agent to directly give penem derivatives. Alternatively, a strong organic base such as diazabicycloundecene (DBU) will give slow cyclization of 5 to 7 at room temperature.
Although in the preferred process the hydroxy group is protected by a t-butyldimethylsilyl group, the presence of this group is not necessary during all of the steps in the reaction sequence. It may be conveniently removed from the thioxo penam (7) either before or after alkylation or it may be removed earlier in the sequence (e.g., from 3) and be replaced with a more readily hydrolyzable group such as trimethylsilyl just before the cyclization to (6).
EXAMPLE 1
Allyl-trans-2-(3-(1-t-butyldimethylsilyloxyethyl)-4-silverthio-2-azetidinon-1-yl)acetate ##STR18##
To a solution of allyl trans-2-(3(1-t-butyldimethylsilyloxyethyl)-4-triphenylmethylthio-2-azetidinon-1-yl)acetate (126 mg, 0.223 mmol) in 1 ml of methanol at 0° was added pyridine (27 μl) followed by a solution of silver nitrate in methanol (2.32 ml of 0.12M solution). After stirring for 30 minutes, the methanol was rapidly evaporated under vacuum and the residue was taken up in 7 ml of methylene cloride. The solution was washed three times with 8 ml portions of water, dried over anhydrous magnesium sulfate and evaporated. The residue was chromatographed on a thin layer silica gel plate eluted with toluene-ethyl acetate (7:3). The band between 4.5 and 11 cm was extracted with methanol to afford the desired product. Yield 76 mg, (73%) of a white solid. NMR δ (200 MHz, CDCl 3 ), 3.10 (dd, J=4.2 and 1.8, H3), 5.21 (d, J=1.8, H4 ).
EXAMPLE 2
Allyl-trans-2-(3-(1-t butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate ##STR19##
To a cooled (0° ) solution of allyl trans 2-(3-(1-t butyldimethylsilyloxyethyl)-4-silverthio-2-azetidinon-1-yl)acetate (104 mg, 0.223 mmol) in 4 ml of methylene chloride was added phenoxythiocarbonyl chloride (30 μl, 0.223 mmol) followed by pyridine (18 μl). After 20 minutes the solution was evaporated to dryness under reduced pressure. The residue was taken up in methylene chloride and the precipitated silver chloride was removed by filtration. The filtrate was concentrated and chromatographed on a silica gel plate developed with 9:1 toluene-ethyl acetate. The band at 5.5-8.5 cm was isolated with ethyl acetate. Yield 69 mg, (62%) of product as an oil. NMR δ (200 MHz, CDCl 3 ), 3.34 (dd, J=6 and 2.5, H3), 5.88 (d and m, J=2.5, H4 and vinylic methylene).
EXAMPLE 3
Allyl-trans-6-(1-t-butyldimethylsilyloxyethyl)-2-thioxopenam-3-carboxylate ##STR20##
A solution of butyllithium (217 μl of 2.3M solution in hexane) was added to a solution of hexanethyldisilizane (106 μl) in tetrahydrofuran (0.68 ml) at room temperature. After 30 minutes, the solution was cooled to -78° and added to a cooled (-78° ) solution of allyl trans 2-[3-(1-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate (100 mg, 0.17 mmol) in 1 ml tetrahydrofuran. The solution was stirred for 20 minutes then neutralized with trifluoroacetic acid (15 μl). The solution was diluted with methylene chloride (8 ml) and washed successively with 0.1M, pH 7 phosphate buffer (6 ml) and water (2×6 ml), then dried (MgSO 4 ) and evoporated. The product was purified by thin layer chromatography eluted with methylene chloride-toluene (6:1). Yield 68 mg, (84%). NMR δ (200 MHz, CDCl 3 ), 3.65 (d, J=1.5, H 6), 5.35 (s, H3 and m, vinylic methylene), 5.9 (s, H5 and m, vinylic methine).
EXAMPLE 4
Ally-trans-(6-(1-t-butyldimethylsilyloxyethyl)-2-methylthiopenem-3-carboxylate
Procedure A ##STR21##
To a solution of penem thiolate prepared as in Example 3 from allyl trans 2-[3(1-t-butyldimethylsilyloxyethyl)-4-phenoxythio-carbonylthio-2-azetidinon-1-yl)acetate (18.1 mg, 0.036 mmol) and lithium hexamethyl disilazide (420 μl of 0.175M solution), methyl iodide (20 μl) was added and the solution is allowed to come to room temperature. The reaction mixture was diluted with methylene chloride, washed with water, dried over magnesium sulfate and evaporated. The residue was purified by thin layer chromatography developed with 9:1 toluene-ethyl acetate giving 8.8 mg (58%) of the desired methylthiopenem, U/V λmax. 337 mμ (ε6150), 256 mμ (ε5480). NMR δ (200 MHz,CDCl 3 ), 2.53 (s, SCH 3 ), 3.66 (dd, J=5.2 and 1.5, H6), 5.65 (d, J=1.5, H5).
Procedure B
A solution of allyl trans 2-[3(1-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonyl]thio-2-azetidinon-1-yl)acetate (12.2 mg, 0.025 mmol) and 1,8-diazabibyclo[5.4.0]undec-7-ene (7.4 μl) in 0.4 ml of THF was stirred at 23° for 8 hours. To the resulting solution of thioxopenam was added methyliodide (20 μl) and the solution was stirred for one hour. The solution was worked up as in procedure A to give 4.8 mg of the above described methylthiopenem.
EXAMPLE 5
P-nitrobenzyl-trans-2-[3-(1-t-butyldimethylsilyloxyethyl)-4-triphenylmethylthio-2-azetidinon-1-yl)acetate ##STR22##
Powdered, fused potassium hydroxide (125 mg, 2.25 mmol) and 18-crown-6 (20 mg) were added to a solution of 3-(1-t-butyldimethylsilyloxyethyl)-4-triphenylmethylthio-2-azetidinone (775 mg, 1.5 mmol) in 7 ml of benzene. The mixture was stirred at room temperature while a solution of P-nitrobenzyl bromoacetate (620 mg, 2.25 mmol) in benzene (7 ml) was added dropwise during one hour. After an additional hour of stirring, 0.5M, pH 7 phosphate buffer (20 ml) was added and the benzene layer was separated, dried (MgSO 4 ) and evaporated. The residual oil was chromatographed on silica gel (2×25 cm column) eluted with methylene chloride. There was first obtained a fraction containing starting azetidinone (230 mg) followed by the desired product (710 mg, 68% yield). NMR δ (200 MHz, CDCl 3 ), 3.42 (t, J=2.3, H3), 4.56 (d, J=2.3, H4).
EXAMPLE 6
P-nitrobenzyl-trans-2-[3-(1-t-butyldimethylsilyloxyethyl)-4-silverthio-2-azetidinon-1-yl)acetate ##STR23##
To a cooled (0° ) solution of P-nitrobenzyl trans 2-[3-1-t-butyldimethylsilyloxyethyl)-4-triphenylmethylthio-2-azetidinon-1-yl)acetate (55 mg, 0.079 mmol) in 1 ml of methanol was added pyridine (10 μl) and 0.12M silver nitrate in methanol (0.82 ml). A precipitate immediately formed. The mixture was stirred at 0° for 30 minutes then the precipitate was recovered by filtration, washed with methanol and dried under nitrogen giving a white powder (44 mg). This was dissolved in methylene chloride and the solution was washed three times with water, dried (MgSO 4 ) and evaporated leaving the desired product as a yellow resin. NMR δ (200 MHz, CDCl 3 ), 3.10 (dd, J=4.2 and 1.8, H3), 5.12 (d, J=1.8, H4).
EXAMPLE 7
P-nitrobenzyl-trans-2-(3-(1-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate ##STR24##
P-nitrobenzyl trans 2-[3-(1-t-butyldimethylsilyloxyethyl)-4-silverthio-2-azetidinon-1-yl)acetate (177 mg, 0.32 mmol) was dissolved in 2 ml of methylene chloride and the solution was cooled to 0°. Plenoxythiocarbonylchloride (43 μl, 0.32 mmol) and pyridine (26 μl) were added and the mixture was stirred for 20 minutes. The mixture was centrifuged and the supernatant liquid was concentrated and chromatographed on silica gel plates developed with toluene-ethyl acetate (9:1). The band at Rf 0.4 was isolated giving the desired product as a strawcolored oil. Yield, 85 mg, (46%). NMR δ (200 MHz, CDCl 3 ), 3.34 (dd, J=6 and 2.8, H3), 5.84 (d, J=2.8, H4).
EXAMPLE 8
P-nitrobenzyl-trans-6-(1-t-butyldimethylsilyloxyethyl)-2-thioxo-penam-3-carboxylate ##STR25##
P-nitrobenzyl trans 2-(3-(1-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate (74 mg, 0.125 mmol) was dissolved in 1 ml of dry tetrahydrofuran and the solution was cooled to -78°. Lithium hexamethyldisilazide (0.6 ml of 0.5M solution) was added and the solution was stirred for 20 minutes. The solution was diluted with methylene chloride (5 ml) then neutralized with glacial acetic acid (29 μl). The solution was extracted with pH 7 phosphate buffer and with water, then dried over MgSO 4 and evaporated. The residue was purified by thin layer chromatography (2% methanol in chloroform) giving 33 mg (53%) of the desired product. NMR δ (200 MHz, CDCl 3 ), 3.68 (dd, J=4 and 1, H6), 5.42 (s, H3), 5.89 (d, J=1, H5).
EXAMPLE 9
P-nitrobenzyl-trans-6-(1-t-butyldimethylsilyloxyethyl)-2-methylthio-penem-3-carboxylate ##STR26##
Lithium hexlamethyldisilazide (0.37 ml of a 0.174M solution) was added to a solution of P-nitrobenzyl trans-2-[3-(1-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate (19 mg, 0.032 mmol) in 0.3 ml of dry tetrahydrofuran at -78°. After 20 minutes methyl iodide (20 μl) was added and the solution was allowed to warm to 0°. The reaction was continued at 0° for 30 minutes. The mixture was diluted with methylene chloride and washed with pH 7 phosphate buffer and with water and dried over magnesium sulfate. The solvent was evaporated and the residue purified by thin layer chromatography (eluent 9:1 toluene-ethyl acetate) to afford 10 mg of the desired compound. NMR (200 MMz, CDCl 3 ), 2.54 (s, SCH 3 ), 3.72 (dd, J=4.5 and 1.5, H6), 5.76 (d, J=1.5, H5).
EXAMPLE 10
Chiral Synthesis
(+)-(3S,4R)-3-(1-R-t-butyldimethylsilyloxy)-4-triphenylmethylthio-2-azetidinone ##STR27##
To a stirred suspension of 1.3 g (0.033 moles) of 61% NaH dispersion in 25 ml of sieve dried DMF at 0° C. under an atmosphere of nitrogen was added dropwise a solution of 9.12 g (0.033 moles) of trityl mercaptan in 50 ml of sieve dried DMF over a period of 23 minutes. The resulting mixture was stirred further at 0° C. under nitrogen for 10 minutes, after which time a solution of (3S,4R)-4-acetoxy-3-(1-R-t-butyldimethylsilyloxy)azetidinone 1 (8.62 g, 0.03 moles) in 50 ml of sieve dried DMF was added over a period of 20 minutes. The mixture was stirred further at 0° C. under nitrogen for 0.5 hours and was then poured onto a mixture of ice-H 2 O and saturated, aqueous NH 4 Cl solution and extracted wth Et 2 O. The Et 2 O extract was washed twice with H 2 O and then with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , filtered, and evaporated. Purification by column chromatography on 500 g EM-60 silica gel eluting with CH 2 Cl 2 gives 12.9 g, (85%) of product; [α] D +3.7 (c 8, CHCl 3 ); mp. 94°-96.5° C.
EXAMPLE 11
Allyl-(3S,4R)-2-(1-R-t-butyldimethylsilyloxyethyl)-4-triphenylmethylthio-2-azetidinon-1-yl)acetate ##STR28##
According to the procedure of T. Kamazaki, et al., Heterocycles, 15, 1101 (1981), 5.04 g (0.01 moles) of (+)-(3S,4R)-3-(1-R-t-butyldimethylsilyloxy)-4-triphenylmethylthio-2-azetidinone 2, 926 mg (0.0165 moles) of powdered KOH, and a catalytic amount of 18-crown-6 was stirred in 50 ml of benzene at ambient temperature and was treated with a solution of 2.67 g (0.015 moles) of allylbromoacetate in 30 ml benzene (added dropwise over 30 minutes) at ambient temperature for 5 hours. After this time the mixture was partitioned between EtOAc and ice-H 2 O. The organic phase was separated, washed with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , filtered and evaporated. Purification by column chromatography on 300 g of EM-60 silica gel eluting with CH 2 Cl 2 and 2% EtOAc in CH 2 Cl 2 gives 3.74 g (62%) of the product as a colorless oil; [α] D +0.8 (c 20, CHCl 3 ).
EXAMPLE 12
Allyl-(3S,4R)-2-(3-(1-R-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate ##STR29##
To a stirred solution of 3.74 g (6.2 mmoles) of allyl (3S,4R)-2-(3-(1-R-t-butyldimethylsilyloxyethyl)-4-triphenylmethlthio-2-azetidinon-1-yl)-acetate in 30 ml MeOH at 0° C. was added sequentially 738.4 mg (9.3 mmoles) of neat pyridine and then 45.6 ml of 0.15M AgNO 3 solution in MeOH. The resulting mixture was stirred at 0° C. under nitrogen for 0.5 hours after which time the mixture was concentrated in vacuo and partitoned between CH 2 Cl 2 and ice-H 2 O. The organic phase was separated, dried over anhydrous Na 2 SO 4 , filtered, evaporated, and dried in vacuo. The residue so obtained was dissolved in 30 ml CH 2 Cl 2 , stirred, cooled to 0° C., and treated sequentially with 500 μl of pyridine and 1.18 g (6.85 mmoles) of phenoxythio chloroformate. After stirring at 0° C. under an atmosphere of nitrogen for 20 minutes, the insolubles were removed by filtration through celite and washed well with EtOAc. The filtrate was partitioned between EtOAc, ice-H 2 O, and 2N HCl. The organic phase was separated, washed with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , filtered, and evaporated. Purification of the residue by chromatography on 100 g of EM-60 silica gel eluting with CH 2 Cl 2 -φMe (10:1) provides 2.23 g (72%) of the desired product, 4, as a yellow oil; [α] D +59.6 (c 13.6, CHCl 3 ).
EXAMPLE 13
Allyl-(5R,6S)-6 -(1-R-t-butyldimethylsilyloxyethyl)-2-thioxopenam-3-carboxylate ##STR30##
To a stirred solution of freshly prepared lithium hexamethyldisilazide (0.54 mmoles) in 5 ml anhydrous THF containing 100 μl of 1,3-dimethyl-2-imidazolidinone at -78° C. under a nitrogen atmosphere was added a solution of 96.6 mg (0.195 mmoles) of allyl (3S,4R)-2-(3-(1-R-t-butyldimethylsilyloxyethyl)-4-phenoxythiocarbonylthio-2-azetidinon-1-yl)acetate in 800 μl of anhydrous THF. The resulting mixture was stirred at -78° C. under nitrogen for 4 minutes and then was partitioned between EtOAc, ice-H 2 O aand 2N HCl. The organic phase was separated, washed with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , filtered, and evaporated. The residue was purified by plate layer chromatogrphy [one development CH 2 Cl 2 ] to give 53.2 mg (68%) of thioxopenam as an orange oil; [α] D -31.70 (C 4.3, CHCl 3 ); λ max EtOH=316 nm; λ max Et 3 N, EtOH=353.2 nm.
EXAMPLE 14
Allyl-(5R, 6S)-6-(1-R-hydroxyethyl)-2-thioxopenam-3-carboxylate ##STR31##
To a stirred solution of Allyl (5R, 6S)-6-(1-R-t-butyldimethylsilyloxyethyl)-2-thioxopenam-3-carboxylate (41.7 mg) 0.1 mmol) in 1 ml of tetrahydrofuran at 0° was added glacial acetic acid (70 μl) followed by tetrabutylammonium fluoride (1M in TMF, 0.3 ml). The solution was stirred at room temperature for 24 hours then diluted with 5 ml of methylene chloride and extracted three times with 0.1M PH 7 phosphate buffer. The methylene chloride solution was dried (MgSO 4 ) and evaporated and the residue purified by plate-layer chromatography (5% MeOH in CHCl 3 ), providing 20 mg of the de-silyated thioxo penam allyl ester or a yellow oil. NMR (200 MHz, CDCl 3 ), 3.65 (dd, J=1.5 and 6.5, H-6), 5.38 (S, H-3), 5.92 (d, J=1.5, H-5) [α] D +22° (C 1.6, MeOH).
EXAMPLE 15
P-nitrobenzyl-5R, 6S)-6-(1-R-hydroxyethyl)-2-thioxopenam-3-carboxylate ##STR32##
Following the procedure in Example 14 substituting p-nitrobenzyl (5R, 6S)-6-(1-R-t-butyldimethyl silyloxyethyl)-2-thioxopenam-3-carboxylate for the corresponding allyl ester, there is obtained the de-silyated thioxopenam p-nitrobenzyl ester.
EXAMPLE 16
Allyl-(5R,6S)-6-(1-R-t-butyldimethylsilyloxyethyl)-2-cyanomethylthio-penem-3-carboxylate ##STR33##
To a stirred solution of 75.5 mg (0.188 mmoles) of allyl (5R,6S)-6-(1-R-t-butyldimethylsilyloxyethyl)-2-thioxopenam-3-carboxylate in 2 ml CH 2 Cl 2 at 0° C. was added sequentially 24.3 mg (0.188 mmoles) of diisopropylethylamine and 31.4 mg (0.188 mmoles) of iodoacetonitrile. The mixture was stirred under an atmosphere of nitrogen at 0° C. for 10 minutes and was then partitioned between EtOAc, ice-H 2 O, and B 2N HCl. The organic phase was separated, washed with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , filtered and evaporated. The residue was purified by plate layer chromatography [one development CH 2 Cl 2 ] to give 62.0 mg (75%) of the cyanomethyl penem. Recrystallization from Et 2 O-hexanes gives mp. 91°-92° C.; [α] D +97.5 (C 2.49, CHCl 3 ).
EXAMPLE 17
General procedure for the alkylations of 2-Thioxopenams. Preparation of Allyl-(5R, 6S)-6-[1-(R)-t-butyldimethylsilyloxyethyl]-2-cyanonethylthiopen-2-em 3-carboxylate
To a stirred solution of allyl (5R, 6S)-6-[1-R-t-butyldimethylsilyloxyethyl)-2-thioxopenam-3-carboxylate (75.5 mg, 0.19 mmol) in 2 ml of methylene chloride at 0° C. was added sequentially 24.3 mg (0.19 mmol) of diisopropylethylamine and 31.4 mg (0.19 mmol of iodoacetonitrile. The mixture was stirred at 0° C. for 10 minutes and then partitioned between ethylacetate, ice-H 2 O and 2N HCl. The organic phase was dried, and evaporated and the residue purified by plate layer chromotography affording 62 mg (75%) of the titled penem. IR(CH 2 Cl 2 ) 1799, 1712, 1684 cm -1 ; NMR 0.09 (S, 6H), 0.9(S, 9H), 1.28 (d, J=6.5 Hz, 3H), 3.69 (d, J=18 HZ, 1H), 3.76 (d, J=18 HZ, 1H), 3.84 (dd, J=1.5, 4.5 HZ 1H), 4.3 (m, 1H), 4.76 (m, 2H), 5.3 (m, 1H), 5.46 (m, 1H) 5.8 (d, J=1.5 HZ) and 5.96 (m, 1H); λ max 338 nm, 252.5 nm; MS m/e 440(M+), 383, 143, 73; [α] D +97.5 (C 2.49); m.p. 91°-92° C. (Et 2 O-hexane).
TABLE I______________________________________Alkylations of 2-Thioxopenams to Penems Solvent,Alkyl Halide.sup.a R T(h) T° C. Yield______________________________________ClCH.sub.2 COCH.sub.3 CH.sub.2 COCH.sub.3 1 CH.sub.2 Cl.sub.2, 80 0°BrCH.sub.2 CH.sub.3 CH.sub.2 CH.sub.3 19 CH.sub.2 Cl.sub.2, 76 0°BrCH.sub.2 CH.sub.2 CH.sub.3 CH.sub.2 CH.sub.2 CH.sub.3 1.5 DME, 80 60°CH.sub.3 CHBrCH.sub.2 CH.sub.3 ##STR34## 0.5 DMF, 80° 77(CH.sub.3).sub.3 CBr.sup.c C(CH.sub.3).sub.3 5 DME, 30 60°ClCH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.3 21 DME, 10 60°ICH.sub.2 CN CH.sub.2 CN 0.2 CH.sub.2 Cl.sub.2, 75 0°______________________________________ .sup.a Isolate Yield .sup.b 1:1 Mixture of diasteromers .sup.c 1 equiv. AgOSO.sub.2 CF.sub.3 added
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Disclosed is a synthesis for preparing substituted 2-thioxopenams which are useful in the synthesis of penem antibiotics 7 which may be conducted in an enantiospecific manner; said process proceeds from azetidinone 1 via the azetidinone acetic ester 2, the 4-metallothiozetidinone 3, and the 4-dithiocarbonylazetidinone 4 to the substituted 2-thioxopenam 5: ##STR1## wherein: R 6 and R 7 are independently selected from: hydrogen; R 6 NH-- (R 6 is acyl or H); substituted and unsubstituted: alkyl, alkenyl, alkynyl, aryl, heterocyclyl, heteroaryl, cycloalkyl, and cycloalkenyl; wherein said substituents are, inter alia: halo (chloro, bromo, fluoro, iodo), hydroxyl, cyano, carboxyl, amino, and the above-recited values for R 6 and R 7 ; in functional terms,
R 2 is a group which potentially forms a stable carbonium ion, for example: trityl (--C(C 6 H 5 ) 3 ),
bis(p-methoxyphenyl)methyl, ##STR2## --2,4-dimethoxybenzyl, ##STR3## 2-(diphenyl)isopropyl, ##STR4## and the like; M is a thiophilic metal such as silver, thallium, mercury, or the like;
and R 1 is a protecting group such as allyl, p-nitrobenzyl or a biologically removable group (pharmaceutically acceptable ester moiety), for example: pivaloyloxymethyl, pivoloyloxyethyl, ethoxycarbonyloxymethyl, phthalidyl (5-methyl-2-oxo-1,3-dioxolen-4-yl)-; and X is a methyl leaving group such as phenoxy, p-chlorophenoxy, p-nitrophenoxy, phenylthio, alkylthio, alkoxy, chloro, or the like.
R 8 is inter alia, substituted and unsubstituted alkyl; the final penem products 7 are known, and their various embodiments are included by this definition.
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TECHNICAL BRANCH
[0001] This invention deals with the use of a pharmaceutical composition, which contains Epidermal Growth Factor (EGF), preferably in an injectable form and to be administered through infiltrations inside and around cutaneous chronic ischemic ulcerative wounds as to prevent diabetic limb amputation. It may be administered on recently induced surgical post-amputation surfaces, or damaged by the process of acute reperfusion with oxygenated blood, following prolonged ischemia. This allows for the prevention of surgical re-interventions, thus assisting in limb preservation.
PRIOR ART
[0002] Every organ and tissue of the body is susceptible to suffer irreversible damages following partial or complete, acute or chronic arterial blood supply suppression. Tissue damages might also occur as a consequence of chronic venous drainage failure (T. D. Lucas y I. L. Szweda. Cardiac reperfusion injury: aging, lipid peroxidation and mitochondrial dysfunction. Proc Natl Acad Sci USA 1998, 95 (2): 510-514). All these disorders are largely frequently found in Diabetes Mellitus affected patients. In these individuals limbs local circulation might fail due to macro and microvascular deteriorum. Furthermore, peripheral nerves structures are also affected which also contributes to the circulatory deterioration. Diabetes-associated damages to the autonomic or sensitive innervations systems ensues the failure of limb's skin defense mechanisms as sweating and sebaceous gland secretion. Local insensibility renders the foot prone to local traumas which might evolve to a problem wound.
[0003] A variety of risk factors have been associated with the difficult-to-heal seen in diabetic patients, i.e., high and sustained glycemia, glycosilation of hemoglobin and of many other circulating and tissue proteins, i.e., collagen, etc (Kurose I, Argenbright L W, Wolf R, Lianxi L, Granger D N. Ischemia/reperfusion-induced microvascular dysfunction: role of oxidants and lipid mediators. Am J Physiol 1997, 272: H2976-H2982). As a result of this healing deficit that is further complicated by the circulatory disturbances, many diabetic patients undergo limb amputation. Patients with inflammatory or degenerative arteriopathies of the limbs frequently exhibit negligible or null perfusion below the knees join. This sustained hypoxic scenario renders other cutaneous, microvascular, nervous and joins complications, while the former often leads to a recalcitrant to treatment ischemic ulcer. Besides, nerves, vessels, and other cutaneous structures may become severely deteriorated and often they succumb. This further sustains the propensity to recalcitrant ulcers. (McCallon S K, Knight C A, Valiulus J P, Cunningham M W, McCulloch J M, Farinas L P. Vacuum-assisted closure versus saline-moistened gauze in the healing of postoperative diabetic foot wounds. Ostomy Wound Manage 2000, 46:28-32).
[0004] Here we will describe some solutions currently used today in the medical arena to afford this affliction.
[0005] Among the general procedures used in the art today, the metabolic balance correction allows for the reduction of risk factors of diabetic complications. In addition, off-loading of the affected limb is a well-focused solution to facilitate limb ulcer healing. Antibiotics administration and frequent surgical debridements of necrotic and fistulized tissues are in the current state of the art. These may be conducted irrespective of the perfusion of the infected foot. However, for severe and recalcitrant cases of serious ischemic and progressive ulcers, amputation is irreversible. Other medical adjunctive interventions for either chronicity or rebounds are used in the art today having shown some benefits.
Haemorrehologic therapy: the rationale of this therapy is based on the well-known haemorrehologic disturbances found in the blood of diabetic patients, which at the same time might increase the opportunistic infection risk. Vasoactive therapy: this intervention has been used to alleviate the perfusion deficits due to the macro and microangiopathy. Some prostanoids have shown to be of benefit at the affected tissue level.
[0008] The use of any of these therapeutic interventions demand however, a prior examination of a number of functional systems, such as cardiovascular, renal, hepatic, etc, which might be found impaired in diabetic patients, particularly, the first and the second ones. Under certain conditions, other therapies have been introduced as to prevent or correct platelet aggregation as well as thrombolytic agents.
[0009] Surgical procedures for major revascularization are always risky for any ischemic patient, whether diabetic or not. Besides, these are expensive, and not applicable to many patients. Its indication is therefore very limited. Endovasacular surgery is also complex, expensive, and has provided a limited applicability for arterial sectors such as aorto-iliacus and femoro-popliteus. Most often these sectors appear calcified while lesions appear in a patched fashion.
[0010] Lumbar sympathectomy is today exceptionally practiced in diabetes. The existence of a previous autonomic neuropathy hinders its usefulness.
[0011] A recently emerged hope to deal with the diabetic foot wounds is the human recombinant platelet derived growth factor, commercially known as Becaplermin or Regranex, which has been approved by the Food and Drug Administration (FDA) of the USA. This medication is particularly indicated for neuropathic foot ulcers. The most recently published data indicate only a 50% of efficacy in a multicenter, controlled, and randomized clinical trial in the USA (T. Jeffery Wieman, Janice M. Smiell, Yachin Su. Efficacy and safety of topical gel formulation of recombinant human platelet derived growth factor—BB (Becaplermin) in patients with chronic neuropathic diabetic ulcers. Diabetes Care 1998, 21: 822-827). It is remarkable that the wounds medicated with Becaplermin in the aforementioned study PDGF-BB are small and shallow and that by no means may be compared in size or severity with those we have treated along our invention. On the other hand the clinical trial is conducted on neuropathic foot ulcers with a normal and standard arterial blood supply. In our case, severe ischemic ulcers referred as in stages IV and V according to Wagner classification have been treated and healed. Most of the wounds we have managed are ischemic. All the wounds we have treated are bigger than 20 cms 2 and from 10 to 40 mm depth. In the PDGF-BB clinical trial wounds involve only about 2.7±3.45 cms 2 and 0.5±0.49 cms in depth. A critical aspect to be solved by PDGF-BB therapy is the high rate of recurrence. This is about 30% in the third month.
[0012] Another recent invention for large acute cutaneous wounds, such as burns, or chronic as venous ulcers, has been the creation of bioartificial human skin equivalents. Yet, controlled clinical trial on diabetic foot ischemic ulcers are missing and it seems unlikely that any of the human skin equivalent could control or reverse the underlying ischemic process (Editorial. New Skin for Old. Developments in Biological Skin Substitutes. Arch Dermatol 1998; 134: 344-348).
[0013] In general terms there is no medical treatment having shown to be efficacious in healing such kind of wounds, which recalcitrant behavior is associated to the local ischemia. Preventing recurrence may turn in an even more complex challenge.
SPECIFICATIONS
DETAILED DESCRIPTION OF THE INVENTION
[0014] The object of the invention herein described is the use of an injectable pharmaceutical composition containing Epidermal Growth Factor (EGF) that enhances tissue survival and adaptation to hipoxia; which allows for the healing of cutaneous ischemic and chronic ulcers of skin and adjacent soft tissues in an irreversible manner. The composition allows for the healing of ischemic ulcerative or not type wounds or those wounds exposed to and damaged by the process of reperfusion with arterial blood on the skin and sift adjacent tissues. It is defined the ischemic wound in this context as that of skin and soft tissues of the lower limb as a result of a failure in the peripheral perfusion due to a long term damage of large and small vessels in a diabetic patient. The wounds affected by the reperfusion process are mostly created upon amputation or sharp debridement when the oxygenated blood supply is reinitiated following prolonged periods of territorial hemodynamic perfusion silence. Alternatively, these processes may appear following revascularization surgical procedures in diabetic patients.
[0015] The use of EGF in these lesions attenuates the progressive tissue deterioration, particularly in the legs and the feet associated to blood flow failure and toxin storage in the tissues.
[0016] The composition of the invention has shown to trigger and steadily sustain the process of healing in chronic ischemic wounds in which the current art therapy has been unsuccessful. By using this composition limb amputation is unnecessary when there are no other medical choices available for the ischemic and chronic wound. The composition has proved to be useful as well in reducing the damages associated to surgical reperfusion allowing for the complete healing of ulcers in ischemic/infected/neuropathic feet. The process of cellular arrest on the wound edges and the subsequent tissue fading are overtly aborted with this therapy. This excludes the need for further and progressive sharp debridements and partial amputations. The composition by mean of a generally cytoprotective and rescue effects enhances the healing of ischemic/infectious/neuropathic diabetic foot ulcers.
[0017] The composition is applied by mean of local infiltration within the wound margins and bottom of the lesions, and might contain the polypeptide obtained by natural, recombinant or synthetic technologies. The administration procedure is like a local anesthetic blockade inserting the needle in different point into and around the lesion, so that all the deep bottom surface and edges are flushed with the composition. The composition is deposited into 4 to 20 infiltration points so that in between each point the distance must be no longer that 1,5 cms. The number of points to be covered is according to that skilled in the art. Such wounds with bigger size will require a larger number of instillation points. The skilled in the art will perceive a couple of well recognized effects on the administration time: local edema and local resistance to the composition flushing. Sharp debridement of wound edges and bottom will be according to the experience of the skilled in the art. In general terms sharp debridements and minor amputations are significantly reduced upon treatment progression. If along the treatment period edges become atonic, they can be conservatively debrided and later infiltrations are to be carried out in a sub-epithelial space. Infiltrations are usually conducted on alternate days of a week so that in each week three infiltration sessions are conducted. The number of infiltration points in each session depends upon the size of the wound, ordinarily ranging between 4-20. In infectious/ischemic wounds as in stages IV and V according to Wagner's classification the outbreak of granulation tissue is following the sixth infiltration session. In less severe wounds, it is possible to see some response since the first week of treatment, so after three infiltration sessions. Alternatively, in very severe ischemia associated to total deficit of peripheral beat and anemia below 9 g/L the treatment has been used under daily bases. In these patients granulation evidences are imitated around the ninth session of infiltration. In all the cases the total volume to inject is about 1 milliliter, so that an ulcer may receive a total volume of 4-20 mL of the composition. It is preferably the use of hypodermic needles 271/2. The composition may contain the EGF polypeptide obtained from a natural source, via chemical synthesis or by mean of recombinant DNA technology. The use of the pharmaceutical composition containing EGF described herein has permitted the complete tissue regeneration of chronic and ischemic lesions whereas the procedure is minimally invasive. The use of the composition has also reduced the number of surgical interventions and the number of minor or major amputations. In other cases, the use of the herein described invention has allowed (I) removal of ischemic capsules with no need for surgical procedures. This is probably due to the emergence of a new remodeling granulation tissue from deep zones, which pushes up and detaches the necrotic material. (II) The growth of a new intra cutaneous fibroangiogenic tissue, consequent to successive infiltrations, before going to amputation as for examples in toes, so that there is a previous pro-granulating environment. This contributes to limit and to abort the septic complications, enhances wound healing and attenuates the reperfusion damages.
[0018] The components of the pharmaceutical composition are as follows:
[0019] Epidermal growth factor (EGF): Cytoprotective agent that allows for the activation of cellular self-defense mechanisms when administered into the ulcer. EGF promotes adaptation and survival rescue of cells within stressful conditions. EGF triggers is apoptosis in aged fibroblasts as those damaged and/or aged, and acts as a survival factor to others that are eventually rescued. EGF plays a selective pressure within the microenvironment, where adapted cells are committed to proliferate. Due to its cytoprotective effect, ischemia/reperfusion damages are prevented. The composition contains 10-1000 micrograms/ml of sterile vehicle. EGF may be natural, synthetic or recombinant. EGF may be in liquid form, suspended in water, in solution with a buffer, freeze-dried to be dissolved, etc. EGF may be as a powder of fine granulate, and to be applied by mean of high pressure shooting device. EGF may be administered as in its DNA form within a proper genetic construct suitable for its expression transiently transfected human cells.
[0020] Polyethyleneimine (PEI): This is highly positively charged—protonated chemical compound that enhances the interaction of EGF with its receptor, prolongs its half life in the extracellular matrix and prevents its intracellular degradation, so that in this way its biological effects are amplified. It may be found in the formulation in a molar relation of 1:1 with EGF up to 1 (EGF): 10 (PEI).
[0021] Sodium Phosphate Buffer: Chemical stabilizer. Its pH is about 6.5 and in a molar range concentration of 5-100 mM. The optimal range in the formulation is 10-20 mM.
[0022] O-Raffinose: Stabilizing agent for the freeze drying process. Concentrations of 5-50 mg/ml can be used whereas its optimal rage is 8-20 mg/ml.
[0023] L-Glycine: Isotonizing agent. Concentrations of 5-50 mg/ml can be used whereas its optimal rage is 10-20 mg/ml.
[0024] Fibronectin: Promotes the stability of EGF as its biological functioning. It promotes the interaction between EGF and its cellular receptors. It is in a range from 10-20 mcg/mL.
[0025] Levane: This is a protecting agent for EGF when it is in solution. It acts as screen agent for EGF. Facilitates its biodistribution within the extracellular space. In the composition it is found in a range fro 1-20 mgs/mL.
[0026] The pharmaceutical composition might combine EGF as well with the following active principles:
[0027] Rutine: Phlebotonic and phlebotrophic. It might be present in the formulation at concentrations of 20-1000 μg/ml. It might be used as a free Rutine hydrate or as a lyophilized salt of Rutine, as in a sulphate.
[0028] Lidocaine: Trophic agent. Lidocaine contributes to attenuate the local secretion of pro-inflammatory cytokines, as the expression of adhesion molecules within the vascular lumen. In the formulation lidocaine is used as a chlorhydrate and its concentration might be present in a range of 5-40 mg/ml.
[0029] Adenosine tri-phosphate (ATP): It plays vasodilator and pro-metabolic effects. Its concentration in the formulation ranges from 0.05 to 20 mg/ml as a sodium salt or free acid.
[0030] Guanosine triphosphate (GTP): Enhances local vasodilatation. It is present in the formulation as a sodium salt. Its concentration ranges from 1 to 100 mg/ml.
[0031] Amide of the nicotinic acid (Nicotinamide): Renders useful anabolic substrates for the cells. Its concentration ranges from 1 to 130 mg/ml.
[0032] L-Arginine: Contributes to the regulation of the vascular tone. Useful in the formulation as hydrochloride crystals. Its concentration ranges from 1-100 ng/ml.
[0033] Heparin: Cytoprotective, pro-mitogenic agent. Useful in the formulation as a sodium salt, in a concentration ranging from 1 to 10 μg/ml (0.1-1 U).
EXAMPLES
[0034] A total number of 9 patients received therapy with the pharmaceutical composition. All the patients shared the following characteristics:
1. All the patients were affected by type-II diabetes mellitus, with an evolution of 10-25 years, basically treated with oral hypoglycemiants. 2. A history of difficult healing was registered for all the patients. Some patients had undergone previous contra lateral amputations. 3. All the wounds treated corresponded to diabetic limb chronic ulcers, being classified as ischemic/infectious/neuropathic diabetic foot or mixed forms. Stages IV or V according to Wagner's classification predominated for all the wounds. 4. All the wounds treated with the present formulation might be considered as recalcitrant or difficult to heal wounds; some with one month or more of age. 5. All the wounds were about or larger than 20 cm 2 ; in most case ulcers depth involved the periosteum, having bone tissue overtly exposed. Among, them a patient is included with concomitant ischemic calcaneous. 6. All the patients treated were highly prone to amputation 7. All the patients were followed after hospital discharge and none of them has recurred so far. Neither late adverse reactions nor local ischemia signs were observed. No adverse reactions have been registered upon time.
[0042] Treatment was based on deep perilesional infiltrations over at least five different and equidistant points of the wound bottom and contours. The syringe needle must always be oriented toward the central basement area of the wound bottom, to the edges and/or to tunnels when exist. On each injection point, 1 ml of solution is deposited. No unwanted reactions are observed along or next to the treatment, except the ordinary local sore. The formulation always borne EGF as main active principle, while in some instances, the formulation contained some of the above mentioned active principles. In all the patients treated toes, foot, or major amputations procedures were prevented. The total number of infiltration sessions for each patient is shown in each example.
Example 1
[0043] Patient ACDF, 49 years old, female. Patient bearing an ischemic/infectious diabetic foot, affected by type-II diabetes mellitus with an evolution of 16 years, the patient had undergone prior sympathectomy and supracondilial amputation of the right limb a couple and half years ago. The first finger of the left foot was surgically removed while showing an ulcerative, humid, atonic, and difficult-to-heal lesion despite many minor surgical debridements to remove ischemic capsules, revitalize the edges and the bottom of the wound. The amputation shaft turned ischemic, with cyanotic and atonic edges following 5 days of the surgery. The infiltration of the composition is initiated expecting spontaneous re-epithelialization of the ulcer. From the fourth infiltration it was noticed a dramatic change of the aspect of the wound, starting a productive granulation tissue, bleeding, and that after a few days it was resurfaced with epithelium. The patient received a total of 9 sessions of infiltration (3/weeks and therefore three weeks of treatment). Following re-epithelialization she was discharged from hospital. Has shows a satisfactory evolution with recurrence.
Example 2
[0044] Patient ERC, 66 years old, female. Patient with a 12 yr. evolution of type-II diabetes mellitus, bearing an ischemic infectious foot and lacking distal beatings. A minor is transmetatarsal amputation was practiced having a large tunnel downward. The base of the amputation turned cyanotic, ischemic, atonic, and with large deposit of a yellow component. The infiltrations are begun with the expectance of producing granulation tissue and a spontaneous second intent healing. The wounded foot had completely healed, granulated and resurfaced with epithelium, including the tunnel after 11 infiltration sessions. It included a lateral tunnel of about 4 cms In depth. Evidences of scar remodeling are observed in this patient for the first time.
Example 3
[0045] Patient ECS, 63 years old, female. Patient type-II diabetes mellitus since she was 41 years old. She is bearing an ischemic infectious foot and with a previous contralateral infra-condilial amputation. She is admitted to receive amputation of her first toe due to severe ischemia. Upon surgery an ischemic capsule is implanted on the base of the next toe that extended back and downward. At this point the lesion is atonic, and no healing progress is observed. Fingers and adjacent soft tissues are removed, opening a large and deep edge, resembling a 6 cms length tunnel. Ischemic and necrosis signs recurred on day 3 post-surgery. Wound contours turn cyanotic and ischemic three days later. The composition infiltrations are initiated expecting a second intent healing response. Complete healing was achieved following 11 sessions when the patient had fully re-epithelialized the wound with well-keratinized epithelium. The patient was discharged from hospital. Scar remodeling was also observed.
Example 4
[0046] Patient RNP, 69 years old, male. A patient with a 12 yr. old evolution of type-II diabetes, with distal beatings deficit, bearing an ischemic/infectious foot. The patient undergoes a transmetatarsal amputation due to ulcerative lesions, recalcitrant to heal with current art therapy. On the surgical area ischemic plaques were onset and the healing process did not show to progress any longer. Patient complained of spontaneous pain on bed. The cyanosis extended around the surgery contours and there was negligible bleeding during debridements. The ischemic plaques were surgically removed, and on day 4 th post-surgery infiltrations therapy were initiated. Evidences of tissue improvement were observed on day 6 post-infiltration, so that spontaneous pain disappeared, and being overtly expressed a red granulation tissue. Following 12 infiltration sessions, the patient had completely re epithelialized the wound, so it means 4 weeks of treatment. He was discharged from hospital and has evolved well with no recurrence upon a 12-months follow up.
Example 5
[0047] Patient ISV, 74 years, female. Patient afflicted by diabetes since 30 years ago. She is bearing an ischemic/infectious foot. There is a previous transmetatarsal amputation and a history of deficit of healing. She is admitted due to necrotic lesion of the 5 th toe. The surgery is practiced and ischemic plaques appear over the next few days. She received further debridement and an external extensive edge is opened with exposed periosteum in the inferior and external side of the foot. The edge became ischemic over the next 48 hours, thus, the infiltration therapy is introduced trying to achieve a spontaneous second intent heal, including the edge. After the 6 th infiltration a useful and bleeding granulation tissue arises. The lesion favorably responded to the treatment and was fully epithelialized following 11 sessions. The patient has had a satisfactory evolution following hospital discharge.
Example 6
[0048] Patient RDR, 44 years old, male. A patient affected by type-II diabetes since 12 years ago. He bears an ischemic/infectious diabetic foot that due to ischemic lesions on two toes receives transmetatarsal amputation. The patient lacks distal beatings and shows clinical evidences of insufficient peripheral perfusion. He has a history of healing failure on the contralateral tibial region. Following amputation cyanotic foci appeared on the cutaneous contours of the wound. The infiltration is begun with the expectance of rendering sufficient granulation tissue to host an auto-graft, or to heal and remodel by second intent. On the 4 th infiltration the first sprouts of granulation tissue appear and reanimation of the wound edges, which also were normochromic and hypertrophic. The auto-graft was unnecessary. By carrying out 15 infiltration sessions (5 weeks) there was no required to make a self auto-grafting. Upon hospital discharge has had a successful evolution.
Example 7
[0049] Patient RGR, 49 years old, female. This is diabetes patient since about 10 years with painful claudicating along 100 meters walk and difficult to heal histories. She has had several recalcitrant ulcers on the paratibial area of both limbs. The lesion to be treated is an ischemic ulcer on the lower third of the left leg on its lateral external side with approximately 6.4 cms of diameter and 0.5 cm depth. The ulcer has progressed for two months with no healing. The first approach was conservative debridement of bottom and edges, starting the treatment on the other day. The lesion began to granulate on third infiltration, with contraction of the edges and proliferation of a simple neo-epithelium that eventually became stratified and keratinized. 12 infiltrations sessions were carried out (4 weeks of treatment). Following hospital discharge has satisfactorily.
Example 8
[0050] Patient GPJ, 57 years old. The patient has a 12 years evolution of a type-II diabetes mellitus. He bears an ischemic/infectious diabetic foot with no sign of tibial beatings. He suffers a transmetatarsal amputation due to ischemia and necrosis of 4 toes of the right foot. Seven days after the amputation the healing process is halted and the wound edges became cyanotic and devitalized with no evidence of wound repair. The infiltrations are initiated as an alternative maneuver of other surgical interventions. After 9 sessions (3 weeks) the patient had fully re-epithelialized. Upon hospital discharge he has successfully evolved with no complications.
Example 9
[0051] Patient DLF, 51 years old, male. A patient with type-II diabetes history and asthma of about 20 years ago. The patient is admitted with a perforating plantar ulcer with severe ischemia and necrosis of the surrounding tissue. The left foot had almost fully demised. The Calcaneus ends up after surgery with an exposed periosteum. Infiltrations are initiated and tried as an alternative of immediate amputation. The only possibility was the uprising of a productive and vascularized granulation tissue suitable to host a skin graft. There were a total of 15 infiltration sessions including the Calcaneus. Upon the 5 th infiltration the granulation tissue starts to bud. When the 15 infiltration sessions were concluded (5 weeks) grafting was implanted. The patient has successfully evolved. He is currently able to walk by himself.
TABLE 1 Composition and active principles administered to each patient. Patient ID Composition ACDF EGF (50 mcg/ml) + Rutine (50 mg/ml) ERC EGF(125 mcg/ml of sodium buffer solution pH 6.5 + 20 mg of O-Raffinose and 10 mg of L-Glycine /ml of buffer) ECS EGF (125 mcg/ml) + Lidocaine (10 mg/ml) RNP EGF (10 mcg/ml) + ATP (2.5 mg/ml) ISV EGF (100 mcg/ml) + GTP (5 mg/ml) RDR EGF (30 mcg/ml + NAD (25 mg/ml) RGR EGF(25 mcg/ml) + L-Arginine (10 ng/ml) GPJ EGF(100 mcg/ml) + Heparin (0.75 U/ml) DLF EGF (100 mcg/ml of sodium buffer solution pH 6.5 + 10 mg of O-Raffinose, 100 mcg of fibronectin and 15 mg of L-Glycine
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The invention relates to the use of Epidermal Growth Factor (EGF) in a preferably-injectable pharmaceutical composition which is administered by means of infiltration into and around chronic cutaneous ischaemic lesions in order to prevent diabetic foot amputation. Said composition can be administered to recently-created surgical surfaces damaged by the effect of acute reperfusion with oxygenated blood following prolonged ischaemia, thereby preventing further surgical procedures and favouring the preservation of the extremity. The aforementioned composition can be used to improve (i) the cell microenvironment, thereby increasing the reparative and defensive capacity and viability of the is tissues and (ii) the cicatrisation of cutaneous ischaemic lesions, thereby stimulating cell proliferation. The invention is suitable for use in human, veterinary and experimental medicine, specifically in vascular angiology and surgery, dermatology, burn treatment and reconstructive surgery and geriatric medicine. Said composition can be used for recalcitrant ulcers which are associated with lesions in the macro and/or microvasculature, patients with inadequate lymphatic and/or venous return and ulcers or other lesions which are difficult to cicatrise and/or heal.
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BACKGROUND OF THE INVENTION
This invention relates to land and amphibious vehicles generally and in particular to amphibious earth moving equipment.
One type of amphibious vehicle has one or more pontoons around each of which an endless track is guided, the track being driven by a prime mover on the vehicle. The application of this technology to earth moving equipment enables one to produce excavators and the like suitable for use in marshy areas. The buoyancy of the pontoons is selected to be sufficient to prevent the vehicle from sinking and furthermore enables the tracks to drive the vehicle even in soft mud and mire. Various excavators and dredges of this type are well known.
Because of the limited demand for amphibious earth working vehicles, it is not commercially feasible to mass produce excavators specifically designed for marshy environments. Therefore, there is a demand for means to convert conventional dry land excavating equipment to an amphibious environment. Previous attempts to satisfy this demand have met with only limited success in part because the approaches taken were too complicated, and therefore too expensive. Some of the prior art attempts in this area utilized separate engines, one for the excavator itself, and one for the track drive, which of course increased weight, cost and maintenance requirements. Other proposals, such as those shown in U.S. Pat. Nos. 3,842,785 and 4,124,124 employed outboard lubricated chains extending between the prime mover and axles supporting the tracks on the pontoons. The drive chains presented serious environmental and safety hazards.
It is an object of this invention to provide a simple, inexpensive, uncomplicated adapter for rendering a dry land excavator amphibious.
A further object of the invention is to avoid the water pollution caused by open lubricated drive chains.
Yet another object is to enable an amphibious excavator to be driven by the standard excavator engine through its standard track motors; that is, to enable one to utilize the existing excavator engine and hydraulic motors to drive the tracks of an amphibious vehicle.
A further object is to avoid the hazards to personnel and animals posed by exposed drive chains.
The invention provides an adapter for converting a dry land earth mover to amphibious operation. The adapter comprises a pair of pontoon assemblies, each of these assemblies having a pontoon with an endless track guided around it in a generally vertical plane, a hydraulic drive motor powered by fluid from the prime mover of the excavator and a drive shaft assembly for transferring power directly from the hydraulic motor to the driven track. The drive shaft assembly includes a tube coaxial with the hydraulic motor and having an internal diameter greater than the outside diameter of the hydraulic motor to enable the tube to be placed over the hydraulic motor; a plate affixed to one end of the tube; a shaft affixed to the plate and coaxial with the tube for unitary rotation therewith; a pillow block for supporting the distal end of the shaft; and plural sprockets for supporting and driving the amphibious track, at least one of said sprockets being affixed to said tube and at least one of said sprockets being affixed to said shaft; whereby the track is driven directly from the hydraulic motor without intermediate linkage.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 is an exploded perspective view of a dry land excavator, looking from the rear;
FIG. 2 is a perspective view of a pontoon assembly embodying the invention;
FIG. 3 is a top view of a drive shaft assembly for driving the track shown in FIG. 2;
FIG. 4 is a perspective view of an amphibious excavator embodying the invention; and
FIG. 5 shows a preferred track cleat in perspective.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a conventional earth-moving machine in an exploded view with the cab assembly 10 raised from the crawling unit or "buggy" assembly 14 for clarity. The turntable 12 permits the cab to swivel upon the buggy assembly, which assembly includes a rigid transverse frame member 16 supporting a pair of hydraulic motors (one for each track) that are powered by fluid delivered from a high-pressure pump in the cab unit via a hose. The frame supports a pair of tracks 24 driven by the respective motors. In practicing the present invention, the entire conventional buggy assembly, except for the motors and hoses, is removed from the cab assembly 10 and is set aside.
FIG. 2 illustrates an amphibious buggy assembly embodying the invention, wherein parts identical to those of FIG. 1 are identified by identical reference numerals. The buggy assembly 114 comprises a transverse frame 116 upon which the turntable 12 may be mounted. Opposite ends of the frame member 116 are affixed to respective buoyant pontoons 120 having sufficient volume to support the entire weight of the excavator. The width of the frame member 116 and the dimensions of the pontoons are chosen to provide the assembled final unit with adequate stability to prevent it from tipping when afloat.
The pontoons 120 have radiused front and rear ends 121 and bottom surfaces that are slightly bowed downward, comprising a pair of sloping surfaces 122, 124, with a slight dihedral angle therebetween, on either side of a three-foot long central, horizontal portion 126. This geometry is superior to that of a flat-bottomed pontoon because it enables the tracks to pivot upon the ground much more easily. Furthermore, the bowed pontoon bottom helps retain the track chains within their channels 128 along the bottom of the pontoon by maintaining a normal force therebetween when the tracks are under tension. Upper guide channels 129 are attached to the tops of the pontoons.
To mount each motor 20 upon its respective pontoon 120, a bracket or motor mount 130 is welded to the rear end of the pontoon, on the inboard side, as shown in FIG. 3. The motors are then attached to their mounts by bolts 132, and this can be done without ever having to disconnect the fluid lines 22. The lines are protected by removable shields 134. Each motor is mechanically connected to a track drive assembly, described below and shown in detail in FIG. 3. Each drive assembly 140 comprises a hollow pipe or tube 142 whose inside diameter is slightly larger than the outside diameter of the hydraulic motor 20 with which it is associated. This tube has at its inboard end (the left in FIG. 3) a flange 144 affixed thereto, as by welding. The other end of the tube is closed by a circular plate 146 that is welded inside the tube. One end of a shaft 148 is attached by welding to the center of plate 146, and this shaft extends in the outboard direction so that the combined length of the tube 142 and shaft 148 approximately equals the width of the pontoon.
Each track is driven by plural, equidistantly spaced sprockets (three - 152, 154 and 156 are shown) that are supported on the shaft-tube assembly. The inboard sprocket 152 has a large inside diameter comparable to the outside diameter of the tube 142 and is attached to the motor and to the tube flange 144 by means of bolts 158. The remaining sprockets 154 and 156 are welded to the shaft 148. Three sprockets are shown, but it should be understood that two sprockets may be sufficient for some applications, while more than three may be needed in others; of course, the number of sprockets will correspond to the number of track chains.
The drive shaft assembly 140 is installed by placing the tube 142 over the motor 20, and then joining the tube flange 144 to the motor drive flange 160 with the bolts 158. The outboard, or distal, end of the shaft 148 is supported by a pillow block 164 provided on a bracket 166 connected to the outboard side of the pontoon.
The opposite, front, end of the pontoon is provided with an idler shaft assembly 170, comprising an idler shaft 172 with sprockets 174, 176, 178 secured thereto. The shaft is supported at both ends by pillow blocks similar to those described above.
FIG. 2 shows details of the tracks 180 that, when looped around the pontoons, are guided by the lower and upper channels 128, 129 and the drive shaft and idler shaft sprockets.
Each track assembly 180 comprises plural, identical endless chains 182, and a plurality of transverse cleats 184 affixed to alternate links thereof. Each of the cleats may comprise a metal U-section, open outwardly, as shown in FIG. 2, which provides good traction in mud and mire. We prefer, however, to use T-shaped cleats 186, one of which is shown in detail in FIG. 5. The generous fillets 188 between the legs of the T, of at least an inch radius, render the cleat self-cleaning. This design avoids the substantial accumulation of mud that can detract from buoyancy with other designs.
FIG. 4 shows the cab assembly 10 reinstalled upon the amphibious buggy assembly. Note the original hydraulic motors 20 and lines 22 for transferring fluid to and from the cab's hydraulic pump, thereby avoiding the need for a separate prime mover for the buggy.
Operation of the FIG. 4 device is identical to that of the prior art in that, when activated, the independently acting motors 20 rotate their drive shaft assemblies, which pull the tracks around the pontoons--normally in the direction indicated by the arrows in FIG. 2--resulting in movement of the excavator over dry ground or even soft mud. When the excavator is fully afloat, the tracks naturally lose a large portion of their effectiveness, and in such instances the unit may be better moved by towing or by using the excavator bucket to pull the excavator along; however, the cleats do function even in water and the excavator can "swim" slowly under its own power.
A particular advantage of the invention is that, owing to the particular structure of the drive assembly 140, the hydraulic motors 20 need not have an intermediate drive such as the exposed chain shown in U.S. Pat. No. 4,124,124, which is typical of prior art in this area. When drive chains are used in amphibious environments, inasmuch as the chains are underwater much of the time, frequent lubrication is required, and such lubrication normally needs to be done on at least a daily basis. As a result, substantial quantities of lubricant inevitably wind up in the water, presenting a particularly objectionable environmental drawback. Furthermore, the existence of exposed chains always creates a safety hazard, and in fact, there are documented cases of people having been badly injured after becoming entangled in such workings. In contrast, the present unit uses only direct drive from hydraulic motors which are fully sealed and do not create either the environmental or safety hazard problems of the prior art. An additional major benefit is that one saves the cost and the weight of a drive chain unit and possibly a separate prime mover.
Inasmuch as the invention is subject to many variations and modifications, it is intended that the foregoing shall be interpreted only as illustrative of the invention, whose full scope is set out in the following claims.
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Disclosed herein is an adapter for rendering an earth mover amphibious, comprising a buggy assembly having a pair of buoyant pontoons and tracks that are driven around the pontoons by hydraulic motors situated coaxially with drive sprockets for the track. The track is driven by the motor without an intermediate chain drive, thus avoiding certain environmental and personal dangers.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a process for drawing gel-spun polyethylene multi-filament yarns and to the drawn yarns produced thereby. The drawn yarns are useful in impact absorption and ballistic resistance for body armor, helmets, breast plates, helicopter seats, spall shields, and other applications; composite sports equipment such as kayaks, canoes, bicycles and boats; and in fishing line, sails, ropes, sutures and fabrics.
[0003] 2. Description of the Related Art
[0004] To place the invention in perspective, it should be recalled that polyethylene had been an article of commerce for about forty years prior to the first gel-spinning process in 1979. Prior to that time, polyethylene was regarded as a low strength, low stiffness material. It had been recognized theoretically that a straight polyethylene molecule had the potential to be very strong because of the intrinsically high carbon-carbon bond strength.
[0005] However, all then-known processes for spinning polyethylene fibers gave rise to “folded chain” molecular structures (lamellae) that inefficiently transmitted the load through the fiber and caused the fiber to be weak.
[0006] “Gel-spun” polyethylene fibers are prepared by spinning a solution of ultra-high molecular weight polyethylene (UHMWPE), cooling the solution filaments to a gel state, then removing the spinning solvent.
[0007] One or more of the solution filaments, the gel filaments and the solvent-free filaments are drawn to a highly oriented state. The gel-spinning process discourages the formation of folded chain lamellae and favors formation of “extended chain” structures that more efficiently transmit tensile loads.
[0008] The first description of the preparation and drawing of UHMWPE filaments in the gel state was by P. Smith, P. J. Lemstra, B. Kalb and A. J. Pennings, Poly. Bull., 1, 731 (1979). Single filaments were spun from 2 wt. % solution in decalin, cooled to a gel state and then stretched while evaporating the decalin in a hot air oven at 100 to 140° C.
[0009] More recent processes (see, e.g., U.S. Pat. Nos. 4,551,296, 4,663,101, and 6,448,659) describe drawing all three of the solution filaments, the gel filaments and the solvent-free filaments. A process for drawing high molecular weight polyethylene fibers is described in U.S. Pat. No. 5,741,451. The disclosures of these patents are hereby incorporated by reference to the extent not incompatible herewith.
[0010] Although gel-spinning processes tend to produce fibers that are free of lamellae with folded chain surfaces, nevertheless the molecules in gel-spun UHMWPE fibers are not free of gauche sequences as can be demonstrated by infra-red and Raman spectrographic methods. The gauche sequences are kinks in the zig-zag polyethylene molecule that create dislocations in the orthorhombic crystal structure. The strength of an ideal extended chain polyethylene fiber with all trans —(CH 2 ) n — sequences has been variously calculated to be much higher than has presently been achieved. While fiber strength and multi-filament yarn strength are dependent on a multiplicity of factors, a more perfect polyethylene fiber structure, consisting of molecules having longer runs of straight chain all trans sequences, is expected to exhibit superior performance in a number of applications such as ballistic protection materials.
[0011] A need exists for gel-spun multi-filament UHMWPE yarns having increased perfection of molecular structure. One measure of such perfection is longer runs of straight chain all trans —(CH 2 ) n — sequences as can be determined by Raman spectroscopy. Another measure is a greater “Parameter of Intrachain Cooperativity of the Melting Process” as can be determined by differential scanning calorimetry (DSC). Yet another measure is the existence of two orthorhombic crystalline components as can be determined by x-ray diffraction. It is among the objectives of this invention to provide methods to produce such yarns by drawing and the yarns so produced.
SUMMARY OF THE INVENTION
[0012] The invention comprises a process for drawing a gel-spun multi-filament yarn comprising the steps of:
a) forming a gel-spun polyethylene multi-filament feed yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents; b) passing the feed yarn at a speed of V 1 meters/minute into a forced convection air oven having a yarn path length of L meters, wherein one or more zones are present along the yarn path having zone temperatures from 130° C. to 160° C.; c) passing the feed yarn continuously through the oven and out of the oven at an exit speed of V 2 meters/minute wherein the following equations 1 to 4 are satisfied
0.25 ≦L/V 1 ≦20, min Eq. 1
3 ≦V 2 /V 1 ≦20 Eq. 2
1.7≦( V 2 −V 1 )/ L≦ 60 min −1 Eq. 3
0.20≦2 L /( V 1 +V 2 )≦10, min Eq. 4
[0016] The invention is also a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein filaments of the yarn have a peak value of the ordered-sequence length distribution function F(L) at a straight chain segment length L of at least 35 nanometers as determined at 23° C. from the low frequency Raman band associated with the longitudinal acoustic mode (LAM-1).
[0017] In another embodiment the invention is a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02. wherein filaments of the yarn have a value of the “Parameter of Intrachain Cooperativity of the Melting Process”, ν, of at least about 535.
[0018] In yet another embodiment, the invention is a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein the intensity of the (002) x-ray reflection of one the filament of the yarn, measured at room temperature and under no load,shows two distinct peaks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is the low frequency Raman spectrum and extracted LAM-1 spectrum of filaments of a commercially available gel-spun multi-filament UHMWPE yarn (SPECTRA® 900 yarn).
[0020] FIG. 2 ( a ) is a plot of the ordered sequence length distribution function F(L) determined from the LAM-1 spectrum of FIG. 1 .
[0021] FIG. 2 ( b ) is a plot of the ordered sequence length distribution function F(L) determined from the LAM-1 spectrum of a commercially available gel-spun multi-filament UHMWPE yarn (SPECTRA® 1000 yarn).
[0022] FIG. 2 ( c ) is a plot of the ordered sequence length distribution function F(L) determined from the LAM-1 spectrum of filaments of the invention.
[0023] FIG. 3 shows differential scanning calorimetry (DSC) scans at heating rates of 0.31, 0.62 and 1.25° K/min of a 0.03 mg filament segment taken from a multi-filament yarn of the invention chopped into pieces of 5 mm length and wrapped in parallel array in a Wood's metal foil and placed in an open sample pan.
[0024] FIG. 4 shows an x-ray pinhole photograph of a single filament taken from multi-filament yarn of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In one embodiment, the invention comprises a process for drawing a gel-spun multi-filament yarn comprising the steps of:
a) forming a gel-spun polyethylene multi-filament feed yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents; b) passing the feed yarn at a speed of V 1 meters/minute into a forced convection air oven having a yarn path length of L meters, wherein one or more zones are present along the yarn path having zone temperatures from about 130° C. to 160° C.; c) passing the feed yarn continuously through the oven and out of the oven at an exit speed of V 2 meters/minute wherein the following equations 1 to 4 are satisfied
0.25 ≦L/V 1 ≦20, min Eq. 1
3 ≦V 2 /V 1 ≦20 Eq. 2
1.7≦( V 2 −V 1 )/ L≦ 60, min −1 Eq. 3
0.20≦2 L /( V 1 +V 2 )≦10, min Eq. 4
[0029] For purposes of the present invention, a fiber is an elongate body the length dimension of which is much greater than the transverse dimensions of width and thickness. Accordingly, “fiber” as used herein includes one, or a plurality of filaments, ribbons, strips, and the like having regular or irregular cross-sections in continuous or discontinuous lengths. A yarn is an assemblage of continuous or discontinuous fibers.
[0030] Preferably, the multi-filament feed yarn to be drawn comprises a polyethylene having an intrinsic viscosity in decalin of from about 8 to 30 dl/g, more preferably from about 10 to 25 dl/g, and most preferably from about 12 to 20 dl/g. Preferably, the multi-filament yarn to be drawn comprises a polyethylene having fewer than about one methyl group per thousand carbon atoms, more preferably fewer than 0.5 methyl groups per thousand carbon atoms, and less than about 1 wt. % of other constituents.
[0031] The gel-spun polyethylene multi-filament yarn to be drawn in the process of the invention may have been previously drawn, or it may be in an essentially undrawn state. The process for forming the gel-spun polyethylene feed yarn can be one of the processes described by U.S. Pat. Nos. 4,551,296, 4,663,101, 5,741,451, and 6,448,659.
[0032] The tenacity of the feed yarn may range from about 2 to 76, preferably from about 5 to 66, more preferably from about 7 to 51, grams per denier (g/d) as measured by ASTM D2256-97 at a gauge length of 10 inches (25.4 cm) and at a strain rate of 100%/min.
[0033] It is known that gel-spun polyethylene yarns may be drawn in an oven, in a hot tube, between heated rolls, or on a heated surface. WO 02/34980 A1 describes a particular drawing oven. We have found that drawing of gel-spun UHMWPE multi-filament yarns is most effective and productive if accomplished in a forced convection air oven under narrowly defined conditions. It is necessary that one or more temperature-controlled zones exist in the oven along the yarn path, each zone having a temperature from about 130° C. to 160° C. Preferably the temperature within a zone is controlled to vary less than ±2° C. (a total less than 4° C.), more preferably less than ±1° C. (a total less than 2° C.).
[0034] The yarn will generally enter the drawing oven at a temperature lower than the oven temperature. On the other hand, drawing of a yarn is a dissipative process generating heat. Therefore to quickly heat the yarn to the drawing temperature, and to maintain the yarn at a controlled temperature, it is necessary to have effective heat transmission between the yarn and the oven air. Preferably, the air circulation within the oven is in a turbulent state. The time-averaged air velocity in the vicinity of the yarn is preferably from about 1 to 200 meters/min, more preferably from about 2 to 100 meters/min, most preferably from about 5 to 100 meters/min.
[0035] The yarn path within the oven may be in a straight line from inlet to outlet. Alternatively, the yarn path may follow a reciprocating (“zig-zag”) path, up and down, and/or back and forth across the oven, around idler rolls or internal driven rolls. It is preferred that the yarn path within the oven is a straight line from inlet to outlet.
[0036] The yarn tension profile within the oven is adjusted by controlling the drag on idler rolls, by adjusting the speed of internal driven rolls, or by adjusting the oven temperature profile. Yarn tension may be increased by increasing the drag on idler rolls, increasing the difference between the speeds of consecutive driven rolls or decreasing oven temperature. The yarn tension within the oven may follow an alternating rising and falling profile, or it may increase steadily from inlet to outlet, or it may be constant. Preferably, the yarn tension everywhere within the oven is constant neglecting the effect of air drag, or it increases through the oven. Most preferably, the yarn tension everywhere within the oven is constant neglecting the effect of air drag.
[0037] The drawing process of the invention provides for drawing multiple yarn ends simultaneously. Typically, multiple packages of gel-spun polyethylene yarns to be drawn are placed on a creel. Multiple yarns ends are fed in parallel from the creel through a first set of rolls that set the feed speed into the drawing oven, and thence through the oven and out to a final set of rolls that set the yarn exit speed and also cool the yarn to room temperature under tension. The tension in the yarn during cooling is maintained sufficient to hold the yarn at its drawn length neglecting thermal contraction.
[0038] The productivity of the drawing process may be measured by the weight of drawn yarn that can be produced per unit of time per yarn end. Preferably, the productivity of the process is more than about 2 grams/minute per yarn end, more preferably more than about 4 grams/minute per yarn end.
[0039] In another embodiment, the invention is a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from 5 dl/g to 35 dl/g, fewer than two methyl groups per thousand carbon atoms, and less than 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein filaments of the yarn have a peak value of the ordered-sequence length distribution function F(L) at a straight chain segment length L of at least 40 nanometers as determined at 23° C. from the low frequency Raman band associated with the longitudinal acoustic mode (LAM-1).
[0040] In yet another embodiment, the invention is a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from 5 dl/g to 35 dl/g, fewer than two methyl groups per thousand carbon atoms, and less than 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein filaments of the yarn have a value of the “Parameter of Intrachain Cooperativity of the Melting Process”, ν, of at least 535.
[0041] In a further embodiment, the invention is a novel polyethylene multi-filament yarn comprising a polyethylene having an intrinsic viscosity in decalin at 135° C. of from about 5 dl/g to 35 dl/g, fewer than about two methyl groups per thousand carbon atoms, and less than about 2 wt. % of other constituents, the multi-filament yarn having a tenacity of at least 17 g/d as measured by ASTM D2256-02, wherein the intensity of the (002) x-ray reflection of one filament of the yarn, measured at room temperature and under no load, shows two distinct peaks.
[0042] Preferably, a polyethylene yarn of the invention has an intrinsic viscosity in decalin at 135° C. of from about 7 dl/g to 30 dl/g, fewer than about one methyl group per thousand carbon atoms, less than about 1 wt. % of other constituents. and a tenacity of at least 22 g/d.
Measurement Methods
[0000] 1. Raman Spectroscopy
[0043] Raman spectroscopy measures the change in the wavelength of light that is scattered by molecules. When a beam of monochromatic light traverses a semi-transparent material, a small fraction of the light is scattered in directions other than the direction of the incident beam. Most of this scattered light is of unchanged frequency. However, a small fraction is shifted in frequency from that of the incident light. The energies corresponding to the Raman frequency shifts are found to be the energies of rotational and vibrational quantum transitions of the scattering molecules. In semi-crystalline polymers containing all-trans sequences. the longitudinal acoustic vibrations propagate along these all-trans segments as they would along elastic rods. The chain vibrations of this kind are called longitudinal acoustic modes (LAM), and these modes produce specific bands in the low frequency Raman spectra. Gauche sequences produce kinks in the polyethylene chains that delimit the propagation of acoustic vibrations. It will be understood that in a real material a statistical distribution exists of the lengths of all-trans segments. A more perfectly ordered material will have a distribution of all-trans segments different from a less ordered material. An article titled, “Determination of the Distribution of Straight-Chain Segment Lengths in Crystalline Polyethylene from the Raman LAM-1 Band”, by R. G. Snyder et al, J. Poly. Sci. Poly. Phys. Ed., 16, 1593-1609 (1978) describes the theoretical basis for determination of the ordered-sequence length distribution function, F(L) from the Raman LAM-1 spectrum.
[0044] F(L) is determined as follows: Five or six filaments are withdrawn from the multi-filament yarn and placed in parallel alignment abutting one another on a frame such that light from a laser can be directed along and through this row of fibers perpendicular to their length dimension. The laser light should be substantially attenuated on passing sequentially through the fibers. The vector of light polarization is collinear with the fiber axis, (XX light polarization).
[0045] Spectra are measured at 23° C. on a spectrometer capable of detecting the Raman spectra within a few wave numbers (less than about 4 cm −1 ) of the exciting light. An example of such a spectrometer is the SPEX Industries, Inc, Metuchen, N.J., Model RAMALOG® 5, monochromator spectrometer using a He—Ne laser. The Raman spectra are recorded in 90° geometry, i.e., the scattered light is measured and recorded at an angle of 90 degrees to the direction of incident light. To exclude the contribution of the Rayleigh scattering, a background of the LAM spectrum in the vicinity of the central line must be subtracted from the experimental spectrum. The background scattering is fitted to a Lorentzian function of the form given by Eq. 5 using the initial part of the Raman scattering data and the data in the region 30-60 cm −1 where there is practically no Raman scattering from the samples, but only background scattering.
f ( x ) ) = H 4 · ( x - x 0 w ) 2 + 1 Eq . 5
[0046] where: x 0 is the peak position
[0047] H is the peak height
[0048] w is the full width at half maximum
[0049] Where the Raman scattering is intense near the central line in the region from about 4 cm −1 to about 6 cm −1 , it is necessary to record the Raman intensity in this frequency range on a logarithmic scale and match the intensity recorded at a frequency of 6 cm −1 to that measured on a linear scale. The Lorentzian function is subtracted from each separate recording and the extracted LAM spectrum is spliced together from each portion.
[0050] FIG. 1 ( a ) shows the measured Raman spectra for a fibermaterial to be described below and the method of subtraction of the background and the extraction of the LAM spectrum.
[0051] The LAM-1 frequency, is inversely related to the straight chain length, L as expressed by Eq. 6.
L = 1 2 c ω L ( Eg c ρ ) 1 / 2 Eq . 6
where: c is the velocity of light, 3×10 10 cm/sec
[0052] ω L is the LAM-1 frequency, cm −1
[0053] E is the elastic modulus of a polyethylene molecule, g(f)/cm 2
[0054] ρ is the density of a polyethylene crystal, g(m)/cm 3
[0055] g c is the gravitational constant 980 (g(m)−cm)/((g(f)−sec 2 )
[0056] For the purposes of this invention, the elastic modulus E, is taken as 340 GPa as reported by Mizushima et al., J. Amer. Chem. Soc., 71, 1320 (1949). The quantity (g c E/p) 1/2 is the sonic velocity in an all trans polyethylene crystal. Based on an elastic modulus of 340 GPa, and a crystal density of 1.000 g/cm 3 , the sonic velocity is 1.844×10 6 cm/sec. Making that substitution in Eq. 6, the relationship between the straight chain length and the LAM-1 frequency as used herein is express by Eq. 7.
L = 307.3 ω L , nanometers Eq . 7
[0057] The “ordered-sequence length distribution function”, F(L), is calculated from the measured Raman LAM-1 spectrum by means of Eq. 8.
F ( L ) = [ 1 - exp ( - hc ω L kT ) ω L 2 I ω ] , arbitrary units Eq . 8
where: h is Plank's constant, 6.6238×10 −27 erg-cm
[0058] k is Boltzmann's constant, 1.380×10 −16 erg/° K
[0059] l ω is the intensity of the Raman spectrum at frequency ω L , arbitrary units
[0060] T is the absolute temperature, ° K
[0000] and the other terms are as previously defined.
[0061] Plots of the ordered-sequence length distribution function, F(L), derived from the Raman LAM-1 spectra for three polyethylene samples to be described below are shown in FIGS. 2 ( a ), 2( b ) and 2( c ).
[0062] Preferably, a polyethylene yarn of the invention is comprised of filaments for which the peak value of F(L) is at a straight chain segment length L of at least 45 nanometers as determined at 23° C. from the low frequency Raman band associated with the longitudinal acoustic mode (LAM-1). The peak value of F(L) preferably is at a straight chain segment length L of at least 50 nanometers, more preferably at least 55 nanometers, and most preferably 50-150 nanometers.
[0000] 2. Differential Scanning Calorimetry (DSC)
[0063] It is well known that DSC measurements of UHMWPE are subject to systematic errors cause by thermal lags and inefficient heat transfer. To overcome the potential effect of such problems, for the purposes of the invention the DSC measurements are carried out in the following manner A filament segment of about 0.03 mg mass is cut into pieces of about 5 mm length. The cut pieces are arranged in parallel array and wrapped in a thin Wood's metal foil and placed in an open sample pan. DSC measurements of such samples are made for at least three different heating rates at or below 2° K/min and the resulting measurements of the peak temperature of the first polyethylene melting endotherm are extrapolated to a heating rate of 0° K/min.
[0064] A “Parameter of Intrachain Cooperativity of the Melting Process”, represented by the Greek letter ν, has been defined by V. A. Bershtein and V. M. Egorov, in “Differential Scanning Calorimetry of Polymers: Physics, Chemistry, Analysis, Technology”, P. 141-143, Tavistoc/Ellis Horwod, 1993. This parameter is a measure of the number of repeating units, here taken as (—CH 2 —CH 2 —), that cooperatively participate in the melting process and is a measure of crystallite size. Higher values of ν indicate longer crystalline sequences and therefore a higher degree of order. The “Parameter of Intrachain Cooperativity of the Melting Process” is defined herein by Eq. 9.
v = 2 R T m 1 2 Δ T m 1 · Δ H 0 , dimensionless Eq . 9
where: R is the gas constant, 8.31 J/° K-mol
[0065] T m1 is the peak temperature of the first polyethylene melting
[0066] endotherm at a heating rate extrapolated to 0° K/min, ° K
[0067] ΔT m1 is the width of the first polyethylene melting endotherm, ° K
[0068] ΔH 0 is the melting enthalpy of —CH 2 —CH 2 — taken as 8200 J/mol
[0069] The multi-filament yarns of the invention are comprised of filaments having a “Parameter of Intrachain Cooperativity of the Melting Process”, ν, of at least 535, preferably at least 545. more preferably at least 555, and most preferably from 545 to 1100.
[0000] 3. X-Ray Diffraction
[0070] A synchrotron is used as a source of high intensity x-radiation. The synchrotron x-radiation is monochromatized and collimated. A single filament is withdrawn from the yarn to be examined and is placed in the monochromatized and collimated x-ray beam. The x-radiation scattered by the filament is detected by electronic or photographic means with the filament at room temperature (˜23° C.) and under no external load. The position and intensity of the (002) reflection of the orthorhombic polyethylene crystals are recorded. If upon scanning across the (002) reflection, the slope of scattered intensity versus scattering angle changes from positive to negative twice, i.e., if two peaks are seen in the (002) reflection, then two orthorhombic crystalline phases exist within the fiber.
[0071] The following examples are presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles of the invention are exemplary and should not be construed as limiting the scope of the invention.
EXAMPLES
Comparative Example 1
[0072] An UHMWPE gel-spun yarn designated SPECTRA® 900 was manufactured by Honeywell International Inc. in accord with U.S. Pat. No. 4,551.296. The 650 denier yarn consisting of 60 filaments had an intrinsic viscosity in decalin at 135° C. of about 15 dl/g. The yarn tenacity was about 30 g/d as measured by ASTM D2256-02, and the yarn contained less than about 1 wt. % of other constituents. The yarn had been stretched in the solution state, in the gel state and after removal of the spinning solvent. The stretching conditions did not fall within the scope of equations 1 to 4 of the present invention.
[0073] Filaments of this yarn were characterized by Raman spectroscopy using a Model RAMALOG® 5, monochromator spectrometer made by SPEX Industries, Inc., Metuchen, N.J., using a He—Ne laser and the methodology described herein above. The measured Raman spectrum, 1. and the extracted LAM-1 spectrum for this material, 3, after subtraction of the Lorenzian, 2, fitted to the Rayleigh background scattering are shown in FIG. 1 ( a ). The ordered-sequence length distribution function, F(L), for this material determined from the LAM-1 spectrum and equations 7 and 8 is shown in FIG. 2 ( a ). The peak value of the ordered-sequence length distribution function, F(L), was at a straight chain segment length L of approximately 12 nanometers (Table I).
[0074] Filaments of this yarn were also characterized by DSC using the methodology described hereinabove. The peak temperature of the first polyethylene melting endotherm at a heating rate extrapolated to 0° K/min. was 415.4° K. The width of the first polyethylene melting endotherm was 0.9° K. The “Parameter of Intrachain Cooperativity of the Melting Process”, ν, determined from Eq. 9 was 389 (Table I).
[0075] A single filament taken from this yarn was examined by x-ray diffraction using the methodology described hereinabove. Only one peak was seen in the (002) reflection (Table 1).
Comparative Example 2
[0076] An UHMWPE gel-spun yarn designated SPECTRA® 1000 was manufactured by Honeywell International Inc. in accord with U.S. Pat. Nos. 4,551,296 and 5,741,451. The 1300 denier yarn consisting of 240 filaments had an intrinsic viscosity in decalin at 135° C. of about 14 dl/g. The yarn tenacity was about 35 g/d as measured by ASTM D2256-02, and the yarn contained less than 1 wt. % of other constituents. The yarn had been stretched in the solution state, in the gel state and after removal of the spinning solvent. The stretching conditions did not fall within the scope of equations 1 to 4 of the present invention.
[0077] Filaments of this yarn were characterized by Raman spectroscopy using a Model RAMALOG® 5, monochromator spectrometer made by SPEX Industries, Inc., Metuchen, N.J., using a He—Ne laser and the methodology described hereinabove. The ordered-sequence length distribution function, F(L), for this material determined from the LAM-1 spectrum and equations 7 and 8 is shown in FIG. 2 ( b ). The peak value of the ordered-sequence length distribution function, F(L), was at a straight chain segment length L of approximately 33 nanometers (Table I).
[0078] Filaments of this yarn were also characterized by DSC using the methodology described hereinabove. The peak temperature of the first polyethylene melting endotherm at a heating rate extrapolated to 0° K/min, was 415.2° K. The width of the first polyethylene melting endotherm was 1.3° K. The “Parameter of Intrachain Cooperativity of the Melting Process”, ν, determined from Eq. 9 was 466 (Table I).
[0079] A single filament taken from this yarn was examined by x-ray diffraction using the methodology described hereinabove. Only one peak was seen in the (002) reflection (Table 1).
Comparative Examples 3-7
[0080] UHMWPE gel spun yarns from different lots manufactured by Honeywell International Inc. and designated either SPECTRA® 900 or SPECTRA® 1000 were characterized by Raman spectroscopy, DSC, and x-ray diffraction using the methodologies described hereinabove. The description of the yarns and the values of F(L) and ν are listed in Table I as well as the number of peaks seen in the (002) x-ray reflection.
Example of the Invention
[0081] An UHMWPE gel spun yarn was produced by Honeywell International Inc. in accord with U.S. Pat. No. 4,551,296. The 2060 denier yarn consisting of 120 filaments had an intrinsic viscosity in decalin at 135° C. of about 12 dl/g. The yarn tenacity was about 20 g/d as measured by ASTM D2256-02. and the yarn contained less than about 1 wt. % of other constituents. The yarn had been stretched between 3.5 and 8 to 1 in the solution state between 2.4 to 4 to 1 in the gel state and between 1.05 and 1.3 to 1 after removal of the spinning solvent.
[0082] The yarn was fed from a creel, through a set of restraining rolls at a speed (V 1 ) of about 25 meters/min into a forced convection air oven in which the internal temperature was 155±1° C. The air circulation within the oven was in a turbulent state with a time-averaged velocity in the vicinity of the yarn of about 34 meters/min.
[0083] The feed yarn passed through the oven in a straight line from inlet to outlet over a path length (L) of 14.63 meters and thence to a second set of rolls operating at a speed (V 2 ) of 98.8 meters/min. The yarn was cooled down on the second set of rolls at constant length neglecting thermal contraction. The yarn was thereby drawn in the oven at constant tension neglecting the effect of air drag. The above drawing conditions in relation to Equations 1-4 were as follows:
0.25 ≦[L/V 1 =0.59]≦20, min Eq. 1
3 ≦[V 2 /V 1 =3.95≦20 Eq. 2
1.7≦( V 2 −V 1 )/ L= 5.04]≦60, min −1 Eq. 3
0.20≦[2 L /( V 1 +V 2 )=0.24]≦10, min Eq. 4
Hence, each of Equations 1-4 was satisfied.
[0084] The denier per filament (dpf) was reduced from 17.2 dpf for the feed yarn to 4.34 dpf for the drawn yarn. Tenacity was increased from 20 g/d for the feed yarn to about 40 g/d for the drawn yarn. The mass throughput of drawn yarn was 5.72 grams/min per yarn end.
[0085] Filaments of this yarn produced by the process of the invention were characterized by Raman spectroscopy using a Model RAMALOG® 5, monochromator spectrometer made by SPEX Industries, Inc., Metuchen, N.J., using a He—Ne laser and the methodology described hereinabove. The ordered-sequence length distribution function, F(L), for this material determined from the LAM-1 spectrum and equations 7 and 8 is shown in FIG. 2 ( c ). The peak value of the ordered-sequence length distribution function, F(L), was at a straight chain segment length L of approximately 67 nanometers (Table I).
[0086] Filaments of this yarn were also characterized by DSC using the methodology described hereinabove. DSC scans at heating rates of 0.31° K/min, 0.62° K/min, and 1.25° K/min are shown in FIG. 3 . The peak temperature of the first polyethylene melting endotherm at a heating rate extrapolated to 0° K/min, was 416.1° K. The width of the first polyethylene melting endotherm was 0.6° K. The “Parameter of Intrachain Cooperativity of the Melting Process”, ν, determined from Eq. 9 was 585 (Table I).
[0087] A single filament taken from this yarn was examined by x-ray diffraction using the methodology described hereinabove. An x-ray pinhole photograph of the filament is shown in FIG. 4 . Two peaks were seen in the (002) reflection.
TABLE I L, nm ν, No. of Ex. or at dimen- (002) Comp. peak sion- X-Ray Ex. No. Identification Denier/Fils of F(L) less Peaks Comp. SPECTRA ® 650/60 12 389 1 Ex. 1 900 yarn Comp. SPECTRA ® 1300/240 33 466 1 Ex. 2 1000 yarn Comp. SPECTRA ® 650/60 28 437 1 Ex. 3 900 yarn Comp. SPECTRA ® 1200/120 19 387 1 Ex. 4 900 yarn Comp. SPECTRA ® 1200/120 20 409 1 Ex. 5 900 yarn Comp. SPECTRA ® 1200/120 24 435 1 Ex. 6 900 yarn Comp. SPECTRA ® 1300/240 17 467 1 Ex. 7 1000 yarn Example Inventive 521/120 67 585 2 Fiber
[0088] It is seen that filaments of the yarn of the invention had a peak value of the ordered-sequence length distribution function, F(L), at a straight chain segment length, L, greater than the prior art yarns. It is also seen that filaments of the yarn of the invention had a “Parameter of Intrachain Cooperativity of the Melting Process”, ν, greater than the prior art yarns. Also, this appears to be the first observation of two (002) x-ray peaks in a polyethylene filament at room temperature under no load.
[0089] Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to but that further changes and modifications may suggest themselves to one skilled in the art all falling with the scope of the invention as defined by the subjoined claims.
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Gel-spun multi-filament polyethylene yarns possessing a high degree of molecular and crystalline order, and to the drawing methods by which they are produced. The drawn yarns are useful in impact absorption and ballistic resistance for body armor, helmets, breast plates, helicopter seats, spall shields, and other applications; composite sports equipment such as kayaks, canoes, bicycles and boats; and in fishing line, sails, ropes, sutures and fabrics.
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BACKGROUND
The useful lifetime of a capacitive power storage device is affected by the voltage level stored on the capacitor(s) of the device. If capacitors in a series circuit configuration are not voltage balanced, some may wear out sooner than others. FIG. 1 shows a conventional circuit to balance (equalize) the voltage across capacitors C 1 and C 2 in series.
A disadvantage of this circuit is that resistor R B has to be selected to provide significant current draw I B1 and I B2 in order to achieve acceptable voltage equalization. However, a small value for R B causes larger power consumption.
Another disadvantage of this circuit is that the leakage current I L1 and I L2 of each capacitor is influenced by temperature, making it difficult to determine the difference between each capacitor's leakage current. Another disadvantage is that leakage current increases as the capacitors age, making the circuit less and less effective with time. Yet another disadvantage is that it takes a long time to balance the capacitor voltages. This reduces the useful life time of the capacitors especially in temperature environments.
A circuit such as the one described in co-assigned application no. US 20120224445 functions better than the passive voltage balance circuit of FIG. 1 . However, there are drawbacks to such a circuit. For example, it is difficult to eliminate the side effects of “firmware halts” of the circuit in systems utilizing the capacitors for power, especially when balancing is underway. Second, it is difficult to balance multiple capacitors in series because the software of said systems typically executes step by step, instead of in parallel as the balancing hardware does.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, the same reference numbers and acronyms identify elements or acts with the same or similar functionality for ease of understanding and convenience. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.
FIG. 1 is a diagram of a prior art circuit for balancing the voltages on capacitors arranged in series.
FIG. 2 is an improved balancing circuit for capacitors arranged in series.
FIG. 3 illustrates an embodiment of a drive circuit for the balancing circuit of FIG. 2 .
FIG. 4 and FIG. 5 illustrate, respectively, an alternate embodiment of a balancing circuit and a drive circuit for a series capacitor arrangement.
DETAILED DESCRIPTION
References to “one embodiment” or “an embodiment” do not necessarily refer to the same embodiment, although they may. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number respectively, unless expressly limited to a single one or multiple ones. Additionally, the words “herein,” “above,” “below” and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. When the claims use the word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list and any combination of the items in the list, unless expressly limited to one or the other.
“Logic” refers to machine memory circuits, machine readable media, and/or circuitry which by way of its material and/or material-energy configuration comprises control and/or procedural signals, and/or settings and values (such as resistance, impedance, capacitance, inductance, current/voltage ratings, etc.), that may be applied to influence the operation of a device. Magnetic media, electronic circuits, electrical and optical memory (both volatile and nonvolatile), and firmware are examples of logic.
Those skilled in the art will appreciate that logic may be distributed throughout one or more devices, and/or may be comprised of combinations memory, media, processing circuits and controllers, other circuits, and so on. Therefore, in the interest of clarity and correctness logic may not always be distinctly illustrated in drawings of devices and systems, although it is inherently present therein.
The techniques and procedures described herein may be implemented via logic distributed in one or more computing devices. The particular distribution and choice of logic is a design decision that will vary according to implementation.
DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS
Referring to FIG. 2 , a resistor divided circuit 203 on node A divides the power supply output voltage VCC_CAP to form the reference voltage Vref. The voltage Vref is provided to the positive input of each of comparators 207 , 209 . Vref is set by the resistors (n−1)R0, e.g. 200K, and R0, e.g. 50K, to (1/n)*VCC_CAP.
The resistor divided circuit 205 at node C, e.g. 300K/100K, divides the voltage Uc on capacitor C i (e.g., 22 F) to form the voltage provided to the negative input of comparator 207 . A similar divider circuit may be located at each capacitor node in the series arrangement. The divided voltage value at node D is (1/i)*Vci, where Vci is the voltage on capacitor Ci. When i=1, the voltage provided to the negative input of the associated comparator via resistor R 1 (e.g., 100K) is Vc1. Not shown but potentially present are capacitors shunting each comparator input to ground, e.g. 1 nF.
There are n−1 comparators. The comparators compare the feedback voltage for C 1 to C n−1 with Vref. The drive circuits 212 , 214 charge or discharge the voltage on C 1 to C n−1 according the signals sent out by the comparators 207 , 209 . Consider the voltage on C i as an example. V c is the voltage on node C, V D is the voltage on node D, and so on. The circuit will maintain:
Vc =( i/n ) VCC _ CAP=i *Vref
If Vc<i*Vref, V D <Vref. V F will be high. Drive circuit 212 will output a positive current (source current) to charge the capacitors between node C and ground (C 1 . . . C i ). If V C >i*Vref, drive circuit 212 will output negative current (sink) to discharge the capacitors between node C and ground (C 1 . . . C i ).
The leakage current of the capacitors doesn't influence the circuit's performance. The precision of the circuit is determined by the precision of the dividing resistors (R0 multiples) and their temperature characteristics. The power consumption of the circuit is mainly determined by the dividing resistors and is typically small (the divided resistors can be 100 KΩ), and by the comparators 207 , 209 .
The switch 216 may be used to switch the output power of the circuit between primary power from an external system, and backup power from the capacitors C 1 . . . Ci in the event primary power fails or is disconnected. Circuits that may be powered from the backup power when primary power fails include, in one implementation, memory circuits 218 .
Referring to FIG. 3 , when the comparator 212 outputs a high voltage, Q 33 is closed. Q 33 closed makes Q 32 open and Q 31 close. The voltage VCC_CAP causes source current through Q 31 , Q 34 and R 34 (e.g., 4.7 ohms). When the comparator 212 outputs low voltage, Q 33 is open. Q 33 open makes Q 31 open and Q 32 close. Vc discharges through R 36 , Q 32 and Q 35 . R 34 and Q 34 form a circuit to limit the output source current. R 35 (e.g., 4.7 ohms) and Q 35 form a circuit to limit the output sink current. D 31 and D 32 are zener and/or other components that prevent both Q 31 and Q 32 from closing at the same time during Q 33 switching. Examples for R 33 and R 36 are 100 KOhms for each.
The following balancing example applies to a series arrangement of five capacitors having a 10V total charge across the full series, and limited source current and sink currents of 150 mA. In this example C 1 =C 2 . . . =C 5 =22 F. At the beginning of the example, one capacitor (Ci) is unbalanced, with a voltage across its terminals equal to 2.5V. A balanced voltage on Ci of 2V is desired.
The current is limited to I=150 mA, so the time to balance the capacitor voltage is
t
=
C
i
Δ
U
ci
I
=
22
*
0.5
0.15
=
74
(
s
)
This example circuit will balance the series capacitor arrangement after approximately 74 seconds. This compares with the passive balancing of the circuit of FIG. 1 which may take around three hours to complete.
A P-channel MOSFET or other switch may be used to shut off the power supply to the comparators in the drive circuits under certain conditions, for example while using the capacitors as a backup power source. When a primary power source (a power source that does not use power from the capacitors) is unavailable, active balancing of the capacitors may be suspended. In one implementation the power supply of the comparators 207 , 209 is provided from a (primary) power supply external to a module that includes the capacitors C 1 . . . Ci. In other words, the capacitors C 1 . . . Ci, comparators 207 , 209 , and drive circuits 212 , 214 are part of a package with a modular interface to a larger system, which may be installed and removed from the larger system (host) as a pluggable module package. The primary supply is provided by the host into the module to power components such as volatile and nonvolatile memory, and is the same power supply that the capacitors are designed to replace as a backup power source when the primary supply fails or is disconnected from the module. Thus in one implementation, the comparators are powered from the primary power source from outside the module, and do not receive backup power from the capacitors when primary power fails, while other module components may receive backup power from the capacitors when primary power fails or in disconnected.
The drive circuits continually operate to charge and discharge each capacitor in the series capacitor arrangement to keep the capacitor voltages equal to one another within an acceptable tolerance. The balancing accuracy depends on the tolerance of the dividing resistors R 0 and on the comparator's operating parameters. One aspect of this design is that the switches in the drive circuits generate heat when they are operated.
FIG. 4-5 illustrate an implementation of a balancing circuit for a series capacitor arrangement in which two reference voltages are obtained by dividing the voltage Vcc_cap. Resistors R 62 , R 61 , and R 60 form a two-way voltage divider, creating two reference voltages Vref 1 and Vref 2 from Vcc-cap. For example, Vref 1 =(1+0.5%)*Vref and Vref 2 =(1−0.5%)*Vref, where Vref=Vcc_cap in this example. Let V be the voltage Ci. If V>Vref 1 *i, comparator Cp 62 outputs a high voltage and comparator Cp 61 outputs a low voltage. Switch Q 71 opens and switch Q 72 closes to discharge the voltage of Ci. If V<Vref 2 *i, comparator Cp 61 outputs a high voltage and comparator Cp 62 outputs a low voltage. Switch Q 71 closes and switch Q 72 opens to charge the voltage of capacitor C 1 . If Vref 2 *i<V<Vref 1 *i, then both comparator Cp 61 and comparator Cp 62 output low voltages and both switches Q 71 and Q 72 open. The voltage on capacitor C 1 remains unchanged.
Rx 2 is a current limited resistor, e.g. 100 Kohm. RD and RX form a voltage divider. RD is for example 100 Kohm. The value selected for Rx will typically vary with the node of the capacitor arrangement to which it is coupled. For node Ci, Rx=(i−1)*RD. Capacitances (e.g., 1 nF) may shunt each input of the comparators to ground.
The embodiment illustrated in FIG. 4-5 utilizes twice the number of comparators as the embodiment illustrated in FIG. 2-3 , but does not require the utilization of diodes. Although the illustrated embodiment uses resistors to limit current in the circuits, it would be understood by those skilled in the art that other current limiting circuits with perhaps more advantageous features as are known in the art may be used to provide a faster balancing of the circuits or other advantages (such as lower current consumption). The balancing circuits and in particular the switches in the embodiment illustrated in FIG. 4-5 do not operate when an associated capacitor in the series capacitor arrangement is in balance. The switches do not switch as frequently as they do in the embodiment illustrated in FIG. 2-3 , so that heat is less of a concern.
The resistors R 62 , R 61 and R 60 construct a circuit to generate Vref 1 and Vref 2 . Vref 1 is the maximum and Vref 2 is the minimum voltage for balancing the capacitors. If the voltage on any capacitor drifts outside this range, the drive circuits activate to balance the capacitors' voltages. The range of Vref 1 and Vref 2 may be designed
Vref1=(1+ε %)VCC CAP /N
Vref2=(1−ε %)VCC CAP /N
Where ε % can be 0.5%, 1%, 2% according the tolerance setting of the circuit (as set by the resistors R 60 -R 62 ).
Implementations and Alternatives
A circuit may be designed in which operational amplifiers (op amps) are utilized to balance the capacitor series arrangement directly. However, there are several disadvantages to this approach. Many op-amps do not have sink and source current capability, or if they do, such capability is limited. This makes it impractical to use many types of op amps to directly drive current into or sink current from the capacitors. Furthermore, op amps typically cannot deliver or sink current fast enough for many balancing applications or requirements, especially at higher temperatures. Op-amps would typically need to utilize a current-limiting resistor that would lower their efficiency as a source or sink of balancing current in many cases. Further still, using op-amps to directly balance the capacitors might require that the power supply for the op-amps be at least as high as the overall voltage across the series arrangement of capacitors, which might be a prohibitively high power supply voltage for many applications.
The techniques and procedures described herein may be implemented via logic distributed in one or more computing devices. The particular distribution and choice of logic is a design decision that will vary according to implementation.
Those having skill in the art will appreciate that there are various logic implementations by which processes and/or systems described herein can be effected (e.g., hardware, software, and/or firmware), and that the preferred vehicle will vary with the context in which the processes are deployed. “Software” refers to logic that may be readily readapted to different purposes (e.g. read/write volatile or nonvolatile memory or media). “Firmware” refers to logic embodied as read-only memories and/or media. Hardware refers to logic embodied as analog and/or digital circuits. If an implementer determines that speed and accuracy are paramount, the implementer may opt for a hardware and/or firmware vehicle; alternatively, if flexibility is paramount, the implementer may opt for a solely software implementation; or, yet again alternatively, the implementer may opt for some combination of hardware, software, and/or firmware. Hence, there are several possible vehicles by which the processes described herein may be effected, none of which is inherently superior to the other in that any vehicle to be utilized is a choice dependent upon the context in which the vehicle will be deployed and the specific concerns (e.g., speed, flexibility, or predictability) of the implementer, any of which may vary. Those skilled in the art will recognize that optical aspects of implementations may involve optically-oriented hardware, software, and or firmware.
The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood as notorious by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in standard integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and/or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies equally regardless of the particular type of signal bearing media used to actually carry out the distribution. Examples of a signal bearing media include, but are not limited to, the following: recordable type media such as floppy disks, hard disk drives, CD ROMs, digital tape, and computer memory.
In a general sense, those skilled in the art will recognize that the various aspects described herein which can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or any combination thereof can be viewed as being composed of various types of “circuitry.” Consequently, as used herein “circuitry” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), circuitry forming a memory device (e.g., forms of random access memory), and/or circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment).
Those skilled in the art will recognize that it is common within the art to describe devices and/or processes in the fashion set forth herein, and thereafter use standard engineering practices to integrate such described devices and/or processes into larger systems. That is, at least a portion of the devices and/or processes described herein can be integrated into a network processing system via a reasonable amount of experimentation.
The foregoing described aspects depict different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality.
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A circuit includes a series arrangement of capacitors and a balancing circuit coupled to the series arrangement of capacitors, the balancing circuit having drive circuits each coupled at a node in the series arrangement at which two of the capacitors are coupled in series. The drive circuit includes an output stage having switches arranged to either push or pull current from a drive circuit output depending on the state of the switches.
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[0001] This application claims the priority benefit of FR Patent application number 14/62091, filed on Dec. 9, 2014, the contents of which is hereby incorporated by reference in its entirety to the maximum extent allowable by law.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to the field of high frequency attenuators, and also to the field of high frequency attenuators with variable attenuation for device testing.
[0004] 2. Description of the Related Art
[0005] In certain applications, it may be desirable to provide an attenuator capable of attenuating high frequency signals, for example having a frequency higher than 120 GHz, and up to 175 GHz or more.
[0006] For example, in the field of high frequency device characterization, a device under test may be driven with a high frequency input signal, and one or more output signals of the device under test are detected using a probe in order to determine characteristics of the device. In order to be able to accurately detect an output signal over a relatively broad voltage range, one or more attenuators are for example provided for reducing the voltage level of the output signal.
[0007] There is however a difficulty in providing an attenuator capable of providing a relatively low level of attenuation, for example as low as −6 dB.
[0008] Furthermore, there is a difficulty in providing an attenuator having a variable attenuation and/or that can operate over a relatively broad bandwidth, for example of 20 GHz or more.
BRIEF SUMMARY
[0009] According to one aspect, there is provided an attenuator comprising: a first circuit including a common collector or common drain amplifier formed of a first transistor having its control node connected to an input of the attenuator and its emitter or source connected to an intermediate node of the attenuator; and a second circuit including a common collector or common drain amplifier formed of a second transistor having its emitter or source connected to the intermediate node and its control node connected to an output of the attenuator.
[0010] According to an embodiment, the emitter or source of the first transistor is further connected to a first variable current source and the emitter or source of the second transistor is further connected to a second variable current source.
[0011] According to an embodiment, the first variable current source is a third transistor receiving at its control node a biasing voltage and the second variable current source is a fourth transistor receiving at its control node the biasing voltage.
[0012] According to an embodiment, the attenuator further comprises a control circuit for generating the biasing voltage based on a control signal.
[0013] According to an embodiment, the control node of the first transistor is coupled to the input of the attenuator via the series connection of a first capacitor and a first waveguide, and the control node of the second transistor is coupled to the output node of the attenuator via the series connection of a second capacitor and a second waveguide.
[0014] According to an embodiment, the emitter or source of the first transistor is coupled to the intermediate node via the series connection of a third capacitor and a third waveguide and the emitter or source of the second transistor is coupled to the intermediate node via the series connection of a fourth capacitor and a fourth waveguide.
[0015] According to a further aspect, there is provided a probe comprising: an integrated circuit comprising the above attenuator connected to at least one input pin suitable for connecting an output pad of a device under test to the integrated circuit.
[0016] According to an embodiment, the integrated circuit comprises a matching network connecting the attenuator to the at least one input pin.
[0017] According to an embodiment, the integrated circuit further comprises: a first power detector, the attenuator and first power detector being both connected to the at least one input pin via a splitter; and a second power detector connected to the output of the attenuator.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] The foregoing and other features and advantages will become apparent from the following detailed description of embodiments, given by way of illustration and not limitation with reference to the accompanying drawings, in which:
[0019] FIG. 1 schematically illustrates an attenuator according to an embodiment of the present disclosure;
[0020] FIG. 2 schematically illustrates a test system according to an embodiment of the present disclosure; and
[0021] FIG. 3 schematically illustrates a detection and attenuation circuit of the test system of FIG. 2 in more detail according to an example embodiment.
DETAILED DESCRIPTION
[0022] In the following description, an attenuator is described in relation to the particular application of device characterization. Such an attenuator can however be used in any of a broad range of applications where the attenuation of high frequency signals is desired. For example, possible alternative applications include wireless receivers, or variable gain amplifiers in wireless transmitters.
[0023] The term “approximately” as used herein implies a tolerance of plus or minus 10 percent of the value in question.
[0024] FIG. 1 illustrates an attenuator 100 , which is for example implemented on an integrated circuit, in other words as an “on-chip” solution.
[0025] The attenuator 100 comprises a circuit portion 100 A on the left-hand side having elements referenced with the suffix “A”, and a circuit portion 100 B on the right-hand side having elements referenced with the suffix “B”. It will be noted that the circuit portions 100 A, 100 B are broadly symmetrical with each other around an intermediate node 101 of the attenuator.
[0026] The circuit 100 A comprises a common-collector amplifier formed of an npn bipolar transistor 102 A having its base coupled to an input 103 of the attenuator. This input 103 receives an input signal RF IN . The emitter of the bipolar transistor 102 A is connected to a variable current source 104 A. In the example of FIG. 1 , the variable current source 104 A is implemented by a MOS transistor having its source connected to ground and receiving, at its gate, a control voltage V BIAS . The emitter of the bipolar transistor 102 A is also coupled to the intermediate node 101 of the attenuator.
[0027] Similarly, the circuit 100 B comprises a common-collector amplifier formed of an npn bipolar transistor 102 B having its base coupled to an output 105 of the attenuator. This output 105 provides an output signal RF OUT . The emitter of the bipolar transistor 102 B is connected to a variable current source 104 B. In the example of FIG. 1 , the variable current source 104 B is implemented by a MOS transistor having its source connected to ground and receiving, at its gate, the control voltage V BIAS . The emitter of the bipolar transistor 102 B is also coupled to the intermediate node 101 of the attenuator.
[0028] In alternative embodiments, the bipolar transistors 102 A, 102 B could be replaced by MOS transistors, such that they form common drain amplifiers rather than common collector amplifiers. Furthermore, in some embodiments, the variable current sources 104 A, 104 B could be implemented by other types of devices, such as bipolar transistors.
[0029] The circuits 100 A, 100 B of FIG. 1 for example further comprise other elements adapted to improve the circuit characteristics at high frequencies.
[0030] For example, the circuit 100 A comprises a waveguide 106 A connected between the collector of the bipolar transistor 102 A and a supply voltage rail V cc . A capacitor 108 A is for example connected between the supply voltage rail V cc and ground for RF and DC decoupling. Furthermore, the base of the transistor 102 A is for example connected to a supply voltage rail V bb via a resistor 110 A, and to one node of a capacitor 112 A. The capacitor 112 A for example provides low frequency isolation of the base of the transistor 102 A from the input RF signal as well as RF and DC decoupling, and for example has a capacitance in a range 30 to 150 fF, for example approximately 50 fF. The other node of capacitor 112 A is for example connected via a waveguide 114 A and a further waveguide 116 A to the input node 103 . A ground stub, in the form of a further waveguide 120 A, for example connects an intermediate node 122 A between the waveguides 114 A and 116 A to ground. The emitter of transistor 102 A is for example connected to the intermediate node 101 via the series connection of a capacitor 126 A and a waveguide 128 A. The capacitor 126 A for example has a capacitance in the range 50 to 150 fF, and for example of approximately 50 fF. Similarly, the circuit 100 B for example comprises a waveguide 106 B connected between the collector of the bipolar transistor 102 B and a supply voltage rail V cc . A capacitor 108 B is for example connected between the supply voltage rail V cc and ground. Furthermore, the base of the transistor 102 B is for example connected to a supply voltage rail V bb via a resistor 110 B, and to one node of a capacitor 112 B. The capacitor 112 B for example has a capacitance equal to that of the capacitor 112 A. The other node of capacitor 112 B is for example connected via a waveguide 114 B and a further waveguide 116 B to the output node 105 . A ground stub, in the form of a further waveguide 120 B, for example connects an intermediate node 122 B between the waveguides 114 B and 116 B to ground. The emitter of transistor 102 B is for example connected to the intermediate node 101 via the series connection of a capacitor 126 B and a waveguide 128 B. The capacitor 126 B for example has the same capacitance as capacitor 126 A.
[0031] The intermediate node 101 between the two circuits 101 A, 101 B is for example connected to ground via a further waveguide 132 .
[0032] A control block (CTRL) 134 for example generates the biasing voltage V BIAS provided to the gates of transistors 104 A, 104 B based on a control signal G indicating a desired attenuation of the attenuator. In some embodiments, the value of the control signal G is a digital value programmed by a user. In other embodiments, the control signal G is for example a voltage signal, and could be generated by other circuits not represented in FIG. 1 , for example in the case that the attenuation is automatically adapted based on a feedback loop.
[0033] The present inventors have found that, by providing an attenuator having circuit portions each comprising an amplifier connected in a symmetrical fashion with respect to an intermediate node, the attenuation provided by the attenuator can be relatively constant over a large frequency bandwidth of over 20 GHz, and for example for a frequency bandwidth of up to 40 GHz or more. For example, the inventors have found that the circuit of FIG. 1 is able to provide a relatively uniform attenuation at approximately −6 dB over the frequency band of 135 to 175 GHz. Furthermore, the input and output impedances of the attenuator can be precisely controlled, and well matched with each other.
[0034] An application of the attenuator 100 of FIG. 1 in a test system for a device under test will now be described with reference to FIGS. 2 and 3 .
[0035] FIG. 2 illustrates a test system 200 comprising an integrated circuit 201 comprising a device under test (DUT) 202 . The DUT 202 for example has connection pads, there being six in the example of FIG. 2 , three of which are input RF pads 203 , and three of which are output RF pads 204 .
[0036] The three input pads 203 are connected to a probe 206 via which input power is applied to the DUT in the form of one or more test signals. The probe 206 for example comprises output pins 210 for contacting the pads 203 , and a circuit 208 for generating the test signals applied to the pads 203 via the output pins 210 .
[0037] A further probe 212 is for example in contact with the three output pads 204 of the DUT 202 , and comprises pins 216 for respectively contacting the three pads 204 , and a test circuit 214 providing attenuation and detection. The test circuit 214 is for example adapted to measure parameters of the DUT, such as noise figure, optimum power, etc. The test circuit 214 is for example implemented by an integrated circuit positioned in the probe 212 , the pins 216 forming input pins of the integrated circuit. Thus, whereas prior art solutions generally connect the test circuit to the probe via a cable that can be tens of centimeters long, in the system 200 , the test circuit 214 is advantageously integrated within the probe. The output pads 204 of the DUT and the test circuit 214 can therefore be separated by a relatively short distance, for example in the order of several millimeters.
[0038] FIG. 3 schematically illustrates the test circuit 214 of FIG. 2 in more detail according to an example embodiment. As indicated above, this circuit is for example implemented by an integrated circuit.
[0039] The circuit 214 for example comprises an input 302 connected to one of the pins 216 of the probe 212 (not illustrated in FIG. 3 ). In the test circuit 214 , the input 302 is for example connected to the input of a matching network 304 , which for example has an input impedance of Z 1 , for example of approximately 50 ohms. The output impedance of the matching network 304 is for example equal to an impedance Z 2 , which may be the same as or different from the impedance Z 1 . In some embodiments, the output impedance Z 2 is equal to approximately 25 ohms.
[0040] The output of matching network 304 is connected to a power splitter 306 , which splits the signal into two parts, for example of approximately equal power. One of the outputs of the splitter 306 is connected to a power detector 308 , which detects the power of the signal. The other output of the splitter 306 is for example provided to an attenuator 310 , which is for example implemented by the circuit 100 of FIG. 1 . The input impedance of both the power detector 308 and of the attenuator 310 are for example chosen to be equal to the impedance Z 1 , and the output impedance of attenuator 310 is for example chosen to be equal to the impedance Z 2 . For example, in the case that the input and output impedances of the attenuator are different from each other, the attenuator may comprise, in addition to the circuit of FIG. 1 , a matching network at its output to bring the output impedance to the appropriate value.
[0041] FIG. 3 also illustrates a subsequent stage of power detection and attenuation, comprising a further splitter 312 , a further power detector 314 , and a further attenuator 316 . These elements are for example the same as the elements 304 , 308 and 310 respectively, and will not be described in detail. By providing several stages of attenuation and power detection, the circuit 214 is capable of detecting the power of the output signal of the DUT at various levels of attenuation, and thus for a broad range of the input power levels of the DUT.
[0042] An advantage of the attenuator described herein is that it is capable of providing a relatively low level of attenuation, for example as low as −6 dB. Furthermore, it is capable of providing a variable level of attenuation, by adjustment of the control value G. Furthermore, the attenuator is capable of operating over a relatively broad bandwidth, for example of 20 GHz or more.
[0043] Having thus described at least one illustrative embodiment, various alterations, modifications and improvements will readily occur to those skilled in the art.
[0044] For example, it will be apparent to those skilled in the art that the particular circuitry illustrated in FIG. 1 provides just one example implementation, and that different arrangements of waveguides, resistors and capacitors would be possible, and one or more of these components could be omitted, depending on the particular application.
[0045] Furthermore, it will be apparent that while a control circuit 134 is provided allowing the attenuation of the attenuator of FIG. 1 to be controlled, in some embodiments this control circuit could be omitted, the attenuator being adapted to provide a relatively constant attenuation. Furthermore, the variable current sources 104 A, 104 B could be replaced by elements of fixed impedance, such as by resistors or waveguides.
[0046] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
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An attenuator includes: a first circuit including a common collector or common drain amplifier formed of a first transistor having its control node connected to an input of the attenuator and its emitter or source connected to an intermediate node of the attenuator; and a second circuit including a common collector or common drain amplifier formed of a second transistor having its emitter or source connected to the intermediate node and its control node connected to an output of the attenuator.
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[0001] This application claims the benefit of U.S. Provisional Application No. 61/301,928, filed Feb. 5, 2010, and is a continuation-in-part of U.S. patent application Ser. No. 11/769,850, filed Jun. 28, 2007, which is a non-provisional of U.S. Provisional Application No. 60/836,737, filed Aug. 10, 2006, all of which are incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is in the field of biomass collection and preconditioning for subsequent refining into ethanol and other products. Specifically, the invention is directed to the collection of agricultural biomass over a large area so as to take advantage of economies of scale. According to embodiments, the biomass may be preconditioned to a selected pH, either in stockpiles, or at a centrally located plant prior to downstream processing.
[0004] 2. Description of the Related Art
[0005] In the search for alternatives to petroleum as a transportation fuel, ethanol has been seen to be of promise, at least as a supplement to petroleum-derived gasoline. Ethanol is derivable from sugar using relatively simple technology, and it is very well-characterized in its properties and its health and environmental impact, humankind having produced ethanol (beer, wine and distilled spirits) for thousands of years. Further, ethanol has had an established use as a motor vehicle fuel for decades; the Ford Model T, first introduced in 1908, was capable of using either gasoline or ethanol as its fuel (or a mixture, as used by automobiles in the U.S. today).
[0006] At the present time, the ethanol used for fuel is largely made from corn, specifically the seed of the plant (kernels), although from a technological standpoint almost any grain or fruit can be used. The corn kernels consist largely of starch, which is readily converted to sugar. Most basically, the sugar derived from corn is fermented, typically using a yeast, which digests the material and produces ethanol as a product of yeast metabolism. Although simple and based on well-established technology, corn-derived ethanol has been criticized for being inefficient and diverting food to fuel use, thus making the price of corn, animal feed and livestock higher.
[0007] In contrast to grain ethanol, ethanol from agricultural, forest and similar biomass (also referred to herein as cellulosic ethanol) is seen to have great promise in energy efficiency and green house gas reduction. The particular biomass of interest is the structural portion of the plant, such as grass straw and corn stalks, or the woody portion of trees. This plant matter is made of lignin and cellulose, and is a not source of food for people. In ethanol manufacture, the lignin is separated and used for fuel and the cellulosic material is converted to sugars. The sugars are fermented as with the grain to ethanol.
[0008] Manufacturing cellulosic ethanol (i.e., ethanol derived from cellulose) is also advantageous because it is sustainable over the long term. In addition, use of biomass as a feedstock for ethanol manufacture can result in no net green house gas emissions, in fact if carbon dioxide from the fermentation step is collected and sequestered, the net green house gas emissions for the entire fuel cycle (field to wheels) is negative. This is because the agricultural biomass removes more carbon dioxide from the atmosphere while it is growing than is emitted during biomass transportation, biomass processing to produce ethanol (when carbon dioxide from fermentation is sequestered), ethanol transportation and ethanol combustion in the vehicle.
[0009] U.S. Pat. No. 4,461,648 to Patrick Foody, herein incorporated by reference in its entirety, discloses technology in which cellulose is made accessible for chemical reaction by a process of steam explosion and chemical disintegration to break down the bonds between the lignin and cellulose in the biomass. During the 1970's, after the first “oil shock” occurred, the inventor was conducting research on making low-grade fiber and wood digestible to ruminant animals. He recognized that accessibility of these materials to ruminant animal microflora and accessibility to enzymes was in fact a very similar problem. Trials were conducted using steam explosion to fractionate the fiber. As it turned out, it was a much more difficult problem than simply “exploding” the fiber to fractionate the internal bonds, and involved a very narrow window across the time/temperature range at which the process could be optimized. Nevertheless, the result of these efforts, disclosed and claimed in U.S. Pat. No. 4,461,648, was a process that made the cellulose completely accessible to enzymes. This was the first breakthrough in the technology and arguably laid the foundation for biomass refining, as the science is currently called.
[0010] U.S. Pat. No. 5,916,780, to Brian Foody, et al., herein incorporated by reference in its entirety, discloses technology for pre-treating and transporting biomass, especially as it relates to the production of ethanol.
[0011] In order to be viable, cellulosic ethanol must overcome advantages that accrue to its industrial competitors, the grain ethanol and petroleum industries. One of these advantages is that the road, rail, pipeline and river infrastructure for transporting conventional energy products is already in place.
[0012] Biomass of the type at issue hereby its nature is at a significant cost and handling disadvantage as compared to these competitors. For example, grain, which is free flowing, weighs 40 lbs to 50 lbs per cubic foot, while biomass weighs 10 lbs per cubic foot in bales, and 5 lbs per cubic foot loose. The largest grain ethanol plants being currently built, without access to water or rail transportation, handle on the order of 2,500 tons per day. At a “test weight” of 5 lbs per cubic foot, the viability of a biomass refining system is largely dictated by access to road systems. The differential in the volume to be moved could challenge the capacity of most road systems.
[0013] Because transportation constraints act as a limiting factor on the size of a biomass-processing plant, most biomass projects are built well below optimum size.
[0014] In order to take advantage of the cheaper unit cost of agricultural biomass, it is estimated that a system capable of processing significantly in excess of 2,500 tons per day of biomass would be necessary for cellulosic ethanol to compete with easily refined starch based grain ethanol.
[0015] The oil industry, the other conventional competitor to biomass refining, has the advantage of “scale” and well established pipeline systems so that it can tolerate significantly higher raw material costs.
[0016] It is estimated that a cellulosic ethanol system capable of processing in excess of 10,000 tons per day of biomass would be required to compete with oil.
[0017] Further technological and scientific advances in materials handling and physical layouts are necessary to make ethanol from biomass commercially competitive with oil, especially with regard to the economies of scale. Japanese Patent No. JP2002330644 proposes a system for biomass collection. However this patent discloses a pneumatic system and does not adequately address the implementation of a large scale biomass collection and refining system.
[0018] Pipeline systems for moving woodchips are not uncommon, but these are normally used on a point-to-point basis. Peter C. Flynn, et al., Bioresource Technology, 96 (2005) 819-829 postulates a biomass refining system wherein the water may be pumped back either completely or in part to the beginning of the system. This requires two pipelines, as noted by the author, and is not economically viable.
[0019] An important object of this invention is to overcome the difficulties and expenses that arise in connection with handling large amounts of relatively light non-free flowing biomass. The inventor herein has developed a “loop” system for moving a ligno-cellulosic feedstock slurry along the same pipeline as the transportation water, as well as adding new biomass at more than one selected point along the pipeline. According to embodiments of the present invention, conventional delivery systems, except for local pick-ups, can be avoided altogether, in favor of the centralized and integrated network of loops described herein.
SUMMARY OF THE INVENTION
[0020] A biomass collection and refining system according to the invention comprises a biomass refining plant and at least one conduit loop having a plurality of collection points serially arranged along the conduit loop, whereby the conduit loop connects the collection points and the refining plant through a continuous circulating arrangement, so that a slurry of water and biomass is transported from the collection points to the refining plant and the transportation water is recovered and reintroduced along with recovered process water to the outgoing conduit. “Conduit,” as used herein includes, without limitation, pipes, canals, or like structures. Optionally, the system comprises a plurality of loops connecting the collection points and the refining plant. Also, each loop optionally has its outgoing leg adjacent its return leg, wherein a first in the series of collection points defines the beginning of the return leg and the remaining one or more collection points are located in the return leg.
[0021] The method according to the invention involves introducing biomass at a plurality of pick-up points (also referred to herein as “collection points”) serially arranged along the conduit loop. The biomass may arrive chopped, or some pH conditioning may be done at the collection points (or elsewhere along the transport path) for introduction into the cooking phase, as desired. The biomass is introduced into the incoming conduit to form a slurry of biomass and liquid (such as, without limitation, a 5 wt % solids mix in water) at one or more of the collection points and is transported through the incoming conduit connecting each of the collection points on a particular “loop” with the central refining plant where the biomass is subjected to cooking. Water is removed from the slurry at the refining plant, using a separating device, cane press, screw press, screens or the like apparatus, and reused for continual transport of biomass through one or more conduit loops.
BRIEF DESCRIPTION OF THE FIGURES
[0022] FIG. 1 depicts a single loop configuration showing the general relationship of a centrally located refining plant, an outgoing pipeline system leaving the plant, water being charged into the pipeline system, introduction of biomass at one or several points along the parallel incoming line, as well as the removal of the water for reuse. The biomass then goes into the refining plant.
[0023] FIG. 1A is a detail of FIG. 1 , depicting a typical water removal system using a centrifuge. Alternatively, a cane press, screw presses or the like water removal apparatus may be used.
[0024] FIG. 1B is a detail of FIG. 1 , depicting the details of a dropleg system to introduce solids into the pipeline to form a slurry. Alternative solids introduction apparatus may also be used.
[0025] FIG. 2 depicts a typical network configuration comprising three loops entering the refining plant.
[0026] FIG. 3 depicts another configuration in which six separate loops carry material into the refining plant
[0027] FIG. 4 shows the expansion of the system to twelve separate loops.
[0028] FIG. 5 shows the further expansion of the twelve-loop system to collect biomass from a larger region.
[0029] FIG. 6 shows an alternative embodiment of a twelve-loop system, in which the outgoing leg of each loop is located adjacent the return leg.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Biomass is grown crop fiber consisting primarily of cellulose, hemicellulose and lignin, and includes, without limitation, grass, switchgrass, straw, corn stover, cane residuals, general cereal wastes, wood chips and the like, that can be converted to ethanol (or other products) according to the aforesaid U.S. Pat. No. 4,461,648 and U.S. Pat. No. 5,916,780, or other known technology. Thus, as used herein, biomass includes materials that are not free flowing in their native state, such as ligno-cellulosic materials. The invention is intended to be used preferably in connection with the collection and transport of non-free flowing materials (ligno-cellulosic biomass), as these materials are conventionally the most intractable from a materials handling standpoint
[0031] An acre of arable land may produce as much as 18 tons of biomass per year (sugar cane), and typically 5 tons per acre of corn stover or switch grass in a temperate climate. To ensure an adequate supply, a system according to the invention is typically designed based on 0.67 tons of biomass per acre per year (cereal grain straw) or 1.34 tons of corn stover. This refers to the average amount of biomass obtainable, accounting for domestic disappearance (including the use of biomass for other purposes), alternative crops, and the like, not the maximum amount that the land will produce. Calculations based on genetically modified grass are also included in the Tables below.
[0032] As shown in FIG. 2 through FIG. 5 , collection points 20 preferably are in the center, or close to the center, of an agricultural area from which biomass will be obtained. These agricultural areas are represented as hexagons in the figures, although that representation is arbitrary, and some variation in the size, shape and topography of the collection areas will be expected. A maximum collection capacity for a facility according to the invention is preferably in a range of up to 50,000 tons per day, which could possibly require a network diameter of about 230 miles, or more. The term “network,” depicted for example as network diameter B in FIGS. 2-5 , refers to the diameter of the region bounded by the outermost conduits, for example. The number of collection points is not critical, and varies depending on the size of the network, and may range (for example only) between 7 and 100 collection points. Outline 22 is the extent of the agricultural areas serviced by all of the collection points 20 .
[0033] As shown in FIG. 2 , the size of the total collection area is based on plant processing capability. The following projections have been made based on a plant capacity of about 5,000 tons/day, 12,500 tons/day, 25,000 tons/day, and 40,000 tons/day, resulting in a distance across the entire collection area in a range of about 50 miles to about 200 miles.
[0000]
TABLE 1
(FIG. 2)
4,590 TPD
PLANT SIZE
TONS PER DAY
SWITCH
GENETICALLY
BIOMASS DENSITY
STRAW
GRASS/
MODIFIED
TONS/YEAR/ACRE
RESIDUAL
CORN STOVER
GRASS
0.667
1.333
2.667
DISTANCE ACROSS FLATS MILES
A
25.4
18.0
12.77
AVERAGE LOCAL HAUL MILES
D
8.47
6.0
4.25
MAX PERIMETER DISTANCE MILES
B
50.8
36.0
25.5
[0000]
TABLE 2
(FIG. 3)
12,456 TPD
PLANT SIZE
TONS PER DAY
SWITCH
GENETICALLY
BIOMASS DENSITY
STRAW
GRASS/
MODIFIED
TONS/YEAR/ACRE
RESIDUAL
CORN STOVER
GRASS
0.667
1.333
2.667
DISTANCE ACROSS FLATS MILES
A
25.4
18.0
12.77
AVERAGE LOCAL HAUL MILES
D
8.47
6.0
4.25
MAX PERIMETER DISTANCE MILES
B
101.6
72.0
51.1
[0000]
TABLE 3
(FIG. 4)
24,262 TPD
PLANT SIZE
TONS PER DAY
SWITCH
GENETICALLY
BIOMASS DENSITY
STRAW
GRASS/
MODIFIED
TONS/YEAR/ACRE
RESIDUAL
CORN STOVER
GRASS
0.667
1.333
2.667
DISTANCE ACROSS FLATS MILES
A
25.4
18.0
12.77
AVERAGE LOCAL HAUL MILES
D
8.47
6.0
4.25
MAX PERIMETER DISTANCE MILES
B
152.4
108.0
76.6
[0000]
TABLE 4
(FIG. 5)
40,000 TPD
PLANT SIZE
TONS PER DAY
SWITCH
GENETICALLY
BIOMASS DENSITY
STRAW
GRASS/
MODIFIED
TONS/YEAR/ACRE
RESIDUAL
CORN STOVER
GRASS
0.667
1.333
2.667
DISTANCE ACROSS FLATS MILES
A
25.4
18.0
12.77
AVERAGE LOCAL HAUL MILES
D
8.47
6.0
4.25
MAX PERIMETER DISTANCE MILES
B
203.2
144.0
102.2
[0034] Biomass feedstocks differ in terms of how much fuel may be produced from a ton of the feedstock, and in terms of which enzymes and other techniques are used for refining the feedstock. Typically 40 to 100 gallons of fuel can be produced from a ton of ligno-cellulosic biomass. It is preferable to have the biomass that is approximately uniform in size collected from the different collection points according to this invention to ease the task of refining.
[0035] A key advantage of the present invention is that the biomass is delivered to collection points by truck or farm wagons traveling a relatively short distance D to the collection points 20 . For example, in a system calculated to accumulate about 12,500 tons of biomass, comprising 19 collection points, with a little over 25 miles separating the adjacent collection points (distance A), as shown in FIG. 3 , and based on a collection of 0.67 tons of biomass per acre per year, the average distance D that would be traveled to a collection site would be on the order of 8.5 miles. This distance from pick-up points is suitable for local hauling, which can be done in a variety of ways by farmers. These numbers are for illustration only and are not to be considered limiting to the invention.
[0036] After delivery, the biomass is introduced into the slurry at the collection points 20 , for example using a dropleg 24 , so that a slurry is formed with the circulating water, as shown in FIG. 1B . The collection points themselves in one embodiment are located in collection areas on the order of one acre in area. The biomass is transported to these collection areas by truck and dumped onto the land for temporary storage; a front loader for example can then be used to move the feedstock such means as are provided to introduce the biomass into dropleg 24 .
[0037] In particular, in FIG. 1B biomass is introduced to dropleg 24 by conveyor 26 , water is supplied through supply line 28 and the water-biomass mixture is agitated by stirrers 32 to form a slurry. The slurry is pumped with a booster pump at 34 into the conduit network. The embodiment described is for illustration only. It is not necessary to use a dropleg. Alternative means, such as a star valve, extrusion screw feeder or the like conventional solids handling means may also be used.
[0038] The biomass is chopped beforehand, or at the collection point, preferably to a range of ½ inch to 1½ inch. A cane press or disk refiner may be used to fractionate the biomass so that it can be more easily contacted with the acid or alkali for pH adjustment. A cane press is probably more suited for grasses or straws while the disk refiner might be more applicable for wood chips.
[0039] The slurry is then transported to the next collection point by pumps provided at each collection point or at lift stations as required. The amount of water in the slurry may be determined by one of ordinary skill in the art, depending on the pump capacity, pipe size, etc. In the case of a conduit consisting of piping, it is contemplated that a slurry having a solids content of about 5 wt % is sufficiently transportable through the pipes. A standpipe, with a large diameter relative to the pipes in the network of pipes, may be used to accommodate pressure variations in the network, or the standpipe may be used in conjunction with a dropleg, star valve or extrusion screw feeder to input solids into the piping.
[0040] Another important aspect of the system is that water, once charged into the network, including excess recovered process water, is reused for transport and the amount of water in the system remains relatively constant, generally without requiring make-up water. Because the agricultural biomass contemplated for use in the present invention contains in a range of about 12 percent to about 50 percent moisture, the addition of biomass to the system results in an increase in the amount of circulating water in the system. A part of this water may be used up in the refining process, for example as steam, or water may be treated and discharged, as necessary, to maintain a constant amount of water in the network. In this context, a relatively constant amount of water will have the meaning ascribed to that term by one of ordinary skill in the art. Preferably, a relatively constant amount of water is an amount required to maintain a solids/liquids ratio of less than 15%. Typically, the amount of water in the system will not vary over the course of operation more than plus or minus 5%.
[0041] The network of conduits is arranged so that the refining plant is accessible from all of the collection points along an incoming conduit via a continuous path which carries the slurry of biomass and water to the centrally located refining plant. In FIG. 1 , the generalized loop diagram illustrates the conduits coming into the plant with feedstock, the water being recovered and fed back into the pipeline for transporting additional feedstock. In embodiments, the system is designed so that loops can be added to an existing network of conduits, as additional refining capacity is added, to bring the total production to the scale of a small oil refinery processing 90,000 to 100,000 barrels. These numbers are for illustration purposes only and are not to be considered limiting to the invention.
[0042] It is preferred that the conduit loops are sized so that 1000 tons/day or more can be collected from collection points in a single loop. A system may be provided with a plurality of conduit loops which can be operated independently, so that one or more loops can be removed from the system, from time to time. In the same manner additional loops can be added in the event more plant capacity and/or agricultural area is added.
[0043] The size of the pipes may be determined by one of ordinary skill in the art. For example, in the system shown in FIG. 3 , based on a system adapted to accumulate approximately 12,500 tons per day, incoming pipes having a diameter of approximately 24 inches could be effectively used, transporting slurry at approximately 5 ft/sec.
[0044] FIG. 2 depicts a loop system of three loops, a loop being defined as a continuous conduit system with each loop passing through the refiner and at least two collection points. A system of loops is a plurality of such loops.
[0045] Water is removed from the slurry at the refining plant using a cane press or other slurry water removal means known in the art, including without limitation, centrifugal apparatus, extruders, screens or filters. The water is thereafter recirculated in the network. In an embodiment depicted in FIG. 1A , solids-liquid separation is conducted in a solids-liquid separator such as centrifuge 42 . Separated solids are directed to refining plant 10 . Water recovered from the refining process 44 and water removed from the slurry 46 may be stored in water storage 48 which may then be used to supply water to the conduit network.
[0046] The use of this invention can be conducted in various ways. For example, it is possible to introduce biomass into the conduit loop at only one collection point at a time (serial utilization). This allows the user to employ only one loading crew, which travels from collection point to collection point to introduce into the conduit loop biomass previously delivered by truck to the collection point. Alternatively, biomass can be introduced into the conduit loop at a number of collection points at the same time (simultaneous utilization). Operation in such a manner would necessarily require multiple loading crews.
[0047] Where closed piping is employed for the conduit loop, the diameter of the piping in the outgoing leg prior to introduction of biomass at the first collection point need be of sufficient diameter only to carry the design circulating water flow. Past the first collection point, the piping needs to have a diameter sufficient to carry both the water and the introduced biomass. In the case where biomass is to be introduced into the conduit loop at only one collection point at a time, the diameter of the piping downstream of that collection point can be sized to have a diameter sufficient to carry both the water and the biomass introduced at a single collection point. In the case where biomass is to be introduced into the conduit loop at a number of collection points at the same time, the diameter of the piping downstream of each such collection point needs to have a diameter sufficient to carry both the water and the biomass introduced at all upstream collection points used simultaneously for biomass collection.
[0048] Accordingly, this invention can utilize a number of piping options. For example, the entire conduit loop can use piping of a single diameter, with that diameter sized to carry both the water and the biomass to be introduced simultaneously at all collection points. If only one collection point is to be utilized at a time, then the piping diameter in such a case need only be the diameter necessary to carry both the water and the biomass to be introduced from one collection point. Alternatively, the conduit loop can be made from piping sections of different diameter, where the diameter at any given section need only be sufficient to carry the water and the biomass to be introduced simultaneously at upstream collection points.
[0049] As depicted in the exemplary conduit arrangements of FIGS. 2 through 5 , the outgoing and return portions of the conduit loop are distal from each other (except adjacent the solids-liquid separation facility) and pass through separate agricultural areas. However, there are circumstances where it is advantageous to place the outgoing and return portions of the conduit loop adjacent one another. In situations where the conduit loop is to be below ground level, this allows the outgoing and return portions to be placed in the same trench, thereby simplifying obtaining the reguiste rights of way. Although there is no particular distance between outgoing and return portions mandated by the present invention, a distance of anywhere from touching to 10 meters would be preferred.
[0050] FIG. 6 depicts one embodiment in which outgoing and return portions of each conduit loop are adjacent each other. In particular, twelve conduit loops are utilized to collect ligno-cellulosic biomass feedstock from thirty-seven agricultural areas, and the outgoing and return portions of each loop are adjacent each other. In this disclosure, the “outgoing portion” (or leg) of a conduit loop is the portion of the conduit between the recirculating water discharge at the refinery and the first collection point, and the “return portion” (or leg) of a conduit loop is the portion of the conduit between the first collection point and the slurry intake of the refinery.
[0051] In the embodiment of FIG. 6 , six of the conduit loops, exemplified by loop 61 , have two collection points 63 and 64 . Collection point 63 is located geographically farthest from the biomass refinery at which all loops originate and return, whereas collection point 64 is placed intermediate between collection point 63 and the biomass refinery. It is preferred for collection point 64 to be located in the return portion of conduit loop 61 . Collection point 63 receives ligno-cellulosic biomass from agricultural regions 66 and 67 , which biomass is harvested and transported preferably by truck proximate to point 63 . Collection point 64 receives ligno-cellulosic biomass from agricultural region 65 . Thus, the outgoing portion of conduit loop 61 , if made of piping, can be sized to have a diameter sufficient to accommodate the design circulating water flow. The return portion of conduit loop 61 between collection points 63 and 64 , if made of piping, should be sized to have a diameter sufficient to accommodate the design circulating, water flow, plus the biomass introduced from agricultural regions 66 and 67 .
[0052] Correspondingly, the return portion of conduit loop 61 between collection point 64 and the biomass refinery should be sized to have a diameter sufficient to accommodate the design circulating water flow plus the biomass introduced from regions 65 , 66 and 67 , should collection points 63 and 64 be simultaneously utilized. Thus, in such a case, relative to the diameter of the outgoing portion of conduit loop 61 (where piping is employed), the diameter of the return portion of conduit loop 61 between points 63 and 64 optionally is greater to accommodate the larger volume flow (assuming the return slurry velocity approximates the outgoing recirculating water velocity), and the diameter of the return portion of conduit loop 64 and the biomass refinery is greater still.
[0053] In the case where collection points 63 and 64 are serially utilized, the diameter of the return portion of conduit loop 61 between points 63 and 64 can be the same as the return portion of conduit loop 61 between point 64 and the biomass refinery.
[0054] The sizing of the piping to accommodate the specific volume flow rate as described above allows for savings in piping costs.
[0055] In the embodiment of FIG. 6 , six of the conduit loops, exemplified by loop 71 , have only one collection point 72 . This collection point receives ligno-cellulosic biomass feedstock from three agricultural regions, depicted as regions 73 , 74 and 75 in FIG. 6 . In general, the number of loops per refinery, and the number of collection points per loop, can be varied to match the agricultural region and to optimize the costs.
[0056] Referring back to FIG. 4 and FIG. 5 , it can be desirable to combine the streams entering and leaving the refinery into larger diameter pipes 70 to reduce the overall length of pipe. In that context, it may be necessary to split the water stream coming from the refining plant or at later collection points to maintain the water balance. In this context, “splitting” means dividing a single larger stream into a plurality of smaller streams. The figures depict joining streams of slurry transported from two or more of the plurality of collection points into a single slurry stream directed to the refining plant and splitting the water removed from the slurry coming from the refining plant for recirculation.
[0057] As noted above, the particular biomass refining technology used is not critical to the operation of the collection system. A plant as described in the aforesaid U.S. Pat. Nos. 4,461,648 and 5,916,780 may be used. As noted therein, preconditioning followed by pretreatment is typically required to initially break the bonds between the lignin and cellulose. Thus, in the practice of this invention, acidic or basic circulating water can optionally be used so that preconditioning is effected in the circulating system. For an acid solution, a 2% sulfuric acid solution may be suitable for this purpose, with the exact requirements being determined based on the skill of one of ordinary skill in the art based on the feedstock and refining process being used.
[0058] The foregoing description of the preferred embodiments is for illustration only and is not to be deemed limiting of the invention, which is defined in the appended claims.
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A system for collecting ligno-cellulosic biomass over a large area to enable the commercial refining of biomass from 2,500 to in excess of 50,000 tons of biomass per day to produce ethanol or other products. The biomass is collected at a series of collection points and then transported through a network of conduit “loops” interconnecting each of the collection points and the central refining plant. The water used to transport the biomass, as a slurry, is recovered and sequentially recycled in the same pipeline system to push the biomass slurry around the system in a “loop.” The outgoing and return legs of each loop optionally are located adjacent each other.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an internal combustion engine of the piston-cylinder type having a spherical rotary valve assembly for the introduction of the fuel/air mixture to the cylinder and the evacuation of the exhaust gases, and is particularly directed to the floating valve seals for such rotary valve assembly and means for regulating pressure therein, particularly in long stroke, high compression engines such as diesels.
[0003] 2. Description of the Prior Art
[0004] The Applicant herein has directed considerable attention to the internal combustion engine of the piston-cylinder type and in particular to the replacement of the poppet valve system, including the poppet valve, springs, mountings and associated cam shaft, with a spherical rotary valve assembly for the introduction of the fuel air mixture into the cylinder and for the evacuation of the exhaust gases. Applicant is the named inventor in U.S. Pat. No. 4,989,576, “Internal Combustion Engine”; U.S. Pat. No. 4,944,261, “Spherical Rotary Valve Assembly for Internal Combustion Engine”; U.S. Pat. No. 4,953,527, “Spherical Rotary Valve Assembly for Internal Combustion Engine”; U.S. Pat. No. 4,976,232, “Valve Seal for Rotary Valve Engine”; U.S. Pat. No. 4,989,558, “Spherical Rotary Valve Assembly for Internal Combustion Engine”; U.S. Pat. No. 5,109,814, “Spherical Rotary Valve”; U.S. Pat. No. 5,361,739, “Spherical Rotary Valve Assembly for Use in a Rotary Valve Internal Combustion Engine”; and U.S. Pat. No. 6,308,676 B1, “Cooling System for Rotary Valve Engine”, and pending U.S. application Ser. No. 10/280,293. The aforementioned U.S. Patents are incorporated herein as if set forth in length and in detail.
[0005] The valve seal as described in Applicant's prior patents is a floating valve seal within a valve seat. The valve seal is positioned in the lower half of the split head assembly proximate the intake port and exhaust port for the cylinder. A biasing means is positioned within the valve seat and the valve seal is positioned above the biasing means. The upper surface of the valve seal is arcuate in shape conforming to the periphery of the rotary intake or rotary exhaust valve of the spherical rotary intake or spherical rotary exhaust valve assembly. The underbody of the valve seal sitting within the valve seat would have one or more sealing rings positioned thereabout in an annular sealing contact with the outer wall of the valve seat. In this configuration the valve seal floats within the valve seat and there is a slight gap between the inner wall of the valve seat and the valve seal which allows for the compressed gases to enter the valve seat through this gap and pressurize the area between the valve seal and the valve seat during the compression stroke which further provides for tight sealing contact between the valve seal and the spherical rotary intake and spherical rotary exhaust valves.
[0006] In short stroke engines, the assembly works without modification because of the relatively short stroke of the piston and the resultant pressures developed. However in long stroke engines, such as diesels, in which the compression is significantly greater than in a conventional internal combustion engine, and which compression actually results in the detonation of the fuel/air mixture under signficantly higher pressure, the valve seal of a rotary valve assembly for a diesel engine requires a modified structure in that the compression gases would cause excessive pressure on the floating valve seal and its contact with the spherical rotary intake valve or spherical rotary exhaust valve.
[0007] The present invention which is the subject to this application relates to the floating valve seal and means for regulating pressure therein.
OBJECTS OF THE INVENTION
[0008] An object of the present invention is to provide for a novel and improved valve seal for a rotary valve engine.
[0009] A further object of the present invention is to provide for a novel and improved valve seal for a rotary valve engine in which the ceramic insert of the valve seal is positioned in a locking angle for improved life span.
[0010] A still further object of the present invention is to provide for a novel and improved valve seal for a rotary valve engine in which a gas tight seal is maintained by the pressure developed in the cylinder and combustion chamber.
[0011] A still further object of the present invention is to provide for an improved and novel valve seal for a spherical rotary valve assembly which requires no external lubrication.
[0012] A still further object of the present invention is to provide for a novel and improved valve, valve seal and cylinder head/combustion chamber arrangement for a rotary valve engine.
[0013] A still further object of the present invention is to provide for a novel and improved floating valve seal arrangement for a rotary valve engine assembly which regulates the pressure within the valve seal.
SUMMARY OF THE INVENTION
[0014] A valve seal for a rotary valve assembly for use in an internal combustion engine of the piston and cylinder type, wherein the cylinder head/combustion chamber is designed for high compression and of long stroke, such as a diesel engine, the rotary valves and the valve seals being positioned in relationship so as to permit charging of the cylinder with a fuel/air mixture and evacuation of spent gases, and to regulate the pressure within the valve seal and valve seat and hence regulate the pressure between the valve seal and the rotary valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other advantages and improvements will be evident, especially when taken in light of the following illustrations wherein:
[0016] FIG. 1 is an end cross-sectional view of the head of the spherical rotary valve assembly showing the relationship of the spherical rotary valve to the cylinder, piston and valve seal;
[0017] FIG. 2 is a top view of the improved valve seal of the present invention;
[0018] FIG. 3 is a side cutaway view of the improved valve seal and valve seat of the present invention along plane 3 - 3 of FIG. 2 ; and
[0019] FIG. 4 is a top view of the pressure regulating ring of the improved valve seal of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring to FIG. 1 , there is illustrated an end cross-sectional view of an embodiment of the spherical rotary valve assembly of Applicant's prior patents detailing the relationship between a rotary intake valve 10 enclosed within an upper half 12 and a lower half 14 of a split head assembly. The split head assembly is secured to an engine block having cylinder 16 within which piston 18 reciprocates.
[0021] The split head assembly comprising upper half 12 and lower half 14 defines a drum accommodating cavity 20 within which rotary intake valve 10 is positioned. Rotary intake valve 10 is positioned on shaft 22 which passes through a centrally positioned aperture 24 on the rotary intake valve 10 . As discussed in detail in Applicant's prior patents heretofore set forth, rotary intake valve 10 provides for communication between fuel air inlet port 26 and cylinder 16 by means of an aperture 30 positioned on the spherical periphery 21 of the rotary valve 10 which comes into successive registration with inlet port 32 to cylinder 16 .
[0022] Rotary intake valve 10 rotating within drum accommodating cavity 20 on shaft 22 is in contact with valve seal 35 , annularly positioned in an annular groove or seat 38 about inlet port 32 to cylinder 16 . Valve seal 35 serves to provide a seal to insure that the fuel/air mixture passes from rotary intake valve 10 into cylinder 16 during the intake stroke and further provides a seal with rotary intake valve 10 during the compression stroke to insure that the ignition of the fuel/air mixture occurs within cylinder 16 and does not migrate into drum accommodating cavity 20 . Further, seal 35 provides a seal with rotary intake valve 10 during the exhaust stroke to insure that the exhaust gases exit through the rotary exhaust valve.
[0023] The description of valve seal as contained herein is made with respect to a rotary intake valve as shown and illustrated in FIG. 1 . Valve seal is of the same design and serves the same purpose and function with respect to its relationship to the rotary exhaust valve of the spherical rotary valve assembly as disclosed in Applicant's prior patents heretofore identified. It is further understood that each cylinder would have at least one rotary intake valve and one rotary exhaust valve and a valve seal associated with each.
[0024] Referring now to FIGS. 2 and 3 , which are a top view and cutaway view of an improved valve seal 36 , there is illustrated a valve seal body 37 and a ceramic carbon insert lubricating ring 52 as more fully described hereafter. Valve seal 36 has a centrally disposed aperture 40 alignable with inlet port 32 when valve seal 36 is seated in annular groove or seat 38 . The upper annular surface 42 of valve body 37 is curved inwardly towards the center of aperture 40 . This curvature corresponding to the spherical periphery curvature 23 of the rotary intake valve 10 . Upper surface 42 of valve body 37 is formed with an annular groove 44 which is defined by an inner side wall 46 and outer side wall 48 . The inner side wall 46 forms a 90 degree angle, while outer side wall 48 forms an angle of less than 90 degrees. Annular groove 44 is for receipt of a ceramic carbon insert lubricating ring 52 . The ceramic carbon insert lubricating ring 52 is positioned in the annular groove 44 such that its upper surface 54 corresponds with the curvature of the upper surface 42 of valve body 37 . In mating the carbon insert lubricating ring to the valve body 37 , valve body 37 would be heated so that it would undergo slight expansion. The ceramic carbon insert lubricating ring 52 would then be inserted into annular groove 44 during its heating process. The valve body 37 would then be allowed to cool. Since outer side wall 48 of the annular groove is slightly offset from 90 degrees in the direction of inner side wall 46 , the ceramic carbon insert lubricating ring 52 is locked in position by this “locking angle” and is assured of remaining in position regardless of how hot the valve seal 36 became during the combustion process of the internal combusion engine. This is particularly important when the internal combustion engine to which the valve seal is affixed is being powered by natural gas or diesel which generate substantially higher temperatures and pressure than conventional gasoline fuel.
[0025] The outer side wall 54 of valve seal 36 is stepped and formed with a spaced apart annular rib 56 for the receipt and positioning of at least one sealing or blast ring 58 which function much like a piston ring establishing a seal between valve seal 36 side wall 54 and the periphery of annular groove or seat 38 about inlet port 32 . In the present embodiment there is illustrated one rib 56 and one sealing or blast ring 58 . However, if the depth of sidewall 54 were increased, the number of blast rings may be increased.
[0026] Contact between the valve body and the peripheral surface of rotary intake valve 10 is maintained by an annular beveled spring 60 positioned in the annular receiving groove of the valve seat. The pressure to be maintained upwardly on valve seal body is in the range of between 1 to 4 ounces as a result of the use of beveled spring 6 .
[0027] Additionally, the inner wall 62 of valve seat 38 has positioned therein a pressure regulating ring 64 . In Applicant's prior embodiments, the increased gas pressure within the cylinder during the compression and power strokes was utilized to augment the sealing of the valve body with the peripheral surface of the rotary valve by means of annular passageway 66 . It has been found that in short stroke engines the increase compression within the valve seat during the compression and power strokes did not have to be regulated. However, in long stroke and high compression engines, such as diesels, the amount of pressure within the valve seat which increases the contact of the valve body with the peripheral surface of the rotary valve must be regulated or the seal will generate a braking effect with respect to the rotation of the rotary valve. Therefore, pressure regulating ring 64 is positioned in an annular groove 65 on the inner wall of the valve seat 38 in the path of the compressed gases from the cylinder during the compression and power stroke. Pressure regulating ring 64 is in contact with the inner annular surface of the valve body 36 and pressure regulating ring 64 has a plurality of apertures 68 formed on its outer circumference which allows the compressed gases from the cylinder to pass through apertures 68 and into the valve seat 38 beneath the valve body 36 to allow for increased pressure on the valve body with the peripheral surface of the rotary valve. FIG. 4 is a top view of the pressure regulating ring of the present invention. The apertures 66 are in the form of semi circular apertures formed on the outer circumference or blast ring 64 .
[0028] Heretofore, Applicant's “floating” valve seal body allowed the compressed gases during the compression and power stroke to bleed into the valve seat by means of an annular gap 66 between the inner circumferential wall of the valve body and the inner wall circumferential 66 of the valve seat 38 . The pressure regulating ring 68 serves to limit the passage of the compressed gases via this route by blocking the route and only having a plurality of apertures 68 available for the introduction of the compressed gases into the valve seat 38 beneath the valve body 36 . The number of apertures 68 can be varied depending upon the stroke and compression of the engine as measured by suitable measuring techniques.
[0029] The valve seal and the valve seat of prior prototypes of the Applicant/Inventor called for the valve seat to be friction fit within an annular groove within the lower head of the split head assembly. The valve and valve seat of the present invention may also be friction mounted in such an annular groove. However, since the valve and valve seat of the present invention are directed to high compression long stroke engines of significantly higher compression than a normal internal combustion engine found in an automobile, the valve seat could be externally threaded on its external circumference 70 so as to be threadedly secured to the annular groove in the lower head of the split head assembly which would similarly be threaded for receipt of the valve seat.
[0030] While the present invention has been described with respect to the exemplary embodiments thereof, it will be recognized by those of ordinary skill in the art that many modifications or changes can be achieved without departing from the spirit and scope of the invention. Therefore it is manifestly intended that the invention be limited only by the scope of the claims and the equivalence thereof.
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A valve seal for a rotary valve assembly for use in an internal combustion engine of the piston and cylinder type, wherein the cylinder head/combustion chamber is designed for high compression and of long stroke, such as a diesel engine, the rotary valves and the valve seals being positioned in relationship so as to permit charging of the cylinder with a fuel/air mixture and evacuation of spent gases, and to regulate the pressure within the valve seal and valve seat and hence regulate the pressure between the valve seal and the rotary valve.
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CLAIM OF PRIORITY
[0001] This application claims priority under 35 U.S.C. 119(e) (1) to U.S. Provisional Application No. 60/755,824 filed Jan. 3, 2006.
TECHNICAL FIELD OF THE INVENTION
[0002] The technical field of this invention is integrated circuit design for low leakage current.
BACKGROUND OF THE INVENTION
[0003] Integrated circuit design involves assembling the combination of circuits that perform the desired function. It is typical to construct the desired circuits from building blocks called cells. Each cell performs a specific function and has a defined set of inputs and outputs. The set of such cells available to the designer is called the library of cells. A selected mix of such cells are assembled depending upon the desired function of the integrated circuit.
[0004] Integrated circuit design generally uses a variety of cells which perform the same function. These differing cells are employed in different contexts with differing needs.
[0005] A crucial factor in the performance of an integrated circuit is the cell timing. Complex circuits often use the cells in cascade with one or more cell outputs driving another cell input. Integrated circuits are typically clock rate driven. This means that many such serial chains of cells must provide their outputs before the expiration of an interval of time. Proper circuit function depends upon meeting such timing restraints in virtually all of the integrated circuit.
[0006] The delay of a cell, that is the length of time from receiving signals at its inputs to generating signals at its outputs is primarily a function of the rail-to-rail supply voltage, the input slew and the output load capacitance. The supply voltage is typically the same for the whole integrated circuit or the integrated circuit is divided into a small number of power domains with differing supply voltages. Thus the metric that has a cascading effect on timing here is the output slew of a cell.
[0007] An increasing problem with digital circuits is leakage current. Leakage current is the current a circuit draws when nominally turned OFF. With increased circuit density made possible by smaller circuit features, more circuits can be constructed on a single integrated circuit. In addition, these same smaller features cause increased leakage current for nominally the same circuit types embodied in smaller features. As a consequence, leakage current is a major portion of the total current drawn by state of the art integrated circuits. This increasingly important leakage current causes problems particularly for integrated circuits intended for portable, battery-powered use.
SUMMARY OF THE INVENTION
[0008] This invention optimizes the overall leakage power of an integrated circuit design using multiple threshold libraries, without deteriorating the overall timing. Timing driven optimization tools, methods often do not refine drive strengths on paths meeting timing. There might be multiple reasons, majority contributed by ways of interpretation of Non Linear Delay Models in a multi-threshold library. The approaches given here address not only the issues of slew refinements but also swapping across multiple threshold, multiple drive strength cells.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other aspects of this invention are illustrated in the drawings, in which:
[0010] FIG. 1 illustrates the algorithm of this invention in flow chart form.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] The delay of a cell is a function of rail-to-rail voltage, input slew and output load capacitance. The factor that has a cascading effect on timing here is the output slew of a cell. Hence in a particular timing path if worst output node slack and slew are well met, then either the cell can be downsized to reduce leakage or can be swapped with a cell with lower leakage. Such a swap preserves timing closure while reducing leakage current. In addition a high drive strength, lower leakage cell can be substituted for a lower drive strength, high leakage cell. The comparisons necessary to determine if such a swap is helpful are made by maintaining a static default leakage hash-table for each cell in the library.
[0012] This invention permits multi-threshold-multi-drive swapping by grouping all cells pertaining to a function class. This grouping is based upon the cell footprint. This invention needs to maximize the number of swaps. Picking a random design cell meeting the slack and slew requirements as a swap candidate might not be optimum. Such a cell may eventually have the maximum timing paths passing through it. In this case just one swap can cause failure to make overall timing or prevent swapping other cells in the transitive nodes of the cell preventing further power optimization.
[0013] This invention includes the strategies to prioritize design cells while sorting candidates for swapping. These strategies include considering their worst node levels forward or backward, considering dependency and considering worst output slews.
[0014] Every standard cell in the library has a cell footprint. Cells with same footprint have same functionality. This invention creates a key-value data base using the footprint as the key and the list of cells with that footprint as value for the key. For a given a footprint as the key to this hash table, the value key will have cells with all drive strengths and threshold voltage classes. This invention also creates plural sequencing databases used in the leakage swap determination.
[0015] This invention creates a sequencing database with a forward level metric for each cell. This is similar to creating a backward level hash table, except that the stage calculation starts from the timing start point. From a timing start point, a node is said to be at a forward level n if there are n more stages of logic from a start point which has worst slack.
[0016] Traversing from the least forward level towards an endpoint, every cell in a level is checked for its output slack and slew. If one of these cells is overdriving and has enough slack at its output, that cell is a candidate for swapping. Once a candidate is identified thus as swappable, the footprint of the cell is determined and leakage of this candidate cell is compared with leakage of each cell with the same footprint in the library. The cells meeting this criteria are then considered with similar input slew and output load, and checked to determine whether delay and output slew are well within limits. The cells identified as within the limits are sorted by their leakage power. The cell with least leakage power is chosen to swap with the existing cell.
[0017] This invention creates a sequencing database with a backward level metric for each cell. Every node in a timing path has an endpoint. The maximum number of logic stages through which the timing path through the node traverses to reach an endpoint defines the backward level of that node. A node may have multiple timing paths running through it and hence have multiple end points. However, the greatest number of stages is considered as the level of that node in a worst case analysis. A cell is at level n, where n is the greatest level amongst all of its outputs.
[0018] Traversing from the least backward level towards a start point results in a better quality of result in designs where the total transitive fan-out is greater than the fan-in. Traversing backwards works on the leaf nodes first and then comes to the parent. Thus this technique can swap a maximum number of cells in such designs. But this advantage comes at the small cost of unpredictability. This will be further described below.
[0019] This invention creates a sequencing database with a dependency metric for each cell. Dependency is defined by how many timing paths pass through that cell. A cell is said to be at dependency level n where n is the sum of total fan-in timing paths and total fan-out timing paths for that cell for short, transitive start and end points. The less dependent a cell, the less timing impact when swapped. Such a cell will be given preference for swapping.
[0020] Traversing from the least dependent level towards the most dependent cell makes sure that the least dependent cells are swapped first. This approach requires a special attention upon implementation to not multiple cells in a cascaded logic path. Consider a water-line like buffer tree structure. Each cell will be at the same dependency level, but only one can be swapped without much computation. This approach will be the most time consuming due to computation of the dependency levels.
[0021] This invention creates a sequencing database with a slew metric for each cell. A driver is a strong driver when it drives its load with a faster slew rate. Such strong drivers are prioritized while swapping. If a strong driver has enough positive worst slack and drives with tighter slew rates, then the driver can be downsized enough to meet the limits of slew and slack.
[0022] Traversing from the strongest driver towards the lowest, if the input maximum slew is more than maximum slew amongst all inputs and all outputs, a level equal to the sum of maximum input slew and maximum output slew is given to the cell.
[0023] This invention uses a set of function subroutines as follows.
[0024] getLeakageHash: This static function returns the default leakage hash table. This default leakage hast table supplies the default leakage power given a standard cell name. The default leakage power is edge sensitization independent for multiple input/output cells. This can be made edge dependent only to increase the run-times.
[0025] getFootprintHash: This static function returns a footprint hash table with the footprint as key and cell identity with that footprint as the values. This footprint hash table supplies all threshold class and drive strength cells for a given footprint.
[0026] getForwardLevelHash: This static function returns a hash table with maximum forward level for a cell as key and cell identity as values. This maximum forward level hash table supplies the maximum forward level of cell outputs for a given cell identity. This function dumps getForwardLevelHash.<designName>.log file.
[0027] getBackwardLevelHash: This static function returns a hash table with maximum backward level for a cell as key and cell identity as values. This maximum backward level hash table supplies the maximum backward level of cell outputs for a given cell identity. This function dumps getForwardLevelHash.<designName>.log file.
[0028] getDependencyHash: This static function returns a hash table with maximum dependency level for a cell as key and cell identity as values. This maximum dependency level hash table for a cell is the sum of all input node dependencies and output node dependencies. This function dumps getDependencyHash.<designName>.log file.
[0029] getSlewLevelHash: This static function returns a hash table with slews found in the design as key and cell identity as values. For the maximum input slew and the maximum output slews if less than the slew limit, cells are assigned slew levels equal to sum of maximum input slew and maximum output slew. This function dumps getSlewLevelHash.<designName>.log file.
[0030] getSwapList: This is a dynamic function which accepts master cell identity name, input capacitance, output load, domain, delay deviation limit, upper area variation limit, lower area variation limit, slew limit, voltage threshold (V T ) preference pattern and V T preference slack limit. All of these accept model name, input slew, output load, delay deviation limit and slew limit are static. The model name is design cell model name under consideration, input slew and output load are of that design cell, delay deviation is the allowable deviation/degradation in delay and slew limit is the slew limit for the worst slack of the design cell outputs.
[0031] optimizeLeakage: This is the main function which calls all the above functions.
[0032] The design to which this application is applied preferably includes a global routed design database and multiple V T cell library. The following list includes inputs and options for the above functions. Every option has default selected for best results on a reference cell library.
[0033] −slackLimit: This is a number with a default value of 300 ps. This default value depends upon the technology used and upon the regression tests. A design cell is considered to be eligible for swapping if it has a slack above this limit and has the worst slack.
[0034] −levelUpdateTimer: This is an integer with a default value of 1. The value of −levelUpdateTime is used to decide after each level swap whether a timer needs to be updated. If levelUpdateTime is set to zero, the total run time would drastically reduce but the quality of results can't be guaranteed. This input is useful for non timing critical blocks.
[0035] −vtPrefPattern: This is a string with a default value of the cell master identity name if it exists. This option sets the of specific type of V T for a cell below a certain slack range. If the return list has cells with this pattern, they will be preferred otherwise this option is ignored.
[0036] −vtPrefSlackLimit: This is a real number with a default value of 300 ps. The V T cell of −vtPrefPattern is used if the design cell is below this slack range.
[0037] −upperAreaHitLimit: This is a real number with a default value of 1.5. This is the upper area hit limit. A design cell can be upsized in area up to this factor.
[0038] −lowerAreaHitLimit: This is a real number with a default value of 0. This is the lower area hit limit. A design cell can be downsized in area maximum by up to this factor. If both upper area hit number and lower hit number are equal, then no area change is allowed. In this case swap is possible only across V T s and not across drive strengths.
[0039] −maxSlewLimit: This is a real number with a default value of 500 ps. Only design cells with worst slews below this limit will be considered for swapping. This slew target is not to be violated even post swapping.
[0040] −method: This is a string with a default value of “forward.” Valid values are “forward,” “backward,” “dependency” and “slew.” These correspond to the sequencing databases described above.
[0041] Apart from these options above, the main function inherits these variables if they exist from the parent shell. Otherwise they assume the listed default values.
[0042] −slewLimitHash: This is a real number having a default value best suited for the technology node after regression testing. This variable defines the co-ordinates for the slew-slack histogram.
[0043] −leakagePowerAnalysisCorner: This is a real number having a default value equal to the most commonly used corner for leakage power analysis. This variable sets the leakage analysis corner for picking up right library information.
[0044] FIG. 1 illustrates the leakage power optimization process 100 of this invention. Process 100 begins by considering every non-sequential cell in the design at block 101 . This selection can be made by any of the four sequencing data bases previously described as determined by the −method switch: forward level metric from the forward level metric hash table produced by the getForwardLevelHash function; backward level metric from the backward level metric hash table produced by the getBackwardLevelHash; dependency metric from the dependency metric hash table produced by the getDependencyHash subroutine; and slew metric from the slew metric hash table produced by the getSlewLevelHash subroutine. Decision block 102 determines if the design cell slack is greater than the slack limit. If this is not true (No at decision block 102 ), then this design cell cannot be swapped. Process 100 exits via exit block 103 . This exit would trigger consideration of the next design cell.
[0045] If this is true (Yes at decision block 102 ), then process 100 tests to determine if the slew of the design cell is less than the slew limit for the slack in decision block 104 . If this is not true (No at decision block 104 ), then process 100 then this design cell cannot be swapped and exits via exit block 105 . If this is true (Yes at decision block 104 ), the process 100 proceeds to block 106 . Block 106 sets a delay hit limit equal to the actual timing slack minus the slack limit.
[0046] Block 107 coordinates several inputs into a determination of candidate design cells to swap. These inputs include the worst input slew, output load cap and footprint of the cell model from block 108 derived from the non-sequential cells identified by block 101 . Another input is the footprint table from block 109 produced by the getFootprintHash subroutine. A third input is the area hit limit from block 110 as controlled by the −upperAreaHitLimit and −lowerAreaHitLimit options. Lastly, is the leakage table indicating the difference between the design cell leakage and the default leakage from block 111 produced by the getLeakageHash subroutine. Block 107 validates the leakage, input slew and output load capacitance for every cell matching the footprint of the design cell.
[0047] Decision block 112 validates the delay and slew for these cells. If the delay and slew are not validated (No at decision block 112 ), then process 100 exits via exit block 113 . If the delay and slew are validated (Yes at decision block 112 ), then process 100 passes to block 114 .
[0048] Block 114 identifies the ideal swap candidate. Block 114 receives the V T preference supplied by block 115 as specified by the −vtPrefPattern option. Block 114 also receives the validated candidate cells from decision block 112 . Block 114 selects the candidate cell having the best set of characteristics for swapping. Block 116 executes the swap of the selected candidate cell for the design cell.
[0049] As previously described, this invention can be applied using forward sequencing, backward sequencing, dependency sequencing and slew sequencing. Using forward sequencing any design cell is considered as a candidate for swapping by its output slew and slack. Following swapping a candidate cell having a degraded slew that is within the slew limits. The slew change propagates through next few stages. The output of this swapped driving cell now has a degraded input slew and the output slew may go beyond the slew limit. This cell thus will not considered in the next iteration as it has slew or slack beyond the limits. To avoid this situation, the slew limits should be tighter for slack ranges than the actual slew limits.
[0050] Using backward sequencing considers a leaf cell first and parent cells later. While swapping a leaf cell, the input slew is controlled by the existing parent cell. This input slew may differ when the parent cell is swapped. This degraded parent cell input slew may make the leaf cell swap invalid. This invention has no way to recover/revert/invalidate the original swap if leaf cell delay and slew worsens due to later swaps. This is similar to the limitation in forward sequencing but can be called faulty strategy.
[0051] Using dependency sequencing care must be taken to avoid swapping multiple instances in a cascaded water-line logic structures. However, the tighter slew limitation known for forward sequencing holds valid in this case. Among the sequencing approaches, this approach takes the maximum run time.
[0052] Using slew sequencing provides no logic to maximize the number of swaps. This approach also has the limitation seen by forward sequencing method requiring a tighter slew limit.
[0053] Generally forward sequencing gives better results in designs with more leaf cells in the input direction than in the output direction. Similarly, backward sequencing gives better results in designs with more leaf cells in the output direction than in the input direction. Dependency sequencing takes large run times with lower slack/slew input limits, but is potentially a good approach for timing critical blocks because it is sequenced to run with least impact on design timing. Slew sequencing gives results comparable to forward sequencing and backward sequencing but might take little longer run time than the two.
[0054] A tighter slew limit ensures that even after swapping, the slew of the new cell remains good enough and for the next few cell stages the slew doesn't go beyond limits. This invention provides no way to recover, if this happens though. Reversing a prior swap it is out of the scope of this invention. Thus the user of this invention needs to be careful while specifying the slew limits. By specifying loose slew, if few cells go beyond the limits, then user may need to manually fix them. The default values have been tested to give good results on an example library in several test cases.
[0055] This leakage optimization algorithm is preferably tested well to run following global route. At this time capacitance and slews are near to realistic. Alternately, this can be run at the detail route phase. In this case the user takes the risk of increased impact on the detail route. This can also be run on a multi-threshold voltage design and is coded to take care of multi-domain delay groups.
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This invention reduces leakage power in an integrated circuit design formed of a plurality of design cells selected from a library of cells. The method of this invention considers all design cells, identifies corresponding candidate cells having the same function and swaps a candidate design cell having a least leakage current for the design cell.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a method for sorting a gas-driven stream of generally flat and light-weight articles of varying dimensions through executing a, preferably optical, inspection and upon so finding a non-conforming article removing the latter from the stream. Such articles may result from production processes that are agriculture-based, or from other sources and a prime example for the products to be sorted are tobacco products such as leaves or parts cut therefrom or stems. Such products once packaged are transported, and then the products are handled for separating them again. Typical sizes for conforming particles of the product under consideration are without limitation lengths and widths in a range from 1 to 500 millimeters. Tobacco is relatively quite expensive and the separated products may be accompanied by various matters of non-conforming tobacco character, as well as by various categories of non-tobacco origin, such as the successive stages of the production may introduce. It is noted here that “optical” means “radiative” and thus including the use of radiation that is not visible for the eye. Moreover, inspection by means of other techniques like by acoustic waves might be feasible.
[0002] Prior art has realized the technical and economic usefulness of automatic sorting, but the present inventor has recognized that an optimized set-up would need at least some, but not necessarily all of the following features:
inspection with one or more relatively straightforward line-scan camera(s) arranged across the direction of motion of the articles; orienting non-conforming articles in such manner that the detection device(s) will find the largest area of the article in question, whilst using only few or no moving parts for introducing and maintaining such orientation; article motion and gas speed being adjustable and relatively uniform, in that relatively low speed will allow easy data processing, whereas higher speed will increase throughput, and requiring only few moving parts for attaining a low noise level; a possibility for designing the apparatus through a substantially closed channel, also for keeping environmental dust level at low values; especially for a product like tobacco this is of great benefit; removing the non-conforming matter through an underpressure facility that connects to the channel; executing inspection and separation during substantially straight, in particular vertical, motion, inasmuch as such would tend to maintain particle orientation; a free fall would be most advantageous, as such would tend to produce uniform particle speeds, especially in combination with gas-suction for particle removal; and keeping the risk for jamming of the overall apparatus at an acceptably low value.
[0011] Now in particular, U.S. Pat. No. 5,862,919 to Eason discloses the sorting of particles through feeding thereof by a horizontal conveyor belt, while separating both conforming and non-conforming articles through selectively activating a gas ejector during a falling trajectory of the particles, which trajectory will always deviate appreciably from a straight line. The present inventor has found that a straight line motion during both the inspection phase and the transmittal phase of the conforming articles is better for accurate detection and accurate removal of the particles. Furthermore, free motion of the particles allows for double-sided visual inspection. Moreover, such could be combined with better orienting the particles before inspection, which should give superior results.
SUMMARY TO THE INVENTION
[0012] In consequence, amongst other things, it is an object of the present invention to provide a reliable method both on the level of the sorting proper and also on the level of overall operation.
[0013] Now therefore, according to one of its aspects, a method according to the invention is characterized according to the characterizing part of Claim 1. Preferably the method is specifically dimensioned for sorting tobacco products such as leaves or parts thereof or stems. Preferably the inspection used is an optical inspection.
[0014] The invention also relates to an apparatus being arranged for implementing the method as claimed in Claim 1 , and in particular as claimed in Claim 5. Further advantageous aspects of the invention are recited in dependent Claims.
BRIEF DESCRIPTION OF THE DRAWING
[0015] These and further features, aspects and advantages of the invention will be discussed more in detail hereinafter with reference to the disclosure of preferred embodiments of the invention, and in particular with reference to the appended Figures that illustrate:
[0016] FIG. 1 , an overall set-up of a sorting system according to the invention;
[0017] FIG. 2 , an enlarged view of a part of a sorting facility proper, according to the invention;
[0018] FIG. 3 , an article carrying channel wall with extensions to keep the articles from moving along the channel wall;
[0019] FIG. 4 , an overall set-up of another sorting system according to the invention;
[0020] FIG. 5 , an enlarged view of a part of the system of FIG. 4 ;
[0021] FIG. 6 , two cross-sections of the part of FIG. 5 at different heights.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] FIG. 1 illustrates in principle an overall set-up of a sorting apparatus according to the invention. It is to be noted that the installation configuration of the individual components of this set-up may be altered depending on the requirements (product, space, etc.), for instance when using the “open channel” organization (see further below). As shown, in this configuration the overall length of the machine is about 17 meters. Item 20 is a feeding conveyor belt that feeds the articles. The providing of the articles proper as resulting from splitting, etcetera, of the tobacco has not been shown for clarity. At indication 22 , the articles fall from the conveyor belt and into the transport system that in this embodiment centers on a substantially closed air-carrying duct arrangement. To this effect, a feeding chute 21 opens towards the conveyor belt side, and particles will fall through this chute. The transporting air circulates through various openings in an inclined plate 23 , although in principle, another gas or gas mixture could be used. The size and distribution of the openings and of other inlets, not shown in detail, would give an appropriate feeding speed for letting the articles or product travel independently from each other through the apparatus channel. Moreover, the net air exchange through chute 21 should be kept low to maintain both dust loss and also maintain air intake at low levels. One way to effect this is keeping the local internal air pressure of the system approximately equal to ambient air pressure.
[0023] At indication 24 a rising duct will carry the particle stream to an appropriate height, in this case some 5 meters; thereafter, the rising duct proceeds as a generally horizontal tube. At indication 26 , the air duct is divided through an inclined and slowly slanting downwardly separation plate 33 that carries an air transmission pattern of holes. In this manner, part of the air stream can be diverted to bypass duct 28 , while the particles of interest cannot pass through the holes. On the other hand, small and generally uninteresting particles such as dust can pass through these holes. This feature allows for adjusting the air speed below the separating plate. Air speed before the separating plate is in a range of 20-30 meters/second, while it is in the range of e.g. 10-20 meters/second in the area where the inspection takes place. Through a certain centrifugal force, the particles of interest are driven to the descending and subsequently, nearly vertical wall at indication 30 , and generally tend to turn their broad area in a more or less horizontal direction to the right side in the Figure.
[0024] Both the centrifugal force and the air outletting through the plate can contribute to orient conforming particles. The result should be a monolayer of well-oriented “good” particles, so that a large fraction thereof will be accepted. On the other hand, the effect on “bad” particles need not be considered, inasmuch as the optical survey discussed hereinafter would be able to pick them out as being non-conforming. The inventor has found that the above manner of orienting the particles is inexpensive, uncomplicated, and has a high success rate.
[0025] Below indication 30 , the separation of unwanted particles is effected during the substantially vertical motion of the particles, through optical inspection and then removal to the right (or alternatively, to the left, or in other directions) in an inspection/separation duct 40 , which operation will be more clearly illustrated in FIG. 2 . Although preferred to be vertical, the duct orientation, and therefore, the particle motion may have some deviation from vertical: it is contemplated that +/−15° would often be acceptable, and in any way, +/−5° would give a good solution. More or less similar deviations from a straight-line motion could apply. At indication 32 , the stream with particles retained and the bypass stream 28 of air merge again. Downstream from indication 32 , the useful particles are removed from the system in an air-operated product separator arrangement 34 for further processing not considered here. The air output of air-product separator 34 goes through further ducts and main driving air pump arrangement 36 . Finally, the overall duct is attached at indication 38 to the particle feeding position discussed earlier. Generally, there is little loss of air, and therefore also little air suppletion will be necessary, so that the process as a whole takes place in a substantially closed system: the air will cycle several times before being exhausted with the useful particles at air-product separator 34 or via the air bleed-off pipe which is connected to the circuit as a standard going to an exhaust air treatment device. This lowers overall noise levels, and also lowers the risk of high dust concentrations outside the system.
[0026] Now, although the preferred embodiment as shown has the sorting during a falling motion of the particles, in principle other straight-line arrangements could operate in a satisfying manner. If the primary motion is horizontal, the removal of non-conforming particle could be effected in a substantially horizontal, in a substantially vertical manner, or according to still other orientations. If the primary motion is ascending or descending, various geometrical arrangements can be designed, also depending on the gas velocity, the size of the channel, the nature of the conforming and/or non-conforming particles, etcetera.
[0027] FIG. 2 illustrates an enlarged view of a part of sorting facility proper according to the invention, showing in particular items 28 , 30 and 40 of FIG. 1 . In particular, note the downwardly inclined course at separation plate 50 (indicated with numeral 33 in FIG. 1 ), which lets the particles more or less “approach” the wall 30 at reduced air velocities in a range of 10 to 20 meters/second. Whereas the downward inclination of plate 50 shown in the figures is plane, said inclination preferably is cylindrically towards wall 30 . The air flow through separation 50 would assist such “approach”. The transition between the part at 50 and the selection facility proper should be short to maintain the particle orientation; in the embodiment it is about 10% of the total system height, or some 35 centimeters. The vertical part of the duct 40 has a more or less square or rectangular cross-section.
[0028] Now, the selecting proper is effected with double-sided background illumination sources such as lighting 56 , double sided narrow beam particle lighting 54 , double mirrors 53 and double-sided line cameras 52 . In this way the particles can be made well distinguishable, in that the nature of the background can be made to stand out relatively distinctly from properties of the particle such as intensity and color. The output signals from the horizontal line of optical detection units such as cameras are processed in a processing facility not shown, which facility can measure particle shapes in appropriate manner, through correlating successive scans, measuring total exposed particle area, and rejecting such particles as considered non-conforming to the standard range of particle shapes. Through the relatively low air speed, the available data processing time interval can be kept sufficiently long for a moderate-power computer.
[0029] If the particle shape, and possibly color or other properties, are good, the particle proceeds downward in a vertical direction. If the particle is considered bad however, at indication 58 the particle will be removed by suction to the right. Through the suction by underpressure, no additional superfluous air motion and no unwanted turbulence will be introduced into the falling duct. The removal operation proper can be further effected or supported by a gas nozzle 66 that is momentarily activated for ejecting the particle through the opening at indication 58 ; this lets the non-conforming particle escape in a horizontal direction that is substantially across the primary motion of the particles before separation.
[0030] Like the vertical orientation of the inspection/separation duct 40 , the removal can have some tolerance from horizontal, such as +/−15°. Anyway, right after the removal operation proper through output 58 , gravity and/or principal air movement will make the rejected particle fall downward. In fact, at indication 60 , a perforated plate separates the reject duct that goes to reject bin 64 , whereas the bulk of the air stream through underpressure by pump 70 will at indication 62 be led to another part of the closed system or elsewhere. In an alternative embodiment said air stream might near indication 62 reenter bypass duct 28 , and therefore remain as well in the overall system. At indication 68 , the two principal streams 28 , 72 of air merge again. This merging can alternatively occur behind air-product separator facility 34 , as in FIG. 1 . For clarity, no extensive discussion of air-product separator facility 34 is given, inasmuch as the removing of particles by air-product separator activity is well-known to persons skilled in the art of air-driving particles in an industrial environment.
[0031] FIG. 3 shows an article carrying channel wall 41 of duct 40 with extensions 42 to keep the articles from moving along the channel wall. It has been found that such will keep particle speed more uniform, so that the arrival of a particular particle at the position of nozzle 66 can be predicted more accurately. Indeed, the particles will not be delayed by extensive friction along the wall. The extensions will influence the boundary layer of the flowing gas and may look like fish scales. Their height (perpendicular to the wall) is in a range of 0.5 to 2.5 millimeters, whereas their area (along the duct's wall) is a few millimeters square. Mechanical working of the wall will allow easy manufacture thereof.
[0032] FIG. 4 shows an overall set-up of another sorting system according to the invention. As in the example of FIG. 1 the a figure shows a side view and the b figure shows a top view. The feeding conveyer 20 feeds the articles to a vibrating plate 46 that forms a uniform layer of the articles and the latter feeds the articles to a speedy tape transporter 47 that reduces the thickness of the layer of articles. The articles then are fed into the feeding chute 21 where below indication 30 the articles enter an inspection/separation duct 40 that is positioned within housing 86 . Again duct 40 forms a part of a quasi-closed system comprising tubes 41 , 42 that connect the duct 40 to air-operated product separator arrangement 34 which is connected to air pump arrangement 36 . In this case the articles are sucked into the duct 40 by an under-pressure that is created in tube 42 .
[0033] FIG. 5 illustrates an enlarged view of a part of the system of FIG. 4 comprising duct 40 below point 30 and chute 21 . The upper part of the duct 40 is here over a length of about 1 meter laterally bordered by a cover tube 84 which feeds though a throttle-valve 83 a leakage air flow into duct 40 at location 85 , below which the inspection and separation of impurities and unwanted articles takes place in a further part of duct 40 having a length of e.g. about 0.5 meter. The effect of said leakage airflow is illustrated in FIG. 6 .
[0034] FIG. 6 shows two cross-sections of the part shown in FIG. 5 at different heights. The a and b FIG. 6 are taken respectively above point 85 and below point 85 in FIG. 5 . In the upper part of duct 40 (see FIG. 6 a ) the particles 99 are present all over the cross-section of duct 40 , their main orientation being parallel to wall 41 of duct 40 . Below level 85 the leakage air flow is introduced into the duct 40 , flows along the walls thereof and forms a compartment 49 in duct 40 with a smaller width, into which compartment the articles 99 are confined. This has several advantages. Firstly, the walls of duct 40 which contain transparent parts below level 85 are kept free from impurities that may hamper the inspection. Secondly the layer of particles 99 is provided with a more uniform velocity distribution, which is important to enable an accurate timing between the observance of a bad particle and the moment of its separation. Thirdly, the focusing into the particles 99 has become easier since the layer thickness of the stream of particles 99 , which corresponds with the width of compartment 49 in FIG. 6 b , is decreased.
[0035] Below level 85 (see FIG. 5 once more) the inspection and separation of particles is performed in housing 86 . The inspection takes place through two optical detection systems, in this example two camera's 52 that observe the reflected light from a particle in duct 40 . Two radiation sources, here lamps 80 are used for each camera 52 that throw angled radiation, here light, beams on the particle stream in order to reduce a possible shadow effect, if any. Radiating units 81 comprising LEDs (=Light Emitting Diodes) emitting radiation, in this example white light, provide a reference radiation beam for the optical detection systems such as camera's 52 in this example. After inspection, the removal of unwanted particles is accomplished by gas nozzle 66 by which such particles are ejected into a side-chamber 91 of the duct 40 which is through tube 93 connected to a reject enclosure and a separate air pump, the latter both not shown in the drawing. Anti back-flow arrangement 92 , which here involves a so-called snail-shell construction of underpressure facility 62 , prevents ejected particles from re-entering duct 40 . In addition chamber 91 can be advantageously provided with an over pressure valve—also not shown in the drawing—which contributes to the prevention of re-entrance of ejected particles to duct 40 in case of pressure fluctuations. The over pressure valve can be provided with a particle filter and can be used together with a pump connected to tube 93 or in stead of such a pump. In stead of an over pressure valve a ventilator may be connected to chamber 91 .
[0036] Now, the present invention has hereabove been disclosed with reference to preferred embodiments thereof. Persons skilled in the art will recognize that numerous modifications and changes may be made thereto without exceeding the scope of the appended Claims. For example, the optical inspection and subsequent selection could be effected in a substantially vertical rising air stream.
[0037] Still further, the overall apparatus could be based on an open channel organization. This will obviate the need for various gas input/output balancing configurations. In that case, conveyor belt 20 ( FIG. 1 ) could immediately feed duct 30 in FIG. 2 . Where in the embodiments lamps are used for the optical inspection, the use of one or more lasers is feasible as well. Furthermore, the arrangement could need only a gas suction facility at the downstream end of the inspection/sorting channel prior to indication 68 in FIG. 2 . Obviously, this would produce a low-cost arrangement as compared with the embodiment of FIG. 2 . In consequence, the embodiments should be considered as being illustrative, and no restriction should be construed from those embodiments, other than as have been recited in the Claims.
[0038] Finally, it is noted that elements of the various embodiments could be combined. The unit of FIG. 5 could e.g. be used in the system of FIG. 1 , the bypass of FIG. 2 could be used in system of FIG. 4 and details of the unit of FIG. 2 could be used in the unit of FIG. 5 and vice versa.
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A method and apparatus for sorting a gas-driven stream of generally flat and light-weight articles of varying dimensions execute a, preferably optical, inspection and upon so finding a non-conforming article remove the latter from the stream. In particular, the inspection and the sorting are executed during a substantially straight movement of the articles. The removing is executed through gas driving in a direction substantially transverse to the straight movement. Advantageously, the inspection is preceded by orienting the articles through a centrifugal force that orients said articles against an inclined wall in a transition to the vertical movement. Also airflow means ( 83,84 ) can be used to confine the articles in a thin layer.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary disk filter element for a liquid filter, especially a beverage filter for biological filtration, with depth effect.
2. Description of the Prior Art
With one known filter element of this general the (German Offenlegungsschrift No. 24 52 524--Ziller dated May 13, 1976 and belonging to the assignee of the present invention), only the radially inner and outer portions of a filter fabric are secured to the filter element by being clamped between collar regions of adjacent filter elements and a radially outer clamping or securing ring placed upon the outer edge of the filter element.
Rotary disk filter elements of this type are used as a filter unit in liquid filters for the filtration of beverages. When filtration has been terminated after a number of hours or even days, filter residue retained by filter fabrics is centrifuged-off the latter by rotating the filter elements. In order to flush the remainder of the impurities still sticking to the filter fabrics, water, along with air, is flushed as wash fluid through the filter fabric counter to the direction of filtration, with the filter element subsequently being rotated in order to remove the residues or impurities that are still present in the filter element. In so doing, the water/air mixture still present in a support fabric is pressed at increased velocity through the filter fabric in order to completely flush out the residue still sticking to the filter fabric. With this extremely effective flushing/cleaning process, the filter fabric is generally subjected to very great mechanical tensile and shearing stresses since the filter fabric is not supported against the base plate counter to the direction of filtration. Since the air added for the cleaning process impedes the discharge of the wash fluid, the filter fabric is raised between the clamping locations counter to the direction of filtration. When, after the filter elements have been flushed, the supply of water and air is terminated, the filter fabric remains raised since the air settles in the fabric passages, as a result of which the pressure below the filter fabric is maintained. During the subsequent acceleration of the filter elementsvia rotation, the water/air mixture that has accumulated below the filter fabric is pressed at increased velocity through the filter fabric, thus unduly stressing the filter fabric beyond the permissible stretching limit. As a consequence of centrifugal force, the water/air mixture is pressed into the radially outer edge region of the filter element. At this location the water/air mixture leaves the filter element, and the impurities are flushed out.
During the subsequent filtration, the over-stretched filter fabric lies upon the base plate or support fabric accompanied by the formation of wrinkles and folds, since due to its great width the filter fabric no longer has enough space on the base plate. These folds adversely affect the filtering process, since at some locations the surface of the filter fabric is inhomogeneous and uneven. During the subsequent flushing processes, the folds are drawn open due to the lifting force acting thereon, whereupon great bending stresses act upon the fabric in the folds. As a result of the constantly changing bending stresses that act upon the folds during flushing, fatigue failures occur, especially in the region of the corners of the folds. At that point the filter element becomes unusable, so that it must be replaced. This is very expensive, especially with large filter elements due to their high manufacturing and assembly costs. The cost is magnified even further because in order to replace filter elements the entire filter unit has to be disassembled, and annular seals disposed between adjacent filter elements have to be removed and replaced, for which purpose also the filter unit has to be disassembled.
The filter fabric can also be stressed and damaged during flushing by the fact that over a long period of time the filter fabric is not sufficiently cleaned, for example by an inadequate water flushing. As a result, residue of filtering aids accumulates in the passages of the filter fabric, so that these passages become narrower. During flushing, the entire pressure of the flushing water then builds up below the unsupported fabric, so that the latter is mechanically overloaded, which again leads to a permanent overstretching of the fabric and, due to the alternating stressing of the filter fabric during filtration and flushing, also leads to the formation of folds and the aforementioned drawbacks connected therewith.
Overstretching of the fabric can also occur if too great a quantity of water per unit area is used for flushing, or if the water pressure or mechanical dynamic stresses are too great during flushing.
Chemical filters are also known where the filter fabric or intermediate layer of a support fabric is secured by rivets directly and in a non-planar manner on a perforated plate. However, these chemical filters are not cleaned by flushing with a wash fluid; rather, to clean the filter element in the filtration device the filter element is sprayed with water at very high pressure. For this purpose, the water is sprayed at an angle onto the surface of the filter element, so that the residues are taken along and the water flows off from the same side of the filter element or filter fabric. In contrast to the aforementioned state of the art, the filter fabric cannot be raised from the perforated plate during cleaning, since it is actually pressed against the perforated plate by the water stream, and is supported by the plate. It is therefore not necessary to secure the filter fabric, because the high water stream pressure is effected at an angle to the fabric, whereby locally great shearing forces occur.
An object of the present invention is to design a rotary disk filter element of the aforementioned general type in such a way that formation of folds due to excessive stretching and bulging of the filter fabric counter to the direction of filtration during flushing is reliably prevented.
BRIEF DESCRIPTION OF THE DRAWINGS
This object, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the schematic drawings, in which:
FIG. 1 shows a filter having a filter unit that comprises a plurality of inventive rotary disk filter elements disposed one above the other on a filtrate withdrawal shaft;
FIG. 2 is a plan view of the filter unit of FIG. 1 taken in the direction of the arrow II in FIG. 3;
FIG. 3 is an axial section taken along the line III'III in FIG. 2; and
FIG. 4 shows a second embodiment of an inventive filter element illustrated in a radially shortened manner.
SUMMARY OF THE INVENTION
The filter element of the present invention comprises: a retaining member; a collar member having at least one supply opening for wash liquid; a closed base plate in the form of a ring-like member disposed between the retaining member and the collar member; a support fabric placed on the base plate; at least one filter fabric placed on the support fabric, with the filter fabric having a radially outer portion secured in the retaining member and a radially inner portion secured by the collar member, with the filter fabric communicating with the supply opening of the collar member so that filter residue can be removed from the filter fabric during general cleaning thereof by having the wash liquid flush through the filter fabric in the direction opposite to the direction of filtration; and securing means for securing the filter fabric to the base plate and the support fabric at a plurality of point locations.
As a consequence of the inventive design, the filter fabric is divided into a number of relatively small regions or zones that rest loosely upon the base plate or the support fabric. As a result, filter fabric regions having relatively short free support or securing lengths are formed; this is an extremely favorable situation, especially for large filter elements, because then during the flushing process only a slight bulging of the small regions is possible due to the wash fluid pressure that acts upon the filter fabric in a direction directed away from the base plate. As a result, only slight tensile stresses act upon these slightly bulged filter fabric regions, so that the stress on the filter fabric is reduced to a minimum during the flushing process. In this way, an overstretching of the filter fabric, and the formation of folds caused thereby, can be easily prevented, so that as a result the filtration process is not adversely affected, and the filter fabric can not break. The inventive filter elements therefore have a very long service life. Whereas up to now filter elements were viewed as parts subject to wear and hence expendable, the filter elements of the present invention can be viewed as a durable machine part that is not subjected to mechanical wear. As a result of the inventive way of securing the filter fabric, the filtration is surprisingly not adversely affected, since now as before a closed cake filter or filtering aid layer is deposited upon the entire filter fabric, in other words, even in the region of the securing means.
Further specific features of the present invention will be described subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings in detail, FIG. 1 shows a filter for the biological filtration of liquids, especially beverages, such as, for example, beer. The filter has a container or housing 1 that can be closed off by a cover 2. Accommodated in the container 1 is a filter unit 4 composed of a plurality of rotary disk filter elements 5 that are disposed axially one above the other, and are secured to a vertical filtrate withdrawal shaft 3. The shaft 3 is disposed within the container 1, and the upper end of the shaft is rotatably mounted in a support 6 provided on the outer side of the cover 2. At the bottom, the filtrate withdrawal shaft 3 extends beyond the container 1 into a sealing and bearing housing 8. The gear mechanism accommodated in the housing 8 is associated with a motor 9 for rotating the shaft 3. The liquid that is to be filtered is introduced into the filter housing 1 via an inlet 10 and into a non-illustrated collecting chamber disposed between the cover 2 and a similarly not-illustrated distributing device mounted on a hub 11.
Each of the filter elements 5 of the filter unit 4 has the same construction. As shown in particular in FIG. 3, the filter elements 5 comprise a bottom or base plate 12 that is in the form of a ring-like member; a support mesh or fabric 14 is placed upon the base plate 12, and a filter fabric 13 is placed upon the support fabric 14, with both the fabrics 13 and 14 being secured to the base plate 12.
The base plate 12 is secured, preferably by being welded, to a collar 15 having a central bore 15a. The base plate 12, via the collar 15, is disposed on the filtrate withdrawal shaft 3. Further structural details of the filter elements 5 will be described subsequently in connection with FIG. 4, since the filter element 5 thereof, with the exception of its radial length and the use of further securing means for the filter fabric 13, has the same construction as do the filter elements 5 of FIGS. 1 and 3. Accordingly, the same parts have the same reference numerals.
As shown in FIGS. 2 and 4, to secure the base plate 12 on the filtrate withdrawal shaft 3, a retaining piece 18 is welded to a shoulder 16 of the inner wall 17 of the collar 15. The retaining piece 18, which extends into a pertaining, non-illustrated adjusting spring of the filtrate withdrawal shaft 3, has the shape of part of a circle, and is provided with a radially inner arresting opening 19. A plurality of transverse passages 20 are preferably uniformly distributed over the periphery of the collar 15. These passages open into the collar bore 15a, via which the filtrate is withdrawn and conveyed to an outlet of the container or housing 1.
The base plate 12 is welded to the collar 15 by means of an inner annular extension 21 that projects in a flange-like manner from the plane of the ring-like base plate 12. The extension 21 tapers conically in the direction toward the collar 15, with which it forms an angle of approximately 30°. When the base plate 12 is stamped, the annular extension 21 is formed by deep drawing.
The central annular zone 22, which forms the greatest part of the base plate 12, serves as the support for the large-meshed support fabric 14, on the outer surface of which, facing away from the annular extension 21, there rests the essentially fine-meshed filter fabric or fine cloth 13. The free edge 24 of the annular extension 21 is welded to the collar 15 in the region below the transverse passages 20, so that the collar 15 and the annular extension 21 together define an annular channel 23 via which the filtrate flows into the individual transverse passages 20.
As shown in particular in FIG. 3, the end faces 25, 26 (FIG. 4) of collars 15 that are disposed one above the other rest upon one another accompanied by the interposition of the associated filter fabric 13, thus preventing unfiltered liquid from flowing through between the collars in an unobstructed manner. Furthermore, to provide radial sealing of the filter fabrics 13, a groove 27 (FIG. 4) is provided in the lower end face 25 of the collar 15. Disposed in the groove 27 is a profiled ring 28 (FIG. 3) that is compressed when adjacent filter elements 5 are placed upon one another and are secured in position.
The base plate 12 is furthermore provided with a radially outer annular zone 29 (FIG. 4) that is offset in the direction opposite to that of the annular extension 21. The filter fabric 13 is looped or wrapped around this annular zone 29 accompanied by the interposition of a preferably resilient profiled seal member 30 that also extends around the outside of the annular zone 29. The profiled seal member 30 assures a good seal between the filter fabric 13 and the edges of the annular zone 29. The support fabric 14 extends only between an outer annular shoulder 31 of the collar 15 disposed above the retaining piece 18, and an opposed shoulder 32 formed between the offset annular zone 29 and the radially outer region of the central annular zone 22 (FIG. 4). The wrapped-around edge 13a of the filter fabric 13 is secured on the annular zone 29 of the base plate 12, i.e. on the seal member 30, by means of a retaining or clamping ring 33 that comprises a thin metal band and is placed over the annular zone 29. The ring 33 extends over the wrapped-around edge 13a of the filter fabric 13. During filtration, residues present in the liquid that is to be filtered are retained by the filter elements 5. In this connection, the residues are deposited on the filter elements 5, i.e. on the filter fabrics 13 thereof, as a coating. To clean the filter elements, the filtrate withdrawal shaft 3 is rotated by the motor 9 after filtration, whereby the filter elements 5 that are rigidly connected to the shaft 3 are also rotated. In so doing, the residues are centrifuged from the filter fabrics 13. In order to remove residue that is still stuck in the passage of the filter fabric 13, the filter elements are flushed with water accompanied by the supply of air, whereby this cleaning fluid or water/air mixture is conveyed through the filter elements 5 counter to the direction of filtration R. Since the air contained in the water impedes the discharge of water, a pressure builds up below the filter fabric 13, as a result of which the filter fabric is raised in the region between the clamping locations on the collars 15 and the securing ring 33. The filter elements 5 are subsequently rotated in order to press the water/air mixture through the filter fabric at greater speed. In order in this connection to avoid the filter fabric 13 being stretched beyond a permissible limit, the filter fabric is secured to the base plate 12 at a number of spaced apart locations 34, 34' (FIGS. 2 and 3). As illustrated in FIG. 2, blind or flush rivets 35 (not shown in greater detail) are preferably provided for this securement. The rivets 35 are preferably disposed in two spaced-apart circles 36 and 37 (FIG. 2) that are concentric to the axis of rotation A of the filter elements 5, i.e. of the filter unit 4.
As also shown in FIG. 2, the rivets 35 disposed on the circles 36 and 37 are offset relative to one another in the radial direction, so that a given rivet of the inner circle 36, when viewed in the radial direction, is disposed half way between two adjacent rivets of the outer circle 37. The inner and outer circles 36 and 37 are preferably spaced approximately the same radial distance from one another and from the inner and outer edge of the filter element, and hence from the securing locations 15 and 33 of the filter fabric 13 on the base plate 12. As a consequence of this securement scheme, a number of filter fabric region or zones 13b, 13c, and 13d having a relatively short free securing length 1, 1', and 1" are formed. The fabric sections 13b, 13c, and 13d have approximately the same radial width.
Furthermore as a result of this securement scheme, the securing lengths 1, 1', 1" of the zones 13b, 13c, and 13d of the filter fabric that can freely bulge during flushing under the existing liquid pressure between the securement location 35, 35', 38, 39 on the base plate 12 are relatively small compared to a filter fabric secured only between the collars 15 and the securing ring 33. As a result, there is reliably avoided an excess stretching and folding of the filter fabric 13, as well as an impairment of the filter action and damage to the filter fabric connected with such stretching and folding.
In place of the rivets, or in addition thereto, screws or bolts can also be used. At those spots where the rivets are located, the filter fabric could also be welded or soldered to the base plate.
In the filter element illustrated in FIG. 4, the securing means are disposed on three circles that are concentric to the axis of rotation A of the filter element. The securing means can either by in the form of rivets 35', or bolts or screws 38 or 39. For the purpose of simplification of illustration, in FIG. 4 these various securing means are illustrated on a single filter element.
As shown in FIG. 4, the base plate 12, the support fabric 14, and the filter fabric 13 are provided with aligned holes 46 and 47 so that the rivets 35' or the bolts 38 can be inserted therethrough; only the holes in the base plate and in the support fabric are shown. In order to prevent the edge region of the holes of the filter fabric 13 from tearing out, especially during flushing, washers or supporting disks 40, 42, 44 are provided at least on the outer side of the filter fabric 13. Preferably, however, a further washer or supporting disk 41, 43 is additionally disposed on the inner side of the filter fabric 13. The edge region of the pertaining hole of the filter fabric is clamped in a sandwich-like manner between the supporting disks 40, 41 or 42, 43.
The rivets 35' or bolts 38 are inserted into the pertaining holes 46, 47 from the underside of the base plate 12, so that the widened ends 48 of the rivets and the bolt heads 49 rest against the underside 50 of the base plate 12, whereas the shaft ends 51, 52 project upwardly beyond the surface 53 of the filter fabric. After fastening of the thus secured rivets, the rivet heads 54 rest against the outwardly disposed supporting disk 40. A nut 55 is threaded onto the end 52 of the bolt shaft; this nut 55 similarly rests against the outwardly disposed supporting disk 42.
In contrast to the bolts 38 or the rivets 35', the screws 39 are screwed into the filter elements 5 from the upper surface 53 of the filter fabric 13. The heads 57 of the screws rest against the supporting disk 44. When the screws 39 are used, no further supporting disk is provided between the filter fabric 13 and the support fabric 14. However, a threaded nut 45 into which the threaded shaft 56 of the screw 39 is screwed is provided in a pertaining opening of the support fabric. The threaded nut 45 is secured to the base plate 12, preferably by being welded thereto.
The rivets 35', or the bolts or screws 38, 39, are respectively disposed on inner, outer, and central circles that are concentric to the axis of rotation of the filter element 5. The radially inner and outer circles are preferably spaced the same distance from the clamping locations and from the central circle. With a particularly large filter element, however, the distance of the radially outer and inner circles from the central circle can be greater than the distance from the clamping locations, whereby nonetheless filter element regions or zones having relatively short free securing lengths are formed. However, it is also possible to provide large filter elements with further securing locations that are either likewise disposed on circles concentric to the axis of rotation A, or are provided at any other desired locations. This is done in order to further reduce the free securing lengths, so that the danger of damage to the filter fabric can be reliably prevented. As with the embodiment of FIGS. 1 to 3, the securing locations of the filter element 5 shown in FIG. 4 are preferably also disposed in a staggered relationship when viewed in the radial direction.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.
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A rotary disk filter element for a beverage filter for biological filtration. The filter element includes a closed base plate that is in the form of a ring-like member and on which is supported a filter fabric, with a support fabric being interposed between the base plate and the filter fabric. The filter fabric is secured to the base plate between an outwardly disposed retaining member and an inwardly disposed collar member. The collar member is provided with a supply opening for a wash fluid, especially a water/air mixture that is flushed through the filter fabric, counter to the direction of filtration, for removing filter residue for the general cleaning of the filter fabric. The filter fabric is secured to the base plate and to the support fabric at a plurality of point locations. This divides the free support or clamping lengths of the filter fabric into a number of relatively short regions that prevent the filter fabric from being overstretched and bulged during flushing. The formation of folds and damage to the filter fabric is thus prevented.
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BACKGROUND
Many power providers are currently experiencing a shortage of electric generating capacity due to increasing consumer demand for electricity. More specifically, generating plants are often unable to meet peak power demands resulting from electricity demanded by many consumers at the same time.
In order to reduce high peak power demand, many power providers have instituted time of use metering and rates which include higher rates for energy usage during ‘on-peak’ times and lower rates for energy usage during ‘off-peak’ times. As a result, consumers are provided with an incentive to use electricity at off-peak times rather than on-peak times and/or look for other ‘local’ or ‘resident’ energy sources for supplemental generation of energy.
Presently, to take advantage of the lower cost of electricity during off-peak times, a user must manually operate appliances or other electronic devices during the off-peak times. This is undesirable because a consumer may not always be present in the home, or awake, to operate the appliance during off-peak hours. This is also undesirable because the consumer is required to manually track the current time to determine what hours are off-peak and on-peak. Therefore, there is a need to provide a system that facilitates operating appliances or other devices during off-peak hours in order to reduce consumer's electric bills and to reduce the load on generating plants during on-peak hours. Additionally, there is a need to provide a system that (in combination with the aforementioned) incorporates a method for enlisting the generation of energy at a ‘local’ source that can be used to supplement the energy being supplied by a utility, wherein a cost of energy generation at the ‘local’ source is compared against the cost of energy supplied from the utility.
SUMMARY
In one aspect of the disclosure, a household energy management system is provided comprising a controller for managing power consumption of at least some of the multiple devices for a household wherein the controller monitors energy usage data from a utility. The system further provides a utility meter for measuring an amount of the energy usage data by the household and a user interface through which a user can enter a parameter of the energy usage. The system yet further provides a local generator for generating local energy at the household for one or more of the energy consuming devices, wherein the controller automatically initiates the operation of the local generator when the energy usage of the energy consuming devices exceeds a predetermined energy usage level. A demand server is provides for switching at least some of the energy usage from the utility to the local generator. A communication network is provided for connecting the controller to the utility meter, the local generator, and the demand server; and, wherein the controller switches circuits through the demand server and changes at least some of the energy usage from the utility to the local generator during a period when said energy usage level is within the predetermined percentage range of the parameter.
In yet another aspect, the disclosure provides a household energy management system comprising: a controller for managing power consumption of multiple devices within a household wherein the controller monitors energy rates from a utility. A utility meter is provided for measuring an amount of energy usage by the household. The system further provides a user interface through which a user can enter a parameter of energy usage. A local generator is also provided for generating local energy at the household for the household, wherein the controller automatically initiates operation of the local generator when the energy rates are above the parameter of energy usage, wherein the parameter is an energy cost of generating local energy at the household. A communication network connects the controller to one or more of the utility meter, the local energy source, and a demand server; and, the controller switches circuits through the demand server and switches or dispatches at least some of the energy demand from the utility to the local energy source when the energy rates are above the parameter of energy usage.
In yet still a further aspect, the disclosure provides a household energy management system comprising a controller for managing power consumption of multiple specified devices within a household, wherein the controller monitors energy demand from a utility. A utility meter is provided for measuring an amount of energy usage by the household. The system further provides a user interface through which a user can enter a parameter of energy usage. The system still further is provided with a local generator for generating local energy at the household for one or more of the energy consuming devices. The controller automatically initiates the generator when the energy demand of the multiple specified devices is above a parameter of energy usage, wherein the parameter is the energy demand from the utility. A communication network connects the controller to one or more of the utility meter, the local energy source, and a demand server; and, wherein the controller switches circuits through the demand server and switches or dispatches at least some of the energy demand from the utility to the local energy source during a period when the energy demand is above the parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a home energy manager; and,
FIG. 2 is a graph displaying energy usage wherein a local or resident generator can be used for energy peak shaving.
DETAILED DESCRIPTION
The present disclosure is an energy management system that may be used with an appliance, and/or a household of devices, in order to reduce household electricity costs and also to reduce the load on generating plants during peak hours of electricity usage. The energy management system is applicable to, and can be used in conjunction with, any type of device(s) such as a dryer, a washing machine, a dishwasher, an oven, a refrigerator, pool pump, load connected to a 120 v outlet, load connected to a 240 v outlet, etc.
In one embodiment, the energy management system may include a user interface, a time keeping mechanism, and a mode selecting device. The user interface may be any type of interface such as a touch screen, knobs, sliders, buttons, speech recognition, etc, to allow a user to input a schedule of on-peak times or schedules and off-peak times or schedules for each day of the week. The schedule of on-peak times and off-peak times for a household may typically be obtained from a generating plant or power utility that services the household. The schedule may be obtained from published tables made available to the public or other means such as billing statements. If the schedule of times changes, the user may use the user interface to alter and update the schedule that was previously entered.
The terms “on-peak” and “off-peak”, as used herein are meant to encompass time periods that an energy supplier has designated as referring to periods of high energy demand or cost and periods of low energy demand or cost, respectively. It may be that in some situations, multiple levels are designated by the energy supplier and thus on-peak is meant to refer to those periods where the energy demand or cost is greater than some other period, with the other period being referred to as off-peak. In any given situation, on-peak may not be the highest level of cost or energy demand and off-peak may not be the lowest level of cost or energy demand.
The energy management system 10 can also include a time keeping mechanism (not shown) that provides information to the devices within a household and user regarding the current time of the day. In one embodiment, the time keeping mechanism also includes a calendar function to provide information regarding the day of the week and the current date. The current time and date may be input or adjusted by the user via controls on the time keeping mechanism.
Utility companies are starting to develop sliding rate scales based upon time of use for power consumption. A home that can manage a response to a different rate schedule will be able to consume energy more cost effectively. A time of day (TOD) import to the devices in the household will allow the unit to run at times, on more occasions, and/or during more periods when utility rates are low or off-peak. The time of day input can be manually entered or automatically received by the devices (an example of automatic updating would be using a radio wave or radio clock to sync to an atomic clock signal, or updates would be received from the meter network or from the interne etc. . . . ). The time of day feature or off-peak manager can effectively save the consumer money by running the devices according to a pre-determined schedule, i.e. predominantly, when the rates are lower. To be described in more detail hereinafter, the energy management system 10 can also provide a local energy source or local/resident generator to substitute, apportion, or supplement energy supplied by the utility for household consumption.
In addition to the aforementioned, the mode selecting device allows the user to select an energy management mode which utilizes the local energy source. The mode selecting device may be a single button such that the energy management mode is selected when the button is depressed. Alternatively, the mode selecting device may also be two separate buttons, a switch, a touch panel, or any other type of device that allows for selection of the energy management mode. Although the control panel, the user interface, the time keeping mechanism and the mode selecting device (not illustrated) can be four separate elements, each of these elements, or any combination thereof, may alternatively be incorporated into a single interface or display to provide for ease of use.
The present disclosure contemplates the use of algorithms in a home energy manager (HEM) or controller 20 to compare the cost of energy 27 (i.e. energy rate) from a utility 21 supplied to the household 22 to the cost of energy 23 from a local generator or local power source 24 (i.e. solar, wind power, gas powered generator etc.). The algorithm will allow the devices in the household to be supplied solely by the “utility generated” energy until the local power source 24 is initiated.
The energy management system 10 can further include the controller 20 connected to the control panel and the mode selecting device in order to receive signals regarding the operation selected by the user via the control panel and the mode selected by the user via the mode selecting device. The controller 20 can also be connected to the user interface and the time keeping mechanism, and preferably includes a memory for storing the schedule of on-peak and off-peak times input via the user interface, as well as the current time and date. In one embodiment, the controller 20 has a circuit, software, and/or firmware (hereafter collectively referred to as “firmware”) to determine a time to initiate the selected operation based on the selected mode, and also to determine whether a local power source or local energy generator 24 should be utilized (to be described hereinafter).
The present disclosure provides a system and method for coordinating a suite of demand response devices that are capable of responding to incoming signals from utilities 21 signifying an on peak period (i.e. a load shedding event). In addition to the devices that are demand response ready, the HEM 20 can provide feedback to the user regarding the performance of the devices through home usage data 30 . The user will be able to monitor and/or modify the device responses as well as get real time feedback as to the energy consumption of the devices. For electrical devices, the HEM 20 can rely upon current transducers, shunts, meter pinging, or lookup tables or algorithms to characterize the power consumption of the devices at any given point.
Referring to FIG. 1 , the present disclosure provides a system and method of providing information to the HEM 20 from the local generator 24 (via generator usage data 32 ) wherein the HEM 20 can control (i.e. load control 33 ) the local generator 24 to optimize the overall energy usage, demand, or need levels. The generator 24 can be used in several ways to optimize the energy usage within a home 22 . For example, the generator 24 can be automatically started and the home 22 can be taken off the utility grid, using switch circuits via isolation circuit, during specific grid loading or price point states. If, for example, generator 24 is a gas powered generator, fuel consumption rates can be monitored on a real time basis using flow sensors, level sensors, or mass sensors or some combination thereof, and the system can make suggestions to which loads to curtail and then predict the remaining time for fuel to run out with each suggestion. In conjunction with knowing the load on the generator 24 (i.e. data can be retrieved from the HEM 20 ), and the fuel usage rates at a given load, a cost analysis can be done to predict cost to operate for remaining hours or minutes of fuel. The HEM 20 can present the user with pie charts showing the usage over a number of days and prioritize the devices in the order of load or consumption over the timeframe. The system can continually and automatically control loads 31 , 33 to prevent running out of fuel, using a priority curtailment scheme (for instance, the refrigerator would be the last item to curtail or possibly the load to never curtail, heat may be next, critical lighting next, etc.). The user can specify a predetermined duration for the fuel in the tank to last last and the system 10 could layout a usage pattern for the user to achieve this goal, or tell the user that the goal was unrealistic. Likewise, the system 10 could predict when the fuel would run out by looking at previous days and assuming that today will be equivalent. The system could also import weather data forecasts using an internet connection to better predict fuel usages. The system 10 can provide this information to the user which would then allow the user to modify the load control 33 to conserve fuel. The system 10 can also process data to search for outliers between different days usage, and flag the devices/appliances that caused any outlier (the HEM would know what device was running when). For example, the system might be aware that the refrigerator used an excessive amount of energy during a given timeframe due to excessive door openings and could flag the user regarding this fact. Suggestions could be made to the user to modify or curtail these loads to minimize the usages. It is to be appreciated that the system 10 networks the HEM or controller 20 to one or more of the utility meter 40 , the local energy source (local generator) 24 , and a demand server 42 . The HEM 20 switches circuits through the demand server 42 and switches or dispatches at least some of the energy demand from the utility 21 to the local energy source generator 24 at pre-determined scheduled periods or per-determined threshold periods.
The generator can be designed with the capability to modify the waveshape of the output signal to provide a different RMS output voltage. This waveform change could be triggered by demand response events to again lessen the load on the generator. The generator's internal combustion engine can further be provided with a turbocharger or supercharger to provide varying output power to coincide with variable loads that might be encountered. The wastegate of the turbocharger or supercharger can be controlled by input signaling to adjust the power output as required. This would provide for a system that would use less fuel in low load conditions, yet have the power for high loading conditions. The generator can be setup with multiple voltages, including a panel setup, to provide lower voltages to be connected to specific branch circuits that have pure resistance loads (such as incandescent lighting, hair dryers, space heaters, etc) to lessen the power consumption. The lower voltage outputs could be triggered via utility demand state or cost signal inputs. Providing the HEM with the ability to determine a conversion rate between electricity/natural gas/other resources, the total cost of running a load can be optimized by using the power from different sources. The local generator 24 can be used for peak demand 64 or energy peak shaving 60 , i.e. if the whole home energy demand 50 is beyond a certain point or threshold 62 then the local generator 24 can be initiated to cover for the peak demand 60 above the threshold 62 ( FIG. 2 )
With reference again to FIG. 2 , the triggering of the generator 24 to supplement or replace the “utility provided” energy can be better defined as noted below. The solid curve shows a given household energy demand 50 during a twenty-four hour period. The threshold 62 is a limit that can be set by the homeowner, beyond which the goal is to truncate the usage of energy provided by the utility 61 . Once this threshold 62 is achieved, the peak shaving generator energy 60 will be supplied to the household by the generator to supplement the “utility provided” energy 61 beyond the threshold level 62 . In this manner, the energy management system will initiate the generator to start and begin providing energy as the threshold 62 is engaged. Referring to FIG. 2 , it is to be appreciated that the demand upon the generator will vary (reference 60 a , 60 b , and 60 c in FIG. 2 ) in time as the total household demand 50 follows the whole home usage curve and the “utility provided” energy level 61 remains constant at threshold 62 . The aforementioned provides a system for managing the energy usage and energy demands of the home and gives the user an option to switch between different sources of energy (main utility and ‘local’ generation). Minimizing the overall cost of running energy loads in the home is an attractive option for the customer. Decreasing the load on the grid during a peak time period or peak consumption 64 is beneficial for the utilities as it is a decrease in load for their system.
It is to be appreciated that the operation of the local generator 24 can be initiated by one of several instances that are being monitored by the energy management system 10 . These instances can be as straight-forward as an incoming signal from the utility requesting the shedding of load on the grid, or can be more complex involving price comparisons between running the local generator 24 to generate power versus purchasing energy 100% from the utility at the going rate. Likewise, the user could select thresholds that are programmed into the energy management system 10 that trigger the local generator 24 to start and deliver energy at the moment the threshold is exceeded. Additionally, the output or loading of the local generator 24 could be adjusted or throttled based on multiple thresholds being achieved. This adjustment in output could be achieved by a speed adjustment in the local generator 24 or with other means of loading or unloading the generator.
In another embodiment, a method is provided for managing energy usage of a plurality of appliances. The method can comprise receiving a schedule having a peak demand or cost period; storing the schedule in a memory; determining the current time; and initiating operation of the local generator during the peak demand or cost period; initiating the operation of the local generator when the total energy usage exceeds a specific user defined threshold as defined via the energy management system user interface.
While various embodiments of the application have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this disclosure. Accordingly, the disclosure is not to be restricted except in light of the attached claims and their equivalents.
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A household energy management system is provided comprising a controller for managing power consumption of multiple devices within a household wherein the controller monitors energy usage data from a utility. The system further provides a utility meter for measuring an amount of energy usage by the household and a user interface through which a user can enter a parameter of the energy usage. The system yet further provides a local generator for generating energy for one or more of the energy consuming devices wherein the controller initiates the generator and changes at least some of the energy usage from the utility to the local generator when the energy usage level is within a predetermined percentage range of the parameter.
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This is a division of application Ser. No. 247,929 filed Mar. 26, 1981, U.S. Pat. No. 4,366,778.
BACKGROUND OF THE INVENTION
There exists on the market so-called "air vent" gas boilers with sealed combustion circuit.
These boilers are in general placed against a wall and raised up. Their power does not, in practice, exceed 70 kW for, above this value, there exists no boiler/burner combination to satisfy the problem of "vent hole" operation.
SUMMARY OF THE INVENTION
The present invention has as its principal objective the provision of a compact and low-priced boiler, which can be operated in a sealed combustion circuit with powers appreciably greater than those of known vent-hole boilers.
To this end, the boiler, closed in a sealed casing forming a fore-hearth, which surrounds it on all sides while providing thereabout a space in which the combustion air arrives is essentially characterized in that said combustion air is injected under pressure into the space which surrounds the boiler.
When this air is taken from the outside, the boiler operates in a sealed combustion circuit, the air-intake ducts and the burnt-gas exhaust ducts being able to be situated close to one another so that the possible wind had no influence on the combustion air flow.
Fresh air may also be sucked into the boiler room, the duct for discharging the combustion products then being connected to a chimney.
The "pressurized" fore-hearth which surrounds the boiler on all sides prevents any leakage of the combustion products from spreading into the boiler room.
It serves as a very efficient heat insulator allowing a very low temperature of the outer walls of the casing to be obtained and protects from the heat the safety and control apparatus which are housed therein.
Advantageously, the casing is disposed vertically and provided with a removable cover at its upper part, the boiler comprising a box containing an exchanger and one or more vertically disposed burners so that the air-gas mixture of these burners flows from top to bottom, the fresh air and the gas being injected at the upper part. Thus, not only is the maintenance of the burner easy, but there occurs natural circulation of the injected air which ensures cooling of the boiler without requiring excess power of the fan and with preheating of the air supplied to the burner, so recovery of heat increasing the overall efficiency of the boiler.
The exchanger is formed preferably from vertical-finned tubes disposed around the burner(s) or on each side thereof, these tubes being connected at their ends to water inlet and outlet manifolds. Thus higher power is obtained in a compact apparatus.
This exchanger may be combined with a tube for supplying hot water for sanitary or industrial purposes for example. The burner(s) are fed with air and gas in substantially stoechiometric proportions. They comprise advantageously a tubular body having holes over the whole of its height facing the tubes of the exchanger, the distribution of the heat flow being provided by partial and suitable closure of the holes.
The boiler is particularly suitable for supplying heating installations combined with a hot-water supply service or not.
In accordance with a particular embodiment of the boiler of the invention, its exchanger is divided into two parts in the vertical direction by a refractory floor, which allows it to play, in the part which is situated above this floor and which contains the burner(s), its conventional role as an exchanger, and in the part which is situated below the floor, and where it receives cold water, both a role as an exchanger and a role as a condenser of the combustion products.
This configuration of the exchanger further improves the efficiency of the boiler of the invention.
Indeed no one is ignorant of the fact that the effiency of boilers is a determining element in the field of energy economy.
The boilers constructed at present have their efficiency pushed practically to their extreme limit. The only reason which prevents a truly maximum efficiency being reached is that the combustion products carry away heat to the outside because of their temperature. These combustion products are nitrogen, CO 2 and especially water vapor whose weight is relatively considerable; 1.611 kg per m 3 of natural gas burnt according to the reaction diagram below:
CH.sub.4 +2O.sub.2 (+N)→CO.sub.2 +2H.sub.2 O(+N)+214 kcal (895.690 kJ),
214 kcal being the exothermic heat.
It is then important to be able to recover the greatest possible part of the heat carried off by the combustion gases and the greatest part of the water vapor whose condensation allows 516 cal/kg (2159.710 J)--latent vaporization heat--to be recovered.
To reach this result, it is sufficient to cause the burnt gases mixed with the water vapor to pass through an exchanger placed at the outlet of the boiler.
This may be formed from smooth or finned tubes in which flows the return water from the radiators. The condensation phenomenon begins as soon as the temperature of this water drops to below 59° (dew point).
The recovery of the heat contained in the combustion gases begin as soon as the temperature of the return water is less than that of the burnt gases.
The price of this exchanger is relatively higher, which limits the use thereof.
This disadvantage is overcome with this new configuration of the exchanger which allows the boiler of the invention to be provided with an exchanger-condenser, and this without great effect on the cost price of the boiler.
According to other particular embodiments of the present invention, structural modifications may be made concerning the burner(s) and the fins of the exchanger.
The first modification to the burner consists in providing additional air intake orifices in the region of the body of the burner which follows after the zone of the mixer.
The advantage of this improvement resides in the fact that a fairly large part of the combustion air which penetrates into these orifices--whose diameter will be judiciously calculated--is taken from that which passes through the mixer. Now, the main pressure drop of the combustion air circuit is situated precisely in the zone of the mixer. Thus, without changing the total amount of air which is introduced into the burner, and by causing less air to pass through the mixer, the pressure drop of the air flow is reduced, which causes a lesser air pressure in the fore-hearth. It is then possible to use a less powerful fan, which economizes electric energy and reduces the construction price. Furthermore, the air introduced through said orifices creates a turbulence favorable to the air-gas mixture.
The second modification consists in making the manifold independent of the burner ramp, which enables this latter to be easily fitted and refitted without removing the manifold which is integral with the gas inlet.
For this purpose a double-wall manifold will be provided, whose inner wall forms a cylinder which is coaxial with the ramp.
The ramp is slidable with an easy fit inside the above-mentioned cylinder.
The gas arrives into the mixer through orifices disposed in a ring and provided in this inner wall. It will be preferably arranged for these orifices to open above the ramp of the burner so that the gas penetrates freely, otherwise it would be necessary to provide also perforations in the ramp itself.
Additional air intake orifices will be advantageously provided, which form the subject matter of the preceding modification. In this case, the extended inner wall of the manifold and the ramp will comprise facing orifices for the introduction of this additional air.
The above-mentioned modification which may be made to the exchanger consists in modifying the arrangement of the fins of the tubes of this exchanger so that the fins of one tube are staggered in height with respect to those of the adjacent tube, which enables the different tubes forming the exchanger to be brought closer together.
In exchangers where the water tubes are disposed either in rings or in lines, the fins of one tube are all situated at the same level as those of adjacent tubes and the fins of the exchanger which are in the same plane are disposed almost touching. V-shaped baffles must be placed on the outside of the tubes so that the combustion flames effect the maximum area of the fins.
The layout of the fins in accordance with this particular embodiment causes the flames and the hot gases to lick directly a large part of the section of the fins, without need for baffleplates.
Furthermore, this arrangement allows, on the one hand, for the same number of tubes, the volume of the exchanger to be reduced, thus causing a reduction in the dimensions of the boiler and so a reduction in its cost price and, on the other hand, for the same space (same diameter of an exchanger with tubes disposed in a ring), a larger number of tubes to be provided (as a general rule 25% more) which contributes to improving the efficiency of the boiler.
It goes without saying that if a zone is provided for condensation of the water vapor resulting from the combustion, as outlined above, the fins of the section of the exchanger-condenser will have to be disposed in the advantageous way which has just been defined.
DESCRIPTION OF THE DRAWINGS
There will be described in detail hereafter by way of indication and in no wise limiting several embodiments of the boiler in accordance with the present invention with reference to the accompanying drawings in which:
FIG. 1 is a top view with partial horizontal section of a boiler in accordance with the invention.
FIG. 2 is a section through II--II of FIG. 1.
FIG. 3 is a similar view of FIG. 1, but showing a variation.
FIG. 4 is a section through IV--IV of FIG. 3.
FIG. 5 is a developed schematical view of an exchanger arranged so as to supply hot water for domestic use.
FIG. 6 is a view in vertical section of a boiler fitted with an exchanger-condenser, in accordance with one particularly advantageous embodiment of the invention.
FIGS. 7 and 8 each show a view in vertical section of a variation of a burner fitted to the boiler of the invention.
FIG. 9 is a view partly in horizontal section of the exchanger of the boiler according to FIG. 1 and FIG. 10 is a view similar to the preceding one, showing an interesting variation of the arrangement relative to the fins.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment shown in FIGS. 1 and 2, the boiler comprises a vertical sealed casing 1, which may be placed on the ground on a base 1a and is closed at its upper part by a removable cover 1b. The cross-section of casing 1 may have any shape, square for example.
Casing 1 contains a box 2, smaller in cross-section and smaller in height, disposed so that there is provided a free space on all its faces. Box 2 is provided with a removable cover 2a.
It contains an exchanger formed of tube 3, disposed vertically along the generatrices of a cylinder, as shown in FIG. 1, between two annular manifolds 4. The water to be heated enters the lower manifold through a pipe 5 and leaves the upper manifold through a pipe 6. As can be seen in FIG. 2, pipes 5 and 6 pass sealingly through the walls of box 2 and casing 1.
The bottom of box 2 and cover 2a are placed in contact with the exchangers through annular bosses 2b with which they are provided (FIG. 2). Tubes 3 are provided, over the whole of their length, with fins 3a for increasing the heat-exchange surface. Furthermore, vertical V-shaped baffles 3b are disposed on the outside of tubes 3, as shown in FIG. 1, for causing the gases to lick said tubes.
Cover 2a of box 2 has a circular axial orifice 2c through which there is introduced, in the axis of the exchanger, a burner 7 which presents in its upper part, a sealing ring 7a which rests on this lid 2a (FIG. 2).
At its upper part, outside box 2, the burner comprises a mixer 8, formed from an annular jacket which surrounds the tubular body of the burner.
The gas arrives through a lateral tube 9, which passes sealingly through the wall of casing 1 and in which are mounted, inside casing 1, the regulation and control devices 9a.
The gas passes into the body of the burner through a ring of injection holes 10 situated at the upper part of the mixer.
The air inlet section of this latter is regulated by means of a cylindro-conical core 11, provided with an upper collar 11a and which is caused to penetrate to a greater or lesser extent into the body of burner 7.
This body extends into box 2 as far as the bottom of the lower manifold. It is closed at its base and pierced over the whole of its portion facing tubes 3 with multiple rings of small holes 12 through which the air and gas mixture leaves. This outlet through multiple small holes prevents flashback of the flame.
So that the fins 3a of the exchanger receive the same amount of heat over the whole height of tubes 3 despite the convection movements of the burnt gases in the vertical direction, the perforated portion of the burner is provided with covering rings 13 which are brought together to a greater or lesser extent so as to free the number of holes required. Two rings 13 only are shown in FIG. 2 so as not to complicate the drawing.
The upper part of casing 1 is connected to a fan 14 which pressurizes the fore-hearth 15 formed by said part, as well as the annular space 16 which surrounds box 2 and the lower part 17, situated under this box.
The burnt gases are collected in space 18 where they arrive after passing between tubes 3, 3a and they leave box 2 through a lateral pipe 19 which passes sealingly through the wall of casing 1 then wall M.
The fresh air is supplied to fan 14 by a pipe 20 which also passes through wall M.
The boiler which has just been described operates as follows: fan 14 draws fresh air through pipe 20 and pressurizes spaces 15, 16 and 17 of casing 1 which forms a fore-hearth. This air is forced into mixer 8 where it is mixed with the gas leaving the injection holes 10.
After ignition, the mixture burns around burner 7, passes between tubes 3, 3a, while circumventing them, because of the presence of baffles 3b, reaches space 18 and leaves through pipe 19.
Pipes 19 and 20 open substantially in the same vertical plane and at a small distance from each other, the wind which is possibly exerted on their orifices makes constant the differential inlet and outlet pressures of the air. The result in this case is an overpressure in the fore-hearth, which has no appreciable effect on the pressure differences and so on the flow of combustion air.
In the variation of FIGS. 3 and 4, the finned tubes 3, 3a of the exchanger are disposed along two parallel lines and vertical screens 3c are provided at the ends of these lines, between these latter, so as to force the gases to pass between the tubes.
The upper manifold has two compartments 4a and 4b which communicate respectively with one and the other of the lines of tubes, water being taken in at 5 in compartment 4a and exiting at 6 from comprtment 4b. The water flows then from top to bottom in the right-hand tubes and from bottom to top in the left-hand tubes, as shown by arrows in FIG. 4. Three burners 7 are disposed vertically and in line between the two lines of tubes 3. They are supplied from pipe 9 by means of a manifold 9b.
The operation is the same as that of the previously described embodiment.
If it is desired to produce hot water, for example for domestic, sanitary or industrial purposes, without being obliged to pass through an external exchanger, all that is required, whatever the variation adopted for the boiler, is to pass a tube 21 through tubes 3 and manifolds 4. The inlet for the water to be distributed is at 22 and the outlet at 23, in FIG. 5.
Tube 21 is preferably made from copper or stainless steel. The heat exchange is very active because of the large contact area and the high speeds of the water on both sides. The volume of the boiler remains the same.
The advantages which the present invention brings are multiple.
The overpressure which reigns constantly in casing 1 about box 2 prevents any leakage of burnt gas from spreading into the boiler room.
The presence of air in spaces 15, 16 and 17 avoids the need to use heat-insulating products on the walls of casing 1. In fact, the air heated in lower spaces 16 and 17 rises in the casing where it mixes, in space 15, with the fresh air blown by the fan. The result is a thermosiphon flow which, on the one hand, prevents excessive heating up of the air and, on the other hand, ensures reheating of the air which penetrates into mixer 8. The heat thus recovered participates in a better overall efficiency of the boiler. The energy to be produced by the fan is moreover economized. The control and regulation apparatus 9a operate well for they are cooled by the intake of fresh air into the upper space 15 where they are placed.
The mixture of air and gas may be proportioned stoechiometrically in the mixer(s) 8, which allows a very short flame to be obtained and so an extremely reduced hearth capacity. The central part of the mixer(s) formed by the cylindro-conical core 11 is easily removable and allows easy access to the body of the burner. Now, it is inside this body and on the small holes 12 that dust may collect. After lifting cover 1b and core 11, simple brushing causes the dust to fall to the bottom of the burner which has been extended for this purpose downwards under the perforated portion. Thus there is no need to provide a filter in the fresh air intake, which would be more difficult to clean than the burner. Furthermore, abnormal fouling up of the inside of the burner is signaled by the air flow controller which automatically stops the boiler. Removal of the burner presents no difficulty once the cover 1b of the casing has been removed.
The vertically positioned exchanger offers advantages: in the embodiment of FIGS. 1 and 2, the intake of water at the bottom and the discharge thereof at the top allow a complete air purge. Furthermore, since water flows through all the tubes at the same temperature, no tension problem occurs due to the differences of expansion.
Whatever the embodiment adopted, the installation is very simple since it is sufficient to cause pipes 19 and 20 to pass on the outside, their outer orifice being preferably protected by a grid.
If the advantage of the sealed circuit is not desired or cannot be put into effect, it is sufficient to connect pipe 19 to a chimnny, the fan then sucking air into the boiler room.
The fan may be calculated so that an appreciable residual pressure is provided at the outlet for the combustion products. Thus the section of the chimney or the section of the pipes 19 and 20 which connect the boiler to the outside may be considerably reduced when the sealed circuit is used as a whole.
A 200 kW boiler has been constructed in accordance with the invention which measured on the ground 0.50×0.45 m and had a height of 1.05 m. This volume is about a seventh of that of a conventional gas boiler. The weight is correlatively reduced, the boiler being able to be transported in the rear boot of a light saloon car.
The boiler shown in FIG. 6 conforms to a particular embodiment of the invention. Like the boiler shown in FIG. 1, it comprises a vertical sealed casing 1 which may be placed on the ground on a base 1a and which contains a box 2 whose cover 2a had a circular axial orifice 2c through which is introduced a burner 7 which presents, in its upper part, a sealing collar 7a which rests on this cover 2a. Burner 7 comprises an air-gas mixer 8, situated outside box 2, into which the gas arrives through a lateral pipe 9 in the path of which are placed the regulating, control and safety apparatus 9a. The air is brought by a fan 14, which causes an overpressure in fore-hearth 15, the annular space 16 surrounding box 2 and the lower part 17 situated under this box. The burner 7 is extended inside box 2, substantially over half of its height or more, by a cylindrical ramp pierced with multiple rings of small holes 12 (about 8/10ths of a millimeter in diameter) through which exits the fired air-gas mixture, closure strips 13 also being provided. Box 2 contains an exchanger formed from tubes 3 having fins 3a, disposed vertically between two annular manifolds 4, and in a ring about the ramp of burner 7.
In accordance with this particular embodiment of the invention, these tubes 3 extend beyond this ramp.
The water to be heated enters the lower manifold through a pipe 5 and leaves the upper manifold through a pipe 6.
A refractory floor 24 situated below the bottom of burner 7 in the space limited by the tubes 3 to which it is fixed by any appropriate means, separates the inside of the exchanger 3 into two parts, the top part 24a forming the exchanger properly speaking and the lower part 24b receiving at 5 the return water (cold water) and operating as an exchanger-condenser.
To this end, the combustion gases (comprising water vapor) leaving part 24a are fed again laterally into part 24b, the water to be heated entering part 24a after recovering the condensation heat in part 24b, thus improving the efficiency of the boiler.
The lower manifold 4 is spaced apart from the bottom of box 2. It rests on a plate 25 having a central opening 26 and a side opening 27 opening into a vertical pipe 28 conveying the burnt gases to the outside and terminating for this purpose in an outlet bend 29 substantially half-way up box 2.
Plate 25 and the bottom of box 2 define a sealed tray 30 having a lateral pipe 31 for discharging the condensation water.
The path followed by the burnt gases, including water vapor, is then the arrowed path 32. The condensation water is collected at 31 and may be recovered as distilled water.
FIG. 7 shows a burner 7 with the annular jacket of mixer 8 and the cylindro-conical core 11 for regulating the air intake section into the mixer, this burner 7 having, in this variation, the particular characteristic of having a series of air intake holes 33 (for example a ring of holes) situated between collar 7a and mixing zone 8. Improved efficiency of the burner has been noted for the reasons which were outlined above in the introduction.
FIG. 8 illustrates another constructional variation of the burner in which the annular jacket 8 which forms the gas manifold is double-walled, the external wall 8a not having undergone any modification and the internal wall 8b forming a cylinder which is coaxial with ramp 7 and which is extended moreover as far as the box 2 of the boiler where it carries a collar 8c which rests on cover 2a of box 2.
The internal wall 8b comprises a ring of holes 10 for the injection of the gas, whose outlets are situated a little above the top of ramp 7.
This latter fits with a sliding fit in tube 8b; it carries at its upper part a lug 36 which may be formed by an extension of its wall and which is perforated to allow a positioning pin 37 to be passed therethrough, which also passes through wall 8b of the manifold.
During maintenance inspection, the operator removes pin 37 and ramp 7 so as to check it and clean it. It may be easily put back in place since all that is required is the reverse operation.
Gas injection holes 10 may also be checked without it being necessary here again to disconnect the gas inlet.
It will also be noted that additional air inlet orifices 33 may be envisaged as a variation in accordance with FIG. 7, orifices 33a situated opposite orifices 33 having to be provided in wall 8b.
Furthermore, insofar as the exchanger of the boiler of the invention is concerned, whose tubes 3 are disposed either in a ring around a single burner (FIG. 1), or in lines (FIG. 3), its fins 3a will be situated in the same horizontal plane practically touching, as can be seen in detail in FIG. 9. In this case, so that the combustion flames affect the maximum area of fins 3a, baffles 3b must be placed to force the flames or very hot gases to pass round the tubes and their fins 3a before leaving through slits 34. To avoid this drawback, tubes 3 may be disposed as shown in FIG. 10, the fins 3a of one tube being staggered in height with respect to the fins 3a of the adjacent tubes 3, and the outer edge of each fin 3a practically touching the adjacent water tubes 3. This disposition forces the flames and hot gases to lick a large part of the section of the fins, which enables baffles 3b to be done away with without any disadvantage.
It will moreover be readily understood that the embodiments of the present invention which have just been described have been given by way of indication and are in no wise limiting and that modifications may be made thereto without departing from the scope and spirit of the present invention.
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This boiler is enclosed in a sealed casing forming a fore-heath which surrounds it on all sides while providing thereabout a space into which the combustion air arrives.
The combustion air is injected under pressure into a space which surrounds the boiler and an exchanger is divided into two parts in the vertical direction by a refractory floor in one embodiment, which enables it to function as an exchanger in the upper part and in the lower part cold water is received where the exchanger functions as an exchanger and a condenser; the burner may have features to reduce the pressure drop of the combustion air flow and to permit ease of assembly and disassembly.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of treating a yarn end which presents in the knitting start portion (hereinafter described as "initial portion") of a fabric knitted by the use of a flat knitting machine.
BACKGROUND OF THE INVENTION
In the case of knitting with a flat knitting machine, the following steps are usually taken at the beginning of knitting. A knitting yarn is fed into a knitting region by a yarn feeder for guiding the knitting yarn to knitting needles on a needle bed in such a state that a yarn end of the knitting yarn is held by a yarn end holder arranged outside the knitting region in a lateral direction of the needle bed on the top face of which a plurality of knitting needles are implanted. Subsequently a suitable quantity of courses are knitted. Thereafter the yarn end held by the yarn end holder is released and pulled down with the knitted fabric in such a state that the yarn end is associated with the initial portion of the knitted fabric. In the fabric knitted in such manner, a portion of the knitting yarn which exists from the yarn end held by the yarn end holder to the position actually fed to the knitting needles is not knitted into the knitted fabric, and becomes a yarn end portion exposed outside the knitted fabric along the initial portion.
In the case of knitting an attachment piece to be sewn together with a piece such as a collar or front body for the purpose of reinforcement, the attachment pieces are usually knitted by continuous knitting. The continuous knitting means continuously knitting such attachment pieces having a predetermined length one by one without cutting the knitting yarn in a state that the respective attachment pieces are connected with one another via a draw yarn. When such continuous knitting is conducted, a yarn is left among the knitted attachment pieces at an interval of a course knitted by the draw yarn. After knitting the attachment pieces is completed, the draw yarn connecting the attachment pieces is cut and removed, and the yarn among the knitted attachment pieces is cut in order to separate the respective knitted attachment pieces from one another. As a result, the cut yarn remains at the initial portion of each attachment piece and exposed itself outside the knitted attachment piece.
In order to treat the yarn end remaining at the initial portion of these knitted fabrics, the yarn end is conventionally pulled into the initial portion of each knitted fabric using a crochet needle after the completion of knitting with a knitting machine.
In such a conventional manner, it is necessary to insert the crochet needle into the knitted fabric in order to pull the yarn end into the knitted fabric. However, it is hard to insert the crochet needle into tight loops of stitches, and when the crochet needle is forcibly inserted into the loops of the knitted fabric, the loops become loose, which damages the commercial value of the knitted fabric.
Besides, technical skill is required to conduct the operations of the manner with a crochet needle. For example, operations carried out by those unskilled in the manner might cause fraying of a yarn end. Thus, such treatment manner of the yarn end with a crochet needle is not an effective and successful treatment which can be achieved regardless of the level of operator's skill.
SUMMARY OF THE INVENTION
In view of the above problem, an object of the invention is to provide a method of treating a yarn end of a knitted fabric which can enhance working efficiency as well as can be successfully and easily conducted without a special tool like a crochet needle even by those unskilled.
In order to achieve the object, the method of treating a yarn end of the invention is practiced in a flat knitting machine wherein at least a pair of needle beds either or both of which can be moved right and left are arranged in front and in rear, and comprises the following steps.
Firstly, knitting needles provided in one of the pair of needle beds and positioned in a range corresponding with the knitting width of a desired fabric are fed with a draw yarn to form at least one course of stitches. Secondly all or a part of the knitting needles used for knitting the draw yarn are fed with a knitting yarn to form at least one course of stitches, and subsequently the knitting needles provided in the front and rear needle beds are fed with the knitting yarn to begin knitting of rib stitches. Then the knitting needles of either the front or rear needle bed are fed with the knitting yarn in order to knit a successive course, and thereafter the knitting needles of the other needle bed are fed with the knitting yarn to knit firstly tubular plain stitches and then desired stitches. After the completion of knitting a desired fabric, the knitted fabric is taken out from the flat knitting machine, and then the draw yarn is drawn from the knitted fabric. Thereafter a yarn end remaining at the initial portion is pulled out from the knitted fabric, and the yarn end pulled out is cut in a region near a side end of the knitted fabric in such a state that the initial portion is contracted. The yarn end remaining at the initial portion after the cutting is pulled back into the initial portion of the knitted fabric.
Besides, the method of the invention is characterized in that after knitting a draw yarn only a suitable number of knitting needles positioned at a side end of a knitting width are fed with a knitting yarn for knitting a desired fabric.
Accordingly to the invention, drawing out a draw yarn from a knitted fabric is carried out after taking out the knitted fabric from the flat knitting machine. Subsequently, a yarn end at the initial portion of the knitted fabric is pulled, and thereby the courses of knitting yarn loops knitted prior to the commencement of knitting rib stitches after knitting the draw yarn are raveled and return to a straight line yarn. The straight line yarn is drawn out from the knitted fabric in such a state that the straight line is penetrated among front and back loops of a rib stitches course of the initial portion. The yarn end is further pulled and then cut in a position near a side end of the knitted fabric in such a state that the initial portion is contracted. Subsequently the contracted initial portion is expanded so that the contraction thereof is loosed and the yarn end drawn out from the knitted fabric is pulled into the knitted fabric and held therein as the contraction is loosed.
The method of treating a yarn end of the invention is characterized in that, prior to the commencement of knitting a desired fabric, firstly a course of draw yarn is knitted, and successively a course of knitting yarn for the purpose of inserting a yarn end thereinto is knitted. A knitted fabric is separated from waste stitches or from a successively knitted fabric by drawing out the knitted draw yarn. Treatment of the yarn end is conducted by cutting the yarn end in such a state that the yarn end is pulled so that it can be later drawn into the knitted fabric. The operation can be very easily carried out without a crochet needle, so that the step of inserting a crochet needle into tight loops of stitches is eliminated. Accordingly, there does not arise the problem that the loops of stitches become loose due to forcibly inserting a crochet needle into the tight loops of stitches and the commercial value of the knitted fabric is not damaged.
Further, if a portion knitted of end yarn having a width equal to that of a fabric to be knitted is formed prior to knitting the initial portion of the fabric, a portion to be inserted into the knitted fabric will be held in the knitted fabric in such a state that the portion is penetrated between front and rear loops of a rib stitches course of the initial portion knitted thereafter. Accordingly, the yarn end can be surely held without raveling and the initial portion of the knitted fabric can be reinforced.
Further, when only a suitable number of knitting needles positioned at a side end of a knitting width are fed with a yarn to be used for knitting a fabric after feeding the knitting needles with a draw yarn, it is not necessary to feed the knitting needles positioned in the entire knitting width with the knitting yarn. As a result, yarn saving can be achieved.
Further, by virtue of the use of the draw yarn, the application of the invention is not limited to knitting one piece, which is conducted in fashioning, and continuous knitting where attachment pieces are continuously knitted without cutting a knitting yarn during a knitting operation is also included in the scope of the application of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:
FIG. 1 is a schematic diagram of attachment pieces knitted continuously on the basis of a method of treating a yarn end of the invention;
FIG. 2 is a schematic diagram of a one fashioned piece singly knitted on the basis of a method of treating yarn end of the invention;
FIGS. 3A-3F are knitting courses diagrams showing a first embodiment of the invention;
FIGS. 4A-4G are knitting courses diagrams showing a second embodiment of the invention;
FIG. 5 is a loop diagram showing an initial portion of a fabric knitted on the basis of the first embodiment of the invention;
FIG. 6 is a loops diagram showing an initial portion of a fabric knitted on the basis of the first embodiment of the invention in a state that a yarn end of the fabric is pulled;
FIG. 7 is a loops diagram showing an initial portion of a fabric knitted on the basis of the second embodiment of the invention;
FIG. 8 is a loops diagram showing an initial portion of a fabric knitted on the basis of the second embodiment of the invention in a state that a yarn end of the fabric is pulled; and
FIG. 9 is a loops diagram showing a method of treating a yarn end of a fabric knitted on the basis of the second embodiment according of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Now referring to the drawings, the yarn end treatment method of the invention will be described in detail.
FIG. 1 shows knitted attachment pieces 5 to be seamed to a suitable portion of a front body or collar for the purpose of reinforcement. It shows the state of a knitted fabric 1 after the completion of knitting which has been conducted so that the method of treating a yarn end of the invention might be applied in the case where knitting is continuously conducted without cutting a knitting yarn by connecting the knitted attachment pieces via a draw yarn 4 with one another. The knitted fabric 1 comprises a draw yarn 4, attachment pieces 5, and a yarn 6. The yarn 6 connects the end of one attachment knit piece 5 with the beginning of the following attachment knit piece 5.
FIG. 2 shows a state of a knit fabric 7 after the completion of knitting wherein a method of treating a yarn end of the invention is employed for fashioning. The knit fabric 7 comprises a yarn end 2, waste stitches 3, a draw yarn 4, bottom rib stitches 8, and a main portion 9. The draw yarn 4 is used in order to separate the waste stitches 3 from the knit fabric 7 and for this purpose is preferably employed a smooth machine sewing thread or the like. A yarn of lower cost than that of a knitting yarn is used for knitting the waste stitches 3. Satisfactory stitches can not be obtained when knitting is started from a state that stitches are engaged with knitting needles of neither a front nor a rear needle bed. If the waste stitches 3 are knitted prior to knitting the knit fabric 7, satisfactory stitches can be obtained from the beginning of knitting the knit fabric 7 because the stitches are knitted successively after the waste stitches of the preceding course. Additionally, the fabric is hardly damaged when the draw yarn 4 is drawn out in order to separate the knit fabric from the waste stitches.
In the case of the knit fabric 1 as shown in FIG. 1, the yarn ends (not shown) will remain in the initial portion of each attachment knit fabric 5 as a result of drawing out the draw yarn 4 connecting the attachment knit pieces 5 with one another and cutting the connecting yarn 6 connecting the attachment knit pieces 5, and the state of the initial portion of the knit fabric 1 is almost the same as that of the knit fabric as shown in FIG. 2. In this embodiment, the cut connecting yarn 6 among the respective attachment knit fabrics 5 will be explained as a yarn end 2 in order to simplify the explanation, and knitting the knit fabric 1 as shown in FIG. 1 will be explained as an example in the following.
First, the first embodiment of the invention will be described. In the method of treating a yarn end of the invention, waste stitches are knitted on both of the front and rear needle beds prior to knitting a desired fabric. As shown in FIG. 3A, the width from a needle A to a needle Z on the front needle bed corresponds with the width of a desired fabric and the needles A-Z are fed with a draw yarn 4 by a yarn feeder, and stitches are knitted. Subsequently, as shown in FIG. 3B, the needles A-Z on the front needle bed are fed by the yarn feeder with a knitting yarn 10 for knitting a fabric and stitches for the purpose of yarn end treatment described below are knitted.
In FIG. 3C, the needles on the front needle bed and those on the rear needle bed are alternately fed with a knitting yarn by the yarn feeder to begin knitting rib stitches of 1×1 over the entire width of the desired fabric. Subsequently, as shown in FIGS. 3D, 3E, after the needles on either the front or the rear needle bed is fed with the knitting yarn 10, the needles on the other of the front and the rear needle bed are fed therewith and knit tubular stitches are knitted. Further, as shown in FIG. 3F, the needles on the front needle bed and those on the rear needle bed are alternately fed with the knitting yarn and knit rib stitches of 1×1 are knitted. In this embodiment, an initial course as shown in FIG. 3C is knitted by the use of all the needles, A-Z and a-z. It is needless to say, however, that the knitting of an initial course might be suitably changed in correspondence with the kinds of stitches such as tubular stitches, rib stitches of 1×1 , rib stitches of 2×1.
After knitting the courses as shown in FIG. 3A-3F is completed, an attachment knit piece 5 is knitted. The knit fabric 1 shown in FIG. 1 wherein the respective attachment knit pieces 5 are connected with one another by the draw yarn 4 is obtained by repeating the above knitting steps.
Secondly, the second embodiment of the invention will be described on the basis of the knitting courses diagrams shown in FIGS. 4A-4G. The second embodiment is different from the first one in the portions as shown in FIGS. 4B, 4C. In the case of the first embodiment, the needles A-Z are fed with the draw yarn as shown in FIG. 3A and thereafter, as shown in FIG. 3B, the needles are fed with the yarn 10 over the entire width of the fabric to be knitted prior to alternately feeding the needles of each of the front needle bed and those of the rear needle with the knitting yarn 10 to begin knitting as shown in FIG. 3C. On the other hand, in the case of the second embodiment, the needles A-Z positioned in the range of the entire width of a fabric to be knitted are fed with the draw yarn 4 by a yarn feeder as shown in FIG. 4A, and thereafter only a predetermined number of needles A-H of the needles on the front bed fed with the draw yarn as shown in FIG. 4A, which are positioned on a side end of the fabric width, are fed with the knitting yarn 10 for knitting the attachment knit pieces 5 as shown in FIG. 4B. Subsequently, as shown in FIG. 4C, the yarn feeder is turned from the state shown in FIG. 4B and the needles H-A, which are the same as those fed with the knitting yarn 10 in FIG. 4B, are fed with the knitting yarn 10. Subsequent steps of knitting courses are conducted, as shown in FIGS. 4B-4G, in the same manner as that shown in FIGS. 3C-3F for the first embodiment. After the completion of the steps of knitting courses shown in FIGS. 4B-4G, attachment pieces 5 are knitted in the same manner as that of the first embodiment. The knit fabric 1 shown in FIG. 1 wherein the respective attachment knit pieces 5 are connected with one another by the draw yarn 4 is obtained by repeating the above knitting steps.
As shown in FIGS. 3D-3E, the needles on each of the front and rear needle beds are fed with the knitting yarn and thereby one course of tubular stitches is knitted on each needle bed. That is for the purpose of holding loops of rib stitches. For example, it is possible that the needles on the rear needle bed are once more fed with the knitting yarn in subsequence to knitting the course shown in FIG. 4F, and thereafter the course shown in FIG. 4G is knitted.
In the second embodiment, the needles A-H positioned on a side end of the knitting width are fed with a knitting yarn 10 for knitting a course shown in FIG. 4B. The number of the needles on the side end to be fed with the knitting yarn 10 can be freely predetermined.
Subsequently, the steps of the method of treating a yarn end after the completion of knitting a fabric with a knitting machine will be described.
In the case of a knit fabric knitted in the manner of the first embodiment for the purpose of applying the method of treating a yarn end, after the fabric has been knitted so that the method of treating a yarn end can be applied, a yarn 6 connecting respective attachment knit pieces 5 with one another is cut off. Thereby the initial portion of each attachment knit piece 5 is put into such a state as shown in FIG. 5 (FIG. 5 shows only loops formed by knitting courses as shown in FIGS. 3A-3F), and the yarn 6 remaining in each attachment knit piece 5 yet after the cutting-off exists as a yarn end 2. In this state, in order to separate the attachment knit pieces 5 from one another, the draw yarn 4 is drawn out in the same manner as that for a fabric knitted in a conventional knitting method. Subsequently, the yarn end 2 existing at the initial portion of each attachment piece 5 is pulled in a direction of drawing out from the knit fabric (wale direction). Thereby, the loop shape of the loops knitted as a course 101 in FIG. 3B, which is maintained by the loops of the draw yarn 4 knitted as a course 100 in FIG. 3A, can not be maintained anymore and the loops of the course 101 come to ravel out as the yarn end 2 is pulled.
The loops of the course 101 in FIG. 3B come to ravel out over the entire knitting width in the direction from a needle A to a needle Z in order by further pulling the yarn end 2. When the raveling-out comes up to the loop formed by the needle Z, the loops of the course 102 in FIG. 3C knitted in succession to the course in FIG. 3B can be maintained without raveling out even when the loops of the preceding course is in a raveled state, because the course 102 is of rib stitches. Consequently, the state of the loops is as shown in FIG. 6.
Subsequently, when, in a state that the raveling-out of the loops does not occur anymore, the yarn end 2 is further pulled in such a direction that the yarn end 2 is drawn out from the knitted fabric 5, the loops of the course 102 in FIG. 3C are tightened in itself, because the raveling out of the loops is stopped in the position of a needle Z of the rear needle bed. Then the yarn end 2 is cut in a position near the side end of the attachment knit piece 5 in such a state that the initial portion of the attachment knit piece 5 is contracted. Thereafter, when the initial portion of the attachment knit piece 5 is expanded in such a direction that the contraction of thereof is loosed, the cut end of the yarn end 2 extruding from the knitted fabric is pulled into the knitted fabric as the contraction is loosed, and held therein. The yarn end 2 is treated in such manner.
Additionally, in this embodiment, the yarn raveled by pulling the yarn end is considered as a part of the yarn end 2 for convenience of explanation.
Next the second embodiment of the method of treating a yarn end will be described. The knit fabric shown in FIG. 1 is used as an example for explanation like the case of the first embodiment. This is because the knitted fabric removed from a knitting machine after the completion of knitting is in the state shown in FIG. 1 or FIG. 2. The same as that of the first embodiment, after the draw yarn has been drawn out in the state of FIG. 7 showing a state after the completion of knitting, the yarn end 2 is pulled in such a direction that the yarn end 2 is drawn out from the knitted fabric (wale direction). The loops formed by the draw yarn 4 are exaggeratedly illustrated for simplification in FIG. 7. In the case of the first embodiment, only the loops knitted as a course 101 in FIG. 3B come to ravel out with the progress of pulling the draw yarn 4. On the other hand, in the case of the second embodiment, after the loops formed as a course 103 in FIG. 4B by needles A through H positioned in a part of the knitting width come to ravel out, the loops of a successively knitted course 104 in FIG. 4C also come to ravel out and are pulled following the yarn end 2 because the loop shape can not be maintained.
The same as that of the first embodiment, when the raveling-out of a knitted course 105 of rib stitches in FIG. 4D reaches a loop positioned at the needle A of the front needle bed, the raveling-out stops.
To pull the yarn end 2 being further continued, the loops of the course 104 in FIG. 4C come to ravel out because the loop shape thereof can not be maintained. Since a knitting yarn used for knitting a course in FIG. 4C extends between the stitch formed as a course 105 in FIG. 4D by needles of the front needle bed and the stitch formed by needles of the rear needle bed, in the region from the needle A to the needle H wherein stitches are formed in the preceding knitting course 103 in FIG. 4B, the raveled yarn of the course 103 extends in the knitted fabric without being exposed outside the knitted fabric. Further the yarn end 2 exposed outside the knitted fabric for the reason that the loop shape thereof can not be maintained is put into being complicated with a knitted yarn of the course 105 in FIG. 4D in a side end region 106 of the knitted fabric. When, in this state, the yarn end 2 is drawn out from the knitted course 105 in FIG. 4D, the yarn end 2 is put into being exposed outward from a loop formed by the needle H of the front needle bed. And then, when the yarn end is further pulled in such a direction that the yarn end 2 is drawn out from the knitted fabric in the position of the needle H of the front needle bed in such a state that the raveling of the loops is at a stop, the loops of the knitted course in FIG. 4D are tightened for the reason that the raveling-out of the loops is at a stop in a position of the needle A of the front needle bed on a side end of the knitted fabric. The yarn end 2 is cut in a position near the loop formed by the needle H of the front needle bed in such a state that the loops of the knitted course 105 in FIG. 4D are tightened. Thereafter, the knitted course in FIG. 4D is expanded so that the contraction thereof is loosed and the yarn end 2 outside the knitted fabric is pulled into the knitted fabric as the contraction is loosed, and held therein. The yarn end is treated in such manner.
Additionally, in the case where the number of needles fed with a knitting yarn 10 is reduced like the knitted course 103 in FIG. 4B of the second embodiment, a consumption of knitting yarn can be cut. Otherwise, when the needles in the entire knitting width are fed with the knitting yarn 10, the yarn end 2 cut and pulled into the initial portion of the knitted fabric is penetrated the front and rear loops of rib stitches of the knitted course of the initial portion over the entire knitting width, resulting in reinforcing the initial portion (see FIG. 6).
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.
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In knitting a knit fabric, knitting needles in a range corresponding with a desired knitting width for the fabric are fed with a draw yarn to form a course of stitches from the draw yarn. The knitting needles may be taken from a pair of needle beds which are sometimes referred to as the front bed and the rear bed. All or part of the knitting needles used for knitting the draw yarn are next fed with a knitting yarn and a course of stitches form from the knitting yarn. Thereafter, knitting needles from the front and rear needle beds in the range corresponding with the desired knitting width are fed with the knitting yarn and the initial portion of the fabric is knitted. Subsequently, knitting needles from either the front or rear needle beds are fed with knitting yarn and thereafter knitting needles from another needle bed are fed with knitting yarn to knit plan tubular stitches until the fabric is completed. The draw yarn is drawn out of the fabric after completion of the knitting. Next, a yarn end remaining at the initial portion is pulled from the fabric and cut near a side end of the initial portion of the fabric will also be contracted by pulling the yarn end. The cut end is pulled back into the initial portion of the fabric by expanding the contracted portion to its original shape.
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BACKGROUND OF THE INVENTION
Smudging is a problem in printing where wet ink is deposited on a medium. To overcome this problem, heated air has been used to accelerate ink drying. In the course of developing this invention it has been found that there are three factor's which control the rate of drying of a liquid deposited upon a medium, when heated air is blown across the medium surface. They are (1) the velocity of the air relative to the medium surface, (2) the temperature of the air, and (3) the relative humidity of the air. None of the earlier teachings have effectively addresses all three factors in their attempts to accelerate drying times. Each has addressed only one or two of these factors, but not all three effectively.
Previous solutions have aided drying by passing heated air over the print media. One example of this technique is taught in U.S. Pat. No. 4,340,893 by Ort, in which heated air is supplied through ports adjacent to the print head at the time of printing. In Ort, air flow must be regulated to avoid interaction with a stream of ink droplets. In another art, that of coating absorbent surfaces, U.S. Pat. No. 2,320,513 by Drummond, teaches drying of a liquid coating by passing a medium coated with liquid through a chamber in which heated air is directed onto the medium to dry the surface. It would appear from the disclosure that there is a recirculation of heated air within this chamber.
Two other U.S. Pat. Nos. 4,714,427 by Tsuruoka et al. and 4,720,727 by Yoshida, teach using heated air blown against an image surface to dry an image created on a medium surface. In each teaching, heated air is blown over a surface area without recirculation or control of velocity across a medium's surface.
SUMMARY OF THE INVENTION
This invention teaches an enhanced drying apparatus and method in which the three factors, air velocity relative to a medium surface, temperature of the blown air, and the relative humidity of the blown air, are optimized. This is accomplished by use of a fan constructed of a cylinder rotatably mounted within a housing with impeller blades mounted around the outer circumference of the cylinder. A housing encloses the fan to create an air chamber and air is drawn into the chamber from a thin cavity created over a media path by a shroud. This air has previously been heated by a heating element arranged either along the media path or within the housing. Air dams are created at the entrance and the exit points of the cavity formed by the media path and a baffle mounted within the housing and an extended shroud attached to the housing. This baffle directs the heated air onto the media at high velocity. The reheated air has a lower relative humidity than newly heated ambient air and reheating lowers the amount of energy needed to heat the blown air.
Accordingly, it is an object of this invention to provide an apparatus for accelerated drying of a liquid on a medium by supplying high velocity heated air across the surface of a medium.
It is another objective of this invention to provide an apparatus that reduces the relative humidity of heated blown air across the surface of a medium for drying liquid thereon.
It is yet another objective of this invention to reduce the amount of energy used to heat air blown across the surface of a medium for drying liquid thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, shows a blower and heater combination acting on a media path.
FIG. 2, shows a blower with an extended shroud with a heater element therein acting on a media path.
FIG. 3, shows a blower with an extended shroud extended to the left, along a media path, with a heater element within the shroud, for acting on media on the media path, moving from left to right.
FIG. 4, shows a half section view of a typical blower and heater unit.
FIG. 5, shows a cross section of a typical blower along the cross section lines A--A.
FIG. 6, shows an alternate configuration for the blower heater combination along an inclined media path.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a media 2, has ink deposited on it by print head 4, reacting against a platen 6. A drive roller 8, acts on the media 2 by rotational force to advance the media which has pressure applied to it by star wheel 10 to maintain frictional contact with the drive roller 8. A guide 12, receives the media 2, as it is advanced away from the printing action where wet ink has been applied. At this stage the ink has not yet set. It is within the scope of this invention that other liquids may be deposited on a media 2, to be acted upon, by the drying process which is now being disclosed.
Further, in FIG. 1, there is shown a housing 14, that is partially open toward and adjacent to the guide 12, on which the media 2 is advanced. The housing may be of may different shapes, but in the embodiment shown, it is a thin tunnel shape with its length perpendicular to the path of the media 2. Mounted within the housing 14, is a fan 16. The positioning of the fan 16 and the housing 14 creates a chamber 17. The fan 16 is rotatably mounted within the housing 14, in axial alignment with the axis of the tunnel shaped housing 14. The fan 16 is a cross-flow fan with impellers 18 mounted on the outer cylindrical circumference 20 of the fan 16. Mounted within the housing 14, between the fan 16 and the guide 12 is a baffle 22. The baffle 22 serves two purposes. Its position between the fan 16 and the guide 12 creates two openings, the first opening 24 for drawing regulated air into chamber 17 by the rotational action of the fan 16 and the second opening 26 expels air from the chamber 17. Air holes 28 in the housing 14 allow ambient air to enter the chamber 17 at a regulated rate.
A heating element 30, as shown in FIG. 1, is affixed to the baffle 22, between it and the guide 12. As air is forced through the second opening 26, it is directed by the housing wall 32 to a thin gap 33 between the baffle 22 and the guide 12. Preferably, this air is supplied at high velocity which aids in the drying of ink on the media 2. In the path of this air stream is the heating element 30, which heats the air blown onto the media 2. The first opening 24, created by the baffle 22 and the housing 14, partially draws this air stream back into the chamber 17, by the action of fan 16. A shroud 34, extends from housing 14, generally parallel to the guide 12 and away from the housing 14 in the direction of media flow from left to right. The heated air blown across the media 2, that is not drawn back into the chamber 17, by fan 16, at the first opening 24, is blown down the thin cavity 33 created between shroud 34 and guide 12 and exits at an opening 36. Another function of the high velocity air blown into the cavity 33 is to hold the media 2 against the guide 12 which keeps the wet ink from being smudged by contact with baffle 22 and shroud 34.
The recirculation of heated air shown in FIG. 1, as well as the succeeding figures, is beneficial because the reheated air requires less energy to heat and has a reduced relative humidity as compared to ambient air. The recirculation of heated air increases the equilibrium temperature of the air within cavity 33 in which the media travels, and also slightly raises the specific humidity of the air in the cavity 33, due to the evaporated ink. Except for sustained heavy printing, this does not have enough effect on relative humidity to significantly affect drying time.
To understand the role of humidity in the drying of ink in this invention, it should be kept in mind that when air at 50° F. and 90% relative humidity (R.H.) is heated to 100° F., the new R.H. is 17%. And when air at 90° F. and 90% R.H. is given the same temperature rise, the new R.H. is approximately 19%. A temperature rise of 50-60° F. is easily attainable by having a 15° F. rise in temperature per cycle of air recirculation, which allows venting off 20-25% of the total air circulation. To increase the rise in temperature per cycle, air dams at the openings 26 and 28, where media 2 enters and exits the drying cavity 33, entrap more heated air for recirculation. An approximation of the heat rise from recirculation of heated air is that if half of the heated air is vented off and half recirculated, then the total rise in temperature would be twice that of a single pass heating system. Likewise, venting one-third of the total heated air flow would raise the equilibrium temperature approximately three time that of a single pass, and a one-fourth vent off would raise result in a fourfold increase in the equilibrium temperature of the drying air. This relationship is set forth in the following formula: ##EQU1##
Δt ss =steady state temperature increase above atmosphere at fan outlet
Δt 1 =temperature increase for one pass with no recirculation
e =flow rate of air exiting system with paper output: not recirculated
t =total flow rate of air exiting fan, before recirculation; includes recirculation
As a consequence, of heated air recirculation, a lower energy source is needed to heat air for drying ink on a media 2 if it is recirculated, than if air is heated and blown onto a wet ink on a media 2 and then vented off into the environment.
Shown in FIG. 2 is an alternate embodiment with a rightwardly extended baffle 38 extended from the housing 14 from left to right, between the shroud 34 and the guide 12, to form a recirculation opening 40. A heating element 30 is affixed to baffle 38 between it and shroud 34 to heat air blown across the surface of media 2 as it moves left to right along guide 12. A shroud lip 42 is tapered to reduce the exit path of media 2, which in cooperation with the air drawn back into recirculation at recirculation opening 40, before the media 2 exits the shroud 34, creates an air dam to restrict the escape of heated air. Variations in the shape of shroud lip 42 will vary the exit opening for the media 2 which in turn will regulate the volume of escaping air and in turn the volume of recirculated heated air.
FIG. 3 shows an another embodiment where the shroud 34 extends from right to left from a housing 14. In this configuration a shroud lip 44 acts to reverse the direction of air flow and bring it back over the printed media for partial recirculation at air dam 42. In this instance, the media 2 helps form a portion of the drying cavity 35. Again, a heating element 30 is mounted within the shroud 34 and heated air is drawn into the housing 14 to the right of the leftwardly extended baffle 45 where between it and an edge of the housing 14 there is formed an exit opening 46 for the advancing media 2. Just prior to this exit opening, air is drawn into chamber 17 through recirculation opening 48 for recirculation.
FIG. 4 shows a frontal cross section of the fan 16 in housing 14. A motor 50, drives a shaft 52 on which is rotatably mounted in a silicon rubber toroid 54. The silicon rubber toroid 54, is mounted in fan 16 which is made of aluminum or plastic. Other suitable materials may be used as well for the construction of the fan and toroid. The drive shaft 52 is secured to the fan 16 which is mounted between the housing walls 58 and 60. The fan 16 is rotatably attached to a Nylatron toroid 55 which is supported by a bearing shaft 62 stationarily mounted on the housing wall 60 opposite to the housing wall 58 through which the drive shaft 52 is mounted.
FIG. 5 shows a cross section of the fan 16 in housing 14 along the section line A-A in FIG. 4. The fan 16 is a cylinder with impellers 18 radiating outwardly. The cylinder of fan 16, along with the inner wall of housing 14 create a chamber 17, into which air is drawn by the rotation of fan 16 at the first opening 24 created by the baffle 22 and the housing 14 wall and exhausted at the second opening 26, into the cavity 33 between the baffle 22 and the guide 12, to dry media that is advanced through this cavity. Some ambient air will be drawn into the chamber 17 through the inlet 70 into which media 2 is advanced. The action of drawing in ambient air, at inlet 70, into the recirculation stream of fan 16, in cavity 33, acts to block heated air from escaping, thereby forming an air dam at inlet 70.
Also shown in FIG. 5 are alternate configurations for arranging the heating elements. In one configuration, a heating element 30 is shown mounted on the baffle between it and the guide 12 in the path of media 2. An alternate configuration is shown in which a heating coil 64 is mounted inside the baffle structure. In fact, a heating element may be mounted at multiple positions within housing 14.
Another feature shown in FIGS. 4 and 5 is the detail for mounting the baffle 22, the housing 14, and the guide 12 onto the housing walls 58 and 60. As can be seen in FIG. 4, the baffle 22, the guide 12, and housing 14, are held between housing walls 58 and 60, by recesses therein. In addition, as shown in FIG. 5, baffle 22 is affixed to the housing 14 by a flange 66 which has ports in it for receiving air drawn into the chamber 17 by the fan 16. Flange 66 acts both as a support and as a means of regulating air flow into the chamber 17.
The recirculation of heated air has been shown to be accomplished by drawing heated air into the chamber 17 for exhausting onto a media 2 in a cavity 33 where the air is again partially drawn back into the chamber 17 for reheating. The amount of air that is reheated and the amount of new air drawn into the chamber for recirculation is a function of the size of the inlet 70 and the amount of air that seeps in through seams in the housing 14. The air drawn into the chamber 17 at the first opening 24 has little ambient air content as a result of the exhausted air stream creating an air dam, which is here directed in the path of the media 2 as indicated by the arrows indicating air flow in FIG. 5. Additional ambient air input may be achieved by an ambient air inlet 68 in the housing 14. Depending on the amount of reheating required, larger or smaller openings may be used to create the desired mix of ambient and reheated air in chamber 17.
FIG. 6 shows an alternate embodiment with the apparatus tilted along a slanted path. Heating element 30, is mounted on an elongated baffle 72, within extended shroud 74, which in turn is attached to housing 14. Media 2 is drawn in along a paper path and enters the cavity 75 formed by elongated baffle 72 and guide 12 at opening 76. The heated air from the action of heating element 30, is directed onto the media 2 at opening 76 and from thence on down the media's 2 path in cavity 75 where a portion of it is drawn into chamber 17 as has been previously described for recirculation. A portion of the heated air continues down the path of the media 2 in cavity 75 and exits at point 78, which is an outlet formed by a second baffle 80 which in turn, runs generally parallel to guide 12 to form a thin exhaust cavity 77 through which the media 2 passes with heated high velocity air being passed over its surface. This configuration has the advantage of having an extended drying cavity, as can be seen from examination of the drawing. It also demonstrates that the invention may be employed in different elevations other than horizontal.
In each application shown, the drying air is supplied at high velocity. One successful fan 16 configuration which was used to achieve this result uses a long, small diameter fan 16, which extends across the media 2 width. In this configuration, the impeller's 18 diameter was 1.0 inch, and the motor 50, as shown in FIG. 4, is a small shaded pole motor with a shaft 52 speed of 3,000 rpm, which creates an impellar 18 velocity of 780-975 fpm, or 13-16 fps, resulting in air velocities lower than the impellers' 18 tip velocities (approximately 100 fpm, but nonetheless, high drying air velocity.
Also shown in FIG. 6 is a means to regulate the temperature within the drying cavity 75. A thermostat 82 is shown located in the drying cavity 75 which senses the temperature of the recirculated air. A signal from the thermostat 82 is transmitted to a sensing and regulating logic 84, well known to those skilled in the art, which senses the temperature to regulate the power source 86, which in turn appropriately adjust the energy and as a consequence, the temperature of heating element 30. This arrangement allows for a constant monitoring and adjustment of temperature within the drying cavity 75 which results in increased control of the drying factors of relative humidity, and temperature. It is envisioned that a humidity sensor could also be employed with its output used to regulate the heating element temperature to thereby further regulate the relative humidity of the drying chamber.
It will be apparent to those skilled in the art of printer technology that various changes may be made in the structure and arrangement of components therein without departing from the spirit and scope of the invention.
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An apparatus is employed for drying liquid, preferably ink, on a medium, which entails heating air and blowing it across the surface of the medium at high velocity. The heated air is recaptured and recirculated resulting in lower energy usage for heating and a reduced relative humidity of drying air to enhance drying. Various structural configurations are disclosed but each has a common feature of creating an air dam at the point of entry of a medium along a media path and at the exit point. The use of a baffle adjacent to the medium path acts as a deflector for the heated air to distribute it across the medium surface at high velocity and also creates ports for expressing and recirculating heated air.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 12/686,134 filed on Jan. 12, 2010, which is incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a connection assembly, and more particularly, to a variable angle spinal implant connection assembly.
BACKGROUND OF THE INVENTION
[0003] Spinal deformities, spinal injuries, and other spinal conditions may be treated with the use of spinal implants. Spinal implants are designed to support the spine and properly position the components of the spine. One such spinal implant includes an elongated rod and a plurality of bone anchors. The elongated rod is positioned to extend along one of more of the components of the spine and the bone anchors are attached to the spinal components at one end and secured to the elongated rod at the other end.
[0004] However, due to the anatomical structure of the patient, the spinal condition being treated, and, in some cases, surgeon preference, the bone anchors may be required to be positioned at various angles and distances from the elongated rod. As a result, it can be difficult to obtain a secure connection between the elongated rod and the bone anchors.
[0005] As such, there exists a need for a connection assembly that is able to securely connect an elongated rod to bone anchors despite a variance in the angle and position of the bone anchors with respect to the rod.
SUMMARY OF THE INVENTION
[0006] In a preferred embodiment, the present invention provides a connection assembly that can be used to securely connect a spinal implant to a bone anchor. In particular, the present invention preferably provides an offset variable angle connection assembly that is able to securely connect the spinal implant to the anchors even when there is a variance in the angle and position of the anchors with respect to the spinal implant. Additionally, in a preferred embodiment, the present invention provides for a medial locking offset bone anchor connection that allows for the preservation of adjacent anatomical structure, such as adjacent facets. Furthermore, in a preferred embodiment, the present invention provides a connection assembly that will not inadvertently lock the components of the connection assembly preventing the relative movement of the components.
[0007] In a preferred embodiment, the connection assembly comprises a housing member that has an aperture for receiving a portion of a spinal implant, an opening for receiving a securing member for securing the spinal implant and a channel for receiving a receiving member. The receiving member preferably has an aperture for receiving a portion of an anchor, a rim portion having at least one ridge, and a lumen. In addition, in a preferred embodiment, the receiving member is configured and dimensioned to be received in the channel of the housing member so that the receiving member is rotatably and translatably connected to the housing member. An interference member is preferably received in the lumen of the receiving member and is translatable in the lumen. In a preferred embodiment, an end of the interference member has an anchor contacting surface for locking the anchor in place.
[0008] In a preferred embodiment, the connection assembly further comprises an annular member that is positioned over the receiving member and received in the channel of the housing member. Preferably, a face of the annular member has at least one ridge and the at least one ridge on the rim portion of the receiving member faces the at least one ridge on the second face of the annular member. In a preferred embodiment, the ridges are configured and dimensioned to engage with each other to lock rotational movement of the housing member and the receiving member.
[0009] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred or exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0011] FIG. 1 is a perspective view of one embodiment of a connection assembly;
[0012] FIG. 2 is an exploded perspective view of the connection assembly shown in FIG. 1 ;
[0013] FIG. 3 is an elevated side view of the connection assembly shown in FIG. 1 ;
[0014] FIG. 4 is a cross-sectional view of the connection assembly shown in FIG. 1 in the direction of arrows A-A; and
[0015] FIG. 5 is a cross-sectional view of the connection assembly shown in FIG. 1 in the direction of arrows B-B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0017] With reference to FIGS. 1-4 , a preferred embodiment of an offset connection assembly 10 is illustrated. The connection assembly 10 preferably includes a housing member 12 and an offset receiving member 14 . The housing member 12 includes an elongated aperture 16 at a first end for receiving at least a portion of a spinal implant 20 , such as a spinal rod, and the offset receiving member 14 includes an aperture 22 for receiving at least a portion of an anchor 24 , such as a bone screw. The aperture 22 (and anchor 24 ) is linearly offset from the spinal implant 20 , or in other words, the center of the aperture 22 is offset a distance x from a central axis 8 . One of ordinary skill in the art would recognize that although only a bone screw is shown, the aperture 22 of the offset receiving member 14 is capable of receiving any number of anchors including, but not limited to, other orthopedic screws, hooks, bolts, or other similar bone anchoring devices. The housing member 12 and the offset receiving member 14 are preferably rotatably connected. The rotatable connection can be of any suitable design, including a threaded connection, a snap-fit, or a captured connection.
[0018] In a preferred embodiment, the housing member 12 also includes a second aperture 26 at the first end for receiving a securing member 28 . The second aperture 26 extends from an outer surface of the housing member 12 toward the elongated aperture 16 . In a preferred embodiment, the second aperture 26 is in fluid communication with the elongated aperture 16 . At least a portion of the second aperture 26 is preferably threaded to receive the securing member 28 , but the second aperture 26 can also be non-threaded.
[0019] The securing member 28 is preferably a threaded set screw, as best seen in FIG. 2 , but can be any type of securing member including, but not limited to, a bolt, a pin, a shoe, an interference member, or a cam member. In a preferred embodiment, the securing member 28 is captured in the second aperture 26 preventing accidental disengagement of the securing member 28 from the housing member 12 . The securing member 28 is captured in the second aperture 26 by including an overhanging portion 29 on the securing member 28 that abuts against the termination of the threading in the second aperture 26 .
[0020] With continued reference to FIG. 2 , the housing member 12 also includes, in a preferred embodiment, a channel 30 which extends from a second end of the housing member 12 toward the first end of the housing member 12 . The channel 30 is in fluid communication with the elongated opening 16 . Preferably, at least a portion of the channel 30 includes threading 31 interrupted by at least one groove 32 extending from the second end of housing 12 toward the first end of housing member 12 . In a preferred embodiment, the at least one groove 32 extends towards the first end of the housing member only a predetermined amount and preferably includes an end face 33 that defines the end of the groove 32 .
[0021] The offset receiving member 14 , in a preferred embodiment, includes a first end and a second end, the aperture 22 located between the ends. The offset receiving member further includes a channel 35 and a resilient leg 50 . Referring to FIGS. 2 and 5 , the offset receiving member 14 , in a preferred embodiment, receives in the channel 35 a connection member 17 which is generally cylindrical in shape with a generally cylindrical lumen 15 .
[0022] The connection member 17 preferably includes threading 63 and a slot 65 at one end of the lumen 15 , at a first end of the connection member 17 . In another preferred embodiment, the lumen 15 may include a tapered shoulder portion 19 . The connection member 17 further includes a radially outwardly extending rim portion 34 on a second end that has a plurality of ridges 36 preferably oriented toward the offset receiving member 14 . In a preferred embodiment, the connection member 17 also has a shoulder portion 38 , spaced from the rim portion 34 , on the second end of the connection member 17 . The connection member 17 is configured and dimensioned to be received within the channel 30 of the housing member 12 and be received within channel 35 of the offset receiving member 14 .
[0023] Turning back to FIGS. 1-5 , the offset connection assembly 10 further includes, in a preferred embodiment, an interference member 40 , a gear 42 , a ring member 44 , a cap member 45 and an end cap member 46 . The interference member 40 has a generally cylindrical shape that tapers, in part, from a second end to a first end. The taper forms a shoulder portion 51 . In a preferred embodiment, the first end of the interference member 40 has an end portion 48 that is configured and dimensioned to abut a resilient leg 50 on offset receiving member 14 . On a second end of the interference member 40 , there is a face 49 which preferably is flat, but may also be arcuate and generally conforms to the shape of the spinal implant 20 . In another preferred embodiment, the interference member 40 has a generally rectangular shape with a first end having an end portion 48 that is configured and dimensioned to abut the resilient leg 50 and a second end that flares outwardly and includes face 49 for abutting the spinal implant. The interference portion 40 is configured and dimensioned to be received within the lumen 15 of the connection member 17 .
[0024] The gear 42 , as best seen in FIG. 2 , preferably is generally annular in shape and has a plurality of ridges 52 on one face and at least one projection 54 extending radially outwardly from the gear 42 . In a preferred embodiment, the gear 42 is configured and dimensioned to fit over the shoulder portion 38 of the connection member 17 and within channel 30 of the housing member 12 . The gear 42 is preferably oriented so that the ridges 52 face the ridges 36 on the rim portion 34 of the connection member 17 and the at least one projection 54 is received within the at least one groove 32 in the housing member 12 .
[0025] In a preferred embodiment, the ring member 44 is generally annular in shape, has a first face and a second face, and is configured and dimensioned to fit over the connection member 17 and abut against the shoulder portion 38 , as best seen in FIGS. 4 and 5 . Preferably, the ring member 44 also is configured and dimensioned to be received within the channel 30 of the housing member 12 . In a preferred embodiment, the ring member 44 is made from titanium, but the ring member 44 can also be made from any biocompatible material including resilient polymers.
[0026] The cap member 45 , in a preferred embodiment, is generally annular in shape and has a first face and a second face. The cap member 45 includes an extension portion 56 on the first face of the cap member 45 and a lumen 60 . As best seen in FIGS. 2 , 4 and 5 , the extension portion 56 preferably is threaded along at least a portion thereof and includes a ramp portion 57 . Although the extension portion 56 preferably includes threading, in another preferred embodiment, the extension portion may not be threaded. Preferably, the diameter of the extension portion 56 is smaller than the diameter of the portion of the cap member 45 immediately adjacent to the extension portion 56 creating a shoulder portion 58 . In a preferred embodiment, the cap member 45 is configured and dimensioned so the extension portion 56 engages the threading 31 in the channel 30 of the housing member 12 and the shoulder portion 58 abuts the second end of the housing member 12 . The lumen 60 of the cap member 45 is configured and dimensioned to receive the connection member 17 . In a preferred embodiment, the cap member 45 is captured in the channel 30 of the housing member 12 to prevent the cap member 45 from inadvertently unthreading from the housing member 12 .
[0027] The end cap member 46 , in a preferred embodiment, is generally annular in shape and has a first face and a second face. The end cap member 46 includes an extension portion 61 on the first face of the end cap member 46 . The extension portion 61 preferably is threaded along at least a portion thereof. Although the extension portion 61 preferably includes threading, in another preferred embodiment, the extension portion may not be threaded. In a preferred embodiment, the end cap member 46 is configured and dimensioned so the extension portion 61 engages the threading 63 in the lumen 15 of the connection member 17 . As best seen in FIGS. 2 , 4 and 5 , at least a portion of the first face of the end cap member 46 abuts the second end of the offset receiving member 14 . In a preferred embodiment, the end cap member 46 is captured in the lumen 15 of the connection member 17 to prevent the end cap member 46 from inadvertently unthreading from the connection member 17 .
[0028] With reference to FIGS. 1 and 3 - 5 , in a preferred arrangement of the elements of the offset connection assembly 10 , the housing member 12 is rotatably connected to the offset receiving member 14 . As mentioned above, the connection member 17 is received within the channel 30 of the housing member 12 and within the channel 35 of the offset receiving member 14 . In a preferred embodiment, a second end of the connection member 17 abuts a medial wall 13 located within the housing member 12 and a first end of the connection member 17 extends beyond the second end of the housing member 12 . Positioned within the lumen 15 of the connection member 17 is the interference member 40 .
[0029] In a preferred embodiment, also received within the channel 30 of the housing member 12 is the gear 42 which fits over the shoulder portion 38 of the connection member 17 . The at least one projection 54 on the gear 42 is received within the at least one groove 32 and preferably abuts the end face 33 of the groove 32 . The end face 33 of the groove 32 is spaced from the medial wall 13 of the housing member 12 by a predetermined amount, so the gear 42 , when placed in the channel 30 , is spaced from the rim portion 34 of the offset receiving member 14 by a predetermined amount. Accordingly, the ridges 36 on the rim portion 34 are spaced from the ridges 52 on the gear 42 . The purpose of this spacing is important and is explained further below.
[0030] In a preferred embodiment, the ring member 44 is also received within the channel 30 of the housing member 12 and also fits over the connection member 17 . However, the inner diameter of the ring member 44 is smaller than the shoulder portion 38 of the receiving member 14 . As a result, at least a portion of the second face of the ring member 44 will abut the shoulder portion 38 . Preferably, the remaining portion of the second face of the ring member 44 will contact the gear 42 .
[0031] The cap member 45 , in a preferred embodiment, is also received within the channel 30 of the housing member 12 and also fits over the connection member 17 . The threads on the threaded potion 56 engage with the threads 31 on the channel 30 to threadingly engage the cap member 46 . Preferably, the threaded portion 56 is threaded into the channel 30 until the shoulder portion 58 contacts the second end of the housing member 12 . In this position, the ramp portion 57 of the threaded portion 56 abuts the first face of the ring member 44 .
[0032] The preferred arrangement of the elements, as discussed above, allow the housing member 12 , the gear 42 and the cap member 45 to rotate with respect to the receiving member 14 , the connection member 17 , the ring member 44 , the interference member 40 , and the end cap member 46 . As the housing member 12 rotates, the gear 42 will also rotate because of the at least one projection 54 located in the at least one groove 32 . Likewise, since the cap member 45 is threaded and preferably captured in the channel 30 of the housing member 12 , the cap member 45 also rotates when the housing member 12 rotates. In contrast, the connection member 17 , although captured within the channel 30 of the housing member 12 by virtue of the cap member 45 and the rim portion 34 , is capable of rotating as well as translating within the channel 30 . Similarly, the ring member 44 , although captured within the channel 30 of the housing member 12 by virtue of the shoulder portion 38 of the connection member 17 and the ramp portion 57 of the cap member 45 , is capable of rotating within channel 30 . Consequently, the ring member 44 does not rotate when the housing member 12 rotates. The receiving member 14 also is capable of rotating with respect to the housing member 12 as the receiving member 14 is connected to the housing member 12 through the connection member 17 , which, as just discussed, is capable of rotating with respect to the housing member 12 .
[0033] A preferred connection of the spinal implant 20 to the anchor 24 through the connection assembly 10 is best depicted in FIGS. 1 , 2 and 3 . In an exemplary use, the anchor 24 is implanted into a component of the spinal column, such as a vertebral body in the spinal column. Preferably, the aperture 22 of the receiving member 14 of the connection assembly 10 receives the anchor 24 . The aperture 22 is configured and dimensioned to receive any portion of the anchor 24 allowing the connection assembly 10 to be placed anywhere along the length of the anchor 24 . Accordingly, the connection assembly 10 can be translated along the anchor 24 until the desired position is achieved.
[0034] In an exemplary use, the spinal implant 20 is typically placed along at least a portion of the length of the spinal column in an orientation that is generally perpendicular to the anchor 24 . Preferably, the spinal implant 20 is also received in the connection assembly 10 , where the spinal implant 20 is received in the elongated opening 16 in the housing member 12 . The elongated opening 16 is configured and dimensioned to receive any portion of the spinal implant 20 allowing the connection assembly 10 to be place anywhere along the length of the spinal implant 20 .
[0035] Additionally, since the housing member 12 and the receiving member 14 are rotatably connected to each other, even if the anchor 24 and the spinal implant 20 are angularly offset, the connection member 10 can be oriented to a desired position to connect the spinal implant 20 and the anchor 24 . Furthermore, as mentioned above, the anchor 24 is linearly offset from the spinal implant 20 , or in other words, the anchor 24 is offset a distance x from the central axis 8 , which is defined as extending from the first end of the housing member 12 to the second face of the end cap member 46 . This linear offset allows for an offset connection of the anchor 24 to the spinal implant 20 thereby allowing for the preservation of adjacent anatomical components, such as the adjacent facets. Once the desired angular orientation and translational positioning of the connection assembly 10 with respect to the anchor 24 and the spinal implant 20 is achieved, the connection assembly 10 can be locked, securing the anchor 24 and the spinal implant 20 .
[0036] To lock the connection assembly 10 , the securing member 28 is threaded into the second aperture 26 in the housing member 12 where it contacts and pushes the spinal implant 20 toward the anchor 24 . The spinal implant 20 contacts the face 49 of the interference member 40 and pushes the interference member 40 towards the anchor 24 . As the interference member 40 is pushed by the spinal implant 20 towards the anchor 24 , the interference member 40 moves in the lumen 15 of the connection member 17 towards the anchor 24 , while the connection member 17 remains stationary. The end portion 48 of the interference member 40 abuts the resilient leg 50 , pushing the resilient leg 50 into the anchor 24 , which, in turn, pushes the anchor 24 into a sidewall of the aperture 22 in the receiving member 14 , locking the anchor 24 in place with respect to the connector assembly 10 .
[0037] As the spinal implant 20 continues to move towards the anchor 24 and continues to push the interference member 40 , the shoulder portion 51 of interference member 40 abuts the walls of the lumen 15 and pushes against the walls of the lumen 15 moving the connecting member 17 . As the connecting member 17 moves, the shoulder portion 38 pushes against the second face of the ring member 44 . Since the first face of the ring member 44 abuts the ramp portion 57 of the cap member 46 , after a predetermined force is applied to the ring member 44 by the shoulder portion 38 , the ring member 44 deflects or bends in the direction of the ramp portion 57 . With the ring member 44 no longer blocking the shoulder portion 38 , the connecting member 17 continues moving towards the anchor 24 until the ridges 36 on the rim portion 34 of the receiving member 14 engage the ridges 52 on the gear 42 . With the ridges 36 and 52 engaged, the relative rotation of the housing member 12 and the receiving member 14 of the connection assembly 10 is locked. At this point, the spinal implant 20 is also locked in place between the threaded member 28 and the walls of the housing member 12 that define the elongated opening 16 . With the spinal implant 20 locked in place, the relative rotation of the housing member 12 and the receiving member 14 locked, and the anchor 24 locked in place, the entire assembly is locked against movement. Adjustments to the entire assembly can be made by loosening the threaded member 28 and then re-tightening the threaded member 28 once the preferred positioning and orientation has be achieved.
[0038] It is important to note that because of the shoulder portion 38 abutting the ring member 44 and the at least one projection 54 of the gear 42 abutting the end face 33 of the at least one groove 32 , prior to the bending or deflection of the ring member 44 , the ridges 36 on the rim portion 34 of the receiving member 14 can not engage the ridges 52 on the gear 42 . This arrangement of elements prevents any inadvertent engagement of the ridges 36 , 52 thereby preventing any unintended rotational locking of the housing member 12 with respect to the receiving member 14 .
[0039] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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In a preferred embodiment, the present invention provides an offset connection assembly that can be used to securely connect a spinal implant to a bone anchor. In particular, the present invention preferably provides a variable angle connection assembly that is able to securely connect the spinal implant to the anchors even when there is a variance in the angle and position of the anchors with respect to the spinal implant. Furthermore, in a preferred embodiment, the present invention provides a connection assembly that will not inadvertently lock the components of the connection assembly preventing the relative movement of the components.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a shape-memory alloy Cu/Zn/Al and to a process for preparing it.
2. Description of the Prior Art
Memory alloys based on the Cu/Zn/Al system are known and have been described in various publications (e.g., U.S. Pat. No. 3,783,037). Such memory alloys, which belong generally to the type having a beta-high temperature phase, are usually produced by fusion techniques.
When these alloys are cast they usually exhibit a coarse texture, which becomes still coarser because of grain growth during subsequent annealing in the temperature range of the beta-phase solid solution, and which cannot be eliminated by hot working. As a result, the mechanical characteristics, particularly elongation and notch ductility, of shape-memory alloys produced in this manner are relatively poor, and their field of application is limited.
Accordingly, a need has existed to improve the metallurgy and preparative technology of these shape-memory alloys so that additional practical applications may be open to them.
It has already been proposed to produce shape-memory alloys of the Cu/Zn/Al type by powder metallurgy, starting with previously prepared alloys corresponding to the final composition (e.g., M. Follon, E. Aernoudt, Powder-metallurgically processed shape-memory alloys, 5th European Symposium on Powder Metallurgy, Stockholm 1978, pp. 275-281). In such processes the prepared powder is encapsulated, cold compacted, hot pressed and extruded.
However, these methods are not adapted to all practical requirements and the finished articles often leave something to be desired in their mechanical properties.
SUMMARY OF THE INVENTION
The basic object of the invention is to provide shape-memory alloys based on copper, zinc, and aluminum and a process for their preparation which provides dense, compact articles having good mechanical properties and at the same time accurately reproducible values of the transition temperature and other properties associated with the shape-memory effect.
This object is attained according to the invention by providing a shape-memory alloy based on copper, zinc and aluminum, which is present in the beta-phase, characterized in that it is prepared by powder metallurgical techniques from pre-alloys and pre-mixtures, that it has a fine-grained structure with a grain size of at most 100 micrometers and that at least one metal oxide is present as a dispersoid in the matrix formed by the beta-phase.
This object is further attained by providing a process for preparing a shape-memory alloy based on copper, zinc and aluminum, characterized by the following steps:
(a) preparing a Powder A having a particle size of 10 to 200 micrometers from a copper-rich pre-alloy containing 60 to 80% by weight Cu, 0 to 1% by weight Al, balance Zn; preparing a Powder B having a particle size from 5 to 100 micrometers by mixing and/or alloying of 95 to 99.5% by weight aluminum powder with 0.5 to 5% weight of copper powder; preparing a Powder C of pure copper having a particle size of 10 to 100 micrometers; preparing a Powder d of Y 2 O 3 or TiO 2 or any mixture of these oxides having a particle size of 10 to 100 micrometers;
(b) mixing 0.5 to 15% by weight of Powder B, 0 to 80% by weight of Powder C and 0.5 to 2% by weight of Powder D, and the balance Powder A, under toluene, ethyl alcohol or another organic solvent in a ball mill or an attrition mill for at least 5 hours at room temperature and finally evaporating the solvent;
(c) isostatically pressing the dried powder mixture in a plastic or rubber tube at a pressure of at least 3000 bar;
(d) reducing and pre-sintering the compact prepared in step (c) in a hydrogen or hydrogen/nitrogen atmosphere at a temperature between 700° and 1000° C. for at least 30 minutes;
(e) sintering the reduced and pre-sintered compact in an argon atmosphere at least 700° C. for at least 10 hours;
(f) alternately hot working at a temperature between 700° and 1000° C. and homogenizing in an inert gas atmosphere at a temperature of at least 700° C. for at least 30 minutes;
(g) finally annealing in an argon atmosphere at a temperature between 700° and 1050° C. for 10 to 15 minutes and immediately thereafter quenching in water.
The nucleus of the invention lies in starting with neither elemental powders nor with powders corresponding to one of the ultimate alloys, but rather with a mixture of pre-alloyed powders and specially formulated powder mixtures, and mechanically alloying these powders with suitable metal oxide powders. By this procedure the ductility can be adjusted as required for working while maintaining great freedom with respect to the composition. The grain size of the crystallites in the finished article can for the most part be predetermined. Grain growth is prevented by incorporating the proper dispersoids. At the same time, oxide shells which hinder the homogenization and adversely effect the mechanical properties need not be feared.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be described by means of the following working examples:
EXAMPLE 1
A rod of a shape-memory alloy was prepared having the following final composition of the matrix:
______________________________________Zinc 20.25% by weightAluminum 6.25% by weightCopper 73.5% by weight______________________________________
The alloy also contained 2% by weight of yttrium oxide as a dispersoid.
The following powders were used as starting materials:
Powder A: Brass: 60% by weight copper; 40% by weight zinc; melted, atomized; grain size 10-200 micrometers; manufacturer, Baudier.
Powder B: Pure aluminum+pure copper: 99.5% by weight aluminum; 0.5% by weight copper; grain size 23-28 micrometers; manufacturer, Alcoa.
Powder C: Pure copper: 100% by weight copper; grain size 0-44 micrometers; manufacturer, Baudier.
Powder D: Yttrium oxide: 100% by weight yttrium oxide; grain size <1 micron.
The following amounts were mixed, milled, and mechanically alloyed for 10 hours under toluene in an attrition mill.
______________________________________Powder A: 495 gPowder B: 61.6 gPowder C: 423.4 gPowder D: 20 gTotal 1000 g______________________________________
The powder mixture was dried by evaporation of the toluene, and subsequently 250 g of the mixture were poured into a rubber tube having an inner diameter of 20 mm and isostatically pressed under a pressure of 3000 bar to a cylinder of 18 mm diameter and 240 mm height. The green compact was reduced and presintered in a hydrogen steam at a temperature of 930° C. for 11/2 hours, and then the sintering was completed in an argon stream at a temperature of 960° C. for 18 hours. The rough sintered billet was turned to a diameter of 17 mm, placed in a tube of annealed copper having an external diameter of 20 mm, and completely encapsulated by closing the end with a cover and soldering in an argon atmosphere. The workpiece so prepared was then alternately subjected to hot working and a homogenizing annealing of one hour each time in an argon stream at a temperature of 940° C. In this case the hot working consisted of circular swaging at 940° C., whereby in the first swaging pass the diameter of the rod was reduced to 18 mm and in each successive pass the diameter was reduced by 2 mm. In this process two hot working operations were performed for each homogenization annealing. After the rod had been swaged down to a diameter of 8 mm, it was subjected to a final annealing at a temperature of 920° C. and immediately quenched in water. The density of the matrix, determined by testing, was 99.3-99.7% of the theoretical value.
Of course, the hot working/homogenizing cycle can be continued as long as desired, until the final shape of the workpiece is attained. When the theoretical density has been reached, further annealing is not generally required.
EXAMPLE 2
A strip of a shape-memory alloy was prepared having the following final composition of the matrix:
______________________________________Zinc 10.10% by weightAluminum 10.05% by weightCopper 79.85% by weight______________________________________
The alloy also contained 1% by weight of yttrium oxide as a dispersoid.
The powders of Example 1, in the following proportions, were mixed, milled and mechanically alloyed for 8 hours under ethyl alcohol in a ball mill:
______________________________________ Powder A: 250 g Powder B: 100 g Powder C: 640 g Powder D: 10 g Total 1000 g______________________________________
After evaporation of the ethyl alcohol, 240 g of the powder mixture were placed in an annealed tombac tube having an inner diameter of 20 mm and a wall thickness of 1.6 mm, and completely encapsulated by covering the ends and soldering in an argon atmosphere. Thereupon the tube and powder were isostatically pressed at a pressure of 10,000 bar, the green compact was reduced and pre-sintered in a hydrogen stream for 2 hours at a temperature of 880° C., and the sintering was completed in an argon stream at a temperature of 840° C. for 22 hours. The workpiece was then reduced by two circular swaging passes at 920° C. to 18 and then to 16 mm diameter and homogenized for one hour at 940° C. in an argon stream. This was followed by two more circular swaging passes at 920° C., so that the bar finally had a diameter of 13 mm. After an additional homogenization for one hour at 940° C., the bar was rolled down in several successive hot rolling passes, each reducing the cross section by 20-25%, to a strip 1.6 mm thick and 18 mm wide. After a final annealing at 960° C. for 12 minutes the strip was quenched in water. The density of the matrix in the finished strip was 99.6%.
EXAMPLE 3
A rectangular bar was prepared from a shape-memory alloy having the following composition of the matrix:
______________________________________Zinc 5% by weightAluminum 12% by weightCopper 83% by weight______________________________________
The alloy also contained 0.5% by weight of titanium dioxide as a dispersoid.
Powders A, B, C and D*(100% titanium dioxide) were weighed out in the following amounts and mixed, milled and mechanically alloyed for 10 hours under toluene:
______________________________________Powder A: 125 gPowder B: 120 gPowder C: 750 gPowder D*: 5 g (100% TiO.sub.2)Total: 1000 g______________________________________
After drying, 600 g of this powder mixture were placed in a rubber tube having an inner diameter of 50 mm and isostatically pressed at a pressure of 10,000 bar to a cylinder 46 mm in diameter and 90 mm high. The green compact was reduced and pre-sintered in a hydrogen/nitrogen stream at a temperature of 900° C. for 2 hours and then the sintering was completed at a temperature of 980° C. for 20 hours in an argon atmosphere. The rough sintered billet was turned to a diameter of 45 mm, placed in the receiving cylinder of an extrusion press and extruded at a temperature of 900° C. into a rectangular bar of square cross section 10 mm on an edge. Accordingly, the reduction ratio (decrease in cross section) amounted to 16:1. Thereupon the bar was homogenized at a temperature of 980° C. for 30 minutes and then drawn down in three passes on a hot drawing bench at 800° C. to 7 mm on an edge. After a final annealing at 920° C. for 15 minutes in an argon stream, the bar was quenched in water. The density of the matrix of the finished bar was 99.7% of the theoretical value.
The invention is not limited to the magnitudes and values disclosed in the examples. The powder compositions and particle sizes can be varied completely generally within the following limits:
______________________________________Powder A: Pre-alloy Copper: 60-80% by weight Aluminum: 0-1% by weight Zinc: Balance Particle size: 10-200 micrometersPowder B: Pre-mix and/or pre-alloy(alloyed mechanically or by fusion techniques) Aluminum: 95-99.5% by weight Copper: 0.5-5% by weight Particle size: 5-100 micrometersPowder C: Pure metal Copper: 100% by weight Particle size: 10-100 micrometersPowder D: Metal oxide (dispersoid Yttrium oxide: 0-100% by weight Titanium dioxide: 0-100% by weight______________________________________
Of course, Powder A could also have a different composition, for example, elemental zinc could be added. However, considering the loss of this element by burning and evaporation, this is not recommended in most instances.
The proportions of the powder mixtures can be within the following limits:
______________________________________Powder B: 0.5-15% by weightPowder C: 0-80% by weightPowder D: 0.5-2% by weightPowder A: Balance______________________________________
A pressure of at least 3000 bar is required for the isostatic pressing.
Reduction and pre-sintering of the compact can conveniently be carried out in the temperature range of 700° to 1000° C. for at least 30 minutes in a hydrogen or hydrogen/nitrogen stream. The sintering of the billet must be carried out above the temperature of the eutectoid transition, i.e., at at least 700° C. for 10 hours in an argon atmosphere, in order to obtain as homogeneous a structure as possible. The hot working, which can be hot pressing, hot extrusion, hot forging, hot rolling, hot drawing and/or hot circular swaging, can be accomplished at temperatures between 700° and 1000° C.; likwise the interposed homogenization in an inert gas atmosphere (intermediate annealing) can be carried out at at least 700° C. for at least 30 minutes. The final annealing in an argon atmosphere is carried out at a temperature between 700° and 1050° C. (beta-phase solid solution region) for 10 to 15 minutes and the workpiece is immediately thereafter quenched in water.
For most types of hot working it is desirable to encapsulate the material beforehand in a ductile metallic shell which does not chemically react with the alloy, and which in most practical applications is removed after the shaping as a surface layer by chemical or mechanical means. Suitable materials for the shell are principally annealed metals and alloys such as copper, copper alloys, and soft iron. The encapsulation can be performed immediately before the hot working, in which case the sintered billet undergoes a mechanical surface treatment by turning, milling, smoothing, or the like, or the powder can instead be immediately placed into a rubber or plastic tube in a suitable tube, capsule, etc.
By the powder metallurgical process of the invention and the dispersion alloys prepared thereby it is possible to prepare articles from shape-memory alloys of the Cu/Zn/Al type which, in comparison with the currently available articles, i.e., those prepared by fusion metallurgical techniques, exhibit a fine-grained-structure and good reproducibility of their physical properties. Their structures may have an average grain size of 30 micrometers, which remains unchanged even by an indefinitely long annealing at a temperature up to 950° C. and their mechanical properties, especially the elongation, notch toughness and the workability of the billets, are significantly better than those of cast and/or additionally hot worked articles. These shape-memory alloys exhibit both a one-way and a two-way shape-memory effect and are characterized by a martensite transition point M s in the temperature range of from -200° to +300° C.
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A fine-grained shape-memory alloy of the Cu/Zn/Al type, prepared by powder metallurgy, exhibiting the beta-high temperature phase, having dispersed in the matrix dispersoids in the form of Y 2 O 3 and or TiO 2 particles which limit grain growth, and a process for preparing this alloy using mechanical alloying.
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FIELD OF THE INVENTION
[0001] The present invention relates to an unplugging apparatus and method for the unplugging of a feeding system; and, more particularly, to an unplugging apparatus and method for a feeding system of hay and foraging systems.
BACKGROUND OF THE INVENTION
[0002] Hay and foraging equipment are utilized in the processing of plant material and include mowers, conditioners, flail choppers, windrowers, and balers for both dry and silage uses. The hay system, such as a round baler, includes a pickup mechanism, which picks the crop material from the ground and supplies it to a bale forming chamber. The bale forming chamber receives the crop material and includes a series of side-by-side moving belts, which rotate the crop material into a round or more accurately a cylindrical bale. Typically, the bale forming chamber has a crop inlet and has a width that corresponds to the width of the bale being formed within the bale forming chamber. The crop material is typically initially formed into windrows on the ground after it is cut and processed through a conditioner. The crop material in the windrow may have varying densities and may even include foreign material. The pickup header of the baler picks the crop material off of the ground and directs it to the bale forming chamber.
[0003] As the baler is driven across the field encountering crop material, the crop material may be bunched or otherwise non-uniformly distributed causing surges in the amount of power required from the power source to process the material encountered. If the material encountered is too thick or even includes some foreign material such as a piece of wood or a stone, a plug can be formed that causes the baling mechanism to be overloaded. Typically, this requires operator intervention requiring the operator to stop the tractor and try to unplug it by perhaps reversing the travel of the tractor to try to pull some of the material out. The encountering of a plug often requires the operator to stop the drive mechanism and then release various aspects of the baler mechanism associated with the flow of the material so that the plug can be removed either manually or by operating portions of the baler with mechanisms in their non-normal operating positions to try to clear the plug from the baler. Once the plug is removed, the operator then goes and repositions the mechanisms that were disengaged, moving them back into a normal operating position. This prior art techniques disadvantageously require operator intervention and the operator can even potentially damage the machine by operating it with only some of the mechanisms being moved to a released position.
[0004] Various unplugging devices are included in the feeding systems on hay and forage equipment which include drop floors, knife disengagement, reversers, rotor movement, pickup baffle positioners, power feed clutches, and the like. These devices are activated electrically, hydraulically, PTO driven, or a combination thereof. These devices are activated individually to make the necessary steps to relieve tight plugs and to then sequentially feed crops through the feeding device. Actuating these devices individually is cumbersome, time-consuming and difficult to understand for inexperienced operators. For example, if knives are not lowered during reversing or dropping the floor operations can cause damage if they are out of position.
[0005] What is needed in the art is a system that manages the unplugging of hay or forage equipment in a cost effective and efficient manner.
SUMMARY OF THE INVENTION
[0006] The present invention provides an unplugging method and apparatus for use with hay and foraging equipment, and, more particularly, provides an apparatus for the unplugging of balers, hay conditioners, windrowers, mowers, flail chopping, and forage harvesting equipment.
[0007] The invention in one form is directed to a method of unplugging hay and forage equipment, including the steps of identifying a plug, activating unplugging devices, unplugging the equipment, and returning the unplugging devices to position of normal operation. The identifying step includes identifying a plug in the equipment caused by the material entering the equipment. The activating step includes activating substantially simultaneously a plurality of unplugging devices. The returning step includes returning the plurality of unplugging devices to their normal operating positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0009] FIG. 1 is a partial schematic illustration of a baler incorporating an embodiment of the unplugging apparatus and utilizing the unplugging method of the present invention and being towed by a tractor;
[0010] FIG. 2 is a schematic illustration of a profile of the baler of FIG. 1 ;
[0011] FIG. 3 is a schematic illustration of elements used in the embodiment of the present invention;
[0012] FIG. 4 is schematic illustration of an embodiment of control system of the present invention; and
[0013] FIG. 5 is another schematic illustration of control system for the baler of FIGS. 1 and 2 .
[0014] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one embodiment of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Referring now to the drawings and, more particularly, to FIGS. 1-3 , there is illustrated a hay or foraging system 10 that includes a tractor 12 towing a baler 14 . While baler 14 is being illustrated herein, it is understood that baler 14 is a hay or foraging device 14 that could include square or round balers for either dry or silage material, forage harvesters, mowers, flail chopping devices, hay conditioners, and windrowers, each of which encounter and process bulk crop material and have a crop inlet which can be plugged. A plug 16 is illustrated where the flow of material has clumped or some foreign matter is substantially blocking the operation of the feeding mechanisms of baler 14 . The handling of plug 16 is a focus of the present invention.
[0016] Tractor 12 has a PTO 18 that provides power to at least some of the mechanisms of baler 14 . Tractor 12 additionally includes an actuator 20 , a display 22 , and an activation button 24 . PTO 18 may be disengaged by action of actuator 20 that may be incorporated into elements of tractor 12 , and which may be under the control of a controller associated with tractor 12 . The controller associated with tractor 12 may receive a signal from baler 14 causing actuator 20 to disengage and even brake power takeoff unit 18 . A display 22 alerts the operator that a plug 16 has been encountered or display 22 may additionally indicate that a plug 16 has been cleared. Additionally, display 22 can display the operating positions of various aspects of baler 14 . Activation button 24 allows the operator to initiate an unplugging sequence to remove plug 16 from baler 14 . The phrase “removing plug 16 from baler 14 ” also incorporates the processing of plug 16 so that the crop material is processed within baler 14 or removed from baler 14 or a combination thereof. Activation button 24 may also include a function commanding baler 14 to reposition mechanisms therein into a normal operating position.
[0017] Baler 14 includes a frame or chassis 26 , a tongue 28 , a baffle 30 , knives 32 , a drop floor 34 , belts 36 , a rotor drive 38 , and a pickup header 40 . Side sheet 42 is schematically shown in FIG. 3 and would exist on another embodiment of a baler to control the pressure encountered by a plunger of a square baler as it presses hay into a square bale. Actuators 44 - 56 are respectively associated with these operational elements of baler 14 , as illustrated in FIG. 3 . Crop material enters baler 14 along material flow path 58 and is picked up by pickup header 40 and travels between baffle 30 and progresses on to knives 32 and drop floor 34 on its way to a bale forming chamber.
[0018] A controller 60 interacts with actuators when a plug is detected to substantially simultaneously actuate several of the elements of baler 14 including some combination at least of baffle 30 , knives 32 , drop floor 34 , belts 36 (or side sheet 42 ), rotor drive 38 , pickup header 40 and power takeoff 18 . Advantageously, the simultaneous moving of these elements and the removal of power supplied by way of power takeoff 18 all work to clear plug 16 from interfering with the operation of tractor 12 and baler 14 . Controller 60 may be an electronic control system that interacts with selective control valves (SCV) or it may be some other combination of control that interacts with actuators 20 and 44 - 56 .
[0019] Now, additionally referring to FIGS. 4 and 5 , there is illustrated some hydraulic schematics to operate functions of baler 14 including the bale tension cylinders and gate release cylinders shown in FIG. 4 as well as a hydraulic circuit to engage knives 32 , drop floor 34 , and pickup 40 when substantially simultaneously activated. It should be understood that this substantially simultaneous operation causes a quick response to the presence of plug 16 . The nearly simultaneous or simultaneous movement of these elements can include the activation of a sequential movement of some portions in the event that one element is better moved before another and that such a sequential operation is initiated by the substantially simultaneous movement initiated by controller 60 . Controller 60 is interfaced with the SCV valves of FIGS. 4 and 5 and the hydraulic cylinders illustrated in FIGS. 4 and 5 correspond to corresponding actuators of FIG. 3 .
[0020] During normal operation, tractor 12 pulls baler 14 , which encounters the crop material that enters along material flow path 58 making its way to the bale forming chamber. When plug 16 is encountered, controller 60 substantially simultaneously activates a plurality of actuators 44 , 46 , 48 , 50 , 52 , and 52 . This action causes the following elements to respond: baffle 30 is moved away from material flow 58 ; knives 32 drop away from material flow 58 ; drop floor 34 moves away from material flow path 58 ; tension on belt 36 is reduced; rotor drive 38 may be stopped or reversed; and pickup header 40 may be moved with its intake mechanism slowed, stopped, or reversed, thereby affecting the amount of flow along material flow path 58 . Additionally, power takeoff 18 may be disengaged from powering baler 14 to thereby prevent the overloading of tractor 12 . Power takeoff 18 may be re-engaged to move plug 16 while the previous elements are in their previously described position to reduce the influence of plug 16 on the normal operation of baler 14 .
[0021] Once plug 16 has been removed or otherwise dissipated in the system, controller 60 then utilizes actuators 44 , 46 , 48 , 50 , 52 , and 54 to respectively move baffle 30 , knives 32 , drop floor 34 back into their operating position and to increase the tension of operating level of belt 36 and to engage rotor drive 38 and pickup head 40 so that they are respectively placed in a normal operating mode for the reception of crop material. Actuator 20 is activated to engage power takeoff 18 so that mechanical power again is restored to baler 14 so that the operations of baler 14 can resume. The movement of these elements can be substantially simultaneous so that baler 14 can quickly resume normal operating functions.
[0022] Controller 60 activates any combination of the mechanisms that also serve as unplugging devices, previously mentioned, simultaneously and additionally include either instructions to back up baler 14 conveyed to the operator by way of display 22 or an automatic function in which baler 14 is automatically reversed. When unplugging is completed, the device is returned to normal operating positions. Another example includes a precutter type feeding system with an electro-hydraulic control. First, a plug occurs at the entrance of the material to baler 14 or along the path of material flow 58 . The operator pushes activation device 24 causing controller 60 to disengage PTO 18 by utilizing actuator 20 . Substantially simultaneously, a solenoid is energized to divert hydraulic pressure to the low pressure circuit of belt tensioner 50 in the form of actuator 50 and additionally energizes solenoids in parallel SCV circuits for moving pickup 40 , knives 32 , and drop floor 34 . In this operation, the operator only actuates a single control such as activation device 24 or it may be in the form of a single SCV lever to thereby position all of the devices to relieve restrictions along material flow path 58 . At this point, actuator 20 is activated causing power takeoff 18 to be engaged to feed the plug through or away from baler 14 . The operator or controller 60 then activates an SCV to return all of the unplugging devices to their normal operating position and continue to bale. With the use of electrical or electronic sensors and actuators, electronic SCV hydraulics, and/or electronic PTO controls, several of these steps are done without operator activation.
[0023] The present invention includes certain advantages including there are fewer steps for the operator that are needed for the removal of plug 16 . This allows a less skilled operator to be productive with baler 14 . There is less wasted time in the moving the devices to an unplugging position and can also include positions that are additionally used to service the elements, such as for the replacement or sharpening of knives 32 . Another advantage is that elements of baler 14 are not inadvertently positioned during a plug clearing operation, such as the positioning of knives 32 during the unplugging operation. The unplugging operation that results from the present invention includes a more positive unplugging of baler 14 by relieving crop restrictions in several areas of the feeding system simultaneously. This not only relieves areas of plugging but it also diverts available PTO drive power to areas where it is most needed. For example, tractor 12 may be limited to 150 PTO horsepower with 50 horsepower being used to form a round bale and 100 horsepower being used to feed through a crop slug. When a crop slug forms a plug and is stuck in the feeding mechanism, it may exceed the 100 horsepower that is available causing the baler or tractor clutch to disengage or to kill the tractor engine. If the tension of belt 36 is reduced, then only 20 horsepower is needed to rotate the bale, rather than 50, thereby allowing a total of 130 horsepower to be available to feed the slug through the feeder.
[0024] Specific to a round baler 14 , bale forming belts are tensioned during bale growth with the belt tension being proportional to bale density but it is also proportional to the power consumption to form and rotate the bale in the bale forming chamber. As such, reducing belt tension reduces belt power consumption, thereby enhancing the ability of baler 14 to deal with plug 16 .
[0025] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
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A method of unplugging hay and forage equipment, including the steps of identifying a plug, activating unplugging devices, unplugging the equipment, and returning the unplugging devices to position of normal operation. The identifying step includes identifying a plug in the equipment caused by the material entering the equipment. The activating step includes activating substantially simultaneously a plurality of unplugging devices. The returning step includes returning the plurality of unplugging devices to their normal operating positions.
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PRIOR APPLICATION
This application is a U.S. national phase application based on International Application No. PCT/SE2004/001985,filed Dec. 23, 2004, claiminq priority from Swedish Patent Application No. 03035821, filed Dec. 30, 2003.
TECHNICAL AREA
The invention concerns a method for the feed of cellulose chips during continuous cooking.
THE PRIOR ART
When cooking cellulose chips in continuous digesters, the chips are transported from a feed system at atmospheric pressure or a pressure slightly above atmospheric pressure to an impregnation vessel or a digester in which the pressure is considerably higher, through what is known as a “transfer flow”. Transport in the transfer flow is made possible in that the chips are formed into a slurry with a transport fluid, preferably a process fluid, which is subsequently separated from the chips in separation equipment, normally designated as a “top separator”, when the chips have reached the impregnation vessel or the digester. The transport fluid is recirculated to the feed system through a return line. The transfer flow has comprised for a long time a special type of sluice feed, known as a “high-pressure feeder”, that has been specially designed to resist and separate the large differences in pressure that exist between the two systems. This high-pressure feeder is equipped with a rotor with symmetrical through pockets that are placed alternately in connection with the low-pressure system and the high-pressure system when the rotor rotates, without there being allowed any form of communication between these systems. The chips can in this manner be transferred from one system with no excess pressure or at a low excess pressure, typically 0-4 bar (abs), and fed through the high-pressure feeder into a system with considerably higher pressure, typically 7-20 bar (abs).
FIG. 1 shows schematically a conventional feed system according to the prior art with a high-pressure feeder 33 and a bin flow 34 , a transfer flow 6 a , 45 and a return flow 50 . The transfer flow is constituted by a transfer line 6 a for the transport of chips that have been formed into a slurry with a transport fluid, and a return line 45 for the transport fluid. The transfer line 6 a connects at its upper end to a top separator 47 arranged at the top of a treatment vessel 48 where excess transport fluid is separated from the chips, after which the transport fluid is returned to the high-pressure feeder 33 through the return line 45 . The top separator 47 is symbolised here by a version that is fed downwards in a treatment vessel that is filled hydraulically, or by some other separation equipment arranged in the transfer line or at the upper section of the treatment vessel.
The return flow 50 controls the level of fluid in the chip bin 32 and ensures that sufficient fluid is available in order to feed the chips out from the high-pressure feeder 33 .
Since the return flow 50 passes from low pressure to high pressure, at least one high-pressure pump 51 is required to be arranged in the return flow 50 .
A major disadvantage of this design is that the high-pressure pump 51 must consume large amounts of electrical energy in order to transport chips from the chip bin 32 to the treatment vessel 48 .
FIG. 2 shows a method according to SE 519262 with the aim of reducing the problems and disadvantages described above. A minimum amount of fluid is used in this case to transport the chips in the transfer line 6 b ′ and the fluid can in this way be allowed to accompany the chips to the subsequent treatment vessel 60 ′. Thus, no return line and no associated pumps, valves or equipment for transport fluid are required, making the feed system cheaper than conventional feed systems. The high-pressure feeder 53 ′ is fed with a mixture of chips and fluid from a chip bin 52 ′ in which an L/W-ratio of between four and ten is established through the active addition of fluid LIQ A . A conventional high-pressure feeder 53 ′ is placed after the chip bin, and is equipped with a rotor with symmetrical through pockets ( 1 , 2 ) that are alternately placed in connection with the chip bin 52 ′ and the transfer line 6 b ′. When one of the pockets of the rotor opens by gradual rotation towards the chip bin 52 ′ it becomes filled by the fluid that in the previous position fed the chips mixture out into the transfer line 6 b ′. The pocket facing the opposing flow line 54 ′ opens at the same time and an open channel through the high-pressure feeder is created. The pocket is placed in the first position when it is located in this filling position.
Under the influence of one or more high-pressure pumps 57 ′, 57 ″ or under the influence of one pump with several pumping stages in the flow line 54 ′, and under the influence of the static pressure that is formed by the column of fluid in the chip bin 52 ′, the fluid in the pocket 1 will be extracted/expelled by suction at the same time as the chips mixture is fed into the pocket.
Furthermore, it can on occasions be desirable to add a makeup fluid LIQ B to the flow line 54 ′. This makeup fluid LIQ B is characterised by not being to any degree part of a withdrawal from subsequent separation equipment connected to the treatment vessel 60 ′.
The disadvantage of this design is that the high-pressure pumps mentioned above consume very large quantities of electrical energy.
Aim and Purpose of the Invention
The principal aim of the present invention is to offer a method that consumes little energy during the transport of chips mixture from a feed system that functions at a first, low pressure and that comprises a high-pressure feeder for the sluice feed of chips mixture to a treatment vessel in a cooking system for the continuous cooking of chemical cellulose pulp that functions at a second, higher pressure.
This is achieved according to the invention through a method that demonstrates the characteristics specified in claim 1 .
A further aim is to fully or partially remove the requirement for high-pressure pumps, which consume large amounts of electrical energy. These high-pressure pumps are described above in the summary of the prior art.
A further aim is to fully or partially exploit the pressurised fluid withdrawn from a subsequent digester or impregnation vessel at a pressure that is essentially maintained and that corresponds to the pressure established in these, which fluid withdrawal normally passes to a recovery system through a pressure-reducer, and instead to use these pressurised fluids in order to transport chips out from the high-pressure feeder.
BRIEF DESCRIPTION OF THE INVENTION
The invention is characterised in that it fully or partially reduces the requirement for high-pressure pumps in order to pump fluid from low pressure to high pressure in association with the transport of chips from a chip bin to a treatment vessel. These high-pressure pumps, which consume a large amount of electrical energy, have been described in more detail above in the description of the prior art.
This is achieved through exploiting, fully or partially, the pressurised fluid withdrawn from the treatment vessel, which is normally withdrawn and passed to a recovery system, and using instead this pressurised fluid to expel chips from the high-pressure feeder, before the previously pressurised fluid is passed to the recovery system, either directly or via a chip bin or an impregnation vessel.
The amount of fluid that passes to the recovery system after the high-pressure feeder is equivalent to the amount of fluid that is required to pump up to high pressure by means of a high-pressure pump in the prior art.
The requirement for large amounts of electrical energy that is required for the use of high-pressure pumps according to the prior art can, according to the invention, be reduced by up to 50%.
The saving in the pumping power required is proportional to the portion that is withdrawn under pressure from the digester and that during its passage through the sluice feeder is later led to the recovery system, either directly or via a chip bin or impregnation vessel.
The pressurised portion has in this case been used to raise the pressure of the chips suspension at the removal position, and since this portion is passed to the recovery system it does not need to be repressurised with a return line 71 , 72 .
Further characteristics and aspects, together with advantages, of the invention are made clear by the attached claims and by the detailed description of a number of embodiments given below.
DESCRIPTION OF THE DRAWINGS
The prior art is described with reference to FIG. 1 and FIG. 2 , where
FIG. 1 shows schematically a conventional feed system with a high-pressure feeder and a bin flow and a transfer flow;
FIG. 2 shows schematically a feed system according to subsequently developed technology without a bin flow and a transfer flow with a return line (according to SE 519262);
FIG. 3 shows a first, a second and a fifth preferred embodiment according to the invention;
FIG. 4 shows a third and a fifth preferred embodiment according to the invention;
FIG. 5 shows a fourth and a fifth preferred embodiment according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The concept of “treatment vessel 60 ″” will be used in the following description of preferred embodiments. The treatment vessel 60 ″ can be either a pressurised digester or a pressurised impregnation vessel.
The concept “pressurised fluid” will also be used. The term “pressurised fluid” is here used to denote a pressurised withdrawal of fluid that has been taken from a treatment vessel 60 ″ and that is characterised in that it is pressurised and maintained at a pressure level that essentially corresponds to the pressure that has been established in the treatment vessel 60 ″. This pressurised fluid can be withdrawn from a top separator 91 on a treatment vessel 60 ″ or from a strainer 90 on a treatment vessel 60 ″ at a position in the treatment vessel 60 ″ at which the chips have had a retention time greater than 60 minutes, preferably greater than 100 minutes.
Furthermore, the concept “previously pressurised fluid” will be used. The term “previously pressurised fluid” is here used to denote pressurised fluid that has been used in order to empty the sluice feeder 53 at its high-pressure position (the emptying position), the pressure of which is subsequently reduced at the subsequent rotation of the pocket of the sluice feeder to the low-pressure position, whereby this fluid has passed the sluice feeder 53 and thus is no longer under pressure.
Finally, the concepts “recovery REC kik ”, “recovery REC extr ” and “recovery REC tot ” will be used.
The term “recovery REC kik ” is here used to denote a portion of the previously pressurised fluid that has been used to empty the sluice feeder 53 , where this portion is subsequently forwarded directly to the recovery system or indirectly to the recovery system via a black liquor impregnation or a pre-impregnation. The term “recovery REC extr ” is here used to denote a fluid withdrawal that has been withdrawn from a chip bin 52 ″ or from an impregnation vessel 60 ″ and where this fluid is forwarded to a recovery system.
The term “recovery REC tot ” is here used to denote the total amount of all fluids from the treatment vessel 60 ″ that are forwarded to the recovery system or to black liquor impregnation or pre-impregnation.
The fluids that are withdrawn via REC kik and REC extr for recovery cannot exceed REC tot and they cannot exceed the amount of new fluid that is fed into the system together with the chips.
FIG. 3 shows a first preferred embodiment according to the invention in the form of a method for the feed of a mixture of cellulose chips and fluid from a low-pressure system to a high-pressure system during the continuous cooking of chemical cellulose pulp. The feed of fluid and cellulose chips between these systems takes place through a sluice feeder 53 ″. The sluice feeder 53 ″ is equipped with a first inlet 53 a ″, a second inlet 53 c ″, a first outlet 53 b ″ and a second outlet 53 d ″. The sluice feeder 53 ″ further comprises a rotor with a first 1 ″ and a second 2 ″ through pocket, which are placed alternately in connection with the high-pressure system and the low-pressure system.
The first pocket 1 ″ is located at a first position and is placed via the first inlet 53 a ″ in connection with a chip bin 52 ″ while the pocket 1 ″ is filled with the chips mixture, while at the same time expulsion of the fluid that is present in the pocket 1 ″ takes place via the first outlet 53 b″.
The second pocket 2 ″ is located at a second position and is placed via the second outlet 53 d ″ in connection with a transfer line 6 b ″ in the high-pressure system, while the chips mixture is fed out from the pocket 2 ″ for transport onwards to a treatment vessel 60 ″ in the high-pressure system with the aid of a fluid that is fed into the pocket 2 ″ through the second inlet 53 c″.
The second inlet 53 c ″ is connected via at least one withdrawal line 70 to the treatment vessel 60 ″, from which pressurised fluid is withdrawn. At least a portion of this pressurised fluid is withdrawn from the treatment vessel 60 ″ with a strainer 90 at a position in the treatment vessel 60 ″ at which the chips have had a retention time greater than 60 minutes, preferably greater than 100 minutes.
In one variant of this embodiment, a portion of the pressurised fluid can also be constituted by fluid withdrawn from a top separator 91 on the treatment vessel 60 ″.
A supplementary pump 81 may be used, where required, to pump the pressurised fluid to the second inlet 53 c ″ of the sluice feed. The pressurised fluid is used to expel the chips mixture from the pocket 1 ″ of the sluice feeder when the pocket is placed in connection with the high-pressure system. The previously pressurised fluid is withdrawn at the first outlet 53 b ″ of the sluice feeder from the pocket 1 ″ and where a portion (REC kik ) of the previously pressurised fluid is forwarded to the recovery system and where this portion constitutes at least 20% of the total amount (REC tot ) that is passed to the recovery system, while constituting at least 1 m 3 /tonne of pulp with the aim of reducing the total amount of electrical energy required to pump the chips suspension from low pressure to high pressure through the sluice feeder 53 .
A second preferred embodiment is also shown in FIG. 3 . It can occasionally be possible that the complete amount of previously pressurised fluid that has been withdrawn from the pocket 1 ″ at the first outlet 53 b ″ of the sluice feeder (REC kik ) is sent to the recovery system, for reasons relating to the process.
FIG. 4 shows a third preferred embodiment, in order to establish a desired L/W ratio in the chip bin. In this embodiment, the main part of the previously pressurised fluid after the first outlet 53 b ″ of the sluice feeder on the low-pressure side is allowed to pass to the chip bin, arranged before the sluice feeder 53 . This main part of previously pressurised fluid is transported in a bin flow line 73 . A pump 74 may be used, where required, to pump the previously pressurised fluid to the chip bin 52 ″. The chip bin 52 ″ has a volume that gives a retention time of the previously pressurised fluid in a chips mixture of at least 10 minutes before the previously pressurised fluid (REC extr ) is withdrawn to the recovery system via a recovery line 77 that extends from the withdrawal strainer 78 on the chip bin 52 ″.
FIG. 5 shows a fourth preferred embodiment according to the invention in the form of a method for the feed of a mixture of cellulose chips and fluid from a low-pressure system to a high-pressure system during the continuous cooking of chemical cellulose pulp. The feed of fluid and cellulose chips between these systems takes place through a sluice feeder 53 ″. The sluice feeder 53 ″ is equipped with a first inlet 53 a ″, a second inlet 53 c ″, a first outlet 53 b ″ and a second outlet 53 d ″. The sluice feeder 53 ″ further comprises a rotor with a first 1 ″ and a second 2 ″ through pocket, which are placed alternately in connection with the high-pressure system and the low-pressure system.
The first pocket 1 ″ is located at a first position and is placed via the first inlet 53 a ″ in connection with an impregnation vessel 3 ″ essentially at atmospheric pressure while the pocket 1 ″ is filled with the chips mixture, while at the same time expulsion of the fluid that is present in the pocket 1 ″ takes place via the first outlet 53 b″.
The second pocket 2 ″ is located at a second position and is placed via the second outlet 53 d ″ in connection with a transfer line 6 b ″ in the high-pressure system, while the chips mixture is fed out from the pocket 2 ″ for transport onwards to a treatment vessel 60 ″ in the high-pressure system with the aid of a fluid that is fed into the pocket 2 ″ through the second inlet 53 c ″. The second inlet 53 c ″ is connected via at least one withdrawal line 70 to the treatment vessel 60 ″ from which pressurised fluid is withdrawn. At least a portion of this pressurised fluid is withdrawn from the treatment vessel 60 ″ with a strainer 90 at a position in the treatment vessel 60 ″ at which the chips have had a retention time greater than 60 minutes, preferably greater than 100 minutes.
In one variant of this embodiment, a portion of the pressurised fluid can also be constituted by fluid withdrawn from a top separator 91 on the treatment vessel 60 ″.
A supplementary pump 81 may be used, where required, to pump the pressurised fluid to the second inlet 53 c ″ of the sluice feed. The pressurised fluid is used to expel the chips mixture from the pocket 1 ″ of the sluice feeder when the pocket is placed in connection with the high-pressure system. The previously pressurised fluid is withdrawn at the first outlet 53 b ″ of the sluice feeder from the pocket 1 ″ and where a portion (REC kik ) of the previously pressurised fluid is forwarded to the recovery system and where this portion constitutes at least 20% of the total amount (REC tot ) that is passed to the recovery system, while constituting at least 1 m 3 /tonne of pulp with the aim of reducing the total amount of electrical energy required to pump the chips suspension from low pressure to high pressure through the sluice feeder 53 . The main part of the previously pressurised fluid is passed onwards through a line 75 to the impregnation vessel 3 ″, which is essentially at atmospheric pressure, arranged before the sluice feeder before a portion (REC extr ) of the previously pressurised fluid is forwarded through a line 79 to the recovery system via a withdrawal from a strainer 80 in the impregnation vessel 3 ″, which is at atmospheric pressure.
Finally, a fifth preferred embodiment is shown in FIGS. 3 , 4 and 5 that can be applied on all of the previously mentioned embodiments. It is sometimes desirable from considerations of the process to add a makeup fluid to the second inlet 53 c ″ on the high-pressure side of the sluice feeder. This makeup fluid is a portion (REC kik ) of the previously pressurised fluid that was destined for recovery after the first outlet 53 b ″ on the low-pressure side of the sluice feeder. The makeup fluid is transported through a recycling line 71 using at least one high-pressure pump 72 .
Alternative Embodiments
With the high-pressure feeder located at a position after a chip bin, it has been traditional to arrange the high-pressure feeder such that its filling process takes place from above when a pocket in its first position has a vertical axis of symmetry, but the method according to the invention is not limited to this method of filling the high-pressure feeder. Filling can also be carried out with the axis of the symmetry of the pocket in a horizontal position. This may be particularly suitable when the high-pressure feeder is arranged after an impregnation vessel. The impregnation vessel is normally placed directly on the ground, due to its size, and thus it is not obvious that there is sufficient space for the filling of the high-pressure feeder from above. If the impregnation vessel is equipped with a bottom scraper, its motor will be centrally positioned under the bottom of the impregnation vessel, and this will probably ensure that it is necessary to place the high-pressure feeder to one side of the vertical axis of symmetry of the impregnation vessel, and it is thus no longer obvious that the filling of the high-pressure feeder is best carried out from above. A horizontal filling procedure may be suitable in this case, and a filling procedure from underneath may be considered.
The invention is not limited to the embodiments described. Several variants are possible within the framework of the claims.
While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.
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Chips are sluiced from a low-pressure section to a high-pressure section with a sluice feeder. The fluid that is used to expel the chips from the sluice feeder principally includes pressurized fluid withdrawn from the treatment vessel. This pressurized fluid is normally withdrawn from the treatment vessel for recovery (REC). By using this pressurized fluid instead for expelling the chips from the sluice feeder and subsequently sending the previously pressurized fluid to the recovery system (REC), the requirement for high pressure pumps that consume large quantities of electrical energy can be considerably reduced.
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The present invention relates to fluid flooding to recover oil from a subterranean oil-bearing formation and, more particularly, to such a fluid flood wherein the formation of harmful viscous zones within the injected fluid banks are prevented.
BACKGROUND OF THE INVENTION
In the production of oil from underground oil-bearing formations, it is known that primary recovery methods remove only a small portion of the in-place oil. Secondary oil recovery methods, such as waterflooding, recover substantially more of this oil, but still leave a large quantity of the oil still in place. This in place oil is difficult to remove due to the fact that the interfacial tension between the immiscible phases within the oil results in entrapping the oil in the pores of the formation material. In order to reduce the interfacial tension of the oil, certain fluid additives are usually introduced into the formation; for example, surface active agents are injected to reduce this interfacial tension. These fluids are usually followed by the injection of mobility control solutions having a viscosity sufficient to drive the now mobilized oil towards a producing well. To achieve this viscosity, the fluid bank containing this mobility control solution may include a polymer. In that this polymer is relatively expensive, efforts have been made to develop recovery methods which reduce the amount of polymer needed for the total flood project. One technique is to grade or decrease the concentration of the polymer within the mobility control fluid bank from a high concentration at the front thereof to a low concentration at the rear thereof. This method has had limited success in recovering additional oil; however, some serious drawbacks have developed through this use. The greatest drawback against utilizing this method of decreased grading is that in utilizing a relatively high concentration of the polymer a viscous polymer build-up forms within the injected fluid which plugs the formation, thereby substantially reducing the oil recovery by affecting the mobility control and the sweep efficiency of the injected fluids. One method of preventing the formation of these viscous zones is to reduce the overall concentration of the polymer within the injected fluid banks. By reducing the polymer concentration, the effective recovery yield from the project is obviously reduced. There is a need for a fluid flooding method which substantially reduces or eliminates the formation of these viscous zones, as well as reduces the amount of polymer needed for the project while maintaining the integrity of the mobility control.
SUMMARY OF THE INVENTION
The present invention contemplates an improved method of oil recovery from a subterranean oil-bearing formation, which is particularly designed to overcome the foregoing disadvantages. The method of the present invention comprises introducing an aqueous fluid bank into the formation to reduce the interfacial tension of the oil, followed by introducing a mobility control fluid bank to drive the now mobilized oil towards the producing well. The viscosity of the fluids which were injected are graded from a low viscosity at the front thereof to a higher viscosity at the rear thereof, thus preventing the formation of viscous zones within the injected fluids. This grading of the viscosity may take place within the first fluid bank only, the mobility control fluid bank only or across all of the injected banks of fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 graphically illustrates a high viscosity zone generated within a micellar fluid due to polymer build up.
FIG. 2 graphically illustrates the absence of adverse viscous zones by eliminating any polymer from the micellar fluid.
FIG. 3 graphically illustrates the elimination of adverse viscous zones by inversely grading the viscosity of the micellar fluid for a low viscosity at the front thereof to a higher viscosity at the rear thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is applicable to fluid flooding to recover oil from an underground formation wherein a first fluid is introduced into the formation to reduce the interfacial tension of the in-place oil followed by the introduction of a mobility control fluid to drive the displaced oil to a production well. Most typically this type of flooding is called micellar flooding where a mobility control agent which provides viscosity necessary to drive the fluid is provided by a biopolymer or polyacrylamide.
In a typical micellar flooding process a preflush slug of water is injected into the formation. This preflush fluid is usually of a low salinity and, if desired, may contain a sacrificial agent to reduce loss of the surface active agent or surfactant to the formation. Next a slug of fluid, such as what is normally called a micellar fluid, containing surface active agents or surfactants is injected into the formation. The micellar slug is equal to about 0.1 to about 0.75 or more pore volume of the formation, and the surfactant concentration generally will be from about 0.05 to about 11 or more percent by weight. The micellar fluid may or may not contain a water soluble polymer to provide a certain amount of mobility control or pushability of the oil. The micellar fluid slug thereafter is followed by the introduction of a mobility control fluid into the formation. This fluid usually contains a certain concentration of lyophilic polymer which is a water soluble polymer. One polymer usually used is an ionic polysaccharide produced by bacteria of the genus Xanthamonus. Many other such water soluble polymers may be used within this invention. The mobility control fluid slug is equal in volume to about 0.5 to about 0.9 or more pore volume of the formation and contains a certain polymer concentration, from about 0 ppm to about 2500 ppm.
It has been found that when the polymer, such as a biopolymer, is added to the micellar fluid, a viscous zone is generated within the micellar bank. This is because the polymer does not interact with the oil and cannot penetrate into the mobilized oil-water bank. As a result, polymer concentration is built up or accumulated behind the mobilized oil-water bank and thus generates a high viscosity zone due to the higher concentration of the polymer. This high viscosity zone or viscous zone is usually followed by the stabilized micellar bank and the mobility control bank. The viscosity of these banks have been designed based on a lack of occurrence of a viscous zone. Hence, this creates a mobility control problem because the less viscous fluid will tend to bypass or channel through the more viscous fluid, and the more viscous fluid will slow down and may eventually become trapped.
To correct this polymer build up, it has been proposed within the present invention to inversely grade the viscosity of the injected fluids. More specifically, it has been proposed to inversely grade the polymer concentration within the micellar fluids. By grading the polymer concentration of the micellar bank from a low concentration at the front thereof to a higher concentration at the rear thereof, the polymer build up may be used to advantage by generating the viscosity needed within the micellar bank, but more importantly, any viscous zones will be prevented thus the integrity of the mobility control of the flood will be preserved.
The mobility control fluid concentration depends upon many field variables but the polymer concentration may be graded from about 0 ppm to about 2500 ppm. Preferably, the polymer concentration may be graded from about 0 ppm to about 1000 ppm, and most preferably from about 0 ppm to about 800 ppm.
It should be noted that the viscosity may be graded across all of the injected fluids. For example, the first fluid may have a polymer concentration graded from about 0 ppm to about 200 ppm at the interface with the mobility control fluid. And, the polymer concentration of the mobility control fluid bank would be graded from 200 ppm to about 1000 ppm.
To illustrate the effectiveness of the present invention, the following tests were conducted. First, an explanation of the core test procedure is presented. A core is prepared by wrapping and installing pressure-tabs as is common practice in the industry. The core is then saturated with injection water saturated with CaSO 4 . Crude oil is then injected to reduce the cores connate water saturation. Next, brine is injected to reduce the fluid saturation of the core to a residual oil saturation, as by secondary water flooding. Finally, a micellar fluid is injected into the core.
In the first test, a 1 ft Berea sandstone core was prepared as described above and saturated with Torchlight Field crude oil. A fluid slug at 100° F. was continuously injected into the core. The micellar fluid bank contained an Xanthan polymer at 900 ppm. As shown in FIG. 1, the effective viscosity (measured in centipoise) of the micellar fluid rose to a peak of 26 cp at 1.25 pore volumes produced. This is 50% or more in excess of the stabilized mobility fluid bank. The single high peak on the graph in FIG. 1 indicates the formation of a viscous zone. The effluent produced from this core, specifically from this viscous zone, was cloudy and contained a much higher polymer concentration than that which was injected. This polymer build-up within the core can be differentiated from the so-called "concentrate" effect of the polymer resulting from the formation of "upper" and "middle" phase microemulsions. The concentrating effect is caused by upper and middle microemulsions taking up brine and excluding the high molecular weight polymer molecules. However, in this test, the viscous zone occurred inside the micellar bank where both micellar tracer and surfactant had reached their injected values.
A second test was conducted and is illustrated in FIG. 2. In this test, a 2 ft Berea core was prepared with Torchlight Field crude oil in the same manner as described above. A large slug of micellar fluid was injected into the core. The micellar fluid did not contain any polymer. As the graph in FIG. 2 shows, there was not a single high peak or ridge which indicated the formation of a viscous zone; however, the mobility control was totally lacking between the oil-water and micellar banks.
A final test was conducted to show the advantages of the present invention and the results are shown in FIG. 3. A 2 ft Berea core was prepared identically to the test illustrated in FIG. 2. The micellar fluid composition was essentially identical, but with the addition of an Xanthan polymer graded from 0 ppm to 800 ppm in accordance with the present invention. The results illustrated in the graph of FIG. 3 do not show a high peak of viscosity thus indicating the prevention of any polymer build-up within the micellar fluid bank. In fact, the viscosity of the produced fluid never increased above 18 cp. It can be seen from the above test that the inverse polymer grading in accordance with the present invention totally prevented or dramatically reduced any viscous zones, thereby allowing for better mobility control within a micellar flood and thus reducing the amount of polymer entrapment within the formation.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the scope or spirit of this invention.
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The method of oil recovery for use within a fluid flood comprising grading the viscosity of injected fluids at a low concentration at the front thereof to a high concentration at the rear thereof to prevent the formation of viscous zones within the injected fluids which reduce oil recovery.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fastener for joining two parts, and more particularly, to a plastic fastener comprising a pin and an isolator grommet for joining the housing of a computer cooling fan to the chassis of the computer. The isolator grommet is preinstalled in the fan housing. Insertion of the pin through the chassis and into the isolator grommet completes the mounting.
2. Description of the Prior Art
Fasteners for joining apertured work pieces are well known in the prior art, and are usually manufactured of metal or plastic. The nut and bolt and the screw are examples of common metallic fasteners, while examples of plastic fasteners are shown in U.S. Pat. Nos. 2,882,780 and 2,941,439.
When joining the cooling fan housing of a computer to the chassis of the computer, however, many prior art fasteners have proven unsatisfactory. With regard to metallic fasteners, they generally have a high elastic modulus, making them poor isolators of the vibrations caused by the operation of the fan, often resulting in bothersome and unacceptable noise. Second, metallic fasteners are relatively more difficult to install than plastic fasteners, often requiring use of a tool, such as a wrench or a screwdriver. Third, metallic fasteners are conductive and thus could prove hazardous if lost inside the computer.
With respect to plastic fasteners, many plastic fasteners have proven unsatisfactory in that they, as with metallic fasteners, insufficiently isolate the vibrations caused by the operation of the fan. Other plastic fasteners are difficult to install and/or remove, and yet other fasteners provide a weak coupling between the fan housing and the chassis.
It is therefore an object of the present invention to provide a plastic fastener for securing a fan housing to the chassis of a computer which results in a quieter mounting than that achieved by currently used fasteners. Another object of the present invention is to provide a plastic fastener which provides a secure connection between the housing and the chassis. Yet another object of the present invention is to provide a fastener which can be easily installed and removed. Other objects will become apparent from the discussion below.
SUMMARY OF THE INVENTION
An isolator fan fastener in accordance with the present invention achieves the above and other beneficial objects by providing a plastic fastener having a pin and a separate isolator grommet with an axial bore extending therethrough. The pin has a head and a shank. The shank has a first engaging portion, a second engaging portion, a third engaging portion and a fourth engaging portion. The four engaging portions have varying diameters and, as discussed below, are frictionally engageable with corresponding portions of the interior walls of the isolator grommet.
The isolator grommet has a head, a shank, a circumferential lip, and an axial bore of varying dimension extending therethrough for receiving the pin. The bore forms a first interior wall portion for receiving the first engaging portion of the pin shank in releasable frictional engagement, a second interior wall portion for receiving the second engaging portion of the pin shank in releasable frictional engagement, a third interior wall portion for receiving the third engaging portion of the pin shank in releasable frictional engagement, and a fourth interior wall portion for receiving the fourth engaging portion of the pin shank in releasable frictional engagement.
In operation the shank of the isolator grommet is inserted into a hole in the fan housing such that the wall of the fan housing is situated between the head and lip of the isolator grommet and the head and lip bear against the outer and inner surfaces of the housing, respectively. The isolator grommet is dimensioned in the manufacturing process to mate with a fan housing of predefined thickness, i.e. the thickness of the fan housing corresponds to the distance between the head and lip on the grommet.
The bore in the grommet is then aligned with the hole on the computer chassis with the isolator grommet head bearing against the inside of the chassis. The pin is inserted into the grommet until the pin head bears against the outside surface of the chassis. The pin is dimensioned in the manufacturing process for use with a computer chassis of predefined thickness. When the pin is fully inserted into the chassis the first engaging portion on the pin shank is in releasable frictional engagement with the first interior wall portion of the grommet, the second engaging portion on the pin shank is in releasable frictional engagement with the second interior wall portion of the grommet, the third engaging portion on the pin shank is in releasable frictional engagement with the third interior wall portion of the grommet, and the fourth engaging portion of the pin shank is in releasable frictional engagement with the fourth interior wall portion of the grommet.
At that point the fan housing is firmly and releasably fastened to the chassis. The isolator grommet is manufactured of a soft plastic such that it isolates a large portion of the vibration of the fan, thereby reducing the noise level. The pin, on the other hand, is manufactured of a hard plastic to ensure secure coupling with the isolator grommet, thereby securely fastening the fan housing to the chassis.
An isolator fan fastener in accordance with the present invention offers numerous advantages over the prior art. First, the noise caused by the operation of the fan is reduced as compared to many prior art fasteners. Second, the frictional engagement of the pin and the isolator grommet ensures a secure fastening. Third, the fan housing may be attached or detached to the computer chassis by simple insertion or extraction of the pin into or out of the isolator grommet without use of excessive force or a special tool. Other advantages will become apparent from the discussion below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a front view of the pin;
FIG. 2 is a front view of the isolator grommet;
FIG. 3 is a front cross-sectional view of the assembled fastener joining a fan housing to the chassis of a computer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The aforementioned Figures illustrate an isolator fan fastener in which the same numbers represent identical elements.
With reference to FIG. 1, numeral 10 represents the fastener pin in accordance with the preferred embodiment of the invention. The pin has a head 12 , a spacer 14 , a tapered shoulder 16 and a shank 18 . The shank is further comprised of a cylindrical first engaging portion 20 , a tapered second engaging portion 22 , a spherical third engaging portion 24 and a cylindrical fourth engaging portion 26 . Pin 10 is circular in cross section and is molded from a hard, impact resistant plastic, such as nylon 6/6 or hard santoprene.
First engaging portion 20 and fourth engaging portion 26 have the same diameter. Second engaging portion 22 , adjacent first engaging portion 20 , tapers on a circular arc to a minimum diameter to form a neck 28 . Third engaging portion 24 , adjacent second engaging portion 22 , expands spherically from said minimum diameter to a maximum diameter and then tapers to a diameter equal to that of first engaging portion 20 and fourth engaging portion 26 .
With reference to FIG. 2, numeral 30 represents the isolator grommet in accordance with the preferred embodiment of the invention. Isolator grommet 30 is circular in cross section and has a head 32 , a shank 33 , a headwardly flexible circumferential outer lip 34 and a circular bore 36 for receiving pin 10 . Bore 34 is of varying diameter and forms a mouth portion 38 for receiving pin shoulder 16 , a coextensive cylindrical first interior wall portion 40 for receiving shank first engaging portion 20 in releasable frictional engagement, a coextensive tapered second interior wall portion 42 for receiving shank second engaging portion 22 in releasable frictional engagement, a coextensive expanding third interior wall portion 44 for receiving shank third engaging portion 24 in releasable frictional engagement, and a cylindrical fourth interior wall portion 46 for receiving shank fourth engaging portion 26 in releasable frictional engagement. Fourth interior wall portion 46 should generally be at least coextensive with shank fourth engaging portion 26 . However, in practice it is generally longer as this allows isolator grommet to be positioned in the fan housing by a pulling action. Second interior wall portion 42 and third interior wall portion 44 form a neck 48 which receives shank neck 28 .
First interior wall portion 40 and fourth interior wall portion 46 are of equal diameter, and said diameter is slightly smaller that the diameter of shank first and fourth engaging portions 20 , 26 , thereby allowing for a friction fit therebetween. Typically, the diameter of first and fourth interior wall portions 40 , 46 will be on the order of 14% smaller than the diameter of shank first and fourth engaging portions 20 , 26 . Similarly, tapered second interior wall portion 42 has a shape complementary to that of shank second engaging portion 22 and has a minimum diameter smaller than the minimum diameter of shank second engaging portion 22 . Typically, the minimum diameter of second interior wall portion 42 will be on the order of 21% smaller than the minimum diameter of shank second engaging portion 22 . Expanding third interior wall portion 44 has a maximum diameter approximately 26% smaller than the maximum diameter of shank third engaging portion 24 . From comparison of FIGS. 1 and 2 it is clear that third interior wall portion 44 is not complementary in shape to shank third engaging portion 24 , i.e. third interior wall portion 44 is not spherical. This configuration ensures that in addition to a tight friction fit, the engagement of shank neck 28 and grommet neck 48 will provide an additional retention force to resist the extraction of pin 10 since spherical shank third engaging portion 24 would have to pass through the narrow passage formed by neck 48 .
So that it may act as a vibration isolator and deform so as to frictionally engage with pin 10 , isolator grommet 30 is manufactured of a soft, resiliently deformable plastic such as a thermoplastic elastomer (TPE) or soft santoprene.
In operation the fastener is used as follows. FIG. 3 shows the assembled fastener joining a fan housing 50 to the chassis of a computer 52 . Isolator grommet 30 is inserted into the hole in fan housing 50 . This is done by insertion of distal end 54 of shank 33 into the hole and the pulling of said distal end until circumferential lip 34 flexes and fan housing 50 becomes positioned between head 32 and circumferential lip 34 such that surface S 1 bears against the underside of head 32 and surface S 2 bears against circumferential lip 34 , as shown in FIG. 3 . Because the distance between head 32 and lip 34 corresponds to the thickness of the fan housing, isolator grommet 30 is manufactured for use with a fan housing of a predetermined thickness. Next, grommet bore 36 is aligned with the hole in the computer chassis 52 such that the upper side of grommet head 32 bears against the interior surface S 3 of the chassis 52 . Pin 10 is then inserted into isolator grommet 30 until spacer 14 bears against the exterior surface S 4 of chassis 52 . Because pin 10 and isolator grommet 30 are made of plastic, a relatively small axial force is needed to effect interengagement, which may even be accomplished by hand.
In order for pin 10 to mate with isolator grommet 30 , the length of shoulder portion 16 is adjusted in the manufacturing process for the thickness of chassis 52 , i.e. the axial length of shoulder portion 16 is equal to the sum of the thickness of chassis 52 plus the axial length of grommet mouth 38 . Thus, pin 10 and isolator grommet 30 are manufactured for use with a fan housing and chassis of predetermined thicknesses.
When pin 10 is fully inserted into isolator grommet 30 the fastener is locked and fan housing 50 is securely fastened to chassis 52 . Because the diameter of pin shank 18 is everywhere larger than the diameter of grommet bore 36 , insertion of pin 10 into isolator grommet 30 causes expansion of the interior walls of isolator grommet 30 , thereby frictionally engaging pin 10 and isolator grommet 30 . Thus, first interior wall portion 40 expands to receive shank first engaging portion 20 , second interior wall portion 42 expands to receive shank second engaging portion 22 , third interior wall portion 44 expands to receive shank third engaging portion 24 , and fourth interior wall portion 46 expands to receive shank fourth engaging portion 26 . Thus, pin shank 18 is everywhere frictionally engaged with isolator grommet 30 . In addition, the engagement of shank neck 28 with neck 48 provides an additional retention force since spherical shank third engaging portion 24 must pass through the narrow passage formed by neck 48 in order to extract pin 10 .
The fastener is thus releasably locked and the fan housing is securely and releasably fastened to the chassis. If one desires to remove the fan housing, pin 10 may simply be extracted from isolator grommet 30 by the application of relatively little axial force. Pin spacer 14 provides a space between pin head 12 and outer surface S 4 of chassis 52 , thereby facilitating the use of an extracting tool, such as a pair of pliers, a screwdriver or even a human hand.
The improved acoustical properties of the fastener are achieved by the use of the soft plastic isolator grommet in connection with the hard plastic pin. The isolator grommet is in direct contact with the fan housing and is able to isolate a significant portion of the fan's vibration. The use of a hard pin, on the other hand, ensures that a tight coupling will be achieved with the isolator grommet and that fan housing will be securely fastened to chassis.
While the present isolator fan fastener is suitable for use with a cooling fan housing and a computer chassis, it should be understood that the fastener is not limited to such use and can be used to join any apertured parts.
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An isolator fan fastener for securing a cooling fan housing to the interior chassis of a computer is described. The fastener is comprised of a pin made of a hard impact resistant plastic and an isolator grommet made of a soft resiliently flexible plastic. The pin is frictionally engageable with the isolator grommet. In operation the isolator grommet is preinstalled in the fan housing. Insertion of the pin through the chassis and into the isolator grommet completes the mounting. An isolator fan fastener in accordance with the invention yields enhanced acoustical properties when compared to prior art fasteners.
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FIELD
[0001] The present invention relates to compositions comprising strains of lactic acid bacteria for use in modifying the enteric nervous system. Such compositions are especially suitable to treat and/or prevent intestinal disorders such as constipation and/or irritable bowel disease.
BACKGROUND
[0002] Irritable bowel syndrome (IBS) or spastic colon is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, a low-grade gut inflammation was reported. Diarrhoea or constipation may predominate, or they may alternate (classified as IBS-D, IBS-C respectively). IBS may begin after an infection (post-infectious, IBS-PI), a stressful life event or onset of maturity without any other medical indicators. In IBS, routine clinical tests yield no abnormalities, though the bowels may be more sensitive to certain stimuli, such as balloon insufflation testing.
[0003] IBS is a very common condition affecting approximately 15% of the population at any one time. There are about twice as many women as men with this condition. IBS is a source of chronic pain, fatigue and other symptoms, and it increases a patient's medical costs, and contributes to work absenteism. Researchers have reported that the high prevalence of IBS, in conjunction with increased costs produces a disease with a high societal cost. It is also regarded as a chronic illness and can dramatically affect the quality of a sufferer's life.
[0004] A leading theory about the cause of IBS relates to the enteric nervous system (ENS). The enteric nervous system (ENS) is a subdivision of the peripheral nervous system (PNS) that directly controls gastro-intestinal (GI) functions and is embedded in the lining of the gastrointestinal system. It includes efferent neurons, afferent neurons, and interneurons. The structural and physiological functioning of the ENS is performed by glial cells (astrocytes). The ENS is organized into two major plexus with functional specific roles.
[0005] The myenteric plexus, located between the longitudinal and circular muscle, contains neurones mainly involved in the control of intestinal motility. Through intestinal muscles, the efferent or motor neurons control peristalsis and churning of intestinal contents. The motor neurons controlling motility are composed of two major classes:
excitatory myenteric neurons liberating acetylcholine (referred to as Choline AcetylTransferase ImmunoReactive neurons (“ChAT-IR” or “ChAT” or “ChAT neurones” or “ChAT nerves”) and/or substance P (SP) for contractions, and inhibitory myenteric neurons liberating nitric oxide (identified as Nitric Oxide Synthase neurons (NOS-IR)) and/or Vaso-active Intestinal Peptide (VIP) for relaxation.
[0008] Choline acetyltransferase EC 2.3.1.6 is an enzyme that is synthesized within the body of a neuron and transferred to the nerve terminal. The role of ChAT is to join Acetyl-CoA to choline, resulting in the formation of the neurotransmitter acetylcholine. Experimentally, effect on acetylcholine production is extrapolated from the determination of the number of ChAT neurons, typically an increase in the number of ChAT nerves is indicative of an increase of acetylcholine.
[0009] The submucosal plexus, located between the circular muscle and the mucosa, contains neurons mainly involved in the control of intestinal epithelial barrier (IEB) functions, such as paracellular permeability. In particular, activation of enteric neurones in the submucosal plexus decreases paracellular permeability, via the liberation of VIP, whereas acetylcholine (Ach) increases paracellular permeability, setting the basis of a fine ‘tuning’ of the IEB permeability by the ENS. Thus, concerning the neuronal control of paracellular permeability, the increase of VIP liberation by submucosal neurons increases IEB integrity while the increase of submucosal plexus ChAT neurons decreases IEB resistance.
[0010] Although there is at current no cure for IBS, there are treatments which attempt to relieve symptoms, including dietary adjustments, medication and psychological interventions.
[0011] Probiotics, in particular strains of lactic acid bacteria, are reported to be beneficial in the treatment and/or prevention of IBS. Examples of such disclosures are WO 2007/036230, WO 03/010297, and WO 2009/080800. However, the bacterial strains are selected for their effect on the immune system, on intestinal permeability or on the intestinal microbiota and not for their effect on improving the function of the ENS. WO 2008/064489 discloses the use of probiotics to block an intermediate conductance calcium dependent potassium current resulting in an anti-inflammatory effect. WO 2007/132359 discloses the use of Lactobacillus and a cannabinoid receptor agonist and/or an opioid receptor antagonist in relation to pain perception. WO 2006/032542 discloses the use of Lactobacillus for analgesic purposes. Kamm et al, 2004, Neurogastrointest. Motil 16: 53-60 disclosed effects of S. boulardii on decreasing calbindin-28 k (CALB) but not on other neuronal markers of the pig jejunum. Metugriachuk et al, 2006, Rejuvenation Res. 9: 342-345 disclose that a symbiotic preparation on motility of small and large intestine in old Wistar rats significantly increased the myoelectric activity of small intestine and colon, an increased mRNA expression of VIP, but no significant effect on VIP concentration.
[0012] Further research is therefore needed on individual strains of probiotic bacteria with a beneficial effect on the ENS for use in IBS, constipation and/or other disorders.
SUMMARY OF THE INVENTION
[0013] The inventors employed a new model system for screening and selecting strains of lactic acid bacteria and bifidobacteria which have an improved effect on the enteric nervous system (ENS). This model contains a (mono)layer of intestinal epithelial cells from human colon carcinoma and, on the basolateral side of the monolayer, a mixture of a primary culture of enteric nervous system cells including neurones from myenteric and submucosal plexus. Using this model the effects of food grade components, in particular strains of lactic acid bacteria and bifidobacteria, on the ENS could be assessed by measuring the effects of apical or luminal addition of these components on the expression of vaso-intestinal peptide (VIP) and/or ChAT releasing nerves on the basolateral side.
[0014] This model therefore allowed to screen and to select new strains of lactic acid bacteria and bifidobacteria for use in improving the function of the enteric nervous system. Such strains improve intestinal motility and peristalsis. With some strains the intestinal transit time can be reduced, which can address some conditions such as constipation. With some strains the intestinal transit time can be increased, which can address some conditions such as diarrhoea. VIP increasing strains also improve intestinal epithelial barrier integrity. Such strains are in particular useful and more efficacious than existing strains in prevention and/or treatment of IBS and/or constipation and other disorders associated with a decreased function of the ENS.
[0015] Increasing cholinergic phenotype, in particular the expression of ChAT neurons is of therapeutic interest in GI tract pathologies associated with inhibition of colonic transit. Using lactic acid bacteria or bifidobacteria selected to have an increasing effect on enhancing cholinergic expression, i.e. ChAT, in neurons are of therapeutical interest for constipated patients, and patients suffering from IBS-C. Therefore, one group of lactic acid bacteria or bifidobacteria strains of the present invention advantageously increases the number of ChAT nerves, which is indicative for an improved effect on intestinal motility, and especially is beneficial for IBS patients, in particular IBS-C patients, and patients suffering from constipation. This group is referred to as group B). Good motility requires a high number of ChAT nerves, which are responsible for contraction and have a prokinetic effect. In some interesting embodiments for this group the TEER levels are not decreased, since the IEB function and ability to relax the muscles is preferably not impaired. The subgroup according to these embodiments is referred to as group B3).
[0016] Increasing VIP beneficially improves relaxation of the muscles of the GI tract and improves IEB, which is beneficial for patients suffering from IBS or inflammatory bowel disease (IBD) and also for elderly people, infants, and obese people. For such subjects a good IEB function is better if not essential. Although patients suffering from IBS or IBD have an oversecretion of neuropeptides such as VIP, this is supposed to be an adaptative response of the ENS to control intestinal inflammation, to re-establish intestinal barrier functions and to increase neuroprotection. A group of lactic acid producing bacteria strains, in particular bifidobacteria, of the present invention advantageously increases VIP. This group is referred to as group A). In one embodiment the ChAT level is not increased. The group according to this embodiment is referred to as group A3). Accordingly the ChAT level can remain substantially unchanged or can decrease.
[0017] All the herein referred bacterial strains have been deposited, according to the Budapest Treaty, before CNCM (“Collection Nationale de Cultures de Microorganismes”, 25 rue du Docteur Roux, Paris) as an International depositary authority.
[0018] Strains found with the screening method were belonging to group B) are DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010), DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) and DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010). Strains belonging to group A) are DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000), DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010), DN — 156 — 007 (CNCM I-2219 filed May 31, 1999), and DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010). Strain DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000) has been disclosed in International application WO 02/02800 and strain DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) has been disclosed in International application WO 01/01785.
[0019] Compositions comprising at least one of these selected strains are therefore part of the invention. A composition comprising a mix of at least one strain belonging to group B) and at least one strain belonging to group A) is preferred. Such a mix will advantageously have an improved effect on motility by improving both contractions and relaxations and additionally have an advantageous effect on IEB function.
[0020] Thus, according to one aspect the invention concerns a composition comprising at least one strain of bacteria, preferably selected from the group consisting of lactobacilli and bifidobacteria, for use in:
[0021] A) increasing vaso-active intestinal peptide (VIP) levels of the enteric nervous system, or
[0022] B) increasing Choline AcetylTransferase ImmunoReactive neurones (ChAT) levels of the enteric nervous system, or
[0023] C) decreasing ChAT levels of the enteric nervous system.
[0024] According to one aspect the invention concerns a composition comprising at least one strain of bacteria selected from the group consisting of the following strains:
[0025] DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)],
[0026] DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)],
[0027] DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)],
[0028] DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)],
[0029] DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and
[0030] DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) [B)-B3)], for use in:
treatment and/or prevention of an intestinal disorder, preferably treatment and/or prevention of an intestinal motility disorder, or treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C, treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, intestinal infection, IBS-D, IBS-PI, and IBD, or treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, or obese people.
[0036] According to one aspect the invention concerns a composition comprising at least one strain of bacteria selected from the group consisting of the following strains:
[0037] DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)],
[0038] DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)],
[0039] DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)],
[0040] DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)],
[0041] DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and
[0042] DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010)[B)-B3)],
[0043] for use in administration to subjects suffering from a disorder selected from the group consisting of:
constipation, IBS-C, diarrhoea, intestinal infection, IBS-D, IBS-PI, IBD, IBS, and disorders found in elderly people, infants, or obese people.
[0048] According to one aspect the invention concerns a composition as mentioned above for use in improving gastro-intestinal motility, improving intestinal peristalsis and/or decreasing intestinal permeability.
[0049] According to one aspect the invention concerns new strains of bacteria selected from the group consisting of:
DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)], DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)], DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)- B3)], and DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)- B3)].
[0054] According to one aspect the invention concerns compositions comprising the new strains.
[0055] According to one aspect the invention concerns a composition comprising:
at least one strain of bacteria selected from the group consisting of lactobacilli and bifidobacteria that B) increases ChAT levels in the enteric nervous system, and at least one strain of bacteria selected from the group consisting of lactobacilli and bifidobacteria that A) increases vaso-active intestinal peptide (VIP) levels in the enteric nervous system.
[0058] According to one aspect the invention concerns a method of selecting strains of bacteria, said method comprising the steps of:
[0059] a) Arranging a coculture of intestinal epithelial cells and enteric neuronic cells, wherein said intestinal epithelial cell are present as a monolayer and wherein said enteric neuronic cells are present at the basolateral side of the monolayer,
[0060] b) Adding strains of bacteria to the apical or luminal side of the monolayer of intestinal epithelial cells, preferably in an amount of about 4 to 400 bacterial cells per epithelial cell,
[0061] c) Incubating the coculture with the strain of lactic acid bacteria,
[0062] d) Preferably isolating the neuronic cells,
[0063] e) Measuring the amount of VIP, ChAT, substance P, Nitrogen Oxide nerves, ATP and/or pituitary adenylate cyclase activating peptide (PACAP) produced by the neuronic cells and optionally additionally the TransEpithelial Electrical Resistance (TEER) of the intestinal epithelial cells layer.
[0064] In this method, the strain of bacteria preferably belongs to the group consisting of lactobacilli and bifidobacteria.
DETAILED DESCRIPTION
Definitions
[0065] In the present application the use of a compound or a composition is intended to cover the use itself, optionally with the connected intention, but also any communication associated to the compound or composition with commercial or legal consequences, for example advertisement, instructions or recommendation on the package of the compositions, instructions or recommendation on commercial support such as leaflets, brochures, posters, documentation filed in support to regulatory registrations for safety purpose, efficacy purpose, or consumer protection, for example at administrations such as EFSA in Europe.
[0066] In the present application groups of strains refer to strains that exhibit a specific property or set of properties. A specific strain can thus pertain to several groups. In the present application the term “or” is not exclusive.
[0067] In the present application a property such as VIP and/or ChAT is considered as substantially unchanged compared to a control if the variation does not exceed 10%, preferably 1% compared to the control.
Preferred Embodiments
[0068] In preferred embodiments, the composition is for use in:
[0069] A3) increasing VIP, provided that ChAT is not increased, or
[0070] B3) increasing ChAT, provided that VIP is not increased, Electrical Resistance (TEER) of the intestinal epithelial cells layer being not decreased or
[0071] C3) decreasing ChAT, provided that VIP is not decreased, or
[0072] C2) decreasing ChAT and decreasing VIP.
[0000] For example the composition of the invention can be used in:
treatment and/or prevention of an intestinal disorder, preferably treatment and/or prevention of an intestinal motility disorder, or treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C, or treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, intestinal infection, IBS-D, IBS-PI, and IBD, or treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, and obese people.
In especially preferred embodiments, the compositions can:
[0078] A) increase VIP levels of the enteric nervous system, and be used in treatment and/or prevention of an intestinal disorder, preferably treatment and/or prevention of an intestinal motility disorder, or
[0079] B) increase ChAT levels of the enteric nervous system, and be used in treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C, or
[0080] C) decrease ChAT levels of the enteric nervous system, and be used in treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, IBS-D, IBS-PI, IBD.
[0000] The strain of bacteria can for example be selected from the group consisting of the following strains:
DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000) [A)-A3)], DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)], DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)- A3)], DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)], DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)], DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) [B)- B3)].
In one embodiment the strain of bacteria is selected from the group consisting of the following strains:
DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)], DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)], and DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)], and the composition is for use in:
treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, or obese people.
In one embodiment the strain of bacteria is selected from the group consisting of the following strains:
DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)], DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) [B)-B3)], and the composition for use in treatment and/or prevention of a disorder selected from the group consisting of constipation and IBS-C.
In one embodiment the strain of bacteria is selected from the group consisting of the following strains:
DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)], DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)], and DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)], and the composition is for use in:
[0099] A) increasing vaso-active intestinal peptide (VIP) levels of the enteric nervous system, preferably for use in A3) increasing VIP, provided that ChAT is not increased.
[0000] In a particular embodiment of this embodiment, the composition is for use in:
treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, or obese people.
In one embodiment the strain of bacteria is selected from the group consisting of the following strains:
DN — 116 — 0047 (CNCM I-4317 filed May 19 ,2010) [B)-B3)], DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) [B)-B3)], and the composition is for use in:
[0105] B) increasing ChAT levels of the enteric nervous system, preferably B3) increasing ChAT, provided that VIP is not increased.
[0000] In a particular embodiment of this embodiment, the composition is for use in treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C.
Further Details of Strains of Bacteria
[0106] As mentioned above the composition comprises at least one or two specific strains of bacteria, preferably lactic acid bacteria. They are preferably selected from the group consisting of the genus Lactobacillus and Bifidobacterium, Lactococcus and Streptococcus . The said specific strain of bacteria were found to be capable to affect VIP levels and/or to affect ChAT nerve levels in a coculture model representing the interaction between the intestine and the ENS.
[0107] A coculture model, described in more detail below, was used to in vitro select strains of lactic acid bacteria or bifidobacteria with these properties. 102 strains belonging to the genera Lactobacillus, Streptococcus or Bifidobacterium were screened.
[0108] Group B) strains with increased effect on ChAT will typically improve intestinal motility. Group B3) strains with increased effect on ChAT, excluding strains wherein VIP is not increased (i.e. VIP is substantially unchanged or VIP is decreased) represent a specific preferred embodiment. Strains of these groups are typically beneficial for treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C. This might be of further particular interest for treatment and/or prevention of disorders found in elderly people, which can often suffer from constipation. Concerning increasing motility, strains increasing ChAT expression would be favoured. This property appears to be very rare. Interestingly, only three strains were found to increase statistically ChAT. These are referred to group B) or group B3) strains. Group B) or group B3) strains comprise strains DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010), DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) and DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010). Such strains beneficially improve motility, especially contractions. It is preferred that Electrical Resistance (TEER) of the intestinal epithelial cells layer be not decreased. Such a property can be indicative of a suitable barrier function. Strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) significantly decreased VIP levels, whereas the other two strains did not have a significant effect on VIP levels. Since a decrease in VIP may have an adverse effect on IEB it was examined with an in vitro model with a monolayer of intestinal epithelial cells whether incubation of this strain resulted in a decrease transepithelial electrical resistance (TEER). This turned out not to be the case, indicating that the IEB function is not impaired.
[0109] Concerning the relaxation of the muscles and reinforcement of IEB function, which is beneficial in IBS and IBD patients, strains would be favoured that increase VIP expression (which would have in addition anti-inflammatory effects). Such strains are referred to as group A) strains. In a preferred embodiment group A) strains do not increase ChAT expression (i.e. ChAT is substantially unchanged or ChAT is decreased). Such strains are referred to as group A3) strains. Strains of these groups are typically beneficial to treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or to treatment and/or prevention of disorders found in elderly people, infants, or obese people. Group A) or group A3) strains comprise strains DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000), DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010), DN — 156 — 007 (CNCM I-2219 filed May 31, 1999), DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010). It is interesting to note that all the strains having this property are bifidobacteria except one: DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010). Furthermore, using another in vitro model with a T84 monolayer and the transepithelial electric resistance (TEER) especially strains DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000), DN — 156 — 007 (CNCM I-2219 filed May 31, 1999), DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) and DN — 156 — 0032 (CNCM I -4321 filed May 19, 2010) of group A) or A3) were found to have a protective effect on the IEB in the presence of LPS. Therefore, these particular strains are especially preferred.
[0110] According to one embodiment the strains allow decreasing ChAT levels of the enteric nervous system. The corresponding group of strains is referred to as group C). In a particular embodiment the strains allow decreasing ChAT, provided that VIP is not decreased (i.e. VIP is substantially unchanged or VIP is increased). This group is referred to as group C3). In a particular embodiment the strains allow decreasing ChAT with decreasing VIP.
[0111] These strains are referred to as group C2). Strains of group C3) are typically beneficial to treatment and/or prevention of a disorder selected form the group consisting of diarrhoea, IBS-D. This might be of further particular interest for treatment and/or prevention of disorders found in elderly people, which can often suffer from diarrhoea. Strains of group C2) are typically beneficial to treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, IBS-D, IBS-PI, and IBD. This might be of further particular interest for treatment and/or prevention of disorders found in elderly people which can often suffer from such conditions, especially diarrhoea.
[0112] The present invention also encompasses the use of the above mentioned strains, but also mutant strains or genetically transformed strains derived from any one of the parent strains still having activity on VIP and effecting ChAT nerves. These mutant or genetically transformed strains can be strains wherein one or more endogenous gene(s) of the parent strain has (have) been mutated, for instance to modify some of its metabolic properties (e. g. its ability to ferment sugars, its resistance to acidity, its survival to transport in the gastrointestinal tract, its post-acidification or its metabolite production). They can also be strains resulting from the genetic transformation of the parent strain by one or more gene(s) of interest, for instance in order to give to said strain additional physiological features, or to allow it to express proteins of therapeutic or vaccinal interest that one wishes to administer through said strains.
[0113] Preferably a mix of at least one strain belonging to group B), preferably group B3), and at least one strain belonging to group A), preferably group A3), is used. Such a mix will advantageously have an improved effect on motility as well as on IEB.
Co-Culture Model and Screening Assay
[0114] In one embodiment the present invention relates to a method of selecting strains of lactic acid bacteria, said method comprising the steps of:
[0115] a) Using a coculture of intestinal epithelial cells and enteric neuronic cells, wherein the intestinal epithelial cells are present as a monolayer and wherein the enteric neuronic cells are present at the basolateral side of the monolayer,
[0116] b) Adding lactic acid bacteria or the apical or luminal side of the monolayer, preferably in an amount of about 4 to 400 bacterial cells per epithelial cell,
[0117] c) Incubating the coculture with the lactic acid bacteria,
[0118] d) Preferably isolating the neuronic cells, and
[0119] e) Measuring the amount of at least one neurotransmitter selected from the group consisting of VIP, ChAT, substance P and Nitrogen Oxide, ATP, PACAP produced by the neuronic cells, and optionally additionally the TransEpithelial Electrical Resistance (TEER) of the intestinal epithelial cells layer.
[0120] In agreement with the peristaltic reflex the ENS contains hardwired circuits that consist of ascending excitatory motor neurons that release acetylcholine and substance P, which contracts smooth muscle through muscarinic receptors, and of descending inhibitory neurons that release a cocktail of transmitters, like NO, ATP, VIP and PACAP, all of which inhibit the circular muscle.
Cell Culture
[0121] A suitable way to set up the coculture with a monolayer of polarized intestinal epithelial cells is given in example 1 and is also described in J. Chevalier et al, 2008, J. Physiol. 586 1963-1975.
[0122] All intestinal epithelial cell cultures forming monolayers are suitable, such as Caco-2, T84, HT29, and TC7. Preferably T84 cells are used.
[0123] As primary enteric nerve system cells, preferably cells are isolated from non-human mammalian foetuses, preferably rodents, more preferably rats.
[0124] Preferably the bacteria strains tested are grown to late exponential phase in a suitable growth medium and washed. Preferably the bacteria are added to the apical side of the coculture at an amount of 4 to 400 bacteria/epithelial cell, more preferably 10 to 100 bacteria/epithelial cell, even more preferably 30 to 50 bacteria/epithelial cell. Preferably, as a control, no bacteria are added. Preferably, as a positive control 1 mM butyrate or 40 mM KCl is used.
[0125] Preferably the incubation step is performed at about 37° C. Preferably the incubation step takes 1 to 72 h, more preferably 2 to 36 h, even more preferably 4 to 12 h.
[0126] Preferably after co-incubation, the compartment containing epithelial cells and bacteria is removed and primary neuronal cells are incubated for 12 to 48 h, more preferably for 20 to 28 h in a humidified incubator containing 5% CO 2 .
[0127] Preferably the amount of ChAT nerves versus total nerves is measured using immunohistochemical staining, using anti-neurone specific enolase (NSE) to count the total number of neurones and anti-choline acetyl transferase to count the ChAT nerves.
[0128] Preferably VIP is determined by ELISA after collecting the neuronal cells and extracting the proteins with the presence of a protease inhibitor cocktail.
[0000] Further Details about Compositions
The invention encompasses compositions with strains of bacteria which allow the above referenced uses or properties. The invention also encompasses compositions comprising one or more of the following strains (encompassing mutants or genetically transformed strains derived thereof):
[0129] DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)],
[0130] DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)],
[0131] DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)],
[0132] DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)],
[0133] DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and
[0134] DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) [B)-B3)], for use in:
treatment and/or prevention of an intestinal disorder, preferably treatment and/or prevention of an intestinal motility disorder, or treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C, or treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, intestinal infection, IBS-D, IBS-PI, and IBD, or treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, or obese people,
[0140] typically when administered in vivo to a subject.
[0141] In the compositions of the invention, said strains can be used in the form of whole bacteria which may be living or not. Alternatively, they can be used in the form of a bacterial lysate or in the form of bacterial fractions; the bacterial fractions suitable for this use can be chosen, for example, by testing their properties of alleviating the effects on VIP levels and levels of ChAT nerves of the coculture model described in the present invention. Preferably the bacterial cells are present as living, viable cells.
[0142] The compositions of the invention can be in any form suitable for administration, in particular oral administration. This includes for instance solids, semi-solids, liquids, and powders. Liquid compositions are generally preferred for easier administration, for instance as drinks.
[0143] The composition can for example comprise at least 10 5 , preferably at least 1×10 6 , cfu per g dry weight, of at least one strain of bacteria, preferably of strains of bacteria as mentioned above. These are preferably selected from the group consisting of lactobacilli and bifidobacteria.
[0144] When the bacteria are in the form of living bacteria, the composition may typically comprise 10 5 to 10 13 colony forming units (cfu), preferably at least 10 6 cfu, more preferably at least 10 7 cfu, still more preferably at least 10 8 cfu, and most preferably at least 10 9 cfu per g dry weight of the composition. In the case of a liquid composition, this corresponds generally to 10 4 to 10 12 colony forming units (cfu), preferably at least 10 5 cfu, more preferably at least 10 6 cfu, still more preferably at least 10 7 cfu, and most preferably at least 10 9 cfu/ml.
[0145] Examples of the compositions of the invention are nutritional compositions, including food products and in particular dairy products.
[0146] The composition can be for example a dairy product, preferably a fermented dairy product. The administration in the form of a fermented dairy product has the additional advantage of low lactose levels, which is further beneficial for IBS. Optionally, other strains of lactic acid bacteria may be present. The fermented product can be present in the form of a liquid or present in the form of a dry powder obtained by drying the fermented liquid. Preferably the fermented product is a fresh product. A fresh product, which has not undergone severe heat treatment steps, has the advantage that bacterial strains present are in the living form. Preferably the fermented product is a dairy product, more preferably fermented milk and/or fermented whey. Preferably the nutritional composition is yoghurt, or fermented milk in set, stirred or drinkable form. Preferably the fermented product is a cheese. Preferably the fermented product is a fermented vegetable, such as fermented soy, cereals and/or fruits in set, stirred or drinkable forms.
[0147] Preferably the present nutritional composition is a baby food, an infant milk formula or an infant follow-on formula. Preferably the present composition is a nutraceutical or a pharmaceutical product, a nutritional supplement or medical food.
[0148] Nutritional compositions of the invention also include food supplements, and functional food. A “food supplement” designates a product made from compounds usually used in foodstuffs, but which is in the form of tablets, powder, capsules, potion or any other form usually not associated with aliments, and which has beneficial effects for one's health. A “functional food” is an aliment which also has beneficial effects for one's health. In particular, food supplements and functional food can have a physiological effect—protective or curative—against a disease, for example against a chronic disease.
[0149] A composition comprising a mix of at least one strain of lactic acid bacterium or bifidobacterium increasing ChAT nerves and at least one strain of lactic acid bacterium or bifidobacterium increasing VIP levels is preferred. Such a mix will advantageously have an improved effect on motility as well as on IEB.
[0150] A mix of at least one strain belonging to group B), preferably B3), and at least one strain belonging to group A), preferably A3), is preferred. Such a mix will advantageously have an improved effect on motility as well as on IEB.
[0151] Therefore the present invention also relates to compositions comprising:
at least one strain of bacteria selected from the group consisting of the following strains:
[0153] DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) [B)-B3)],
[0154] DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010) [B)-B3)], and
[0155] DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010)[B)-B3)]; and
at least one strain of bacteria selected from the group consisting of the following strains:
[0157] DN — 173 — 010 (CNCM I -2494 filed Jun. 20, 2000) [A)-A3)],
[0158] DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010) [A)-A3)],
[0159] DN — 156 — 007 (CNCM I-2219 filed May 31, 1999) [A)-A3)], and
[0160] DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) [A)-A3)].
[0161] The compositions of the invention can also comprise one or more other strain(s) of lactic acid bacteria, probiotic or not, for instance one or more bacterial strain(s) selected from the genera Lactobacillus, Lactococcus, Streptococcus , and Bifidobacteria . In particular, this (these) other strain(s) can include one or more strain(s) of Streptococcus thermophilus , and/or one or more strain(s) of Lactobacillus bulgaricus.
Application
[0162] In one embodiment strains of the present invention were found to increase the number of ChAT nerves. Choline acetyltransferase EC 2.3.1.6 is an enzyme that is synthesized within the body of a neuron and transferred to the nerve terminal. The role of choline acetyltransferase is to join Acetyl-CoA to choline, resulting in the formation of the neurotransmitter acetylcholine. It is used as an immunohistochemical marker for motor neurons. The effects on the ChAT nerve result in the improved contractions resulting in improved peristalsis. Therefore, the strains and compositions of the present invention able to increase ChAT nerves are advantageously administered to improve the ENS, to improve or enhance peristalsis, to improve intestinal motility and/or to decrease the gastro-intestinal transit time. Increasing cholinergic phenotype is of therapeutic interest in GI pathologies associated with inhibition of colonic transit. In particular, various studies have shown that slow transit could be associated with a reduced expression of ChAT neurons. In particular, (i) severely constipated patients generally have a lower amount of ChAT nerves, (ii) the production of myenteric ACh significantly decreased both during the course of infection and post infection (PI), (iii) during aging a reduction of the proportion of cholinergic neurons has been reported.
[0163] In this context, using strains of bacteria, preferably lactic acid bacteria or bifidobacteria to enhance cholinergic expression in neurons could be of future therapeutically interest for severely constipated patient and IBS-C. Therefore, the strains and compositions of the present invention are advantageously administered to patients suffering from IBS-C, and/or constipation. Strains that are most useful are the group B) or B3) strains mentioned above.
[0164] In one particular embodiment the strains and compositions of the present invention are used by or for elderly people. Elderly people in the present invention are defined as human with an age above 65 years, preferably above 70 years, preferably above 75 years, preferably above 80 years, preferably above 85 years. Elderly people typically have decreased number of ChAT neurons in the enteric nervous system located in the colon, most preferably in the transversal colon. Therefore, the strains and compositions of the present invention are advantageously administered to treat and/or prevent IBS, preferably IBS-C, and/or constipation for elderly people. Strains able to increase ChAT nerves are group B), such as strain DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010), DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010) and DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010). They preferably do not decrease VIP, since VIP is necessary for a good IEB function and for relaxation of the GI tract, another important part of the GI tract motility such as peristalsis. The strains meeting this criterion were DN — 154 — 0067 (CNCM I-4320 filed May 19, 2010), and DN — 116 — 0047 (CNCM I-4317 filed May 19, 2010). However, also strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) did not negatively affect IEB function as determined by TEER experiments, as TEER did not decreased.
[0165] In one embodiment the strains of the present invention were found to increase the levels of VIP. With respect to the digestive system, VIP induces smooth muscle relaxation (lower oesophageal sphincter, stomach, gallbladder), stimulates secretion of water into pancreatic juice and bile, and causes inhibition of gastric acid secretion and absorption from the intestinal lumen. Its role in the intestine is to greatly stimulate secretion of water and electrolytes, as well as dilating intestinal smooth muscle, dilating peripheral blood vessels, stimulating pancreatic bicarbonate secretion, and inhibiting gastrin-stimulated gastric acid secretion. These effects work together to increase motility. Therefore this finding is indicative for these strains to have an improved effect on intestinal motility, in particular the relaxation part of motility. VIP also beneficially increases IEB function. Therefore, the strains and compositions of the present invention are advantageously administered to improve the ENS, to improve or enhance peristalsis, to decrease permeability, to improve intestinal motility and/or to decrease the gastro-intestinal transit time. Therefore, the strains and compositions of the present invention are advantageously administered for use in or to patients suffering from:
treatment and/or prevention of an intestinal disorder, preferably treatment and/or prevention of an intestinal motility disorder, or treatment and/or prevention of a disorder selected form the group consisting of constipation and IBS-C, or treatment and/or prevention of a disorder selected from the group consisting of diarrhoea, intestinal infection, IBS-D, IBS-PI, and IBD, or treatment and/or prevention of a disorder selected from the group consisting of IBS and IBD, or treatment and/or prevention of disorders found in elderly people, infants, and obese people.
Strains that are most useful are the group A) or A3) strains mentioned above. Details or advantages of the present invention can be found in the non limitative examples below.
EXAMPLES
Example 1
Screening of Probiotic in a Co-Culture Model Involving Epithelial Cells and Enteric Neuronal Cells
Cell Culture
[0171] Pregnant Sprague-Dawley rats were purchased (CERJ, Le Genest St Isle, France and Janvier-Breeding Center, Belgium) and killed by an overdose of CO 2 followed by severing the carotid arteries. The embryos (35-45 per isolation from 3 pregnant rats) were removed and killed by decapitation. The small intestines of embryos were removed and finely diced in HBSS (Sigma, France). Tissue fragments were collected in 5 ml of medium (DMEM-F 12 1:1 medium) and digested at 37° C. for 15 min in 0.1% trypsin (Sigma). The trypsin reaction was stopped by adding 10 ml of medium containing 10% foetal calf serum and then treated by DNAse I (0.01%, Sigma) for 10 min at 37° C. After triturating with a 10 ml pipette, cells were centrifuged at 750 r.p.m. for 10 min. Cells were counted and then seeded at a density of 2.4×10 5 cells/cm 2 on 24 well plates previously coated for 6 h with a solution of gelatine (0.5%, Sigma) in sterile phosphate buffered saline (PBS). After 24 h, the medium was replaced with a serum free medium (DMEM-F12 1:1 containing 1% of N-2 supplement (Life technologies, France). Cells were maintained in culture for 14 days to obtain primary culture of enteric nervous system (ENS). Half of the medium was replaced every other day. At 14 days the primary neuronal cells were ready for the establishment of the co-culture model.
[0172] T84 cell line (EATCC) was cultured in DMEM-F12 (1:1, GIBCO) supplemented with 10% heat inactivated FBS and 50 IU/ml penicillin and 50 μg/ml streptomycin. Cells were seeded in 12-well Transwell® filters (Corning, NY USA) at a density of 2×10 5 cells/insert and cultured to obtain confluence.
[0173] One day after epithelial cells arrived to confluence, Transwell ® filters were transferred in the 12-well plates seeded at the bottom with enteric nervous cells. Epithelial and neuronal cells were co-cultured in the medium for epithelial cells.
Growing of Strains of Bacteria
[0174] Bacteria were grown for 16 hrs in TGYH for bifidobacteria and lactobacilli, except for strain DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000) which was grown on MRS+cysteine medium, washed in PBS twice and adjusted to 4.10 8 cfu/ml in order to add consistently the same volume of bacterial suspension to the filter. The strains were added in the filter compartment at a MOI of 40 bacteria/epithelial cell. As a control, no bacteria were added.
[0175] After 8 hrs of co-incubation, the filter compartment containing epithelial cells and bacteria was removed and primary neuronal cells were incubated for 24 h in a humidified incubator containing 5% CO 2 . In the control wells neuronal cells where stimulated with 1 mM butyrate and 40 mM KCl when ChAT and VIP measurements were performed, respectively.
[0000] Immunohistochemical Staining. Measuring ChAT Nerves
[0176] After the incubation, immunohistochemistry was performed to detect neuronal cell populations. After cells fixation (in 0.1 M PBS containing 4% paraformaldehyde for 1 h at room temperature), cells were washed 3 times in PBS, then permeabilized for 30 min in PBS/NaN 3 containing 0.5% Triton X-100 and 4% horse serum. Primary antibody: rabbit anti-neurone specific enolase (NSE) (1:2000; Biovalley, France) and rabbit anti-choline acetyl transferase was diluted in PBS/NaN 3 , 0.5% Triton X-100 and 4% horse serum and incubated overnight at room temperature. After incubation with primary antiserum, cells were washed 3 times with PBS and incubated for 3 h with donkey anti-rabbit IgG conjugated to fluoresceine isothiocyanate (FITC) (1:200 Immunotech, France) and 7-amino-4-methyl-coumarin-3-acetate respectively. Specimens were viewed under an Olympus IX50 fluorescence microscope fitted with white video camera (Mod. 4910, Cohu Inc, Germany) connected to macintosh computer through a frame grabber card (Scion Image, SL Microtest). VIP measurements:
[0177] For VIP determination, neuronal cells were collected from the 12-well plates, the proteins were extracted using RIPA lysis buffer (Millipore, France) containing protease inhibitor cocktail (Roche Diagnostics, France) and VIP levels were measured by ELISA (Bachem, Germany).
Results
[0178] Differential response of primary enteric neurones on VIP and ChAT markers following interaction of some of 102 probiotic strains including lactic acid bacteria and Bifidobacteria are shown in Table 1. Only some strains belonging to group A3) or B3) or C3) are shown. Additionally it is mentioned that 26 strains were shown to have no significant effect on VIP and ChAT (including strains Bifidobacterium longum NCC 2705 (CNCM I-2618), Lactobacillus rhamnosus GG (ATCC 53103) and Lactobacillus casei Shirota), 11 strains belonging to group C2) were shown to decrease both VIP and ChAT (including strain Bifidobacterium longum W11 of Alfa-Wass (LMG P-21586)), 10 strains decreased VIP and had no effect on ChAT (including bench mark strains Bifidobacterium infantis UCC 3564, Bifidobacterium longum Bb536, Bifidobacterium animalis spp lactis Bb12 (DSM 15954), and Bifidobacterium animalis spp lactis Bi-07 (ATCC SD5220) and 41 strains belonging to group C3) decreased ChAT and had no effect on VIP including strains Lactobacillus johnsonii Lal (CNCM I-1225), Lactobacillus plantarum 299v (DSM 9843) Lactobacillus reuteri SD 2122 (ATCC 55730)).
[0000]
TABLE 1
Effect of incubation with lactic acid bacteria and bifidobacteria on VIP and ChAT levels in a
coculture model with epithelial cell monolayer and primary ENS cells.
VIP
ChAT
Estimated
Estimated
DN Number
difference*
Empiric
difference
Empiric
Group
species (CNCM number)
vs control
p value
mean
vs control
p value
Mean
1
DN_154_0067 (CNCM I-
−0.0097
0.9
0.0790
0.2709
0.09
0.1796
4320 filed May 19, 2010)
Bifidobacterium bifidum
1
DN_116_0047 (CNCM I-
−0.0389
0.7
0.0397
0.3151
0.10
0.2535
4317 filed May 19, 2010)
Lactobacillus rhamnosus
1
DN_119_0118 (CNCM I-
−0.1329
0.09
−0.2221
0.2847
0.02
0.2796
4279 Filed Feb. 25. 2010)
Lactobacillus acidophillus
2
DN_173_010 (CNCM I-2494
0.2345
0.01
0.2001
−0.2615
0.05
−0.0825
filed Jun. 20, 2000)
Bifidobacterium lactis
2
DN_156_0032 (CNCM I-
0.2248
0.01
0.2020
−0.5450
0.00
−0.5723
4321 filed May 19, 2010)
Bifidobacterium breve
2
DN_156_007 (CNCM I-2219
0.2715
0.02
0.3552
−0.3632
0.01
−0.1281
filed May 31, 1999)
Bifidobacterium breve
2
DN_121_0304 (CNCM I-
0.5976
0.00
0.6813
−0.6269
0.00
−0.3918
4318 filed May 19, 2010)
Lactobacillus plantarum
*Values are given as a difference compared to the control, where no bacterial strains were added.
[0179] Although strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) decreases VIP levels, it turned out with a TEER model (Hirotani et al, 2008, Yakugaku Zasshi Sep. 128(9):1363-8) that incubation with the strain for 4 or 6 h did not significantly reduce TEER values, even in presence of damage vs. control. In short, bacteria were cultured in TGYH. The culture suspensions were washed with PBS. Subsequently, the bacteria (100 cfu/cell) were added to the apical side of the T84 cell monolayers. After 2h incubation, LPS (L4516,—EPEC-0127: B8) was added on the apical side at 40 ng/ml or not added. Then, after 2 h and 4 h incubation, the TEER value was measured to assess epithelial barrier function. All experiments were performed three times independently and in triplicate in presence and in absence of LPS. The value of the T84 at t=0 was set at 100%. In the absence of LPS TEER at T4 was 98.7% and at T6 100.2% with strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010); for T84 alone this was still 100%. In the presence of LPS the control T84 at T4 was 56.2% compared to t=0 and with strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) 47.9%; At T6 the T84 control was 46.7% and with strain DN — 119 — 0118 (CNCM I-4279 filed Feb. 25, 2010) 52.2%.
[0180] Using this same TEER model especially strain DN — 173 — 010 (CNCM I-2494 filed Jun. 20, 2000), DN — 156 — 007 (CNCM I -2219 filed May 31, 1999), DN — 121 — 0304 (CNCM I-4318 filed May 19, 2010) and DN — 156 — 0032 (CNCM I-4321 filed May 19, 2010), all belonging to group A3), showed good results on the intestinal barrier function as assessed by TEER in presence of LPS. See Table 2.
[0000]
TABLE 2
TEER results in presence of LPS of selected bacteria showing the
best results
TEER T4/
TEER T6/
TEER T0 (%)
TEER T0 (%)
Signifi-
Empiric
Signifi-
Empiric
Strain
cance
mean
cance
mean
T84 control
56.20
46.76
DN_173_010
B. lactis
***
71.27
***
51.03
(CNCM I-2494 filed
Jun. 20, 2000)
DN_156_007
B. breve
***
70.70
***
55.87
(CNCM I-2219 filed
May 31, 1999)
DN_121_0304
L. plantarum
***
65.84
***
64.37
(CNCM I-4318 filed
May 19, 2010)
DN_156_0032
B. breve
***
84.44
***
80.38
(CNCM I-4321 filed
May 19, 2010)
*** p value < 0.05
|
The invention relates to the use of lactic acid bacteria, for use in modifying the enteric nervous system and more particularly in treating and/or preventing intestinal disorders such as constipation and/or irritable bowel disease.
| 2
|
This invention was made with government support under Control No. 1RO1 CA47858 by the National Institutes of Health. The government has certain rights in the invention.
This is a divisional of application Ser. No. 08/014,090, filed 4 Feb. 1993, which issued as U.S. Pat. No. 5,344,919, which was a continuation of application Ser. No. 07/293,384, filed 4 Jan. 1989, now abandoned, which was a continuation-in-part of application Ser. No. 07/016,552, filed 19 Feb. 1987, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to a novel antigen and to novel hybridoma cell lines, and more specifically to monoclonal cell lines producing monoclonal antibodies reactive with the novel antigen, which antigen can be found on human pancreatic cancer cells.
Cancer currently constitutes the second most common cause of death in the United States. Carcinomas of the pancreas are the eighth most prevalent form of cancer and fourth among the most common causes of cancer deaths in this country. The incidence of pancreatic cancer has been increasing steadily in the past twenty ears in most industrialized countries, exhibiting the characteristics of a growing epidemiological problem.
The prognosis for pancreatic carcinoma is, at present, very poor, it displays the lowest five-year survival rate among all cancers. Such prognosis results primarily from delayed diagnosis, due in part to the fact that the early symptoms are shared with other more common abdominal ailments. The diagnosis of pancreatic cancer is often dependent on exploratory surgery, inevitably performed after the disease has advanced considerably.
Substantial efforts have been directed to developing tools useful for early diagnosis of pancreatic and other carcinomas. Nonetheless, a definitive diagnosis is often dependent on exploratory surgery which is inevitably performed after the disease has advanced past the point when early treatment may be effected. One promising method for early diagnosis of various forms of cancer is the identification of specific biochemical moieties, termed antigens present on the surface of cancerous cells. Antibodies which will specifically recognize and bind to the antigens present on the surfaces of cancer cells potentially provide powerful tools for the diagnosis and treatment of the particular malignancy. Tumor specific cell surface antigens have previously been identified for certain melanomas, lymphomas malignancies of the colon and reproductive tract.
There thus exists a great and long-felt need for a cell surface marker which is present on the surface of neoplastic cells, including those of the pancreas, and for antibodies which specifically recognize such a cell surface marker. Such markers and corresponding antibodies would be useful not only in the early detection of pancreatic and other cancers, but in their treatment as well. The present invention satisfies these needs and provides related advantages as well.
Cell adhesion is critical to many biological processes, including embryonal development, tissue repair, immune response, and malignant transformation. (Ekblom, P., et al. (1986) Ann. Rev. Cell. Biol. 2:27-47; Yamada, K. M. (1983) Ann. Rev. Biochem. 52:761-799; Edelman, G. M. (1983) Science 219:450-457.) Several laboratories have recently done biochemical characterization of adhesion receptors for extracellular matrix and plasma proteins such as fibronectin and vitronectin as well as leukocyte adhesion receptors. (Tamkun, J. W., et al. (1986) Cell 46:271-282; Damsky, C. H., et al. (1981) J. Cell. Biol. 89:173-184; Pytela, R., et al. (1985) Cell 40:191-198; Fitzgerald, L. A., et al. (1987) J. Biol. Chem. 262:3936-3939; Giancotti, F. G. (1985) Exp. Cell Res. 156:182-190; Springer, T. A. (1985) Nature 314:540-542.) These adhesion receptor proteins have been shown to be structurally homologous to each other. (Charo, I. F. (1986) Proc. Natl. Acad. Sci. USA 83:8351-8355; Suzuki, S. (1986) Proc. Natl. Acad. Sci. USA 83:8416-8418; Kishimoto, T. K. (1987) Cell 48:681-690; Takada, Y. (1987) Nature 326:607-609.) These related molecules have now been organized into a protein superfamily, designated "integrins", after the chicken fibronectin/laminin receptor. (Hynes, R. O. (1987) Cell 48:549-554.)
SUMMARY OF THE INVENTION
The present invention provides monoclonal antibodies characterized in that the antibodies react specifically to human pancreatic carcinoma (HPC) cells. These monoclonal antibodies, which recognize and bind to cell surface markers in HPC cells, may be advantageously used for diagnosis and treatment of HPC.
In accordance with the present invention there are provided monoclonal antibodies which react specifically with antigenic markers on the surface of HPC cells. In accordance with a further aspect of the invention, there are provided hybridoma cell lines which produce monoclonal antibodies specifically reactive with HPC cell surface markers.
Preferred hybridoma cell lines are those termed S3-41 and S3-53 identified by ATCC accession numbers HB 9318 and HB 9319, respectively. The monoclonal antibodies produced and the antigens recognized by these cell lines are also a part of the present invention.
It will be appreciated from the foregoing that the present invention provides novel markers for antibodies against HPC tumor cells. In one aspect of the invention, the monoclonal antibodies are used for in vitro immunoassays to detect HPC. In another aspect of the invention, the monoclonal antibodies, conjugated with certain detectable labels, are useful as in vivo imaging agents for detecting HPC. Moreover, when conjugated with certain toxins, such monoclonal antibodies are useful for therapeutic treatment of HPC.
Another aspect of the invention concerns the cell surface markers reactive with the antibodies of the invention. These markers are useful in characterization of the cells bearing them and in design of agonists and antagonists of their functions. The antigens reactive with HB 9318 antibodies are members of the integrin super family.
The antigen reactive with HB 9318 is a new member of the integrin superfamily. As with other integrins, this molecule is a heterodimer comprised of structurally unrelated subunits, both of which are glycosylated. That this integrin, isolated from human epithelial cells, is novel was shown by amino acid sequence homologies. No obvious serologic cross-reactivities were detected with other integrins. The β-chain of the epithelial integrin has a molecular weight which is significantly higher than other integrin β-chains. It is postulated that this is due to a large sialic acid content.
Because integrin heterodimers are grouped into three families, based upon which of the three β-chains they contain, it is proposed that the β-chain of the present invention be designated β4 in recognition of its defining a fourth integrin β-chain family.
Other features and advantages of the present invention will become apparent from the following detailed description which illustrates, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows two-dimensional gel analysis of immunoprecipitates obtained by reacting HB 9318 with radiolabeled extracts of FG cells.
FIG. 2 shows two-dimension gel analysis of immunoprecipitates obtained by reacting HB 9319 with radiolabeled extracts of FG cells.
FIG. 3A shows the amino acid residue sequence of alpha-chain, gp125. FIG. 3B shows the amino acid residue sequence of beta-chain, gp150.
FIG. 4 shows a comparison of N-terminal sequences of various integrin α- and β-chains.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
I. DEFINITIONS
"Monoclonal antibodies (Mabs) reactive with HPC" refers to homogenous populations of immunoglobulins which are capable of immunoreaction with antigens expressed on human pancreatic cancer (HPC) cells. It is understood that there may be a number of antigens present on the surface of any cell and, alternatively, that certain receptors present on HPC cells may also occur on other malignant or normal cell types. Moreover, such antigens may, in fact, have a number of antigenic determinants. The antibodies of the invention may be directed against one or more of these determinants. Any characteristic antigen associated with HPC may provide the requisite antigenic determinant.
Immunoglobulins, like all proteins, may exist in acidic, basic or neutral form depending on their amino acid composition and environment, and may be found in association with other molecules such as saccharides or lipids. The immunoglobulins of the present invention fall within the definition regardless of status in this regard as long as they remain capable of selectively reacting with HPC associated antigens.
"Cells" or "cell line" refers to the cells apparently denoted as well as the progeny thereof. It is known that during cell multiplication and growth cells or cell lines may not remain precisely constant in their genetic makeup and the progeny may, indeed, be distinguishable in some way from the parent cells. So long as the cells referred to herein retain the characteristic of secretion capability for Mabs reactive with HPC, as defined above, they are to be considered included in the definition.
"Immortalizing cell line" refers to a cell line which can be maintained perpetually, for practical purposes, in cell culture, i.e., for an indefinite number of transfers. It must also, when fused to an ordinary non-transformed cell line, which would normally not survive for more than a few days or weeks as a unicellular culture, be able to confer on the fusion product its own immortal properties.
II. HYBRIDOMA PREPARATION
A. GENERAL DESCRIPTION OF HYBRIDOMA PREPARATION
The examples below describe the preparation of specific hybridoma cell lines producing monoclonal antibodies reactive with HPC cell antigens. It will be appreciated, however, that alternative methods may be employed to obtain alternative embodiments of the specific Mabs reactive with HPC cell antigens.
Techniques for preparing hybridomas are generally well-known in the art. Generally speaking, such hybridoma cell lines are prepared by a process involving the fusion under appropriate conditions of an immortalizing cell line and a B lymphocyte cell line appropriately immunized to produce the desired antibody. While the immortalizing cell lines so used are often of murine origin, those of any other mammalian species may be employed alternatively including those of rat, bovine, canine, human origin and the like. The immortalizing cell lines are most often of tumor origin, particularly myeloma cells, but may also include normal cells transformed with, for example, Epstein Bart Virus. Any immortalizing cell here may be used to prepare the hybridomas of the present invention.
Cells capable of secreting antibodies were employed as fusion partners, such as spleen cells or peripheral blood lymphocytes. The animal from which the cells were to be derived was immunized at intervals with whole cell suspensions of human pancreatic cancer cells. Alternatively, cell extracts or purified antigen may be used for immunization.
The immortalizing cells and lymphoid cells were fused to form hybridomas according to standard and well-known techniques employing polyethylene glycol as a fusing agent. Alternatively fusion may be accomplished by electrofusion. Hybridomas are screened for appropriate monoclonal antibody secretion by assaying the supernatant or protein purified from the ascites for reactivity with the desired cell or antigen. Such assay techniques include, among others, ELISA, RIA Western Blotting, or immunoprecipitation.
In the present invention, hybridomas were initially screened for production of antibodies reactive with HPC cells. Alternatively, HPC cell extracts or purified antigens could be used for screening. In order to further characterize the monoclonal antibodies, their reactivity with various HPC cell lines, other tumor cell lines and a variety of other normal, malignant and non-malignant pathological human tissues was determined using standard assay techniques such as ELISA, RIA, immunoprecipitation, histochemical staining procedures including indirect immunoperoxidase or indirect immunofluorescence staining. The hybridomas of the present invention were found to produce monoclonal antibodies generally highly reactive with all human pancreatic cell lines. They also displayed high reactivity with cells derived from other tumors, noticeably those of gastrointestinal and genitourinary tract origin. Moreover, although they displayed some reactivity with certain normal tissues, the Mab displayed negligible reactivity with major organs such as liver and kidney. Apparently, the antigens against which the antibodies are directed are highly expressed on HPC cells but only moderately or less on other cell types.
Because of their selective reactivity with HPC cell derived antigens the monoclonal antibodies are useful for both diagnosis and therapy of HPC and other carcinomas. Moreover, their non-reactivity with liver and kidney cells in particular permits them to be used therapeutically with relatively little risk of targeting these critical organs.
The antibodies of the invention are also useful in the preparation of cell surface markers reactive with them using immunoprecipitation and/or affinity chromatography of cell membrane preparations. The marker reactive with HB 9318 antibodies described below is a member of the integrin super family, and is functional in mediating binding to the extracellular matrix. Accordingly, this marker is involved in metastasis and colonization of malignant cells.
B. PARTICULAR HYBRIDOMA EMBODIMENTS
The following examples illustrate a method for preparing hybridomas which can serve as sources for the desired monoclonal antibodies, and the antibodies thus produced. While the methods described are typical of those which might be advantageously used, other alternative procedures known to those skilled in the art may be alternatively employed. The examples are thus intended to illustrate, but not to limit the invention.
EXAMPLE 1
Preparation of Hybridoma Cell Line
Murine Mabs reactive with HPC cell lines were produced essentially according to the standard techniques of Kohler and Milstein, Nature 256:495 (1975). Briefly, standard HPC cell lines such as COLO 357 and its subclones were used to obtain the antigenic preparation. Preferably cells of the cell line termed FG were employed. (Kajiji, S. M., Intraneoplastic Diversity in Human Pancreatic Cancer, Ph.D. Thesis, Brown University (1984). Alternatively other pancreatic cell lines expressing the antigens may be used, such as B×PC-3 (ATCC No. CRL1687). The cells were grown in a monolayer culture and harvested by EDTA treatment. Briefly, confluent monolayers were incubated for 20 minutes at 37° C. with PBS containing 10 mM EDTA and 0.02% KCl. The detached cells were collected, centrifuged at 1000×g for 10 minutes and washed twice with cold PBS. Alternatively, cell suspensions were derived from FG xenografts grown in Balb/c athymic nude mice.
Two to four month old normal Balb/c mice were immunized with whole cell suspensions at weekly intervals with six intraperitoneal 0.5 ml injections, containing approximately 5×10 6 to 5×10 8 cells/injection/mouse. Three days after the final injection, the mice were sacrificed and the spleens removed. The spleens were placed in serum free Dulbecco's Minimal Essential Medium (DMEM) in separate Petri dishes and washed. The splenocytes were gently teased out of the fibrous splenic capsule using a rubber policeman. The cell suspension was then placed in a 15 ml tube and centrifuged at 1000×g for 10 minutes. The pellet was then washed twice with serum-free DMEM.
The washed spleen cells and the P3X63Ag8 myeloma cells were fused according to the method of Kohler and Milstein, supra. The immortalized cell line fusion partners used were the murine myeloma cell line P3X63Ag8 (ATCC Accession No. T1B9) These myeloma cells were grown at a density of 5×10 5 cells/ml and harvested by centrifugation at 1000×g for 10 minutes. The cell pellet was washed twice with serum free DMEM. Finally, the spleen cells and the P3X63Ag8 myeloma cells were combined at a ratio of 7:1 in a 50 ml tube and pelleted by centrifugation (1000 g for 10 minutes). The pellet was gently loosened and 1 ml of a 35% polyethylene glycol (PEG) solution was gently bubbled over the cells. After 1 minute, 1 ml of DMEM, containing 10% fetal calf serum (FCS)(Gibco, Grand Island, NY) was added to the cell suspension and gently mixed.
The PEG was subsequently diluted by the addition of 10 ml DMEM containing 10% FCS and the cells were repelleted. The cell pellet containing hybridoma fusion products was resuspended in 30 ml hypoxanthine-aminopterin-thymidine (HAT) medium (aminopterin from Sigma Chemical Co., St. Louis, Mo.; hypoxanthine and thymidine from Calbiochem, La Jolla, Calif.).
This cell suspension was then combined with 400 ml of HAT medium containing 2×10 6 thymocytes per ml (feeder cells). The contents were distributed into sterile 96 well plates (Costar, Cambridge, Mass.) and placed immediately in an incubator at 37° C. The spent media was replaced with fresh thymocyte containing HAT media after one week. Using this type of protocol successful hybridoma cultures were obtained which could be maintained with periodic addition of fresh DMEM containing 10% FCS.
Hybridomas producing monoclonal antibodies reactive with HPC cells were selected. After the cultures reached a cell density that covered 75-100% of the microtiter well surface, media from the hybridomas were screened for the presence of anti-HPC antibody, using a standard ELISA protocol. (Schultz, Cancer Res. 44:5914(1984)). Briefly, tumor cells dried onto the bottom of 96-well miniplates (Dynatech Microtiter Plates, American Scientific Products, McGaw Park, Ill.) were used as targets. The wells of antigen-coated 96 well plates to be used were rinsed with buffer A pH 8.0 (20 mM Tris, containing 150 mM NaCl, 0.2% Tween 20 and 0.01% Thimerosal). The hybridoma supernatant diluted 1:2 in buffer B (buffer A containing 0.1% bovine serum albumin) was added to the wells and incubated for 1 hour at room temperature to permit binding of specific antibodies. Specifically bound antibodies were detected by adding horseradish peroxidase-conjugated rabbit anti-mouse inununoglobulin (BioRad, Richmond, Calif.) to wells that were rinsed free of the excess hybridoma supernatant by washing with buffer A. After incubation for 1 hour at room temperature the secondary antibody was decanted, the wells washed with buffer A, and 50 μl/well of substrate solution (ten milliliters of 80 mM citrate phosphate buffer, pH 5.0 containing 4 mg 0-phenylenediamine (Sigma Chem. Co., St. Louis, Mo.) and 4 μl 30% hydrogen peroxide) was added. The plates were incubated in the dark for 30 min at RT and the color reaction was stopped by adding 25 μl of 4M sulfuric acid to each well. Specifically-bound antibodies were detected by measuring-the absorbance at OD 490 on an ELISA scanner C model EL310, Biotek Instruments Winooski, Vt.) within 30 min. Reactivity was graded as follows: A 490 ≦0.15, -; A 490 =0.15 to 0.3, 1+; A 490 =0.3 to 0.6, 2+; A 490 =0.6 to 1.2, 3+; A 490 ≧1.2, 4+. Hybridomas that were reactive with the immunizing FG cells but not with the lymphoblastoid 721-P cells were further screened for reactivity with frozen sections of HPC according to the procedure of Example II below. Only those that were reactive with frozen sections of HPC but not reactive with frozen sections of normal human liver, kidney and lung were selected. The two hybridoma cells lines selected for further study were designated HB 9318 and HB 9319, respectively.
III. CHARACTERIZATON OF MONOCLONAL REACTIVITY
EXAMPLE 2
A. REACTIVITY WITH HUMAN TUMOR TISSUES.
The reactivity of the monoclonal antibodies was determined by indirect immunoperoxidase staining as follows. Two- to 4-μm sections of frozen tissue blocks were cut on a cryotome, mounted on gelatin-coated glass slides, air-dried, and tested immediately in an indirect immunoperoxidase assay using the method of Taylor, Arch. Pathol. Lab. Med. 102:113 (1970). Briefly, after washing once in Hanks' balanced salt solution (Gibco, Grand Island, NY) and phosphate buffered saline (PBS 10 mM sodium phosphate, 0.15M Nacl, pH 7.0), sections were incubated at room temperature sequentially with: diluting buffer (PBS containing 5% normal goat serum and 1% bovine serum albumin) for 15 min; a 1:2 dilution of hybridoma supernatants or appropriate isotype-matched controls for one hour; horseradish peroxidase-conjugated goat anti-mouse Ig antiserum (Bio-Rad, Richmond, Calif.) diluted 1:50 and containing 5% normal human serum for one hour; and finally substrate buffer (10 mM Tris, pH 7.4, 0.6 mg/ml 3,3'-diaminobenzidine, 0.015% H 2 O 2 ) for 15 min. Washes with HBSS and PBS were performed between incubations. Sections were counterstained in 1% methylene blue, dehydrated through graded ethanol, washed in Histo-Clear (National Diagnostics, Somerville, NJ), mounted in Pro-Texx (Lerner Laboratories, New Haven, Conn.), and examined by light microscopy.
Table 1 summarizes the reactivity of monoclonal antibodies produced by hybridoma cell lines HB 9318 and HB 9319 with 65 different tumors. HB 9318 was generally reactive only with carcinomas of the pancreas gastrointestinal tract, genitourinary tract, and head and neck tumors. Moreover, in virtually all instances, staining by the HB 9318 Mabs was distinctly associated with the basement membranes surrounding tumor foci, producing a characteristic one-sided basal surface staining of cells at the epithelial stromal interface. In the few cases of lung carcinomas, melanoma and breast cancer tissues that were stained, reactivity was also confined to the basement membranes.
Mab HB 9319 reacted with each of the seven pancreatic adenocarcinomas tested, including pancreatic carcinoma of the acinar cell type. Mab HB 9319 displayed a wide range of reactivity among tumor tissues examined. Moreover, reactivity of HB 9319 was generally intense with the majority of tumor cells within a tissue. Tumor cell basement membranes were also stained in some cases.
TABLE 1______________________________________REACTIVITY.sup.a OF MONOCLONAL ANTIBODIESWITH FRESH FROZEN HUMAN TUMOR TISSUE SECTIONSBY IMMUNOPEROXIDASE STAINING HB 9318 HB 9319______________________________________Pancreatic Cancerductal adenocarcinoma .sup. --.sup.b 2+ 2+.sup.b 1+ 2+.sup.b 4+ -- 1 4+.sup.b 1+ 3+.sup.b 3+ 4+.sup. 4+islet cell Cancer/insulinoma -- -- -- 1+acinar cell Cancer -- 3+Oral Squamous Cancer 1.sup.b 3+ 1.sup.b 4+ -- 2+ .sup. --.sup.b 4+Adenoid Cystic Cancer 3+.sup. 2+Salivary Gland Cancer 4+.sup.b 3+Esophageal Cancer 3+.sup.b 3+Gastric Cancer 3+.sup.b 3+ 2+.sup. 4+ 3+.sup. 3+ 1+.sup.b 3+Colon Cancer 3+.sup.b 3+ .sup. --.sup.b 1+ 3+.sup. 3+ 3+.sup.b 4+Hepatoma -- 2+ -- 2+Laryngeal Cancer 2+.sup.b 4+ 2+.sup.b .sup. 3+.sup.bMelanoma 1+.sup.b 4+ -- 4+ -- 4+Sarcoma -- 4+ -- 4+Lung Canceradenocarcinoma 1+.sup. 1+ -- 3+ -- 1+squamous Cancer 1+.sup.b 3+ -- 2+ -- 3+ -- 3+ -- 3+adenosquamous 1+.sup.b 3+oat cell Cancer -- -- -- --large cell Cancer 4+.sup. 4+mesothelioma -- 1+Breast Cancer -- 3+ -- 4+ -- 3+ -- 2+ 1+.sup. 2+Cervical Cancer 2+.sup.b 1+ 1+.sup. 4+Endometrial Cancer -- 3+ -- 4+ 3+.sup.b 2+Ovarian Cancer -- 4+ -- 3+ 3+.sup.b 2+Prostatic Cancer 1+.sup.b 4+Bladder Cancer 1+.sup.b 2+ 3+.sup.b .sup. 2+.sup.bKidney Cancer -- 4+ 2+.sup. --______________________________________ .sup.a Intensity of staining was scored from 1+ to 4+ with 4+ indicating greatest intensity and with "--" indicating lack of staining. .sup.b Basement membrane staining.
B. REACTIVITY WITH HUMAN CELL LINES
The reactivity of Mabs against a panel of cell lines in culture was determined by ELISA reactivity, according to the Method of Schultz (1984), Cancer Res. 44:5914, as detailed in Example 1
Cells dried onto the bottom of 96-well miniplates were used as targets for ELISA. Horseradish peroxidase-conjugated goat anti-mouse Ig antiserum (Bio-Rad, Richmond, Calif.) was used as the secondary antibody.
The reactivity of Mabs HB 9318 and HB 9319 is shown in Table 2. Both Mabs were reactive with the majority of the ten HPC cell lines tested. Moreover, both displayed particularly strong reactivity with cell lines derived from lung cancer, skin cancer and gastrointestinal and genitourinary tract tumors. HB 9319 displayed moderate to strong positivity with tumor cell lines of neuroectodermal origin including melanoma, glioblastoma and neuroblastoma lines. Both antibodies were generally non-reactive with human red blood cells of blood types AB+, A+, B+, O+, and O-, normal diploid fibroblasts and leukemic or lymphoid cell lines.
TABLE 2______________________________________ELISA REACTIVITY OF MONOCLONAL ANTIBODIESWITH CULTURED HUMAN CELLSCell lines (ATCC NO.) HB 9318 HB 9319______________________________________Pancreatic CancerColo 357.sup.a 3+ 2+FG.sup.a 3+ 3+SG.sup.a 3+ 3+FG-Met-2.sup.a 4+ 4+RWP-1.sup.a 4+ 2+RWP-2.sup.a 3+ 1+PANC-1 (CRL 1469) 3+ 3+ASPC-1 (CRL 1682) 3+ 1+Hs 766T (HTB 134) 4+ 1+BxPC-3 (CRL 1687) 4+ 4+Lung CanceradenocarcinomaUCLA-P3.sup.b -- 2+A549 (CCL 185) 2+ 1+CALU 6 (HTB 56) -- 4+squamous cancerT-222.sup.b 2+ 4+SK-MES-1 (HTB 58) 3+ 3+CALU-1 (HTB 54) 2+ 3+USCLS-1.sup.b 3+ 3+oat cell CancerT-293.sup.c -- 1+NCI-H69 (HTB 119) -- --Breast Cancer734B.sup.d -- 3+BT-20 (HTB 19) 3+ 4+MDA-MB-435S (HTB 129) -- 3+Bladder CancerT24 (HTB 4) -- 2+J82 (HTB 1) -- 2+5637 (HTB 9) 2+ 3+Cervical CancerME-180 (HTB 33) 3+ 4+Prostatic CancerDU-145 (HTB 43) 2+ 3+Pharyngeal CancerFaDu (HTB 43) 3+ 4+Skin cancerA-431 (CRL 1555) 3+ 3+Colon CancerCOLO 396.sup.d 4+ 4+HepatomaSK-HEP-1 (HTB 52) 3+ 2+Mesodermal TumorSK-UT 1 (HTB 114) -- 2+MelanomaML-873-1.sup.c -- 2+WM239A.sup.c -- 3+WM2664 (CRL 1676) -- 3+A-375P.sup.c -- 4+A-375M.sup.c -- 3+M14.sup.c -- 3+M21.sup.c -- 4+MS-1.sup.c -- 3+FOSS.sup.c -- 3+Melur.sup.c -- 3+GlioblastomaU38MG (HTB 16) -- 1+U87MG (HTB 14) -- 3+U-373MG (HTB 17) -- 3+NeuroblastomaSK-N-SH (HTB 11) -- 2+SK-N-MC (HTB 10) -- --LAN-1.sup.c 2+ 1+B-LymphoblastoidL14.sup.b -- 1+LG-2.sup.b -- 1+721-p.sup.e -- --GM3107.sup.b -- 2+T-LymphoblastoidMOLT-4 (CRL 1582) -- --HPB-ALL.sup.b -- 2+HSB-2.sup.d -- --Promyelocytic LeukemiaHL-60 (CCL 240) -- --ErythroleukemiaK562 (CCL 243) -- --Diploid FibroblastW1-38 (CCL 75) -- --Human RBC -- --______________________________________ Cell lines were obtained as follows: .sup.a P. Meitner, Department of Medicine, Brown University .sup.b L. Walker, Department of Immunology, Scripps Clinic and Research Foundation .sup.c R. Reisfeld, Department of Immunology, Scripps Clinic and Research Foundation .sup.d T. Edginton, Department of Immunology, Scripps Clinic and Research Foundation .sup.e F. Bach, University of Minnesota.
C. REACTIVITY WITH NON-MALIGNANT PATHOLOGIC HUMAN TISSUES
The reactivity of the Mabs with a panel of inflammatory pancreases, benign tumor and hyperplastic epithelia was determined by indirect immunoperoxidase staining of frozen tissue sections, according to the method of section A, above. Both Mab HB 9318 and Mab HB 9319 showed some reactivity with the duct cells of chronic pancreatitis tissues. Mab HB 9319 was widely reactive in that it stained every non-malignant pathologic tissue examined, although always in discrete areas. Table 3 shows the results of testing with this panel of tissues.
TABLE 3______________________________________REACTIVITY OF MONOCLONAL ANTIBODIES WITH FRESHFROZEN NON-MALIGNANT PATHOLOGIC HUMAN TISSUESECTIONS BY IMMUNOPEROXIDASE STAINING HB 9318 HB 9319______________________________________Pancreas (chronic pancreatitis)acini -- -- -- --ducts 2+ .sup. --.sup.b 2+ 1+islets of Langerhans -- -- -- --Pancreas (SLE).sup.aacini -- 4+ducts .sup. --.sup.b --islets of Langerhans -- --Uterus (leiomyoma) -- -- -- -- 3+ 4+ 4+ 4+Ovary (fibroadenoma) -- 2+Endometrium (hyperplastic) 3+ 4+Prostate (hyperplastic)upper layers of epithelium -- 3+basal layers of epithelium 4+ 3+basement membrane 4+ --______________________________________
D. REACTIVITY WITH NORMAL ADULT AND FETAL TISSUES.
The reactivity of the Mabs with fresh frozen normal adult and fetal tissues was determined by indirect immunoperoxidase staining according to the method of section A, above. The antibodies were unreactive with the vast majority of normal tissues examined.
Mab HB 9318 displayed some reactivity with the basal epithelial layers or basement membranes of the esophagus, cervix, and large intestine, plantar skin, breast tissue and ileal epithelium. The restricted expression of the HB 9318 antigen by the proliferating cell layers of normal stratified epithelia and its localization at the epithelial stromal interface suggests that this molecule may be an early differentiation antigen (possibly involved in cell adhesion) of epithelial cells that is re-expressed following malignant transformation. Further, the HB 9318 antigen may be useful for diagnosis and therapeutic intervention of other skin-related disorders such as psoriasis and basal cell carcinomas and may prove to be a valuable cell surface marker for investigating epidermal cell biology.
Mab HB 9319 reacted with the acinar cells of adult and fetal pancreases, fetal pancreatic ducts, and the parenchyma and bile ducts of 1/3 livers that were tested. It was moderately reactive with the esophagus, stomach and small intestine, cervix, uterus, breast, fetal and adult lung parenchyma, fetal kidney, cerebral cortex, and with the molecular layers and Purkinje cells within the adult cerebellum. All layers of plantar skin including basement membrane were also intensely stained.
Table 4 summarizes the results of this panel of tests.
TABLE 4______________________________________REACTIVITY OF MONOCLONAL ANTIBODIESWITH FRESH FROZEN NORMAL HUMAN TISSUESECTIONS BY IMMNOPEROXIDASE STAINING HB 9318 HB 9319______________________________________Esophagusstratified squamous epitheliumupper layers -- 3+basal layers 4+ 4+basement membrane 4+ --Stomachgastric pits -- 3+gastric glandsparietal cells -- 2+chief cells -- 2+lamina propria -- 1+Small Intestinejejunal epithelium -- 2+ileal epithelium 3+ 3+basement membrane 4+ --Large Intestinecolonic epithelium -- 1+crypts of Lieberkuhn -- 1+basement membrane 4+ --lamina propria -- 1+Liverparenchyma -- -- -- -- 3+ --bile ducts -- 1+ -- -- 3+ --Pancreas (adult)acini -- -- --.sup. -- 4+ 4+ 4+ 4+ducts -- -- --.sup.a -- -- -- -- --islets of Langerhans -- -- --.sup. -- -- -- -- --Pancreas (fetal)acini -- 4+ducts .sup. --.sup.a 4+islets of Langerhans -- --Thymuscortex -- --medulla -- --Lymph nodenodules -- --germinal centers -- 1+Spleenwhite pulp -- --red pulp -- 1+ 1+Kidney (adult)glomeruli -- -- -- -- -- --proximal tubules -- -- -- -- -- --distal tubules -- -- -- -- -- --Kidney (fetal)glomeruli -- 3+proximal tubules 1+ 3+distal tubules -- 3+Cervixcolumnar epithelium -- 1+ 4+ 3+basement membrane 4+ 4+ -- --squamous epitheliumupper layers -- -- 3+ 3+basal layers 4+ 4+ 4+ 4+basement membrane 4+ 4+ -- --Uterusendometrium 1+ -- 3+ 2+myometrium -- -- 4+ 2+Ovarycortex -- --medulla -- --Breastlobule 4+ 2+ 4+ 4+duct 4+ 3+ 4+ 4+basement membrane 4+ 4+ 4+ 4+Lung (adult)parenchyma -- -- -- 2+ 2+ --Lung (fetal)parenchyma -- 3+Thyroidepithelial cells -- 1+colloid -- --Cerebrumcortex -- 3+Cerebellumgranular layer -- --molecular layer -- 2+Purkinje cells -- 2+Plantar skinstratum corneum -- 3+stratum granulosum -- 3+stratum spinosum 1+ 3+stratum germinativum 3+ 4+basement membrane 4+ 4+______________________________________ .sup.a Basement membrane staining
E. REACTIVITY WITH CELL SURFACES
To determine whether the antigens recognized by the Mabs were expressed on surface of cells of reactive tissues, viable HPC cells were tested with the Mabs in indirect immunofluorescence assays as follows:
INDIRECT IMMUNOFLUORESCENCE STAINING
Cells grown to confluence on glass cover slips were washed once with cold HBSS, overlaid with 0.1 ml of 1:2 hybridoma supernatant for one hour at 4° C., washed in cold HBSS, and overlaid with 0.1 ml of 1:50 fluorescein isothiocyanate-conjugated goat anti-mouse Ig antiserum (Tago, Burlingame, Calif.) for one hour at 4° C. After washing and fixing in 3% paraformaldehyde, cells were mounted in 80% glycerol, 1 mg/ml p-phenylenediamine, 200 mM Tris, pH 8.5, examined and photographed with a Zeiss fluorescence microscope.
Both Mab HB 9318 and HB 9319 showed distinct staining of the plasma membrane, indicating recognition of cell surface structures. Both stained the entire cell population, displaying a contiguous, linear membrane pattern.
IV. ANTIGEN CHARACTERIZATION
EXAMPLE 3
Immunochemical Characterization of Antigens
In order to assess the chemical nature of the antigens recognized by Mabs, HPC cells were radiolabeled by incubation with either L-[ 3 H] leucine or [ 3 H] glucosamine, detergent solubilized and then subjected to immunoprecipitation with Mab immunosorbents, as follows:
Ten μl of a 10% suspension of protein-A-Sepharose (Pharmacia, Uppsala, Sweden) were incubated at 4° C. for 1 hour with 5 μl of rabbit anti-mouse Ig antibodies (Accurate Chemicals, Westbury, NY) in 0.3 ml of PORT buffer (10 mM Tris, pH 8.5, 0.15M NaCl, 0.5% Tween 20, 0.1% Renex 30, 2.5 mM sodium azide, 0.1% ovalbumin). After washing twice with PORT buffer, incubating 1 hour at 4° C. with 1 ml hybridoma supernatants and washing twice with PORT buffer, the beads were incubated overnight at 4° C. with radiolabeled cell extract ((1-2×10 7 cpm). The immunosorbents were washed 8 times with PORT buffer (10 mM Tris, pH 8.5, 0.15M NaCl, 0.5% Tween 20, 0.1% Renex 30, 2.5 mM sodium azide) and bound antigens were eluted in Laemmli buffer (Nature 227:680(1970)). The samples were analyzed by SDS-PAGE on slab gels and visualized by fluorography.
Initial results of the SDS-PAGE analysis indicated that Mab HB 9318 recognized a doublet protein antigen, of 205 kd and 135 kd, respectively. Both bands were glycosylated as they incorporated [ 3 H]-glucosamine. In some cases two additional bands of 150 kd and 185 kd were also seen. A band of 116 kd co-precipitated with HB 9318 bands, but was non-specific since it could be removed by preabsorption with control immunosorbants. Mab HB 9319 recognized a highly glycosylated 140 kd protein.
Immunoprecipitation of a metabolically labeled HPC indicated that the antigenic determinants recognized by each of the monoclonals are carried by protein molecules. These proteins are also glycosylated, so that it remains to be determined whether the recognized epitopes are expressed by the protein or the glycan part of these molecules.
EXAMPLE 4
Characteristics of HB 9318 Antigen
Characterization of the antigen which immunoprecipitates with HB 9318 demonstrates that it is a two-chain heterodimer which is a member of the integrin class of cell adhesion receptors.
Integrins are heterodimers comprised of noncovalently associated transmembrane glycoproteins. (reviews of the characteristics of integrins have been published by Hynes, R. O., Cell (1987) 48:549-554; Ruoslahti, E., et al, Science (1987) 238:491-497; and Buck, C. A. & Horwitz, A. F. (1987) Ann. Rev. Cell. Biol. 3:179-205. The α-chains have high degrees of homology and the differences in the β-chain serve to place the various integrins into subfamilies. Integrin heterodimers are grouped into three families, based on which of the three β-chains (β 1 , β 2 or β 3 ) they contain. The integrin of the present invention is believed to represent a fourth member of the integrin family because of its structurally distinct β-chain.
The integrin class of cell surface adhesion receptors is distinct from another type designated CAMs which are monomers which use polysialylation as a control element. The integrin to which HB 9318 binds is distinguished from other known integrins by its polysialylation. The designation of α E β 4 has been proposed as a designation for this novel integrin. Alternatively, the name intepsin has been proposed for this antigen.
The HB 9318 antigen contains two non-covalently bound glycopeptides, designated herein gp205 and gp125. The gp125 represents an analog to the α-chains of other integrins, the gp205 peptide is analogous to other integrin β-chains, and has been shown to be polysialylated. This two-chain antigen has been shown by immunoperoxidase staining to be expressed only on the basolateral surfaces of the germinative layer of epithelial cells while cells from the prickle-cell layer outwards were progressively devoid of reactivity. The integrin is evidently involved in cell adhesion.
When HB 9318 monoclonal antibody is used to immunoprecipitate pancreatic cancer cell lysates gp125 and gp205 are precipitated. When HB 9318 monoclonal antibody is used to immunoprecipitate placental cell lysates, gp125 is again precipitated, however a second gp150 β subunit is precipitated. This gp150 appears to be identical to the gp205 β subunit present in pancreatic cancer, with the exception that it is not as glycosylated.
A. DISTRIBUTION OF THE ANTIGEN AND α- AND β-CHAINS
Immunohistology of human epidermal sections with HB 9318 shows that staining is concentrated near the basement membrane and basolateral cell surfaces of the germinative layer. Upper cell layers are progressively devoid of reactivity. Thus its expression is restricted to this particular portion of the cell surface.
FG-met2 pancreatic carcinoma cells were used as test substrates; lung adenocarcinoma lines and short term normal human keratinocyte cultures gave identical results.
Cultures of FG-met2 pancreatic carcinoma cells were surface radioiodinated using 125 -I sodium iodide in standard protocols. Detergent lysates of these labeled cells were immunoprecipitated with HB 9318, and the immunoprecipitate applied to polyacrylamide gels under reducing and non-reducing conditions. Under reducing conditions, a 205 kd band was detected; under non-reducing conditions the single band appeared at 190 kd. This represents the β-chain of intepsin, designated herein gp205.
The α-chain, which migrates as a 150 kd band under non-reducing conditions,. and a 125 kd band under reducing conditions was detectable only when the cells were metabolically labeled either with [ 35 S]-methionine or with tritiated glucosamine. It is believed that the absence of the 125 kd/150 kd bands from the surface-labeled cells is due to an artifact of the iodination procedure.
That gp205 and gp125 components are non-covalently associated with each other at the cell surface was verified by treating FG-met2 cells (a human pancreatic carcinoma line) with a membrane impermeable cross-linker, DTSSP, and lysing the cells with detergent. This resulted in a 400 kd band upon SDS-PAGE. The 400 kd band disappeared and was replaced by 205 kd and 125 kd by subjecting the preparation to reduction, as DTSSP results in reversible cross-linking. The non-covalent complexing of gp205 and gpt25 was further confirmed by immunoprecipitating protein from FG-met2 which had been labeled with [ 35 S]-methionine. The immunoprecipitate showed an approximate MW of 500 kd as analyzed by gel filtration. (The discrepancy in apparent MW is an artifact of the procedures.)
B. PURIFICATION OF gp205 AND gp125
The surface proteins were isolated both from the lung adenocarcinoma cell line UCLA-P3 and from FG-met2.
The cells were grown in sufficient quantity to obtain 50 g wet weight and 20 g wet weight respectively. After washing, the cells were lysed in an equal volume of TBS containing 2% Renex 30, centrifuged at 10,000×g for 30 min at 4° C. and stored at -70° C.
The lysates were passed sequentially through a Sepharose column and through one or two sequential HB 9318 immunosorbent columns at 5-10 ml/hr. After washing with TBS containing 0.1% Renex 30, pH 8.5 to remove unadsorbed material, the HB 9318 column was inverted, washed with 3 column volumes of TBS, pH 8.5 containing 1.0% n-octyl β-D-glucopyranoside, and the bound material eluted with 50 mM diethylamine, pH 11.5 containing 150 mM NaCl, 1.0% n-octyl β-D-glucopyranoside. Eluted material was collected in 1.5 ml Eppendorf tubes containing 0.1M Tris HCl pH 6.8, 150 mM NaCl, and 1.0% n-octyl β-D-glucopyranoside, to lower the pH rapidly to approximately 8.5. Elution was detected by SDS-PAGE stained with silver stain or Coomassie blue, and eluate from peaks containing protein was pooled and concentrated.
C. AMINO ACID SEQUENCING OF PURIFIED ANTIGEN
Antigen corresponding to gp205 and to gp125, purified as above was subjected to amino acid sequencing from the N-termini using standard techniques. The gp125 fragment had the N-terminal sequence:
F-N-L-D-T-R-E-D-N-V-I-R-K-Y-G-D-P-G-S-L-F
which shows extensive homology with α N-terminal sequences of α-chains in other integrins, as illustrated in FIG. 4.
The gp150 fragment had the N-terminal sequence:
N-R-C-K-K-A-P-V-K-S-C-T-E-C-V-Y-V-D-P
which shows extensive homology with β N-terminal P47 sequences of β-chains in other integrins, as illustrated in FIG. 4.
In addition, FIG. 3 shows the amino acid residue sequences of the gp125 α-chain and the gp150 as precipitated by the-HB 9318 antibody.
The gp205 β-chain is apparently blocked at the N-terminus.
Automated microsequencing of gp125, purified on an HB 9318 immunoaffinity column from either carcinoma cells or placental tissues yielded information up to residue 21. The sequences of gp125 from these two sources were identical, with the exception of position 6 which could not be assigned for carcinoma gp125 in three separate sequencing runs. The gp125 sequence showed several similarities with integrin α chain N-termini, as depicted in FIG. 4. The first five residues, FNLDT, are identical in four α chains, and occur with one replacement in four other α chains and with two replacements in the remaining three α chains. Another segment of significant homology among α chains occurs between residues 15 and 21. In this region, gp125 shares one residue with at least one other α chain at five positions, and at three positions has unique residues. Overall, the homology of gp125 to the integrin α chains appears to be equivalent to the homology of the α chains to each other. The highest level of similarity was observed with the VLA-2 α chain, where eleven of thirteen residues available for comparison are shared.
Placenta gp150 was sequenced up to residue 19 (FIG. 3). When this sequence was compared to the imino-termini of the three human integrin β chains, several similarities were found (FIG. 4). Of particular importance is the exact correspondence of the three cysteines, the serine in position 10 and the proline in position 19, as these residues are invariant among integrin β chains. Overall, gp150 showed eleven identities with β 1 , eight with β 2 and seven with β 3 . However, the gp150 sequence was distinct from those of the other β chains since its N-terminus was offset with respect to β 1 (as predicted from cDNAs) and β 3 sequences, and since it contained six unique residues (FIG. 4).
To further check the relationship between gp150 and gp180, placental gp180 was also sequenced up to residue 13. This sequence was identical to gp150 (not shown), except for four residues of uncertain assignment, thus providing further evidence for the structural similarity of gp150 and gp180. Since the neuraminidase digestions suggested that the M r differences between gp205, gp180 and gp150 are due to variations in sialic acid content, gp205 was expected to display an amino-terminal sequence identical to that of gp150 and gp180. However, gp205 is undetectable in placental lysates, and two attempts to sequence carcinoma-derived gp205 failed, presumably due to insufficient quantities and/or N-blocking during purification.
D. METABOLIC LABELING WITH [ 35 S]-METHIONINE IN THE PRESENCE OF TUNICAMYCIN
Indirect immunoprecipitation with Mab HB 9318 of detergent lysates of cells intrinsically labeled with [ 35 S]-methionine in the presence of tunicamycin (an inhibitor of N-linked glycosylation) and subsequent analysis by SDS-PAGE under reducing conditions revealed the presence of two major bands of 190 kd and 100 kd, respectively.
Semiconfluent cultures of FG cells were incubated for 10-12 hours at 37° C. with 1 μg/ml tunicamycin. The cells were then pulsed for an additional 12 hours with 1 mCi [ 35 S]-methionine in methionine-free RPMI medium containing 3% FCS and 1 μg/ml tunicamycin. Control flasks, similarly labeled with [ 35 S]-methionine in the absence of tunicaymcin, were also prepared. The metabolically-labeled cells were then harvested as previously described and lysed using RIPA lysis buffer. Cell lysates were clarified by centrifugation at 100,000×g for 45 min at 4° C. and subsequent storage was at -70° C.
E. TWO-DIMENSIONAL GEL ANALYSES
Immunoprecipitations were carried out by overnight incubation of cell lysates with immunoabsorbents prepared by activated-CNBr conjugation of Mab to Sepharose 4B-CL beads (Pharmacia, Uppsala, Sweden). After elution in 8M urea at room temperature, samples were analyzed by two-dimensional electrophoresis, consisting of nonequilibrium pH electrophoresis on tube gels in the first dimension, followed by SDS-PAGE on 7.5% acrylamide slab gels. Gels were impregnated with 2, 5,-diphenyloxazole, dried and exposed for the indicated times to Kodak XAR-5 X-ray film at -70° C. The resulting pattern of migration is shown in FIG. 1.
F. CHARACTERIZATION OF THE gp205 AS A POLYSIALYLATE INTEGRIN β-CHAIN
Both gp205 and gp125, alone or together were treated with various enzymes which cleave carbohydrate chains.
EndoF and EndoH cleave N-linked complex oligosaccharides, and the results were consistent with one or two such oligosaccharides on gp205 and three or four on gp125:
______________________________________EndoF: 205 kd → 195 kd EndoH: 205 kd → 205 kd 125 kd → 105 kd 125 kd → 115 kd______________________________________
Neuraminidase (NA) cleaves complex N-linked carbohydrates and polysialyl chains; endo-N-acetyl-neuraminidase (Endo-N) cleaves polysialylates only as α-2,8-linked linear sialic acid homopolymers. The results were consistent with gp205 as a polysialylated integrin β-chain:
______________________________________NA: 205 kd → 95 kd EndoN: 205 kd → 95 kd, 150 kd 125 kd → 120 kd______________________________________
These results are consistent with a heavily polysialylated β integrin chain wherein the sialylation is through β-linkage. (Most integrin β-chains have MW of 95-125 kd).
G. BINDING TO LECTINS
When radiolabeled lysates were preabsorbed with lentil lectin-agarose beads (Vector Labs, Burlingame, Calif.), the antigens reactive with HB 9318 were removed. Removal of antigen was shown by immunoprecipitation of bead supernatant, followed by SDS-PAGE. Similar treatment of radiolabeled lysates with wheat germ agglutinin-agarose beads (E. Y. Labs., San Mateo, Calif.) did not remove the HB 9318 antigen. Therefore, the antigen reactive with HB 9318 was characteristically bound to lentil lectin, but not to wheat germ agglutinin.
H. GEL FILTRATON OF ANTIGEN
Radiolabeled detergent cell lysates were absorbed on wheat germ agglutinin-Sepharose columns (E. Y. Labs, San Meteo, Calif.), The breakthrough was absorbed onto lentil lectin-Sepharose columns. After washing, the absorbed material was eluted by the addition of 2% alpha-methyl-mannoside (Sigma Chemical Co., St. Louis). The eluted material was subjected to gel filtration, in the presence of 10 mM Tris, pH 8.0 containing 0.15M NaCl, 1 mM CaCl 2 , 1 mM MgCl 2 .6H 2 O, 0.02% sodium azide and 0.1% Renex 30 by using an FPLC instrument (Pharmacia, Uppsala, Sweden), equipped with a Sepharose 6 column. Molecular weight standards were run in parallel. One ml fractions were collected (approximately 40 fractions), and subjected to immunoprecipitation with HB 9318 antibody. SDS-PAGE analysis of immunoprecipitates revealed that the following molecular species were reactive with HB 9318 in the indicated fractions:
______________________________________SDS-PAGE m.w. Fraction # FPLC MW______________________________________135; 205 25 669 kd135; 205 26 669 kd135; 150; 205 27 approximately 669 kd135; 150; 205 28 approximately 669 kd135; 150; 205 29 between 669 kd and 440 kd135; 150 30 between 669 kd and 440 kd135; only 31-36 between 440 kd and 232 kd______________________________________
The estimated molecular weights corresponding to the FPLC fractions are indicated in the right column. Since the estimated MW exceeds the MW determined by SDS-PAGE, the HB 9318 antigens must exist as multimeric complexes, probably heterodimers formed by the association of one 205 kd component with one 125 kd component. The presence of excess free 125 kd component was also suggested by the material immunoprecipitated from fractions 31-36.
I. PULSE CHASE BIOSYNTHETIC STUDIES:
Single cell suspensions of exponentially growing FG cells were propagated for one hour at 37° C. in methionine-free medium (Irvine Scientific, Santa Ana, Calif.) and then pulse labeled for 10 min with [ 35 S]-methionine (1295 Ci/mM NEN Research Products, Boston, Mass.) at a concentration of 1.0-1.5 mCi/3×10 7 cells/ml. After the removal of an aliquot of 5×10 6 cells that constituted the zero-time point, the remaining cells were washed three times with cold Tris-buffer, pH 7.5 containing 10 mM unlabeled L-methionine (Sigma Chemical Co., St. Louis, Mo.). The labeled cells were resuspended in complete medium containing 10 mM unlabeled methionine and incubated on a shaker at 37° C. Aliquots were removed at the different time points indicated and the cells were centrifuged and extracted in RIPA lysis buffer as previously described.
After a 10 minute pulse with [ 35 S]-methionine, a faint band of 150 kd was detected at the zero time point of chase. This 150 kd component was clearly visible after 15 minutes of chase. Within the next 45 minutes of chase it appeared to be processed and the appearance of the 135 kd component was seen. Both the 205 kd and 135 kd molecules were detectable after 4 hours of chase until up to 20 hours of chase. It is presently not clear whether a precursor/product relationship exists between the two forms of the HB 9318 antigen. While not wishing to be bound by the explanation, it appears that post-translational processing of the 150 kd molecule gives rise to the 135 kd subunit. Moreover, the 205 kd component could either arise by further processing of 135 kd component or by altered processing of the 150 kd precursor. Alternatively, it could have its own precursor molecule that is not recognized by Mab HB 9318, thereby suggesting that the HB 9318 antigen is a heterodimer comprised of two distinct non-covalently linked subunits.
Western blots of material immunopurified with HB 9318 from carcinoma cells and placental tissue in which 5710 antiserum reacted predominantly with gp205, gp180, and gp150 and displayed little, if any, reactivity with gp125. This antigenic similarity of gp205, gp180, and gp150 was authentic since, in a further refinement, antibodies that were adsorbed and eluted from gp150 reacted with gp180 (in addition to gp150 itself). Antibodies adsorbed and eluted from gp180 reacted with gp150 (in addition to gp180 itself). Furthermore, S 35-methionine labeled gp205, gp180, gp150 and gp125 purified by immunoaffinity and electroelution were subject to "hot" blotting with gp150 purified antibodies. These antibodies only reacted with gp205, gp180, and gp150, but not with gp125. Subsequent autoradiography of the blot confirmed that the four proteins were present in approximately equal amounts. These results provided further evidence for the structural relatedness for gp205, gp180, and gp150, and for the dissimilarity of gp125. Therefore, co-precipitation of gp125 by HB 9318 and 5710 antibodies is probably due to noncovalent associations with gp205, gp180 and gp150.
J. LIMITED PEPTIDE MAPPING
Limited peptide mapping was used to determine the structural relationships between gp205 and gp125. Cells labeled with [ 35 S]-methionine were immunoprecipitated with HB 9318 and subjected to SDS-PAGE. The bands to be analyzed were located on the dried gel by autoradiography.. These bands were then excised from the gel, rehydrated and inserted in slots on a 15% acrylamide SDS-PAGE gel containing a 0.5 microgram/ml solution of Staphylococcus aureus V8 protease (Cleveland, et al. (1977) J. Biol. Chem. 252: 1102-1106.) After the bands were stacked, electrophoresis was suspended for 30 min. to allow enzymatic digestion. The gels were thereafter fluorographed.
SDS-PAGE resolved eight peptides for gp205 and ten peptides for gp125. Each generated distinct profiles, suggesting that gp205 and gp125 are structurally unrelated. HB 9318 precipitates two minor bands, gp180 and gp150. Limited peptide mapping of gp180 resolved seven fragments; gp150 resolved six fragments. The fragments of both gp180 and gp150 co-migrated with gp205 fragments, except for one gp150 peptide which co-migrated with the major fragment of gp125. (Due to its significantly greater intensity, this fragment may be derived from minor contamination of gp150 with the closely-spaced gp 125.) These data suggest that gp205, gp180, and gp150 are structurally related, but distinct from gp125.
This conclusion was further supported by investigations with a polyclonal antiserum (5710) raised against antigen purified from carcinoma cells by immunoaffinity chromatography on the monoclonal antibody HB 9318. Antiserum 5710 was prepared by bleeding of an NZW rabbit, subcutaneously injected with approximately 2 micrograms of immunopurified carcinoma HB 9318 antigen at day 0 in Freund's complete adjuvant, and at days 30 and 45 with the same amount of antigen in incomplete adjuvant.
From carcinoma lysates, the 5710 antiserum precipitated a set of proteins identical to those reactive with HB 9318. If, however, the cell lysates were previously treated at 100° C. in the presence of SDS to disrupt noncovalent associations, then antiserum 5710 precipitated only gp205, gp180 and gp150, but not gp125. The isolated gp205, gp180 and gp150 displayed their characteristic M r downshift under nonreducing conditions. These results suggest that at least some of the epitopes present on gp205, gp180 and gp150 are not found on gp125 and that all 5710 epitopes on gp125, if any, are sensitive to denaturation. This conclusion was verified by Western and "hot" blots.
K. WESTERN AND "HOT" BLOTS
The general procedure of Towbin, H. et al. (1979) Proc. Nat'l. Acad. Sci. USA 76:4350-4354, was followed. Proteins separated by SDS-PAGE on a 5% gel were transferred overnight at 4° C. to Immobiolon (Millipore Corp., Bedford, Mass.) using a 25 mM Tris, 192 mM glycine buffer. The filter was saturated with 3% (w/v) nonfat dry milk in TBS, pH 8.0 with 0.05% Tween 20 and 0.02% azide, incubated for 3 h with primary antibody, washed, overlaid for 1 hour with alkaline phosphatase-conjugated goat anti-rabbit (Promega Biotec, Madison, Wis.) or anti-mouse (Boehringer Mannhelm, Indianapolis, Ind.) IgG, washed again and then developed with 0.33 mg/ml 5-bromo-4-chloro-3-indolyl phosphate in 100 mM Tris-HCL pH 9.5, 100 mM NaCl, 5 mMMgCl 2 , followed by 5 mM EDTA in 20 mM Tris-HCl pH 8.0. For affinity purification (Weinberger, C., et al. (1985) Science 228:740-742) of 5710 antibodies, vertical strips cut from the edges of gp205, gp125 whole-gel blots previously incubated with 5710 were developed to locate reactive bands. Horizontal strips corresponding to these were excised from the undeveloped mid-part of the filter. Bound antibodies were eluted by three one-minute washes with 5 mM glycine-HCl pH 2.3 containing 150 mM NaCl, 0.05% Tween 20, 100 micrograms/ml bovine serum albumin, 2.5 mM sodium azide, and quickly neutralized by addition of Tris-HCl pH 8.0.
For "hot" blots, 1×10 7 cells were metabolically labeled with [ 35 S]-methionine, immunoprecipitated with HB 9318 and electrophoresed on a 5% SDS-PAGE gel. The wet gel was autoradiographed overnight to locate radioactive bands, which were then excised. Proteins were electroeluted in an ISCO apparatus as described (Hunkapiller, M. W., et al (1983) Methods Enzymol. 91:399-413), run on a 5% SDS-PAGE and transferred to Immobilon filters. The filters were first immunostained and then autoradiographed.
EXAMPLE 5
Additional Biochemical Characteristics of HB 9319 Antigen
A. MOLECULAR PROFILE UNDER NON-REDUCING CONDITIONS
FG-met2 cells labeled with [ 35 S]-methionine were immunoprecipitated using HB 9319 and analyzed by SDS-PAGE under non-reducing conditions. HB 9319 antigen migrates as a single band of 125 kd under these conditions.
B. EXTRINSIC RADIOLABELING WITH 125 I
Cultures of FG-met2 cells were surface iodinated using 125 -I sodium iodide, and detergent lysates were immunoprecipitated with HB 9319. The precipitated antigen migrates on SDS-PAGE under reducing conditions as a single species of 140 kd.
Similar results were obtained when the antigen was labeled metabolically with labeled inorganic sulfate or phosphate.
C. METABOLIC LABELING WITH [ 35 S]-METHIONINE IN THE PRESENCE OF TUNICAMYCIN
The method follows that of Example 4(D) using HB 9319 in place of HB 9318. HB 9319 immunoprecipitated a single band in SDS-PAGE of 100 kd under reducing conditions.
D. TWO-DIMENSIONAL GEL ANALYSIS
The method follows that of Example 4(E) using HB 9319 in place of HB 9318. The resulting pattern of migration is shown in FIG. 2.
E. TREATMENT WITH GLYCOLYTIC ENZYMES
The antigen recognized by HB 9319 is isolated by immunoprecipitation of radiolabeled cell lysates. The immunoprecipitates are treated with a variety of exoglycolytic and endoglycolytic enzymes. After treatment the apparent mobility of the precipitated antigens is determined in a SDS-PAGE system. The glycolytic enzymes characteristically modify the apparent molecular weight of the HB 9319 antigens, by removing discrete portions of O-linked or N-linked glycans. The results obtained can be schematically summarized as follows:
______________________________________Enzyme Apparent MW After Treatment______________________________________Endo H 140 kdNA 135 kdEndo N 140 kd______________________________________
F. BINDING TO LECTINS
The method follows that of Example 4(G), using HB 9319 in place of HB 9318. When radiolabeled lysates were preabsorbed with lentil lectin-agarose beads, the antigens reactive with HB 9319 were removed. When they were preabsorbed with wheat germ agglutinin-agarose beads, the antigens were not removed. Removal of antigen was shown by immunoprecipitation of bead supernatant, followed by SDS-PAGE. Therefore, the antigen reactive with HB 9319 characteristically binds to lentil lectin, but not to wheat germ agglutinin.
G. BIOSYNTHESIS OF HB 9319 ANTIGEN
The method is as described in Example 4(I). Pulse-chase biosynthetic studies revealed the presence of a precursor molecule of 120 kD after a 10 minute pulse with [ 35 S]-methionine. At the 15 minute time point of chase small amounts of the 140 kda HB 9319 antigen were also visible. Both of these molecules were observed to be present until 60 minutes after chase. However, only the 140 kd molecule was detectable at 4 hours after chase until 20 hours after chase. Thus, the 120 kd component serves as a precursor for the 140 kd component of the HB 9319 antigen.
V. EXAMPLES OF USES FOR THE PRESENT INVENTION
EXAMPLE 6
Therapeutic Treatment of HPC
Patients determined to have HPC are treated with monoclonal antibodies reactive with HPC cells and conjugated with a toxin such as ricin, or any cytotoxic drug. The monoclonal antibody conjugates are administered (intravenously, intramuscularly, intraperitoneally, or the like, in a physiologically acceptable carrier solution, Such as phosphate buffered saline. The dosage is determined by the body weight of the host, it preferably being in the range of about 0.1 mg/kg to abut 40 mg/kg body weight, and usually about 1 mg/kg to about 10 mg/kg of host body weight. Alternatively, the dosage is established by evaluating the extent of the tumor as by quantitatively standardized ELISA, radioimaging or other methods. Treatment is repeated at intervals as necessary, to effect enhancement of the host's ability to recover from the infection.
EXAMPLE 7
Imaging of HPC Tumor
Monoclonal antibodies reactive with HPC cells are utilized to determine the location and extent of HPC by methods well-known in the art, for example, Larson et al. (1983) J. Clinical Investigation 72:2101, which is incorporated by reference. Monoclonal antibodies are preferably radiolabeled by radioiodination or by other radiolabeling techniques well known in the art, such as chelation using a chelating agent such as diethylene-triaminepenta-acetic acid (DTPA); or are otherwise labeled, such as with agents having paramagnetic properties, with chemiluminescent substrates, or with components of an enzymatic reaction. The radiolabeled monoclonal antibodies are purified and formulated for pharmaceutical use. A solution of the labeled monoclonal antibodies in a carrier, for example in phosphate buffered saline, is injected intravenously into a host. The appropriate dose is in the range of abut 100 μg to 50 mg. Time is permitted for the antibodies to migrate to regions of the body having concentrations of cells with antigenic determinants reactive therewith. Concentrations of radioisotypes in certain tissues are determined or may be mapped either by techniques of whole body imaging which are well-known in the art, .(See, for example, Rainsbury et al. (1983) Lancet October 22, 934 (1983)) which is incorporated by reference, or by evaluating biopsied tissue or extracted body fluid using a scintillation counter. Where non-radioactive labels are used, other appropriate monitoring means are employed, such as a detector of nuclear magnetic resonance or a spectrophotometer. Areas of high radiation levels are indicative of the presence of cells such as HPC, having the cell surface markers of the present invention.
The foregoing examples provide specific embodiments of the present invention, other embodiments being readily within the skill in the art. Thus, the scope of the present invention is defined by the following claims without limitation to the foregoing examples.
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Novel hybridoma cell lines producing monoclonal antibodies which react specifically with human pancreatic cancer cells are described. Methods for producing antigenic preparations to generate the hybridoma cell lines and for selecting, purifying and characterizing the monoclonal antibodies reactive with human cells, including pancreatic cancer cells, are disclosed. The antigens to which the antibodies of the invention are specific are characterized.
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FIELD OF THE INVENTION
[0001] This invention is in the field of a single or combinations of drugs for medicinal purposes, in particular, analgesic compositions for the treatment of pain and is more particularly concerned with three things; (1) the prevention of three particular types of drug abuse, i.e., the illicit use by snorting/inhalation, parenteral administration, or crushing and oral ingestion of dosage forms intended for oral administration (2) the prevention of dose dumping in the presence of alcohol and (3) timed or extended release compositions in gelatin capsules which despite its pseudoplastic or thixotropic nature maintains its integrity sufficiently to perform its controlled release functions during transit in the GIT. The invention describes liquid or semi-solid matrix or magma or paste of narcotic analgesic compositions containing oily, waxy or fatty substances, clays and controlled release agents. Optionally nasal irritants may be included in the invention.
[0002] It was surprisingly discovered that narcotic analgesic compositions containing materials selected from oily, waxy or fatty substances, clays and controlled release agents discouraged abuse and made it harder to abuse by crushing, dissolving, heating to cause evaporation and snorting, “shooting” or inhalation. This is due to the physicochemical nature of the composition.
[0003] The pharmaceutically acceptable nasal irritants when present bring about nasal irritation and annoyance feeling when the composition is brought in contact with the nasal membrane. The irritant agent is not in amounts sufficient to precipitate allergic type reactions or immune response upon snorting.
[0004] It was also surprisingly discovered that in the present invention the narcotic agent is not easily soluble and immediately available upon crushing and attempt at dissolving it for intravenous injection or to get access to the total drug immediately upon oral ingestion of the crushed dosage form does not met with easy success.
[0005] It was unexpectedly discovered that the composition of the present invention prevents and makes it harder for dose dumping of opioid agonists or narcotic analgesics in the presence of alcohol or during co-ingestion of alcohol.
[0006] It will be appreciated that this invention can be variously described, e.g., as a means of preventing dose dumping (when co-ingested with alcohol) and drug abuse by route of administration, or as an improvement in the formulation and compounding of narcotic analgesics or abuse-able substances compositions. However, all based on the discovery that unique combinations of characteristics of various analgesics and materials selected from the group nasal irritants, clays, controlled release agents, oily, waxy or fatty substances can be utilized to provide valuable medicaments substantially free of dose dumping and any potential for illicit use specifically by administration via a means other than the intended oral route.
BACKGROUND OF THE INVENTION
[0007] Oral opioid formulations are not only being abused by the parenteral route, but also via the nasal route when the abuser snorts the crushed dosage form and via the oral route when the abuser orally administers the crushed dosage form in order to obtain instantaneous access to all the drug in the dosage form.
[0008] Another route of abuse which has become of serious concern is snorting of fine powder obtained from crushed opioid dosage form or the oral ingestion of finely crushed extended release oral dosage form in order to instantaneously obtain the benefit of the total opioid present in the slow release dosage form.
[0009] Another phenomenon that has become of concern regarding the use of extended release opioid analgesics is the discovery that they dose dump in the presence of alcohol and release all their content at once.
[0010] Applicants are of the opinion that the prior art neither teaches nor suggests that compositions of the instant invention can be effectively employed to overcome the problem of abuse of opioid agonist or abuse-able substances.
[0011] Applicants are also of the opinion that the prior art neither teaches nor suggests that compositions of the instant invention can be effectively employed to overcome the problem of dose dumping of opioid agonist or abuse-able substances in the presence of alcohol.
[0012] Drug abuse has almost become a way of life to a rapidly growing segment of the world population, especially in the United States and Canada. It has become the vogue of many of the younger generation to experiment with any type of drug that will produce an emotional, psychological, euphoric, depressive or generally psychedelic experience.
[0013] Those drugs most commonly employed for such illicit purposes include the barbiturates, lysergic acid diethylamide (LSD), mescaline, marijuana (tetrahydrocannabinol), strong analgetics (heroin, codeine, morphine, meperidine, propoxyphene [Darvon], methadone, dihydrocodeinone, pentazocine, hydromorphine and the like), the central nervous system stimulants (the amphetamines and the like) and some of the major and minor tranquilizers (the promazines, meprobamate, the diazepines, and the like). Most of these compounds are commonly used in medicine for the legitimate treatment of various conditions and therefore have a limited availability in our society. While these agents are a necessary part of modern medicine, it would be highly desirable (1) to produce new drugs that do not possess drug abuse potential or (2) to “denature” the old agents to prevent their illicit use. The pharmaceutical industry has been striving to achieve the first goal for many years but most regrettably has only achieved very moderate success. If one focuses on the strong analgesics, it becomes apparent that much effort and money has been expended to produce chemicals possessing good analgesic activity but little or no addictive liability. While good progress has been made as evidenced, for example, by the development of propoxyphene as a replacement for codeine and pentazocine as a replacement for morphine or meperidine, it is unfortunate that these compounds are still reported in the medical literature to be addictive and/or euphoric and subjected to abuse by crushing and dissolving and heating/evaporation of the drug composition to enable immediate access to the drug by swallowing, inhalation, snorting, “shooting” or parenteral administration. Furthermore, some of these agents have undesirable side effects, i.e., bad hallucinations, etc.
[0014] It is commonly known to the narcotic enforcement agencies and others in the medical trades that a substantial amount of the strong analgesics destined for legitimate medicinal use are diverted to illicit use through dishonest or careless handling. In many instances, these drugs are obtained by the addict or potential addict by theft or casual prescribing practice by the physician.
[0015] It is known from experience that the true narcotic addict must feed his habit by the crushing and/or dissolving and heating and/or evaporation of the drug composition to enable immediate access to the drug by swallowing, inhalation, snorting, “shooting” or parenteral route (mainlining) to obtain the maximum euphoric effect. The potential addict or thrill-seeker will also experiment in the same manner. Unfortunately, a substantial amount of the legitimate strong analgesics formulated in oral dosage form are diverted to illicit parenteral use, i.e., the type of abuse with which this invention is concerned. Since the oral dosage forms of these drugs diverted from legitimate channels must be easily crushed, dissolved and heated/evaporated in order to get a form in which it can be administered to produce the desired euphoria, it follows that if these oral dosage forms are in some way rendered difficult or impossible to crush, dissolve, heated/evaporate or extract and made unpleasant for abuse via swallowing, snorting, inhalation and “shooting” or parenteral use the addict or potential addict will be cut off from this particular supply of euphoric drugs. Obviously, oral activity must be retained if a useful medicament is to be provided.
[0016] Many interchangeable terms are commonly used to describe the psychic or physical dependence of people upon drugs. The term addiction is most commonly used when talking about the strong analgesics or opioid agonist or abuse-able substances. The strong analgesics or opioid agonist or abuse-able substances, in contrast to the weaker agents such as aspirin, acetaminophen, and the like, are employed in the relief of more severe pain. They usually produce a euphoric effect when crushed and swallowed, snorted and “shoot” parenterally. When taken as oral controlled release composition there is usually no significant euphoria.
[0017] Addiction can develop to the barbiturates and strong analgesic agents or opioid agonist or abuse-able substances, in the sense of the term “addiction” as defined by the Committee on Problems of Drug Dependence of The National Research Council, namely, a state of periodic or chronic intoxication, detrimental to the individual and to society, produced by the repeated administration of a drug, its characteristics are a compulsion to take the drug and to increase the dose, with the development of psychic and sometimes physical dependence on the effects of the drug, so that the development of means to continue the administration of the drug becomes an important motive in the addict's existence.
[0018] Addiction to narcotics or narcotic-like strong analgesics often occurs by the legitimate chronic oral or parenteral administration of these agents in the alleviation of deep pain. More commonly, however, addiction to these agents occurs when the psychologically unbalanced or thrill-seeking individual looking for an escape from the realities of life finds his escape in the euphoria produced by the oral or parenteral administration of strong analgesics or opioid agonist or abuse-able substances. Euphoria is generally defined as a feeling of well-being. Euphoria can be produced in many ways, e.g., an exhilarating experience, alcohol, stimulants, depressants, narcotics, etc. For the purpose of this disclosure, “euphoria” is defined as an abnormal state of well-being produced by the parenteral administration of strong analgesics. The terms or “abuse-able substances”, “euphoric analgesics” and “strong analgesics,” often called narcotic or narcotic-like analgesics or opioid agonist, are also defined herein as including those chemical agents which upon oral or parenteral administration are capable of maintaining or partially maintaining a known addict addicted to heroin or the like without substantial withdrawal symptoms. For the purpose of this disclosure, a “strong analgesic” can also be described as any analgesic agent whose analgesic, euphoric or dependence producing actions are negated by the parenteral administration of an opioid antagonist.
[0019] There has been a lot of concern with regards to the performance of extended release narcortics taught in prior art and currently commercialized. This is because the extended release or controlled release mechanism of current extended release opioid agonists using compositions and methods taught in the prior art is compromised and destroyed in the presence of alcohol leading to the loss of controlled release effects and complete release or dose dumping of its opioid content. The danger and economic consequences of dose dumping in the presence of alcohol for current controlled release narcotic analgesics was highlighted when in Jul. 14, 2005 Purdue Pharma voluntarily took its pain-relieving Palladone (hydromorphone hydrochloride) capsules off the market. The company took the action on July 13 following an FDA request to withdraw Palladone because of safety concerns. The FDA approved Palladone in September 2004. The drug was launched by Purdue Pharma in February 2005. Palladone was approved for the management of persistent, moderate-to-severe pain in patients requiring continuous, around-the-clock pain relief with a high-potency opioid for an extended period of time. An FDA news release stated that “serious and potentially fatal adverse reactions can occur when Palladone extended release capsules are taken together with alcohol. Hydromorphone is a narcotic analgesic; used to relieve pain and also to suppress cough.
[0020] According to the FDA news release, “Palladone is a once-a-day pain management drug containing a very potent narcotic. New data gathered from a company-sponsored study testing the potential effects of alcohol use shows that when Palladone is taken with alcohol the extended release mechanism is harmed which can lead to dose-dumping. The FDA described “Dose-dumping, as the rapid release of the drug's active ingredient into the bloodstream. The agency's news release pointed out that dose-dumping, even with a low dose of Palladone (12 milligrams), could lead to “serious, or even fatal, adverse events in some patients. The FDA also warned that the risk increases for higher doses of Palladone.
[0021] Health Canada also issued an Advisory to warn of serious health risks associated with the consumption of alcohol while taking any slow-release opioid analgesics, following data from Purdue Pharma.
[0022] It can be argued that just like in the case of Palladone all powerful pain management drugs such as opioid agonists or narcotic analgesics have serious risks if used incorrectly, and this is particularly true for the current extended release formulations in the prior art or under commercialization. In fact Health Canada has advised patients receiving other slow-release opioids to be aware that these products may react in a similar way to hydromorphone slow release formulation when co-ingested with alcohol i.e., they may be released into the blood quickly (dose-dumping) instead of over 24 hours.
[0023] This situation continues to present an unacceptably high level of patient risk. There is a great concern that as more patients take current compositions, safety problems will arise since even having one alcoholic drink could have fatal implications. The use of patient information vial label warnings regarding the dangers of using opioids and alcohol concomitantly is not expected to solve this problem. As a matter of fact the FDA has said that the agency doesn't believe that “potentially fatal, adverse events can be effectively managed by label warnings alone. . . . ”
[0024] Health authorities have turned up the heat and are demanding the pharmaceutical companies come clean and put interests of patients first. Accordingly, to investigate if the same effect occurs with other slow-release drugs, Health Canada requests that all manufacturers of these products provide information on the interaction between their drug and alcohol; if this is not possible, studies investigating product interactions with alcohol are to be conducted and completed within six months. Health Canada states that the data will be assessed within a three-month period and that further action will be taken if required.
[0025] From the foregoing there is therefore an urgent and great need for compositions of opioid agonist or narcotic analgesics or abuse-able substances which are abuse resistant and or do not dose dump in the presence of alcohol.
[0026] Attempts have been made in the past to control the abuse potential associated with opioid analgesics. Parenteral dose of opioid analgesics are more potent as compared to the same dose administered orally. Therefore, drug abuse is often carried out by the extraction of the opioid from the dosage form, and the subsequent injection of the opioid (using any “suitable” vehicle for injection) in order to achieve a “high.” Attempts to curtail abuse have therefore typically centered around the inclusion in the oral dosage form of an opioid antagonist which is not orally active but which will substantially block the analgesic effects of the opioid if one attempts to dissolve the opioid and administer it parenterally.
[0027] U.S. Pat. No. 3,254,088, describes the preparation of naloxone and its activity as a narcotic antagonist.
[0028] U.S. Pat. No. 3,493,657, describes the combination of morphine and naloxone as a composition for parenteral use “which has a strong analgesic, as well as antagonistic effect, without the occurrence of undesired or dangerous side effects.”
[0029] A New York Times article appearing in a Jul. 14, 1970 issue described the oral administration of naloxone to narcotic addicts as a method of treatment. The oral administration of naloxone (in high doses) “makes it impossible for the addict to experience a high no matter how much heroin he uses.”
[0030] The combination of pentazocine and naloxone has been utilized in tablets available in the United States, commercially available as TalwinB from Sanofi-Winthrop. TalwinB contains pentazocine hydrochloride equivalent to 50 mg base and naloxone hydrochloride equivalent to 0.5 mg base. TalwinB is indicated for the relief of moderate to severe pain. The amount of naloxone present in this combination has no action when taken orally, and will not interfere with the pharmacologic action of pentazocine. However, this amount of naloxone given by injection has profound antagonistic action to narcotic analgesics. Thus, the inclusion of naloxone is intended to curb a form of abuse of oral pentazocine which occurs when the dosage form is solubilized and injected. Therefore, this dosage has lower potential for parenteral abuse than previous oral pentazocine formulations. However, it is still subject to patient misuse and abuse by the oral route, for example, by the patient taking multiple doses at once.
[0031] Sunshine, et al. “Analgesic Efficacy of Pentazocine Versus a Pentazocine-Naloxone Combination Following Oral Administration”, Clin. J. Pain, 1988:4:35-40, reported on the effect of the addition of 0.5 mg naloxone on the analgesic efficacy of pentazocine 50 mg. The combination was found to be significantly less efficacious than pentazocine for the sum of the pain intensity difference (SPID), and for relief and pain intensity difference (PID) at the fourth hour. For patients with moderate baseline pain, the combination produced significantly less pain relief than pentazocine for SPID and for relief and PID at hours 3 and 4. In patients with severe baseline pain, there was no significant difference found between pentazocine and the combination of pentazocine plus naloxone.
[0032] Wang, et al. “Crossover and Parallel Study of Oral Analgesics”, J. Clin. Pharmaco.l 198 1; 21:162-8, studied the combination of naloxone 0.25 mg and PercodanB (composed of 4.5 mg oxycodone HC1, oxycodone terephthalate 0.28 mg, aspirin 224 mg, phenacetin 160 mg, and caffeine 32 mg) compared to PercodanB alone, and placebo in a crossover study of patients with chronic pain. The combination had lower mean scores than PercodanB alone for most of the analgesic hourly parameters in the later hours of the trial. However, for the summary variables, the combination showed no significant difference from either placebo or PercodanB.
[0033] A fixed combination of buprenorphine and naloxone was introduced in 1991 in New Zealand (TemgesicB, Reckitt & Colman) for the treatment of pain.
[0034] A fixed combination therapy comprising tilidine (50 mg) and naloxone (4 mg) has been available in Germany for the management of severe pain since 1978 (ValoronB, Goedecke). The rationale for the combination of these drugs is effective pain relief and the prevention of tilidine addiction through naloxone-induced antagonisms at the morphine receptor.
[0035] U.S. Pat. No. 3,773,955 (Pachter, et al.) described orally effective analgesic compositions which upon parenteral administration do not produce analgesia, euphoria, or physical dependence, and thereby prevent parenteral abuse of the analgetic agents. Such compositions contained from about 0.1 mg to about 10 mg naloxone per analgetic oral dose. This reference was not concerned with oral abuse of opioids.
[0036] U.S. Pat. No. 3,493,657 (Lewenstein, et al.) described compositions comprising naloxone and morphine or oxymorphone, which compositions were said to provide a strong analgesic effect without the occurrence of undesired side effects such as hallucinations.
[0037] U.S. Pat. No. 4,457,933 (Gordon, et al.) described a method for decreasing both the oral and parenteral abuse potential of strong analgetic agents such as oxycodone, propoxyphene and pentazocine, by combining an analgesic dose of the opioid with naloxone in a specific, relatively narrow range. Oxycodone-naloxone compositions having a ratio of 2.5-5:1 parts by weight and pentazocine-naloxone compositions having a ratio of 16-50:1 parts by weight were preferred. The dose of naloxone which was to be combined with the opioid is stated to substantially eliminate the possibility of either oral or parenteral abuse of the opioid without substantially affecting the oral analgesic activity thereof.
[0038] U.S. Pat. No. 4,582,835 (Lewis) describes a method of treating pain by administering a sublingually effective dose of buprenorphine with naloxone. Lewis describes dosage ratios of naloxone to buprenorphine from 1:3 to 1:1 for parenteral administration, and from 1:2 to 2:1 for sublingual administration.
[0039] U.S. Pat. No. 6,627,635 teaches a method of preventing abuse of opioid dosage forms wherein an analgesically effective amount of an orally active opioid agonist is combined with an opioid antagonist into an oral dosage form which would require at least a two-step extraction process to be separated from the opioid agonist, the amount of opioid antagonist including being sufficient to counteract opioid effects if extracted together with the opioid agonist and administered parenterally.
[0040] U.S. Pat. 6,696,088 discloses tamper-resistant oral opioid agonist formulations comprising (i) an opioid agonist in releasable form and (ii) a sequestered opioid antagonist which is substantially not released when the dosage form is administered intact, such that the ratio of the amount of antagonist released from said dosage form after tampering to the amount of said antagonist released from said intact dosage form is about 4:1 or greater, wherein said agonist and antagonist are interdispersed and are not isolated from each other in two distinct layers.
[0041] Despite all the above attempts in the prior art to address the problem of drug abuse, the problem persists partly because of design faults in the compositions and the addicts coming up with creative ways to beat the anti drug abuse mechanism. As at today the problem is escalating with at an alarming rate with devastating financial and social consequences.
[0042] To the best of our knowledge, the prior art neither teaches nor suggests that compositions of the instant invention can be effectively employed simultaneously to reduce the problem of, or discourage or make it difficult for drug abuse via snorting (nasal), oral or parenteral administration of crushed oral dosage formulations and that compositions of the instant invention when taken orally in the ordinary course, the irritant, sequestering agent and narcotic antagonist have no significant effect and do not block the therapeutic effect of the opioid analgesic.
[0043] The current invention makes use of compositions in gelatin capsules particularly hard gelatin capsules. The following information discloses the use of soft gelatin capsules as carriers for drugs in the prior art. However these do not teach the composition of the current invention
[0044] The fill material used in a soft gelatin capsule generally contains a pharmaceutical dissolved or dispersed in a carrier that is compatible with the capsule wall. In addition to liquids, U.S. Pat. No. 4,935,243 to L. Borkan et al. suggests that the fill material may take the form of a semi-solid, solid, or gel. Conventional tablets or pellets containing an active ingredient are examples of solid fill materials that may be encapsulated within a soft gelatin capsule.
[0045] Semi-solid (dispersion) fill material are discussed in U.S. Pat. No. 4,486,412 to D. Shah et al. A fill material containing an orally-administered antacid salt that is dispersed in a water-free, liquid carrier containing a major proportion of one or more polyalkylene glycols and a minor proportion of a C.2-C.sub.5 polyol, such as propylene glycol or glycerin. The carrier forms a stable dispersion of the antacid salt and coats the antacid particles, thereby rendering them nonreactive with the soft gelatin capsule wall. The dispersion may also contain a polysiloxane flatulence-relieving agent, such as sirnethicone, as an optional ingredient. Such optional ingredients comprise about 0-5% by weight of the total dispersion.
[0046] U.S. Pat. No. 4,708,834 to Cohen et al. suggests a controlled release pharmaceutical dosage form comprising a soft gelatin capsule that encloses a water soluble or dispersible gelled polymer matrix. The fill material comprises an aqueous solution or dispersion of a polysaccharide gum, the pharmaceutical active and, optionally, an alcohol. The liquid fill is introduced into a soft gelatin capsule that contains a cationic gelling agent, which gels the liquid fill after it has been incorporated into the capsule shell. The alcohol used in the fill includes liquid polyethylene glycols, lower alkanols, C.sub.2-C.sub.4 polyols and mixtures thereof.
[0047] U.S. Pat. No. 5,071,643 to M. Yu et al. also discusses the use of polyethylene glycols (PEG) as a fill material in soft gelatin dosage forms. PEGS having an average molecular weight between 400-600 are preferred for liquid fills, between 800-10,000 for semi-solid fills and between 10,000-100,000 for solid fills.
[0048] Remington's Pharmaceutical Sciences, 18th ed, Chapter 83, pp. 1539-40 (1990), reports that gelling agents used to make gels for pharmaceutical and cosmetic products, include sodium alginate and triethanolamine.
[0049] PCT Publication No. WO 91107950 describes a soft or two-piece hard gelatin capsule shell containing benzodiazepine dissolved or suspended in a gel. The gel contains by weight at least 63% of polyethylene glycol 600, at least 4% of polyethylene glycol 4000 or 6000, and at least 21% of polyethylene glycol 600-4000. This gel fill cannot be expelled with a syringe at ambient temperature and therefore avoids the reported abuse of liquid filled capsules by intravenous drug abusers.
[0050] Antiflatulents are typically incorporated into compressible tablets by mixing the oily-like substances, such as simethicone, with standard tableting excipients prior to tableting. U.S. Pat. No. 5,073,384 to Valentine et al. describes a composition suitable for tableting comprising simethicone and a water soluble, maltodextrin agglomerate. The resulting combinate is reported to be free flowing and possess defoaming activity.
[0051] Hungarian Patent No. 203,477, published Jan. 28, 1991, describes an antiflatulent, solid dispersion containing poly(dimethylsiloxane) as a dispersed phase in a water soluble carrier. The dispersion also contains a lattice-forming and/or a crosslinking, viscosity-increasing macromolecular auxiliary substance such as polyvinyl chloride, polyacrylic acid, or polyvinylpyrrolidone and/or inorganic solidifying agent, such as tricalcium phosphate, calcium sulfate hemihydrate or calcium hydrogen phosphate. Example 1 reports a solid mass containing 60 g of polyethylene glycol 6000, 15 g of polyvinyl chloride and 25 g of activated dimethicone (simethicone) that can be ground and filled into solid gelatin capsules or made into tablets.
[0052] French Patent Application No. 2,624,012, published Jun. 9, 1989, relates to a soft gelatin capsule containing a suspension or solution of chloral hydrate in a high viscosity inert vehicle. Suitable vehicles for use in the capsule include oily solvents of mineral or vegetable oil, such as olive oil, peanut oil, paraffin oil, vaseline oil or mixtures of several oils; a liquid silicone such as dimethicone or simethicone; a glycol polymer such as polyethylene glycol 600, 800 or 1200; and a glycol such as ethylene glycol, propylene glycol or glycerol.
[0053] Simethicone has been incorporated in syrup or clear base liquid oral formulations. A. Banga et al. in “Incorporation of Simethicone into Syrup or Clear Base Liquid Orals,” Drug Development and Industrial Pharmacy, 15(5), pgs. 691-704 (1989) describes a variety of vehicles for simethicone, but reports the best results were obtained with neutralized CARBOPOL™ (carboxypolymethylene) resins in combination with glycerin and propylene glycol.
[0054] U.S. Pat. No. 4,514,538 teach a self-sustaining waterproofing composition prepared by a method comprising mixing at least 75 parts of solvent wetted bentonite with (A) a material selected from the group consisting of dialkylphthalate, dialkyloxalate, sucrose acetate isobutyrate, glycerine and mixtures thereof, (B) said solvent being substantially unreactive with said bentonite and containing from about 30 to 50 parts benzene, and (C) a material selected from the group consisting of polyalkylmethacrylate, cellulose acetate, polyvinylalcohol, polyvinylbutyral, and mixtures thereof. This invention relates to compositions useful in the construction industry useful in waterproofing a structure.
[0055] U.S. Pat. No. 4,517,112 teaches Modified organophilic clay complexes, their preparation and non-aqueous systems containing them and more especially, organophilic organic-clay complexes which are dispersible in organic liquids to form a gel therein, which comprises the reaction product of (a) a smectite-type clay having a cation exchange capacity of at least 75 milliequivalents per 100 grams of said clay; (b) a primary anion selected from the group consisting of anions derived from organic sulfonic acids, alkylsulfates and mixtures thereof containing at least one lineal or branched alkyl group having greater than 9 carbon atoms, aromatic sulfonic acids and mixtures thereof; (c) a secondary anion different from said primary anion and selected from the group consisting of anions derived from organic acids having a pKa of less than about 11.0 and mixtures thereof; and (d) an organic cation is an amount sufficient to satisfy the cation in exchange capacity of said clay and the cationic activity of the primary and secondary anions wherein the resulting organic cation-organic anion complexes are intercalated with the smectite-type clay and wherein the combination of said primary and secondary anion synergistically increases the ease of dispersion of said organophilic clay gellant in an organic liquid. This invention relates to compositions gels which may be useful as lubricating greases, oil base muds, oil base packer fluids, paint-varnish-lacquer removers, paints, foundry molding sand binders, adhesives and sealants, inks, polyester laminating resins, polyester gel coats, and the like.
[0056] U.S. Pat. No. 4,676,929 This invention is concerned with useful gels generated from expandable, hydrated sheet silicates, also known as lattice layered silicates, or phyllosilicates. It is also concerned with articles of manufacture produced by further treatment of such gels, and with methods of generating and treating the gels. The silicate minerals of interest include vermiculite, beidellite, nontronite, volchonskoite, saponite, stevensite, sauconite, pimelite, bentonite, montmorillonite, hectorite, the smectites, attapulgite, sepiolite, phlogopite and biopyrobole; i.e., in essence the entire genus of hydrated or hydratable phyllosilicates whether of natural or synthetic origin.
[0057] These do not teach compositions of opioid agonists in hard gelatin capsule that are difficult to abuse and that will not does dump in the presence of alcohol or on co-ingestion with alcohol.
[0058] To date, there has been no disclosure of the use of the composition of the present invention to prevent and or make it harder for dose dumping of opioid agonists or narcotic analgesics in the presence of alcohol or during co-ingestion of alcohol.
[0059] There has also been no disclosure of the use of the composition of the present invention to prevent or discouraged abuse and make it harder to abuse opioid analgesics, narcotic analgesics or abuse-able substances. Furthermore, there has also been no disclosure of the composition of the present invention.
SUMMARY OF THE INVENTION
[0060] This invention is concerned with the development of a potent, orally effective, but abuse resistant analgesic composition that has substantially reduced drug abuse potential and, more particularly, essentially no abuse potential.
[0061] The object of the invention are also achieved by the formulation of a composition comprising narcotic or narcotic-like, analgesic agent in oral liquid or semi-solid matrix, magma, or paste in a capsule and composed of materials selected from clays, controlled release agents and oily, waxy or fatty substances in an amount and ratios which is sufficient to prevent the compromising or loss of integrity of the controlled release mechanism of the composition upon oral administration or co-ingestion with alcohol.
[0062] Another aspect of the invention is to provide a means to discourage three particular types of drug abuse, i.e., the illicit use by snorting/inhalation, parenteral administration, or crushing and oral ingestion of dosage forms intended for oral administration over 12 or 24 hours in order to rapidly release or make available the abuse-able agent.
[0063] Another objective achieved by this invention is the provision of a means for preventing dose dumping in the presence of alcohol and the prevention of the abuse of oral formulations of therapeutically valuable strong analgesics or opioid analgesics by the improvement in formulating such medicaments which comprises admixing therewith a balanced amount of opioid analgesic and materials selected from clays, oily, waxy or fatty substances and controlled release agents.
[0064] It is another object of this invention to provide a controlled release product and method in which the physicochemical nature of the composition helps to prevent dose dumping in the presence of alcohol and also discourage abuse and make it harder to abuse by crushing, milling or grinding and dissolving, heating to cause evaporation and snorting, “shooting” or inhalation.
[0065] It is yet another object of this invention to provide a composition in which the presence of pharmaceutically acceptable nasal irritants in sufficient amount to bring about nasal irritation and present an annoyance feeling (but not allergic type reactions or immune response) when the composition is brought in contact with the nasal membrane and hence discourage drug abuse via snorting or inhalation.
[0066] Yet another objective achieved by this invention is the provision of a means for preventing dose dumping of opioid analgesics in the presence of alcohol
[0067] A further object of this invention is to provide high dose loading of opioid analgesic in a liquid or semi-solid matrix, magma or paste in a hard gelatin capsule.
[0068] A still further object of this invention is to provide a stable composition of opioid analgesic in a liquid or semi-solid matrix, magma or paste which does not interact with or compromise the integrity of the hard gelatin capsule
[0069] Another objective of this invention is Compositions containing pharmaceutical active substances and materials selected from the group clays, controlled release agents, oily, waxy, and fatty substances for preventing dose dumping in the presence of alcohol and which makes it difficult for drug abuse
[0070] A still further object of this invention is to provide a stable composition of opioid analgesic in a liquid or semi-solid matrix, magma or paste in hard gelatin capsule in which dissolution using a USP dissolution tester is not significantly different by the rotation speed of the basket or paddle in the speed range from about 25 rpm to about 150 rpm, or at about 50 rpm and about 100 rpm or at about 50 rpm and about 75 rpm or at about 100 rpm and about 150 rpm. The rotation speed does not interact with or compromise the integrity of the composition and release mechanism. Compositions that meet these requirements perform consistently in the GIT without fear of collapse or disintegration. They are not perturbed, crushed or damaged by GIT content, resident time or motility. These types of composition will be more reliable and highly prized.
[0071] A further objective of this invention is to provide compositions of the active substances, clays, controlled release agents and oily, waxy or fatty substances that are compatible with the gelatin capsule shell and not compromise the integrity of the capsule shell
[0072] Another objective is to provide compositions of the active substances, clays, controlled release agents and oily, waxy or fatty substances in a gelatin capsule and applying a pH or non pH sensitive film coat to the internal and or external surface of the gelatin capsule in other to control the site and or rate of delivery of the active substances or protect the composition from environmental factors such as moisture or for aesthetic appeal.
[0073] The concentration of controlled release agents in the invention may be from about 2% to about 90% while the concentration of the oily substance may be from about 3% to about 99%. The concentration of the waxy or fatty substance may be from about 0.5% to about 70%. The concentration of clays in the invention is from about 0.1% to about 95%.
[0074] According to the method of treatment embodiment of the invention, a medical condition or dose dumping is sought to be prevented or treated by administering to a patient a pharmaceutical composition, as described above, comprising a narcotic analgesic and clays, controlled release agent and oily, waxy or fatty substances wherein the quantity and combination of materials in the composition is sufficient to form a liquid or semi solid matrix, paste or magma.
[0075] In a preferred composition, the particle size of non dissolved materials should be less than 1000 microns and the composition maintains its consistency/viscosity and homogeneity at room temperature conditions and during storage. A more preferred composition is a homogeneous non Newtonian, thixotropic or pseudoplastic paste or liquid/semi solid matrix.
[0076] In yet another preferred composition and method of application and manufacture of the embodiment of the invention, a controlled release composition may be filled into a gelatin capsule or dispensing device alone and utilized. Or it may be co-filled with non controlled release composition containing opioid antagonist and or immediate release non-narcotic analgesics or other pharmaceutically active substances. Such compositions allow for a clean break during formation or dosing (“stringing”) into gelatin capsule or device. The right viscosity is critical. If the viscosity is too low splashing of the bushings may occur which could contaminate the area of overlap between the capsule body and cap and prevent a good seal from being formed. The present invention prevents the above mentioned problems.
[0077] The formulation may also be in the form of a solid. The means and area of application will depend on the particular condition that is being treated. It may be taken orally, implanted, intravenously or as a depot. It may be targeted at specific sites in the gastrointestinal tract (GIT) or to specific organs. It may be applied buccally and transdermally in a pouch or patch. The composition may be applied to bodies of water, such as rivers, lakes, or oceans, to the atmosphere, or to land. It is evident that the physical state of the formulation and the particular method of application may vary accordingly.
[0078] In a preferred method and composition the administration in man or animal may be internal, such as oral or parenteral. Such internal parenteral administration includes but is not limited to intravascular, intramuscular, subcutaneous, intradermal, intrathecal, and intracavitary routes of administration, as well as application to the external surface of an internal bodily organ, such as during a surgical or laparoscopic procedure. The administration may be topical, including administration to the skin or to a mucosal surface, including the oral, vaginal, rectal surfaces, to the surface of the eye, to the nasal passages, or to the ear canal.
[0079] The manufacture of the composition of this invention is relatively simple. Formulation is prepared at room temperature. Typically, no heating of the ingredients are required. However, when materials that are solid at room temperature are to be used, heating may be necessary. For this invention, solvent having high volatile properties are not preferred. Examples of such volatile solvents are: benzene, toluene, xylene, hexane, cyclohexanole, cyclohexane, methylcyclohexanole, dioxane, ethylacetate, acetone, amylacetate, propylacetate, methylethylketone, ethylcellosolve, isopropylalcohol, methanol, ethylalcohol and isoarnylalcohol.
DETAILED DESCRIPTION OF THE INVENTION
[0080] Examples of some of the opioid agonists or narcotic analgesics contemplated for use in this invention include alfentanil, allylprodine, alphaprodine, anileridine, benzylmorphine, bezitramide, buprenorphine, butorphanol, clonitazene, codeine, desomorphine, dextromoramide, dezocine, diampromide, diarnorphone, dihydrocodeine, dihydromorphine, dimenoxadol, dimepheptanol, dimethylthiambutene, dioxaphetyl butyrate, dipipanone, eptazocine, ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazene, etorphine, dihydroetorphine, fentanyl hydrocodone, hydromorphone, hydroxypethidine, isomethadone, ketobemidone, levorphanol, levophenacylmorphan, lofentanil, meperidine, meptazinol, metazocine, methadone, metopon, morphine, myrophine, narceine, nicomorphine, norlevorphanol, norrnethadone, nalorphine, nalbuphene, normorphine, norpipanone, opium, oxycodone, oxymorphone, papaveretum, pentazocine, phenadoxone, phenomorphan, phenazocine, phenoperidine, piminodine, piritramide, propheptazine, promedol, properidine, propoxyphene, sufentanil, tramadol,tilidine, alphaprodine, dextroporpoxyphene, propiram, profadol, phenampromide, thiambutene, pholcodeine ,3-trans-dimethylamino-4-phenyl-4-trans-carbethoxy-.DELTA.′-cyclohexene, 3-dimethylamino-0-(4-methoxyphenylcarbamoyl)-propiophenone oxime, (−).beta.-2′-hydroxy-2,9-dimethyl-5-phenyl-6,7-benzomorphan, (−)2′-hydroxy-2-(3-methyl-2-butenyl)-9-methyl-5-phenyl-6,7-benzomorphan, pirinitramide, (−).alpha.-5,9-diethyl-2′-hydroxy-2-methyl-6,7-benzomorphan, ethyl 1-(2-dimethylaminoethyl)-4,5,6,7-tetrahydro-3-methyl-4-0×0-6-phenylindole-2-carboxylate, 1-Benzoylmethyl-2,3-dimethyl-3-(m-hydroxyphenyl)-piperidine, N-allyl7. alpha.-(1-(R)-hydroxy-1-methylbutyl)-6,14-endo-ethanotetrahydron ororipavine, (−)2′-hydroxy-2-methyl-6,7-benzomorphanno,r acylmethadol, phenoperidine, .alpha.-dl-methadol, .beta.-dl-methadol, .alpha.-1-methadol (2-15 mg), .beta.-dl-acetylmethadol, .alpha.-dl-acetylmethadol and beta-dl-acetylmethadol and pharmaceutically acceptable salts thereof, stereoisomers thereof, ethers thereof, esters thereof, and mixtures thereof.
[0081] The compositions of the instant invention can also contain other active ingredients. These include amongst others for example, opioid antagonists (such as naloxone), aspirin, phenacetin, caffeine, acetaminophen, antihistamines, homatropine methylbromide, phenyltoloxamine citrate, barbiturates, or the like, or multiple combinations thereof. Also included within the scope of the present invention are those compositions comprising narcotic analgesics in combination with non narcotic analgesics, antitussive preparations which contain narcotic or narcotic-like cough suppressants such as codeine, dihyrocodeinone, pholcodeine, and the like. Other products comprising a narcotic or narcotic-like composition for use as an antispasmotic in the gastro-intestinal tract, such as Camphorated Opium Tincture, U.S.P., Opium Tincture, U.S.P., Opium extract, N.F., and the like are to be considered an integral part of this invention.
[0082] Included in the compositions of this invention would be drugs most commonly employed for illicit purposes (to bring about a “high”, euphoria, excitement, stupor, sleep deprivation etc.,) such as the barbiturates, lysergic acid diethylamide (LSD), mescaline, marijuana (tetrahydrocannabinol), heroin, and the like, the central nervous system stimulants (the amphetamines and the like) sedative, hypnotics and some of the major and minor tranquilizers (the promazines, meprobamate, the diazepines, and the like)
[0083] Examples of clays suitable for use in this invention are bentonite, veegum and other clay minerals such as phyllosilicates (Smectite, illite, sepiolite, palygorskite, muscovite, allevardite, amesite, hectorite, fluorohectorite, saponite, beidellite, talc, nontronite, stevensite, mica, vermiculite, fluorovermiculite, halloysite and fluorine-containing synthetic types of mica, phyllosilicates, beidellite; volkonskoite; hectorite; sauconite; sobockite; svinfordite; and the like. Other usehl materials include micaceous minerals, such as mixed illite/smectite minerals, such as rectorite, tarosovite, ledikite and admixtures of illites with the clay minerals named above. A swelling bentonite is preferred.
[0084] Oily, fatty and waxy components are a preferred embodiment of the current invention. These include oils and fats, waxes, hydrocarbons, higher fatty acids, higher alcohols, esters, metal salts of higher fatty acids, and the like. Specific examples of oils and fats include plant oils, e.g. cacao butter, palm oil, Japan wax (wood wax), coconut oil, etc.; animal oils, e.g. beef tallow, lard, horse fat, mutton tallow, etc.; hydrogenated oils of animal origin, e.g. hydrogenated fish oil, hydrogenated whale oil, hydrogenated beef tallow, etc.; hydrogenated oils of plant origin, e.g. hydrogenated corn oil, hydrogenated rape seed oil, hydrogenated castor oil, hydrogenated coconut oil, hydrogenated soybean oil, etc.; and the like. Of these hydrogenated oils are preferred as an oil component of the present invention. Specific examples of waxes include plant waxes, e.g. carnauba wax, candelilla wax, bayberry wax, auricurry wax, espalt wax, etc.; animal waxes, e.g. bees wax, breached bees wax, insect wax, spermaceti, shellac, lanolin, etc.; and the like. Of these preferred are carnauba wax, white beeswax and yellow beeswax. Paraffin, petrolatum, microcrystalline wax, and the like, are given as specific examples of hydrocarbons, with preferable hydrocarbons being paraffin and microcrystalline wax. Given as examples of higher fatty acids are caprilic acid, undecanoic acid, lauric acid, tridecanic acid, myristic acid, pentadecanoic acid, palmitic acid, malgaric acid, stearic acid, nonadecanic acid, arachic acid, heneicosanic acid, behenic acid, tricosanic acid, lignoceric acid, pentacosanic acid, cerotic acid, heptacosanic acid, montanic acid, nonacosanic acid, melissic acid, hentriacontanic acid, dotriacontanic acid, and the like. Of these, preferable are myristic acid, palmitic acid, stearic acid, and behenic acid. Specific examples of higher alcohols are lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, stearyl alcohol, nonadecyl alcohol, arachyl alcohol, behenyl alcohol, carnaubic alcohol, corianyl alcohol, ceryl alcohol, and myricyl alcohol. Particularly preferable alcohols are cetyl alcohol, stearyl alcohol, and the like. Specific examples of esters are fatty acid esters, e.g. myristyl palmitate, stearyl stearate, myristyl myristate, behenyl behenate, ceryl lignocerate, lacceryl cerotate, lacceryl laccerate, etc.; glycerine fatty acid esters, e.g. lauric monoglyceride, myristic monoglyceride, stearic monoglyceride, behenic monoglyceride, oleic monoglyceride, oleic stearic diglyceride, lauric diglyceride, myristic diglyceride, stearic diglyceride, lauric triglyceride, myristic triglyceride, stearic triglyceride, acetylstearic glyceride, hydoxystearic triglyceride, etc.; and the like. Specific examples of metal salts of higher fatty acid are calcium stearate, magnesium stearate, aluminum stearate, zinc stearate, zinc palmitate, zinc myristate, magnesium myristate, and the like.
[0085] In a preferred embodiment the oils used in the invention are one or more selected from Almond Oil, Apricot Kernel Oil, Avocado Oil, Black Currant Oil, 14% GLA, Borage Oil, 20% GLA, Canola Oil, Carrot Oil, Castor Oil, Clove Leaf Oil, Coconut Oil, Corn Oil, Cottonseed Oil, Evening Primrose Oil, 9% GLA, Flaxseed Oil, 55% ALA, Grapeseed Oil, Hazelnut Oil, Hemp Oil, ALA/GLA, Hydrogenated Oils, Jojoba Oil, Golden Jojoba Oil, Water-white Kukui Nut Oil, Macadamia Nut Oil, Oat Oil, Olive Oil, Extra Virgin Olive Oil Pomace/“B” grade, Olive Oil, Pure/NF, Palm Oil, Parsley Seed Oil, Peach Kernel Oil, Peanut Oil, Pecan Oil, Pistachio Oil, Pumpkinseed Oil, Rice Bran Oil, Rose Hip Seed Oil, Rosemary Oil, Safflower Oil, Linoleic' Safflower Oil, High-Oleic, Sesame Oil NF, Sesame Oil Toasted, Soybean Oil, Sunflower Oil, Salad Sunflower Oil High-Oleic, Tea Tree Oil, Vegetable, Glycerine, USP, Walnut Oil, Wheat Germ Oil, Cold-pressed and mineral oil or other similar oils.
[0086] Controlled release agents that may be used in the composition of this invention include naturally occurring or synthetic, anionic or nonionic, hydrophobic, hydrophilic rubbers, polymers, starch derivatives, cellulose derivatives, polysaccharides, carbomer, reseins, acrylics, proteins, vinylpyrrolidone- vinyl-acetate-copolymers, glactomannan and galactomannan derivatives, carrageenans and the like. Specific examples are acacia, tragacanth, Xanthan gum, locust bean gum, guar-gum, karaya gum, pectin, arginic acid, polyethylene oxide, polyethylene glycol, propylene glycol arginate, hydroxypropyl methylcellulose, methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, carboxymethylcellulose sodium, polyvinylpyrrolidone, carboxyvinyl polymer, sodium polyacrylate, alpha starch, sodium carboxyrnethyl starch, albumin, dextrin, dextran sulfate, agar, gelatin, casein, sodium casein, pullulan, polyvinyl alcohol, deacetylated chitosan, polyethyoxazoline, poloxamers, ethylcellulose, chitin, chitosan, cellulose esters, aminoalkyl methacrylate polymer, anionic polymers of methacrylic acid and methacrylates, copolymers of acrylate and methacrylates with quaternary ammonium groups, ethylacrylate methylmethacrylate copolymers with a neutral ester group, polymethacrylates, surfactants, aliphatic polyesters, zein, polyvinyl acetate, polyvinyl chloride, and the like.
[0087] The following may be used in a preferred embodiment, a pharmaceutically acceptable acrylic polymer. Specific examples includes, but is not limited to, acrylic acid and methacrylic acid copolymers, methyl methacrylate copolymers, ethoxyethyl methacrylates, cyanoethyl methacrylate, aminoalkyl methacrylate copolymer, poly(acrylic acid), poly(methacrylic acid), methacrylic acid alkylamide copolyer, poly(methyl methacrylate), poly(methyl methacrylate) copolymer, polyacrylamide, aminoalkyl methacrylate copolymer, poly(methacrylic acid anhydride), and glycidyl methacrylate copolymers. Additionally, the acrylic polymers may be cationic, anionic, or non-ionic polymers and may be acrylates, methacrylates, formed of methacrylic acid or methacrylic acid esters. The polymers may also be pH independent or pH dependent.
[0088] Further examples of additives that may be used in the composition of the invention include, but are not limited to, ethyl lactate, phthalates such as dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate, glycol ethers such as ethylene glycol diethyl ether, propylene glycol monomethyl ether, PPG-2 myristyl ether propionate, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monotertiary butyl ether, dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 2 pyrrolidone, isopropyl myristate, isopropyl palmitate, octyl palmitate, dimethylacetamide, propylene glycol, propylene glycol monocaprylate, propylene glycol caprylatelcaprate, propylene glycol monolaurate, glycofurol, linoleic acid, linoeoyl macrogol-6 glycerides, oleic acid, oleic acid esters such as glyceryl dioleate, ethyl oleate, benzoic acid, oleoyl macrogol-6 glycerides, esters such as ethylbenzoate, benzylbenzoate, sucrose esters, sucrose acetate isobutyrate, esters of lactic acid, esters of oleic acid, sebacates such as dimethyl sebacate, diethyl sebacate, dibutyl sebacate, dipropylene glycol methyl ether acetate (DPM acetate), propylene carbonate, propylene glycol laurate, propylene glycol caprylatelcaprate, gamma butyrolactone, medium chain fatty acid triglycerides, glycerol and PEG esters of acids and fatty acids, PEG-6 glycerol mono oleate, PEG-6 glycerol linoleate, PEG-8 glycerol linoleate, caprylic acid esters such as caprylocapryl macrogol-8 glycerides, PEG-4 glyceryl caprylatelcaprate, PEG-8 glyceryl caprylatelcaprate, polyglyceryl-3-oleate, polyglyceryl-6-dioleate, polyglyceryl-3-isostearate, polyglyceryl polyoleate, decaglyceryl tetraoleate and glyceryl triacetate, glyceryl monooleate, glyceryl monolinoleate, dimethylformamide, dimethylsulfoxide, tetrahydrofuran, caprolactam, decylmethylsulfoxide, and, 1-dodecylazacycloheptan-2-one. The invention may contain surface active agents with varying hydrophilic lipophilic balance (HLB) values such as polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl esters, polyoxyethylene alkyl ethers, polyoxyethylene glycerol esters, sorbitan fatty acid esters, and sodium lauryl sulphate.
[0089] The antioxidants that may be used in this invention is selected from ascorbic acid, fbmaric acid, malic acid, alpha tocopherol, ascorbic acid palmitate, butylated hydroxyanisole, propyl gallate, sodium ascobate, and sodium metabisulfite or other suitable antioxidants and stabilizers.
[0090] Plasticizers that may be used in this invention include adipate, azelate, enzoate, citrate, stearate, isoebucate, sebacate, triethyl citrate, tri-nbutyl citrate, acetyl tri-n-butyl citrate, citric acid esters, and those described in the Encyclopedia of Polymer Science and Technology, Vol. 10 (1969), published by John Wiley & Sons. The preferred plasticizers are triacetin, acetylated monoglyceride, acetyltributylcitrate, acetyltriethylcitrate, glycerin sorbitol, diethyloxalate, diethylmalate, diethylfbmarate, dibutylsuccinate, diethylmalonate, dioctylphthalate, dibutylsebacate, triethylcitrate, tributylcitrate, glyceroltributyrate, and the like. Depending on the particular plasticizer, amounts of from 0 to about 25%, and preferably about 0.1% to about 20% of the plasticizer can be used. The addition of plasticizer should be approached with caution so as not to compromise the integrity of the gelatin capsule or cause leakage. In certain compositions it is better not to use plasticizers.
[0091] Examples of other additives that may be used as part of the formulations of the invention include, but are not limited to carbohydrates, sugars, sucrose, sorbitol, mannitol, zinc salts, tannic acid salts; salts of acids and bases such as sodium and potassium phosphates, sodium and potassium hydroxide, sodium and potassium carbonates and bicarbonates; acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, citric acid, tartaric acid, and benzoic acid.
[0092] Materials such as the alkali metal chlorides, ammonium chloride, and chlorides of Ba, Mg, Ca, Cu, Fe and Al; alkali or alkaline earth solutions of acetates, nitrates, phosphates, and hydroxides may be used in this invention.
[0093] Hygroscopic or aqueous materials must be used with caution if at all. Limited quantities have been incorporated in certain compositions.
[0094] The composition of the invention containing one or more opioid agonist or narcotic analgesic or abuse-able substances may be made by any method wherein the quantity or ratio and type of clays, controlled release agents, oily, fatty or waxy substance and optionally fillers is sufficient to form a paste, liquid or semi solid matrix, magma of the entire composition. Preferably, the entire quantity of the composition is dissolved, dispersed, emulsified or suspended in the oily, fatty or waxy substances. Typically, the clays, controlled release agent and oily, fatty or waxy substances are combined, such as by blending or mixing under high shear until the clays, controlled release agent is completely dissolved, or homogeneous paste is formed. The components may be added separately one after the other. The narcotic agent is added under high shear to form a homogeneous non Newtonian, thixotropic or pseudoplastic paste or liquid/semi solid matrix. The order of incorporation depends on the outcome to be achieved. A cold process under room temperature conditions is preferred, however solid substances may be heated to their liquid state prior to incorporation. Alternatively, the composition may be processed in a jacketed vessel which allows precise control of the processing temperature. Other pharmaceutically acceptable additives, such as those described above, may be incorporated before, after, or during the addition of controlled release agents or narcortic analgesics.
EXAMPLE 1
[0095] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
20
Corn Oil
50
Carbopol 971
8
Hydroxypropylmethyl cellulose
22
(METHOCEL ™ K100M Premium)
[0096] The samples were prepared:
1) Weigh corn oil in a glass beaker and immerse Silverson high shear mixer fitted with a homogenizing head into the oil. 2) Gradually add carbopol followed by hydroxypropylmethyl cellulose while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules
EXAMPLE 2
[0103] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
20
Corn Oil
49
Carbopol 971
8
Bentonite
1
Hydroxypropylmethyl cellulose
22
(METHOCEL ™ K100M Premium)
[0104] The samples were prepared:
1) Weigh corn oil in a glass beaker and immerse Silverson high shear mixer fitted with a homogenizing head into the oil. 2) Gradually add bentonite, carbopol and hydroxypropylmethyl cellulose while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules
EXAMPLE 3
[0111] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
26
Corn Oil
49
Sucrose acetate isobutyrate
2
Bentonite
1
Hydroxypropylmethyl cellulose
22
(METHOCEL ™ K100M Premium)
[0112] The samples were prepared:
1) Weigh Sucrose acetate isobutyrate and place in a glass beaker. Place beaker on a hot plate and heat until the Sucrose acetate isobutyrate becomes molten. Immerse SiIverson high shear mixer fitted with a homogenizing head into the molten liquid and gradually add the oil under high shear. 2) Gradually add bentonite, and hydroxypropylmethyl cellulose while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules
[0119] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
26
Cotton seed oil
45
Carbopol 934
5
Bees Wax
3
Bentonite
1
Hydroxypropylmethyl cellulose
20
(METHOCEL ™ KI OOM Premium)
[0120] The samples were prepared:
1) Weigh Bees Wax and place in a glass beaker. Place beaker on a hot plate and heat until the Bees Wax becomes molten. Immerse Silverson high shear mixer fitted with a homogenizing head into the molten liquid and gradually add the oil under high shear. 2) Gradually add bentonite, carbopol and hydroxypropylmethyl cellulose while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules
EXAMPLE 5
[0127] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
26
Castor oil
45
Carbopol 934
5.5
Polyethylene Glycol 8000
5
Bentonite
2.5
Polyethylene Oxide WSR-303
16
[0128] The samples were prepared:
1) Weigh polyethylene glycol and place in a glass beaker. Place beaker on a hot plate and heat until the polyethylene glycol becomes molten. Immerse Silverson high shear mixer fitted with a homogenizing head into the molten liquid and gradually add the oil under high shear. 2) Gradually add bentonite, carbopol and polyethylene oxide while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules
[0135] Extended Release Oxycodone (Abuse Resistant and Alcohol Resistant Capsules)
[0000]
Component
Amount (% w/w)
Oxycodone
25
Corn oil
40
Carbopol 934
8
Sodium lauryl sulphate
10
Hydroxypropylmethyl cellulose
18
(METHOCEL ™ K100M Premium)
[0136] The samples were prepared:
1) Weigh the oil in a glass beaker. Immerse Silverson high shear mixer fitted with a homogenizing head into the oil. 2) Gradually add carbopol and hydroxypropylmethyl cellulose while stirring vigorously until a homogeneous blend is observed. 3) Add oxycodone gradually while stirring vigorously until a homogeneous blend is observed. 4) The result is a semi-solid or paste which can be filled into hard gelatin capsules without “stringing”. 5) Take samples from top, middle and bottom to determine potency and homogeneity of the mix. 6) Fill into hard gelatin capsules Example 7
[0143] Combination Extended release Oxycodone+Immediate release Tramadol (Abuse resistant and alcohol resistant capsules) (i) Preparation of immediate release tramadol paste (Preparation 1)
[0000] Component Amount (% w/w) Tramadol 25 Corn oil 40 Starch 1500 8 Crospovidone 5 Hydroxypropylmethyl cellulose 18 (METHOCEL ™ E5 Premium LV)
(ii) Preparation of controlled release Oxycodone paste (Preparation 2) This is made as taught in Example 1.
(iii) Preparation of combination Extended release Oxycodone+Immediate release Tramadol (Abuse resistant and alcohol resistant capsules)
Fill the required amount of preparation 1 into the hard gelatin capsule followed by preparation 2. Seal the capsule.
[0144] In another embodiment a separation layer made of a wax such as carnuba wax or a high molecular weight poloyethylene glycol e.g., PEG 8000 may be filled into the capsule to separate two or preparations in situation incompatibility or cross migration of components is of concern. In this way several combinations of active substances are possible.
EXAMPLE 8
[0145] Film coated Abuse resistant and alcohol resistant capsules This consist of film coating capsules made in Example 1 with a polymethacrylate such as Eudragit L or S to impart a delayed or timed release characteristics or lag phase.
EXAMPLE 9
[0146] Film coated Abuse resistant and alcohol resistant capsules This consist of film coating capsules made in Example 1 with a cellulose ether such as ethylcellulose alone or in combination with water soluble polymers e.g., hydroxypropylmethyl cellulose.
EXAMPLE 9
[0147] Film coated Abuse resistant and alcohol resistant capsules This consist of film coating capsules made in Example 1 with a polymethacrylate such as Eudragit E to provide a protective sealing coat or moisture barrier or improve mechanical properties.
[0148] It should be understood that various modifications and ramifications of this basic invention will become apparent to those skilled in the art upon a reading of this disclosure. These are intended to be included within the scope of this invention. Also, substances can be added to this composition or can be used together in this composition; these also are contemplated to be included within the spirit of this invention. The present composition can be used alone without any supporting structure or can be used if desired with open faced grids, one face open structures, or completely closed structures. It can also be used in foams, sponges, walls, around pipes or can be deposited or sprayed onto any desired structure.
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A liquid or semi-solid matrix or magma or paste which is non-newtonian, thixotropic and pseudoplastic and composed of one or more controlled release agent, and/or one or more clays such as bentonite and/or one or more fillers in a non aqueous vehicle, and optionally materials selected from disintegrants, humectants, surfactants and stabilizers. The composition and physicochemical properties makes it harder or prevents dose dumping of narcotic analgesics in the presence of alcohol and harder to abuse opiod agonists or narcotic analgesics and discourages drug abuse via crushing, milling or grinding the dosage form to powder or heating the dosage form to vapour and snorting or inhalation by the nasal route or dissolving to abuse via the parenteral route.
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FIELD OF THE INVENTION
This invention concerns a method of constructing a multistory building from precast concrete using columns and slabs as its structural elements.
BACKGROUND OF THE INVENTION
The use of precast concrete components for multistory buildings has earned significant position in the building construction industry for the benefits it offers. Benefits include:
Shorter construction time;
Better quality assurance;
Smooth concrete surfaces;
Cleaner construction area; and
Lower cost of production from standardized mass production.
In pre-fabricated precast systems, the joints between the components are the most crucial elements. Joining several precast concrete components in one single joint or at one place has to be done fast and efficiently, and more importantly is the assurance of its construction strength. The joint has to withstand all forces resulting from external load, such as its own weight, live load, and seismic forces. In the conventional construction system, where the columns, slabs, and beams are cast on site, structural problems at the joint between columns and beams or floor do not appear. As the components are cast on site together, they form a monolithic structure.
The use of precast concrete systems as the structure of multistory buildings has been limited by the difficulty in creating a joint system that is practical and economical, and able to overcome all forces resulting from its own weight, especially from seismic forces. Some popular and simple methods such as connecting columns and beams or floors with bolts or welding, have a handicap in their capability to withstand horizontal forces imposed by seismic forces. Those simple methods were designed only for withstanding gravitational force.
The objective of this invention is to produce a seismic resistant and fast method for connecting and joining precast concrete elements, consisting of reinforced concrete columns and beams, which indeed form the floor itself (hereafter called slab).
SUMMARY OF THE INVENTION
The floor element in this system is a panel made from ribs and concrete with thin plates in between, where the ribs function as beams. The sequence of assembling the precast elements is as follows.
Firstly, precast concrete columns are positioned vertically so that the steel anchors at the base floor fit in the steel pipe holes implanted in the lower section of the columns. Each concrete column is able to stand firmly by bonding it to steel anchors mounted on the base floor or at the head of the foundation. Special mortar cement is poured or injected through the other openings of the said pipes that are on the side surface of the column. The mortar cement flows down by gravity and fills up the passage of the pipes. As the mortar cement hardens, the column is sufficiently firm to stand without support. Then precast slabs are placed on top of the columns.
One slab with four corners is supported by four columns. One column is the junction of four slab corners of four slabs. A column of the next story of the building is placed on top of the junction. Hence at one junction meet six ends of precast structural elements consisting of the top of the lower column, the four corners of four slabs, and the base of the next higher column, where they all form a single joint.
There is a structural bond among the reinforcement of the lower column, the structure of the four corners of slabs, and the upper column from the existence of high tensile steel strands rooted in the upper section of the lower column and anchored at the lower section of the upper column, There is also a structural bond among the slab corners by means of tying the steel pipes of the slabs'corners with high tensile steel wire rope through the holes drilled horizontally on the pipes'walls. The pipes and the gaps among the pipes are filled with mortar cement so that the wire rope and the four pipes of the four slabs come in contact and bind together. This system results in a practical and economical method of assembly and a reliable construction in terms of its strength. The following drawings are presented to illustrate the above description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view illustrating the precast concrete elements of the invention;
FIG. 2 is a perspective view illustrating the assembled precast concrete elements;
FIG. 3a is an elevation view in section of a lower column;
FIG. 3b is a cross-section view of a steel strand taken along line 3--3;
FIG. 4 is an elevation view in section of an upper column;
FIG. 5 is an elevation view in section of a slab corner;
FIG. 6a and 6b are elevation views in section of the assembled elements; and
FIG. 7 is a plan view in section of an assembled joint between the elements of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows in perspective the precast concrete elements: the upper section of the lower column (1), the four corners of the four slabs (3), and the lower section of the upper column (2) separately before joining. On the top of the lower column (1), there are a number of steel strands protruding (16), which are embedded in the lower column (1). In the lower section of the upper column (2) are implanted a number of steel pipes (17) vertically positioned at the bottom surface of the column (2) and bent toward the side surface of the column, so the other openings of the pipes are on and flat to the side surface of the column, The number of the steel pipes (17) is equal to the number of the steel strands (16) protruding from the lower column (1). FIG. 1 shows a partial view of four slabs (3) between the lower column (1) and the upper column (2). The corner of each slab (3) is laid on the surface of the steel plate (12) that is mounted on the top surface of the column (1). Steel pipes (20) which are firmly integrated in a vertical position to the corner of the slab (3) will convey the steel strand (16) protruding from the lower column (1) to enter the pipes (17) in the lower section of upper column (2).
FIG. 2 shows in perspective the six structural elements in unity. A gap (25) between adjacent slabs (3) will be filled with special mortar mixed from portland cement, sand, and finely crushed stone. The perimeter of the slab has shear keys (28) which provide binding strength to one another at the meeting line.
FIG. 3a shows the vertical cross-section of a lower column (1). Steel strands (16) which penetrate through holes (32) on the steel plate (12) are made of high quality steel with flexible properties. A single steel strand (16) consists of seven steel wires, each of approximately 4 mm. diameter, as illustrated in FIG. 3b. A steel strand made of seven 4 mm wires is standard in production and commerce and is known as pc strand. The main reinforcements (7) are surrounded by a stirrup reinforcement (8), and the ends of the main reinforcement (7) are connected by welding (24) them to the steel plate (12) along the edge of the holes on the plate surface that is in contact with the lower concrete column (1).
FIG. 4 shows the vertical cross-section of the upper column, (2). The steel pipes (17) function to take the steel strands (16) from the lower column (1), and through the pipe openings (19) which are on and flat to the side surface of the column (2). The special mortar cement (18) is injected to bind the steel strands (16) and the pipes (17) together (see FIG. 6a). The bottom ends of the pipes (19) are welded at the edge of the hole (34) on the steel base plate (11) surface that is in contact with the bottom of the upper column (2). The ends of the main reinforcements (10) are welded to the edge of the hole (33) on the surface of steel base plate (11) that is in contact with the concrete column. Hence, the free outer surface of the steel base plate (11) is flat and smooth. The main reinforcement (10) is surrounded by stirrup reinforcement (9) at a predetermined distance.
FIG. 5 shows the vertical cross-section of a slab corner (3). A steel pipe (20) with a height equal to the thickness of the slab (3) is mounted perpendicularly to the two pairs of steel anchors (4 and 6) that are in perpendicular position to each other, by welding at the pipe holes (23), (25), and (26). A high tensile wire (29) of the prestress precast slab beam will slip through the holes (28) and (30) on the pipe wall (20).
FIGS. 6a and 6b show the vertical cross-section of the upper section of lower column (1), the slab side (3), and the lower section of the upper column, (2), in an integrated position as one single joint. The steel strand (16), protruding from the lower column (1), is inside the steel pipe (20) of the beam (3) and the steel pipe (17) of the upper column (2). The four steel pipes (20) of four slabs (3) have holes (13), (14), and (15) through which slips flexible wire rope (31), (31a), and (31b) to tie the four steel pipes (20) together. Each steel pipe (20) and the gap between the pipes are filled with mortar cement (21) and (27).
FIG. 7 shows the horizontal cross-section of the joint of four slab corners (3). The steel strand (16) protruding from the lower column (1) penetrates the steel pipe (20) of the slab (3), with two steel strands through each pipe (20). The drawing also shows a wire rope (31) tying together four steel pipes (20) through the pre-bored holes (13) on each pipe wall. The passage of the steel pipe (21), the gaps between pipes (27), and also the gaps between slabs (25), are filled with mortar cement. To the holes (23) of each steel pipe (20) are welded the ends of two pairs of anchors (6) in perpendicular position to each other.
As shown in FIG. 2, the precast structure components of the system are columns and slabs. The shape of the slab can be rectangular, but can also be a combination of small beams connected with thin concrete plates. The most important and critical part of construction is that the corners meet at the column ends. The firm integration of the structural elements which in this system consists of the joint of the top of the lower column with the bottom of the upper column, the joint of the top of the lower column and the four slab corners, and the tying of the slab corners together, all in one single joint and the practicality in assembly are the essence of this invention The interconnection of the reinforcement of each structural element meeting at the single joint is able to take and distribute vertical forces, horizontal forces, moment, and shear forces. This has been proven in a series of tests conducted by the Structural Laboratory of Housing Research Center, Department of Public Works of the Republic of Indonesia.
The steel strands (16) rooted at the upper section of the lower column (1) are to extend the reinforcement from the lower column (1) to the upper column (2). The passage of the steel pipe (17) with the steel strand (16) inside, is filled with special mortar cement so that the steel strand (16) adheres to the pipes, thus uniting firmly to the upper column (2). The adherence of the steel strand (16) and the lower column (2) results from the confined nature of the steel pipe (17) and the steel strand (16). For columns of 26×26 cm with four main reinforcement of diameter of 19 mm, to transfer maximum force that can be endured by the columns, that is from the lower column to the upper column or vice versa, eight high tensile steel strands of a diameter of 1/2 inch are used (16). From the technical specification of each main reinforcement (10) and steel strand (16), the tensile strength of two steel strands (16) is 2 to 3 times of the tensile strength of one main steel reinforcement (7) or (10). The high quality steel strand (16) consists of seven wires, each of 4 mm diameter. High tensile steel strands are commonly used for main reinforcement of prestressed concrete, but in this invention, the strand is not tensioned and does not function as prestressed steel. The characteristics of the steel strand suitable for this invention are the high tensile strength and the flexibility, so it is easy to direct the eight strands (16) to slip through the steel pipe holes (17) of upper column (2). The rugged surface of the strand (16) helps to increase the adherence between the mortar (18) and the strand (16). The steel strand of a relatively short length in this invention, is easily acquired as a waste from the high tensile steel strand usage in the prestress pretension concrete industry. FIG. 5 and 7 show the construction detail and the connection with the slab corners (3). Steel rods (4) and (6) that are welded to the steel pipe (20) at a point (23) with the steel rods (4) and (6) of approximately 100 cm in length function as anchors for the steel pipe (20) of the concrete slab (3). Several pairs of straight steel rods (5) are welded at uniform distances connecting the two steel anchors (4) and (6) to serve two functions: as a steel reinforcement to receive shear force, especially around the slab corner or around the steel pipe (20), and as a link for reinforcement (4) and (6) to become one construction frame that works together and as a strengthening reinforcement system in critical spots at corners where the load can come from external forces such as an earthquake, with a changing load direction. On the steel pipe wall (20) and between steel anchors (4) and (6), there are holes (30). The holes (30) enable steel rods (29) to cross steel pipe (20) from the peripheral beams of the slab and to function as prestress pretension reinforcement on the said beams.
FIG. 7 shows four slab corners (3) on column (1). It also shows a connection between the steel pipes (20) of the slabs (3) which are tied together by three high tensile wire ropes (31) that are slipped through pre-bored holes (13), (14), (15) on the pipe wall (20). The three wire ropes (31), (3la), and (31b), are also shown in FIG. 6b. The passage of the steel pipe (21), the gaps between pipes (27) on the lower column (1), and the gaps between the slabs (25) are filled with special mortar. Observing FIGS. 6a and 6b, the flow of forces from one component to another especially those resulting from moment at the peripheral beams of the slab (3) and shear force from earthquake at the joint, can be explained as follows. Positive or negative moment from the peripheral beams of the slab (3) is firstly transferred to the steel pipe (20), then through the wire rope (31a) or (31b), some is conveyed to the next steel pipe (20) and some is taken by the high tensile steel strand (16) inside the pipe (20). The steel strand (16) in the upright position is confined in the pipe (17) with special mortar cement. The wire rope (31) positioned in the middle, functions to take shear force in the center of the joint, with the direction of the shear force being at a 45 degree angle due to the shear force. The uniting characteristic of the structural construction at the bottom of the upper column (2) and also the top of lower column (1) is provided by the firm connection between the main reinforcement of each column (7) and (10) with the steel plate (1 1) and (12), so that the horizontal force or shear force between the column and the top surface of the pipe of the four corners (20) can be transferred from the main reinforcement (10) to the steel strand (16) through the steel plate (11).
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A precast concrete system is provided that consists of columns and slabs joined together in one point. Each corner of the slab is equipped with a steel pipe mounted on a steel plate that is attached at and covers the top surface of the column. Each column is equipped with high tensile steel reinforcement strands protruding at the top end to penetrate the steel pipes of the four corners of four slabs, through the holes in the steel base plate attached at the bottom surface of the next column above it, and through the pipes implanted vertically at the lower section of the next column. The implanted pipes are in line with the holes on the base plate. The four steel pipes of four slabs meeting on one column are tied together with high tensile steel wire rope through three holes drilled horizontally at three places of the pipe length: upper, middle, and lower sections. The pipes of the slab corners and the gaps between pipes and slabs are filled with a special mortar cement that hardens fast. Then a special mortar cement is injected to the implanted pipes through each pipe's opening on the side surface of the column.
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BACKGROUND OF THE INVENTION
a) Field of the Invention
The invention relates to a device for transporting and for handling microtiter plates, wherein by microtiter plates is meant standardized carriers for specimens to be examined and/or processed for development of pharmaceutic agents in medical diagnoses or the like.
b) Description of the Related Art
The prior art in this field is substantially set forth in the following publications:
1. “Accelerating Drug Discovery Process with Automation and Robotics in High Throughput Screening”, Ed.: John P. Delvin, 1997 Marcel Decker Inc., ISBN 0-8247-0067-8; 2. Examples in “Laboratory Automation News”, Ed.: Robin A. Felder, Health Sciences Center Charlottesville, Va. 22908; 3. “Microplate Standardization Report 3”, Journal of Biomolecular Screening, Vol. 1, No. 4, 1996; 4. “Spektrum der Wissenschaft Spezial Nr. 6”, Pharmaforschung 1997, Spektrum der Wissenschaft Verlagsgesellschaft mbH, Heidelberg, ISSN 0943-7096 . . . ; 5. “Industrieroboter [Industrial Robots]”, Kreuzer/Lugtenburg/MeiBner/Trukenbrodt 1994, Springer Verlag ISBN 3-540-54630-8.
The following abbreviations will be used hereinafter:
HTS high throughput screening MTP microtiter plate SPS stored program control.
The analysis of a large number of specimens is a recurring task in the development of pharmaceutic substances as well as in medical diagnoses.
The development of a new pharmaceutic substance is a process extending over a number of years and incurring high costs. In this process, a suitable pharmacogenic substance is sought as target structure (target) (see prior art reference 4). By means of a suitable biochemical determining reaction (assay), reactions between targets and suitable bonding partners can be detected quantitatively.
There currently exist in the pharmaceutics industry libraries of active agents with from 300,000 to 1,000,000 different pure substances. With each new target, bonding partners or ligands must be identified from these substances with a suitable assay. This process is known as high throughput screening (HTS). A screening of this kind results in a small quantity of substances (typically 0.5% to 1% of the total number) showing a positive reaction in the assay. These cardinal structures represent the basis for the continued development of a medication.
In medical diagnoses, similar problems result when infections, diseases, genetic disposition and the like are to be determined through analysis of a number of individual specimens (in this case mostly blood specimens, urine specimens, and so on) based on standardized determining reactions. An example of this would be screening in blood banks of donor blood for infections and routine examinations in risk groups for infections or other symptoms of illness.
Another area of application in the field of biochemistry is combinatorial chemistry. In this case, several hundred different individual substances are generated simultaneously by parallel synthesis and must be processed and characterized subsequently by suitable techniques.
A specimen carrier standard has been developed for parallel processing of large quantities of specimens: microtiter plates (MTP) with standardized dimensions and 96-well, 384-well and 1536-well grids (see prior art reference 3). This arrangement enables parallel processing of many individual specimens. Analysis for such MTPs is carried out by automatic running of assay protocols. A protocol of this kind comprises a fixed quantity of processing steps, including, for example, dissolving and mixing of substances, incubating for a fixed period of time and determining measurement values by means of a suitable analyzing device. For this purpose, there are automated specimen processing devices (see prior art reference 2) for dissolving, pipetting, mixing, incubating, and measuring.
Typical HTS systems are laboratory devices which are linked together by a central handling system. Such a handling system essentially comprises a robot with grippers for MTP which transports the plates between individual stations either in a circular movement (revolving-sliding arm) or straight-line movement.
The running of individual work steps is regulated by software control (scheduler) which optimizes the flow of process steps with respect to any existing boundary conditions (e.g., plate may only be transferred to a free position; fixed time intervals must be maintained between successive process steps, etc.).
The performance or efficiency of such handling systems is limited because in most cases the robot arm is not located in the position in which the next operation is to be carried out. The time required for arriving at that position depends on the last operation carried out and is therefore not always the same.
A robot arm requires three movements to advance two plates by one position. The above-mentioned limitation must be taken into account by the software controlling the total system.
In order to link the process steps in a linear manner, it is necessary to adhere to the boundary condition of maintaining fixed time intervals between two processing steps for all operations.
In rotary cycles (revolving-sliding arm), the number and size of the components taking part in the process are limited, but paths are short. On the other hand, when moving on a straight line, the idle times in which the arm moves to the next position become increasingly longer as the length increases.
The control of a system of this kind is coordinated by the scheduler, that is, a program which calculates the flow of control commands with respect to time in such a way that every MTP undergoes the same treatment (process steps and process duration). There are two types of scheduler:
Static schedulers are those in which the flow of control commands with respect to time is calculated before the start of the process and is not updated.
Dynamic schedulers are those in which the flow of control commands with respect to time is calculated before the start of the process and continuously recalculated when there are deviations.
Dynamic schedulers can respond to changes resulting from slight disturbances or variations in the process, but at the cost of identical treatment of all plates. Both types of schedulers must carry out very complex optimizing resulting from the above-mentioned boundary conditions of the transport systems as currently used in HTS.
OBJECT AND SUMMARY OF THE INVENTION
It is the primary object of the invention to provide a transport system of the type mentioned in the beginning which overcomes the limitations described above.
According to the invention, the linear process flow is divided into partial steps which are carried out in autonomous processing units (modules), each having its own transport system.
All of the processing steps of a process requiring a fixed time relationship with one another, such as strict adherence to an incubation time, are combined in one module of this kind.
Transport between processing stations within a module is carried out synchronously: the sequence of operations depending on the respective process flow is freely definable. Every module has a buffer for incoming and outgoing plates. All modules have a common standardized interface.
Transport between the modules is carried out asynchronously with a separate transport system between the output buffer and input buffer of successive modules. The sequence of plate transport is freely definable. The control of a module is carried out via a local control unit.
The individual module controls are connected with one another via a standardized network (Ethernet, field bus or future developments) with an appropriate protocol (TCP/IP, CAN or future developments).
A master computer takes control over the entire system (client server architecture).
The transport system between the modules can be realized by:
a linear transport system with grippers; a revolving-sliding arm with grippers and corresponding arrangement of modules (see prior art reference 5); a conveyor belt with stoppers and in/out locks for the plates at the modules.
The transport system within the modules can be realized by a conveyor belt with transfer systems to the individual components on the module. The following possibilities are available for transfer:
by means of grippers as “pick and place” operations; by means of stoppers on the belt in combination with input slides and output slides between the transport system and the individual components; rotary table with 2 receptacles for MTPs between which the plates are moved; articulated-arm robot (see prior art reference 5) within whose reach the individual components are located.
The controlling of the module can be realized by:
stored program control (SPS), e.g., Siemens S5; industrial PC with plug-in locations; microcontroller with peripheral modules (PLC=programmable logic controller).
The control of the entire system can be realized, for example, by the following:
stored program control (SPS), e.g., Siemens S5; or industrial PC with plug-in locations.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawiwngs:
FIG. 1 shows communication via Ethernet by TCP/IP;
FIG. 2 shows the principle of synchronous/asynchronous plate transport;
FIG. 3 shows the total system according to the invention; and
FIG. 4 shows the transfer of microplates to/from the transport system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one embodiment example, the control would be carried out by the arrangement of module controls and the master computer in a client server architecture. The control units are PCs which are linked with one another by Ethernet. The operating system used for realizing communications via Ethernet by means of TCP/IP is, e.g., Windows NT.
This is shown in FIG. 1 . Every module M has a local computer PC and all local computers have the same interface and are connected with a master computer LR via module M. The different hardware within module M is controlled via the local computer PC, and the master computer LR has access via the uniform interfaces to the hardware operated in module M and controls the latter via a control unit AE.
The above-mentioned construction has the following advantages: the process steps which are critical with respect to time are comprised in module M which receives and transfers microtiter plates via buffers. Because of the buffers, not all of the process steps need to be synchronized in the control of plate flow but, rather, only those processes occurring within a module M.
Modules M are autonomous functional units that can carry out partial steps of a process. They can be operated alone without the entire system by a suitable control. In sole operation, the transfer of microtiter plates is carried out either via the buffer locations or with additional plate storages (stackers) which can receive and transfer a plurality of microtiter plates.
The modules M are less complex than the entire system. This facilitates maintenance and integration of new hardware as well as the testing of new processes. When module M functions, integration into the entire system based on the standardized interface is ensured.
The entire system is scalable. Modules M can be added or removed. A belt system serving as central transport means can be lengthened. Efficiency can be increased by the parallel connection of modules M.
FIG. 2 shows the principle of synchronous/asynchronous microtiter plate transport.
The drawing shows two modules M 1 , M 2 , each with a plurality of laboratory devices C 1 , C 2 , C 3 , e.g., pipetting devices, readers and incubators required for handling of specimens in microtiter plates.
Modules M 1 , M 2 have contact with a central transport system TS (e.g., a conveyor belt) at the transfer point E 1 for advancing the microtiter plates into one of the modules M 1 or M 2 and at the transfer point E 2 for conveying microtiter plates out of modules M 1 , M 2 , wherein transport system TS takes over the transport between modules M 1 , M 2 , but also between the input storage units for the microtiter plates that are to be read out and end storage units for microtiter plates that have been read out.
Transfer to units E 1 , E 2 can be carried out, for example, via sliding units by raising and lowering the microtiter plates or via grippers.
FIG. 3 shows the entire system according to the invention comprising the central transport system TS and input and output buffers EAP for transferring microtiter plates to/from the transport system TS.
A more detailed view is shown in FIG. 4 . In FIG. 4 , a revolving table DT assumes the function of input and output buffer EAP with its two plate positions. A microtiter plate MTP is lifted from the central transport system TS and conveyed to the revolving table DT via a stopping-sliding device (not shown). The latter revolves and, in the diametrically opposite position of the revolving table DT, the microtiter plat MTP is taken over by other revolving tables DT by means of which the feed to module units M 1 , M 2 , M 3 , M 3 or provided incubators IK, dispensers DP and pipetting robots PR is also carried out.
On the respective remote side of the revolving table DT, a microtiter plate MTP which has already been processed can be loaded simultaneously, and during rotating of the revolving table DT this microtiter plate MTP can then be transported in the direction of the module output or a stacker ZP for stacking microtiter plates MTP.
A sensor, for example, which detects whether or not the respective side of the revolving table DT is unoccupied can ensure that no collisions occur, so that a microtiter plate MTP can be loaded for return transport.
Another possible variant would be a clocked operation, so that the revolving table DT is always inserting one microtiter plate MTP and guiding out another microtiter plate MTP.
The reader RE for optical readout of the microtiter plates MTP shown in FIG. 4 in module M 3 by way of example can also be a component part of module M.
Readout by means of reader RE can be carried out one or more times by transmitted light or incident light, wherein absorption, fluorescence, luminescence, scintillation or other occurring effects can be determined for the individual specimens.
The detection of fluorescence, for instance, is described in prior art reference 1, pages 357 to 356.
Additional intermediate storages ZP can be provided for the microtiter plates MTP in modules M 1 to M 5 .
For example, preparation of specimens can also be carried out via module M 2 and the readout via an optical reader RE can be carried out in module M 3 .
A plate storage PSP communicating with the transport system TS via a transfer system TRS and a revolving table DT is provided, by way of example, in module M 1 . Module 5 can be outfitted with additional devices and connected with the transport system TS via a revolving table DT.
While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention.
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A transport system for transporting and handling microtiter plates, for use in high throughput screening, diagnosis and/or combinatorial chemistry, comprising modules with devices for preparing specimens and/or introducing specimens, and/or for optical readout and/or for plate storage and/or devices for further processing steps or readout steps. The system includes an inter-modular transport system for transporting the microtiter plates between the different devices and at least one central transport system for asynchronous plate transfer between individual modules via input and output buffers.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to measuring systems and methods, and more particularly, to a system and method for integrating dispersed point-clouds of an object.
DESCRIPTION OF RELATED ART
[0002] A point-cloud, often created by probing a surface of an object utilizing a three-dimensional (3-D) measurement machine, is a set of 3D points describing the outlines and/or surface features of the object. Generally, multiple scans, or even hundreds of scans, are required in order to obtain information of all surfaces of the object (multiple-angles data acquisition). In order to obtain a complete 3-D model/space point-cloud, multiple point-clouds from the multiple scans are aligned with each other and merged into an integrated point-cloud of the object.
[0003] At present, methods for aligning the multiple point-clouds requires delicate and complicated equipments, or accurate data acquisition procedures, such as presetting some reference points on the object before scanning, identifying common reference points in 3D point-clouds at different angles, ascertaining locations of the common reference points, computing coordinate transformation relations of the 3D point-clouds based on the locations of the common reference points, and aligning the 3D point-clouds according to the coordinate transformation. A predetermined condition of the method is that the reference points are represented by characteristics of the object, so it's inevitable that the method would have errors.
[0004] What is needed, therefore, is a system and method for aligning multiple dispersed point-clouds of an object with simpler operations and higher precision, so as to restore original space location relations of the multiple dispersed point-clouds, and obtain an integrated point-cloud of the object.
SUMMARY OF THE INVENTION
[0005] A system for integrating dispersed point-clouds of multiple scans of an object in accordance with a preferred embodiment includes a computer, a measurement machine connected to the computer, and a fixture for locating an object to be scanned. The fixture includes three reference balls. The computer includes: a point-cloud reading module for reading a point-cloud of the object and references point-clouds of the three reference balls corresponding to each of the scans; a sphere fitting module for fitting a group of three spheres which forms a scalene triangle, according to the reference point-clouds of each of the scans; a computing module for computing a location of each sphere and a distance between two adjacent spheres in each scalene triangle; a matching module for selecting one scan of the object as a base scan and selecting the scalene triangle corresponding to the base scan as a base triangle, mapping each sphere of other scalene triangles corresponding to other scans with a corresponding base sphere in the base triangle, based on the distance between two adjacent spheres in each scalene triangle; and an aligning module for aligning each sphere in each of other scalene triangles to the corresponding base sphere based on a location of the sphere and a mapping relation with the base sphere, obtaining transformation matrixes of the alignment, and for aligning the point-clouds of the object corresponding to other scans to the point-cloud of the object corresponding to the base scan according to the transformation matrixes, to obtain an integrated point-cloud of the object.
[0006] Another preferred embodiment provides a method for integrating dispersed point-clouds of multiple of an object by utilizing the above system. The method includes the steps of: (a) fixing the object on a rotatable fixture holding three reference balls; (b) rotating the fixture to scan all surfaces of the object, and scanning the three reference balls once when scanning each surface of the object; (c) reading a point-cloud of the object and reference point-clouds of the three reference balls corresponding to each scan towards the object; (d) fitting a group of three spheres which forms a scalene triangle, according to the reference point-clouds of the three reference balls corresponding to each scan towards the object; (e) computing a location of each sphere and a distance between two adjacent spheres in each scalene triangle; (f) selecting one scan of the object as a base scan and the scalene triangle corresponding to the base scan as a base triangle, mapping each sphere in other scalene triangles with a corresponding base sphere in the base triangle, based on a distance between two adjacent spheres in each scalene triangle; (g) aligning each sphere in each of other scalene triangles to the corresponding base sphere based on a location of the sphere and a mapping relation with the base sphere; (h) obtaining transformation matrixes of the alignment; and (i) aligning the point-clouds of the object corresponding to other scans to the point-cloud of the object corresponding to the base scan according to the transformation matrixes, to obtain an integrated point-cloud of the object.
[0007] The invention computes a complete space point-cloud of an object by integrating space point captures of the object. The space point captures of the object are integrated by aligning triangles formed by reference point-clouds of three reference balls in each of the captures.
[0008] Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of the preferred embodiment and preferred method of the present invention with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic diagram illustrating a system for integrating dispersed point-clouds of multiple scans of an object according to a preferred embodiment;
[0010] FIG. 2 is a block diagram illustrating main function modules of a computer in FIG. 1 ;
[0011] FIG. 3 is a flowchart of a preferred method for integrating dispersed point-clouds of multiple scans of an object; and
[0012] FIG. 4 to FIG. 6 show an aligning process of two groups of fitted spheres.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] FIG. 1 is a schematic diagram illustrating a system for integrating dispersed point-clouds of multiple scans of an object according to a preferred embodiment. The system typically includes a fixture 10 , a measurement machine 20 , and a computer 30 .
[0014] The fixture 10 can be rotated 360 degrees, and is configured for receiving an object A to be scanned and exposing all surfaces of the object A to be scanned by the measurement machine 20 . There are three reference balls a, b, and c on the fixture 10 . In this embodiment, the three reference balls, which are of the same size and made of china, form three corners of a scalene triangle. In other embodiments, the three reference balls may be of different sizes and made of other materials that provide smooth and bright surfaces.
[0015] The measurement machine 20 is used for scanning the surfaces of the object A to obtain space point captures. Each space point capture includes a point cloud of the object A and a reference point-cloud of each of the three reference balls corresponding to one scanned surface of the object A.
[0016] The computer 30 is used for reading the point-cloud of the object A and reference point-clouds of the three reference balls corresponding to the scanned surface of the object A, fitting a group of three spheres of the three reference balls a, b and c according to the reference point-clouds of the three reference balls, and aligning the point-clouds of the object A to obtain an integrated point-cloud of the object A by utilizing the group of spheres (detailed description is given in FIG. 2 ).
[0017] FIG. 2 is a block diagram illustrating main function modules of the computer 30 . The computer 30 includes a point-cloud reading module 310 , a sphere fitting module 320 , a deleting module 330 , a computing module 340 , a matching module 350 , an aligning module 360 , and a point-cloud outputting module 370 .
[0018] The point-cloud reading module 310 is programmed for reading the point-clouds of the object A and the reference point-clouds of the three reference balls corresponding to each scanned surface of the object obtained by the measurement machine 20 . For example, the point-cloud reading module 310 reads three reference point-clouds “scan 0 ”, “scan 1 ”, “scan 2 ” of the three reference balls a, b, and c corresponding to a top surface of the object A, and reads three reference point-clouds “scan 3 ”, “scan 4 ”, “scan 5 ” of the three reference balls a, b, and c corresponding to a back side of the object A.
[0019] The sphere fitting module 320 is programmed for fitting a group of three spheres according to the reference point-clouds of the three reference balls corresponding to each scanned surface of the object A. For example, the sphere fitting module 320 fits a first group of three spheres Q 1 , Q 2 , and Q 3 according to the three reference point-clouds “scan 0 ”, “scan 1 ”, “scan 2 ”, and fits a second group of three spheres M 1 , M 2 , and M 3 according to the three reference point-clouds “scan 3 ”, “scan 4 ”, “scan 5 ”, by applying the least square method.
[0020] The deleting module 330 is programmed for deleting messy points surround each fitted sphere. Furthermore, the deleting module 330 is programmed for deleting all the spheres and all the reference point-clouds of the three reference balls a, b and c, after obtaining the integrated point-cloud of the object A.
[0021] The computing module 340 is programmed for computing a location of each of the spheres in the space point captures, and computing a distance between adjacent spheres of the group of spheres, such as
|Q 1 Q 2 |, |Q 2 Q 3 |, |Q 1 Q 3 |, and |M 1 M 2 |, |M 2 M 3 |, |M 1 M 3 |.
[0022] The matching module 350 is programmed for selecting one of the space point captures of the object A as a base space point capture and selecting the group of three spheres corresponding to the base space point capture as base spheres, mapping each sphere in other groups corresponding to other space point captures to a corresponding base sphere according to the distance between adjacent spheres in each group. Suppose that, taking the first group of spheres Q 1 , Q 2 , and Q 3 as base spheres, because the three reference balls a, b, c on the fixture 10 form a scalene triangle, that is to say,
[0000] |ab|≠|bc|≠|ac|,
the spheres in each group also form a scalene triangle, namely,
|Q 1 Q 2 |≠|Q 2 Q 3 |≠|Q 1 Q 3 |, and |M 1 M 2 |≠|M 2 M 3 |≠|M 1 M 3 |.
If |Q 1 Q 2 |=|M 1 M 2 |, |Q 2 Q 3 |=|M 2 M 3 |, and |Q 1 Q 3 |=|M 1 M 3 |,
[0023] the sphere M 1 maps the sphere Q 1 , the sphere M 2 maps the sphere Q 2 , and the sphere M 3 maps the sphere Q 3 .
[0024] The aligning module 360 is programmed for aligning each sphere in the other groups of three spheres to each corresponding base sphere based on a location of the sphere and a matching relation with the corresponding base sphere, and reading transformation matrixes of the alignment. For example, the aligning module 360 aligns the scalene triangle M 1 , M 2 , M 3 to the scalene triangle Q 1 , Q 2 , Q 3 by translating and rotating the scalene triangle M 1 , M 2 , M 3 until the spheres M 1 , M 2 , M 3 superposes the spheres Q 1 , Q 2 , Q 3 respectively, and reads a translating matrix and a rotating matrix. Furthermore, the aligning module 360 is programmed for aligning the point-clouds of the object A of other space point captures to the base point-clouds of the object A of the base space point capture according to the transformation matrixes, such as the translating matrix and the rotating matrix, to obtain the integrated point-cloud of the object A.
[0025] The point-cloud outputting module 370 is programmed for outputting the integrated point-cloud of the object A into a CAD system.
[0026] FIG. 3 is a flowchart of a preferred method for integrating dispersed point-clouds of multiple scans of an object. In step S 100 , an object A is fixed on a fixture 10 . The fixture 10 can be rotated 360 degrees to expose all surfaces of the object A to be scanned by the measurement machine 20 . There are three reference balls a, b and c on the fixture 10 . In this embodiment, the three reference balls, which are of the same size and made of china, form three corners of a scalene triangle. In other embodiments, the three reference balls may be of different sizes and made of other materials that provide smooth and bright surfaces.
[0027] In step S 102 , the fixture 10 is rotated to expose all surfaces of the object A to be scanned by the measurement machine 20 . The measurement machine 20 obtains space point captures of the object A and the three reference balls a, b, and c. Each space point capture includes a point cloud of the object A and a reference point-cloud of each of the three reference balls corresponding to one scanned surface of the object A.
[0028] In step S 104 , the point-cloud reading module 310 reads point-clouds of the object A and reference point-clouds of the three reference balls corresponding to each scanned surface of the object obtained by the measurement machine 20 . For example, the point-cloud reading module 310 reads three reference point-clouds “scan 0 ”, “scan 1 ”, “scan 2 ” of the three reference balls a, b, and c corresponding to a top surface of the object A, and reads three reference point-clouds “scan 3 ”, “scan 4 ”, “scan 5 ” of the three reference balls a, b, and c corresponding to a back side of the object A.
[0029] In step S 106 , the sphere fitting module 320 fits a group of three spheres according to the reference point-clouds of the three reference balls corresponding to each scanned surface of the object A. For example, the sphere fitting module 320 fits a first group of three spheres Q 1 , Q 2 , and Q 3 according to the three reference point-clouds “scan 0 ”, “scan 1 ”, “scan 2 ”, and fits a second group of three spheres M 1 , M 2 , and M 3 according to the three reference point-clouds “scan 3 ”, “scan 4 ”, “scan 5 ”, by applying the least square method.
[0030] In step S 108 , the deleting module 330 deletes messy points surround each of the fitted spheres.
[0031] In step S 110 , the computing module 340 computes a location of each sphere, and computes a distance between each adjacent spheres in the each group such as
|Q 1 Q 2 |,|Q 2 Q 3 |,|Q 1 Q 3 |, and |M 1 M 2 |,|M 2 M 3 |,|M 1 M 3 |.
[0032] In step S 112 , the matching module 350 selects one of the space point captures of the object A as a base space point capture and selects the group of three spheres corresponding to the base space point capture as base spheres, maps each sphere in other groups corresponding to other space point captures to a corresponding base sphere according to the distance between adjacent spheres in each group. Suppose that, taking the first group of spheres Q 1 , Q 2 , and Q 3 as base spheres, because the three reference balls a, b, c on the fixture 10 form a scalene triangle, that is to say,
[0000] |ab|≠|bc|≠|ac|,
the spheres in each group also form a scalene triangle, namely,
|Q 1 Q 2 |≠|Q 2 Q 3 |≠|Q 1 Q 3 |, and |M 1 M 2 |≠|M 2 M 3 |≠|M 1 M 3 |.
If |Q 1 Q 2 |=|M 1 M 2 |, |Q 2 Q 3 |=|M 2 M 3 |, and |Q 1 Q 3 |=|M 1 M 3 |,
[0033] the sphere M 1 maps the sphere Q 1 , the sphere M 2 maps the sphere Q 2 , and the sphere M 3 maps the sphere Q 3 .
[0034] In step S 114 , the aligning module 360 aligns each sphere in the other groups of three spheres to each corresponding base sphere based on a location of the sphere and a matching relation with the corresponding base sphere, and reading transformation matrixes of the alignment. For example, the aligning module 360 aligns the scalene triangle M 1 , M 2 , M 3 to the scalene triangle Q 1 , Q 2 , Q 3 by translating and rotating the scalene triangle M 1 , M 2 , M 3 until the spheres M 1 , M 2 , M 3 superposes the spheres Q 1 , Q 2 , Q 3 respectively, detailed description is as that: (a) translating the first triangle M 1 M 2 M 3 until the sphere (or vertex) M 1 superposes the sphere (or vertex) Q 1 of the second triangle Q 1 Q 2 Q 3 (shown in FIG. 5 ), to obtain a first transformation matrix D 1 ; (b) taking the vertex Q 1 as a rotating origin, a normal vector of the plane Q 1 Q 2 M 2 as a first rotating axis, and a first inner angle between a first side Q 1 Q 2 and a second side Q 1 M 2 as a first rotating angle, to rotate the third side M 1 M 2 until the third side M 1 M 2 superposes the first side Q 1 Q 2 , to obtain a second transformation matrix D 2 ; (c) taking the vertex Q 1 as the rotating origin, the first side Q 1 Q 2 as the second rotating axis, and a second inner angle between the second side Q 1 M 2 and a fourth side Q 1 Q 3 as a second rotating angle, to rotate a fifth side M 1 M 3 until the fifth side M 1 M 3 superposes the fourth side Q 1 Q 3 (shown in FIG. 6 ), to obtain a third transformation matrix D 3 .
[0035] In step S 116 , the aligning module 360 reads transformation matrixes of the alignment, such as the first translating matrix D 1 , the second transformation matrix D 2 and the third transformation matrix D 3 .
[0036] In step S 118 , the aligning module 360 aligns the point-clouds of the object A of other space point captures to the base point-clouds of the object A of the base space point capture according to the transformation matrixes, such as the transformation matrixes D 1 , D 2 , and D 3 , to obtain an integrated point-cloud of the object A.
[0037] In step S 120 , the deleting module 330 deletes all the point-clouds of the three reference balls a, b and c, and all the spheres.
[0038] In step S 122 , the point-cloud outputting module 370 outputs the integrated point-cloud of the object A to a CAD system.
[0039] Although the present invention has been specifically described on the basis of a preferred embodiment and preferred method, the invention is not to be construed as being limited thereto. Various changes or modifications may be made to the embodiment and method without departing from the scope and spirit of the invention.
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A system for integrating dispersed point-clouds of an object is provided. The system includes a fixture for fixing an object, a measurement machine to scan all surfaces of the object and a computer. The fixture, which has three reference balls, is 360-degree rotatable. The computer includes a point-cloud reading module, a sphere fitting module, a computing module, a matching module and an aligning module. The system utilizes three reference objects to integrate dispersed point-clouds of multiple scans of the object, restore original space location relations of the point-clouds, so as to obtain a complete space point-cloud of the object with simple operation and higher precision. A related method is also provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an application member for the application of a product, particularly a cosmetic or dermatological product, to a surface such as the skin, and to an application assembly containing the product and equipped with an application member of this type.
2. Discussion of the Background
The assembly envisaged by the present invention is of the type comprising a reservoir containing the product and provided with an open end over which a stopper acting as a gripping member is removably fastened. The stopper is integral with the application member, generally by means of a wand, so that the application member, in the closed position of the assembly, is permanently immersed in the product.
The reservoir is intended, in particular, to contain a dermatological product, a make-up product or a product for specific treatment of the body and more particularly of the face, such as a liquid foundation, a blusher or an eyeshadow. More specifically, the application member is designed for the application of a product for treating the signs of skin aging, such as wrinkles and small wrinkles and the signs of fatigue, particularly those of the face, neck or décolletage.
A number of products have been proposed in the past with the aim of erasing or blurring the signs of skin aging. More recently, in Patent Applications FR-A-2 758 083 and FR-A-2 759 084, the Applicant has described novel products intended for treating signs of aging and of fatigue, based on particularly effective “tightening agents”. During aging, the skin has an increasingly irregular micro relief and exhibits wrinkles and small wrinkles.
In the case of tightening agents, these are compounds which are capable of tightening the skin and, through this tightening effect, smoothing the skin and immediately reducing or even erasing wrinkles and small wrinkles thereof. These products have a particular texture and have rapid drying properties.
The direct application of this type of product using the fingers is unsuitable. In fact, even with the lightest massaging, finger friction suffices to break up the product's texture.
Thus, the problem posed by the present invention consists in providing an application member capable of:
depositing just the necessary quantity of product;
having a geometry to suit the surface to be treated;
being flexible, supple and soft, given the sensitivity of the skin of the eye contour area and of the fragility of the product's texture;
spreading the product rapidly, particularly in a single stroke, before the product dries.
The areas of the face particularly targeted by the invention are wrinkles in the eye contour area, such as “crow's feet” at the outer corner of the eyes, dark rings and bags under the eyes, wrinkles at the corners of the mouth, etc.
FR-A-2 506 580 discloses a flat, supple applicator, in the form of a spatula, for applying a make-up product. This applicator, intended to be loaded with a very fluid product by capillary effect, cannot be used for the products envisaged by the present invention. Moreover, its shape is not particularly suited to the application of the said products to the areas of the body targeted by the invention.
SUMMARY OF THE INVENTION
Thus, a first object of the present invention is to provide an application member adapted to the treatment of the skin, particularly of the aforesaid areas of the face.
A second object of the invention consists in an application member capable of conferring as gentle an application as possible to the skin whilst still guaranteeing a high level of precision during application.
A further object of the invention consists in an application member capable of selectively treating a single wrinkle or a “bundle” of wrinkles.
A yet further object of the invention consists in an application assembly including a treatment-product reservoir and provided with an application member of this type.
The application assembly according to the invention is intended for carrying in the user's handbag or it may be used for renewing the treatment during the day, particularly whilst travelling.
Thus, the subject of the present invention is an application member, for the application of a product to the skin, including a gripping element and an application element, integral with the said gripping element, the said application element being flexible, and having at least a first substantially planar face, the width of which in a direction perpendicular to an axis of the gripping element decreases in the direction of a free end located opposite the said gripping element, the said first face being delimited by two lateral edges, at least one of which is of concave form. Thus, when the application member is loaded with product, the first face may be used as an application surface. The lateral edge of concave form is adapted particularly to the shape of the lower part of the eyes. To this end, the concave lateral edge advantageously has a radius of curvature of between 16 mm and approximately 30 mm.
In the sense of the present invention, the term “flexible” is used to denote the ability of the application element to curve, in response to a stress, and to resume its initial form by means of elasticity when the stress ceases. The ability of a material of this type to flex may be characterized by its flexural modulus in flexure. Generally, the materials envisaged by the invention have a flexural modulus of flexure which is at least equal to 200 MPa (Young's modulus in flexure). The flexibility may be the result of the nature of the material forming the application element and/or its configuration.
According to a particularly preferred embodiment, one of the lateral edges is of concave shape, the other of the lateral edges being of convex shape. In this case, the two lateral edges may have different radii of curvature. Advantageously, the radius of curvature of the convex lateral edge is greater than the radius of curvature of the concave lateral edge. Alternatively, the two lateral edges may be concave.
Thus, the user, holding the gripping element in the right hand, applies the planar face to the area to be treated, located, for example, below the right eye, the concave edge of the application element matching the edge of the lower eyelid.
In order to be able to carry out the same treatment on the lower part of the left eye, using the same hand or the left hand, the second face of the application element, opposite the first one, is also preferably substantially planar.
Preferably, at least the free end of the application element is of rounded form. In this case, the curvature of this free end has a radius of between approximately 1 mm and approximately 3 mm.
As regards the application element, it may be produced from natural or synthetic rubber, particularly from polyurethane or from thermoplastic elastomer. It may consist of a foam with closed or semi-open cells or include a flocked covering. Advantageously, the application element has a mean thickness of between approximately 1 mm and approximately 3 mm.
By virtue of the choice of these materials and of the thickness of the application element, the latter has a flexibility such that, as it brushes against the skin, a portion of the corresponding face of the application element is applied tangentially to the surface of the skin, without giving rise to notable deformation of the latter.
According to a preferred embodiment, the application element has a length of approximately 20 mm measured along the axis of the gripping element. Advantageously, this gripping element is connected to the application element by means of a wand of small diameter, which makes it easier to handle the application member.
Advantageously, the application element has a mean width of approximately 7 mm measured in a direction perpendicular to the axis of the gripping element. This width is adapted to cover the essential part of the wrinkles in the targeted wrinkled areas.
In practice, the application member is associated with a reservoir intended to contain a product, for example an anti-wrinkle treatment product, thus forming an application assembly. This reservoir includes an open end defining an opening over which a closure element is removably fastened. Advantageously, this closure element consists of a generally cylindrical stopper, which forms the gripping element integral with the application element described above.
In order to be able to guarantee correct metering of the product and its homogeneous distribution on the application element, a drying member is advantageously provided, located in the vicinity of the open end of the reservoir. This drying member is capable of metering the quantity of product taken up by the application member. Preferably, this drying member consists of an elastomeric material and has at least one slit extending over a substantial part of the section of the drying member. In the storage position of the assembly, the wand carrying the application element passes through the slit.
According to one embodiment, the drying member may comprise a plurality of slits intersecting in the vicinity of the center of the drying member. According to an advantageous aspect of the invention, each end of the slit or slits may be extended by at least one portion oriented in a different direction from the axis of the corresponding slit. In particular, each end ends in a “V” portion centred on the axis of the corresponding slit and the apex of which is adjacent to the corresponding slit. The free ends of the “V” portion may be oriented away from the corresponding slit or, alternatively, towards the corresponding slit. The angle of opening of the “V” slit may be between 30° and 180° and preferably between 30° and 90°.
Alternatively, each end of a slit ends in an opening, the form of which is advantageously circular. Typically, the diameter of this opening is of the order of 1 mm.
The application member which has just been described can be used, in particular, for the application of a product capable of treating wrinkles and small wrinkles, particularly of the eye contour area and of the corners of the mouth, based on a product containing tightening agents of the type mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects of the invention will become apparent in a detailed manner upon reading the following description of an embodiment of the invention which is given by way of purely illustrative and non-limiting example, shown in the appended drawing.
In this drawing:
FIG. 1 shows a view in axial section of an application assembly according to the invention;
FIG. 2 is an enlarged view of the application member of the assembly of FIG. 1;
FIG. 3 a shows an enlarged top view of a drying member according to a first embodiment;
FIG. 3 b shows a view in axial section of the drying member of FIG. 3 a:
FIG. 4 a shows an enlarged top view of a drying member according to a second embodiment;
FIG. 4 b shows a view in axial section of the drying member of FIG. 4 a:
FIG. 5 shows an enlarged top view of a drying member according to a third embodiment;
FIG. 6 illustrates the application of an anti-wrinkle product to the face, using the application member according to the invention;
FIG. 7 illustrates an enlarged view of a second embodiment of the application member of the assembly of the present invention;
FIG. 8 shows as enlarged top view of a drying member according to a fourth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 and 2, an application assembly 1 can be seen, of axis X, for the application of a product P and equipped with an application member 2 . The application member 2 includes a stopper 4 serving as a gripping element and a closure element, and capable of being fastened, by screwing, onto the neck 21 of a bottle 20 of cylindrical form. The bottle 20 forms a reservoir containing the product P of liquid to pasty or gel consistency. The neck 22 includes an outer screw thread 23 capable of interacting with a complementary screw thread 5 on the lower portion inside the stopper 4 , thereby allowing the stopper 4 to act as a closure element. The stopper 4 acts as a gripping element since the stopper has a general elongate cylindrical form, allowing easy gripping. The stopper 4 is provided with a central wand 6 emerging from the lower side of the stopper 4 . This wand 6 has a lower end 6 a to which an application element 8 is fastened, for example by adhesive bonding, interlocking or heat welding.
The application element has two ends, a first end 8 a adjacent to the wand 6 and a second free end 8 b . The two ends have a rounded form, the radius of curvature R 4 of the first end 8 a being greater than the radius of curvature R 3 of the second free end 8 b . According to the example in question, R 4 is approximately 4 mm R 3 being approximately 1 mm. The distance between the two ends 8 a and 8 b , measured along the axis X, is approximately 20 mm.
The two ends 8 a , 8 b are separated from each other by two edges 9 a , 9 b . The edge 9 a is concave and has a radius of curvature R 1 . The edge 9 b is convex and has a radius of curvature R 2 . In the embodiment illustrated, R 1 is greater than R 2 . This makes it possible to obtain good convergence of the lateral edges 9 a , 9 b in the direction of the free end 8 b.
R 1 is adapted to the curvature of the lower eyelid. Typically, R 1 is of the order of 20 mm. R 2 is of the order of 16 mm. The mean distance l separating the two lateral edges 9 a and 9 b , measured in a direction perpendicular to the axis X of the wand, is of the order of 7 mm. In its widest portion, the application element 8 has a width of approximately 8 mm.
The application element has two principal faces 10 which are substantially planar and parallel to each other. The distance between these two surfaces defines the thickness of the application element, this thickness being chosen as a function of the flexibility of the material used for producing the application element 8 . Generally, this thickness is between approximately 1 mm and approximately 3 mm.
FIG. 7 depicts a second embodiment of the application element 8 where the later edge 9 a 1 , and the lateral edge 9 b 1 , are both concave.
The material forming the application element 8 is a material which is elastically deformable, particularly in flexure. It may be chosen from natural or synthetic rubbers and preferably from thermoplastic elastomers. Advantageously, a closed-cell or semi-open-cell elastomer foam is chosen. Optionally, the surface of the application element 8 may be flocked, which makes it possible to increase its capacity to retain product P and thus to increase its autonomy.
The neck 21 of the bottle has a free circular edge 22 defining an opening 24 . A drying member 26 (FIG. 1) formed from an elastically deformable material is fitted in this opening. The drying member has the form of a thin membrane and has a circular peripheral edge 27 resting on the free edge 22 of the neck of the bottle. The central portion 25 of the drying member is shaped as a dish, the bottom of which faces the reservoir 20 . The drying member has one or more slits 28 (FIGS. 3 a , 3 b ), 28 a- 28 d (FIGS. 4 a , 4 b ). When several slits are present, these intersect at a central point C. In a storage position, the wand 6 passes through this slit or these slits.
As may be seen in FIGS. 3 a and 3 b , a single rectilinear slit 28 is made, the terminal portions 29 of which are extended by means of two branches 30 a , 30 b arranged as a “V” and together defining an angle α of approximately 60°.
FIGS. 4 a and 4 b show a further embodiment of a drying member 26 b , according to which the bottom 25 is provided with four slits 28 a - 28 d intersecting at the center C of the membrane. In a similar manner to the embodiment of the slit of FIG. 3 a , the slits 28 a - 28 d shown in FIGS. 4 a and 4 b have a terminal part 29 extended by two branches 30 a , 30 b in the form of a “V”.
The structure of the slits with their “V” terminal part allows supple opening of the edges of the slit 28 , 28 a - 28 d during removal of the application element 8 from the bottle 20 or during its insertion into it. Moreover, the edges of the slit or slits ensure correct spreading of the product P on the application element during removal of the application member, removing any excess of product P and ensuring homogeneous distribution over the application surface 10 .
FIG. 5 shows a third embodiment of a drying member 26 c , according to which the bottom 25 is provided with four slits 28 a - 28 d intersecting at the center C of the membrane in a similar manner to the embodiment of the slits of FIG. 4 a . Each slit 28 a - 28 d shown in FIG. 5 has two terminal parts formed by an opening 29 a . Typically, each opening 29 a is circular and has a diameter of approximately 1 mm.
FIG. 6 illustrates the application of an anti-wrinkle product using the application member 2 according to the invention to the wrinkled areas of the contour area of the eyes Y and of the corners of the mouth Z. By lightly applying just the free end 8 b of the application element, it is possible to spread the product P over a single wrinkle, ensuring homogeneous and precise smoothing of the product over the wrinkle in question without deposition of excess product at the edge of the wrinkle. The product is applied gently, without detrimental effect on the product's texture. In this application mode, the user holds the application member so that an angle of approximately 30° to 60° is formed between the wand 6 and the surface of the skin.
In order to treat a more extensive wrinkled area, for example the wrinkled area below the eye, the application element 8 is applied with a greater bearing force than in the previous case. This gives rise to flexing of the application element so that a larger and particularly wider surface area of the application element comes into contact with the skin. In this case, the surface 10 of the application element comes into contact with the skin tangentially. By following the area to be treated with the application element, product is spread just in the depths of the wrinkles where, through the action of the tightening agent present in the product, blurring and even erasing of the wrinkles is produced after drying.
The form of the application element is particularly adapted to the treatment of rings under the eyes. The product may be spread in a single operation. Thus, a first face of the application element is used to apply the product to the rings under the right eye, using the right hand, whilst the other face is applied to the rings under the left eye, using the left hand.
FIG. 8 depicts a fourth embodiment of a drying member 26 d having at least one slit 28 with terminal portions 29 of which are extended by means of two branches 30 a 1 , 30 b 1 arranged as a “V”. The branches 30 a 1 , 30 b 1 are oriented such that the free ends thereof are oriented in a direction towards the slit 28 .
In the above detailed description, reference has been made to particular embodiments of the invention. Obviously, variations may be made to it without departing from the spirit of the invention as claimed hereinbelow.
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Application member for the application of a product to the skin, including a gripping element and an application element, integral with the gripping element, the application element being flexible, and having at least a first substantially planar face, the width of which in a direction perpendicular to an axis of the gripping element decreases in the direction of a free end located opposite the gripping element, the first face being delimited by two lateral edges, at least one of which is of concave form. Further included herein is an application assembly equipped with such an application member and a method to the use of this application member for the treatment of wrinkles.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to generally to a rotator, which is connected with and driven by an endless cord member, for use in a window blind for driving a roller around which a blind shade is wound, and more particularly to such a cord-driven rotator, which has a cord member clamping function that prevents the cord member from slipping relative to the rotator.
[0003] 2. Description of the Related Art
[0004] A conventional cord-driven rotator for use in a lifting window blind or the like is known comprising a base, which has a shaft, a friction wheel, which is pivoted to the shaft and has a V-shaped groove extended around the periphery, and an axle sleeve sleeved onto the shaft and connected between the friction wheel and the roller for synchronous rotation with the friction wheel on the shaft for driving the roller of the lifting window blind. The endless lift cord of the lifting window blind is hung in the V-shaped groove of the friction wheel and extended around the periphery of the upper half of the friction wheel. When pulling the lift cord, the friction wheel is driven by the lift cord to rotate the axle sleeve on the shaft, thereby causing the roller of the lifting window blind to rotate and to further lift or lower the blind shade that is connected to the roller. The V-shaped groove receives the lift cord, preventing slipping of the lift cord. In an alternative design of the conventional cord-driven rotator, the friction wheel is made having recessed round holes in two opposite sides thereof adjacent to the V-shaped groove for accommodating the beads of a lift cord formed of a chain of beads. However, because the pitch between each two adjacent recessed round holes is fixed, the friction wheel fits only one specific chain of beads. Therefore, different friction wheels shall be used to fit different sizes of chains of beads.
[0005] Further, after a long time of use of the cord-driven rotator, the V-shaped groove or the recessed round holes may become wear, thereby not enabling to hold the lift cord in place.
SUMMARY OF THE INVENTION
[0006] It is one objective of the present invention to provide a cord-driven rotator, which has a cord member clamping function that prevents the cord member from slipping relative to the rotator.
[0007] It is another objective of the present invention to provide a cord-driven rotator, which fits any of a variety of cord members of different thickness.
[0008] To achieve these objectives of the present invention, the cord-driven rotator, which is driven by an endless cord member to rotate and is used in a window blind for driving a roller of the window blind, comprises a base having a shaft, a first clamping plate and a second clamping plate rotatably serially mounted on the shaft of the base for clamping the cord member therebetween, and an elastic biasing device provided between the base and one of the first and second clamping plates for urging the first and second clamping plates against each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a cord-driven rotator according to a first preferred embodiment of the present invention.
[0010] FIG. 2 is an exploded view of the cord-driven rotator according to the first preferred embodiment of the present invention.
[0011] FIG. 3 is a front view of the cord-driven rotator according to the first preferred embodiment of the present invention.
[0012] FIG. 4 is a sectional view taken along line 4 - 4 of FIG. 3 .
[0013] FIG. 5 is a perspective view of a cord-driven rotator according to a second preferred embodiment of the present invention.
[0014] FIG. 6 is an exploded view of the cord-driven rotator according to the second preferred embodiment of the present invention.
[0015] FIG. 7 is a sectional view taken along line 7 - 7 of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIGS. 1-4 , a cord-driven rotator 100 according to the first preferred embodiment of the present invention is shown comprised of a base 10 , a first clamping plate 20 , a second clamping plate 30 , two positioning members 40 , a hub 50 , and an elastic biasing device 60 .
[0017] The base 10 comprises a shaft 11 , which has a screw hole 12 axially extended in the distal end.
[0018] The first clamping plate 20 is shaped like a circular member having a stop face 21 , a clamping face 22 opposite to the top face 21 , a center axle hole 23 cut through the stop face 21 and the clamping face 22 at the center and coupled to the shaft 11 of the base 10 to let the stop face 21 be set in close contact with the inside wall of the base 10 , a coupling groove 221 formed in the clamping face 22 , and a plurality of fins 24 equiangularly spaced around the periphery. The fins 24 each have a radially extended groove 241 corresponding to the clamping face 22 , and two sloping edges 242 radially extended along two sides of the groove 241 . The height of the sloping edges 242 gradually reduces in direction from the inner side toward the outer side.
[0019] The second clamping plate 30 is shaped like a circular member having a stop face 31 , a clamping face 32 opposite to the stop face 31 , a center axle hole 33 cut through the stop face 31 and the clamping face 32 at the center and coupled to the shaft 11 of the base 10 to let the clamping face 32 face be set in contact with the clamping face 22 of the first clamping plate 20 , an axle sleeve 34 perpendicularly extended from the stop face 31 around the border of the center axle hole 33 and sleeved onto the shaft 11 of the base 10 , the axle sleeve 34 having a slot 341 axially extended to the front and bottom ends thereof, a coupling block 321 perpendicularly extended from the clamping face 32 and coupled to the coupling groove 221 of the first clamping plate 20 to let the second clamping plate 30 be synchronous rotatable with the first clamping plate 20 on the shaft 11 of the base 10 , and a plurality of fins 35 equiangularly spaced around the periphery. The fins 35 each have a radially extended groove 351 corresponding to the clamping face 32 , and two sloping edges 352 radially extended along two sides of the groove 351 . The height of the sloping edges 352 gradually reduces in direction from the inner side toward the outer side. On design, the first clamping plate 20 and the second clamping plate 30 can be arranged to have the grooves 241 of the fins 24 of the first clamping plate 20 correspond to the grooves 351 of the fins 35 of the second clamping plate 30 . Alternatively, the first clamping plate 20 and the second clamping plate 30 can be so designed to have the grooves 241 of the fins 24 of the first clamping plate 20 and the grooves 351 of the fins 35 of the second clamping plate 30 be arranged in a staggered manner.
[0020] The two positioning members 40 are two tensile springs mounted inside the axle sleeve 34 and adapted to stop the first clamping plate 20 and the second clamping plate 30 from rotation and to further stop the blind shade or slats of the window blind in position after release of an external driving force from the clamping plates 20 , 30 . Since the structural relationship of the positioning member 40 are of known art, no more detailed description concerning the positioning members is recited.
[0021] The hub 50 is a hollow member having a center through hole 521 , which diameter is greater than the outer diameter of the axle sleeve 34 of the second clamping plate 30 , a circular partition plate 51 radially extended around one end thereof, an inside annular flange 52 suspended in the center through hole 521 , an inside rib 54 axially extended from the inside annular flange 52 toward the circular partition plate 51 , and a plurality of radial flanges 53 equiangularly spaced around the periphery for engaging into the roller of a window blind (not shown). The hub 50 is sleeved onto the axle sleeve 34 of the second clamping plate 30 to engage the inside rib 54 into the slot 341 of the axle sleeve 34 of the second clamping plate 30 and to stop the circular partition plate 51 against the stop face 31 of the second clamping plate 30 . By means of the engagement between the inside rib 54 of the hub 50 and the slot 341 of the axle sleeve 34 , the hub 50 can be synchronously rotated with the second clamping plate 30 on the shaft 11 of the base 10 .
[0022] The elastic biasing device 60 is comprised of a spring member 61 , a washer 62 , and a screw 63 . The spring member 61 has one side stopped at the inside annular flange 52 of the hub 50 . The washer 62 is stopped at the other side of the spring member 61 , having a center through hole 621 . The screw 63 is inserted through the center through hole 621 of the washer 62 and the spring member 61 and then threaded into the screw hole 12 of the shaft 11 of the base 10 to secure the washer 62 and the spring member 61 to the shaft 11 , thereby causing the spring member 61 to urge the hub 60 on the second clamping plate 30 and to further force the second clamping plate 30 against the first clamping plate 20 . Therefore, a clamping force is produced between the clamping face 22 of the first clamping plate 20 and the clamping face 32 of the second clamping plate 30 to retain the lift cord. Therefore, the invention effectively prevents slipping of the lift cord (insufficient friction force between the lift cord and the cord-driven rotator causes the lift cord to slip). When used with a lift chain of beads, the beads of the lift chain of beads be positioned in the between the matched grooves 241 , 351 or in the grooves 241 , 351 that are arranged in a staggered manner, preventing slipping of the lift chain of beads. In addition to the aforesaid cord member clamping effect, the pitch between the clamping face 22 of the first clamping plate 20 and the clamping face 32 of the second clamping plate 30 can be elastically adjusted to fit different thickness of lift cords or lift chains of beads.
[0023] FIGS. 5-7 show a cord-driven rotator 200 constructed according to the second preferred embodiment of the present invention. The cord-driven rotator 200 is comprised of a base 10 , a first clamping plate 20 , a second clamping plate 30 , two positioning members 40 , and an elastic biasing device 60 .
[0024] The base 10 comprises a shaft 11 , which has a screw hole 12 axially extended in the distal end.
[0025] The first clamping plate 20 is shaped like a circular member having a stop face 21 , a clamping face 22 opposite to the top face 21 , a center axle hole 23 cut through the stop face 21 and the clamping face 22 at the center and coupled to the shaft 11 of the base 10 to let the stop face 21 be set in close contact with the inside wall of the base 10 , a coupling groove 221 formed in the clamping face 22 , and a plurality of fins 24 equiangularly spaced around the periphery. The fins 24 each have a radially extended groove 241 corresponding to the clamping face 22 , and two sloping edges 242 radially extended along two sides of the groove 241 . The height of the sloping edges 242 gradually reduces in direction from the inner side toward the outer side.
[0026] The second clamping plate 30 is shaped like a circular member having a stop face 31 , a clamping face 32 opposite to the stop face 31 , a center axle hole 33 cut through the stop face 31 and the clamping face 32 at the center and coupled to the shaft 11 of the base 10 to let the clamping face 32 face be set in contact with the clamping face 22 of the first clamping plate 20 , a coupling block 321 perpendicularly extended from the clamping face 32 and coupled to the coupling groove 221 of the first clamping plate 20 to let the second clamping plate 30 be synchronous rotatable with the first clamping plate 20 on the shaft 11 of the base 10 , an axle sleeve 34 perpendicularly extended from the stop face 31 around the border of the center axle hole 33 and sleeved onto the shaft 11 of the base 10 , and a plurality of fins 35 equiangularly spaced around the periphery. The fins 35 each have a radially extended groove 351 corresponding to the clamping face 32 , and two sloping edges 352 radially extended along two sides of the groove 351 . The height of the sloping edges 352 gradually reduces in direction from the inner side toward the outer side. The axle sleeve 34 has radial flanges 36 equiangularly spaced around the periphery for engaging into the roller of a window blind (not shown).
[0027] The two positioning members 40 are two tensile springs mounted inside the axle sleeve 34 and adapted to stop the first clamping plate 20 and the second clamping plate 30 from rotation and to further stop the blind shade or slats of the window blind in position after release of an external driving force from the clamping plates 20 , 30 .
[0028] The elastic biasing device 60 is comprised of a spring member 61 , a washer 62 , and a screw 63 . The spring member 61 is sleeved onto the shaft 11 of the base 10 , having one side stopped at the inside wall of the base 10 and the other side stopped at the stop face 21 of the first clamping plate 20 . The washer 62 is stopped at the remote end of the axle sleeve 34 of the second clamping plate 30 , having a center through hole 621 . The screw 63 is inserted through the center through hole 621 of the washer 62 and threaded into the screw hole 12 of the shaft 11 of the base 10 to secure the washer 62 to the shaft 11 . Therefore, the spring member 61 imparts a resilient contacting force to the first clamping plate 20 against the second clamping plate 30 , and a clamping force is produced between the clamping face 22 of the first clamping plate 20 and the clamping face 32 of the second clamping plate 30 to retain the lift cord that is positioned in between the clamping face 22 of the first clamping plate 20 and the clamping face 32 of the second clamping plate 30 . Therefore, the invention effectively prevents slipping of the lift cord. This embodiment can also be used with a lift chain of beads. When used with a lift chain of beads, the beads of the lift chain of beads can be positioned in the between the matched grooves 241 , 351 or in the grooves 241 , 351 that are arranged in a staggered manner, preventing slipping of the lift chain of beads. In addition to the aforesaid cord member clamping effect, the pitch between the clamping face 22 of the first clamping plate 20 and the clamping face 32 of the second clamping plate 30 can be elastically adjusted to fit different thickness of lift cords or lift chains of beads.
[0029] In the aforesaid two embodiments, an elastic biasing device is used to urge two separated clamping plates toward each other. In the aforesaid first embodiment, the elastic biasing device indirectly forces the second clamping plate against the first clamping plate. In the aforesaid second embodiment, the elastic biasing device directly forces the first clamping plate against the second clamping plate.
[0030] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A rotator, which is driven by an endless cord member to rotate, is used in a window blind for driving a roller of the window blind. The rotator includes a base having a shaft, a first clamping plate and a second clamping plate rotatably serially mounted on the shaft of the base for clamping the cord member therebetween, and an elastic biasing device provided between the base and one of the first and second clamping plates for urging the first and second clamping plates against each other.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims an invention which was disclosed in Provisional Patent Application No. 60/596,631, filed Oct. 07, 2005, entitled “Rotational Obstruction and Beacon Signaling Based on High Brightness LED”. The benefit under 35 USC §119(e) of the above mentioned United States Provisional Applications is hereby claimed, and the aforementioned application is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a signaling apparatus, and more specifically to a rotational obstruction and beacon signaling apparatus based on high intensity light emitting diodes (LEDs).
BACKGROUND
[0003] Light emitting diodes (LEDs) are considered as an ideal replacement for incandescent lamps for warning and guidance signaling applications owing to their high wall-plug efficiency and long lifetime. The LED based warning and guidance signaling apparatus disclosed in prior arts employ traditional T-pack LED units with luminous intensity less than a few tens of candelas. Thus they either are limited in visibility range or require a large number (several hundreds or even thousands) of LEDs to produce the desired luminous intensity. In addition, some mechanical rotating elements are generally used to produce a rotational emission effect, which elements lack in long-term reliability. Those previous disclosures include U.S. Pat. No. 5,608,290 issued to Hutchisson et al., U.S. Pat. No. 5,313,188 issued to Choi et al., and U.S. Pat. No. 6,753,762 issued to Jorba Gonzalez, and U.S. patent application Nos. 2002/0114161 disclosed by Barnett, and 2002/0145533 disclosed by Bushell et al.
[0004] Recent development in LED technology makes it possible to deliver high lumen power in one LED unit. Such LEDs have been used for maritime signaling applications as disclosed by Trenchard et al. in U.S. patent application No. 2004/0095777. These LED units have large emission area and beam divergence angle. Thus they can not be treated as point light sources. This makes it extremely difficult for LED beam profile control. In the Trenchard patent application, the signaling apparatus comprise twelve high flux LED units and the light beam produced by the entire LED array is controlled by a specially designed Fresnel lens. This lens is both complicated in structure and difficult to manufacture. In addition, such a lens design is not suitable to produce a rotational signaling effect since the divergence angle of the LED units can not be individually controlled.
[0005] Therefore, there is a need for an improved LED warning and guidance signaling apparatus with high luminous intensity and mechanical reliability, in which the apparatus is modular designed for efficient production, configuration, and installation, as well as for precise beam property control.
SUMMARY OF THE INVENTION
[0006] According to one aspect of the present invention, the luminous intensity of the LED signaling apparatus is enhanced by adopting chip-on-board (COB) packaged high intensity LEDs, in which the LED chips are surface mounted on a thermal conductive substrate for improved heat dissipation. The COB approach provides superior thermal control over conventional T-pack devices as the LED chips are directly attached on the substrate with their whole surfaces as the heat dissipation channel. The improved heat-sinking keeps the temperature of the LED PN junction as low as possible, which makes the LED capable of operating at much higher currents or output levels. It also leads to long lifetime as well as wavelength and intensity stability.
[0007] According to another aspect of the present invention, the light beam produced by each LED unit in the signaling apparatus is controlled individually by an optical beam transformer, which precisely defines its intensity distribution, divergence angle, and other relevant properties. The spatial distribution and angular orientation of the LED units and the corresponding optical beam transformers are precisely controlled so that the LED beams mix in a pre-determined manner to produce an emission pattern with desired intensity distribution. Such a discrete LED beam control method eliminates the need for complex lens design. It also provides the flexibility to produce relatively complex emission patterns.
[0008] According to yet another aspect of the present invention, the LED units in the signaling apparatus can operate in a time sequenced flashing mode, where the on-off status, intensity, and wavelength of the LED units are modulated in time domain. The flash sequence of the LED units is controlled by an electronic timing circuit to simulate a rotational or other motional emission effect. The flashing frequency, the intensity and wavelength variation pattern of the LED units can be programmed to achieve different motional signaling effects. The signaling apparatus comprises no mechanical moving parts, which enhances it long-term reliability.
BRIEF DESCRIPTION OF THE FIGURES
[0009] The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
[0010] FIG. 1 illustrates the optical and mechanical structure of one exemplary LED obstruction and beacon signaling apparatus.
[0011] FIG. 2 illustrates one exemplary rotational flash pattern produced by the LED obstruction and beacon signaling apparatus shown in FIG. 1 . LEDs in different mechanical stacks are represented by different shades in the figure.
[0012] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION
[0013] Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to an LED based rotational obstruction and beacon signaling apparatus. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
[0014] In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0015] One preferred embodiment of the present invention is illustrated in FIG. 1 . The signaling apparatus comprises twelve high intensity COB LED units 10 mounted in three vertically adjacent stacks. Each stack comprises four LED units separated by 90 degrees (90°) angularly in the horizontal plane. A 30° angular offset is applied between adjacent LED stacks. Thus the twelve LED units can cover a 360° emission angle. Each LED unit 10 comprises one or more LED chips 11 surface mounted on a thermal conductive substrate 12 , and a secondary optical system 13 , preferably a non-imaging optical lens, to collect and collimate the light emitted from the LED chips 11 . The collimated LED beam has a divergence angle of <10° in both the horizontal and vertical direction. The LED unit 10 further comprise a cylindrical lens array or a high-transmission holographic diffuser 14 as described by Lieberman et al. in U.S. Pat. No. 6,446,467 to homogenize and anisotropically expand the LED beam to a divergence angle of 30°×10° in the horizontal and vertical direction, respectively. The optical beam from the twelve LED units 10 thus cover a full 360° emission angle in the horizontal plane, and a small emission angle in the vertical plane. The COB LED unit in combination with the multi-stack structure makes it possible to produce a greatly improved luminous intensity. The LED beam in the present embodiment exhibits a luminous intensity of several hundred or even several thousand candelas, which enhances its visibility by an order of magnitude over the prior arts. The luminous intensity can be further increased by employing more LED units so that each LED unit operates at a smaller horizontal divergence angle. The LED units 10 may have different emission wavelengths (colors), such as red, blue, yellow or even in the infrared wavelength range for special night vision based warning and guidance signaling applications. The LED units 10 are mounted on a cylindrical shaped metal heat sink 15 for improved heat dissipation. The whole LED signaling module is enclosed in a transparent waterproof housing 16 .
[0016] The signaling apparatus is controlled by an electronic timing circuit 17 , which can be AC, DC or battery powered. The timing circuit 17 is enclosed in an electronic compartment 18 underneath the housing 16 . A base element 19 below the electronic compartment 18 is used to support the whole signaling apparatus. The timing circuit 17 controls the on-off status and intensity of individual LED units, thus generating a flash pattern. A typical flash pattern of the LED signaling apparatus is illustrated in FIG. 2 , where the LED units 10 are switched on and off in a sequential manner so that a rotational emission effect is realized. LED units in different mechanical stacks are represented by different shades in the figure. Other emission patterns can be easily realized by programming the timing circuit 17 to control the LED flash frequency, duty cycle, average luminous intensity or even intensity variation profile with time. The modular design of the LED signaling apparatus make it possible to realize complex rotational signaling effects since the divergence angle and intensity distribution of each LED unit are precisely defined. The LED signaling apparatus disclosed in the present invention comprises no mechanical moving parts, which enhances its long-term reliability.
[0017] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. For example, the signaling apparatus can adopt other mechanical layouts. The holographic diffuser may be replaced by a micro-lens array. Recitations of the numerical values are illustrative rather than limiting. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
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A rotational obstruction and beacon signaling apparatus is disclosed, in which chip-on-board (COB) packaged light emitting diodes (LEDs) are employed to provide a flashed emission pattern with high luminous intensity. The flash sequence of individual LEDs is controlled by an electronic timing circuit to simulate a rotational or other motional signaling effect.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field of the Invention
[0002] The invention relates to resource reservation in a packed switched telecommunications network. In particular, and not by way of limitation, the present invention is directed to a system and method for making efficient resource reservation in an Internet Protocol (IP) network for achieving strict Quality of Service (QoS) requirements controlling traffic in a Universal Mobile Telecommunications Network (UMTS) Terrestrial Radio Access Network (UTRAN).
[0003] 2. Description of Related Art
[0004] UTRAN is the Radio Access Network of 3 rd rd generation mobile networks. Efficient bandwidth utilization is an essential problem in UMTS access networks because radio links or narrow leased lines are used in this part of the network. In UTRAN different traffic types having different QoS requirements are delivered in the same time and in the same link. UTRAN is characterized by strict delay requirements and short buffers. In order to meet the strict QoS requirements advanced traffic control methods have to be used. Traffic control usually includes packet scheduling, classification and call admission control (CAC).
[0005] Transport technology of UTRAN is based on currently on Asynchronous Transport Method (ATM) and Internet Protocol (IP) as it is described in 3GPP TS 25.401, 3GPP, TSG RAN: UTRAN overall description. As a general tendency, earlier versions of UTRAN are based on ATM while new versions will be based on IP technology. The major motivation to introduce IP technology in UTRAN is that IP allows more flexible fault handling and auto-configuration functions. Besides, it is expected to be a cheaper technology because of the wide deployment of IP routers.
[0006] The traffic parameters have to be signaled to UTRAN nodes when a new call is set up. The signaled parameters should be conformed to standard traffic control solutions. The control plane for AAL2/ATM transport network in UTRAN is specified in Q.2630.2 ITU-T recommendation (12/2000): “AAL Type 2 signaling protocol (Capability Set 2)”. The control plane for IP based transport network is under specification in 3GPP.
[0007] For ATM based UTRAN an accurate CAC algorithm was developed that calculates the required bandwidth for the configuration of the number of active calls belonging to different traffic classes and for the new call in a link. The CAC algorithm is described in Sz. Malomsoky, S. Racz and Sz. Nadas, “Connection Admission Control in UMTS Radio Access Networks,” Computer Communications, Special Issue on 3G Wireless and Beyond for Comp. Communication, June 2002. It takes into account the activity of the calls and also exploits the periodicity of the traffic at the so-called Iub or Iur interface.
[0008] In IP based UTRAN, in order to achieve QoS, different QoS models and provisioning methods are considered such as Integrated Services (IntServ), Differentiated Services (Diffserv), different measurement based methods or over provisioning. These methods have different signaling requirements, which are analyzed in Manner, J. and X. Fu, “Analysis of Existing Quality of Service Signaling Protocols”, draft-ietf-nsis-signalling-analysis-01.txt, February 2003 in more detail.
[0009] In IP networks RSVP is the most common resource reservation signaling protocol which is published by R. Braden et. al.: Resource ReSerVation Protocol (RSVP)—Version 1 Functional Specification, RFC 2205, September 1997.
[0010] In Next Steps in Signaling (NSIS) working group Internet Engineering Task Force (IETF) a new signaling protocol for providing QoS in IP network is under development. The protocol will be based on RSVP and it will support different QoS models. NSIS protocol aims to meet the requirements of mobile networks and it may be used for transport network control plane in UTRAN in the future.
[0011] FIG. 1 shows packet arrival of a periodic ON-OFF like traffic model, where the time is denoted by t, packet size by v, transmission time interval by TTI, time of ON periods by T on and time of OFF periods by T off . T on and T off define a so-called activity factor measured by A=T on /(T off +T on ). In UTRAN the traffic through the Iub or Iur interface can be characterized by a periodic ON-OFF like model as it is described in 3GPP TS 25.401, 3GPP, TSG RAN: UTRAN overall description. The CAC method described in this document checks two different criteria: whether there is congestion due to ON-OFF like behavior and, in a smaller time scale, the probability of the delay violation of the packets are below the required limit. In a link where different traffic types are multiplexed, the delay of packets depends significantly on the queuing and scheduling method used in the system. Priority for the traffic classes having strict delay requirements are applied.
[0012] Investigations showed that the delay violation probability monotonously increases with the length of the ON periods, by fixing the activity factor value. Furthermore, considering typical UTRAN delay requirement and transmission time interval TTI values, the delay violation probability only little depends on the length of the ON and OFF periods.
[0013] Therefore, as a worst case scenario, infinite ON and OFF periods are assumed in the model and application level call activity is taken into account by using average activity factors characterizing the different connection types.
[0014] FIG. 2 depicts another model called token bucket model, which is used to describe and shape bursty traffic of Internet applications presented by J. Wroclawski: “The Use of RSVP with IETF Integrated Services, RFC 2210, September 1997”. A token bucket allows peak rate p for a limited time period, determined by the bucket size b, after which traffic rate cannot exceed the token rate r. The maximum packet size is denoted by M in the figure.
[0015] The traffic envelope in these cases is an upper bound of the user traffic. If user traffic is shaped by e. g. a leaky bucket algorithm the traffic envelope is a curve as it shown in FIG. 2 . If the traffic is a periodic traffic, the traffic envelope is as it is shown in FIG. 1 .
[0016] Future NSIS protocol will support standard IP based QoS models like IntServ and DiffServ. IntServ is based on a one-token bucket model. Token bucket traffic descriptors cannot be converted one-by-one to the traffic descriptors of a periodic ON-OFF like traffic model described above.
[0017] A one-token bucket model is not suitable to describe periodic ON-OFF like traffic in efficient way. In a one-token bucket model the bucket size should be set to the packet size, the token rate should be set to at least v/TTI, peak rate to v/D in order to conform Iub or Iur traffic where v denotes the packed size, TTI is the time period and D stands for the delay criterion. In this way neither activity of a call (ON-OFF like behaviour) nor the periodic behaviour of Iub or Iur traffic can be taken into account easily in a resource reservation function. This results in that over-dimensioning and over-provisioning is needed and, therefore, link utilization is less efficient.
[0018] If infinite ON and OFF periods do not provide a good approximation for a traffic type, the long-time behavior of the traffic sources cannot be characterized by a single activity factor parameter. In this case a more detailed traffic descriptor is needed.
[0019] In general, there is no standard solution yet how to describe a periodic ON-OFF like traffic in an IP based resource reservation signaling protocol.
[0020] Thus there is a particular need for a new QoS service object proposed for resource reservation signaling protocols that can be used for making efficient resource reservation for a periodic ON-OFF like traffic in a packed switched, especially in an IP based network.
SUMMARY OF THE INVENTION
[0021] The present invention enables that an object contains the traffic envelope, QoS descriptors and a source description characterizing the statistical behaviour of a traffic source. The source statistics description can be used to characterize the average length of ON and OFF periods. The object can be used to reserve resources in a per-flow reservation method or for calculation of the number of resource units in edge nodes in case of an aggregated reservation method.
[0022] Accordingly, the invention is directed to a method for resource reservation meeting the QoS requirement of a packet switched telecommunications network.
[0023] In another aspect, the present invention is directed to a system in which the resource reservation of an ON-OFF like traffic is implemented.
[0024] In yet another aspect, the present invention is directed to an object including source statistics description describing the statistical behavior of a source.
[0025] In a further aspect, the present invention is directed to a node in a packet switched telecommunications network furnished with computing means for interpreting resource reservation objects including sub-object of source statistics description.
[0026] The most important advantage of the invention is that using the QoS object the statistical behaviour of a source can be signalled to another network node and it can be taken into account in the reservation method. Therefore more efficient and accurate resource reservation can be made in IP routers. For example in case of a periodic ON-OFF like traffic (traffic through Iub or Iur interface of UTRAN) the flow activity can be exploited and the periodicity of the traffic can also be taken into account in the resource reservation algorithm. Both features result in more efficient link utilization.
[0027] It is also advantageous that the QoS object is defined in general way: it can be used either in a future resource reservation protocol or in another resource reservation protocol in which individual QoS models can be defined.
[0028] Another advantage is that the invention can be used in a per flow reservation method to perform accurate traffic control in each node. It can be used also for an aggregated reservation method in the edge nodes to calculate the required resources to be reserved in the domain. In both case more efficient link utilization can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] For a more complete understanding of the invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings wherein:
[0030] FIG. 1 shows time diagram of a periodic ON-OFF like model according to the prior art;
[0031] FIG. 2 depicts the time diagram of a token bucket traffic model relating to the prior art too;
[0032] FIG. 3 illustrates the chart of the general form of the source statistics sub-object;
[0033] FIG. 4 is a simplified block diagram illustrating resource reservation is a per flow method;
[0034] FIG. 5 shows a simplified block diagram depicting resource reservation in an aggregation domain;
[0035] FIG. 6 is a flow chart illustrating the steps of one embodiment of the method of the present invention;
[0036] FIG. 7 is a flow chart illustrating the steps of another embodiment of the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0037] In the present invention, the QoS object supporting an efficient resource reservation method is similar to the future QoS object describing the IntServ model: It contains a traffic envelope for the traffic bunches, description of the required QoS descriptors. In addition to this, the QoS object according to the invention includes a new sub-object that characterizes the statistics of the source.
[0038] Therefore, the QoS object includes at least three sub-objects:
[0039] (1) The descriptors of the desired QoS including maximum delay of a packet, delay violation probability, maximum packet loss ratio, etc.
[0040] (2) Packet level traffic parameters characterizing the traffic envelope. This can be a token bucket traffic parameter set as in case of IntServ. Or for a simple periodic traffic flow including packet size v and peak rate p.
[0041] (3) Description of the source statistics: distribution types and parameters of the distributions. For example for an Iub or Iur traffic it can be the length of the ON and OFF periods:
[0042] (a) The distribution type of the length of the ON periods: e.g. Exponential= 1
[0043] (b) The parameters of the length of the ON periods: m, mean time of ON periods
[0044] (c) The distribution type of the length of the OFF periods: e.g. Exponential= 1
[0045] (d) The parameters of the length of the OFF periods: n, mean time of OFF periods
[0046] The activity factor A can be obtained as m/(n+m). The definition of the source traffic statistics sub-object is more general than it is needed for model described in the prior art, therefore it can be used to characterize other traffic sources as well, by specifying the parameters and its distribution characterizing the source.
[0047] FIG. 3 illustrates the chart of the general form of the source statistics sub-object. The source statistics sub-object includes fields of data bits coding source type field 31 , field of type for the first distribution 311 , field of first parameter for the distribution 312 and further fields of parameters for the distribution if any 313 . . . 31 N; then field of type for the second distribution 321 , field of first parameter for the distribution 322 and further fields of parameters for the distribution if any 323 . . . 32 N, and so on.
[0048] The source statistics sub-object can be used either to make reservation for a traffic flow in case of a ‘per flow’ reservation method, or for calculation of number of resource units in an aggregated reservation method.
[0049] FIG. 4 is a simplified block diagram illustrating the first method, that is, resource reservation in a per flow method. Setting up a new flow in the network, a reservation initiator RI sends a RESERVE message towards reservation receiver RR including QoS object for each flow. Practically, a reservation initiator RI can be a base station controller (BSC) and reservation receiver RR can be a radio network controller (RNC), or vice versa, RI can be an RNC and RR is a BSC. In each node where reservation has to be done an algorithm mentioned in 3GPP TS 25.401, 3GPP, TSG RAN: UTRAN overall description or a similar algorithm calculates the needed resources and makes reservation for the new flow. Such nodes can be implemented as IP routers having computing means for switching flow of transmissions and are linked together by transmission channels. In the figure routers R- 1 , R- 2 and R- 3 participate in resource reservation for the new flow, while router R- 4 does not. So the RESERVE message is sent along reservation initiator RI-routers R- 1 -R- 2 -R- 3 -reservation receiver RR. If reservation is successful the connection can be established. If it is unsuccessful an error message is sent and processed and so the new flow is not allowed to enter the network.
[0050] FIG. 5 shows a simplified block diagram depicting resource reservation in an aggregation domain. In the second method, shown in this figure, resource initiator RI sends a RESERVE message to resource receiver RR including QoS object. An algorithm described in Sz. Malomsoky, S. Racz and Sz. Nadas, “Connection Admission Control in UMTS Radio Access Networks” Computer Communications, Special Issue on 3G Wireless and Beyond for Comp. Communication, June 2002; or a similar algorithm is running in the edge node of the aggregation domain and calculates the required resource units that should be reserved for the traffic flow in the aggregation domain. In this embodiment the edge nodes are routers R- 5 and R- 9 , while routers R- 6 , R- 7 and R- 8 are interior routers. The advantage of this method is that a simple reservation is carried out, that is, QoS object is not processed and, advanced algorithm does not have to be run inside the aggregation domain D. In the aggregation domain D usually only aggregated states are stored and maintained, which require less processing capacity. In this case the edge nodes, that are routers R- 5 and R- 9 , are responsible to handle the error in the aggregation domain D. So the RESERVE message is sent along reservation initiator RI-routers R- 5 -R- 6 -R- 7 -R- 9 -reservation receiver RR. QoS object may be tunneled in the aggregation domain D and used for resource reservation outside the domain D. The tunnel T is established between router R- 5 and R- 9 performing complex reservation (dashed line). In this embodiment only edge routers R- 5 and R- 9 have calculating means for interpreting resource reservation objects including source statistics descriptors.
[0051] FIG. 6 is a flow chart illustrating the steps of one embodiment of the per flow method the diagram of which is shown in FIG. 4 . In the first step 61 we initialize the reservation in the reservation initiator. In step 62 reservation is carried out in the routers along the flow of transmission. When RESERVE message arrives at reservation receiver this message is received in step 63 and an acknowledgement is sent backward in step 64 . In this embodiment CAC exploits sub-object of source statistics description in each router along the flow of transmission.
[0052] FIG. 7 is a flow chart illustrating the steps of one embodiment of the method of the resource reservation in an aggregation domain the diagram of which is depicted in FIG. 5 . In the first step 71 the reservation is initialized similar to the previous case. When RESERVE message arrives at the edge of an aggregation domain complex reservation is carried out in step 72 in an edge router where the message enters into the domain and the sub-object of source statistics description is tunneled through the domain up to an edge router where the message leaves the domain, meanwhile simple reservation takes place in interior routers in steps 73 . Edge router where the message leaves the domain also performs complex reservation in step 74 and sends acknowledgement backwards in step 77 to the previous edge router. Finally, reservation receiver receives the message in step 75 and sends an acknowledgement backward to the reservation initiator in step 78 . In this embodiment CAC uses sub-object of source statistics description in edge routers of the domain along the flow of transmission.
[0053] Although the present invention has been described in detail with reference to only two exemplary embodiments of IP network, those skilled in the art will appreciate that various modifications can be made without departing from the invention. Accordingly, the invention is defined only by the following claims, which are intended to embrace all equivalents thereof.
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Resource reservation in a packed switched telecommunications network is provided. System and method are directed to make resource reservation especially in an Internet Protocol (IP) network for achieving Quality of Service (QoS) requirements controlling traffic preferable in a Terrestrial Radio Access Network (UTRAN) of a Universal Mobile Telecommunications Network (UMTS). A sub-object of source statistics description characterizes the statistical behavior of a traffic source for example the average length of ON and OFF periods. The sub-object is used to reserve resources in a per-flow reservation method or for calculation of the number of resource units in edge nodes in case of an aggregated reservation method.
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FIELD OF THE INVENTION
[0001] The present invention relates to firewalls used in most Internet Protocol networks to reduce the threats and/or attacks against users of those networks and particularly to using firewalls in new applications, such as Voice over IP applications.
BACKGROUND OF THE INVENTION
[0002] A firewall is a packet filtering device that matches an incoming packet against a set of policy rules and applies the appropriate actions to the packet. The firewall essentially filters incoming packets coming from external networks to the network protected by the firewall and either accepts, denies or drops the incoming packets of information. Current firewalls may use a packet filtering method, a proxy service method or a stateful inspection method to control traffic flowing into and out of the network. The packet filtering method allows the firewall to analyze incoming packets against a set of filters. Packets that are allowed through the filters are sent to the requesting/receiving system and all other packets are discarded. The proxy service method enables the firewall to retrieve information sent from the Internet and then the firewall sends the information to the requesting/receiving system and vice versa. The stateful inspection method enables the firewall to compare certain key parts of the packet to a database of trusted information. Information travelling from inside the firewall to the outside is monitored for specific defining characteristics and then incoming information is compared to these characteristics. If the comparison yields a reasonable match, the information is allowed through, otherwise, it is discarded.
[0003] Current firewalls use policy rules for decisions on data packet treatment. The policy rules include a 5-tuple and an associated action. The 5-tuple includes a source IP address, a destination IP address, a transport protocol, a source port number and a destination port number. The source address is the IP address from where the data originates. The destination address is the IP address to where the data is headed. The protocol is the protocol carried in the IP data packet. The source port is the transport layer port from where the data originates and the destination port is the transport layer port to where the data is headed. When an incoming data packet matches the 5-tuple policy rule, the firewall applies an appropriated policy rule action to the data packet. Policy rule actions implemented by the firewall are an allow action for enabling the firewall to forward the packet through the firewall, a deny action for enabling the firewall to block the data packet and discard it, and an other action for enabling the firewall to log, divert or process the data packet in a way that is different from the allow action and the deny action. Therefore, based on the 5-tuples in the policy rules, the firewall decides to either let incoming packets pass through the firewall, drop incoming packets or perform another function, such as logging the incoming packet.
[0004] In addition to filtering packets based on the source IP address, destination IP address, Protocol, and port numbers, most firewalls perform additional filtering functionality on other fields and perform many other operations to prevent attacks. For example, most firewalls include a Transmission Control Protocol (TCP) Sequence Verifier feature for keeping track of TCP sequence numbers in packets that pass thorough the firewall. During TCP connection setup, when nodes exchange TCP SYN, TCP SYN ACK and TCP ACK messages, they exchange and agree on the values of TCP sequence numbers to be used during communications between the nodes. The firewall typically learns the initial values of the sequence numbers from the connection setup messages. Thereafter, every packet in a TCP session includes a sequence number in the TCP header information. The sequence number is the mechanism used to allow reliable communications between hosts. The sequence number identifies each packet of data so that a receiving host can reassembly the stream of incoming packets in the correct order and acknowledge each individual packet as it is received. If a sequence number is not acknowledged within a predetermined period of time, the sending host retransmits the unacknowledged packet. If the retransmission and the acknowledgment pass each other on the network, the receiving host discards the duplicate packet because of the previously received sequence number. The Sequence Verifier feature of a firewall enables the firewall to watch all traffic flows going through the firewall and keep track of the sequence numbers in the packets. If the firewall receives a packet with an incorrect sequence number, the firewall will consider the packet to be out of state and drop the packet.
[0005] Although firewalls provides security for networks, they are also obstacles to many application since firewalls using the 5-tuple rules only allow specific applications, for example web browsing from a node in the network protected by the firewall. Other applications, such as IP telephony and peer-to-peer applications, with dynamic properties do not work with firewalls.
[0006] Several solutions are created to enable any application to traverse a firewall. One solution is the Next Step Of Signaling (NSIS) firewall protocol that is a path-coupled protocol carried over the NSIS Network Transport Layer Protocol. This Network Transport Layer Protocol is used to open pin-holes in the firewalls and thereby enable any type of communication between endpoints across networks, even in the presence of firewalls. Specifically, the NSIS Network Transport Layer Protocol is used to install such policy rules for enabling NSIS signalling messages in all firewalls along the data path and the firewalls are configured to forward data packets matching the policy rules provided by a NSIS Signaling Layer Protocol (NSLP). Therefore, applications located at endpoints/hosts establish communication between them and use the NSLP signalling to establish policy rules on a data path which allows any type of data between the hosts to travel unobstructed from one endpoint to another.
[0007] According to the NSIS protocol, a data sender that intends to send data to a data receiver starts the NSLP. A NSIS initiator at the data sender sends NSLP signalling request messages towards the address of the data receiver. The NSLP request messages are processed each time they are passed through a NSIS forwarder, i.e., a signalling entity, between a NSIS initiator and NSIS responder, that propagates NSIS signalling through the network. Each NSIS forwarder in the network processes the message, checks local policies for authorization and authentication, possibly creates policy rules and forwards the signalling message to the next NSIS node. The request message is forwarded until it reaches the NSIS responder which checks the received message and generates response message(s) that are sent to the requesting NSIS initiator through the NSIS forwarder. The response messages are also processed at each NSIS forwarder in the data path. After the requesting NSIS initiator receives a successful response message(s), the data sender associated with the requesting NSIS initiator can send any type of data through the data path established during the NSIS setup to the data receiver associated with the responding NSIS responder. This creates a pinhole in the firewall, wherein data not implementing the conventional policy rules will be allowed through the firewall via the data path established during the NSIS setup.
[0008] Nevertheless, current firewall configuration protocols, such as NSIS, only allows a limited set of parameters to be included in the signalling messages. Because of the limited number of parameters allow in the protocols, the firewall is provided with limited information when data is transmitted between nodes and some essential information may not be provided to the firewall. In the absence of the needed information, some firewall functions may be disabled thereby lowering the protection provided by the firewall. For example, if a terminal in a network protected by a firewall establishes a NSIS connection with another terminal, then moves to a different subnet that is protected by a new firewall and changes its IP address, the terminal may use the NSIS protocol to create the necessary packet filters in new firewall in order to let incoming packets to the terminal's new IP address pass through the new firewall. However, because of the limited number parameters allowed in current firewall configuration protocols, the terminal will not be able to provide the TCP Sequence numbers of the packet flows between the terminal and its correspondent nodes, and the new firewall will be unable to perform TCP Sequence verification. This exposes the network protected by the new firewall to potential threats and/or attacks.
SUMMARY OF THE INVENTION
[0009] According to one aspect of the invention, there is provided a network implementing at least one firewall for providing protection for users on the network. The network includes at least one host system protected by the at least one firewall, the host system being configured to send and receive information from external host systems through the at least one firewall. The at least one firewall including installation means for installing policy rules that are transmitted from at least one network entity to the at least one firewall. The policy rules include an option field for allowing the at least one network entity to send additional information to the firewall on at least one state to be created. The additional information is optionally used by the at least one firewall to perform services on data travelling through the at least one firewall.
[0010] According to another aspect of the invention, there is provided a firewall for providing protection for users on a network. The firewall includes installation means for installing policy rules that are transmitted from at least one network entity to the firewall, wherein the policy rules comprise an option field for allowing the at least one network entity to send additional information to the firewall on at least one state to be created. The additional information is optionally used by the firewall to perform services on data travelling through the firewall.
[0011] According to another aspect of the invention, there is provided a host system including a firewall for providing protection. The host system also includes installation means, on the firewall, for installing policy rules that are transmitted from at least one network entity through the firewall. The policy rules include an option field for allowing the at least one network entity to send additional information to the firewall on at least one state to be created. The additional information is optionally used by the firewall to perform services on data travelling through the firewall.
[0012] According to another aspect of the invention, there is provided a method for protecting systems connected to at least one firewall by providing additional information to the at least one firewall on states to be created. The method includes the steps of transmitting policy rules from at least network entity connected to the at least one firewall and installing the policy rules on the at least one firewall. The policy rules comprise an option field for allowing the at least one network entity to send additional information to the at least one firewall on at least one state to be created. The method also includes the step of optionally using the additional information by the at least one firewall to perform services on data travelling through the at least one firewall.
[0013] According to another aspect of the invention, there is provided an apparatus for protecting systems connected to at least one firewall by providing additional information to at least one firewall on states to be created. The apparatus includes transmitting means for transmitting policy rules from at least one network entity connected to the at least one firewall. The apparatus also includes installation means for installing the policy rules on the at least one firewall, wherein the policy rules comprise an option field for allowing the at least one network entity to send additional information to the at least one firewall on at least one state to be created. The apparatus further includes implementation means for optionally using the additional information by the at least one firewall to perform services on data travelling through the at least one firewall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention that together with the description serve to explain the principles of the invention.
[0015] In the drawings:
[0016] FIG. 1 illustrates a network that includes firewalls for protecting end users from threats and attacks from outside users;
[0017] FIG. 2 illustrates the steps implemented in setting up communications in a network that implements the NSIS protocol;
[0018] FIG. 3 a illustrates the format of message transmitted in the inventive system;
[0019] FIG. 3 b illustrates the NSLP objects in each message type;
[0020] FIG. 4 illustrates the elements of the inventive policy rule object; and
[0021] FIG. 5 illustrates the steps implemented by a create session request message in an embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
[0022] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The present invention described below extends firewall configuration protocols to carry more information about the states to be created during communications between network nodes.
[0023] The present invention relates to extended firewall configuration protocols to enable an end user to include information on a state to be created. FIG. 1 illustrates a network that includes firewalls for protecting end users from threats and/or attacks from outside users. The network includes a first network 102 that includes multiple end users 104 - 106 and a second network 108 that includes end users 110 - 112 . The network also includes firewalls 114 and 115 for protecting end users 104 - 106 from external attacks and firewalls 116 and 117 for protecting end user 110 - 112 from external attacks. It should be apparent to one skilled in the art, that firewalls 114 - 117 may include one or more packet filtering devices for matching packets travelling through those devices against a set of police rules and applying the appropriate action to the data packets. Although firewalls are place more toward the edge of a network, it should be apparent to one skilled in the art that firewalls 114 - 117 may be located at different locations in the network, for example, at enterprise network borders, within enterprise networks, or at mobile phone gateways. It should also be apparent to one skilled in the art, that networks 102 and 108 may include other network entities, such as servers, that may also transmit information through firewalls 114 - 117 .
[0024] In one embodiment of the invention, firewalls 114 - 117 may implement Next Step of Signaling (NSIS) protocol where after communication setup between endpoints/hosts, any communication between the endpoints across the network is enabled, even in the presence of firewalls. During communication setup, firewalls 114 - 117 are configured in such a way that NSIS signalling messages are allowed to traversed them. The NSIS signalling messages exchanged between the hosts during communication setup are used to install appropriate policy rules in all firewalls 114 - 117 along the communications path and firewalls 114 - 117 are configured to forward subsequent data packets matching the policy rules provided by the NSIS signalling messages. This allows data to travel from one end point to another end point unobstructed by firewalls 114 - 117 . In order to run NSIS signalling across a data path, it is necessary that each firewall in the data path have an associated NSIS agent 118 - 121 .
[0025] FIG. 2 illustrates the steps implemented in setting up communications in a network that implements the NSIS protocol. According to FIG. 2 , both end hosts 202 and 204 are behind firewalls 206 and 208 that are connected via the Internet. Firewalls 206 and 208 provide traversal service for NSIS Signaling Layer Protocol (NSLP) in order to permit NSIS messages to reach end hosts 202 and 204 . As such, during communication setup, firewalls 206 and 208 process NSIS signalling and establish appropriate policy rules so that subsequently received data packets conforming to the policy rules can traverse firewalls 206 and 208 . Trust relationships and authorization are very important for the protocol machinery. Various kinds of trust relationships, such as peer-to-peer trust relationship, intra-domain trust relationship, end-to-middle trust relationship, and one or more trust relationships may exists between network nodes.
[0026] Specifically, during communications setup, NSLP for firewall traversal is carried over the NSIS Transport Layer Protocol. NSLP messages are initiated by a NSIS initiator 210 , handled by NSIS forwarders 206 and 208 and processed by NSIS responder 216 . A data sender, such as end host 202 , that intends to send data messages to a data receiver, such as end host 204 , must start its NSLP signalling, whereby NSIS initiator 210 associated with the data sender starts NSLP signalling towards the address of the data receiver. The NSLP request messages from NSIS initiator 210 are process each time the messages pass through NSIS forwarders 206 and 208 that support NSLP functions. NSIS forwarders 206 and 208 process the messages, check local policies for authorization and authentication, possible create policy rules and forward the signalling messages to the next node. As such, the request messages are forwarded until it reaches NSIS responder 216 . NSIS responder 216 checks the received message, performs the applicable processes and generates response messages that are sent back to NSIS initiator 210 via the same communications path as the request messages. The response messages are also processed at NSIS forwarders 206 and 208 during transmission from NSIS responder 216 to NSIS initiator 210 . Upon receiving a successful response message, the data sender may thereafter send data flows to the data receiver.
[0027] FIG. 3 a illustrates the format of a message transmitted in the inventive system. All NSIS messages include a NSIS Transport Layer Protocol header 302 and a NSLP header 304 . A NSLP node uses header 300 to distinguish between a request message and a response message. NSLP header 304 includes a version number 305 , a header length 306 for specifying the length of the NSLP payload in bytes, object count number 307 for specifying the number of objects that follow after NSIS header 300 and the message type 308 for specifying if the message is a response or request message. For request messages, four sub-types are defined in message type 308 . The sub-types are create-session 309 , prolong session 310 , delete session 311 and reserve session 312 . Create-session 309 request message is used to create policy rules on the firewalls so that data packets of a specified data flow can traverse the firewall. Prolong session 310 request message is used to extend the lifetime of a NSLP session. The NSIS initiator uses the prolong session request message to request a certain lifetime extension. Delete session request message 311 is used to delete a NSLP session. Reserve session 312 request message is used to reserve a session. For response messages, three sub-types are defined in message type 308 . The sub-types are return-an-external address 313 , path succeeded 314 and error 315 . Return-an-external address 313 response message is sent as a successful reply to a reserve external address request. Path succeeded 314 response message is sent as a successful reply to a create session request message 309 . Error response message 315 reports any error occurring at the NSIS forwarder or NSIS responder to the NSIS initiator.
[0028] Each message type includes one ore more NSLP objects which carry the actual information about policy rules, lifetimes and error conditions. FIG. 3 b illustrates the NSLP objects in each message type. All objects share the same object header 316 which is followed by the object data 317 . Object header 316 includes the total length 318 of the object and the object type 319 that identifies data 317 . The format of object data 317 depends on object type 319 . Object type 319 include a session id object 320 for providing a randomly generated session ID handed by the NSIS initiator to the NSIS session at a particular node, the lifetime object 322 for indicating the lifetime of a NSLP session, policy rule objects 324 that includes the flow information for the data traffic from the data sender to the data receiver, and an external address object 326 that includes a reserved external address and if applicable a port number.
[0029] FIG. 4 illustrates the elements of the inventive policy rule object. The policy rule object includes a source address 402 , a destination address 404 , a protocol 406 , a source port 408 , a destination port 410 , and IPv6 flow label 412 and an option field 414 . Source address 402 is the IP address from where the data originates. For example, if data sender 104 illustrated in FIG. 2 is sending data to data receiver 110 , source address 402 will be the address of data sender 194 . Destination IP address 404 is the IP address to where the data is headed. Again returning to FIG. 2 , destination address 404 is either the data receiver's 110 address or the public address that data receiver 110 reserved for itself. Protocol 405 is the protocol carried in the IP data packet. Source port 408 is the transport layer port from where the data originates and destination port 410 is the transport layer port to where the data is headed. Option field 414 allows the end user to include additional information on the state to be created. Code 416 in option field 414 indicates the type of information that follows. For example, option field 414 may include a TCP sequence number that is required by a firewall for the firewall to perform TCP sequence verification. In this case, code 416 will be “TCP sequence number” and value 418 will include the TCP sequence numbers of the flows created when creating the states in the firewalls. As is apparent to one skilled in the art, option field 414 may be broken up to include multiple codes 416 and corresponding values 418 . Various currently known means may be implemented to allow the firewall to determine how many values are provided by option field 414 and what each value represents.
[0030] FIG. 5 illustrates the steps implemented by create-session message 309 for enabling communication between a data sender and a data receiver. Thereafter, both the data sender and the data receiver are enabled to exchange data packets even with one or more firewalls on the communications path. In step 5010 the data sender generates create-session request message 309 with a chosen session ID, the policy rule object associated with the subsequent data flow and a requested lifetime. In Step 5020 , the data sender sends create-session request message 309 towards the data receiver. In Step 5030 , the firewalls in the communications path remember the rules specified in the message and forward the message to the next node. The firewall may also examine the option field to determine if the value identified by code is needed by the firewall. If it is, the firewall obtains the value from option field prior to forwarding the message to the next node. In Step 5040 , upon receiving create-session 309 request message, the data receiver responses with path succeeded 314 response message, as a successful reply to create-session 309 response message, or with error 315 response message. In Step 5050 , if path succeeded 314 response message is received by the data sender, the data sender may thereafter send data packets that implement the rules identified in create-response message.
[0031] In another embodiment, the invention may be used in a network implementing IP security protocols (IPsec). IPsec provides security services at the IP layer by enabling a system to select required security protocols, determine the algorithm(s) to use for the service(s) and put in place any cryptographic keys that are required to provide the requested services. IPsec can be used to protect one or more communication paths between a pair of hosts, between a pair of security gateways, i.e., any intermediate system that implements IPsec protocols, or between a host and a security gateway.
[0032] IPsec uses Authentication Header (AH) protocol and Encapsulating Security Payload (ESP) protocol to provide traffic security. The AH protocol provides connectionless integrity, data origin authentication and an optional anti-replay service. The ESP protocol may provide confidentiality (encryption) and limited traffic flow confidentiality. It may also provide connectionless integrity, data origin authentication and an anti-replay service. The protocols may be applied alone or in combination with each other to provide a desired set of security services. Each protocol supports a transport mode for providing protection primarily for upper layer protocols and a tunnel mode which is applied to tunnelled IP packets.
[0033] Both the AH and ESP use security association which is a simplex “connection” that affords security services to the traffic carried by it. Security services are afforded to a security association by the use of the AH protocol or the ESP protocol, but not both. If both AH and ESP protection is applied to a traffic stream, then two or more security associations are created to afford protection to the traffic stream. Therefore, to secure typical, bi-directional communication between two hosts or between two security gateways, two security associations (one in each direction) are applied.
[0034] A security association is uniquely identified by a triple consisting of a Security Parameter Index (SPI) an IP destination address and a security protocol (AH or ESP) identifier. In the inventive system, a network implementing IPsec protocol may include the SPI in option field 414 . Therefore, referring to FIG. 4 , the policy rule object will include source address 402 , destination IP address 404 , protocol 405 , option field 414 which includes the SPI value and optionally source port 408 and destination port 410 . Code 416 in option field 414 will indicate that option field 414 includes the SPI that is required by a firewall for the firewall to implement the appropriate IPsec protocol(s).
[0035] The foregoing description has been directed to specific embodiments of this invention. It will be apparent, however, that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.
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A network implementing at least one firewall for providing protection for users on the network. The network includes at least one host system protected by the at least one firewall, the host system being configured to send and receive information from external host systems through the at least one firewall. The at least one firewall including installation means for installing policy rules that are transmitted from at least one network entity to the at least one firewall. The policy rules include an option field for allowing the at least one network entity to send additional information to the firewall on at least one state to be created. The additional information is optionally used by the at least one firewall to perform services on data travelling through the at least one firewall.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of German Application No. P 40 29 412.9 filed Sep. 17, 1990, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to an apparatus for separating foreign bodies, particularly metal foreign bodies, from a textile fiber stream advanced in a fiber processing line. In a conventional separating apparatus, the fiber material (fiber tufts) is pneumatically conveyed in a duct which has a branch-off location provided with a deflecting mechanism for the foreign bodies. A metal detector is situated upstream of the branch-off location as viewed in the travelling direction of the fiber tufts. The deflecting mechanism and the metal detector are operatively coupled with a control device in such a manner that the deflecting mechanism is, as a result of a response signal from the metal detector upon passage of a metal foreign body, switched to a position in which the fiber stream is guided to a waste collector.
2. Background Art
In a known apparatus, as disclosed in European Patent Application 033 a long, closed pneumatic fiber tuft conveying duct includes a metal detector and a branch-off location which is connected to a waste removing conduit in which a complex vacuum generating device--which requires its own compressor--is arranged for generating the suction stream that transports the fiber tufts. Apart from the expensive arrangement, the system is disadvantageous in that a complex collecting device for the separated material is needed in the region of the closed pneumatic transport system which further requires additional gates for material removal.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved apparatus of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, is of simple construction and in which the distance between the metal detector and the deflecting mechanism is shortened as compared to prior art constructions.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for separating foreign bodies from a stream of fiber material includes a vertical chute having an upper inlet and a lower outlet; a mechanism for introducing the fiber material into the chute inlet; and a detector positioned in the chute for emitting a sensor signal upon passage of a foreign body. The fiber material is propelled from the detector towards the chute outlet substantially solely by gravity. The apparatus further has a waste discharge opening provided in the chute between the detector and the chute outlet; a deflecting mechanism arranged in the chute and having first and second positions. In the first position the deflecting mechanism causes the stream of fiber material to proceed in the chute to and through the chute outlet and in the second position the deflecting mechanism causes the stream of fiber material to proceed through the waste discharge opening. The deflecting mechanism is moved from the first position into the second position in response to a sensor signal emitted by the detector.
Thus, according to the invention, downstream of a separator assembly (such as a condenser) for the tuft/air mixture and below the exit location for the fiber material a foreign body detector is arranged which is followed in the vertical direction by a separating gate. If in the operative position, the separating gate deflects the free-falling material, together with the foreign body contained therein, from its normal path of conveyance.
It is an advantage of the invention that the sensing and the separating operations are performed externally of pneumatic ducts or channels.
It is an important feature of the invention to provide for a free fall of the material and to arrange the detector at or close to the location where the free fall starts. The separating gate is arranged spaced from the detector in the direction of free fall. In this manner, the reaction time for the gate is changed by several orders of magnitude which is realized with simple gates without the need of long distances between the detector and the location of separation. For example, the separating gate may be pivoted within 0.5 seconds after receipt of an electric actuating pulse. During such period the foreign body has moved in a free fall only approximately 1.2 m and has a velocity of approximately 4.4 m/sec s that the separating process may be controlled in a simple manner with the apparatus structured according to the invention. It is a further advantage of the construction according to the invention that in contrast to prior art arrangements, a complex and expensive collecting device for the separated material in the region of the closed pneumatic transport system is no longer necessary. Further, an expensive vacuum-generating device may also be dispensed with. It is of particular advantage that a long conveying track of, for example, 8-10 m between the detector and the deflecting device is also no longer necessary. The apparatus according to the invention is operationally reliable because it is based on a fail-safe free fall of the fiber material and the foreign bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a fiber processing line--including cleaning and carding machines incorporating the invention.
FIGS. 2-6, 7a, 7b and 8a are schematic side elevational views of seven preferred embodiments of the invention.
FIG. 8b is a diagram illustrating an impact force/time function.
FIG. 8c is a diagram illustrating the frequency of fiber tuft size occurrences.
FIG. 9 is a schematic side elevational view of yet another preferred embodiment of the invention.
FIG. 10 is a schematic side elevational view of a modified detail of the structure illustrated in FIG. 9.
FIG. 11 is a schematic side elevational view of the construction of the apparatus in the zone of a metal detector.
FIG. 12 is a schematic side elevational view of still another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is illustrated therein a fiber processing (cleaning) line which receives fiber tuft material detached from fiber bales 1a by a bale opener 1 which may be, for example, a BLENDOMAT BDT model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. Between the bale opener 1 and a multiple fiber tuft blender 4 there is situated the apparatus 2 according to the invention, followed by a heavy particle separator 3. The multiple blender 4 is followed in the downstream direction by a fine opener 5, and a plurality of card feeders 6 each associated with a carding machine 7 (only a single feeder-and-card assembly is shown). The fiber tufts detached by the bale opener 1 from the fiber bales ia are conveyed pneumatically in a duct 9 to a condenser 8 which is provided with a screening drum. From the condenser 8 there extends a vertical chute 10, the bottom of which opens into a pneumatic duct for advancing material to consecutive processing machines. The chute 10 and the other, downstream-arranged machines are connected to one another with respective pneumatic ducts. No pneumatic conveying duct is provided between the condenser 8 and the chute 10.
In the chute 10, vertically underneath the condenser 8 a metal detector coil 11 is arranged. The fiber material A drops from the condenser 8 through the detector coil 11 and a guide element 12 of the chute 10 in a free fall as indicated by the arrow C. Between the guide element 12 and the chute 10 a discharge opening 13 is provided, adjacent which, on the opposite wall of the chute 10, a pivotal gate 14 is mounted which serves as a deflecting member. An upwardly open waste container 15 is arranged laterally of the chute 10 and underneath the discharge opening 13. As soon as the gate 14 pivots into its operative position (shown in FIG. 1) in response to a sensor signal from the detector coil 11, the fiber material, together with the sensed foreign body, is deflected into the waste container 15, as indicated by the arrow B.
Downstream of the apparatus 2 a heavy particle separator 3 is arranged which may be a SEPAROMAT model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany. The separator 3 has an intake channel 3a to which there is coupled an end of an air branch-off conduit 3b so that air quantities indicated by the arrow E in the air branch conduit 3b may be set by a throttle gate 3c as a function of the air quantities (arrow D) flowing through the intake channel 3a. The intake channel 3a is a rising pneumatic conduit between the apparatuses 2 and 3.
In FIG. 2, the detector coil 11 is mounted on a non-illustrated holder underneath the condenser 8. The fiber material A drops in a free fall in the chute 10 and is pneumatically carried away through a suction pipe 16 at the bottom of the chute 10. The deflector gate 14 lies flush against the wall 10a of the chute 10 during normal passage of the fiber material and upon generation of a signal by the detector coil 11, responding to the passage of a metallic foreign body, the deflector gate 14 is pivoted away from its flush position with the chute wall 10a into the phantom-line position 14'. The gate 14 is secured to the wall 10a by a pivot 14a to which there is connected one end of a crank lever 14b, whose other end is operatively connected with a pneumatic cylinder 14c which, in turn, is coupled with the detector coil 11 with the intermediary of a control device as will be discussed in connection with FIG. 4.
In FIG. 3, underneath the condenser 8 a detector plate 17, containing a plurality of inductive detector coils, is arranged at an angle α to the horizontal. The chute 10 has at its lower end two slowly rotating, cooperating delivery rolls 18a, 18b which remove the fiber material from the chute 10 and cause the fiber material to fall on a removal conveyor 18c.
Turning to FIG. 4, underneath the condenser 8 an obliquely oriented detector plate 17 and an obliquely oriented wall 19a of a guide element 19 are provided. The guide element opens into the chute 10. The wall 19a supports the pivotal deflector gate 14. Upon rotation of the gate 14 into its phantom-line position 14', a branch-off aperture in the wall 19a is opened, through which the material passes, together with the metal foreign bodies, and falls into the waste container 15. In their travel from the condenser 8 downwardly, the fiber material and the foreign body are exposed exclusively to gravitational forces. The detector plate 17 is electrically connected with a control device 20 which, in turn, is coupled to the pressure cylinder 14c with the intermediary of a transducer 21.
In FIG. 5, underneath the branch-off aperture 13 and adjacent the chute 10 a fiber tuft accumulator 22 is arranged. At the bottom of the fiber tuft accumulator 22 two slowly rotating delivery rolls 23a, 23b are mounted. Underneath the delivery rolls 23a, 23b a further detector coil 21 and a pivotal gate 25 as well as a chute 26 are provided. The chute 26 and the chute 10 open into a common suction duct 27. Between the tuft accumulator 22 and the chute 26 an opening 28 is provided under which a waste container is arranged. In this embodiment two separating devices are serially connected to ensure that the useful fiber quantities 31 which are separated out with the metal foreign body 30 are maintained small. Thus, in operation, the coil 11 generates a signal as a metal foreign body passes therethrough, together with useful fiber material. In response, the cylinder 14c places the pivotal gate 14 into its phantom-line position 14' whereupon the fiber material, together with the metal foreign body, falls into the fiber tuft accumulator 22. Thereafter, the gate 14 is returned into its solid-line position whereupon the fiber material dropping from the condenser 8 may fall through the chute 10 into the pneumatic duct 27 to combine with the air stream P into an air/fiber stream R. Parallel to this operation, the slowly rotating delivery rolls 23a, 23b at the bottom of the accumulator 22 advance the material through the sensor coil 24 and as the earlier collected metal foreign body passes through the coil 24 the latter causes energization of the pressure piston 14c' whereupon the gate 25 is pivoted counterclockwise, thus closing the channel 26 and deflecting the fiber material, together with the metal foreign body, through the opening 28 into the waste collector 29.
The embodiment illustrated in FIG. 6 is similar to that of FIG. 5 except that in the normal position of the gate 25 the fiber material advanced by the delivery rolls 23a, 23b is deflected into the chute 10 at a location below the gate 14, whereas in the non-illustrated operative position, that is, when the gate 25 is pivoted counterclockwise in response to a sensor signal from the coil 24, the gate 25 allows the fiber material, together with the metal foreign body 30 to fall, as indicated at B, vertically into the waste container 29 situated vertically below the sensor coil 24.
Turning to FIG. 7a, underneath the condenser 8 which includes a screening drum 8a and a vaned dispenser wheel 8b, there is mounted an obliquely oriented weighing plate 32 connected with a weighing cell 32a. The fiber stream A 1 impinges on the weighing plate 32 and is deflected thereby as a fiber stream A 2 . FIG. 7b shows that the weighing cell 32a is connected to the control device 20 which, in turn, is coupled to the pneumatic cylinder 14c that operates the gate 14 to guide the fiber material, together with the sensed metal foreign body, into the waste conveyor 15 when a predetermined excess weight is sensed by the weighing plate 32.
In FIG. 8a, between the weighing cell 32a which may, for example, comprise expansion measuring strips, and the control device 20 an electric amplifier 33 and an evaluating device 34 are connected. The evaluating device 34 sums in an analog manner the electric signals emitted by the weighing cell 32a for the purpose of determining the weight of the fiber tufts and/or heavy foreign bodies impinging on the weighing plate 32. When a predetermined limit pulse amplitude or energy is reached, the heavy body separating device is triggered as described in connection with FIG. 7b.
The evaluating device 34 may be so structured that not only the total weight is evaluated but also the under-the-curve areas of the individual coherent pulse signals are statistically evaluated as shown in FIGS. 8b and 8c. This additionally permits a determination of the fiber tuft sizes and the degree of the opening of the fiber tufts.
In the diagram illustrated in FIG. 8b the force P applied to the weighing plate 32 is shown over time t. P1 designates a threshold value for the heavy particle separation. The force signal corresponding to F4 triggers the foreign body separation.
The sum of the areas F 1 -F 5 under the curve corresponds to the fiber tuft weight. The magnitude of each area under the curve, for example, F 1 is proportional to the tuft size, that is, to the degree of opening of the fiber tuft. FIG. 8c shows a diagram which illustrates the occurrence frequency as a function of the tuft size F. F m designates the mean fiber tuft size corresponding to the mean fiber tuft weight.
Turning to FIG. 9, there is shown therein an embodiment similar to that illustrated in FIG. 4, except that the surface 17a of the detector plate 17 oriented towards the fiber tufts A is situated at a distance a of a horizontally supported plastic roller 35 which is rapidly rotating in the direction of the arrow H. The fiber material A passes through the gap a and is pressed by the surface of the roller 35 against the face 17a of the detector plate 17. Instead of a plastic roller 35 an endless belt 36 may be provided which is supported by end rollers 35'.
The detector plate 17 in FIGS. 9 and 10 is a surface sensor which contains a plurality of inductive sensor elements 17b which generate on their active surfaces a high-frequency electromagnetic field that changes as any metal part passes by. For generating such a field there is provided a coil of a high-frequency oscillator, embedded in a ferrite core. If a metal part enters into the field generated by the coil, in the metal part eddy currents appear which cause an energy loss in the field. The energy loss dampens the amplitude of the oscillation of the field, and this phenomenon is converted into a definite electric switching signal.
In FIG. 11, there are provided two cooperating conveyor belts 37, 38 trained about support rollers 39a, 39b, 39c and 40a, 40b, 40c, respectively. The belt portions between the support rollers 39b, 39c and 40b, 40c define a narrow channel 41 through which the fiber material A passes after the free fall. At the inside of the belt portion an area pressure sensor 42 and 43 is arranged. By virtue of the narrow channel 41, the fiber material A, together with any foreign body, is brought into the sensitive operational range of the sensors 42, 43.
Turning to FIG. 12, there is illustrated a further embodiment of the invention. In this embodiment, between the condenser 8 and the chute 10 a curved fiber tuft guiding channel 44 is provided. In the zone where the channel 44 merges with the inlet of the chute 10 a roll 35 is arranged which is provided with a plurality of webs 35'. The channel 44 is formed in part by a wall portion 44a which is made of plastic and which is spaced at a distance a from the roll 35. Underneath the chute 10 there is positioned a conveyor 37 which receives fiber material, together with the metal foreign body sensed by the detector plate 17. Between the upper reach and the lower reach of the conveyor 37 a metal detector 42 is disposed. Normally, the endless conveyor belt 37 is driven such that its upper reach travels from the left towards the right as viewed in FIG. 12. Above the upper reach of the conveyor belt 37, generally in alignment with the metal detector 42, a roll 45 is positioned. When the metal detector 42 senses the presence of a metal body on the upper reach of the conveyor belt 37, the driving mechanism of the belt 37 is reversed so that the metal body and some fiber material is moved to a waste collecting location towards the left. It is seen that in the normal, rightward travel of the upper reach of the conveyor belt 37 the material which is deposited onto the conveyor belt by the waste branch extending from the chute 10, rejoins the normal material flow beyond the right-hand end of the conveyor belt 37.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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An apparatus for separating foreign bodies from a stream of fiber material includes a vertical chute having an upper inlet and a lower outlet; a mechanism for introducing the fiber material into the chute inlet; and a detector positioned in the chute for emitting a sensor signal upon passage of a foreign body. The fiber material is propelled from the detector towards the chute outlet substantially solely by gravity. The apparatus further has a waste discharge opening provided in the chute between the detector and the chute outlet; a deflecting mechanism arranged in the chute and having first and second positions. In the first position the deflecting mechanism causes the stream of fiber material to proceed in the chute to and through the chute outlet and in the second position the deflecting mechanism causes the stream of fiber material to proceed through the waste discharge opening. The deflecting mechanism is moved from the first position into the second position in response to a sensor signal emitted by the detector.
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FIELD OF THE INVENTION
The invention relates generally to ancillary automotive equipment and more specifically to a collapsible rack for supporting an automotive body panel, such as a removable hardtop roof.
BACKGROUND OF THE INVENTION
Some cars are equipped with automotive body panels that can be removed. Removal of the automotive body panel can either be for short periods of time, such as portions of days or several days, or for extended periods, such as months. A removable automotive body panel gives the automobile owner the ability to reconfigure their automobile for any number of reasons.
The removal of an automotive body panel, however, presents the automobile owner with an issue of what to do with the automotive body panel until it is reinstalled on the automobile. The storage location of the automotive body panel must protect the automotive body panel against damage. Therefore, suitable supports and padding must be provided. An additional issue, however, to be considered is that automotive body panels can be heavy and/or bulky making lifting awkward and difficult. Therefore, if the storage location is not proximate to a location to which the automobile can be brought for removal of the automotive body panel, movement of the automotive body panel to the storage location must be accomplished. Movement of the automotive body panel can be difficult and can potentially cause damage to the automotive body panel.
One typical method of storing and moving an automotive body panel is to place it in a rack having wheels. However, a rack is typically not in use all of the time and, therefore, must be stored when it is not. For example, hardtop roofs, which are available for some convertible cars, can be typically stored for up to several months and then used for several months. Therefore, the rack must not only have the necessary structure to support and protect the automotive body panel, but it must have provisions to be easily stored when not holding the automotive body panel.
Based on the foregoing, it is the object of this invention to overcome the problems and drawbacks associated with the prior art.
SUMMARY OF THE INVENTION
The present invention is a collapsible rack for an automotive body panel, such as a hard top. The collapsible rack has a rigid frame with at least two abutment surfaces. A member projects outwardly from the frame and defines a support. The member is coupled to the frame to permit placement of the member in a first position or a second position. In the first position, the support of the member is so arranged to cooperate with the abutment surfaces to define a resting site for the automotive body panel and the member in the second position has the support either located relatively closer to the abutment surfaces, or laid alongside the frame.
With the member in its first position, the collapsible rack is designed to support the automotive body panel, while in the second position the collapsible rack is designed to be stored. As such, the collapsible rack takes up a much smaller volume in the stowed condition. In the preferred embodiment of the present invention, the frame has a plurality of wheels attached thereto that permit the collapsible rack to be rolled in both the first, with or without the automotive body part therein, and second positions. This assists in bring the empty collapsible rack to a location to be loaded, moving the loaded collapsible rack to a storage location, and storing an empty collapsible rack. As with any collapsible rack designed to hold items subject to damage from scratching due to contact with the surfaces of the collapsible rack, the collapsible rack optimally employs appropriate padding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the collapsible rack with the member in the first position.
FIG. 2 is a side view of the collapsible rack depicted in FIG. 1 .
FIG. 3 is a perspective view of the collapsible rack with the member in the first position and with a hardtop positioned therein.
FIG. 4 is a perspective view of the collapsible rack with the member in the second position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, the collapsible rack, generally referred to by reference number 10 , has a rigid frame 12 and projecting upwardly therefrom a member 14 . Referring to FIGS. 1 and 4, the member 14 has two positions. The first position, as shown in FIG. 1, is the position wherein the member extends at a right angle from the frame 12 . In this position, the collapsible rack 10 is ready to receive and support an automotive body panel. In the second position, shown in FIG. 4, the member has been repositioned relative to the frame 12 into a position to accommodate easy storage.
Returning to FIG. 1, the frame 12 has two abutment surfaces 16 positioned on the frame 12 , with one proximate each end 18 of the frame 12 . Each abutment surface 16 is defined by a bumper 20 that attaches to frame 12 . The abutment surfaces 16 can be created by any number of methods including but not limited to bends in the frame 12 . The location of the abutment surfaces 16 on the frame 12 is application dependent. Where the abutment surfaces 16 are placed at the ends 18 and bumpers 20 are employed, the bumpers 20 can double as end caps for the ends 18 of the frame 12 .
The frame 12 is rigid. It is depicted as manufactured from a tubular element, but other structures can be used depending upon the application. The frame 12 can be made from a single piece 22 or any number of segments 22 a-e . Where multiple segments 22 a-e are used, the segments 22 a-e are attached in turn one to the other and are fixed in position relative one to the other by any suitable means, such as welding or through bolts and nuts. The frame can be of any shape, but a simple U shape having two corners 24 is preferred. The U shape defines a plane 26 .
The frame 12 has a plurality of wheels 28 . The wheels 28 are attached to the frame 12 by any suitable means, such as threaded fasteners with nuts 29 . The wheels 28 , which define a plane 30 , are attached to the frame 12 opposed to the member 14 such that the wheels allow the collapsible rack 10 to be rolled on the wheels 28 with the member 14 in either the first (loaded or unloaded) or second position.
As shown in FIGS. 1 and 2, member 14 is T-shaped, and is received in a neck 32 of the frame 12 that positions the member 14 within a footprint 33 defined by the frame 12 . The neck 32 is designed to allow for the member 14 to rotate therein and be secured in the first or second positions by a spring detent 34 positioned in the member 14 . As those skilled in the art will appreciate, rotation is but one option to permit placement of the member 14 in the first position or the second position and the spring detent 34 is but one method of locking it in position. Other options for coupling of the member 14 in the first or second position include removing the member 14 from the neck 32 and placing the member 14 back in the neck 32 in an orientation of 180 degrees to the position shown in FIG. 1 . In addition, other temporary means for securing the member 14 could be used such as pins and the means might only function with the member 14 in one or the two positions. Where the neck 32 and member 14 are shaped appropriately, such as square, no additional securing means may be required.
The member 14 has a stem 36 with a free end 38 opposite a support 40 , which in the case of a T-shaped member is a crossbar. Referring to FIGS. 1 and 2, the support 40 with the member 14 in the first position is generally perpendicular to the stem 36 and parallel with the abutment surfaces 16 . Depending upon the material chosen for the support 40 , grips 42 , made from for example an elastomeric material, can be provided around the support 40 to cushion the hardtop or automotive body panel. The stem 36 of the member 14 is not straight throughout but has a 45 degree bend as shown at a in FIG. 1 .
As shown in FIG. 2, the member 14 can rotate within the neck 32 on a swivel axis. Preferably when the member 14 rotates within the neck 32 , the member 14 is capable of rotation from the first position to the second position and back without interference from the U-shaped frame 12 .
As shown in FIG. 3 when the member 14 is in the first position, the collapsible rack 10 will support an automotive body panel 44 . The automotive body panel 44 is placed in a resting site 46 defined by the abutment surfaces 16 and the support 40 , in this case more precisely grips 42 . The abutment surfaces 16 are positioned to prevent movement of the automotive body panel 44 in at least one direction. In this case, the abutment surfaces 16 prevent the automotive body panel 44 from sliding along the frame 12 .
FIG. 4 shows the member 14 in the second position, such that the support 40 moves closer to the abutment surfaces 16 , but preferably remains within the footprint 33 of the U-shaped frame 12 . In this case, the support 40 is equidistant from each abutment surface 16 . Preferably in this second position, the support 40 defines a line 47 that is generally parallel to the plane 26 defined by the frame 12 . As should be readily apparent, the support 40 is also closer to the frame 12 than when in the first position. The collapsible rack 10 is therefore taking up less volume. In this view, an optional feature of the wheels 28 can be seen. Any one, or all, of the wheels 28 can have a brake 48 for stopping the rotation of the wheels 28 for holding the collapsible rack 10 , in either the first (loaded or unloaded) or second positions, in a location on a surface, such as a floor.
Although the present invention has been described in considerable detail with reference to the preferred version thereof, other versions are possible. Therefore, the spirit and scope of the invention should not be limited to the description of the preferred versions contained herein, but it should be construed according to the following claims.
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A collapsible rack for supporting an automotive body panel, such as a removable automobile hardtop. The collapsible rack supports the panel and becomes more compact for storage. The collapsible rack has a T-shaped member that is removable for placement of the rack in a truck of an automobile, or for stowage in a neck defined by the frame. In a first position, the frame and member hold the hardtop or automotive body panel upright. In a second position, the member is stowed in the frame.
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BACKGROUND OF THE INVENTION
This invention is generally directed to a novel joint for joining composite panels together to form a wall for a trailer body. More particularly, the invention relates to joined composite panels for trailer bodies, wherein each composite panel includes a plastic core member sandwiched between thin metal skins and joined together by novel joints.
Trailers of the general type disclosed herein include a variety of types of sidewalls. A typical well-known construction is a panel-type trailer which includes aluminum side posts. Generally, it is desirable to have a relatively thin trailer sidewall so that the total inside dimensions of the trailer body can be increased to carry the optimum amount of cargo. In addition, it is desirable to have a trailer sidewall which is lightweight.
OBJECTS AND SUMMARY OF THE INVENTION
A general object of the present invention is to provide a novel joint configuration for joining a pair of composite panels together in a trailer wall, wherein a plurality of such joined panels may be used to form the trailer wall.
An object of the present invention is to provide a novel wall for use in a trailer body, which wall is simple in design and economical to manufacture while at the same time providing maximum interior space in the trailer body.
Another object of the present invention is to provide a novel wall having a plurality of joined composite panels, wherein each composite panel includes a plastic core member sandwiched between thin metal skins.
These and other objects and features of the present invention will become more apparent from a reading of the following descriptions.
Briefly, and in accordance with the foregoing, the present invention discloses a novel joint for joining panels adapted for use in a wall of a trailer. The joint has at least two composite panels joined together. Each panel is formed from inner and outer thin metal skins and a plastic core sandwiched between the skins. At least a portion of the ends of the panels are spaced apart from each other a predetermined distance to define a gap therebetween.
Structure is provided to join the panels together along the outer skins. The joining structure may be formed by a portion of the outer skin of one of the panels overlapping the outer skin of the other of the panels and being attached thereto by suitable means, such as rivets. The overlapping portion may have a bulging section along the length thereof which aligns with the gap between the panels. The bulging section may extend along the entire height of the panels or may extend along substantially the entire height, such that flattened portions are provided at the top and bottom edges of the panels adjacent to the bulging section. This facilitates the attachment of top and bottom rails to the joined panels when the assembly is used as a trailer wall.
A member is attached to the inner skin of at least one of the panels. The member has a plurality of slots therethrough which are aligned with the gap for attachment of items to the wall.
In most embodiments, a portion of the inner skin of one of the panels overlaps the member. The overlapping portion has a plurality of slots therethrough which align with the slots provided through the member. In these embodiments, the member acts as a doubler to reinforce the slots provided through the overlapping portion.
In one embodiment, the member is attached to the inner skins of the panels and acts as a logistics plate.
In some embodiments, the member is seated against a stepped end portion of at least one of the panels. The member may have rolled edges which seat in indentations formed in the inner skins of the panels.
The member may be positioned between the inner skin and said core member of one or both of the panels. When the embodiments which use the stepped end portion, the member is preferably seated between the overlapping portion and the stepped end portion.
The member may be a separate member from the inner skins. Alternatively, the member may be formed by folding over the inner skin of one of the panels such that the member is integrally formed with the panel.
BRIEF DESCRIPTION OF THE DRAWINGS
The organization and manner of the structure and operation of the invention, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, wherein like reference numerals identify like elements in which:
FIG. 1 is a perspective view of a trailer having a plurality of joined panels forming the walls of the trailer which incorporates the features of the invention;
FIG. 2 is a perspective view of a trailer having a plurality of joined panels forming the walls of the trailer which incorporates the features of the invention;
FIG. 3 is a perspective view of a pair of joined panels used in forming a first embodiment of the wall of the trailer shown in FIG. 1, such panels being shown with the exterior side of the wall being predominantly shown;
FIG. 4 is a perspective view of the pair of joined panels of FIG. 3 shown with the inside of the wall being predominantly shown;
FIG. 5 is a cross-sectional view of the pair of joined panels shown in FIGS. 3 and 4;
FIG. 6 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 2 which incorporates the features of a second embodiment of the invention;
FIG. 7 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 2 which incorporates the features of a third embodiment of the invention;
FIG. 8 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 1 which incorporates the features of a fourth embodiment of the invention;
FIG. 9 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 1 which incorporates the features of a fifth embodiment of the invention;
FIG. 10 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 2 which incorporates the features of a sixth embodiment of the invention; and
FIG. 11 is a cross-sectional view of a pair of joined panels used in forming a wall of the trailer shown in FIG. 2 which incorporates the features of a seventh embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, specific embodiments with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that as illustrated and described herein.
Turning now to the drawings, a trailer 20, 20a constructed in accordance with the present invention is shown in FIGS. 1 and 2 can be connected to a tractor (not shown) by conventional means, such as a fifth wheel assembly. The trailer 20, 20a includes a body 22, 22a formed from a pair of rectangular sidewalls 24, 24a, a front wall 26, 26a, rear doors 28, 28a, a top panel or roof 30, 30a and a floor. The floor is supported by a conventional rear undercarriage assembly 34, 34a and has a landing gear 36, 36a secured thereunder. The top panel 30, 30a and an upper portion of the sidewalls 22, 22a are secured to a top rail 38, 38a, and the floor and lower portion of the sidewalls 22, 22a are secured to a bottom rail 40, 40a. Each of the top and bottom rails 38, 38a, 40, 40a are usually formed by an aluminum extrusion.
Each sidewall 22, 22a includes a plurality of vertical upstanding composite side panels joined together by a novel joint configuration formed in accordance with the present invention. Each composite side panel includes a core member sandwiched between an inner thin metal skin and an outer thin metal skin and bonded thereto by a suitable known adhesive or other like means. One advantage the composite panel used in the present invention is that it can be coined or stepped down easily by applying pressure to the area to be coined or stepped down, whereas in the prior art aluminum sidewalls, the aluminum sidewall could not be easily coined.
The inner skin and the outer skin are preferably approximately 0.026 inches thick. The skins are preferably made of aluminum; galvanized, full hardened steel, such as AISI Grade E full hard steel because of its cost effectiveness, or the like. Preferably, the outer skin is made of ASTM G90 galvanized steel and the inner skin is made of ASTM G60 galvanized steel. Aluminum may be used, but it may be too soft for some purposes and strength and punch resistance are sacrificed, however, aluminum is lightweight. Typically, each panel is four feet in width, but can be longer or shorter depending on the application. At least two panels are joined together by the novel joint configuration to form the sidewall 24, 24a of the trailer body 22, 22a.
Each core member is made of some type of compressible non-metal material, preferably thermal plastic, such as polypropylene or high density polyethylene. These materials are relatively inexpensive as compared to aluminum found in prior trailer wall constructions. In addition, because a composite panel is used, the weight of the trailer construction is reduced over trailers having aluminum sidewalls.
Attention is now directed to the various embodiments of the novel joint configuration used in forming the trailer sidewalls 24, 24a as shown in FIGS. 3-12. A first embodiment of the novel joint configuration 144 is shown in FIGS. 3-5. A second embodiment of the novel joint configuration 244 is shown in FIG. 6; a third embodiment of the novel joint configuration 344 is shown in FIG. 7; a fourth embodiment of the novel joint configuration 444 is shown in FIG. 8; a fifth embodiment of the novel joint configuration 544 is shown in FIG. 9; a sixth embodiment of the novel joint configuration 644 is shown in FIG. 10; a seventh embodiment of the novel joint configuration 744 is shown in FIG. 11; and a eighth embodiment of the novel joint configuration 844 is shown in FIG. 12. Like elements are denoted with like reference numerals with the first embodiment being in the one hundreds, the second embodiment being in the two hundreds, the third embodiment being in the three hundreds, the fourth embodiment being in the four hundreds, the fifth embodiment being in the five hundreds, the sixth embodiment being in the six hundreds, the seventh embodiment being in the seven hundreds and the eighth embodiment being in the eight hundreds. As shown in the drawings, only a portion of two joined panels 142a, 142b; 242a, 242b; 342a, 342b; 442a, 442b; 542a, 542b; 642a, 642b; 742a, 742b; 842a, 842b are shown. It is to be understood that a plurality of joined panels may be used to form each wall 124, 224, 324, 424, 524, 624, 724, 824. In addition, the novel joint 144, 244, 344, 444, 544, 644 ,744, 844 is only shown between one end of the two panels 142a, 142b; 242a, 242b; 342a, 342b; 442a, 442b; 542a, 542b; 642a, 642b; 742a, 742b; 842a, 842b. It is to be understood that a like joint is provided between each adjacent end of each panel used to form the trailer walls.
Directing attention to FIGS. 3-5, the first embodiment of the novel joint configuration 144 is shown connecting the ends of first and second composite panels 142a, 142b.
Panel 142a has an outer skin 150a which terminates at the edge of the core member 146a. The inner skin 148a extends a predetermined distance beyond the end of the core member 146a to define an extending portion 152. The extending portion 152 of the inner skin 148a has a plurality of spaced logistics slots 156 therethrough along the height of the panel 142a.
Panel 142b has an inner skin 148b which terminates at the edge of the core member 146b. The outer skin 150b extends a predetermined distance beyond the end of the core member 146b to define an extending portion 158. The portion 160 of the extending portion 158 proximate to the end of the core member 146b is coined or rolled and the portion 162 from the coined or rolled portion 160 to the end of the outer skin 150b is flat.
When the first and second panels 142a, 142b are connected together, the ends of the core members 146a, 146b are spaced from each other to define an air gap 164. The flat portion 162 of the outer skin 150b of panel 142b abuts and overlaps the outer skin 150a of panel 142a and the coined or rolled portion 160 of the outer skin 150b is aligned with and spans the air gap 164 between the ends of the core members 146a, 146b. The slots 156 in the inner skin 148a align with the air gap 164. The shape of the extending portion 158 provides for additional space in the air gap 164.
A flat member or doubler 166 is also provided in the joint configuration 144. In this embodiment, a portion of the doubler 166 is positioned between the extending portion 152 of the inner skin 148a and the air gap 164 and the other portion of the doubler 166 is positioned between the inner skin 148b and the core member 146b such that the extending portion 152 overlaps a portion of the doubler 166. One end of the doubler 166 abuts against the end of core member 146a and the other end is positioned between the inner skin 148b and the core member 146b. The doubler 166 is bonded to the inside of the extending portion 152 by suitable means. The doubler 166 has a plurality of logistics slots 168 therethrough which align with the logistics slots 156 provided through the extending portion 152 and with the air gap 164.
To secure the joint configuration 144 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 170 are provided through the flat portion 162, the outer skin 150 the core member 146a and the inner skin 148a. A plurality of spaced rivets 172 are also provided through the outer skin 150b, the core member 146b, the doubler 166 and the inner skin 148b.
Attention is now directed to the second embodiment of the novel joint configuration 244 shown in FIG. 6. The novel joint configuration 244 is shown connecting the ends of first and second composite panels 242a, 242b.
Panel 242a has an outer skin 250a which terminates at the edge of the core member 246a. The inner skin 248a extends a predetermined distance beyond the end of the core member 246a to define an extending portion 252. The extending portion 252 of the inner skin 248a has a plurality of spaced logistics slots 256 therethrough along the height of the panel 242a.
Panel 242b has an inner skin 248b which terminates at the edge of the core member 246b. The outer skin 250b extends a predetermined distance beyond the end of the core member 246b to define an extending portion 258. As shown in the drawings, the extending portion 258 is flat; that is to say, it is not shown in the drawings with a coined or rolled portion as is shown in the first embodiment.
When the first and second panels 242a, 242b are connected together, the ends of the core members 246a, 246b are spaced from each other to define an air gap 264. A portion of the extending portion 258 of the outer skin 250b of panel 242b abuts and overlaps the outer skin 250a of panel 242a and a portion of the outer skin 250b is aligned with and spans the air gap 264 between the ends of the core members 246a, 246b. The slots 256 in the inner skin 248a align with the air gap 264. The extending portion 258 is bent outwardly to overlap the outer skin 246a of the panel 242a.
A flat member or doubler 266 is also provided in the joint configuration 244. In this embodiment, an end portion of the doubler 266 and one end thereof is positioned between the inner skin 248a and the core member 246a; a middle portion of the doubler 266 is positioned between the extending portion 252 of the inner skin 248a and the air gap 264; and the other end portion of the doubler 266 and other end thereof is positioned between the inner skin 248b and the core member 246b such that the extending portion 252 overlaps the a portion of the doubler 266. The doubler 266 is bonded to the inside of the inner skins 248a, 248b and the extending portion 252 by suitable means. The doubler 266 has a plurality of logistics slots 268 provided through its middle portion which align with the logistics slots 256 provided through the extending portion 252 and with the air gap 264.
To secure the joint configuration 244 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 270 are provided through the extending portion 258 which abuts against the outer skin 250a, the outer skin 250a, the core member 246a, the end portion of the doubler 266, and the inner skin 248a. A plurality of spaced rivets 272 are also provided through the outer skin 250b. the core member 246b, the other end portion of the doubler 266, and the inner skin 248b.
Attention is now directed to the third embodiment of the novel joint configuration 344 shown in FIG. 7. The novel joint configuration 344 is shown connecting the ends of first and second composite panels 342a, 342b.
Panel 342a has an outer skin 350a which terminates at the edge of the core member 346a. The inner skin 348a extends a predetermined distance beyond the end of the core member 346a to define an extending portion 252. The extending portion 352 of the inner skin 348a has a plurality of spaced logistics slots 356 therethrough along the height of the panel 342a.
Panel 342b has an inner skin 348b which terminates at the edge of the core member 346b. The inner skin 348b is coined or stepped to define a coined or stepped end portion 374. The outer skin 350b extends a predetermined distance beyond the end of the core member 346b to define an extending portion 358. As shown in the drawings, the extending portion 358 is flat; that is to say, it is not shown in the drawings with a coined or rolled portion.
When the first and second panels 342a, 342b are connected together, the ends of the core members 346a, 346b are spaced from each other to define an air gap 364. A portion of the extending portion 358 of the outer skin 350b of panel 342b abuts and overlaps the outer skin 350a of panel 342a and a portion of the outer skin 350b is aligned with and spans the air gap 364 between the ends of the core members 346a, 346b in an identical manner to that of the second embodiment. The slots 356 in the inner skin 348a align with the air gap 364. The extending portion 358 is bent outwardly to overlap the outer skin 346a of the panel 342a.
A flat member or doubler 366 is also provided in the joint configuration 344. In this embodiment, an end portion of the doubler 366 and one end thereof is positioned between the inner skin 348a and the core member 346a; a middle portion of the doubler 366 is positioned between the extending portion 352 of the inner skin 348a and the air gap 364; and the other end portion of the doubler 366 and other end thereof is positioned between the extending portion 352 of the inner skin 348a and the coined or stepped end portion 374 of the inner skin 348b such that the extending portion 352 overlaps a portion of the doubler 366. Thus, the extending portion 352 of the inner skin 348a in this embodiment is much longer than the extending portion 152, 252 in the first and second embodiment. The doubler 366 is bonded to the inside of the inner skin 348a and the extending portion 352 by suitable means. The doubler 366 has a plurality of logistics slots 368 provided through its middle portion which align with the logistics slots 356 provided through the extending portion 352 and with the air gap 364. The end of the extending portion 352 and the end of the doubler 366 terminate at the transition point of the coined or stepped end portion 374 and the remainder of the inner skin 348b. Because of the coined or stepped end portion 374, the inner skin 348a of the panel 342a is coplanar with the inner skin 348b of the panel 342b.
To secure the joint configuration 344 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 370 are provided through the extending portion 358 which abuts against the outer skin 350a, the outer skin 350a, the core member 346a, the end portion of the doubler 366, and the inner skin 348a. A plurality of spaced rivets 372 are also provided through the outer skin 350b, the core member 346b, the other end portion of the doubler 366, and the extending portion 352 of the inner skin 348b, such that the rivets 372 pass through the coined or stepped end portion 374.
Attention is now directed to the fourth embodiment of the novel joint configuration 444 shown in FIG. 8. The novel joint configuration 444 is shown connecting the ends of first and second composite panels 442a, 442b.
Panel 442a has an outer skin 450a which terminates at the edge of the core member 446a. The inner skin 448a extends a predetermined distance beyond the end of the core member 446a to define an extending portion 452. The extending portion 452 of the inner skin 448a has a plurality of spaced logistics slots 456 therethrough along the height of the panel 442a.
Panel 442b has an inner skin 448b which terminates at the edge of the core member 446b. The inner skin 448b is coined or stepped to define a coined or stepped end portion 474. The outer skin 450b extends a predetermined distance beyond the end of the core member 446b to define an extending portion 458. The portion 460 of the extending portion 458 proximate to the end of the core member 446b is coined or rolled and the portion 462 from the coined or rolled portion 460 to the end of the outer skin 450b is flat.
When the first and second panels 442a, 442b are connected together, the ends of the core members 446a, 446b are spaced from each other to define an air gap 464. Portion 462 of the extending portion 458 abuts and overlaps the outer skin 450a and the coined or rolled portion 460 is aligned with and spans the air gap 464 between the ends of the core members 446a, 446b in an identical manner to that of the first embodiment. The slots 456 in the inner skin 448a align with the air gap 464.
A flat member or doubler 466 is positioned such that one end abuts against core member 446a and the other end thereof is positioned between the extending portion 452 of the inner skin 448a and the coined or stepped end portion 474 of the inner skin 448b such that the extending portion 452 overlaps the doubler 466. The doubler 466 is bonded to the inside of the extending portion 452 of the inner skin 448a by suitable means. The doubler 466 has a plurality of logistics slots 468 provided through its middle portion which align with the logistics slots 456 provided through the extending portion 452 and with the air gap 464. The end of the extending portion 452 and the end of the doubler 466 terminate at the transition point of the coined or stepped end portion 474 and the remainder of the inner skin 448b. Because of the coined or stepped end portion 474, the inner skin 448a of the panel 442a is coplanar with the inner skin 448b of the panel 442b to provide a generally smooth surface therebetween.
To secure the joint configuration 444 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 470 are provided through the extending portion 458 which abuts against the outer skin 450a, the outer skin 450a, the core member 446a, and the inner skin 448a. A plurality of spaced rivets 472 are also provided through the outer skin 450b, the core member 446b, the end portion of the doubler 466, and the extending portion 452 of the inner skin 448b, such that the rivets 472 pass through the coined or stepped end portion 474.
Directing attention to the fifth embodiment of the novel joint configuration 544 shown in FIG. 9. This embodiment of the joint configuration 544 is identical to the embodiment of the joint configuration shown in FIG. 8, except that the doubler 566 is formed by folding or rolling the extending portion 552 under to form a double layer. Therefore, the doubler 552 is not a separate member as is shown in the other embodiments. Reference numerals in this embodiment shown in the drawings denote like structure in the other embodiments. The doubler 566 can be elongated such that it will have an end which is positioned between the core member 546b and the inner skin 548a and the rivets 570 will pass therethrough.
Attention is now directed to the sixth embodiment of the novel joint configuration 644 shown in FIG. 10. The novel joint configuration 644 is shown connecting the ends of first and second composite panels 642a, 642b.
Panel 642a has an outer skin 650a which terminates at the edge of the core member 646a. The inner skin 648a extends a predetermined distance beyond the end of the core member 646a to define an extending portion 652. The extending portion 652 of the inner skin 648a has a plurality of spaced logistics slots 656 therethrough along the height of the panel 642a and is shaped as described herein.
Panel 642b has an inner skin 648b which terminates at the edge of the core member 646b. The inner skin 648b is coined or stepped to define a coined or stepped end portion 674. In addition, the inner skin 648b has an indentation 680 proximate to the transition point of the coined or stepped end portion 674 and the remainder of the inner skin 648b, such indentation 680 being formed by coining the inner skin 648b. The outer skin 650b extends a predetermined distance beyond the end of the core member 646b to define a flat extending portion 658.
When the first and second panels 642a, 642b are connected together, the ends of the core members 646a, 646b are spaced from each other to define an air gap 664. A portion of the extending portion 658 of the outer skin 650b of panel 642b abuts and overlaps the outer skin 650a of panel 642a and a portion of the outer skin 650b is aligned with and spans the air gap 664 between the ends of the core members 646a, 646b in an identical manner to that of the second embodiment. The slots 656 in the inner skin 648a align with the air gap 664.
In this embodiment, the member or doubler 666 is not completely flat. The doubler 666 has rolled ends 674, 676 with a flat middle portion 678. The logistics slots 668 are provided through the flat middle portion 678.
The doubler 666 is positioned such that the end of rolled end 674 abuts against core member 646a and the other rolled end 676 is positioned between the extending portion 652 of the inner skin 648a and the coined or stepped end portion 674 of the inner skin 648b. The rolled end 676 is seated within the indentation 676. The extending portion 652 overlaps and is bent over to conform to the shape of the doubler 666. The doubler 666 is bonded to the inside of the extending portion 652 of the inner skin 648a by suitable means. The plurality of logistics slots 668 provided through its flat middle portion 678 align with the logistics slots 656 provided through the extending portion 652 and with the air gap 664. The shape of the doubler 666 provides for additional space in the air gap 664.
To secure the joint configuration 644 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 670 are provided through the extending portion 658 which abuts against the outer skin 650a, the outer skin 642a, the core member 646a, and the inner skin 648a. A plurality of spaced rivets 672 are also provided through the outer skin 650b, the core member 646b, the end portion of the doubler 666, and the extending portion 652 of the inner skin 648b, such that the rivets 672 pass through the coined or stepped end portion 674. The doubler 666 can be elongated such that it will have an end which is positioned between the core member 646b and the inner skin 648a and the rivets 670 will pass therethrough.
Attention is now directed to the seventh and final embodiment of the novel joint configuration 744, shown in FIG. 11, which is used to join panels 742a, 742b together.
Panel 742a has inner and outer skins 746a, 750a which terminate at the edge of the core member 746a. Inner skin 746a has an indentation 782 at a predetermined distance from the end thereof. The indentation 782 is formed by coining the inner skin 748b.
Panel 742b has an inner skin 748b which terminates at the edge of the core member 746b. Inner skin 746b has an indentation 784 at a predetermined distance from the end thereof. The indentation 784 is formed by coining the inner skin 748b. The outer skin 750b extends a predetermined distance beyond the end of the core member 746b to define a flat extending portion 758.
When the first and second panels 742a, 742b are connected together, the ends of the core members 746a, 746b are spaced from each other to define an air gap 764. A portion of the extending portion 758 of the outer skin 750b of panel 742b abuts and lays against the outer skin 750a of panel 742a and a portion of the outer skin 750b is aligned with and spans the air gap 764 between the ends of the core members 746a, 746b in an identical manner to that of the second embodiment.
A member 784 is provided for connection to the inner skins 746a, 746b. The member has rolled ends 786, 788 with a flat middle portion 790. A plurality of logistics slots 792 are provided through the flat middle portion 790.
The member 784 is positioned such that rolled end 786 is seated within indentation 782 and rolled end 788 is seated within indentation 784. The flat middle portion 790 spans the air gap 764. The plurality of logistics slots 792 provided through the flat middle portion 790 align with the air gap 764.
To secure the joint configuration 744 together, suitable means are provided. As shown in the drawings, a plurality of spaced rivets 770 are provided through the extending portion 758 which abuts against the outer skin 750a, the outer skin 742a, the core member 746a, the inner skin 748a, and the member 784. A plurality of spaced rivets 772 are also provided through the outer skin 750b, the core member 746b, the inner skin 748b, and the member 784. The rolled ends 786, 788 are seated within the respective indentations 782, 784 to provide for a smooth transition between the member 784 and the inner skins 746a, 746b.
In the embodiments which have a coined or stepped portion, i.e., FIGS. 7-11, when the panel is coined or stepped, the core member is squeezed or compressed between the inner and outer skins and the core member may slightly extrude outwardly from the end of the panel. In addition, coining the end portion of the panels condenses the plastic core member sufficiently to support clamping force or pressure from the rivets without subsequent loosening.
In each of the embodiments shown in FIGS. 1-10, the member or doubler 166, 266, 366, 466, 566, 666 is a member which reinforces the logistics slots 156, 256, 356, 456, 556, 656 provided through the extending portion 152, 252, 352, 452, 552, 652 of the inner skin 148a, 248a, 348a, 448a, 548a, 648a. In the embodiments shown in FIGS. 3-8, 10 and 11, the doubler 166, 266, 366, 466, 666 is a separate member and is formed from a heavier and stronger material than the material that is used for the skins 148a, 150a, 148b, 150b, for example, to provide strength and rigidity to the joint. It is to be understood that the folding over of the inner skin to form the doubler 566 as shown in FIG. 9 can be used in any of the embodiments shown in FIGS. 1-8 and 10.
The attachment of the doubler to the panels can be done by various methods including, but not limited to, adhesive, adhesive tie layers, rivets, staples, slug upset and pierce and coin. The slug upset consists of punching through both layers of material, but not to the point of shearing out the slug, removing the punch and upsetting, or coining, the pushed through slug material to produce an interlock. The pierce and coin involves shearing through both materials on multiple sides, but not all the way around a slug and then coining it to clinch the two pieces together.
The logistics slots 156, 168; 256, 268; 356, 368; 456, 468; 556, 568; 656, 668 provide means for which equipment can be engaged, for example by a clip, to the inner side of the sidewall 24, 24a of the trailer 20, 20a. The coined or rolled portion 160, 460, 560 of the outer skin extending portion 158, 458, 558 which is in line with the logistics slots 156, 168; 556, 568; 656, 668 and/or the rolled member 666, 766 provides extra clearance for logistics attachment. In the embodiments shown in FIGS. 3-5, 8 and 9, because the bulge formed by the coined or rolled portion 160, 460, 560 is provided on the outside of the trailer 20, a substantially smooth inner surface is provided within the trailer 20.
It is to be understood that the coined or rolled portion along the outside of the trailer can be used with joint configurations 244, 344, even though it is not shown in the drawings. It is also to be understood that the extending portion in any embodiment can be flat, as described with respect to the illustrated second embodiment.
Further, it is to be understood that while the present invention is described with respect to the trailer side walls, the novel joint could be used to join together panels used to form the front wall, rear doors, or a rear wall if rear doors are not provided.
While preferred embodiments of the present invention are shown and described, it is envisioned that those skilled in the art may devise various modifications of the present invention without departing from the spirit and scope of the appended claims.
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A novel joint is used to join panels of a trailer wall. The joint is formed by joining to two composite panels joined together. Each panel is formed from inner and outer skins and a core therebetween. At least a portion of the ends of the panels are spaced apart from each other to define a gap therebetween. A member is attached to the inner skin of at least one of the panels and has a plurality of slots provided therethrough which are aligned with the gap for attachment of items to the wall. Structure is provided to join the panels together along the outer skins. In most embodiments, a portion of one panel's inner skin overlaps the member and has a plurality of slots therethrough which align with the slots provided through the member. In these, the member acts as a doubler to reinforce the slots provided through the overlapping portion. In one embodiment, the member is attached to the inner skins of the panels and acts as a logistics plate. The member may be seated against a stepped end portion of at least one of the panels or may have rolled edges which seat in indentations formed in the panel inner skins. The joining structure may be formed by a portion of one panel's outer skin overlapping the other panel's outer skin and being attached thereto. The overlapping portion may have a bulging section along the length thereof which aligns with the gap between the panels.
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FIELD OF THE INVENTION
[0001] The present invention relates to hand tools, and particularly to a hand tool with an earphone, wherein the hand tool is installed with a digital processor which stores music and setting value about the twisting force applied to the hand tools so that as the applied twisting force is greater than the setting value, the user will be alerted, moreover, the user can hear music in working.
BACKGROUND OF THE INVENTION
[0002] Currently, the conventional hand tools are arranged with electronic devices, for example, strain gauges are widely applied to various spanners. Furthermore, some alert devices are equipped to the spanners for alerting the user that the applied twisting force is greater than a predetermined value so that the user can adjust the operation not to destroy the spanner or the driven object.
[0003] The general principle for measuring strain is to measure the pressure in some positions of the hand tools, generally, the positions are easily deformable portions of the hand tool. The pressure is transferred to the gauge for converting into twisting force. The twisting force value is displayed on a display on the hand tool. In some design, if an over-large force is applied, an alarm is emitted to the user by light effect or sound effect.
[0004] However in many working environment, noises are very large, which deeply affect the hearing ability of the worker so that it is often that the worker cannot hear the noises. As a result, the user cannot alert that the applied force has attained to a preset twisting value and the operation is continued. It is often that some expensive instruments will be destroyed.
SUMMARY OF THE INVENTION
[0005] Accordingly, the primary object of the present invention is to provide a hand tool with an earphone, wherein the hand tool is installed with a digital processor which stores music and setting value about the twisting force so as the applied twisting force is greater than the setting value, the user will be altered, moreover, the user can hear music in working.
[0006] To achieve above objects, the present invention provides a hand tool with an earphone which comprises a hand tool having an earphone hole for output sound from the hand tool. The hand tool is installed with an earphone. The hand tool is an electronic spanner. The hand tool is installed with a digital processor which stores with music file. The digital processor stores setting values about twisting force.
[0007] The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic view about the hand tool with an earphone of the present invention.
[0009] FIG. 2 is a schematic perspective view of the hand tool with an earphone of the present invention.
[0010] FIG. 3 shows the second embodiment of the present invention.
[0011] FIG. 4 shows the third embodiment of the present invention.
[0012] FIG. 5 shows the fourth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In order that those skilled in the art can further understand the present invention, a description will be provided in the following in details. However, these descriptions and the appended drawings are only used to cause those skilled in the art to understand the objects, features, and characteristics of the present invention, but not to be used to confine the scope and spirit of the present invention defined in the appended claims.
[0014] Referring to FIG. 1 , the hand tool with earphone function of the present invention is illustrated. The present invention includes a hand tool 1 has an earphone hole 11 at a predetermined position for speech output of the hand tool 1 . The hand tool 1 further has an electronic panel 12 which is connected to a digital processor (not shown). The digital processor is connected to the earphone hole 11 .
[0015] The digital processor can emit sound as the applied twisting force has achieved to a predetermined value. The digital processor further stores music files. Thus, the user can hear the music in working.
[0016] With referring to FIG. 2 , when the user operates the hand tool 1 of the present invention, the user can set a desired twisting force value, the plug 21 of the earphone 2 is inserted into the earphone hole 11 . Then the user wears the earphone 2 on the ears. Then the user can be alerted to known whether the twisting force applied has achieved to a predetermined twisting value.
[0017] Referring to FIG. 3 , the second embodiment of the present invention is illustrated. The present invention has a hand tool 1 . A predetermined position of the hand tool 1 is connectable to an earphone 2 for outputting sounds from the hand tool 1 . The hand tool 1 is installed with an electronic panel 12 . A digital processor is connected in the electronic panel 12 . The digital processor is connected to the earphone 2 .
[0018] The digital processor can emit sound as the applied twisting force has achieved to a predetermined value. The digital processor further stores music files. Thus, the user can hear the music in working.
[0019] With referring to FIG. 4 , the third embodiment of the present invention is illustrated. The present invention is used to an electronic adjustable spanner. The present invention has a hand tool 1 . A predetermined position of the hand tool 1 is connectable to an earphone 2 for outputting sounds from the hand tool 1 . The hand tool 1 is installed with an electronic panel 12 . A digital processor is connected in the electronic panel 12 . The digital processor is connected to the earphone 2 .
[0020] The digital processor can emit sound as the applied twisting force has achieved to a predetermined value. The digital processor further stores music files. Thus, the user can hear the music in working.
[0021] With referring to FIG. 5 , the fourth embodiment of the present invention is illustrated. The present invention is used to a spanner with a strain gauge. The present invention has a hand tool 1 . A predetermined position of the hand tool 1 is connectable to an earphone 2 for outputting sounds from the hand tool 1 . The hand tool 1 is installed with an electronic panel 12 . A digital processor is connected in the electronic panel 12 . The digital processor is connected to the earphone 2 .
[0022] The digital processor can emit sound as the applied twisting force has achieved to a predetermined value. The digital processor further stores music files. Thus, the user can hear the music in working.
[0023] The present invention is thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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A hand tool with an earphone comprises a hand tool having an earphone hole for output sound from the hand tool. The hand tool is installed with an earphone. The hand tool is an electronic spanner. The hand tool is installed with a digital processor which stores with music file. The digital processor stores setting values about twisting force.
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REFERENCE TO PROVISIONAL APPLICATION
[0001] This application is based on, claims priority to, and hereby refers to U.S. Provisional Patent Application Ser. No. 61/350,107, filed Jun. 1, 2010, the entire contents of which are incorporated herein by this reference.
FIELD OF THE INVENTION
[0002] This invention relates to shaping heated polymeric materials in a mold and more particularly, although not necessarily exclusively, to heating selected areas of the materials to forming temperatures while not forming other areas of the materials.
BACKGROUND OF THE INVENTION
[0003] Conventional thermoforming involves heating a polymer sheet to a pliable forming temperature (which depends at least in part on the type of sheet being heated), forming the sheet to a specific shape on a mold, and thereafter trimming unformed portions of the sheet to create a useful product. The sheet, sometimes referred to as “film” when thin gauges or certain types of materials are formed, is typically heated in an oven to the forming temperature so that it may be stretched into or onto a mold and then cooled to retain a finished shape. During the heating process, the entire sheet of material is heated to the forming temperature. Portions of the sheet that are not formed are usually referred to as “trim” and not reused until after further processing.
[0004] U.S. Pat. No. 4,878,826 to Wendt, the entire contents of which are incorporated herein by this reference, is one of many patents disclosing apparatus for thermoforming articles from sheets of plastic material. The apparatus of the Wendt patent may include both male and female molds together with a heating means and evacuation equipment. One such heating means is described as being hot oil circulating through an associated manifold such that it crystallizes a sheet of plastic material. See Wendt, col. 10, 11. 9-12. According to the Wendt patent, the sheet also may be pre-heated to 10-15% crystallization before entering the mold. See id., col. 12, 11. 50-57. Indeed, over-crystallization of the sheet apparently is an issue with the apparatus of the Wendt patent, requiring cold air to be injected into various mold cavities. See id., col. 13, 11. 53-65.
[0005] Thermoforming a plastic sheet necessarily distorts it. However, in some circumstances distortion of certain portions of a sheet is undesirable. As an example, distortion of portions of a sheet containing printing or art work may render them unintelligible or, at minimum, diminish their aesthetic appeal. Consequently, conventional thermoforming requires pre-printing of text and art in a distorted form so that the further distortion caused by the thermoforming can counteract the pre-distortion and, at least theoretically, produce intelligible images. Thus, providing apparatus and methods that would allow thermoforming of selected portions of a plastic sheet while avoiding distortion of other portions of the sheet thus would be a beneficial—albeit difficult—achievement.
SUMMARY OF THE INVENTION
[0006] The present invention accomplishes this desired result. Notwithstanding its use of an integral sheet of polymeric material, the present invention allows heating and forming of only selected portions of the material. By contrast, unformed portions of the material remain substantially undistorted and thus may contain undistorted printing, art work, or other text, symbols, or information without concern as to whether intelligibility of the information will be degraded during the forming process. Even if information is not present in unformed regions of a sheet, the mere fact that the unformed regions may retain their original shapes (typically but not necessarily flat) and thicknesses permits a broader range of products to be created. Further, apparatus and methods of the present invention admit productive use of the vast majority of each sheet (e.g. 95% in some cases), so that little trim is created when products are formed.
[0007] In at least some embodiments of the invention, energy-absorbing or -reflecting material may be employed to limit heat or other energy transferred to the polymer sheets. Such material may be in the form of metallic or other plates having simple or complex shapes. The plates may include cut-outs so that heat or other energy may be transferred efficiently to areas of a sheet that is to be thermoformed. Various embodiments of the invention also may utilize controllable banks of heaters to allow variable heating of the molds themselves.
[0008] It thus is an optional, non-exclusive object of the present invention to provide apparatus and methods for selectively thermoforming integral polymeric materials.
[0009] It is another optional, non-exclusive object of the present invention to provide apparatus and methods for thermoforming portions of a polymer sheet while not forming, or otherwise materially distorting, other portions of the sheet.
[0010] It is an additional optional, non-exclusive object of the present invention to provide apparatus and methods permitting text, art work, or other information to be printed on to-be-formed material in an undistorted manner yet remain intelligible post-forming.
[0011] It is also an optional, non-exclusive object of the present invention to provide apparatus and methods for selective thermoforming including use of mechanical heat-transfer barriers.
[0012] It is yet another optional, non-exclusive object of the present invention to provide apparatus and methods in which the heat-transfer barriers are in the form of plates having cut-outs through which heat may readily pass.
[0013] It is a further optional, non-exclusive object of the present invention to provide apparatus and methods for selective thermoforming using controllable banks of heaters to allow variable heating of the molds themselves.
[0014] It is, moreover, an optional, non-exclusive object of the present invention to provide apparatus and methods for selective thermoforming while limiting the amount of trim.
[0015] Other objects, features, and advantages of the invention will be apparent to persons skilled in the relevant art with reference to the remaining text and the drawings of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of exemplary thermoforming apparatus useful as part of or in connection with the present invention.
[0017] FIG. 2 is a perspective view of a portion of a mold comprising part of the apparatus of FIG. 1 .
[0018] FIG. 3 is a close-up view of part of the mold portion of FIG. 2 illustrating especially various plugs protruding upward from its surface onto which a formable sheet may be placed.
[0019] FIG. 4 is a generally elevational view of an exemplary heat-sinking plate that may comprise part of the present invention.
[0020] FIG. 5 is a close-up view illustrating a formed polymer sheet contacting the mold part of FIG. 3 .
[0021] FIG. 6 is a generally elevational view of an exemplary product thermoformed in the manner of the present invention.
[0022] FIG. 7 is a generally side (edge) view of an exemplary product similar to that shown in FIG. 6 .
[0023] FIGS. 8A-C are various views of a plug consistent with FIG. 3 .
DETAILED DESCRIPTION
[0024] Depicted in FIG. 1 is exemplary thermoforming apparatus 10 . Apparatus 10 may be a conventional thermoforming machine, any number of which are available commercially. Preferably included as part of apparatus 10 are mold 14 (see also FIGS. 2-3 ) and heater 18 . A computerized controller including actuating means 22 may, if desired, be connected to heater 18 to control aspects of its operation. Actuating means 22 may comprise one or more manual switches as shown in FIG. 1 . Those skilled in relevant fields will recognize, however, that other manners of actuating heater 18 may be employed instead and that no controller is required.
[0025] Heater 18 preferably is positionable above mold 14 so as to supply heat only to one side of the mold 14 , which itself may be heated. FIGS. 2-3 show aspects of an exemplary version of mold 14 , which preferably (although not necessarily) is made of aluminum. Alternatively, mold 14 may be of composite type with both male and female components. As illustrated particularly in FIG. 3 , mold 14 may comprise a generally planar upper surface 26 from which one or more plugs 30 protrude. In use of apparatus 10 , plugs 30 function as three-dimensional objects about which sheets of polymer material are formed.
[0026] FIGS. 8A-C illustrate aspects of an exemplary plug 30 . Plug 30 may, if desired, be shaped generally as a cylinder and include section 31 comprising upper surface 32 together with side 33 . Formed in side 33 may be one or more notches 35 . At least two, and preferably three (or more) such notches 35 are incorporated into side 33 , with the notches 35 preferably (although not necessarily) being angularly spaced evenly about the circumference of plug 30 . For example, if plug 30 includes three notches 35 , each notch 35 may be spaced one hundred twenty degrees ( 120 °) from adjacent notches 35 . As depicted in the side view of FIG. 8B , notches 35 need not extend completely to upper surface 32 —although they may do so if desired.
[0027] Also detailed in FIGS. 2-3 as part of mold 14 are clamps 34 and alignment pins 38 . Clamps 34 surround some or all of perimeter 42 of mold 14 and retain to-be-formed material in place relative to upper surface 26 . Pins 38 , which like plugs 30 extend upward from upper surface 26 , facilitate alignment of the to-be-formed material relative to the plugs 30 .
[0028] An exemplary heat sink 46 appears in FIG. 4 . Sink 46 may be sized and shaped in any appropriate manner and may of any suitable heat-absorbing (or -reflecting) material. Preferably, however, sink 46 conforms to the shape of the corresponding mold or surface to be heated; as shown in FIG. 4 , exemplary sink 14 is in the form of a generally rectangular, generally planar aluminum plate. Consistent with the present invention, sink 46 may include one or more cut-outs 50 through its depth, each of which preferably is approximately the size and shape of an associated plug 30 . Sink 46 additionally may include openings 54 for receiving alignment pins 38 .
[0029] Apparatus 10 may be utilized with any thermoformable material. For certain purposes identified herein, however, the material beneficially is polyethylene terephthalate (“PET”), a polymeric plastic resin. Additionally beneficial for various of these purposes is that the PET be transparent. Again, though, the thermoformable material need not necessarily be clear or transparent, nor need it be PET. For ease of handling, the material advantageously may be preformed into a generally planar sheet of predetermined size and shape.
[0030] Among products usefully created using the present inventive techniques are plastic display holders for coins or souvenirs. Collector-quality versions of such holders may, and indeed typically, include color printing, art work, and text in unformed regions. By contrast, formed regions—into which coins are placed—preferably remain clear so as not to impede viewing of the coins. In some cases the holders may be combined back-to-back or placed within clear housings for further protection of the coins. Objects other than coins or souvenirs may be displayed, and products other than display holders may be created, however, as should be apparent to persons skilled in the art.
[0031] According to at least one method of the present invention, mold 14 may be heated to a preset temperature. The temperature may be selected so as to allow thermoformable material to be formed by the mold 14 and so as to be sufficient to remove heat from the material. Preferably, however, the selected temperature is such that warping or chill marks will not be formed on or in the material.
[0032] After mold 14 is heated adequately, a sheet of material containing undistorted color printing, art work, or text (or combinations thereof) may be laid onto upper surface 26 of mold 14 . For at least some display holders, up to six colors may be printed on each side of the sheet, with opaque material (text and art work) then printed over the printed colors. Of course, any or all of the printed matter may be omitted if not needed in the final product. Nevertheless, when present, the printed matter need not be pre-distorted, as it is not subject to material distortion during the forming process.
[0033] Assuming the above-described coin display holders are to be created, the sheet preferably contains openings through its depth for receiving alignment pins 38 , with the openings themselves positioned so that, when pins 38 are received, unprinted (clear) areas of the sheet are positioned on upper surface 26 atop some or all of plugs 30 . Clamps 34 may then be employed to secure the periphery of the sheet against upper surface 26 . Thereafter, sink 46 may be placed atop the sheet, with its openings 54 likewise receiving alignment pins 38 and at least some of its cut-outs 50 aligned with clear areas of the sheet. So placing sink 46 effectively sandwiches the sheet between mold 14 and sink 46 , precluding its longitudinal and lateral movement.
[0034] Following placement of the sheet relative to mold 14 , heater 18 is repositioned closely above sink 46 and activated for a selected period of time. Continuing with the display holder example, heater 18 may be activated for approximately thirty seconds. Heat or other energy from heater 18 transfers to sink 46 and, where cut-outs 50 in sink 46 exist, to (clear) areas of the sheet therewith aligned, where it is absorbed by the polymeric material.
[0035] As the exposed areas of the sheet absorb sufficient heat to reach their forming temperatures, mold 14 is evacuated so as to stretch (form) the material around plugs 30 . Heater 18 then may be repositioned away from mold 14 , the formed sheet of material may be allowed to cool, and sink 46 may be removed so as to expose the sheet of material. FIG. 5 illustrates material 58 in this exposed state, with the material 58 including (in this example) both unformed portions 62 and formed portions 66 . The sheet of material 58 thereafter may be removed from mold 14 and, if appropriate, divided into display holders, examples of which (designated 70 A and 70 B) are depicted in FIGS. 6-7 . Moreover, because only the periphery of material 58 was clamped during the forming process and need be trimmed, the vast remaining majority of the material 58 was available to create products. The processes of the invention may be repeated for any number of sheets of material.
[0036] Exemplary holder 70 A includes six formed portions 66 , five generally circular in shape and configured to receive a coin for display (see, e.g., FIG. 7 ). In FIG. 6 , the sixth formed portion ( 66 A) of holder 70 A includes embossed letters “USA.” By contrast, many of unformed portions 62 include color printing, with additional text and art work 74 printed thereon. Distortion-free text spelling “TEST” in printed areas of unformed portions 62 renders apparent the fact that the portions 62 did not distort while portions 66 were forming. Because holder 70 A is merely one of many examples of holders capable of being made by the present invention, in no way is the invention limited to holders having any particular number or type of formed portions 66 or unformed portions 62 . (Further, although not presently preferred, any of portions 66 may include distorted printing that becomes more legible when portions 66 are formed.)
[0037] Because plugs 30 may include notches 35 against which material 58 may be fashioned, formed portions 66 may include a corresponding number of “crush tabs” or “click-in features” protruding inward into the coin-receiving regions. These tabs provide some tolerances for portions 66 . If, for example, a portion 66 is slightly larger in diameter than a to-be-received coin, the coin, when inserted, may (frictionally) bear against the inwardly-protruding tabs to be retained in position. If unneeded, the tabs will be crushed or otherwise deformed upon insertion of the coin so as not to impede its retention.
[0038] The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention.
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Apparatus and methods of forming selected portions of integral sheets of material are disclosed. Unformed portions of the sheets may remain undistorted during the forming process, allowing them to contain text, art work, or other desired information without material risk of the information being degraded or becoming unintelligible during the forming process. This result may be accomplished, moreover, with less trim than usually occurs in conventional forming processes.
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ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected not to retain title.
this is a continuation of application Ser. No. 07/550,775 filed Jul. 10, 1990, now abandoned.
TECHNICAL FIELD
The invention relates to a systolic array architecture for a Vector Quantizer (VQ) for real-time compression of data to reduce the data communication and/or archive costs, and particularly to a tree-searched VQ.
BACKGROUND ART
Efficient data compression to reduce the data volume significantly decreases both data communication and archive costs. Among existing data compression algorithms, Vector Quantization (VQ) has been demonstrated to be an effective method capable of producing good reconstructed data quality at high compression ratios. The primary advantage of the VQ algorithm, as compared to other high compression ratio algorithms such as the adaptive transform coding algorithm, is its extremely simple decoding procedure, which makes it a great potential technique for the single-encoder, multiple-decoder data compression systems.
The VQ algorithm has been selected as the data compression algorithm to be used for rapid electronic transfer of browse image data from an on-line archive system to end users of the Alaska SAR Facility (ASF) and the Shuttle Imaging Radar C (SIR-C) ground data systems. For this on-line archive application, VQ is required to reduce the volume of browse image data by a factor of 15 to 1 so that the data can be rapidly transferred through the Space Physics Analysis Network (SPAN) having a 9600 bits per second data rate, and be accurately reconstructed at the sites of scientific users.
Another application of the VQ algorithm is the real-time downlink of the Earth Observing System (EOS) on-board processor data to the ground data users. For this data downlink application, VQ is required to reduce the volume of image data produced by the on-board processor by a factor of 7 to 1 so that the data can be transferred at real-time through the direct downlink channel limited at 1 Megabits per second data rate. These flight projects are currently undertaken by the National Aeronautics and Space Administration (NASA) for imaging and monitoring of global environmental changes.
Aside from these space applications, VQ can also be applied to a broad area in commercial industry for data communication and archival applications, such as digital speech coding over telephone lines, High Definition TV (HDTV) video image coding and medical image coding.
Vector quantization is a generalization of scalar quantization. In vector quantization, the input data is divided into many small data blocks (i.e., data vectors). The quantization levels (i.e., codevectors) are vectors of the same dimension as the input data vectors. A general functional block diagram for vector quantization is shown in FIG. 1. A codebook 10 comprised of codevectors C 0 , C 1 , . . . , C N-1 , is used at the transmit end of a communication channel 11 for data encoding and a duplicate codebook 10' is used at the receive end for data decoding. An encoding functional block 12 carries out the algorithm indicated by ##EQU1## where: x.sup.[k] represents the input data vector at time k; C i is the codevector; D(x.sup.[k], C i ) is the distortion function; N the total number of codevectors; and i.sup.[k] the optimal codevector index. The procedure defined by that equation is to select the stored codevector which yields the minimum distortion between an input data vector x.sup.[k] and the stored codevectors C 0 , C 1 . . . , C N-1 . The optimal index i.sup.[k] transmitted through the channel 11 is used at the receive end for the decoding function in block 13 carried out by using the index i.sup.[k] to look up the codevector C i .spsb.[k] in the codebook 10' that is then used as the reconstructed data vector x.sup.[k], which closely approximates the original data vector x.sup.[k]. The decoding procedure can be expressed as
x.sup.[k] =C.sub.i.spsb.[k] ( 2)
which is a table look-up procedure. Data compression is achieved since fewer bits are needed to represent the codevector indices than the input data vectors.
The codebook is generated by training a subset of the source data. The performance of the codebook is highly dependent on the similarity between the training data and the coded data. It then follows that the encoding procedure need only involve computing the distortion between each input data vector and all of the stored codevectors to select the best match. This algorithm is known as the full-searched VQ algorithm.
The major drawback of the full-searched VQ algorithm is the high complexity involved in drawing up (training) the codebook and then data encoding, which poses a great challenge for real-time application. To reduce the encoding complexity, the tree-searched VQ algorithm is employed such that the complexity only grows linearly rather than exponentially as the codebook size increases. For the tree-searched VQ, the codebook is divided into several tree levels, as illustrated in FIG. 2 for a 2-level tree-structured codebook. In the encoding process, the input data x.sup.[k] is first compared with the first level codebook C 0 ,C 1 , . . . C N .sbsb.1 -1 . Based on the selected codevector, the input data x.sup.[k] vector is then compared with the codevectors of the corresponding second level subcodebook C 0 ,0,C 0 ,1 . . . C N .sbsb.1 -1 , N .sbsb.2 -1 . This encoding procedure is repeated until the input data vector is compared with the last level subcodebook. The best matched codevector at the last level subcodebook is then used to represent this input data vector.
STATEMENT OF THE INVENTION
An objective of this invention for real-time data compression is to employ a systolic process in the VQ encoding procedure by taking advantage of the regular data flow pattern inherent in the VQ algorithm, particularly with a tree-searched codebook. By a combination of tree-searched VQ and systolic processing, a high throughput data compressor can be realized at a low hardware cost to meet the real-time rate requirement. This is the main theme of this invention. Thus, the primary objective of this invention is to provide a data compression system that can achieve a real-time encoding rate with small hardware cost utilizing systolic array architecture for a tree-searched VQ algorithm.
The systolic array consists of a network of identical Processing Elements (PE) that rhythmically process and pass data among themselves. It exploits design principles such as modularity, regular data flow, simple connectivity structure, localized communication, simple global control and parallel/pipeline processing functions. The systolic array is an effective architecture for implementation of matrix type computation.
This invention applies the systolic array architecture to both full-searched and tree-searched VQ. Briefly, the encoding procedure of a full-searched VQ can be formulated as a matrix-vector computation in a general form, where the multiply operator represents the scalar distortion computation and the add operator represents the summation of weighted scalar distortions, while the encoding procedure of a tree-searched VQ can be formulated as a series of matrix-vector computations with proper access to codevectors in the subcode-books. Examples are specifically given for a Binary Tree-Searched VQ (BTSVQ) of both a raw codebook and a difference codebook referred to hereinafter as RCVQ and DCVQ, respectively.
A secondary objective of this invention is to provide a fault tolerant systolic VQ encoder by including a spare Processing Element (PE) in a systolic array of PEs and a means for detection and replacement of a faulty PE with the spare PE to enhance the system reliability.
The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention will best be understood from the following description when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generalized functional block diagram of the prior-art vector quantization (VQ) algorithm.
FIG. 2 is a diagram of the prior-art encoding procedure of the 2-level tree-searched vector quantization algorithm.
FIG. 3 illustrates a block diagram of a systolic full-search vector quantizer.
FIG. 4 illustrates a systolic architecture for a Binary Tree-Search Vector Quantizater (BTSVQ).
FIG. 5 illustrates major functional blocks of a systolic binary tree-searched VQ encoder as applied to EOS on-board SAR processor.
FIG. 6 illustrates a functional block diagram of a BTSVQ Processing Element (PE) in the system of FIG. 5 for RCVQ.
FIGS. 7a and 7b together illustrate a detailed functional design of the memory bank shown in FIG. 5.
FIG. 8 illustrates a major functional block diagram for a systolic vector quantizer in which each vector quantization processing element has its own codebook memory.
FIG. 9 illustrate the distortion computing data path of the processing elements in the system of FIG. 8.
FIG. 10 illustrates a preferred implementation for the processing elements of FIG. 9.
FIG. 11 illustrates fault tolerance augmentation of a systolic vector quantization array using a spare processing element and dynamic reconfiguration switches for replacing a processing element when it is found to have a fault.
DETAILED DESCRIPTION OF THE INVENTION
As noted hereinbefore, Vector Quantization (VQ) is essentially a generalization of scalar quantization. For input image data, the stream of input pixels is divided into vectors (small blocks of pixels, e.g., 4×4 pixel blocks) and for a full-searched VQ, each input data vector is compared with every vector stored in a codebook. The index of the codebook vector of the smallest distortion is chosen as the encoded quantization vector to be transmitted. To reduce the encoding complexity, the tree-searched VQ technique is employed. This technique divides the codebook into levels of subcodebooks of a tree structure as illustrated in the background art section. The input data vector is successively compared with the stored codevectors in the subcodebook levels, i.e., ##EQU2## where x.sup.[k] is the input data vector sequence, k represents the time index, and the codevector notation is: C i .sbsb.1 for level 1; C i .sbsb.1 i .sbsb.2 for level 2; and so forth with C i .sbsb.1 i .sbsb.2 . . . i .sbsb.L for level L. The distortion function is D(x.sup.[k],C i . . . ) and the output coded data sequence is i.sup.[k]. The number of bits per input pixel is K and the input vector dimension is m pixels. Decoding is still a table look-up procedure,
x.sup.[k] =C.sub.i [k]=C.sub.i.sbsb.1 [k].sub.i.sbsb.2 [k] . . . .sub.i.sbsb.L [k] (4)
The compression ratio is Km/n for a fixed codebook scheme. The codebook memory size is
(2.sup.n.sbsp.1 +2.sup.n.sbsp.1.sup.+n.sbsp.2 + . . . +2.sup.n.sbsp.1.sup.+ . . . +n.sbsp.L)mK bits,
where n l represents the subcodevector bit length at level i, 1≦i≦L and N L =2 n .sbsp.L represents the number of codevectors. The encoding complexity is
2.sup.n.sbsp.1 +2.sup.n.sbsp.2 + . . . +2.sup.n.sbsp.L
operations per pixel. Compression ratios are more easily controlled by adjusting m (vector dimension) since the variation in n (codebook bit-length) significantly affects the codebook size and the encoding complexity.
The Binary Tree-Searched VQ (BTSVQ) is a special case of tree-searched VQ. For the BTSVQ, the number L of tree-levels is equal to the codebook bit length (n). The encoding of the BTSVQ can be expressed as ##EQU3##
For an RCVQ, namely a raw-codebook BTSVQ, the distortion computation between the input vector x.sup.[k] and the codevectors at the same binary tree level (C 0 and C 1 ) is, ##EQU4##
The codebook memory size is (2 n+ -2)mK bits. The encoding complexity is 2n operations per pixel.
For a DCVQ, namely a difference-codebook BTSVQ, the distortion computation between the input vector x.sup.[k] and the codevectors at the same binary tree level (C 0 and C 1 ) is simplified as follows ##EQU5##
Instead of saving of C 0 (j) and C 1 (j), the terms, ##EQU6## and δ(j)=C 0 (j)-C 1 (j) are stored in the subcodebook. The codebook memory size is (2 n -1) [m(K+1)+(2K+log m)] bits. The encoding complexity is n operations per pixel.
The DCVQ is an improved version of the RCVQ. For the RCVQ, the encoding and hardware complexity is reduced by half of that of the RCVQ. This is a unique characteristic for a BTSVQ.
Systolic Architecture for the Full-Searched VQ
For most distortion measures, such as the weighted mean square error, the vector distortion can be shown as the weighted sum of the scalar distortion, i.e., ##EQU7## for 0≦i≦N-1 and 0≦j≦m-1, where x(j) represents the j th component of the input data vector, C i (j) the j th component of the i th codevector, w(j) the weighting factor in the distortion measure, and d(i) the distortion between x and C i . The index of the codevector of the minimum distortion represents the coded data of the input data vector, i.e., ##EQU8##
For this class of distortion measure, the encoding procedure of the full-searched VQ shown in Equation (1) can be expressed in a general matrix-vector multiplication form, where the multiply operator represents the evaluation of scalar distortion and the add operator is the summation of the weighted scalar distortions. Therefore, Equation (9) can be systolic processed since matrix type computations are well suited for systolic processing.
A systolic architecture for the full-searched VQ may thus be an array of processors, 0, 1, . . . ,N-1 and codebooks 0,1, . . . ,N-1, each codebook i having a stored codevector comprised of m components C i (0), C i (1), . . . ,C i (m-1), as shown in FIG. 3. The distortion parameter, d(i), is associated with processor i where the distortion is computed, for 0≦i≦N-1. The parameter d(i) accumulates the intermediate result as the codevector component C i (j) moves downward and the input data x(j) moves to the right synchronously. After m clock cycles, d(i) will consecutively contain the distortion between the input data vector and the i th Codevector. To perform Equation (9), two variables, I and D, are required to record the index and distortion of the codevector of the current minimum distortion. The variable D is initialized to be a large number. Both I and D enter processor 0 when d(0) is determined. They move down the array one processor per clock cycle. At processor i, D is compared with d(i). If d(i)<D, then I=i and D=d(i). As they flow out of processor N-1, I will contain the codevector index of the minimum distortion, representing the coded data.
For continuous data encoding, the next data vector with its own pair of I and D follows right after the current data vector so that the data are continuously pumped into the array. This can be achieved by cycling the codevector components C i (j) into processor i as the input data flows into the array. Each d(i) is reset after the vector distortion is determined.
For this systolic architecture having N processors and N codevectors, and each codevector has m components, the encoding speed is increased by a factor of N over a single processor architecture. The pipeline latency is N+m clock cycles. The throughput rate is constant at 1 pixel/clock for any vector dimension and code book size. Since typically N is chosen to be large to attain good reproduced image quality, a large number of processors are required. Therefore, in accordance with the present invention, by combination of tree-searched VQ and systolic processing, a high throughput VQ encoder can be realized with minimal hardware.
Systolic Architecture for Tree-Searched VQ
Equation (3) shows that the tree-searched VQ encoder is in effect a series of the full-searched VQ encoders. The key is to correctly address the next level subcodebook. This can be realized by tagging the index of the current tree level l to the indices of the previous tree levels 1,2, . . . l-1. The combined indices are then used to address the next level subcodebook l+1.
A systolic architecture for the tree-searched VQ is essentially a concatenation of L systolic arrays of the full-searched VQ, where L is the number of tree levels. Each stage l corresponds to one tree level l. The codevectors of each subcodebook are arranged as follows. Codevector components C i .sbsb.1 . . . i .sbsb.l (j) are allocated to processor i l of the lth stage array. There are N 1 . . . N l-1 m codevector components in each processor of the l th stage array. During the VQ encoding, the codevector components are addressed by the combined indices of the previous stages, i 1 . . . i l-1 . For this pipeline architecture the l th stage contains N l processors, which in total is ##EQU9## processors. The pipeline latency is ##EQU10## clock cycles. The system throughput rate is 1 pixel/clock, constant for any tree-structured codebook.
Systolic Architecture for Binary Tree-Search Raw Codebook VQ
A systolic architecture for the raw codebook binary tree-searched VQ (RCVQ) defined by Equation (6) is shown in FIG. 4 where the blocks d l (0) and d l (1) are distortion computation elements for implementing Equation (6); CP(0) and CP(1) are elements for comparison of the distortion; and buffer elements l delay the input data sufficiently to maintain synchronization of the data flow through the pipeline of distortion computation elements with the concatenated indices used to address the next stage l+1 codebooks. The preferred organization of each stage will be described more fully in the next sections.
The input data sequence continuously flows into the array. Note that at each stage the data vector is compared with two codevectors in memory. After the index of the current tree stage (level) is obtained, it is tagged to the indices of the previous tree stages (levels) to address the next stage (level) subcodebook. The index is attained at a rate of one bit per stage. At the end of the array, the concatenated indices, n=L bits in length, are formed to represent the coded data.
Since n=L for the binary tree-searched VQ, the overall system requires 2n processors. The pipeline latency equals n(2+m) clock cycles. The input data rate is 1 pixel per clock cycle, and the output data rate is n bits per m clock cycles. Therefore, the output data rate is effectively reduced by a factor of Km/n, the compression ratio. This systolic architecture of FIG. 4 only requires a small number of processors compared to the full-searched VQ scheme. It has the advantages of modularity, regular data flow, simple interconnection, localized communication, simple global control, and parallel/pipelined processing such that it is well suited for VLSI implementation.
Preferred Design of Systolic Binary Tree-Searched Raw Codebook VQ
An example of a preferred design RCVQ which lends itself to VLSI implementation for EOS on-board SAR applications is detailed in this section for a 10-bit codebook of a 4×4 pixel vector dimension. This results in 12.8:1 maximum compression ratio. Limited flexibility in compression ratio can be realized by varying the vector dimension. The mean square error criterion is chosen as the distortion measure. FIG. 5 illustrates the major functional blocks of a systolic binary tree-searched VQ encoder which are the processing element (PE) array 20, the VQ codebook memory banks 21 and an array controller 22, all of which are under synchronized control of an EOS Control and Data System (CDS) 23 as are a SAR processor 24 which presents the serial pixels in digital form and a downlink packetizer 25 which forms packets of VQ data for transmission to a ground station.
Detailed RCPE Design
The PE array 20 performs the distortion computation of the VQ algorithm. For a VQ encoder with an n-bit codebook, this can be realized by n identical PEs. FIG. 6 shows a functional block diagram of a PE for a RCVQ. It is designed to compute the mean square error distortion between an input data vector and each codevector pair.
The distortion computing of the raw codebook processing element (RCPE) design is primarily two mean square error operations. During the VQ encoding, the codevector pair components are addressed by the combined indices of the previous PEs i 1 i 2 . . . i l-1 . An accumulator accumulates the intermediate result as the codevector pair component C 1 and C 0 moves downward and the input data x(j) moves to the right synchronously. After m clock cycles, the accumulator will consecutively contain the mean square errors d 1 and d 0 between the input data vector x and the selected codevector pairs.
The index generator compares the distortion measurement d 1 and d 0 . If d 1 ≧d 0 then i l =0 else i l =1. Index i l is tagged to the indices of the previous tree levels to correctly address the next level subcodebook. At the end of the array, the concatenated indices, n bits in length, are formed to represent the coded data.
The RCPEs are identical, designed to fit into a single chip using VLSI space-qualifiable 1.25 μm CMOS technology. Assessment based on a detailed logic diagram and VLSI layout of the RCPE shows that the gate count is about 3,000 and the pin count about 37, which is well within the capability of present VLSI technology.
A detailed functional design of an RCPE is shown in FIG. 6. The pin name and definition of the RCPE and associated Memory Bank shown in FIGS. 7a and 7b is summarized in the following table:
______________________________________Signal Type Description______________________________________MEMORY BANKCLK Input System clockHA.sub.-- EN Input To enable the pixel address generatorHA.sub.-- LD Input To load the hierarchical vector addressCS (10:1) Input To enable the memory module #1 to #10A (15:0) Input System address busH/A Input To select either system address or hier- archical encoding addressR/W Input To select either memory read or memory writeOE Input Tri-state output controlD (15:0) Input System data busDCn (15:0) Output 16-bit output port of subcodebook #nPROCESSING ELEMENTDC (15:0) Input Codevector pairs from subcodebook moduleCLK Input System clock (at pixel rate)DI (7:0) Input 8-bit input image dataDO (7:0) Output 8-bit 16-stage pipelined image dataHn Output Index of vector generated at PE#n______________________________________
Detailed Memory Bank Design
The memory bank is composed of subcodebook memory modules, each storing a VQ subcodebook. FIGS. 7a and 7b show a detailed functional design of the memory bank 21 in FIG. 5. For the binary tree-searched VQ, the n-bit codebook is divided into n(=L for binary tree-searched VQ) hierarchical levels. The codevectors in each level l are stored in their corresponding memory module l. The size of the memory module l is 2 l mK(=2 l+7 ) bits. The total size of the memory bank is (2 n+1 -2)mK(=2 n+8 -2 8 ) bits. Although the modules of the memory bank differ in size, they assume a regular structure in terms of memory cell design. To enable the programmability of the codebook, the memory bank can be accessed in both read and write modes by the host system 23 of FIG. 5 via the array controller 22 during the initialization. During VQ encoding operation, each memory module can only be accessed to read or write by its associated RCPE. The total size in terms of the primitive memory cell for a 10-bit codebook is 2 18 bits.
Systolic Architecture for Binary Tree-Searched Difference Codebook VQ
FIGS. 8 and 9 show the architecture of the systolic array for the difference-codebook BTSVQ. The input data vector sequence continuously flows into the array. For difference-codebook BTSVQ at each stage, the inner product between input data vectors and the difference codevectors is computed and compared with the 2 th order difference codewords. After the index of the current tree level is obtained, it is tagged to the indices of the previous tree levels to address the next level subcodebook. The index is attained at a rate of one bit per stage. At the end of the array, the concatenated indices of n-bit length are formed and represent the coded data of the corresponding input data vector.
The array controller 22 interprets control parameters from the host system via the on-board SAR processor to set up P-0 the BTSVQ encoder and provides status data for the host system to do house keeping. It also provides the interface timing to upload/download the data among the VQPEs, SAR processor 24 and downlink formatter 25. It also generates timing and control signals to operate the VQPEs 22. The array controller is implemented with a programmable logic array (PLA) device and several data buffers. Due to the localized data/control flow of systolic array processors, the array controller logic is simple.
In this systolic difference codebook BTSVQ, each PE corresponds to one of several binary tree-levels, such as ten numbered 1 through 10 in the example to be described. The major functional blocks of each VQPE1, 2 . . . n of a BTSVQ shown in FIG. 8 are a subcodebook memory 26, distortion computation data path 27 and index generator 32.
For the DCPE of a BTSVQ, an n-bit codebook is divided and converted into n difference subcodebooks. The first-order and second-order differences of each codevector pair in level l are stored in the subcodebook as shown in FIG. 9. The size of difference subcodebook memory of DCPE at level l is 2 l-1 [m(K+1)+(2K+log m)] bits.
Referring to FIG. 9, the distortion computing datapath 27 of the DCPE design is primarily an inner product operator which is much simpler than the distortion calculator of the RCPE. During the VQ encoding, the difference-codevector components are addressed by the combined indices of the previous PEs, i 1 , i 2 . . . i l-1 . An accumulator accumulates the intermediate result as the difference-codevector component δ(j) moves downward and the input data x(j) moves to the right synchronously. After m clock cycles, the accumulator will consecutively contain the inner product Δ' between the input data vector x and the selected difference codevector.
The index generator compares the 2 th order difference codeword Δ with the distortion measurement Δ'. If Δ≧Δ', then i l =1 else i l =0. Index i l is tagged to the indices of the previous tree levels to correctly address the next level subcodebook. At the end of the array, the concatenated indices, n bits in length, are formed to represent the coded data. The comparator-based index generator makes it easy to perform error detection for PE. However, the subtracter-based index generator has simpler hardware.
Preferred Design of Systolic Binary Tree-Searched Difference Codebook VQ
To attain the light-weight, small-volume, and low-power requirements, VLSI technology is preferred for implementation of the DCPE of FIG. 9 as shown in FIG. 10. The building blocks include a pipeline buffer 30, one ID register 31, multiplexers 32, 33 and 34, static RAM array 35, complement or 36, multiplier array 37, carry save adder 38, and comparator 39. The on-chip static RAM array 35 includes a 512×9 RAM and an 32×20 RAM which are used to store the difference subcodebook up to level 6. For levels from 7 to 10, an additional external subcodebook memory is required for each level. An external memory interface is represented by an input EXTCD(8'.0) from external memory to a multiplexer 33 enabled by an input EXTCDEN for levels 7-10. This interface is built as part of each DCPE to support a 10-level systolic BTSVQ encoder with a common VLSI chip for each DCPE.
To enable the programmability, the difference subcodebook memory 35 can be read out of and written into by the host system via the controller 20 (FIG. 8) during the setup mode. While in the encoding mode, each subcodebook memory can only be read out of and written into by its associated PE. In the setup mode, the first-order codevector differences δ are stored into the subcodebook memory 35. Meanwhile, the second-order codevector differences Δ are entered and stored in a threshold register 40 of each PE. In the encoding mode, the input vectors, D1(7:0), are received from the on-board SAR processor 24 via the array controller 22.
The PE performs an inner product between the input vectors and the codevector differences. The inner product is stored in a register 41 and compared with the second-order codevector differences Δ stored in the threshold register 40 at the rising edge of a vector clock VCLK. A one-bit index bit is generated at level l and concatenated with index bits of the previous PEs for lower levels to address the next level l+1 subcodebook. The concatenated index bits of the last PE thus formed represent the coded data for the input data vector x. The pin name and definition of DCPE is summarized in the following table:
______________________________________Signal Type Description______________________________________VCLK Input Vector clockPCLK1 Input Pixel clock (phase 1)PCLK2 Input Pixel clock (phase 2)AB (8:0) Input 9-bit system address bus for subcodebook memoryD (19:0) Input 20-bit system data bus for subcodebook memoryWRCD* Input Write enable of subcodebook (active low)DI (7:0) Input 8-bit input image dataDO (7:0) Output 8-bit 16-stage pipelined image dataWRCSD* Input Write enable of threshold registerEXTCD (8:0) Input 9-bit codeword from the external subcode- book memoryEXTCDEN Input To enable multiplexer to accept EXTCD (8:0)AP (3:0) Input Address of pixel elements of vectorsIDP (8:0) Input 9-bit concatenated indices from previous PEsID (9:0) Output 10-bit concatenated indices______________________________________
Fault Tolerance Design
For a space mission, it is reasonable to assume a 5 to 10 year unmaintained mission life with a processor reliability goal well above 0.95. A fault tolerant architecture is required to achieve these goals. By combination of architectural fault tolerance and inherent error detection capability, a highly reliable VQ encoder can be attained, such as by a programmed diagnostic routine initiated by the control and data system which supervises the SAR processor, VQ compressor and downlink packetizer. When a fault is detected in any one PE, a "fault" signal is generated and associated with the PE suffering a fault.
As shown in FIG. 11, the linear systolic array of the VQ encoder is augmented with a spare Processing element SPE at the end of the array and dynamic reconfiguration switches (RS). Two switch designs, type RS-A and type B, are presented to support the fault tolerance reconfiguration. If there is a permanent fault in any active PE, the faulted PE will be detected and bypassed by a type RS-B switch at its output. Meanwhile the spare Processing element SPE at the end of the array will be activated by type RS-A switches for all PEs downstream in the array. The spare Processing element SPE is bypassed by a type RS-B switch at its output until called upon to serve. It is at that time that the VQ codebooks of the PEs are all switched starting with the PE having a fault and thus shifting each PE code book to the next PE of the array in a direction from the input end to the output end of the PE array. The reconfiguration switches are controlled by a "fault" signal stored in an array register by the diagnostic subroutine system which conducts the tests for detection of a faulty PE during the set-up time before encoding SAR data for transmissions.
In detecting a fault, a single computation unit (such as multiplier or adder) fault model may be used where it is assumed that at most one PE could suffer a fault within a given period of time which will be reasonably short compared with the mean time between failures. Since effective error detecting and correcting schemes, such as parity and Hamming codes, exist for communication lines and memories, failures in these parts can be readily detected and corrected by those methods. The fault mode concentrates on the permanent failures of a PE.
Two basic mechanisms can be applied to detecting faults in this type of system: on-line concurrent error detection and periodic self-test. On-line single error correction for arithmetic operations can be accomplished by arithmetic codes such as AN code or Residue code. For the EOS SAR processor, temporary distortion of images due to transient faults may be tolerable. Hence second error if any can be detected by periodic self-test which is performed during power-up and periodically during operation by temporarily halting compression of data. For the dual data path (RCPE) implementation, each PE is tested by applying the same input data and codevector to both its paths and use the comparator to determine if the two results are equal or not. If they are not equal, a permanent or a transient fault may exist in the PE. To determine whether it is a transient fault or a permanent fault, the same input and codevector are reapplied following the first detection of error. If the two data paths still generate different results, a permanent fault has been detected and reconfiguration is needed to avoid faulty PE.
For the DCPE design, predetermined test inputs are applied since there is only one data path and precomputed results corresponding to the inputs need to be stored. The comparator then compares the generated results with the stored values. If the two are the same, the PE is fault-free: otherwise, the same input is reapplied to find out whether it is a permanent or transient fault. Following the location of the faulty PE, the spare PE is switched in to maintain the size of the PE array.
The hardware overhead of the self-test and reconfiguration scheme is about 20%. In PE level, the overhead hardware includes two reconfiguration switches, one multiplexer, two registers, two comparators, one flag resister, one n-input OR gate, one control line, n input lines, and one output line. In PE array level, only one spare PE is required. It has been shown that error correction using arithmetic code is also cost effective. The encoding introduces redundant bits in the number representation. A proportional hardware increase takes place in register array and data path. The estimated hardware overhead is from 20% to 40% which should be able to fit in the PE chip of available die size 300 mils×300 mils.
The reliability improvement can be addressed as follows: If each PE has a reliability of R, then the reliability of 10 PEs is R 10 . For the reconfigurable array with one spare PE, the reliability becomes R 11 +11 R 10 (1-R). For example, if R=0.95, the reliability of nonredundant PE array is 0.60 while the reliability of redundant array is 0.90. This represents a 50% increase in reliability.
Conclusion
Although particular embodiments of the invention have been described and illustrated herein, it is recognized that modifications and variations may readily occur to those skilled in the art. Consequently, it is intended that the claims be interpreted to cover such modifications and variations.
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A system for data compression utilizing systolic array architecture for Vector Quantization (VQ) is disclosed for both full-searched and tree-searched. For a tree-searched VQ, the special case of a Binary Tree-Search VQ (BTSVQ) is disclosed with identical Processing Elements (PE) in the array for both a Raw-Codebook VQ (RCVQ) and a Difference-Codebook VQ (DCVQ) algorithm. A fault tolerant system is disclosed which allows a PE that has developed a fault to be bypassed in the array and replaced by a spare at the end of the array, with codebook memory assignment shifted one PE past the faulty PE of the array.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present disclosure relates generally to techniques for signal transmission with antenna diversity and has been developed with particular but not exclusive attention paid to the possible application in the framework of telecommunications systems based upon the CDMA/3GPP (Code-division Multiple Access/Third Generation Partnership Project) standard in its various versions, for example.
Reference to this possible application must not, however, be interpreted as in any way limiting the scope of the invention.
2. Description of the Related Art
In order to increase the performance of the aforesaid telecommunication systems, there have been proposed various transmission schemes: in this connection, the 3GPP standard has defined both open-loop techniques, referred to, respectively, as STTD and TSTD, and closed-loop solutions, based upon beam-forming techniques.
In order to improve the performance of the system, the 3GPP standard contemplates the use of techniques based upon the use of two transmitting antennas set at the base stations (BTS) in combination with strategies for encoding the data transmitted by them.
Recourse to the principle of antenna diversity in transmission, and, in particular, to the approach referred to as space-time coding (STC) with a number of transmitting antennas greater than two and increasingly complex encodings, draw on the pioneering results reported by G. J. Foschini et al. in Bell Labs Tech. J., Autumn 1996, and in the works of Telatar, “Capacity of multiantenna Gaussian channels” AT&T Bell Labs, Tech. Rep., June 1995 and once again of Foschini and Gans in Wireless Personal Comm., March 1998.
The above studies have demonstrated that the spectral efficiency of a device can be considerably increased by adopting diversity techniques, not only in reception, but also in transmission. Space-time coding (STC) techniques are able to exploit the characteristics of multiple-reflection transmission environments to distinguish independent signaling transmitted simultaneously in the same frequency band. These techniques prove very effective in environments (such as, precisely, the environment of mobile communication networks), in which the main problem to be faced is that of multipath fading.
In particular, Space-Time Transmit Diversity (STTD) techniques, to which reference has already been made previously, is a type of space-time coding that enables improvement of the performance in terms of error probability by maintaining unvaried the transmission rate by means of a pair of antennas in transmission and a corresponding encoding of the data flow sent to them. In view of its simplicity, this solution has been introduced in the 3G standard in the implementation stage.
The essential characteristics of this solution adopted by the 3GPP/UMTS standard may be inferred from the diagram of FIG. 1 . This scheme for data encoding, which is applicable in the cellular-communication environment in so far as it functions also with just one antenna in reception, basically envisages that the sequence of the input bits (b 0 , b 1 , b 2 , b 3 ) is transmitted unaltered via a first antenna A and is, instead, subjected to a combined action of shuffling and of complementing that is such as to bring the sequence of four bits referred to previously to be sent for transmission via the second antenna in the form of the modified sequence (b 2 , b 3 , b 0 , b 1 ).
From the point of view of QPSK coding and its representation in complex notation, this operation on the bits is mapped in a conjugation if the second bit (LSB) of the pair is complemented or in a conjugation with phase reversal (i.e., multiplication by −1) in the case where it is the first bit (MSB) of the pair that is complemented.
To complete the picture of the currently available solutions, it is also possible to cite the technique known as BLAST (Bell Labs Layered Space-Time), which contemplates the use of more than one antenna both in transmission and in reception. With this technique, spectral efficiencies higher than 30 bits/sec/Hz have been obtained, which cannot be obtained with conventional detection schemes, in environments that are not very noisy or not noisy at all and affected by multiple reflections.
Also a solution known as V-BLAST (Vertical BLAST) can be cited, which is substantially based upon a scheme that is simplified as compared to the BLAST technique, such as not to require codings between the flows transmitted and such as to enable, albeit with a presumably lower complexity, a performance in terms of spectral efficiency that is comparable with that of the BLAST technique.
At the moment, there are being studied techniques that envisage further improvement of the performance of the system by increasing the number of antennas in transmission and by partially modifying encoding, albeit by maintaining the compatibility with respect to the preceding versions of the 3GPP/UMTS standard—Release 1999.
For example, in the document RP020130 (now TR25.869) entitled “Tx diversity solutions for multipath antennas” presented at the TSG-RAN Meeting No. 15 held on Mar. 5-8, 2002, there is proposed the solution represented in FIG. 2 .
This is, in practice, a scheme that contemplates the presence of four antennas or, more precisely, four pseudo-antennas designated, respectively, by A a , A b , A c and A d . By adopting said scheme, the input signal x(t) is subjected, in a block designated by S, to the STTD-Rel. '99 coding procedure for each pair of antennas. This procedure uses the technique also known as Alamouti space-time block coding for generating two distinct signals x 1 and x 2 , which are to be subjected first to a multiplication by respective factors X and ξ in two multipliers in view of the supply to the antennas A a and A c . The same signals are once again subjected to a multiplication by two factors e jφ and e jΨ , respectively, (in practice, a phase rotation is performed) in view of the supply to the antennas A b and A d .
In practice, the pseudo-antennas in question are defined, respectively, as:
A a =A 1 +A 2 ,
A b =A 3 +A 4 ,
A c =A 1 −A 2 , and
A d =A 3 −A 4 ,
in the case where a balancing of power is required between the transmitting antennas; otherwise, we have:
A a =A 1 ,
A b =A 2 ,
A c =A 3 , and
A d =A 4 ,
where A 1 , A 2 , A 3 and A 4 are the physical antennas.
The diagram represented in FIG. 2 uses the Alamouti technique, which is based upon the concept of transmitting the first branch with diversity according to the STTD scheme (s 1 , s 2 , . . . ) via a first antenna (A 1 ) and a replica subjected to phase rotation via the second antenna (A 2 ). The second branch with STTD diversity is transmitted in a similar way via the antennas A 3 and A 4 .
Once again, FIG. 3 illustrates schematically a technique referred to as “phase hopping”, which contemplates a phase rotation between the antennas and between the symbols according to a given sequence of values (by maintaining the phase constant for at least two consecutive symbols).
In particular, the phase patterns proposed for the pseudo-antenna 2 and for the pseudo-antenna 4 are respectively: { 0 , 135 , 270 , 45 , 180 , 315 , 90 , 225 } and { 180 , 315 , 90 , 225 , 0 , 135 , 270 , 45 }, i.e., φ=Ψ+π. Of course, the values indicated in braces refer to angles expressed in degrees.
BRIEF SUMMARY OF THE INVENTION
One embodiment of the present invention provides an innovative solution for a diversity transmission scheme, which can be applied, for example, in a 3GPP UMTS system with more than two antennas, whilst maintaining, however, a complete compatibility with the currently standardized STTD scheme and, in general, with the transmission schemes that envisage using just two antennas in transmission.
An embodiment of the invention also regards a corresponding transmitter, a corresponding receiver and also a computer product directly loadable into the memory of at least a digital computer and comprises software code portions for performing the steps of a method according to the invention when the computer product is run on a computer.
An idea underlying an embodiment of the solution described herein contemplates inserting a further degree of freedom in the four-antenna system, separating the two pairs of antennas.
This can be obtained using for each of the two pairs of antennas:
a different CDMA code—for example, a different OVSF (Orthogonal Variable Spreading Factor) code or equivalent, such as a different Walsh-Hadamard (WH) code—and the same scrambling code; or else the same CDMA code, but with a different scrambling code.
In addition, the encoding on the two new antennas is partially changed by inserting an interleaving operation on 4 symbols—in this case (more in general on M symbols), whilst on the first two antennas the coding of the Release '99 standard is maintained to ensure compatibility in regard to systems that use the preceding versions of the standard.
In this connection, it is to be noted that the Release '99 in question is in course of implementation, and the first services are at the moment served on limited areas by some operators. This enables a higher performance to be achieved both with respect to the current scheme and with respect to the scheme currently under discussion at the 3GPP, eliminating at the same time the need for implementing a phase-hopping technique on the antennas 2 and 4 , this being an operation which of course presupposes the need to have available corresponding circuits, of which it is, instead, possible to do without by adopting the technique described herein.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
One or more embodiments of the invention will now be described, purely by way of non-limiting example, with reference to the annexed drawings, in which:
FIGS. 1 to 3 , which regard the prior art, have already been described previously;
FIG. 4 is a block diagram illustrating an embodiment of the transmission technique described herein; and
FIG. 5 illustrates an embodiment of the corresponding reception technique.
DETAILED DESCRIPTION
Embodiments of a method for transmitting signals using antenna diversity, for instance in mobile communication systems, transmitter, receiver and computer program product therefor are described herein. In the following description, numerous specific details are given to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
An embodiment of the solution provided herein refers to the case of the use of four transmission antennas designated respectively by Tx 1 , Tx 2 and Tx 3 , Tx 4 .
The solution described herein can, however, be extended also to a larger number of antennas. This can be obtained in a simple way both by varying the length of the interleaving on the additional pairs of antennas and by using another channeling/spreading code for these antennas, albeit maintaining unvaried the data rate. The implementation of such extensions on the basis of what is described herein constitutes for a person skilled in the art a design task such as not to require a further detailed description herein.
In this connection, it is once again to be noted that the aforesaid extensions do not in general entail an added burden in terms of hardware in so far as the generic base station of a third-generation mobile communication system (BTS 3 G) must already be able to transmit all of the codes simultaneously.
In the diagram of FIG. 4 , it is assumed that there is at input a flow of data S 1 , S 2 , S 3 , S 4 coming from a generic modulator a known type (M-PSK or M-QAM).
Said flow of data is sent to a block 10 capable of performing simultaneously a demultiplexing function (DMUX), together with a permutation function.
Basically, the module 10 splits the flow of input data between two lines designated, respectively, by 12 and 14 .
On the output line 12 , the data flow is sent without undergoing any variation, then to be transmitted to an STTD encoder 16 built in accordance with Release '99 of the 3GPP standard. There are then provided subsequent spreading operations with a code c 1 implemented in blocks 181 , 182 in view of forwarding to the antennas Tx 1 and Tx 2 after prior combination, in two adder nodes designated, respectively, by 201 and 202 , with the respective pilot flows, which are to be used by the receiver for channel estimation.
The portion of the transmitter associated to the output line 14 of the block 10 is structurally similar, in the sense that this too comprises an STTD encoder designated by 22 , with associated thereto at output two spreading modules 241 , 242 , which are to generate signals with a correspondingly widened spectrum. These signals are then supplied to the antennas Tx 3 and Tx 4 after addition of the respective pilot flows in two nodes designated by 261 and 262 , respectively.
The basic differences between the two “channels” coming under the lines 12 and 14 are the following:
whereas on the line 12 there is present the unaltered flow of data, just as it comes from the modulator at input to the block 10 , on the line 14 there is present a data flow in which each set of four symbols is temporally swapped (and consequently subjected to shuffling or interleaving) by subsets, typically in pairs, causing the sequence (S 1 , S 2 , S 3 , S 4 ) to become, at output from block 10 , the sequence (S 3 , S 4 , S 1 , S 2 ); and the spreading operation performed in the blocks 241 and 242 uses a second code c 2 , different from the code c 1 used by the spreading blocks 181 , 182 ; in other words, the two pairs of antennas Tx 1 , Tx 2 , on the one hand, and Tx 3 , Tx 4 , on the other hand, use different spreading codes, i.e., c 1 and c 2 , respectively.
The corresponding reception and decoding system, illustrated in FIG. 5 , contemplates the presence of a receiving antenna Rx, which is to receive, in a combined way, the signals coming from the transmission antennas Tx 1 , Tx 2 , Tx 3 and Tx 4 . The signals received present, of course, the typical alterations induced by propagation in the transmission channel C, namely, the addition of noise N and the presence, in the signals received by the various transmission antennas, of phenomena of multipath fading that act in different ways in regard to each signal (this fact being, precisely, at the basis of the operation of diversity techniques).
The signal coming from the receiving antenna Rx is sent to two matched filters 301 and 302 , which are to perform the de-spreading operation, eliminating the two spreading codes c 1 and c 2 introduced in the transmission stage.
The operation of the filters 301 , 302 is based upon the formulae given in what follows, which have been developed just for the case of just one antenna in reception but can be extended (according to criteria that are evident to a person skilled in the art) to the case of more than one antenna in reception.
In particular, the signal received in four signalling intervals can be expressed in the following way:
r 1 =S 1 h 1 ′c 1 −S 2 *h 2 ′c 1 +S 3 h 3 ′c 2 −S 4 *h 4 ′c 2
r 2 =S 2 h 1 ′c 1 −S 1 *h 2 ′c 1 +S 4 h 3 ′c 2 −S 3 *h 4 ′c 2
r 3 =S 3 h 1 ″c 1 −S 4 *h 2 ″c 1 +S 1 h 3 ″c 2 −S 2 *h 4 ″c 2
r 4 =S 4 h 1 ″c 1 −S 3 *h 2 ″c 1 +S 2 h 3 ″c 2 −S 1 *h 4 ″c 2
where:
−h 1 ′ and h i ″ represent the channel coefficients, and −c 1 and c 2 are the two spreading codes used on the two pairs of antennas Tx 1 , Tx 2 and Tx 3 , Tx 4 , respectively.
In the example given above, there has been considered, for reasons of simplicity, just one path from the generic transmitting antenna to the receiving antenna, but the mathematical expression given above can be readily extended—as is evident for a person skilled in the art—to the case of propagation on multiple paths, in general on N different paths.
The channel coefficients h 1 ′ and h i ″ are assumed as being more or less constant (or estimated to be such) on two symbol time intervals. The corresponding estimation, implemented according to what is proposed by the 3G standard in Release '99 (but also already starting from Release 5 ), is performed according to known criteria in a channel-estimation block 32 that sends the corresponding coefficients to a linear receiver 34 , which is to supply at output the symbols received S 1 , S 2 , S 3 , S 4 .
It will, however, be appreciated that the solution described herein, as regards the channel-estimation function, is in no way tied down to the adoption of the specific technique described in the 3G standard. The solution described herein can in fact be used also together with other estimation methods.
After executing the de-spreading operation, in the first two symbol time intervals, there is obtained:
S 1 ′=h 1 ′*r 11 +h 2 ′r 21 *
S 2 ′=h 2 ′r 11 *+h 1 ′*+r 21
S 3 ′=h 3 ′*r 12 +h 4 ′r 22 *
S 4 ′=−h 4 ′r 12 ′*+h 3 ′+r 22
whence we obtain the estimates S l ′ S 2 ′ S 3 ′ S 4 ′.
After another two symbol time intervals there is likewise obtained:
S 1 ′=h 3 ″*r 32 +h 4 ″r 42 *
S 2 ′=−h 4 ″r 32 *+h 3 ″*+r 42
S 3 ′=h 1 ″*r 31 *+h 2 ″r 41 *
S 4 ″=−h 2 ″r 31 *+h 1 ″*+r 41
whence we obtain the estimates S 1 ″ S 2 ″ S 3 ″ S 4 ″, where
r 11 =r 1 c 1
r 12 =r 1 c 2
r 21 =r 2 c 1
r 22 =r 2 c 2
r 31 =r 3 c 1
r 32 =r 3 c 2
r 41 =r 4 c 1
r 42 =r 4 c 2
Finally, the estimates of the four symbols received are extracted by summing the two sets of partial estimates according to the relations:
{tilde over (S)} 1 =S 1 ′+S 1 ″
{tilde over (S)} 2 =S 2 ′+S 2 ″
{tilde over (S)} 3 =S 3 ′+S 3 ″
{tilde over (S)} 4 =S 4 ′+S 4 ″
The estimates in question constitute, precisely, the output signals indicated in the diagram of FIG. 5 by S 1 S 2 S 3 S 4 .
The above convention has been adopted for reasons of simplicity, taking into account the fact that, clearly, the estimation of the output signals corresponds exactly to the input signals transmitted, i.e., the signals sent at input to the block 10 of FIG. 4 in the case of ideal operation of the system.
It will be appreciated that the decoding technique just described can be readily extended to the case of M generic pairs of transmitting antennas with M>2. Also in this case, the result can be obtained simply (and according to criteria that are evident for a person skilled in the art on the basis of the indications here provided) both by varying the interleaving length on the pairs of additional antennas, and by using another channeling/spreading code for them.
Also at the receiver end, it is possible to use a number of receiving antennas. Given that the reception system is linear, using the same method just described for each receiving antenna, the total estimate of the symbol will now be given by the sum of the various contributions of estimation supplied by each receiving antenna.
The tests conducted by the present applicant show that the adoption of an embodiment of the technique just described leads to considerable advantages in terms of performance. This applies as regards the performance in terms of bit-error rate (BER) and according to a direct comparison with the proposals currently under debate at the 3GPP (usually indicated by the post-fix “Rel 5 ”).
With respect to the known solution referred to above, one embodiment of the technique described herein moreover enables elimination from the base station of the phase-rotation function and the corresponding circuit (both at a hardware level and at the level of software components) by maintaining, at the same time, the so-called full rate; in other words, space-time coding does not reduce the transmission data rate. The results of the comparisons to which reference has been made previously used the same channel-estimation system proposed by the standard.
Once again, the demodulation technique described herein is maintained in the linear form, involving just de-spreading on two or more codes, which can be rendered perfectly serial and in line with a possible adoption of multiple-code transmission for a single client already envisaged by the standard.
Of course, as already indicated previously, instead of using, as in the example embodiments illustrated herein, two different scrambling codes c 1 , c 2 , with a solution that is altogether equivalent it is possible to keep the same scrambling code for the two sets of spreading blocks 181 , 182 and 241 , 242 illustrated in FIG. 2 , using, however, for the two channels corresponding to the lines 12 and 14 , at output from the module 10 , two different codes of the OVSF type (or of any other type that can be used in a CDMA scheme).
Consequently, without prejudice to the principle of the invention, the details of implementation and the embodiments may vary widely with respect to what is described and illustrated herein, without thereby departing from the scope of the present invention, as this is defined in the claims that follow.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety. These items referred to in the specification and/or listed in the Application Data Sheet that are incorporated by reference include the following:
G.J. Foschini et al. in Bell Labs Tech. J., Autumn 1996; Telatar, “Capacity of multiantenna Gaussian channels” AT&T Bell Labs, Tech, Rep., June 1995; Foschini and Gans in Wireless Personal Comm., March 1998; Third Generation Partnership Project/Universal Mobile Telecommunications System (3GPP/UMTS) standard—Release 1999; RP020130 (now TR25.869), “Tx diversity solutions for multipath antennas”, presented at the TSG-RAN Meeting No. 15, Mar. 5-8, 2002; and European Patent Application No. 03425535.6, filed Aug. 5, 2003.
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Encoded digital symbols are transmitted via a first pair of antennas and at least one second pair of antennas. The sets of symbols used for the transmission via the second pair of antennas are re-ordered temporally into subsets of symbols with respect to the symbols used for the first pair of antennas. For the first pair of antennas, there is used a signal subjected to encoding with a code-division-multiple-access code and subjected to spreading with a spreading code, and, likewise, for the second pair or pairs of antennas there are used signals subjected to encoding with respective code-division-multiple-access code and subjected to spreading with a respective spreading code. At least one between the respective code-division-multiple-access code and the respective spreading code used for the transmission via the second pair of antennas is different from the code-division-multiple-access code and from the spreading code used for the transmission via the first pair of antennas. The solution can be extended to the use of a plurality of second pairs of antennas in transmission and/or to the use of a plurality of antennas in reception.
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FIELD OF THE INVENTION
This invention relates to the fragrance and flavor fields.
SUMMARY OF THE INVENTION
Theaspiran (2,6,10,10-tetramethyl-1-oxaspiro[4,5]-dec-6-ene) of formula IV given in the following Formula Scheme is a known compound disclosed in Tetrahedron Letters 1995 (1969). It has now been found in accordance with the present invention that this compound has special organoleptic properties on the basis of which it is particularly suitable as an odor-and/or flavor-imparting substance.
Theaspiran can be detected in extremely slight concentrations in various essential oils, for example in raspberry oil or in the oil of the yellow passion fruit [see Helv. Chim. Acta 57, 1301 (1974); 55, 1916 (1972); 54, 1881 (1971)]. Nevertheless, the finding that theaspiran is well suited as an odor- and/or flavor-imparting substance must be considered to be surprising since none of these publications contain any reference to the special organoleptic properties of theaspiran.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention is accordingly concerned in one of its aspects with odorant and/or flavouring compositions which contain as the essential odour- and/or flavour-imparting ingredient theaspiran in practically pure form or in the form of mixtures (with the exception of natural mixtures containing theaspiran).
By practically pure theaspiran there should be understood, in particular, theaspiran which is free from the accompanying substances which are present in addition to theaspiran in the said natural extracts. As practically pure theaspiran in the scope of the present invention, there should also be understood, for example, synthetically prepared theaspiran.
The theaspiran used in accordance with the invention as an odour- and/or flavour-imparting substance is distinguished by special fresh, fruity odour or flavour properties. Of particular interest is a berry-like, green note and a sweetish, woody nuance appearing with increasing concentration. The theaspiran can accordingly be used, for example, for the perfuming or flavoring of products such as cosmetics (soaps, salves, powders etc), detergents, foods, luxury goods and drinks, the theaspiran preferably not being used alone but in the form of compositions which also contain other odour- or flavour-imparting substances.
In another of its aspects, the invention is concerned with a process for the manufacture of the odorant and/or flavouring compositions aforesaid, which process comprises adding theaspiran in practically pure form or in the form of mixtures (with the exception of natural mixtures containing theaspiran) to known odorant and/or flavouring substance compositions or mixing theaspiran in practically pure form or in the form of mixtures (with the exception of natural mixtures containing theaspiran) with natural or synthetic compounds or mixtures thereof suitable as ingredients of odorant and/or flavouring substance compositions.
Because of its very natural notes, theaspiran is especially suited as an odorant for modifying known compositions; for example, those of the Chypre type. Thus, for example, it is very well suited to combination with flower notes such as, for example, neroli and rose notes.
The concentration of theaspiran in the present compositions can vary within wide limits depending on the purpose of use; for example, between about 1 wt.% (detergents) and about 15 wt.% (alcoholic solutions). In perfume bases or concentrates, the concentrations can of course also be higher.
As a flavour-imparting substance, theaspiran can be used, for example, for the production or improvement, intensification, enhancement or modification of fruit or berry (e.g., raspberry, strawberry, apricot, citrus fruit, pear etc.) flavors in foods (yoghurt, confectionery etc), in luxury goods (tobacco etc) and in drinks (lemonades etc).
The pronounced flavour qualities of practically pure, especially synthetically prepared theaspiran, enables it to be used in low concentrations. A suitable amount lies in the range of 0.00001 ppm - 1 ppm, preferably 0.001 ppm - 0.1 ppm, in the finished product, namely the aromatised feed, luxury goods or drink.
Theaspirane may be added as such or in the form of flavouring agents to the products to be aromatized. In the latter case the flavouring agent can naturally contain other flavouring ingredients, especially those customarily used for the various aforementioned purposes.
The manufacture of odorant or flavourant compositions containing theaspiran can be effected in a manner known per se, see for example Perfume and Flavour Chemicals, S. Arctander, Montclair 1969, Perfume and Flavour Chemicals of Natural Origin, S. Arctander, 1960, Food Flavourings, Composition, Manufacture and Use, 2nd, ed., J. Merory, Westport 1968. Thus, flavouring agents may contain e.g. from 0.01 ppm-5°/oo of theaspiran.
Some effects which can be produced with theaspiran are compiled in the following Table.
Table______________________________________Aroma Amount Effect______________________________________Tobacco 0.005 ppm in the Better tenacity(Top flavour) finished product aroma; intensified fruitier impres- sion.Vanilla 0.03 ppm in the Rounding-off finished product effect; woody nuance.Raspberry 0.001 ppm in the Rounding-off finished product effect; pleasant, woody natural nuance.______________________________________
Theaspiran can be mixed with the ingredients used for flavouring substance compositions or added to such flavorants in the usual manner. By the flavorants used in accordance with the present invention there are to be understood flavouring substance compositions which can be diluted or dispersed in edible materials in a manner known per se. They can be converted according to methods known per se into the usual forms of use such as solutions, pastes or powders. The products can be spray-dried, vacuum-dried or lyophilised.
In the production of the aforementioned usual forms of use, the following carrier materials, thickening agents, flavour-improvers, spices, auxiliary ingredients and the like may, for example, be mentioned:
Gum arabic, tragacanth, salts or brewer's yeast, alginates, carrageens or similar absorbants, indoles, maltol, dienals, spice oleoresins, smoke flavors, cloves, diacetyl, sodium citrate, monosodium glutamate, disodium inosine-5'-monophosphate (IMP), disodium guanosine-5-phosphate (GMP), special flavor-imparting substances, water, ethanol, propylene glycol and glycerine.
From the foregoing it will be appreciated that the invention also includes within its scope a method of imparting an odour and/or a flavour to materials by applying thereto or incorporating therein an odorant and/or flavoring composition as hereinbefore defined or theaspiran in practically pure form or in the form of mixtures (with the exception of natural mixtures containing theaspiran).
The present invention is also concerned with a novel improved process for the manufacture of theaspiran, which process comprises treating 4-(2,6,6-trimethyl-2-cyclohexen-1-ylidine)-butan-2-ol of formula III in the following Formula Scheme with an acid.
Especially suitable acids are protonic acids such as inorganic and organic protonic acids (e.g. sulphuric acid, phosphoric acid, p-toluenesulphonic acid etc) or Lewis acids (e.g., BF 3 , SnCl 4 , ZnCl 2 , etc). p-Toluenesulphonic acid is the preferred protonic acid.
The cyclization of 4-(2,6,6-trimethyl-2-cyclohexen-1-ylidene)-butan-2-ol of formula II to theaspiran of formula IV can be carried out in the presence or absence of a solvent. Suitable solvents are inert solvent such as hexane, benzene, nitromethane, chlorinated hydrocarbons (e.g. chloroform etc) and ethers (e.g. dioxane etc). Benzene and toluene are the preferred solvents. The temperature is not critical; the treatment can be carried out at room temperature or at a higher or lower temperature.
Since it is known that theaspiran can be oxidised to the flavour-imparting substance theaspirone of formula V in the following Formula Scheme (see, for example, U.S. Pat. No. 3,645,755), the process provided by the present invention also provides an advantageous access to theaspirone. The preparation of theaspirone by oxidising theaspiran (prepared according to the foregoing process) in accordance with methods known per se also forms part of this invention.
Formula Scheme__________________________________________________________________________ ##STR1## ##STR2##β-Ionone 4-(2,6,6-Trimethyl-2- cyclohexen-1-ylidene)-2- acyloxy-but-2-ene R = acyl such as lower alkanoyl e.g. acetyl or aroyl, e.g. benzoyl. ##STR3## ##STR4##2,6,10,10-Tetramethyl-1- 4-(2,6,6-Trimethyl-2-oxaspiro[4,5]-dec-6-ene cyclohexen-1-ylidene)- butan-2-ol ##STR5##2,6,10,10-Tetramethyl-1-oxaspiro[4,5]-dec-6-en-8-one__________________________________________________________________________
Having regard to the foregoing Formula Scheme, the alcohol of formula III can be obtained from an acyloxy compound of formula II which, in turn, can be obtained from β-ionone of formula I. An acyloxy compound of formula II can be converted into the alcohol of formula III using, for example, a complex hydride such as lithium borohydride, sodium borohydride, potassium borohydride, lithium aluminium hydride etc. The reaction is expediently carried out in an alcohol, for example an alkanol, an alcohol/ether mixture or an ether as the solvent. The temperature at which the reaction is carried out is not critical. It is, however, preferred to carry out the reaction at a temperature of ca -10° C to 80° C.
An acyloxy compound of formula II can be obtained by reacting β-ionone of formula I with an enol acylate. Suitable enol acylates are isopropenyl acetate, isobutenyl acetate etc. The formation of an acyloxy compound of formula II is expediently carried out in the presence of catalytic amounts of acids (e.g. one of the aforementioned acids). p-Toluenesulphonic acid is the preferred acid. The enol acylate is expediently used in excess, whereby it also serves as the solvent. The reaction is preferably carried out at the reflux temperature of the reaction mixture and the ketone (acetone in the case of isopropenyl acetate) formed during the reaction is continuously removed by distillation.
It will be appreciated that formulae II and III include the four possible stereoisomers. Likewise, formulae IV and V include both diastereomeric compounds (i.e. both enantiomeric pairs).
The following Examples illustrate the present invention:
EXAMPLE 1
96 g of β-ionone are dissolved in 500 ml of isopropenyl acetate and treated with 0.6 g of p-toluenesulphonic acid monohydrate. The mixture is stirred at reflux temperature under an inert gas atmosphere for 24 hours. The excess isopropenyl acetate is distilled off from the mixture under a vacuum (temperature ≦50° ) and then the mixture is treated several times with hexane in order to liberate residual amounts of isopropenyl acetate and concentrated again. In this manner, there are obtained 108 g of brown-red 4-(2,6,6-trimethyl-2-cyclohexen-1-ylidene)-2-acetoxy-but-2-ene (formula II; R = acetyl).
UV (ethanol): λ max = 279 nm, log ε = 4, 265
IR (film): 1755, 1650, 1580, 1370, 1220/1205, 1150/1140, 1040, 1020, 945, 925, 885/875/865, 818 cm.sup. -1 .
NMR (CDCl 3 + TMS): δ = 6.65 - 5.85 (2H, m); δ = 5.78 (1H, broad t); δ = 2.20 and 2.15 (3H, each S); δ = 2.05 (3H, broad S); δ = 1.85 (3S, narrow m); δ = 1.28 ppm (6H, S). Ms: m/e: 234, fragments at 192, 177, 159, 149, 136, 121, 107, 91, 81, 77, 71, 65, 55, 43 = base peak.
The resulting crude acetoxy compound of formula II (108 g) is dissolved in 400 ml of ethanol (96%) and added dropwise within 10 minutes at 20°-30° C with slight cooling to a suspension of 20 g of sodium borohydride in 600 ml of 96% ethanol. The mixture is then heated until a slight reflux occurs and stirred at this temperature for 15 minutes. The end of the reaction can be detected by a spontaneous colour change from dark-yellow to lemon-yellow. After cooling to room temperature, the cloudy mixture is poured on to saturated ammonium chloride solution/ice and the mixture is extracted with hexane. After the usual washing to neutrality with water and drying over anhydrous sodium sulphate, the solvent is evaporated under a vacuum. There are obtained 96 g of crude 4-(2,6,6-trimethyl-2-cyclohexen-1-ylidene)-butan-2-ol (formula III).
UV (ethanol: λ max : 239 nm (log ε = 4).
IR (film): 3300, 1380/1370/1360, 1125, 1085, 950, 880, 830 cm.sup. -1 .
NMR (CDCl 3 + TMS). ε = 5.7 (1H, broad t); δ = 5.4 (1H, t with J = 7 Hz); δ = 3.9 (1H, m with J = 6Hz); δ = 2.55 (2H, broad t with J = 7 Hz); δ = 1.85 (3H, narrow m); δ = 1.25 (3H, d with J = 6Hz); ε = 1.23 ppm (6H, S).
MS: m/e: 194, fragments at 189, 161, 150, 135 = base, 121, 107, 93, 79, 69, 55, 45, 41.
96 g of the crude alcohol of formula III are heated to reflux in 1.3 liters of absolute benzene in the presence of 1 g of p-toluenesulphonic acid monohydrate for 10 hours. The solution is poured on to a cold saturated bicarbonate solution and extracted with hexane. After washing to neutrality and drying the extract over sodium sulphate, the solvent is evaporated in vacuo. The resulting 96 g of brown oily crude theaspiran of formula IV are separated from the first runnings and residue by short-path distillation. Yield: 77 g. of theaspiran of formula IV; boiling point = 75° C/0.2 mm Hg; n D 20 = 1.492.
IR (film): 1475, 1455, 1380, 1360, 1285, 1195, 1160/1150, 1130, 1110/1085/1080/1060, 1040, 1005, 990, 975, 930, 910/900, 880, 825, 775, 725 cm.sup. -1 .
NMR (CDCl 3 + TMS):
Isomer A
δ = 5.25 (1H, narrow m); δ = 4.1 (1H, broad m); δ = 1.75 (3H, narrow m); δ = 1.26 (3H, d with J = 6Hz); δ = 0.95 and 0.88 ppm (each 3H, s).
Isomer B
δ = 5.40 (1H, narrow m); δ = 4.05 (1H, broad m); δ = 1.7 (3H, narrow m); δ = 1.28 (3H, d with J = 6Hz); δ = 1.00 and 0.88 ppm (each 3H, s).
MS: m/e: 194, fragments at 179, 151, 135 = base peak, 123, 109, 96, 82, 77, 67, 55, 41.
EXAMPLE 2
5.7 g (30 mmol) of theaspiran are dissolved in 60 ml of anhydrous tert.butanol and treated within 2 hours at 40° C with 120 ml (ca 30 mmol of CrO 3 ) of tert.butylchromate solution [150 g of CrO 3 , 400 ml of tert.butanol, 140 ml of acetic anhydride]. The mixture is then stirred at 40° C. A further 20 ml of tert.butylchromate solution are added dropwise after 8 days and the same amount is added after 10 days. After a total of 16 days, the mixture is worked-up. The mixture is taken up in 1 liter of methylene chloride, covered with ice and stirred for 1 hour with 1 liter of sulphite/bisulphite solution [40 g of sodium bisulphite, 50 g of sodium sulphite, 1 liter of water]. The mixture is subsequently washed neutral with saturated sodium bicarbonate solution and water, dried over magnesium sulphate and evaporated to dryness. There are obtained 3.0 g of a yellow oil which is purified by column chromatography on a 30-fold amount of silica gel (particle size 0.063-0.200 mm) using hexane/ether mixtures containing 5-10% ether. The yield is 20% of theaspirone of boiling point 88° C/0.12 mm Hg.
UV (ethanol): λ max = 235 nm (ε = 11740).
MS: m/e: 208 = M+, 193, 175, 152, 110, 96, 82, 69, 55, 41. IR (film): 1675, 1630, 1480, 1450, 1390/80/70, 1345, 1310, 1280, 1270, 1160, 1090, 980, 920, 890 cm.sup. -1 .
NMR (CDCl 3 + TMS): 1H at δ = 5.72 (narrow quadruplet with J = 1.5 H 2 ); 1H at δ = 4.2° centred (multiplet); 3H at δ = 2.01 and δ = 1.99 (each singlet for the two diastereomers); 3H at δ = 1.30 (doublet with J = 6Hz)l 6H at δ = 0.99 and 1.02 (singlet for the gem dimethyl groups).
EXAMPLE 3
Example 3______________________________________Tobacco flavour (Top Flavour) Parts by weight______________________________________ A BMethylcyclopentenolone 2.0 2.0Ethyl acetate 2.0 2.0Ethyl anisate 4.0 4.0Butyl formate 4.0 4.0Cinnamaldehyde 7.0 7.0Capric aldehyde (10% in ethanol) 10.0 10.0Vanillin 10.0 10.0Amyl Salicylate 10.0 10.0C.sub.14 -Aldehyde (10% in ethanol) 10.0 10.0Ethylvanillin 20.0 20.0Heliotropin 20.0 20.0Propyl acetate 25.0 25.0Amyl formate 25.0 25.0Isoamyl acetate 25.0 25.0Coumarin 60.0 60.0Ethyl butyrate 75.0 75.0Benzaldehyde 110.0 110.0Benzyl benzoate 250.0 250.0Theaspiran -- 5.0Ethanol 331.0 326.0 1000.0 1000.0______________________________________
Composition B has a much fruitier aroma compared with composition A and persists substantially longer than composition A.
A 10% ethanolic solution of this top flavour is sprayed onto fresh cut tobacco, e.g. 2-10 g of the 10% solution onto 50 g of tobacco.
EXAMPLE 4
Example 4______________________________________Vanilla flavour Parts by weight______________________________________ A BGuaiacol (1% in ethanol) 1.0 1.0Heliotropin (1% in ethanol) 1.0 1.0Isoeugenol (1% in ethanol) 2.0 2.0p-Hydroxybenzaldehyde (1% inethanol) 3.0 3.0Vanillin 20.0 20.0Ethylvanillin 120.0 120.0Theaspiran (1% in ethanol) -- 3.0Ethanol 853.0 850.0 1000.0 1000.0______________________________________
Composition B differs organoleptically in a very advantageous manner from the composition A which is a conventional vanilla aroma. In particular, the theaspiran imparts a weakly woody and fruity note, by which means the vanilla fragrance is rounded off in a remarkable manner.
100 g of the above vanilla flavour are incorporated (using methods known per se) into 100 kg of caramel (milk/cream) toffees.
EXAMPLE 5
Example 5______________________________________Raspberry flavour Parts by weight______________________________________ A BLeaf alcohol 1 1Heliotropin 1 1Maltol 2 2Bergamotte oil 3 3Citral 12 12Diethyl succinate 13 13C.sub.14 -Aldehyde 15 15Jasmin absolute 15 15Celery oil 16 16Anethole 21 21Ethyl valerate 21 21Methyl anthranilate 22 22Yara-Yara 26 26C.sub.16 -Aldehyde 30 30Cinnamic alcohol 36 36Vanillin 40 40Indole 38 38Ethyl acetate 58 58β-Ionone 630 630Theaspiran (1% in ethanol) -- 10 1000 1000______________________________________
Composition B has a substantially more rounded-off action, is less obtrusively sweet and is more natural than composition A. The composition B provides a very pleasant, woody undertone.
100 g of the above flavour composition are incorporated into 100 kg of hard boild sweets (hard candy), using methods known per se.
EXAMPLE 6
Example 6______________________________________Pear flavour Parts by weight______________________________________ A BEugenol 1.0 1.0Geraniol 1.0 1.0Maltol 1.0 1.0Anethole (10% in ethanol) 2.0 2.0Vanillin 2.0 2.0Piperonyl acetate 2.5 2.5Geranyl propionate 5.0 5.0Linalyl acetate 10.0 10.0Amyl acetate 100.0 100.0Ethanol 875.5 875.5Theaspiran -- 5 1000.0 1005.0______________________________________
Composition B has a substantially rounder and fresher action than the composition A. Further, a pleasant woody undertone can also be detected in composition B.
50 g of the above flavour composition are used to aromatize 100 kg of jelly, using methods known per se.
EXAMPLE 7
Example 7______________________________________Composition (Fougere) Parts by weight______________________________________Bergamotte oil 200Amyl salicylate 150Coumarin 100Rhodinol extra 50Linalool 50Phenylethyl alcohol 30Citronellol 30Tree moss absolute (50% in ethylphthalate) 20Patchouli oil 20Eugenol 10Lilial 40Linalyl acetate 100Alcohol 95° 150Theaspiran (10% in ethyl phthalate) 50 1000______________________________________
By the addition of theaspiran, a very original Fougere composition can be produced from an initially conventional Chypre composition; especially remarkable is the aromatic fragrance reminiscent of woodland soil.
EXAMPLE 8
Example 8______________________________________Composition Parts by weight______________________________________Petitgrain oil Paraguay 400Geraniol extra 200Phenylethyl alcohol 160Methyl anthranilate 160p-Methylquinoline (10% in ethanol) 10Theaspiran (10% in diethylphthalate) 70 1000______________________________________
The initially slightly original flowery composition (neroli) has a substantially more rounded-off action and is fuller, softer and sweeter by the addition of theaspiran. The impression of a fresh, natural blossom fragrance is striking.
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Theaspiran is a novel fragrance and flavor substance. Its uses and novel process for making it are disclosed.
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BACKGROUND OF THE INVENTION
The present invention broadly relates to weaving machines and, more specifically, pertains to a new and improved construction of a warp let-off control device for weaving machines, especially for weaving machines with two or more partial or segmental warp beams.
Generally speaking, the warp let-off control device of the present invention comprises a warp beam, a stationary bar-shaped deflection element for the warp arranged subsequent to the warp beam in the direction of motion of the warp or warp threads as well as a tensioning beam movable by spring action and arranged subsequent to the deflection element in the direction of motion of the warp.
In a previously known control device of this type (cf. Swiss Pat. No. 629,549, granted Apr. 30, 1982) the warp let-off speed is controlled in that the tension, respectively the position, of the warp is sensed by the movable tensioning beam itself. According to the position of the tensioning beam, a signal is transmitted to the control device through an associated sensor. The control device transmits an appropriate signal to the warp beam drive means, whereby the warp let-off speed is adjusted. The reaction speed of this known warp let-off control device is limited in that the entire tensioning beam must follow warp tension changes, for which a certain time interval is required; consequently the warp let-off speed can only be adjusted after this time interval has passed.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved construction of a warp let-off control device which does not exhibit the aforementioned drawbacks and shortcomings of the prior art constructions.
Another and more specific object of the present invention aims at providing a new and improved construction of a warp let-off control device of the previously mentioned type which more rapidly adjusts the warp let-off speed of the weaving machine.
Yet a further significant object of the present invention aims at providing a new and improved construction of a warp let-off control device of the character described which is relatively simple in construction and design, extremely economical to manufacture, highly reliable in operation, not readily subject to breakdown or malfunction, and requires a minimum of maintenance and servicing.
Now in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the warp let-off control device of the present invention is manifested by the features that a sensing element of the control device is arranged at the warp or warp threads between the deflection element and the tensioning beam and which senses the tension, respectively the momentary path of travel of the warp threads leading over the deflection element and the tensioning beam, and the warp let-off speed is appropriately adjusted.
This permits displacing the working or operating region of the tensioning beam by appropriately preloading its return spring, for instance constituted by a torsion-bar spring, into such a position that a relatively large included angle of the warp threads arises at the sensing element. In this manner, a particularly large resultant sensing force can be produced by the warp tension components. This sensing force acts upon the sensing element and results in particularly rapid reaction to changes in the warp tension and therefore in an immediate adjustment of the warp let-off speed.
In one exemplary embodiment of the invention the warp beam comprises several partial or segmental warp beams. A separate sensing element together with an associated partial control device is associated with each such partial or segmental warp beam. The deflection element and the tensioning beam are each made in one piece and extend over the entire weaving width of the weaving machine. This permits achieving the situation in which the warp tension on one of the partial warp beams is reduced when the warp tension is increased on the other partial warp beam, since the increase of tension on the other partial warp beam pivots the continuous tensioning beam. As a result, the warp tension at the aforementioned one partial warp beam is reduced in consequence of geometry. The warp let-off speed associated with this aforementioned one partial warp beam is immediately reduced by this reduction in warp tension via the associated sensing element.
It is of particular significance that this mutually opposing modification of the warp let-off speeds of the two partial warp beams proceeds independently of whether the two partial warp beams have the same width or different widths. Due to the rapid responsiveness of the control device according to the invention, the adjustment of the warp let-off speeds on both sides of the weaving machine takes place in particularly short time.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 is a schematic representation of a weaving machine constructed according to the invention and seen from the warp side; and
FIG. 2 is a section taken along line II--II in FIG. 1 on an enlarged scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that to simplify the showing thereof only enough of the structure of the warp let-off control device has been illustrated therein as is needed to enable one skilled in the art to readily understand the underlying principles and concepts of this invention. Turning now specifically to FIG. 1 of the drawings, the apparatus illustrated therein by way of example and not limitation will be seen to comprise two machine end frames or cheek plates 1 and 2, between which a warp beam for instance as here shown by way of example constituted by two partial or segmental warp beams or warp supply rolls 3 and 4 are arranged. The partial warp beams 3 and 4 have the partial weaving widths A and B, respectively. The partial warp beam 3 is driven by an electric drive motor 5 and the partial warp beam 4 by an electric drive motor 6 via respective gear transmissions or gearing 7. The weaving warp or warp threads 8 run off the partial warp beam 3 and the weaving warp or warp threads 9 run off the partial warp beam 4 in the direction of the arrows 11 and 11a, wherein the arrow 11a designates the warp direction of motion when the warp at the associated partial warp beam is about to be depleted. The reference numeral 8a designates the position of the warp or warp threads when the associated partial warp beam or warp supply roll is empty. The entire weaving width of the machine is designated with the reference character C. The two partial warp beams 3 and 4 are supported in the interior of the weaving machine by an intermediate column or post 12.
The weaving warps 8 and 9 are conducted over a non-rotatable guide or deflection roll or element 13 stationarily mounted in the weaving machine frame subsequent to the warp beam or partial warp beams 3 and 4 in the direction of warp motion 11 and are further conducted over a tensioning beam or roll 14 arranged subsequent to the deflection roll or element 13, whence they are conducted through the further components of the weaving machine such as harnesses, reeds and so forth. The components 13 and 14 extend over the entire width C of the weaving machine.
A number of warp threads 15, for instance 100 warp threads, of the warp 8 is guided over a sensing or feeler roll 16. Analogously, a number of warp threads 17 of the warp 9 is guided over a sensing roll 18. Each sensing roll or element 16 and 18 is fastened upon a leaf spring 20 or equivalent member which is mounted in a mounting shoe 21 at the location 19. The mounting shoe 21 is fastened to the deflection roll 13 by threaded fastening means 22, such as threaded bolts. The mounting shoe 21 also carries a sensor 23. This sensor or sensing element 23 is connected by means of an electrical conductor 24 with a partial control device 25 associated with the partial warp beam 3. The other sensing roller 18 is fastened upon the deflection roll 13 in entirely analogous manner and a control line or conductor 26 leads to a partial control device 27 associated with the partial warp beam 4. The electrical drive motors 5 and 6 of the two partial warp beams 3 and 4 are controlled by the partial control devices 25 and 27 via conductors or lines 28 and 29, respectively.
The tensioning beam 14 is seated on a pivot lever 31 only schematically indicated in FIG. 2. The pivot lever 31 is connected at one of its ends with a torsion-bar spring 33 arranged in a stationary support beam or support beam tube 32. The torsion-bar spring 33 is connected at its other end with the side or check plates 1 and 2 of the weaving machine frame, for instance as disclosed in Swiss Pat. No. 631,756, granted Aug. 31, 1982. The tension of the warps 8 and 9 is accommodated by the torsion-bar spring 33 which is torqued at one of its ends.
The manner of operation of the described let-off control is as follows. The tensioning beam 14 can, for instance by appropriate preloading of the torsion-bar spring 33, be adjusted such that it assumes the position shown in full lines in FIG. 2. The warp threads 15 of the warp 8 of the partial warp beam 3 run directly from the deflection roll 13 to the tensioning beam 14. The warp threads 15, however, run at a certain angle over the sensing roller 16. The force parallelogram at the point of contact D of the warp threads 15 and the sensing roller 16 is drawn in full lines in FIG. 2. The two equally great warp tension forces are designated with the reference characters E and F. They give rise to the resultant sensing force G directed toward the sensor 23. Its amount can, for instance, be about 20% of the amount of the tension vectors E and F. The force G moves the sensing roller 16 counter to the action of the spring 20 downward to the left in FIG. 2, causing the spring 20 to approach the sensor 23 which may be constituted by a standard proximity sensor. This causes a signal to be transmitted to the related partial control device 25. The partial control device 25 adjusts an appropriate warp let-off speed of the related partial warp beam 3.
If the responsiveness of the control device at a sensing force G of about 20% of the warp tension is not sufficient, the tensioning beam 14 can be, for instance by means of appropriately greater preloading of the torsion-bar spring 33, urged into a working or operating region corresponding to the position 14a represented in chain-dotted lines in FIG. 2. The warp tension arising at the location D and directed toward the tensioning beam located at the position 14a now corresponds to the vector E'. There therefore arises a considerably greater sensing force corresponding to the vector G' of about 60% of the warp tension E'. This considerably increases the responsiveness of the control device and therefore the rapidity of adjustment of the momentary warp let-off speed.
The force relationships at the other sensing roller 18 correspond to those at the sensing roller 16 as is shown in FIG. 2.
When, for instance, the tension in the warp 8 increases and the tensioning beam 14 is temporarily pivoted out of the position 14a shown in chain-dotted lines in FIG. 2 into a position 14b shown in broken lines, then the warp let-off speed at the partial warp beam 3 is immediately increased through the associated sensor 23 and partial control device 25. Since the tensioning beam 14 is in the position 14b, the tension in the warp 9 is reduced in consequence of geometrical reasons. A correspondingly opposite signal is then transmitted to the partial control device 27 by the sensing roller 18, causing the warp let-off speed at the related partial warp beam 4 to be immediately reduced. The desired equal warp tensions in the two warps 8 and 9 are therefore reestablished in very short time.
As previously indicated, the warp let-off control device can also be employed with a continuous single warp beam having a length or width corresponding to the entire weaving width C. In this case, a single sensing roller 16 or 18 suffices. On the other hand, the control device can also be employed in weaving machines with, for instance, three partial warp beams. Then three sensing rollers are necessary, one for each partial warp beam. The tensioning beam 14 can also be subject to the action of two laterally arranged spiral or coil springs, for instance corresponding to the arrangement shown in German Pat. No. 1,138,715, granted May 16, 1963.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. Accordingly,
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The control device contains a deflection roll extending over the entire weaving width of the weaving machine, a tensioning beam pivotable about a support beam and also extending over the entire weaving width as well as a sensing roller arranged therebetween and subject to the action of a spring for sensing a portion of the warp threads of the warp, respectively of each partial warp beam. The tensioning beam is subject to the action of a preloaded torsion-bar spring. In this manner a sensing force arises at the sensing roller which can be increased from a first value to a second value according to the position of the tensioning beam. This permits the realization of increased responsiveness of the control device.
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FIELD OF INVENTION
The present invention relates to model aircraft and has particular reference to multi-propeller propulsion means therefor.
BACKGROUND
Prior practice in model aircraft with multiple propellers has been to use a separate engine for each propeller, resulting in a complex system with many operational difficulties. Primarily the multiple engines are not easy to start, tune and get running properly all at the same time. If one engine fails in flight the model aircraft is likely to go out of control in the hands of any but the most skillful and experienced hobbyist, suffering considerable and costly damage. In the present invention the multiplicity of propellers are driven by a single engine through a system of pulleys, belts, and gears so that the model operates similarly to the familiar single engine aircraft. Now if the engine fails in flight even the neophyte modeler can guide the aircraft to a safe landing. For added realism, the propellers on one side of the aircraft can be made to turn clockwise and on the other side to turn counterclockwise through reversing gearing, if desired.
DRAWINGS
For a more complete understanding of the invention, reference may be had to the accompanying diagrams in which:
FIG. 1 shows a typical four engine propeller driven model aircraft,
FIG. 2 shows the propulsion system of the aircraft of FIG. 1 in more detail,
FIG. 3 is a view of FIG. 2 from the front of the aircraft,
FIG. 4 is an alternative arrangement of FIG. 3, and
FIG. 5 is another alternative of FIG. 3.
DESCRIPTION
With reference now to FIG. 1 there is shown a pictorial view of a four engine model aircraft 10 in which the left wing 11 and fuselage 12 are partly broken away to reveal a portion of the new propulsion system 13. It will be seen that the engine 14 drives pulley 15 directly and through a system of belts 16, 17 and pulleys 18, 19 drives the propeller shafts 20, 21. A similar arrangement of pulleys and belts in the right wing 22 (see FIG. 2 and 3) drives the propellers of the right hand propulsion means 23 and 24. FIG. 2 is a top view (compressed sidewise due to space limitations) and FIG. 3 is a forward view of the complete propulsion system 13 driving both the right and left side propellers. As seen in FIG. 2 the engine 14 is mounted on transverse wing beam 25, with its shaft 26 protruding through beam 25. Carried on shaft 26 are a flywheel 28, pulley 15 and an air circulating fan 30 and a spinner 27 for engine starter engagement. Preferably, the shaft 26 is substantially on the centerline of the aircraft.
Propeller shaft 20 is journalled on one end in bearing 31 held in plate 29, which is secured to beam 25, and on the other end in thrust bearing 32 held in plate 33. Supports 34 span the space between the plates 29 and 33, and hold the plate 33 in fixed position. The toothed pulley 18 is attached to shaft 20 within the supports 34. The outer end of shaft 20 is threaded and shaped to accept the hub 35 of a propeller and a nut 36 to hold it in place. Propeller shaft 21, similarly journalled in bearings 37, 38 on plates 39, 40 respectively, carries the toothed pulley 19. Supports 41 hold the plate 40, and the outer end of shaft 21 is adapted to accept the propeller hub 42 and nut 43, The cowlings 54 are slipped over supports 41 and attached to the wing, with the end of shafts 20, 21 protruding therethrough. Serrated belt 16 extends around pulleys 15 and 18, driving shaft 20 and propeller hub 35, while serrated belt 17 over pulleys 18 and 19 drives shaft 21 and hence propeller hub 42 thereon.
Shafts 20 and 21 are also provided with collars 44 and 45 at the bearings 32 and 38 which prevent outward movement of the shafts 20, 21. A ball thrust bearing may also be used between collar 44 and bearing 32 if desired. When the belts 16, 17 need replacement, the collars 44, 45 are loosened to permit shafts 20, 21 to be taken out of bearings 31, 37 and the new belts slipped over the pulleys 18 and 19. Should any of the supports 34 or 41 be within the belt loop (as shown on the left of FIG. 3) they too must be capable of disassembly to permit replacement of the belts.
The basic system just described is repeated for the right hand propellers (on the left of FIG. 2) where shafts 46 and 47 are driven by belts 50, 51 and pulleys 52, 53.
All of the propeller shafts in FIG. 3 are driven in the same direction, e.g. clockwise. If counter rotation on one side of the aircraft is desired, a reversing gear set 54 (FIG. 4) may be inserted between engine shaft 26 and an intermediate pulley 55. The counter rotating propellers may be desirable for scale simulation or to reduce propeller net torque on the aircraft to zero, or to make the airflow over the model symmetrical right to left.
It will also be recognized that while the figures show a system where the thrust centerline passes essentially through the wing the thrust centerline may be above or below the wing in other models. If the offset is so large that a simple angular displacement of driving and driven shafts cannot be made within the model envelope, an idler pulley and belt or gears may have to be provided as outlined in FIG. 5. Here the shaft 20 is below the engine shaft 26, so that an idler pulley 57 is driven by belt 16, and shaft 20 is driven by belt 56.
It will be understood that many changes from the example described are possible. Six or more propellers could be driven this way. The engine may be mounted in any desired position: upright as shown facing forward; or facing aft; inverted, facing forward or aft; or on its side. The engine and propeller shafts are shown essentially parallel, but the engine shaft could be skewed for some starting configurations. In this case the inboard belts are twisted.
The fan for cooling the engine draws air through internal passages not shown but whose necessity will be recognized. Alternatively, the fan tip protrudes through the model belly and blows over the cylinder head of an inverted engine with the head external. The propellers can be geared up or down with selected pulley sizes. A recent trend is to geared down propellers for larger, slower models and more low speed thrust for large models.
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A multi-propeller propulsion system for model aircraft having a single engine and positive driving connections between the engine and each of the multiplicity of propellers. The positive drive may include toothed pulleys and serrated belts and gearing for example.
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FIELD OF THE INVENTION
This invention relates to a cable-controlled electrical safety switch device.
The invention relates more particularly to a cable-controlled electrical safety switch device, in which a movable assembly adapted to be connected to the cable and guided in a direction of movement with respect to a casing is subjected to the force of a cable-tensioning spring and has, on either side of an actuating member associated with an electrical switch, two flanks of a groove which actuate said member when the cable breaks and when the cable undergoes a transverse deflection respectively.
BACKGROUND OF THE INVENTION
Switch devices of this kind are intended more particularly to provide safety for personnel concerned with supervising, controlling or maintaining an installation extending over a considerable length along which the cable is tensioned. In the event of danger, the personnel apply a deflection to the cable to pull the movable assembly against the return force exerted by the spring. One of the groove flanks encounters the actuating member and this actuates the switch.
Amongst the malfunctioning to which devices of this kind may be subject we should first mention unintentional deflection to which the cable may be subjected when an operator comes into contact with it involuntarily. It is desirable that such involuntary deflection should not result in actuation of the switch. The same applies to quick deflections due to unauthorized use, to simulate a breakdown.
Another disorder to which such devices are subject is due to the elongation or shrinkage of the cable due to heat as a result of temperature variations in the cable environment. Variations of the order of 10° C. are in no way exceptional in any latitude, resulting in a steel cable 30 m long having length variations of the order of 3.5 mm.
It has also been found that inadequate tension of the cable allows very low frequency oscillations to develop, the amplitude of which may be sustained or increased in response to pulses due, for example, to the wind. When a certain amplitude is reached the result is abnormal actuation of the switches even in the absence of nearby staff.
The various factors which are likely to result in undesirable actuation of the switches therefore shows that the adjustment of such a device is relatively complex despite its apparent simplicity, and it is advisable to provide the installation engineer with adjustable such devices to allow for accommodation of the influence of the various parameters mentioned above.
OBJECT OF THE INVENTION
The object of the invention therefore is to provide a cablecontrolled electric safety switching device in which steps are taken to satisfy the above requirements.
SUMMARY OF THE INVENTION
According to the invention, the switch device is characterised in that the groove is disposed at the periphery of an adjustable element and has, in the direction of movement of the assembly, a dimension which varies along said periphery, the adjustable element being adapted to be oriented about its direction of movement so as to adjust the distance measured, along the direction of movement, between the actuating member and at least one of the flanks.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood from the following description and the accompanying drawings wherein:
FIG. 1 is an elevation of the device according to the invention in section along a plane containing the axis XX' of a movable control piston and the axis YY' of an actuating push member.
FIG. 2 is a side view in partial section along a plane containing the axis YY' and perpendicular to the axis XX'.
FIG. 3 is a perspective view of the control piston.
FIG. 4 is a detail in elevation of the control piston and
FIGS. 5 to 7 are diagrammatic views of three modified embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A safety switch 1 controlled by a cable 2 visible in FIG. 1 comprises a body 3 made preferably of a pressure cast metal so that, on the one hand, two separate compartments 4, 5 may be readily formed in its interior, said compartments having separate functions which will be described in detail hereinafter, and, on the other hand, to give it sufficient rigidity in response to the forces which may be transmitted to it on deflection of the cable 2, particularly when it is very long.
An inner surface 6 of the compartment 4 is elongated along an axis XX' and guides along said axis a piston 15 of a movable sliding assembly 7. Compartment 4 is closed laterally by a plate 3a (see FIG. 2) which is fixed to the body 3 and has a cylindrical surface 6a which completes the axial guidance of the piston 15, the outer side surface of which is of a generally cylindrical shape.
The movable sliding assembly 7 also comprises a rod 10 having a non-circular, e.g. hexagonal, sectional shape. An outer end 11 of rod 10, remote from the piston 15, is fixed adjustably by a screwthread 12a to a ring 12 receiving the end of the actuating cable 2.
Between its two ends the rod 10 is guided through a matching hexagonal aperture 13a in a bearing 13 fitted into an aperture 9 in the body 3. The bearing 13 also supports one of the ends of a deformable sealing bellows 14, the other end of which is fixed to the end of the ring 12.
The rod 10 has a collar 10a received in an axial inner recess 21 of the piston 15 and axially retained between a shoulder 20a and a retainer 20b so that the piston 15 is connected to the rod 10 in respect of axial displacement.
The end 16 of the rod has radial recesses in which springs 18 urge radially outwards balls 17 which are thus urged to engage in inner splines 19 of an axial bore 20 of the piston 15. This provides angular locking of the rod 10 relatively to the piston 15 while allowing orientation of the piston 15 with respect to the rod 10 about the axis XX' provided that sufficient force is transmitted to urge the balls 17 radially inwards against the springs 18.
The splined bore 20 is connected by the shoulder 20a to the end of the recess 21 remote from the ring 12.
The recess 21 receives the movable end 22 of a safety spring 23 operating in compression between the collar 10a and a fixed surface 24 such as the inner surface of the bearing 13.
Between two longitudinal ends of its outer side surface the piston has a peripheral recess or groove 25 having a trapezoidal sectional shape. The distance separating two opposite inclined flanks 31, 32, of groove 25, as measured parallel to the axis XX', increases progressively from one end to the other of the peripheral extent of the recess.
One of the flanks 31 of the recess is a conical surface while the other flank 32 is a surface of helicoidal type.
Thus as shown in FIG. 3 the said dimension progresses between a dimension--d--and a dimension--D--during a rotation of, for example, 180° about the piston axis. Thus by rotating the piston 15 about its axis XX' with respect to the rod 10 it is possible to vary the width of the recess 25 in front of an aperture 29a formed through a partition 29 between the compartments 4 and 5. To rotate the piston 15 a cover 27 (FIG. 2) is removed and access is available to the piston 15, with or without the use of a special tool, via an aperture or suitable recess in the plate 3a.
When the piston is in the inoperative state, while the cable 2 experiences an appropriate initial tension from the spring 23, a rounded push member 28 extending through the aperture 29a is engaged in the recess 25. The tension is provided by giving the cable an appropriate length or by adjusting the position of the ring 12 on the rod 10 by means of the screwthread 12a.
In the event of breakage of the cable, the spring 23 urges the piston in the direction G, and this movement is converted into a movement of direction J of the push member 28 when the latter is pushed by the flank 31 of the recess 25.
If, on the other hand, the cable 2 experiences deflection due, for example, to a person in danger actuating it, the piston 15 moves in the direction F and the flank 32 of the recess 25 acts on the push member to transmit thereto a movement in direction J.
Depending upon whether the distance between the flank 32 and push member 28 is larger or smaller, the cable must be given a varying deflection to produce a movement of the push member in the direction J.
The construction of the piston 15 enables the apparatus to be adjusted to various cable parameters. Depending on the length of the cable, the initial tension will have to be increased or reduced. This operation is carried out in the inoperative state by adjusting the length of the cable, which causes a reference, such as a circular index line 33 on the side surface along the conical flank 31 of the groove 25, to come into register with an axial graduation 34 which may be carried either by the body of the device or by the guide plate. The position of the line 33 with respect to the graduation 34 is indicative of the state of compression of the spring 23, which provides tension of the cable 2.
The graduation 34 is, for example, in Newtons, or alternatively in metres of cable length if each cable length has a corresponding predetermined optimal tension.
The cable is also subject to unintentional lengthening or shortening due to heat. It is important that such phenomena should not cause actuation of the push member 28. To this end, the side surface of the piston has a second temperature index line 35 which follows a substantially helicoidal curve along the flank 32 of the recess 25.
When the piston 15 is rotated with respect to the rod 10, the line 35 moves with respect to a second fixed graduation 36, 37, which may be a graduation in temperature intervals, or in deflections to give a cable of specific length to result in actuation of the push member. The reading allowed in this way is a measurement of the distance between the push member 28 and the flank 32 and hence measurement of the shortening that the cable 2 can experience without actuating the push member 28.
The graduation could alternatively be measured in degrees C. m, in other words in temperature intervals multiplied by metres of cable length. A distance between the flanks and the push member 28 allowing a temperature interval of 40° C. for 10 m of cable allows only an interval of 20° C. for 20 m of cable, for example. The second graduation 36 or 37 may also be carried by the body of the device or by the guide plate.
For example, for a given angular position of the piston 15, if the latter is adjusted axially in the direction of increasing the tension of the cable 2, the flank 32 moves towards the push member 28 and the temperature drop admissible without the push member 28 being actuated drops. However, this axial movement of the piston 15 results in a displacement of the line 35 with respect to the scale 36, such displacement taking into account the said reduction in the admissible temperature variation. The operator is therefore quite naturally induced then to adjust the piston 15 angularly to return the admissible temperature variation to its initial value.
The compartment 5 receives a system of switches 40, an intermediate transmission device 41, and a display means 42. The transmission device 41, examples of which are given in copending French patent application 88 03 961 to the same applicant and inventor, and enjoying the same priority date, is adapted to ensure that any quick unauthorized actuation of the switches 40a and 40b causes a specific condition which is then retained by the switches. More particularly, the transmission device 41 transmits the movements of the push member 28 to a yoke 52 which simultaneously actuates the two switches 40a and 40b irreversibly, even if the piston 15 has remained only a very short time in the position for actuation of the push member 28. Resetting of the device to enable the push member 28 and the switches 40a and 40b to return to the inoperative position requires the action of an authorized person on a lock 43 provided with a key.
Thus to adjust the device, the primary element to be taken into account is the properties of the cable, i.e. its length and its linear density; these two parameters allow the tension which is to be transmitted to it to be determined by adjusting its length either by means of a clamp or a tensioner, or by means of the ring 12, to bring the first index 33 into register with the corresponding graduation of the scale 34.
The piston 15 is then rotated until the second index 35 registers with the selected graduation on the second scale 36 which gives the temperature intervals which must not be exceeded when the adjustment operation is, for example, carried out at an ambient temperature of 15° C. Since a relatively high tension, and hence a relatively large distance between the flank 31 and the push member 28, is selected, on the one hand, for a relatively long cable while on the other hand the distance selected between the flank 32 and the push member 28 is substantially proportional to the cable length in the case of any given possible temperature interval, once the push member 28 is set it will be substantially in the middle of the groove 25 in most cases. The adjustment of the distance between the flank 31 and the push member 28 with respect to any thermal expansion of the cable is of course dependent upon the cable tension adjustment and may therefore be inaccurate in certain cases. However, the flank 31 is the one having the function of actuating the push member 28 in the event of cable breakage. It is therefore not particularly inconvenient to construct the device in such a manner that the distance between the flank 31 and the push member 28 is relatively large and the piston stroke is even larger in the event of cable breakage so that actuation of the push member takes place despite the magnitude of such distance.
Moreover, the distance between the flank 32 and the push member 28 as set for a maximum proposed temperature interval may be greater than the variation in length that the cable would experience in the event of such temperature variation taking place, so that when the temperature reaches the intended limit the piston can again perform a supplementary stroke without actuating the switch, e.g. in response to an unintentional action on the cable such as an action due to wind, an involuntary movement by an operator, and so on.
In the embodiment shown in FIG. 5, which will be described only in respect of its differences from FIGS. 1 to 4, the variable-width groove 25 of the rotary piston 15 with respect to the rod 10 has opposite flanks 31, 32 whose width progresses between a minimum value and a maximum value as a result of a helicoidal inclination which is substantially symmetrical with respect to a central plane PP' containing the push member 28.
In this embodiment, the compression spring 23 bears, at its end 76 remote from the piston 25, against an internal screwthreaded member 79 adjustable axially in the body 3 along the axis XX' as shown by the two-headed arrow M in FIG. 5, in order to give the cable the required tension while retaining the push member 28 in a substantially central position between the two flanks 31 and 32.
In the embodiment shown in FIG. 6, the rod 10 and the piston 15 of the movable assembly 17 are axially and angularly connected to one another; the bearing 13 which can be angularly oriented about the axis XX' in the body 3 has a temperature scale 88 moving with respect to an index 86 carried by the body 3. Angular adjustment of the bearing 13 resulting in adjustment of the rod 10 and the piston 15 can be carried out from outside the body 3 as can the reading of the index 86. The flanks 31, 32 of the groove 25 move apart asymmetrically with respect to the central plane PP' containing the push member 28, bearing in mind that, as in the embodiment shown in FIGS. 1 to 4, adjustment of the compression of the spring 23 is obtained by adjusting the cable length while the spring bears on an axially fixed member, e.g. the bearing 13.
In the embodiment shown in FIG. 7, rotation of the bearing 83a in the body 3 allows angular adjustment of the piston as in the embodiment of FIG. 6. Adjustment of the compression of the spring 23 is carried out by means of a screwthreaded plug 79a which is fitted from outside into a tapped aperture 93 in the casing 3 remote from the rod and transmitting an axial movement to the end 76a of the spring 23, as shown by the two-headed arrow N, by means of a yoke 96 forming part of a movable assembly.
In this embodiment, there is therefore no need to open the cover to carry out the tension and temperature adjustments. The components to be actuated for these adjustments are both accessible from outside.
In the embodiments shown in FIGS. 1 and 6, the flank 31 could have a slight helicoidal slope opposed to that of the flank 32 and less than that of the flank 32 so that for a given adjustment of the spring compression the rotation of the piston results in a variation of the distance between the flank 31 and the push member 28.
In the embodiment shown in FIG. 6, the bearing 13 could be screwed adjustably into the body. The number of turns of the bearing 13 then correspond to the adjustment of the spring while the last fraction of a turn angularly adjusts the piston. The rod 10 is coupled to the cable by a device of the swivel hook type which allows a relative rotation of several turns.
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A cable-controlled electrical safety switch device comprises a piston 15 tensioning a cable 2 under the action of a spring 23 via a rod 10 and a screw thread 12a for adjusting the tension of the spring and of the cable. A piston groove 25 actuates a push member 28 for the switch 40. The piston is angularly adjustable. The flank 32 of the groove remote from the spring is helicoidal. When the cable is long, a higher tension is selected so that the groove flank 31 moves away from the push member 28. This distancing is desirable in order that any length variations due to heat--which are greater with a long cable--may be prevented from triggering the switch. The clearance between the other flank 32 and the push member 28 is then corrected by rotation of the piston.
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BACKGROUND OF THE INVENTION
This invention relates generally to gravity flow storage silos, vessels, bins and the like, for bulk particulate solids. More particularly, the invention relates to silos used in material handling processes that require a uniform residence time of material in a silo. Examples of such processes include purging of volatiles from bulk solid particles, and curing of particles from one bulk state to another state.
A principal object of the invention is to provide a gravity flow silo that achieves uniform residence time of the particles in the sense that if a thin horizontal layer of bulk solid particles is placed on the top free surface of material in the silo and discharged, all of the particles that constituted such layer will exit the silo at substantially the same time.
A second object of the invention is to provide a silo producing relative interparticle motion throughout its volume for reasons which will be evident from the following description.
A third object of the invention is to provide a silo causing mass flow of the solids. By mass flow it is meant that all of the material is in motion whenever any material is withdrawn from the silo. With mass flow, material from the periphery as well as the center moves toward the outlet. Advantages of mass flow include the achievement of a first-in/first-out flow sequence, the elimination of stagnant, nonmoving material, the reduction of sifting segregation, the provision of a steady discharge with a consistent bulk density, and a flow that is uniform and well controlled.
Mass flow is distinguished from funnel flow, wherein an active flow channel forms above the outlet of the silo, with non-flowing material at the periphery. As the level of material in the silo decreases, layers of non-flowing material may or may not slide into the flowing channel which can result in the formation of stable ratholes. In addition, funnel flow can cause product caking, can provide a first-in/last-out flow sequence, and can increase the extent to which sifting segregation occurs in the discharging material.
A typical prior art silo for use where a uniform residence time is required is a vertical cylinder to which a converging hopper is affixed. It is known that within a tall, slender, vertical cylinder, except for localized conditions at the bottom caused by the hopper, all particles move at a constant velocity with no relative interparticle motion. This is characterized as rigid body motion. However, without relative interparticle motion some bulk solids form a stable cohesive arch at the transition, that is, the intersection between the cylinder and the hopper sections. Gravity flow of the solids then ceases. The formation of such cohesive arches at the intersection is often due to strong bonds that form between individual bulk material particles as they flow down through the cylinder section. If these bonds develop sufficient strength in the time required to flow through the cylinder, then the material may arch at the transition. Whether the bulk solid particles form sufficient strength to produce an arch is a function of the material in question and the residence time of the material in the cylinder. Increasing the size (diameter or width) of the cylinder section to reduce the propensity of the material to arch may not be possible in many cases, particularly those in which there is a requirement for a uniform residence time of all particles within the silo.
Soviet Union Patent No. 628273 issued to Vladimir Polytechnic Institute describes a silo (with inserts) for dry, free flowing materials. The inserts are comprised of converging and diverging pyramids. Vertical side walls enclose the pyramids. Both the converging and diverging surfaces have slits cut into them, with the diverging pyramid having square openings cut into the flat walls at the base of the section. These slits and square openings allow the free flowing bulk solid to pass from within the converging and diverging sections, into the outer region formed by the vertical silo walls and the pyramids. The material is also allowed to flow from the outer region, back into the pyramid sections. If the material is cohesive in nature (i.e., not free flowing), the material is likely to form arches over the slits and square openings, thus rendering gravity flow through the walls of the pyramids impossible.
By its very nature, the design with square openings at the base of the diverging pyramid sections will create dead zones of material. This implies that mass flow of material within the silo will not result. Furthermore, the design will create large velocity differentials on a horizontal slice of material (these differentials will also vary as a function of level within the silo), thereby resulting in a non-uniform residence time.
BRIEF SUMMARY OF THE INVENTION
With the above stated objects in view, including the avoidance of arching, funnel flow and other drawbacks of prior art silos, the features of this invention include a silo structure comprising downwardly converging and downwardly diverging walls. The downwardly converging walls form angles to the vertical that satisfy the conditions for mass flow. The walls impose relative interparticle motion at every horizontal cross section, which assists in the elimination of arching. The basic silo wall elements may be formed into modules that may be used singly or in multiple vertically stacked configurations to form the silo. Such vertical configurations may be used singly or in multiple clusters. Silos in any such forms may be attached to suitable hopper configurations, either directly or through vertical transitional sections that minimize particle velocity differentials within the converging/diverging structure.
The foregoing and other features of the invention are described and will be evident from the following description of presently preferred embodiments.
DESCRIPTION OF THE DRAWING
FIG. 1 is a partially diagrammatic elevation of a prior art cylinder silo fitted with a conical hopper.
FIG. 2 is an oblique view of a silo comprising two modules according to a first embodiment of the invention.
FIG. 3 is a front elevation of the silo of FIG. 2.
FIG. 4 is a right side elevation of the silo of FIG. 2.
FIG. 5 is a top plan view of the silo of FIG. 2.
FIG. 6 shows a second embodiment comprising the embodiment of FIG. 2 fitted with a converging hopper.
FIG. 7 shows third embodiment comprising the embodiment of FIG. 2 fitted with an outer hopper and an insert to produce mass flow.
FIG. 8 shows a fourth embodiment comprising multiple clustered silos, each similar to the first embodiment.
FIG. 9 illustrates a fifth embodiment showing a variation of the cluster arrangement.
FIG. 10 is an oblique view of the fourth embodiment of FIG. 8 fitted with a converging hopper.
FIG. 11 is an oblique view of the fourth embodiment of FIG. 8 fitted with an outer hopper and an insert.
FIG. 12 is another view of the embodiment of FIG. 11 with external silo and hopper walls omitted for purposes of illustration.
DETAILED DESCRIPTION
FIG. 1 illustrates a prior art gravity flow silo comprising a cylindrical section 12 and a conical hopper section 14. It is well known that except for a transitional region 16 all bulk solid particles move in the cylinder at the same velocity under gravity flow, as diagrammatically represented by velocity vectors 18 of equal length over the horizontal cross section. It is also well known that at any horizontal cross section within the hopper 14 the particles nearer the central axis move downward with greater velocity than those nearer the hopper walls as represented by velocity vectors 20 of variable length. This is true for hoppers having mass flow. Within the transitional region 16 this velocity differential established at the top of the hopper section propagates upwardly into the cylindrical section and gradually attenuates to zero at a height "h" determined by the geometry of the silo and the material properties of the particles.
In the silo of FIG. 1, if it is required that there be a uniform residence time, then the hopper section 14 must be minimized in volume because of the velocity differential that is inherent in this geometry, while the vertical cylinder 12 should have a volume and height-to-diameter ratio that are maximized. A tall, slender cylinder is therefore preferred. However, as above noted, such configurations also fail in use for certain processes due to the formation of arches at the transition 21 between the cylinder and the hopper.
FIGS. 2 to 5 illustrate structures according to a first embodiment of the invention. Four elements 22, 24, 26 and 28 of similar construction are shown. The element 22 is typical and comprises two flat, downwardly converging walls 30 and 32 and two flat, downwardly diverging walls 34 and 36, the walls being joined at their edges so that the cross sections of the element 22 are rectangular from the top to the bottom extremity. The converging walls 30 and 32 each form an angle θ with the vertical. The diverging walls 34 and 36 each form an angle α with the vertical. Preferably, each of the elements 24, 26 and 28 is formed of four walls in the same manner as the element 22. The elements are vertically stacked with their adjoining walls connected to form complete annular peripheral closures.
In the embodiment shown the sides of the downwardly converging walls 30 and 32 arc of equal length A at their upper extremities and of equal length B at their lower extremities. The sides of the downwardly diverging walls 34 and 36 are of equal length B at their upper extremities and equal length A at their lower extremities. The elements 22 and 24 stacked together comprise a module 38. In this configuration the element 24 is rotated 90° about the axis of symmetry of the silo relative to the element 22. This stacking arrangement may be used singly or stacked with a similar module 40, or a greater number of modules, with the rotation of the elements repeated. A single element such as 22 or any odd or even number of stacked elements such as 22 may be used to form a silo.
It is well known in the art that to ensure mass flow in a hopper the downwardly converging walls must be sufficiently smooth and steep to promote flow at the walls. The same criterion applies to the described embodiment. Specifically, the downwardly converging walls must form an angle θ that is equal to or smaller than the empirically determined mass flow angle of the solids. Angles less than this critical value may be used and still provide mass flow, with the benefit that small angles produce reduced velocity differentials of the particles moving within any given horizontal cross section. Those skilled in the art are able to determine an appropriate angle θ for the particular bulk solid.
The angle of divergence α, that is, the angle to the vertical formed by the downwardly diverging walls such as 34 and 36, is preferably chosen to be equal to θ, although this is not an absolute requirement. When θ=α the cross sectional areas of the top and bottom openings of each element such as 22 are equal, thus promoting a uniform residence time when the element is used to form a silo either alone, in combination with another element such as 24, or in multiple modules 38, 40.
The minimum outlet width A of the silo is preferably determined by the flow characteristics of the particular bulk solid. It is chosen so that neither a cohesive nor a mechanical arch will form. The determination of the other dimensions of the elements will reflect other considerations such as the level of material induced flow stresses in each element of the silo and the residence time requirements as well as the flow stress field in each channel with converging and diverging walls.
In the embodiment of FIG. 2, if the areas of the top and bottom of each element are equal or nearly so, the average velocities of all moving particles are substantially the same, thus promoting a uniform residence time in the silo. Also, the particles move in mass flow and relative interparticle motion exists throughout the silo.
As illustrated in FIGS. 2-5, the silo provides a flow channel that may be discharged either by unrestricted gravity flow or by means of a feeder. If a conventional feeder is used to control the discharge rate, the capacity of the feeder must increase along its length in the direction of discharge.
In some cases the bulk solid storage capacity requirements dictate the use of a silo having a large cross sectional area. However, as the physical size of the silo increases, the stress level in the flowing bulk solid also increases. This stress level may be detrimental by causing unwanted particle attrition, product degradation or other undesired results. In particular, the stress may result in an increase in the strength of the material, promoting its propensity to form an arch. One means to avoid this problem is to employ clusters comprising multiple silos of the form shown in FIGS. 1 to 5. This is illustrated by FIGS. 8 and 9. In FIG. 8 silos 42, 44, 46 and 48, all of the form shown in FIG. 2, are clustered and nested so that they form a square opening with side dimensions A+B at the top and bottom, forming convenient shapes for attachment of square shaped filling and discharging apparatus. In FIG. 9 silos 50, 52, 54 and 56 of similar construction are clustered in an alternative configuration.
In some applications the outlet dimensions of the silo of FIG. 2 or of clustered silos as in FIGS. 8 and 9 are larger than practicable to feed a downstream process. In this case a converging mass flow hopper section is attached to the silo as illustrated in FIGS. 6, 7 and 10-12. Referring to FIG. 6, the silo of FIG. 2 is connected to a structure having an upper section 58 with four vertical walls, and a wedge-shaped hopper 60 comprising two downwardly sloping walls 62 and 64 and two vertical walls 66 and 68. The walls 62 and 64 form angles with the vertical that are equal to or smaller than the critical mass flow angle for the solids. It will be evident that mass flow hoppers of other converging shapes may be employed in the alternative, and they may converge to slotted, round, oval or other shaped outlets.
The purpose of the vertical section 58 relates to the fact that, as noted above, the geometry of the converging hopper imposes velocity gradients on the particles within any horizontal cross section, the particles closer to the axis of symmetry moving faster than those nearer the sloping walls 62 and 64. On the other hand, it is desirable that all of the particles moving through the silo above the vertical section 58 shall move at the same average velocity, without reference to their positions relative to the axis of symmetry. The velocity gradient in the cross section at the top of the hopper 60 is propagated upwardly, and the difference between the maximum and minimum velocities within the cross section decreases to zero progressively up to a height "h" at or near the top of the vertical walls. Thus the use of a converging hopper does not propagate a velocity differential into the silo elements that provide a uniform residence time as above described. The height of the vertical section 58 is determined in the same manner as that of the region 16 in FIG. 1, as will be understood by those skilled in the art.
It should be noted that the selection of a suitable hopper geometry and wall surface may in some cases result in a low velocity differential within the hopper, and a relatively small effect on the residence time of particles in the silo measured from the top of the silo to the outlet of the hopper. In such a case the vertical section 58 may be omitted and the hopper may be attached directly to the silo modules of FIG. 2.
FIG. 7 illustrates an embodiment similar to that of FIG. 6 having a modified form of hopper 70 comprising downwardly converging walls 72 and 74 and vertical walls 76 and 78. The angles formed by the walls 72 and 74 and the vertical are greater than the critical mass flow angle for the solids. In this case an insert 80 is provided, having walls 79 and 81 opposing the walls 72 and 74 in accordance with the teachings of Johanson U.S. Pat. No. 4,286,883. In such applications the angles between the opposed walls 72 and 79 and between the opposed walls 74 and 81 are each equal to or smaller than the critical mass flow angle for the solids, and the angles of each of the insert walls 79 and 81 relative to the vertical are also equal to or less than the mass flow angle. The conditions for mass flow are therefore satisfied.
FIG. 10 illustrates a silo comprising the cluster 82 of FIG. 8 attached through a vertical section 84 similar in function to the section 58 of FIG. 6, to a wedge-shaped hopper 86 similar in function to the hopper 60 of FIG. 6.
Similarly, FIGS. 11 and 12 illustrate the cluster 82 attached to a modified hopper 88 similar to the hopper 70 of FIG. 7. FIG. 12 illustrates the same embodiment as FIG. 11 with external walls omitted to show the flow channels of the solids through the silo. Sloping walls 90 and 100 of the hopper form angles to the vertical that are greater than the critical mass flow angle of the solids. An insert 102 having sloping walls 104 and 106 is provided. As in FIG. 7, the angles between the opposed walls 90 and 104 and between the opposed walls 100 and 106 are each equal to or smaller than the critical mass flow angle for the solids, and the angles of each of the insert walls 104 and 106 relative to the vertical are also equal to or less than the mass flow angle. The conditions for mass flow are therefore satisfied.
In the embodiments shown in the drawings the walls that form the converging and diverging sides of each element such as 22 are shown as flat for purposes of description. However, it will be evident to those skilled in the art that in fabrication the comers formed by the walls may be rounded to eliminate sharp internal valleys. Also, the walls may be other than planar in shape, without departing from the spirit or scope of the invention.
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A silo for gravity flow storage of bulk particulate solids comprises downwardly converging and downwardly diverging walls. The downwardly converging walls form angles to the vertical that satisfy the conditions for mass flow. The walls impose particle velocity gradients in the horizontal cross sections of the silo, reducing interparticle cohesion, preventing the formation of arches and promoting uniformity of residence time within the silo. The modules may be vertically stacked, and may be clustered to increase capacity and to reduce pressure stress levels where required.
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FIELD OF THE INVENTION
This invention relates to a motorized operator for opening and closing an upwardly acting door and, in particular, to an operator having an improved switch mechanism associated therewith to permit optimum control over the door movement.
BACKGROUND OF THE INVENTION
Persons acquainted with the operation of upwardly acting doors having an electrical operator for effecting door movement are aware that some door operators have a safety switch whereby the direction of door movement is automatically reversed if the door engages an obstruction during movement in its downward or closing direction. This safety feature, as disclosed in U.S. Pat. No. 3,474,317 owned by the assignee of this application, has been provided to prevent damage to equipment and injury to personnel which might result from continued operation of the door. While operators of this type have been commercially acceptable, nevertheless they do possess structural and operational features which have been undesirable either from a cost, maintenance or operational viewpoint.
To improve upon operators of this type, U.S. Pat. No. 3,764,875 discloses an operator having a mechanical override system for deactivating the safety switch when the door is within a preselected distance from either its fully opened or fully closed position to prevent reversal of the door movement. While the operator of this patent does possess the ability to deactivate the safety switch, nevertheless this operator is structurally complex and does not possess the degree of flexibility necessary to provide for optimum control over all of the door movements.
Accordingly, the objects and purposes of the invention have been met by providing a motorized door operator having improved switch mechanism and circuitry capable of overcoming the problems and achieving the results set forth above.
A further object of the invention is the provision of a door operator, as aforesaid, which represents a substantial improvement, both structurally and operationally, over the operators disclosed in the patents mentioned above.
A still further object of the invention is the provision of a door operator, as aforesaid, which is fool proof in operation, simple in construction, can be adapted to existing door operating mechanisms, and does not interfere with the normal manual or remote control conventionally utilized for energizing the electrical system.
Still a further object of the invention is the provision of a door operator, as aforesaid, which possesses (1) a reversing safety switch for automatically causing upward movement of the door when the door strikes an obstruction during the downward movement thereof, (2) up and down limit switches for deactivating the operator when the door respectively reaches its fully opened and fully closed positions, and (3) up and down cut-off switches for overriding the safety switch when the door is within a preselected distance from its respective fully opened and fully closed position.
Another object of the invention is the provision of a door operator, as aforesaid, which incorporates a slide assembly within the switch mechanism for controlling the limit and cut-off switches in a simple yet reliable manner.
Other objects and purposes of this invention will be apparent to persons familiar with this type of equipment upon reading the following specification and inspecting the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a broken, elevational view of an upwardly acting door in combination with a motorized door operator embodying the switch mechanism and circuitry of the present invention.
FIG. 2 is a bottom view of the structure as appearing in FIG. 1, same being taken substantially along line II--II in FIG. 1.
FIG. 3 is a fragmentary view of the switch mechanism according to the present invention.
FIG. 4 is an enlargement of the switch mechanism of FIG. 2.
FIG. 5 is a fragmentary sectional view taken along line V--V in FIG. 4.
FIG. 6 is a sectional view taken along line VI--VI in FIG. 4.
FIG. 7 illustrates a portion of the switch mechanism except that the screw and traveling nuts have been eliminated for purposes of illustration.
FIG. 8 is a perspective view of the slide assembly.
FIG. 9 is a fragmentary sectional view taken along line IX--IX in FIG. 4.
FIG. 10 is a diagrammatic sketch of the circuitry associated with the switch mechanism of the invention.
FIG. 11 illustrates the manner in which the sliders coact with the limit and cut-out switches.
For convenience in description, the terms "upper", "lower", "leftward" and "rightward" will have reference to directions as appearing in the drawings. The word "front" and "rear" will be used to designate the structure appearing on the left and right sides, respectively, of FIG. 1. The words "inwardly" and "outwardly" will refer to directions toward and away from, respectively, the geometric center of the apparatus and designated parts thereof. Said terminology will include the words above specifically mentioned, derivatives thereof, and words of similar import.
SUMMARY OF THE INVENTION
The objects and purposes of the present invention have been met by providing an operator which includes a reversible electrical motor drivingly connected to the door by an intermediate power transmitting device. A safety switch coacts with the power transmitting device for causing reversal in the rotational direction of the motor during downward movement of the door when the driving force exceeds a preselected maximum. A switch mechanism is associated with the operator and includes a control member in the form of a rotatable screw having first and second nuts mounted thereon. The first nut which controls the door when adjacent its closed position, coacts with a first slide which is adjacent the screw and is slidable relative thereto, whereupon the nut contacts the first slide and causes movement thereof only when the door approaches its closed position. The second nut coacts with a second slide which is slidably disposed adjacent the screw and is also slidable with respect to the first slide. The second nut and second slide have a limited amount of lost motion therebetween. The first and second slides are connected by a slide rod which permits the two slides to move with respect to one another but limits the maximum separation therebetween. The first slide coacts with a first pair of microswitches, one of which functions as the down limit switch for shutting off the motor when the door reaches its fully closed position and the other of which functions as a down cut-off switch for deactivating the safety switch when the door is a preselected distance from its fully closed position. The second slide coacts with a second pair of microswitches which includes an uplimit switch for shutting off the motor when the door is in its fully open position and an up cut-off switch which deactivates the safety switch when the door is within a preselected distance from its fully opened position.
DETAILED DESCRIPTION
FIGS. 1 and 2 illustrate therein a motor driven door operator 11 which may be manually or remotely controlled for opening and closing an upwardly acting door 12. One such door, which is designed for covering an opening 13 defined above a floor 14, is comprised of several horizontally hinged sections having rollers 16 mounted thereon for engagement with side rails 17 for guiding the movement of the door between a substantially vertical closed position and a substantially horizontal open position. However, the invention can be readily adapted to other types of doors and other patterns of door movement.
The operator 11 includes an elongated horizontal beam 18 defined by a pair of guide rails 19 and 21 between which a carriage 22 is supported for movement lengthwise thereof. The carriage 22 is pivotally connected to the upper end of an arm 23, which arm at its lower end is connected to the door 12 by means of an intermediate spring box 24.
To permit movement of the carriage 22, the operator 11 includes a reversible electric motor 26 which is drivingly connected by an intermediate belt 27 to an intermediate shaft 28, which in turn is drivingly connected by a chain drive 29 to a main drive shaft 31. The shaft 31 is rotatably supported by bearings 32 and 33 on a housing 34 which is fixed with respect to the stationary beam 18. A driving sprocket 36 is fixed to the shaft 31 and is engaged with an elongated chain 37 which is connected at its opposite ends to the opposite ends of a cable 38, which cable extends around a pulley 39 rotatably supported upon the front end of the beam. Two corresponding ends of the chain 37 and cable 38 are interconnected by mutual engagement with the shuttle 22, as shown in FIG. 2. Accordingly, as the chain and cable are moved around the sprocket 36 and pulley 39, respectively, the carriage 22 is moved lengthwise of the guide rails 19 and 21, whereby the door 12 is moved in either an opening or closing direction. The lengths of the chain 37 and cable 38 are selected so that the chain is always in engagement with the sprocket 36 and the cable is always in engagement with the pulley 39 throughout the full extent of linear movement of carriage 22.
To control energization of reversible motor 26, the operator 11 includes a switch mechanism 41 associated therewith, which switch mechanism includes a threaded control shaft 42 which comprises an extension of the main drive shaft 31. Shaft 42 threadably supports a pair of traveling nuts 43 and 44 which have a plurality of closely spaced slots 46 in the peripheral portions thereof. A U-shaped timing bar 47 is pivotally supported on and extends between the sidewalls 48 and 49 of the housing, and is resiliently urged by spring 51 into a pair of aligned slots 46 as formed in the nuts 43 and 44 for preventing rotation of the nuts. Rotation of shafts 31 and 42 thus causes the nuts 43 and 44 to move lengthwise of the shaft.
As shown in FIG. 9, the chain 37 engages an idler sprocket 52 supported by a bracket 53 having a safety switch actuating plate 54. Bracket 53 is pivotally mounted on the beam 18 adjacent the switch mechanism 41 for movement around an axis parallel with the drive shaft 31. The bracket 53 is normally urged against a portion of the beam by means of a spring 57. The bracket 53, when urged in opposition to the spring 57 due to an increase in the drive force being transmitted through the chain, causes the plate 54 to engage a switch actuator 58 associated with a normally open safety switch 59 for closing same. Thus, when the door is being moved in a downward direction and strikes an obstruction which interferes with further downward movement, the chain cannot continue to move around the drive sprocket 36, whereby the tension applied by drive sprocket 36 to chain 37 tends to straighten out the bend in the chain where it passes around the idler sprocket 52, so that bracket 53 is swung outwardly against the urging of spring 57. The plate 54 thus engages the switch actuator 58 and causes the safety switch 59 to be closed, thus causing reversal in the rotational direction of motor 26.
The above described structure substantially corresponds to the operator disclosed in U.S. Pat. No. 3,474,317, whereby further description of same is not believed necessary.
In the present invention, the switch mechanism 41 additionally includes a first pair of normally closed microswitches 61 and 62 having actuators 63 and 64, respectively, associated therewith. Switch 61 functions as an "up" limit switch, whereas switch 62 functions as a "down" limit switch.
The limit switches 61 and 62 are controlled by a floating slide assembly 66 which includes first and second sliders 67 and 68 positioned for engagement with the up and down limit switches 61 and 62, respectively. The slide assembly 66 also coacts with a second pair of normally closed microswitches 71 and 72 which are positioned directly beneath the limit switches 61 and 62, respectively. The limit switch 71, which will be referred to as the up cut-out switch, has a switch actuator 73 positioned for engagement with the slider 67. In a similar manner, the switch 72, which will be referred to as the down cut-out switch, has an actuator 74 positioned for engagement with the slider 68.
The sliders 67 and 68 are each slidably supported on an elongated rail 76 which is of a substantially channel-shaped cross-section and extends between and is fixedly mounted on the sidewalls 48 and 49. The rail 76, as illustrated in FIG. 6, has opposed inwardly directed flanges which are slidably accommodated within narrow slots formed in the opposite sides of the sliders 67 and 68 so as to confine the sliders for slidable movement longitudinally of the rail 76. The rail 76 also has a flange 77 fixed thereto and projecting sidewardly therefrom, which flange has the pairs of switches 61-62 and 71-72 stationarily mounted thereon. The sliders 67 and 68 are also connected together by an elongated rod 78, such as a bolt, which rod slidably extends through each of the sliders 67 and 68 and has an enlarged head 79 on one end thereof and a nut 81 on the other end thereof. Rod 78 permits each slider 67 or 68 to be individually slidably displaced therealong, while at the same time the rod 78 limits the maximum spacing between the sliders.
As illustrated in FIG. 8, each of the sliders 67 and 68 has a leaf spring 82 associated therewith, which spring coacts between the respective slider and the bottom wall of the rail 76 to create a frictional holding force which prevents undesired displacement of the individual sliders along the rail. While the springs 82 may comprise individual leaf springs if desired, they are each preferably formed integrally with the respective sliders, as by being molded from nylon or other suitable plastic materials.
To permit actuation of the microswitches, slider 67 is provided with a pair of cams 83 and 84 positioned to respectively engage the actuators 63 and 73 as associated with the switches 61 and 72, respectively. Slider 68 similarly has cams 86 and 87 positioned to respectively engage the switch actuators 64 and 74 associated with the switches 62 and 72. The cams 83 and 84 associated with the slider 67, and the cams 86 and 87 associated with the slider 68, are offset from one another in the direction of slider movement so that cams 83 and 86 are positioned inwardly and spaced a smaller distance apart than the cams 84 and 87. The sliders 67 and 68 also have suitable support walls 67A and 68A, respectively, formed thereon and projecting outwardly beyond the cams as illustrated in FIG. 8.
The liner displacement of sliders 67 and 68 along the rail 76 is controlled by the traveling nuts 43 and 44, respectively. For this purpose, the slider 68 has a wall 88 formed thereon and projecting outwardly in a direction substantially transverse to the direction of movement. The wall 88 projects upwardly a sufficient extent so as to lie within the path of movement of the traveling nut 44, whereupon the traveling nut 44 will abut the wall 88 when the nut 44 approaches an endmost position which corresponds to the door being in a closed position. The other slider 67 has a pair of walls 91 and 92 formed thereon and projecting outwardly therefrom in a direction substantially transverse to the direction of slider movement. The walls 91 and 92 project outwardly a sufficient extent so as to be positioned for abutting engagement with the traveling nut 43, and define therebetween a slot 93 into which projects a portion of the nut 43. However, as illustrated in FIG. 5, the slot 93 has a width which is substantially greater than the thickness of the nut 43 for a purpose to be explained hereinafter.
Referring now to FIG. 10, same diagrammatically illustrates therein an electrical circuit 94 for the operator of the present invention. The circuit 94 includes the reversible electric motor 26 which is adapted to be energized from a conventional 110-volt source. Motor 26 is connected to two parallel paths which contain the up and down limit switches 61 and 62, respectively. Motor 26 is also connected in series with a heater coil 98 which, when energized, causes closure of the normally-open delay contact 97 so that lights 96 will be energized during the opening and closing movement of the door. The contact 97 also remains closed for a preselected time after the motor 26 is deenergized.
To permit selection in the direction of motor rotation and to permit activation of the overall circuit, same includes a start circuit 99 which is connected to the potential source by means of an intermediate transformer 101. The start circuit contains therein a conventional relay coil 102 which in turn controls a double throw relay switch 103 in a conventional manner, whereby sequential energization of coil 102 results in relay switch 103 being alternately connected to the up and down limit switches 61 and 62. A manually controlled start button 104, which in a conventional manner is normally maintained in an open position, is also connected in series with the coil 102 so that the coil can be energized whenever the start button 104 is manually depressed. Coil 102 is also connected in series with a further circuit branch which contains therein the normally closed cutout switches 71 and 72 and the normally open safety switch 59. These latter switches, which are all connected in series, are disposed in a circuit branch which is in parallel with the manual push button 104. Coil 102 can also be energized in a conventional manner from a remote control, such as a conventional radio frequency control panel, and for this purpose start circuit 99 includes a radio frequency receiver 106 which includes contacts 107 and 108 therein, which contacts are electrically connected upon receipt of an appropriate signal so as to permit energization of coil 102.
OPERATION
Before considering the operation of operator 11, it will be assumed that the door is initially in its upper opened position substantially as illustrated in FIGS. 3-7 and 11. When in this uppermost or open position, the sliders 67 and 68 are maintained at their maximum spacing adjacent the opposite ends of the rod 78, and the nuts 43 and 44 are both positioned adjacent the free end of the threaded control shaft 42 with the nut 43 abutting the slider wall 92, as shown in FIG. 5. The slider 67 when so positioned results in the switch actuators 63 and 73 being engaged with the cams 83 and 84, respectively, as illustrated in FIGS. 7 and 11, whereby switches 61 and 71 are maintained in open positions. At the same time, the slider 68 is positioned slightly inwardly from its endmost position so that, as illustrated in FIG. 11, the switch actuators 64 and 74 are engaged with the bearing surface 68A whereby the switches 62 and 72 are in their normally closed positions. The safety switch 59 is also in its normal open position and the relay switch 103 is connected in series with the up limit switch 61 (which is now open), as illustrated in FIG. 10.
When closing of the door is desired, then button 104 is manually depressed or a suitable radio signal is supplied to receiver 106 so that coil 102 is momentarily energized, thereby causing relay switch 103 to shift into series connection with the closed down limit switch 62, whereby motor 26 is energized in a direction suitable to cause movement in the door closing direction. The energization of motor 26 causes rotation of threaded control shaft 42 whereby the traveling nuts 43 and 44 are moved upwardly along the shaft as illustrated in FIG. 5. Due to the lost motion connection provided between the nut 43 and the slider walls 91 and 92, the nut 43 moves upwardly through a small distance until coming into contact with the slider wall 91, which lost motion permits a limited amount of door movement away from its fully open position, which amount may be in the order of approximately 6 inches of door travel depending upon the magnitude of lost motion between nut 43 and slider 67. This lost motion connection and the permissible door travel permitted thereby is desirable since it prevents the door from receiving another signal after it has been opened, should the door coast back down due to wear or slight misadjustment of the springs, which would otherwise cause the door to undergo a "yo-yo" or oscillating motion.
After this lost motion is taken up, whereby nut 43 contacts slider wall 91, slider 67 is then slidably displaced along the rod 78 due to continued upwardly movement of nut 43 as caused by rotation of shaft 42. When slider 67 is displaced upwardly a small distance by nut 43, then actuator 63 drops off of the cam 83 onto the surface 67A, whereby up limit switch 61 returns to its normally closed position. After closing of switch 61, the slider 67 is still further moved upwardly by the nut 43 whereby after a further preselected displacement of the slider 67, the switch actuator 73 falls off of the cam 84 and engages the surface 67A, whereby cut-out switch 71 is accordingly returned to its normally closed position. This additional displacement required to close switch 71 after closure of switch 61 will normally amount to an additional door travel of approximately six inches. However, during this initial travel of the door away from its fully open position, the holding open of the up cut-out switch 71 allows the operator to overcome the force required to start the door moving in its closing direction, which force would normally be sufficient to cause closure of the safety switch 59 but, in this situation, the closure of the safety switch 59 is immaterial since it is connected in series with the cut-out switch 71 which is maintained open during at least approximately the first 12 inches of door closing travel.
After the door has moved in its closing direction a sufficient extent to result in closing of the up cut-out switch 71, the door will continuously move towards its closed position and, during this time, the slider 67 will be moved upwardly in FIG. 5) by the nut 43, whereas the slider 68 will remain stationary with respect to the rail 76 due to the frictional holding force developed by its spring 82. If the door should encounter an obstruction which prevents further closing movement of the door, then this results in the force transmitted through the chain being substantially increased and causes displacement of bracket 53 in opposition to the urging of spring 57, whereby safety switch 59 is momentarily closed. Since the cut-out switches 71 and 72 are already closed, this results in momentary energization of the coil 102 so that relay switch 102 flips over into engagement with the already closed down limit switch 62. Motor 26 is thus energized to rotate in the reverse direction, thereby moving the door upwardly in an opening direction.
On the other hand, if the door does not encounter an obstruction during its closing movement, then as the door approaches its fully closed position, the traveling nut 44 engages the wall 88 of slider 68. After a small displacement of slider 68 in the upwardly direction in FIG. 5, the cam 87 causes switch actuator 74 to be cammed outwardly whereby down cut-out switch 72 is moved into an open position when the lower edge of the door is spaced a small distance above the threshold 14, which distance may be in the order of approximately 2 inches. This opening of the cut-out switch 72 thus overrides the safety switch 59 due to the series connection therebetween, so that the motor cannot be reversed when the door is adjacent its fully closed position. The motor continues to move the door downwardly and continues upward movement of slider 68 until switch actuator 64 engages cam 86 and activates down limit switch 62 into an opened position, which results in immediate deenergization of motor 26 and stoppage of the door in its fully closed position wherein the lower edge of the door is substantially in engagement with the threshold 44.
When the door, during its closing movement, reaches the position wherein the down cut-out switch 72 is deactivated (which position may occur when the lower edge of the door is about two inches above the threshold), the top section of the door is almost vertical at this point and the carriage 22 is moving the arm 23 through an overcenter position. Accordingly, if the door should encounter an obstruction during the last two inches of travel (after opening of the cut-out switch 72), which obstruction may constitute mud, ice or the like, then the motor 26 will continue to drive the carriage 22 and likewise the slider 68 until it engages and opens the down limit switch 62. However, since the door is prevented from moving downwardly during this latter phase, the movement of the carriage 22 and specifically the arm 23 will be absorbed by the spring box 24 inasmuch as the actual downward movement during this phase is relatively small. Thus, the operator will still operate until it reaches and activates the down limit switch so as to shut off the operator. This thus allows the door to remain closed and also allows the motor to shut off, and an undesired reversing or opening of the door is thus avoided.
When the door is in its down or closed position as described above, the down limit switch 62 and the down cut-out switch 72 are both open, whereas the up limit switch 61 and the up cut-out switch 71 are both closed. If it is desired to open the door, the relay coil 102 is again energized either due to depression of push button 104 or receipt of a radio signal from a remote operator. Relay switch 103 is thus shifted so as to be again connected in series with the closed up limit switch 61, and motor 26 is thus energized in a direction causing an opening movement of the door. This energization of motor 26 causes the control shaft 42 to rotate in a reverse direction so that nuts 43 and 44 now travel downwardly in FIG. 5. During the initial downwardly movement of the door, the nut 44 moves away from the slider wall 88, and the slider 68 remains stationary due to the frictional holding force created by its respective spring 82. The other nut 43 also moves across the slot 93 and engages the wall 92, whereby slider 67 is thus moved downwardly along the rail 76. If, during this upward or opening movement of the door, the push button 104 or the remote radio is again activated so as to cause energization of the coil 102, which in turn causes a shifting of relay switch 103 so that same is connected in series with the down limit switch 62, then the motor 26 will be energized and the door stopped (and not reversed) since the down limit switch 62 is still being held in its open position by the slider 68. Thus, an accidental or deliberate activation of coil 102 during the opening movement of the door will merely result in a stoppage of the door at a location disposed between the fully open and fully closed positions. A still further energization of the coil 102 will again cause switch 103 to shift into a series connection with the closed up limit switch 61 so that the upward opening movement of the door will then continue.
As the door approaches its fully open position, the slider 67 first contacts the actuator 73 whereby up cut-out switch 71 is opened and then contacts actuator 63 whereby up limit switch 61 is opened, thereby deenergizing motor 26 so that the door is stopped in a fully opened position. However, just before slider 67 engages the actuator 63, the slider 67 will be spaced from the slider 68 by the maximum spacing permitted between the bolt head 79 and the nut 81. Thus, during the last portion of downward travel of the slider 67, the slider 68 will also be pulled downwardly due to the connection provided by the intermediate rod 78. Slider 68 is thus moved downwardly a sufficient distance to cause both of the followers 64 and 74 to move into engagement with surface 68A so that down limit switch 62 and down cut-out switch 72 both return to their normal closed positions. Thus, the complete system is accordingly returned to its original position and is ready for initiation of the next closing cycle.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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An operator for an upwardly acting door. A reversible electric motor is drivingly connected to the door by an intermediate drive linkage. A switch assembly is associated with the operator for controlling the upward and downward movement of the door, which switch assembly includes first and second limit switches for deactivating the motor when the door reaches its lowermost and uppermost positions, respectively. A third switch functions as a safety switch for causing reversal in the motor rotation when the driving force exceeds a preselected maximum. Fourth and fifth cut-off switches are respectively positioned adjacent the first and second switches for overriding the third switch when the door is within a preselected distance from its closed or open position. The limit and cut-off switches are controlled by a rotatable screw member having a pair of traveling nuts thereon which coact with a pair of individually movable control slides. One of the control slides activates the first and fourth switches, and the other control slide activates the second and fifth switches.
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This invention relates to the stability of floating and submersible structures when moored-to or operated alongside a pier or any other lateral support structure.
A free-floating structure with a positive GM (metacentric height), when disturbed by external transient forces due to wind and wave action, goes through a complex pattern of rotational and traversal motions to regain its equilibrium. The frequency and amplitude of these restorative motions vary according to certain physical characteristics of the structure. The tri-axial components in the three principal planes cause the structure to sway by roll and pitch, swing by yaw, move back-and-forth laterally and longitudinally, and rise and fall vertically. Under these motions, the mooring of a floating structure, to secure in position and to minimize impact damage and fatiguing stresses in both moored and support structures and protective piling, has remained a difficult problem to cope with. This is due mainly to the inability of conventional line moorings to provide for the contradictory requirements of tightness and slackness; the former to reduce the amplitude of movements, and the latter to allow for rise-and-fall from tides and surge.
It is one objective of this invention to restrain all rotary and traversal movements of a floating structure at mooring flotation, by replacing conventional flexible mooring lines with a simple structural framing system which, in effect, will eliminate all displacements--except those occurring vertically, to which movements it will provide vertical guidance.
Another and still more important objective is to utilize the same framing device as stabilizer element for a floating submersible structure, such as the dock pontoon described in my U.S. Pat. No. 3,688,719, entitled "Lift Pontoon and Dock," issued Sept. 5, 1972. In that application, the stability in the submerged position is provided by a set of cables suspended from winches mounted on two flanking piers. By the use of the stabilizing device, the winches, cables and support piers will be eliminated from dry dock assembly; and the pontoon will thus become a stable floating dry dock--without wing walls. In effect, then, the simple framing adjunct contemplated by this invention will bring about not only radical changes in dry dock assembly and operational site layout but also a new concept of stability for submersible buoyant structures. For, by the substitution, in lift docks, gone will be the ever-troublesome winches with motors to synchronize, and their adjunct cables or chains--together with associated problems of slackening, corrosion and replacements; and in conventional floating dry docks, the removal of costly and restrictive wing walls. As for stability, for the first time in drydocking history, a hydrostatically unstable structure will be made statically stable through the aid of the stabilizing device of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the framing assembly embodying the invention.
FIG. 1a is a top view of the framing assembly.
FIG. 1b is a cross section view of leg 7.
FIG. 1c is a cross section view of track 8.
FIGS. 2, 3 and 4 schematically show a vessel being docked and shore transferred.
FIG. 5 shows the stabilizer 16 on a service pier.
FIG. 6 shows the stabilizer used alone for mooring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device, which is called "Stabilizer for mooring and submergence of buoyant structures," and referred to simply as "Stabilizer," is shown in FIG. 1, in elevational view, fitted between the inboard face 1 of the dock pontoon and the outboard face 2 of fixed mooring support structure. The basic unit consists of a rectangular rigid frame 16, composed of an upper horizontal arm 3, lower arm 4, and vertical legs 6 and 7. In general, all four members of the frame are of hollow circular cross section. On the mooring support side 2, the leg 6, through top and bottom cylindrical joint segments 5, engages a slitted cylindrical member 8, which is fastened to support 2 and extends from top of the support to a depth required by submergence of the dock pontoon 1, and provides a track for sliding engagement of joint segments 5 of the frame.
On the dock pontoon 1 side, the frame 16 is connected to the pontoon through pins engaging holes in three brackets rigidly attached to the inboard face of the pontoon 1. The details of the arrangement are indicated in FIGS. 1, 1a and 1b. In FIG. 1a, which is a top view of the frame 16, the upper arm 3 is shown with a piercing welded gusset plate 10 at mid-height, reinforced with stiffeners 11, and contains holes for two pin connectors 13, to attach the arm 3 to corresponding two upper brackets 12 on the pontoon 1. The lower arm 4 connection is shown in FIG. 1b, which is a vertical cross section of the frame 16, looking towards the pontoon 1. There the leg 7 is framed to arm 4, from bottom of which a projecting tapered pin 15 engages a tapered hole in a bracket 14 fastened to the pontoon 1. The three-point connection thus proviced enables the frame 16 to receive from the pontoon 1 and transmit through arms 3 and 4 to engaging track 8 shear and twist forces caused by longitudinal or end wind yaw, as well as shear and bending due to transverse wind and water current. The cylindrical slitted track 8, reinforced with stiffeners 9, is rigidly fastened to mooring support structure 2. FIG. 1c, which is a vertical cross-section of the frame 16, looking towards the support structure 2, shows the vertical slit in the track 8.
The connection arrangement of the frame 16 is designed for ease of installation and removal. To install it, first, the bottom joint segment 5 of the frame 16 is inserted into track 8 from the top. Then, after pulling pontoon 1 closer, the frame 16 is lowered into place by engaging the hole in lower bracket 14 through the tapered pin 15. Next, the holes in upper arm gusset 10 are aligned with corresponding holes in upper two brackets 12 and the threaded pins 13 are inserted and secured by locking nuts. Removal of the frame is accomplished by simply removing the two pins 13 and raising the frame.
The advantages obtainable by the use of the Stabilizer are many and vary according to the function of the structure to which it is attached. Functionally, the submersible pontoon--used as a floating dry dock, is, of course, the most important application contemplated by the invention. This particular use of the Stabilizer is shown schematically in FIGS. 2, 3 and 4, where a vessel is docked and shore transferred. FIG. 4 is a plan view of the site of operation. It consists of a corner of a slip or basin, enclosed by bulkheads 2, and, where the dock pontoon 1 is held in place through two Stabilizers 16. A vessel 19 is brought into the basin and maneuvered into one of two alternative positions for docking it on the pontoon 1; one for access from the end, and the other from the side. FIG. 2 is a cross-section of the basin, showing the dock 1 lowered to the bottom, with the Stabilizer 16 engaged in the vertical guidance track 8 and its support truss 17 anchored to bulkhead 2, and the vessel 19 positioned for contact and pick-up on docking blocks 20, prior to start of the lift. FIG. 3 shows the pontoon 1 elevated, by removing its water ballast through application of compressed air, to bring the top deck in levelment with adjacent bulkheads 2 deck pavements, at which time, the transfer carriage 18, mounted on swivel rollers or wheels 21, is released for shore transfer of the vessel 19. As explained above and indicated in FIG. 4, the transfer can be made endwise or sideway.
It is especially to be noted that, during the full cycle of drydocking, that is, docking a ship on the pontoon, rendering the needed repair services in-place while the dock remains afloat, and then undocking or lowering it back into water, the dock remains laterally motionless, and thus a level deck is maintained at all times. This favorable condition, further enhanced by the absence of restrictive deck obstructions--such as wing walls in a conventional floating dry dock, would make in-place repair work both desirable and advantageous. In this case, the transfer carriage 18 is eliminated, and docking blocks 20 are placed directly on the pontoon deck.
Where a shore transfer is not contemplated, and a service pier is available, both docking and repairs to ship may be rendered at a pier. FIG. 5 depicts such a case. Here track 8 of Stabilizer 16 is supported on a vertical truss 17 which, in turn, is fastened at the top to deck framing of pier 2 and at the bottom to additional foundation piling 22. This also illustrates the dual function of a single berth--serving both as a docking and mooring site. However, if the berth is to be used for mooring alone, a simplified support arrangement, such as one shown in FIG. 6 can be utilized. Of course, this is the general case of rigid mooring, provided by the Stabilizer 16 to vessel 19. Here the track 8 is attached directly and through bracket 17 to longitudinal pier girder 2, with a height sufficient to allow for tidal rise and fall.
In some other applications, the Stabilizer would be used to improve the efficiency and to lower the maintenance cost of an existing facility. A good example of this case is presented by the conventional floating dry dock. By eliminating the wing walls and installing Stabilizers, and also replacing mechanical pumps with compressed air, the old dock would be converted into a simple yet most advantageous lift dock--rendering many drydocking services not obtainable in the old system.
Aside drydocking facilities, the Stabilizer can also be utilized in ocean-bed exploratory structures, in the form of oil drilling platforms, and equipment and materials transfer shuttles to great depths--unpenetrated heretofore. In fact, this may well constitute the most exciting field of application for the Stabilizer.
The details and arrangement of the stabilizer frame shown in FIG. 1a, 1b and 1c and described above constitute the full basic concept of this invention. While a number of variations, either in arrangement or detail, can be introduced in a particular application, it will be understood that such modifications may be made without departing from the intent and spirit of the invention. For example, in the arrangement shown, all stabilizer frames 16 are assumed to be alike, and placed in paralleling vertical planes normal to the longitudinal axis of lateral support structure 2. In certain applications requiring greater longitudinal rigidity than that provided by two-bracket 12 connection of upper arm 3 in FIG. 1a, some of the frames 16 may be placed in vertical planes inclined to the longitudinal axis. Also, while in the basic arrangement the frames 16 are not interconnected to simplify their placement and connection problem, in a particular case, the designer may choose to brace them laterally in pairs. Changes may also be introduced in connection details, provided that such alterations are made to further simplify the attachment and detachment problem. With respect to this consideration, in some instances, the use of suction-type, vacuum-pad connections may be found as advantageous substitution for the sketched details. Improvements may also be made in the vertical guide track 8 by providing roller-bearing liners to further minimize frictional binding during vertical movements. Also, the lengths of arms 3 and the heights of legs 6 and 7 may vary to fit the contour and profile of the floating structure to which the stabilizer frames 16 are to be attached. In some of such cases, the needed variation may be made through the use of splice sleeves adjustable at the site of installation.
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A series of simple detachable frames, fitted between a floating body and its' mooring support structure, will provide static stability to the floating body, by restraining all movements--except those occurring vertically under tides and buoyancy lift, and to which movements it will provide vertical guidance. Called "Stabilizer for Floating and Submersible Structures," many uses are anticipated for the device. Among these are: pontoon lift docks, where it will eliminate the need for winches and their lift cables or chains, as well as their support piers; ocean-bed exploratory structures, where it will create a new type of stabilized oil-drilling platform and transfer shuttle; and for water craft at mooring, a safer securing system to replace conventional mooring lines.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Patent Application No. 10-2009-0075719 filed on Aug. 17, 2009, with the Korea Intellectual Property Office, the contents of which are incorporated here by reference in their entirety.
BACKGROUND
1. Technical Field
It relates to a metal ink composition for ink-jet and more particularly, a metal ink composition which causes no formation of cracks on a PCB substrate, allows a low temperature curing, and provides improved adhesive strength after coating.
2. Description of the Related Art
Noncontact direct writing technology through inkjet offers advantages in reduction of manufacturing costs and time since it allows ejecting an exact amount of ink to only a desired portion. For applying the inkjet method to form metal wires on a PCB substrate, a metal ink has been greatly developed with growth of interests in the metal ink.
Metal inks in market are a water-based metal ink, a non-water-based metal ink and a solvent-based ink which are divided according to types of solvent. A solvent of metal ink is selected according to a coating material to be used in manufacturing metal nanoparticles. Each ink has advantages and disadvantages. The non-water-based metal ink has a less particle size than the water-based metal ink and allows mass production in high concentration and continuous ejection through a head. However, it causes significant cracks of wires in a printed image and requires a surface treatment due to ununiform CD (critical dimesion) and curing at a high temperature of 250° C. or higher.
Metal nano ink, which is printed on a polyimide, is needed to maintain its adhesive strength and be thus used for printed wires after a coating process in order to be applied for PCB substrates. However, the non-water-based nano ink does not maintain the adhesive strength since a coating solution percolates after printing wires so that it causes delamination of wires and deteriorates mechanical property of wires. Providing appropriate properties as wires is the most important factor in the nano metal ink. Such properties are adhesive strength to a substrate, a low curing temperature and prevention of forming cracks for a metal ink composition. It is the most difficult problem to satisfy such requirements in the development of metal ink composition.
SUMMARY
In order to resolve such problems associated with the conventional technology, it provides a metal ink composition for ink-jet print which does not cause the formation of cracks, allows a low temperature curing, and provides improved adhesive strength and mechanical strength.
A metal ink composition for ink-jet according to the invention does not cause cracks on a PCB substrate, allows curing at a low temperature and particularly provides improved adhesive strength after coating which further allows forming circuit patterns.
According to an embodiment, there is provided a metal ink composition for ink-jet including 20 to 85 parts by weight of metal nanoparticles, 10 to 70 parts by weight of a non-water-based organic solvent, and 1 to 10 parts by weight of at least one additive chosen from unsaturated polyester polymer, butadiene based monomer and butadiene based polymer.
According to an embodiment, the metal nanoparticles may be at least one metal chosen from gold, silver, nickel, indium, zinc, titanium, copper, chromium, tungsten, platinum, iron, cobalt and an alloy thereof.
According to an embodiment, the surface of the metal nanoparticles may be capped with at least one dispersing agent chosen from fatty acid and fatty amine.
According to an embodiment, the metal nanoparticles may have a size of 200 nm or less, preferably 50 nm or less.
According to an embodiment, the non-water-based organic solvent may be at least one chosen from hexane, dodecane, decane, undecane, tetradecane, hexadecane, 1-hexadecene, 1-octadecene, hexylamine, bis-2-ethylhexylamine, octanol, decalin and tetralin.
According to another aspect of the invention, the butadiene based polymer or monomer may be at least one chosen from polybutadiene oil and butadiene monomer.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a method for determining adhesive strength of printed wires formed by using a metal ink composition according to tape test.
FIG. 2 illustrates adhesive strength of printed wires formed by using a metal ink composition of Example 4.
DETAILED DESCRIPTION
While the present invention has been described with reference to particular embodiments, it is to be appreciated that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention, as defined by the appended claims and their equivalents. Throughout the description of the present invention, when describing a certain technology is determined to evade the point of the present invention, the pertinent detailed description will be omitted.
The terms used in the description are intended to describe certain embodiments only, and shall by no means restrict the present invention. Unless clearly used otherwise, expressions in the singular number include a plural meaning. In the present description, an expression such as “comprising” or “consisting of” is intended to designate a characteristic, a number, a step, an operation, an element, a part or combinations thereof, and shall not be construed to preclude any presence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts or combinations thereof.
Hereinafter, preferred embodiments will be described in detail of the metal ink composition for ink-jet according to the present invention.
A metal of metal nanoparticles in the metal ink composition may be at least one chosen from gold, silver, nickel, indium, zinc, titanium, copper, chromium, tungsten, platinum, iron, cobalt and an alloy thereof, but it is not limited thereto. The less size of the metal particles the easier ejection of ink through a nozzle of an ink-jet. A size of 200 nm or less of metal nanoparticles, preferably 50 nm or less, may be used in ink for ink-jet to form proper droplets during the ejection.
The metal ink composition for ink-jet may include 20 to 85 parts by weight of metal nanoparticles, 10 to 70 parts by weight of a non-water-based organic solvent and 1 to 10 parts by weight of at least one additive chosen from unsaturated polyester and butadiene polymer and monomer. The surface of the metal nanoparticles may be capped with fatty acid or fatty amine or with both fatty acid and fatty amine as a dispersing agent. The additive may be well mixed and compatible with a non-water-based solvent and be suitable for capping the nanoparticles as a fat-soluble dispersing agent such as fatty acid or fatty amine. Such additives are not suitable when a water-soluble dispersing agent such as PVP and polyacid is used for capping.
In the metal ink composition, the metal nanoparticles may be included by 20 to 85 parts by weight. When the amount is less than 20 parts by weight, it limits its applications as wire since the amount of metal is not enough and when it is more than 85 parts by weight, it increases viscosity too high and thus deteriorates ejection result which is not finally suitable for a metal ink. Preferably, it may be included by 50 to 70 parts by weight not only to maintain a high concentration of a metal but also to facilitate flow of ink.
An organic solvent used in the metal ink composition may be a non-water-based solvent which is at least one chosen from hexane, octane, decane, undecane, tetradecane, hexadecane, 1-hexadecene, 1-octadecne, hexylamine, and bis-2-ethylhexylamine. It may be used alone or in a combination of 2 or more.
Since a solvent in the metal ink plays a key role to dry ink wires ejected on a substrate, it can be mixed to have an appropriate dry property for ink-jet by using difference in temperature between boiling point (BP) and Host point (FP) of a solvent. For example, a solvent having a high boiling point such as 1-octadecane may delay drying and a solvent having a low boiling point such as bis-2-ethylhexylamine, tetralin, decalin, dodecane, octanol and the like may accelerate drying.
The non-water-based organic solvent may be used by 10 to 70 parts by weight and in order to maximize the concentration of a metal, it is apparent to use a minimum amount of the organic solvent. When amount of the organic solvent is less than 10 parts by weight, it may cause blocking of a nozzle since drying rate becomes too fast and deteriorates the dispersion of particles. On the other hand, when it is more than 70 parts by weight, it may not be preferable to form metal wires having reliability since the amount of a metal becomes relatively low. Preferably, amount of the non-water-based organic solvent is used by 20 to 40 parts by weight.
Unsaturated polyester polymers which can be used in the metal ink composition of the invention are FA156 (Aekyung Chemical), propylene glycol (industrial grade, PGI, Dow), Dynapol (Evonik Degussa DYNAPOL® LH 828 Polyester Resin), SOLPLUS® TX 5 (Lubrizol) and the like.
COMPARISON EXAMPLES AND EXAMPLES
Comparison Examples 1-3 and Examples 1-5 were performed by the following procedure and the result therefrom was summarized in Table 1.
A metal ink composition including metal nano powder, a solvent and an additive (not used in Comparison Examples) was prepared and then wire was printed to be 0.5 cm*10 cm (700 dpi) by using an ink-jet print. Electrical conductivity, adhesive strength and pencil hardness of the printed wire were determined (Table 1).
The adhesive strength was determined by using 3M tape having adhesiveness of 0.65 kN/m and BYK gardener according to ASTM D3359(Measuring Adhesion by Tape Test) as shown in FIG. 1 . The adhesive strength was rated as follows.
<Adhesive Rating>
5 B: No noticeable removal of the coating 4 B: Less than 5% of the coating removed 3 B: 5-15% of the coating removed 2 B: 15-35% of the coating removed 1 B: 35-65% of the coating removed 0 B: more than 65% of the coating removed which is worse than 1 B
The mechanical strength (hardness) of the wire, which was printed to be 0.5 cm*10 cm (700 dpi) using an ink-jet print and cured at a temperature of 250° C. for 1 hr, was determined by using a pencil hardness tester.
The electrical conductivity was determined by measuring specific resistance (μΩcm). It was determined, after forming wire to be 0.5 cm*10 cm (700 dpi) by using Spectra Se-128 Head, by measuring a thickness to determine specific resistance using a 3D profiler.
Comparison Example 1
An ink composition was prepared by using 60 wt % of Ag nanoparticles and 40 wt % of decalin without adding any additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 0 B and pencil hardness was 1 H which was very low.
Comparison Example 2
An ink composition was prepared by using 30 wt % of Cu nanoparticles and 70 wt % of tetradecane without adding any additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 0 B and pencil hardness was 2H which was very low.
Comparison Example 3
An ink composition was prepared by using 50 wt % of Au nanoparticles and 50 wt % of tetradecane without adding any additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 0 B and pencil hardness was 3H which was very low.
Example 1
An ink composition was prepared by using 60 wt % of Ag nanoparticles, 38 wt % of decalin, and 2 wt % of Dynapol (Evonik Degussa DYNAPOL® LH 828 Polyester Resin) as an additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 4 B and pencil hardness was 7 H which were much higher than those in Comparison Examples.
Example 2
An ink composition was prepared by using 30 wt % of Cu nanoparticles, 68 wt % of octanol, and 2 wt % of FA156 (Aekyung Chemical) as an additive. Each property of Electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 3 B and pencil hardness was 7 H which were much higher than those in Comparison Examples.
Example 3
An ink composition was prepared by using 50 wt % of Au nanoparticles, 48 wt % of tetradecane, and 2 wt % of polyisobutene oil (BASF) as an additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 3 B and pencil hardness was 6H which were much higher than those in Comparison Examples.
Example 4
An ink composition was prepared by using 40 wt % of Cu nanoparticles, 67 wt % of tetralin, and 3 wt % of Dynapol (Evonik Degussa DYNAPOL® LH 828 Polyester Resin) as an additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 5 B and pencil hardness was 8H which were much higher than those in Comparison Examples.
Example 5
An ink composition was prepared by using 40 wt % of Ag nanoparticles, 58 wt % of tetralin, and 1 wt % of Dynapol (Evonik Degussa DYNAPOL® LH 828 Polyester Resin) and 1 wt % of polyisobuene oil as an additive. Each property of electrical conductivity, adhesive strength and pencil hardness was determined by the same procedure described above and the result was summarized in Table 1. Adhesive strength was 5 B and pencil hardness was 8H which were much higher than those in Comparison Examples.
TABLE 1
Poly
Electric
Nano-
isobutene
conductivity
Pencil
particles
solvent
Dynapol
FA156
oil
(uΩ · cm)
Adhesive
hardness
Example 1
Ag
Decalin,
2 wt %
10
4B
7H
60 wt %
38 wt %
Example 2
Cu
Octanol,
2 wt %
11
3B
7H
30 wt %
68 wt %
Example 3
Au
Tetradecane,
2 wt %
30
3B
6H
50 wt %
48 wt %
Example 4
Cu
Tetralin,
3 wt %
7
5B
8H
40 wt %
67 wt %
Example 5
Ag
Tetralin,
1 wt %
1 wt %
80
5B
8H
40 wt %
58 wt %
Comparison
Ag
Decalin,
—
—
—
8
0B
1H
Example 1
60 wt %
40 wt %
Comparison
Cu
Tetradecane,
—
—
—
6
0B
2H
Example 2
30 wt %
70 wt %
Comparison
Au
Tetradecane,
—
—
—
27
0B
3H
Example 3
50 wt %
50 wt %
As shown in Table 1 for Comparison Examples 1 to 3 and Examples 1 to 5, it was noted that when the lipophilic metal ink composition prepared by adding an additive such as Dynapol, FA156 and polyisobutadiene oil was cured at a low temperature, there was no formation of cracks and it exhibited significantly improved adhesive strength and pencil hardness (see FIG. 2 ). The electrical conductivity was also determined as 7-30 uΩ·cm. Therefore, it proves that the metal ink composition of the invention eliminates the problems associated with the conventional technology and shows excellent physical properties so that it is suitable for PCB uses.
While it has been described with reference to particular embodiments, it is to be appreciated that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the embodiment herein, as defined by the appended claims and their equivalents.
Much more Examples except Examples described herein will be in the scope of the invention.
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The invention is to provide a metal ink composition for ink-jet and more particularly, a metal ink composition which causes no formation of cracks on a PCB substrate, allows a low curing temperature, and provides improved adhesive strength even after coating.
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FIELD OF THE INVENTION
This invention relates to an attachment to a boom on a materials handling machine and more particularly to a log splitter attachment for splitting full length logs.
BACKGROUND OF THE INVENTION
It is not uncommon to station a log chipper in the field, i.e., in the area where logs are being harvested. Logs are converted into chips on site and in the chip form are hauled more efficiently to pulp mills in large truck boxes. These field chippers are typically designed for efficient chipping of small diameter logs. A large diameter log, e.g., of eighteen inch diameter and larger, is not readily accommodated by the field chipper and requires special handling.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is directed to the provision of a machine for lengthwise splitting of large diameter logs to facilitate the chipping process. In the preferred embodiment, a machine designed for back hoe digging provides the base component of the log splitting machine. The back hoe machine is typically a tractor having an articulated boom. A rearward facing bucket is mounted on the end of the boom and the bucket includes digging teeth. Hydraulic cylinders manipulate the boom and the bucket. In operation, the articulated boom is extended and the bucket teeth are directed into the ground. The boom then draws the bucket back toward he machine. An important feature of the back hoe is the power that is provided to the boom for forcing the bucket teeth into and along the ground, e.g., for digging ditches.
The attachment of the invention replaces the bucket on the back hoe machine and is manipulated by the same hydraulic cylinders. The attachment includes a splitting and slicing blade. In operation, a log is positioned so as to be extended outwardly from the machine. The positioned log is prevented from moving, e.g., one end of the log is butted against the machine body. The boom is extended over the log with the blade edge hooked over the outer end of the log. The blade is then drawn rearwardly through the log, the action being the same action applied when digging a trench with the back hoe bucket.
The attachment preferably includes a grapple and heel arrangement that enables the operator to pick up and position a log, the heel being provided by a claw that cooperates with the blade to enable the operator to also cut the log slices (or a whole log) to length. These and other features and benefits will become more clearly understood upon reference to the following detailed description and drawing.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a back hoe machine of the prior art, being operated to dig a trench;
FIG. 2 illustrates the same basic machine of FIG. 1 with the bucket portion replaced with an attachment in accordance with the present invention and positioning a log to be split;
FIGS. 3A and 3B illustrate the attachment of the present invention installed on the machine of FIG. 2;
FIG. 4 is a block diagram of the control sets for controlling the functions of the machine of FIG. 2;
FIG. 5 is a view of the machine of FIG. 2 in the process of splitting a log with the attachment of the present invention;
FIG. 6 is another view of the machine of FIG. 2 showing the progression of the attachment of the present invention as the log is being split; and,
FIG. 7 is a view of the machine of FIG. 2 in the process of grappling and slicing a log.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Refer now to FIG. 1 of the drawings which illustrates a material moving machine 10 often referred to as a back hoe. The machine 10 is of known construction, therefore only a brief description will be provided. The machine 10 has an articulated boom 12 extending from a base 14. The base 14 is mounted on a carriage 16 with the base arranged to be rotatable on the carriage about an axis 18. The boom 12 may thus be swung in a horizontal plane about axis 18. The base 14 is rotated relative to the carriage 16 by known power transmission apparatus (out of view). The carriage 16 includes crawler type tracks 17 to facilitate movement and steerage of the machine 10 with motive power being supplied to the tracks 17 in a known conventional manner. The articulated boom 12 has an end of a beam 20 pivotally mounted to the base 14 at 22. Dual cylinders (motors) 24 are provided to pivotally move the beam 20 relative to the base 14. A second beam 30 of the articulated boom 12 is pivotally mounted to the beam 20 at 32. A cylinder (motor) 34 is provided to pivotally move the beam 30 relative to the beam 20 about the pivotal connection 32. A bucket 36 is pivotally mounted on an end 31 of the beam 30 on shaft 38. A cylinder (motor) 40 in conjunction with paired control arms 44, 46 are provided to pivotally move the bucket 36 about the pivotal mount 38. A heel rack 54 is pivotally mounted on the end of the beam 30 opposite the bucket 36 on shaft 38 and is moveable by a cylinder (motor) 56 in conjunction with paired control arms 60, 62.
An operator's compartment 11 is provided on the base 14 and includes a control station 15 (out of view) to control the operation of the machine 10. The machine 10 is thus arranged for the controlled movement of the articulated boom 12, the rotation of the base 14 on the carriage 16 and the movement of the machine 10 relative to the ground. Movement of the above components (boom, base rotation and machine movement) either individually or in conjunction with each other provide for the controlled movement of the end 31 of the boom 12. The end 31 thus may be elevated and lowered, extended and retracted relative to the base 14, may be swung about axis 18 and may also be moved by movement of machine 10. In addition, the bucket 36 and/or the heel rack 54 and the like are individually controllable.
A conventional power supply unit 70 supplies motive power to the machine 10. Suitable control sets (illustrated in the block diagram of FIG. 4 and later described) are provided for controlling the function of the components of the machine 10. The control sets are arranged so that each component controlled may be moved or controlled independently or in conjunction with other components. The control sets are operable by the operator at the control station 15.
The machine 10 of FIG. 1 is illustrated digging a trench and the controlled movements of the components of the machine 10 are employed to accomplish the task.
Refer now to FIG. 2 of the drawings which illustrates the machine of FIG. 1 with the bucket 36 removed and with an attachment 80 of the present invention pivotally installed on the end of the articulated boom 12 on shaft 38. A member such as a log 170 is shown being positioned by the machine 10. A log 170 is shown for the purpose of illustration however this member may be a variety of different kinds of members such as stumps, timbers, construction materials and the like. The attachment 80 is pivoted on the end 31 of the beam 30 by cylinder 40. As shown, the cylinder 40 has one end pivotally connected to the beam 30 and the opposite end pivotally connected to shaft 48. Ends of paired control arms 44, 46 are mounted on the shaft 48. A control arm 44 is provided on each end of the shaft 48 and thus on each side of the beam 30 with the opposite ends of control arms 44 pivotally mounted on each side of the beam 30 on shaft 50. A control arm 46 is provided at each end of the shaft 48 with the opposite ends of control arms 46 pivotally mounted at each side of the attachment 80 on shaft 52. The attachment 80 is thus pivoted on the shaft 38 o end 31 of the beam 30 by extension and retraction of the cylinder 40. The attachment 80 is further illustrated in FIGS. 3A and 3B. A structural support 82 of the attachment 80 is configured to be pivotally mounted on shaft 38. The structure 82 is fabricated as by welding. The support 82 has side walls 84, 86 in a spaced relation to receive therebetween the end 31 of the beam 30. To facilitate mounting the attachment 80 on the end of the beam 31, the side walls 84, 86 have bushings 88 fitted in bores 90 with the bushings 88 sized to receive the shaft 38. Another set of bushings 88' are provided in another set of bores 90 in the side walls 84, 86. The bushings 88' receive the shaft 52 on which the ends of the control arms 46 of the machine 10 are pivotally mounted, with one control arm 46 adjacent wall 84 and the other control arm 46 adjacent wall 86. The side walls 84, 86 are fixedly joined by bottom walls 92, 94 and 96. Cross rails 98 and 100 joined to the side and bottom walls are provided for added strength and rigidity. A bracket 110 is provided on the end of the support 82 as shown for mounting a known grapple 112 on shaft 114. The grapple 112 has opposed moveable grappling jaws 118 for grappling material in a conventional manner with the jaws 118 being rotatable about axis 116. Known hydraulic circuitry coupled to the power unit 70 is provided on the machine 10 to provide motive power to the grapple 112. Blade brackets 120 extending from wall 92 are provided to support and hold a splitter blade 130. The blade 130 is removably mounted to the brackets 120 by bolts 132 fitting in mateable bores provided in the brackets 120 and the blade 130 with the bolts 132 being secured by nuts 134. The blade 130 is a shaped elongate flat plate member that extends from bottom 92 when installed on the structure 82. The blade 130 has a beveled knife edge 138 that extends substantially along the length of the front edge 136 including the angled toe portion 140. The attachment 80 mounted on the machine 10 provides the capability of splitting logs, handling logs and splitting, slicing other wood debris.
As previously mentioned, the components of the machine 10 are controlled by control sets operable by the operator at the control station 15. Referring to FIG. 4, the power unit 70 supplies motive power for operation of the components of the machine 10. A control set 150 is provided to control the cylinders 24 (the cylinders 24 pivot the beam 20 of the boom 12 relative to the base 14), a control set 152 is provided to control cylinder 34 (the cylinder 34 pivots the beam 30 relative to beam 20 of the boom 12), a control set 154 is provided to control cylinder 40 (the cylinder 40 pivots the attachment 80 about its pivotal mount and other attachments mounted in its stead such as bucket 36), a control set 156 is provided to control cylinder 56 (cylinder 56 pivots the heel rack 54 about its pivotal mount), a control set 158 is provided to control the power transmission apparatus that provides rotative movement of the base 14 relative to the carriage 16, a control set 160 is provided to control the carriage 16 (propulsion and steerage) and a control set 162 is provided to control the grapple 112 (rotation of, clamping and unclamping).
Refer now to FIG. 2 of the drawings. The machine 10 with the attachment 80 is positioning a log 170 relative to the machine 10 so that it may be split along its longitudinal length by the blade 130 of the attachment 180. The capability of the machine 10 to extend and retract, elevate and lower the boom 12 and move the boom by rotation of the base 14 on the carriage 16 enables retrieval of logs from stockpiles placed in the vicinity of the machine 10. The log 170 is gripped by the grapple 112 and is elevated by elevating the boom 12. The log 170 is most often gripped by the grapple 112 at a position that is offset from the center of gravity. The log will thus tend to pivot the grapple 112 with the log coming into contact with the heel rack 54 and/or the blade 130. This feature permits gripping the log nearer one of its ends for ease of placement. The log 170 is positioned by manipulation of the machine 10 with the log being placed with one end 172 in abutment with one of the tracks 17 (see FIG. 5). Alternatively, another log 176 (shown in dashed outline in FIG. 6) may be placed transverse to and in front of the tracks 17. Log 170 is then placed with the end 172 in abutment with the log 176. In either case the log 170 is placed so that it extends outwardly away from the machine with the boom 12 basically aligned with the longitudinal axis of the log 170. The grapple 112 is released and the boom 12 is extended outwardly over the log 170 and lowered with the blade 130 coming into contact with the extended end 174 of the log. The toe 140 of the blade being at an angle to the edge 136 facilitates the initial splitting action by the blade 130. With the blade 130 in contact with the end of the log 170, the boom 12 is retracted toward the machine to force the blade through the log 170, thus splitting the log into two longitudinal pieces. FIG. 5 shows the blade 130 as it is entering the end 174 of the log 170 to start the splitting process. As the boom 12 is retracted further toward the machine 10 (one position being illustrated in FIG. 6), the attachment 80 may be pivoted to position the blade 130 at a near normal attitude to the longitudinal axis of the log 170. The beveled edge 138 on the blade 130 provides a wedge to facilitate splitting the log 170. The operation is repeated until the log has been split into multiple longitudinal pieces of the desired dimensions. The split longitudinal pieces of the log 170 are grappled by the grapple 112 and are moved to an area such as a stockpile by manipulation of the machine 10.
Referring now to FIG. 7, the heel rack 54 and the blade 130 of the attachment 80 are used in combination as a grappling device and as a slicing or cutting device. As shown, a member such as a log 180 is gripped between the heel rack 54 and the blade 130 of the attachment 80. The angled toe portion 140 of the blade 130 provides a projection to aid in gripping the log 180. To cut the log 180, the heel rack 54 and the blade 130 are pivoted toward each other. The heel rack 54 may be pivoted toward the blade 130, the blade 130 may be pivoted toward the heel rack 54 or the pivoting movement toward each other may be accomplished by the simultaneous pivoting movement of both the heel rack 54 and the blade 130
The attachment 80 mounted on the machine 10 is a versatile tool for reducing the size of members, such as by splitting and cutting. It will be appreciated that the attachment 80 is not limited to the processing of logs which are illustrated by way of example. The attachment 80 may be utilized in many other areas where reduction in the size of members is desired or required.
Those skilled in the art will recognize that modifications and variations may be made without departing from the true spirit and scope of the invention. The invention is therefore not to be determined from the appended claims.
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An attachment configured and arranged for mounting onto the end of an articulated boom. The attachment preferably includes a grapple for handling and positioning whole logs under the articulated boom. A splitter blade extending from the structure is manipulated to engage and split the logs as the boom of the machine is retracted toward the machine through articulation.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to water evaporation systems, and particularly to a flexible belt evaporator for cooling and humidifying closed areas and for the desalination of water.
[0003] 2. Description of the Related Art
[0004] Water evaporation systems are well known for various purposes, e.g., removing seawater to recover salt and/or other minerals, cooling due to the heat absorption of evaporating water, and humidifying air. Accordingly, a number of different water evaporation devices, systems, and methods of operation have been developed in the past.
[0005] A general class of such systems comprises the spreading of a relatively thin film or layer of water on a sheet of material so that the relatively large surface area per volume of water provides reasonably efficient evaporation. The problem with this principle of operation is that salt or other contaminants or impurities in the water will rapidly coat the sheet of material once the water evaporates. Some means must be provided for removal of the salt and/or other residue from the evaporation sheet or substrate material, at least from time to time. The more efficient the evaporative process, the more rapidly the salt and/or other residue builds upon the evaporative base material. Some method for preventing salt from accumulating on the evaporator would increase the efficiency and extend the life of the device.
[0006] Thus, a flexible belt evaporator solving the aforementioned problems is desired.
SUMMARY OF THE INVENTION
[0007] The flexible belt evaporator has an endless water absorbent textile belt or web that is continually advanced over and around a plurality of rollers. The textile material is preferably formed with hydrophilic weft or woof strands or threads disposed generally horizontally, i.e., across the width of the web, and hydrophobic warp strands or threads disposed vertically, i.e., in the direction of travel of the web. This limits or obviates water absorption along the vertical strands, thus slowing any dripping that might otherwise occur from an overly saturated belt or web.
[0008] Most, or all, of the rollers are located clear of any liquid water. The water that is contaminated with salt and/or other materials is sprayed onto the textile belt from above as the belt passes over a series of upper rollers. Evaporation takes place as the textile belt or web is advanced over and about the rollers. The salt and/or other residue remains on the belt. The belt is then passed through a wash tank, where the salt and/or other residue is washed or otherwise cleaned from the belt. The wash tank preferably includes an ultrasonic generator using ultrasonic energy to better remove the salt and/or other residue from the textile belt or web. The belt then passes from the wash tank to continue its endless path about the rollers, where it is again wetted by the overhead spray nozzles.
[0009] In one embodiment, belt tension is maintained by one or more rollers immersed in the lower portion of the wash tank. In another embodiment, the belt passes loosely through the wash tank, and no rollers are installed in the tank. Belt tension exterior to the wash tank is maintained by pinch rollers adjacent to the wash tank. This embodiment avoids the need for installation of rollers in the salt contaminated wash tank, and the corresponding difficulties in maintenance of the rollers in such an environment. The evaporative system may be applied to cooling systems, humidifying systems, and salt and/or contaminant recovery systems for water.
[0010] These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagrammatic elevation view of a first embodiment of a flexible belt evaporator according to the present invention, having rollers disposed within the wash tank.
[0012] FIG. 2 is a diagrammatic elevation view of a second embodiment of a flexible belt evaporator according to the present invention, having no rollers installed within the wash tank.
[0013] FIG. 3 is a diagrammatic elevation view of a third embodiment of a flexible belt evaporator according to the present invention, having a large number of closely spaced rollers.
[0014] FIG. 4 is a partial perspective view of a woven textile incorporating mutually orthogonal hydrophilic and hydrophobic strands in its weave for use as the belt in a flexible belt evaporator according to the present invention.
[0015] FIG. 5 is a flowchart illustrating the flow paths of water and air in a solar-heated heat exchanger and desalination system.
[0016] FIG. 6 is a flowchart illustrating the flow paths of water and air in a solar-powered evaporative cooling system.
[0017] Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The flexible belt evaporator has an endless flexible woven textile belt or web that passes about a series of rollers. A spray system is provided above the rollers to wet the belt with salt water or water containing other impurities. The belt is exposed to the air between the rollers to evaporate water from the belt. A wash bath is provided to rinse the salt and/or other impurities from the belt. The apparatus may be used to cool the surrounding air by means of the heat absorbed by the evaporating water, to humidify air as the water evaporates from the belt, and/or to collect salt and/or other residue from the belt after the water evaporates therefrom.
[0019] FIG. 1 of the drawings is a diagrammatic drawing of a first embodiment 110 of the flexible belt evaporator. The evaporator 110 includes a plurality of closely spaced upper guide rollers 112 a , 112 b , 112 c , 112 d , and 112 e , and a plurality of closely spaced lower guide rollers 114 a , 114 b , 114 c , 114 d , and 114 e . It will be seen that more or fewer upper and lower guide rollers may be provided. The guide rollers 112 a through 114 e , and other rollers employed with the evaporator 110 , may have their rotational axes sloped slightly from the horizontal to encourage water runoff toward one end thereof, if desired. The upper guide rollers 112 a through 112 e are separated vertically from the lower rollers 114 a through 114 e by a clear span that is greater than the span between adjacent rollers, through which air may be circulated for evaporation. This configuration provides a very compact horizontal area for the flexible belt evaporator 110 in comparison to the overall evaporative area of the belt 118 , as most of the area of the belt 118 is oriented generally vertically between the alternating upper and lower rollers. First and second master rollers 116 a and 116 b are disposed above the upper guide rollers 112 a through 112 e . One of the rollers, e.g., the first master roller 116 a , may be motorized, as is conventional in the art of conveyor belts and the like.
[0020] An endless, water-absorbent, flexible woven fabric belt 118 travels a sinusoidal path about the guide rollers 112 a through 114 e . The belt 118 passes about the first lower guide roller 114 a , then up and over the first upper guide roller 112 a , back down to the second lower guide roller 114 b , and continues in sequence about guide rollers 112 b , 114 c , 112 c , 114 d , 112 d , 114 e , and 112 e . A wash bath or tank 120 is provided adjacent to the last guide rollers 112 e and 114 e , to wash salt and/or other residue from the belt 118 after saltwater or other contaminated water evaporates from the belt. The belt 118 forms a loop portion 122 that passes through the wash bath or tank 120 . The belt 118 is guided into the wash bath 120 by an entrance roller 124 a , and is guided from the wash bath 120 and back to the second master roller 116 b by a wash bath exit roller 124 b . While the return path for the belt 118 is shown extending over the two master rollers 116 a and 116 b and above the upper rollers 112 a through 112 e , it will be seen that the belt return path may extend beneath the lower rollers 114 a through 114 e and beneath the wash bath 120 by providing rollers in appropriate locations. One or more wash bath rollers, e.g., first and second wash bath rollers 126 a and 126 b , are installed within the wash tank 120 to maintain tension on the endless belt 118 as it travels about the rollers 112 a through 116 b and the wash bath entrance and exit rollers 124 a and 124 b.
[0021] A water dispenser 128 is disposed above the upper rollers 112 a through 112 d or 112 e , generally between the two master rollers 116 a and 116 b . The water dispenser 128 preferably comprises a plurality of spray nozzles 130 a through 130 d , oriented to spray saltwater or water containing other contaminants onto the belt 118 as it passes over and around the upper guide rollers 112 a through 112 e . More or fewer spray nozzles may be provided, the drawing being exemplary. The woven fabric of the belt 118 absorbs the saltwater (saline) or otherwise contaminated water from the spray nozzles 130 a through 130 d and travels around the various upper and lower rollers to expose the wet belt surface to the air for evaporation. Individual drip catch trays or a single large drip catch pan may be placed beneath the lower rollers 114 a through 114 e . Any collected salt and/or other residue remains on the belt. The belt 118 continues its travel around the rollers 112 a through 114 e , eventually reaching the wash bath 120 via the entrance roller 124 a . The loop portion 122 of the belt 118 is immersed in the wash bath 120 so that the salt and/or other residue is washed from the belt 118 . An ultrasonic device 132 may be installed within the wash bath 120 to remove fine particulates from the belt 118 ultrasonically. Also, chemicals may be provided in the wash bath 120 for further cleaning of the belt 118 . After passing through the wash bath 120 , that portion of the endless belt 118 continues its travel back across the master rollers 116 a , 116 b to travel through the upper and lower rollers 112 a through 114 e in order to be wetted once again for further evaporation.
[0022] FIG. 2 of the drawings is a diagrammatic illustration of an alternative embodiment of the flexible belt evaporator, designated as flexible belt evaporator 210 . The flexible belt evaporator 210 of FIG. 2 includes most of the components of the flexible belt evaporator 110 of FIG. 1 , i.e., upper and lower guide rollers 112 a through 114 e , master rollers 116 a and 116 b , belt 118 , wash bath 120 , the belt loop 122 immersed in the wash bath 120 (the loop is flaccid, in the embodiment of FIG. 2 ), the water dispenser 128 and spray nozzles 130 a through 130 d , and the ultrasonic device 132 . These like numbered components are essentially identical in the two embodiments 110 of FIGS. 1 and 210 of FIG. 2 . However, it will be noted that there are no rollers immersed within the wash bath 120 in the flexible belt evaporator 210 of FIG. 2 . This results in the belt loop 122 being loosely suspended within the wash bath tank 120 in the embodiment of FIG. 2 . The remainder of the belt 118 is kept taut by a first or entrance pair of pinch rollers 224 a and 224 b , and a second or exit pair of pinch rollers 226 a and 226 b . These pinch rollers 224 a through 226 b are roughly analogous to the entrance and exit rollers 124 a and 124 b of the embodiment 110 of FIG. 1 , but two rollers at each location are required to grip or pinch the belt 118 therebetween in order to prevent the slack in the loop 122 from spreading about the remainder of the endless belt as it passes over and around the rest of the roller system. The flexible belt evaporator 210 of FIG. 2 avoids the need for any rollers within the water of the wash bath 120 , thus avoiding the problems of operation and maintenance of a moving mechanical device within a corrosive liquid, i.e., the salty or otherwise contaminated water that collects in the wash bath 120 .
[0023] FIG. 3 provides a diagrammatic illustration of another embodiment of the evaporator, designated as flexible belt evaporator 310 . The configuration of the flexible belt evaporator 310 is similar to that of the evaporator 110 of FIG. 1 , but includes a much greater number of upper and lower guide rollers. These guide rollers are designated as upper guide rollers 312 a through 3121 and lower guide rollers 314 a through 314 l . They differ from their corresponding rollers 112 a through 112 e and 114 a through 114 e of the embodiments 110 of FIGS. 1 and 210 of FIG. 2 in that the diameters of the rollers 312 a through 3141 are considerably smaller than the diameters of the rollers 112 a through 114 e . Advantageous placement of the smaller diameter rollers 312 a through 3141 to one another may be made, even though their bases and bearings may be essentially the same diameter as the diameters of the rollers 112 a through 114 e , by staggering the alternating rollers of each set relative to one another. Thus, the first upper roller 312 a is offset vertically slightly below the second upper roller 312 b , the second upper roller 312 b is slightly higher than the third upper roller 312 c , etc. This places every other upper roller 312 a , 312 c , 312 e , 312 g , 312 i , and 312 k in a horizontal row below a horizontal row containing the other upper rollers 312 b , 312 d , 312 f , 312 h , 312 j , and 312 l . The lower rollers are arranged similarly, so that the lower rollers 314 a , 314 c , 314 e , 314 g , 314 i , and 314 k are aligned in a horizontal row slightly above another horizontal row containing lower rollers 314 b , 314 d , 314 f , 314 h , 314 j , and 314 l . This configuration allows a much larger vertical evaporative surface area for the belt 118 as it passes back and forth between the much greater number of rollers. The remaining components 116 through 132 of the embodiment 310 of FIG. 3 are substantially identical to those like designated components in the embodiment 110 of FIG. 1 and operate in the same manner.
[0024] The provision of relatively large diameter bearings is desirable in order to reduce the rolling friction of the various rollers. This friction can be substantial when a large number of rollers is considered. It will be seen that by staggering the adjacent rollers in each of the upper and lower sets or rows, the bases and/or bearings of each roller may be larger than would otherwise be the case, and/or the rollers may be placed closer to one another than in a linear array of rollers in order to increase the density of the flexible belt and the evaporative surface area as the belt runs among the closely spaced rollers. In fact, the diameters of the bearings and their bases in the configuration of FIG. 3 may be a few times larger (e.g., 2-4 times larger) than the diameters of the rollers because the rollers and their bearings are staggered in the manner illustrated in FIG. 3 . The two upper and lower rows of rollers illustrated in FIG. 3 are exemplary, and are not intended to be limiting. Even larger bearings may be used by configuring the system to have three or more upper and lower rows of rollers, as desired.
[0025] FIG. 4 is a perspective view of a portion of the absorbent, flexible woven fabric belt 118 used in the various embodiments of the flexible belt evaporator. The belt or web 118 is preferably formed with the warp strands or threads 118 a , i.e., those strands extending vertically between the upper guide rollers and the lower guide rollers, being hydrophobic or water-repellent. The weft or woof strands or threads 118 b , i.e., those strands extending parallel to the rotary axes of the rollers, are hydrophilic or water-absorbent. A belt or web 118 manufactured in this manner will have the horizontal or weft strands 118 b absorbing water as the water is repelled from the vertical or warp strands 118 a , thus greatly reducing vertical runoff along the belt or web 118 as it extends vertically between upper and lower rollers.
[0026] FIG. 5 is a schematic diagram or flowchart illustrating the components of an evaporative cooling and desalination system incorporating the flexible belt evaporator of the present invention. The evaporator of FIG. 5 is designated as 510 , but it will be understood that it may comprise any of the flexible belt evaporators 110 , 210 , or 310 respectively of FIG. 1 , 2 , or 3 , and/or any of the variations thereof described further above. In FIG. 5 , solar energy is applied to a solar-powered liquid heater 512 . The heated fluid is used to heat seawater or other contaminated water in a water heater 514 . The heated seawater (or other water) then passes to the flexible belt evaporator 510 , where the heat assists in the evaporative process. The heat absorption accomplished by the water as it evaporates in the flexible belt evaporator 510 results in a cooling of the air (or other gas) in which the water vapor is suspended. The high humidity air or gas is then passed to a condenser 516 , and the condensed water is returned to the water heater 514 to repeat the cycle. Additional water may be added as necessary, but the water cycling is essentially a closed system. The evaporative cooling and desalination system of FIG. 5 requires no net energy input, other than the solar energy used to heat a fluid that is, in turn, used to heat the saline water circulating in the system.
[0027] FIG. 6 is a schematic flowchart of an air conditioning system using a flexible belt evaporator 610 according to the present invention. As in the case of the flexible belt evaporator 510 of FIG. 5 , the evaporator 610 may comprise any of the embodiments of the flexible belt evaporator described herein. As in the ease of the system of FIG. 5 , the system of FIG. 6 initially uses a solar heater 612 to heat a fluid. The hot fluid is used to heat a moisture-absorbent (desiccant) material 614 , driving any absorbed moisture therefrom. The desiccant 614 receives warm and moist air from the flexible belt evaporator 610 after the water input has been evaporated therein. As the evaporative process removes heat from the air, the cooled and moist air is used as a heat exchanger to accept waste heat output from an air conditioning system (air conditioning heat load). Other than the energy required to run any required circulation fans or pumps in the system, the air conditioning system of FIG. 6 requires no additional energy, other than the solar input to the solar heater 612 , resulting in a very energy efficient system.
[0028] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The flexible belt evaporator employs an endless woven textile belt serving as a carrier for saline or otherwise contaminated water for evaporation of the water therefrom, and also serves as the evaporator surface. Mechanical equipment immersed in the saltwater and corresponding maintenance difficulties are largely avoided by placing most or all belt rollers clear of the liquid water tank of the system. Saltwater or contaminated water is sprayed onto the belt from above. The continuing passage of the belt about the exposed rollers results in water evaporation from the belt. Scale and residue buildup on the belt is removed by passing the belt through a wash tank. The wash tank preferably contains an ultrasonic generator to produce ultrasonic energy for removal of residue from the textile belt. The flexible belt evaporator system may be applied to evaporative cooling systems, humidifying systems, and salt or residue recovery systems.
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The present invention relates generally to machine cutting tools and more particularly to an internal broaching tool which is adapted to enable adjustable positioning of cutting teeth thereon.
A tool of the type to which the present invention relates is generally formed with an elongate base member adapted to be held in a broaching machine and having external teeth for effecting a broaching operation. Usually, such a broaching tool will include a part which operates to center a workpiece relative to the tool. The tool may also include a first set of teeth which are formed with progressively increasing dimensions to enable relatively rapid removal of material from the workpiece in order to approximate the required final dimension of the workpiece. A second set of teeth which are formed of the same size are used to accurately finish the workpiece during the broaching operation. Broaching tools known in the prior art are disclosed in U.S. Pat. Nos. 1,744,217 and 1,945,535. In such tools, cutters bearing cutting teeth are removably secured to the base member of the tool by screws. The cutters may be replaced when they are worn, but it becomes necessary for newly replaced cutters to be provided with required dimensions and this involves grinding of the teeth.
In U.S. Pat. No. 4,041,590, there is disclosed a broaching tool in which cutter parts are secured to a base member by bolts, but in which the teeth of the cutters are not interrupted by the necessity of accommodating such bolts. The life of cutters can be prolonged by placing shims beneath the cutters, and cutter elements which have been excessively reduced by grinding may be used at the beginning of the broaching tool to prolong their effective life.
However, in the broaching tools previously proposed in the prior art, the teeth of the tools which accurately produce the required finished dimension of the broached workpiece are not capable of being replaced and although the cutters bearing the teeth of progressively increasing size can be replaced, the life of the broaching tool will be determined by the wear limit of the finishing of calibrating teeth thereof.
Accordingly, the present invention is directed toward providing a broaching tool in which the aforementioned disadvantage may be overcome. More specifically, the invention is directed toward a broaching tool design which is arranged in such a way that the cutting teeth producing the finished dimensions will be provided with a setting and resetting device which will be easily accessible from inside and outside of the broaching machine even if the tool is in the fitted condition.
SUMMARY OF THE INVENTION
Briefly, the present invention may be defined as an internal broaching tool comprising an elongate base portion adapted to be held in a broaching machine, recess means formed in said base portion for receiving therein an adjusting element and cutting tooth means provided on said broaching tool at least in the vicinity of said recess means, said adjusting element cooperating with said recess means to deform said base member thereby to adjust the operating dimensions of said cutting tooth means.
Thus, in accordance with the invention, there is provided an internal broaching tool wherein the part of the broaching tool defining the elongate base member is formed to include a recess or slot formation therein which is adapted to receive an adjusting element. The adjusting element cooperates with the slot or recess to deform the sides of the base member between which the slot is defined. As a result of the deformation of the base member sides, the operative dimension, i.e., the spacing between cutting teeth arranged externally of the broaching tool alongside the slot, may be adjusted by operation of the adjusting element.
The advantage of the arrangement in accordance with the present invention, which preferably is applied to a tooth or teeth of the finishing or calibrating set of teeth of the broaching tool, is that the final dimensions produced in the workpiece by the broaching tool may be accurately set. If the teeth of the broaching tool are worn and must be reground, rapid resetting may be achieved merely by simple operation of the adjusting element. In service, resetting may be made possible without requiring even the removal of the broaching tool from the machine. If slight dimensional changes are required in the workpiece, the same broaching tool may be capable of being continuously used with suitable adjustments and tight tolerances can be maintained.
The recess or slot may extend transversely through the base member relative to the longitudinal axis thereof or it may extend axially of the base member. The adjusting element may be accessible through an aperture in the side of the base member or, in the case of an axially extending recess formation, in the end surface of the base member.
The invention is applicable to broaching tools wherein the teeth are on opposite sides of the base member. It is also applicable to broaching tools which have circumferential teeth extending around the base member, in which case an axially extending formation in the base member would be utilized and the adjusting element therein would be accessible from the end of the broaching tool.
The adjusting element may be a tapered element of any desired form, for example a cone, a ball, an eccentric element, or a cam. Such adjusting elements, by cooperation with appropriately shaped surfaces of the base member, will deform the base member elastically in order to adjust the spacing between the teeth. The base member may return to its original configuration upon release of the adjusting element.
It would be possible to utilize assemblies of adjusting elements which cooperate with one another to engage the base member of the broaching tool in order to effect the desired adjustment. Thus, the base member itself need not have a tapered surface or similar formation in order to achieve cooperation with an adjusting element.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1A is a side view of a broaching tool embodying the invention;
FIG. 1B is a front view of a part of the broaching tool shown in FIG. 1A;
FIG. 2A is a cross-sectional view and FIG. 2B is an elevational view showing in greater detail an adjusting element of the broaching tool of FIG. 1A;
FIG. 3 is a sectional view taken through a broaching tool showing a further embodiment of the adjusting element;
FIG. 4 is a sectional view showing another embodiment of the adjusting element;
FIG. 5 is an elevational view of a part of a broaching tool which comprises a further embodiment of the adjusting element of the invention;
FIG. 6 is a longitudinal section of the broaching tool shown in FIG. 5;
FIG. 7 is a transverse sectional view of the broaching tool of FIG. 5; and
FIG. 8 is a longitudinal sectional view of the broaching tool comprising a further embodiment of the adjusting element of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and particularly to FIGS. 1A and 1B, there is shown a broaching tool which comprises an elongate base member 1 having at one end thereof a shank 2 defining surfaces 3 which enable the broaching tool to be tensioned by an appropriate holder in a broaching machine.
At the opposite end of the base member, there is provided a portion 5 which also operates to enable the tool to be held in a machine. Adjacent the shank 2 there is provided a surface for centering a workpiece relative to the tool.
The broaching tool is formed with cutting teeth 6 which are arranged so that their size will progressively increase taken in the direction away from the shank 2. The teeth 6 operate to remove material relatively rapidly from a workpiece. The teeth 6 are followed by another set of teeth 7 which are not of increasing size and which operate to finish a broached workpiece to required dimensions.
A recess or slot 8 is provided in the base member of the broaching tool in the region of the finishing teeth 7 with the recess 8 operating to accommodate an adjusting element. The adjusting element and the various forms which may be provided in accordance with preferred embodiments of the invention will be described in greater detail hereinafter with reference to FIGS. 2A, 2B, 3, and 4.
In FIGS. 2A and 2B, there is shown in greater detail the form of the recess 8. As indicated in the drawings, the recess or slot 8 is shaped to comprise a main bore 10 which extends transversely through the base member 1 and a pair of further bores 11 spaced axially on opposite sides of the bore 10. The bores 10 and 11 are joined together to form the overall slot or recess of the invention. The bore 10 receives an adjusting element which, in the embodiment of FIGS. 2A and 2B, is provided in the form of an eccentric member 12 held in place by retaining rings 13 and including a hexagonal socket 14 by means of which the adjusting element 12 may be rotated within the bore 10.
Because the section of the adjusting element 12 which is located within the bore 10 is not circular, rotational adjustment of the element 12 will operate to deform the base member and hence to increase or decrease the distance between the tips of the teeth 7 adjacent the element 10. The bores 11 operate to impart resilience to the base member in this region.
An alternative form of the adjusting element is shown in FIG. 3 where the bore 10 is shown as comprising two opposed frustoconical portions and the adjusting element as comprising a bolt 15 having a frustoconical head 16 and a nut 17 with an external surface which is frustoconical. The bolt 15 has an hexagonal socket 14 in the head thereof whereby it may be rotated. Drawing the nut and bolt toward one another will operate to expand the base member across the cutting teeth 7.
A further embodiment of the invention is shown in FIG. 4 in which the bore in the base member is provided with a screw-threaded portion 20 and a frustoconical portion 19. The adjusting element comprises a bolt with a screw thread engaging the threaded portion 20 in the base member and a frustoconical head 18 having a socket 14. Tightening of the tensioning element will operate to expand the broaching tool across the teeth 7.
In FIGS. 5, 6, and 7, there is shown a further embodiment of the invention wherein the broaching tool is formed with a recess 8 which is in the shape of an elongated wedge. An adjusting element in the form of a wedge 22 is received in the recess 8 with the wedge 22 being adjusted by operation of grub screws 23 which are received in screw-threaded bores 21 at the ends of the recess 8 and which engage end portions of the element 22. Tightening of the grub screws 23 will operate to force the wedge 22 further into the recess 8 thereby causing an increase in the dimension of the broaching tool across the teeth 7.
Referring now to FIG. 8, there is shown an embodiment of the invention wherein the recess 8 is formed to extend through the base member in a direction parallel to the longitudinal axis 9 thereof. The recess 8 extends between two transverse bores 24 and includes a frustoconical surface 25. The surface 25 is engaged by a spherical surface 27 provided at the end of a rod 26 which extends axially from adjacent the free end of the base member.
Alternatively, a separate ball engaged by a rod 26 could be provided. A grub screw 29 received in a screw-threaded end portion 28 of the base member engages the rod 26 so that when the screw 29 is tightened, the teeth of the tool will be expanded in the region between the bores 24.
An embodiment similar to that shown in FIG. 8 may be utilized wherein the broaching tool is formed with circular teeth for broaching a circular bore in a workpiece and wherein a radial expansion of the teeth 7 may also be effected.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A broaching tool is formed with a slot within which an adjusting member is received. By adjusting the position of the adjusting member within the slot, forces are developed against the sides of the slot to deform the broaching tool thereby to adjust the operating dimensions of cutting teeth arranged on the broaching tool in the vicinity of the slot.
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BACKGROUND OF THE INVENTION
This invention relates to a multi-blow cold forging apparatus and, more particularly, to cold forging apparatus for forming nuts.
In a typical prior art cold forging apparatus for forming nuts, the nut blank is progressively formed by a plurality of punches respectively coacting with a plurality of individual dies. The nut blank, following each forming blow at each die station, is transferred to the next station for a further blow. Typically, at the final die station, the die is mounted for rearward movement and the nut blank is simultaneously front formed by the punch and back pierced by a fixed piercing pin positioned concentrically behind the die. Whereas this apparatus, and its variants, produce a generally satisfactory finished nut, the overall speed of the apparatus is limited by the necessity of ejecting the partially formed nut blank from the die after each punching operation and then transferring the ejected blank to the next die station.
SUMMARY OF THE INVENTION
The object of the present invention is to increase the operational speed of conventional nut forming apparatus without diminishing the quality of the nuts produced.
According to the invention, a die is mounted for movement between a first die station and a second die station and means are provided to preclude rearward movement of the die while positioned at the first die station while allowing rearward movement of the die in response to movement of the die to the second die station. With this arrangement, a punch positioned at the first die station may deliver a forming blow to the front of a nut blank positioned in the die at that station whereafter the die, with the formed nut blank therein, may be moved to the second die station where the rearward move of the die will allow back piercing of the nut by a suitable fixed piercing pin.
According to a further feature of the invention, the nut forming apparatus includes two identical dies which are moved alternately and successively between the first and second die stations, and each die is precluded from rearward movement while positioned at the first die station but is allowed to move rearwardly while positioned at the second die station.
According to another feature of the invention, the dies are respectively mounted in diametrically opposed bores in a rotary block so that the dies may be moved successively and alternately between the first and second die stations by selective rotation of the rotary block.
According to another feature of the invention, each individual die forms a part of an identical die assembly, each die assembly includes two cylindrical members fitted front to back in a respective bore in the rotary block and having coacting cam means at their interface, and the cylindrical members undergo selective relative rotation as the rotary block is rotated between an axially abutting configuration, in which rearward movement of the related die is precluded, and an axially spaced configuration, in which rearward movement of the related die is allowed.
In the disclosed embodiment of the invention, the forward cylindrical member of each die assembly is precluded from rotation in the respective bore in the rotary block, and a planet gear is coaxially secured to each rearward cylindrical member and meshes with a fixed central gear so that the rearward members are rotated in response to rotary movement of the rotary block to selectively move the cylindrical members of each die assembly between their axially abutting configuration and their axially spaced configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view of a nut forming apparatus according to the invention;
FIG. 2 is a view taken on line 2--2 of FIG. 1 with the punches omitted for purposes of clarity;
FIG. 3 is a fragmentary somewhat schematic view of a cutter assembly for use with the nut forming apparatus of FIG. 1;
FIG. 4 is an exploded view of a set of cammingly coacting cylindrical members employed in the invention nut forming apparatus;
FIG. 5 is a development of the coacting cam faces on the cylindrical members of FIG. 4; and
FIGS. 6 and 7 are front and rear views respectively of the left hand cylindrical member of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The nut forming apparatus seen in FIG. 1 includes a punch assembly 10 positioned for coaction with a fixed die assembly 12; another punch assembly 14 positioned for coaction with a die positioned at a die station 16; another punch assembly 18 positioned for coaction with a die positioned at a die station 19; a housing 20; a rotary assembly 22 mounted for selective rotary movement in housing 20; and a fixed gear assembly 23.
Punch assembly 10 delivers the first blow in the nut forming operation and includes a hammer casing 24, an upset punch 26 seated in the tip of hammer casing 24, an upset pin 28, an anvil upset pin 30, and a backup plug 32.
Fixed die assembly 12 includes a die case 34, a die 36 seated concentrically in the forward end of die case 34, an anvil 38, and an ejector pin 40.
Punch assembly 14 delivers the second blow in the nut forming operation and includes a punch holder 42, an intermediate punch 44 seated in the tip of holder 42, and a backup plug 46.
Punch assembly 18 delivers the final piercing blow in the nut forming operation and includes a punch casing 48, a punch holder 50 seated in casing 48, a pierce punch 52 seated in holder 50, a slug guide pin 54, and a backup plug 56.
Housing 20 defines a large central bore 20a opening in the forward face 20b of the housing, a counterbore 20c, and a further counterbore 20d opening in the rear face 20e of the housing.
Rotary assembly 22 includes a rotary block 58 and a pair of identical die assemblies 60 carried by rotary block 58. Rotary block 58 is cylindrical and is rotatably mounted in housing central bore 20a with its front face 58a flush with housing front faces 20d, its rear face 58b seated on the shoulder formed between housing bore 20a and housing counterbore 20c, and a rearwardly extending hub portion 58c positioned in housing counterbore 20d. Rotary block 58 defines a central longitudinal bore 58d opening adjacent the front face of the block, a central counterbore 58e, a further central counterbore 58f, and a still further central threaded counterbore 58g opening at the rear end of the block. Rotary block 58 further defines a pair of identical diametrically opposed bores 58h opening in the front face of the block. The rear end of each bore 58h breaks through central counterbore 58e to provide communication between bores 58h and the central bore of the block. An access opening 58i is provided in the rear end of the block in coaxial alignment with each bore 58h.
Each die assembly 60 includes a planet gear 62, a ramp block 64, an anvil 66, a die case 68, a shrink ring 70, a die 72, a backup 72, a backup block 74, a pierce pin holder 76, a pierce pin 78, a stripper 80 and a plurality of ejector pins 82.
Planet gear 62 is seated on a hub portion 64a of ramp block 64 and secured to the ramp block by pins 84. Ramp block 64 is annular and includes a central bore 64b. Anvil 66 is annular and includes a central bore 66a and a series of circumferentially spaced bores 66b. Ramp block 64 and anvil 66 are fitted front to back in bore 58h with ramp block 64 positioned against a wear bushing 86 seated at the rear of bore 58h. The front annular face of ramp block 64 and the confronting rear annular face of anvil 66 are provided with complementary ramp or cam surfaces seen in developed form in FIG. 5. The cam surface of ramp block 64 includes a series of flat peaks 64c and a series of flat valleys 64d interconnected by a series of upramps 64e and a series of downramps 64f. The cam surface of anvil 66 is complementary to the ramp block cam surface and includes a series of flat peaks 66c and a series of flat valleys 66d interconnected by a series of upramps 66e and a series of downramps 66f.
Die case 68 is annular and includes a central bore 68a and a counterbore 68b. Die case 68 is bolted to the front face of anvil 66 and includes a flat 68a for coaction with a key 84. Key 84 is seated in a cutout 58j in the front face of rotary block 58 and is secured to the block by bolts 88.
Shrink ring 70 is seated with a force fit in counterbore 68b of die case 68.
Die 72 is seated with a force fit in shrink ring 70 and seats against die case shoulder 68c.
Backup block 74 is cylindrical and is positioned in central bore 64b of ramp block 64 and seats against rotary block shoulder 58k. Block 74 includes a plurality of circumferentially spaced bores 74a.
Pierce pin holder 76 is cylindrical and is positioned in ramp block bore 64b in front of backup block 74. Holder 76 includes a central bore 76a, a counterbore 76b, and a plurality of circumferentially spaced bores 76c in registry with bores 74a of block 74. Holder 76 is secured to block 74 by bolts 88.
Pierce pin 78 includes a head portion 78a positioned in holder counterbore 76b, a shaft portion 78b extending forwardly through holder central bore 76a and through anvil central bore 66a, and a working portion 78c positioned centrally and immediately rearwardly of die 72.
Stripper 80 is annular and is telescopically mounted on the forward end of pierce pin 78. Ejector pins 82 extend slidably through aligned bores 74a, 76c and 66b for pushing engagement at their forward ends with the rear face of head portion 80a of stripper 80. The rearward ends of pins 82 are positioned in access openings 58i.
Fixed gear assembly 23 includes a central shaft 90 and a support arm 92.
Central shaft 90 includes an integral gear portion 90a meshing with planet gears 62 of die assemblies 60, a shaft portion 90b extending through central bore 58d of rotary block 58 and through a central bore 84a in key 84, a tip portion 90c extending forwardly from the front face of rotary block 58 and having a flat 90d, and a journal portion 90e. Tip portion 90c is received in a flatted hole 92a in the upper end of support arm 92. The lower end of arm 92 is secured to housing 20 by bolts 94 and thereby functions to fix shaft 90 against rotation. Shaft journal portion 90e is journaled in a bearing 96. Bearing 96 is seated in rotary block counterbore 58f against a shoulder 58l and held against axial displacement by a spacer 98 and a plug 100 threaded into rotary block threaded counterbore 58g.
The invention nut former is designed for use with a suitable cutter assembly such, for example, as the cutter assembly 102 of FIG. 3. Cutter assembly 102 includes a cutoff quill assembly 104 having a carbide insert 106, a cutoff knife 108 having a carbide insert 110, a pusher pin 112 slideably mounted in a pusher pin bushing 114, and a pair of transfer fingers 116.
OPERATION
In operation, suitable steel rod stock 118 is fed through quill assembly 104 and served by knife 108. The advancing knife transfers the cut blank over slug 118a to a position in alignment with pusher pin 112, whereafter pusher pin 112 is advanced to deliver the blank to transfer fingers 116. Fingers 116 in turn deliver the block to fixed die assembly 12 where it is dealt a first forming blow by upset punch 26 of punch assembly 10. Following this first forming blow, punch assembly 10 is retracted, ejector pin 40 is slid forwardly to eject the partially formed nut blank from die 36, and another pair of transfer fingers (not shown) receives the partially formed blank at it is ejected and delivers it to die station 16. At the same time, transfer fingers 116 are delivering another freshly cut slug to die assembly 12. U.S. Pat. No. 4,272,978 discloses a suitable mechanism for transferring partially formed blanks from die assembly 12 to die station 16 while simultaneously transferring a freshly cut slug from cutter 102 to die assembly 12. Punches 10 and 14 are now simultaneously advanced. Punch 10 delivers a first forming blow to the freshly cut slug and punch 14 delivers a second forming blow to the partially formed blank is cooperation with the die 72 then positioned at die station 16. Since the flat peak 64c of the confronting annular cam surfaces of ramp block 64 and anvil 66 are in firm, abutting engagement at this time, as seen in solid lines in FIG. 5, die 72 is precluded from moving rearwardly in response to the blow from punch assembly 14. As a result, pierce pin 78 plays no part at this time in the nut forming action. Following delivery of the second forming blow, punch assembly 14 is retracted and rotary block 58 is rotated through 180° to move the die 72 positioned at work station 16, together with the partially formed blank positioned therein, to the upper die station 18 while simultaneously moving the die 72 positioned at the upper work station 18 to the lower work station 16. A suitable mechanism for rotating block 58 in timed relation to the operation of the transfer fingers is disclosed in the referenced U.S. Pat. No. 4,272,978. As rotary block 58 is rotated through 180°, fixed gear assembly 23 coacts with die assemblies 60 to generate relative rotation between each ramp block 64 and its associated anvil 66 and thereby vary the angular relationship of the annular confronting cam faces on these members. More particularly, as rotary block 58 is rotated, planet gears 62, and thereby ramp blocks 64, rotate in rotary block bores 58h. Since anvils 66 and die casings 68 are precluded from rotating in the rotary block bores by virtue of the engagement of flats 68a with key 84, the rotary movement or ramp blocks 64 results in relative movement at the interface of each ramp block and the associated anvil. Specifically, as the lower die assembly is rotated from lower die station 16 to upper die station 18, ramp block 64 moves from its solid line position of FIG. 5, in which peaks 64c are in firm abutting engagement with peak 66c, to its dash line position, in which peaks 64c are in axial registry with valleys 66d. As the upper die assembly is simultaneously rotated from the upper die station 18 to the lower die station 16, ramp block 64 moved from its dash line position of FIG. 5, in which peaks 64c are aligned with valleys 66d, to its solid line position in which peaks 64c are in abutting engagement with peaks 66c. This movement may be accomplished, for example, by a system wherein central gear portion 90a has 12 teeth and planet gears 62 have 48 teeth, so that movement of rotary block through 180° rotates planet gears 62 through 45°, and wherein successive peaks 64c and successive peaks 66c are angularly spaced apart by 90°.
At the same time that rotary block 58 is being rotated as described to move the partially formed nut blank from lower die station 16 to upper die station 18, the transfer mechanism functions to deliver a partially formed nut blank from fixed die 12 to lower die station 16 and a freshly cut slug from the cutter to fixed die 12. Punches 10, 14 and 18 are now simultaneously advanced. Punch 10 delivers a first forming blow to the freshly cut slug positioned at die assembly 12, punch 14 delivers a second forming blow to the partially formed blank positioned at lower die station 16, and punch 18 delivers a final forming blow to the partially formed blank positioned at die station 19. However, since the coacting cam surfaces of the ramp block and anvil of the die assembly now positioned at the upper die station are spaced apart axially, die 70 moves rearwardly in response to the blow from punch 18 to force the nut blank against the forward tip of the fixed pierce pin and backpierce the blank. The nut blank thus undergoes a final forming blow and backpiercing at upper die station 19. The rearwardly displaced position of the anvil is seen in chain lines in FIG. 5. Following this final forming and piercing operation, the punches are withdrawn and rotary block 58 is rotated to move the upper die assembly to lower die station 16. As the upper die assembly moves toward the lower die station, ejector pins 82 are moved forwardly by a suitable ejector mechanism (not shown) to eject the finished nut from the die, and fixed gear 90a coacts with planet gear 62 to relatively rotate ramp block 64 and anvil 66. As these two parts relatively rotate, ramp 64e on ramp block 64 cammingly engages complementary ramp 66e on anvil 66 to cammingly displace the anvil forwardly with continued relative rotary movement, return the anvil and ramp block to the fully abutting, solid line position of FIG. 5. The die assembly is now positioned at lower die station 16 with die block 68 flush with the front face of rotary block 58 and die 72 blocked against rearward displacement. When punches 10, 14 and 18 are again actuated, punch 10 delivers a first forming blow to the slug in die assembly 12, punch 14 delivers a second forming blow to the nut blank at die station 16, and punch 18 delivers a final forming blow to the nut blank at die station 19 and displaces the die rearwardly to achieve backpiercing. Every advance of punches 10, 14 and 18 thus produces a fully formed, backpierced nut.
The invention nut forming apparatus produces high quality nuts and since the formed blank at die station 16 may be transferred to die station 18 without first ejecting the blank from the die, produces these high quality nuts at a higher speed than the prior art nut forming apparatus.
Whereas a preferred embodiment of the invention has been illustrated and described in detail, it will be apparent that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention.
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A nut forming apparatus in which a pair of identical die assemblies are housed in a pair of diametrically opposed boxes in a rotary block and rearward movement of the die assembly relative to the rotary block at a first die station is precluded but rearward movement of that die assembly is allowed as it is moved to a second die station by rotary movement of the rotary block. A fixed back pierce pin, associated with each die assembly, is thus inoperative in response to a front forming blow struck by a punch positioned at the first die station but operates to back pierce the nut blank upon rearward movement of the die assembly in response to a front forming blow struck by a punch positioned at the second die station. A pair of cammingly interfaced cylindrical members associated with each die undergo relative rotation as the die assembly is moved by rotation of the rotary block between the first and second die stations to respectively preclude and allow rearward movement at that die assembly.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] The present application claims priority under 35 USC section 119(e) to U.S. Provisional application Serial No. 60/384,484, filed May 31, 2002, which is incorporated by reference herein as if fully set forth.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The invention relates to crystalline polymorphs of a polycyclic xanthine phosphodiesterase (“PDE”) V inhibitor.
[0004] 2. Background
[0005] WO 02/24698, which is incorporated herein by reference in its entirety, teaches a class of xanthine PDE V inhibitor compounds useful for the treatment of impotence. A general process disclosed therein (page 75, line 6 to page 80, line 2) for preparing xanthine PDE V inhibitor compounds having the formula (I) follows:
[0006] (i) reacting a compound having the formula (III) with an alkyl halide in the presence of a base (introduction of R 2 or a protected form of R 2 );
[0007] (ii) (a) debenzylating and then (b) alkylating the compound resulting from step (i) with an alkyl halide, XCH 2 R 3 ;
[0008] (iii) (a) deprotonating and then (b) halogenating the compound resulting from step (ii);
[0009] (iv) reacting the compound resulting from step (iii) with an amine having the formula R 4 NH 2 ; and
[0010] (v) removing a protecting portion of R 2 , if present, on the compound resulting from step (iv) to form the compound having the formula (I).
[0011] R 1 , R 2 , R 3 and R 4 are each defined in WO 02/24698.
[0012] WO 02/24698 (pages 44 & 68-73) further teaches a synthesis for a specific xanthine PDE V inhibitor compound identified therein as Compound 13 or Compound 114 of Table II. Compound 13 can be named as 1-ethyl-3,7-dihydro-8-[(1R,2R)-(hydroxycyclopentyl)amino]-3-(2-hydroxyethyl)-7-[(3-bromo-4-methoxyphenyl)methyl]-1H-Purine-2,6-dione:
[0013] Compound 13 exhibits good PDE V inhibitor activity (potency) and selectivity, and is useful for treating erectile dysfunction. However, when made according to the process described in WO 02/24698, Compound 13 can exhibit some undesirable properties with respect to thermodynamic stability.
[0014] Polymorphism can be characterized as the ability of a compound to crystallize into different crystal forms, while maintaining the same chemical formula. Polymorphs of a given drug substance are chemically identical in containing the same atoms bonded to one another in the same way, but differ in their crystal forms, which can affect one or more physical properties, such as solubility, melting point, bulk density, flow properties, etc.
[0015] It would be beneficial to improve the thermodynamic properties of Compound 13. It would further be beneficial to produce Compound 13 in a stable crystalline form, which has consistent physical properties. The invention seeks to provide these and other benefits, which will become apparent as the description progresses.
SUMMARY OF THE INVENTION
[0016] The invention provides two crystalline polymorphs of Compound 13. A crystalline polymorph can be identified by its x-ray powder diffraction pattern expressed in terms of “2θ Angles (°).”
[0017] One aspect of the invention provides a crystalline polymorph Form 2 of Compound 13:
[0018] that exhibits an x-ray powder diffraction pattern having characteristic peak locations of 8.1, 11.3, 17.2, and 22.2 degrees 2θ+/−0.5 degrees 2θ.
[0019] Another aspect of the invention provides crystalline polymorph Form 2 of Compound 13, which exhibits an x-ray powder diffraction pattern having characteristic peak locations of 8.1, 11.3, 13.1, 15.3, 16.1, 17.2, 17.6, 18.9, 20.9, 21.8, 22.2, 23.4 24.1, 25.8 and 30.6 degrees 2θ+/−0.5 degrees 2θ.
[0020] Another aspect of the invention provides crystalline polymorph Form 2 of Compound 13, which exhibits an x-ray powder diffraction pattern substantially the same as the x-ray powder diffraction pattern shown in FIG. 5.
[0021] Another aspect of the invention provides crystalline polymorph Form 2 of Compound 13, which exhibits a differential scanning calorimetry pattern substantially the same as the differential scanning calorimetry pattern shown in FIG. 2.
[0022] The invention comprises polymorph Form 2 of Compound 13 and any isomer e.g., enantiomer, stereoisomer, rotomer and tautomer, thereof.
[0023] Another aspect of the invention provides crystalline polymorph Form 1 of Compound 13 that exhibits an x-ray powder diffraction pattern having characteristic peak locations of 7.3, 9.2 and 20.2 degrees 2θ+/−0.5 degrees 2θ.
[0024] Another aspect of the invention provides crystalline polymorph Form 1 of Compound 13, which exhibits an x-ray powder diffraction pattern having characteristic peak locations of 7.3, 8.4, 9.2, 12.7, 14.3, 15.0, 15.4, 16.5, 18.8, 20.2, 20.9, 24.0, 25.8, 26.4, 27.2, 27.6, 29.3, 31.9 and 34.6 degrees 20+/−0.5 degrees 20.
[0025] Another aspect of the invention provides crystalline polymorph Form 1 of Compound 13, which exhibits an x-ray powder diffraction pattern substantially the same as the x-ray powder diffraction pattern shown in FIG. 6.
[0026] Another aspect of the invention provides crystalline polymorph Form 1 of Compound 13, which exhibits a differential scanning calorimetry pattern substantially the same as the differential scanning calorimetry pattern shown in FIG. 4.
[0027] The invention comprises polymorph Form 1 of Compound 13 and any isomer, e.g., enantiomer, stereoisomer, rotomer and tautomer, thereof.
[0028] Other aspects of the invention comprise pharmaceutically-acceptable compositions prepared from the inventive polymorphs. The inventive compounds can be useful for treating a variety of diseases, symptoms and physiological disorders, such as sexual dysfunction (e.g., impotence).
[0029] A further understanding of the invention will be had from the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] [0030]FIG. 1 is a graph of an x-ray powder diffraction pattern of crystalline polymorph Form 2 of Compound 13 crystallized from acetonitrile. The graph plots the intensity of the peaks as defined by counts per second versus the diffraction angle 2θ in degrees. The sample was unmicronized and not packed in the sample holder. The data were generated on a Rigaku MiniFlex diffractometer.
[0031] [0031]FIG. 2 is a graph of a differential scanning calorimetry pattern of crystalline polymorph Form 2 of Compound 13 crystallized from acetonitrile. The graph plots the normalized heat flow in units of Watts/gram (“W/g”) versus the measured sample temperature in degrees C.
[0032] [0032]FIG. 3 is a graph of an x-ray powder diffraction pattern of crystalline polymorph Form 1 of Compound 13 crystallized from methanol/water. The graph plots the intensity of the peaks as defined by counts per second versus the diffraction angle 2θin degrees. The sample was unmicronized and not packed in the sample holder. The data were generated on a Rigaku MiniFlex diffractometer.
[0033] [0033]FIG. 4 is a graph of a differential scanning calorimetry pattern of crystalline polymorph Form 1 of Compound 13 crystallized from methanol/water. The graph plots the normalized heat flow in units of Watts/gram (“W/g”) versus the measured sample temperature in degrees C.
[0034] [0034]FIG. 5 is a graph of an x-ray powder diffraction pattern of crystalline polymorph Form 2 of Compound 13 crystallized from acetonitrile. The graph plots the intensity of the peaks as defined by counts per second versus the diffraction angle 2θ in degrees. The data were generated on a Bruker D8 diffractometer.
[0035] [0035]FIG. 6 is a graph of an x-ray powder diffraction pattern of crystalline polymorph Form 1 of Compound 13 crystallized from isopropanol/water. The graph plots the intensity of the peaks as defined by counts per second versus the diffraction angle 2θ in degrees. The data were generated on a Bruker D8 diffractometer.
DETAILED DESCRIPTION
[0036] As used above, and throughout the specification, the following terms, unless otherwise indicated, shall be understood to have the following meanings:
[0037] “Patient” includes both human and other animals.
[0038] “Mammal” includes humans and other mammalian animals.
[0039] “Alkyl” means an aliphatic hydrocarbon group which may be straight or branched and comprising 1 to about 20 carbon atoms in the chain. Preferred alkyl groups contain 1 to about 12 carbon atoms in the chain. More preferred alkyl groups contain 1 to about 6 carbon atoms in the chain. Branched means that one or more lower alkyl groups such as methyl, ethyl or propyl, are attached to a linear alkyl chain. The alkyl group can be substituted by one or more substituents which may be the same or different. Non-limiting examples of suitable alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, n-pentyl, heptyl, nonyl, decyl, fluoromethyl, trifluoromethyl and cyclopropylmethyl.
[0040] “Aryl” means an aromatic monocyclic or multicyclic ring system comprising about 6 to about 14 carbon atoms, preferably about 6 to about 10 carbon atoms. The aryl group can be optionally substituted with one or more ring system substituents which may be the same or different. Non-limiting examples of suitable aryl groups include phenyl and naphthyl.
[0041] “Polymorph” means a crystalline form of a substance that is distinct from another crystalline form but that shares the same chemical formula.
[0042] “Relative Intensity” means the intensity of a peak relative to the intensity of the largest peak measured in an x-ray powder diffraction analysis. The relative intensity can be calculated as either the ratio of the heights of the peaks (measured in counts per second) or the ratio of the areas of the peaks. Relative intensity data presented herein are calculated as the ratios of the heights of the peaks.
[0043] “Anti-solvent” means a substance that reduces the solubility of a solute in a solvent.
[0044] “c-GM P” means cyclic guanosine monophosphate.
[0045] “Alcohol” means an organic compound containing a hydroxyl group (—OH).
[0046] “Nitrile” means an organic compound containing a —C≡N group.
[0047] “Ester” means an organic compound containing an RC(O)OR group, wherein the R's are independently alkyl or aryl and the parentheses indicate that the enclosed 0 is doublebonded to the C.
[0048] “Ketone” means an organic compound containing a carbonyl group (C═O) attached to two alkyl groups.
[0049] “Excipient” means an essentially inert substance used as a diluent or to give form or consistency to a formulation.
[0050] “Hydrocarbon” means an organic compound consisting of carbon and hydrogen.
Polymorphs of Compound 13
[0051] Compound 13 can exist in at least two distinct crystalline polymorphic forms, each having distinct physical properties. These two different crystalline polymorphs of Compound 13 have been identified as Form 1 and Form 2. Forms 1 and 2 of Compound 13 can be characterized by x-ray powder diffraction (FIGS. 1, 3, 5 and 6 ) and/or differential scanning calorimetry (FIGS. 2 and 4).
Analytical Methodology for Chemical Identification of Polymorphs
[0052] Samples of the two polymorphs—Forms 1 and 2 of Compound 13—were analyzed as dry powders for x-ray powder diffraction (“XRPD”) and differential scanning calorimetry (“DSC”) analyses. The samples were analyzed with minimal preparation to prevent any form changes. The samples were lightly rubbed to insure that particles were not clumped together. No solvents, drying or other preparation steps were used for these analyses. The XRPD and DSC data can each uniquely identify Forms 1 and 2 of Compound 13.
[0053] A number of XRPD analyses were performed using a variety of analyzers. Some of the samples were micronized, while others were not. One set of measurements was made using a Rigaku MiniFlexe diffractometer (manufactured in 1999) that rotated the specimen at 54 revolutions per minute (“rpm”) to reduce preferred orientations of the crystals. The polymorph samples were supplied in powder form and were placed onto a face of a Si-coated low background scatter aluminum plate using a hand held dowel with a minimum of force. A crystalline silicon standard was used to check peak position accuracy. The samples were exposed to ambient conditions. The x-ray patterns presented in FIGS. 1 and 3 are filtered with a nine-point Savitzky-Golay parabolic filter, but otherwise are essentially raw patterns without a background correction or a K-α2 peak removal. The counts presented on the y-axes of FIGS. 1 and 3 plots are in units of counts per second. The instrument uses a variable divergence slit with a θ/2 θ scan axis configuration. The intensity of the peaks (y-axis is in counts per second) is plotted versus the 2θ angle α-axis is in degrees 2θ). The data of FIGS. 1 and 3 were plotted with detector counts normalized for the collection time per step versus the 2θ angle. The data were evaluated using JADE® pattern processing software version 5.0 from Materials Data Inc. (“MDI”). The software automatically does a final filtering, fits a background, and measures the area and height of each peak. The relative peak intensities are calculated using a ratio of the height of each reported peak to the height of the largest peak measured. The relative peak intensities used were directly equal to the filtered counts per second of the raw data. Form 2 of Compound 13 (FIG. 1) and Form 1 of Compound 13 (FIG. 3) each exhibited unique XRPD patterns. X-ray powder diffraction is discussed in the Encyclopedia of Analytic Science, Alan Townshend, ed., vol. 9, pp. 5585-5593, Academic Press, London (1995), which is incorporated herein by reference.
[0054] Using the Rigaku MiniFlex® diffractometer and the above-described methods, it was found that crystalline polymorph Form 2 of Compound 13 exhibits an x-ray powder diffraction pattern as shown in FIG. 1. The relative intensities and the 20 angle locations of the characteristic peaks of FIG. 1 are displayed in TABLE 1:
TABLE 1 Form 2 of Compound 13 Relative Intensity Relative Intensity 2θ Angle (°) (% Height) (Peak Strength) 8.44 31.1 S 11.54 3.6 VW 13.36 13.9 M 15.56 5.2 W 16.42 100.0 S 17.44 28.3 S 17.92 20.3 S 19.18 15.2 M 21.20 12.8 M 22.12 10.1 M 22.50 13.9 M 23.06 2.8 VWD 23.70 15.3 M 24.46 50.1 S 25.70 16.5 M 26.04 18.4 M 26.40 12.3 M 27.34 5.1 W 27.86 3.0 VW 28.58 2.2 VW 29.08 6.4 W 29.74 11.2 M 30.48 5.5 W 30.88 43.2 S 31.62 2.2 VW 32.14 3.1 W 32.68 7.6 W 33.02 8.7 W 33.82 5.2 WD 34.68 4.3 W 35.78 4.2 W 36.30 3.9 VW 37.78 4.6 W 38.44 7.0 WD 38.86 3.4 VW 39.28 2.1 VW 40.04 1.1 VWD 40.48 1.9 VW 41.08 8.5 W 41.72 3.7 W 42.88 2.0 WD 43.76 6.2 W 44.76 4.1 W 45.40 2.3 VWD 45.82 3.2 VWD 46.72 3.0 VWD 47.44 3.5 VWD 48.68 1.0 VWD 49.60 8.9 W
[0055] wherein peak strengths categorize relative intensities according to the following scheme: S is Strong (20.0-100.0%); M is Medium (9.0-19.9%); W is Weak (4.0-8.9%); VW is Very Weak (0.1-3.9%); and VWD is Very Weak and Diffuse (broad).
[0056] Using the Rigaku MiniFlex® diffractometer and the above-described methods, it was found that crystalline polymorph Form 1 of Compound 13 exhibits an x-ray powder diffraction pattern as shown FIG. 3. The relative intensities and the 20 angle locations of the characteristic peaks of FIG. 3 are displayed in TABLE 2:
TABLE 2 Form 1 of Compound 13 2θ Angle Relative Intensity Relative Intensity (°) (% Height) (Peak Strength) 7.48 100.0 S 8.52 0.9 VW 9.36 11.7 M 12.84 64.8 S 14.44 4.8 WD 15.10 2.7 VWD 15.52 2.2 VWD 16.58 13.2 M 19.02 35.8 S 20.34 14.4 M 21.00 4.7 W 21.94 4.1 W 22.70 3.1 VWD 22.98 4.5 WD 24.14 7.8 W 25.04 3.1 VWD 25.84 21.8 S 26.40 4.5 W 27.32 5.8 W 27.74 8.4 W 28.78 4.5 WD 29.20 9.9 M 30.40 1.2 VWD 32.08 3.4 W 33.02 4.3 W 33.66 5.1 W 34.63 5.0 WD 37.24 3.3 VWD 38.12 1.7 VWD 40.46 4.8 W 41.94 5.1 W 45.44 2.3 WD 47.52 2.3 WD
[0057] wherein peak strengths are categorized according the scheme described above.
[0058] The XRPD analyses were repeated using different analytic equipment. Rigaku DMAX 2200 and Bruker D8 diffractometers were used to collect the XRPD data. In these analyses, the samples were packed into the sample holders in such a way as to reduce measurement error that might result from uneven sample surfaces or inconsistent sample thicknesses.
[0059] The Rigaku DMAX-2200 diffractometer (manufactured in 1998) was operated with a take-off angle of 6 degrees and automatic, variable divergence slits. The beam width was 20 mm. The apparatus uses a graphite monochromator and a scintillation detector. During scanning, the step size was 0.02 degrees over a step duration of 0.3 seconds. Scanning speed was 4 degrees per minute. The sample spin rate was 40 rpm.
[0060] The Bruker D8 diffractometer (manufactured in 2002) has a parallel optic configuration with a GOBEL beam focusing mirror and a PSD detector equipped with a fixed radial soller slit was used with an Anton Paar TTK450 temperature stage. The divergence slits are fixed at 0.6 mm. The sample holder was a top-loading brass block. Specimens were leveled using a glass microscope slide. The sample chamber was not purged, not heated above 30 deg. C., and not under vacuum. Instrument calibration was verified using mica standards. During scanning, the step size was 0.013 degrees over step durations of 0.1 and 0.5 seconds. Data smoothing was accomplished using EVA analysis software, version 7.0, supplied by Bruker® written by SOCABIM®. The data were filtered with a Fast Fourier smoothing program (20.000×1). The radiation sources for all three diffractometers are copper (Kα).
[0061] Examples of XRPD data collected using the Bruker D8 are presented in FIGS. 5 and 6, which are XRPD patterns for Forms 2 and 1, respectively. Peak locations from patterns generated on the three instruments described above are given in Tables 3 and 4. Table 3 provides peak location data from five examples of XRPD patterns generated from Form 1 samples. The locations of nineteen characteristic peaks are presented for each example. The peak location data for each characteristic peak are further analyzed for average and standard deviations. Table 4 provides similar peak location data from six examples of XRPD patterns generated from Form 2 samples. The sample-to-sample variation is generally about +/−0.5 degrees 2θ, preferably about +/−0.3 degrees 2θ.
TABLE 3 FORM 1 POWDER X-RAY DIFFRACTION DATA EXAMPLE NUM- BER: → 1 2 3 4 5 INST. Rigaku Bruker Rigaku Rigaku Mini- Rigaku DMAX RND. PEAK NO.↓ Mini-Flex D8 Mini-Flex Flex 2200 AVG. AVG. σ 2 σ RND 2 σ MAX 2 σ 1. 7.341 7.224 7.481 7.401 7.26 7.341 7.3 0.10 0.21 0.2 0.3 2. 8.419 8.293 8.523 8.518 8.34 8.419 8.4 0.10 0.21 0.2 3. 9.220 9.106 9.361 9.299 9.14 9.225 9.2 0.11 0.21 0.2 4. 12.719 12.633 12.841 12.820 12.64 12.731 12.7 0.10 0.20 0.2 5. 14.299 14.205 14.440 14.380 14.26 14.317 14.3 0.09 0.19 0.2 6. 14.960 14.872 15.100 15.020 14.90 14.970 15.0 0.09 0.18 0.2 7. 15.360 15.272 15.519 15.419 15.30 15.374 15.4 0.10 0.20 0.2 8. 16.439 16.632 16.580 16.520 16.38 16.456 16.5 0.09 0.19 0.2 9. 18.880 18.700 19.019 18.860 18.72 18.836 18.8 0.13 0.26 0.3 10. 20.200 20.150 20.340 20.340 20.14 20.234 20.2 0.10 0.20 0.2 11. 20.861 20.803 21.001 20.960 20.82 20.889 20.9 0.09 0.17 0.2 12. 23.980 23.900 24.140 23.980 23.92 23.984 24.0 0.09 0.19 0.2 13. 25.720 25.749 25.840 25.880 25.76 25.790 25.8 0.07 0.13 0.1 14. 26.261 26.443 26.400 26.520 26.44 26.413 26.4 0.10 0.19 0.2 15. 27.200 27.184 27.320 27.341 27.18 27.245 27.2 0.08 0.16 0.2 16. 27.620 27.545 27.740 27.700 27.56 27.633 27.6 0.09 0.17 0.2 17. 29.060 29.320 29.200 29.419 29.28 29.256 29.3 0.13 0.27 0.3 18. 31.920 31.862 32.079 31.960 31.86 31.936 31.9 0.09 0.18 0.2 19. 34.579 34.508 34.640 24.640 34.54 34.581 34.6 0.06 0.12 0.1
[0062] [0062] TABLE 4 FORM 2 POWDER X-RAY DIFFRACTION PEAK LOCATIONS (DEGREES 2 θ) EXAMPLE NUM- BER: → 6 7 8 9 10 11 INST. Rigaku Bruker Rigaku Rigaku Rigaku Bruker RND. RND. 2 PEAK NO.↓ Mini-Flex D8 Mini-Flex Mini-Flex DMAX 2200 D8 AVG. AVG. σ 2 σ σ MAX 2 σ 1. 8.179 7.977 8.139 8.439 8.200 7.954 8.148 8.1 0.176 0.352 0.4 0.4 2. 11.261 11.175 11.240 11.540 11.320 11.068 11.267 11.3 0.159 0.318 0.3 3. 13.081 12.851 13.059 13.359 13.120 12.886 13.059 13.1 0.183 0.366 0.4 4. 15.279 15.164 15.260 15.560 15.340 15.107 15.285 15.3 0.159 0.317 0.3 5. 16.141 15.993 16.100 16.420 16.180 15.492 16.129 16.1 0.168 0.337 0.3 6. 17.179 17.028 17.140 17.440 17.220 16.973 17.163 17.2 0.164 0.329 0.3 7. 17.659 17.430 17.600 17.919 17.680 17.442 17.622 17.6 0.180 0.361 0.4 8. 18.920 18.726 18.899 19.180 18.980 18.723 18.905 18.9 0.171 0.343 0.3 9. 20.900 20.948 20.880 21.200 20.940 20.735 20.934 20.9 0.151 0.303 0.3 10. 21.840 21.732 21.820 22.120 21.900 21.669 21.847 21.8 0.157 0.314 0.3 11. 22.221 22.039 22.219 22.500 22.280 22.050 22.218 22.2 0.169 0.339 0.3 12. 23.439 23.353 23.420 23.699 23.480 23.250 23.440 23.4 0.150 0.300 0.3 13. 24.200 24.095 24.000 24.461 24.100 23.854 24.118 24.1 0.204 0.409 0.4 14. 25.780 26.655 25.720 26.039 25.800 25.562 25.759 25.8 0.162 0.325 0.3 15. 30.640 30.547 30.600 30.880 30.680 30.450 30.633 30.6 0.145 0.290 0.3
[0063] Referring to Table 3, peak numbers 1, 3 and 10, having average peak locations at 7.3, 9.2 and 20.2, respectively, are representative of Form 1. Referring to Table 4, peak numbers 1, 2, 6 and 11, having average peak locations at 8.1, 11.3, 17.2 and 22.2, respectively, are representative of Form 2. Peak numbers 7, 9 and 12 of Form 1, have average peak locations of 15.4, 18.8 and 24.0. These appear to roughly coincide with peak numbers 4, 8 and 13 of Form 2.
[0064] The DSC instrument used to test the polymorph samples was a Perkin-Elmere model Pryis 1 (manufactured in 1999), which came equipped with a refrigerated cooling system. The DSC cell/sample chamber was purged with 40 mL/min of ultra-high purity nitrogen gas. The instrument was calibrated with high purity indium. The accuracy of the measured sample temperature with this method is within about +/−1° C., and the heat of fusion can be measured within a relative error of about +/−5%. The samples were placed into a standard Perkin-Elmer aluminum DSC pan without a lid. Between about 3 mg and about 6 mg of polymorph sample powder was placed into the bottom of the pan and lightly tamped down to make contact with the pan. The weight of each sample was measured accurately and recorded to about a hundredth of a milligram. The instrument used an empty reference pan. The instrument was programmed to hold the sample at about 30° C. for about 1 minute before starting a 10° C./min dynamic heating ramp to about 300° C. The data were reported in units of “Watts/gram,” which reflects the heat flow normalized by a sample weight. The normalized heat flow was plotted versus the measured sample temperature. The plots were made with the endothermic peaks pointing up. The endothermic melt peaks were evaluated for extrapolated onset and end (outset) temperatures, peak temperature, and heat of fusion in these analyses. The melt temperature and the heat required to melt a sample were unique for Form 2 of Compound 13 (FIG. 2) and Form 1 of Compound 13 (FIG. 4). Differential scanning calorimetry is discussed in the Encyclopedia of Analytic Science, Alan Townshend, ed., vol. 9, pp. 5155-5160, Academic Press, London (1995), which is incorporated herein by reference.
[0065] [0065]FIG. 2 shows a DSC pattern graph for Form 2 of Compound 13. This graph shows an endotherm beginning at 165.300° C. and ending at 171.729° C., which corresponds to the polymorph's melting point.
[0066] [0066]FIG. 4 shows a DSC pattern graph for Form 1 of Compound 13. This graph shows an endotherm beginning at 178.092° C. and ending at 181.022° C., which corresponds to the compound's melting point.
[0067] The preparation of Compound 13 is taught in WO 02/24698. An alternative process for preparing Compound 13 is taught in a copending U.S. patent application entitled Process for Preparing Xanthine Phosphodiesterase V Inhibitors and Precursors Thereof (Compound 13 is identified as Compound 13A in the copending application), which was filed on the same day as the present application and is incorporated herein in its entirety by reference. This process is depicted in Scheme I, which employs the following abbreviations: Me is methyl; Et is ethyl, OMe is methoxy, M + is a metal ion and OAc is acetate:
[0068] Using the process depicted in Scheme I will produce a crude Form I of Compound 13 before the final crystallization step. One can prepare pure Forms 1 or 2 of Compound 13 depending on the crystallization solvent in which the final step is carried out.
[0069] The crystallization of any form of Compound 13 to Form 2 of Compound 13 is preferably accomplished in an organic solvent selected from the group consisting of alcohols (e.g., methanol, ethanol, normal propyl alcohol, isopropyl alcohol, etc.), nitrites (e.g., acetonitrile, propionitrile, butionitrile, valeronitrile, benzonitrile, p-tolunitrile, etc.), esters (e.g., methyl acetate, ethyl acetate, normal propyl acetate, isopropyl acetate, etc.), ketones (e.g., methyl isobutyl ketone, acetone, etc.) and mixtures thereof. Higher homologs of the exemplified alcohols, nitriles, esters and ketones will also transform Compound 13 to Form 2 of Compound 13. More preferred solvents comprise isopropyl alcohol, acetonitrile, and mixtures thereof. The Form 2 crystallization step is carried out in an essentially non-aqueous solvent mixture, which for this step means a crystallizing solvent mixture comprising less than or equal to about 5%, preferably, less than or equal to about 2%, of water content by weight based on the weight of the crystallizing solvent mixture.
[0070] Crystallization can be carried out without the application of heat, but it is preferred that it is initiated upon the cooling of a heated saturated solution of Compound 13 dissolved in a crystallizing solvent. Generally, Compound 13 is put into a crystallizing solvent and heat is applied thereto until Compound 13 dissolves into solution. The heat applied can vary (e.g., heat sufficient to raise the solvent temperature to about 30-100° C.) depending on the process conditions and the concentration of Compound 13 in the crystallizing solvent. After the solution forms, the application of heat is continued to concentrate the solution (e.g., until about its super-saturation point). The concentrated solution is then cooled to provide the desired crystals.
[0071] It is also preferred to seed control the cooling of a saturated solution of Compound 13 in the Form 2 crystallizing solvent in order to minimize and/or prevent encrustation of product on the reactor walls (the sticking of crystallized particles to reactor walls), which can be difficult to remove. It is preferred that the Form 2 crystallization solution is seeded with a small amount (e g., about 0.2% w/w to about 1% w/w) of Form 2 of Compound 13 to help facilitate the conversion to Form 2, increase the yield of the batch, and avoid the potential of product encrustation on reactor walls. Encrustation of product on reactor walls will result in yield loss and solvent entrapment in the isolated crystallized product substance. The trapped solvent often cannot be lowered to a preferred level of about 0.1% w/w to about 0.2% w/w, even after prolonged drying. Seeding the batch at an appropriate time during crystallization will minimize and/or obviate this problem. Preferably, the batch is seeded at or around the super-saturation point; for acetonitrile crystallizing solvent, the super-saturation point would be around a concentration of about 7 volumes to about 8 volumes of solvent (1 g of solid per about 7 ml to about 8 ml of solvent).
[0072] The crystallization of Compound 13 to Form I of Compound 13 is preferably accomplished by dissolving Compound 13 in an organic solvent, then adding water. Preferred organic solvents comprise any of the Form 2 crystallizing solvents described above (i.e., alcohols, nitrites, esters and ketones). More preferred organic solvents comprise methanol and isopropanol. As for the Form 2 crystallizations described above, it is preferred to dissolve Compound 13 in a Form I crystallization organic solvent by heating the mixture until Compound 13 dissolves into solution, and continuing the heating until about the super-saturation point is reached. Then, water is added to precipitate the Form I crystals of Compound 13.
[0073] Alternatively, Form 1 of Compound 13 can be obtained by adding an anti-solvent (rather than water) to a solution of Compound 13 in a crystallization solvent. Preferred anti-solvents are hydrocarbons, such as hexane, heptane, toluene, xylene, and the like. For instance, hexane can be added to a solution of Compound 13 in an ester solvent (e.g., ethyl acetate, isopropyl acetate, and the like), and Form 1 of Compound 13 will precipitate out. The anti-solvent technique is generally preferable for isolating kinetic Form 1 of Compound 13. With regard to the organic solvent/followed by water technique, it is generally preferable to control crystallization conditions in order to isolate kinetic Form 1 of Compound 13. This can be accomplished by filtering the product as soon as possible (preferably, immediately) after crystallization has occurred.
[0074] Forms 1 and 2 of Compound 13 can be obtained from an amorphous form of Compound 13 or from another form of Compound 13 by choosing the appropriate crystallization procedure. For example, Form 2 of Compound 13 can be crystallized into Form 1 of Compound 13 by dissolving the former substance in an organic solvent, and adding water to that solution until Form I of Compound 13 precipitates out. Similarly, Form 2 of Compound 13 can be obtained from Form 1 of Compound 13 by crystallization in a Form 2 of Compound 13 crystallizing solvent.
[0075] As can be seen from a comparison of FIGS. 1 and 2 with FIGS. 3 and 4, respectively, Forms 1 and 2 exhibit different DSC and XRPD graphs. The two polymorphs also further differ in their water solubilities (Form 1: about 50 μg/mL vs. Form 2: about 30 μg/mL). Form 2 of Compound 13 is more thermodynamically stable than Form 1 of Compound 13 at process temperatures. Form 1 can equilibrate to Form 2 when slurried in one of the Form 2 crystallizing solvents (e.g., alcohol, nitrile, ester, etc.). For example, when a mixture of Form 1 of Compound 13 and Form 2 of Compound 13 is suspended in an organic crystallizing solvent (e.g., ethyl acetate, isopropanol, acetonitrile, and the like), and stored for an extended period of time (e.g., greater than or equal to about 10 hours), the Form I component of the mixture will convert to Form 2 of Compound 13.
[0076] Scheme II depicts preferred reaction conditions for the Scheme I steps utilized to prepare Forms 1 and 2 of Compound 13. Scheme II is also taught in a copending US patent application entitled Process for Preparing Xanthine Phosphodiesterase V Inhibitors and Precursors Thereof (Compound 13 is identified as Compound 13A in the copending application). Scheme II allows for an efficient, commercial scale preparation of Forms 1 and 2 of Compound 13, without the need for chromatographic purification of intermediates. The experimental conditions disclosed herein are preferred conditions, and one of ordinary skill in the art can modify them as necessary to achieve the same products. The following abbreviations are used in Scheme II: EtOH is ethanol; Me is methyl; Et is ethyl; Bu is butyl; n-Bu is normal-butyl, t-Bu is tert-butyl, OAc is acetate; KOt-Bu is potassium tert-butoxide; NBS is N-bromo succinimide; NMP is 1-methyl-2-pyrrolidinone; DMA is N,N-dimethylacetamide; Bu 4 NBr is tetrabutylammonium bromide; BU 4 NOH is tetrabutylammonium hydroxide; and equiv is equivalents.
[0077] Compound Activity, Pharmaceutical Compositions and Methods of Use
[0078] Forms 1 and 2 of Compound 13 are each useful for inhibiting PDE V isoenzymes. Their isoenzyme activities (potencies) and isoenzyme selectivities can be measured by the PDE V IC 50 value, which is the concentration (in nM) of compound required to provide 50% inhibition of PDE V isoenzyme. The lower the value of PDE V IC 50 , the more active is the compound to inhibiting the PDE V isoenzyme. Similarly, an IC 50 value may be obtained for other PDE isoenzymes, such as the PDE VI isoenzyme. Isoenzyme selectivity in this respect may be defined as the activity of a PDE inhibitor compound for a particular PDE isoenzyme as opposed to another PDE isoenzyme, for example, the activity of a compound to inhibit a PDE V isoenzyme compared to the activity of the same compound to inhibit a PDE VI isoenzyme. Once the PDE V IC 50 and PDE VI IC 50 values have been measured, one can calculate a selection ratio of PDE VI IC 50 /PDE V IC 50 , which is an indicator of isoenzyme selectivity—the larger the selection ratio, the more selective is the compound to inhibiting PDE V isoenzyme relative to PDE VI isoenzyme.
[0079] Forms 1 and 2 of Compound 13 each have a PDE V IC 50 of between about 2 nM and about 3 nM. These compounds are relatively highly potent inhibitors of the PDE V isoenzyme. In contrast, Forms 1 and 2 of Compound 13 each have a PDE VI IC 50 Of greater than about 350 nM, which means they exhibit relatively low potency for inhibiting the PDE VI isoenzyme. The PDE V and VI IC 50 data allow for the calculation of an indicator for isoenzyme selectivity—the ratio of PDE VI IC 50 /PDE V IC 50 (identified as “PDE VI/PDE V”). The higher the ratio of PDE VI/PDE V, the more selective is the compound for inhibiting PDE V isoenzyme relative to PDE VI isoenzyme. Forms 1 and 2 of Compound 13 each have a PDE VI/PDE V ratio of greater than about 140, which means they each exhibit relatively high selectivity for inhibiting the PDE V isoenzyme (relative to the PDE VI isoenzyme).
[0080] As can be seen from these data, Forms 1 and 2 of Compound 13 are potent (as measured by PDE V IC 50 ) and selective (as measured by PDE VI IC 50 I PDE V IC 50 ) PDE V isoenzyme inhibitors. A skilled worker in the art would find the biological data significant, and along with the pharmaceutical properties of compositions comprising the inventive compounds, would find therapeutic uses for the inventive compounds in a number of applications, some of which are specified herein.
[0081] Forms 1 and 2 of Compound 13 each have at least one asymmetrical carbon atom. All isomers, including stereoisomers, enantiomers, tautomers and rotational isomers, are contemplated as being part of the invention. The invention comprises d- and I-isomers in pure form, and in admixture, including racemic mixtures. Isomers can be prepared using conventional techniques, either by reacting optically pure or optically enriched starting materials, or by separating isomers of the inventive compounds.
[0082] Forms 1 and 2 of Compound 13 can exist in unsolvated as well as solvated forms, including hydrated forms. In general, the solvated forms, with pharmaceutically-acceptable solvents, such as water, ethanol, and the like, are equivalent to the unsolvated forms for purposes of this invention.
[0083] The invention comprises Forms 1 and/or 2 of Compound 13, a method for making either inventive compound, and methods for making and using a pharmaceutical composition comprising at least one inventive compound and at least one pharmaceutically-acceptable excipient or carrier to treat a variety of disorders, symptoms and diseases. The inventive compounds exhibited unexpectedly favorable properties with respect to PDE V isoenzyme activity and selectivity, which means they may be particularly useful for treating urogenital diseases, such as male and female sexual dysfunction, e.g., erectile dysfunction.
[0084] Forms 1 and 2 of Compound 13 can be formulated together with a pharmaceutically-acceptable excipient or carrier. The resulting compositions may be administered in vivo to mammals (e.g., men or women) and non-mammals to treat a variety of disease states (disorders, symptoms and diseases). For example, the inventive compounds and compositions may be used to treat diseases of the urogenital system, specifically, male erectile dysfunction (e.g., impotence) and female sexual dysfunction. Male erectile dysfunction may be defined as an inability of a male to sufficiently obtain, achieve and/or sustain a penile erection adequate to have intercourse with his mate. In the treatment of erectile dysfunction, it is believed that the inventive PDE V inhibitors are beneficial therapeutic agents because they elevate cGMP levels in the human body. Such an action may facilitate corpus cavernosum smooth muscle relaxation, which would provide an increased flow of blood therein, resulting in an erection. This makes the inventive compounds especially useful for treating impotence and other types of diseases that are affected by CGMP levels.
[0085] Accordingly, another aspect of the invention is a method for treating erectile dysfunction in a mammal in need of such treatment, comprising administering to the mammal at least one Form 1 of Compound 13 and/or at least one Form 2 of Compound 13, or a pharmaceutical composition thereof, in an amount effective to ameliorate and/or reduce one or more of the symptoms associated with erectile dysfunction sufficiently so that the patient can conduct and complete intercourse.
[0086] Introduced in 1998 as a treatment for impotence, Viagra® is currently the most commonly prescribed medication to treat physiologically-caused (male) erectile dysfunction (“MED” or “ED”). Certain patients, however, can experience undesirable side effects while taking Viagra®. For instance, it has been reported that Viagra® can cause a visual side effect by impairing the patient's color discrimination (blue/green), causing a “blue-halo” light visual alteration. This side effect is presumably due to inhibition of the PDE VI isoenzyme (found in a retina). See Physicians' Desk Reference®, 55 th Ed, pp. 2534-37 (2001).
[0087] An advantage of Forms 1 and 2 of Compound 13 is that they can be particularly selective for the PDE V isoenzyme in comparison to other types of PDE isoenzymes, such as the PDE VI isoenzyme. It is believed that this increased selectivity will ameliorate side effects associated with the use of Viagra®. In particular, the high selectivity of the inventive compounds should minimize, and may even prevent, the occurrence of a “blue-halo” light visual alteration. It is believed that the increased isoenzyme selectivity in inhibiting PDE V isoenzyme (found in a penis) versus PDE VI isoenzyme (found in a retina) accounts for obviating the “blue-halo” visual side effect.
[0088] Forms 1 and 2 of Compound 13 can be employed alone or in combination with other active agents, particularly, other types of PDE inhibitors (especially cGMP PDE V inhibitors), prostanoids, α-adrenergic receptor, dopamine receptor agonists, melanocortin receptor agonists, endothelin receptor antagonists, endothelin converting enzyme inhibitors, angiotensin 11 receptor antagonists, angiotensin converting enzyme inhibitors, neutral metalloendopeptidase inhibitors, renin inhibitors, serotonin 5-HT 2c receptor agonists, nociceptin receptor agonists, rho kinase inhibitors, potassium channel modulators and inhibitors of multidrug resistance protein 5. Examples of therapeutic agents that may be used in combination with Forms 1 and 2 of Compound 13 are the following: other types of PDE V inhibitors, such as sildenafil citrate (Viagra®, Pfizer, Connecticut, United States), Vardenafil™ (Bayer, Germany) and IC-351 (Cialis™, Lilly-ICOS, Washington and Indiana, United States); prostanoids, such as prostaglandin E1; α-adrenergic agonists, such as phentolamine mesylate; dopamine receptor agonists, such as apomorphine; angiotensin II antagonists, such as losartan, irbesartan, valsartan and candesartan; and ETA antagonists, such as bosentan and ABT-627.
[0089] It is understood that combinations other than those described above may be undertaken with routine experimentation by one of ordinary skill in the art to treat mammalian disease states, while remaining within the scope of the invention. While Forms 1 and 2 of Compound 13 can each be used in an application of monotherapy to a patient, they also can be used in a combination therapy, in which one or both of them are administered in combination with one or more other pharmaceutical compounds (either separately or physically combined in a single form). The combination therapy is useful for treating a variety of disorders, symptoms and diseases, such as one or more of the mammalian disease states described above.
[0090] Due to their cGMP-PDE V inhibitory activities (as discussed above), Forms 1 and 2 of Compound 13 are useful for treating urological disorders, in particular, male and female sexual dysfunctions. Other physiological disorders, symptoms and diseases can also benefit from cGMP-PDE V inhibition. More specifically, the inventive compounds, and pharmaceutical compositions thereof, may be used to treat cardiovascular and cerebrovascular diseases, angina pectoris, hypertension, restenosis post angioplasty, endarterectomy, stent introduction, peripheral vascular diseases, cerebral stroke, respiratory tract disorders, such as reversible airway obstruction, chronic asthma and bronchitis, allergic disorders associated with atopy, such as urticaria, eczema, and rinitis, pulmonary hypertension, ischemic heart diseases, impaired glucose tolerance, diabetes and related complications, insulin resistance syndrome, hyperglycemia, polycystic ovarian syndrome, glomerular diseases, renal insufficiency, nephritis, tubular interstitial disease, autoimmune diseases, glaucoma, intestinal motility disorders, cachexia and cancer.
[0091] Another aspect of the invention is to provide a kit comprising separate containers in a single package, wherein inventive pharmaceutical compounds, and/or compositions are used ion combination with pharmaceutically-acceptable excipients or carriers to treat physiological disorders, symptoms and diseases in which cGMP-PDE V inhibition plays a role.
Pharmaceutically-Acceptable Dosage Forms
[0092] Forms 1 and 2 of Compound 13 can be administered to humans or other mammals by a variety of routes, including oral dosage forms and injections (intravenous, intramuscular, intraperitoneal, subcutaneous, and the like). Numerous other dosage forms comprising the inventive compounds can be readily formulated by one skilled in the art, utilizing the suitable pharmaceutical excipients or carriers as defined below. For considerations of patient compliance, oral dosage forms are generally most preferred.
[0093] The rate of systemic delivery can be satisfactorily controlled by one skilled in the art, by manipulating any one or more of the following:
[0094] (a) the active ingredient(s) proper;
[0095] (b) the pharmaceutically-acceptable excipient(s) or carrier(s), so long as the variants do not interfere in the activity of the particular active ingredient(s) selected;
[0096] (c) the type of excipient(s) or carrier(s), and the concomitant desirable thickness and permeability (swelling properties) of the excipient(s) or carrier(s);
[0097] (d) the time-dependent conditions of the excipient(s) or carrier(s);
[0098] (e) the particle size of the active ingredient; and
[0099] (f) the pH-dependent conditions of the excipient(s) or carrier(s).
[0100] Pharmaceutically-acceptable excipients or carriers comprise flavoring agents, pharmaceutical-grade dyes or pigments, solvents, co-solvents, buffer systems, surfactants, preservatives, sweetener agents, viscosity agents, fillers, lubricants, glidants, disintegrants, binders and resins.
[0101] Conventional flavoring agents can be used, such as those described in Remington's Pharmaceutical Sciences, 18 th Ed., Mack Publishing Co., 1288-1300 (1990), which is incorporated by reference herein. The pharmaceutical compositions of the invention generally comprise from 0% to about 2% of flavoring agent(s).
[0102] Conventional dyes and/or pigments can also be used, such as those described in the Handbook of Pharmaceutical Excipients, by the American Pharmaceutical Association & the Pharmaceutical Society of Great Britain, 81-90 (1986), which is incorporated by reference herein. The pharmaceutical compositions of the invention generally comprise from 0% to about 2% of dye(s) and/or pigment(s).
[0103] The pharmaceutical compositions of the invention generally comprise from about 0.1% to about 99.9% of solvent(s). A preferred solvent is water. Preferred co-solvents comprise ethanol, glycerin, propylene glycol, polyethylene glycol, and the like. The pharmaceutical compositions of the invention can comprise from 0% to about 50% of co-solvent(s).
[0104] Preferred buffer systems comprise acetic, boric, carbonic, phosphoric, succinic, malic, tartaric, citric, acetic, benzoic, lactic, glyceric, gluconic, glutaric and glutamic acids and their sodium, potassium and ammonium salts. Particularly preferred buffers are phosphoric, tartaric, citric and acetic acids and salts thereof. The pharmaceutical compositions of the invention generally comprise from 0% to about 5% of buffer(s).
[0105] Preferred surfactants comprise polyoxyethylene sorbitan fatty acid esters, polyoxyethylene monoalkyl ethers, sucrose monoesters and lanolin esters and ethers, alkyl sulfate salts and sodium, potassium and ammonium salts of fatty acids. The pharmaceutical compositions of the invention generally comprise from 0% to about 2% of surfactant(s).
[0106] Preferred preservatives comprise phenol, alkyl esters of parahydroxybenzoic acid, o-phenylphenol benzoic acid and salts thereof, boric acid and salts thereof, sorbic acid and salts thereof, chlorobutanol, benzyl alcohol, thimerosal, phenylmercuric acetate and nitrate, nitromersol, benzalkonium chloride, cetylpyridinium chloride, methyl paraben and propyl paraben. Particularly preferred preservatives are the salts of benzoic acid, cetylpyridinium chloride, methyl paraben and propyl paraben. The pharmaceutical compositions of the invention generally comprise from 0% to about 2% of preservative(s).
[0107] Preferred sweeteners comprise sucrose, glucose, saccharin, sorbitol, mannitol and aspartame. Particularly preferred sweeteners are sucrose and saccharin. Pharmaceutical compositions of the invention generally comprise from 0% to about 5% of sweetener(s).
[0108] Preferred viscosity agents comprise methylcellulose, sodium carboxymethylcellulose, hydroxypropyl-methylcellulose, hydroxypropylcellulose, sodium alginate, carbomer, povidone, acacia, guar gum, xanthan gum and tragacanth. Particularly preferred viscosity agents are methylcellulose, carbomer, xanthan gum, guar gum, povidone, sodium carboxymethylcellulose, and magnesium aluminum silicate. Pharmaceutical compositions of the invention generally comprise from 0% to about 5% of viscosity agent(s).
[0109] Preferred fillers comprise lactose, mannitol, sorbitol, tribasic calcium phosphate, diabasic calcium phosphate, compressible sugar, starch, calcium sulfate, dextro and microcrystalline cellulose. Pharmaceutical compositions of the invention generally comprise from 0% to about 75% of filler(s).
[0110] Preferred lubricants/glidants comprise magnesium stearate, stearic acid and talc. Pharmaceutical compositions of the invention generally comprise from 0% to 7%, preferably, from about 1% to about 5%, of lubricant(s)/glidant(s).
[0111] Preferred disintegrants comprise starch, sodium starch glycolate, crospovidone and croscarmelose sodium and microcrystalline cellulose. Pharmaceutical compositions of the invention generally comprise from 0% to about 20%, preferably, from about 4% to about 15%, of disintegrant(s).
[0112] Preferred binders comprise acacia, tragacanth, hydroxypropylcellulose, pregelatinized starch, gelatin, povidone, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, sugar solutions, such as sucrose and sorbitol, and ethylcellulose. Pharmaceutical compositions of the invention generally comprise from 0% to about 12%, preferably, from about 1% to about 10%, of binder(s).
[0113] Additional agents known to a skilled formulator may be combined with the inventive compounds to create a single dosage form. Alternatively, additional agents may be separately administered to a mammal as part of a multiple dosage form.
[0114] A pharmaceutical composition typically comprises from about 0.1% to about 99.9% (by weight or volume, preferably, w/w) of active ingredient (Forms 1 and/or 2 of Compound 13), preferably, from about 5% to about 95%, more preferably, from about 20% to about 80%. For preparing pharmaceutical compositions comprising the inventive compound(s), inert, pharmaceutically acceptable excipients or carriers can be either solid or liquid. Solid form preparations comprise powders, tablets, dispersible granules, capsules, cachets and suppositories. Suitable solid excipients or carriers are known in the art, for example, magnesium carbonate, magnesium stearate, talc, sugar and lactose. Tablets, powders, cachets and capsules can be used as solid dosage forms suitable for oral administration. Examples of pharmaceutically-acceptable excipients or carriers and methods of manufacture for various compositions may be found in Remington's Pharmaceutical Sciences, 18 th Ed., Mack Publishing Co. (1990), which is incorporated in its entirety by reference herein.
[0115] Liquid form preparations comprise solutions, suspensions and emulsions. Common liquid form preparations comprise water and water-propylene glycol solutions for parenteral injection or addition of sweeteners and opacifiers for oral solutions, suspensions and emulsions. Liquid form preparations may also comprise solutions for intranasal administration.
[0116] Aerosol preparations suitable for inhalation comprise solutions and solids in powder form, which may be combined with a pharmaceutically acceptable excipient or carrier, such as an inert compressed gas (e.g., nitrogen).
[0117] Further included are solid form preparations that may be converted, shortly before use, to liquid form preparations for either oral or parenteral administration. Such liquid forms comprise solutions, suspensions and emulsions.
[0118] The compounds of the invention may also be delivered transdermally. The transdermal compositions can take the form of creams, lotions, aerosols and emulsions, and may be included in a transdermal patch of a matrix or reservoir type as is conventional in the art for this purpose.
[0119] The preferred mode of administering the compounds of the invention is oral. Preferably, the pharmaceutical preparation is in a unit dosage form. In such a form, the preparation is subdivided into suitable sized unit doses comprising appropriate quantities of the active component, for example, an effective amount to achieve the desired purpose.
[0120] The quantity of active ingredient (Forms 1 and/or 2 of Compound 13) in a unit dose of preparation may be varied or adjusted from about 0.01 mg to about 4,000 mg, preferably, from about 0.02 mg to about 2,000 mg, more preferably, from about 0.03 mg to about 1,000 mg, even more preferably, from about 0.04 mg to about 500 mg, and most preferably, from about 0.05 mg to about 250 mg, according to the particular application. A typical recommended daily dosage regimen for oral administration can range from about 0.02 mg to about 2,000 mg/day, in two to four divided doses. For convenience, the total daily dosage may be divided and administered in portions during the day as required. Typically, pharmaceutical compositions of the invention will be administered from about 1 time per day to about 5 times per day, or alternatively, as a continuous infusion. Such administration can be used as a chronic or acute therapy. The amount of active ingredient that may be combined with excipient or carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. As disclosed above, a typical preparation will comprise from about 0.1% to about 99.9% of active compound, preferably, from about 5% to about 95%, more preferably, from about 20% to about 80%. The actual dosage employed may be varied depending upon the requirements of the patient and the severity of the condition being treated. Determination of the proper dosage regimen for a particular situation is within the skill of the art. For convenience, the total daily dosage may be divided and administered in portions during the day as required.
[0121] The pharmaceutically-acceptable excipients or carriers employed in conjunction with the compounds of the present invention are used at a concentration sufficient to provide a practical size to dosage relationship. The pharmaceutically-acceptable excipients or carriers, in total, can comprise from about 0.1% to about 99.9% (by weight or volume, preferably, by w/w) of the pharmaceutical compositions of the invention, preferably, from about 5% to about 95% by weight, more preferably, from about 20% to about 80% by weight.
[0122] Upon improvement of a patient's condition, a maintenance dose of a compound, composition or combination of the invention can be administered, if desired or warranted. Subsequently, the dosage or frequency of administration, or both, may be reduced, as a function of the symptoms, to a level at which the improved condition is retained. When the symptoms have been alleviated to the desired level, treatment should cease. Patients may, however, require intermittent treatment on a long-term basis upon any recurrence of disease symptoms.
[0123] Specific dosage and treatment regimens for any particular patient may be varied and will depend upon a variety of factors, including the activity of the specific compound employed, the age, body weight, general health status, sex and diet of the patient, the time of administration, the rate of excretion, the specific drug combination, the severity and course of the symptoms being treated, the patient's disposition to the condition being treated and the judgment of the treating physician. Determination of the proper dosage regimen for a particular situation is within the skill of the art. The amount and frequency of the administration of Forms 1 and/or 2 of Compound 13, or the pharmaceutical compositions thereof, may be regulated according to the judgment of the attending clinician, based on the factors recited above. As a skilled artisan will appreciate, lower or higher doses than those recited above may be required.
[0124] For instance, it is often the case that a proper dosage level is based on the weight of the patient. For example, dosage levels of between about 0.01 mg/kg and about 100 mg/kg of body weight per day, preferably, between about 0.5 mg/kg and about 75 mg/kg of body weight per day, and more preferably, between about 1 mg/kg and about 50 mg/kg of body weight per day, of the inventive compound(s), and compositions described herein, are therapeutically useful for the treatment of a variety of biological disorders, particularly, male and female sexual dysfunction. Between two patients of differing weights, a higher dosage will be used for the heavier patient, all other things being equal.
[0125] Forms 1 and/or 2 of Compound 13 are understood to provide efficacious treatment of (male) erectile dysfunction, including a reasonable time of onset upon administration, and a reasonable duration after administration. For example, in the treatment of erectile dysfunction, a dosage of the inventive compound(s) can be taken about an hour before a sex act is to be undertaken. Particular dosages will work within about thirty minutes of their administration. Ideal dosages will affect a patient within about fifteen minutes of their administration. While food, diet, pre-existing conditions, alcohol and other systemic conditions could lengthen the time delay for an inventive drug to work after its administration, it is understood that optimum dosages in combination with sexual stimulation will result in an efficacious drug treatment within and for a reasonable amount of time.
Polymorph Purity
[0126] Preferably, the inventive polymorphs of Compound 13, Forms 1 and 2, are each substantially free of chemical impurities (e.g., by-products generated during the preparation of Forms 1 or 2 of Compound 13). “Substantially free” of chemical impurities for the purposes of this invention means less than or equal to about 5% w/w of chemical impurities, preferably, less than or equal to about 3% w/w of chemical impurities, more preferably, less than or equal to about 2% w/w of chemical impurities, and even more preferably, less than or equal to about 1% w/w of chemical impurities.
[0127] The inventive polymorphs of Compound 13 are, preferably, essentially free of other forms of Compound 13. “Essentially free” of other forms of Compound 13 for the purposes of this invention means less than or equal to about 15% w/w of other forms of Compound 13, preferably, less than or equal to about 10% w/w of other forms of Compound 13, more preferably, less than or equal to about 5% w/w of other forms of Compound 13, and even more preferably, less than or equal to about 2% w/w of other forms of Compound 13.
Preparation of Compound 13 in Form 1 and Form 2
[0128] Preparation 1: Form 1 of Compound 13
[0129] About 1 g of Compound 13 (in any form, both crystalline and non-crystalline) is dissolved into solution by heating it in about 5-10 volumes of an alcohol (e.g., methanol or isopropanol) to about the solution boiling point, and the solution is then filtered to remove any particulate matter. If desired, Darco can be added in the dissolution step to remove any color impurities from the batch. The solution is concentrated to about half the original volume, cooled to about room temperature, and diluted with about an equal volume of water. The precipitated solid is cooled, filtered, washed with about a 25% aqueous alcohol solution, and dried at about 70-80° C. under a vacuum to provide Form 1 of Compound 13.
[0130] Yield: about 90-95%.
[0131] Morphology: needles.
[0132] Melt Point: about 175-182° C.
[0133] Average DSC Heat of Fusion: about 70 J/g. See FIG. 4 which shows 71.112 μg.
[0134] X-ray Powder Diffraction Angle [in degrees]: See Table 2 and FIG. 3.
[0135] Preparation 2A: Form 2 of Compound 13 Without Seeding About 1 g of Compound 13 (in any form, both crystalline and non-crystalline) is dissolved by heating it in about 10-20 volumes of a Form 2 crystallizing solvent (e.g., alcohol, nitrile, ester or ketone). The solution is then filtered to remove any particulate matter. If desired, Darco can be added in the dissolution step to remove any color impurities from the batch. The solution is concentrated to about half of the original volume and cooled to about room temperature. The batch is then stirred at about room temperature for about 18 hours to obtain equilibrated pure Form 2 of Compound 13.
[0136] Yield: about 75-85%.
[0137] Morphology: plates.
[0138] Melt Point: about 164-172° C.
[0139] Average DSC Heat of Fusion: about 100 J/g. See FIG. 2 which shows 98.521 μg.
[0140] X-ray Powder Diffraction Angle [in degrees]. See Table I and FIG. 1.
[0141] Preparation 2B: Form 2 of Compound 13 with Seeding
[0142] The batch is run in the same manner as described above for the preparation 2A up to the cooling of the solution to about room temperature. At this point, the solution is seeded with a small amount of Form 2 of Compound 13 solid (e.g., about 0.2% w/w to about 1% w/w based on the weight of starting material). The crystallized solid is then cooled, filtered, washed with crystallization solvent, and dried at about 70-80° C. under a vacuum to provide Form 2 of Compound 13. The yield obtained (about 90-95%) is a little more than is achieved in preparation 2A above (due to avoidance of product encrustation that occurs during preparation 2A).
[0143] The morphology, melt point, DSC heat of fusion and x-ray powder diffraction data are the same as shown below for Form 2 made by preparation 2A.
EXAMPLE
[0144] About 10 g of Form I of Compound 13 was added to and dissolved in about 17 volumes of acetonitirile by heating the batch to about 80-85° C. The batch was Darco treated to remove any color impurities. The hot solution was filtered to remove any particulate matter, and the batch was concentrated atmospherically to a final volume of about 6-7 volumes. About 0.05 g of Form 2 of Compound 13 seed (which is about 0.5% of the weight of initial charge of Form 1 of Compound 13) was added as a slurry in acetonitrile. The batch was gradually cooled to room temperature, held there for about 3 hours, and then cooled to about 0-5° C. The resulting suspension was filtered, washed with acetonitrile, and dried at about 70-80° C. in a vacuum to provide Form 2 of Compound 13 in about a 90-95% yield.
[0145] The morphology, melt point, DSC heat of fusion and x-ray powder diffraction data are the same as shown above for Form 2 made by preparation 2B.
[0146] Other than as shown in the operating example or as otherwise indicated, all numbers used in the specification and claims expressing quantities of ingredients, reaction conditions, and so forth, are understood as being modified in all instances by the term “about.” The above description is not intended to detail all modifications and variations of the invention. It will be appreciated by those skilled in the art that changes can be made to the embodiments described above without departing from the inventive concept. It is understood, therefore, that the invention is not limited to the particular embodiments described above, but is intended to cover modifications that are within the spirit and scope of the invention, as defined by the language of the following claims.
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Crystalline polymorphs of 1-ethyl-3,7-dihydro-8-[(1R,2R)-(hydroxycyclopentyl)amino]-3-(2-hydroxyethyl)-7-[(3-bromo-4-methoxyphenyl)methyl]-1H-Purine-2,6-dione in Form 1 and Form 2, which exhibit x-ray powder diffraction profiles substantially the same as those shown in FIGS. 5 and 6, respectively, and which exhibit differential scanning calorimtery profiles substantially the same as those shown in FIGS. 2 and 4, respectively, and are represented by the formula:
Pharmaceutical compositions comprising the polymorph Form 1 or 2 of Compound 13 and at least one excipient or carrier, and methods of using the polymorph Form 1 or 2 of Compound 13 to treat a variety of physiological disorders, such as erectile dysfunction.
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This is a division of application Ser. No. 206,613, filed Nov. 13, 1980 now U.S. Pat. No. 4,391,210 dated July 5, 1983.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to tag attaching machines, and more particularly, to an apparatus and method for attaching tags of any size and thickness to a garment or other article by means of inexpensive thread.
2. Description of the Prior Art
In the mass merchandising of articles such as garments, handbags, wallets, gloves, hats and the like, it is necessary to place a price tag on each and every article prior to sale to the consumer. In view of the diversity of the types of articles and their shapes and materials, the tag attaching process is not generally amenable to automation. Furthermore, the size, shape and configuration of the tags used for different articles will vary depending upon the requirements or desires of the retailer and the nature of the article itself.
It can be appreciated from the above that the tag attaching operation for all retailers, both large and small, is an expensive, labor intensive operation presenting many serious obstacles.
In an effort to overcome some of the disadvantages noted above, attempts have been made in the past to develop automated or semi-automated equipment for attaching tags of different sizes to garments of different types. The prior art approaches which have thus far received most attention can be divided into two basic types. The first type in essence consists of apparatus for stapling tags directly onto garments using small metal staples. The second type takes the form of a gun-like device which is designed to shoot small nylon connectors into the article whereupon the tag is held in place by short, perpendicular lengths of nylon at each end of the fastener in much the same fashion as the barbs on a fishhook.
While the above types of machines appear to provide a cost-effective way of semi-automating the tag attaching process, it is quite clear that the overall operation nonetheless remains highly labor intensive. Moreover, the fasteners used by these prior art devices, be they staples or nylon links, often cause considerable damage to the article both during the attaching process and, subsequently, when the consumer attempts to remove the tag after purchase. This latter problem is particularly troublesome with respect to clothing apparel made of synthetics or other fine or delicate fabrics.
Of the above two categories of prior art devices, the gun-type device has achieved greatest popularity and for quite some time has been regarded as the best solution to the troublesome tag attaching problem. However, it is now being recognized by retailers in general that the nylon fastener elements, being petroleum based products, are rapidly becoming a high cost factor suggesting that the full solution has not yet been achieved. The high cost of the nylon fastener elements and the increasing use of fabrics and materials which are easily damaged when such fasteners are shot into them from a gun has rekindled interest in the design and development of an improved generation of tag attaching devices.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to attach tags of any size to garments or other articles quickly, inexpensively and without damaging the garment or article.
The present invention has another object in the construction of a tag attaching machine which may be operated rapidly and automatically to feed and affix tags to garments or other articles using inexpensive thread.
A further object of this invention is to construct a tag feed mechanism for a tag attaching machine in which gauges for tag width and thickness are coupled to internal operating mechanisms so that the positioning of the gauge against the tag automatically conditions the apparatus to precisely feed the tags, one at a time, from a stacked array to a tag attaching station.
Another object of this invention is to feed and attach tags to garments or other articles manually or by automatic cycling, with both tag feed mechanisms and tag attaching mechanisms controlled by a single, solid state microprocessor.
The present invention has yet a further object in the construction of a microprocessor controlled tag attaching mechanism including adjustments for automatic cycle time periods, single tag feeding time periods, and tag attaching loop diameters.
The present invention is summarized as a tag attaching machine including a mechanism for feeding single tags from a stacked array to a tag attaching station, a tag affixing mechanism for attaching the tag to a garment or article at the tag attaching station, and microprocessor controls for controlling and sequencing the apparatus. The present invention further contemplates the provision of tag feed adjustment mechanisms which automatically adjust the length of movement of tags from the position of a stacked array to a tag attaching station in response to the adjustment of tag gauge members whereupon the measurement of a particular tag dimension automatically conditions the apparatus for proper feed alignment of tags to the attachment station.
The present invention exhibits numerous advantages over the prior art in that tags of any desired dimension and thickness may be automatically fed from a stacked array, that adjustment of the apparatus to accommodate tags of varying sizes and shapes may be accomplished automatically by merely placing the tag between adjustable measuring gauges, that apparatus control and sequencing is accomplished by a solid state microprocessor, that tags may be quickly and efficiently attached to garments or other articles with an adjustable period between cycles, and that tags may be attached by inexpensive thread from a supply spool without using expensive or potentially damaging metal or plastic fasteners.
Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of a tag attaching machine in accordance with the present invention;
FIG. 2 is a partial front elevational view, with parts broken away, of the tag feed and adjustment mechanism of the machine in FIG. 1 in accordance with the present invention;
FIG. 3 is a partial elevational view similar to FIG. 2 but showing the tag feed adjustment mechanism in a different position;
FIG. 4 is a partial top plan view of the tag feed mechanism of FIGS. 2 and 3;
FIG. 5 is a partial plan view of the mechanism of FIG. 4 showing the tag feed assembly in an intermediate position,
FIG. 6 is a detailed front elevational view of the tag pick-up member of the feed mechanism of FIGS. 1 and 2;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 4;
FIGS. 8, 9 and 10 are partial perspective views of the tag attaching station of the machine of FIG. 1 in start, intermediate and finish positions, respectively;
FIG. 11 is a diagrammatic block diagram of the microprocessor controlled functional elements of the tag attaching machine according to the present invention; and
FIG. 12 is a schematic diagram of the microprocessor control circuitry of FIG. 11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is embodied in a tag attaching machine shown in perspective view in FIG. 1 and identified generally by the number 20. The tag attaching machine 20 includes a main frame member or base 22 on which is mounted a motor 24 which is coupled through a solenoid actuated clutch mechanism 26 to a main drive gear 28 which in turn is coupled to the tag attaching mechanism at a tag attaching station identified generally with the numeral 30.
The main frame member 22 also supports a pneumatic compressor 32 which provides a source of air, under slight pressure, for actuating various pneumatically controlled mechanisms as will be discussed in more detail hereinbelow. The tag attaching machine 20 also includes a transport mechanism, indicated generally at 34 for moving individual tags from a tag supply 36 to the tag attaching station 30.
The tag transport mechanism 34, the clutch and gear assembly 26, 28, and the mechanism at the tag attaching station 30 are all sequenced and controlled by a solid state microprocessor circuit indicated generally at 38.
For control of the tag attaching machine, several externally accessible switches are provided. Disposed on a convenient control panel 40 above the transport assembly 34 is an on/off switch 42 controlling the supply of power to the overall machine. Next to the on/off switch 42 is a pushbutton switch 44 which, as will be further described hereinbelow, causes the feed of a single tag from the tag supply 36 to the tag attaching station 30 without initiating a tag attaching operation at the tag attaching station. A further two-position switch 46 is disposed next to pushbutton switch 44 and controls the programming of microprocessor 38 between a manual mode and an automatic mode. In the manual mode, the tag attaching machine 20 may be caused to feed a single tag and attach the same to a garment or article upon depression of a main operator control switch 48. The actuation of switch 48 by the operator causes only a single operation to be performed when switch 46 is in the manual position. When the switch 46 is moved to its automatic position, the machine will repetitively and periodically continue to sequence through successive tag attaching operations thereby permitting the operator to automatically attach tags to garments or articles without having to separately actuate command switch 48 for each sequence. Referring to FIGS. 2, 3 and 4, the tag feed mechanism 34 includes a main mounting member 50 attached to the main frame 22. Journaled for rotation about an upstanding pin 52 on member 50 is a transport actuating lever 70. As can be appreciated from FIG. 4, transport lever 70 is journaled at an intermediate point for rotation in both clockwise and counter clockwise directions about the axis of pin 52. A first end 72 of arm 70 is pivotally attached to a piston 90 by an intermediate connecting element 74. Piston 90 is disposed within a conforming cylinder 80 which is connected by pneumatic lines to a solenoid operated pneumatic valve 82 via an extending outlet 84 and a retracting outlet 86 connected respectively at opposite ends of the cylinder 80 as shown. As will become clear below, the solenoid operated valve 82, when at rest, supplies compressed air from compressor 32 through retracting outlet 86 to the end of cylinder 80 so as to cause the piston 90 to retract to the position shown in FIGS. 2 and 4.
The opposite end 76 of lever arm 70 is bifurcated to receive an upright post 78 carried upon a tuning fork-like tag push member 92. The tag pusher member 92 has two tines 94 each provided at their distal ends with an offset shoulder 96 having a slightly downwardly inclinded bottom surface 98.
Pusher member 92 is disposed atop plate 52 between a pair of spaced, elongated channel guides 31. The top surface of the channel guide members 31 is coplaner with the top surface of the tines 94 of pusher member 92 as can best be seen in the sectional view of FIG. 7. These members thus form a generally flat transport plate or surface so as to enable tags to be fed from the tag supply stack 36 to the tag attaching station 30 whenever the pusher member 92 is rectilinearly shifted from the left to the right as visualized in FIG. 4 under the driving force of the counter clockwise rotating lever arm 70.
Turning to FIGS. 2 and 3, a generally U-shaped frame member 33 is secured to the top of support plate 50. Rotatably disposed across frame 33 is a threaded rod 35 having a crank handle 37 attached at one end. An adjustable support block 39 is attached to a threaded nut 41 carried on the opposite end of rod 35, as illustrated. The upper edge of block 39 is adapted to be received within a shallow groove or channel 43 in the lower surface of the cross portion of frame 33 so as to preclude the block 39 from rotation as crank handle 37 is turned. In this manner, turning of the crank handle causes linear transposition of the block 39 as can be appreciated from a comparison of FIGS. 2 and 3.
Carried upon block 39 is a microswitch 120 having an actuating roller 45. The microswitch 120 is mounted on block 39 such that the roller 45 is in the path of rotary movement of lever arm 70. As will be described in more detail herein below, the microswitch is actuated each time the lever arm 70 moves in a counter clockwise direction, as visualized in FIG. 4. Thus, as the lever arm rotates from the rest position shown in FIGS. 2 through 4 to a tag feed position as shown in phantom lines in FIG. 4, the microswitch will be actuated.
Mounted on the cross member of frame 33 is an upright pin or arm 47. Similarly, a pair of spaced upright arms 49 and 51 are attached to moveable block 39. Pin 47, which is fixed with respect to frame 33, cooperates with arms 49 and 51 to form a tag width gauge. As can be appreciated from FIGS. 2 and 3, the tag width gauge may be easily used by merely positioning a single tag such that a prepunched hole therein is placed over pin 47. With the tag thus in position, crank 37 is rotated to move arm 49 until it just engages the edge of the tag as shown in FIG. 3. Since the movement of arm 49 on block 39 by turning crank 37 also causes a like movement of microswitch 120, it can be appreciated that the end point of travel of lever 70, which is determined by the microswitch 120, will be adjusted each time as the tag width is measured. By coordinating the tag width gauge measurement with the positioning of the microswitch 120 on block 39 and with the distance between the tag supply stack 37 and the tag attaching station 39, the tag pusher member 92 can be caused to move precisely the amount required to shift a tag from the stacked array to the tag attaching station by merely taking a representation tag and placing it in the width measurement gauge and adjusting crank 37.
Since the tag width may vary over a considerable extent, it may be necessary in certain instances to remove tag push member 92 and replace the same with one having shorter tines 94. When the substitute push member is thus installed, the second gauge arm 51 carried by moveable block 39 may be used in conjunction with fixed arm 47 to measure tag width and set the microswitch 120 accordingly.
It can be appreciated from the above that the tag attaching machine according to the present invention is quickly and precisely adaptable to use with tags of widely varying widths. Moreover, the adjustment is extremely simple and merely requires that the operator place the tag between the appropriate gauge members 47 and 49 or 47 and 51 and then merely rotate the crank 37 to conform to the tag dimension. This action automatically transpositions the microswitch 120 so as to establish the end point of travel of lever arm 70 whereupon the push member 92 will move the tag the precise distance necessary to bring the same into perfect alignment at the tag attaching station 30.
The apparatus according to the present invention further includes a tag thickness gauge. Refering again to FIGS. 2 and 3, the tag supply stack 36 is adapted to be placed against a retaining member 53 which is mounted such that its lower edge is spaced from the upper surface of the support plate formed by guides 31 and tines 94 of push member 92 so as to permit a tag of maximum intended thickness to pass therebetween. At the top of retaining member 53, a perpendicular leg 55 extends toward the tag attaching station such that the retaining member 53 and attached leg 55 have a generally L-shaped section. A shutter 57 is mounted against the retaining member 53 by suitable means such as a screw 59 which extends through a slot in member 53. A perpendicularly disposed leg 61 extends from the top edge of shutter 57 such that the shutter also has a generally L-shaped section. The dimensions of shutter 57 are such that the spacing between leg members 55 and 61 is precisely the same as the opening at the bottom of the shutter above the tag supporting plate formed by tines 94 and support members 31. By placing a selected tag between members 55 and 61, and, after loosening screw 59, adjusting the shutter 57 accordingly, the shutter opening will be quickly and precisely set to permit only one tag to be withdrawn from the tag supply 36 and shifted to the tag attaching station 30.
On the opposite side of the tag supply stack 36 from retaining member 53 is a second retaining member 63. This member may be moved to the left and to the right so as to accommodate tags of different widths and maintain the same in a neat stack. A weight 65 is attached, preferably with some degree of freedom to the bottom end of a rod 67 which is loosely held in an elongated slot 69 in a holding member 71. A handle 73 is attached to the top of rod 67 so that the rod and weight may be picked up and moved and then replaced atop a stack of tags 36 to maintain the same in proper alignment.
The tag supply 36 is also provided with a tag retention member 75 in the form of a generally flat strip of material having its top end bent over to form a finger grip portion 77 and having an ear 79 attached to wall member 63 by any suitable means such as screw 81. Member 75 may be positioned to accommodate tags of varying depths and effectively prevents the tag supply from inadvertent dislodgement.
A metal tube 83 has an opening 85 shaped to form a nozzle. The tube 83 is held in position by an appropriate block 87 and is adapted to be connected to compressor 32 so as to feed a stream of air against the needle 132. The stream of air eminating from nozzle 85 clears the severed loose ends of the thread after each tag attaching sequence and blows the remaining tag end to the right, as visualized in FIGS. 2 and 3, so as to place the thread end in the proper position for pick up during the next tag attaching sequence.
Referring to FIGS. 8, 9 and 10, FIG. 8 shows the positioning of the various elements at or near the tag attaching station 30 just prior to the first tag attaching operation. At this time, a single tag has been moved from the tag supply stack 36 to the tag attaching station 30 and is sitting between the upper surface of the support plate and a guard plate 89. An article to which a tag is to be attached is positioned over the presser block 128, as shown. The operator then commences the tag attaching sequence by engaging switch 48 (FIG. 1). This begins the entire sequence and initially causes the needle 132 to move down. The needle will continue to travel down through the hole in the tag and through article until it reaches the lowest position of travel. At this point, a pick up mechanism 91 is operated to grasp the end of the thread at the lower end of the needle under the article. At this time, the presser foot 116 will have pressed the article against presser block 128 to hold it securely in place. As the needle 132 begins to move back in the upward direction, the pick up mechanism will also move the end of the thread up above the guard plate 89 as shown in FIG. 9. Depending upon the duration of the down position of the presser foot 116, the length of the loop thus formed, as depicted in FIG. 9, will vary. As will be described more fully herein below, the presser foot down duration is controlled by the microprocessor 38, and a timing network included therein may be adjusted to select any desired loop diameter.
At the conclusion of the tag attaching sequence, the article is pulled from the tag attaching station whereupon the knotting mechanism (not shown) completes its function and the next article may be then moved into position.
Referring now to FIG. 11 the operation of the present invention through the control of microprocessor circuitry 38 will be explained in detail. The microprocessor circuitry 38 is connected to a source of power designated generally as power supply 100. The power derived from supply 100 is utilized by the microprocessor to selectively operate the other elements of the invention.
Control of the microprocessor circuitry 38 is achieved through a plurality of switches connected to its inputs. As discussed above, a control panel 40 includes a two-position switch 42 which turns the microprocessor on and off, a push button switch 44 to cause movement of the transport mechanism without actual attachment of the tag, and a two-position switch 46 to operate the microprocessor in either manual or automatic modes. In the manual mode, a first operation of switch 46 followed by operation of a command switch 48 causes movement and attachment of a single tag, whereas in automatic mode successive operations of the tag attaching mechanism result from a single operation of the command switch 48.
The motor 24 receives power from the microprocessor via line 102. The gear 28 is engaged to be driven by the motor 24 upon operation of a clutch 26 controlled by the microprocessor via line 104. A limit switch 29 detects the position of gear 28 and directs this information to the microprocessor via line 106.
The transport mechanism 34 operated via cylinder 80 is controlled through a solenoid valve 82 connected to the microprocessor via line 108, to the cylinder 80 by outlets 84 and 86 to control respectively extending and retracting piston 90, and to a pneumatic compressor 32. Power to the pneumatic compressor 32 is controlled by the microprocessor via line 112. A microswitch 120 which detects the position of the tag feeder arm 70 transmits this information to the microprocessor on line 114.
The microprocessor also controls a presser foot 116 by means of a solenoid valve 118 connected to line 121, to extending outlet 122 and retracting outlet 124 of air cylinder 126, and to the pneumatic compressor 32. In operation, the presser foot 116 is extended to retain the material against presser block 128 directly below the attaching station 30 during movement of the attaching mechanism 130 including needle 132 and thread 134.
To perform a single tag attaching operation, switch 42 is first moved to its "On" position, thereby causing power to be applied to the motor 24 and the pneumatic compressor 32. Switch 46 is placed in "Manual" position and switch 44 is operated once. In response, microprocessor circuitry 38 institutes movement of the transport mechanism 34 by operating the solenoid valve 82 via line 108 thereby directing air from the pneumatic compressor 32 into extending outlet 84 which causes a tag to be moved from the stack of tags 36 towards the tag attaching station 30. When the selected tag has been completely moved into place in the tag attaching station 30, microswitch 120 is engaged by the tag feeder arm 70 and transmits this information to the microprocessor on line 114. Upon receipt of this signal the microprocessor disables solenoid valve 82 which causes air from the compressor 32 to be directed to retracting outlet 86 so that the piston 90 retracts into the cylinder 80 and the transport mechanism 34 moves back to its initial position.
By operating switch 44 once, the resulting movement of tag mechanism 34 causes a selected tag to be moved to the tag attaching station 30. At this time, the alignment of the tag can be verified and any needed changes in the tag gauges can be made.
If attachment of the selected tag to the garment is desired, operation is continued by placing a garment on presser block 128 and pressing the command switch 48 one time. In response, the microprocessor simultaneously institutes movement of the presser foot 116 and the attaching mechanism 130. A signal on line 120 causes the solenoid valve 118 to direct air from the compressor 32 to the extending outlet 122 of the presser foot cylinder 126, thereby driving the presser foot 116 against the presser block 128 to hold the garment in place. After a predetermined albeit adjustable time, solenoid valve 118 is switched off thereby directing air into retracting outlet 124 so the presser foot 116 lifts off a presser block 128. Meanwhile, the attaching mechanism 130 is activated by controlling the clutch 26 so that cam gear 28 engages the motor 24.
The needle 132 and thread 134 of the attaching mechanism pass through the selected tag and garment in the manner described hereinabove. As the attaching mechanism draws the thread around the presser foot 116 a loop is formed and subsequently tied by further operation of the attaching mechanism. Thus, the length of the resulting loop is dependent upon the distance between the actuating mechanism 130 and the presser foot at the moment the thread is tied.
Therefore, the length of time the presser foot 116 is extended is directly related to the length of the resulting loop: if the presser foot is retracted early, the distance is small when the thread is tied whereas keeping the presser foot down causes a greater distance and hence a longer loop at the moment of tying. The length of time the presser foot is extended is controlled by an adjustable delay circuit 136 located in the microprocessor.
Continued movement of the attaching mechanism 130 via the gear 28 and the motor 24 results in completed attachment of the selected tag by means of needle 122 containing thread 124. At the time when the selected tag has been properly attached, position-indicating means 138 located on gear 28, such as a notch 138, causes operation of the limit switch 29. This information is received by the microprocessor on line 106 which, in response thereto, directs operation of the clutch 26 so as to disengage the gear 28 from the motor 24. There is, however, sufficient momentum left in gear 28 to cause continued movememt of the position-indicating notch 138 of the gear past the limit switch 29 so that the limit switch 29 is no longer engaged.
At this point, the tag attaching procedure has completed one full cycle and the garment with tag can be removed thereby simultaneously cutting the tied thread free.
The signal generated by engagement of the limit switch 29 is used for second function by the microprocessor, however, to prepare for another tag-attaching operation. In addition to disengaging the clutch 26, the microprocessor in response to operation of the limit switch causes the transport mechanism 34 to deposit another tag in the attaching station 30 per the steps set forth herein above. The last step of each attaching cycle, therefore, is to deposit another tag in the attaching station so as to be ready for a second operation of the command switch 48.
An adjustable delay circuitry 140 is included in the microprocessor connected to line 108 leading to the transport mechanism solenoid valve 82 to vary the interval between completion of tag attachment by attaching means 130 and the delivery of another tag in the manner described immediately above. This allows an operator sufficient time to remove the previous garment and tag from the attaching station 30 and presser block 128 so as to avoid jamming the device by delivering a new tag before removal is completed. The interval is adjustable to provide for varying degrees of skill among operators of the machine.
Successive operations of the command switch 48 while switch 46 is in "Manual" setting causes the foregoing sequences to be repeated each time in response thereto. If the switch 46 is moved to "Automatic" position and the command switch 48 is then operated, the foregoing events occur as described above with the additional step that operation of the limit switch 29 by gear 28 also causes the microprocessor to initiate another cycle of the attaching means, presser foot and transport mechanism upon completion of the prior cycle. In this manner, successive attachments of the tags occur automatically in response to a single operation of the command switch 48, until switch 46 is moved back to "Manual" position thereby completing the current cycle and then stopping.
An adjustable delay circuit 142 included in the microprocessor may be used to control the interval of time between successive cycles of tag attaching when operating in the automatic mode.
It may be appreciated that many different devices may be used to implement the circuitry and control mechanisms described hereinabove. For example, the clutch 26 engaging gear 28 may be a magnetic-type clutch, a pneumatic or hydraulic clutch, or a fully electronic braking system. Similarly, the devices used to operate the transport mechanism 34 and the presser foot 116 may comprise pneumatic devices as discussed above or, alternately, bi-directional electric motor, hydraulic devices of any other suitable mechanisms.
The microprocessor circuitry 38 may be designed in a variety of ways so as to accomplish the particular operating functions discussed hereinabove. A preferred embodiment of the microprocessor is illustrated in FIG. 12, wherein the reference characters correspond to those used in FIG. 11.
The preferred embodiment comprises a known DC power supply 200 connected through the on/off switch 42 to the power source 100 to develop an internal voltage and ground. A reset pulse ICL is developed by circuitry 202 connected to the power supply 200. The pulse ICL is characterized by the generation of a slowly increasing voltage waveform upon turning switch 42 on and is used to effect automatic reset and initialization of the other microprocessor circuitry.
The command switch is connected to the input of a NAND gate 204 having an output connected to an input of AND gate 206. The output of AND gate 206 is connected to a negative pulse shaping circuit 208 and to the SET input of a latch 210 comprising NAND gates. The output of the shaping circuit 208 is also connected to the monostable multivibrator 136 adjustable via resistor 210. The pulse produced by the miltivibrator 136 is connected to a driving circuit 212 for a relay 214 controlling the presser foot solenoid valve 118.
The output of the latch 210 is connected to another driving circuit 216 for a relay 218 controlling the cam gear clutch 26. The input of the shaping circuit is connected to the limit switch 29 of the cam gear 28. One RESET input of the latch 210 is connected to master reset ICL, and a second to the input of the monostable multivibrator 140 adjustable via resistor 222. The output of multivibrator 140 is connected to a positive waveform pulse shaping circuit 224, having an output connected to a SET input of latch 226. The latch 226 is connected to a driving circuit 228 for control of the feeder mechanism solenoid valve 82 through triac 230.
The microswitch 120 is connected to a negative pulse shaping circuit 232 which has an output connected to the RESET inputs of latch 226 and latch 234. Another RESET input of latch 234 is connected to master reset ICL, a SET input to shaping circuit 208, and the inverted output of the latch 234 to an input of NAND gate 204 and NAND gate 236. This latter gate has another input connected to switch 44 and its output connected to the latch 226.
The output of shaping circuit 224 is also connected to a monostable miltivibrator 142 adjustable via resistor 238. The output of the multivibrator is connected to a negative pulse shaping circuit 240, having an output connected to the RESET input of a latch 242 and an inverted output connected to a NAND gate 244. The switch 46 is connected to the SET input of latch 242, the output of the latch is connected to the other input of NAND gate 244, having its output connected to the input of AND gate 206.
The operation of the circuit of FIG. 12 will now be described to illustrate the sequence of operations occuring during attachment of a tag. As discussed above, the first step is operating switch 44 which causes latch 226 to be set and the feeder arm solenoid valve 82 to be operated via driving circuit 228 and triac 230. The feeder mechanism advances a selected tag towards the attaching station until it is in place and microswitch 120 is engaged, resulting in resetting latch 226 and turning off solenoid valve 82 thereby causing the feeder mechanisn to return. A tag is now properly in place in the attaching station.
The next step is to operate command switch 48 which simultaneously turns on the presser foot solenoid valve 118 via shaping circuit 208, multivibrator 136, driving circuit 212 and relay 214, and turning on the cam gear clutch 29 via latch 210, driving circuit 216 and relay 218. Thus, the presser foot engages the garment and the attaching mechanism begins operation. Meanwhile, latch 234 has been set, thereby temporarily blocking via gate 204 any further operation from pressing command switch 48.
The duration of operation of the presser foot solenoid valve 118 is controlled by multivibrator 136. As discussed above, this has a direct effect upon the length of thread loop attaching the selected tag to the garment. When the multivibrator 136 times out, the presser foot is released.
Since the cam gear solenoid 26 is still being operated, the attaching mechanism completes its cycle of operation thereby attaching the tag. When the cycle is completed and limit switch 29 is momentarily engaged, the feeder mechanism solenoid valve 82 is again operated via the chain comprising the shaping circuit 220, multivibrator 140, shaping circuit 224, driving circuit 228 and relay 230. The feeder mechanism operates until a tag is deposited in the attaching station, microswitch 120 is engaged and the feeder mechanism is returned as described hereinabove. The latch 234 is also reset by engagement of the microswitch 120 so the system is prepared for another attaching cycle.
In the above-described sequence, the multivibrator 140 is adjusted to delay the interval between completion of the attaching mechanism and a new operation of the feeder mechanism.
If manual operation has been selected, the above sequence constitutes a finished cycle since gate 206 is blocked until another pulse is received from the command switch. If automatic operation is selected by engaging switch 46 and setting latch 242, however, the pulse causing operation of the feeder mechanism as a result of triggering of the limit switch 29 also causes multivibrator 142 to produce a pulse which is used to repeat the entire attaching cycle via shaping circuit 240, gates 244 and 206. The multivibrator 142 is adjustable to control the interval between successive attaching cycles.
Thus, successive operations of the command switch 48 are not needed to initiate an attaching cycle when the automatic mode has been selected. Disengaging switch 46 causes gate 206 to be blocked again, thereby switching to manual operation and halting the operation sequence at the conclusion of the last attaching cycle.
It may be appreciated from the foregoing that many other circuit designs can be incorporated in the microprocessor to produce the desired functions and the disclosed embodiment is intended to be illustrative of just one possible design. For example, the circuitry can be replaced or altered to include transistors or operational amplifiers. Alternately, the microprocessor may be incorporated in a single integrated circuit of an appropriate design to produce the desired operation.
Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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Apparatus and method for attaching tags to garments, gloves, handbags and the like includes an assembly for feeding tags from a stacked supply to a tag attaching station, an assembly for affixing the tag to the garment at the tag attaching station, and a control network for controlling and sequencing the tag feed and tag affixing operations. The tag feeding assembly includes a mechanism for gauging the width and thickness of a tag and for adjustably accommodating the same. The assembly also includes a pair of upright arms designed so that a tag having a prepunched hole can be placed with the hole over one of the arms. The other arm may be adjusted relative to the first arm and the positioned tag so that it touches the tag edge. The adjustment of the measuring arm automatically adapts the tag feed mechanism to precisely the required distance necessary to transport the tag from the stacked supply to the tag attaching station. The sequencing and control circuit includes a solid state microprocessor having a manual mode for feeding and attaching one tag at a time and an automatic mode for continuously cycling the assembly during operation.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a doctor blade device, also called a scraper device, for machines for the coating of fibrous webs.
[0003] 2. Description of the Related Art
[0004] Devices of this type are generally known, in particular in the paper industry, for the coating of paper or cardboard or for keeping rotating rollers clean (see, for example, DE 198 41 637 A1). In this context, a leaf-shaped doctor blade or scraper element runs axially along a roller, the front end of the doctor blade element being pressed with a scraper edge against the surface of the roller. The doctor blade element is guided and held in a holding means. The holding means is generally designed to be pneumatically adjustable in the direction of the roller.
[0005] The doctor blade element is in this case mounted, for example via a multiplicity of pins, in a longitudinal groove of the holding means. When the doctor blade element, which is subjected to high wear, is exchanged, it is drawn out of the holding means laterally, that is to say axially parallel to the roller. A new doctor blade element is subsequently pushed into the holding means in the same way in the opposite direction.
[0006] This exchange has the disadvantage, however, that there are sometimes considerably difficulties in recovering the doctor blade element or scraper element from the holding means. The doctor blade element, due to operation, is often heavily soiled and is stuck to the holding means. As a result, considerable forces have to be exerted by the operator in order to pull the doctor blade element out of the holding means.
[0007] One problem, here, is that considerable sliding lengths are involved, since the length of the rollers and therefore also of the doctor blade element amounts to several meters. Furthermore, the application area for the pulling forces to be exerted is restricted to the narrow front region of the doctor blade element with which the latter projects from the holding means. Since the exchange work is carried out several meters above the floor of a scaffold or platform, there is consequently also a high risk of accidents when the exchange of the doctor blade element presents difficulties because of heavy soiling and/or stubborn sticking.
SUMMARY OF THE INVENTION
[0008] The object on which the present invention is based, therefore, is to provide a doctor blade device, in which the doctor blade element can be exchanged essentially reliably by relative simple means.
[0009] This object is achieved, according to the invention, by means of a doctor blade device for machines for the coating of fibrous webs, in particular of paper or cardboard, and for keeping rotating rollers clean, with a leaf-shaped doctor blade element which is held by a holding means and which, for a change, can be drawn out laterally on the holding means, wherein the doctor blade element is provided at least on one side with a grip part.
[0010] By virtue of the grip part according to the invention, then, a separate region or part on the doctor blade element is provided, which may be provided specially for the exchange operation.
[0011] When, in an advantageous refinement of the invention, there is provision for the grip part to be located outside the normal working range, for example in a corresponding prolongation of the doctor blade element, it can then be adapted optimally to the set object. This applies, for example, with regard to appropriate grip and size. Moreover, the most diverse possible driving and retaining members can be provided on or in the grip part in a simple way.
[0012] For example, a bore, into which a push-out tool appropriately engages with a mandrel or pin, can be introduced in the grip part in a simple way. A very reliable and positive connection is thereby afforded, with the result that, even in the case of high resistance forces which occur, for example, because of heavy soiling and resulting sticking, it becomes possible for the doctor blade element to be exchanged to be pulled out.
[0013] Conversely, of course, it is also possible for the grip part to be provided with corresponding elevations, abutments, shoulders, bosses or pins and the like, on which or in which a push-out tool can engage with a corresponding countermember, for example a lug.
[0014] In a highly advantageous refinement of the invention, there may be provision for the width of the grip part to correspond at least approximately to the width of the holding means. In this case, the front region of the doctor blade element remains unchanged for its satisfactory functioning. The region with which the grip part projects laterally from the holding means is generally fully sufficient for this region to be capable of being used as a grip part.
[0015] Further advantageous refinements and developments may be gathered from the remaining subclaims and from the exemplary embodiment described in principle below with reference to the drawing in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 shows a top view of a device with a grip part according to the invention,
[0017] [0017]FIG. 2 shows an enlarged illustration of the lateral end region of the doctor blade element or scraper element with the grip part according to the invention, in an enlargement of the detail II in FIG. 1 (without the holding means);
[0018] [0018]FIG. 3 shows a section along the line III-III in FIG. 1 in an enlarged illustration.
DETAILED DESCRIPTION
[0019] The doctor blade device has a leaf-shaped doctor blade element or scraper element 1 which is held and guided in a holding means 2 . For this purpose, the doctor blade element 1 has a multiplicity of pins 3 which extend from the underside of the doctor blade element 1 and project into a slot 4 of the holding means 2 . The doctor blade element 1 is firmly clamped in the holding means 2 in a known way. The doctor blade element 1 is pressed with a front doctor blade edge 5 against a fibrous web 7 running over a roller 6 .
[0020] To exchange the doctor blade element 1 , the latter must be drawn out of the holding means 2 laterally or axially, with respect to the-roller C, in the direction of the arrow A. For this purpose, then, the doctor blade element 1 is provided with a lateral prolongation which is designed as a grip part 8 . The grip part 8 possesses a width b which corresponds at least approximately to the width of the holding means 2 . A region a of the doctor blade element 1 , the functioning of said region being unchanged, consequently remains on the front side.
[0021] As may be seen particularly from the enlarged illustration in FIG. 2, the grip part 8 narrows outwardly toward its end to a width d. An oblique front edge 9 of the grip part 8 is thereby obtained. The rear edge 10 of the grip part 8 constitutes a prolongation of the rear edge 11 of the doctor blade element 1 .
[0022] As is clear, there is a radius R between the “normal” end of the doctor blade element 1 in its front region and the oblique front edge 9 . What is achieved thereby is greater safety against breaks which could occur due to sharp edges. This applies particularly when the doctor blade element 1 consists of a composite carbon-fiber or glass-fiber structure.
[0023] As may also be seen from FIGS. 1 and 2, the grip part 8 has a bore 12 . A push-out tool, not illustrated, can engage with a corresponding mandrel or pin into the bore 12 . A positive connection is thereby made, and consequently, when pulling forces are exerted in the direction of the arrow A, the push-out tool is reliably prevented from being capable of slipping off.
[0024] However, the bore 12 , of course, constitutes only one possibility of making a reliable connection between a push-out tool and the grip part 8 .
[0025] Further possibilities would be shoulders, elevations, pins or bolts and the like which project from the surface of the grip part 8 and consequently form corresponding engagement points for a push-out tool.
[0026] The upper and the lower surface of the grip part 8 may likewise be provided with corresponding roughenings, flutings and the like, in order to provide reliable application surfaces for a push-out tool.
[0027] The length of the grip part 8 over which the latter projects laterally from the holding means 2 may be between 40 and 100 mm. In practice, values of 60 to 90 mm, preferably 70 mm, have proved highly suitable. The width b of the grip part 8 may be between 40 and 50 mm.
[0028] In order to achieve a very good force profile or force distribution, in conjunction with the radius (R), it is advantageous if the final width d of the grip part 8 amounts approximately to half the initial width b. In the exemplary embodiment, this means that the width b is between 15 and 25 mm, preferably approximately 20 mm.
[0029] The front free or unchanged region a of the doctor blade element 1 should generally be between 30 and 40 mm, so that the doctor blade edge 5 of the doctor blade element 1 can be reground more than once.
[0030] By the grip part 8 being arranged and formed outside the normal working range of the doctor blade element 1 , the work of the latter is not impaired by the grip part 8 . On the other hand, a substantially higher accident safety is achieved by means of the grip part 8 , along with a marked simplification in a change in the doctor blade element 1 . This applies particularly to heavily soiled doctor blade elements 1 , since substantially higher pulling forces can be exerted with a push-out tool by virtue of the grip part 8 and of the positive connection made in this way.
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A doctor blade device for machines for the coating of fibrous webs, in particular of paper or cardboard, and for keeping rotating rollers clean has a leaf-shaped doctor blade element ( 1 ) which is held by a holding means ( 2 ) and which, for a change, can be drawn out laterally on the holding means ( 2 ). The doctor blade element ( 1 ) is provided at least on one side with a grip part ( 8 ).
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BACKGROUND OF THE INVENTION
[0001] The invention generally relates to interventional or surgical procedures, specifically relating to interventional cardiology and other intra-luminal procedures. The invention more particularly concerns a valve mechanism that allows modulation of pressure within a balloon or expandable member attached to, or otherwise located thereon, of a guide-wire or other catheter-like instrument.
[0002] The use of a balloon attached to the end of a guide-wire is not new, see for example U.S. Pat. Nos. 6,251,084 (Coelho), and 4,790,813 (Kensey). In this arrangement, the guide-wire is actually a small diameter tube, with the lumen therethrough serving to allow fluid to be injected, and with the fluid being an agent used to expand the balloon.
[0003] The balloon may serve various functions (e.g., locating and/or securing the wire or associated device within the artery, securing a wire within a catheter, or blocking the distal flow of fluid and/or debris created during one or more of the procedures).
[0004] The balloon/guide-wire system may be used in various types of therapeutic and/or diagnostic procedures (e.g., percutaneous transluminal angioplasty, stent placement, the placement of ultrasonic or other diagnostic instruments, and the placement of thrombectomy devices, etc.). During the procedure several catheters or elongate instruments (together “catheters”) may be used sequentially, with the same guide-wire. Inserting instruments over, or alongside, a single guide-wire saves procedural time, since only one guide-wire would need to be placed. This approach may also improve safety, and reduce chance of infection, etc.
[0005] Inserting a plurality of catheters, whether singularly or concurrently, requires the catheter(s) to be placed over the proximal end of the guide-wire. Where the guide-wire is arranged with a balloon at or near the distal end, the catheter(s) would need to be passed over any valve located at the proximal end of the guide-wire.
[0006] Multiple catheters are commonly used when, for example, a physician performs an angiogram or other diagnostic procedure, and then decides to perform angioplasty or other therapeutic procedure or other interventional procedure. Most interventional procedures will require the placement of a guide wire for the subsequent delivery of the interventional instruments, and more recently some guide wires incorporate distal balloons to protect the distal tissues from debris generated during those same procedures. Since treatment and diagnostic procedures are becoming more commonplace, and the advancements in each of these technologies have led to procedures using even more catheters. These catheters are continually getting smaller, which allows the physician to reach tighter arteries and lumens within the body.
[0007] For distal protection to be effective the balloon must remain inflated as catheters are exchanged over the guide wire. This necessitates a small diameter valve, which some refer to as a low-profile valve. Self-sealing valves have previously been disclosed; see for example U.S. Pat. Nos. 3,477,438 (Allen, et al.), 3,495,594 (Swanson), 3,837,381 (Arroyo), and 4,752,287 (Kurtz, et al.). These valves are commonly made from elastic (Allen, et al., and Kurtz, et al.) or resilient (Swanson) materials, and may require pressure in the system to operate (Arroyo). The properties of these valve materials, together with their operational pressures, require various of these valves to have large sealing areas. This does not facilitate the design of smaller catheters. Additionally, the valves would ideally operate over a wide range of pressures; including positive and negative pressures.
[0008] Check valves have also been disclosed, see for example U.S. Pat. No. 4,653,539 (Bell), however these are directional valves, and therefore will not operate in both positive and negative pressure environments. Employing a vacuum in the system during navigation will facilitate the securing of the balloon to the guide-wire, that is, the balloon will stay folded or otherwise securely pressed against the side of the wire. This may allow the system to navigate tighter vessels or lumens. However, check valves, such as the one disclosed by Bell, do not meet this bi-directional operation need. Additionally, this type of valve, as well as the previously described self-sealing valves, require a syringe or special instrument to allow evacuation around the valve's sealing surface. These syringes or needles must be in-place during the entire evacuation procedure, or the valve will cease the fluid flow. This opens the systems up to situations where malfunctions or equipment breakage may yield an inserted and expanded balloon, which may not readily be collapsed. A system is needed that will allow evacuation without the application of vacuum or other specialized components.
[0009] In addition to these stated concerns, the length of time required to complete the procedure is affected by these valves. This procedure time is of concern because of escalating medical costs, as well as the stress on the patient. These valves must allow rapid infusion and evacuation of balloon-filling fluids.
[0010] Yet another low profile catheter valve, designed to fit small diameter catheters to navigate small pathways within the body such as blood vessels and ducts, is disclosed in U.S. Pat. No. 4,911,163 (Fina). A syringe is attached to the proximal end of an elongated tubular conduit (e.g. catheter) and used to inflate a distal balloon. Once the balloon is inflated, the catheter is clamped at the proximal end, the syringe is removed, and a plug is inserted into the lumen of the catheter, and then the clamp is removed. The plug is retracted and reinserted to adjust the balloon inflation volume as needed, using this same multi-step procedure. Needless to say, this type of valve is tedious to handle and the need for a separate clamping system further complicates the procedure and may potentially damage the catheter. Certainly the clamping pressures are very high, in order to totally collapse the circular catheter bore such that fluid will not leak (until the plug is inserted). Reinflating the balloon would also cause integrity problems if the catheter were reclamped at the same location.
[0011] Another such low profile catheter valve is disclosed in U.S. Pat. No. 6,325,778 (Zadno-Azizi, et al.). This valve features a needle which is inserted coaxially with the guide-wire, wherein the needle is arranged to cover a fluid outlet port. The rate of balloon inflation and collapse is limited by the rate at which gas leaves the fluid outlet port. Since the fluid outlet port is radially outward from the guidewire's longitudinal axis, its size is geometrically constrained; that is, the larger diameter of the port, the less strength the guide-wire has. Since the guide-wire must withstand significant bending and torsional stress during the procedure, the port must be significantly less than the inside diameter of the guide-wire, thereby limiting the rate of evacuation of the balloon-filling fluid.
[0012] This slow evacuation phenomenon may have been recognized by Coelho, as the disclosure prescribes a vacuum to collapse the balloon. Indeed, the tortuous path in the orifice of the Coelho device, through which the balloon inflation fluid is evacuated, must be nearly as small as the one disclosed by Zadno-Azizi. Here, the orifice must be considerably smaller than the inside diameter of the guide-wire, because the path of fluid escape is through a self-sealing valve; and the valve must have sufficient integrity to cause a seal against itself, after an evacuation needle is withdrawn.
[0013] A valve which may utilize the overall inside diameter (or bore) of the guide wire is disclosed in U.S. Pat. No. 5,807,330 (Teitelbaum). The two basic concepts disclosed by Teitelbaum are a valve that is basically an insert with threads, wherein the threads secure the valve in the proximal end of the guide-wire; and an insert with a press-fit geometry, that is pressed into the proximal end of the guide-wire. Both of these concepts suffer similar shortcomings.
[0014] The threaded insert requires extremely fine threads, which are expensive and tedious to manufacture even before considering the limited wall thickness of the guide-wire available for threading (perhaps only a few thousandths of an inch). Additionally, it is extremely difficult to align small threaded parts of this sort, which leads to misalignment and cross-threading. This problem would be especially prevalent where the same valve was actuated more than once during the same procedure—a common occurrence.
[0015] The press-fit geometry requires parts of very tight tolerance, which are also tedious and expensive to produce. Press-fit components are normally manufactured for mechanical support, but press-fitting to cause a gas impermeable seal is possible; however, the insert would require an extremely uniform surface, which mates exactly with the inside surface at the proximal end of the guide-wire. It is this guide-wire surface which poses great manufacturing challenges.
[0016] Boring or machining the inside surface of the guide-wire is very challenging because of the fine wall thickness—perhaps only a few thousandths of an inch. Machining of this component may produce irregular wall thinning, since no tube inside and outside is truly concentric, which could lead to premature failure.
[0017] The aforementioned threaded and press-fit concepts disclosed by Teitelbaum both suffer manufacturing challenges as well as economic disadvantages. Finally, they have features that may lead to premature failure, necessitating removal of the device, following by re-insertion of a new balloon/guide-wire assembly.
[0018] It is the intent of the embodiments of the present invention to overcome these and other shortcomings of the prior art.
SUMMARY OF THE INVENTION
[0019] These and other objects of this invention are achieved by providing a valve mechanism for inflating and deflating a balloon or other expandable member on a guide-wire or catheter (e.g., at or near the distal end of a guide-wire), such that while the balloon is inflated, the proximal end of the wire would have a low profile and would not interfere with the use of other interventional devices using over-the-wire technique or rapid exchange systems. The system basically consists of detachable tools, one each for inflation and deflation of the balloon; additionally the inflation tool features in a preferred embodiment a gripping means, an inflating means, and a sealing means.
[0020] The inflation tool serves the functions of gripping and releasing the guide wire proximal end; providing a means of modulating the pressure inside the guide wire resulting in balloon or expandable member inflation; and applying a deformable plug into the bore of the guide wire.
[0021] In use, the proximal end of the guide wire is inserted into a chamber of the inflation tool; pressure is introduced via the inflation means thereby inflating the balloon or expandable member. The detachable inflation tool inserts a malleable plug in the proximal bore of the guide wire, thereby avoiding the need for costly machining and stringently tight tolerances of other devices, in order to maintain pressure within the guide wire upon the detaching the inflation tool. The sealing means prevents the escape of fluid (e.g., gas or liquid) from the guide wire for the duration of the procedure, or until release of pressure becomes necessary.
[0022] The deflation tool serves the function of relieving the pressure in the balloon or expandable member of the guide wire, by piercing the sealing means in the proximal bore of the guide wire, and upon tool removal allows the fluid contained therein to escape. The valve mechanism herein described allows repeated inflation and deflation of the catheter or guide wire, by engaging the appropriate inflation or deflation tool.
DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a sectional view of one design of tool for applying the sealing plug.
[0024] FIG. 2 is a perspective view of the sealing plug holding rod.
[0025] FIG. 3 is a perspective view of the cam sleeve.
[0026] FIG. 4 is a sectional view of the deflation needle tool prior to application.
[0027] FIG. 5 is a sectional view of the deflation needle tool during application.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Description of Inflation Tool
[0028] The preferred embodiment tool shown in FIGS. 1, 2 and 3 , performs various functions, including but not limited to:
a) Gripping and releasing the guide wire proximal end; b) Inflating the balloon on the distal end of the guide-wire, or placed somewhere therealong; and c) Applying a sealing member in the proximal bore of the guide wire.
[0032] These various device embodiments comprise sealing means, gripping means, and inflation means; while a separate device features deflation means. It is recognized that the device arranged for deflation may be attached to the device arranged for inflation (for convenience), although they may not share any componentry other than structural or housing. Additionally, it is contemplated by this invention that an inflation device or “inflation tool” may not necessarily comprise each of a gripping means, an inflation means, and a sealing means. As a non-limiting example, it is recognized that the inflation means may be a traditional syringe (where the inflation device was arranged to accept same). It is also recognized that the gripping means may be useful to perform other functions (e.g., gripping tubes at diagnostic and/or therapeutic equipment inlet ports, e.g., those found on bypass and dialysis machines.)
[0033] Referring now to FIGS. 1, 2 , and 3 , describing a preferred embodiment of the inflation tool, wherein like numbers indicate like components. A preferred gripping means is disclosed, wherein a tubular guide wire 12 , enters bore 37 in shaft 18 and passes through deformable member 19 , through pierceable diaphragm 20 , into cavity 21 , and stops against the face 23 A of rod 23 . Shaft 18 is slidably mounted in bore 41 of housing 28 , and, driven proximally (relative to the guide-wire 12 ) by spring 16 , thereby compressing deformable member 19 against the tapered bore 40 in housing 28 . Pierceable diaphragm 20 is an intact disc until pierced by the entering tubular guide wire 12 , the purpose of the diaphragm being to capture a charge of fluid (e.g., CO 2 or saline) in cavities 45 , 21 , and channel 35 , prior to the piercing by the guide-wire 12 . Axial compression of the deformable member 19 results in the tubular guide wire 12 being gripped as the deformable member is moved radially inward by the taper 40 . An alternative to the pierceable diaphragm for retaining the charge of fluid in the cavity 21 and 45 is to ship the assembly with a smooth mandrel gripped in the deformable member 19 (not shown).
[0034] In a preferred embodiment, the gripping means further features an insertion-release means, wherein the shaft 18 can be driven distally (relative to the guide-wire 12 ) by movement of lever 15 which, pivoting on pin 14 , moves the cone 13 attached to shaft 18 . Thus movement of the lever 15 radially inward relieves the pressure on the deformable member 19 and hence releases the guide wire 12 (the same feature may also be used in reverse, to assist the entry of the guide-wire into the device, as will be described later).
[0035] In a preferred embodiment the inflation tool features a sealing means, with the sealing means arranged to deliver a sealing member material into the guide-wire to effect a seal, as will be described later. In this embodiment, the sealing means is preferentially located at the proximal end of the device, wherein there exists a mounted rod 23 which can move axially and rotationally in bore 21 A of housing 28 . Rod 23 is driven distally by spring 25 acting through flange 24 and is restrained by arm 26 coming in contact with one of the grooves 42 or 43 . An O-ring seal 29 seals rod 23 against bore 21 A. A sealing member material 22 is inserted in an off center bore in rod 23 . Surface 23 A of rod 23 is striated with grooves (not shown) to permit flow of fluid into the bore of tubular guide wire 12 .
[0036] In a preferred embodiment the sealing member material is made from a plastically deformable or inelastic material, wherein such material may comprise organic and/or inorganic material. It is recognized that various materials may be suitable for this application, and the totality of material properties (e.g., strength, ductility, thixotropy, toughness, malleability, hysteresis, adhesiveness and fluid permeability, etc.) may reveal several good candidates.
[0037] In a preferred embodiment the inflation tool features inflation means. At the lower portion of FIG. 1 is shown a preferred embodiment of the inflation means, comprising an inflation syringe 44 , wherein the syringe contains a barrel 30 arranged to be attached to body 28 using adhesive or a threaded joint (not shown). The charge of fluid is pre-charged into cavities 45 , 21 and 35 . A piston 31 attached to a plunger 32 drives fluid (gas or liquid) from chamber 45 via channel 35 into chamber 21 and thence into tubular guide wire 12 . Another preferred embodiment additionally features a latch 33 fastened to barrel 30 , wherein the latch 33 engages flange 34 after the plunger has been moved inward to deliver the fluid. The latch serves to prevent the piston and plunger from being driven back by the pressure trapped in cavity 21 (etc.) and balloon 11 .
Description of Inflation Tool Use
[0038] A preferred embodiment inflation tool includes the gripping, inflation, and sealing means in combination, and allows the operator to hold the assembly 1 in one hand and with the thumb and fore-finger to squeeze the lever 15 toward the body 28 thus moving shaft 18 distally and relieving pressure on the deformable member 19 . The guide wire 12 is then inserted into shaft 18 , centralized by the tapered inlet 38 , passed through the deformable member 19 , to pierce the diaphragm 20 and come to rest against rod 23 at surface 23 A. Chamfers at 39 and 36 further aid in centralizing the guide wire. Surface 23 A of rod 23 is striated with fine grooves (not shown) to permit flow of fluid into the bore of tubular guide wire 12 . When the guide wire has bottomed on surface 23 A, the user releases the lever 15 , whereupon the shaft 18 is propelled to proximally and deformable member 19 is placed in compression. In turn this action, through taper 40 , causes the deformable member 19 to grip the guide wire 12 securely.
[0039] In a preferred embodiment, the position of the guide wire may be confirmed visually by viewing the location via the lens 46 built in to a clear plastic housing 28 . Alternatively, if the housing is made from an opaque material the viewing lens 46 can be inserted in a tunnel as a separate component (not shown).
[0040] In yet another embodiment, the correct position of the guide wire 12 can alternatively be ascertained by observing the location of a contrasting band of color 60 , formed on the guide wire 12 , relative to the entrance 61 of shaft 18 .
[0041] Now returning to the preferred combination embodiment, the plunger 32 and attached piston 31 are then driven inward to propel the fluid in cavity 45 through channel 35 into cavity 21 and thence through the bore of guide wire 12 into the balloon 11 . In the case where gas is used to inflate the balloon, the plunger 32 may be driven to the bottom of the bore and allowed to return to a position controlled by flange 34 and latch 33 . This over-compression of the gas permits the initial pressure to be high to overcome the balloon resistance but drops the pressure as the balloon reaches full size, thus reducing the tendency to overpressure the vessel (not shown) in which the balloon is residing.
[0042] With the balloon 11 inflated in the vessel, the arm 26 is rotated 180 degrees in this example (but any other angle would work with slots 42 & 43 placed differently) so that rod 23 revolves to place the sealing material 22 to a position opposing the guide wire 12 . Then spring 25 urges rod 23 distally and drives the sealing material 22 into the open end of tubular guide wire 10 thus trapping the fluid in the guide wire and balloon. A plug 50 of sealing material 22 , is driven into the bore of the tubular guide wire 12 , as shown in FIG. 4 .
[0043] At this point the lever 15 is again pressed inward radially and the guide wire is removed from the device, and the wire is ready for the rest of the interventional procedure, which might involve the passage of angioplasty balloons, stent balloons, diagnostic ultrasound, or other procedure requiring a balloon protected or anchored guide wire with the balloon inflated.
Description of Deflation Tool
[0044] Referring to FIGS. 4 and 5 , a preferred embodiment of the deflation tool 56 is basically constructed from four elements, a handle 51 , a tube 54 , a spring 52 , and a needle 53 . The handle has a bore 57 of about 0.016 inch diameter, a little larger than the outside diameter of the guide wire 12 which is typically 0.015 inch, and has a lead in taper 55 to allow the operator to easily locate the bore 57 .
[0045] The proximal end (relative to the user's hand while utilizing the tool) of the needle 53 is held centrally in the bore 57 by tube 54 . Tube 54 , together with the needle 53 , and the handle 51 can be assembled together by any convenient means, including but not limited to welding, using an adhesive, or a crimping operation. The needle is approximately 0.005 inch in diameter in this embodiment, and is supported by the spring coils 52 to prevent the needle from being bent during use and to align the distal end (relative to the user's hand while utilizing tool) of the needle on the centerline of the bore 57 . The length of the plug 50 of sealing member material 22 (see FIG. 1 ) in the proximal end of the guide wire 12 is preferably about 0.030 inch long axially, although other dimensions may be more suitable depending on the composition of the sealing material and the pressure at which the balloon requires. The guide wire outside diameter 59 is typically 0.015 inch and the bore 58 can typically range from 0.011 inch to 0.005 inch. The needle needs to be sufficiently large to provide a bore through the plug 50 that it will allow the balloon to be deflated rapidly, but not so large that the plug 50 is smeared along the bore 58 too far to require a very long needle. It has been found that a 0.005 inch diameter needle permits deflation times that are acceptable (less than 30 seconds), utilizing a 0.007 inch diameter guide wire bore. Clearly these dimensions are examples only and could be adjusted to accommodate guide wires or catheters of different diameters.
[0046] The deflation tool embodiment described can be used multiple times, but it is unlikely that the operator will ever need to inflate and deflate the balloon more than 5 times in a procedure. The needle 53 is therefore preferably required to penetrate several times the length of the plug 50 into the guide wire bore 58 for this to be achieved.
Description of Deflation Tool Use
[0047] The operator inserts the proximal end of the guide wire 12 into the lead taper 55 of the deflation tool 56 compressing the spring 52 to the fully compressed condition. The plug 50 is pierced as shown in FIG. 5 , and smears into an elongated tubular shape 62 concentric to the bore 57 . The balloon 11 (see FIG. 1 ) then deflates due to its inherent elastic recovery, and/or vacuum can be applied to the tubular guide wire 12 by syringe or other means (neither shown) to accelerate the deflation time. The tool is then removed and is available for any subsequent use.
[0048] Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive, by applying current or future knowledge. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
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An apparatus for modulating the pressure of a fluid such as a gas within the expandable portion of a guide wire catheter. A preferred embodiment apparatus features a means for controllably gripping and releasing the open, proximal end of a tubular guide wire, means for introducing a fluid to a desired pressure and volume into the expandable portion of the tubular guide wire through the open end, and, while maintaining the pressure and volume of fluid in the tubular guide wire, a means for introducing a sealing member into the open end of said tubular guide wire to seal the fluid in the tubular guide wire. In a particularly preferred embodiment, the apparatus also features a deflation tool for piercing the seal and letting the fluid out. Using this apparatus, the tubular guide wire can be re-sealed and re-opened as necessary.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application 61/594,248 filed on Feb. 2, 2012 which is hereby incorporated herein by reference.
TECHNICAL FIELD
This disclosure relates to segmenting digital images, and more particularly to image segmentation using parallel processing.
BACKGROUND
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Image segmentation is a branch of digital image processing that performs the task of categorizing, or classifying, the elements of a digital image into one or more class types. The class types can correspond to objects within an image. Classifying elements in a digital image has permitted a new understanding of biology, physiology, anatomy, as well as facilitated studies of complex disease processes and medical diagnostic purposes in clinical care settings. Modern medicine and clinical care are particularly poised to benefit from greater imaging capabilities.
Initial volumetric images from may be provided from known imaging devices such as X-ray computed tomography (CT), magnetic resonance (MR), 3-D ultrasound, positron emission tomography (PET) and many other imaging devices. The imaging device typically provides a 3D image data set from which to perform image segmentation in typical medical imaging applications with the classification types related to anatomical structure. For example, in thoracic medical images, it is convenient to segment the image voxels into classes such as bone, lung parenchyma, soft tissue, bronchial vessels, blood vessels, etc. There are many reasons to perform such a task, such as surgical planning, treatment progress, and patient diagnosis.
Various known analytical techniques are utilized to perform image segmentation. One known technique includes analyzing 3-D medical images as sequences of 2-D image slices that form the 3-D data. This is undesirable as contextual slice-to-slice information is lacking when analyzing sequences of adjacent 2-D images. Performing the segmentation directly in the 3-D space tends to bring more consistent segmentation results, yielding object surfaces instead of sets of individual contours. 3-D image segmentation techniques—for example, techniques known by the terms region growing, level sets, fuzzy connectivity, snakes, balloons, active shape and active appearance models—are known. None of them, however, offers a segmentation solution that achieves optimal results. The desire for optimal segmentation of an organ or a region of pathology, for example, is critical in medical image segmentation.
Recently, graph-based approaches have been developed in medical image segmentation. A common theme of these graph-based approaches is the formation of a weighted graph in which each vertex is associated with an image pixel and each graph edge has a weight relative to the corresponding pixels of that edge to belong to the same object. The resulting graph is partitioned into components in a way that optimizes specified, preselected criteria of the segmentation.
For example, one known technique adaptively adjusts the segmentation criterion based on the degree of variability in the neighboring regions of the image. The method attains certain global properties, while making local decisions using the minimum weight edge between two regions in order to measure the difference between them. This approach may be made more robust in order to deal with outliers by using a quintile rather than the minimum edge weight. This solution, however, is computationally complex, making the segmentation problem Non-deterministic Polynomial-time hard (NP-hard).
Additionally, many 2-D medical image segmentation methods are based on graph searching or use dynamic programming to determine an optimal path through a 2-D graph. Attempts extending these methods to 3-D and making 3-D graph searching practical in medical imaging are known. An approach using standard graph searching principles has been applied to a transformed graph in which standard graph searching for a path was used to define a surface. While the method provided surface optimality, it was at the cost of significant computational requirements.
A third class of graph-based segmentation methods is known to utilize minimum graph cut techniques, in which a cut criterion is designed to minimize the similarity between pixels that are to be partitioned. The approach, however, was biased towards finding small components. The bias was addressed later by ratio regions, minimum ratio cycles, and ratio cuts. However, all these techniques are applicable only to 2-D settings. Considering the self-similarity of the regions and captures non-local properties of the image, a novel normalized cut criterion for image segmentation was developed. Recently, it has been shown that Eigen vector-based approximation is related to the more standard spectral partitioning methods on graphs. However, all such approaches are computationally impractical for many applications.
Recently, energy minimization frameworks that utilize minimum s-t cuts to obtain medical image segmentation. Some embodiments consider non-convex smooth priors and developed heuristic algorithms for minimizing the energy functions. Cost functions may be utilized including those employing the “Gibbs model.” Interactive segmentation algorithms for n-dimensional images based on minimum s-t cuts was further developed. In some cases, a cost function used is general enough to include both the region and boundary properties of the objects.
When applied to graphs, the minimum s-t cut produces a partition of the graph at a mathematical optimal partition of two parts. There are many algorithms that have been developed to perform the minimum s-t cut of a graph. To date, the algorithms that have proven to have the greatest execution speed for performing the minimum s-t cut involve the simulation of flow through an analogous transportation or communication network. In this analogy, the weights of the edges of the graph are considered to be maximum allowable flows. A relatively new approach to the computation of the minimum s-t cut involves the use of numerical operations. Algorithms that use numerical operations for obtaining the minimum s-t cut or an approximation to the minimum s-t cut have been developed based on the linear programming methods.
Like other graph-based approaches, the energy minimization framework utilizing s-t cuts is fairly computationally complex when utilized in medical applications. Therefore, a need exists to more efficiently execute image segmentation using an energy-based framework utilizing s-t cuts.
SUMMARY
Method and system is disclosed for image segmentation. The method includes acquiring a digital image, constructing a graph from the digital image, calculating a plurality of cost functions, constructing an electrical network based upon the constructed graph and the plurality of calculated cost functions, simulating the electrical network using fixed-point linearization, and segmenting the image using the simulated electrical network to produce segmented layers. Fixed-point linearization may be executed in parallel to achieve desirable computational efficiencies.
The minimum s-t cut can theoretically be modeled by construction of an analog electrical network that naturally assumes a binary-voltage state equivalent to the minimum s-t cut. The fundamental unit of the analog electrical network is a non-linear resistive device with a current-limiting characteristic. An algorithm is presented here for computational simulation of such an analog network as a basis for segmentation of medical images. The solution to the governing system of equations is obtained by the fixed-point method that allows for linearization of the system of equations. In certain embodiments the use of Ruge-Stuben algebraic multigrid for solution of the linear system of equations may be utilized at each iteration.
This summary is provided merely to introduce certain concepts and not to identify key or essential features of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 schematically shows a flowchart of a segmentation algorithm, in accordance with an embodiment the present disclosure;
FIGS. 2A-2E depicts a series of exemplary images illustrating an exemplary application of the simulated s-t cut approach to a random-intensity image, in accordance with an embodiment of the present disclosure;
FIG. 3 graphically shows a simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the exemplary random-intensity image, in accordance with an embodiment of the present disclosure;
FIGS. 4A-4E depicts a series of exemplary images illustrating an exemplary application of the simulated s-t cut approach to a magnetic resonance image, in accordance with an embodiment of the present disclosure;
FIG. 5 graphically shows results of the simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the exemplary magnetic resonance image, in accordance with an embodiment of the present disclosure;
FIGS. 6A-6E depicts a series of exemplary images illustrating an exemplary application of the simulated s-t cut approach to a computed tomogram image, in accordance with an embodiment of the present disclosure;
FIG. 7 graphically shows results of the simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the exemplary computed tomogram image, in accordance with an embodiment of the present disclosure; and
FIG. 8 schematically shows an exemplary computing system in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
Various embodiments of the present invention will be described in detail with reference to the drawings, where like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the claimed invention.
Referring now to the drawings, wherein the depictions are for the purpose of illustrating certain exemplary embodiments only and not for the purpose of limiting the same, FIG. 1 schematically shows a flowchart of a segmentation algorithm according to an exemplary embodiment. The algorithm begins at step 105 by acquiring an n-dimensional digital image from an imaging scanner. For the purposes of this application, an image is any scalar or vector function on n-dimensional coordinates. The image may be two-dimensional, and/or three-dimensional. The digital image may be provided by any one of a number of known imaging devices including medical-based imaging device such as a magnetic resonance image, a computed tomography image, an optical coherence tomography image, or an ultrasound-originating image. It is to be appreciated that imaging, for use in embodiments of the present disclosure, can be achieved utilizing traditional scanners or any other image acquisition technique as would be appreciated by those having ordinary skill in the art.
A graph is constructed at step 110 from the n-dimensional image or, in one embodiment, a series of images. Each pixel i.e., point, of said image is associated with a vertex of said graph and said graph includes an edge connecting each pair of vertices corresponding to adjacent points in said image. The graph may be defined as G=(V, E) with V representing a set of vertices of a graph, and E representing a set of edges of a graph such that every pixel u or v has a corresponding vertex.
In one embodiment, limited segmentation may be performed by a user-operator 115 . The limited segmentation, or initial segmentation, may be outputted to an electrical network 120 and defined as sets of vertices S 0 and T 0 each having member nodes s and t. In one embodiment, limited segmentation may be optionally performed by assigning foreground and background seeds, either interactively or automatically by acquiring landmarks that belong to the foreground/background.
A weight W representing a sum of the weights of the edges that define the partition obtained by a minimum s-t cut, may be calculated and inputted into the electrical network 120 . As one skilled in the art will readily recognize, the minimum s-t cut can be a utilized to identify two components of graph partitioning. As used herein, an s-t cut is defined with respect to two nodes, s and t, of a weighted, directed graph G=(V,E). Thereby, a partition of the vertices of a graph that defines the partition obtained by the minimum s-t cut may be represented by:
C v =( S,T ) [1]
given:
sεS,tεT and S∩T=φ,S∪T=V [2]
the s-t cut may be defined as a set of edges, C E , as:
{( i,j )ε C E |iεS,jεT} [3]
wherein C V is a partition of the vertices of a graph that defines the partition obtained by the minimum s-t cut, S and T are sets of vertices from the graph G that, respectively, have members s and t, C E is a subset of the edges in the graph G the defines the partition obtained by the minimum s-t cut, and i and j are vertices in the graph or nodes in the corresponding simulated electrical network as described herein below.
Given that each edge of the graph has an associated non-negative weight, w, the weight the s-t cut is the sum of the weights W of the set of edges of the cut. The sum W may be determined by:
W = ∑ C E w ij [ 4 ]
wherein w ij describes the weight of the edge (i,j).
As one skilled in the art will readily recognize, preferential partitioning of the graph can thus be formulated by obtaining the minimum-weight s-t cut. Algorithms for obtaining the minimum s-t cut can be developed based on the flow-network analogy in which the maximum allowable flow, or capacity, between a pair of nodes is equated with edge weight. In this analogy, if a flow pattern in the network is consistent with the capacities of all edges in the network and if an s-t cut can be formed from the set of edges in which the flow is equal to the capacity, the s-t cut is minimal, according to the Ford-Fulkerson theorem.
One method for obtaining the minimum s-t cut is by iteratively applying a push-relabel operation in which flow, or push, is constrained to occur only in a descending manner with respect to the node labels. The labels are an estimate of distance from a given node to the sink along edges with non-zero residual capacity. The computation time for the minimum s-t cut algorithms may vary depending on the graph. Algorithms in this class have obtained worst-case computational complexities of O(nm log 2+m/(n log n) n) and O(min{m 1/2 , n 2/3 }m log(n 2 /m)log u max ) where the graph has n nodes, m edges and a maximum edge weight or flow capacity of u max .
An algorithm based on a linear-resistor electrical network model can be developed that allows for approximation of the minimum s-t cut with a (1+ε) approximation ratio. The approximate minimum s-t cut is obtained by modulation of the resistances in the network to obtain flow solutions that satisfy the maximum-flow constraints. The solution is obtained based on a near linear-time algorithm for the approximation to the solution of the system of linear equations associated with the linear-resistor network. The computational complexity of the algorithm is Õ(m+n 4/3 ε −8/3 ) where Õ(n)=O(n log c n) for an unspecified constant c.
A method for physically obtaining the minimum s-t cut for an undirected graph can be been developed. The method is to fabricate a non-linear resistive network where each resistive element represents an edge of the graph. The non-linear resistive network will naturally approach a binary-voltage state corresponding to the minimum s-t cut of the graph as the input voltage applied between the source and sink nodes approaches infinity. To obtain this behavior, the resistive elements must have the following characteristics: the current through the resistor is a non-decreasing function of the voltage across the resistor, and for a given voltage polarity, the current through the resistor is equal to or asymptotically approaches the flow capacity in the direction of the voltage polarity of the corresponding graph edge, as the voltage across the resistor approaches infinity.
Subsequent to receiving the graph-based information which may be represented as G=(V, E, W), an analog electrical network may be generated at block 120 based upon the graph-based information. In one embodiment, an analog electrical network is formed by a set of non-linear resistors that represent the edges in a given graph. To simulate the electrical network, the current-voltage characteristic of the resistors must sufficiently align with or satisfy the Frisch criteria described herein above. The following function provides valid current-voltage behavior:
I ij ( x ) = w ij ( x i - x j ) 1 + x i - x j [ 5 ]
wherein x=(x 1 , . . . , x |V| ) is a vector of voltages at the nodes in the network, i and j are vertices in the graph or nodes in the corresponding simulated electrical network, w ij represents the weight of the edge at (i,j), and I ij is a function representing the current between each pair of nodes in the simulated electrical network.
The electrical network is thus described by a non-linear system of equations where source and sink nodes are set to the high and low input voltages respectively and voltages at the remaining nodes are governed by Kirchhoff's current law:
F ( x )= b [6]
where F=(f 1 , . . . , f |V| ) and:
f
i
(
x
)
=
{
x
i
i
∈
{
s
,
t
}
∑
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∈
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i
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ij
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x
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i
∈
V
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{
s
,
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[
7
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Wherein the vector b=(b 1 , . . . , b |V| ) represents the input conditions:
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i
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=
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-
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8
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The system of non-linear equations [6] can be rewritten in the following form:
A ( x ) x=b [9]
wherein A is an |V|×|V| matrix of functions with the following non-zero elements:
a ij ( x ) = { 1 i , j ∈ { s , t } , i = j - 1 × I ij ( x ) x i - x j i , j ∉ { s , t } , i ≠ j ∑ j ∈ Ω i I ij ( x ) x i - x j i , j ∉ { s , t } , i = j [ 10 ]
wherein |V| is a number of vertices in the graph or the number of nodes in the simulated electrical network, and x as described herein above, is a vector representing the voltages at particular nodes, e.g., i or j, in the simulated electrical network.
A solution can then be obtained in an iterative manner. The following fixed-point linearization approach preferably requires the solution of a linear system of equations at each iteration:
A ( {tilde over (x)} k ) {tilde over (x)} k+1 =b [11]
wherein {tilde over (x)} k is a vector representing the approximate voltage at all nodes in the simulated electrical network at the k th fixed-point iteration.
In the solution to the equations governing the system of non-linear resistors, voltage gaps between adjacent nodes represent the degree to which the flow between the two nodes has saturated or reached its limiting flow capacity. In the limit, the voltage assumes a state in which it is homogeneous within each of two regions connected to the source and sink, respectively, and a voltage gap equal to the input voltage occurs along the minimum s-t cut. An approach to determining the minimum s-t cut from the simulation is to use a graph cut based on thresholding of the voltage at step 130 as shown in FIG. 1 . Such a cut based on the simulation of the non-linear resistive network is represented by: C k simulation =(S k simulation , T k simulation ), where:
S k simulation ={i|{tilde over (x)} k,i ≧0} and T k simulation ={i|{tilde over (x)} k,j <0} [12]
wherein C k Simulation is a partition of the vertices of a graph that is obtained by thresholding of the voltages in the simulated electrical network, S k Simulation is a sub-set of the vertices of the graph that is obtained by thresholding of the voltage in the simulated electrical network that contains the vertex s, and T k Simulation is a sub-set of the vertices of the graph that is obtained by thresholding of the voltage in the simulated electrical network that contains the vertex t.
The minimum s-t cut has significant potential value for image segmentation. In one approach, image segmentation can be formulated as the detection of an optimal boundary that lies between two user-defined regions or sets of pixels U 0 and V 0 . Given a segmentation of the images described by:
A =( U,V ) [13]
and where:
U 0 ⊂U,V 0 ⊂V and U∩V=φ,U∪V=P [14]
where P is the set of pixels in the image, a boundary B can be defined as a set of all pairs of pixels as follows:
B={ ( u,v )ε U×V∥r ( u )− r ( v )|< d} [15]
wherein the function r is the position of a given pixel, and d is distance threshold between any given pair of pixels below which the pixels are considered to be adjacent.
The cost of a given boundary can be defined in terms of the pair of image intensities, g, of each pair of pixels along the boundary:
C
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∈
B
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[
16
]
In this formulation of image segmentation, the minimum-cost boundary is equivalent to the minimum s-t cut in the analogous graph. As such, the weight of the edges in the analogous graph is the cost function associated with pairs of pixels.
As one skilled in the art will readily recognize, various image thresholding techniques and pixel conditioning processes may be allied to the image. In one embodiment, one or more filters may be applied to an image including filters based upon pixel thresholding such as variance in pixel color intensity. In one embodiment, pixels are removed or conditioned from the image when an associated pixel color intensity value is greater than a predetermined threshold. For pixels associated with multiple colors, a pixel color intensity of any particular color that varies greater than the predetermined threshold may be removed from the image. In one embodiment, an analysis of pixel intensity changes occurring between or among a sequence of images may be used. For example, pixels associated with a pixel color intensity that changes greater than a predetermined threshold from the sequential images may be removed from the image. In one embodiment, pixels associated with identified edges or transitions in visual data may be removed or conditioned. For example, pixels having color intensity values that correspond to edges using one of several known edge detection filters, e.g., a Sobel filter, may be removed or conditioned.
In one exemplary implementation, the simulation s-t cut was successfully implemented in Python v. 2.5.4 using the packages Numerical Python (Numpy), Scientific Python (Scipy), and Algebraic Multigrid Solvers in Python (Pyamg). Two methods were implemented for solving the linear systems of equations associated with the simulation s-t cut. In the first method, the linear systems of equations were solved using Gaussian elimination. In the second method, the linear system of equations was solved in an approximate manner using Algebraic Multigrid. Coarse-fine splitting was performed by the Ruge-Stuben method based on a strength-of-connection threshold of 0.9. Coarse-fine splitting terminated at a coarse-grid size of 100 nodes. Matrix coarsening was obtained using Galerkin projection. The solution was obtained using a single V-cycle with Symmetric Gauss-Seidel relaxation for both pre- and post-smoothing. Simulations were performed for an input voltage magnitude of 10 6 . Pixel adjacency was defined based on 8-pixel neighborhood.
FIGS. 2A-2E depicts a series of exemplary images consisting of 100×100 pixel dimension and illustrating an exemplary application of the simulated s-t cut approach as described herein. FIG. 2A shows an initial random-intensity image having randomly distributed pixel intensities in the range of 0 to 100. Source and sink regions are designated as the right-most and left-most columns in a random-intensity image. Progression of voltage at fixed-point iterations including the 1 st iteration is shown in FIG. 2B and iterations at which the simulation s-t cut capacity is within 10% of the maximum flow is shown in FIG. 2C , 1% of the maximum flow is shown in FIG. 2D and equal to the maximum flow is shown in FIG. 2E .
The two regions used for initialization of the segmentation were the right-most and left-most columns of pixels, respectively. Segmentation was based on optimization of the boundary with respect to the following cost function:
c random ( u,v )= g ( u )+ g ( v ) [17]
FIG. 3 graphically shows the simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the above exemplary random-intensity image. Convergence of the simulation s-t cut capacity to the minimum s-t cut capacity for the Gaussian elimination is shown as the full-line and the Algebraic Multigrid implementations is shown as a dashed-line. For comparison, the maximum flow (equivalent to the capacity of the minimum s-t cut) of the graph was obtained using h_prf implementation of the push-relabel algorithm. The simulated s-t cut converged identically to the minimum s-t cut in 178 iterations using the algorithm based on Gaussian elimination and 218 iterations using the algorithm based on Algebraic Multigrid. Time for convergence of the simulation s-t cut to the minimum s-t cut was 12.94 seconds. In comparison, the minimum s-t cut was obtained in 31 msec by the h_prf implementation of a push-relabel algorithm.
FIGS. 4A-4E depicts a series of exemplary images for illustrating the simulated s-t cut approach as described herein applied to a magnetic resonance image. FIG. 4A illustrates an exemplary initial magnetic resonance image having source and sink regions designated as a square 100×100 region at the center of the image and the outer border of pixels in the image. The exemplary image was obtained from the Stroke Imaging Repository. Image segmentation based on the simulation s-t cut was applied to an axial section of a T2-weighted magnetic resonance image of the brain. The dimensions of the exemplary image of FIG. 4A as used in the analysis was 255×255 pixels. The two regions used for initialization of the segmentation were, respectively, a square with dimensions of 100×100 located at the center of the image and the outer border of pixels in the image.
The segmentation was based on the descending-order ranking with respect to the absolute value of the difference in the image intensity between the two pixels over the set of all adjacent pairs of pixels in the image, Q. Given a function of the intensity difference between pixels:
δ( u,v )=| g ( u )− g ( v )| [18]
wherein δ is a function of the image intensities of a pair of pixels,
The cost function c mri for pixels u and v may then be expressed as:
c mri ( u,v )=|{( u′,v ′)ε Q |δ( u,v )≦δ( u′,v′ )}| [19]
wherein Q is a set of adjacent pairs of pixels in the image.
Progression of voltage at fixed-point iterations including the 1 st iteration is shown in FIG. 4B and iterations at which the simulation s-t cut capacity is within 10% of the maximum flow is shown in FIG. 4C , 1% of the maximum flow is shown in FIG. 4D and equal to the maximum flow is shown in FIG. 4E .
FIG. 5 graphically shows results of the simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the above exemplary magnetic resonance image application. Convergence of the simulation s-t cut capacity to the minimum s-t cut capacity for the Gaussian elimination is shown as the full-line and the Algebraic Multigrid implementations is shown as a dashed-line. As FIG. 5 shows, the simulation s-t cut converged to the minimum s-t cut after 19 iterations using the Gaussian elimination method and after 31 iterations using the Algebraic Multigrid method. Time for convergence of the simulation s-t cut to the minimum s-t cut was 6.11 seconds. In comparison, the minimum s-t cut was obtained in 140 msec by the h_prf implementation of the push-relabel algorithm.
FIGS. 6A-6E depicts a series of exemplary images for illustrating the simulated s-t cut approach as described herein applied to a computed tomogram image. FIG. 6A illustrates the exemplary initial computed tomogram image having dimensions of 191×191 pixels and having source and sink regions designated as a square 50×50 region at the center of the image and the outer border of pixels in the image. The exemplary image shown in FIG. 6A was obtained from the Medical College of South Carolina.
The simulation s-t cut was applied to the segmentation of the heart in a computed tomographic angiogram. The cost function used in the segmentation was intended to force the segmentation boundary as close as possible to an intensity threshold of −350 Hounsfield units, the units of image intensity in computed tomograms. For a function that describes the proximity of the intensity of a pair of pixels to the threshold of −350 HU:
ε( u,v )=|(−350 −g ( u ))+(−350 −g ( v ))| [20]
wherein ε is a function of the image intensities of a pair of pixels.
A cost function c ct associated with a given pair of image intensities that is ascending order rank based on the function ε of the pair of image intensities may be expressed as:
c ct ( u,v )={( u′,v′ )ε Q |ε( u,v )≧ε( u′,v′ )}[ 21]
Progression of voltage at fixed-point iterations including the 1 st iteration is shown in FIG. 6B and iterations at which the simulation s-t cut capacity is within 10% of the maximum flow is shown in FIG. 6C , 1% of the maximum flow is shown in FIG. 6D and equal to the maximum flow is shown in FIG. 6E .
FIG. 7 graphically shows results of the simulation s-t cut capacity relative to maximum flow in comparison to the number of iterations as applied to the above exemplary computed tomogram image. Convergence of the simulation s-t cut capacity to the minimum s-t cut capacity for the Gaussian elimination is shown as the full-line and the Algebraic Multigrid implementations is shown as a dashed-line. In one implementation, a simulation s-t cut converged to the minimum s-t cut in 31 iterations using Gaussian elimination version and 38 iterations using the Algebraic Multigrid version. Time for convergence of the simulation s-t cut to the minimum s-t cut was 4.72 seconds. In comparison, the minimum s-t cut was obtained in 219 msec by the h_prf implementation of the push-relabel algorithm.
As one skilled in the art will readily recognize, the segmentation map resulting from the image segmentation processing may also be viewed in the form of sequential slices. Interactive 3D editing and image manipulation tools may be utilized to construct clipping planes to modify segmented voxel image data by projecting vertices of a region of interest (ROI) in one plane and transforming the data within the ROI to allow all of a plurality of slices on the inside of the ROI to be along one axis of a three axis coordinate system. Known methods typically require representing the inside of the ROI as a plurality of line segments or other geometric shapes such as triangles.
FIG. 8 schematically shows an exemplary computing system 100 that may help implement the methodologies of the present disclosure. The system 100 includes a computing device 5 , a network 20 , and an imaging scanner 10 . As shown in FIG. 1 , the computing device 5 may be directly communicatively connected and communicatively connected via the network 20 . The imaging scanner 10 is may be wired or wirelessly communicatively connected to the network 20 . Components of the communication system 100 are shown in FIG. 1 as single elements. Such illustration is for ease of description and it should be recognized that the system 100 may include multiple additional implementations of the components, e.g., a mobile device may be physically connected to the network 20 during selected periods of operation.
The network 20 may be any suitable series of points or nodes interconnected by communication paths. The network 20 may be interconnected with other networks and contain sub networks network such as, for example, a publicly accessible distributed network like the Internet or other telecommunications networks (e.g., intranets, virtual nets, overlay networks and the like). The network 20 may facilitates the exchange of data between the imaging scanner 10 and the computing device 5 although in various embodiments the imaging scanner 10 may be directly connected to the computing device 5 .
The server system 5 may be one or more of various embodiments of a computer including high-speed microcomputers, minicomputers, mainframes, and/or data storage devices. The computing device 5 preferably executes database functions including storing and maintaining a database and processes requests from the imaging scanner 10 to extract data from, or update, a database as described herein below. The server may additionally provide processing functions for the imaging scanner 10 .
In addition, the imaging scanner 10 may include one or more applications that the consumer may operate. Operation may include downloading, installing, turning on, unlocking, activating, or otherwise using the application. The application may comprise at least one of an algorithm, software, computer code, and/or the like, for example, mobile application software. In the alternative, the application may be a website accessible through the world wide web.
The computing device 5 includes a central processing unit (CPU) 50 , random access memory (RAM) 52 , input/output circuitry 54 for connecting peripheral devices such as a storage medium 56 to a system bus 60 , a display adapter 58 for connecting the system bus 60 to a display device, a user interface adapter 62 for connecting user input devices such as a keyboard, a mouse, and/or a microphone, to the system bus 60 , and a communication adapter 64 for connecting the computing device 5 to the network 20 . In one embodiment, the communication adapter 64 is a wireless adapter configured for extraterrestrial communication such as in a communications satellite. The storage medium 56 is configured to store, access, and modify a database 66 , and is preferably configured to store, access, and modify structured or unstructured databases for data including, for example, relational data, tabular data, audio/video data, and graphical data.
The central processing unit 50 is preferably one or more general-purpose microprocessor or central processing unit(s) and has a set of control algorithms, comprising resident program instructions and calibrations stored in the memory 52 and executed to provide the desired functions including parallel processing functions. As one skilled in the art will recognize, the central processing unit 50 may have any number of processing “cores” or electronic architecture configured to execute processes in parallel. In one embodiment, an application program interface (API) is preferably executed by the operating system for computer applications to make requests of the operating system or other computer applications. The description of the central processing unit 50 is meant to be illustrative, and not restrictive to the disclosure, and those skilled in the art will appreciate that the disclosure may also be implemented on platforms and operating systems other than those mentioned.
The present disclosure is directed to a number of imaging applications. Applications include segmentation of single surfaces, e.g., volumetric CT images, intravascular ultrasound or magnetic resonance and its 4-D extension, or tracking of such surfaces over time during the breathing cycle or over the cardiac cycle; segmentation of liver or kidney surfaces, tumor surfaces, as well as surfaces of bones, joints, or associated cartilages; surfaces separating cerebro-spinal fluid, gray matter and white matter in the brain, or surfaces of deep anatomical structures in the brain. The simulated minimum s-t cut may be utilized in non-image segmentation applications such as shape reconstruction from e.g., stereo views.
It is to be understood that while the present disclosure is described with particularity with respect to medical imaging, the principles set forth in detail herein can be applied to other imaging applications. For example, other areas of application include geological, satellite imaging, entertainment, image-guided therapy/surgery and other applications as would be appreciated by those skilled in the art.
The disclosure has described certain preferred embodiments and modifications thereto. Further modifications and alterations may occur to others upon reading and understanding the specification. Therefore, it is intended that the disclosure not be limited to the particular embodiment(s) disclosed as the best mode contemplated for carrying out this disclosure, but that the disclosure will include all embodiments falling within the scope of the appended claims.
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Method and system is disclosed for image segmentation. The method includes acquiring a digital image, constructing a graph from the digital image, calculating a plurality of cost functions, constructing an electrical network based upon the constructed graph and the plurality of calculated cost functions, simulating the electrical network using fixed-point linearization, and segmenting the image using the simulated electrical network to produce segmented layers. Simulation may be executed in parallel to achieve desirable computational efficiencies.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a fastener for plates effective for use, for example, in mounting a trim board on the inner surface of a vehicle passenger compartment.
2. Prior Art Statement
A commonly used conventional fastener for mounting a vehicle trim board comprises a head portion and a leg portion projecting from the head portion. The trim board is secured to an inner wall of the passenger compartment by mounting the head portion on the trim board and engaging the leg portion in a mounting hole formed in the inner wall of the vehicle.
Referring to FIG. 1, in a known structure for mounting a fastener on a trim board, a trim board 10 is provided with a first hole 11 having a large diameter and a second hole 12 having a small diameter, the first and second holes being communicated with each other.
In mounting the conventional fastener on the trim board 10, the head portion is once inserted in the first large hole 11, and is then moved into the second hole 12 along the outer surface of the trim board 10 thereby to permit the head portion to be retained by the trim board 10.
However, this structure for mounting a fastener to a trim board has a shortcoming in that complicated machining is required to make the special configurations of the mounting holes 11 and 12. Furthermore, since it is difficult to tightly mount the head portion of the fastener in the small hole 12, play is likely to occur between the fastener and the trim board. The result is that the head portion of the fastener may accidentally move from the small hole 12 to the large hole 11 and become detached from the large hole 11. When this happens, the trim board 10 mounted on the inner surface of the passenger compartment comes loose and may, in some cases, become completely detached and fall off the inner wall when subjected to a shock. In addition, since the large hole 11 remains open after the trim board is mounted, dust etc. is likely to enter through the large hole 11.
Japanese Utility Model Publication No. 47-39170 discloses a fastener for mounting a trim board, in which the head portion has a special configuration and is mounted on the trim board with a rotating action. However, the overall configuration of the fastener is complicated and play between the trim board and the fastener is not eliminated.
OBJECT AND SUMMARY OF THE INVENTION
The present invention was accomplished in view of the above-mentioned facts. It is therefore an object of the present invention to provide a fastener for plates which permits a second mounting plate (trim board) to be simple in the configuration of its mounting hole, the fastener to be tightly mounted on the second mounting plate without play therebetween, and dust etc. to be prevented from reaching the inner side of the second mounting plate from the mounting hole of the second mounting plate after the second mounting plate is mounted on a first mounting plate (inner surface of a passenger compartment).
A fastener for plates according to the present invention comprises a leg portion for engaging with a first mounting plate, a flange portion integrally secured to the leg portion, a head portion projecting from the flange portion for holding a second mounting plate between the flange portion and the head portion, a cut-away portion formed by cutting away part of the head portion from its outer periphery towards its axis for allowing the head portion to be inserted into a mounting hole of the second mounting plate by a rotating action, and a resilient portion for pressing against an inner periphery of the mounting hole of the second mounting plate which is secured to the flange portion.
In the above-mentioned fastener for plates, the head portion is brought to be in alignment with the mounting hole of the second mounting plate and is inserted into the mounting hole from the cut-away portion first, and is then rotated, generally by one turn, around its axis. As a result, the head portion is allowed to penetrate through the mounting hole of the second mounting plate and to project from the opposite side, and the second mounting plate is held between the head portion and the flange portion. By this, the fastener is mounted on the second mounting plate. In the foregoing state where the fastener is mounted on the second mounting plate, the resilient portion is disposed in the mounting hole of the second mounting plate. Therefore, no play arises in the radial direction of the mounting hole of the second mounting plate because the inner periphery of the mounting hole is pressed by the resilient force of the resilient portion. When the leg portion is inserted into and engaged with the first mounting plate after the fastener is mounted on the second mounting plate, the second mounting plate can be mounted on the first mounting plate.
Other objects and features of the present invention will become apparent from the following description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a trim board formed having holes for mounting a conventional fastener;
FIG. 2 is a perspective view showing one embodiment of a fastener for plates according to the present invention;
FIG. 3 is a sectional view showing the fastener of FIG. 2 as used to mount a trim board;
FIG. 4 is a sectional view taken along line IV--IV of FIG. 3;
FIG. 5 is a perspective view showing the steps for mounting the fastener of FIG. 1 on a trim board;
FIG. 6 is a sectional view showing another embodiment of a fastener according to the present invention, in which the fastener is being used to mount a trim board; and
FIG. 7 is a sectional view taken along line VII--VII of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 2 through 5 illustrate a first embodiment of a fastener 20 according to the present invention. As is shown in FIG. 3, the fastener 20 is employed for mounting a trim board 22 on an inner panel 24 of a vehicle passenger compartment. In this specification, the inner panel 24 and the trim board 22 are at times referred to as the first and second mounting plates, respectively.
The fastener 20, as shown in FIGS. 2 and 3, is formed at one end thereof with a rod-like leg portion 26. The leg portion 26 is formed at a tip end portion thereof with an anchor portion 28 which can be brought into press engagement with an engaging hole 30 formed in the inner wall 24 of the vehicle. The leg portion 26 is coaxially formed on a base portion thereof with an umbrella-shaped skirt portion 31 and a thin disk-shaped flange portion 32. The skirt portion 31 is thin and able to flexibly deform in the axial direction of the leg portion 26. The skirt portion 31 is abutted against an outer surface of the inner panel 24 thereby to firmly hold the inner panel 24 between the anchor portion 28 and the skirt portion 31. The flange portion 32 is coaxially formed with a shaft portion 34 projecting in the opposite direction to the leg portion 26. The shaft portion 34 is coaxially formed at the top end thereto with a thin disk-shaped head portion 36.
The head portion 36 is formed with a cut-away portion 38 which extends over 90° about the axis when viewed from the axial direction. More specifically, the head portion 36 is cut away such that a sector-shaped space is formed between one cut-away end face 38A and the other cut-away end face 38B.
The head portion 36 is formed such that the length L (see FIG. 3) from the outer circumference thereof to the outer circumference of the shaft portion 34 via the axis is smaller than the inner diameter D of a circular mounting hole 40 formed in the trim board 22. Therefore, as shown in FIG. 5, when the head portion 36 is rotated by approximately one full turn about the shaft portion 34 in the direction as shown by the arrow A in FIG. 5 after the head portion 36 is inserted into the mounting hole 40 from the cut-away end face 38A first, the head portion 36 is spirally moved through the mounting hole 40 and caused to project from the other side. By this, the flange portion 32 comes to face one surface of the trim board 22, while the head portion 36 comes to face the other surface, so that the trim board 22 is held between the head portion 36 and the flange portion 32.
A resilient portion 42 is formed between the head portion 36 and the flange portion 32. As shown in FIG. 4, the resilient portion 42 includes a radial portion 42A projecting in the radial direction from the shaft portion 34, and an arcuate portion 42B encircling the shaft portion 34 by about 3/4 of a full circle with a space 43 left between the front end of the radial portion 42A and the shaft portion 34.
The radial portion 42A is positioned immediately under the cut-away end face 38A when viewed from the axial direction of the head portion 36. As shown in FIG. 5, when the head portion 36 is inserted into the mounting hole 40 of the trim board 22, the radial portion 42A moves smoothly into the mounting hole 40 together with the head portion 36. By this, the arcuate portion 42B is also smoothly inserted into the mounting hole 40. As a result, when being inserted into the mounting hole 40, the resilient portion 42 is rotated counterclockwise in FIG. 4.
The radial portion 42A and the arcuate portion 42B are comparatively small in sectional dimension and are resilient. The outer diameter of the arcuate portion 42B is larger than the inner diameter D (see FIG. 3) of the mounting hole 40 of the trim board 22. As shown in FIG. 5, when the head portion 36 is inserted into the mounting hole 40 of the trim board 22 and rotated by approximately one full turn about the shaft portion 34, the arcuate portion 42B is inserted into the mounting hole 40 while pressing the inner periphery of the mounting hole 40, whereas when the entire head portion 36 penetrates through the mounting hole 40, the arcuate portion 42B presses the inner periphery of the mounting hole 40 to absorb play between the shaft portion 34 and the trim board 22.
The head portion 36 is formed therein with a lightening (weight-reduction) hole 44 extending about the shaft portion 34 by about 3/4 of a full circle from one cut-away end face 38A to the vicinity of the other cut-away end face 38B. The lightening hole 44 corresponds to the space 43 (see FIG. 4) between the head portion 36 and the shaft portion 34 when viewed from the axial direction of the head portion 36. The lightening hole 44 is formed as a space for inserting a core when molding the resilient portion 42. The shaft portion 34 is formed with a lightening (weight-reduction) hole 46 reaching a predetermined depth from the side of the head portion 36.
The steps for mounting the trim board 22 on the inner panel 24 of the vehicle will be described next.
The fastener 20 is mounted on the trim board 22 first. In order to mount the fastener 20 on the trim board 22, the fastener 20 is placed on one side of the trim board 22 and thereafter, as shown in FIG. 5, the head portion 36 is inserted into the mounting hole 40 from the cut-away end face 38A first and is rotated by about one turn in the direction shown by the arrow A of FIG. 5. As a result, the head portion 36 is spirally advanced through the mounting hole 40 to a state where it holds the trim board 22 between the flange portion 32 and itself. At the same time, the resilient portion 42 is inserted into the mounting hole 40 together with the shaft portion 34. By this, the fastener 20 is mounted on the trim board 22.
When the fastener 20 is mounted on the trim board 22, the arcuate portion 42B of the resilient portion 42 is in pressure abutment with the inner periphery of the mounting hole 40 of the trim board 22 absorbs play between the shaft portion 34 and the inner periphery of the mounting hole 40. As a result, the fastener 20 is restricted from movement in the radial direction of the mounting hole 40, i.e., the left and right direction of FIG. 3.
Furthermore, the fastener 20 is safe from being accidentally detached from the trim board 22 and will remain mounted thereon until the head portion 36 is intensionally inserted into the mounting hole 40 from the cut-away end face 38A or cut-away end face 38B side and rotated. Thus, the fastener 20 is firmly mounted on the trim board 22. The mounting hole 40 of the trim board 22 is blocked by the head portion 36 and the flange portion 32 from opposite sides thereof.
In this way, after the fastener 20 is mounted on the trim board 22, the leg portion 26 of the fastener 20 is press-fitted into the engaging hole 30 of the inner panel 24 of the vehicle passenger compartment. As a result, the inner panel 24 is caught between the anchor portion 28 and the skirt portion 31. By this, the trim board 22 is mounted on the inner panel 24 as shown in FIG. 3.
When the trim board 22 is mounted on the inner panel 24, since the mounting hole 40 of the trim board 22 is blocked by the head portion 36 and the flange portion 32 at opposite sides thereof, dust etc. cannot enter the space between the trim board 22 and the inner panel 24 through the mounting hole 40. Since the fastener 20 is safe from being accidentally detached from the trim board 22, it is highly resistant against shock etc., too. Moreover, since the fastener 20 is tightly mounted on the trim board 22 by the resilient portion 42, the trim board 22 is restricted from movement with respect to the inner panel 24.
In the above-mentioned embodiment, the arcuate portion 42B of the resilient portion 42 is connected only at one end thereof with the shaft portion 34 through the radial portion 42A. Alternatively, as shown in FIG. 7, the arcuate portion 42B may be connected at both ends thereof with the shaft portion 34 through two radial portions 42A.
Furthermore, in the above-mentioned embodiment, the fastener 20 is provided at the leg portion 26 with the anchor portion 28, so that the leg portion 26 is directly engaged with the inner panel 24 through the anchor portion 28. Alternatively, as shown in FIG. 6, the fastener 20 may be provided with a female member 50, so that the fastener 20 is engaged with the inner panel 24 by inserting the leg portion 26 into the female member 50.
As described in the foregoing, in the fastener according to the present invention, even if the mounting hole of the trim board is round, the fastener can be tightly mounted because of the presence of the resilient portion. Moreover, since the mounting hole is blocked by the head portion and the flange portion from opposite sides thereof, dust etc. can be prevented from reaching the inner side of the trim board.
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A fastener for plates includes a leg portion for engaging with a first mounting plate, a flange portion integrally secured to the leg portion, a head portion projecting from the flange portion for holding a second mounting plate between the flange portion and the head portion, a cut-away portion formed by cutting away part of the head portion from its outer periphery towards its axis for allowing the head portion to be inserted into a mounting hole of a second mounting plate by a rotating action, and a resilient portion for pressing against the inner periphery of the mounting hole of the second mounting plate which is secured by the flange portion.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to xanthine derivatives and to nephelometric inhibition immunoassays and kits wherein they can be employed.
2. Description of the Prior Art
Nephelometry involves the detection of light scattered or reflected toward a detector that is not in the direct path of the transmitted light (1).
The basic principles governing nephelometric inhibition immunoassay (NIIA) were reported over 40 years ago by Pauling et al. (2,3) and examined again in detail by Pressman (4). These authors proved that one could quantify small amounts of hapten (molecules of less than 4000 M r ) by measuring chemically the decrease in the amount of precipitate formed from the interaction of hapten-specific antisera with polyhaptenic substances or conjugates of hapten with protein. The magnitude of the inhibition was best explained by the preferential interaction of the small quantity of hapten with antibodies of high avidity. The measurement of hapten by NIIA in which an endpoint nephelometer is used to measure the light scattered by reaction between a specific antibody and a hapten-macromolecular conjugate has been reported (5,6). Nishikawa et al. advanced the method into the area of therapeutic drug monitoring by describing similar endpoint NIIAs for phenytoin, phenobarbital, and theophylline (7,8).
Nephelometric procedures are a convenient tool for monitoring antigen-antibody reactions at an early stage, by detecting the growth of complexes ("scattering centers") capable of scattering light before they separate out of solution as immunoprecipitates. The formation of these scattering centers can be accelerated by the use of hydrophilic non-ionic polymers (e.g., dextran, polyethylene glycol), which increases the probability of protein-protein interaction by excluding a significant fraction of water. The use of polymers in an immunonephelometric assay also gives the advantages of increased sensitivity and less antiserum consumption (9).
The hapten of interest (a substance that can react with an antibody but cannot cause an immunological response) is covalently linked to a carrier protein, and the resulting conjugate is used to immunize animals. The specific antiserum is then reacted with a second conjugate or developer antigen, such that several hapten molecules are bound to each molecule of an unrelated carried protein. Therefore, although haptens cannot be quantitated by direct nephelometric procedures, by taking advantage of the fact that haptens will form soluble immune complexes, one can develop assays in which the hapten inhibits the formation of light-scattering centers produced by reacting a developer antigen with a limited amount of specific antibody.
Rate NIIAs have also been reported (10,11).
Nephelometric inhibition immunoassays as a whole also possess those advantages characteristic of all homogenous immunoassays (e.g., enzyme multiplied immunoassay and substrate-labeled fluorescence immunoassay), namely, increased accuracy and precision because of the elimination of a separation step (which is common to all heterogeneous immunoassays radioimmunoassays, enzyme-linked immunosorbent assay, etc.). In addition, NIIAs, which are readily adaptable to automation, involve extremely stable reagents, compared with assays that require radioactive or enzymelabeled tags, for which shelf life is a constant problem.
In the prior art there exists a nephelometric assay and kit for theophylline which employs a theophylline-8-butyric acid derivative having the following formula: ##STR1## wherein n is the number of xanthine derivatives bonded to apoferritin. The cross-reactivity of the theophylline antiserum against major drugs and drug metabolites, i.e., the concentrations of cross-reactants in micrograms (μg) per milliliter (mL) required to produce a 30% error at a theophylline concentration of 10 μg/mL is set forth in Table I.
TABLE I______________________________________CROSS REACTIVITY OF THEOPHYLLINE ANTISERA Concentration μg/mL Producing a 30% ErrorCompound at Theoophylline 10 μg/mL______________________________________Caffeine >200Theobromine >1001,7-Dimethylxanthine >2501-Methylxanthine >1003-Methylxanthine >1007-Methylxanthine >1001,3,7-Trimethyl Uric Acid >2501,3-Dimethyl Uric Acid >401-Methyl Uric Acid >200Uric Acid >2003-Methyl Uric Acid >100Xanthine >200Hypoxanthine >1008-Chlorotheophylline >45Diphenhydramine >200Diphylline >100Aminophylline >2.5______________________________________
The correlation of this prior art theophylline assay kit with Syva Company's EMIT brand theophylline assay kit on a Gilford Instruments Model 203-S spectrophotometer is set forth in Table II.
TABLE II______________________________________COMPARISON OF PRIOR ART THEOPHYLLINETEST AND REFERENCE METHOD Least Squares CorrelationReference Method (X) N Regression Equation Coefficient______________________________________Syva/Gilford 203-S 83 y = 1.01X + 0.361 0.972______________________________________
Although this prior art theophylline assay kit possesses a very low cross-reactivity and an excellent correlation with a reference method, it is very temperature sensitive. For example, the least square regression equations for observed (Y) versus expected (X) theophylline concentrations obtained at three different environmental (reaction) temperatures is set forth in Table III:
TABLE III______________________________________TEMPERATURE SENSITIVITY STUDY Least Squares RegressionTemperature, °C. Equation______________________________________18 Y = 1.7663X - 6.989525 Y = 0.9211X + 1.168430 Y = 0.8971X + 3.0655______________________________________
Accordingly, it would be very desirable to have a NIIA and kit for use therein which also exhibits a low crossreactivity and an excellent correlation with a reference method, but in addition thereto is less sensitive to environmental temperature changes.
SUMMARY OF THE INVENTION
In accordance with the present invention, there are provided an improved nephelometric inhibition immunoassay (NIIA) and a kit for use therein which exhibit low cross-reactivity and an excellent correlation with a reference method. In addition thereto, the NIIA and kit of the present invention exhibit a substantially lower dependence on environmental temperature changes. Because of such lower temperature dependence, the NIIA and kit of the present invention have improved precision and accuracy.
The improvement in the NIIA and kit is due to the use of a novel conjugate having a formula selected from a group consisting of ##STR2## wherein: (a) Z is a label;
(b) n is an integer of at least 1;
(c) R is a linking group; and
(d) X 1 and X 2 are independently selected from a group consisting of hydrocarbon and heterocarbon substituents containing from 1 to about 8 atoms other than hydrogen, said atoms being selected from a group consisting of carbon, oxygen, nitrogen, and sulfur.
The conjugate of the present invention, wherein Z is a poly(amino acid), also enables the NIIA and kit of the present invention to provide better sensitivity in the therapeutic range than the prior art NIIA and kit.
Also within the scope of this invention is a nephelometric inhibition assay of the type wherein a sample, which may have theophylline present therein, is contacted with a conjugate to form a solution. This solution is then contacted with a theophylline antibody to start a reaction in which the endogenous theophylline and the conjugate compete for the antibody. A function of any resulting conjugate-antibody complexation reaction is then measured. The NIIA of the present invention is characterized in that the above conjugate, wherein Z is a poly(amino acid), is employed therein.
The present invention also encompasses a kit. The kit is of the type which comprises a first unit comprising a conjugate and a second unit which comprises theophylline antibody. The kit is characterized in that the above conjugate is employed therein.
Still other features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferably, the label Z is selected from a group consisting of fluorescent, bioluminescent, chemiluminescent, and radioactive labels and poly(amino acids) having a molecular weight of at least about 3,000. Usually, the poly(amino acid) is selected from a group consisting of polypeptides, proteins, antigens, and enzymes having a molecular weight of from about 3,000 to about 10,000,000. More preferably, the poly(amino acid) is as shown in Table IV.
TABLE IV______________________________________Type ofpoly(amino acid) molecular weight n______________________________________polypeptides, 3,000-10,000,000 1-250 ↓ Increasingproteins, or 10,000-1,000,000 2-150 ↓ preferenceantigens 25,000-800,000 4-100 ↓enzymes 10,000-600,000 1-30 ↓ Increasing 10,000-150,000 2-20 ↓ preference 12,000-80,000 2-12 ↓______________________________________
When Z is a poly(amino acid), n is preferably from about 1 to about 250. Further preferred embodiments of n are set forth in Table IV.
When Z is either a fluorescent, bioluminescent, chemiluminescent, or radioactive label, n is 1.
Preferably, R is selected from the group consisting of from 1 to about 12 atoms other than hydrogen, such atoms being selected from the groups consisting of carbon, oxygen, nitrogen, and sulfur. More preferably, R has a formula ##STR3## wherein:
Y 1 and Y 2 are independently selected from a group consisting of oxygen, imino, and sulfur;
T 1 is a hydrocarbon radical containing from 1 to about 10 carbon atoms;
T 2 is selected from a group consisting of hydrocarbon and hydrocarbylamino radicals containing from about 1 to about 10 carbon atoms, provided that when T 2 is hydrocarbylamino, the nitrogen is bonded to (CY 2 );
G is selected from a group consisting of a bond, amido, and oxy;
m is zero or 1;
p is zero or 1; and
(CY 1 ) is bonded to N 1 or N 3 and (CY 2 ) is bonded to the poly(amino acid). Optimally, R has a formula ##STR4## wherein:
q is an integer from 1 to about 8, more preferably from about 2 to about 6; and
(CO) is bonded to the poly(amino acid).
Preferably, X 1 and X 2 are independently selected from the group consisting of hydrocarbon substituents. It is further preferred that the hydrocarbon substituents contain from 1 to about 6, more preferably 1 to about 4, and optimally 1 to about 2 carbon atoms.
In one particularly preferred embodiment, the poly(amino acid) is apoferritin; X 1 and X 2 are both methyl groups; R is --(CH 2 ) 4 --(CO)--, wherein (CO) is bonded to apoferritin; and n is an integer from about 6 to about 60.
The conjugates of the present invention can be synthesized via any applicable procedure known to those skilled in the art.
The conjugates of the present invention wherein Z is a poly(amino acid) can be employed in any known nephelometric methodology. In a nephelometric methodology it is necessary to measure a function of any resulting conjugate-antibody complexation reaction. In the case of an end-point assay, the function to be measured is the intensity of scattered light. In a rate assay, the function to be measured is the rate of change of the intensity of the scattered light.
In an NIIA rate assay, it is also preferred that a trigger be incorporated into either the first or second units of the kit. Such a trigger is well known to those skilled in the art and is described in U.S. Pat. No. 4,157,871 (11). In this preferred aspect of the invention, either the first solution, which comprises endogenous theophylline and a conjugate within the scope of this invention, will further have a trigger present therein or a first solution devoid of such trigger will be simultaneously contacted with theophylline antibody and the trigger.
When Z is selected from a group consisting of enzyme, fluorescent, bioluminescent, chemiluminescent, and radioactive labels, the conjugates of the present invention can be employed in enzyme, fluorescent, bioluminescent, chemiluminescent, and radio immunoassays, respectively.
The following examples are provided for the purpose of further illustration and are not intended to be limitations on the disclosed invention.
EXAMPLE 1
The cross-reactivity of a theophylline antiserum against major drugs and drug metabolites in an NIIA assay employing conjugates of the following formulas is set forth in Table V. ##STR5##
TABLE V______________________________________Cross-Reactivities Concentration μg/mL Producing a 30% Error at Theophylline 10 μg/mL Paraxanthine Theobromine-1- 3-apoferritin apoferritinCompound Conjugate Conjugate______________________________________Caffeine 60 ≧75Theobromine 80 ≧801,7-dimethylxanthine 80 ≧801-methylxanthine >100 ≧1003-methylxanthine >100 ≧1007-methylxanthine >100 ≧1001,3,7-trimethyluric acid >250 >2501,3-dimethyluric acid ≧10 ≧101-methyl uric acid >105* ≧200Uric acid >105* ≧2003-methyl uric acid 100 ≧200Xanthine >105* ≧200Hypoxanthine >100 ≧2008-chlorotheophylline ≧20 ≧17Diphenhydramine >100 ≧200Dyphylline >100 ≧100Aminophylline >2.5* ≧25______________________________________ *Highest concentration tested
Although the extent of cross-reactivity is somewhat increased with the conjugates within the scope of this invention, the extent of cross-reactivity is still better than or equal to the cross-reactivity claimed by various commercial kits. Further, although the conjugates within the scope of this invention exhibited an increase in cross-reactivity with 1,3-dimethyl uric acid, such increase is not of conern because it is believed that this compound will not be found in serum in concentrations which will effect theophylline values reported.
EXAMPLE 2
The correlation of a theophylline assay kit employing the theobromine conjugate was made with Syva Company's EMIT brand theophylline assay kit run on a Gilford instrument Model 203-S spectrophotometer. The results from this study is set forth in Table VI.
TABLE VI______________________________________Composition Within Scope ofPresent Invention and Reference Methodsof a Theophylline TestReference Least Squares CorrelationMethod (X) N Regression Equation Coefficient______________________________________Syva/Gilford203-S 61 y = 1.00X + 0.14 0.989______________________________________
Table VI indicates that a theophylline assay kit within the scope of the present invention also has an excellent correlation with a reference method.
EXAMPLE 3
Temperature studies were performed to determine the extent to which values would be affected by environmental temperature changes. For each temperature indicated, a linearity run was performed on two different manual Beckman Instruments brand ICS II nephelometric instruments located in a temperature-controlled environmental chamber. The least square regression equations for observed (Y) versus expected (X) theophylline concentrations obtained at three different environmental temperatures is set forth in Table VII.
TABLE VII______________________________________Temperature Sensitivity Study Least SquaresTemperature, °C. Regression Equation______________________________________18 Y = 1.0829 × -0.845425 Y = 1.0397 × -0.791630 Y = 0.9581 × -0.2882______________________________________
As can be seen from the least square regression equations set forth in Table VII, a theophylline assay and kit within the scope of this invention is much less sensitive to environmental temperature changes.
Based on this disclosure, many other modifications and ramifications will naturally suggest themselves to those skilled in the art. These are intended to be within the scope of this invention.
BIBLIOGRAPHY
1. Kusnetz et al., Automated Immunoanalysis, 1, R.F. Ritchie, Ed., Marcel Dekker, Inc., New York, N.Y. (1978) pp. 1-42.
2. Pauling, et al., J. Am. Chem. Soc., 64:2994-3003 (1942).
3. Pauling et al., J. Am. Chem. Soc., 64:3003-3009 (1942).
4. Pressman, Methods Med. Res., 10:122-127 (1964).
5. Cambiaso et al., J. Immunol. Methods, 5:293-302 (1974).
6. Gauldie et al., Automated Immunoanalysis, 1, R.F. Ritchie, Ed., Marcel Dekker, Inc., New York, N.Y. 1978) pp. 321-333.
7. Nishikawa et al., J. Immunol. Methods, 29:85-89 (1979).
8. Nishikawa et al., Clin. Chem. Acta, 91:59-65 (1979).
9. Hellsing, Protides Biol. Fluids, 21, H. Peters, Ed., Pergamom, Oxford (1974) pp. 579-583.
10. Anderson et al., Automated Immunoanalysis, 2, R.F. Ritchie, Ed., Marcel Dekker, Inc., New York, N.Y. (1978) pp. 409-469.
11. U.S. Pat. No. 4,157,871.
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A novel competitive assay for theophylline wherein caffeine-like (7-substituted) labeled conjugates are used to detect the presence and/or amount of theophylline present in a test sample. The use of such conjugates in a competitive assay for theophylline results in improved sensitivity of the assay method. Where the assay method is a nephelometric or turbidimetric inhibition immunoassay procedure, the assay was found to be less temperature dependent than prior art immunoassays.
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BACKGROUND OF THE INVENTION
This invention relates to a crossbow comprising a prod and a stock having a fore-end portion on which the prod is supported. When the bow is in use, a bow string is connected to the prod adjacent to opposite ends thereof to extend across the stock, the prod extending transversely of the stock. The combination of prod and stock, without a string, is called herein a crossbow.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a crossbow wherein the prod is arranged for swinging relative to the stock whilst remaining connected with the stock, whereby the configuration of the bow can be changed between a configuration in which the bow is used and a more compact configuration.
It is known to mount the prod of a crossbow releasably in the stock so that the bow can be dis-assembled to achieve a compact configuration. However, known means for mounting the prod in the stock does not enable the crossbow to be dis-assembled and re-assembled conveniently and known crossbows are normally transported and stored between periods of use in an assembled condition. A crossbow in accordance with the present invention can conveniently be changed from its configuration of use to a more compact configuration and returned to its configuration of use.
While the entire prod may swing as a unit relative to the stock, it is preferred that the prod be in two relatively movable parts, which parts can swing relative to the stock and relative to each other whilst remaining connected with the stock. The arrangement may be such that opposite end portions of the prod can swing towards each other to relieve the tension in a bow string, when connected to the prod.
In a case where each part of the prod can swing from a position in which it is approximately perpendicular to the stock to a position in which it is approximately parallel to the stock, movement throughout a major part of the range of swinging can conveniently be effected by the user applying force directly to each part of the prod by hand. However, a final part of the swinging movement into the configuration of use establishes tension in a string attached to opposite end portions of the prod and flexing of the prod. Thus, the preferred crossbow comprises a mechanism for transmitting force with a mechanical advantage from a handle of the mechanism to the parts of the prod to swing said parts into respective positions relative to the stock which are occupied when the bow is in use.
BRIEF DESCRIPTION OF THE DRAWINGS
An example of a crossbow embodying the invention will now be described, with reference to the accompanying drawings, wherein
FIG. 1 shows an underneath plan view of a part of the crossbow including a fore-end portion of the stock and the bow prod;
FIG. 2 shows a side elavation on the arrow II of FIG. 1; and
FIG. 3 shows on a reduced scale a side elevation similar to FIG. 2 but showing a clamping mechanism of the crossbow in released position.
DETAILED DESCRIPTION
The crossbow comprises an elongated stock, only a fore-end portion 10 of which is illustrated in the drawing. The remainder of the stock may be of known form and include a butt. The remainder of the stock carries a trigger mechanism (not shown) arranged in a known manner. An upper surface 11 of the stock constitutes a guide surface for guiding a bolt (not shown) when the bolt is fired from the crossbow in a known manner. In the guide surface, there is provided a rectilinear groove 12 in which the bolt can slide. Adjacent to its free end, there is a formed in the fore-end portion 10 a slot 13 which extends downwardly from the groove 12 to the underside of the stock. A laterally extending aperture 14 is formed in the fore-end portion at a position spaced somewhat towards the butt from the slot 13, this aperture opening at opposite side faces of the stock but being closed from the guide surface 11 and from the underside of the stock.
On the fore-end portion 10 there is supported a bow prod formed in two identical parts 15 and 16. One end portion of the prod part 15 is engaged in a shoe 17 mounted in the fore-end portion 10 for pivoting about an axis 18 which is perpendicular to the guide surface 11. An end portion of the prod part 16 is received in a similar shoe 19 mounted for pivoting relative to the stock about an axis 20. The axis 18 and 20 are parallel to each other, spaced apart laterally of the stock to lie on opposite sides of the groove 12 and are spaced from the aperture 14 somewhat in a direction away from the free end of the fore-end portion 10.
It will be seen that the prod parts 15 and 16 can swing independently of each other relative to the stock between a first position occupied by the part 15 in FIG. 1, in which the shoe 17 lies outside the aperture 14 and the prod part 15 is approximately parallel to the length of the stock, so that the prod part contacts the stock at a position remote from the shoe 17, and a second position occupied by the prod part 16 in FIG. 1, in which the prod part extends approximately at right angles to the length of the stock and the shoe 19 lies partly within the aperture 14.
It will be understood that, when the bow is in use, both of the prod parts 15 and 16 would occupy their second positions. In this configuration, the crossbow is somewhat cumbersome. For transport and storage of the crossbow between periods of use, the two prod parts would be moved to their first positions to provide a relatively compact configuration of the crossbow.
Each prod part 15, 16 may be releasably mounted in its shoe 17, 19. Alternatively, the prod parts may be permanently secured in their shoes, the shoes being removed from the fore-end portion 10 if it is required to substitute a new prod for the prod originally mounted on the fore-end portion.
For establishing and maintaining the second positions of the prod parts, there is provided a clamping mechanism which is mounted on the fore-end portion 10 of the stock. The clamping mechanism comprises a handle 21 which, in the particular example illustrated, has the form of stirrup. This handle is mounted for pivoting relative to the fore-end portion about an axis 22 which, when the crossbow is in use, lies below the aperture 14 and is generally horizontal. The mechanism further comprises a lever 23 mounted for pivoting on the fore-end portion 10 about an axis 24 parallel to the axis 22, spaced somewhat further from the guide surface 11 than is the axis 22 and spaced somewhat further from the butt of the crossbow than is the axis 22. For transmitting force between the handle 21 and the lever 23, there is provided a strut 25 pivoted adjacent to one of its ends on the handle 21 at a position between the axis 22 and a free end of the handle and the strut being pivoted adjacent to its other end on the lever 23 at a position between the axis 24 and a free end of the lever. The handle 21, strut 25 and lever 23 together constitute a toggle linkage which provides a large mechanical advantage to the handle as the strut becomes aligned with the handle.
The clamping mechanism further comprises a pressure plate 26 disposed within the aperture 14 and guided for rectilinear movement relative to the fore-end portion 10 along the length of the stock. A guide pin 27 extends from the pressure plate 26 into the slot 13. On the end portion of the lever 23 remote from the axis 24, there is provided an adjustable abutment 28 which, by pivoting of the handle 21, can be moved into the slot 13 and engaged with the guide pin 27 to urge the pressure plate in a direction away from the free end of the fore-end portion 10. It will be seen that the clamping mechanism provides a considerable mechanical advantage to a user who grasps an end portion of the handle 21 remote the axis 22, so that a user can apply a relatively large force to the pressure plate.
When the handle 21 is pivoted to the position illustrated in FIG. 3, the abutment 28 is withdrawn from the slot 13 and the pressure plate 26 can move within the aperture 14 away from the shoes 17 and 19. The prod parts 15 and 16 can then be swung from their second positions to their first positions.
Even if a bow string (not shown) is connected between the free ends of the prod parts 15 and 16, these can easily be moved by application of force to the prod parts directly by the hands of a user through a major part of their travel from the first position to the second position. In this way, the shoes 17 and 19 can be re-introduced into the aperture 14 to lie just to the rear of the pressure plate 26. If the handle 21 is then pivoted by the user towards the position illustrated in FIG. 2, the abutment 28 is driven along the slot 13 to force the pressure plate 26 against shoes 17 and 19 so that pivoting of the shoes is continued until the prod parts occupy their second position.
As the prod parts 15 and 16 move into their second positions, the strut 25 moves into or through a central position by which we mean a position in which the axis of the pivotal connection between the strut and the lever 23 lies in a plane containing the axis 22 and the axis of the pivotal connection between the strut and the handle 21. An abutment may be provided on one of the handle 21 and lever 23 to engage the strut and limit movement of the strut when this central position has been reached or has just been passed. It will be seen that, when the lever 23 is in the position shown in FIG. 2, any force exerted on the pressure plate 26 by the shoes 17 and 19 does not tend to pivot the handle 21 from the position shown in FIG. 2 towards the position shown in FIG. 3.
In a case where, during clamping of the prod parts 15 and 16 in their second positions, the strut 25 moves through the central position, pivoting of the handle 21 from the position shown in FIG. 2 towards the position shown in FIG. 3 will initially increase the stress in the strut 25 and lever 23 and will therefore be opposed by the force exerted on the pressure plate 26 by the shoes 17 and 19. Thus, the handle will normally be held releasably in the position shown in FIG. 2. In a case where the strut 25 moves to, but not beyond, the central position a releasable fastener may be provided for holding the handle 21 in the position shown in FIG. 2.
It will be noted that, in the position shown in FIG. 2, the handle 21 projects beyond the fore-end portion 10 in a direction away from the butt of the stock. The handle is conveniently formed as a stirrup into which a user can insert his foot to hold the stock during cocking of the bow. During clamping of the prod parts 15 and 16 in their second positions, the handle 21 is used as a lever. When used for this purpose and when used to hold the stock during cocking, a moderately long handle is more convenient than is a short handle.
In the particular example of stock illustrated, the two parts of the prod can swing relative to each other so that respective free ends move towards and away from each other. This results in the tension in the bow string being relieved when the parts of the prod move from their respective positions of use. Tension must be reestablished in the string before subsequent use of the crossbow. In an alternative arrangement, the bow prod comprises a single piece, to opposite end portions of which the bow string is attached, and this piece can swing relative to the stock, for example pivoting about an axis which extends through the groove 12. By such pivoting, the distance to which the prod extends transversely from the stock can be reduced without relieving the tension in the bow string but the length of the crossbow may be increased somewhat by such swinging of the prod.
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A crossbow has a prod in two parts, each of which is pivotally connected with the stock so that the prod parts can lie alongside the stock when the bow is not in use. When the bow is prepared for use, the prod parts are clamped in operative positions by a mechanism which includes a handle and which provides a substantial mechanical advantage to the operator.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of the application Ser. No. 08/554,252 filed on Nov. 6, 1995 now abandoned, titled Collapsible Shopping Cart.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a collapsible shopping cart which has removable baskets and bags to hold shopping items. The baskets and bags are removed at the checkout counter, the items removed, processed and returned. Then the baskets and bags are returned to the cart for movement to transportation. The invention reduces or eliminates the need for the typical bags provided by stores and solves the problem of containing shopping items at wholesale stores that do not provide bags. The cart collapses when not in use for storage.
2. Description of the Prior Art
Portable shopping carts have been utilized for decades. However, until now a versatile portable shopping carts able to be collapsible but none are capable of being converted from a four wheeled cart to a two wheeled cart.
Numerous innovations for a collapsible shopping cart have been provided in the prior art that are described as follows. Even though these innovations may be suitable for the specific individual purposes to which they address, they differ from the present invention as hereinafter contrasted.
In U.S. Pat. No. 4,669,743, Collapsible Wheeled Material Carrier, invented by Jime Tipke comprises a Collapsible Wheeled Material Carrier which folds to a storage position when not in use. The carrier has a frame with transversely folding braces and a folding bottom. It also has a folding extendable handle assembly. The carrier can be hand propelled or moved by a vehicle.
The present invention differs from the above described patented invention for the following reasons: the present invention does not have ridged sides and bottom, the frame of the present invention is designed to hold unique tubs for holding shopping items and finally the present invention has castors for steering.
In U.S. Pat. No. 5,028,060, Utility Cart, invented by David Martin comprises a cart having a load receiving box supported by a rectangular frame inset within the box lower perimeter. End members of the frame swingably carry front and rear axil frames while side members of the frame swingably carry struts which engage the ail ends to retain same in a deployed position. The axil frame and struts are upwardly repositionable adjacent the box ends and sides, subsequent to wheel removal, to collapse the cart for storage or for carrying in a vehicle. A U-shaped handle has lower ends detachable mounted to a box end wall by a pair of sleeve structures.
The present invention differs from the above described patented invention for the following reasons: the present invention is collapsible with out removing the wheels or the handle. The present invention further has a upper section with tubs for small items and a lower area for large bulk items.
In U.S. Pat. No. 3,837,667, Lugs and Cart Therefor, invented by Morton A. Sernovitz comprises a combination of an open frame cart and a plurality of containers or lugs, as they are called in this art, is disclosed which fit together in a number of convenient carrying arrangements. The containers have transverse spaced grooves in there bottom surfaces which fit upon and coincide with pairs of longitudinal and transverse frame members of the cart to hold the containers thereon during produce handling procedures. The cart has two tiers in the frame such that each tier can hold one container longitudinally or two transversely. The containers also nest in a stacked relationship within each other and the longitudinal distance between the bottom grooves of the containers is the same as the transverse distance between their top longitudinal rolled flange edges so that one container will rest on the other in a stable relationship.
The present invention differs from the above described patented invention for the following reasons: the present invention collapses and is made from light weight materials so it is easily transportable.
In U.S. Pat. No. 2,544,220, Shopping Carrier for Stores, invented by George W. Concklin comprises a cart with two shelves for holding items typically in self-service stores. Additionally it folds for storage. Further it is designed to nest with other carts to minimize on floor storage.
The present invention differs from the above described patented invention for the following reasons; the present invention has a web tub for carrying bulk items and containing irregularly shaped items, the tubs in the present invention interlock with the frame with out additional locking parts or special parts.
Numerous innovations for collapsible shopping cart have been provided in the prior art that are adapted to be used. Even though these innovations may be suitable for the specific individual purposes to which they address, they would not be suitable for the purposes of the present invention as heretofore described.
SUMMARY OF THE INVENTION
The present invention allows a user to grocery shop or "mall" shop with their own personal collapsible cart. The user can unfold the cart at the grocery store or mall and is then ready to load items therein. If a user is shopping with a very long list of items, he has the option of inserting two upper baskets which are custom designed to fit within the cart frames. The two baskets will snugly fit therein. If only one basket is required, or access to the main container is required, one of the baskets is designed to accommodate a small infant, by flipping up a hinged cover that reveals leg openings at the bottom end of the basket. After shopping is complete, the groceries are removed as usual at checkout, and then reinserted into the cart. The cart is then utilized for the return trip home. The bottom container is equipped with at least two heavy duty removable bags which are preferably canvas. Therefore, a need for large grocery bags would be virtually eliminated. If the cart is full, remove the two top baskets and place them in a user's car, then remove the two bottom canvas bags. The cart is now ready to fold and return to your car.
If the user lives in an apartment complex where the car is a good distance from his unit, the process is simply reversed by rolling the groceries to the user's door or elevator. In addition, the cart can be utilized in large shopping malls or stores without shopping carts for people with large shopping lists such as at Christmas time.
The two wheeled version allows single or older shoppers with much smaller requirements to shop with the same advantages. In addition, older shoppers living within a few blocks of the grocery store could easily walk thereto utilizing the cart and return with their shopping items therein.
The invention relates to an improved shopping cart that is useful to contain shopping items chosen by customers in self service stores.
The carts of this type are preferably constructed of light weight materials so they can be easily moved and stored. One object of the invention is to provide a light weight design that becomes increasingly more ridged as it is loaded.
The inventions encountered in the prior art do not meet the need of a consumer shopping in a self serve store in that the prior inventions do not have a bottom container made form a light weight web to hold bulk items and have tubs to hold small items. Further, the current invention folds for storage or transport in a consumers vehicle to the self service store.
Accordingly, it is an object of the present invention to provide a folding cart with provisions to hold shopping items.
More particularly, it is an object of the present invention to provide a web container to hold large bulky shopping items.
Another feature of the present invention are tubs that are designed to hold small items and be placed on the checkout counter of a self service store.
Yet another feature of the present invention is that the tubs may be stacked in such a way that the upper tub is held by the rim of the lower tub so that the upper tub does not press upon the items in the lower tub.
Still another feature of the present invention is that it is designed so that, when the cart is in the open position, as more items are placed in the cart the critical structural members of the webbing are placed under tension making the cart more ridged.
Another feature of the present invention is that it has wheels so that it may be pushed by the user.
Still another feature of the present invention is that it has one pair of wheels that swivel to provide directional control.
When the tub is designed in accordance with the present invention, the transverse grooves on the bottom of the tubs securely lock into the frame.
The novel features which are considered characteristic for the invention are set forth in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read and understood in connection with the accompanying drawings.
EMBODIMENT
110--collapsible shopping cart (110)
112--frame (112)
112A--frame left bottom longitudinal member (112A)
112AA--frame left bottom longitudinal member adapter (112AA)
12AB--frame left bottom longitudinal member left slide assembly (112AB)
112B--frame right bottom longitudinal member (112B)
112BB--frame right bottom longitudinal member right slide assembly (112BB)
112C--frame cross brace assembly (112C)
112CA--frame cross brace assembly right cross brace (112CA)
112CAA--frame cross brace assembly left upper fastener (112CAA)
112CB--frame cross brace assembly left cross brace (112CB)
112CBA--frame cross brace assembly pivot fastener (112CBA)
112CD--frame cross brace assembly front cross brace pivot (112CD)
112E--frame left upper longitudinal member (112E)
112F--frame right upper longitudinal member (112F)
113--web basket (113)
113A--web basket right diagonal (113A)
113B--web basket left diagonal (113B)
113CA--web basket front upper cross brace (113CA) 113CB--web basket front lower cross brace (113CB)
113DA--web basket rear upper cross brace (113DA)
113DB--web basket rear lower cross brace (113DB)
114--handle (114)
114A--handle left riser bar (114A)
14AA--handle left riser bar lower fastener (not shown)
114B--handle right riser bar (114B)
114BA--handle left riser bar lower fastener (not shown)
114C--handle push bar (114C)
114CA--handle push bar left riser bar joint (114CA)
114CB--handle push bar right riser bar universal joint (114CB)
116--mainwheel (116)
116AA--main wheel left tire (116AA)
116AAA--main wheel left axil (116AAA)
116AAB--main wheel left hub (116AAB)
116AAC--main wheel left axil retainer fastener (116AAC)
116AAD--main wheel left axil retainer (116AAD)
116AB--main wheel right tire (not shown)
116ABA--main wheel right axil (not shown)
116ABB--main wheel right hub (not shown)
116ABC--main wheel right axil retainer fastener (not shown)
116ABD--main wheel right ail retainer (not shown)
120--tub (120)
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a perspective left side view of the two wheeled shopping cart having a tub positioned thereon.
FIG. 2 is a perspective view from the left front side of a two wheeled shopping cart in a fully collapsed position.
FIG. 3 is a perspective view of a main wheel left tire mounting onto a main wheel left axil retainer attached to a frame left bottom longitudinal member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Firstly, referring to FIG. 1 and FIG. 2 which are a perspective left front view of a collapsible shopping cart (110) in an opened position having a tub (120) being positioned thereon, and a perspective view from the left front side of a two wheeled shopping cart in a fully collapsed position, respectively. The collapsible shopping cart (110) comprises a frame (112) which comprises a frame left bottom longitudinal member (112A) having a frame left bottom longitudinal member adapter (112AA) positioned at a front distal end thereof The frame left bottom longitudinal member (112A) further comprises a frame left bottom longitudinal member left slide assembly (112AB) rotatably mounted within the frame left bottom longitudinal member (112A) and the frame left bottom longitudinal member adapter (112AA), the frame (112) further comprises a frame right bottom longitudinal member (112B) having a frame right bottom longitudinal member right slide assembly (112BB) rotatably mounted therein and extending from a front distal end thereof
The collapsible shopping cart (110) further comprises a frame cross brace assembly (112C) which comprises a frame cross brace assembly right cross brace (112CA) securely attached at a bottom distal end to the frame right bottom longitudinal member right slide assembly (112BB). The frame cross brace assembly (112C) further comprises a frame cross brace assembly left cross brace (112CB) securely attached at a bottom distal end to the frame left bottom longitudinal member left slide assembly (112AB). A frame cross brace assembly front cross brace pivot (112CD) movably connects the frame cross brace assembly right cross brace (112CA) to the frame cross brace assembly left cross brace (112CB) in a mid section thereof
The collapsible shopping cart (110) further comprises a front distal end of a frame left upper longitudinal member (112E) pivotally connected to a top distal end of the frame cross brace assembly right cross brace (112CA) by a frame cross brace assembly left upper fastener (112CAA).
The collapsible shopping cart (110) further comprises a front distal end of a frame right upper longitudinal member (112F) pivotally connected to a top distal end of the frame cross brace assembly left cross brace (112CB) by a frame cross brace assembly pivot fastener (112CBA).
The collapsible shopping cart (110) further comprises a web basket (113) which comprises a first set of plurality of web basket right diagonals (113A) securely attached at a top distal end to the frame left upper longitudinal member (112E) and securely attached at a bottom distal end to the frame left bottom longitudinal member (112A). A second set of plurality of web basket right diagonals (113A) are securely attached at a top distal end to the frame right upper longitudinal member (112F) and securely attached at a bottom distal end to the frame right bottom longitudinal member (112B). A third set of plurality of web basket right diagonals (113A) are securely attached at a top distal end to a web basket front upper cross brace (113CA) which is securely attached on a left distal end to the front distal end of the frame left upper longitudinal member (112E) and further securely attached on a right distal end to the front distal end of the frame right upper longitudinal member (112F). The third set of plurality of web basket right diagonals (113A) are securely attached at a bottom distal end to a web basket front lower cross brace (113CB) which is securely attached at a left distal end to the front distal end of the frame left bottom longitudinal member (112A) and further securely attached at a right distal end to the front distal end of the frame right bottom longitudinal member (112B). A fourth set of plurality of web basket right diagonals (113A) are securely attached at a top distal end to a web basket rear upper cross brace (113DA) which is securely attached on a left distal end to the rear distal end of the frame left upper longitudinal member (112E) and further securely attached on a right distal end to the rear distal end of the frame right upper longitudinal member (112F). The fourth set of plurality of web basket right diagonals (113A) are securely attached at a bottom distal end to a web basket rear lower cross brace (113DB) which is securely attached at a left distal end to the rear distal end of the frame left bottom longitudinal member (112A) and further securely attached at a right distal end to the rear distal end of the frame right bottom longitudinal member (112B). The web basket (113) further comprises a first set of plurality of web basket left diagonals (113B) which are securely attached at a top distal end to the frame left upper longitudinal member (112E) and securely attached at a bottom distal end to the frame left bottom longitudinal member (112A). A second set of plurality of web basket left diagonals (113B) are securely attached at a top distal end to the frame right upper longitudinal member (112F) and securely attached at a bottom distal end to the frame right bottom longitudinal member (112B). A third set of plurality of web basket left diagonals (113B) are securely attached at a top distal end to the web basket front upper cross brace (113CA). The third set of plurality of web basket left diagonals (113B) are securely attached at a bottom distal end to the web basket front lower cross brace (113CB). A fourth set of plurality of web basket left diagonals (113B) are securely attached at a top distal end to a web basket rear upper cross brace (113DA), the fourth set of plurality of web basket left diagonals (113B) are securely attached at a bottom distal end to a web basket rear lower cross brace (113DB).
The collapsible shopping cart (110) further comprises a handle (114) which comprises a handle left riser bar (114A) securely attached at a bottom distal end to the rear distal end of the frame left upper longitudinal member (112E) by a handle left riser bar lower fastener (not shown). The handle left riser bar (114A) is pivotally connected at a top distal end to left distal end of a handle push bar (114C) by a handle push bar right riser bar universal joint (114CB). The handle (114) further comprises a handle right riser bar (114B) securely attached at a bottom distal end to the rear distal end of the frame right upper longitudinal member (112F) by a handle left riser bar lower fastener (not shown). The handle right riser bar (114B) is removably attached at a top distal end to a right distal end of the handle push bar (114C) by a handle push bar left riser bar joint (114CA).
The collapsible shopping cart (110) is manufactured from a material selected from a group consisting of plastic, plastic composite, epoxy, fiberglass, carbon-graphite, wood, wood composite, metal, and metal alloy.
Lastly, referring to FIG. 3 is a perspective view of a main wheel left tire (116AA) mounting onto a main wheel left ail retainer (116AAD) attached to a frame left bottom longitudinal member (112A). At least two main wheels (116) comprise a main wheel left tire (116AA) mounted on a main wheel left hub (116AAB) which is securely connected to an outer distal end of a main wheel left axil (116AAA) which is rotatably connected at an inner distal end to a main wheel left axil retainer (16AAD) securely mounted on the frame left bottom longitudinal member (112A) by at least one main wheel left axil retainer fastener (116AAC). A main wheel right tire (not shown) is mounted on a main wheel right hub (not shown) which is securely connected to an outer distal end of a main wheel right ail (not shown which is rotatably connected at an inner distal end to a main wheel right axil retainer (not shown) securely mounted on the frame right bottom longitudinal member (112B) by at least one main wheel right axil retainer fastener (not shown).
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the type described above.
While the invention has been illustrated and described as embodied in a collapsible shopping cart, it is not intended to be limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
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The collapsible shopping cart has a main basket made of a web material for placing shopping items. Additional volume is provided by adding nesting tubs to the upper perimeter of the cart. The collapsible shopping cart is rolled on four wheel one set of which permit the cart to be steered. The cart is collapsible to a small volume for storage or transportation in a users vehicle.
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[0001] Priority is claimed to U.S. Provisional Patent Application No. 60/563,376 (filed in the U.S. Patent and Trademark Office on Apr. 19, 2004), U.S. Provisional Patent Application No. 60/579,067 (filed in the U.S. Patent and Trademark Office on Jun. 10, 2004), U.S. Provisional Patent Application No. 60/586,746 (filed in the U.S. Patent and Trademark Office on Jul. 10, 2004), U.S. Provisional Patent Application No. 60/590,469 (filed in the U.S. Patent and Trademark Office on Jul. 24, 2004), U.S. Provisional Patent Application No. 60/598,527 (filed in the U.S. Patent and Trademark Office on Aug. 3, 2004), U.S. Provisional Patent Application No. 60/599,826 (filed in the U.S. Patent and Trademark Office on Aug. 7, 2004), U.S. Provisional Patent Application No. 60/626,152 (filed in the U.S. Patent and Trademark Office on Nov. 8, 2004), U.S. Provisional Patent Application No. 60/645,245 (filed in the U.S. Patent and Trademark Office on Jan. 20, 2005), U.S. Provisional Patent Application No. 60/658,242 (filed in the U.S. Patent and Trademark Office on Mar. 3, 2005), which are all herein incorporated by reference in entirety.
BACKGROUND
[0002] The reproduction of images has had a positive effect on many people's lives. One of the earliest technologies for reproducing images was the movie projector, which allowed for audiences to view theatrical productions without live actors and actresses. Televisions were invented, which allowed people to watch moving pictures in the comfort of their own homes. The first televisions were cathode ray tube (CRT) televisions, which is a technology that is still being used today. During the computer age, it has been desirable to reproduce images which are output from computers through monitors. Like many televisions, many computer monitors use CRT technology.
[0003] Other technologies have been developed as substitutes for CRT technology. For example, liquid crystal display (LCD) technology is commonplace for both computer monitors and televisions. A LCD is a relatively thin display, which is convenient for many people. Other examples of displays are plasma displays, rear projections displays, and projectors. As display technology has improved, many new applications are being developed. For example, many attempts have been made to develop displays which create viewable images in glass. However, there have been many technical challenges that have prevented creation of viewable images in glass or other transparent material. Specifically, it has been difficult for glass to be maintained in a substantially transparent state and be able to display viewable images with sufficient illumination and clarity.
SUMMARY
[0004] In accordance with embodiments, viewable images can be created in glass. Viewable images may be created in glass by using at least one ultraviolet light source (e.g. a projector) to excite light emitting material. Clear images may be created in glass because the size the light emitting particles in the glass is relatively small (e.g. less than 500 nanometers). In embodiments, the visible illumination of a transparent substrate to display an image is possible, while the transparent substrate remains transparent. Accordingly, for example, drivers of automobiles may view images (e.g. map images) on their windshield while they are driving. As another example, window shoppers may view enhanced advertisements in the windows of stores that they are approaching, while the windows remain transparent. In embodiments, different colors may be illuminated on glass by adjusting the wavelength of the ultraviolet light to create color images.
[0005] Embodiments relate to an apparatus including a light source, a projection modulator, and a variable light filter. The projection modulator is configured modulate light emitted from the light source. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light include light with a wavelength less than 500 nanometers.
[0006] Embodiments relate to a method including emitting light from a light source, modulating the light at a projection modulator, and filtering the light at a variable light filter. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light include light with a wavelength less than 500 nanometers.
[0007] Embodiments relate to a method including integrating a light source, a projection modulator, and a variable light filter into a projector. The projection modulator is configured modulate light emitted from the light source. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light comprise light with a wavelength less than 500 nanometers.
DRAWINGS
[0008] FIG. 1 is an example diagram of a substantially transparent display.
[0009] FIG. 2 is an example diagram of a transparent display illuminated with excitation light from a projector.
[0010] FIG. 3 is an example diagram of light emitting particles integrated into a substantially transparent substrate.
[0011] FIG. 4 is an example diagram of a micro mirror device, illustrating general operation characteristics when used in a projector.
[0012] FIG. 5 is an example diagram illustrating direct reflection operation of a micro mirror device.
[0013] FIGS. 6 and 7 illustrate example relationships of components of a projector that includes a micro mirror device.
[0014] FIGS. 8 through 11 illustrate examples of different variable light filters.
DESCRIPTION
[0015] FIG. 1 is an example diagram of a substantially transparent display, in accordance with embodiments. Viewer 110 is able to see an arbitrary object (e.g. cube 112 ) through substrate 114 . Substrate 114 may be transparent or substantially transparent. While viewer 110 sees arbitrary object 112 through substrate 114 , the viewer can also see images (e.g. circle 115 and triangle 116 ) that are created at substrate 114 . Substrate 114 may be part of a vehicle windshield, a building window, a glass substrate, a plastic substrate, a polymer substrate, or other transparent (or substantially transparent) medium that would be appreciated by one of ordinary skill in the art. Other substrates may complement substrate 114 to provide for tinting, substrate protection, light filtering (e.g. filtering external ultraviolet light), and other functions.
[0016] FIG. 2 is an example diagram of a transparent display illuminated with excitation light (e.g. ultraviolet light) from a projector 118 , in accordance with embodiments. Substrate 114 may receive excitation light from projector 118 . The received excitation light may be absorbed by light emitting material at substrate 114 . When the light emitting material receives the excitation light, the light emitting material may emit visible light. Accordingly, images (e.g. circle 115 and triangle 116 ) may be created at substrate 114 by selectively illuminating substrate 114 with excitation light.
[0017] The excitation light may be ultraviolet light, in accordance with embodiments. If the excitation light is ultraviolet light, then when the light emitting material emits visible light in response to the ultraviolet light, a down-conversion physical phenomenon occurs. Specifically, ultraviolet light has a shorter wavelength and higher energy than visible light. Accordingly, when the light emitting material absorbs the ultraviolet light and emits lower energy visible light, the ultraviolet light is down-converted to visible light because the ultraviolet light's energy level goes down when it is converted into visible light; In embodiments, the light emitting material is fluorescent material.
[0018] In embodiments illustrated in FIG. 2 , the excitation light is output by projector 118 . Projector 118 maybe a digital projector. In embodiments projector 118 is a micro mirror projector (e.g. a digital light processing (DLP) projector). Projector 118 may include a micro-mirror array (MMA). In embodiments, projector 118 includes a digital micromirror device (DMD). In other embodiments, projector 118 includes an analog micromirror device. Projector 118 includes a variable light filter which is tailored to the ultraviolet light spectrum. In embodiments, the variable light filter is a color wheel with at least two light filters that let different ranges of ultraviolet light pass.
[0019] FIG. 3 is an example diagram of light emitting material (e.g. light emitting materials 178 , 180 , and/or 182 ) integrated into a substantially transparent substrate, according to embodiments. When excitation light is absorbed by the light emitting materials 178 , 180 , and/or 182 , the light emitting materials emit visible light. Accordingly, when ultraviolet light is absorbed by light emitting materials 178 , 180 , and/or 182 , visible light is emitted from the light emitting materials. In embodiments, each of light emitting materials 178 , 180 , and/or 182 may be a different type of light emitting material, which emits a different range of wavelengths of visible light in response to a different range of wavelengths of excitation light (e.g. ultraviolet). The different ranges of wavelengths of excitation light may be controlled by a variable light filter. Light emitting material can be integrated in a substantially transparent substrate in a variety of ways. As examples, light emitting materials can be dispersed in a substrate (as shown in example FIG. 3 ), layered on a substrate, and disposed on a surface of a substrate.
[0020] Light emitting material (e.g. light emitting materials 178 , 180 , and/or 182 ) may be fluorescent material, which emits visible light in response to absorption of electromagnetic radiation (e.g. visible light, ultraviolet light, or infrared light) that is a different wavelength than the emitted visible light. Light emitting material may include light emitting particles. The size of the particles may be smaller than the wavelength of visible light, which may reduce or eliminate visible light scattering by the particles. Examples of particles that are smaller than the wavelength of visible light are nanoparticles, individual molecules, and individual atoms.
[0021] According to embodiments, each of the light emitting particles has a diameter that is less than about 500 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 450 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 420 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 400 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 300 nanometer. According to embodiments, each of the light emitting particles has a diameter that is less than about 200 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 100 nanometers. According to embodiments, each of the light emitting particles has a diameter that is less than about 50 nanometers. The light emitting particles may be individual molecules or individual atoms.
[0022] Different types of light emitting particles (e.g. light emitting materials 178 , 180 , and/or 182 ) may be used together that have different physical characteristics. For example, in order to create color images in substrate 114 , different types of light emitting particles may be utilized that are associated with different colors. For example, a first type of light emitting particles may be associated with the color red, a second type of light emitting particles may be associated with the color green, and a third type of light emitting particles may be associated with the color blue. Although the example first type, second type, and third type of light emitting particles are primary colors, one of ordinary skill in the art would appreciate other combinations of colors (e.g. types of colors and number of colors) in order to facilitate a color display.
[0023] In down-conversion embodiments (e.g. absorption of ultraviolet light to emit visible light), light emitting particles which emit red light may include Europium, light emitting particles which emit green light may include Terbium, and/or light emitting particles which emit blue or yellow light may include Cerium (and/or Thulium). In embodiments, light emitting particles which emit blue light may include Erbium. In embodiments, light emitting materials which emit blue light may include an organic fluorescent dye.
[0024] Different types of light emitting particles may absorb different ranges of excitation light to emit the different colors. Accordingly, the wavelength range of the excitation light may be modulated to control the visible color emitted from the light emitting particles in substrate 114 . In embodiments, different types of light emitting particles may be mixed together and integrated into substrate 114 . By modulating the wavelength of the excitation light, visible light with specific color characteristics can be created in substrate 114 . For example, by selectively exciting specific combinations of different types of light emitting particles associated with primary colors, virtually any visible color can be emitted from substrate 114 . In embodiments, modulating of the excitation light wavelength can utilize a variable light filter. In embodiments, the variable light filter is a color wheel with specific ultraviolet pass filters.
[0025] FIG. 4 is an example diagram illustrating operation of a projector which uses micro mirror device 10 , in accordance with embodiments. However, other implementations and configurations of a projector can be appreciated, in accordance with embodiments. The projector may include light source 9 (e.g. a lamp), micro mirror device 10 , projection lens 11 , and absorption plate 13 . Micro mirror device 10 may receive light output from light source 9 and may reflect the incident light at an angle in accordance with a control signal input to micro mirror device 10 . Projection lens 11 may focus light reflected from micro mirror device 10 onto screen 15 when a corresponding mirror is at a first angle. Absorption plate 13 may absorb light reflected off of micro mirror device 10 when a corresponding mirror is at a second angle. Accordingly, light can be either projected onto screen 15 or absorbed at absorption plate 13 , depending on an angle of each respective mirror of micro mirror device 10 . Micro mirror device 10 may include an array of micro mirrors which can be selectively controlled to form images on screen 15 .
[0026] In embodiments, light source 9 may output ultraviolet light. Light source 9 may be a gas discharge lamp, a solid state lamp, a light emitting diode lamp, and/or a metal halide lamp. Other types of lamps that can output ultraviolet light can be appreciated. Light source 9 may include a reflector. In embodiments, the reflector has a reflective enhancement coating. In embodiments, the reflective enhancement coating reflects light having a wavelength less than 500 nanometer. In embodiments, the reflective enhancement coating reflects light having a wavelength less than 450 nanometer. In embodiments, the reflective enhancement coating reflects light having a wavelength less than 420 nanometer. In embodiments, the reflective enhancement coating reflects ultraviolet light.
[0027] Micro mirror device 10 may include blackboard 1 , a plurality of electrodes 3 , micro mirrors 5 , and support 7 . Plurality of electrodes 3 may be coupled to the blackboard 1 . Micro mirrors 5 may receive light output from light source 9 and selectively reflect the light at different angles to form images on screen 15 . Support 7 mechanically supports micro mirrors 5 .
[0028] Plurality of electrodes 3 may generate an electrostatic field by an input voltage signal to modulate movements of supporting member 7 . Micro mirrors 5 (which may be relatively small) may be attached to supporting member 7 and rotated at a relatively small angle. Light is reflected from light source 9 to either projection lens 11 or absorption plate 13 , depending on the angle of micro mirror 5 . Projection lens 11 may receive light reflected from micro mirror device 10 and project the light to the screen 15 to display an image.
[0029] Micro mirrors 5 may be slanted at an initial angle. When light output from light source 9 is projected onto micro mirrors 5 , micro mirrors 5 reflect the light to absorption plate 13 . Accordingly, under these circumstances, since micro mirrors 5 do not reflect light to projection lens 11 , a blank image (e.g. black image) appears on screen 15 .
[0030] When a signal is input to plurality of electrodes 3 on blackboard 1 , plurality of electrodes 3 may generate an electrostatic field which selectively causes supporting member 7 to rotate within a sufficient angle range. When micro mirrors 5 are rotated at an appropriate angle, light incident on micro mirrors 5 is reflected to projection lens 11 , which projects the light onto screen 15 , causing selective illumination of pixels (associated with rotated micro mirrors 5 ). Micro mirrors 5 may be selectively rotated at high speeds (e.g. on/off operations) to produce a moving (or static) image on screen 15 .
[0031] FIG. 5 is an example illustration of a projector operating with direct reflection off of micro mirror device 20 , in accordance with embodiments. A projector may include light source 19 , filter wheel 17 , and micro mirror device 20 . Micro mirror device 20 may be in the form of a chip and may be attached to board 21 . Filter wheel 17 (an example of a variable filter) may be for varying the wavelength of the light output from light source 19 into different spectrums of ultraviolet light. For example rotation of filter wheel 17 may vary the wavelength of light that is allowed to pass through filter wheel 17 . Micro mirror device 20 may receive light output from filter wheel 17 and reflect the light onto screen 23 .The selective reflection of light from micro mirror device 20 and the position in rotation of filter wheel 17 may be calibrated so that images with predetermined characteristics can be displayed.
[0032] FIG. 6 is an example illustration of projector components which includes a prism, in accordance with embodiments. FIG. 7 is a different view of the projector components illustrated in FIG. 6 . A projector may include light source 25 , filter wheel 27 , light pipe 29 , lens 30 , mirror 31 , lens 32 , prism 33 , micro mirror device 35 , and/or lens 37 , which may be configured to manipulate ultraviolet light.
[0033] Filter wheel 27 may be for varying the wavelength of the light output from light source 25 in the ultraviolet spectrum. Filter wheel 27 may rotate to vary the wavelength of light that is allowed to pass through filter wheel 27 . Micro mirror device 35 may receive light output from filter wheel 27 and reflect the light onto screen 38 . The selective reflection of light from micro mirror device 35 and the position in rotation of filter wheel 27 may be calibrated so that images with predetermined characteristics can be displayed. Light pipe 29 may receive light from filter wheel 27 and spatially redistribute the light at a substantially uniform intensity. In embodiments, light pipe 29 is designed to reflect ultraviolet light, so that incident ultraviolet light is spatially redistributed at a substantially uniform intensity. Lens 30 may be for focusing light output from light pipe 29 to reduce the diameter of the light. In embodiments, lens 30 is configured to collect ultraviolet light. Mirror 31 may be for reflecting light output from lens 30 at an angle. Lens 32 may be for focusing light output from mirror 31 . In embodiments, lens 30 and lens 32 are configured to focus ultraviolet light. Prism 33 may receive light output from lens 32 and transmit the light in a direction according to angles of mirrors of micro mirror device 35 , in accordance with control signals input into micro mirror device 35 . In embodiments, prism 33 is configured to transmit ultraviolet light.
[0034] In FIG. 4 through 7 , micro mirror device 13 , micro mirror device 20 , and micro mirror device 35 are examples of projection modulators. However, other types of projection modulators can be appreciated. Arrangement, inclusion, and/or exclusion of components which have functional relationships with a projection modulator can be appreciated. In embodiments, a projection modulator can be configured to modulate ultraviolet light.
[0035] In FIGS. 4 through 7 , filter wheel 17 and filter wheel 27 are examples of variable light filters. However, other types of variable light filters can be appreciated. Arrangement, inclusion, and/or exclusion of components which have functional relationships with a variable light filter can be appreciated. In embodiments, a variable light filter can be configured to pass different spectrums of ultraviolet light.
[0036] In FIGS. 6 and 7 , light pipe 29 is an example of a light integrator. However, other types of light integrators can be appreciated. Arrangement, inclusion, and/or exclusion of components which have functional relationships with a light integrator can be appreciated. In embodiments, a light integrator can be configured to spatially redistribute ultraviolet light substantially uniformly. In embodiments, a light integrator may include an ultraviolet transparent material (e.g. material which transmits light having a wavelength less than 500 nanometers). Example ultraviolet transparent materials are fused silica, calcium fluoride, magnesium fluoride, sapphire, barium fluoride, beryllium oxide, calcite, and/or germanium oxide.
[0037] FIGS. 8 through 11 illustrate examples of different variable filters. FIG. 8 illustrates variable light filter 214 with a first region 210 and a second region 212 . Variable light filter 214 may be a filter wheel. First region 210 and second region 212 may be filters that pass different ranges of excitation light.
[0038] FIG. 9 illustrates variable light filter 216 with four regions (regions 224 , 222 , 218 , and 220 ). Any number of regions could be implemented in accordance with embodiments.
[0039] FIG. 10 illustrates variable light filter 226 with three regions (regions 232 , 230 , and 228 ). As illustrated in FIG. 10 , the different regions can be distributed non-uniformly. As illustrated in FIGS. 8 and 9 , the different regions can be distributed uniformly. Regions may be distributed non-uniformly to compensate differences in visible light emission of light emitting materials.
[0040] FIG. 11 illustrates variable light filter 234 with four regions (regions 242 , 240 , 238 , and 236 ) distributed in a spiral pattern. A variable light filter with a spiral pattern may increase efficiency of a projector by reusing back reflected light. As illustrated in FIGS. 8 through 10 , regions of a variable light filter may be distributed in a radial direction. Other distributions of light filter regions can be appreciated.
[0041] Embodiments relate to an apparatus including a light source, a projection modulator, and a variable light filter. The projection modulator is configured to modulate light emitted from the light source. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light include light with a wavelength less than 500 nanometers. The at least two different wavelength ranges of light may include light with a wavelength less than 450 nanometers. The at least two different wavelength ranges of light may include light with a wavelength less than 420 nanometers. The light transmitted through the light source may be projected onto a substantially transparent substrate. Fluorescent particles may be integrated into the substantially transparent substrate. Fluorescent particles may emit visible light in response to absorption of light emitted from the light source. Each of the fluorescent particles may have a diameter less than 500 nanometers. The at least two different wavelength ranges of light may include ultraviolet light. The at least two different wavelength ranges of light may consist of ultraviolet light. The projection modulator may include an array of modulators. Each modulator of the array of modulators may be a movable mirror. The projection modulator may be a micro mirror device. The micro mirror device may be an analog micro mirror device. The micro mirror device may be a digital micro mirror device. The micro mirror device may be configured to modulate light having a wavelength less than 500 nanometers. The variable light filter may be configured to transmit light prior to the light being modulated by the projection modulator. The variable light filter may include a disk with at least two different types of light filters. The variable light filter may be configured to selectively transmit the at two different wavelength ranges of light by selectively rotating the disk to control which of the at least two different types of light filters is in a path of light emitted from the light source. The at least two different types of light filters may be substantially evenly distributed on the disk. The at least two different types of light filters may be non-uniformly distributed on the disk. The at least two different types of light filters may be distributed on the disk in a radial direction. The at least two different types of light filters may be distributed on the disk in a spiral pattern. At least one lens may be configured to focus light having a wavelength less than 500 nanometers. A light integrator may be configured to redistribute light having a wavelength less than 500 nanometers. The light integrator may include an ultraviolet transparent material and an anti-reflective coating for light having a wavelength less than 500 nanometers. The ultraviolet transparent material may include fused silica, calcium fluoride, magnesium fluoride, sapphire, barium fluoride, beryllium oxide, calcite, and/or germanium oxide. The light source may include a reflector. The reflector may have a reflective enhancement coating for light having a wavelength less than 500 nanometers. The light source may include an ultraviolet lamp. The ultraviolet lamp may be one of a gas discharge lamp, a solid state lamp, a light emitting diode lamp, and a metal halide lamp. A visible light filter may be configured to substantially remove visible light emitted from the light source prior to light from the light source being modulated by the projection modulator. A light separator may be configured to separate light having a wavelength less than 500 nanometers.
[0042] Embodiments relate to a method including emitting light from a light source, modulating the light at a projection modulator, and filtering the light at a variable light filter. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light include light with a wavelength less than 500 nanometers.
[0043] Embodiments relate to a method including integrating a light source, a projection modulator, and a variable light filter into a projector. The projection modulator is configured modulate light emitted from the light source. The variable light filter is configured to selectively transmit at least two different wavelength ranges of light. The at least two different wavelength ranges of light comprise light with a wavelength less than 500 nanometers.
[0044] The foregoing embodiments (e.g. light emitting material integrated into a substantially transparent substrate) and advantages are merely examples and are not to be construed as limiting the appended claims. The above teachings can be applied to other apparatuses and methods, as would be appreciated by one of ordinary skill in the art. Many alternatives, modifications, and variations will be apparent to those skilled in the art.
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In accordance with embodiments, viewable images can be created in glass. Viewable images may be created in glass by using a projector which projects ultraviolet light to excite light emitting material. Clear images may be created in glass because the size the light emitting particles in the glass is less than 400 nanometers. In embodiments, the visible illumination of a transparent substrate to display an image is possible, while the transparent substrate remains transparent. Accordingly, for example, drivers of automobiles may view images (e.g. map images) on their windshield while they are driving. As another example, window shoppers may view enhanced advertisements in the windows of stores that they are approaching.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transducer for detecting pressure changes in pipes, for example, pipes for supplying a fuel oil to be injected into a diesel engine and pipes in oil pressure systems, by detecting deformation of the pipes.
2. Description of the Prior Art
A typical prior art arrangement is shown in FIGS. 1(1)-1(3). On a pressure pipe 1 in which a pressure change is to be detected, a piezoelectric element 3 having a bimorph structure is arranged circularly and forced against the pipe 1 by means of a holder 4. A holder 5 is also provided on the pipe 1. The holders 4, 5, hitherto, have been made of a material such as synthetic rubber. From outside the holders 4, 5, cases 6, 7 in the form of two half structures are mounted by means of tightening pieces 8.
When fuel oil is fed into the pipe 1 under pressure, the diameter of the pipe 1 varies accordingly. Thereby, a voltage corresponding to the change in the radius of the pipe 1 is generated in the piezoelectric element 3. By detecting this voltage change, the pressure change in the pipe 1 may be detected.
The holder 4 serves to press the piezoelectric element 3 against the pipe surface so as to trace changes in the pipe diameter at high fidelity.
The piezoelectric element 3 is in tight contact with the pipe 1 when its radius is R in the natural condition as shown in FIG. 1(1).
As schematically shown in FIG. 1(2), when fluid pressure developed in the pipe 1 is enhanced for an instant, the pipe 1 is deformed as shown by the reference numeral 1a and has a radius R1 larger than the radius R of FIG. 1(1). Accordingly since both circumferential ends 3a of the piezoelectric element 3 are contacted tightly to the surface of the pipe 1a, the element 3 is stressed to be spread, and thus the element 3 generates a signal of an electrical voltage which makes it possible to detect the pressure change in the pipe 1a. When the pressure of the fluid in the pipe returns to the original state, the diameter of the pipe simultaneously returns to the original diameter and the piezoelectric element recovers accordingly.
In such prior art arrangement, as shown in FIG. 1(3), when the transducer is utilized on a pipe 1b having a radius R2 smaller than the pipes 1, 1a, opposite circumferential ends 3a of the piezoelectric element 3 may possibly contact loosely the surface of the pipe 1b of reduced diameter. The inventors determined that since the holder 4 is made of synthetic rubber as aforementioned and its compression elastic modulus (young modulus) is relatively small, 10 to 10 2 kg/cm 2 , the ends 3a of the piezoelectric element 3 will not be tightly pressed against the pipe.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a transducer for detecting pressure changes in pipes and designed to be utilized generally with pipes having various diameters.
The invention is directed to a transducer for detecting pressure changes in a pipe by converting the deformation of the pipe resulting from internal pressure changes of the pipe into electrical signals, such transducer includes a piezoelectric element having a bimorph structure and constructed in such a way that an intermediate layer is interposed between a pair of piezoelectric pieces. A holder presses the piezoelectric element against an outer surface of the pipe and is elastic so as to allow opposite ends of the piezoelectric element in the circumferential direction of the pipe to abut elastically against the pipe periphery.
In a preferred embodiment of the invention, an outer surface of the holder is covered by a rigid case.
In another preferred embodiment of the invention, the holder is formed into a pair of semi-cylindrical shapes and has a compression modulus of elasticity of 10 to 10 4 kg/cm 2 .
In a further preferred embodiment of the invention, the holder is mounted directly on the outer surface of the pipe.
In a still further preferred embodiment of the invention, the material of the holder consists of at least one material selected from the group consisting of polyurethane, polyethylene, polypropylene, tetrafluoroethylene-hexafluoropropene copolymer, tetrafluoroethylene-perfluoro (alkylvinyl ether) copolymer, thermoplastic-polyester elastomer and olefin thermoplastic elastomer.
In another preferred embodiment of the invention, the piezoelectric element pressed against the pipe has, in the natural condition, an inside diameter smaller than the outside diameter of the pipe to be measured.
In a further preferred embodiment of the invention, the holder which presses the piezoelectric element against the pipe surface is formed into a semi-cylindrical shape, and a member having a V-shaped groove faces the holder and contacts the pipe surface with the pipe clamped therebetween.
In a preferred embodiment, the holder is formed into a semi-cylindrical shape, and a member facing the holder has an inner surface having a radius larger than that of the pipe surface.
According to the invention, a piezoelectric element having a bimorph structure is pressed against the pipe surface by a holder which is elastic so as to allow opposite ends of the piezoelectric element in the circumferential direction of the pipe to abut elastically against the outer surface of the pipe. Accordingly, the ends of the piezoelectric element will be contacted tightly against pipe surfaces of pipes having various diameters. Therefore, the internal pressure of such pipes can be detected reliably.
In particular, by selecting a compression modulus of elasticity between 10 2 to 10 4 kg/cm 2 for the holder, the piezoelectric element can be reliably contacted tightly to outer surfaces of pipes having various different diameters.
As described above, according to the invention, the internal pressure of pipe having various diameters can be detected accurately by the same configuration of transducer.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects of the invention as well as features and advantages thereof will be better understood from the following detailed description taken in conjunction with the drawings in which:
FIGS. 1(1)-1(3) are a sectional views of a prior art arrangement,
FIG. 2 is a sectional view of one embodiment of the invention,
FIG. 3 is a sectional view taken along line 3-3 in FIG. 2,
FIG. 4 is a sectional view of a piezoelectric element,
FIG. 5 is a perspective view illustrating a tightening device 18,
FIGS. 6(1)-6(3) are a sectional views explaining the operation of the embodiment shown in FIGS. 2 through 5,
FIG. 7 is a sectional view of another embodiment of the invention,
FIG. 8 is a sectional view of a further embodiment of the invention,
FIG. 9 is a sectional view of still another embodiment of the invention,
FIG. 10 is a sectional view of another embodiment of the invention,
FIG. 11 is a sectional view of still another embodiment of the invention,
FIG. 12 is a sectional view taken along line 12--12 in FIG. 11,
FIGS. 13(1)-13(3) are graphs showing experimental results based on the arrangements shown in FIGS. 2 through 5 of the invention, and
FIGS. 14(1)-14(3) are wave-form diagrams showing the experimental results of a relative example.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, preferred embodiments of the invention will be described in detail as follows.
FIG. 2 shown a pipe 11, the internal pressure changes of which are to be detected and through which, for example, fuel oil is supplied. A piezoelectric element 13 having a bimorph structure as a sensor element is pressed against pipe 11 by a holder 14 according to the invention via a protective layer 12. The protective layer 12 is to protect the piezoelectric element 13 and consists of a metal foil or the like. A holder 15 directly supports the pipe 11. From outside the holders 14, 15, a pair of generally semi-cylindrical cases 16, 17 are mounted detachably by a tightening device 18 as shown in FIG. 5 to be described later.
FIG. 4 is a sectional view of the piezoelectric element 13. The piezoelectric element 13 comprises two piezoelectric pieces 20, 21 adhered together via an intermediate layer 22 interposed therebetween.
There are two types of bimorph, namely (1) a serial-type bimorph in which two piezoelectric pieces 20, 21 are adhered together in mutually opposite polarization directions, and electrodes mounted respectively outside thereof are coupled with electric terminals, and (2) a parallel-type bimorph in which two piezoelectric pieces are adhered together in identical polarization directions via an electrode interposed therebetween, and electrodes mounted outside thereof are electrically connected and coupled with the electric terminals together with the intermediate electrode, and both types of bimorph can be used with the invention.
The piezoelectric pieces 20, 21 constituting the bimorph are made of (a) high polymer piezoelectric material or (b) a composite piezoelectric material composed of a mixture of ceramic piezoelectric material with high polymer material or high polymer piezoelectric material. For example, as the high polymer piezoelectric material, vinylidene fluoride polymers such as vinylidene fluoride homopolymer or vinylidene fluoride-trifluoroethylene copolymer may be used.
The measuring principle of the bimorph will be described. The bimorph can detect changes in the pipe diameter caused by pipe internal pressure changes by sensing voltage changes. Supposing the output voltage of the bimorph to be Vp [V], it is expressed as follows:
Vp=cgt.sup.2 r.sup.-1 (1)
where
c: elastic modulus of piezoelectric piece [N/m 2 ]
g: voltage output coefficient of piezoelectric piece [V.m/N]
t: thickness of piezoelectric piece (single) [m]
r: radius of curvature (distance from pipe center to center of bimorph) [m]
As is clear from equation (1), since the output voltage Vp is proportional to the square of the thickness t of a single piezoelectric piece, a greater output voltage is obtained when the thickness of the piezoelectric pieces 20, 21 is increased, so that the sensitivity of detection is enhanced.
Installing the intermediate layer 22 between the piezoelectric pieces 20, 21, is equally efficacious as increasing the thickness of the piezoelectric pieces 20, 21 by the thickness of the intermediate layer 22, so that the sensitivity of detection is improved similarly. The material of the intermediate layer 22 is not particularly limited as long as it is a conductor, and more preferably metal sheets such as copper, aluminum, phosphor bronze, etc. are used. The thickness t of the intermediate layer 22 may be preferably 0.1 to 2.0 mm.
FIG. 5 is a perspective view showing the tightening device 18 provided on the cases 16, 17. First ends of the cases 16, 17 are angularly displaceable about an axis parallel to an axis of the pipe 11 and defined by a pin 23. On the other end of the case 16, a manual lever 25 which is angularly displaceable is pivoted by means of a pin 24. A connecting piece 26 is pivoted at base end portions 27 thereof in an angularly displaceable fashion on manual lever 25. The connecting piece 26 can tighten the cases 16, 17 by being engaged into an engaging groove 28 in the case 17 and being displaced angularly about the axis of the pin 24 of the manual lever 25. It is not intended to limit the invention to the tightening device 18 constructed as shown in FIG. 5.
It is required that the piezoelectric element 13 be pressed on the outer surface of the pipe 11 so as to trace changes in the pipe diameter at high fidelity. For this purpose, the holder 14 is used. Thereby, fine changes in diameter caused by the pipe internal pressure changes of the pipe can be detected. According to the invention, as the material for the holders 14, 15, one or more following materials may be used, polyurethane, polyethylene (PE), polypropylene (PP), tetrafluoroethylene-hexafluoropropene copolymer (FEP), tetrafluoroethylene-perfluoro (alkylvinyl ether) copolymer (PFA), thermoplastic polyester elastomer (commercially available as "Hytrel" trade name by Toray-Dupont) and olefin thermoplastic elastomer (commercially available as "Milastramer" trade-name by Mitsui Petrochemical). A compression modulus of elasticity (Young modulus) of the holders 14, 15 is preferably 10 2 to 10 4 kg/cm 2 and more preferably about 10 3 kg/cm 2 . The cases 16, 17 are made of a material such as nylon or the like and their compression modulus of elasticity is 3×10 4 kg/cm 2 .
FIG. 6(1) shows the piezoelectric element 13 attached tightly to the outer surface of the pipe 11 having a radius R in the natural condition. When a transducer having such a configuration is utilized on a pipe 11a having a radius R1 larger than the radius R as shown in FIG. 6(2), both ends 13a of the piezoelectric element 13 are expanded as shown by arrows 29, and the piezoelectric element 13 is pressed tightly against the outer surface of the pipe 11a by the holder 14. In both cases, fine changes in pipe diameter may be measured.
When the transducer of the invention is then utilized again on the pipe 11 having the radius R as shown in FIG. 6(3) from the state shown in FIG. 6(2), the piezoelectric element 13 is returned to the original shape, that is, to the shape shown in FIG. 6(1) by the strong force of the holder 14 being compressed, because the holder 14 has relatively large compression modulus of elasticity as aforementioned. A large force f generated thereby acts on the ends 13a in the circumferential direction of the pipe 11 to press ends 13a tightly against the pipe 11. Accordingly, fine pressure changes in the pipe 11, that is fine deformations of the pipe, can be detected. In FIGS. 6(1)-6(3) the protective layer 12 is omitted for simplification. The protective layer 12 need not be used.
It is enough that the piezoelectric element or the bimorph be pressed on the outer surface of the pipe so as to trace the pipe diameter changes. It is not necessary that the contact be frictional engagement to cause a frictional force to transmit deformation of the pipe surface accurately between the pipe and the piezoelectric element. When the piezoelectric element was a mere piezoelectric piece as in the prior art, it was required that the piezoelectric piece be pressed in frictional engagement in order to detect changes in the peripheral length of the pipe. However, in the case of the present invention using the bimorph, the measuring principle is different, that is, changes in the pipe diameter are detected instead of the changes in the peripheral length of the pipe, and hence it is not necessary to press the piezoelectric piece into frictional engagement with the pipe. Incidentally, in the case of a bimorph, if a force acts in the circumferential direction of the pipe due to changes in the peripheral length of the pipe, changes in voltage are not detected because electric charges generated in the two piezoelectric pieces cancel each other.
In the transducer of the invention, since a bimorph is used in the sensor element, the effects of noise signals cause by vibration of the pipe may be prevented without using a transducer case of a special structure to absorb the supporting force for the sensor element, as in conventional transducers. That is, when an inertial force is built up between the pipe and the piezoelectric element of bimorph type due to pipe vibration, the piezoelectric element is pressed in the direction of thickness by its inertial force, but in this case, the electric charges generated in the piezoelectric pieces of the piezoelectric element cancel each other, so that voltage changes are not detected. Therefore, the structure of the transducer may be much simplified.
FIG. 7 is a sectional view of another embodiment of the invention. The parts corresponding to the aforesaid embodiment are designated by the same reference numerals. A case 30 includes a longitudinal V-shaped groove 31. In this embodiment, since the piezoelectric element 13 need not necessarily be disposed symmetrically to the pipe 11, a simplified structure is realized.
FIG. 8 is a sectional view of a further embodiment of the invention. A case 32 includes an inner surface 33 having a large radius of curvature for supporting the pipe 11.
The case 30 in FIG. 7 and the case 32 in FIG. 8 may be either elastic or rigid.
FIG. 9 is a sectional view of still another embodiment of the invention. A holder 34 for pressing the piezoelectric element 13 against the pipe 11 serves also as the case 16 aforementioned. As the material for the holder 34, a synthetic resin is used and its thickness t1 is made thinner so as to act the same as the holder 14 having the compression modulus of elasticity previously stated. Another case 35 is rigid.
FIG. 10 is a sectional view of another embodiment of the invention. A holder 36 holding the piezoelectric element 13 acts also as the case 16 and its thickness t2 is made thicker. A case 37 may be made of the same material as the holder 36.
FIG. 11 is a sectional view of a further embodiment of the invention, and FIG. 12 is a sectional view taken along the line 12--12 in FIG. 11. The piezoelectric element 13 is pressed against the outer surface of the pipe 11 by a band 41 made of an elastically expandable material. Opposite ends of the band 41 are connected by a tightening device 45, tightening pieces 42, 43 of which are connected by means of a bolt 44. The band 41 is in the same manner as the aforesaid holder 14. Since it is not necessary to provide the cases 16, 17 in the embodiment of FIGS. 11 and 12, the structure may be simplified.
Referring to FIGS. 13(1)-13(3) and 14(1)-14(3) experiment results will be described. An engine used in the experiment was that of a Camry (1984 trade mark) by Toyota. The experiment was carried out at an engine speed of 5,000 r.p.m. A transducer was mounted on a fuel injection pipe. FIGS. 13(1)-13(3) and 14(1)-14(3) show wave forms taken after the output of the piezoelectric element 13 was passed through a low-path filter having the characteristics of 120 HZ cut-off frequency and 24 dB/oct Butterworth to remove high-frequency noises. FIGS. 13(1)-13(3) show results of the configurations shown in FIGS. 2 through 6, "Hytrel" (trade-name) was used as the material for the holder 14 and compression modulus of elasticity of 900 kg/cm 2 was employed. The piezoelectric element 13 was arranged beforehand so as to be pressed on the pipe 11 and the pipe had an outside diameter of 6.0 mmφ in the natural condition. FIG. 13(1) shows a wave form detected when the outside diameter of the pipe 11 was 6.0 mmφ. At this time, the internal pressure of the pipe 11 was 100 to 200 kg/cm 2 . FIG. 13(2) shows the wave form detected when a pipe 11 of 6.12 mmφ outside diameter was measured by a detector having the same construction. FIG. 13(3) shows the wave form when the detector was utilized again on the pipe 11 of 6.0 mmφ diameter after the pipe 11 of 6.12 mmφ stated above was clamped and measured. When the output wave forms in FIGS. 13(1) and 13(3) are compared, it is clear that the ends 13a of the piezoelectric element 13 are pressed in tight contact to the outer surface of the pipe 11, thus enabling accurate detection of fine pressure changes.
FIGS. 14(1), 14(2) and 14(3) show a comparative example wherein experiments the same as those of FIGS. 13(1), 13(2) and 13(3) were carried out. In this example, synthetic rubber having a small compression modulus of elasticity was used as a holder material. According to such example, it is clear that substantial noise are involved in FIG. 14(3) and the pipe internal pressure is difficult to measure.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.
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A transducer for detecting pressure changes in pipes by detecting deformation of the pipes and for converting the pressure changes in the pipes into electric signals includes a piezoelectric element having a bimorph structure as a sensor element. The piezoelectric element is constructed in such a way that an intermediate layer is interposed between two piezoelectic pieces. The element is pressed against the pipe surface by a holder which is sufficiently elastic to allow opposite ends of the piezoelectric element in the circumferential direction of the pipe to elastically abut against the pipe periphery. Thereby the ends of the piezoelectric element can be pressed in tight contact against the outer surfaces of pipes having various diameters, and the internal pressure of the pipes can be detected reliably.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to oil field downhole tools. Particularly, the invention relates to flow control valves used in tubulars in a wellbore.
2. Background of the Related Art
In the operation of oil and gas wells, it is often necessary to enter the wellbore to perform some downhole task. Tool retrieval, formation stimulation and wellbore clean out are all examples of tasks carried out in a live well to improve production or cure some problem in the wellbore. Typically, a tubular of some type is inserted into a wellbore lined with casing or is run in production tubing to perform these tasks. Because so many wells are located in remote locations, coil tubing is popular for these operations because of its low cost and ease of use compared to rigid tubulars.
Selectively pumping a pressurized liquid or gas into a live well presents some challenges regardless of the use of rigid or coil tubing. For example, most operations require the fluid to be pumped at a predetermined depth in order to effect the right portion of a formation or to clean the effected area of the wellbore. In order to maintain the liquid in the tubular until a predetermined time, a valve proximate the downhole end of the tubular string is necessary to prevent the fluid from escaping until the operation begins. Additionally, to prevent loss of pressure in the tubular, the valve must open and close rapidly. The rapidity of operation is especially critical when coil tubing is used, because the maintenance of pressure within the coil tubing is necessary to prevent the tubing from collapsing due to adjacent pressure in the wellbore.
FIG. 1 is an exemplary well 10 which could be the subject of a downhole cleaning, removal or formation perforation operation. Typically, the wellbore hole is cased with a casing 12 that is perforated to allow pressurized fluid to flow from the formation 18 into the wellbore 15 . To seal the mouth of the well, a wellhead 20 is mounted at the upper end of the wellbore. The wellbore in FIG. 1 is shown with a string of coil tubing 14 inserted therein. As herein described, the tubing is typically filled with a liquid or gas, such as water, foam, nitrogen or even diesel fuel for performing various operations in the well, such as cleaning or stimulating the well.
The weight of the fluid in the tubular member 14 creates a hydrostatic pressure at any given depth in the tubular member. The hydrostatic pressure in the tubing at the top surface is approximately zero pounds per square inch (PSI) and increases with depth. For example, the hydrostatic pressure caused by the weight of the fluid in the tubing in a 10,000 feet deep well can be about 5,000 PSI. In many instances, the hydrostatic pressure at a lower zone 22 of the tubing is greater than the wellbore pressure at a similar depth in the wellbore zone 24 . Thus, a flow control valve 16 is used to control or stop the flow of the fluid from the tubular member 14 into the wellbore 15 .
Even though the hydrostatic pressure in the tubing can be greater than the wellbore pressure near the bottom of the well, the opposite effect may occur at the top of the well. If the wellbore pressure is high, for example, in a gas well, the wellbore pressure at the top of the well can be several thousand PSI above the relatively low hydrostatic pressure in the tubing at the top of the well. It is generally known to well operators that a wellbore pressure greater than about 1,500 PSI can crush some tubing customary used in well operations, such as coil tubing. Thus, operators will pressurize the tubing 14 with additional pressure by pumping into the coil tubing to overcome the greater wellbore pressure at the top of the wellbore. In some high differential pressure applications, fluid must be pumped continuously through the tubular to maintain a pressure at the top of the tubular and waste the fluid into the wellbore because of the inability of a valve to control the high differential pressures.
In other applications, such as in lower differential pressure applications, a flow control valve can be mounted to the end of the tubular to attempt to adjust for the differences between the downhole hydrostatic pressures and associated wellbore pressures. The valve allows the wellbore pressure to counteract the hydrostatic pressure in conjunction with an upwardly directed spring force. FIG. 2 is a schematic of one exemplary differential flow control valve. The valve 26 is disposed at the lower end of a tubing (not shown) and has an upper passageway 28 through which tubing fluid can flow. The lower passageway 29 of the valve 26 allows wellbore fluid at a wellbore pressure to enter the valve 26 . A poppet 30 is disposed within the valve 26 and engages a seat 32 . Belleville washers 34 , acting as a disk shaped spring, are disposed below the poppet 30 to provide a sufficient upward bias to override the hydrostatic pressure in the passageway 28 . When the sealing member is sealingly engaged with the seat 32 , the two passageways are fluidly disconnected from each other. When the pressure is increased sufficiently to override the upward bias, the sealing member 30 separates from the seat 32 and the two passageways are in fluid communication. The valve 26 operates on differential pressures in that the wellbore pressure provides an upward force on the poppet in addition to the Belleville washers 34 .
However, it has been discovered that while the Belleville washers can open quickly, the washers close slowly, i.e., operate with different opening and closing speeds, known as a hysteresis effect. Thus, the valve 26 can be opened to flow pumped fluid from the tubing 14 into the wellbore 15 (shown in FIG. 1 ), but is insufficient to quickly close the valve to retain pressure in the tubing once a pump has stopped pumping fluid into the tubing to allow the valve to close. Thus, the differential pressure at the upper portion of the tubing is not maintained and the tubing can be deformed or crushed when a high differential pressure exists between the inside of the tubing and the surrounding wellbore. Other manufacturers, such as Cardium Tool Services, use a coil spring in a hydrostatic valve, but enclose the coil spring in a sealed chamber that is not open to varying pressures and thus not a differential flow control valve. Such valves can collapse and seize when high differential pressures are encountered.
It would be desirable to use a coil spring in a differential flow control valve, which has less hysteresis effects and generally equal opening and closing speeds, but the required forces generated from a typical coil spring in the relatively small diameters of the valve are insufficient to simply replace the Belleville washers. Thus, the use of a coil spring is not practical in a typical differential flow control valve.
Thus, there exists a need for a differential flow control valve which is more responsive to hydrostatic pressures, especially in applications having a high hydrostatic pressure compared to a surrounding wellbore pressure.
SUMMARY OF THE INVENTION
A downhole differential flow control valve is provided that utilizes a differential pressure area having one pressure area on which the wellbore pressure acts and a second area different from the first area on which pressure in the tubing acts. The differential area reduces the load in which the spring is required to exert a closing force in the valve. Thus, a coil spring can be used to improve the closing speeds of the valve.
In one aspect, a valve is provided for use in a wellbore, the valve comprising a body, a piston disposed in the body for engaging a valve seat disposed in the body, a biasing member producing a spring force to urge the sealing end of the piston into engagement with the valve seat, whereby the valve opens when the second force exceeds a combination of the spring force and the effective force. In another aspect, a differential pressure control valve is provided for oil field applications, comprising a valve housing having a housing passageway, a valve seat coupled to the housing and having a seat passageway disposed therethrough, a sealing member at least partially disposed within the valve housing and selectively engagable with the valve seat, a bias cavity in fluid communication with the seat passageway; and a bias member coupled to the sealing member that biases the sealing member toward the valve seat. In another aspect, a method of actuating a differential flow control valve is provided, comprising allowing a sealing member to engage a seat on a first piston surface, allowing a first fluidic pressure to apply a first force on at least a first portion of the first piston surface while allowing the first fluidic pressure to apply a greater force on a second piston surface distal from the first piston surface, biasing the sealing member toward the seat with a bias member having a cavity in fluidic communication with the first fluidic pressure, and applying a second fluidic pressure to at least a second portion of the first piston surface to open the valve, wherein a cross sectional area of the second portion is greater than a cross sectional area of the first portion.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a schematic of a well.
FIG. 2 is a schematic cross sectional view of an exemplary differential flow control valve.
FIGS. 3A and 3B depict a schematic cross sectional view of a valve assembly.
FIG. 4 is a detailed cross sectional schematic of a portion of the valve.
FIG. 5 is a cross sectional schematic of a force diagram.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 3A and 3B depict a cross sectional schematic view of one embodiment of the valve assembly 50 . The assembly is shown with the upper end, as the valve would generally be positioned in a wellbore, on the left side of the figure. A top subassembly 52 is coupled to a housing enclosure 56 on an upper end of the valve assembly 50 . A bottom subassembly 54 is coupled to the enclosure 56 on a lower end of the valve assembly 50 . A seat assembly 58 is disposed between the subassemblies and internal to the enclosure 56 . A sealing member, herein a “stem” 60 , sealably engages the seat assembly 58 . The seat assembly 58 includes a passageway 59 , formed therethrough, in fluidic communication with a passageway through the bottom subassembly 54 . Similarly, the stem 60 includes a passageway 61 , formed therethrough, in fluidic communication with the passageway 59 . A stem holder 62 is disposed circumferentially around the stem 60 where the stem is slidably and sealably engaged with the stem holder 62 . A spring guide 64 is disposed above the stem holder 62 and surrounds a portion of the stem 60 on one end and has an elongated center rod disposed upwardly. A bias member, such as a coil spring 66 , is disposed about the spring guide 64 in a spring cavity 67 . A spring casing 68 surrounds the spring 66 and the spring guide 64 and is sealably engaged on a lower end to the stem holder 62 . A spring holder 70 is disposed above the spring 66 and forms a bearing surface for an upper end of the spring 66 . A roller ball 72 engages an upper end of the spring holder 70 .
An adjustor sleeve is disposed above the roller ball 70 , where the roller ball reduces friction between an adjustor sleeve 74 and the spring holder 70 . The lower end of the adjustor sleeve 74 can also be threadably engaged with an upper end of the spring casing 68 and sealed thereto. An upper end of the adjustor sleeve 74 can be threadably engaged with a cap 78 . The cap 78 forms a sealed cavity using seal 81 between the cap 78 and the adjustor sleeve 74 . An adjustor 76 is disposed within the cap 78 . The adjustor 76 has external threads which threadably engage internal threads of the adjustor sleeve 74 . The adjustor 76 can be rotated so that the adjustor traverses longitudinally and applies a force to the spring 66 to vary the compression or expansion of the spring. A cavity 79 is formed above the cap 78 and is open in fluidic communication with the mouth 53 of the top subassembly 52 .
A mouth 53 of the top subassembly 52 is fluidicly coupled to the inside of the tubing 14 , shown in FIG. 1, to form a housing passageway therethrough. Thus, pressure existing in the tubing 14 (herein P T ) adjacent the valve assembly 50 can be transmitted through the mouth 53 through the top subassembly 52 into the chamber 79 . The pressure can then be transmitted into an annulus formed between the inside diameter of the enclosure 56 and the outside diameters of the various components of the valve, including the cap 78 , the adjustor sleeve 74 and the spring casing 68 . The pressure P T then can exert a force on the stem 60 as disclosed in reference to FIGS. 4-5.
From the bottom of the valve, similarly the mouth 55 of the bottom subassembly 54 is in fluidic communication with the wellbore 15 (shown in FIG. 1) and the wellbore pressure (herein P W ) adjacent the valve assembly 50 . The pressure in the wellbore P W is transmitted through the mouth 55 of the bottom subassembly 54 and through the passageway 59 in the seat assembly 58 . The pressure Pw creates a force on the lower end of the stem 60 . Further, the pressure P W is transmitted through the passageway 61 of the stem 60 and exerts a pressure on the top surface of the stem adjacent the spring guide 64 .
A port 90 is disposed through the stem 60 and is fluidicly coupled to the passageway 61 of the stem 60 , so that pressure P W is transmitted into and through port 90 . Port 90 is fluidicly coupled to the spring cavity 67 by a space between the stem 60 and the stem holder 62 and by an annulus between the spring guide 64 and the spring casing 68 . Thus, the spring cavity 67 , the passageway 61 of the stem 60 , the passageway 59 of the seat assembly 58 , and the mouth of the bottom subassembly 54 are in fluidic communication to the pressure P W in the wellbore. The fluidic communication allows the valve assembly 50 to adjust to varying pressures in the wellbore at different depths and at different production pressures.
FIG. 4 is a detailed cross sectional schematic of the valve assembly 50 . A bottom subassembly 54 , shown in FIG. 3B, is coupled to a housing enclosure 56 and may be sealed thereto. A seat assembly 58 includes a seat support 82 and a replaceable seat 84 . The seat assembly includes a passageway 59 formed herein. An annulus between the seat 84 and the seat support 82 may be sealed by seal 86 . A stem 60 disposed above the seat 84 has a lower seating surface 88 that can contact an upper surface of the seat 84 . A stem holder 62 circumferentially surrounds a portion of the stem 60 and may be slidably and sealably engaged to the stem with a seal 92 . The stem holder 62 can be sealably engaged with a spring casing 68 using a seal 94 . The housing enclosure 56 surrounds the stem 60 , the stem holder 62 and spring casing 68 , forming an annulus therebetween. The stem 60 includes a passageway 61 formed therein that is in fluid communication with the passageway 59 of the seat 84 and seat support 82 and the passageway through the bottom subassembly 54 . Thus, the interior portions of the above mentioned members are in fluidic communication to the wellbore pressure P W . A port 90 is disposed into the stem 60 and is in fluidic communication with the passageway 61 of the stem 60 and wellbore pressure P W . The spring cavity 67 is in fluidic communication with the port 90 and allows wellbore pressure P W to be created therein. A spring guide 64 is disposed above the stem 60 . A spring 66 is disposed adjacent the spring guide 64 . Generally, spring 66 is a compression spring which exerts a downward force on the spring guide 64 and then to the stem 60 . A spring casing 68 surrounds the spring 66 , the spring guide 64 and the stem holder 62 .
Tubing pressure zone 100 is fluidicly coupled to fluid in the tubing through port 91 and the associated pressure P T . Pressure P T occurs through the top sub 53 shown in FIG. 3 A and in the annulus between the enclosure 56 and the spring casing 68 . At least a portion of the exterior surface 99 of the stem 60 is exposed to the tubing pressure P T . When the stem 60 is lifted from the seat 84 , fluid flow can occur through the tubing and into the wellbore zone 28 , shown in FIG. 1 . Lower wellbore pressure zone 96 and upper wellbore pressure zone 98 are fluidicly coupled to fluid in the wellbore and the associated wellbore pressure P W.
It is believed that the wellbore pressure P W exerts an upward force on the stem 60 at the seating surface 88 , acting as a piston surface, to a diameter D 2 approximately equal to one-half the distance between the outer and the inner diameters of the stem 60 , shown as diameter D 1 and D 3 , respectively. The upper portion 102 of the stem 60 , also acting as a piston surface, has a larger diameter D 1 than the diameter D 2 . Thus, the same pressure acting on the top of the stem 60 at diameter D 1 has a greater surface area compared to the area formed by diameter D 2 on which to act and creates a greater downhole effective force on the stem 60 . The diameter D 1 is shown as a consistent diameter inside and outside of the stem holder 62 . However, it is understood that the diameter could very such as a stepped diameter. Because the upper annular pressure zone 98 is exposed to the wellbore pressure P W , and because the cross sectional area formed by diameter D 1 is larger than the cross sectional area formed by diameter D 2 , the wellbore pressure P W acting on diameter D 1 overcomes the upward forces created by the pressure P W acting on the diameter D 2 . Thus, the stem is pressurized to a closed position where the stem 60 engages the seat 84 at the seating surface 88 . The spring 66 can also be used to supplement the downward force created by the wellbore pressure P W by applying a spring force S F to the spring guide 64 and then to the stem 60 .
Similarly, the tubing pressure P T in the tubing pressure zone 100 acts on the outer circumference of the stem 60 between the seal 92 and the seating surface 88 to about the diameter D 2 . The resultant force created by P T is an upwardly directed force acting on the difference in diameters between diameterD 1 and diameter D 2 . In a closed valve position, the combination of the spring force S F and an effective force created by the wellbore pressure P W acting on the upper piston surface 102 of the stem 60 well forces the stem 60 into sealing engagement with the seat 84 at the seating surface 88 . To open the valve, the tubing pressure P T can be increased, so that the upward force created by P T on the portion of the seating surface 88 between diameters D 1 , and D 2 overrides the downward force created by the spring 66 and the wellbore pressure P W acting on the upper piston surface 102 .
FIG. 5 is a schematic force diagram of the forces acting on the stem 60 . On the left portion of the figure, at an upper end of the stem 60 , a spring force S F acts on the upper piston surface 102 . Pressure P W creates a pressure force on the cross sectional area between diameters D 1 and D 3 , where D 3 is the passageway 61 diameter of the stem 60 . On the seating surface 88 , P W creates a force on the cross sectional area between D 2 and D 3 . Because pressure P W counteracts the forces created between diameters D 2 and D 3 on each end, a net effective downward force is created on the cross sectional area defined betweenD 1 and D 2 on the upper piston surface 102 .
On the seating surface 88 , the tubing pressure P T creates a net force resultant upward on the cross sectional area of the seating surface 88 defined between the diameterD 1 and D 2 . A net closing force can be defined by the equation F C =P W [(D 1 /2) 2 −(D 2 /2) 2 ]π+S F , where F S equals a closing force and the other variables have been defined herein. A net opening force, in this example, directed upward toward the top of the wellbore would equal F O =P T [(D 1 /2) 2 −(D 2 /2) 2 ]π, where F O equals the opening force. Thus, to close the valve, force F C is greater than force F O and, conversely, to open the valve, force F O is greater than force F C . Generally diameter D 1 is greater than diameter D 2 .
The ability to use a coil spring or other springs exerting a relatively small force is enabled by controlling the differential areas between diameters D 1 and D 2 . The differential area can be defined as [(D 1 /2) 2 −(D 2 /2) 2 ]π. For example, a relatively small differential area between diameters D 1 and D 2 results in compensating for a large difference between pressures P W and P T . The difference in pressures is multiplied by a relatively small differential area and results in a relatively small difference in resultant forces. Thus, spring force S F may be relatively small to counteract relatively large pressure differences between the pressure P T in the tubing 14 , shown in FIG. 1, and the pressure in the wellbore P W . As merely one example, and others are available, if the P T equal 10,000 PSI, P W equals 5,000 PSI and the differential area between diameters D 1 and D 2 equals 0.1 square inches, then the resultant spring force S F required to override a 5,000 PSI difference in pressure would equate to merely 500 pounds. Similarly, with the same pressures, a differential area of 0.05 square inches would equate to a spring force of about 250 pounds to override the 5,000 PSI difference.
Other types of springs may be used and variations of the embodiments described herein are contemplated. For example, a gas spring can be used in addition to or in lieu of the coil spring. The gas spring can be a nitrogen filled cavity that exerts a downward force generally according to the formula PV=nRT for ideal gases where P is the pressure, T is the temperature, n is the number of moles, R is the universal gas constant and V is the volume. Thus, if downhole conditions are known, such as pressure and temperature, for a given volume, the gas spring can be precharged at a certain pressure and inserted downhole to a given position. The resultant effect is that the gas spring exerts a downward force on the stem 60 as described herein. In some embodiments, the gas charged cavity may operate in conjunction with a wellbore pressure P W so that the differential pressure is maintained.
While foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. Further, the pressures described herein are approximate and have not been adjusted for friction losses. For example, the pressure in tubing P T may have some friction loss resulting in a smaller pressure after traversing the flow circuit in the valve. However, the principles of valve operation remain the same as described herein.
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A downhole differential flow control valve is provided that utilizes a differential pressure area having one pressure area on which the wellbore pressure acts and a second area different from the first area on which pressure in the tubing acts. The differential area reduces the load in which the spring is required to exert a closing force in the valve. Thus, a coil spring can be used to improve the closing speeds of the valve.
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BACKGROUND OF THE INVENTION
The present invention, which is a "subject invention" under INTELSAT Contract No. Intel-683 (INTERSAT VII-A), relates generally to the field of energy cells such as batteries and fuel cells, and more particularly to such energy cells which employ pressure vessel type cells such as those currently used in earth orbiting satellites, and in other applications which employ pressure-vessel type cells.
It is well known that a plurality of electrical cells can be connected in series to obtain an electrical output from a battery consisting of the cells which will have a voltage equal to the sum of the voltages of the individual cells. However, the problem exists in such an arrangement that if one cell in the series is defective or is damaged during use, which results in the cell failing in an open circuit condition, the entire battery is rendered useless because it is impossible to pass an electric current through the battery for either charging or discharging purposes.
It is also well known that communications satellites utilize batteries to provide electric power for a variety of purposes, principally in connection with the operation of electronic communications and instrumentation equipment. Such satellites are typically put into a geo-synchronous orbit in which the satellite maintains a fixed location in space relative to a given position on the earth. But regardless of the nature of the orbit, a satellite is virtually isolated from the earth and from contact with man, since it is such an extremely complicated and expensive undertaking to put men and equipment into space to repair a satellite that it is virtually never done. Under these conditions, it is apparent that a battery failure can render the entire satellite useless, which can result in tremendous loss in terms of the cost of the satellite, the expense involved in the launching and the lost communications capability. It would not be unreasonable to assume that a battery failure in a communications satellite could result in a multi-billion dollar loss.
Other applications, such as electric automobiles and generators, and other applications where battery and/or fuel cell failure causes great harm or inconvenience, are candidates for the invention whenever the batteries or fuel cells employ high pressure cells such as nickel-hydrogen, silver-hydrogen, hydrogen-zinc, chloride-bromide, and sealed hydrogen-oxygen.
Thus, from the inception of communications satellites, there has been a continuing effort to improve the reliability of satellite batteries. This effort has met with considerable success, particularly with the development of the electrochemical cell which can operate over a wide range of ambient temperatures, has a relatively high energy density and can be constructed in a variety of configurations, all of which characteristics contribute to rendering this cell ideal for use in outer space. However, some electrochemical cells such as nickel hydrogen cells, by their nature, will only operate in a high pressure environment, typically in the range of 700 to 900 PSI when fully charged, and there must be confined in a pressure vessel which can withstand such internal pressures.
Unfortunately, it is this requirement of such electrochemical cells that renders them vulnerable to a hostile condition of outer space over which man's technological ability has little or no effect, and that is bombardment by meteorites which damage the pressure vessel, causing holes or cracks so that it leaks or completely ruptures. The loss of pressure within the vessel is the only known failure mechanism which results in an open circuit cell and therefore renders it useless since it will not pass electric current therethrough.
Open circuit protection devices currently available consist of one large diode in the "forward" direction to pass the load current, and several diodes in series in the "reverse" direction to allow recharging of the remaining cells to occur. For high current batteries, in the range of 50 to 100 amperes, such as are becoming common for synchronous orbit communications satellites, the "forward" diode dissipates a large amount of power under discharge conditions because of its in inherent 0.6 to 0.7 volt drop. At 100 amperes, the power dissipation is 60 to 70 watts. The thermal design, and accompanying mass, of providing such a circuit for every cell in a battery are very undesirable.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an electric energy cell of the nickel-hydrogen type having an improved open circuit protection device which will operate effectively in the event of loss of cell operating pressure to prevent the cell from destroying the integrity of the entire battery, and does so in a manner which avoids the disadvantages of heretofore known open circuit protection devices.
In its broader aspects, the electric energy cell of the present invention comprises generally a hollow vessel of any convenient configuration which is sealed against ambient atmosphere and is adapted to withstand internal pressures substantially greater than atmospheric pressure. The vessel contains an electrochemical means which is capable of generating an electric current. A first cell terminal is mounted on the vessel and extends through the wall thereof to the outside of the vessel, and is connected to a first terminal of the electrochemical means. A second cell terminal is also mounted on the vessel and extends through the wall thereof to the outside of the vessel, and is connected to a second terminal of the electrochemical means. Finally, a pressure sensitive switch means is mounted within the vessel and is connected to the first and second cell terminals and to one of the terminals of the electrochemical means for alternately permitting electric current to flow between the electrodes through the electrochemical means or between the electrodes directly through the switch means, depending upon the extent of pressure in the vessel. Thus, the pressure sensitive switch means is effective to cause electric current to flow between the electrodes through the electrochemical means when normal operating pressure is maintained in the vessel, and is effective to by-pass the electrochemical means and cause electric current to flow between the cell terminal directly through the switch means when the pressure in the vessel drops below a predetermined level.
In some of its more limited aspects, the pressure sensitive switch is normally biased to a closed circuit condition and is maintained in an open circuit condition by the pressure in the vessel, so that loss of pressure in the vessel causes the switch to close and provide a short circuit between the electrodes which by-passes the electrochemical means.
In one form of the invention, the pressure sensitive switch means comprises a housing mounted within the vessel and containing a diaphragm which divides the chamber into a hermetically sealed portion of relatively low pressure and another portion which is in communication with the internal pressure in the vessel. An electrical contact is mounted on the diaphragm, and a second electrical contact is mounted on the housing in position to contact the first electrical contact if the pressure in the vessel drops below a predetermined level and the pressure in the sealed portion of the housing causes the diaphragm to move.
In other embodiments of the invention, other forms of pressure sensitive switches could be utilized. These include a helical Bourdon tube and a liquid manometer, which can be implemented to work in zero gravity, and any other form of a pressure sensor which can cause electrical contacts to close and conduct current.
The electric energy cell of the present invention has several distinct advantages over current technology. A major advantage is that the barometric switch inside the cell pressure vessel is of very low mass, since it involves only very short internal straps to conduct the electric current, unlike the diode solution, which could involve several feet of very heavy wire for each cell depending on the location required for the diodes for thermal reasons. And the heat sinking of the diodes to accommodate their dissipation is an additional significant mass factor. Obviously, the reduction of mass in any component of a satellite is of major importance in terms of the fuel consumption and power required to put the satellite into orbit.
Another advantage of the barometric switch is that, as mentioned above, in the forward direction the diode drop is about 0.6 to 0.7 volt, so the battery voltage would drop by this amount in addition to the loss of the cell voltage. In contract, the energy cell of this invention would provide a voltage drop of typically 10 to 30 millivolts, reducing the battery voltage drop to essentially the loss of the single failed cell.
Another advantage of the present invention, particularly when considered in connection with its use in otherwise very expensive satellites, is that it has a relatively low cost. The barometric switch is incorporated within the cell housing by the cell manufacturer and avoids the separate design, manufacturing and assembly of a diode protection system for each cell.
Another advantage of the present invention is improved reliability. The semiconductor diodes used to allow both the forward current flow and the reverse charging current flow have finite failure rates and these rates, when multiplied by the total number of semiconductors which must be used (for example, in a 42 volt battery with 27 cells there are 108 diodes) becomes very significant. On the other hand, the infinitesimal failure rate of the barometric pressure switch, (of which only 27 are required in this example), could significantly reduce the predicted failure rate, and therefore the reliability, of the battery.
Another advantage of the present invention is that essentially no heat is generated by the bypass device, in contrast to the typically 70 watts generated by the diodes of the previously discussed open circuit protection device. This absence of heat improves the capacity and energy density of the battery as well as its life, thereby reducing the cost of a battery to satisfy a particular power load.
Having briefly described the general nature and some of the significant advantages of the present invention, it is a principal object thereof to provide an electric energy cell for use in a satellite having unique features of construction which provide advantages not heretofore obtained and obviates or eliminates the disadvantages of current technology.
It is another object of the present invention to provide an electric energy cell for use in a satellite which provides a short circuit by-pass through the cell in the event of failure of the operating pressure within the cell to maintain the operating integrity of the battery which contains the cell.
It is still another object of the present invention to provide an electric energy cell for use in a satellite which has the characteristics of low mass, low voltage drop and low cost which are essential to any electric energy cell intended for satellite use.
These and other objects and advantages of the present invention will become more apparent from an understanding of a presently preferred embodiment of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a battery which consists of a plurality of electric energy cells constructed in accordance with the present invention.
FIG. 2 is a side sectional view through one of the cells shown in FIG. 1.
FIG. 3. is a view similar to FIG. 2 showing an alternate embodiment of the pressure sensitive switch means.
FIG. 4. is a view similar to FIG. 3 showing a further alternate embodiment of the pressure sensitive switch means.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and particularly to FIG. 1 thereof, the reference numeral 10 designates generally a battery of the type used in satellites and which incorporates the present invention. The battery 10, which in practice may be nothing more than a frame that provides a convenient holder for the energy cells, may be constructed of any suitable, light weight material and have any suitable configuration depending on the nature of the specific satellite in which it is used. For convenience of connection, the battery may be provided with a pair of master terminals 12 and 14 suitably mounted on a housing or other frame part 16 of the battery, one being designated positive and the other being designated negative, to which wires or cables are connected to conduct electric current to any part of the satellite requiring power.
The battery 10 consists of a plurality of electric energy cells 18, of which three are shown, although it will be apparent that any number of cells 18 may be included in the battery depending on the power requirements for the particular application. Each cell 18 has positive and negative cell terminals 20 and 22 respectively mounted thereon in a manner described below the cell terminals 20 being designated positive and the cell terminals 22 being designated negative for reference purposes. Adjacent cells are connected together by suitable wires or straps 24 which connect the positive cell terminals 20 to the negative cell terminals 22 of the cells 18, and additional wires or straps 26 connect the positive cell terminal 20 or the negative cell terminal 22 to the master positive terminal 12 and the negative terminal 14 respectively of the battery 10. In this manner, the cells are connected in series within the battery 10 so that the voltage output of the battery 10 is the sum of the voltages of the individual cells 18. As mentioned briefly above, with this arrangement it is clear that if any cell 18 is defective or is damaged during use in such a manner that it fails in an open circuit condition, the entire battery is useless since no current will flow through an open circuit cell.
Referring now to FIG. 2, the reference numeral 18 designates generally one of the cells shown in FIG. 1. The cell 18 comprises a hollow, hermetically sealed pressure vessel 30 having a generally cylindrical configuration with a flat bottom and a domed top, although this specific configuration is not critical, and other configurations may be utilized. The pressure vessel 30 has sufficient strength to safely withstand internal pressures as high as 700-900 PSI, which is the normal fully charged pressure of a nickel-hydrogen cell with which the present invention is used.
The pressure vessel 30 has a pair of cell terminals 32 and 34 (which correspond to the cell terminals 20 and 22 in FIG. 1) suitably mounted on the upper domed portion in a manner so as to be electrically insulated from the pressure vessel 30 such as by the rubber sealing rings 33. For convenience of explanation, the cell terminal 32 is designated positive and the cell terminal 34 is designated negative. An electrochemical current generating means 35 is contained within the vessel 30 and comprises a plurality of cathode discs 36 and a plurality of anode discs 38 which are suitably mounted within the pressure vessel 30, and an insulating separator disc 40 containing a suitable electrolyte is interposed between each adjacent pair of anode and cathode discs. A wire 42 connects all of the cathode discs 36 to a terminal 44 which is mounted on a portion of pressure sensitive switch means yet to be described. Another wire 46 connects the terminal 44 to the positive cell terminal 32 of the cell 18. Another wire 48 connects all of the anode discs 38 to the negative cell terminal 34 of the cell 18. With this arrangement, all of the cathode discs 36 and all of the anode discs 38 are connected to the positive and negative cell terminals 32 and 34 respectively.
The interior of the pressure vessel 30 is filled with two gases. One is an inert gas such as helium or argon which is of sufficient pressure to keep the contacts of the pressure sensor in an open circuit condition when the cell is fully discharged but intact. The second gas is the result of the charging process, which is hydrogen in the case of the nickel-hydrogen cell. This electrolyte gas changes pressure in proportion to the stat of charge of the cell. The total pressure within the cell will never drop below that of the inert gas, and therefore the pressure switch will not operate so long as the integrity of the pressure vessel is maintained and it does not leak Further details of the construction and arrangement of the electric energy cell are not described herein since the energy cell is of the conventional nickel-hydrogen type and forms no part of the present invention.
The energy cell 18 further includes a pressure sensitive switch means indicated generally by the reference numeral 50 which controls the flow of electric current either through the electrochemical means 35 or directly between the cell terminals 32 and 34, thereby by-passing the electrochemical means, depending on the state of pressure of the inert gas in the vessel 30. The pressure sensitive switch means 50 comprises a housing 52 mounted within the domed portion of the vessel 30 in any suitable manner, the housing having any suitable configuration and preferably being formed of an electrically conductive material, although the housing could be formed of a non-conducting material if suitable wire connections are provided. A flexible diaphragm 54, also formed of an electrically conductive material, is mounted within the housing 52 around the periphery thereof so as to divide the housing 52 into an upper compartment 56 and a lower compartment 58. The upper compartment 56 is hermetically sealed and contains a gas at a pressure which is below the minimum operating pressure of the inert gas in the cell 18. The lower compartment 58 is in communication with the gas in the vessel 30 through openings 60 provided in a bottom wall 62 of the housing 52, thereby normally maintaining the diaphragm 54 in a flexed condition.
The diaphragm 54 has an electrical contact 64 suitably mounted thereon so as to move with the diaphragm. In addition, the terminal 44 mentioned above is mounted on the bottom wall 62 so as to be electrically insulated therefrom as by the rubber insulating ring 45, but in a position to underlie the contact 64 mounted on the diaphragm.
From the foregoing description the operation of the cell 18 should be apparent. In the normal operating condition of the cell 18, the pressure in the vessel 30 in sufficient to flex the diaphragm upwardly against the lower pressure in the upper compartment 56 of the housing 52 to maintain the contact 64 out of contact with the terminal 44, thereby maintaining the housing 52 electrically isolated from the electrochemical means 35. In this condition, electric current generated by the electrochemical means will flow through a circuit consisting of the cathode discs 36, wire 42, terminal 44, wire 46, cell terminal 32, through the device being powered or through adjacent cells 18, and back to the electrode 34, wire 48 and the anode discs 38. This mode of operation will continue so long as there is sufficient pressure within the vessel 30 to maintain the diaphragm 54 in the position shown in FIG. 2.
In the event of any damage to the vessel 30 which causes a hole or crack in the wall of the vessel 30, thereby allowing all the internal gas to escape, when the pressure drops below the threshold of the pressure in the upper compartment 56, the diaphragm 54 will move downwardly to bring the contact 64 into contact with the terminal 44. When this happens, a short circuit is established through the cell terminal 32, wire 46, terminal 44, contact 56, diaphragm 54, housing 52 and wire 66 to the negative cell terminal 34, which provides a current path through the cell 18 even though no current will pass through the electrochemical means 35. Thus, the battery as a whole can continue to function in both charge and discharge modes even though one or more cells of the battery have failed in an open circuit condition.
FIG. 3 illustrates an alternate form of the invention in which the pressure sensitive switch means 50 of the previous embodiment is replaced by the pressure sensitive switch means 150. In this embodiment, a housing 152 encloses and supports a Bourdon pressure sensor 154 by means of any suitable form of bracket as indicated by the numeral 156. The Bourdon tube is fabricated from an electrically conductive material, and includes a contact 158 near the closed end 160 of the tube. Alternatively, the tube may be fabricated from a non-conducting material with a wire connected between the housing and the contact 158. A positive terminal 144, which corresponds to the terminal 44 in the previous embodiment, is suitably supported within the housing 152 as by the insulated bracket 162, and is connected to the positive terminal 32 of the cell by a wire 146 which corresponds to the wire 46 in the previous embodiment. A wire 142 generally corresponds to the wire 42 of the previous embodiment.
During normal operation of the energy cell 18, the pressure within the cell housing 30, which communicates with the inlet end 164 of the tube through the openings 161 in the housing 152, is sufficient to stress and deform the tube 150 in an "uncoiling" direction to maintain the terminal 144 and the contact 158 separated, with the result that the cell functions in the normal manner in series with other cells in the battery to maintain a normal closed circuit through the cell. However, in the event of any damage to the pressure vessel 30 which results in loss of all internal gas pressure, the tube will tend to reform to its normal configuration and by moving in a "coiling" direction, which will bring the contact 158 on the end of the tube into contact with the terminal 144, thereby closing a short-circuit through the cell terminal 32 on the pressure vessel 30, wire 146, terminal 144, contact 158, tube 154, bracket 156, housing 152 and wire 166 to the negative cell terminal 34, thereby providing the same current path through the cell as described above in connection with the previous embodiment.
A further embodiment of the invention is illustrated in FIG. 4 in which the pressure sensitive switch means 250 is in the form of a manometer 254 which is mounted within the housing 252 by any suitable bracket means as indicated by the numeral 256. The tube 254 is generally of U-shaped configuration and is fabricated from an electrically insulating material, and is partially filed with mercury 255. A positive terminal 244 and a negative terminal 245 are mounted on opposite sides of the tube 254 adjacent the open end 264 such that they are out of contact with each other. Components 242, 246, 264, and 266 generally correspond to the components 142, 146, 164, and 166 of the FIG. 3 embodiment described above.
As with the previous embodiments, during normal operation of the cell 18, the pressure in the vessel 30, which communicates with the open end 264 of the manometer 254, maintains the mercury sufficiently displaced in the tube so that it is out of contact with the terminals 244 and 245, thereby maintaining a normal operating circuit through the cell in the same manner as with the previous embodiments. However, again, in the event of damage to the vessel 30 which results in loss of all gas pressure, the mercury shifts in the tube 254 due to the trapped pressure in the closed end 265 to cause the mercury to bridge the gap between the terminals 244 and 245, which will establish the same "short-circuit" through the cell as described above in connection with the previous embodiments.
It will be apparent that in both of the embodiments illustrated in FIGS. 3 and 4, the housings 152 and 252 provide a measure of convenience in assembling the components of the pressure sensitive switch means in the pressure vessel 30, but they are not essential since the Bourdon tube 154 and the manometer tube 254 could be mounted directly on the inner wall of the pressure vessel 30
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An electrochemical energy cell for use in a satellite or other environment where failure of the cell can cause great harm or inconvenience is disclosed in which the cell operates within a sealed pressure vessel in which a gas is maintained under high pressure and which is subject to bombardment by meteorites which can cause holes or cracks in the pressure vessel, thereby rendering the cell incapable of conducting an electric current therethrough, which in turn renders a battery of such cells useless. To prevent this, a pressure sensitive switch is provided in each cell which is connected in a circuit which by-passes the current generating discs of the cell when the switch is closed. The switch is normally maintained open by the pressure within the vessel, and is biased to close in the event that the pressure in the vessel drops below a predetermined minimum, so that the damaged cell will still conduct current therethrough to maintain the integrity of the entire battery.
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FIELD
The present invention relates to an elevator installation in which at least one elevator car or at least one car and at least one counterweight are moved in opposite directions in an elevator shaft, wherein the at least one elevator car and the at least one counterweight run along guide rails, are supported by one or more supporting and driving means and are driven via a driving pulley of a drive unit. The present invention relates to a drainage system for extinguishing water and, in particular, to the configuration of the elevator car.
BACKGROUND
Modern elevator installations or so-called firefighters' elevators designed specifically therefor have to ensure reliable operation even in the event of a fire, on the one hand in order for individuals or at-risk material to be evacuated from the floors affected by the fire, but on the other hand also for transporting the firefighters and their extinguishing equipment. In both cases, the use of extinguishing water—whether by means of a sprinkler installation or on the part of the fire department or both—must not result in the elevator installation or the firefighters' elevator no longer functioning.
This means that the electrical components of the elevator installation have to remain dry. Furthermore, the supporting and driving means must not become so wet as to result in uncontrollable slippage between the driving pulley and the supporting and driving means. Slippage can occur particularly easily because the extinguishing water can have a direct adverse effect on the coefficients of friction between the driving pulley and the supporting and driving means, and/or can change the viscosity of any lubricants, and, on the other hand, it usually contains soap for better firefighting purposes.
The slippage occurring between the driving pulley and supporting and driving means thus gives rise to a reduction in traction or even to a complete loss of traction of the elevator installation and—if there is a large difference between the weight of the elevator car and the weight of the counterweight—possibly to uncontrolled movement of the elevator car, which has to be stopped by its safety brake. However, the satisfactory function of the safety brake or the braking deceleration of the brake shoes thereof on the guide rail, in turn, can also only be ensured when the brake shoes or the guide rail are not moistened with (soap-containing) extinguishing water.
All these requirements make it necessary for the extinguishing water to be drained off and/or intercepted in a controlled manner. The extinguishing water normally penetrates into the elevator shaft via the doors of the latter. International publication WO A1 98/22381 discloses an elevator installation having a drainage system on the shaft doors and flow barriers interengaging with a form fit on each shaft door. The attempt is thus made to keep the elevator shaft free of extinguishing water over its entire height from the outset. The disadvantage with this solution, however, is that high costs are involved in order to equip each floor with corresponding drain pipes and said flow barriers beforehand.
SUMMARY
It is an object of the present invention to provide at least one alternative solution for protecting—in particular the supporting and driving means of the elevator installation—against the extinguishing water penetrating into the shaft, while avoiding, to the greatest extent, the disadvantage cited above.
This object is achieved, in the first instance, by a drainage system being arranged on the elevator car rather than on the individual shaft doors.
This basic inventive concept is derived from the finding that the extinguishing water, rather than having to be kept away, in principle, from the elevator shaft, can also flow off in a controlled and/or deflected manner. It has been observed that a main cause of the supporting and driving means becoming wet is the splashing or spraying of the extinguishing water as it comes into contact with the roof of the elevator car.
The invention relates to a drainage system in an elevator installation having at least one elevator car with an upper edge running more or less parallel to a horizontal, wherein a drainage panel on the upper edge of the elevator car is arranged at at least one angle of inclination to the horizontal, and therefore extinguishing water which falls onto the elevator car is directed, at least in part, from the drainage panel toward the upper edge. The terms “horizontal” and “vertical” are used herein to refer directions in which various surfaces extend relative to the orientation of the elevator car.
A basic variant of a drainage system for extinguishing water according to the invention thus provides a car roof having a panel arranged obliquely, or as a slanting plane, over the cross section of the elevator car. Extinguishing water coming into contact with this oblique panel is thus fed, in principle, just to a lateral upper edge of the—usually mostly cuboidal—basic structure of the elevator car and drained off along a more or less vertical side surface of the cuboidal basic structure of the elevator car, said side surface adjoining said lateral upper edge. In this way, the extinguishing water is thus kept away from that side, or those sides, of the basic car structure on which, depending on how the elevator car is suspended, the supporting and driving means is or are located. The present application, however, is not restricted to cuboidal basic elevator-car structures; inclined drainage panels and draining side surfaces adjoining the same can also be arranged on cylindrical or prism-shaped basic structures—with three or more edges.
A first variant of the above-described basic variant of a drainage system for extinguishing water in the form of a panel arranged obliquely over the cross section of the roof of the elevator car provides an adjustable roller-shutter structure instead of a rigid and fixed panel. This roller-shutter structure can preferably be displaced by a motor and/or is biased by a spring and, furthermore, is preferably connected to a safety contact, which gives a signal for movement to commence. This variant with an adjustable or displaceable roller-shutter structure has the advantage for a fitter, or someone servicing or operating the elevator, that the roof of the elevator car and technical equipment located there, and a hatch which may be located in the roof of the elevator car, are more easily accessible.
The oblique drainage panel or the roller-shutter structure may be of planar configuration, but preferably open out into a gutter, which preferably in turn runs obliquely in relation to the horizontal and by means of which extinguishing water collected by the drainage panel or the roller-shutter structure is fed to a flow-off means at just one corner of the elevator car. The flow-off means here may still be arranged in the vicinity of the upper edge of the basic structure of the elevator car, but it may prove advantageous for the gutter and the flow-off means to be arranged such that the extinguishing water collected flows off on the underside of the basic structure of the elevator car. It is also conceivable to have variants of the collecting gutter by means of which the extinguishing water collected is fed to two, three or even four flow-off means each at a corner of the elevator car, which may prove advantageous, in particular, for managing large quantities of extinguishing water.
As a further option, the flow-off means—whether via one, two, three or all four or more corners of the basic structure of the elevator car—may be configured as a flexible hose which moves along with the elevator car. It is also possible for a simple cable, along which the extinguishing water collected flows down, to provide a solution for avoiding splashing and spraying extinguishing water in the elevator shaft.
A second variant of the basic variant with a rigid panel provides for the panel to be divided, for example more or less centrally, or also in an offset manner, into two or more surfaces which slope down to the side. The extinguishing water coming into contact therewith is thus drained off, for example, to two corners of the basic car structure.
The same drainage principle can be realized for the variant with adjustable roller-shutter structure by two or more roller-shutter structures being arranged not just obliquely in relation to an upper edge of the basic car structure, but, at the same time, also such that they slope down to the side.
The shaft wall which is located opposite the side of the car along which drainage takes place, or the corners of the car at which drainage takes place, preferably has, for its part, an intercepting and drainage system which corresponds to the elevator-car drainage system according to the invention. This intercepting and drainage system belonging to the shaft can preferably be arranged for combination with the elevator-car drainage system and is distinguished by open intercepting devices, which are arranged preferably in the corners of the elevator shaft as open intercepting profiles, and by open intercepting panels, which are arranged on at least one shaft wall, and open drainage panels, which are spaced apart from one another over the height of the elevator shaft. Via the resulting interspaces between these open intercepting devices in the form of open intercepting profiles, open intercepting panels and open drainage panels, or via similarly open receiving openings of the same, it is possible to feed both extinguishing water which is collected on the roof of the elevator car and extinguishing water which enters the elevator shaft through the shaft doors.
The above-described obliquely arranged drainage surfaces of the car roof are preferably equipped, in addition, with a peripheral rebate and/or a more or less vertical connecting panel or a more or less vertical metal connecting sheet. The above-described drainage panels are preferably produced from sheet metal, although plastics-material panels are also possible.
The obliqueness of the drainage surfaces constitutes, in principle, a compromise between an overly high roof construction of the elevator car and the obliqueness being so shallow that the extinguishing water coming into contact with the drainage surfaces would still be able to splash or spray. The obliqueness is thus preferably 45 degrees, but may, in principle, be in a range from 20 to 70 degrees in relation to the horizontal.
The inclined drainage panel may be inclined, in principle, in relation to that shaft wall in which the shaft doors are arranged or else also in relation to the opposite shaft wall, or approximately from an elevated center in relation to both sides—as it were as a roof ridge with two drainage surfaces; but not in relation to the sides of the elevator car, or to those shaft walls, past which the supporting and driving means is or are guided. In the case of the supporting and driving means being guided along just one side of the elevator car, or along just one shaft wall, a third possible direction of inclination, in principle, is also that side which is located opposite the supporting and driving means, regardless of whether this is the side with the shaft doors or not.
It is also possible for the inclined drainage panel to cover the entire cross section of the roof of the elevator car, or also just a sub-surface thereof, extending only just behind the supporting and driving means. That is to say, if the supporting and driving means passes or pass beneath the elevator car, for example, in the center, the drainage panel extends from the lower flow-off edge to a higher edge arranged on the far side of the center. The remaining interspace here between the higher edge and an elevator-car upper edge located opposite the flow-off edge can remain free or be covered in a horizontally planar manner.
It is also possible for the oblique drainage panel to be configured with two or more different angles of inclination. It is thus possible, for example, for a first drainage surface, with an angle of inclination of, for example, more or less 30 degrees, to merge into a second drainage surface of, for example, more or less 60 degrees.
An elevator car configured according to the invention may optionally be equipped, in addition, with one or more vertical drainage panels in splashguard form, these drainage panels being arranged on those side surfaces of the basic car structure past which the supporting and driving means is or are guided. These vertically arranged drainage panels shield the supporting and driving means against extinguishing water and can extend over the entire height of the elevator car or even beyond this, both on the upper side, and on the underside, of the elevator car.
These vertically arranged drainage panels can optionally run along in a slot provided for this purpose in the respectively opposite shaft wall, and therefore it is no longer possible for any extinguishing water to penetrate through even between any gap between the vertical drainage panel and the opposite shaft wall.
The edges of the obliquely arranged drainage surfaces from which the extinguishing water flows off are preferably equipped with a lip which is, again, of oblique or curved configuration. This prevents extinguishing water which flows off from the edge from being deflected in the direction of the center of the shaft on account of adhesion to the drainage surface. As a further option, the drainage surfaces may be coated with adhesion-reducing substances or paints, for example with a lotus-effect paint, which forms a highly water-repellent surface. It may further be advantageous for the edges between the drainage surface and/or the drainage surfaces and the side surface of the basic elevator-car structure and/or of the gutter or gutters to be rounded.
A further variant of an elevator car or of an elevator installation provides a collecting device which collects the extinguishing water and is disengaged or opened as it moves past a triggering lever. This has the advantage that the extinguishing water, firstly, in some circumstances, drips not just in an uncontrolled manner from the side surface or out of the flow-off means, but, secondly, is discharged in a directionally better controllable surge at a desirable location. This can take place at a location of the elevator shaft which is designed specifically for receiving and channeling away the surge of extinguishing water. The collecting device is preferably equipped with a sensor which indicates when the collecting device is full and movement past the triggering lever has to take place.
The individual features according to the invention described above can be combined with one another to form an elevator car or an elevator installation; it is therefore possible to combine, for example, a rigid oblique drainage panel or a plurality of rigid oblique drainage panels with the lip and/or the collecting device and/or the flow-off means, in one and/or more parts, and the vertical drainage panels and this all, in turn, with the roller-shutter structure or the roller-shutter structures.
A drainage system for extinguishing water according to the invention, whether in the form of the above-described elevator-car drainage system, and variants thereof, alone or in combination with the corresponding drainage system for extinguishing water belonging to the shaft, is suitable both for elevator installations having a machinery compartment and for elevator installations without a machinery compartment. Existing elevator installations can advantageously be retrofitted with a drainage system for extinguishing water according to the invention.
An elevator car equipped according to the invention and an elevator installation according to the invention provide the following advantages:
Extinguishing water penetrating into the elevator shaft through the shaft doors is kept away from the supporting and driving means. The elevator car serves as an element which regulates the controlled flow-off of the extinguishing water in the elevator shaft as a whole. The elevator car is streamlined, which provides for optimized displacement of air in the elevator shaft and for smoother and more stable running of the elevator car. At high speeds, this is also manifested in the driving forces being reduced. In some circumstances a similar design is advantageous not just on the upper side, but also on the underside of the elevator car. The amount of space required for an elevator installation is reduced, and assembly is simplified, in relation to an elevator installation as disclosed by the prior art and, for example, the international publication cited.
DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail, symbolically and by way of example, with reference to figures. An overall description of the figures, taken together, is given. Like reference signs denote like components; reference signs with different indices indicate functionally identical or similar components.
In the figures:
FIG. 1 shows a schematic illustration of an example of an elevator installation having an elevator car according to the prior art;
FIG. 2 shows a schematic illustration of a first variant of an elevator car according to the invention and/or of an elevator installation;
FIG. 3 shows a schematic illustration of a second variant of an elevator car and/or of an elevator installation;
FIG. 4 shows a schematic illustration of a first variant of a drainage system for extinguishing water which belongs to the shaft and can optionally be combined with the elevator-car drainage systems shown in FIGS. 2 and 3 ; and
FIG. 5 shows a schematic illustration of a second variant of a drainage system for extinguishing water which belongs to the shaft and can optionally be combined with the elevator car drainage systems shown in FIGS. 2 and 3 .
DETAILED DESCRIPTION
FIG. 1 shows an elevator installation 100 as is known from the prior art, for example with 2:1 suspension illustrated. An elevator car 2 is arranged in a displaceable manner in an elevator shaft 1 and is connected to a displaceable counterweight 4 via a supporting and driving means 3 . The supporting and driving means 3 is driven, during operation, by means of a driving pulley 5 of a drive unit 6 , these being arranged in a machinery compartment 12 in the uppermost region of the elevator shaft 1 . The elevator car 2 and the counterweight 4 are guided by means of guide rails 7 a and 7 b and 7 c extending over the height of the shaft.
Over a conveying height h, the elevator car 2 can serve an uppermost floor door 8 , further floor doors 9 and 10 and a lowermost floor door 11 . The elevator shaft 1 is formed from shaft side walls 15 a and 15 b , a shaft ceiling 13 and a shaft floor 14 , on which are arranged a shaft-floor buffer 19 a for the counterweight 4 and two shaft-floor buffers 19 b and 19 c for the elevator car 2 .
The supporting and driving means 3 is fastened at a fixed-location fastening point or supporting-means-fixing point 16 a on the shaft ceiling 13 and is guided, parallel to the shaft side wall 15 a , to a supporting roller 17 for the counterweight 4 . From here, in turn, the supporting and driving means 3 is guided over the driving pulley 5 to a first deflecting or supporting roller 18 a and, passing beneath the elevator car 2 , to a second deflecting or supporting roller 18 b and to a second fixed-location fastening point for a supporting-means-fixing point 16 b on the shaft ceiling 13 .
FIG. 1 also shows, symbolically, a closed drainage system 200 for extinguishing water which uses closed pipelines and pipe connections to channel away extinguishing water into the shaft floor 14 from each individual floor and/or each individual shaft door 8 - 11 .
FIG. 2 shows, schematically, an example of an elevator car 2 a , which is a constituent part of an example of an elevator installation 100 a . The elevator car 2 a is supported by a supporting and driving means 3 a which is guided by deflecting or supporting rollers 18 c and 18 d , of which only the deflecting or supporting roller 18 c is visible in the perspective illustration shown. The cuboidal basic structure of the elevator car 2 a has four fastening struts 21 a - 21 d in extension of four more or less vertical corner edges 20 a - 20 d (of which, on account of the perspective view, only the corner edges 20 a - 20 c are visible).
A rigid drainage panel 22 is fastened on these four fastening struts 21 a - 21 d , flush in relation to an upper edge 27 of the elevator car 2 a , and forms a first drainage surface 23 a , having an approximate angle of inclination W 1 of 30 degrees to a horizontal H, and a second drainage surface 23 b , having an angle of inclination W 2 of more or less 60 degrees to the horizontal H. A more or less vertical connecting panel 24 a or 24 b is connected to the drainage surfaces 23 a and 23 b and to the fastening struts 21 a , 21 d and 21 b , 21 c , respectively.
Extinguishing water which comes into contact with the drainage surfaces 23 a and 23 b is thus collected and will flow down a side surface 25 of the elevator car 2 a and be deflected by an optional lip 26 . The drainage surfaces 23 a and 23 b , the connecting panels 24 a and 24 b , the side surface 25 and the lip 26 thus form a first elevator-car drainage system 200 a according to the invention.
FIG. 3 illustrates, schematically a variant of an elevator car 2 b and/or of an elevator installation 100 b . The elevator car 2 b , supported by a supporting and driving means 3 b in a visible deflecting or supporting roller 18 e and in a concealed deflecting or supporting roller 18 f , has a side surface 25 a between a corner edge 20 e and a further corner edge 20 f , a further side surface 25 b between the corner edge 20 f and a further corner edge 20 g , and a further side surface 25 c between the corner edge 20 e and a corner edge 20 h , which is not visible in the perspective view illustrated. The side surfaces 25 a , 25 b and 25 c form an upper edge 27 a of the elevator car 2 b . Fastening struts 21 e , 21 h are arranged on this upper edge 27 a , in extension of the corner edges 20 e - 20 h , and a drainage panel 22 a and more or less vertical connecting panels 24 c and 24 d are fastened on said fastening struts.
In a manner analogous to the drainage panel 22 from FIG. 2 , the drainage panel 22 a is formed from two drainage surfaces 23 c and 23 d , of which the drainage surface 23 c is inclined by an angle of inclination W 3 of more or less 30 degrees to a first horizontal H 1 and the drainage surface 23 d is inclined by an angle of inclination W 4 of approximately 60 degrees to said first horizontal H 1 . The drainage surfaces 23 c and 23 d , in turn, each form two sub-surfaces 28 a , 28 b and 28 c , 28 d , which are inclined in a mirror-inverted manner, and in the direction of the upper edge 27 a , by a respective angle of inclination W 5 and W 6 of more or less 30 degrees to a second horizontal H 2 .
Two gutters 29 a and 29 b , each with a flow-off means or discharge means 30 a and 30 b , respectively, are arranged on the side surface 25 a , flush with the sub-surfaces 28 c and 28 d . This means that the extinguishing water is collected on the roof of the elevator car 2 b , channeled away to the side surfaces 25 a - 25 c , collected in the gutters 29 a and 29 b and discharged via the flow-off means or discharge means 30 a and 30 b at the corner edges 20 e and 20 f of the elevator car 2 b.
For further protection of the supporting and driving means 3 b , a vertical drainage panel or splash guard 31 a , 31 b is arranged, in the form of an angled profile, on each of the side surfaces 25 b and 25 c , respectively.
The drainage panel 22 a illustrated, the more or less vertical connecting panels 24 c and 24 d , the gutters 29 a and 29 b and the vertical drainage panels or splashguard 31 a and 31 b form a second variant according to the invention of a drainage system 200 b on the elevator car 2 b and/or in the elevator installation 100 b.
As an optional variant, it is possible for the flow-off means or discharge means 30 a and 30 b to be arranged by means of two connecting tubes on the lower edge of the elevator car 2 b and, as a further option, for the extinguishing water which collects on the vertical drainage panels or splashguard 31 a and 31 b to be fed to these discharge means 30 a and 30 b or flow-off means arranged on the lower edge.
FIG. 4 shows, schematically, an example of an elevator shaft 1 a , which is a constituent part of an example of an elevator installation 100 c . Of the side walls of the elevator shaft 1 a , shaft side walls 15 c and 15 d , which are at more or less right angles to one another, are illustrated in the figure. The floors are indicated by an intermediate floor or screed floor 40 a , and each have a floor door or shaft door 9 a and 10 a . A respective door lintel 39 a , 39 b is located on the upper side of the shaft doors 9 a and 10 a . Located on the underside of the shaft door 9 a is a shaft-door sill 32 a , which comprises channel crosspieces and has through-openings or apertures or bores 33 a , preferably both in the channel crosspieces and in the grooves located therebetween. The bores 33 a here are in a pattern which is narrower in the center of the shaft-door sill 32 a and widens in the direction of the sides.
Beneath the shaft-door sill 32 a , the shaft side wall 15 c has arranged on it an intercepting panel 34 a , which forms a more or less vertical sub-surface 35 a —that is to say one which is parallel to a vertical V 1 —and a sub-surface 36 a which is inclined at an angle of inclination W 7 to the vertical V 1 . At least the inclined sub-surface 36 a , or also, in addition, the more or less vertical sub-surface 35 a , forms, in a mirror-inverted manner, from approximately the center of the intercepting panel 34 a , a respective angle of inclination W 8 or W 9 to a horizontal H 3 .
Accordingly, as indicated by arrows, extinguishing water 46 a flows through the shaft-door sill 32 a , is collected by the intercepting panel 34 a and fed laterally, in each case through outflow openings 45 a and 45 b , into receiving openings 38 a and 38 b of a respective intercepting profile 37 a , 37 b . In order to show clearly an open drainage system 200 c for extinguishing water belonging to the shaft, further intercepting profiles 37 c and 37 d , each with respective receiving openings 38 c and 38 d , are arranged at a distance A 1 and serve for receiving the extinguishing water which would come out of a shaft door above the shaft door 9 a . The distance A 1 , on the one hand, is decisive for reliable transfer of extinguishing water from the higher intercepting profiles 37 c and 37 d into the lower intercepting profiles 37 a and 37 b and, on the other hand, is decisive for extinguishing water being reliably received from the outflow openings 45 a and 45 b , but also for extinguishing water which is intercepted on the roof of the elevator car 2 a and 2 b from FIGS. 2 and 3 being reliably received.
FIG. 5 illustrates, schematically, a variant of an elevator shaft 1 b and/or of an elevator installation 100 d . In a manner analogous to FIG. 4 , a shaft door 9 b with a door lintel 39 c and a shaft-door sill 32 b , with through-openings or apertures or bores 33 b , and a further shaft door 10 b with a door lintel 39 d are illustrated in a shaft side wall 15 e . An intermediate floor 40 b passes through both the shaft side wall 15 e and a further shaft side wall 15 f , which is ranged more or less at right angles.
Beneath the shaft-door sill 32 b , an intercepting panel 34 b is arranged on the shaft side wall 15 e . This intercepting panel 34 b is open at the top and has a more or less vertical sub-surface 35 b and an inclined sub-surface 36 b , which adjoins the surface 35 b and is at an angle of inclination W 10 to a vertical V 2 . The intercepting panel 34 b also has side surfaces 41 a and 41 b . Beneath the intercepting panel 34 b , a flow-off panel 42 is arranged likewise on the shaft side wall 15 e , and this flow-off panel improves the flow-off behavior of extinguishing water 46 b which has penetrated through the shaft-door sill 32 b and is intercepted by the intercepting panel 34 b and passed on, on account of the laterally bounding side surfaces 41 a and 41 b , exclusively centrally through a gap-like outflow opening 45 c between the inclined sub-surface 36 b and the shaft side wall 15 e.
It is also possible for the flow-off panel 42 to be larger than illustrated and/or to be connected to the inclined sub-surface 36 b and a drainage panel 43 arranged beneath the flow-off panel 42 . Said drainage panel 43 is at an angle of inclination W 11 to the vertical V 2 and, in addition, is inclined downward in a mirror-inverted manner, from approximately its center toward the sides in each case, by an angle of inclination W 12 , W 13 to a horizontal H 4 , and therefore the extinguishing water 46 b flowing off from the flow-off panel 42 is directed thereby, via respective outflow openings 45 d and 45 e , into a receiving opening 38 e of an intercepting profile 37 e and a receiving opening 38 f of an intercepting profile 37 f.
Once more, in order to show clearly an open drainage system 200 d for extinguishing water belonging to the shaft, it is illustrated that further intercepting profiles 37 g and 37 h , each with respective receiving openings 38 g and 38 h , are arranged at a distance A 2 above the intercepting profiles 37 e and 37 f in the corners of the elevator shaft 1 b.
Furthermore, the elevator shaft 1 b has, in the shaft side wall 15 f , a vertically running slot 44 , in which the drainage panel 31 a or 31 b from FIG. 3 , said drainage panel being arranged on the elevator car 2 b , can run along, as a splashguard, in a recessed manner.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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A drain system, in an elevator system having at least one elevator car with an upper edge running approximately parallel to a horizontal plane, includes a deflector plate arranged on the upper edge of the elevator car at at least one angle of inclination to the horizontal plane and inclined against a shaft wall in which shaft doors are arranged, so that extinguishing water, which falls onto the elevator car is directed at least partially from the deflector plate against the upper edge and against the shaft wall in which the shaft doors are arranged.
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SUMMARY OF THE INVENTION
This invention relates to a fluid pressure braking system for a vehicle.
One important object of my invention is to provide an interlocking valve in a vehicle fluid pressure braking system having both emergency and service braking circuits which prevents release of the vehicle parking brakes until a predetermined fluid pressure level is communicated to the vehicle service brakes.
Another important object of my invention is to prevent movement of the vehicle after application of the parking brakes if the service braking circuits malfunction.
Still another important object of my invention is to require a two-step procedure to release the vehicle parking brakes.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a vehicle braking system made pursuant to the teachings of my present invention;
FIG. 2 is a detailed schematic illustration of a portion of a braking system illustrated in FIG. 1, and includes a cross-sectional view of one of the valves used therein;
FIG. 3 is a schematic illustration similar to FIG. 1, but illustrating another embodiment of my invention.
DETAILED DESCRIPTION
Referring now to FIGS. 1 and 2 of the drawings, a vehicle fluid pressure braking system generally indicated by the numeral 10 includes a conventional air compressor 12 which is powered by the vehicle engine and which compresses atmospheric air to charge a supply reservoir generally indicated by the numeral 14. The supply reservoir 14 charges a primary service reservoir 16, a secondary service reservoir 18, and a parking-emergency reservoir 20. Each of the reservoirs 16, 18, and 20, are protected by a one-way check valve 22, 24, and 26 which permit fluid communcation from the reservoir 14 into the corresponding reservoirs 16, 18, and 20, but which prevent escape of fluid pressure therefrom in the reverse direction. The fluid pressure content of the reservoirs 6 and 18 is communicated to corresponding inlet ports 28, 30, respectively, of a conventional dual brake valve generally indicated by the numeral 32. The dual brake valve 32 is constructed in accordance with the teachings of U.S. Pat. No. 3,266,850, owned by the assignee of the present invention and incorporated herein by reference. When a brake application is effected by operation of the treadle 34 on the valve 32 by the vehicle operator, the inlet ports 28 and 30 are communicated to their corresponding delivery ports 36, 38, respectively. When the treadle 34 is released, the delivery ports 36, 38 are vented to atmosphere through the exhaust port 40. The delivery port 38 is communicated to a control port 42 of a conventional relay valve generally indicated by the numeral 44. The relay valve 44 may be of any conventional design well known by those skilled in the art and is provided with a supply port 46 which is communicated to the service reservoir 18 and with delivery ports 48 which are communicated to the front wheel brake actuators 50, 52. The relay valve 44 is responsive to operation of the treadle 34 to communicate a predetermined pressure level from the secondary reservoir 18 to actuators 50, 52. Since the pressure communicated to the actuators 50, 52, corresponds to the pressure communicated to the control port 42 by the brake valve 32, a modulated brake application is effected. The actuators 50 and 52 may be of any conventional design well known to those skilled in the art.
The delivery port 36 of the brake valve 32 is communicated to a control port 54 of a conventional relay valve 56 which may be identical to the relay valve 44. The supply port 58 of relay valve 56 is communicated to the primary service reservoir 16, and the delivery ports 60 of the relay valve 56 are communicated to service ports 62, 64 of service and parking actuators generally indicated by the numerals 66 and 68. Actuators 66, 68 are made pursuant to the teachings of U.S. Pat. No. 3,228,729, owned by the assignee of the present invention and incorporated herein by reference. The actuators 66, 68, in addition to their service ports 62, 64, are also provided with emergency-parking ports 70, 72 and lock ports 74, 76. The actuators 66, and 68 are adapted to effect a brake application when fluid pressure is communicated to either the service ports 62, 64 or the emergency-parking ports 70, 72. If fluid pressure is also communicated to the lock ports 74, 76, the brake actuators are released in the normal manner when the fluid pressure level at the service ports 62, 64 or at the emergency-parking ports 70, 72 is exhausted. However, if the pressure at the lock ports 74, 76 is vented when the brake application is effected, the brake application will be "locked-on", thereby providing a parking brake capability.
The ports 70, 72 of the actuators 66, 68, ae communicated to corresponding delivery ports 78 of a relay valve 80 which may be made identical to the relay valves 44 and 56. The supply port 82 of the relay valve 80 is connected to the emergency-parking reservoir 20, and the control port 84 of the relay valve 80 is connected through a double check valve 86 of conventional construction. The handle 88 of a conventional push-pull parking control valve 90 is mounted in the vehicle operator's compartment and is movable from a normal or running position, in which the supply port 92 of the valve 90 is communicated to the delivery port 94 of the latter, to a parking position in which communication between supply port 92 of the delivery port 94 is terminated and the delivery port 94 is vented to an exhaust port 96. The supply port 92 is communicated directly to the emergency-parking reservoir 20, and the delivery port 94 is communicated to the supply port 98 of an interlocking valve mechanism enclosed by the dashed lines and generally indicated by the numeral 100. The control port 102 of the valve mechanism 100 is communicated to the delivery port 36 of the brake valve 32, and the delivery port 104 of the valve 100 is communicated to the lock ports 74, 76 of the brake actuators 66 and 68. The interlock valve 100 will be described in greater detail hereinafter.
The delivery port 104 of the interlock valve 100 is also communicated to the control port 106 of a parking valve enclosed by the dashed lines and generally indicated by the numeral 108. The supply port 110 of the parking valve 108 is communicated to the emergency-parking reservoir 20, and the delivery port 112 of the valve 108 is communicated to control port 84 through the double check valve 86. The parking valve 108 is described in detail in copending U.S. patent application Ser. No. 636,384 filed Nov. 28, 1975, owned by the assignee of the present invention and incorporated herein by reference. The parking valve 108 is responsive to movement of the handle 88 of the valve 90 from the running to the parking position to communicate a predetermined fluid pressure level to the control port 84 of relay valve 80 and to immediately release this fluid pressure level. It is necessary to communicate this predetermined pressure level to port 84 when the vehicle is parked, as the actuators 66 and 68 must be actuated at the time the pressure is vented from the lock ports 74 and 76 to "lock-on" a brake application. Since the parking valve 108 forms no part of the present invention, it will not be described in detail herein.
The other side of the check valve 86 is communicated to the delivery port 114 of a standby valve generally indicated by the numeral 116. Standby valve 116 further includes a control port 118 which is communicated to the supply port 28 of the brake valve 32, and an inlet port 120 which is communicated to delivery port 38 of the brake valve 32. The standby valve is described in detail in the aforementioned copending application Ser. No. 636,384, filed Nov. 28, 1975, and is adapted to sense a failure in the primary braking circuits to enable actuation of the brake valve 32 to communicate fluid pressure to the emergency-parking ports 70 and 72 of actuators 66, 68 when a brake applications is effected. Since the standby valve 116 forms no part of the present invention, it will not be described in further detail herein.
Referring now to FIG. 2, the interlock valve 100 will be described in detail. The valve mechanism 100 includes a control valve generally indicated by the numeral 115 and a double check valve generally indicated by the numeral 117. The valve 115 includes a housing 119 defining a bore 121 therewithin which communicates with the supply port 98 and with a delivery port 122. An exhaust port 124 is provided which communicates the bore 121 with the atmosphere. The housing 119 further includes a control port 126 which is communicated directly to a delivery port 128 on the check valve 117. The delivery port 128 is common with the delivery port 104 which, as described hereinabove, is communicated to the lock ports 74, 76 of the brake actuators 66 and 68. A piston 130 is slidably mounted in the bore 121, and a spring 132 yieldably urges the piston 130 to the right viewing FIG. 2, in opposition to the pressure level at the control port 126. The left-hand end (viewing FIG. 2) of the piston 130 is adapted to engage a valve member 134 which is slidably mounted within the housing 119 and is adapted to sealingly engage a valve seating area 136 provided on the wall of the bore 121. A spring 138 yieldably maintains the valve member 134 in sealing engagement with the valve seat 136. The piston 130 is further provided with a passage 140 extending through the piston which communicates with the exhaust port 124. As can be seen from FIG. 2, when pressure level at control port 126 acting on the piston 130 generates a force less than the force generated by the spring 132, the piston 130 is urged into the position illustrated in the drawing, thereby permitting the valve member 134 to sealingly engage the valve seat 136 to terminate communication between the ports 98 and 122, and to exhaust the port 122 to atmosphere through the passage 140 and the exhaust port 124. A conduit 142 communicates the port 122 of the housing 119 with port 144 on the check valve 117. As discussed hereinabove, the port 102 of the check valve 117 which is opposite the port 144, is communicated to the outlet port 36 of the brake valve 32. A shuttle 146 is slidably mounted within the check valve 117 and is responsive to pressure differential between the ports 102 and 144 to communicate the higher of the pressures communicated to the ports 102 and 144 to outlet ports 128, 104 of the check valve 117. The check valve 117 is of a conventional construction well known to those skilled in the art and will not be further described herewithin.
MODE OF OPERATION
When the vehicle engine is started, the air compressor 12 charges the reservoirs 14, 16, 18, and 20 with compressed air. When the pressure level in the reservoir 20 attains a predetermined value, the vehicle operator operates the control handle 88 of the parking valve 90 to communicate the delivery port 94 with the supply port 92 to thereby communicate fluid pressure to the supply port 98 of the valve 115. However, since the pressure level at the control port 126 of the valve 115 is exhausted, the valve member 134 remains in sealing engagement with the valve seat 136 thereby preventing communication from the port 98 to the port 122 of the latter. However, when the treadle 34 is operated to operate the control valve 32 to effect a service brake actuation, communication is initiated between the inlet ports 28, 30 of the latter to the outlet or delivery ports 36, 38, thereby communicating fluid pressure to the actuators 50 and 52, and also communicating fluid pressure to the service ports 62, 64 of the actuators 66, 68. Since the port 102 of the check valve 117 is also communicated to the delivery port 36 and the brake valve 32, fluid pressure will be communicated to this port when a service brake application is effected. Service pressure communicated to the port 102 is greater than the fluid pressure level at port 144 since, as pointed out hereinabove, the pressure level at the port 122 of the valve 115 is at a substantially atmospheric pressure level because it is communicated to the exhaust port 124. Therefore, the high pressure fluid at the port 102 forces the shuttle 146 into the position illustrated in the drawing, to thereby communicate air at port 102 to the control port 126 of the valve 115. High pressure fluid at the port 126 urges the piston 130 to the left, viewing the Figure, thereby engaging the left-hand end of the piston 130 with the valve member 134 and thereafter urging the valve member 134 away from the valve seat 136 to thereby terminate fluid communication through the passage 140 and to initiate fluid communication between the inlet 98 and the port 122. Fluid pressure is communicated from the port 122 of the valve 115 to the port 144 of the check valve 117 and, upon release of the brake valve 32, to the control port 126 of the valve 115. Consequently, once fluid pressure is initially communicated through the valve 115, communication is permitted between the ports 98 and 122 until the control valve 90 is again moved to the parking position to vent port 98. High pressure fluid communicated through the outlet port 104, from either of the inlets 144 or 102, is communicated to the lock ports 74, 76 of the actuators 66, 68 thereby releasing the locking mechanisms to permit release of the vehicle brakes. As pointed out hereinabove, once the valve 115 is initially opened, substantially uninhibited fluid communication is permitted to the lock ports 74, 76, thereby maintaining release of the locking mechanisms, until the control valve 90 is returned to the parking position. When this occurs, the fluid pressure level at the port 98 of the valve 115 is exhausted, thereby also exhausting the fluid pressure in the control port 126 of the latter through the conduit 142 and the port 122. Therefore, piston 130 moves to the position illustrated in the drawing, thereby venting the port 122 to the exhaust port 124 and therefore exhausting the fluid pressure level communicated to the lock ports 74, 76 to prevent movement of the brake actuators 66, 68 in the brake-releasing direction. However, if the actuators 66, 68 are already in the brake-released position, parking valve 108 automatically applies, and then releases a predetermined pressure level to the parking-emergency ports 70, 72 of the brake actuators 66, 68 thereby effecting a predetermined brake application after the locking ports 74, 76 are vented. This brake application is "locked-on" thereby preventing movement of the vehicle.
DESCRIPTION OF THE ALTERNATE EMBODIMENT
In the alternate embodiment of FIG. 3, elements substantially the same as those in the preferred embodiment retain the same reference numerals, but are increased by 200. In FIG. 3, the actuators 66, 68 are replaced by spring brake actuators 348, 350 which are manufactured pursuant to any well known design, such as the design disclosed in U.S. Pat. No. 3,800,668, owned by the assignee of the present invention and incorporated herein by reference. The spring brake actuators 348, 350 include service ports 352, 354, and parking-emergency ports 356, 358. Of course, the brake actuators 348, 350 are responsive to fluid communication to the service ports 352, 354 to effect a service brake application in the normal manner. The spring brake actuators 348, 350 also include relatively heavy springs which normally urge the actuator into a brake-applied condition, but are "held off" by fluid pressure communicated to the parking-emergency ports 356, 358. In other words, the spring brake actuators 348, 350 are automatically applied by the spring brake mechanism unless a predetermined fluid pressure level is communicated to the parking-emergency ports 356, 358. The system disclosed in FIG. 3 further includes an inverting relay valve generally indicated by the numeral 360 which is described in detail in U.S. Pat. No. 3,863,992 owned by the assignee of the present invention and incorporated herein by reference. The valve 360 includes a control port 362 which is communicated to the primary braking circuit and therefore to the inlet port 228 of the brake valve 232, an inlet port 364 which is communicated to the secondary braking circuit and therefore to the outlet or delivery ports 238 of the brake valve 232, and a second inlet port 366 which is communicated to the delivery port 304 of the interlocking valve generally indicated by the numeral 300. The valve 360 is responsive to loss of control pressure at port 362 to permit a modulated spring brake application upon operation of the brake valve 32 to therefore effect a brake application upon failure of communication of fluid pressure to the service ports 352, 354 due to a failure in the primary service braking system. When pressure is available at the other inlet port 366, the valve 360 automatically communicates this pressure through the valve 360 to the parking-emergency ports 356, 358 to thereby provide release pressure holding off the spring brake actuators 348, 350 for normal operation of the vehicle. The interlocking valve 300 functions as described above to prevent fluid communication through the outlet port 302, and therefore to the inlet port 366, and, unless a service brake application is first effected by operation of the brake valve 232, to communicate a service brake application through the primary braking circuit.
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A vehicle fluid pressure braking system is disclosed which includes brake-applying devices having separate service and parking actuators. Separate service and parking actuation circuits are provided to control actuation of the service and parking actuators, respectively. An interlocking valve is provided which prevents release of the parking actuator until a predetermined fluid pressure level is communicated to the service actuator. This interlocking valve prevents inadvertent release of the parking actuators, and also prevents release of the parking actuators in a situation in which a malfunction of the service braking circuit would render operation of the vehicle dangerous.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of co pending U.S. Provisional Patent Application Nos. 61/573,900, 61/573,957, 61/573,958, 61/573,956, 61/573,955, 61/573,954, 61/573,953 and 61/573,952, all filed on Sep. 14, 2011, the disclosures of which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention is generally directed toward the treatment of water and, more particularly, toward the treatment of water containing large amounts of dissolved solids as may result, for example, from use of the water as a fracking fluid used in drilling gas wells. However, the embodiment proposed herein may be used in any situation where impurities to be removed from water exist.
BACKGROUND OF THE INVENTION
[0003] Ensuring a supply of potable water has been a frequent concern in many locations. Further concerns arise about the environmental impact of the disposal of contaminated water.
[0004] Conventional water treatment techniques for such purposes as, for example, municipal water treatment and/or obtaining potable water from sea water are known and are successful in many instances. However, some current activities show those techniques to have limited cost effectiveness.
[0005] For example, mining with water used to fracture rock or shale formations to recover natural gas (e.g., in the shale regions in the United States and western Canada including, but not li8mited to, Pennsylvania, Maryland, New York, Texas, Oklahoma, West Virginia and Ohio) requires a very large amount of water input and a significant amount of return (flowback) water that contains a great deal of contaminants and impurities. In order for this flowback water to be used in an environmentally responsible manner, it needs to be relatively free of contaminants/impurities. Water used, for example, in natural gas well drilling and production may contain organic materials, volatile and semi-volatile compounds, oils, metals, salts, etc. that have made economical treatment of the water to make it potable or reusable, or even readily and safely disposable, more difficult. It is desirable to remove or reduce the amount of such contaminants/impurities in the water to be re-used, and also to remove or reduce the amount of such contaminants/impurities in water that is disposed of.
[0006] The present invention is directed toward overcoming one or more of the above-identified problems.
SUMMARY OF THE INVENTION
[0007] The present invention can take numerous forms among which are those in which waste water containing a large amount of solids, including, for example, dissolved salts, is pressurized to allow considerable heat to be applied before the water evaporates, and is then subjected to separation and recovery apparatus to recover relatively clean water for reuse and to separate solids that include the afore-mentioned dissolved salts. In some instances, the concentrated solids may be disposed of as is, e.g., in a landfill. Where that is not acceptable (e.g., for reasons of leaching of contaminants), the concentrated solids may be supplied to a thermal, pyrolytic, reactor (referred to herein as a “crystallizer”) for transforming them into a vitrified mass which can be placed anywhere glass is acceptable.
[0008] Particular apparatus for systems and processes in accordance with the present invention can be adapted from apparatus that may be presently currently available, but which has not been previously applied in the same manner. As an example, conventional forms of flash evaporation equipment, such as are used for treating sea water, in one or in multiple stages, may be applied herein as separation and recovery apparatus. Likewise, conventional forms of gasification/vitrification reactors, such as are used for municipal solid waste (“MSW”) processing including, but not limited to, plasma gasification/vitrification reactors, may be applied for final separation of the contaminants from the water and for initial heating of the waste water.
[0009] The present disclosure presents examples of such systems and processes in which, in one or more successive concentration stages, waste water with dissolved solids (e.g., salts) is pressurized (e.g., from 14.7 psia to 150 psia) and heated (e.g., to 358° F.) before flash evaporation of the waste water to a significantly lower flash pressure and temperature (e.g., 25 psia and 239° F.) of the output brine water with more concentrated salts (e.g., higher Total Dissolved Solids—“TDS”).
[0010] Steam output from the various concentration stages may be, at least in part, supplied to a stripper to remove volatile organic compounds (“VOCs”) which are also included in the waste water.
[0011] Depending on the nature and levels of TDS, the brine water from the various concentration stages may be utilized, as is, for other uses, e.g., de-icing fluid, etc., with a significant amount of clean water recovered (e.g., as distilled water from heat exchangers of the concentration stages). The brine water may alternatively be treated in a thermal (e.g., plasma) reactor or crystallizer in order to separate the salts and recover water included in the brine water from the concentration stages.
[0012] Examples also include supplying saturated steam from the crystallizer directly to the condensers of the concentration stages, and then from each of which it is then applied as a heating fluid or source of a preheater for the waste water. Incoming waste water or brine water to each concentration stage is initially pressurized and heated (e.g., to 230° F.) by, for example, a pump, a preheater, and a condenser by use of the steam from the crystallizer and/or from the flash evaporator of that stage. The waste water is further heated, prior to flash evaporation, by an additional heater device that mixes the waste water with a hot gas. The hot gas heater may be, for example, a plasma torch gas heater or gas heated by a natural gas burner. However, other types of hot gas heaters may be included without departing from the spirit and scope of the present invention.
[0013] A method for treating waste water is disclosed, the method including the steps of: (a) receiving waste water at a first pressure and a first temperature, the waste water comprising dissolved solids, volatile organic compounds and other components generally and collectively called impurities; (b) pressurizing the received waste water to a second pressure greater than the first pressure; (c) preheating the pressurized waste water to a second temperature greater than the first temperature, wherein said preheating step produces distilled water and pressurized/preheated waste water without boiling of the waste water across heat transfer surfaces; (d) heating the pressurized/preheated waste water to a third temperature greater than the second temperature to produce pressurized/heated waste water without boiling of the waste water across heat transfer surfaces; (e) further heating the pressurized/heated water with a heater operated with a hot gas developed by a plasma torch or a natural gas burner to a fourth temperature greater than the third temperature to produce a second pressurized/heated waste water without boiling of the waste water across heat transfer surfaces; and (f) removing dissolved solids from the second pressurized/heated waste water by evaporation caused by depressurization of the waste water to produce steam and brine water, wherein the brine water has a total dissolved solids content greater than a total dissolved solids content of the received waste water. The heater used in step (e) may have a plasma power input appropriately adjusted to produce the heating of the pressurized waste water by direct contact of the hot plasma gas and the waste water. In one example, the power input may be approximately 150-226 kW; however, other levels are contemplated.
[0014] The first pressure may be approximately 11.8-17.6 psia, and the first temperature may be approximately 48-72° F.
[0015] The second pressure may be approximately 120-180 psia, and the fourth temperature may be approximately 286-430° F.
[0016] The second temperature may be approximately 71-114° F.
[0017] The third temperature may be approximately 184-276° F.
[0018] In one form, the steam produced in step (f), when cooled, produces distilled water. Additionally, the steam produced in step (f) may be used as a heat source in at least one of steps (c) and (d).
[0019] In another form, steps (a)-(f) comprise a stage, and wherein the method is performed in multiple stages with the brine water output by step (f) in one stage used as the received waste water in step (a) of a next stage. The brine water output in step (f) of each stage has a total dissolved solids content that is higher than that of a previous stage.
[0020] In a further form, the method further includes the steps of: (g) crystallizing the brine water to produce a solid mass of waste product and steam. The steam produced by step (g) may be used as a heat source in at least one of steps (c) and (d). A plasma crystallizer using a plasma torch may be used to crystallize the brine water. The solid mass of waste product may include a vitrified glass of the salts in the brine water.
[0021] In yet a further form, the method further includes the steps of: (b′) prior to step (b), removing the volatile organic compounds from the received waste water, wherein the removed volatile organic compounds are used as a heat source by the plasma torch to crystallize the brine water. The steam produced by step (g) may be used as a heat source in step (b′).
[0022] A system for treating waste water is also disclosed, the system including: a pump receiving waste water at a first pressure and a first temperature and pressurizing the received waste water to a second pressure greater than the first pressure, the waste water comprising dissolved solids, volatile organic compounds and other components generally and collectively called impurities; a preheater receiving the pressurized waste water from the pump and preheating the pressurized waste water to a second temperature greater than the first temperature to produce distilled water and pressurized/preheated waste water without boiling of the waste water across heat transfer surfaces; a condenser receiving the pressurized/preheated waste water and further heating the pressurized/preheated waste water to a third temperature greater than the second temperature to produce a pressurized/heated waste water without boiling of the waste water across heat transfer surfaces; a heater operated with a hot gas developed by a plasma torch or a natural gas burner receiving the pressurized/heated waste water and further heating the pressurized/heated waste water to a fourth temperature greater than the third temperature to produce a second pressurized/heated waste water without boiling of the waste water across heat transfer surfaces; and an evaporator removing dissolved solids from the second pressurized/heated waste water by evaporation caused by depressurization of the waste water to produce steam and brine water, wherein the brine water has a total dissolved solids content greater than a total dissolved solids content of the received waste water. The evaporator may include a flash evaporator. The heater may have a plasma power input appropriately adjusted to produce the heating of the pressurized waste water by direct contact of the hot plasma gas and the waste water. In one example, the power input may be approximately 150-226 kW; however, other levels are contemplated.
[0023] The first pressure may be approximately 11.8-17.6 psia, and the first temperature may be approximately 48-72° F.
[0024] The second pressure may be approximately 120-180 psia, and the fourth temperature may be approximately 286-430° F.
[0025] The second temperature may be approximately 71-114° F.
[0026] The third temperature may be approximately 184-276° F.
[0027] In one form, the steam produced by the evaporator may include distilled water. The steam produced by the evaporator may be used as a heat source by at least one of the preheater and the condenser.
[0028] In another form, the pump, preheater, condenser, heater and evaporator comprise a stage, and wherein the system comprises multiple stages with the brine water output by one stage used as the received waste water of a next stage. The brine water output by each stage has a total dissolved solids content that is higher than that of a previous stage.
[0029] In a further form, the system further includes a crystallizer crystallizing the brine water to produce a solid mass of waste product and steam. The steam produced by the crystallizer may be used as a heat source by at least one of the preheater and condenser. The solid mass of waste product may include a vitrified glass of the salts in the brine water.
[0030] In yet a further form, the crystallizer includes a plasma crystallizer and includes a plasma torch for vaporizing the water from the brine water and producing the solid mass of waste product and steam.
[0031] In still a further form, the system further includes a stripper initially receiving the waste water and removing volatile organic compounds from the waste water prior to the waste water being pressurized by the pump, wherein the removed volatile organic compounds are used as a heat source by the plasma torch to crystallize the brine water. The steam produced by the crystallizer is used as a heat source by the stripper.
[0032] Further explanations and examples of various aspects of the present invention are presented in the following disclosure.
[0033] It is an object of the present invention to provide a system and method for the economic and environmental treatment of waste water.
[0034] Various other objects, aspects and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Further possible embodiments are shown in the drawings. The present invention is explained in the following in greater detail as an example, with reference to exemplary embodiments depicted in drawings. In the drawings:
[0036] FIGS. 1 , 2 and 3 are schematic flow diagrams of particular examples of various stages of a water treatment system in accordance with the present invention; and
[0037] FIG. 4 is a schematic flow diagram of an exemplary thermal reactor for use in a water treatment system in conjunction with elements such as those show in FIGS. 1-3 , in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] FIGS. 1 , 2 and 3 will be individually discussed, but first their relation to each other in an example multi-stage system will be described. FIG. 1 shows Stage # 1 . This first stage, shown generally at 5 , takes in waste water at an inlet 10 , processes it, and produces first stage brine water at an outlet 30 of the first stage. The first stage brine water from the outlet 30 is then input to the second stage (Stage # 2 ) shown in FIG. 2 . The second stage, shown generally at 5 ′, takes in the brine water 30 , performs additional processing on it, and produces a resulting second stage brine water output at an outlet 50 . Similarly, the brine water from outlet 50 of the second stage is supplied as an input to the third stage (Stage # 3 ) shown in FIG. 3 . The third stage, shown generally at 5 ″, receives the brine water 50 , performs further processing, and produces a resulting third stage output of brine water at an outlet 70 .
[0039] It will be seen and appreciated by on skilled in the art how the successive stages of FIGS. 1 , 2 and 3 increase the concentration of salts in the brine water (e.g., TDS). It will also be appreciated how the number of stages is a variable that can be chosen according to factors including, but not limited to, the salts content of the original waste water and the desired salt content after concentration. In general, a system in accordance with these exemplary embodiments may include any one or more stages such as are shown, for example, in FIGS. 1-3 . The examples being presented are illustrative of systems and methods that may be chosen not merely for good technical performance but also for reasons relating to economic factors, such as, for example, initial capital cost and operating cost, as well as convenience factors, such as, for example, space requirements and portability. While three stages are shown and described herein, one skilled in the art will appreciate that any number of stages may be utilized depending on the particular application without departing from the spirit and scope of the present invention.
[0040] Each of the FIGS. 1-4 , merely by way of further example and without limitation, are described in this specification and include legends, including numerical values (all of which are merely representative approximations and are not necessarily exact technical values and/or calculations). Further, these legends are not necessarily the only suitable values that represent the nature and characteristics of materials as applied to, affected by, and resulting from the operations of the exemplary system(s). Not all such legends will be repeated in this text, although all form a part of this disclosure and are believed understandable to persons of ordinary skill in water treatment and thermal processes. As appreciated by one skilled in the art, such data are sometimes referred to as heat and material balances. It is specifically to be understood and will be appreciated by one skilled in the art that the various values indicated in the legends may have a tolerance of ±20%, as they are representative approximations and not exact technical values.
[0041] Referring to FIG. 1 , which is Stage # 1 , the waste water progresses from the input 10 to the output 30 successively through a pump 11 , a preheater 12 , a condenser 13 , an additional heater 24 , and a flash evaporator 15 . An alternative is to have, in place of a single preheater 12 , a series of preheaters or heat exchangers. The heating medium or source for the preheater(s) 12 can be excess steam available from a crystallizer 90 (see FIG. 4 ) and/or hot water available from the condenser 13 .
[0042] The pump 11 pressurizes the waste water 10 and elevates the pressure from approximately 14.7 psia (1 atm) to approximately 150 psia. The level of pressurization of waste water in all Stages is such that there is no boiling of the waste water inside and across the heat exchanger surfaces of all heat exchanger used in this system. This is done to prevent formation of deposits (scales, fouling etc.) on the heat exchanger surfaces. The temperature of the waste water 10 is raised by the preheater 12 and the condenser 13 so the input waste water to the additional heater 24 at an inlet 17 is at approximately 150 psia and 230° F. In the embodiment show in FIG. 1 , the preheater 12 heats the waste water from approximately 60° F. at the inlet 10 to approximately 89° F. at an inlet 18 to the condenser 13 . The preheater 12 also outputs clean, distilled water at output 20 that is generally free from contaminants/impurities. The condenser 13 further heats the waste water to approximately 230° F. The heater 24 further heats the waste water to a temperature of approximately 358° F. at an inlet 19 to a flash evaporator 15 .
[0043] In the exemplary system, the initial elevation in temperature is due to the effect of saturated steam from a steam output 80 of the crystallizer subsystem 90 of FIG. 4 , plus steam 15 a from the flash evaporator 15 that joins with steam output 80 from the crystallizer 90 at a junction 16 . The steam continues to the condenser 13 and the preheater 12 , until it exits the preheater 12 as distilled water at outlet 20 . Under certain operating conditions, the steam addition from the crystallizer 90 may be negative, i.e., steam is sent as excess to the crystallizer for other uses (e.g., as a heat source for the stripper 96 ).
[0044] The heating in the additional heater 24 is accomplished by a hot gas mixed with the waste water. The hot gas may be, for example, a plasma torch gas or gas heated by a natural gas burner. However, other types of hot gas heaters may be included without departing from the spirit and scope of the present invention. Additionally, the gas in the heater 24 can be chosen from a wide range of choices and it is subsequently vented from the system at vent 21 . In one exemplary embodiment, air may be conveniently used as the heated gas.
[0045] The Stage # 1 output 30 has the volume of waste water reduced from the input 10 with the salts more concentrated to approximately 23% TDS, which is increased from the initial approximately 20% TDS in the exemplary waste water at the input 10 .
[0046] Stage # 2 of the system as shown in FIG. 2 has elements substantially like those of Stage # 1 as shown and described with respect to FIG. 1 , but with some different operating parameters as shown in the legends in FIG. 2 . Referring to FIG. 2 , which is Stage # 2 , the brine water 30 from Stage # 1 progresses to the output 50 successively through a pump 31 , a preheater 32 , a condenser 33 , an additional heater 34 , and a flash evaporator 35 . An alternative is to have, in place of a single preheater 32 , a series of preheaters or heat exchangers. The heating medium or source for the preheater(s) 32 can be excess steam available from a crystallizer 90 (see FIG. 4 ) and/or hot water available from the condenser 33 .
[0047] The pump 31 pressurizes the brine water 30 and elevates the pressure from approximately 14.7 psia (1 atm) to approximately 150 psia. The temperature of the brine water 30 is also raised by the preheater 32 and the condenser 33 so the input brine water to the additional heater 34 at an inlet 37 is at approximately 150 psia and 230° F. In the embodiment show in FIG. 2 , the preheater 32 heats the brine water from approximately 60° F. at the inlet 30 to approximately 92° F. at an inlet 38 to the condenser 33 . The preheater 32 also outputs clean, distilled water at output 40 that is generally free from contaminants/impurities. The condenser 33 further heats the brine water to approximately 230° F. The heater 34 further heats the brine water to a temperature of approximately 358° F. at an inlet 39 to a flash evaporator 35 .
[0048] In the exemplary system, the initial elevation in temperature is due to the effect of saturated steam from a steam output 80 of the crystallizer subsystem 90 of FIG. 4 , plus steam 35 a from the flash evaporator 35 that joins with steam output 80 from the crystallizer 90 at a junction 36 . The steam continues to the condenser 33 and the preheater 32 , until it exits the preheater 32 as distilled water at outlet 40 . Under certain operating conditions, the steam addition from the crystallizer 90 may be negative, i.e., steam is sent as excess to the crystallizer for other uses (e.g., as a heat source for the stripper 96 ).
[0049] The heating in the additional heater 34 is accomplished by a hot gas mixed with the waste water. The hot gas may be, for example, a plasma torch gas or gas heated by a natural gas burner. However, other types of hot gas heaters may be included without departing from the spirit and scope of the present invention. Additionally, the gas in the heater 34 can be chosen from a wide range of choices and it is subsequently vented from the system at vent 41 . In one exemplary embodiment, air may be conveniently used as the heated gas.
[0050] The Stage # 2 output 50 has the volume of brine water reduced from its input 30 with the salts more concentrated to approximately 26% TDS, which is increased from the initial approximately 23% TDS in the exemplary brine water at its input 30 .
[0051] Similarly, Stage # 3 of FIG. 3 has elements substantially like those of Stage # 2 as shown and described with respect to FIG. 2 , but with still some differences in operating parameters as shown in the legends in FIG. 3 . Referring to FIG. 3 , which is Stage # 3 , the brine water 50 from Stage # 2 progresses to the output 70 successively through a pump 51 , a preheater 52 , a condenser 53 , an additional heater 54 , and a flash evaporator 55 . An alternative is to have, in place of a single preheater 52 , a series of preheaters or heat exchangers. The heating medium or source for the preheater(s) 52 can be excess steam available from a crystallizer 90 (see FIG. 4 ) and/or hot water available from the condenser 53 .
[0052] The pump 51 pressurizes the brine water 50 and elevates the pressure from approximately 14.7 psia (1 atm) to approximately 150 psia. The temperature of the brine water 50 is also raised by the preheater 52 and the condenser 53 so the input brine water to the additional heater 54 at an inlet 57 is at approximately 150 psia and 230° F. In the embodiment show in FIG. 3 , the preheater 52 heats the brine water from approximately 60° F. at its inlet 50 to approximately 95° F. at an inlet 58 to the condenser 53 . The preheater 52 also outputs clean, distilled water at output 60 that is generally free from contaminants/impurities. The condenser 53 further heats the brine water to approximately 230° F. The heater 54 further heats the brine water to a temperature of approximately 358° F. at an inlet 59 to a flash evaporator 55 .
[0053] In the exemplary system, the initial elevation in temperature is due to the effect of saturated steam from a steam output 80 of the crystallizer subsystem 90 of FIG. 4 , plus steam 55 a from the flash evaporator 55 that joins with steam output 80 from the crystallizer 90 at a junction 56 . The steam continues to the condenser 53 and the preheater 52 , until it exits the preheater 52 as distilled water at outlet 60 . Under certain operating conditions, the steam addition from the crystallizer 90 may be negative, i.e., steam is sent as excess to the crystallizer for other uses (e.g., as a heat source for the stripper 96 ).
[0054] The heating in the additional heater 54 is accomplished by a hot gas mixed with the waste water. The hot gas may be, for example, a plasma torch gas or gas heated by a natural gas burner. However, other types of hot gas heaters may be included without departing from the spirit and scope of the present invention. Additionally, the gas in the heater 54 can be chosen from a wide range of choices and it is subsequently vented from the system at vent 61 . In one exemplary embodiment, air may be conveniently used as the heated gas.
[0055] The Stage # 3 output 70 has the volume of brine water reduced from its input 50 with the salts more concentrated to approximately 30% TDS, which is increased from the initial approximately 26% TDS in the exemplary brine water at its input 50 . In addition, the volume of water with the salts is reduced at the outlet 70 of Stage # 3 by 54% from that at the inlet 10 of Stage # 1 .
[0056] The exemplary system includes multiple (three) concentration stages ( FIGS. 1-3 ) that are substantially alike in the combination of equipment used. However, other exemplary systems with multiple concentration stages may have individual stages of more varied combinations of equipment without departing from the spirit and scope of the present invention.
[0057] The inputs and outputs of the individual stages can all be simply at 14.7 psia or at a pressure chosen by the process operator to optimize energy utilization within the process. Advantage can be taken within each stage to pressurize the inputs to the respective flash evaporators 15 , 35 , 55 to about 150 psia. The level of pressurization of waste water in all Stages is such that there is no boiling (nucleate or other type) of the waste water inside and across the heat exchanger surfaces of both the condensers, heaters and preheaters of each Stage. This prevents the formation of deposits (scales, fouling etc.) on the heat exchanger surfaces and reduces the requirement for cleaning of the heat exchangers. This results in the reduction of the operating cost. In this example, such an increase in pressure can result in a temperature of about 358° F. input to the flash evaporators 15 , 35 , 55 for quicker, more efficient separation and concentration in the respective flash evaporator 15 , 35 , 55 .
[0058] FIG. 4 represents an exemplary embodiment of applying the output brine water (line 70 ) of the Stage # 3 treatment ( FIG. 3 ) to a plasma crystallizer 90 . The plasma crystallizer 90 is an example of a known thermal reactor that can be used to finish separation of water from salts dissolved therein. One skilled in the relevant art will appreciate, however, that other thermal reactors may also be used without departing from the spirit and scope of the present invention. The example of a plasma reactor, which can be consistent with known plasma gasification/vitrification reactors, operated with one or more plasma torches 92 , as is well-known in published literature, is believed to provide opportunity for a favorable cost-benefit ratio.
[0059] In general, for multistage operation, the plasma crystallizer 90 (or other reactor) is typically utilized after the final concentration stage when the output brine water has been concentrated to a desired level, as described in the above example. It can also be suitable to have a multistage system not only for salts concentration (as in FIGS. 1-3 ), but also a separation subsystem with a reactor (e.g., plasma crystallizer 90 ) after any individual one of the early concentration stages (e.g., after either, or both, of Stages # 1 and # 2 ). However, it is generally more cost effective to have a single separation subsystem after the last of determined number of concentration stages for the desired separation.
[0060] In general, any thermal reactor may be used to separate the salts and the water. A reactor operated to produce disposable salts (referred to herein as a “crystallizer”) is generally suitable. Where the salts have toxicity, it may be desirable to operate the reactor in a manner so they are vitrified or made into glass. Accordingly, any reference to a crystallizer herein can also include a vitrifier.
[0061] As shown in FIG. 4 , the crystallizer has a salts output at an outlet 85 that is generally equivalent to the total salts content of the original waste water. The water output of the total system is recovered as clean, distilled water from the preheaters 12 , 32 , 52 of the respective Stages of FIGS. 1-3 , and/or may be recovered directly from steam exiting the crystallizer 90 .
[0062] FIG. 4 shows the brine water 70 entering the crystallizer 90 without need for additional pressurization. FIG. 4 also shows how steam from the crystallizer 90 can be redirected back to the respective earlier Stages of FIGS. 1-3 . The steam output from the crystallizer 90 at line 80 may be provided back to the various Stages # 1 , # 2 and # 3 and used for heating by the respective preheaters and condensers therein. Also, FIG. 4 shows an “Excess Steam to Stripper” of a certain amount at line 94 . This steam 94 is used in a stripper 96 (which may be an additional flash evaporator) which is utilized to remove, for example, Volatile Organic Compounds (“VOCs”) from the waste water before processing. Some excess steam from the crystallizer 90 may also be used for other purposes, e.g., to preheat the input waste water in a preheater or condenser.
[0063] Before treatment in the Stages shown in FIGS. 1-3 , the incoming waste water 9 can be first, in this exemplary embodiment, sent to the stripper 96 where the steam 94 is used to remove VOCs from the waste water 9 . Alternatively, the excess steam 94 may be used to preheat air in a separate heater first (not shown), and then the heated air can be used in the stripper 96 . The stripped waste water 10 is sent as feed at the input 10 of Stage # 1 (see FIG. 1 ). The VOCs which are removed from the waste water 9 exit the stripper 96 through a conduit 98 which connects to the plasma crystallizer 90 . Additionally or alternatively, a condenser with a knock-out pot (not shown) can be used between the plasma crystallizer 90 and the stripper 96 with the condensed VOCs (as well as any stripped VOCs) fed directly to the plasma crystallizer 90 . The VOCs are fed in front of the plasma torch 92 (e.g., along with brine water from Stage # 3 ) such that they intensely mix with the high temperature gases exiting from the plasma torch 92 . The plasma torch 92 is operated using appropriate gas (e.g., air, oxygen, hydrogen, etc.) that will aid in, or result in, the complete destruction of the VOCs. The VOCs are substantially converted to carbon dioxide and steam. The heat generated by this conversion of VOCs to carbon dioxide and steam is utilized in the plasma crystallizer 90 , along with heat inputted through the plasma torch 92 , to vaporize the water from the brine water 70 . This reduces the amount of heat and the corresponding amount of electricity utilized in the plasma torch 92 of the plasma crystallizer 90 , thus increasing its cost effectiveness.
[0064] The steam exiting the plasma crystallizer 90 can be, in this exemplary embodiment, periodically vented to the atmosphere (not shown) to help keep the levels of non-condensable gases low enough such that they do not degrade the performance of the heat exchangers used in the inventive system and process.
[0065] It is therefore seen that systems and processes in accordance with the present invention can make use of known and available components (such as, for example, flash evaporators for concentration of salts and plasma (or other) gasifier reactors for crystallization (or vitrification) of the salts) in particular innovative ways with insight as to both the capital cost and the operating cost. A need for such cost effective water treatment has been heightened by practices, such as, for example, the use of large amounts of water in natural gas drilling. However, the present invention may be used in any situation where impurities to be removed exist.
[0066] In general summary, but without limitation, the present invention can be characterized in the following ways, for example: A system, and a corresponding method, in which waste water is supplied to one or more stages of equipment including a pump for pressurizing the water (e.g., to about 150 psia), a preheater that heats the pressurized water (as well as removing distilled water) well above normal boiling temperature, and a condenser that effects further heating of the pressurized waste water. The system additionally has a heater after the condenser of each stage that raises the temperature even higher well above normal boiling temperature. That heater is operated with a hot gas developed by a plasma torch or a natural gas burner or other similar device. Then, the heated and pressurized waste water goes to a flash evaporator, or other device, that receives the heated, pressurized waste water and results in fluid evaporation and concentration of solids that were in the waste water. In, for example, instances in which the waste (brine) water with concentrated solids cannot be otherwise readily and safely disposed of, a thermal or pyrolytic reactor is provided to crystallize or otherwise yield a form of the solids that can be readily and safely disposed of. In one form, such a reactor may also be applied as a heater for the original incoming waste water. Also, or alternatively, such a reactor may be used to form a vitrified glass of the salts output of any water treatment system that produces a brine water.
[0067] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teachings of the disclosure. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention, which is to be given the full breadth thereof. Additionally, the disclosure of a range of values is a disclosure of every numerical value within that range.
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System and method of treating waste water includes: receiving waste water at a first pressure and temperature, the waste water comprising dissolved solids and VOCs; pressurizing, by a pump, the received waste water to a second pressure greater than the first pressure; preheating, by a preheater, the waste water to a second temperature greater than the first temperature producing distilled water; heating, by a condenser, the waste water to a third temperature greater than the second temperature; heating the pressurized/heated water with a heater operated with a hot gas developed by a plasma torch to a fourth temperature greater than the third temperature; and removing dissolved solids from the waste water by evaporation to produce steam and brine water, wherein the brine water has a total dissolved solids content greater than a total dissolved solids content of the received waste water. The brine water is crystallized to a solid mass.
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This application claims priority from U.S. Provisional Application No. 60/257,584 filed Dec. 22, 2000.
FIELD OF THE INVENTION
This invention is directed to a method and apparatus for controlling fiber or filament distribution and orientation in the manufacture of nonwoven fabrics, including spunbond nonwovens, as well as to the resulting nonwovens having a desired fiber or filament distribution and orientation. More particularly, this invention is directed to a controlled application of an electrostatic field in combination with specific target electrode deflection means acting on fibers or filaments prior to deposition on a forming wire or other web forming means. The design of the deflector means located below fiber drawing means, when combined with the controlled application of electrostatics provides separation of the fibers or filaments and directional distribution on the forming surface to result in webs with desired preferential orientation and resulting web properties. The invention also includes a method of producing spunbond and other nonwoven fabrics that can be tailored to achieve a wide variety of physical and other properties for numerous applications in personal care, health care, protective apparel and industrial products.
BACKGROUND
Nonwoven fabrics or webs constitute all or part of numerous commercial products such as adult incontinence products, sanitary napkins, disposable diapers and hospital gowns. Nonwoven fabrics or webs have a physical structure of individual fibers, strands or threads which are interlaid, but not in a regular, identifiable manner as in a knitted or woven fabric. The fibers may be continuous or discontinuous, and are frequently produced from thermoplastic polymer or copolymer resins from the general classes of polyolefins, polyesters and polyamides, as well as numerous other polymers. Blends of polymers or conjugate multicomponent fibers may also be employed. Methods and apparatus for forming fibers and producing a nonwoven web from synthetic fibers are well known, common techniques and include meltblowing, spunbonding and carding. Nonwoven fabrics may be used individually or in composite materials as in a spunbond/meltblown (SM) laminate or a three-layered spunbond/meltblown/spunbond (SMS) fabric. They may also be used in conjunction with films and may be bonded, embossed, treated or colored. Colors may be achieved by the addition of an appropriate pigment to the polymeric resin. In addition to pigments, other additives may be utilized to impart specific properties to a fabric, such as in the addition of a fire retardant to impart flame resistance or the use of inorganic particulate matter to improve porosity. Because they are made from polymer resins such as polyolefins, nonwoven fabrics are usually extremely hydrophobic. In order to make these materials wettable, surfactants can be added internally or externally. Furthermore, additives such as wood pulp or fluff can be incorporated into the web to provide increased absorbency and decreased web density. Such additives are well known in the art. Bonding of nonwoven fabrics can be accomplished by a variety of methods typically based on heat and/or pressure, such as through air bonding and thermal point bonding. Ultrasonic bonding, hydroentangling and stitchbonding may also be used. There exist numerous bonding and embossing patterns that can be selected for texture, physical properties and appearance. Qualities such as strength, softness, elasticity, absorbency, flexibility and breathability are readily controlled in making nonwovens. However, certain properties must often be balanced against others. An example would be an attempt to lower costs by decreasing fabric basis weight while maintaining reasonable strength. Nonwoven fabrics can be made to feel cloth-like or plastic-like as desired. The average basis weight of nonwoven fabrics for most applications is generally between 5 grams per square meter and 300 grams per square meter, depending on the desired end use of the material. Nonwoven fabrics have been used in the manufacture of personal care products such as disposable infant diapers, children's training pants, feminine pads and incontinence garments. Nonwoven fabrics are particularly useful in the realm of such disposable absorbent products because it is possible to produce them with desirable cloth-like aesthetics at a low cost. Nonwoven personal care products have had wide consumer acceptance. The elastic properties of some nonwoven fabrics have allowed them to be used in form-fitting garments, and their flexibility enables the wearer to move in a normal, unrestricted manner. The SM and SMS laminate materials combine the qualities of strength, vapor permeability and barrier properties; such fabrics have proven ideal in the area of protective apparel. Sterilization wrap and surgical gowns made from such laminates are widely used because they are medically effective, comfortable and their cloth-like appearance familiarizes patients to a potentially alienating environment. Other industrial applications for such nonwovens include wipers, sorbents for oil and the like, filtration, and covers for automobiles and boats, just to name a few.
It is widely recognized that properties relating to strength and barrier of nonwoven fabrics are a function of the uniformity and directionality of the fibers or filaments in the web. Various attempts have been made to distribute the fibers or filaments within the web in a controlled manner. These attempts have included the use of electrostatics to impart a charge to the fibers or filaments, the use of spreader devices to direct the fibers or filaments, the use of deflector means for the same purpose, and reorienting the fiber forming means. However, it remains desired to achieve still further capability to gain this control in a way that is consistent with costs dictated by the disposable applications for many of these nonwovens.
SUMMARY OF THE INVENTION
The present invention includes the use of electrostatics in combination with a segmented target electrode deflector plate below the fiber drawing means acting on fibers or filaments prior to laydown on a forming surface to control the distribution and orientation of the fibers or filaments in the resulting web. Particularly when used in a spunbond process, the resulting web can be made to achieve widely varying degrees of physical and barrier properties, including a very high degree of uniformity if desired. The invention is applicable to spinning a wide variety of polymers in monocomponent, biconstituent or conjugate filaments and using many different bonding steps, such as patterned thermal or ultrasonic bonding as well as adhesive bonding. Also, the filaments or fibers may vary widely in denier, cross-sectional shape and the like and may be combined as mixtures of the foregoing. Single layer nonwoven webs or multilayer laminates may be formed in accordance with the invention.
The invention provides a process for forming a nonwoven web includes the steps of:
a. providing a source of fibers and/or filaments;
b. subjecting the fibers and/or filaments to an electrostatic charge;
c. directing the fibers and/or filaments to a deflector device while under the influence of the electrostatic charge; and
d. collecting the fibers and/or filaments on a forming surface to form a nonwoven web.
In one embodiment the fibers and/or filaments are provided by melt spinning. In a further aspect the meltspun filaments may be continuous and subjected to pneumatic draw forces in a fiber draw unit prior to being subjected to said electrostatic charge. In a specific embodiment the deflector device includes a series of teeth separated by a distance determined by the desired orientation of the fibers and/or filaments in the nonwoven web. Also, in one aspect the teeth are oriented at an angle with respect to the directed fibers and/or filaments, the angle determined by the desired orientation of the fibers and/or filaments in the nonwoven web. The invention also includes the apparatus and resulting nonwoven webs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a spunbond process including the fiber or filament control of the invention.
FIG. 2 is an enlarged view of the combined electrostatics and segmented target electrode deflector device in accordance with the invention.
FIG. 3 is a detailed view of a target electrode deflector device in accordance with the invention.
DETAILED DESCRIPTION
Definitions
As used herein and in the claims, the term “comprising” is inclusive or open-ended and does not exclude additional unrecited elements, compositional components, or method steps.
As used herein the term “nonwoven fabric or web” means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from many processes such as for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of nonwoven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and the fiber diameters useful are usually expressed in microns. (Note that to convert from osy to gsm, multiply osy by 33.91).
As used herein the term “microfibers” means small diameter fibers having an average diameter not greater than about 75 microns, for example, having an average diameter of from about 0.5 microns to about 50 microns, or more particularly, microfibers may have an average diameter of from about 2 microns to about 25 microns. Another frequently used expression of fiber diameter is denier, which is defined as grams per 9000 meters of a fiber and may be calculated as fiber diameter in microns squared, multiplied by the density in grams/cc, multiplied by 0.00707. A lower denier indicates a finer fiber and a higher denier indicates a thicker or heavier fiber. For example, the diameter of a polypropylene fiber given as 15 microns may be converted to denier by squaring, multiplying the result by 0.89 g/cc and multiplying by 0.00707. Thus, a 15 micron polypropylene fiber has a denier of about 1.42 (15 2 ×0.89×0.00707=1.415). Outside the United States the unit of measurement is more commonly the “tex”, which is defined as the grams per kilometer of fiber. Tex may be calculated as denier/9.
As used herein the term “spunbonded fibers” refers to small diameter fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to Hartman, and U.S. Pat. No. 3,542,615 to Dobo et al. Spunbond fibers are generally not tacky when they are deposited onto a collecting surface. Spunbond fibers are generally continuous and have average diameters (from a sample of at least 10) larger than 7 microns, more particularly, between about 10 and 20 microns. The fibers may also have shapes such as those described in U.S. Pat. No. 5,277,976 to Hogle et al., U.S. Pat. No. 5,466,410 to Hills and 5,069,970 and 5,057,368 to Largman et al., which describe fibers with unconventional shapes.
As used herein the term “meltblown fibers” means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al. Meltblown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in average diameter, and are generally tacky when deposited onto a collecting surface.
As used herein “multilayer laminate” means a laminate wherein some of the layers may be spunbond and some meltblown such as a spunbond/meltblown/spunbond (SMS) laminate and others as disclosed in U.S. Pat. No. 4,041,203 to Brock et al., U.S. Pat. No. 5,169,706 to Collier, et al, U.S. Pat. No. 5,145,727 to Potts et al., U.S. Pat. No. 5,178,931 to Perkins et al. and U.S. Pat. No. 5,188,885 to Timmons et al. Such a laminate may be made by sequentially depositing onto a moving forming belt first a spunbond fabric layer, then a meltblown fabric layer and last another spunbond layer and then bonding the laminate in a manner described below. Alternatively, the fabric layers may be made individually, collected in rolls, and combined in a separate bonding step. Such fabrics usually have a basis weight of from about 0.1 to 12 osy (6 to 400 gsm), or more particularly from about 0.75 to about 3 osy. Multilayer laminates may also have various numbers of meltblown layers or multiple spunbond layers in many different configurations and may include other materials like films (F) or coform materials, e.g. SMMS, SM, SFS, etc.
As used herein the term “polymer” generally includes but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” includes all possible geometrical configurations of the molecule. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
As used herein, the term “machine direction” or MD means the length of a fabric in the direction in which it is produced. The term “cross machine direction” or CD means the width of fabric, i.e. a direction generally perpendicular to the MD.
As used herein the term “monocomponent” fiber refers to a fiber formed from one or more extruders using only one polymer. This is not meant to exclude fibers formed from one polymer to which small amounts of additives have been added for color, antistatic properties, lubrication, hydrophilicity, etc. These additives, e.g. titanium dioxide for color, are generally present in an amount less than 5 weight percent and more typically about 2 weight percent.
As used herein the term “conjugate fibers” refers to fibers which have been formed from at least two polymers extruded from separate extruders but spun together to form one fiber. Conjugate fibers are also sometimes referred to as multicomponent or bicomponent fibers. The polymers are usually different from each other though conjugate fibers may be monocomponent fibers. The polymers are arranged in substantially constantly positioned distinct zones across the cross-section of the conjugate fibers and extend continuously along the length of the conjugate fibers. The configuration of such a conjugate fiber may be, for example, a sheath/core arrangement wherein one polymer is surrounded by another or may be a side by side arrangement, a pie arrangement or an “islands-in-the-sea” arrangement. Conjugate fibers are taught in U.S. Pat. No. 5,108,820 to Kaneko et al., U.S. Pat. No. 4,795,668 to Krueger et al., U.S. Pat. No. 5,540,992 to Marcher et al. and U.S. Pat. No. 5,336,552 to Strack et al. Conjugate fibers are also taught in U.S. Pat. No. 5,382,400 to Pike et al. and may be used to produce crimp in the fibers by using the differential rates of expansion and contraction of the two (or more) polymers. Crimped fibers may also be produced by mechanical means and by the process of German Patent DT 25 13 251 A1. For two component fibers, the polymers may be present in ratios of 75/25, 50/50, 25/75 or any other desired ratios. The fibers may also have shapes such as those described in U.S. Pat. Nos. 5,277,976 to Hogle et al., U.S. Pat. No. 5,466,410 to Hills and 5,069,970 and 5,057,368 to Largman et al., which describe fibers with unconventional shapes.
As used herein the term “biconstituent fibers” refers to fibers which have been formed from at least two polymers extruded from the same extruder as a blend. The term “blend” is defined below. Biconstituent fibers do not have the various polymer components arranged in relatively constantly positioned distinct zones across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead usually forming fibrils or protofibrils which start and end at random. Biconstituent fibers are sometimes also referred to as multiconstituent fibers. Fibers of this general type are discussed in, for example, U.S. Pat. Nos. 5,108,827 and 5,294,482 to Gessner. Bicomponent and biconstituent fibers are also discussed in the textbook Polymer Blends and Composites by John A. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of is New York, IBSN 0-306-30831-2, at pages 273 through 277.
As used herein the term “blend” means a mixture of two or more polymers while the term “alloy” means a sub-class of blends wherein the components are immiscible but have been compatibilized. “Miscibility” and “immiscibility” are defined as blends having negative and positive values, respectively, for the free energy of mixing. Further, “compatibilization” is defined as the process of modifying the interfacial properties of an immiscible polymer blend in order to make an alloy.
“Bonded carded web” refers to webs that are made from staple fibers which are sent through a combing or carding unit, which breaks apart and aligns the staple fibers in the machine direction to form a generally machine direction-oriented fibrous nonwoven web. Such fibers are usually purchased in bales which are placed in a picker which separates the fibers prior to the carding unit. Once the web is formed, it then is bonded by one or more of several known bonding methods. One such bonding method is powder bonding, wherein a powdered adhesive is distributed throughout the web and then activated, usually by heating the web and adhesive with hot air. Another suitable bonding method is pattern bonding, wherein heated calender rolls or ultrasonic bonding equipment are used to bond the fibers together, usually in a localized bond pattern, though the web can be bonded across its entire surface if so desired. Another suitable and well-known bonding method, particularly when using bicomponent staple fibers, is through-air bonding.
As used herein, “ultrasonic bonding” means a process performed, for example, by passing the fabric between a sonic horn and anvil roll as illustrated in U.S. Pat. No. 4,374,888 to Bornslaeger.
As used herein “thermal point bonding” involves passing a fabric or web of fibers to be bonded between a heated calender roll and an anvil roll. The calender roll is usually, though not always, patterned in some way so that the entire fabric is not bonded across its entire surface, and the anvil roll is usually flat. As a result, various patterns for calender rolls have been developed for functional as well as aesthetic reasons. One example of a pattern has points and is the Hansen Pennings or “H&P” pattern with about a 30% bond area with about 200 bonds/square inch as taught in U.S. Pat. No. 3,855,046 to Hansen and Pennings. The H&P pattern has square point or pin bonding areas wherein each pin has a side dimension of 0.038 inches (0.965 mm), a spacing of 0.070 inches (1.778 mm) between pins, and a depth of bonding of 0.023 inches (0.584 mm). The resulting pattern has a bonded area of about 29.5%. Another typical point bonding pattern is the expanded Hansen Pennings or “EHP” bond pattern which produces a 15% bond area with a square pin having a side dimension of 0.037 inches (0.94 mm), a pin spacing of 0.097 inches (2.464 mm) and a depth of 0.039 inches (0.991 mm). Another typical point bonding pattern designated “714” has square pin bonding areas wherein each pin has a side dimension of 0.023 inches, a spacing of 0.062 inches (1.575 mm) between pins, and a depth of bonding of 0.033 inches (0.838 mm). The resulting pattern has a bonded area of about 15%. Yet another common pattern is the C-Star pattern which has a bond area of about 16.9%. The C-Star pattern has a cross-directional bar or “corduroy” design interrupted by shooting stars. Other common patterns include a diamond pattern with repeating and slightly offset diamonds with about a 16% bond area and a wire weave pattern looking as the name suggests, e.g. like a window screen, with about a 19% bond area. Typically, the percent bonding area varies from around 10% to around 30% of the area of the fabric laminate web. As in well known in the art, the spot bonding holds the laminate layers together as well as imparts integrity to each individual layer by bonding filaments and/or fibers within each layer.
As used herein, the term “personal care product” means diapers, training pants, swimwear, absorbent underpants, adult incontinence products, and feminine hygiene products. It also includes absorbent products for veterinary and mortuary applications.
As used herein, the term “protective cover” means a cover for vehicles such as cars, trucks, boats, airplanes, motorcycles, bicycles, golf carts, etc., covers for equipment often left outdoors like grills, yard and garden equipment (mowers, rototillers, etc.) and lawn furniture, as well as floor coverings, table cloths and picnic area covers.
As used herein, the term “outdoor fabric” means a fabric which is primarily, though not exclusively, used outdoors. Outdoor fabric includes fabric used in protective covers, camper/trailer fabric, tarpaulins, awnings, canopies, tents, agricultural fabrics and outdoor apparel such as head coverings, industrial work wear and coveralls, pants, shirts, jackets, gloves, socks, shoe coverings, and the like.
Description
Turning to FIG. 1, there is shown an example of a spunbond nonwoven forming process in accordance with the invention. As illustrated, spinplate 10 receives polymer from a conventional melt extrusion system (not shown) and forms filaments 12 which may be monocomponent, conjugate or biconstituent as described above. Fiber draw unit 14 includes a source of drawing air from chambers 16 directed at high velocity pulling filaments 12 causing orientation of the filaments, increasing their strength properties. Below the fiber draw unit 14 there is shown electrostatics unit 18 including rows 20 of pins producing a corona discharge against target electrodes 22 and deflector 24 . The charged filaments 12 then are directed to the forming wire 26 moving around rolls 28 , one or both of which may be driven. A compaction device such as air knife 30 may be used to consolidate web 32 prior to bonding nip 34 between calender rolls 36 , 38 (one or both of which may be patterned as described above) which form bonded web 40 . If desired, conventional means 15 for removing or reducing the charge on the web may be employed such as applying an oppositely charged field or ion cloud. Such devices are known and described, for example, in U.S. Pat. No. 3,624,736 to Jay, incorporated herein in its entirety by reference.
It will be recognized by those skilled in the art that various combinations of charge polarity may be used in carrying out the invention. For example, with reference to FIG. 1, the following chart illustrates exemplary alternatives. A charge of zero indicates the device is connected to ground.
V 1
V 2
V 3
—
+
+
—
0
+
+
—
—
+
0
—
Turning to FIG. 2, there is shown a view of one corona discharge arrangement 201 useful in accordance with the invention. The exit from fiber draw unit 14 is indicated at 203 and is separated by insulation 205 , 225 from ammeter 207 connected to power supply 209 forming target 235 including plate 211 . The electrode array 229 is comprised of multiple bars, for example four bars 213 , 215 , 217 , 219 , each of which contains a plurality of recessed emitter pins 221 connected through ammeter 227 to power supply 223 . Also forming part of the target 235 is deflector 231 attached by conductive means such as bolt 233 to plate 211 . The deflector target can be isolated from or connected to the target plate by a conductive means.
Turning to FIG. 3, there is shown a perspective view of one target electrode deflector 231 in accordance with the invention. The deflector is segmented by grooves 301 formed by teeth 303 is mounted by bolts 305 to support 307 . Although not apparent from the drawing, teeth 303 may be separated by a spacing of, for example, about one eighth inch to provide for additional control of fiber distribution. The shape and spacing of the teeth 303 may be varied to produce intended degrees of fiber separation and orientation on laydown.
EXAMPLES
While the invention will be illustrated by means of examples, the examples are only representative and not limiting on the scope of the invention which is determined in reference to the appended claims.
Electrode
Emitter pins are spaced apart at ¼ inch, and recessed at ⅛ inch in a cavity of 0.5 inch high×0.25 inch deep. These 26 inch wide rows (24 effective inch) of pins are stacked up in four, and the distance between pins is ¾ inch (See FIG. 2 ). The row of pins was manufactured by The Simco Company, Inc., 2257 North Penn Road, Hartfield, Pa. 19440. These electrodes were connected to a high voltage DC source through a single 100 mega ohm resistor to measure the discharge current via the corresponding voltage. The power supply was Model EH3OR3, 0-30 KV, 0-3 MA, 100 watt regulated, reversible with respect to chassis ground, but the negative voltage was applied here although opposite charge may also be used. It was manufactured by Glassman High Voltage, Inc., PO Box 551, Route 22 East, Salem Park, Whitehouse Station, N.J. 08889.
Target
Two target objects were used: a target plate and target deflector. The plate was 3 inches high×26 inches wide conducting steel plate. The deflector was comprised of a multitude of 60 degree angle×⅜ inch wide×1.88 inches long, conducting steel teeth. They were stacked at an angle 32 degrees with respect of the center line of the fiber draw unit with a spacing of ⅛ inch (see FIG. 3 ). Their steel surfaces were coated with ceramic PRAXAIR LA-7 coating 0.002-0.005 inch thick. This abrasion resistant coating had very little surface resistance of 7 ohms over approximately ¾ inch distance, while the corresponding value of the uncoated steel resistance was close to 0.0002 ohms. These two targets were joined with conducting steel bolts to each other, and connected to another power supply through another 100 mega-ohm resistor. The power source was the same Glassman power supply, but with different, positive sign, polarity. Thus, the net current between the value at the electrode and that at the target indicates the amount of discharge in the air borne fiber stream, and estimated the amount of charge in the fibers.
Examples A through E
Spinning Condition
A 17 inches effective wide spin plate of 130 holes/inch was used at 0.65 grams/hole to obtain 0.5 ounce/yd 2 web of approximately 2 denier/filament spunbond polypropylene fibers. The equipment used was generally in accordance with above-described Matsuki U.S. Pat. No. 3,802,817, incorporated herein in its entirety by reference, except as specifically described herein.
TABLE 1
Results of Electrostatic Charging and Combing
Example ID
A
B
C
D
E
Electrode Voltage, V1 KV
0
−5
−5
−5
−17
Target Voltage, V2 KV
0
15
18
18
5
Net Current, Inet = A1-A2
Microamp/inch (1)
0
2.5
3.3
3.3
3.3
Overall Voltage, V1-V2 KV
0
−20
−23
−23
−22
Specific Charge
MicroCoulomb/g fiber (2)
0
2.51
3.34
3.34
3.34
MicroCoulomb/m 2 fiber
0
10
13.3
13.3
13.3
surface (3)
Target Deflector
No
No
No
Yes
Yes
Web Formation Rating (4)
0
1
2
5
5
Note:
(1) Current indication was fluctuated severely, perhaps implying the fluctuating fiber flux
(2) Based on throughput indicated above, and assumed the net charge on fibers
(3) Based on specific fiber surface area = 0.25 m 2 /g at 2 dpf
(4) Visual subjective rating with 5 being the best
As shown in Table 1, the electrostatic charging in this bias circuitry at −20 to −23 improved formation, but much greater improvements were made with target deflector plate with a high voltage bias circuitry.
While this invention is not limited to any theory of operation, it is believed that such dramatic improvement has been made as follows. Typically the fibers are easily moved around in the flowfield due to local fluctuations in velocity which is a characteristic of turbulent flow. As fibers are charged, the resulting electrostatic repulsion force prevents the fibers from roping or clumping together. A typical velocity at the exit of the fiber draw unit is of the order of 6000 m/min. Assume the turbulent fluctuation in velocity is of the order of 10% of the mean velocity, i.e., 6000×10/100=600 m/min. Further assume this fluctuating velocity component is directed perpendicular to the fiber axis. The drag force acting on the fiber due to this fluctuation in velocity would be of the order of 1 dyne. This force would correspond to a filament spacing of 0.02 cm for two 2 dpf and 1 cm long fibers with 3.3 microcoulomb/gram charge according to the Coulombic Law. Essentially there is a balance between the electrostatic force and turbulence induced forces at a length scale of 0.02 cm. Strictly speaking the electrostatic forces insure filament separation on a small length scale.
On the other hand the mechanical deflector provides mixing that helps improve formation defects that are of the order of 1.2 to 2.5 cm in scale. Coupling the electrostatics with the mechanical deflector insures fiber uniformity over a length scale of 0.02 to 2.5 cm. Consider the following analogy. A sand box contains sand of varying depth resulting in a bumpy surface. Dragging a rake across the sand would help reduce surface texture on a length scale equal to the spacing of the tines. Dragging a screen across the sand would help smooth the surface on a length scale of the mesh in the screen. For this analogy the mechanical deflector acts as the rake and electrostatics acts like the screen.
While the invention has been described in terms of its best mode and other embodiments, variations and modifications will be apparent to those of skill in the art. It is intended that the attached claims include and cover all such variations and modifications as do not materially depart from the broad scope of the invention as described therein.
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Improvements to processes and equipment for the manufacture of nonwoven webs useful in numerous applications including personal care, protective apparel, and industrial products. The fiber and/or filaments used to form the nonwoven fabric are deposited on a forming surface in a controlled orientation using application of an electrostatic charge to the fibers and/or filaments in combination with directing them to an electrode deflector plate while under the influence of the charge. The plate may be made up of teeth with a separation and angle orientation that are selected in accordance with the desired arrangement of the fibers and/or filaments in the nonwoven web. As a result, properties of the web such as relative strengths in the machine direction and cross-machine direction can be controlled.
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[0001] The present invention relates to the field of compositions that are polymerisable via a cationic pathway, possibly using radiation or electron bombardment, comprising a reactive monomer and an initiator system that can initiate cationic polymerisation, comprising a cationic salt and a co-initiator. The cationic polymerisation in the context of the present invention may be initiated by two different pathways, which may be combined: irradiating the cationic salt with light for the first pathway; and a thermal reaction between the reactive monomer and one or more species liberated by exothermic reaction between the cationic salt and the co-initiator, in particular without adding external heat, for the second pathway. The invention also relates to a method of cationic polymerisation of a composition of this type.
BACKGROUND OF THE INVENTION
[0002] Cationic photopolymerisation was developed with the intention of permitting the polymerisation, under light irradiation, of monomers that cannot be polymerised by a radical pathway, for example epoxy resins.
[0003] Photopolymerisation of epoxy resins by a cationic pathway was thus primarily developed in the field of paints, coatings, and adhesives. However, cationic photopolymerisation suffers from slower polymerisation rates and lower final degrees of conversion than those obtained by means of polymerisation via a radical pathway. Drying epoxy-based paints or curing epoxy-based parts may thus take from about 10 minutes (min) to several hours (h).
[0004] In addition, photopropagation within the thickness of coatings to be polymerised, and thus the photopolymerised thicknesses obtained, are more limited with the cationic pathway because of the limited number of potential initiators and monomers, and also because of the complexity of polymerisation mechanisms.
[0005] Thus, cationic photopolymerisation is more suitable for thin products and/or products with a low filler content and/or products that are not highly colored. Cationic photopolymerisation has become highly developed, starting from the academic and industrial work by J. V. Crivello who discovered the family of onium salts as photoinitiators (see the following publications: J. V. Crivello, T. P. Lockart, and J. L. Lee: Journal of Polymer Science Polymer Chemistry, Edition 21, 97-109 (1983), studying the thermal decomposition of iodonium and sulfonium salts with the addition of heat; J. V. Crivello: Advances in Polymer Science. 62, 1-48 (1984), studying iodonium and sulfonium salts as photoinitiators).
[0006] This family of photoinitiators includes iodonium, sulfonium, phosphonium and pyridinium salts.
[0007] Iodonium and sulfonium salts are the most widely used. Phosphonium salts are difficult to use because of their toxicity. Pyridinium salts are more complete photoinitiators because they can be used alone to initiate a cationic polymerisation by irradiation or thermally, but with heating of the salt in order to destabilize it and cause it to decompose, the heating temperature being higher than 40° C.; it may be up to 120° C. These latter salts have been developed and studied by Y. Yagci (see publications: Y. Yagci and T. End. Advances in Polymer Science 127, 59-86 (1997), studying pyridinium salts as a photoinitiator or thermal initiator; Y. Yagci and I. Reetz, Progress in Polymer Science 23, 1485-1538 (1998), studying pyridinium salts as a photoinitiator or thermal initiator).
[0008] Cationic polymerisation via a thermal pathway, in particular of epoxies, is rather limited because of the small number of initiators that are available. Epoxy resins are usually polymerised by amines as the principal or secondary initiator (co-initiator).
[0009] Initiator systems composed of acid anhydrides or indeed thiols are also known. These initiator systems, namely amine, acid anhydride, and thiols, result in polymerisation of the anionic type or in polycondensation. The structure of the polymer obtained by polycondensation is very different from structures obtained by an anionic or cationic pathway. With polycondensation, a three-dimensional (3D) network is constituted by polymer chains connected together via nitrogen-type bridges. Thus, its nature is more that of a copolymer than a homopolymer, in particular an epoxy. With cationic and anionic polymerisation, a 3D network may be generated with cross-linking ties of the same chemical nature as the polymer chains. A polyether matrix is formed thereby.
[0010] In order to be able to polymerise larger thicknesses than those obtained by photopolymerisation, hybrid initiator systems have been developed that involve two different chemistries, namely that of epoxies and that of urethanes, for example.
[0011] Initiator systems are also known that can be used for photochemical polymerisation followed by a thermal pathway using heat.
[0012] EP 0 066 543 relates to polymerisable compositions comprising epoxy monomers (A) polymerised by adding external heat to said compositions, i.e. by heating, in the presence of a catalyst (B) and a co-catalyst (C). The catalyst (B) or initiator comprises a quaternary ammonium salt, in particular an aromatic N-heterocyclic compound. Under the effect of heat, the co-catalyst (C) generates a radical that reduces the catalyst (B) in a redox reaction, producing a by-product that initiates the polymerisation reaction by reaction with the monomer (A). Without adding heat, and thus at ambient temperature, a polymerisation reaction cannot take place.
[0013] Thus, there is a need for a cationic polymerisation initiator system that can be used to combine photopolymerisation and/or polymerisation via a thermal pathway in the presence of a co-initiator, without adding heat, and that can be used for polymerisation via a photochemical pathway at the surface and via a thermal pathway in the core of the layer to be polymerised as a function of said layer, regardless of whether it is filled and/or pigmented and/or includes reinforcement. Systems of this type are known as dual-cure cationic systems.
[0014] The term “dual-cure” as used in the context of the present invention means any system that involves two polymerisation processes, i.e. a photochemical process and a thermal process (in particular via the exothermicity of the reaction). The term “dual-cure” means that the chemistries of polymerisation by a photochemical pathway and by a thermal pathway are similar. When there are two chemistries that are different, for example a radical chemistry and a cationic chemistry, or indeed an epoxy chemistry and a urethane chemistry, for example, that is termed hybrid polymerisation.
[0015] Thus, the present invention relates to a composition that can be polymerised by a dual-cure cationic pathway, using the same chemistry issuing from the same initiator for photochemical initiation and/or thermal initiation as a function of the thickness and transparency of the coating to be polymerised (which may optionally be filled and/or pigmented).
OBJECT AND SUMMARY OF THE INVENTION
[0016] In a first aspect, the present invention provides a kit for a polymerisable composition, said kit comprising:
a portion A constituted by a composition comprising at least one monomer (a1) that is reactive towards a cationic species or a Lewis or Brönsted acid species, and at least one co-initiator (b); a portion B optionally comprising a solvent and/or at least one monomer (a2) that is reactive towards a cationic species or a Lewis or Brönsted acid species, and at least one cationic salt (e) selected from the salts with formula S1, S2, S3, and S4 below;
[0000]
[0000] in which:
X represents a carbon atom or a positively charged heteroatom other than nitrogen; Y represents one or more stabilizing anionic species for the cationic species of the salt S1 or S2 or S3, or S4, in particular comprising at least one anionic species selected, alone or in combination, from Br, Cl, BF 4 − , PF 6 − , AsF 6 − , AnF 6 − , SbF 6 − , SnF 6 − , ClO 4 − , sulfonates such as trifluoromethane sulfonate, perfluorosulfonate, tris [(trifluoromethyl)sulfonyl]methanide and tetra (pentafluorophenylborate); R 1 to R 6 , independently of one another, are selected from the following atom or atoms or group or groups, alone or in combination, optionally arranged so as to carry one or more positive charges: a hydrogen atom; a nitro group —NO 2 ; a cyano group —CN; a halogen atom; a C 1 -C 20 alkyl group, optionally substituted with one or more group(s) or one or more atoms selected independently from list I comprising the following groups or atoms: hydroxyl; carbonyl, alkenyl, aryl, heteroaryl, ether, ester, aldehyde, ketone, carboxylic acid, halogen, primary amine, secondary amine, tertiary amine, primary amide, secondary amine, tertiary amine, urea, thioester, thiocarbonate, sulfoxide, sulfone, phosphine, phosphorane, phosphine oxide, cycloalkyl, heterocycloalkyl, or combinations thereof; a C 1 -C 20 alkoxy group, optionally substituted with a C 1 -C 20 alkyl group and/or one or more group(s) or one or more atoms selected equally well from list I; an aryl group; a heteroaryl group; a cycloalkyl group; a heterocycloalkyl group; the or said (hetero)aryl groups and/or the or said (hetero)cycloalkyl groups optionally being substituted with one or more group(s) independently selected from list I; an acyl group; an aroyl group; an alkoxycarbonyl group; a carbamyl group.
[0022] Said kit also optionally includes a photosensitizer (c) that may equally well be in the portion A and/or in the portion B.
[0023] It has been discovered that the initiators S1 and/or S2 and/or S3 and/or S4 can initiate polymerisation of the reactive monomer(s) (a1) and/or (a2) by reaction with a co-initiator (b), in particular without adding external heat to the mixture comprising the portions A and B.
[0024] Advantageously, the reaction between said salt of the invention with a co-initiator is exothermic, in the presence or absence of radiation and/or electron bombardment, in a manner such that thermal polymerisation may be initiated at greater depths and at ambient temperature, and thus without adding external heat to the mixture comprising the portions A and B.
[0025] The invention may be employed to carry out polymerisation, over thicknesses from a few micrometers to several centimeters, in a properly controlled manner, of monomers (a) that are reactive to the addition of cations or acid species, and in particular of monomers that are or include one or more cyclic ether group(s).
[0026] Advantageously, the kit in accordance with the invention may be used to produce a polymer of the same nature with an identical polymerisation reaction: cationic polymerisation. A 3D network may be generated with cross-linking ties having the same chemical nature as the polymer chains. As an example, a polyether matrix is formed that involves a reactive monomer that is or includes at least one cyclic ether group.
[0027] The term “given radiation” means any radiation such as ultraviolet and/or visible radiation, in particular with wavelengths in the range [100 nanometers (nm)-1000 nm], limits included. The photopolymerisation of the invention may also be induced by electron bombardment. The term “irradiated” means any component such as the salt (e) in accordance with the invention, which is subjected to irradiation or to bombardment with electrons.
[0028] Trifluoromethane sulfonate is also known as the triflate ion (CF 3 SO 3 − ), and tetra (pentafluorophenylborate) is also known as tris(2,3,5,6-tetrafluorophenyl)borate.
[0029] The kit in accordance with the invention comprises, as the initiator system, at least one salt selected from the salts S1, S2, S3, and S4, preferably selected from the salts S1, S3, and S4, more preferably selected from the salts S1 and S4, more particularly a salt selected from the salts S1, which are capable of forming an initiator species for the polymerisation reaction of said reactive monomer (a1, a2) by reaction with a co-initiator (b), under the effect of or in the absence of radiation or electron bombardment.
[0030] The polymerisable composition may comprise a plurality of salts selected equally well from S1, S2, S3, and S4.
[0031] The cationic salt (e) may include a plurality of positive charges.
[0032] If the cationic salt S1, S2, S3, or S4 includes a plurality of positive charges, Y may be a plurality of identical or different anionic species.
[0033] The term “initiator” means a chemical compound that can be used to initiate the cationic polymerisation reaction, which is not to be confused with a co-initiator. A co-initiator reacts with the initiator, either with the aim of starting the polymerisation reaction by reaction with the initiator, or with the aim of supplementing the action of the initiator and increasing the rate of the polymerisation reaction.
[0034] Preferably, the co-initiator or co-initiators is/are a nucleophilic species or a metallic salt or an organometallic salt, more preferably a nucleophilic species.
[0035] The term “nucleophile” means any entity that is rich in electrons that has a negative charge or that has at least one free electron pair that has an affinity for any electron-depleted center (known as an electrophile).
[0036] The term “organometallic salt” means any compound in which a metal atom is directly bonded to one or more carbon atoms.
[0037] Preferably, the reactive monomer (a1) and/or the reactive monomer (a2) and/or the co-initiator (b) and/or the photosensitizer (c) and/or the polymerisation rate regulating agent (d) and/or the cationic salt (e) is/are different.
[0038] The reactive monomer (a1) and the reactive monomer (a2) may be identical. Each of the portions A and B (independently of each other) may comprise a plurality of reactive monomers (a1, a2) in accordance with the invention that are different. The portion A may include a plurality of co-initiators in accordance with the invention that are different. The portion B may include a plurality of cationic salts (e) in accordance with the invention that are different.
[0039] Each of the portions A and B may include a plurality of polymerisation rate regulating agents (d) in accordance with the invention that are different and/or a plurality of photosensitizers (c) that are different.
[0040] Preferably, concerning the salt S1, X is a sulfur atom or an oxygen atom, more preferably an oxygen atom.
[0041] The salt S4 is a carbenium salt, which may be a primary salt R 1 —CH 2 + , a secondary salt R 1 R 2 CH + , or a tertiary salt R 1 R 2 R 3 C + .
[0042] The cationic species coupled to a counter-ion Y forms a cationic salt.
[0043] The substituents R 1 and/or R 2 and/or R 3 and/or R 4 and/or R 5 and/or R 6 may optionally be identical.
[0044] Without wishing to be bound to a scientific theory, under the effect of radiation or electron bombardment, the performance of the invention could be explained by means of the mechanisms illustrated in FIG. 1 accompanying the present text, in the absence of a photosensitizer (c), a co-initiator (b) and a polymerisation rate regulating agent (d).
[0045] The cationic salts S1, S2, S3, and S4 behave as cationic photoinitiators. Under irradiation, the species S1, S2, S3, or S4 should become an excited species S1*, S2*, S3*, or S4*. After excitation, the molecule should be neutralized by transfer of an electron with the salt S1 or by decomposition with the salts S2, S3, and S4.
[0046] With the salt S1, a radical species (S1) should result from the reaction. In addition, liberation of the acid species HY (with S1) should take place.
[0047] With the salts S2, S3, and S4, after decomposition, either liberation of novel cationic species is observed with S2 and S3 in particular, or liberation of acid species HY is observed with S4. Furthermore, the photoinitiator S3 releases gaseous dinitrogen N 2 in addition to the acid species. The acid species HY or cationic species that are liberated then initiate the cationic polymerisation by reaction with said reactive monomer (a).
[0048] In accordance with one embodiment, the cationic polymerisation is accelerated in the presence of at least one radical photosensitizer (c) of type I or II, or indeed by one or more co-initiators (b) and/or polymerisation rate regulating agent(s) (d) described below. The polymerisation rate regulating agent(s) (d) can be used to adapt the absorption spectrum of the photoinitiator selected from S1, S2, S3, and S4, improving, for example, the efficiency of the photoinitiator under visible light.
[0049] In accordance with one embodiment, said polymerisation rate regulating agent (d) is, for example, a molecule of cyclodextrin, for example alpha, beta, or gamma-cyclodextrin, or indeed a crown ether.
[0050] In accordance with one embodiment, R 1 to R 6 , independently of one another, are selected from the following atom or atoms or group or groups, alone or in combination, optionally arranged so as to carry one or more positive charges: a hydrogen atom; a nitro group —NO 2 ; a cyano group —CN; a halogen atom; a C 1 -C 20 alkyl group, optionally substituted with a hydroxyl group or a carbonyl group; an alkoxy group; a C 1 -C 20 alkyl group substituted with a primary or secondary amine; an aryl group; a heteroaryl group; a cycloalkyl group; a heterocycloalkyl group; a C 1 -C 20 alkyl group substituted with at least one aryl group; an alkenyl group; an alkynyl group; an acyl group; an aroyl group; an alkoxycarbonyl group; a carbamyl group; a C 1 -C 20 haloalkyl group.
[0051] Preferably, R 1 to R 6 , independently of one another, are selected from the following atom or atoms or group or groups, alone or in combination, optionally arranged so as to carry one or more positive charges: a hydrogen atom; a C 1 -C 20 alkyl group, optionally substituted with a hydroxyl group; a C 1 -C 10 alkoxy group, optionally substituted with a C 3 -C 10 aryl group, preferably a phenyl group; it may, for example, be an alkylphenylether; chlorobenzene; a halogen atom; a C 3 -C 20 aryl group such as a phenyl group (—C 6 H 5 ), optionally substituted with a hydroxyl group and/or an alkyl chain optionally substituted with a hydroxyl group.
[0052] More preferably, R 1 to R 6 , independently of one another, are selected from the following atom or atoms or group or groups, alone or in combination: a hydrogen atom; a phenyl group C 6 H 5 ; a methyl group —CH 3 ; an ethyl group; an isopropyl group; a n-propyl group, a n-butyl group; a sec-butyl group; a ter-butyl group; an isobutyl group; a chlorobenzene group (—C 6 H 5 Cl); a phenylalkoxy group, such as the group —(C 6 H 5 )OCH 3 ; a phenol group, —C 6 H 5 (OH); a phenyl group optionally substituted with a hydroxyl group and/or an alkyl chain optionally substituted with a hydroxyl group, such as the group C 6 H 5 ((CH 2 ) 2 OH).
[0053] Within the context of the present invention, the expression “R 1 to R 6 , independently of one another, are selected from the following atom or atoms or group or groups, alone or in combination” means that said group(s) and/or said atom(s) may be combined together.
[0054] Within the context of the present invention, the term “arranged so as to carry one or more positive charges” means that said atom(s) and/or said group(s) may include a positive charge.
[0055] The definitions indicated below apply to cationic salt(s) (e), but also to the reactive monomers (a1, a2) and/or to the co-initiator(s) (b), and/or to the polymerisation rate regulating agents (d).
[0056] Within the context of the present invention, when a group is “C n -C p ” (also described as C n to C p ), this means that it contains n to p carbon atoms, n and p being integers.
[0057] The term “heteroatom” means any atom other than a carbon atom and a hydrogen atom, which is not metallic, in particular oxygen, sulfur, nitrogen, phosphorus, or indeed the halogens.
[0058] The term “halogen atom” means: fluorine, chlorine, bromine, iodine and astatine.
[0059] Within the context of the present invention, the term “(halo)alkyl group or chain” means any alkyl group or chain, which may optionally be saturated, linear or branched, optionally substituted with one or more halogen atoms, preferably C 1 -C 20 , more preferably C 1 -C 15 , yet more preferably C 1 -C 10 , more particularly C 1 -C 6 , yet more particularly C 1 -C 4 , in particular C 1 -C 4 .
[0060] Within the context of the present invention, the term “alkoxy group” means any group with formula R a —O in which R a represents an alkyl group that may optionally be saturated, linear or branched, optionally including an —OH function, preferably C 1 to C 20 , yet more preferably C 1 to C 10 , more preferably C 1 to C 6 , more particularly C 1 to C 4 , such as, for example, the groups methoxy, ethoxy, isopropoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, and n-hexyloxy.
[0061] Within the context of the present invention, the term “aryl group” means one or more aromatic ring(s), each of said rings being C 3 to C 20 , preferably C 3 to C 10 , more particularly C 3 to C 7 , yet more particularly C 5 to C 7 , which may be coupled or fused. Said aromatic ring(s) may be bonded via an ether bond, —O—. In particular, the aryl groups may be monocyclic or bicyclic or tricyclic or tetracyclic or pentacyclic groups; for example, a phenyl group or an anthracene group or indeed anthracenium, or indeed the tropylium ion; preferably, it is the phenyl group.
[0062] The aryl group in the invention may also be combined with a halogen atom, in which case the aryl group is substituted with a halogen atom; it may be chlorobenzene, for example.
[0063] Within the context of the present invention, the term “heteroaryl group” means one or more C 3 to C 20 aromatic rings, preferably each of said rings being C 3 to C 10 , more particularly C 3 to C 6 , wherein one or more atom(s) of the carbocycle(s) is/are substituted with one or more heteroatom(s), said carbocycle(s) possibly being coupled or fused. Said heteroaryl group is pyridine, for example. In particular, said aryl groups may be monocyclic or bicyclic or tricyclic or tetracyclic or pentacyclic groups.
[0064] Within the context of the present invention, the term “cycloalkyl group” means one or more cyclic alkyl group(s), optionally coupled or fused, each of said cycle(s) preferably being C 3 to C 10 , more particularly C 3 to C 7 , for example the cyclohexyl or cyclopropyl or cyclopentyl group.
[0065] Within the context of the present invention, the term “heterocycloalkyl group” means one or more cyclic alkyl group(s), optionally coupled or fused, wherein one or more atom(s) of the carbocycle(s) is/are substituted with one or more heteroatom(s), each of said heterocycle(s) preferably being C 3 to C 10 , more particularly C 3 to C 7 , for example pyrane.
[0066] The aryl group and/or the cycloalkyl group and/or the heterocycloalkyl group and/or the heteroaryl group may be combined, optionally via a group such as that described in the present text, for example an alkyl group or an ether function —O—, and/or coupled or fused; as an example, it could be thioxanthene or xanthene, or indeed thioxanthenium or xanthenium.
[0067] Within the context of the present invention, the term “ether group” means any group with formula R d —O—R e ; the term “ester group” means any group with formula R d —(CO)—OR e ; the term “aldehyde group” means any group with formula R e —CHO; the term “ketone group” means any group with formula R d —(CO)—R e ; the term “carboxylic acid group” means any group with formula R d —(CO)—OH; the term “urea group” means any group with formula (R d ,R e )N—(CO)—N (R f ,R g ); the term “carbamate group” means any group with formula (NR d R e )—(CO)—OR f ; preferably (NHR d )—(CO)—OR f ; the term “anhydride carbonate group” means any group with formula R d —O—(CO)—O—R e (preferably, R d and R e are other than a hydrogen atom); the term “acetal group” means any group with formula R d —CH(OR e ) 2 ; the term “thioether group” means any group with formula R d —S—R e ; the term “thioester group” means any group with formula R d —CO—S—R e ; the term “thiocarbonate group” means any group with formula R d —O—CO—S—R e ; the term “sulfoxide group” means any group with formula R d —(S═O)—R e ; the term “sulfone group” means any group with formula R d —S(═O)(═O)—R e ; the term “phosphine group” means any group with formula PH 3 ; the term “carbonate group” means any group with formula R b —O—CO—OR e ; the term “orthoester group” means any group with formula R b C (OR c-d-e ) 3 ; the term “phosphine oxide group” means any group with formula R d —P (═O) (R e ) (R f ); the term “alkenyl group” means any group with formula R d R e C═CR f R g ; the term “primary amine” means any group with formula R b NH 2 ; the term “secondary amine” means any group with formula R b R c NH; the term “tertiary amine” means any group with formula R b N R c R d ; the term “primary amide” means any group with formula R b CONH 2 , or R b CONHR c or R b CONR c R d ; the term “secondary amide” means any group with formula (R b CO) 2 NH or (R b CO) 2 NR c ; the term “tertiary amide” means any group with formula (R b-c-d CO) 3 N; the term “acyl group” means any group with formula R l C═O—; the term “carbamyl group” means any R 1 CO(NH 2 ) group; the term “carbonyl group” means any R k R 1 C═O group.
[0068] R b , R c , R d , R e , R f , R g , R j , R k , R l , as defined above are, independently of one another: a hydrogen atom; a (halo)alkyl chain within the context of the present invention; an aryl group; a heteroaryl group; a cycloalkyl group; a heterocycloalkyl group; a primary amine; a secondary amine; a tertiary amine; a primary amide; a secondary amide; a tertiary amide; a thiol group; or combinations thereof; preferably a hydrogen atom or an alkyl chain. As an example, said alkenyl group is a vinyl group.
[0069] Within the context of the present invention, the term “alkynyl group” means any group with formula R h C≡CR i in which R h and R i , independently of each other, are a hydrogen atom or an alkyl chain, saturated or unsaturated, linear or branched, preferably C 2 to C 20 , more preferably C 2 to C 10 , more particularly C 2 to C 4 .
[0070] Within the context of the present invention, the term “aroyl group” means any group with formula —C 6 H 5 COR k in which R k is a heteroatom, for example chlorine, or a (halo)alkyl chain or identical to R b as defined above.
[0071] Within the context of the present invention, the term “hydroxyl group” means any —OH group.
[0072] Within the context of the present invention, when a group or an atom is substituted onto a benzene ring, this latter may be substituted at the ortho, meta, or para position, in particular at the para position.
[0073] As an example, concerning the salt S4, the groups R 1 and R 3 may be fused into an aryl group, and the salt S4 is, for example, the tropylium ion; R 2 is then a hydrogen atom.
[0074] Concerning the salt S4, the groups R 1 , R 2 and R 3 may also be phenyl groups, each of said groups optionally being substituted with an alkoxy group.
[0075] Concerning the salt S4, the groups R 2 and R 3 may be a heteroaryl group coupled and fused with two phenyl groups, the group R 1 being a phenyl group; the salt S4 is, for example, the anthracenium ion, wherein a carbon atom of the central carbocycle is substituted with oxygen and said central carbocycle is also substituted with a phenyl group.
[0076] The kit in accordance with the invention or the polymerisable composition resulting from mixing the portions A and B is preferably used to form a protective coating in the railroad sector or in the automobile sector, or indeed as a protective coating optionally filled and/or pigmented as a film of paint or lacquer.
[0077] The kit in accordance with the invention or the polymerisable composition resulting from mixing the portions A and B may also be used as a matrix for a composite material including reinforcement.
[0078] In a particular embodiment, said reinforcement is or comprises fibers or yarns considered individually or in combination, in particular deployed by weaving, knitting or braiding, and/or nonwovens, and/or particles, in particular selected from the following family of materials: para-aramid, meta-aramid, silica-based fibers, glass fibers, polyethylene-terephthalate, high density polyethylene, poly(p-phenylene-2,6-benzobisoxazole) (PBC)), carbon, silicon carbide, hydrated alumina, stainless steel, grit, sand, glass beads, steel balls, and silica.
[0079] When the reinforcement is insufficiently transparent to radiation or insufficiently irradiated, for example reinforcement comprising carbon fibers, the kit or the composition comprising the portions A and B combined also includes a co-initiator that reacts with the cationic salt (e), for example at ambient temperature, so that the polymerisation reaction takes place throughout the thickness of the composite material, this reaction propagating because of the exothermicity of the reaction between the salt or the salts and the co-initiator or co-initiators. The composite material may also undergo radiation or electron bombardment so that a photopolymerisation also takes place, in particular at the surface of said composite material.
[0080] The term “ambient temperature” (T° C.) as used in the context of the present invention means the temperature of the production shop or laboratory in which the polymerisation reaction in accordance with the invention takes place, generally at a temperature in the range 10° C. to 30° C., more particularly without adding external heat to the mixture comprising the portions A and B.
[0081] In a variation, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from or include(s) at least one group selected from the list constituted by: cyclic ethers, in particular oxiranes, such as ethylene oxide; oxetanes such as 1,3-propylene oxide; oxolanes such as tetrahydrofuran; oxanes such as tetrahydropyran; cyclic acetals such as dioxanes, trioxanes and dioxolanes; cyclic amines such as aziridines and azetidines; cyclic iminoethers such as oxazolines; cyclic sulfides such as thietanes and thiiranes; vinyls such as vinyl ethers and vinylcarbazole; cyclic esters such as lactones, lactides, cyclic carbonates and orthoesters; cyclic amides such as lactams; cycloalkyls substituted with at least one phosphorus atom, such as phosphazenes; and cyclic siloxanes; preferably in the group constituted by cyclic ethers.
[0082] Preferably, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from or include(s) at least one group selected from the list constituted by: cyclic ethers, in particular oxiranes, such as ethylene oxide; oxetanes such as 1,3-propylene oxide; oxolanes such as tetrahydrofuran; oxanes such as tetrahydropyran; vinyls such as vinyl ethers and vinylcarbazole.
[0083] Preferably, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from or include(s) at least one group selected from the list constituted by: oxiranes, oxetanes, oxolanes, and oxanes.
[0084] Preferably, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from the list constituted by: aliphatic epoxies, aromatic epoxies, cycloaliphatic epoxies and oxetanes, or mixtures thereof.
[0085] Preferably, the reactive monomer (a) is selected from the list constituted by: Cyracure 6110 (DOW); Uvacure 1500 (CYTEC); Genomer 7210 (RAHN); CELLOXIDE 2021P (DAICEL); S-100, S-32, VCHX, S-28, S-60, S-186 (SYNASIA); EPOLEAD GT401 (DAICEL); Doublemer 4300 (DOUBLE BOND CHEMICAL); D.E.R 331 (HUNTSMAN); Epalloy 5000 (CVC); HBE 100 (HUNTSMAN specialty thermosets); butyl glycidyl ether, castor oil glycidyl ether, 1,4-butanediol diglycidyl ether, diglycidyl-1,2-cyclohexane dicarboxylate (which are aliphatic epoxies); bis[4-(glycidyloxy)phenyl]methane (DGEBA), bis[4-(glycidyloxy)phenyl] (DGBF), 1,2-epoxy-3-phenoxypropane, 4,4-methylene bis(N,N-diglycidylaniline), resorcinol diglycidyl ether, styrene oxide, phenyl glycidyl ether (which are aromatic epoxies); cyclohexene oxide, vinylcyclohexene oxide, dicyclopentadiene dioxide, 3,4-epoxycyclohexyl(3,4-epoxycyclohexanecarboxylate), triethoxy[2-(7-oxabicyclo[4.1.0]hept-3-yl]silane, bis(3,4-epoxycyclohexyl)methyladipate (which are cycloaliphatic epoxies); bis(1-ethyl-3-oxetane-methyl)ether, 3-ethyl-3-[(phenoxy)methyl]oxetane, (3-ethyl-3-oxetane) methanol, 3-ethyl-3-hydroxy-methyl-oxetane (Aron oxetane OXT-101), bis[[1-ethyl(3-oxetanil)methyl]ether] (Aron oxetane OXT-221), 3-ethyl-3-[(2-ethyl-hexyloxy)methyl]oxetane] (Aron oxetane OXT-212) (which are in the oxetanes family).
[0086] In a variation, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from or include(s) a (C 3 -C 20 (hetero)cycloalkyl) n group, with 1≦n≦5, n being an integer, said (hetero)cycloalkyl(s) being saturated or unsaturated and comprising, in at least one cycle, at least one function or one or more atom(s) or a group selected from the list constituted by: an ether group; an oxygen atom; two oxygen atoms; three oxygen atoms; a primary amine; a secondary amine; a tertiary amine; a primary amide; a secondary amide; a tertiary amide; an ester group; a carbonate group; an orthoester group; a —O—Si—O function; a vinylether function (—O—CH═CH 2 ); a halogen atom and a sulfur atom.
[0087] In a variation, the reactive monomer (a) is selected from cycloaliphatic epoxies, in particular dicycloaliphatic epoxies.
[0088] In a variation, the reactive monomer (a1), and optionally the reactive monomer (a2), is/are selected from oxetanes, cycloaliphatic epoxies, or a mixture thereof comprising at least one epoxy and at least one oxetane.
[0089] In a variation, the co-initiator (b) is selected from or includes at least one group selected from list II constituted by: hydrogen peroxide (H 2 O 2 ); water (H 2 O); a C 1 -C 20 (halo)alkyl group substituted with a hydroperoxide (—OOH) and/or with a thiol group (—SH); a C 1 -C 20 aryl group substituted with a hydroperoxide (—OOH) and/or with a thiol group (—SH); a C 1 -C 20 heteroaryl group substituted with a hydroperoxide (—OOH) and/or with a thiol group (—SH); a C 1 -C 20 cycloalkyl group substituted with a hydroperoxide (—OOH) and/or with a thiol group (—SH); a C 1 -C 20 heterocycloalkyl group substituted with a hydroperoxide (—OOH) and/or with a thiol group (—SH); an alkenyl group optionally including at least one ether group, such as vinylether; said group(s) optionally being substituted with one or more (—OH) groups; and from list III constituted by a primary amine, a secondary amine; a C 1 -C 20 alkyl group including a —PH or —PH 2 function; phosphine, PH 3 ; metallic salts and organometallic salts such as zinc salts; or combinations thereof.
[0090] Preferably, said at least one co-initiator is selected from or includes at least one group selected from list II. More preferably, when it/they is/are substituted with a thiol group (—SH), said group(s) is/are substituted with at least two thiol groups, more preferably at least three thiol groups, in particular at least four thiol groups.
[0091] Preferably, said above-mentioned alkenyl group including an ether group mentioned above has formula R Z —O—CH═CH 2 , in which the group R z is selected from the list constituted by: a hydrogen atom; a (halo)alkyl chain; an aryl group; a heteroaryl group; a cycloalkyl group; a heterocycloalkyl group; a primary amine; a secondary amine; a tertiary amine; a primary amide; a secondary amide; a tertiary amide; a thiol group; an alkynyl group; an acyl group; an aroyl group; a carbamyl group; an alkoxy group; or combinations thereof.
[0092] The term “metallic salt” means any salt that is free of an organic portion, for example CuBr 2 .
[0093] The term “organometallic salt” means any salt comprising one or more metallic centers bonded to at least one organic portion by covalent bonding.
[0094] With the exception of metallic salts and organometallic salts, the co-initiators mentioned above are nucleophilic species.
[0095] It has been discovered that in the presence of a co-initiator, the salts S1, S2, S3, and S4 can initiate a thermal cationic polymerisation (i.e. in the absence of irradiation, for example in the absence of light, and at low temperature, for example at ambient temperature).
[0096] This disposition advantageously means that the salts S1 and/or S2 and/or S3 and/or S4 can be used in a dual-cure system, thus combining a photopolymerisation, in particular at the surface of a coating, and a thermal polymerisation, in particular at the core and throughout the thickness of the coating, advantageously without adding external heat to the mixture comprising the portions A and B.
[0097] Said salts may also simply be used for a cationic polymerisation by a thermal pathway alone in the absence of radiation. Advantageously, the thermal polymerisation is carried out at ambient temperature, in particular in the range 10° C. to 30° C., without it being necessary to heat the polymerisable composition comprising the mixed portions A and B.
[0098] A plurality of mechanisms may be involved, depending on the nature of the co-initiator:
[0099] For the nucleophilic species Nu:
[0100] S + 1/2/3/4 Y − +Nu=>S 1/2/3/4 −− Nu + Y − or
[0101] S 1/2/3/4 −− Nu+HY
[0102] The reaction between a cationic salt (e) as the initiator and a nucleophilic species (Nu) generates a new intermediate cationic species. This new cationic species may be stable or unstable. In this latter case, a liberation of acid species HY takes place. Initiation of the thermal polymerisation may be carried out either by the new cationic species or via the acid species HY that is formed.
[0103] For the metallic or organometallic salts Mt:
[0104] S + 1/2/3/4 Y − +Mt=>S 1/2/3/4 −+ Mt −1 +HY
[0105] The reaction between a cationic salt as the initiator (e) with the metallic salt forms a redox pair. The metallic salt Mt reduces the cationic salt (e) to become Mt −1 . This involves a transfer of a single electron. The cationic salt (e) is thus neutralized.
[0106] In a variation, the portion A and/or the portion B include(s) a polymerisation rate regulating agent (d) that is or includes:
a C 3 -C 6 heteroaryl wherein at least one atom of the carbocycle is nitrogen, said heterocycle being substituted with: one or more C 3 -C 6 aryl group(s), such as a phenyl group, a pyrane group, a furan group, or a thiophene group; and/or with one or more C 1 to C 10 alkyl chains, preferably C 3 to C 6 , which may optionally be saturated, linear or branched, for example isobutyl; a C 3 -C 6 aryl group substituted with: a primary amine, a secondary amine, or tertiary amine, preferably a tertiary amine; and/or with a C 3 -C 6 aryl group, such as a phenyl group, a pyrane group, a furan group, or a thiophene group; and/or with one or more C 1 to C 10 alkyl chains that may optionally be saturated, linear or branched, preferably a tertiary amine such as a dimethylamine group, —N(CH 3 ) 2 .
[0109] Said polymerisation rate regulating agent (d) can regulate the polymerisation rate in accordance with the following two mechanisms, in combination with the cationic salt (e):
by regulating the reaction rate between the cationic salt (e) and the co-initiator (b), which results in adjusting the initiation rate. The initiation rate is then controlled by complexing the cationic salt with said polymerisation rate regulating agent (d). It has also been discovered that N, N-dimethylaniline or N-vinyl carbazole can act as the regulating agent (d) in accordance with this first mechanism. A molecule of cyclodextrin may also act in accordance with this first mechanism; by regulating the rate of propagation of the polymerisation. In this case, said polymerisation rate regulating agent (d) is preferably a nucleophilic or basic compound which interacts with the center of propagation. It has been discovered that 2,6-di-tert-butylpyridine or N,N-dimethylaniline can act as the regulating agent (d) in accordance with this second mechanism. Crown ethers that are known from the prior art may also act in accordance with this second mechanism, as well as sulfur-containing derivatives (such as DMSO and thiophene).
[0112] Preferably, said polymerisation rate regulating agent is selected from: 2,6-di-tert-butylpyridine, N,N-dimethylaniline and N-vinyl carbazole.
[0113] In a variation, the solvent is selected from propylene carbonate, 1,4-dioxane and dimethylsulfoxide, acetonitrile, acetone, tetrahydrofuran, and dichloromethane.
[0114] Preferably, the solvent has a polarity of 1 or more.
[0115] In a variation, the cationic salt (e) in accordance with the invention is dissolved in at least one monomer (a2) in accordance with the invention, optionally combined with a solvent.
[0116] In a variation, the photosensitizer (c) is selected from radical photoinitiators of type I, such as benzophenone; and from radical photoinitiators of type II, such as thioxanthone or anthracene.
[0117] The radical photoinitiators of type I sensitize the cationic salt (e) by transfer of electrons.
[0118] The radical photoinitiators of type II sensitize the cationic salt (e) by transfer of electrons or by transfer of energy.
[0119] In a variation, the proportion by weight of salt (e) relative to the weight of the final polymerisable composition comprising the portions A and B is in the range 0.10% to 5%, preferably in the range 0.5% to 3%, more preferably in the range 1% to 3%.
[0120] In a variation, the proportion by weight of monomer(s) (a1 and/or a2) relative to the weight of the final polymerisable composition comprising the portions A and B is in the range 80% to 95%.
[0121] In a variation, the proportion by weight of solvent relative to the weight of the final polymerisable composition comprising the portions A and B is more than 0 and less than or equal to 20%, preferably in the range 0.10% to 10%.
[0122] In a variation, the proportion by weight of co-initiator (b) relative to the weight of the final polymerisable composition comprising the portions A and B is in the range 0.10% to 5%, preferably in the range 0.5% to 3%, more preferably in the range 1% to 3%.
[0123] In a second aspect, the present invention provides a polymerisable composition comprising:
[0124] a. at least one monomer (a1) that is reactive towards a cationic species or a Lewis or Brönsted acid species as defined in any one of the preceding variations in accordance with a first aspect;
[0125] b. at least one co-initiator (b) as defined in any one of the preceding variations in accordance with a first aspect;
[0126] c. optionally, a photosensitizer (c) as defined in any one of the preceding variations in accordance with a first aspect;
[0127] d. at least one cationic salt (e) as defined in any one of the preceding variations in accordance with a first aspect; and
[0128] e. optionally, a solvent as defined in any one of the preceding variations in accordance with a first aspect; and
[0129] f. optionally, at least one polymerisation rate regulating agent (d) as defined in any one of the preceding variations in accordance with a first aspect.
[0130] In a third aspect, the present invention provides a method of producing a coating or a composite material employing the kit described in any one of the preceding variations or the polymerisable composition described above, comprising the following steps:
[0131] i) providing a portion A and a portion B defined in accordance with any one of the preceding variations with reference to a first or to a second aspect, and mixing the portions A and B in order to form a polymerisable composition; or i″) providing a polymerisable composition defined in accordance with any one of the preceding variations with reference to a first or to a second aspect; and
[0132] ii) applying said polymerisable composition in one or more layers to a substrate or impregnating a reinforcement with said polymerisable composition; and
[0133] iii) polymerising said at least one monomer (a1) under the action of a cation or of a Lewis or Brönsted acid species formed by the salt (e) under the action of said at least one co-initiator (b), without adding external heat to said polymerisable composition, and optionally of a radiation or an electron bombardment, in order to form a coating or a composite material.
[0134] The method in accordance with the invention means that, depending on the polymerisable composition, for example whether it is pigmented and/or filled, the thickness thereof applied to the substrate or the thickness and the transparency of the reinforcement, the following can be carried out: 1/photopolymerisation alone under the effect of radiation or electron bombardment acting on the cationic salt (e); 2/thermal polymerisation alone, in the absence of radiation or bombardment under the effect of the co-initiator acting on the cationic salt (e) without adding external heat to said polymerisable composition (the reaction between the salt and the co-initiator being exothermic) and finally the combination of a photopolymerisation and a thermal polymerisation 3/resulting from the combination of 1/and 2/for a dual-cure system as defined in the present invention.
[0135] Advantageously, said at least one co-initiator (b) is selected such that it is capable of reacting with said at least one cationic salt (e) without adding external heat, in an exothermic reaction, the exothermicity of the reaction contributing to maintaining and initiating the cationic polymerisation reaction of said at least one monomer (a1, a2).
[0136] Advantageously, applying radiation or electron bombardment means that the polymerisation reaction can be controlled, in particular by accelerating the kinetics for the rate of polymerisation.
[0137] Said method may be used to irradiate the polymerisable composition from completion of the application or molding, and to thereby cure the composition very rapidly. The zones that are not subjected to much irradiation or that are located in a shadowed zone are cured completely because of the thermal reactivity of the initiator system, which reacts even at low temperatures (for example: 20° C.) (comparatively, thermal curing of epoxy resins is often carried out by adding an amine or by heating with a melamine).
[0138] The method in accordance with the invention can be used to polymerise the polymerisable composition without adding external heat to said composition, and thus to obtain a thermoset matrix that may optionally be reinforced, which can be used.
[0139] In accordance with one embodiment, the method in accordance with the invention comprises a step (iv) for thermal post-treatment applied to the polymerised polymerisable composition obtained at the end of step (iii) in order to further organize the polymer chains of the thermoset matrix.
[0140] Preferably, the thermal post-treatment comprises a step of heating to a temperature of 60° C. or more, more preferably less than or equal to 100° C., for at least 10 minutes, more preferably for at least 60 minutes.
[0141] Preferably, the polymerisable composition is applied in the form of a layer or a plurality of layers, optionally with the application of radiation or electron bombardment between each layer and optionally to the assembly comprising superimposed said layer or layers.
[0142] The surface(s) of the layer or layers that are optionally exposed to radiation or electron bombardment are preferably in contact with oxygen of the air. Advantageously, the oxygen of the air does not inhibit the cationic polymerisation reaction at the surface.
[0143] In a variation, step iii) is carried out at a temperature in the range 10° C. to 30° C., preferably in the range 15° C. to 30° C., without adding external heat to said polymerisable composition.
[0144] In a variation, since said polymerisable composition is transparent to ultraviolet radiation or to visible radiation, polymerisation of the monomer (a) occurs throughout the thickness of the composition under the effect of a radiation, in particular at ambient temperature (for example in the range 20° C. to 30° C.) without adding thermal energy.
[0145] In a variation, when said composition is insufficiently transparent to ultraviolet radiation or to visible radiation or is insufficiently irradiated or is intended to form a coating with a thickness of more than 1 millimeter (mm) or that has non-irradiated shadowed zones, the co-initiator (b) acting on the initiator or cationic salt (e) leads, at ambient temperature, to polymerisation of said composition throughout its thickness, generating a polymer of the same nature and via the same cationic polymerisation reaction as the photo-induced polymerisation.
[0146] In a fourth aspect, the present invention provides the use of a cationic salt (e) defined in accordance with any one of the preceding variations with reference to a first, second or third aspect, for the cationic polymerisation of at least one reactive monomer (a1), optionally of at least one second reactive monomer (a2), defined in accordance with any one of the preceding variations with reference to a first, second or third aspect, in the presence of at least one co-initiator (b), in particular defined in accordance with any one of the preceding variations with reference to a first, second or third aspect, optionally under radiation or electron bombardment.
[0147] In a variation, the cationic salt (e) used is the salt S1, and X is an oxygen atom.
DETAILED DESCRIPTION OF THE FIGURES
[0148] FIG. 1 shows the reaction mechanism between a cationic salt (e) and a cationic species or Lewis or Brönsted acid;
[0149] FIGS. 2 and 3 show three thermometric curves measured for examples of polymerisable compositions in accordance with the invention;
[0150] FIGS. 4A, 4B and 4C show examples of cationic salts S4(1), S4(2) and S4(3) in accordance with the invention; and
[0151] FIGS. 5, 6, 7 and 8 show thermometric curves measured for examples of polymerisable compositions in accordance with the invention;
[0152] FIG. 9 shows a first series of thermometric curves measured at different thicknesses in a polymerisable composition in accordance with the invention and a second series of thermometric curves measured at different thicknesses in a reference polymerisable composition;
[0153] FIG. 10 shows values for the flexural modulus (GPa) (ISO standard 178: 2010) obtained for industrial matrices, high performance matrices and a matrix in accordance with the invention;
[0154] FIG. 11 shows the values obtained for the maximum stress as a function of the percentage deformation (ISO standard 178:2010) for industrial matrices, high performance matrices, and a matrix in accordance with the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0155] The invention can be better understood from the following exemplary embodiments presented below as non-limiting examples. The conversion kinetics of the oxirane bonds were monitored using Fourier transform infrared spectroscopy, which allowed the polymerisation process to be monitored in real time.
[0156] Lists of compounds employed in the polymerisable compositions described in Tables 1 to 4 below and in paragraphs I to IV:
reactive monomer (a): dicycloaliphatic epoxy, in particular (3,4-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate (a1), such as Uvacure 1500; (3,4-epoxycyclohexane) methyl 3,4-epoxycyclohexanecarboxylate (a11), such as UVACURE 6110; an oxetane monomer (OXT-101, 3-methyl-3-oxetanemethanol) (a111); cationic salts (e): cationic salt S1(1) in which X: O; R 2 , R 4 and R 6 : C 6 H 5 , R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(2) in which X: O, R 2 and R 4 and R 6 : CH 3 , R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(3) in which X: O, R 2 and R 4 and R 6 : C 6 H 5 Cl, R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(4) in which X: O, R 2 and R 4 and R 6 : C 6 H 5 OCH 3 , R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(5) in which X: O, R 2 : CH3, R 4 and R 6 : C 6 H 5 , R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(6) in which X: O, R 2 and R 6 : C 6 H 5 , R 4 : CH 3 , R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(7) in which X: O, R 2 and R 6 : C 6 H 5 , R 4 : C 6 H 5 OH, R 3 and R 5 : H, Y=BF 4 − ; cationic salt S1(8) in which X: O, R 2 and R 6 : C 6 H 5 , R 4 : C 6 H 5 (CH 2 )2OH, R 3 and R 5 : H, Y=BF 4 − ; cationic salt S2(1) in which R 2 , R 4 and R 6 : C 6 H 5 , R 3 and R 5 : H, Y: BF 4 − ; cationic salt S3(1) in which R 2 , R 3 , R 5 and R 6 : H, and R 4 : Br, Y=BF 4 − ; and the salts S4(1), S4(2) and S4(3) shown in FIG. 4 . The substituents on the benzene rings were in the para position. Each of said salts (e), previously dissolved to approximately 25% by weight in a solvent, in particular propylene carbonate, was present in an amount of 3% by weight relative to the total weight of the polymerisable composition; co-initiators (b): hydrogen peroxide (H 2 O 2 ) (b1); isobutylvinylether (b2); 4-mercaptophenol (b3); photosensitizer (c): phenothiazine (c1).
I—Various Polymerisable Compositions in Accordance with the Invention were Subjected to Irradiation without Adding External Heat to Said Compositions (i.e. at Ambient Temperature)
[0161] The proportion by weight of cationic salt relative to the total weight of the polymerisable composition (in this case 1 gram (g)) was 3%, regardless of whether the salt was S1(1), the salt S3(1) or Irgacure 250, which is an iodonium salt.
[0162] The proportions by weight of the co-initiator (b1) and of the co-initiator (b2) relative to the total weight of the polymerisable composition were respectively 3% and 1%.
[0163] The proportion by weight of photosensitizer (C1) relative to the total weight of the polymerisable composition was 1%.
[0164] The irradiation lamp was a Hamamatsu Hg—Xe lamp with a 365 nm reflector and a power of 40 milliwatts per square centimeter (mW/cm 2 ). The polymerisable composition was applied to a substrate, in this example a KBr pellet, in the form of a single layer with a thickness of 20 micrometers (μm).
[0165] The maximum rates of polymerisation (Rp) as well as the conversions (x %) after 400 seconds irradiation under the Hg—Xe lamp obtained are contained in Table 1 below.
[0000]
TABLE 1
Final
Rp
conversion
Example
(a)
(b)
(c)
(e)
(mol · l −1 · s −1 )
degree (%)
1
(a1)
—
—
S1(1)
0.19
75
2
(a1)
—
(c1)
S1(1)
0.11
100
3
(a1)
(b1)
—
S1(1)
0.38
93
4
(a1)
(b2)
—
S1(1)
0.29
87
5
(a1)
—
—
S3(1)
0.054
65
6
(a1)
(b1)
—
S3(1)
0.059
64
7
(a1)
(b2)
—
S3(1)
0.059
70
8
(a1)
—
—
Irgacure
0.64
60
250
[0166] The high efficiency of the salt S1(1) alone should be noted; it reached a degree of conversion of approximately 75% in less than 400 seconds of irradiation. This efficiency was accentuated by the presence of a photosensitizer (c1) or indeed a co-initiator (b1) or (b2).
[0167] The salt S3(1) was less reactive under irradiation, but it reached degrees of conversion that were higher than the degree of conversion of the iodonium salt (Irgacure 250) after 400 seconds (s) of irradiation.
[0000] II—Study of the Impact of Different Structures of Cationic Salts S1 in Accordance with the Invention on the Rate of Polymerisation Rp and the Final Degree of Conversion (%) in the Absence of Co-Initiator (b), without Adding External Heat to Said Compositions, (i.e. at Ambient Temperature)
[0168] The proportion by weight of cationic salt relative to the total weight of the polymerisable composition (in this case 1 g) was 3%, regardless of whether it was for the salts S1(1) to S1(6), or Irgacure 250, which is an iodonium salt. The irradiation lamp was a Hamamatsu Hg—Xe lamp with a 365 nm reflector and a power of 40 mW/cm 2 .
[0169] The polymerisable composition was applied to a substrate, in this example a KBr pellet, in the form of a single layer with a thickness of 20 μm.
[0000] TABLE 2 Final Rp conversion Example (a) (e) (mol · l −1 · s −1 ) degree (%) 9 (a1) S1(1) 0.19 75 10 (a1) S1(2) 0.01 20 11 (a1) S1(3) 0.23 57 12 (a1) S1(4) 0.08 97 13 (a1) S1(5) 0.01 11 14 (a1) S1(6) 0.03 35 15 (a1) S1(7) 0.04 89 8 (a1) Irgacure 0.64 60 250
III—Thermometric Measurements Carried Out on Various Polymerisable Compositions in Accordance with the Invention Polymerised in the Absence of Irradiation, Said Compositions Including a Co-Initiator (b), without Adding External Heat to Said Compositions, (i.e. at Ambient Temperature)
[0170] The proportion by weight of cationic salt relative to the total weight of the polymerisable composition (in this case 1 g) was 3%. The proportions by weight of the co-initiators (b1), (b2) and (b3) relative to the total weight of the polymerisable composition were respectively 1%, 3%, and 3%.
[0171] FIG. 2 shows three thermometric curves obtained from a K type thermocouple in the polymerisable compositions with references (A), (B) and (C) all comprising at least one reactive monomer (a1), a cationic salt S1(1) and a co-initiator, respectively (b1), (b2) and (b3). It can thus be observed from said curves that an efficient thermal polymerisation can be accompanied by the release of a large amount of heat. FIG. 3 shows two thermometric curves obtained from a type K thermocouple immersed in the polymerisable compositions with references (D) and (E), each comprising a reactive monomer (a1), a cationic salt S3(1) and a co-initiator, respectively (b1) and (b2).
[0172] Thermal polymerisation for the polymerisable compositions examples (D) and (E) was also observed, but with a much stronger exothermic reaction than with the co-initiator (b1).
[0000] IV—Measurements of Gelling Times (Min) Carried Out on Polymerisable Compositions Including Different Cationic Salts in Accordance with the Invention Polymerised in the Absence of Irradiation, without Adding External Heat to Said Compositions, (i.e. at Ambient Temperature), Said Polymerisable Compositions Including a Co-Initiator (b)
[0173] The gelling times were calculated from the thermometric curves obtained as described above in point III. The gelling times corresponded to the maximum of the exothermic polymerisation peak.
[0174] Table 3 below sets out the gelling times obtained for various cationic salts in combination with various co-initiators (b). The proportion by weight of cationic salt relative to the total weight of the polymerisable composition (in this case 1 g) was 3%, regardless of whether it was for the salt S1(1), the salt S2(1), the salt S3 (1) or the salts S4 (1) (2) (3). The proportions by weight of the co-initiator (b1) and of the co-initiator (b2) relative to the total weight of the polymerisable composition were respectively 1% and 3%.
[0000]
TABLE 3
Gelling times
Examples
(a)
(e)
(b)
(min)
20
(a1)
S1(1)
(b1)
15
21
(a1)
S1(1)
(b2)
6
30
(a1)
S1(3)
(b1)
10
22
(a1)
S2(1)
(b1)
360
23
(a1)
S2(1)
(b2)
>600
24
(a1)
S3(1)
(b1)
10
25
(a1)
S3(1)
(b2)
20
26
(a1)
S4(1) (2) (3)
(b1)
Instantaneous
[0175] The structure of the co-initiator (b) meant that the rate of polymerisation could be adjusted, as demonstrated in Table 4 below.
[0000]
TABLE 4
Gelling
Examples
(a)
(e)
(b)
times (min)
27
(a1)
S1(1)
R—OOH with
2
R: ClC 6 H 5 CO
28
(a1)
S1(1)
R—OOH with
6
R: CH 3 CO
31
(a1)
S1(1)
R z —O—CH═CH 2
25
R z : (CH 3 ) 2 CH 2 )
32
(a1)
S1(1)
R z —O—CH═CH 2
16
R z : CH 3 (CH 2 ) 2
33
(a1)
S1(1)
R z —O—CH═CH 2
12
R z : CH 3 CH 2
34
(a1)
S1(1)
R z —O—CH═CH 2
6
R z : (CH 2 ) 2 OH
35
(a1)
S1(1)
R—OOH
45
R: C 6 H 5
36
(a1)
S1(1)
R—OOH
45
R: (CH 3 ) 3 C
29
(a1)
S3(1)
R—OOH
>600
R: (CH 3 ) 3 C
[0176] The gelling times were measured for the polymerisable compositions of Example 9 (S1(1)), 11 (S1(3)) and 12 (S1(4)) described above in point I and each including hydrogen peroxide as the co-initiator (b1), in the absence of irradiation. These gelling times were: <<60 minutes, of the order of 15 minutes, and of the order of 12 minutes respectively for those of Example 9 (S1(1)), 11 (S1 (3)) and 12 (S1(4)).
[0177] The high efficiency of the S1/ROOH pair (with R=ClC 6 H 5 CO) or —O—CH═CH 2 ) should be noted. The gelling times were adjustable (a few minutes to several hours) by adjusting the nature of the co-initiator, the nature of the substituents carried by these co-initiators as well as the structure of the cationic salt.
[0178] FIG. 5 shows three thermometric curves: the first curve (F) corresponds to Example 20, which did not contain a polymerisation rate regulating agent (d); the second curve (G) corresponds to Example 20 to which 1% by weight of N-vinylcarbazole (d1) relative to the total weight of the polymerisable composition had been added; the third curve (H) corresponds to Example 20 to which 1% by weight of N,N-dimethylaniline (d2) relative to the total weight of the polymerisable composition had been added. It should also be noted that, following the addition of (d1) or (d2), the gelling times were displaced by almost 30 minutes. It is thus possible to adjust the rate of initiation.
[0179] FIG. 6 shows six thermometric curves: the first curve (I) corresponds to Example 20, which did not include polymerisation rate regulating agent (d); the curves (J), (K), (L), (M) and (N) correspond to Example 20 to which 0.5%, 1%, 1.5%, 3% and 6% by weight respectively of 2,6-di-tert-butylpyridine (d3) relative to the total weight of the polymerisable composition had been added.
[0180] A shift of the gelling times as a function of the proportions of the agent (d3) was thus observed, with a substantial exothermic release of heat when the proportion of agent (d3) reached 6% by weight.
[0000] V—Polymerisation of Aromatic or Aliphatic Epoxy Resins Including One or More Oxetane Groups as the Reactive Monomer (a1), Under Irradiation and Combined with a Co-Initiator (b) in a Dual-Cure System, without Adding External Heat to Said Compositions, (i.e. at Ambient Temperature).
[0181] FIG. 7 shows a thermometric curve (0) corresponding to a polymerisable composition comprising 1,2-epoxy-3-phenoxypropane (sold by SIGMA-ALDRICH) as the reactive monomer (a1), isobutylvinylether as the co-initiator (b2), and a cationic salt S1(1). It should be noted that the reaction was of low exothermicity.
[0182] By way of comparison, FIG. 8 shows two curves (P) and (Q) representing the exotherms of the surface and the core respectively in the layer to be polymerised. The polymerisable composition employed in FIG. 8 corresponded to Example 21. An exothermic peak at 70° C. should be noted, which was much higher than the exothermic peak of the order of 19.5° C. shown in FIG. 7 .
[0183] Cationic polymerisation, under irradiation or via a thermal pathway, i.e. at ambient temperature, of aromatic or aliphatic epoxy resins is less effective than for cycloaliphatic epoxy resins.
[0000] VI—Photopolymerisation at Depth of a Polymerisable Composition in Accordance with the Invention Compared with a Reference Polymerisable Under Irradiation and Combined with a Co-Initiator (b) in a Dual-Cure System, without Adding External Heat to Said Compositions, (i.e. at Ambient Temperature)
[0184] The polymerisable composition in accordance with the invention (Example 37) comprised a mixture of monomers: 92.5% of (a11) for 7.5% of (a111); and a salt S1(1) and a co-initiator (b2) in an amount of 3% and 1.5% by weight respectively relative to the total weight of the composition (in this case 5 g), the remainder being formed by the mixture of monomers. The reference composition (Example 38) comprised the same mixture of monomers as Example 37; and an Irgacure 250 salt and a co-initiator (b2) respectively in an amount of 3% and 1.5% by weight relative to the total weight of the composition, the remainder being formed by the mixture of monomers.
[0185] The photopolymerisation at depth was monitored by thermometry. Each polymerisable composition was placed in a test tube produced from plastic material which had previously been perforated over the length in order to accommodate thermocouples at predetermined depths on the tube (at the surface; 8 mm; 16 mm; 24 mm; 32 mm and 40 mm). Irradiation of the mixture of monomers was carried out at the level of the opening to the tube, which was covered with a glass plate, using a lamp (UV Hammamatsu lamp with 365 nm reflector) disposed at a distance of approximately 2 cm above the glass plate. The glass plate absorbed the infrared radiation produced by the lamp. In this manner, the temperature detected by the surface thermocouple would solely be from the photopolymerisation reaction.
[0186] The first series (R) of thermometric curves corresponding to the polymerisable composition in accordance with the invention (Example 37) and the second series of thermometric curves (S) corresponding to the reference polymerisable composition (Example 38) were very different.
[0187] Concerning Example 38 (reference), the temperature increased rapidly at the surface due to the photopolymerisation reaction in the mixture of monomers. The curve associated with the thermocouple located 8 mm below the surface fairly rapidly followed the same profile as the curve associated with the surface thermocouple. The curves associated with the thermocouples located at more than 8 mm were very different, since it can be seen that the temperature measured in the polymerisable composition 38 dropped. In this case, photopolymerisation at depth occurred in accordance with a process of thermal transfer/diffusion, the heat generated at the surface only propagating to a small extent into the thickness. Curing at depth (beyond 8 mm) was thus incomplete.
[0188] Concerning Example 37 (composition in accordance with the invention), the surface temperature also increased rapidly for the same reasons as those given for Example 38. However, the profile for the curve associated with the surface thermocouple and the curves associated with the other thermocouples were almost identical throughout the thickness of the composition 37 (40 mm). In this case, photopolymerisation at depth occurred along a polymerisation front, changing the polymer, polymerised and hot, into a mixture of liquid polymers that were thus not polymerised and cold. The fact that the maximum temperature was the same throughout the thickness means that the polymerisable composition in accordance with the invention, 37, caused the polymerisation front to be self-sustaining—this is an essential element with photopolymerisation at depth without adding external heat.
[0000] VII—Comparison of the Mechanical Properties Obtained for a Polymerisable Composition in Accordance with the Invention, Example 39, (the Composition of which Corresponds to Example 21 Described Above) Compared with the Mean of the Values Obtained for Reference Polymerisable Compositions from the Prior Art.
[0189] Table 5 below indicates the commercial names of reference compounds from the prior art (commercial reference of epoxy monomer/commercial reference of amine monomer), the implementation cycles and their applications.
[0000]
TABLE 5
Commercial name
Implementation cycles
Application
DER 332/DEH 619
8 days at ambient temp.
Industrial
DER 331/DEH 2919
8 days at ambient temp.
matrices
Epikote 05475/
5 min to 120° C.
High
Epikure 05443
performance
Araldite LY 5052/
1 day at ambient temp.
matrices
Aradur 5052
followed by thermal post-
treatment of 4 h at 100° C.
Or 4 h at 80° C.
Araldite MY 0816/
2 h at 100° C. followed by
Aradur 976-1
two thermal post-
treatments: 2 h at 150° C.
and 2 h at 220° C.
Araldite MY 0510/
2 h at 150° C. followed by
Aradur 976-1
two thermal post-
treatments: 4 h at
180° C. + 2 h at 200° C.
Araldite MY 720/
2 h at 80 followed by
Aradur 976-1
three thermal post-
treatments: 1 h at
100 + 4 h at 150 + 7 h at
200° C.
[0190] The polymerisable composition in accordance with the invention, Example 39, (the composition of which corresponds to Example 21) was polymerised for one day at ambient temperature without adding external heat to the composition 39. A step of thermal post-treatment applied to the thermoset matrix in order to reorganize the polymer chains that had been formed was carried out for 4 h at 100° C. The means of the values measured for the flexural moduluses in gigapascals (GPa) and for the maximum stresses in mega pascals (MPa) obtained for the industrial matrices, the high performance matrices and the matrix obtained from polymerisation of the polymerisable composition 39 are recorded in the accompanying FIGS. 10 and 11 . Thus, it can be seen that the matrix obtained by cationic polymerisation of the composition 39 can be used to obtain highly satisfactory mechanical performances.
[0000] VIII—Comparison of Thermal Properties Obtained for Two Polymerisable Compositions in Accordance with the Invention
[0191] Example 39 mentioned above (the composition of which corresponds to Example 21 described above) and Example 40, identical to Example 39 with the difference that no thermal post-treatment steps were carried out, were compared with the reference polymerisable compositions from the prior art described in Table 5.
[0192] Table 6 below records the glass transition temperatures (T G ) determined by DMA (dynamic mechanical analysis) for the prior art compositions, corresponding to those also indicated in Table 5, which had undergone the implementation cycles described in Table 5, as well as for the compositions in accordance with the invention (Examples 39 and 40). This Table 6 also records the decomposition temperatures (Td) determined by TGA (thermogravimetric analysis) for a prior art composition corresponding to that also indicated in Table 5 and which had undergone the implementation cycle described in Table 5, and for a composition in accordance with the invention corresponding to Example 40.
[0000]
TABLE 6
References for the
polymerisable compositions
T G (° C.)
DER 332/DEH 619
77° C.
Araldite CY 179/Aradur 917
189° C.
Epikote/Epikure
127° C.
Araldite LY 5052/Aradur
126° C.
Araldite MY 0510/Aradure
191° C.
Example 39
160-200° C.
Example 40
125° C.
Td (° C.)
Araldite CY 179/Aradur 917
372° C.
Example 40
404° C.
[0193] Advantageously, the polymerisable compositions in accordance with the invention could be used to obtain values for T G and Td that were similar, or even superior, to the prior art compositions.
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In a first aspect, the present invention concerns a kit for a polymerisable composition comprising a portion A constituted by a composition comprising at least one monomer (a1) that is reactive towards a cationic species (b) or a Lewis or Brönsted acid species, and at least one co-initiator, and a portion B comprising at least one cationic salt (e) selected from the salts with formula S1, S3, and S4 shown and defined in claim 1 . In a second aspect, the present invention concerns a method of producing a coating or a composite material starting from polymerisable composition comprising at least one salt (e) selected from the salts with formula S1, S2, S3, and S4 shown and defined in claim 10 , said composition being polymerised without adding external heat thereto.
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FIELD OF THE INVENTION
The present invention relates to a process for the preparation of a polyaniline salt. The present invention particularly relates to a process for preparation of a polyaniline salt using protonic acid such as hydrochloric, sulfuric, nitric, phosphoric and 5-sulfosalicylic acid. The present invention more particularly relates to an emulsion polymerization process for preparing an electrically conductive polyaniline salt wherein the polyaniline salt is in organic carrier solvent and the solution is optically transparent.
BACKGROUND OF THE INVENTION
A lot of research work in the area of electrically conductive polymers is being carried out at the moment all over the world. These polymers make it possible to replace metallic conductors and semi-conductors in many applications such as batteries, transducers, switches, solar cells, circuit boards, heating elements and in electrostatic discharge (ESD) and electromagnetic interference shielding (EMI) applications. The advantages of electrically conductive polymers compared to metals are, for instance, their low weight, good mechanical properties, corrosion resistance and cheaper synthesis and processing methods.
Exemplifying kinds of inherently electrically conductive polymers are polyacetylene, poly-p-phenylene, polypyrrole, polythiophene and polyaniline. An advantage with the inherently electrically conductive polymers is that their electrical conductivity is easily varied as a function of the doping time, which is especially seen in the case of low conductivities. It is difficult to obtain low conductivities for filled electrically conductive plastics.
Polyaniline has emerged as one of the promising conducting polymers and can be used in a variety of applications, such as paint, antistatic protection, electromagnetic protection, electro-optic devices such as liquid crystal devices (LCDs) and photocells, transducers, circuit boards, etc. However, processing of polyaniline into useful products or devices as described above has been problematic because of its insolubility in common solvents.
Synthesis of polyaniline is commonly performed by the method of chemical oxidative polymerization based upon the aqueous solution polymerization system. (see Cao et al., Polymer 30:2305, 1989). Typically polyaniline is produced as solid emeraldine salt from chemical oxidative polymerization in the presence of protonic acid such as HCl and H 2 SO 4 . The polyaniline obtained in such way is normally insoluble, which hinders the application of the polyaniline.
Smith et al., U.S. Pat. No. 5,470,505, disclosed that the emeraldine salt prepared by standard methods of oxidative polymerization of aniline monomer in the presence of a protonic acid can be dissolved in an acid, particularly strong acid such as concentrated H 2 SO 4 CH 3 SO 3 H, CISO 3 H, CF 3 SO 3 H and HNO 3 (70% or fuming). The emeraldine salt (polyaniline) dissolved in one of these acid solutions is then processed into desired articles in the applications.
Abe et al., U.S. Pat. No. 5,728,321, disclosed a solution of polyaniline (dissolved in an aprotic polar solvent, such as N-methyl-2-pyrolidone) in doped state can be obtained by a method using a specific protonic acid, such as hydrofluoroboric acid, perchloric acid, or any other organic acids having acid dissociation constant pKa values of less than 4.8, as dopants in the oxidative polymerization of aniline monomer Also, the polyaniline obtained according to the above method, which is insoluble in an organic solvent, can be dissolved in an aprotic polar solvent in an undoped state. The undoping of doped polyaniline in order to permit the polyaniline to be soluble in organic solvent is burdensome and increases the production cost.
Traditional methods of preparation of polyaniline in a processable form, including the prior arts mentioned above, have to go through the processes of recovering, filtering, washing, and drying of the reaction product to obtain the solid polyaniline due to the insolubility of the polyaniline formed in the reaction mixture, and need additional processes, such as transforming the emeraldine salt into emeraldine base and dissolving the solid polyaniline or emeraldine base in a solvent, to obtain the desired solution of polyaniline.
To improve the processability, emulsion polymerization processes for preparing a polyaniline salt of a protonic acid have been reported (Cao et al. U.S. Pat. No, 5,232,631, Example 6B, 1993; Cao and Jan-Erik, WO94/03528, 1994 I; Cao and Jan-Erik, U.S. Pat. No. 5,324,453, 1994 II; see also, Osterholm et al. P. Synthetic Metals 55:1034-9, 1993). In these disclosures aniline, a protonic acid, and an oxidant were combined with a mixture of polar liquid, typically water and a non-polar or weakly polar liquid, e.g. xylene, chloroform, toluene, decahydronaphthalene and 1,2,4-tricholorobenzene, all of which are either sparingly soluble or insoluble in water.
Smith et al ( Polymer 35, 2902, (1994)) reported the polymerization of aniline in an emulsion of water and a non-polar or weakly polar organic solvent. This polymerization was carried out in the present of functionalized protonic acid such ad dodecylbenzenesulfonic acid which simultaneously acted as a surfactant and protonating agent for the resulting polyaniline. This polyaniline produced thereby has good solubility in non-polar solvents.
Protonic acid primary dopants are described as acting as surfactants in that they are purportedly compatible with organic solvents and enable intimate mixing of the polyaniline in bulk polymers (Cao et al, Synthetic Metals 48:91-97, 1992; Cao et al U.S. Pat. No. 5,232,631, 1993; which are incorporated by reference). Thus, any surfactant aspect of the primary dopants was thought to contribute to the processability rather than the conductivity of the polyaniline.
Heeger's group ( Synthetic Metals 48, 91, (1992)); ( Synthetic Metals 3514 (1993)) reported that emeraldine base doped with a functionalized protonic acid, for example, camphorsulfonic acid and dodecylbenzenesulfonic acid, can be dissolved in a non-polar or moderate polar organic solvent. This three component system has good solubility in common organic solvents and is compatible with many of the classical polymers.
Polyaniline salt has been categorized as an interactable material that is neither soluble nor fusible under normal conditions. Several strategies were worked out to introduce solubility and processability in polyaniline.
They are:
Dedoping of polyaniline salt to polyaniline base. Dissolving polyaniline base in aprotic solvent and redoping to polyaniline salt. However, this procedure is burdensome and increases the production cost.
Dissolving the polyaniline salt in concentrated acid. However, they are highly corrosive because of the use of concentrated acid.
Preparation of substituted polyaniline; preparation of polyaniline copolymers that are not homopolymers of polyaniline salt The conductivity of the substitute polyaniline and copolymer may be much lower than that of the polyaniline.
Preparing of polyaniline salt using functionalized protonic acids both by aqueous and emulsion polymerization process—functionalized protonic acid is costly.
As can be seen, it is important to develop processes for the preparation of polyaniline salt that is economical and provides good yield.
OBJECTS OF THE INVENTION
The main object of the present invention is to provide a process for the preparation of a polyaniline salt economically and in good yield.
It is another object of the invention to provide a process for the preparation of a polyaniline salt wherein the electrically conductive polyaniline salt is in organic carrier solvent.
Another object of the present invention is to provide a process for the preparation of polyaniline salts using cheaper protonic acids such as hydrochloric, sulfuric, nitric, phosphoric and 5-sulfosalicylic acid protonic acid.
Yet another object of the present invention is to provide a process for the preparation of an electrically conductive polyaniline salt in powder form.
SUMMARY OF THE INVENTION
The present method involves a process for the polymerization of aniline into polyaniline salts using cheaper protonic acids such as hydrochloric, sulfuric, nitric, phosphoric and 5-sulfosalicylic acid wherein the polyaniline salt is in carrier organic solvent such as chloroform, dichloromethane, toluene and the solution is optically transparent. This solution can be used directly for blending with other insulating polymers using conventional methods.
Polyaniline salts in organic carrier solvent were prepared directly in one step by polymerizing aniline with cheaper organic and inorganic acids. In addition to polyaniline sulfate salt, using this process, other polyaniline salts may be prepared using other acids such as hydrochloric, nitric, phosphoric and 5-sulfosalicylic acid. Polyaniline-salt with higher conductivity (0.1 S/cm) can be prepared when compared with that of polyaniline-sulfate salt (0.01 S/cm).
The following drawbacks of the prior art do not occur in the process of the invention.
(i) use of costlier functionalized protonic acid
(ii) use of concentrated acid for dissolving the polyaniline salt resulting in corrosion and handling problems, and
(iii) converting polyaniline salt into polyaniline base, dissolving the polyaniline base in solvents then adding insulating polymer and converting into electrically conducting polyaniline blend.
Accordingly the present invention relates to a process for the preparation of a polyaniline salt which comprises polymerizing an aromatic amine in the presence of a protonic acid and a mixture of aqueous and hydrocarbon solvents, separating the polyaniline slat in solution form from the reaction mixture.
In one embodiment of the invention, the polymerisation is carried out in the presence of an ionic surfactant and a radical initiator at ambient temperature for at least 24 hours
In another embodiment of the invention, if desired a non-solvent is added to the above polyaniline salt solution to precipitate salt and the polyaniline salt precipitated is separated by known methods.
The present invention is directed to a process for the preparation of an electrically conductive polyaniline salt in non-aqueous organic carrier solvent.
The present invention is also directed to a process for the preparation of an electrically conductive polyaniline-salt in the powder form.
In another embodiment of the invention, the protonic acid used is selected from the group comprising of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid 5-sulfosalicylic acid and any mixture thereof.
In a further embodiment of the present invention, the aromatic amine used comprises aniline or substituted aniline selected from 2-methyl aniline and 3-methyl aniline.
In another embodiment of the invention, the hydrocarbon solvent used comprises a chlorinated solvent selected from the group consisting of chloroform, dichloromethane, and an aromatic hydrocarbon such as toluene.
In yet another embodiment of the invention, the ionic surfactant used is selected from the group consisting of an anionic surfactant selected from sodium lauryl sulfate and dioctyl sodium sulfosuccinate, and a cationic surfactant such as cetyltrimethylammonium bromide.
In still another embodiment of the invention, the radical initiator used comprises benzoyl peroxide.
In a feature of the present invention, the separation of polyaniline sulfate in organic solvent is effected by pouring the reaction mixture into water.
In another embodiment of the invention, the non-solvent used to precipitate the polyaniline salt out of the organic phase comprises acetone
In another embodiment of the invention, the separation of the polyaniline sulfate salt from the reaction mixture is carried out by filtration.
These embodiments will be apparent from the ensuing detailed description of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention.
EXAMPLE-1
The following example illustrates the preparation of the polyaniline-5-sulfosalicylic acid salt in weakly polar organic solution by the emulsion-polymerization pathway using sodium lauryl sulfate anionic surfactant.
A solution containing 1.44 g of sodium lauryl sulfate, dissolved in 40 ml of distilled water is mixed with a solution containing 5.85 g benzoyl peroxide in 60 ml chloroform. The milky white emulsion thus foamed is mechanically stirred at 25° C. 2.3 ml aniline and 5-sulfosalicylic acid (5.1 g) in 100 ml of water, is added drop wise to the mixture over a period of approximately 20 minutes. The reaction is allowed to proceed for 24 hours (reaction time was varied as 12, 16, 24 hrs). The color of the emulsion at this time becomes green. The bottom oily green phase containing the polyaniline and an upper aqueous phase were separated. The upper aqueous phase was removed with a separating funnel and 1500 ml water was added to the green phase. The aqueous phase is removed and the green polyaniline phase was subsequently washed with three 1500 ml portions of water. Sodium sulfate (5 g) was added to the polyaniline phase and filtered through filter paper. The polyaniline phase thus obtained appeared uniform to the naked eye and the polymer remained solubilized in the organic phase.
EXAMPLE-2
The following example illustrates the preparation of the polyaniline salts in weakly polar organic solution by the emulsion polymerization pathway using sodium lauryl sulfate anionic surfactant.
A solution containing 1.44 g of sodium lauryl sulfate dissolved in 40 ml of distilled water was mixed with a solution containing 5.85 g benzoyl peroxide in 60 ml chloroform. The milky-white emulsion thus formed was mechanically stirred at 25° C. 2.3 ml aniline and acid (hydrochloric acid 17.5 ml; sulfuric acid 9.0 ml; phosphoric acid 5.5 ml, nitric acid 12.6 ml and 5-sulfosalicylic acid 5.1 g) in 100 ml of water was added drop wise to the mixture over a period of approximately 20 minutes. The reaction was allowed to proceed for 24 hours. The color of the emulsion at this time became green. The bottom oily green phase containing the polyaniline and an upper aqueous phase were separated. The upper aqueous phase was removed with a separating funnel and 1500 ml water was added to the green phase. The aqueous phase was removed and the green polyaniline phase was subsequently washed with three 1500 ml portions of water. Sodium sulfate (5 g) was added to the polyaniline phase and filtered through filter paper. The polyaniline phase thus obtained appeared uniform to the naked eye and the polymer remained solubilized in organic phase.
The isolated polyaniline-salt samples are analyzed by electronic absorption spectral technique using Hitachi U 2000 spectrophotometer Polyaniline sulfate salt in organic solvent according to Example 1 was recorded. Three peaks were observed at around 360-380, 530-540 and 825-850 nm corresponding to polyaniline salt system.
EXAMPLE-3
The following example illustrates the preparation of the polyaniline salt in powder form by the emulsion polymerization pathway.
The organic layer obtained in Examples 1 and 2 containing polyaniline salt in organic solvent was poured into 500 ml of acetone. Polyaniline sulfate salt precipitated out from the organic solvent. The precipitate was then recovered by filtration and the solid washed with 2000 ml of distilled water followed by 250 ml of acetone. The powder was dried at 100° C. till constant mass was reached.
The polyaniline sulfate salts in dry powder form were compressed into pellets using a 16 mm diameter Macro-Micro KBR die and a 12-ton laboratory hydraulic press. The powder was placed in the die and a pressure of 2000 lbs applied thereto. Each pellet thus formed was measured to determine its diameter and thickness. The pellets were in the shape of disks. To measure the conductivity each pellet was coated with silver paint on both the sides having the same cross-sectional area and the resistance measured using an ohmmeter. Lead resistance was 0.03 Ohms for the pellets. Conductivity was calculated using the following formula:
Conductivity−(Thickness)/(resistance.times.area)= d /( RA )
The conductivity of the polyaniline 5-sulfosalicylic acid prepared by Example 3 with time periods 16, 24 and 36 hours were found to be 0.4, 0.6 and 0.01 S/cm respectively.
The conductivity of the polyaniline salt prepared by Example 3 with different acids such as hydrochloric, sulfuric, nitric, phosphoric and 5-sulfosalicylic acid were found to be 0.1, 0.1, 0.2, 0.005 and 0.6 S/cm respectively.
Thermal analysis was performed by the simultaneous differential thermal analysis and thermogravimetric analysis technique using the Metler Toledo Star system, and accordingly the samples of Example 3 are evaluated. Polyaniline sulfate samples were found to be stable up to 200° C.
EXAMPLE 4
The following example illustrates the preparation of the polyaniline sulfuric acid salt in weakly polar organic solution by the emulsion-polymerization pathway using dioctyl sodium sulfosuccinate anionic surfactant.
A solution containing 2.0 g of dioctyl sodium sulfosuccinate dissolved in 40 ml of distilled water was mixed with a solution containing 5.85 g benzoyl peroxide in 60 ml chloroform. The milky-white emulsion thus formed was mechanically stirred at 25° C. 2.3 ml aniline and sulfuric acid (6 ml) in 100 ml of water was added drop wise to the mixture over a period of approximately 20 minutes. The reaction was allowed to proceed for 24 hours. The color of the emulsion at this time became green. The bottom oily green phase containing the polyaniline and an upper aqueous phase were separated. The upper aqueous phase was removed with a separating funnel and 1500 ml water was added to the green phase. The aqueous phase was removed and the green polyaniline phase subsequently washed with three 1500 ml portions of water. Sodium sulfate (5 g) was added to the polyaniline phase and filtered through filter paper. The polyaniline phase thus obtained appeared uniform to the naked eye and the polymer remained solubilized in the organic phase.
EXAMPLE 5
The following example illustrates the preparation of the polyaniline sulfuric acid salt in weakly polar organic solution by the emulsion polymerization pathway using cetyltrimethylammonium bromide cationic surfactant.
A solution containing 2.0 g of cetyltrimethylammonium bromide dissolve in 40 ml of distilled water was mixed with a solution containing 5.85 g benzoyl peroxide in 60 ml chloroform. The milky-white emulsion thus formed was mechanically stirred at 25° C. 2.3 ml aniline and sulfuric acid (6 ml) in 100 ml of water, was added drop wise to the mixture over a period of approximately 20 minutes. The reaction was allowed to proceed for 24 hours. The color of the emulsion at this time became green. The bottom oily green phase containing the polyaniline and an upper aqueous, phase were separated. The upper aqueous phase was removed with a separating funnel and 1500 ml water was added to the green phase. The aqueous phase was removed and the green polyaniline phase was subsequently washed with three 1500 ml portions of water. Sodium sulfate (5 g) was added to the polyaniline phase and filtered through filter paper. The polyaniline phase thus obtained appeared uniform to the naked eye and the polymer remained solubilized in the organic phase.
EXAMPLE 6
The following example illustrates the preparation of poly(2-methyl aniline)-sulfuric acid salt in weakly polar organic solution by the emulsion polymerization pathway.
A solution containing 1.44 g of sodium lauryl sulfate dissolved in 40 ml of distilled water was mixed with a solution containing 5.85 g benzoyl peroxide in 60 ml chloroform. The milky-white emulsion thus formed was mechanically stirred at 25° C. 2.7 ml of 2-methyl aniline and sulfuric acid (6 ml) in 100 ml of water was added drop wise to the mixture over a period of approximately 20 minutes. The reaction was allowed to proceed for 24 hours. The color of the emulsion at this time became green. The bottom oily green phase containing the poly(2-methyl aniline) and an upper aqueous phase were separated. The upper aqueous phase was removed with a separating funnel and 1500 ml water was added to the green phase. The aqueous phase was removed and the green poly(2-methyl aniline) phase was subsequently washed with three 1500 ml portions of water. Sodium sulfate (5 g) was added to the poly(2-methyl aniline) phase and filtered through filter paper. The poly(2-methyl aniline) phase thus obtained appeared uniform to the naked eye and the polymer remained solubilized in the organic phase.
ADVANTAGES OF THE INVENTION
The main advantages of the present invention are:
(i) Preparation of polyaniline salt in organic carrier solvent wherein the polyaniline salt is electrically conductive
(ii) Preparation of an electrically conductive polyaniline salt using cheaper protonic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and 5-sulfosalicylic acid.
As various changes could be made in the above methods and compositions without departing from the scope of the invention it is intended that all matter contained in the above description shall be interpreted as illustrative and not limiting.
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The present invention provides a process for the preparation of a polyaniline salt by polymerizing an aromatic amine in the presence of a protonic acid and a mixture of aqueous and hydrocarbon solvents to obtain polyaniline salt dissolved in organic phase or in powder form.
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RELATED APPLICATIONS
This application is a continuation of application Ser. No. 07/995,331 filed Dec. 23, 1992 and now issued as U.S. Pat. No. 5,714,389. Application Ser. No. 07/995,331 is a continuation of application Ser. No. 07/702,450 filed on May 16, 1991, now abandoned. Application Ser. No. 07/702,450 is a continuation of application Ser. No. 07/211,582 filed on Jun. 27, 1988, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to assays for ligands, e.g., antigens, in a liquid sample such as a body fluid. More particularly, the invention relates to a method and apparatus for the detection of a ligand in a body fluid such as urine using a conjugate comprising colored particles and a novel flow-through test cell.
Many types of ligand-receptor assays have been used to detect the presence of various substances, often generally called ligands, in body fluids such as urine. These assays involve antigen antibody reactions, synthetic conjugates comprising radioactive, enzymatic, fluorescent, or visually observable metal sol tags, and specially designed reactor chambers. In all these assays, there is a receptor, e.g., an antibody, which is specific for the selected ligand or antigen, and a means for detecting the presence, and often the amount, of the ligand-receptor reaction product. Most current tests are designed to make a quantitative determination, but in many circumstances all that is required is a positive/negative indication. Examples of such qualitative assays include blood typing and most types of urinalysis. For these tests, visually observable indicia such as the presence of agglutination or a color change are preferred.
Even the positive/negative assays must be very sensitive because of the often small concentration of the ligand of interest in the test fluid. False positives can also be troublesome, particularly with agglutination and other rapid detection methods such as dipstick and color change tests. Because of these problems, sandwich assays and other sensitive detection methods which use metal sols or other types of colored particles have been developed. These techniques have not solved all of the problems encountered in these rapid detection methods.
It is an object of this invention to provide a rapid, sensitive method for detecting ligands in body fluids. Another object is to provide an assay which has high sensitivity and fewer false positives than conventional assays. A further object is to provide a test cell for detection of low levels of ligands in body fluids. Another object is to provide an assay system which involves a minimal number of procedural steps, and yields reliable results even when used by untrained persons.
These and other objects and features of the invention will be apparent from the following description, drawings, and claims.
SUMMARY OF THE INVENTION
The invention features a method and test cell for the detection of a preselected ligand in a liquid sample such as a body fluid.
The test cell useful in the practice of the invention has an elongate outer casing which houses an interior permeable material, e.g., glass fiber, capable of transporting an aqueous solution by capillary action, wicking, or simple wetting. The casing defines a sample inlet, and interior regions which, for ease of description, can be designated as a test volume and a reservoir volume. The reservoir volume is disposed in a section of the test cell spaced apart from the inlet, and preferably is filled with sorbent material. The reservoir acts to receive liquid transported along a flow path defined by the permeable material and extending from the inlet and through the test volume. In the test volume is a test site comprising a first protein having a binding site specific to a first epitope of the ligand immobilized in fluid communication with the flow path, e.g., bound to the permeable material or to latex particles entrapped in or bonded to the permeable material. A window such as a hole or transparent section of the casing permits observations of the test site through the casing wall.
In a preferred embodiment, the flow path is restricted or narrowed in the test area, thereby channeling and concentrating fluid flow into contact with the test site. It is also preferred that the test cell include a solution filtering means disposed in the flow path between the sample inlet and the test site. The filtration means can comprise a separate, conventional filter element disposed within the casing of the test cell in fluid communication with the permeable material defining the flow path, but preferably is defined simply by a portion of the permeable material itself. The provision of such a filtration means in the test cell has the effect of removing by entrapment from impure samples, such as urine samples, a portion of the particulates and nonspecific interfering factors which sometimes cause false positive readings.
The method of the invention requires the use of a conjugate comprising a second protein bound to colored particles such as a metal sol or colloid, preferably gold. The conjugate can take two distinct forms, depending on whether the assay is designed to exploit the "sandwich" or "competitive" technique.
In the case of the sandwich technique, the second protein comprises a site which binds to a second epitope on the ligand. This type of conjugate reacts with the ligand to form a complex in the liquid sample. The complex is detected by visual observation of color development at the test site in the test cell. At the test site, the ligand bound with the conjugate reacts with the immobilized first binding protein to form a "sandwich" of the first protein, ligand, second protein, and colored particles. This sandwich complex is progressively produced at the test site as sample continuously passes by, filling the reservoir. As more and more conjugate is immobilized, the colored particles aggregate at the test site and become visible through the window, indicating the presence of ligand in the liquid sample.
In the case of the competitive technique, the second protein binds with the first protein in competition with the ligand. The second protein comprises, for example, an authentic sample of the ligand or a fraction thereof which has comparable affinity for the first protein. As the liquid sample is transported in contact with the test site, ligand, if any, and the conjugate compete for sites of attachment to the first protein. If no ligand is present, colored particles aggregate at the test site, and the presence of color indicates the absence of detectable levels of ligand in the sample. If ligand is present, the amount of conjugate which binds at the test site is reduced, and no color, or a paler color, develops.
In one embodiment of the invention, the test liquid is mixed with the conjugate outside the test cell. In another embodiment, the conjugate is disposed in freeze-dried or other preserved form on the permeable material between the inlet and the test site, and the sample liquid resolubilizes the conjugate as it passes along the flow path.
Color development at the test site may be compared with the color of one or more standards or internal controls to determine whether the development of color is a true indication of the presence or absence of the ligand, or an artifact caused by nonspecific sorption.
In one embodiment employing the sandwich technique, the standard consists of a negative control site, preferably disposed adjacent the test site, and visible through a second window proximate the first. The negative control site preferably is prepared identically to the test site, except immobilization of the first binding protein is omitted. Therefore, although the conjugate will reach the control site, it aggregates due only to non-specific binding. If the test site is not appreciably more intense in color than the control site, the assay is considered negative.
In another embodiment, the assay and test cell may include a positive control. Thus, when exploiting the sandwich technique, the cell may have an authentic sample of the ligand immobilized at a control site. If no color develops at this control site, the assay is considered inconclusive. When exploiting the competitive technique, the development of color at the positive control site means the assay results are inconclusive.
Broadly, the method of the invention involves the use of a test cell of the type described above to achieve an easily readable, sensitive, reproducible indication of the presence of a ligand, e.g., human chorionic gonadotropin (hCG), in a test sample such as a human urine sample. The method involves the step of transporting the sample and a conjugate comprising a protein bound to a metal sol or other colored particle along a flow path and in contact with a test site comprising immobilized binding protein specific to an epitope of the ligand, and preferably also in contact with a control site. Preferably, the colored particle comprises a gold sol; the flow path in the region of the test site is reduced in cross-section relative to other parts of the flow path; the sample is passed through a filtration means after it enters the test cell but before it contacts the test site; and the test site comprises latex particles entrapped or otherwise fixed in the flow path having the immobilized protein on their surface. In the practice of the process, either the conjugate is premixed with the sample, or the conjugate is disposed in preserved form, e.g., lyophilized, in the flow path between the inlet and the test site. In either case, placement of the test cell in the sample, or application of the sample to the inlet, initiates flow, and the result is read by observing color development at the test site, or by comparing the color of the test site and control site.
The use of the colored particle detection system in combination with the filtration means, the concentrating effect of flow of the sample, and the ease of comparison between the colors of the test and control sites, together enable construction of a family of extremely sensitive assay systems which minimize false positives and can be used effectively by untrained persons.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cut-away, schematic, top view of an embodiment of a test cell useful in explaining the test cell and process of the invention;
FIG. 2 is a cross-sectional side view of the test cell of FIG. 1;
FIG. 3 is a perspective view of a currently preferred test cell constructed in accordance with the invention;
FIG. 4A is a cross-sectional, top view of the test cell of FIG. 3;
FIG. 4B is a cross-sectional, side view of the test cell of FIG. 3 taken at line 4B--4B of FIG. 4A;
FIG. 5 is a cross sectional view of the cell of FIG. 3 taken at line 5--5 of FIG. 4B; and
FIG. 6 is a perspective view of another embodiment of a test cell constructed in accordance with the invention.
Like reference characters in the respective drawn figures indicate corresponding parts.
DESCRIPTION
The invention provides a test cell for conducting a sandwich or competitive immunoassay, and a process which utilizes the test cell and a conjugate comprising colored particles. As disclosed below, various features of the process and test cell of the invention cooperate to enable untrained personnel reliably to assay a liquid sample for the presence of extremely small quantities of a particular ligand while avoiding false positives and simplifying test procedures. The invention is ideal for use in over-the-counter assay test kits which will enable a consumer to self diagnose, for example, pregnancy, venereal disease, and other disease, infection, or clinical abnormality which results in the presence of an antigenic marker substance in a body fluid, including determination of the presence of metabolites of drugs or toxins. The assay process and the cell are engineered specifically to detect the presence of a preselected individual ligand present in a body or other fluids.
Broadly, the test cell and process of the invention can be used to detect any ligand which has heretofore been assayed using known immunoassay procedures, or known to be detectable by such procedures, using polyclonal or monoclonal antibodies or other proteins comprising binding sites for ligands. Various specific assay protocols, reagents, and analytes useful in the practice of the invention are known per se, see, e.g., U.S. Pat. No. 4,313,734, columns 4-18, and U.S. Pat. No. 4,366,241, columns 5-40.
The combination of features believed to be responsible for the excellent sensitivity and reproducibility of assays constructed in accordance with the invention is the use of the novel test cell which serves to concentrate ligand from a test sample at a test site in the cell, and the use of a metal sol or other colored particle as a marker system which permits direct visual observation of color development. False positives are reduced while maintaining excellent sensitivity by including in the test cell a negative control or control site whose color is compared with the test site, and by including a filtration means which limits the introduction to the test site of contaminants from the sample.
The assay is conducted by simply placing the inlet of the test cell in contact with a liquid test sample. One then merely waits for the test sample to pass through the cell and into reactive contact with the test site (and optionally one or more control sites) visible through a window or windows in the cell's exterior casing. In one embodiment, the conjugate is mixed with the sample and incubated briefly before the test cell is inserted. In another embodiment, the conjugate is disposed in preserved form in the flow path within the cell. If the ligand is present in the sample, it passes through the inlet and the interior of the cell along the flow path past the test and control sites, where, in the sandwich embodiment, it reacts with immobilized binding protein, e.g., antibody, at the test site, and perhaps also non-specifically at the control site. A "sandwich" forms at the test site comprising immobilized binding protein-ligand binding protein-colored particle. The presence of the sandwich complex and thus the ligand is indicated by the development of color caused by aggregation of the metal sol particles at the test site. A deeper color at the test site than at the negative control site is a positive indication of the presence of the ligand.
By providing a reservoir of sorbent material disposed beyond the test and control sites, a relatively large volume of the test liquid and any ligand it contains can be drawn through the test area to aid sensitivity. Optionally, the region of the flow path in the test cell defining the test and control sites is restricted in cross-sectional area relative to other regions of the flow path. This feature produces a "bottle-neck" effect wherein all ligand in the entire volume of sorbed sample must pass through the restricted flow area immediately about the test site where it will be immobilized by reaction with binding protein.
From the foregoing, it will be apparent that the success of the test procedure is dependent on ligand present in the sample reacting with the conjugate, or on reproducible competition between the ligand and the conjugate for sites of attachment at the test site. In accordance with the invention, as noted above, the assays can be conducted by premixing the conjugate with the liquid sample prior to introduction into the elongate test cell. Alternatively, the conjugate may be disposed in preserved form, e.g., freeze-dried, in the flow path within the test cell upstream of the test and control sites. In this case, the cell is placed directly in the liquid sample solution without premixing. Ligand, if any, passing up through the cell and entrained within the liquid moves into contact with the conjugate forming an immune complex or initiating competition in situ as flow continues. This latter technique has the advantage that it eliminates a manipulative step in the assay procedure, and accordingly a possible source of error.
Referring to the drawing, FIGS. 1 and 2 illustrate schematically an embodiment of a test cell 5 constructed in accordance with the invention useful in explaining its principles of construction. It comprises an outer, molded casing 10 which defines a hollow, elongate enclosure filled with a permeable, sorbent material 12. Casing 10 also defines a test liquid inlet 14 and a pair of circular openings 16, 18 comprising windows through which sorbent material 12 is visible.
Sorbent material 12 and the interior of casing 10 together define a flow path passing generally from left to right in FIGS. 1 and 2. When the test cell is placed with inlet 14 disposed within or otherwise in contact with a liquid sample, the liquid is transported by capillary action, wicking, or simple wetting along the flow path through downstream flow section 20, test volume 22, and into reservoir volume 24, generally as depicted by the arrows. The flow section 20 of the flow path disposed inwardly of the inlet 14 serves as a filter which can remove from impure test samples particulate matter and interfering factors. The provisions of such a flow section 20 defining a filtration means downstream of the inlet 14 is believed to contribute to the success of the system and its ability to avoid false positives.
Disposed within sorbent material 12 is a band 26 of dehydrated conjugate, e.g., antibody-metal sol. As the liquid sample moves past band 26, the conjugate is entrained in the liquid, reconstituted, and reacts or competes with ligand, if present, dissolved in the liquid sample. Of course, conjugate band 26 may be eliminated, and the conjugate added to the test liquid prior to introduction of the cell 5 as previously noted.
Within the volume of sorbent material 12 disposed directly beneath circular openings 16 and 18 in casing 10 is disposed, respectively, control site 16' and test site 18'. In the drawing, the control and test site are illustrated as being disposed serially along the flow path. Alternatively, the control and test site or sites may be disposed side by side or in other spacial relationships.
Test site 18' comprises a preselected quantity of antibody against an epitope of the ligand to be detected immobilized in place within the flow path. Its detailed chemical structure can vary widely. Control site 16' is preferably identical in size and chemical makeup to test site 18', excepting that the immobilized antibody present at the test site 18' is omitted at the control site 16'. Thus, any nonspecific aggregation of, e.g., ligand-conjugate or free conjugate, which occurs at test site 18' also will occur at control site 16'. A deeper color at test site 18' as compared with control site 16' is a positive indication of ligand in the sample in the sandwich assay.
The invention is not limited by the precise nature of the test site 18' and corresponding control site 16', and in fact, control site 16' may be entirely eliminated if a reduction in sensitivity can be tolerated. Generally, antibody or other binding protein may be immobilized at test site 18' using adsorption, absorption, or ionic or covalent coupling, in accordance with methods known per se. A currently preferred formulation for test site 18' is to immobilize monoclonal antibody against an epitope of the ligand on latex beads, and then to entrap or otherwise link the beads in sorbent material 12 at region 18'. Control site 16' is fabricated identically, except that the latex beads contain non specific immunoglobulin, e.g., immunoglobulin from bleedings from an animal that has not been immunized.
Disposed beyond test volume 22 is a reservoir volume 24 comprising a relatively large mass of sorbent or supersorbent material. The purpose of reservoir volume 24 is to assure that a reasonably large amount of test liquid is drawn through test volume 22. Increasing the volume of reservoir 24 can have the effect of increasing the sensitivity of the assay procedure, as it results in an increase in the amount of ligand passing through the test area 22. Suitable sorbents include commercial materials of the type available, for example, from The Dow Chemical Company of Midland, Mich., and the Chemical division of American Colloid, Arlington Heights, Ill. These materials can absorb many times their weight in water and are commonly used in disposable diapers. They comprise lightly crosslinked polyacrylate salts, typically alkali metal salts.
Polyclonal antisera and indeed monoclonal antibodies or fractions thereof having specific binding properties and high affinity for virtually any antigenic substance are known and commercially available or can be produced from stable cell lines using well known cell fusion and screening techniques. The literature is replete with protein immobilization protocols. See, for example, Laboratory Techniques in Biochemistry and Molecular Biology, Tijssen, Vol. 15, Practice and Theory of Enzyme immunoassays, chapter 13, The Immobilization of Immunoreactants on Solid Phases, pp. 297-328, and the references cited therein.
Metal sols and other types of colored particles useful as marker substances in immunoassay procedures are also known per se. See, for example, U.S. Pat. No. 4,313,734, Feb. 2, 1982, to Leuvering, the disclosure of which is incorporated herein by reference. For details and engineering principles involved in the synthesis of colored particle conjugates see Horisberger, Evaluation of Colloidal Gold as a Cytochromic Marker for Transmission and Scanning Electron Microscopy, Biol. Cellulaire, 36, 253-258 (1979); Leuvering et al, Sol Particle Immunoassay, J. Immunoassay 1 (1), 77-91 (1980), and Frens, Controlled Nucleation for the Regulation of the Particle Size in Monodisperse Gold Suspensions, Nature, Physical Science, 241, pp. 20-22 (1973).
The cell can take various forms. It will usually comprise an elongate casing comprising interfitting parts made of polyvinyl chloride, polypropylene, or other thermoplastic resin. Its interior flow path will contain a relatively inert material or a combination of materials suitable for transporting the liquid. In some circumstances it may be preferable to use a material of higher sorptivity as the reservoir, promoting the flow of liquid, and a different material for remaining portions of the flow path.
From the foregoing it should be apparent that the advantages in reproducibility, sensitivity, and avoidance of false positives of assay systems constructed in accordance with the invention are traceable to a combination of features of the invention. In use, the test cell of the invention and the metal sol particles used as a marker together cooperate to result in an increase in color intensity progressively as ligand complexed with conjugate is trapped at the test site by the immobilized binding protein. This approach can be utilized to design assays and test cells for essentially any antigenic material.
The invention will be further understood from the following non-limiting examples.
EXAMPLE 1
The currently preferred test device embodying the invention is shown in FIGS. 3, 4A, 4B, and 5. A modification of the device depicted in FIG. 3 is shown in FIG. 6, and includes a second control site 19 in addition to control site 16' and test site 18', as well as a stand 21 useful for maintaining the test cell in an incline position with the reservoir downhill. When a test sample is applied to inlet 14, gravity as well as sorption aids in transporting the sample along the flow path.
As shown in FIGS. 3, 4A, 4B, and 5, the preferred test cell of the invention differs from the exemplary device discussed above and shown in FIGS. 1 and 2 in certain of its more specific internal features. Specifically, the casing 10 comprises a pair of interfitting polymeric parts including a U-shaped top part 10' which, when the device is assembled, interfits with lower part 10". Top and bottom parts 10' and 10" may be connected through a hinge region 11. The bottom section 10" defines a pair of channels 28 above which is disposed a strip of glass fiber paper 13 (available commercially from Eaton Dikeman, Grade 111, or Whatman, Grade GFA). Test liquid applied through inlet 14 soaks along the paper strip 13 which defines the flow path and a filtering means region 20, as well as a positive control site 16' and test site 18' visible through windows 16 and 18 consisting of openings through upper mating member 10'. The paper strip 13 overlaps into reservoir volume 24, which is defined by a cavity between the interfitting top and bottom mating members 10' and 10'. The cavity in this case is filled with sorbent blotting paper 25 comprising the sorbent reservoir. A suitable paper is sold as Grade 12A absorbent paper, a cellulose product available from Schleicher and Schuell. In one preferred embodiment, the dimensions of the glass fiber paper 13 were approximately one quarter inch by three inches, and those of the absorbent material 25 approximately two inches by five thirty seconds of an inch on each side. A number of these devices were produced and further treated to adapt them to detect pregnancy by assay of urine.
Test site 18' in each device was fabricated as a spot within fiber paper 13 using the following technique. Latex beads available commercially and comprising polystyrene particles 0.3 micron in diameter were passively coated with purified rabbit anti-human chorionic gonadotropin. The polyclonal antibody was purified using conventional techniques from bleedings of a rabbit previously immunized with human chorionic gonadotropin in a manner know per se. Equal parts of a latex (0.6% by weight) having a continuous phase of glycine buffer, pH=8.3, and a 1 mg/ml antibody solution in the same buffer were mixed and incubated at 37° C. 15 microliters of this solution, comprising approximately 0.6% solids, were added, one drop at a time, to the glass fiber paper 13 to produce spot 18' after the devices had been assembled. The spots were then allowed to dry at 37° C. The control site 16' was produced identically to the test site disclosed immediately above, excepting that rabbit polyclonal non-immune gamma globulin was used in place of the anti-hCG gamma globulin.
Metal sol particles were prepared in accordance with the method of Frens, Controlled Nucleation for the Regulation of the Particle Size in Mono Dispersed Gold Solutions (1973), supra. Briefly, the gold sol was prepared by reducing a 4% solution of gold chloride with 1% sodium citrate to produce gold particles of approximately 18 nm in diameter. The particles were made immunochemically reactive by admixture with a monoclonal antibody specific for human chorionic gonadotropin with no detectable cross-reactivity with human leutinizing hormone. The antibody was purchased from Charles River Labs, and is produced using standard techniques including purification from ascites using HPLC ion exchange chromatography. It was added to the gold sol as a 10 ug/ml solution in borate buffer, pH-6. The bound antibody fraction is separated from the free fraction by either density centrifugation or gel filtration chromatography. Additional details of the currently preferred procedure for making the antibody sol conjugate are disclosed by Leuvering et al, J. Immunoassay (1980) supra. Individual batches of the latex and the conjugate are titrated to optimize activity so that a suitable amount of latex is applied to the test site and a suitable amount of conjugate is used in conducting the test.
Test Protocol
To a 10×50 mm test tube of lyophilized gold sol antibody conjugate is added 0.5 ml urine sample containing a known quantities of hCG. The samples comprised hCG standards purchased from Sigma Chemical Company diluted in processed, hCG negative urine. The contents of the tube are mixed by shaking in a horizontal motion until the lyophilized antibody is dissolved. The device depicted in FIGS. 3-5 is then inserted into the tube, and the results are read after the entire fluid volume has been absorbed.
The results of this qualitative procedure are as follows:
______________________________________ Color of Color ofmIU hCG Control Spot Reagent Spot______________________________________0 grey grey25 grey pink hue50 grey pink100 grey rose150 grey rose>150 grey dark rose______________________________________
The pink color clearly visible at 50 mIU of human chorionic gonadotropin means that the test can detect pregnancy one day after a missed menstrual period. In initial stages of testing, approximately 50 negative samples from various sources have been run with no false positives or even border-line cases. It is anticipated that the commercial device will have less than 1% false positives.
Non-limiting examples of materials which may be assayed in accordance with the invention in addition to the human chorionic gonadotropin noted above include human leutinizing hormone, progesterone, estrogen, and streptococcus.
Other embodiments are within the following claims.
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Disclosed is a test cell and a method for detection of a preselected ligand in a liquid sample such as a body fluid. The test cell includes an elongate outer casing which houses an interior permeable material capable of transporting an aqueous solution and defining a sample inlet, a test volume, and a reservoir volume. The reservoir volume is disposed in a section of the test cell spaced apart from the inlet and is filled with sorbent material. The reservoir acts to receive liquid transported along a flow path defined by the permeable material and extending from the inlet and through the test volume. In the test volume is a test site which includes a first protein having a binding site specific to a first epitope of the ligand immobilized in fluid communication with the flow path. The test site can be observed through a window of the casing.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional patent application No. 60/854,940 filed Oct. 27, 2006 and entitled “Parallel Data Transfer and Structure,” which is incorporated herein by reference, and further, the present invention is related to co-pending U.S. patent application entitled “Multi-Channel Solid-State Storage System” filed on even date herewith, and co-pending U.S. patent application entitled “Parallel Data Transfer in Solid-State Storage” filed on even date herewith, each of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present invention generally relates to data storage systems, and more particularly to data storage systems using one or more or solid-state storage devices.
[0004] 2. Description of Related Art
[0005] The demand for solid-state data storage capacity, including Flash data storage capacity, is continually increasing. While the capacities available from storage devices are also increasing, many applications have data storage requirements that exceed the capacity available from a single storage device. One storage solution for these applications is a data storage system using more than one, or an array of, storage devices.
[0006] Storage device arrays increase storage capacity by providing more storage locations to store data from a host system or host device. However, a host system typically transfers data to and from the data storage system at a faster rate than individual storage devices can read or write the data. Thus, while storage capacity may be increased by adding storage devices, the data transfer performance of the data storage system may not be improved, and thus, as a whole is typically limited to the level of performance of the individual storage devices.
[0007] In light of the above, a need exists for improving the performance and the data transfer rate of a data storage system.
SUMMARY
[0008] In various embodiments, a data storage system includes a data management system that transfers data between a host system and multiple storage devices. The transferred data includes data segments, each of which includes one or more data sectors. The data management system transfers the data segments to the storage devices in parallel through data channels. Additionally, the data management system updates a selected data sector contained in a storage device by performing an erasure operation on the selected data sector and writing an updated data sector into that storage device. In this way, the erasure operation is performed only in the storage device containing the selected data sector, which reduces the number of erasure operations in the storage devices that would otherwise occur if the data sectors of each data segment were distributed among the storage devices.
[0009] The present invention improves the performance of conventional data storage systems by transferring data segments in parallel between the host system and the storage devices and by reducing the number of erasure operations performed to update data sectors in those data segments. The improvement in parallelism allows the array of storage devices to collectively attain a data transfer rate greater than that available from any of the storage devices individually. Further, the improvement in updating the data sectors reduces the number of erasure operations performed on the storage devices, which increases the lifetimes of the storage devices and the data storage system.
[0010] A method for storing data, in accordance with one embodiment, includes receiving a plurality of data segments. Each data segment of the plurality of data segments includes at least one data sector. The method also includes storing the data segments in a buffer and distributing the data segments among a plurality of storage devices. The data segments are distributed among the plurality of storage devices such that the data segments are transferred to the plurality of storage devices substantially in parallel but the data sectors of each data segment are sequentially transferred to the storage devices.
[0011] A method for storing data, in accordance with one embodiment, includes receiving a plurality of the data segments from a plurality of storage devices. Each data segment includes at least one data sector. The data segments are received substantially in parallel but the data sectors of each data segment are sequentially received from the storage devices. The method also includes storing the data segments into a buffer.
[0012] A data storage system, in accordance with one embodiment, includes a plurality of storage devices, a plurality of communication channels corresponding to the plurality of storage devices, and a data management system coupled to the storage devices through the corresponding data channels. The data management system is configured to receive a plurality of data segments, each which at least one data sector. The data management system is further configured to distribute the data segments among the storage devices. The data management system distributes the data segments among the storage devices such that the data segments are transferred to the storage devices substantially in parallel but the data sectors of each data segment are sequentially transferred to the storage devices.
[0013] A data storage system, in accordance with one embodiment, includes a plurality of storage devices and a data management system coupled to the storage devices. The data management system is configured to receive a plurality of the data segments from the storage devices. Each data segment includes at least one data sector. The data management system receives the data segments in parallel from the storage devices but receives the data sectors of each data segment sequentially from the storage devices.
[0014] A method for storing data, in accordance with one embodiment, includes receiving a plurality of data segments. Each data segment of the plurality of data segments includes at least one data sector. The method further includes storing the plurality of data segments in a buffer and generating an address map for mapping each data segment of the plurality of data segments to a respective storage device of a plurality of storage devices. Additionally, the method includes distributing the data segments among the plurality of storage devices based on the address map, such that the data sectors of each data segment of the plurality of data sectors are sequentially transferred to the plurality of storage devices, and the data segments of the plurality of data segments are transferred to the plurality of storage devices substantially in parallel.
[0015] A data storage system, in accordance with one embodiment, includes a plurality of storage devices, a plurality of communication channels corresponding to the plurality of storage devices, and a data management system coupled to the plurality of storage devices through the corresponding data channels. The data management system is configured to receive a plurality of data segments. Each data segment of the plurality of data segments includes at least one data sector. The data management system is further configured to generate an address map for mapping each data segment of the plurality of data segments to a respective storage device of the plurality of storage devices. Additionally, the data management system is further configured to distribute the data segments of the plurality of data segments among the plurality of storage devices based on the address map, such that the data sectors of each data segment of the plurality of data segments are sequentially transferred to a storage device of the plurality of storage device associated with the data segment, and the plurality of data segments are transferred to the plurality of storage devices substantially in parallel.
[0016] The foregoing summary of embodiments of the present invention has been provided so that the nature of the present invention can be quickly understood. A more detailed and complete understanding of embodiments of the present invention can be obtained by reference to the following detailed description of the present invention together with the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present invention, and together with the description, serve to explain the principles of the present invention. In the drawings,
[0018] FIG. 1 is a block diagram of a data storage system coupled to a host system, in accordance with an embodiment of the present invention;
[0019] FIG. 2 is a block diagram of a data management system, in accordance with an embodiment of the present invention;
[0020] FIG. 3 is a block diagram of a buffer manager, in accordance with an embodiment of the present invention;
[0021] FIG. 4 is a block diagram of an address map, or an address translation table, in accordance with an embodiment of the present invention;
[0022] FIG. 5 is a block diagram of data segments striped across the storage devices, in accordance with an embodiment of the present invention;
[0023] FIG. 6 is a block diagram of address maps, in accordance with an embodiment of the present invention;
[0024] FIG. 7 is a block diagram of pages containing data sectors, in accordance with an embodiment of the present invention;
[0025] FIG. 8 is a block diagram of storage devices containing data sectors, in accordance with an embodiment of the present invention;
[0026] FIG. 9 is a flowchart of a method of transferring data in a data storage system, in accordance with an embodiment of the present invention;
[0027] FIG. 10 is a flowchart of a portion of a method of transferring data in the data storage system, in accordance with an embodiment of the present invention;
[0028] FIG. 11 is a flowchart of a portion of a method of transferring data in the data storage system in which data is written to data storage devices, in accordance with an embodiment of the present invention;
[0029] FIG. 12 is a diagram representing a data transfer from a host system to storage devices in which data is written into the storage devices, in accordance with an embodiment of the present invention;
[0030] FIG. 13 is a flowchart for a portion of a method of transferring data in the data storage system in which data is read from storage devices, in accordance with an embodiment of the present invention; and
[0031] FIG. 14 is a diagram representing a data transfer in a data storage system in which data is transferred from storage devices to a host system, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0032] In various embodiments, a data storage system includes a data management system and storage devices. The data management system communicates, and transfers data to and from, the storage devices through communication channels. The storage devices are coupled to the data management system through the channel corresponding to the storage device. In some embodiments, more than one storage devices may transfer data through one channel, while in other embodiments, there is a one-to-one correspondence between the number of channels and storage devices.
[0033] The data management system receives data sequentially from a host system and transfers the data, as data segments, to the channels in parallel. Thus, the storage devices receive the data segments in a parallel manner. Additionally, the data management system receives data segments from the storage devices and channels in parallel. The data management system may reassemble the data segments into data for transfer to the host system, and sequentially transfers the data to the host system.
[0034] FIG. 1 illustrates a data storage system 100 , in accordance with an embodiment of the present invention. The data storage system 100 includes a data management system 110 and storage devices 115 (e.g., storage devices 115 a , 115 b , 115 c , and 115 d ). The data management system 110 is coupled to the storage devices 115 through corresponding data channels 112 (e.g., data channels 112 a , 112 b , 112 c , and 112 d ). The data channels 112 may be referred to as channels or communication channels. The data channels 112 may be any system, device, connection, or interface system for facilitating communications between the data management system 110 and the storage devices 115 . For example, each of the communication channels 112 may a communication bus. Additionally, the data management system 110 is coupled to a host system 105 . As is described in more detail below, the data management system 110 stores data received from the host system 105 in the storage devices 115 . Additionally, the data management system 110 retrieves data stored in the storage devices 115 at the request of the host system 105 and transfers the requested data to the host system 105 .
[0035] In one embodiment, the data storage system 100 includes four storage devices 115 a - d coupled to the data management system 110 through four corresponding data channels 112 a - d . It is to be understood, however, that the present invention is not limited to four storage devices 115 or four data channels 112 and may be implemented with more or less than four storage devices 115 and more or less than four data channels 112 . For example, the data storage system 100 may include four, eight, sixteen, thirty-two, or any other number of storage devices 115 and data channels 112 . In some embodiments, there may be a one-to-one correspondence between the data channels 112 and storage devices 115 , and yet in other embodiments, there may not be a one-to-one correspondence. For example, in some embodiments, more than one storage device 115 may be coupled, and transferred data through, one data channel 112 . Although FIG. 1 illustrates the data management system 110 and the storage devices 115 a - d as separate components in the data storage system 100 , the data management system 110 and the storage devices 115 a - d may be assembled and packaged as a single component or as separate components which are later connected together by an end user or manufacturer of the data storage system 100 . For example, the data management system 110 and the storage devices 115 may all be manufactured on an integrated circuit.
[0036] In various embodiments, each of the storage devices 115 includes a storage medium for storing data. In operation, the storage devices 115 write data to the storage mediums and read data from the storage mediums. The storage medium of a storage device 115 may be any type of data storage, such as a flash storage system, a solid-state drive, a flash memory card, a secure digital (SD) card, a universal serial bus (USB) memory device, a CompactFlash card, a SmartMedia device, a flash storage array, or the like. One skilled in the art will recognize that other types of storage devices such as hard drives and optical media drives may also be used without departing from the scope of the present invention. The storage devices 115 may be the same type of device or may be different types of devices. The storage devices 115 may have the same storage capacity or the storage devices 115 may have differing storage capacities.
[0037] The host system 105 may be any system or device having a need for data storage or retrieval and a compatible interface for communicating with the data storage system 100 . For example, the host system 105 may a computing device, a personal computer, a portable computer, or workstation, a server, a personal digital assistant, a digital camera, a digital phone, or the like. The host system 105 may communicate with the data storage system 100 by using a communication interface, such as an Integrated Drive Electronics (IDE) interface, a Universal Serial Bus (USB) interface, a Serial Peripheral (SP) interface, an Advanced Technology Attachment (ATA) interface, a Serial Advanced Technology Attachment (SATA), a flash interface, a Small Computer System Interface (SCSI), an IEEE 1394 (Firewire) interface, or the like. In some embodiments, the host system 105 includes the data storage system 100 . In other embodiments, the data storage system 100 is remote with respect to the host system 105 or is contained in a remote computing system coupled in communication with the host system 105 . For example, the host system 105 may communicate with the data storage system 100 via a wireless communication link.
[0038] FIG. 2 illustrates components of the data management system 110 , in accordance with an embodiment of the present invention. The data management system 110 includes a controller 200 , a buffer manager 205 , a host interface 210 , a switch 215 , and storage interfaces 220 (e.g., storage interfaces 220 a , 220 b , 220 c , and 220 d ). The host interface 210 is coupled to the host system 105 , the controller 200 , and the switch 215 . The storage interfaces 220 are coupled to the controller 200 and the switch 215 . The storage interfaces 220 are also coupled to respective storage devices 115 . In this way, each storage interface 220 is associated with one of the storage devices 115 . In some embodiments, the storage interfaces 220 include buffers for synchronizing a data transfer rate of the switch 215 with a data transfer rate of the storage devices 115 . For example, each of the storage interfaces 220 may include a ping-pong buffer for synchronizing the data rate of the switch 215 with the data rate of the storage device 115 coupled to the storage interface 220 . The buffer manager 205 is coupled to the controller 200 and the switch 215 . Additionally, the controller 200 is coupled to the switch 215 .
[0039] The host interface 210 facilitates communication between the host system 105 and the data management system 110 . The storage interfaces 220 facilitate communication between the data management system 110 and the storage devices 115 . The switch 215 functions to selectively connect the host interface 210 and storage interfaces 220 to the buffer manager 205 , thereby allowing the host interface 210 and the storage interfaces 220 to transfer data to and from the buffer manager 205 . The controller 200 monitors and controls operation of the data management system 110 and components contained therein.
[0040] As mentioned above, the host interface 210 facilitates communication between the host system 105 and the data management system 110 . This communication includes the transfer of data as well as command and control information. In some embodiments, the host interface 210 is optional in the data management system 110 . For example, the host system 105 may include the host interface 210 or the host interface 210 may be between the host system 105 and the data management system 110 . In other embodiments, the host interface 210 is partially external of the data management system 110 . In one embodiment, the host interface 210 is an Advanced Technology Attachment (ATA) interface which functions as an ATA target device that receives and responds to commands from an ATA host operating in the host system 105 . In other embodiments, the host interface 210 may include another type of interface, which may use a variable or fixed data packet size. For example, the host interface 210 may include a Small Computer System Interface (SCSI), which uses a fixed data packet size. The host interface 210 may include a physical interface, such as CompactFlash or other ATA compatible interfaces. In some embodiments, a bridge or other conversion device may be used to interconnect the host interface 210 and the host system 105 through other types of ports or interfaces, such as a Universal Serial Bus (USB) port, a Serial Advanced Technology Attachment (SATA), a flash interface, or an IEEE 1394 (Firewire) port.
[0041] The storage interfaces 220 facilitate communication between the data management system 110 and the storage devices 115 . This communication includes the transfer of data as well as command and control information in some embodiments. In one embodiment, the storage interfaces 220 are ATA interfaces implemented as ATA host devices and the storage devices 115 are implemented as ATA target devices. In this embodiment, the storage interfaces 220 generate commands which are executed by the storage devices 115 . The storage interfaces 220 are not limited to any one ATA interface standard and may use other types of interfaces, which may use a fixed or variable data packet size. For example, the storage interfaces 220 may include a SCSI interface, which uses a fixed data packet size. The storage interfaces 220 may include a physical interface such as a CompactFlash interface or other ATA compatible interfaces. Additionally, a bridge or other conversion device may be used to interconnect the storage interfaces 220 and the storage devices 115 through other types of ports, such as a USB port or an IEEE 1394 port. In some embodiments, the storage interfaces 220 may use a different type of interface than that used by host interface 210 . In some embodiments, the storage interfaces 220 may include a combination of interfaces. For example, some of the storage interfaces 220 may be CompactFlash interfaces and some of the storage interfaces 220 may be SCSI interfaces. The storage interfaces 220 may also use other interfaces such as SATA, a flash interface, or the like
[0042] In one embodiment, the switch 215 is a multiple port bus. In this embodiment, the host interface 210 , each of the storage interfaces 220 , and the buffer manager 205 are coupled to a respective port of the multiple port bus. The controller 200 controls the operation of the switch 215 to selectively connect the host interface 210 and the storage interfaces 220 to the buffer manager 205 . Additional details on the connections between the host interface 210 , the storage interfaces 220 , and the buffer manager 205 according to one embodiment are provided below. Not all embodiments will have all the components or connections depicted in FIG. 2 , and some embodiments may have additional components or connections not depicted in FIG. 2 .
[0043] FIG. 3 illustrates the buffer manager 205 , in accordance with an embodiment of the present invention. The buffer manager 205 includes a read arbiter 300 , a write arbiter 305 , and a buffer memory 310 (e.g. a buffer). The buffer memory 310 is used to store data being transferred between the host system 105 and the storage devices 115 . The buffer memory 310 may include any type of buffer, register, memory, or storage, such as a random access memory (RAM), a dynamic random access memory (DRAM), a static random access memory (SRAM), a synchronous dynamic random access memory (SDRAM), a flash storage, an erasable programmable read-only-memory (EPROM), an electrically erasable programmable read-only-memory (EEPROM), or the like. The buffer memory 310 may be a single port memory or a dual port memory or the like.
[0044] The buffer memory 310 preferably includes sufficient storage capacity to store a maximum amount of data to be transferred between the host system 105 and the storage devices 115 during a single read or write operation. For example, under an ATA standard, 256 sectors of 512 bytes each is the maximum amount of data read or written in response to a single ATA command. In this example, buffer memory 310 has sufficient capacity to store at least 256 sectors of data (e.g., 256 data sectors).
[0045] The read arbiter 300 and the write arbiter 305 handle requests for operations on the buffer memory 310 . Specifically, the read arbiter 300 manages requests for read operations for transferring data from the buffer memory 310 , and the write arbiter 305 manages requests for write operations for transferring data to the buffer memory 310 . In one embodiment, each of the read arbiter 300 and the write arbiter 305 is implemented using digital logic and is capable of managing three simultaneous requests received from any of the controller 200 , the host interface 210 , or the storage interfaces 220 . The read arbiter 300 and the write arbiter 305 may handle more or fewer than three simultaneous requests in other embodiments.
[0046] Priorities for granting access to buffer memory 310 may be varied depending on the design requirements of the data storage system 100 . For example, requests from the controller 200 may be given top priority followed by requests from the host interface 210 and the storage interfaces 220 . One skilled in the art will recognize that arbiters having different configurations and capacities may be used in various embodiments of the present invention.
[0047] The controller 200 may include a microprocessor, a microcontroller, an embedded controller, a logic circuit, software, firmware, or any kind of processing device. In one embodiment, the controller 200 is a microcontroller including a processor and a memory, which is programmed to execute code for performing the operations of the data storage system 100 . In other embodiments, controller 200 may include a microprocessor and a finite state machine, or may include a call processor. Although only a single controller 200 is illustrated in FIG. 2 , it is to be understood that the data management system 110 may include more than one controller 200 with various control tasks being distributed between the controllers 200 . The operation of the controller 200 will be described further below.
[0048] Some or all of the components of the data management system 110 described above may be implemented using individually packaged application specific integrated circuits (ASICs) or programmable gate arrays. For example, the host interface 210 , the storage interfaces 220 , the switch 215 , and the buffer manager 205 may be implemented using a single ASIC or a single field programmable gate array (FPGA).
[0049] The data storage system 100 further includes address maps 315 corresponding to the data channels 112 and storage devices 115 for mapping addresses of the host system 105 to addresses of the storage devices 115 . The address maps 315 may also be referred to as address translation table, logical-to-physical table, virtual-to-physical table, directory, or the like. The address maps 315 may be any type of data structure, such as a table. For example, an address map 315 may be a logical-to-physical address table, a virtual-to-physical address table, a translation table, a directory, a formula, or the like. In one embodiment, each of the address maps 315 maps logical block addresses (LBAs) of the host system 105 to physical block addresses (PBAs) of the storage device 115 corresponding to the address map 315 . In various embodiments, an LBA of the host system 105 identifies data to be transferred between the host system 105 and one or more of the storage devices 115 . A data segment is a portion of data which may comprise a data sector, two or more data sectors, or a portion of a data sector, depending on the embodiment or implementation. The address map 315 maps each data segment identified by the LBA to a PBA of one of the storage devices 115 .
[0050] In some embodiments, the address map 315 maps the data identified by an LBA of the host system 105 to respective PBAs across the storage devices 115 such that the data is striped across the storage devices 115 . In these embodiments, each of the address maps 315 maps a data block identified by an LBA of the host system 105 to a respective PBA in the storage device 115 corresponding to the address map. In this way, the each data sector in a data segment is mapped to the same storage device 115 . An advantage of mapping the data sectors of a data segment to the same storage device 115 is that an erasure operation need only be performed on that storage device 115 when a data sector in the data segment is updated in a write operation. Consequently, the number of overall erasure operations performed on the storage devices 115 is reduced, which increases the lifetimes of the storage devices 115 and the data storage system 100 .
[0051] In one embodiment, data segments are mapped to corresponding data channels 112 and storage devices 115 based on least significant bits of the LBAs of the data segments. For example, a data segment may be mapped to a data channel 112 computing a value equal to the LBA modulo the number of data channels 112 in the data storage system 100 . In one embodiment, the data storage system 100 includes four data channels 112 . In this embodiment, LBAs having two least significant bits equal to ′b00 are mapped to a first data channel 112 (e.g., data channel 112 a ), LBAs having two least significant bits equal to ′b01 are mapped to a second data channel 112 (e.g., data channel 112 b ), LBAs having two least significant bits equal to ′b10 are mapped to a third data channel 112 (e.g., data channel 112 c ), and LBAs having two least significant bits equal to ′b11 are mapped to a fourth data channel 112 (e.g., data channel 112 d ). Moreover, the data storage system 100 transfers data segments between the data management system 110 and the storage devices 115 through the data channels 112 corresponding to the LBAs of the data segments. In other embodiments, the data storage system 100 may have more or fewer than four data channels 112 , such as 2, 8, 16, 32, or any other number of channels which may not necessarily be a power of 2 in the particular embodiment.
[0052] Although FIG. 3 illustrates the address maps 315 in the buffer memory 310 , the address maps 315 may be external of the buffer memory 310 or external of the buffer manager 205 in other embodiments. In some embodiments, the address maps 315 are stored in a random access memory of the data storage system 100 . For example, the random access memory may be a static random access memory (SRAM) or a dynamic random access memory (DRAM).
[0053] In some embodiments, the data management system 110 includes a flash storage for storing the address maps 315 . In these embodiments, the data management system 110 loads the address maps 315 from the flash storage into the random access memory at the occurrence of an event, such as power-up or reset of the data management system 110 . Further, the data management system 110 stores the address maps 315 into the flash storage at the occurrence of an event, such as power-down of the data management system 110 , or during power failure. In this way, the address maps 315 are maintained in the flash storage during power-down or reset of the data management system 110 .
[0054] FIG. 4 is a block diagram of the address map 315 , in accordance with an embodiment of the present invention. The address map 315 includes logical block addresses (LBAs) 400 of the host system 105 and physical block address (PBAs) 405 of the storage device 115 corresponding to the address map 315 . In this embodiment, the address map 315 maps data segments identified by an LBA 400 of the host system 105 to respective PBAs 405 the storage device 115 corresponding to the address map 315 .
[0055] FIG. 5 is a block diagram of data segments 500 striped across the storage devices 115 , in accordance with an embodiment of the present invention. In this embodiment, the data management system 110 receives the data segments 500 a - h sequentially from the host system 105 and maps the LBAs 400 data segments 500 a - h to PBAs 405 of the storage devices 115 a - d such that the data segments 500 a - h are striped across the storage devices 115 a - d . As illustrated in FIG. 5 , the storage device 115 a contains the data segments 500 a and 500 e , the storage device 115 b contains the data segments 500 b and 500 f , the storage device 115 c contains the data segments 500 c and 500 g , and the storage device 115 d contains the data segments 500 d and 500 h.
[0056] FIG. 6 is a block diagram of the address maps 315 , in accordance with an embodiment of the present invention. In this embodiment, the address maps 315 a - d map LBAs 400 a - h of the data segments 500 a - h to PBAs 405 a - h of the storage devices 115 a - d such that the data segments 500 a - h are striped across the storage devices 115 a - d . The address map 315 a maps the LBA 400 a of the data segment 500 a to the PBA 405 a of the storage device 115 a and the LBA 400 e of the data segment 500 e to the PBA 405 e of the storage device 115 a . The address map 315 b maps the LBA 400 b of the data segment 500 b to the PBA 405 b of the storage device 115 b and the LBA 400 f of the data segment 500 f to the PBA 405 f of the storage device 115 b . The address map 315 c maps the LBA 400 c of the data segment 500 c to the PBA 405 c of the storage device 115 c and the LBA 400 g of the data segment 500 g to the PBA 405 g of the storage device 115 c . The address map 315 d maps the LBA 400 d of the data segment 500 d to the PBA 405 d of the storage device 115 d and the LBA 400 h of the data segment 500 h to the PBA 405 h of the storage device 115 d . The mappings are used as an illustrative example to describe the invention since in many data transfers, or many storage systems, there are substantially more mappings referencing a larger storage area than depicted in these examples.
[0057] In a further embodiment, the LBAs 400 of the address maps 315 are mapped to the storage devices 115 based on the least significant bits of the LBAs 400 . For example, the least significant bits of the LBAs 400 in the address map 315 a of the storage device 115 a may be equal to b′ 00 , the least significant bits of the LBAs 400 in the address map 315 b of the storage device 115 b may be equal to b′01, the least significant bits of the LBAs 400 in the address map 315 c of the storage device 115 c may be equal to b′10, and the least significant bits of the LBAs 400 in the address map 315 d of the storage device 115 d may be equal to b′ 11 . In this way, consecutive LBAs 400 are striped across the storage devices 115 based on the address maps 315 containing the LBAs 400 .
[0058] FIG. 7 illustrates data segments 500 a - d containing data sectors 505 , in accordance with an embodiment of the present invention. In this example, the data segment is a page of data as conventionally known in the art. As illustrated, each of the data segments 500 includes four data sectors 505 . Data segment 500 a includes the sequence of data sectors 505 a (Sector 0 ), 505 b (Sector 1 ), 505 c (Sector 2 ), and 505 d (Sector 3 ). Data segment 500 b includes the sequence of data sectors 505 e (Sector 4 ), 505 f (Sector 5 ), 505 g (Sector 6 ), and 505 h (Sector 7 ). Data segment 500 c includes the sequence of data sectors 505 i (Sector 8 ), 505 j (Sector 9 ), 505 k (Sector 10 ), and 505 l (Sector 11 ). Data segment 500 d includes the sequence of data sectors 505 m (Sector 12 ), 505 n (Sector 13 ), 505 o (Sector 14 ), and 505 p (Sector 15 ). In a write operation, the data segments 500 a - d are transferred from the host system 105 to the storage devices 115 according to the address map 315 . In this process, the data management system 110 associates a PBA 405 with each data sector of a data segment 500 a - d based on the LBA 400 of the data segment. In one embodiment, the first data sector 505 (e.g., sector 505 a ) in a data segment 500 (e.g., data segment 500 a ) is mapped to a PBA 405 of a storage device 115 and each subsequent data sector (e.g., sectors 505 c - d ) in the sequence of data sectors in the data segment 500 (e.g., data segment 500 a ) is mapped to an offset of the PBA 405 . For example, the least significant bits of the PBA for the first data sector may be equal to b′00, the least significant bits of the PBA for the second data sector may be equal to b′01, the least significant bits of the PBA for the third data sector may be equal to b′ 10, and the least significant bits of the PBA for the fourth data sector may be equal to b′ 11. The data management system 110 then transfers each data sector to the storage device 115 based on the PBA 405 associated with the data sector.
[0059] FIG. 8 illustrates the storage devices 115 containing data sectors, in accordance with an embodiment of the present invention. As may be envisioned from FIG. 7 , each of the data segments 500 , or pages, is stored in a corresponding storage device 115 a - d such that the data sectors 705 of a given data segment 500 are stored in the same storage device 115 according to the address map 315 of FIG. 5 . As illustrated in FIG. 8 , the storage device 115 a contains the data sectors 705 a (Sector 0 ), 705 b (Sector 1 ), 705 c (Sector 2 ), and 705 d (Sector 3 ). The storage device 115 b contains the data sectors 705 e (Sector 4 ), 705 f (Sector 5 ), 705 g (Sector 6 ), and 705 h (Sector 7 ). The storage device 115 c contains the data sectors 705 i (Sector 8 ), 705 j (Sector 9 ), 705 k (Sector 10 ), and 705 l (Sector 11 ). The storage device 115 d contains the data sectors 705 m (Sector 12 ), 705 n (Sector 13 ), 705 o (Sector 14 ), and 705 p (Sector 15 ).
[0060] While FIGS. 7 and 8 illustrate a data segment comprising a page (e.g. conventionally 4 sectors), other embodiments may utilize a data segment more or less section (e.g. 1, 2, or more sectors), or a portion of a sector.
[0061] FIG. 9 illustrates a method of transferring data in the data storage system 100 , in accordance with an embodiment of the present invention. The method represents the general operating process executed by the data storage system 100 . The process may be initiated at power up, following a reset of the data storage system 100 , or at another time as desired.
[0062] In step 900 , the controller 200 runs a diagnostic test in one or more of the storage devices 115 . The diagnostic test confirms operability and determines the current status of the storage devices 115 . The type of diagnostic test may depend upon the type of the storage device 115 and are well known to those skilled in the art. During execution of the diagnostic tests, the host interface 210 preferably provides a busy indicator to the host system 105 indicating that the data storage system 100 is currently unavailable. The method then proceeds to step 905 .
[0063] In step 905 , the controller 200 receives results of the diagnostic tests from the storage devices 115 . If a result received from any of the storage devices 115 indicates an error has occurred in the storage device 115 , the method proceeds to step 910 . Otherwise each storage device 115 provides a ready indicator to the controller 200 , and the controller 200 sends a ready indicator to the host system 105 via the host interface 210 . For example, the controller 200 may send a ready indicator to the host system 105 indicating the status (e.g., ready) of the data management system 110 . The method then proceeds to step 915 .
[0064] In step 910 , arrived at from the determination in step 905 that an error has occurred in the storage devices 115 , the controller 200 determines the type of error that has occurred and stores data representing the error, for example in an error register. The controller 200 then reports the error to host system 105 via host interface 210 . For example, the controller 200 may provide an error indicator to the host system 105 via the host interface 210 . If the controller 200 reports the error to host system 105 , the data management system 110 may perform additional operations in various embodiments. In one embodiment, the host system 105 provides a reset command to the controller 200 to attempt to clear any errors by resetting the data storage system 100 . If the error persists, or if the type of error reported to host system 105 is not likely to be cleared through a reset, the host system 105 may notify a user of the error and shut down data storage operations until the data storage system 100 is fully operational. Alternatively, if one or more of the storage devices 115 provides a ready indicator to the data management system 110 after the data storage system 100 is reset, the controller 200 reports a ready indicator to the host system 105 . The method then proceeds to step 915 .
[0065] In step 915 , arrived at from the determination in step 905 that an error has not occurred in one of the storage devices or from step 910 in which an error status has been reported to the host system 105 , the data management system 110 waits to receive a command from the host system 105 . If the data management system 110 receives a command from the host system 105 , the host interface 210 stores the command in one or more command registers and notifies the controller 200 that a command has been received. The method then proceeds to step 920 .
[0066] In step 920 , the controller 200 retrieves the command from the command registers, decodes the command, and executes the command. Possible commands include, but are not limited to, a fix data transfer command (e.g., identify drive), a write command, a read command, an erasure command, or a purge command. In response to any command either not recognized or simply not supported by the data storage system 100 , the controller 200 provides an abort command indicator to the host system 105 via the host interface 210 .
[0067] For fix data transfer commands, the controller 200 issues requests for drive information to each of the storage devices 115 via the respective storage interfaces 220 . The request format and protocol may vary depending on the type of storage device 115 and are well known to those skilled in the art. The drive information is then reported to the host system 105 via the host interface 210 . Likewise, in response to a purge command, the controller 200 issues a purge command to each of the storage devices 115 via the respective storage interfaces 220 . The format and protocol of the purge command may vary depending on the type of the storage device 115 and are well known to those skilled in the art. The method then returns to step 1015 . In an alternative embodiment, the method ends instead of returning to step 915 .
[0068] FIG. 10 illustrates a portion of a method of transferring data between the host system 105 and the storage devices 115 , in accordance with an embodiment of the present invention. This portion of the method is performed in response to the data management system 110 receiving a read command or a write command from the host system 105 . In various embodiments, this portion of the method is performed in step 920 of FIG. 9 . In this portion of the method, the controller 200 determines that the command received from the host system 105 is a read command or a write command, calculates the parameters of the data transfer based on the command, initiates the system hardware to be used in the data transfer, and initiates the data transfer. Upon completion of the data transfer, the controller 200 confirms the data transfer and provides an error report or a completion report to the host system 105 via the host interface 210 . This portion of the method is described more fully below, in which various steps of the method are described in more detail.
[0069] In step 1000 , the host interface 210 receives a command from the host system 105 and stores the command in one or more command registers. The controller 200 retrieves the command from the command registers and calculates parameters for the data transfer. The parameters of the data transfer include the logical block address (LBA) and the block count, or number of sectors, of the data to be transferred. Using these parameters, the controller 200 calculates parameters for one or more direct memory access (DMA) transfers for transferring the data between the storage devices 115 and the host system 105 . For example, each of the host interface 210 and the storage interfaces 220 may include a DMA engine used to transfer data between an internal buffer of the respective host interface 210 or storage interface 220 and the buffer manager 205 . The controller 200 provides each of these DMA engines with data transfer parameters which include addresses, a transfer count, and a transaction size. The method then proceeds to step 1005 .
[0070] In step 1005 , the controller 200 initiates the hardware to be used in the data transfer. This includes providing the respective DMA engines with the transfer parameters mentioned above. In addition, the controller 200 sends commands to the storage devices 115 via the respective storage interfaces 220 to set up the data transfer. The method then proceeds to step 1010
[0071] In step 1010 , the DMA engines of the storage interfaces 220 transfer the data to the respective storage devices 115 , and the storage devices 115 store the data. If a data error occurs in any of the storage devices 115 , the storage device 115 in which the data error occurs provides an error indicator to the controller 200 via the respective storage interface 220 . The method then proceeds to step 1015 .
[0072] In step 1015 , the controller 200 determines whether an error has occurred in any of the storage devices 115 based on whether the controller 200 receives an error indicator from any of the storage devices 115 or if a time-out condition occurs in the data transfer. If the controller 200 determines an error has occurred in one or more of the storage devices 115 , this portion of the method proceeds to step 1120 . Otherwise the controller 200 sends a ready indicator to the host system 105 via the host interface 210 and this portion of the method proceeds to step 1125 . The method then proceeds to step 1020 .
[0073] In step 1020 , arrived at from the determination in step 1115 that an error has occurred in the storage devices 115 , the controller 200 determines the type of error that has occurred and reports the error to host system 105 via the host interface 210 . For example, the controller 200 may provide an error indictor or send an error message to the host system 105 . Additionally, the controller 200 may store a representation of the error message, for example in an error register, for subsequent access by the host system 105 . The method then proceeds to step 1025 .
[0074] In step 1025 , arrived at from the determination in step 1115 that an error has not occurred in any of the storage devices 115 or from step 1120 in which an error has been reported to the host system 105 , the controller 200 reports the completion of the data transfer to the host system 105 . This portion of the method then ends. In an alternative embodiment, this portion of the method instead returns to step 915 of FIG. 9 .
[0075] FIG. 11 illustrates a portion of a method of writing data to the storage devices 115 a - d , in accordance with an embodiment of the present invention. For example, this portion of the method of transferring data from the host system 105 to the storage devices 115 may be performed in response to the data management system 110 receiving a write command from the host system 105 . In various embodiments, this portion of the method is performed during step 1010 of FIG. 10 . The data management system 110 receives data from the host system 105 and stores the data. The data management system 110 then distributes the data among the storage devices 115 and the storage devices 115 store the data. This portion of the method is described more fully below, in which various steps of the method are described in more detail.
[0076] In step 1100 , the host interface 210 receives data from the host system 105 . The data of a data unit may be any portion of the data unit. As data is received, the host interface 210 facilitates the storage of the data segments in a buffer, which may be internal or external of the host interface 210 . The host interface 210 may also receives a write command from the host system 105 along with the data segments. The method then proceeds to step 1105 .
[0077] In step 1105 , the DMA engine of the host interface 210 transfers the data to the buffer memory 310 of the buffer manager 205 based on the write command. If the buffer memory 310 is implemented using a dual port memory, the host interface 210 may be connected directly to one of the ports of the buffer memory 310 so that the DMA engine of the host interface 210 writes the data into the buffer memory 310 without going through switch 215 . Additionally, the controller 200 may be configured to directly access to the buffer manager 205 without having to go through the switch 215 . If the buffer memory 310 is implemented as a single port memory, the DMA engine of the host interface 210 transfers the data segments to buffer memory 310 via switch 215 .
[0078] In the arrangement shown in FIG. 2 , in which the host interface 210 is coupled to the buffer manager 205 via the switch 215 , access to the buffer manager 205 is granted using an arbitration scheme. Specifically, the switch 215 is controlled by the controller 200 to selectively couple the host interface 210 and the storage interfaces 220 to buffer manager 205 by alternating access to the buffer manager 205 from the host interface 210 and one of storage interfaces 220 based on an arbitration scheme. Possible arbitration schemes include, but are not limited to, a round-robin scheme, a fixed priority scheme, a dynamic priority scheme, and the like. For example, a fixed priority scheme may provide access from the host interface 210 to the buffer manager 205 and then successively provide access from each of the storage interfaces 220 to the buffer manger 205 in a predetermined order before again providing access from the host interface 210 to the buffer manager 205 .
[0079] As another example, a dynamic priority scheme may provide access from the host interface 210 and the storage interfaces 220 to the buffer manager 205 based on measured performance characteristics of the data management system 110 . In the way, performance of the data management system 110 may be optimized based on the performance characteristics. The arbitration of access by the individual storage interfaces 220 is described in more detail below. During each time slot of the arbitration scheme, the DMA engine of the host interface 210 transfers a portion of the data to the buffer manager 205 . By alternating access to the buffer manager 205 , the subsequent transfer of data to the storage devices 115 may begin prior to receiving all of the data from the host system 105 . The method then proceeds to step 1110 .
[0080] In step 1110 , the data stored in the buffer manager 205 is distributed among the storage devices 115 . In this process, data segments are individually transferred from the buffer manager 205 to one of the storage interfaces 220 . In this way, the data segments are distributed among the storage devices 115 a - d coupled to the respective storage interfaces 220 . In one embodiment, each of the storage interfaces 220 includes a DMA engine that transfers the data segments from the buffer manager 205 to the corresponding storage interface 220 in a DMA transfer.
[0081] In various embodiments, the data segments are transferred to the storage interfaces 220 using an arbitration scheme. In this process, a data segment is selected based on an arbitration scheme and are transferred to one storage interface 220 by the DMA engine of that storage interface 220 during sequential time slots. The next data segment is then selected and transferred to another storage interface 220 by the DMA engine of that storage interface 220 during sequential time slots. The arbitration scheme may include a round-robin scheme, a fixed priority scheme, a dynamic priority scheme, or any other arbitration scheme. Using the round-robin scheme for example, each of the storage interfaces 220 receives the data segments during each round of the arbitration scheme. For example, the storage interface 220 a receives a first data segment, the storage interface 220 b receives a second data segment, the storage interface 220 c receives a third data segment, and the storage interface 220 d receives a fourth data segment. The process is then repeated until all of the data segments are transferred from the host system 105 to the storage interfaces 220 .
[0082] In one embodiment, the data segments are routed to particular storage interfaces 220 using a static routing algorithm controlled by the controller 200 . In this process, a given data segment is sent to the same storage interface 220 for storage in a respective storage device 115 . For example, all of the data of a first data segment are sent to the storage interface 220 a , all of the data of a second data segment are sent to the storage interface 220 b , all of the data of a third data segment are sent to the storage interface 220 c , and all of the data for a forth data segment are sent to the storage interface 220 d . This process is repeated to distribute the data segments among the storage interfaces 220 a - d.
[0083] Access to the buffer manager 205 may be allocated between the host interface 210 and the storage interfaces 220 by using an arbitration scheme. In this way, the switch 215 is controlled to alternate access to the buffer manager 205 between the host interface 210 and the storage interfaces 220 . For example, using a round-robin scheme, the switch 215 is controlled to allow the host interface 210 to facilitate the transfer of one data segment to the buffer manager 205 , followed by the storage interface 220 a transferring one data segment out of the buffer manager 205 , followed by the host interface 210 transferring another data segment to the buffer manager 205 , and then the storage interface 220 b transferring a data segment out of buffer manager 205 . This allocation process is repeated to allow each of the storage interfaces 220 access to the buffer manager 205 with alternating access being granted to the host interface 210 .
[0084] In various embodiments, the data segments are distributed among the storage interfaces 220 based on the write command. This distribution process may promptly begin as soon as data is available in the buffer manager 205 . Alternatively, the distribution process may wait until a minimum number of data segments have been transferred and stored in the buffer manager 205 before starting the distribution process. In one embodiment, the distribution process begins once the number of data segments stored in the buffer manager 205 is sufficient to allow the transfer of data to begin for one of the storage interfaces 220 . Splitting access to the buffer manager 205 between the host interface 210 and the storage interfaces 220 allows the distribution of data segments to occur while the transfer of data into the buffer manager 205 continues until all the data segments have been received from the host system 105 .
[0085] During the data distribution process, the controller 200 monitors each of the buffers internal to the storage interfaces 220 to prevent overflow from occurring. In the event that one of the storage interfaces 220 has no capacity for receiving additional data, the controller 200 stops the transfer of data to that storage interface 220 until the buffer has recovered. During this time, data transfers from the host interface 210 into the buffer manager 205 may continue. In addition, the controller 200 uses a buffer register to monitor and control the flow of data into the buffer manager 205 . The buffer register includes one or more registers and a finite state machine. The buffer register is updated by the controller 200 to reflect the status of the buffer manager 205 . The status information in the buffer register may include a full/empty indicator, a capacity used indicator, a capacity remaining indicator, among others. The buffer register may be part of the controller 200 or the buffer manager 205 , or the buffer register may be implemented as a separate component accessible by the controller 200 . The method then proceeds to step 1115 .
[0086] In step 1115 , the data segments received by the storage interfaces 220 are transferred to the respective storage devices 115 . In this process, the storage interfaces 220 may store the data segments before the data segments are transferred to the respective storage devices 115 . This data transfer process occurs in parallel thereby providing improvements to overall storage performance of the data storage system 100 . These advantages become significant when the data transfer rates of the individual storage interfaces 220 and the storage devices 115 are slower than the data transfer rate between the host system 105 and the host interface 210 . For example, solid-state storage devices using flash memory typically have a data transfer rate slower than that of conventional hard drives. In various embodiments, an array of solid-state storage devices may be used as the storage devices 115 to provide a cumulative data transfer rate comparable to that of a typical hard disk drive. The method then proceeds to step 1120 .
[0087] In step 1120 , the storage devices 115 store the data received from the respective storage interfaces 220 . Improvements in the overall data transfer rate of the data storage system 100 are achieved when the individual components of the data storage system 100 have adequate data transfer rates. For example, in the above-described embodiment in which the switch 215 allocates access to the buffer manager 205 between the host interface 210 and the storage interfaces 220 , the switch 215 should have a data transfer rate at least twice as fast as the fastest data transfer rate of each of the storage interfaces 220 . This allows the data transfer through the data storage system 100 to be maintained without the back end data transfer to the storage devices 115 having to wait for data transfers on the front end from the host system 105 .
[0088] In one embodiment, the host interface 210 receives a write command in step 1100 along with an updated data segment for updating a selected data segment in one of the storage devices 115 . In this embodiment, the host interface 210 transfers the updated data segment to the buffer memory 310 of the buffer manager 205 in step 1105 based on the write command. In step 1110 , the controller 200 identifies the storage device 115 containing the selected data segment and transfers the updated data segment to the storage interface 220 coupled to the storage device 115 . In turn, the storage interface 220 transfers the updated data segment into the storage device 115 containing the previous data segment for replacement of the previous data segment with the updated data segment. In this process, the controller 200 may provide an erasure command to the storage device 115 for erasing the previous data segment from the storage device 115 followed by a write command for writing the updated data segment into the storage device 115 . Because the data of the updated data segment are stored in the same storage device 115 , the erasure operation occurs only in that storage device 115 . In this way, the overall number of erasure operations performed on the storage devices 115 of the data storage system 100 is reduced. Because the lifetime of each storage device 115 is inversely related to the number of erasure operations performed on that storage device 115 , reducing the number of erasure operations performed on each storage device 115 increases the lifetimes of the storage devices 115 and the data storage system 100 .
[0089] Once the data transfer is completed, this portion of the method ends. In one embodiment, the method then proceeds to step 1015 of FIG. 10 , in which it is determined if an error occurred during the data transfer. If an error occurred in any of the storage devices 115 during the data transfer, the controller 200 reports the error to host system 105 in step 1020 . If no error occurred in any of the storage devices 115 during the data transfer, the controller 200 reports the completion of the data write command in step 1025 .
[0090] An optimal number of data sectors in each data segment, and hence a preferred size of the individual data sectors, is influenced by several factors. For example, the internal data bus bandwidth of the switch 215 sets one performance limit. The internal data bus bandwidth (P) is the sum of the effective bandwidth (E), the overhead bandwidth (O), and the idle bandwidth (I) of the switch 215 . As data segment size is reduced, system overhead increases due to the increase in switching and in the number of data transfer transactions that are completed. As overhead increases, the effective bandwidth of the switch 215 decreases thereby reducing performance of the data storage system 100 .
[0091] Another factor that influences the data segment size is the capacity of internal buffers of the host interface 210 and the storage interfaces 220 , which are typically implemented as first-in-first-out (FIFO) buffers. As the data segment size increases, the internal buffers store more data prior to transferring the data. Larger buffers require larger logic circuits in the host interface 210 and storage interfaces 220 , which may not be acceptable in view of other design constraints.
[0092] Yet another factor is the back-end bandwidth available from the storage devices 115 . The back-end bandwidth is derived from a combination of the number of storage devices 115 used in the system and the individual bandwidths of the storage devices 115 . Once the effective bandwidth (E) of the switch 215 reaches the back end bandwidth of the storage devices 115 , increasing the data segment size may not result in additional significant performance improvements of the data storage system 100 .
[0093] FIG. 12 illustrates a data transfer from the host system 105 to the storage devices 115 a - d , in which data is written into the storage devices 115 a - d , in accordance with an embodiment of the present invention. For example, the data transfer from the host system 105 to the storage devices 115 a - d may be a write operation. In the data transfer, the data management system 110 receives a sequence 1200 of eight data segments 500 (e.g., data segments 500 a - h ) from the host system 105 . The eight data segments are used as for exemplary illustrative purposes to describe the invention; however, in many data transfers would involve substantially more data segments. The data management system 110 transfers a sequence of two data segments 1205 to the storage device 115 a , a sequence of two data segments 1210 to the storage device 115 b , a sequence of two data segment 1215 to the storage device 115 c , and a sequence of two data segments 1220 to the storage device 115 d . As illustrated in FIG. 12 , each of the sequences of data segments 1205 , 1210 , 1215 , and 1220 are transferred to the storage devices 115 a - d subsequent to the time slot in which the data segment 1202 is received by the data management system 110 from the host system 105 in the sequence of data segments 1200 .
[0094] Because the data transfer rate from the host system 105 to the data management system 110 is generally faster than the data transfer rate from the data management system 110 to each of the individual storage devices 115 , the transfer of each sequence of data segments 1205 , 1210 , 1215 , and 1220 overlaps the transfer of at least one other sequence of data segments 1205 , 1210 , 1215 , or 1220 in time. Stated differently, the sequence of data segments 1205 , 1210 , 1215 , and 1220 are transferred from the data management system 110 to the storage devices 115 substantially in parallel. This is possible because each of the storage interfaces 220 independently transfers a respective sequence of data segments 1205 , 1210 , 1215 , and 1220 to the respective storage devices 115 through the corresponding data channels 112 a - d after that storage interface 220 receives the first data segments 1202 of the sequence 1205 , 1210 , 1215 , or 1220 from the host interface 210 .
[0095] FIG. 13 illustrates a portion of a method of transferring data from the storage devices 115 to the host system 105 , in accordance with an embodiment of the present invention. For example, this portion of the method of transferring data from the storage devices 115 to the host system 105 may be performed in response to the data management system 110 receiving a read command from the host system 105 . In various embodiments, this portion of the method is performed during step 920 of FIG. 9 . The data management system 110 requests data segments (e.g., data segments 500 a - h ) from the storage devices 115 . The data segments are then transferred from the storage devices 115 to the respective storage interfaces 220 . The data segments are then transferred from the storage interfaces 220 to the buffer manager 205 using an arbitration scheme, such as a round-robin arbitration scheme. In this process, a data segment is selected based on the arbitration scheme and the data segments are transferred from the storage interface 220 containing the selected data segment to the buffer manager 205 during sequential time slots. The next data segment is then selected and transferred from the storage interface 220 containing this data segment to the buffer manager 205 during sequential time slots. The buffer manager 205 transfers the data segment to the host system 105 via the host interface 210 . This portion of the method is described more fully below, in which various steps of the method are described in more detail.
[0096] In step 1300 , the data segments requested by host system 105 are received by the storage interfaces 220 from the respective storage devices 115 . In one embodiment, the controller 200 receives a read command from the host system 105 via the host interface 210 and provides a read command to each of the storage devices 115 via the respective storage interfaces 220 . Each of the storage interfaces 220 then individually transfers one or more data segments to the respective storage interface 220 based on the read command received from the respective storage interface 220 . The method then proceeds to step 1305 .
[0097] In step 1305 , the storage interfaces 220 transfer the data segments to the buffer manager 205 one data segment at a time as the data segments are received from the respective storage devices 115 . In one embodiment, DMA engines of the storage interfaces 220 transfer the data segments to the buffer manager 205 based on transfer parameters provided by the controller 200 . Similar to the process described above with respect to FIG. 11 , access to the buffer manager 205 is controlled via the switch 215 using an arbitration scheme performed by the controller 200 . In this way, the storage interfaces 220 are given alternating access to the buffer manager 205 for transferring data cells according to the arbitration scheme. The method then proceeds to step 1310 .
[0098] In step 1310 , the data segments are reassembled in the buffer manager 205 into data for transfer to the host system 105 . In one embodiment, the buffer manager 205 reassembles data segments by storing data of the data segments together as they are transferred into buffer manager 205 . The method then proceeds to step 1315 .
[0099] In step 1315 , the DMA engine of the host interface 210 transfers the data segments to the host system 105 using transfer parameters provided by the controller 200 . The controller 200 allocates access to the buffer manager 205 by the host interface 210 and the storage interfaces 220 by using an arbitration scheme, such as those described above. As with the data storage process of FIG. 11 , the host interface 210 may begin transferring data to the host system 105 immediately upon buffer manager 205 receiving the first data segment from one of the storage interfaces 220 . Alternatively, the host interface 210 may wait until a minimum amount of data has been transferred to the buffer manager 205 from the storage devices 115 . In one embodiment, the controller 200 alternates access to the buffer manager 205 between the host interface 210 and the storage interfaces 220 based on an arbitration scheme. This portion of the method then ends. In one embodiment, the method then proceeds to step 1110 of FIG. 10 .
[0100] FIG. 14 illustrates a data transfer from the storage devices 115 to the host system 105 , in which data is read from the storage devices 115 , in accordance with an embodiment of the present invention. For example, the data transfer from the host system 105 to the storage devices 115 - a - d may be a read operation. In the data transfer, the data management system 110 receives eight data segments 1402 (e.g., data segments 1402 a - h ) from the respective storage devices 115 substantially in parallel. The eight data segments are used as for exemplary illustrative purposes to describe the invention; however, in many data transfers would involve substantially more data segments. The data management system 110 receives a sequence 1400 of two data segments 1402 a and 1402 e from the storage device 115 a , a sequence 1405 of two data segments 1402 b and 1402 f from the storage device 115 b , a sequence 1410 of two data segments 1402 c and 1402 g from the storage device 115 c , and a sequence 1415 of two data segments 1402 d and 1402 h from the storage device 115 d . The data management system 110 begins to transfer the data segments 1402 received from the storage devices 115 to the host system 105 once the first data segment 1402 is received from the storage devices 115 . As illustrated in FIG. 14 , the data management system 110 transfers a sequence 1420 of the data segments 1402 received from the storage devices 115 to the host system 105 . For example, the data management system 110 may transfer the sequence of data segments 1420 to the host system 105 during sequential time slots by transferring one data segment at a time during each time slot.
[0101] The foregoing description of the present invention illustrates and describes the preferred embodiments of the present invention. However, it is to be understood that the present invention is capable of use in various other combinations and modifications within the scope of the inventive concepts as expressed herein, commensurate with the above teachings, and/or the skill or knowledge of the relevant art. The embodiments described hereinabove are further intended to explain the best modes known of practicing the present invention and to enable others skilled in the art to utilize the present invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the present invention. Accordingly, the description is not intended to limit the scope of the present invention, which should be interpreted using the appended claims.
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A data storage system includes a data management system that transfers data between a host system and multiple storage devices through multiple channels. The data addressing is distributed amongst channels to improve system performance and durability. In one embodiment, each channel has an address translation table or address map which is utilized to gain performance improvement during data transfer or erasure, and an increase of the device's useful life span.
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RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 10/791,073, filed Mar. 1, 2004 now U.S. Pat. No. 7,191,388.
TECHNICAL FIELD
The present invention relates to parity calculation, and more particularly to the calculation of a diagonal interleaved parity (DIP) word.
BACKGROUND
Although modern communication protocols enable the transmission of billions of bits per second, conventional backplane switching systems and related components do not have comparable clock rates. For example, the System Packet Interface 4 (SPI4) Phase 2 (SPI4-2) protocol requires a minimum throughput rate of 10 gigabits per second over a SPI4-2 native bus having a width of 16 bits using Double Data Rate (DDR) techniques. At a throughput rate of 10 gigabits, such a bus is thus sampled at a 625 MHz rate. Because of the DDR sampling (sampling at both the rising and falling edge of the clock), the bus is clocked at 312.5 MHz. However, many application specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs) cannot achieve even a 312.5 MHz clocking rate. Thus, external SPI4-2 buses routed to such devices must be demultiplexed according to a slower single edge clock rate that is a fraction of the external 625 MHZ sampling rate for the native SPI4-2 bus. For example, an FPGA having a single edge clock rate that is ¼ th the sampling rate of the native SPI4-2 bus receives four 16-bit words (typically denoted as tokens) per FPGA clock cycle. The four tokens are then routed within the FPGA on a four-token wide bus that is clocked at the lower clock rate. In general, the native SPI4-2 bus is demultiplexed according to an FPGA clock that is 1/nth the rate of the bus clock, where n is a positive integer. As just discussed, using a value of n=4 is typical although that may be increased to, for example, a value of n=8 if the FPGA clock rate is relatively slow. At each cycle of the FPGA clock, n words or tokens are demultiplexed from the SPI4-2 native bus.
This demultiplexing of the native SPI4-2 bus causes a number of complications when implementing a SPI4-2 interface using a programmable logic device (PLD) such as an FPGA. For example, the SPI4-2 standard uses a diagonal interleaved parity (DIP) scheme for point-to-point error detection. In a SPI4-2 interface, a SPI4-2 packet such as packet 100 shown in FIG. 1 includes a variable number of sixteen-bit data words 105 that are followed by a single sixteen-bit control word 110 . Packet 100 (which may also be denoted as a SPI4-2 burst) thus does not include a control word 115 from a previously-transmitted packet. As illustrated in FIG. 1 , packet 100 includes eight data words 105 but it will be appreciated that the number of data words in a given SPI4-2 packet will vary. In other words, a receiver will not know how many data words 105 a given SPI4-2 packet contains until a control word 110 has been detected. Regardless of the number of data words 105 included in a SPI4-2 packet, the packet's end is demarcated by control word 110 .
Having received the control word 110 for packet 100 , a sixteen bit parity word 120 may be calculated using a diagonal-interleaved parity (DIP) scheme. Each bit of parity word 120 corresponds to a diagonal XOR calculation chain starting at the first data word 105 in packet 100 . For example, a diagonal exclusive OR (XOR) calculation chain 121 starts from the most significant bit (bit position 15 ) of the first data word 105 and propagates through the remaining data words 105 and control word 110 to produce the value for bit position 7 of parity word 120 . Calculation chain 121 begins with the XOR of the most significant bit of the first data word 105 and the next-most-significant bit (bit position 14 ) of the second data word 105 . As can be seen from FIG. 1 , bit position 15 of the first data word 105 holds a logical one whereas bit position 14 of the second data word 105 holds a logical zero. The XOR product is thus a logical 1. This XOR product propagates through calculation chain 121 by being XORed with the bit stored in bit position 13 of the third data word 105 , the resulting XOR product then XORed with the bit stored in bit position 12 of the fourth data word 105 , and so on, until the final XOR product is XORed with the bit stored in bit position 7 of control word 110 to produce a value for bit position 7 of parity word 120 . It may be seen that the XOR product of the resulting bit sequence {1,0,0,1,0,0,0,0,1} in calculation chain 121 produces a value of logical one for bit position 7 of parity word 120 .
The remaining diagonal XOR calculation chains are processed analogously. For example, diagonal XOR calculation chain 122 starts at bit position 14 of the first data word 105 and propagates through the remaining data words 105 and control word 110 . In chain 122 , the starting bit is XORed with the bit stored in bit position 13 of the second data word 105 . The resulting XOR product is XORed with the bit stored in bit position 12 of the third data word 105 , and so on, until the value for bit position 6 of parity word 120 is produced. Note that the least four significant bits of control word 110 are replaced with logical ones during the calculation of the least four significant bits for parity word 120 .
There will always be diagonal XOR calculation chains that must wrap around in a circular modulo-16-bit fashion. For example, diagonal XOR calculation chain 123 starts at bit position 2 of the first data word 105 before propagating through the remaining data words 105 and control word 110 . By the third data word 105 , chain 123 is at the least significant bit (bit position 0 ). Thus chain 123 must wrap around to the most significant bit (bit position 15 ) as it propagates through the fourth data word 105 .
After sixteen-bit parity word 120 has been calculated, its most significant byte is XORed with the least significant byte to produce 8-bit parity word 130 . In turn, parity word 130 is folded and the two halves XORed to produce a DIP4 parity word 135 . In this fashion, sixteen-bit parity word 120 is collapsed to produce DIP4 parity word 135 . In a receive function, DIP4 parity word 135 is compared to the original value stored in the least four significant bits of control word 110 (which had been treated as being all logical ones for the DIP calculation) to determine if the data words 105 and control word 110 were received correctly. Conversely, in a transmit function, DIP4 parity word 135 would replace these four bits in control word 110 .
The calculation of DIP4 parity word 135 becomes problematic when performed by a programmable logic device such as an FPGA as a result of the demultiplexing of the native SPI4-2 bus. Because of the demultiplexing, the position of the control word cannot be readily determined, requiring in prior approaches that a number of sets of calculation chains be calculated. As discussed previously, to implement a SPI4-2 interface in an FPGA, there will be n 16-bit words from packet 100 received for every FPGA clock cycle. Should the received packet contain more than n words, the XOR calculation chains cannot be finished in just one FPGA clock cycle. For example, assume that n equals four as discussed previously and that the packet corresponds to packet 100 of FIG. 1 . At each FPGA clock cycle, four words from packet 100 will be received into a register 200 as shown in FIG. 2 . The four words stored within register 200 may be designated word 3 through word 0 according to their sequence within packet 100 . For example, if this FPGA clock cycle is such that the beginning of packet 100 is captured, then word 3 corresponds to the first data word 105 , word 2 corresponds to the second data word 105 , word 1 corresponds to the third data word 105 , and word 0 corresponds to the fourth data word 105 . Given just these four words, it is clear that the diagonal XOR calculation chains such as chains 121 , 122 , and 123 of FIG. 1 cannot be completed during this FPGA clock cycle.
Instead, diagonal XOR calculation chains 210 will be propagated through words 3 , 2 , 1 , and 0 and the results stored such as in an inter-slice parity summing register 205 . For example, a diagonal XOR calculation chain 210 a begins at the most significant bit of word 3 and continues through bit position 14 of word 2 and bit position 13 of word 1 to include bit position 12 of word 0 . This resulting value is then stored in bit position 12 of an inter-slice parity summing register 205 . Similarly, another diagonal XOR calculation chain 210 b begins at bit position 14 of word 3 and continues through bit positions 13 of word 2 and bit position 12 of word 1 to include bit position 11 of word 0 . This resulting value is then stored in bit position 11 of inter-slice parity summing register 205 . At the next FPGA clock cycle, the values stored in inter-slice parity summing register 205 will load into the diagonal XOR calculation chains 210 . But note that it will not be known where control word 110 will be placed within register 200 . For example, with respect to packet 100 , register 200 would contain the first four data words 105 in the initial FPGA clock cycle. At the second FPGA clock cycle, register 200 would contain the next four data words. Finally, at the third FPGA clock cycle register 200 would store control word 110 . Because there were eight data words 105 preceding control word 110 in packet 100 , control word 110 would be received as word 3 in register 200 . However, if register 200 was processing a packet having nine data words 105 , then control word 110 would be received as word 2 in register 200 . It thus follows that control word 110 may be received as any one of words 3 through word 0 in register 200 , depending upon the size of the packet being processed.
Because it cannot be predicted where control word 110 will end up in register 200 , it cannot be predicted where a diagonal XOR calculation chain will end when register 200 contains control word 110 . For example, diagonal XOR calculation chain 210 a could end at any one of four extraction points 220 a , 220 b , 220 c , and 220 d , depending upon where control word 110 was received. If control word 110 is received as word 3 , diagonal XOR calculation chain 210 would end at extraction point 220 a . Alternatively, if control word 110 is received as word 2 , diagonal XOR calculation chain 210 a would end at extraction point 220 b . As yet another alternative, if control word 110 is received as word 1 , diagonal XOR calculation chain 210 a would end at extraction point 220 c . Finally, if control word 110 is received as word 0 , diagonal XOR calculation chain 210 a would end at extraction point 220 d . In this fashion, the number of XOR calculation chains 210 is increased by n times because each extraction point must be considered. For example, with respect to a value of n=4 such as used in register 200 , there would thus be four sets of diagonal XOR calculation chains, each set having 16 chains corresponding to the sixteen bits for each word in packet 100 . This is very inefficient because only one set will provide the DIP4 parity word 135 as determined by which position control word 110 ends up in register 200 . The 16-bit value from this particular set of diagonal XOR calculation chains forms parity word 120 , which is then collapsed to form DIP4 parity word 135 as discussed with respect to FIG. 1 . However, the 16-bit values from the remaining diagonal XOR calculation chain sets would be of no use with respect to forming DIP4 parity word 135 . This inefficiency is worsened as the value of n increases.
Accordingly, there is a need in the art for improved DIP parity word calculation techniques.
SUMMARY
One aspect of the invention relates to a programmable device configured to calculate a diagonal interleaved parity word for a packet formed from a sequence of data words and ending in a control word, the programmable device comprising: a plurality of programmable blocks, one or more of the programmable blocks being configured to propagate a set of diagonal XOR calculation chains through the packet to provide the diagonal interleaved parity word, the one or more programmable blocks being configured such that the diagonal XOR calculation chains have the same length regardless of the number of data words in the packet.
Another aspect of the invention relates to a method of calculating a diagonal interleaved parity (DIP) word from a packet formed from a succession of data words ordered from a first data word to a last data word, the packet ending in a control word. The method includes the acts of successively sampling a predetermined number of ordered words from a bus, wherein the first sample starts at the first data word; for each successive sample of words, determining whether the control word is included in the sample: if the control word is not included in the sample, propagating a set of diagonal XOR calculation chains through the sample; if the control word is included in the sample, assigning the words following the control word in the sample to logical zeroes and then propagating the set of diagonal XOR calculation chains through the sample to provide a DIP parity word.
In accordance with another aspect of the invention, a programmable device is provided that is configured to calculate a diagonal interleaved parity (DIP) word from a packet formed from a sequence of data words arranged from a first data word through a last data word, the packet ending in a control word. The programmable device includes: a plurality of programmable blocks, one or more of the programmable blocks being configured to sequentially process the packet by sampling an external bus an ordered sample of words at a time to form a first ordered sample through a last ordered sample, the first ordered sample beginning with the first data word, the last ordered sample containing the control word, wherein any words following the control word in the last ordered sample are assigned to logical zeroes, the one or more programmable blocks being configured to sequentially process the ordered samples by propagating a set of diagonal XOR calculation chains through each ordered sample to produce an intermediate DIP word and then adjusting the intermediate DIP word according to the number of words assigned to logical zeroes in the last ordered sample to produce a second DIP parity word.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the XOR calculation chains necessary to calculate a DIP4 parity word for a SPI4-2 packet comprised of eight data words and one control word.
FIG. 2 illustrates the implementation of a DIP4 parity word calculation in a programmable logic device that demultiplexes four words from a SPI4-2 packet at each programmable logic device clock cycle.
FIG. 3 is a flowchart for a DIP parity word calculation scheme according to one embodiment of the invention.
FIG. 4 illustrates a 4-input AND implementation for checking a DIP parity word according to one embodiment of the invention.
FIG. 5 is a block diagram of an FPGA that may be configured to implement the DIP parity word calculation scheme of FIG. 3 . Use of the same reference symbols in different figures indicates similar or identical items.
DETAILED DESCRIPTION
The diagonal interleaved parity (DIP) calculation techniques disclosed herein will be described with respect to a SPI4-2 implementation, wherein each packet is comprised of sixteen-bit words such as those discussed with respect to packet 100 of FIG. 1 . However, it will be appreciated that the calculation techniques disclosed herein are widely applicable to any arbitrary word width. Moreover, the DIP calculation need not be performed with respect to the SPI4-2 standard, any standard needing a DIP parity word calculation would benefit from the techniques discussed herein.
As discussed with respect to FIG. 2 , any system implementing a SPI4-2 standard that cannot process the tokens within a SPI4-2 packet at the rate of the native SPI4-2 bus will need to demultiplex the bus at a clock rate that is 1/nth the rate of bus' clock rate, where n is a positive integer. A typical value for n is four but eight may also be necessary if the bus clock rate is too high with respect to the system's clock rate. In the following discussion, the system will be assumed to be a field programmable gate array (FPGA) but it will be appreciated that the DIP parity word calculation disclosed is widely applicable to any system that must demultiplex the native SPI4-2 bus during the calculation of the DIP parity word.
At each FPGA clock cycle, n sixteen-bit SPI4-2 words (typically denoted as “tokens”) are demultiplexed from the native SPI4-2 bus. To avoid the inefficiencies discussed with respect to prior art DIP parity word calculation schemes, only one set of sixteen diagonal XOR calculation chains (one for each bit in the sixteen-bit words) need be used to generate DIP4 parity word 135 shown in FIG. 1 . Thus, regardless of the value of n, the number of diagonal XOR calculation chains remains the same. This is very efficient when compared to prior art schemes that require n sets of diagonal XOR calculation chains, each set comprised of sixteen diagonal XOR calculation chains.
To enable the use of just one set of diagonal XOR calculation chains, the present invention exploits the following property of the XOR function: a diagonal XOR calculation chain will not have its value changed by propagating through additional bits, so long as those additional bits are all logical zeroes. In other words, if a diagonal XOR calculation chain has a value of logical zero and is XORed with another logical zero, the result is still logical zero. Similarly, if a diagonal XOR calculation chain has a value of logical one and is XORed with another logical zero, the result is still logical one. In formal terms, logical zero is the identity element for an XOR operation.
This property of logical zero with respect to the XOR operation may be exploited as follows. During each FPGA clock cycle, the n words received from the demultiplexing of the native SPI4-2 bus are examined. As discussed with respect to FIG. 2 for register 200 , these n words have an inherent order with respect to how they were carried on the native SPI4-2 bus. In other words, to acquire the set of n words for each demultiplex cycle (or equivalently, each FPGA clock cycle) first one word is received from the native SPI4-2 bus, then another, and so on, until all n words are received. For example, word 3 is the first word received with respect to register 200 of FIG. 2 , word 2 is the second word received, word 1 is the third word received, and word 0 is the last word received. This order should be maintained for each set of n words so that the XOR calculation chains may be formed properly. But recall that it cannot be predicted ahead of time what position control word 110 will have in this order. Instead, control word 110 may arrive as any one of the n words. Any words arriving after control word 110 have no bearing on the calculation of DIP4 parity word 135 . Thus, the identity property of logical zero with respect to an XOR calculation may be exploited by assigning all words that arrive after control word 110 to comprise all logical zeroes.
For example, assume with respect to register 200 that control word 110 is received as word 1 . The bits within word 0 would then be assigned to be all logical zeroes to complete the values within register 200 . However, diagonal XOR calculation chains 210 continue through word 0 as described previously. Consider diagonal XOR calculation chain 210 a . Because only one set of diagonal XOR calculation chains will be used, diagonal XOR calculation chain 210 a need not be complicated with the possible extraction points 220 a , 220 b , and 220 c discussed with respect to prior art applications. Instead, diagonal XOR calculation chain 210 a would have just a single extraction point 220 d.
The same extraction point 220 d would be used for the remaining diagonal XOR calculation chains 210 . Because it is assumed in this example that control word 110 is received as word 1 in register 200 , the prior art extraction point 220 c provides the correct value for sixteen-bit parity word 120 . If the correct value for sixteen-bit parity word 120 is assumed to be [1100100111101001] as shown in FIG. 2 , these values are shifted to the right in a circular modulo-16-bit fashion by 1 a continuing to propagate the diagonal XOR calculation chains through word 0 before extraction at point 220 d . This would produce a value for sixteen-bit parity word 120 as [1110010011110100]. Thus, sixteen-bit parity word 120 must then be shifted back to the left in a circular modulo-16-bit fashion to recover the correct value. Parity word 120 may then be collapsed to produce DIP4 parity word 135 as discussed previously.
The resulting DIP calculation technique may be summarized with respect to FIG. 3 . At step 300 , n words are demultiplexed from the native SPI4-2 bus. For example, with respect to register 200 , words 3 through 0 are received. Then, at step 305 , the n words are examined to see if control word 110 has been received. If control word has not been received, the diagonal XOR calculation chains may be propagated through the n words in a conventional fashion and the result stored such as in inter-slice summing register 205 at step 310 . If, however, the control word 110 was received, then words received after control word 110 in the set of n words are set to all logical zeroes at step 315 . The diagonal XOR chains may then be propagated through the resulting n words to produce a value for an intermediate 16-bit parity word 120 at step 320 . At step 325 , 16-bit parity word 120 is shifted to the left one bit for each word that was set to all logical zeroes in step 315 . After this adjustment, 16-bit parity word 120 may be collapsed into a second DIP parity word such as DIP4 parity word 135 in step 330 .
Although the just-described technique is very efficient with respect to having just a single extraction point for the diagonal XOR calculation chains, additional improvements may be carried out. For example, if n equals eight, 16-bit parity word 120 may have to be shifted up to 7 bit positions. Three bits are required to code for this value. But note that 16-bit parity word 120 will be collapsed into four-bit DIP4 parity word 135 . Thus, these potential shifts of up to 7 bit positions will be folded into one of three possible values. For example, if 16-bit parity word 120 must be shifted to the left by one bit position, this operation is equivalent to shifting DIP4 parity word 135 to the left by one position also. Similarly, if 16-bit parity word 120 must be shifted to the left by either 2 or 3 bit positions, such operations are equivalent to shifting DIP4 parity word 135 to the left by 2 or 3 bit positions, respectively. If 16-bit parity word 120 must be shifted by four bit positions, such an operation is equivalent to shifting DIP4 parity word 135 by no bit positions. However, if 16-bit parity word 120 must be shifted by five bit positions, such an operation is equivalent to shifting DIP4 parity word 135 by one bit position. Thus, it may be summarized that the number of bit positions that 16-bit parity word 120 must be shifted by may be converted to a 2-bit value in a circular modulo-2-bit fashion. Then, rather than shift 16-bit parity word 120 , DIP4 parity word 135 is shifted by the converted bit value. In this fashion, the adjustment of from 1 to seven bits is converted by 12 to just one to 3 bits, making the required logic simpler to implement.
As described so far, the DIP4 parity word 135 calculation techniques may be used for either a transmit or a receive operation. In a transmit operation, DIP4 parity word 135 is calculated and then inserted into the least four significant bit positions of control word 110 . The seed values of all logical ones in these bit positions are thus replaced by DIP4 parity word 135 . In a receive operation, DIP4 parity word 135 would be compared to the original values of those bit positions in control word 110 to determine if the SPI4 packet had been received correctly.
The receive operation may be modified further for additional simplification. For example, rather than replace the last four bits of control words with logical ones as discussed with respect to FIG. 1 , the received values may be used instead. In such a case, DIP4 parity word 135 will simply equal the seed values of all logical ones if the SPI4-2 packet has been received correctly. The check of DIP4 parity word 135 may then be minimized to the use of a 4-input AND gate 405 as seen in FIG. 4 rather than a comparison between a calculated and a received value. If AND gate 405 outputs a logical one, the received packet was correct. Otherwise, if AND gate 405 outputs a logical zero, the received packet contained one or more errors.
To implement the above-described technique, an FPGA need only be configured correctly and have the appropriate registers. For example, an FPGA 500 shown in FIG. 5 contains a plurality of logic blocks 505 . Suppose FPGA 500 is being used for a demultiplex rate of n=4 as described with respect to FIG. 2 . Inter-slice summing register 205 and register 200 are not shown in FPGA 500 for ease of illustration. Logic blocks 505 would be configured with the appropriate logic to carry out the required intermediate XOR calculation chains 210 . For example, with respect to the implementation of two of diagonal XOR calculation chains 210 , logic blocks 505 may be configured according to the following RTL statement:
par_sum_reg[0]=par_sum_reg[4]^rdata[0]^rdata[17]^rdata[34]^rdata[51] par_sum_reg[15]=par_sum_reg[3]^rdata[15]^rdata[16]^rdata[33]^rdata[50] where par_sum_reg[n] represents the nth bit stored in inter-slice summing register 205 , rdata[n] represents the nth bit stored in register 200 , and A represents an XOR operation.
The above-described embodiments of the present invention are merely meant to be illustrative and not limiting. For example, although described as being implemented in an FPGA, it will be appreciated that the DIP parity calculation techniques disclosed herein are equally applicable to an ASIC implementation of SPI4-2 interface. It will thus be obvious to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. Accordingly, the appended claims encompass all such changes and modifications as fall within the true spirit and scope of this invention.
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A method of calculating a diagonal interleaved parity word for groups of words sampled from a bus is provided, wherein a predetermined number of words are included in each sampling cycle. The bus carries successive data words that are followed by a control word. At each sampling cycle, diagonal XOR calculations chains are propagated through the words that were sampled. However, if a sampling cycle includes the control word, the words following the control word are assigned to logical zero values. The diagonal XOR calculation chains may then be terminated after processing the words in this sampling cycle to derive an intermediate diagonal parity word. The intermediate diagonal parity word may then be adjusted according to the number of words that were assigned logical zero values to calculate a second diagonal interleaved parity word.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. Patent Application No. 61/948,850, filed on Mar. 6, 2014, the entirety of which is hereby incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to fasteners. In particular, the present invention relates to a drive spike for driving into a substrate and preventing inadvertent removal of the drive spike from the substrate.
BACKGROUND
[0003] Many types of fasteners are known in the art for firmly holding a variety of components together. For example, railroad drive spikes are used to hold tie plates to wooden ties. Drive spikes may also be used to hold together bridges, trestles, wooden piers, and docks.
[0004] Typically, for railways, the steel rails have mounting flanges adapted to mate with metallic plates. The metallic plates also contact the wooden ties and are adapted to receive drive spikes to secure the rails to the ties. The spikes are inserted through openings or recesses in the metal plate and driven into the wooden ties. Thus, the steel rails are secured to the wooden ties via the metal plates and the drive spikes.
[0005] In use, the drive spikes eventually loosen from the wooden ties as a result of events such as repeated train crossings and environmental conditions. The weight and vibrations from the passing trains cause the spikes to loosen and enlarge the entry holes within the wooden ties. Environmental conditions such as humidity, temperature changes, rain, snow, etc. may also cause the drive spikes to become loosed within the wooden ties. Additionally, vandals may purposely loosen or remove the drive spikes. As the drive spikes become loose, the holes into which the drive spikes are inserted in the wooden ties enlarge. The enlarged holes then become further exposed to environmental conditions, causing the wood to decay more quickly.
[0006] Tightening or replacement of the drive spikes is often difficult and costly. Removal of a drive spike may cause further destruction to the wooden tie, making the replacement of the drive spike nearly impossible. Once the drive spike is loosened and/or the wood becomes damaged, the entire wooden tie often requires replacement in order to provide a steel rail that is securely fastened to the wooden tie.
[0007] Similar to the railway example, the bridge, trestle, pier and dock drive spike connections are also subject to vibrational and environmental stresses, as well as vandalism, that cause unwanted loosening of the drive spikes within the substrate. Once the drive spike loosens, the substrate into which the spike is driven usually must be replaced in order to securely fasten the bridge, trestle, etc. to the substrate. Replacement of the drive spike itself is generally insufficient to securely fasten objects to the substrate. The enlarged hole in the substrate causes the substrate to become more quickly degraded and thus prevents the drive spike from securely gripping the substrate.
[0008] Therefore, it is an object of the present invention to provide a drive spike that securely fastens an object to a substrate, such as wood, and prevents inadvertent loosening or removal of the drive spike from the substrate, thus further reducing the requirement for replacement of the substrate due to damage caused by the insecure fastening of an object to a substrate.
BRIEF SUMMARY
[0009] In order to alleviate one or more shortcomings discussed above, a drive spike is provided herein.
[0010] A fastener is provided. The fastener includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the annular flange. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section.
[0011] In some embodiments, a fastener is provided that includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis and an abutment surface adapted to abut a substrate into which the fastener is driven. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the head portion. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section.
[0012] In some embodiments, a fastener is provided that includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a first section extending along at least a portion of the shank and disposed adjacent to the annular flange, the first section having a first diameter. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the first section. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The smooth section has a second diameter that is smaller than the first diameter. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section.
[0013] Advantages of the present invention will become more apparent to those skilled in the art from the following description of the preferred embodiments of the invention which have been shown and described by way of illustration. As will be realized, the invention is capable of other and different embodiments, and its details are capable of modification in various respects. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a side elevational view of a fastener according to some embodiments;
[0015] FIG. 2 is a side elevational view of a fastener according to some embodiments;
[0016] FIG. 3 is a side elevational view of a fastener according to some embodiments;
[0017] FIG. 4 a top plan view of FIG. 1 ;
[0018] FIG. 5 is a sectional view through line A-A of FIG. 2 ; and
[0019] FIG. 6 is a sectional view through line B-B of FIG. 2 .
DETAILED DESCRIPTION
[0020] FIG. 1 shows a fastener 10 in the form of a drive spike, according to some embodiments. The lengths and diameters of the fastener 10 described herein are meant to be non-limiting examples and may be varied as will be understood by one of skill in the art.
[0021] The fastener 10 includes an elongated shank 20 , a head 22 at a first end portion 24 of the shank 20 and a tip 26 at a second end portion 28 of the shank 20 . The tip 26 may be any shape, including blunt and pointed. The fastener 10 has a longitudinal axis 30 extending from the first end portion 24 to the second end portion 28 .
[0022] The head 22 further comprises an annular flange 32 that extends radially from the shank 20 . The annular flange 32 may include a dome-shaped upper surface 34 and a flattened lower surface 36 that extends radially beyond the shank 20 . The head 22 may further comprise a protrusion 37 that extends from the first end portion 24 of the shank 20 . The protrusion 37 may be hemispherical in shape and adapted to be engaged by a striking tool to drive the fastener 10 into a substrate S. The protrusion 37 is adapted to receive significant force and is further adapted to deform as a result of the striking force.
[0023] The head 22 also comprises an outer surface 38 adapted to be engaged by a gripping tool such as a wrench or a socket that may be used to apply torque to the fastener 10 to drive the fastener 10 into the substrate S. In some embodiments, the outer surface 38 may be polygonally shaped. However, the outer surface 38 may be any shape that may be used with a variety of tools. Alternatively, the outer surface 38 does not need to be engaged to drive the fastener 10 into the substrate S. For example, a hole may be pre-drilled in the substrate S and the fastener 10 may be driven into the substrate S using a striking tool to strike the protrusion 37 of the head 22 and thereby insert the fastener 10 into the substrate S. As described below, additional features of the fastener 10 facilitate insertion of the fastener 10 into the substrate S using a driving force. FIG. 4 shows a top view of the head 22 of the fastener 10 , according to some embodiments. By way of non-limiting example, the head 22 may have a square cross sectional shape having sides extending radially outwardly from the longitudinal axis 30 . Each side may extend about 0.75 to about 0.81 inches in some embodiments.
[0024] As shown in FIGS. 1 and 2 , the annular flange 32 extends radially from the longitudinal axis 30 of the fastener 10 . In some embodiments, the annular flange 32 extends beyond the circumference of the shank 20 . As shown in FIGS. 1 and 2 , the annular flange 32 has a diameter D 1 that is greater than a diameter D 2 of a threaded portion of the shank 20 (described below). In some embodiments, the fastener 10 further includes a first section 40 adjacent to the annular flange 32 . The first section 40 may be cylindrically shaped and have a smooth surface. The first section 40 may also be polygonally shaped or may include one or more flattened sides. In some embodiments, the first section 40 is positioned directly adjacent to the annular flange 32 . The first section 40 includes an abutment surface 42 positioned apart from the annular flange 32 . The abutment surface 42 is configured to abut the substrate S into which the fastener 10 is driven so that the first section 40 is positioned above the substrate S when the fastener 10 has been driven into the substrate S. The abutment surface 42 has a diameter that is wider than the cavity of the tie plate so that it rests on the tie plate bearing surface. The first section 40 has a diameter D 3 that is less than the diameter D 1 of the annular flange 32 and greater than the diameter D 2 of the shank 20 .
[0025] By way of non-limiting example, the diameter D 1 may be about 1.75 inches, the diameter D 2 may be about 0.94 inches, and the diameter D 3 may be about 1.25 inches. In some embodiments, the diameter D 1 is about 1.9 times wider than the diameter D 2 , and the diameter D 1 is about 1.4 times wider than diameter D 3 . In some embodiments, diameter D 3 is about 1.3 times wider than the diameter D 2 . The first section 40 may be sized and shaped to receive a tool (not shown) to remove the fastener 10 from the substrate S. The smaller diameter D 3 of the first section 40 relative to the diameter D 1 of the annular flange 32 allows the tool to contact the lower surface 36 of the annular flange 32 that is positioned above the substrate S so that the tool can pull the fastener 10 out of the substrate S. A length L 1 of the first section 40 may be provided so that the tool fits between the substrate S and the lower surface 36 of the annular flange 32 . By way of non-limiting example, the length L 1 may be about 0.38 inches.
[0026] As shown in FIGS. 1 and 2 , the fastener 10 may also include a knurled section 44 adjacent to the first section 40 so that the first section 40 is between the annular flange 32 and the knurled section 44 . In some embodiments, the knurled section 44 is disposed between the first section 40 and a smooth section 46 . The knurled section 44 may be cylindrically shaped and may include a plurality of axial grooves 45 and peaks 47 as shown in the cross sectional view in FIG. 4 . In some embodiments, the peaks 47 may include a leading edge. The knurled section 44 is configured to allow the fastener 10 to be driven into the substrate S and to resist removal of the fastener 10 from the substrate S. The knurled section 44 has a diameter D 4 measured at the peaks 47 that is slightly larger than the diameter D 2 and the diameter D 5 and less than the diameter D 3 . By way of non-limiting example, the diameter D 4 may be about 0.97 inches and the length L 2 of the knurled section 44 may be about 1.5 inches. For the knurled section 44 having a diameter of D 4 of about 0.97 inches, the number of peaks 47 is greater than 40. The peaks 47 may all be equal in size and shape extending around the shank 20 . In some embodiments, the depth of grooves 45 may be about 0.025 inches to about 0.035 inches. In some embodiments, the peaks 47 extend substantially parallel to the longitudinal axis 30 of the shank 20 .
[0027] The shank 20 may also include a smooth section 46 adjacent to the knurled section 44 . In some embodiments, the knurled section 44 is directly adjacent to the smooth section 46 . The smooth section 46 may be cylindrically shaped and have a smooth surface. The smooth section 46 may also be polygonally shaped or may include one or more flattened sides. In some embodiments, the smooth section 46 is free from knurls, protrusions and threads. The smooth section 46 has a diameter D 5 that is less than the diameter D 1 and the diameter D 3 . In some embodiments, the diameter D 5 is about substantially the same as the diameter D 2 of the shank 20 . By way of non-limiting example, the diameter D 5 may be about 0.94 inches. The smooth section 46 is configured to be positioned within the substrate S. A length L 3 of the smooth section 46 may be about 0.25 inches. In some embodiments, a shank transition section (not shown, see FIG. 3 ) may be included between the smooth section 46 and the knurled section 44 . The shank transition section may be a result of manufacturing and machining tolerances, limitations, and capabilities where the knurled section 44 does not extend all the way to the smooth section 46 .
[0028] The shank 20 may also include a transition section 48 extending between the knurled section 44 and a threaded portion 50 . In some embodiments, the transition section 48 tapers inward from the knurled section 44 to the threaded portion 50 so that the threads 52 can be rolled on the threaded portion 50 . In some embodiments, the transition section 48 is disposed between the smooth section 46 and the threaded portion 50 . In some embodiments, the transition section 48 has a length L 4 of about 0.2 inches. In some embodiments, the transition section 48 may have a length L 4 that is less than about 0.1 inches.
[0029] The shank 20 also includes a threaded portion 50 that includes one or more threads 52 . In some embodiments, the threads 52 may be helical fluted threads as shown in FIG. 1 . The threads 52 extend from the transition section 48 to about the tip 26 of the shank 20 . The angle at the end of the threads 52 may be about 40° to about 50°, more preferably about 45°. In some embodiments, the threaded portion 50 may include 4 fluted threads 52 .
[0030] FIG. 5 is a sectional view through line A-A of FIG. 2 . As shown in FIG. 5 , in some embodiments, a width 62 of each helical turn of the threads 52 is about 0.5 inches, although any width may be used. In some embodiments, a depth 64 of the threads 52 protruding from the shank 20 is about 0.13 inches, although any depth may be used.
[0031] In some embodiments, a length L 5 of the head 22 and the first section 40 and the protrusion 37 is about 1.38 inches. The protrusion 37 extends about 0.13 inches above the head 22 . The length L 5 represents the length that is positioned above the substrate S. The length L 6 of the shank 20 from the knurled section 44 to the tip 26 is about 6.5 inches. The length L 6 represents the length of the fastener 10 that is inserted into the substrate S. In some embodiments, the length of the fastener 10 may be about 7.88 inches and the knurled section 44 may be about ⅕ of the length of the fastener 10 . In some embodiments, the length L 6 may be about 4.7 times longer than the length L 5 . In some embodiments, the knurled section 44 may be spaced about 1.13 inches from the first section 40 . In some embodiments, the first section 40 may be about 1/21 of the length of the fastener 10 . In some embodiments, the length of the smooth section 46 may be about 1/32 of the length of the fastener 10 . In some embodiments, the length of the transition section 48 may be about 1/39 the length of the fastener 10 . Other lengths and diameters for each of the dimensions described herein may be used and remain within the scope of the invention.
[0032] In some embodiments, the fastener 10 comprises a metal, more preferably iron or steel, most preferably carbon steel, for example C1035. Any material suitable for forming and having sufficient strength for the fastener may be used as will be understood by one of skill in the art.
[0033] FIG. 3 shows a fastener 100 in the form of a drive spike, according to some embodiments. The lengths and diameters of the fastener 100 described herein are meant to be non-limiting examples and may be varied as will be understood by one of skill in the art.
[0034] The fastener 100 includes an elongated shank 120 , a head 122 at a first end portion 124 of a shank 120 and a tip 126 at a second end portion 128 of the shank 120 . The tip 126 may be any shape, including blunt and pointed. The fastener 100 has a longitudinal axis 130 extending from the first end portion 124 to the second end portion 128 .
[0035] The head 122 further comprises an annular flange 132 that extends radially from the shank 120 . The annular flange 132 may include a dome-shaped upper surface 134 and a flattened lower surface 136 that extends radially beyond the shank 120 . Although not featured, the head 122 may further include a protrusion that extends from the first end portion 124 of the shank 120 . The protrusion may be hemispherical in shape and adapted to be engaged by a striking tool to drive the fastener 100 into a substrate S 11 . The protrusion is adapted to receive significant force and is further adapted to deform as a result of the striking force.
[0036] The head 122 also comprises an outer surface 138 adapted to be engaged by a gripping tool such as a wrench or a socket that may be used to apply torque to the fastener 100 to drive the fastener 100 into the substrate S 11 . In some embodiments, the outer surface 138 may be polygonally shaped. However, the outer surface 138 may be any shape that may be used with a variety of tools. Alternatively, the outer surface 138 does not need to be engaged to drive the fastener 100 into the substrate S 11 . For example, a hole may be pre-drilled in the substrate S 11 and the fastener 100 may be driven into the substrate S 11 using a striking tool to strike the head 122 and thereby insert the fastener 100 into the substrate S 11 . As described below, additional features of the fastener 100 facilitate insertion of the fastener 100 into the substrate S 11 using a driving force. By way of non-limiting example, the head 122 may have a square cross sectional shape having sides extending radially outwardly from the longitudinal axis 130 . Each side may extend from about 0.82 to about 0.88 inches in some embodiments.
[0037] As shown in FIG. 3 , the annular flange 132 extends radially from the longitudinal axis 130 of the fastener 100 . In some embodiments, the annular flange 132 extends beyond the circumference of the shank 120 . As shown in FIG. 3 , the annular flange 132 has a diameter D 11 that is greater than a diameter D 12 and diameter D 13 of a threaded portion 150 of the shank 120 (described below). The annular flange 132 has a bottom surface 136 . The bottom surface 136 of the annular flange 132 comprises an abutment surface configured to abut the substrate S 11 into which the fastener 100 is driven so that the annular flange 132 is positioned above the substrate S 11 when the fastener 100 has been driven into the substrate S 11 . The annular flange 132 has a diameter that is wider than the cavity of the tie plate so that it rests on the tie plate bearing surface.
[0038] By way of non-limiting example, the diameter D 11 may be about 1.75 inches and the diameter D 12 may be about 0.94 inches. The shank 120 may have an inner diameter D 13 . The inner diameter D 13 may be about 0.69 inches. In some embodiments, the diameter D 11 is about 1.9 times wider than the diameter D 12 , and the diameter D 11 is about 2.5 times wider than the inner diameter D 13 . In some embodiments, the diameter D 12 is about 1.4 times wider than the inner diameter D 13 .
[0039] As shown in FIG. 3 , the fastener 100 may also include a knurled section 144 adjacent to the annular flange 132 . In some embodiments, a shank transition section 140 may be included between the annular flange 132 and the knurled section 114 . The shank transition section 140 may be a result of manufacturing and machining tolerances, limitations, and capabilities where the knurled section 144 does not extend all the way to the annular flange 132 . The shank transition section 140 has a diameter that is less than diameter D 11 of the annular flange 132 . Although not featured in FIG. 3 , the fastener may not include a shank transition section, according to some embodiments. In some embodiments, the knurled section 144 is disposed between the shank transition section 140 and a smooth section 146 . In some embodiments, the smooth section 146 is free from knurls, protrusions and threads. In some embodiments, the smooth section 146 has a length L 12 of about 0.2 inches. The knurled section 144 may be cylindrically shaped and may include a plurality of axial grooves and peaks. In some embodiments, the peaks may include a leading edge. The knurled section 144 is configured to allow the fastener 100 to be driven into the substrate S 11 and to resist removal for the fastener 100 from the substrate S 11 . The knurled section 144 has a diameter D 14 measured at the peaks that is slightly larger than the diameters D 12 , the inner diameter D 13 , and the diameter D 15 and less than the diameter D 11 . By way of non-limiting example, the diameter D 14 may be about 0.97 inches and a length L 11 of the knurled section 144 may be about 1.5 inches. For the knurled section 144 having a diameter D 14 of about 0.97 inches, the number of peaks is greater than 40 . The peaks may all be equal in size and shape extending around the shank 120 . In some embodiments, the depth of the grooves may be about 0.025 inches to about 0.035 inches. In some embodiments, the peaks extend substantially parallel to the longitudinal axis 130 of the shank 120 .
[0040] In some embodiments, the shank 120 may also include a transition section (not shown) similar to the transition section 48 shown in FIG. 1 and described above. The transition section extends between the smooth section 146 and a threaded portion 150 . In some embodiments, the transition section tapers inward from the knurled section 144 to threaded portion 150 so that the threads 152 can be rolled on the threaded portion 150 . In some embodiments, the transition section has a length L 12 that is less than about 0.1 inches.
[0041] The shank 120 also includes the threaded portion 150 that includes one or more threads 152 . In some embodiments, the threads 152 may be helical fluted threads as shown in FIG. 3 . The threads 152 extend from the smooth section 146 or the transition section where included to about the tip 126 of the shank 120 . The angle at the end of the threads 152 may be about 40° to about 50°, more preferably about 45°. In some embodiments, the threaded portion 150 may include 4 fluted threads 152 .
[0042] Similar to FIG. 5 , the width of each helical turn of the threads 152 at A 10 -A 10 is about 0.5 inches, although any width may be used. In some embodiments, a depth of the threads 152 protruding from the shank 120 is about 0.13 inches, although any depth may be used.
[0043] In some embodiments, a length L 13 of the head 122 is about 1.25 inches. In some embodiments, the length of the outer surface 138 of the head 122 is about 0.88 inches. A Length L 13 represents the length that is positioned above the substrate S 11 . The length L 14 of the shank 120 from the knurled section 144 to the tip 126 is about 6.5 inches. The length L 14 represents the length of the fastener 100 that is inserted into the substrate S 11 . In some embodiments, the length of the fastener 100 may be about 7.75 inches and the knurled section 144 may be about ⅕ of the length of the fastener 100 . In some embodiments, the length L 14 may be about 5.2 times longer than the length L 13 . In some embodiments, the length of the smooth section 146 may be about 1/32 of the length of the fastener 100 . Other lengths and diameters for each of the dimensions described herein may be used and remain within the scope of the invention.
[0044] In some embodiments, the fastener 100 comprises a metal, more preferably iron or steel, most preferably carbon steel, for example C1035. Any material suitable for forming and having sufficient strength for the fastener may be used as will be understood by one of skill in the art.
[0045] Although the invention herein has been described in connection with a preferred embodiment thereof, it will be appreciated by those skilled in the art that additions, modifications, substitutions, and deletions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
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A fastener is provided. The fastener includes an elongated shank having a longitudinal axis. The fastener also includes a head portion formed at a first end of the shank. The head portion includes an annular flange extending radially from the longitudinal axis. The fastener also includes a knurled section extending along at least a portion of the shank and disposed adjacent to the annular flange. The knurled section includes a plurality of grooves circumferentially surrounding the portion of the shank. The fastener also includes a smooth section extending along at least a portion of the shank and disposed adjacent to the knurled section. The fastener also includes a helical threaded portion extending axially along at least a portion of said shank toward a second end of the shank and disposed adjacent to the smooth section.
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BACKGROUND OF THE INVENTION
The present invention generally relates to railroad grade crossing safety systems and more particularly relates to on-board railroad grade crossing safety systems.
In the past, numerous steps have been taken to help reduce accidents between trains and automobiles at railroad grade crossings. One step commonly used is to provide railroad grade crossing barriers or barricades which extend across the roadway as a train approaches and crosses the grade crossing. This would be considered a protected grade crossing. These barricades are usually associated with flashing red lights to catch the attention of approaching motorists. While these barricades are very helpful at reducing automobile to train collisions, they are expensive, and it is often viewed as cost prohibitive to place these barricades at every railroad grade crossing. One method that has been used in the past to help reduce automobile/train collisions is to require the locomotive engineer to sound a loud horn as the train approaches every grade crossing. While this approach of sounding a horn at a grade crossing has been helpful, the primary benefit is for trains which are approaching a grade crossing, and it does very little to help with collisions between automobiles and a rear section of the train. Every year numerous automobiles drive into the side of a train occupying a grade crossing, especially during times of low visibility, such as snow, fog, or a late-night rainstorm, etc.
Consequently, there exists a need for improved railroad grade crossing systems which help reduce collisions occurring between automobiles and rear sections of a train as it passes an unprotected railroad grade crossing.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide enhanced railroad grade crossing safety.
It is a feature of the present invention to include running lights disposed on railcars.
It is an advantage of the present invention to warn automobiles of the existence of all sections of a train as it crosses a railroad grade crossing.
It is another object of the present invention to enhance railroad safety in an economically efficient manner.
It is another feature of the present invention to utilize a power line extending between the railcars which is used for operating electronic air brake systems.
It is another advantage of the present invention to minimize the financial investment necessary to deploy such a system.
The present invention is a method and apparatus for improving railcar visibility at grade crossings which is designed to satisfy the aforementioned needs, achieve the above-mentioned objects, include the herein-described features and achieve the already articulated advantages.
Accordingly, the present invention includes a plurality of railcars with an electronic communication/power line extending therebetween for use by an electronic air brake system and at least one running light disposed on the railcar where the running light is powered by the communication/power line for the electronic air brake system.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more fully understood by reading the following description of the preferred embodiments of the invention in conjunction with the appended drawings wherein:
FIG. 1 is a side view of a train, of the present invention, as it crosses a highway at an unprotected grade crossing.
FIG. 2 is a block diagram of components of the present invention in its intended environment in which the components of the invention found on a single car are detailed while a series of dots represents a series of similarly constructed railcars.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Now referring to the drawings, wherein like numerals refer to like matter throughout, and more particularly to FIG. 1, there is shown a side view of a train of the present invention generally designated 100 , as it crosses a highway 102 . Train 100 is shown including cars 110 , 112 and 114 . Interconnecting the cars 110 , 112 and 114 of train 100 is an electronic air brake power line designated 120 , which is used to provide power for the electronic air brake system, as well as a medium for communicating messages from a locomotive (not shown) to the various railcars of the train 100 , including cars 110 , 112 and 114 . The cars 110 , 112 and 114 are shown having running lights 130 , 132 and 134 respectively disposed thereon. Connecting running lights 130 , 132 and 134 to power line 120 are lines 140 , 142 and 144 respectively. Also shown on cars 110 , 112 and 114 are electronic air brake systems 150 , 152 and 154 respectively. Power line 120 runs the length of the train 100 and connects the various air brake systems, including electronic air brake systems 150 , 152 and 154 . It should be understood that a similar running light may be disposed on the opposite side of the railcar to alert motorists approaching from the opposite direction. It should also be understood that the system of the present invention could be employed with a power line that does not relate to an electronic air brake system.
Now referring to FIG. 2, there is shown a train 100 of the present invention, having a locomotive 202 and a head end control unit 204 disposed thereon. Running the length of train 100 is power line 120 . Train 100 could include numerous railcars; however, FIG. 2 shows a representative railcar 112 having an air brake control 152 thereon, as well as running lights 132 . Running lights 132 may be any type of device which utilize power on the power line 120 to generate or regulate emission of light in a direction toward motorists approaching a train at a railroad grade crossing, including but not limited to incandescent, fluorescent, iridescent, luminescent, phosphorescent, gas discharge, electroluminescent, among others. Light-emitting diodes (LEDs) with their ruggedness and low power consumption may be well suited as running lights 132 . Each railcar may also include a car ID module 262 , which includes a unique identification for each railcar and may further include an intra-car network which couples the various electronic components on the car. The car ID module 262 may also be responsible for running light power regulation from power line 120 and illumination control as it receives running light messages from the powerline. Such components may be additional sensors 272 which are optional and are not necessary for operation of the present invention.
In operation, the present invention may be operated in conjunction with the horn 280 located on the locomotive 202 and connected with a horn switch 282 . For example, as a train approaches a grade crossing, the locomotive engineer may sound a horn by pushing a button 282 or pulling a lever. This action could also be used to activate the running lights 132 . The lights may all be turned on simultaneously or, in the alternative, only those sections approaching and crossing a road may be illuminated. It is expected that various schemes may be employed to provide the necessary illumination and to concomitantly limit the power consumption and the duration of illumination of lights 132 , such as using the speed of the train, the known length of the train, distance traveled (e.g. odometer readings) and a timer to activate and deactivate the running lights at appropriate times.
It is thought that the method and apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form, construction, steps and arrangement of the parts and steps thereof, without departing from the spirit and scope of the invention or sacrificing all of their material advantages. The form herein described being a preferred or exemplary embodiment thereof.
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A method and apparatus for providing warning lamps on the side of railcars where the lamps are powered by and receive information from a power line extending across numerous cars of the train and where the power line also provides power and information to the electronic air brakes disposed on the various railcars.
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This is a division of application Ser. No. 781,925 filed Mar. 28, 1977 and now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to an improved heat exchange tubing assembly and to an improved method for fabricating a heat exchange tubing assembly.
Various forms of heat exchange apparatus such as heating and air conditioning apparatus, include a heat exchange tube assembly through which is conveyed a heating or cooling medium. An exchange of thermal energy occurs between this medium and a second medium flowing over the tubing. Heat exchange with the second medium is enhanced by provided a plurality of heat exchange blades which are maintained in thermal contact with the tubing. The blades have a surface area substantially greater than their thickness and increase the effective heat transfer surface which is exposed to the surrounding atmosphere. One such arrangement is described in U.S. Pat. No. 3,457,756, wherein the tube includes integral flat flange segments and the blades are integrally formed with the tube from the flange segments. In another arrangement, the blades are integrally formed in a strip of material which is then continuously helically wound on the tube and secured thereto by an adhesive which is positioned between the strip and the tube.
These prior techniques for increasing the effective heat transfer surface exhibit several disadvantages. When the blades are integrally formed with the tubulation, the number of blades which can be provided to increase the heat transfer surface is substantially limit since a tabulation can provide only a limited number of flat flanges before the cost and assembly procedures become uneconomical and cumbersome. When the blades are formed in a strip which is wound about the tubulation, it has been found that the adhesive used for bonding limits the thermal-conductivity between the blades and the tubulation. In some cases, additional metal, with concomitant additional weight and cost, may be used in the tubing or in the bladed strip or in both to compensate for the thermal insulation effect of the non-metallic bonding layer between the tubing and bladed strip. In addition, fabrication of the heat exchange assembly by helically winding the strip on the tubing is relatively slow and reduces the production capability while increasing the overall cost of the heat exchange tubing assembly.
Furthermore, with the helically wound bladed strip the individual blades become generally uniformly distributed around the full periphery of the circular tubing. When the external fluid medium flows past this bladed tubing in a direction generally perpendicular to the tubing axis, there are fluid flow "dead spaces" which occur immediately ahead of and immediately behind the tubing. The particular blades which happen to project forward ahead of the tubing or backward behind the tubing are resident in these dead space regions where the fluid flow is slow or stagnant. Accordingly, such blades are not very effective in contributing to the overall heat exchange capacity of any apparatus in which such prior art tubing is utilized.
Accordingly, it is an object of this invention to provide an improved heat exchange tube assembly.
Another object of the invention is to provide an improved method for fabricating a heat exchange assembly.
Another object of the invention is to provide a heat exchange tube assembly having improved means of mounting a blade strip to the tubulation.
It is a further object of the present invention in accordance with a presently preferred embodiment thereof to provide a streamlined tube assembly which reduces the dead spaces ahead of and behind the tubing and wherein the blades fan out into regions on opposite sides of the tubing where the external fluid flow is relatively unimpeded by the streamlined tubing itself.
SUMMARY OF THE INVENTION
In accordance with the general features of this invention, a heat exchange tubing and multiple heat exchange blade assembly comprises an elongated tube having a longitudinal axis and an elongated heat exchange blade strip positioned thereon. The heat exchange strip includes a longitudinally extending array of integrally formed blade segments which extend from a continuous support segment of the strip stock. This continuous support segment, in a preferred embodiment, is centrally located in the strip stock and is bent into a generally U shape, as seen in cross section. The strip is supported on an outer surface of the tube and extends in the direction of a longitudinal axis of the tube. A means integrally formed with the tube, maintains the support segment on the tube in thermal contact with the surface of the tube. The blades are positioned at a favorable angle of attack to optimize heat transfer versus fan energy ratio, and the blades in one illustrative embodiment are shown positioned for orienting their surfaces in planes which are generally normal to the longitudinal axis of the tube.
In accordance with more particular features of the invention, the means for maintaining the strip in thermal contact with the tube comprises first and second tube segments which are integrally formed with the tube, which extend longitudinally with the tube and which extend outwardly from the exterior surface of the tube and which are spaced apart for captivating the support segment of the strip therebetween. A plurality of strips are provided which are spaced about the circumference of the tube and extend longitudinally therewith. In a preferred arrangement, the captivating tube segments comprise buttresses at least one of which is deformable to mechanically engage and restrict movement of the strip. The tube preferably has an elliptical shaped cross-sectional configuration wherein a major axis thereof is positioned substantially parallel to a direction of flow of an exterior heat transfer fluid stream.
The blades of a strip are shown arrayed longitudinally in pairs in a same plane normal to the longitudinal axis of the tube or they are alternatively positioned in a staggered array. In addition, the blades of laterally adjacent strips are positioned in alignment or are relatively staggered.
In accordance with other features of the invention, a method for fabricating a multi-bladed heat exchange tube assembly comprises the steps of shearing strip stock to provide a plurality of blade segments, rotating the sheared blade segments to achieve the desired angle of attack in the final heat exchange tubing assembly, and forming the rotated blade segments to provide a longitudinally extending array of juxtaposed or staggered blades which extend from the support segment of the strip stock, which support segment is shown as generally U-shaped. A tube is formed to provide a plurality of longitudinally extending, integrally formed captivating segments. The blade support segment is applied between the captivating tube segments and at least one of the segments is deformed to mechanically engage the strip and secure it to the tube.
In a presently preferred embodiment, the tube has a generally streamlined oval cross section for utilization in heat exchanger apparatus, such as in an air conditioner, refrigerator, heat pump, oil cooler, automobile radiator, automotive space heater, air heater for dwelling or working space, with the tubing arranged such that the minor axis of the oval extends perpendicular to the external fluid flow and its major axis extends parallel therewith for reducing the frictional drag and turbulence of external fluid flow and with the multiple blades fanning out from opposite sides of the oval along its two gently curving arcuate faces where the fluid flow is relatively unimpeded. Moreover, the individual blades in a preferred embodiment are tapered so as to decrease in thickness from root to tip, thereby reducing the mass and weight of thermally conductive material in the blade strips while providing suitable thermal conduction and mechanical strength in the individual blades.
As used herein, the term "strip" or "strip stock" is intended to include thermally conductive flat wire of uniform thickness or of tapered cross section, and is intended to include thermally conductive strip material of uniform thickness or of tapered cross section.
In accordance with other features of the method of the invention, a plurality of strips are mounted on the tube by advancing the tube with blade strips previously mounted thereon to successive stations at which blade strips are similarly applied to the tube at different circumferential locations. The heat transfer assembly thus formed is shaped into a desired configuration, cut to length, and coupling fittings are mounted thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention will become apparent with reference to the following specification and to the drawings wherein:
FIG. 1 is a schematic diagram, partly in block form, of a heat transfer apparatus having a heat transfer tube assembly constructed in accordance with features of the invention;
FIG. 2 is a fragmentary sectional view in perspective of a section of a tube of a heat transfer tube assembly constructed in accordance with the features of one embodiment of the invention;
FIG. 3 is a fragmentary perspective view of strip stock from which a heat transfer blade strip of this invention is fabricated;
FIG. 4 is a perspective view of an apparatus for forming a heat exchange blade strip in accordance with one embodiment of the invention;
FIGS. 5-8 are views of tooling means employed in shearing and rotating blade segments while forming the heat exchange blade strip of this invention;
FIG. 9 is a view taken along line 9--9 of FIG. 4;
FIG. 10 is an enlarged view of a portion of the apparatus of FIG. 4 for forming and setting the blade strips;
FIG. 11 is an enlarged, fragmentary view of the apparatus utilized for securing a blade strip to a tube;
FIG. 12 is an enlarged fragmentary view of a section of a heat exchange tube and multiple heat exchange blade assembly constructed in accordance with features of this invention;
FIG. 13 is a view taken along line 13--13 of FIG. 12;
FIG. 14 is a plan view of an array of heat exchange blades constructed in accordance with one embodiment of the invention;
FIG. 15 is a fragmentary view in elevation and partly in section of the blade array of FIG. 14;
FIG. 16 is a plan view of an array of heat exchange blades constructed in accordance with an alternative embodiment of the invention;
FIG. 17 is a fragmentary view in elevation and partly in section of the blade array of FIG. 16;
FIG. 18 is a plan view of an array of heat exchange blades constructed in accordance with another alternative embodiment of the invention;
FIG. 19 is a fragmentary view in elevation and partly in section of the blade array of FIG. 18;
FIG. 20 is a plan view of another array of heat exchange blades constructed in accordance with another alternative embodiment of the invention;
FIG. 21 is a fragmentary view in elevation and partly in section of the blade array of FIG. 20;
FIG. 22 is a plan view of an array of heat exchange blades constructed in accordance with another alternative embodiment of the invention;
FIG. 23 is a fragmentary view in elevation and partly in section of the blade array of FIG. 22;
FIG. 24 is a side view of an assembling apparatus for applying an elongated blade strip to a heat exchange tube;
FIG. 25 is a flow diagram in block form illustrating the method for forming a heat exchange tubing and multiple heat exchange blade assembly in accordance with features of the method of this invention;
FIG. 26 is a diagram of a plurality of tube and heat exchange strip assembly stations illustrating the application of the heat transfer strips to the tubulation at a number of successively positioned assembly stations;
FIG. 27 is a greatly enlarged elevational sectional view illustrating a continuous method and apparatus for rotary shear with blade pre-twist;
FIG. 28 is an elevational view of a continuous method and apparatus for shearing and pre-twisting the blades followed by final twisting thereof;
FIG. 29 is a greatly enlarged elevational sectional view of a continuous method and apparatus for final twisting of the blades; and
FIG. 30 illustrates method and apparatus for ovalizing the tube with strip captivating segments thereon.
DETAILED DESCRIPTION
Referring now to the drawings, a heat exchange tube and multiple heat exchange blade assembly constructed in accordance with features of the invention is represented generally in FIG. 1 by reference numeral 30. Assembly 30 comprises an elongated tube 32 and one or more elongated heat exchange strips represented generally as 34. The tube 32 is shown formed into a serpentine configuration such as may be provided with a heat transfer apparatus 36 as for example an air conditioning apparatus. Other various configurations can be provided to satisfy the needs of particular apparatus. A heat transfer fluid medium in liquid or gaseous form flows from the apparatus 36 and through the tube 32. Fluid tight fittings 35 and 37 couple the tube 32 to conduit 38 of the apparatus. Thermal energy is exchanged with a second fluid medium flowing over the assembly and which, for example, comprises air flowing in a direction normal to the length of the tube. In FIG. 1, this flow is into the plane of the paper as represented by the arrow tails 39.
Referring now to FIG. 12, the plurality of elongated heat exchange strips 34 includes strips 40, 42, 44, 46, 48, 50, 52, 54, 56 and 58 spaced circumferentially about an exterior surface 60 of the tube 32 and extending in a direction outwardly therefrom. The elongated strip 40 which is typical of each of the strips is formed of aluminum, copper or other material which exhibits relatively high thermal conductivity. It includes an integral support segment 62 of generally U-shaped configuration having an arc-shaped base segment 64 and outwardly extending, spaced apart leg segments 66 and 68. The base segment is arc-shaped to conform with a surface arc of the tube 32. The U-shaped segment is positioned between longitudinally extending and outwardly extending tube segments 67 and 69 and is captivated in thermal contact with the tube 32 as described in greater detail hereinafter. A surface 70 of the leg segment 66 is shaped to curve in a first angular direction, when viewed from above the strip, from an orientation substantially parallel to a longitudinal axis 72 of the tube 32 to an orientation substantially normal to the axis 72. Similarly, a surface 74 of leg segment 68 curves, but in a second opposite angular direction. The leg segments 66 and 68 extend to integral blade segments 76 and 78 respectively, which fan out in a plane normal to the axis 72 from a relatively narrow spacing at a location 80 of close spacing between the leg segments 66 and 68 to a relatively larger spacing at a location 82 near their distal segments 84 and 86 respectively. Surfaces 88 and 90 of the blade segments 76 and 78 extend in substantially the same plane which is substantially normal to the longitudinal axis 72 of the tube 32 and parallel to the direction of air flow, as indicated by the arrow 92. The strip 40 includes a plurality of blade pairs which extend in a longitudinal array. Blades may be spaced apart longitudinally of the strip by a distance determined by the minimum desired spacing in the direction normal to the fluid flow direction to achieve a reasonable upstream (downstream) pressure drop. This normal spacing may be as small as 0.030 of an inch for air at standard temperature and pressure for a reasonable pressure drop. In this embodiment, as shown assembled in FIG. 12, and as being formed in FIG. 4, there are twenty blades per inch of strip stock and their spacing is 0.050 of an inch longitudinaly of the strip 158. This wider spacing produces less pressure drop as compared with a blade spacing of 0.030 of an inch.
In a preferred arrangement, the thickness of the blades tapers. The U-shaped support segment is semi-rigid in that it can be bent during the assembly process in a longitudinal direction yet it is sufficiently stiff to support the blade segments in an upstanding attitude, as is shown. The blades preferably taper in thickness to a relatively more narrow thickness at the distal edges 84 and 86. For example, as shown, there is a tapering in thickness from 0.006 of an inch at the center of the base segment to 0.003 of an inch at the distal edges 84 and 86, which provides a combination of desirable mechanical and heat transfer characteristics for a strip.
As indicated hereinabove, the elongated heat exchange blade strips are supported in thermal contact with the exterior surface of the tubing 32. A heat transfer medium flows through the tube and heat transfer is effected by thermal conductivity between the tube 32 and the strips. The tube 32 is fabricated of a material exhibiting relatively high thermal conductivity as, for example, aluminum or copper. Thermal transfer with the fluid medium is enhanced by reducing friction drag. The tube 32 has a preferred cross-sectional configuration, as illustrated in FIG. 2, which is elliptical and having a major axis 130 parallel to the direction of air flow which is indicated in FIG. 2 by the arrow 92 and with its minor axis 131 perpendicular to this air flow.
By virtue of this elliptical cross section, the tubing assembly, as shown also in FIG. 12, offers a generally streamlined configuration for the airflow 92 passing by. Thus, the turbulence induced in the airflow 92 is minimized so that a vigorous airflow can be provided for effective efficient heat transfer with a minimum amount of fan or blower horsepower required for the heat exchanger. The "dead spaces" D 1 and D 2 (FIG. 12) immediately in front of and immediately behind the tubing 32 where the air flow tends to be slow or stagnant are minimized in extent. Advantageously, the multiple blades fan out from opposite sides of the elliptical tubing along its two gently curving arcuate faces, as seen in FIG. 12. Therefore, all of these blades project into and are resident in the two regions on opposite sides of the tubing where the airflow is substantially unimpeded by the tubing itself.
For minimizing the streamline effect and for maximizing the extent of the two gently curving arcuate surfaces on opposite sides of the tubing 32 from which the multiple blades fan out, it is desirable to form this tubing with a relatively great ellipticity, i.e. to increase the ratio of its major axis to minor axis. However, if the ellipticity becomes too great, then the passage for fluid flow within the tubing 32 becomes unduly restricted. Accordingly, the practicable limit on ellipticity is a ratio of major axis to minor axis of approximately 2 to 1, which is the ratio as shown in FIGS. 2, 11 and 12.
A means is integrally formed with the tubing for maintaining the heat exchange blade strips in thermal contact with the exterior tube surface 60. This means comprises first and second longitudinally extending, integrally formed tube segments 67 and 69 which extend outwardly from the surface and are circumferentially spaced apart for receiving the base segment 64 (FIG. 12) of the U-shaped support segment 62 therebetween and for captivating it. At least one of the segments 67, 64, 69 is mechanically deformed along its length such as by crimping and folds over a portion of the U-shaped base segment 64 for captivating it along its length in thermal contact with the exterior surface 60. A plurality of similar tube segments are spaced circumferentially and extend longitudinally for captivating a plurality of strips. In FIGS. 2 and 12 the tube segments are shown as barb or buttress shaped. Other suitable deformable cross sectional configurations can be utilized. The tube segments are formed simultaneously with the tube during a tube extrusion process or they are alternatively machined in the tube surface after the tube itself has been formed.
As illustrated in FIG. 14, the strip 40 includes a longitudinally extending array 94 of blades wherein the blades are aligned as pairs 96 in a same plane. Alternatively, the blades of an array 98 are not aligned as pairs in a same plane but are staggered as shown in FIGS. 16 and 17 so that the blades are substantially equidistant in a longitudinal direction. A further alternative longitudinally offset array is illustrated in FIGS. 18 and 19 wherein blades 100 and 102 of a pair 104 are longitudinally offset. However, the blades 100 and 102 are separated by a distance X 1 while the blades 102 and 106 are offset by a greater distance X 2 .
In addition to a longitudinal offset of blades in a same array, the blade locations of the different strips are staggered as illustrated in FIGS. 20 and 21. Although blades of pair 108 of strip 110 are aligned in a same plane, the blade pairs 112 of adjacent strip 114 are longitudinally offset from the blades 108.
Various combinations of blade offsets of the same and adjacent strips can be made to increase fluid medium contact with the surfaces of the blades. In FIGS. 22 and 23, the blade offset of FIG. 18 and strip offset of FIG. 20 are combined. In this arrangement, the blades 120 and 122 of strip 116 are offset. Similarly, the blades 124 and 126 of strip 118 are offset. Strips 116 and 118 have the same blade arrangements, but the strips are longitudinally offset one from the other. Similar strips are utilized and the strips are positioned to provide for offset between lateral adjacent blades of the different strips.
A method in accordance with the features of the invention for fabricating an assembly of elongated tube having elongated heat exchange strips is illustrated in the flow diagram of FIG. 25. As represented by the blocks 150, 152, 154 and 156, tapered strip stock 158 (FIG. 3) is formed having a width 160 substantially equal to the sum of the lengths of the blade segments and the U-shaped segment of a blade. The thickness of the stock tapers from a greater central thickness to relatively smaller dimensions near the elongated edges 162 and 164. The stock is formed of aluminum or copper or other material of relatively high thermal conducitivity. In a preferred particular embodiment, the stock tapers from a central thickness of about 0.006 of an inch to a thickness of about 0.003 of an inch near the edges 162 and 164. The tapered strip stock 158 is supplied to a shearing station 152 (FIG. 25) at which location the stock is sheared into relatively narrow blades 166 and 167, as illustrated in FIG. 4. The sheared blades are rotated an angular distance of about ninety degrees about their roots thereby providing that the planes of rotated blades are normal to the plane of a centrally located planar segment 168 (FIG. 4).
Shearing the rotating of the blades 166 and 167 is conveniently accomplished in a single operation, as illustrated in FIGS. 5-8. The stock is advanced with stepwise motion a distance 170, which is a multiple of the blade width, so that a length of the stock is positioned between three sets of cutter bits 172-182. Each of these cutter bits includes a cutting edge as represented by the edges 184 and 186 of the cutter bits 180 and 182, respectively. These tool bits have lengths equal to the length of the sheared blades 166 extending from the flat segment 168 to the distal edges of these blades. A similar set of cutter bits are provided and disposed for shearing and rotating the blades 167. These extend from an opposite edge of the flat segment 168. For purposes of clarity in the drawing, the shear press which is well known is not shown.
The cutter bits are operated with a reciprocating motion in the direction of the arrows 188 and 189 (FIGS. 5-8) in synchronization with a stepping of a length of stock between the cutter bits. During a shearing and blade rotating stroke, the cutter bits 180 and 182 advance in the direction of arrows 188 and shear the stock to provide juxtaposed blades 166. In addition, the cutter bits overtravel the fully cut position and continue to advance to cause deformation and rotation of the sheared blade segments. This is best illustrated in FIGS. 6 and 7 wherein the bits 180 and 182 continue to travel beyond the fully sheared position. Tapered shoulder segments 190 and 192 engage the surface of the sheared segments forcing them to rotate in a counterclockwise direction, as viewed in FIGS. 5, 6 and 7. The cutter bits continue their rectilinear motion until the sheared blade segments 166 have been rotated an angular distance of about ninety degrees with respect to a plane of the flat segment 168 of the stock. This is illustrated in FIG. 7. After thus having sheared and rotated the blades 166, the bits are withdrawn from the workpiece by reversing the direction of their rectilinear motion as indicated by the arrows 189 of FIG. 8. When the tool bits clear the workpiece, the stock is then advanced a distance 170 to initiate a subsequent shearing cycle. Longitudinally staggered blades, as illustrated in FIGS. 16-19 are fabricated by offsetting the cutter bits in the direction of motion of stock advance which form the respective right and left blades 166 and 167.
An alternate method for forming and twisting of the blades with continuous strip motion is shown in FIGS. 27-29 which are described further below. When stepwise strip motion is used for fabricating the blades, as shown in FIGS. 5-8, then a slack input loop and a slack output loop are provided in the strip stock preceding and subsequent to the shearing and twisting operation. These slack loops are similar to the slack loops provided in a motion picture projector for accommodating the local stepwise motion, relative to the continuous motion occurring elsewhere in the whole assembly method.
As indicated in FIG. 4, the sheared and rotated blades are formed into U-shaped segments having a base segment which conforms with the surface of a tube upon which the strip is to be mounted. In FIGS. 4 and 9, the strip having sheared and twisted blades is shown being advanced through a blade fan out positioning operation 198 which includes deformation of the continuous center strip segment 168 during which the sheared and twisted blades are progressively deflected toward each other in a direction normal to the plane of the original strip stock 158 by positioning mechanisms 194 and 196. These blade fan out positioning mechanisms 194 and 196 may include moving skewed surfaces 191 and 193, respectively, of belts moving at approximately the same speed as the twisted blades 166 and 167 for progressively deflecting these blades into their fan out position. Guides 195 and 197 are shown for guiding the respective moving surfaces. A plurality of rolling surfaces arranged in a suitable pattern may be used for performing the forming operation 198. A forming wheel 202' (FIG. 9) engaging the continuous strip segment 168 is shown located upstream from the wheel 202 (FIGS. 4 and 10) for initiating the bending of the U-shaped support segment 64 for the blades.
The blade positioning operation 198 is shown using forming wheels 200, 202, 204 and 206. These wheels, as shown in FIGS. 4 and 10, establish forces on the strip being formed which shapes the flat segment 168 of the strip to conform to the shape of the tube 32, forms the U-shaped segment 64 referred to hereinbefore, and sets the blade segments to the desired degree of fan out. The wheel 200 provides a rotating arcuate rest for the strip while the wheel 202 operates to form the base segment to the desired curvature of the tool rest.
The convex transverse rim curvature 201 (FIG. 10) of the wheel 200 is selected to conform to the curvature of a tube surface 60 (FIG. 2) upon which a strip is to be mounted. At the same time that the base segment is being formed, the tool wheels 204 and 206 in cooperation with tool wheel 202 form the integral U-shaped strip segment 64 and set the blades 166 and 167 to the desired degree of blade fan out. This is accomplished by tool wheels which are configured and dimensioned to provide the desired shaping of the base segment and fan out of the blades. These characteristics are selected to satisfy the needs of particular heat exchange tube arrangements. The strip thus formed is supplied to one or more assembly stations 210-218 (FIG. 25). Forming of the bladed strip will progress at a rate adapted for supplying bladed strip material to each of the forming stations 210-218, as shown by the infeed arrows 157 in FIG. 25. Alternatively, separate strip forming means 150, 152, 154 and 156 as thus described are provided to independently supply each of the assembly stations with a bladed strip, as indicated by the respective infeed arrows 157.
In addition to supplying the formed bladed strip to each of the assembly stations, the tube 32 is formed and is supplied in sequence to the stations 210, 212, 214, 216 and 218. The tube is formed by extrusion and the longitudinally and outwardly extending tube segments 67 and 69 for captivating the tube strip are formed simultaneously and integrally with the tube during the extrusion process. In an alternative arrangement, the captivating tube segments 67 and 69 are formed by a machining process after the tube has been formed.
Alternatively, the tube with its multiple pairs of parallel longitudinal protruding attachment segments 67, 69 may initially be made as a strip which is thereafter rolled up and butt welded along its longitudinal edges into a tube.
A tube having a plurality of captivating tube segment pairs 67, 69 is supplied to a first assembly station 210, as illustrated in FIGS. 24, 25 and 26. In FIG. 24, the tube 32 is shown transported between strip supply wheels 220 and 222. The wheels 220 and 222 are symmetrically located with respect to the tube cross section. They are oriented for providing that a periphery 226 of the wheel 220 and a periphery 224 of the wheel 222 supply and position the base segments of strips 230 and 228, respectively, between pairs of captivating tube segments. For example, the arrangement of FIG. 11 illustrates strips 58 being similarly applied simultaneously. In this manner, the pairs of opposed bladed strips 56 and 54, 58 and 52, 40 and 50, 42 and 48, and the strips 44 and 46 are each simultaneously applied in paired relationship. This symmetrical application of bladed strip pairs in opposed relationship on opposite sides of the elliptical tube major axis 130 reduces the possibility of cross-sectional distortion as a result of the forces exerted on the tube during this bladed strip installation process.
There are also positioned at each of the assembly stations 210-218 crimping wheels such as the crimping wheels 232 and 234 at assembly station 212 and best illustrated in FIG. 11. The spacing between the captivating tube segments 67 and 69 is selected to provide a snug grip on the U shaped base segment 64 of the blade strip. Wheels 220 and 222 insert the U shaped segments between the segments 67 and 69. The segment 69 is then contacted and deformed by the crimping wheels 232 and 234 as the tube and strip traverse the crimping station. The crimping wheel causes the segment 69 to partly fold over and secure the strip in thermal contact with the exterior surface 60 of the tube 32. The tube 32 with the strips secured thereto is advanced from station 210 to successive stations 212-218 at which locations additional pairs of blade strips are inserted and crimped. Each of these stations applies pairs of strips in symmetrical fashion as indicated hereinbefore to the tube surface 60 at unoccupied locations on the surface between available tube segments 67 and 69. In FIG. 26, the assembly station 214 is shown to include wheels 236 and 238 for applying strips 240 and 242 respectively to the tube 32 while at assembly station 218, the wheels 244 and 246 are shown applying strips 248 and 250 respectively to the tube 32. Offset of the strips as illustrated in FIGS. 20-23 is provided by establishing an offset in the feed of the strips at successive stations.
The assembly of tube and strips is supplied from the station 218 to a shaping station represented by the block 252 in FIG. 25. The assembly of tube and blade strips is shaped into a desired configuration such as the serpentine configuration of FIG. 1. The tube is cut to desired length and coupling fittings as shown in FIG. 1 are mounted to the tube at a station 254.
There has thus been described an improved heat exchange tube assembly and method for fabricating the same wherein a heat exchange blade assembly is supported on and maintained in thermal contact with a heat exchange tube by means integrally formed with the tube. The arrangement is advantageous in that a relatively high density of heat exchange blades are formed on a heat exchange tube and an enhanced thermal conductivity between the blade strip and the tube is thereby provided.
It is to be noted, as seen in FIG. 10, that the tool wheels 200, 202, 204 and 206 form the generally U-shaped base of the bladed strip. The configuration of the arc-shaped base segment 64 plus the two leg segments 66 and 68 has an overall dovetail shape, as seen in cross section. Moreover, in FIGS. 2, 11 and 12, each of the integral projecting segments 67 and 69 of the tubing surface 60, which are spaced apart to define a channel between them, have a generally saw-tooth shape, as seen in cross section. The abrupt surface of each saw tooth faces inwardly toward the channel, while their more gently sloping surface faces away from the channel. Thus, the abrupt faces of the projecting saw-tooth segments or buttresses 67 and 69 are well adapted to captivate the dove-tailed configuration of the U-shaped base of the bladed strip. Also, their more gently sloping outer surfaces are advantageously oriented for crimping inwardly and downwardly onto the dove-tailed configuration of the U-shaped base of the strip. In this crimping operation, as seen in FIG. 11, the corner positions of the dovetail are driven inwardly and downwardly by the inclined crimping wheels 232 and 234 into firm contact with the tubing surface for providing excellent thermal conductivity between the tubing and the blades strips. The inclined crimping wheels 232 and 234 have rims 233 which slope inwardly toward the tubing axis 72 for camming the saw-tooth buttresses 69 inward and downward toward the captivated base segment 64. These crimping wheels 232 and 234 are supported by arms which are positioned at an angle to avoid the blades of the bladed strip being crimped onto the tubing.
The legends in FIG. 25 of the drawings read as follows:
______________________________________STEPS LEGEND______________________________________150 TAPER STRIP STOCK152 SHEAR STOCK INTO BLADES154 ROTATE BLADES156 SHAPE STRIP INTO U SHAPED CONFIGURATION WITH FAN OUT209 EXTRUDE TUBE & FORM STRIP- CAPTIVATING SEGMENTS210 ASSEMBLE TUBE & STRIP212 ASSEMBLE TUBE & STRIP214 ASSEMBLE TUBE & STRIP216 ASSEMBLE TUBE & STRIP218 ASSEMBLE TUBE & STRIP252 SHAPE & CUT TUBING TO LENGTH254 MOUNT FITTINGS______________________________________
With reference to FIG. 10, the transverse rim curvature 201 of the arcuate wheel rest can be arranged to provide for toggle insertion of the U-shaped segment 64 between the captivating tube segments 67 and 69. Thus, the transverse curvature 201 is made considerably more abrupt, i.e. of smaller radius, than the mating tube surface. Therefore, the central portion of the base segment 64, as seen in FIG. 11, will initially hump up away from the tube surface. The insertion wheel 220 pushes down on this humped region, to deform it down against the tube surface, providing a toggle action for driving the two corners of the dovetail blade base into tight fitting engagement with the captivating tube segments 67 and 69. If desired, this toggle insertion step 220 plus the tube captivating segment crimping step 234 may both be employed for securely mechanically locking the bladed strip into good thermally conductive relationship with the tube.
As shown greatly enlarged in section in FIG. 27, the blades 166 (and 167) may be sheared from the strip stock 158 (FIG. 4) by a pair of opposed rotary shear wheels 260 and 262. Each shear wheel has a saw-shaped contour with sharp tooth tips 264 and 266 pressing in shearing relationship against opposite surfaces of the strip stock 158. The blades 166 (and 167) are sheared one from another and are initially twisted significantly out of the plane of the strip stock 158. This is a first-stage twist. Thus, the leading edge of each pre-twisted blade 166 presents an abrupt leading face 268, which is subsequently used to register each blade for a final twisting operation, as will be explained.
FIG. 28 shows a first station 270 for producing rotary shear and first stage twist of the blades. Downstream is a second station 272 for final twist of each blade. The opposed rotary shear wheels 260 and 262 have already been described with reference to FIG. 27. They are kept in registration by a mechanical interconnection 274 between their respective shafts 276 and 278. This mechanical interconnection is a pair of mating gears (not shown) mounted on the respective shafts 276 and 278 and having equal gear pitch circles for keeping the shear wheels 260 and 262 in registration and moving at a peripheral speed synchronized with the advancing strip stock 158.
In the final twist station 272, there are a pair of mating blade-twisting wheels 280 and 282 mounted on shafts 284 and 286, respectively. They are kept in registration by a mechanical interconnection 274 which is similar to that as discussed above.
In order to synchronize the final twist wheels 280 and 282 with the rotary shear wheels 260 and 262, there is an idler gear 288 mating with gears 290 and 292 on the respective shafts 276 and 284. A guide 284 serves to support and guide the strip having pre-twisted blades toward the final twist station 272.
As shown greatly enlarged in FIG. 29, the blade-twisting wheel 282 has relatively narrow teeth 294 which serve as pivot fulcrums about which the individual pre-twisted blades are finally twisted. Moreover, the abrupt leading face 268 of each successive blade 166 bumps against a successive one of the pivot teeth 294, as shown at the registration position "R" for positively registering each pre-twisted blade 166 with a pair of cooperating teeth of the blade-twisting wheels 280 and 282. In summary, the narrow pivot teeth 294 serve to index the pre-twisted blades and also serve as pivot fulcrums about which these blades are twisted into their final orientation.
The other blade-twisting wheel 280 has broader and more rounded teeth 296. The rounded tip 298 of each tooth 296 acts as a rolling cam. This rounded tip 294 produces a rolling camming action, as shown by arrow 305, for pushing the leading edge 268 of the blade down. Each blade is thereby progressively rotated about the pivot fulcrum "F" provided by the rounded leading corner of the cooperating pivot tooth 294.
The teeth 296 also have a more gently rounded trailing surface 300 which slopes inwardly toward the root 302 of the tooth 296. This rounded trailing surface 300 acts as a shallow cam for combing each blade to twist it down parallel with the cooperating combing surface 304 along the leading face of each pivot tooth 294. This twisting combing action is indicated by the successive arrows 306, 307, 308, 309 and 310. Arrows 309 and 310 show the final combing action in which the twisted blade 166 essentially reaches parallelism with the leading combing surface 304 of the pivot tooth 294.
As shown by the arrow 312 (FIG. 28), the strip with fully twisted blades 166 issues from the continuous motion blade twist station 272 and is fed into the blade fan out positioning operation 198 (FIG. 4).
As shown in FIG. 30, the tube 32 with its integral longitudinal segments 67 and 69 may be initially extruded circular. Thereafter, the tube 32 is ovalized by rolling between a pair of rolls 320 (only one is shown) each having a saddle-shaped elliptical rolling face 322, as seen in cross section. There are clearance grooves 324 and 325 in the rolling face of each roll for accommodating the strip-captivating segments 67 and 69, respectively, to prevent crushing thereof. For simplicity of illustration, the lower half of the tube and the other ovalizing roll is omitted from FIG. 30.
It is to be understood that each of the individual blades 166 and 167 may be shaped into a particular configuration which is most appropriate for a specific application. For example, each of these blades may be stamped into a streamlined airfoil configuration or into a rounded pin or finger-like configuration. Thus, the word "blade" is to be interpreted broadly to include protruding heat-exchange elements having such configurations.
Moreover, where the individual blades have an airfoil, rectangular or similar elongated contour with a major chord, as seen in cross section, the blade may be turned slightly relative to the incident fluid stream to produce a small angle of attack for example in the range up to 12° between the direction of the incident fluid stream and the major chord of the blade. Such an angle of attack may be used to produce a more intensive scrubbing of the fluid along the blade surface for augmenting the transfer of heat from the blade into the moving fluid.
Furthermore, it is to be understood that the incident fluid flow may be at an angle of less than 90° to the longitudinal tube axis 72. For example, the incident fluid flow may be at an angle in the range from 30° to 90° relative to the tubing axis 72, and the major chord of the individual blades will be correspondingly oriented. In cases where the blades are pin-shaped or have finger-like contours, they do not have such major chord to be oriented relative to the fluid flow stream.
While I have described a particular embodiment of the apparatus and method of my invention, it will be understood that variations may be made thereto without departing from the spirit of the invention and the scope of the appended claims.
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An improved heat exchange tubing and blade assembly and a method for fabricating the same are described. The heat exchange assembly comprises an elongated tube and an elongated heat exchange blade strip positioned thereon, said strip including an array of integrally formed blade segments which extend from a U-shaped support segment. Surfaces of the blades extend at a favorable angle of attack to the incident fluid flow stream, and in a preferred embodiment the chords of the blades extend substantially normal to the length of the tube. The strip is supported on an outer surface of the tube, and means integrally formed with the tube maintain the support segment in thermal contact with the tube. In a preferred embodiment, the tube has a generally streamlined oval cross section for utilization in heat exchanger apparatus such as air conditioner, refrigerator or heat pump, with the tubing arranged such that the minor axis of the oval extends perpendicular to external fluid flow and its major axis extends parallel therewith for reducing frictional drag and reducing stagnant regions of external fluid flow. Multiple blades fan out from opposite sides of the oval tubing along its two gently curving arcuate faces where fluid flow is relatively unimpeded. The individual blades in a preferred embodiment are tapered, decreasing in thickness from root to tip, thereby reducing mass and weight of thermally conductive material in the blade strips while providing suitable thermal conduction and mechanical strength in individual blades.
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This application is a continuation of application Ser. No. 08/373,156, filed Jan. 17, 1995, now abandoned.
FIELD OF THE INVENTION
The present invention relates to improvements in a lighting control system and improvements in the components used to implement a fluorescent lamp lighting system.
BACKGROUND OF THE INVENTION
Controls for fluorescent lamp lighting systems have been devised and are now commercially available that will turn a light circuit ON and OFF depending on the signals provided by sensors such as motion detectors. Generally, the motion detector is a Passive Infra-Red (PIR) or Doppler technology device that provides a signal whenever motion is detected in the control zone. Motion created by occupants working in the area is not continuous and a detectable signal is not always available for a motion sensor. In an attempt to ensure that the lights are not turned off while the area is still occupied, a manually adjustable time delay or a preset time delay is provided within each sensor to keep the lighting circuit powered for the time delay before turning off the circuit. One disadvantage to circuit-switching occupancy sensors relates to the requirement to manually set a time delay in each sensor. In practice, most such sensors are set to the maximum delay time to minimize the annoyance of having the lights turned off when people are still occupying the area. Having the delay time set to the maximum value reduces the energy saving potential of this control method. A second disadvantage of circuit-switching occupancy sensors relates to having only an ON and an OFF state, the controlled area is either at full light or dark.
Controls for lighting systems have been devised and are now commercially available that will turn a light circuit on and off based on the availability of adequate light from an external source such as daylight. Generally, a photo sensor is provided to look at a window or at a representative area of the workspace to "see" if there is sufficient natural light available. If not, the artificial lighting circuit is switched ON. This type of control is usually provided with a manual adjustment in each sensor to set the activation light level. In order to have a stable control system, the additional light provided by the artificial lights controlled by the circuit must not cause the sensor to immediately turn the lights off again. One disadvantage to circuit-switching photo sensor controls relates to the requirement to manually set the operative light level in each sensor. A second disadvantage of circuit-switching photo sensors relates to having only an ON and an OFF state.
Dimming fluorescent ballasts are commercially available with a light level adjustment control (dimmer) so that the light level can be set manually. The purpose for such controls is primarily for aesthetic purposes rather than for energy saving. Relying on the occupant to set a lower light level to save energy is not a practical method for energy management. The primary purpose for manual dimming of fluorescent fixtures is for aesthetic lighting control and the cost of the ballast and dimmer components does not require economic justification from an energy saving perspective. This type of ballast is too expensive to be implemented in a large scale in a building for the purpose of saving the cost of energy.
Lighting control systems have been devised and are now commercially available that will adjust the light output of a special electronic ballast in response to a control signal provided by a light level controller. Such light level controllers are stand-alone controllers that are connected to a group of light fixtures using extra control wires. These controllers require manual adjustment of the setpoint light level at each sensor. Frequent adjustments of the light sensor is not practical if the light level should be changed daily in order to optimize energy consumption. The significant disadvantages of this type of controller is the high cost of the components because of their individual complexity, the high cost of installation because of their need for distributed control signal wiring to every ballast, the high cost of maintenance due to the requirement for individual calibration and adjustment at each sensor, and that the dimming controller cannot be interfaced to manual controls, timeclocks, or occupancy sensors.
Circuit-Switching controls such as those just described may cause the lighting circuits to be turned ON and OFF many times throughout the day. Most fluorescent lighting systems installed in North America still use magnetic ballasts to power the fluorescent lamps. Recently, fixed output instant start electronic ballasts are being used to replace traditional magnetic ballasts. Magnetic ballasts typically provide a cathode heating circuit in addition to the current to operate the plasma within the lamp. When this type of ballast is turned on, the plasma voltage is applied at the same time as the cathode heating power. It takes about one second before the lamp begins to operate properly. During this starting phase, damage is done to the lamp cathodes that shortens the lamp life. Repeated ON-OFF cycles with a magnetic ballast will dramatically reduce lamp life. Fixed output instant start electronic ballasts generally do not provide auxiliary cathode heat but the cathodes are heated by the plasma current. Again, damage is done to the lamp cathodes until they are indirectly heated to emission temperature. Repeated ON-OFF cycles with instant start ballasts drastically reduces lamp life. For circuit-switching controls applied to conventional magnetic ballast and instant start electronic ballast driven fluorescent lighting circuits, any benefit from the reduced cost of energy is offset by the need for increased lamp replacement.
Present technology dimmable electronic ballasts provide continuous lamp cathode heating which is maintained while the plasma current is reduced to maintain lamp life. There are also electronic ballasts now available that provide a soft start sequence for applying cathode heat before allowing plasma current to flow into the lamps. This soft starting sequence is described in the International Electrotechnical Commission (IEC) standard publication number 929. Many electronic ballasts that claim to have a soft start sequence for the lamps do not conform to the requirements of the IEC standard. For example, a dimming ballast described by Chen et al in U.S. Pat. No. 5,363,020 shows a so-called soft start sequence that does not achieve the intent of the IEC standard because damaging glow current will flow during the heating phase since the plasma voltage is also applied during that time.
Programmable lamp controllers such as described by Luchaco et al in U.S. Pat. No. 5,357,170 can accept input signals from occupancy sensors, light level sensors and manual dimming controls as well as signals from a central time clock, security system and the like. There are three disadvantages to the approach taken by Luchaco, one is that signals from a central time clock and security system require additional signal wiring in the building and the ballasts suggested for use require additional control wiring in addition to the standard power wiring. This additional wiring significantly adds to the cost of installation and increases the payback time. Also, the programmable lamp controllers have setpoints for minimum and maximum light levels and for photo sensor sensitivity that are manually set in the controller at the time of installation. The same disadvantages relating to adapting the control setpoints to optimize energy efficiency apply to this type of controller. The same cost disadvantages of using current technology dimmable electronic ballasts that were primarily designed for aesthetic dimming applications makes their use for the purpose of reducing energy costs not economically viable considering current energy costs.
A further disadvantage of present technology electronic ballasts are that they are fragile with respect to power line voltage transients. It is expensive to apply adequate surge protection in every ballast.
In view of the foregoing discussion, an object of the present invention is to overcome the noted disadvantages of current technology lighting control systems.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a lighting control system to minimize energy consumption and therefore minimize the cost of energy required to operate a building. In order to have a short payback period to recover the additional cost of implementing an energy saving lighting control system, the cost of the components, the cost of installation and the cost of maintenance must be recovered through a reduction in the cost of energy. Another object of the present invention is to operate an electronic ballast more efficiently than a conventional magnetic ballast.
In one aspect of the invention, there is therefore provided a lighting control system for a building having several zones and a power source, with several zone controllers controlling and powering one or more fluorescent light fixtures. Each fluorescent light fixture includes a communication receiver for receiving control signals from the zone controller. Current carrier communication is preferably used for transmission of control signals.
Preferably, each fluorescent light fixture includes an electronic ballast with a power level adjustment circuit responsive to control signals appearing on the load side of the zone controller.
Efficient operation of the fixture may be obtained by: firstly by providing a high frequency current to the lamps which is known to provide more light output per watt than when operating at the 60 cycle mains frequency, secondly by providing a current waveshape to the lamps that has a low form factor which is known to provide more light output per watt than when operating with a high current form factor, thirdly by providing cathode heating power that is high enough to maintain lamp life but low enough to provide additional energy saving over operating the cathode heat continuously at levels required for starting the lamps, and fourthly, the circuitry employs active power factor correction and harmonic distortion control for the mains power current to minimize losses in the building power distribution system. The combination of these four energy saving measures results in a reduction in the cost of energy of at least 30% compared to conventional magnetic ballasts.
In another aspect of the invention, an electronic ballast has a soft start sequence for the lamps so as to maintain the life of the lamps and therefore minimize lighting system maintenance cost. This capability is required when the lighting control system demands many ON-OFF cycles as is the case when operating in response to an occupancy sensor(s).
Preferably, the electronic ballast provides a method and circuitry for controlling the power delivered to the lamps in response to a power control signal. The power level can be controlled from 100% to 25% or over a similar range. If a power level below 25% or some other given level is requested, then the lamps are turned OFF. The light output of the lamps is nearly linearly related to the power delivered to the lamps. If the lamps can be operated at a lower than maximum power level, then the cost of energy is proportionately reduced. When the control signal voltage exceeds a given level, the fluorescent light fixture may be turned off.
The electronic ballast also preferably includes a communication receiver that is able to detect control signals sent along the power wires from a zone controller to the ballast. This control signal is used to adjust the lighting power level being delivered to the lamps and also enables a soft start sequence if the lamps had been turned off. By implementing only a communication receiver in the ballasts, all ballasts are interchangeable and can be readily mass produced compared to implementing a two-way communication scheme. By utilizing Current Carrier Communication (CCC), additional control wiring is not required which minimizes the cost of installation, both for materials and for labor.
The zone controller preferably contains a port for connection of sensors such as occupancy sensors, light level sensors, and manual control switches that can sense conditions within the control zone. By mounting the zone controller at the first light fixture in the control zone, the distance from the zone controller to where the sensors are mounted to detect conditions within the zone is minimized. Minimized distances for wiring results in minimized installation cost.
The zone controller preferably provides a power source to operate active sensors such as occupancy sensors and light level sensors. The low voltage power source being integral with the zone controller means that auxiliary power adaptors are not required. The wiring from the zone controller to the sensors can be inexpensive low voltage control wiring which also minimises the cost of installation.
The zone controller preferably operates on the signals from the sensors and applies delay times, calibration values, and control setpoints that are appropriate for the zone and for the sensors. The sensors do not require such capability in themselves. Therefore the occupancy sensors, light level sensors, manual dimming input devices can be rudimentary and the cost of manufacturing suitable sensor is minimized.
The zone controller may provide transient protection for all of the ballasts connected on the load side of the zone controller. By passing the power to operate the ballasts through a zone controller, it provides a convenient place to implement additional power line surge protection and removes the cost of duplicating such protection in each ballast. The life expectancy of the ballasts can be greatly improved which results in lower cost of maintenance for the lighting system.
The zone controller may have a method of communicating with a central control computer using a CCC. This second current carrier communication means allows a central control computer to adjust setpoints in the zone controller. For example, setpoints include calibrate light level sensors, time delays for occupancy sensors, fade rates when changing light levels, and minimum and maximum light levels suitable for each zone. By having a central method of adjusting setpoints for sensors that are mounted in each control zone makes it possible to optimize the efficiency of the lighting control system without incurring substantial maintenance labor costs. Additional direct control over the zone lighting from the central computer can provide occupancy scheduling, over-rides to the zones in response to emergency situations and the like. Providing central control and central adjustment minimises the cost of energy and minimises maintenance costs. By using a CCC method of communication, there is no need for additional control wiring throughout the building from the central location which minimises installation cost.
The zone controller may have a two-way CCC means so that operating conditions within the zone can be monitored by a central control computer. Monitoring can provide valuable information to the building manager regarding maintenance scheduling by logging the effective operating hours for the lamps in each zone. Also, a central control computer can pass sensor information between zones to reduce the number of sensors required in a given building which reduces the installation cost further.
In a further aspect of the invention, there is provided a method of controlling fluorescent light fixtures distributed within distinct zones in a building, the method comprising the steps of connecting fluorescent light fixtures within each distinct zone to receive control signals from a zone controller associated with each distinct zone and supplying power and control signals to each fluorescent light fixture through the zone controller. Preferably, both power and control signals are supplied to each fluorescent light fixture along the same conductors.
The control signals provided to the fluorescent light fixture preferably control the power levels used by the fixture. A central computer may communicate with each zone controller and override signals from the sensors and provide direct control of the power level of the fixture. The central computer may also receive status information from the zone controllers.
The following detailed description of a preferred embodiment with reference to the accompanying drawings will make the advantages of these features better understood.
BRIEF DESCRIPTION OF THE DRAWINGS
There will now be described preferred embodiments of the invention, with reference to the drawings, by way of illustration, in which like numerals denote like elements and in which:
FIG. 1 shows a block diagram of a lighting control system that uses a zone control architecture with Dimmable Controllable Electronic Ballast(s) (DCEB), zone controller(s), central control computer, and two Current Carrier Communication (CCC) control means.
FIG. 2 shows a curve of light output vs power consumed by a fluorescent light fixture operated by a DCEB.
FIG. 3 the components comprising a light fixture that is one component of a lighting control system.
FIG. 4 shows a block diagram of the functional blocks of a DCEB that is suitable for use in a light fixture of a lighting control system.
FIG. 5a shows circuitry and FIGS. 5b, 5c, 5d and 5e show waveforms of a CCC receiver means implemented in a DCEB.
FIG. 6a shows circuitry and FIGS. 6b, 6c, 6d, 6e and 6f show waveforms of the power control stage of a DCEB.
FIG. 7a shows circuitry and FIGS. 7b, 7c, 7d and 7e show waveforms of the lamp plasma drive of a DCEB.
FIG. 8 shows a curve describing the phases of operation of the variable light output from a DCEB.
FIGS. 9a and 9b show curves describing the International Electrotechnical Commission (IEC) soft start sequence for rapid start lamps that is provided by a DCEB.
FIG. 10a a shows circuitry and FIGS. 10b, 10c and 10d show waveforms of the cathode heater drive of a DCEB.
FIGS. 11a and 11b show a block diagram and circuitry used to implement dimming and soft start control in a DCEB.
FIGS. 12a and 12b show waveforms and FIGS. 12c and 12d show curves describing the method of power control in a DCEB.
FIGS. 13a and 13c show circuitry and FIG. 13b shows waveforms describing the method of heater power control used in a DCEB.
FIG. 14 shows a detailed schematic of a preferred embodiment of the DCEB.
FIG. 15 shows a block diagram of a suitable zone controller.
FIG. 16 shows circuitry used to implement a zone controller.
FIGS. 17, 18, and 19 flow charts of the preferred software used in a zone controller.
FIG. 20a shows circuitry and FIGS. 20b and 20c show curves of a preferred light level sensor.
FIG. 21a shows a block diagram of a prior art sensor system.
FIGS. 21b and 21c show respectively preferred occupancy sensors and circuitry used to implement an occupancy sensor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, note that the first digit of three digit reference numbers and the first two digits of four digit reference numbers relate to the drawing number in which the element is first described. Further references to the same element in other drawings use the same reference number.
FIG. 1 is a block diagram of a lighting control system showing fluorescent light fixture(s) 101, zone controller 108 operatively connected to power source 119, sensors 103, mains power distribution system 104 containing the mains power source 119, central controller 105, a first communication means for control signals 106 appearing on the load side of zone controller to the fixtures, and a second communication means 107 for exchanging data between the central controller and the zone controller.
The central controller includes a central computer connected to communicate with each zone controller through the power leads of the power distribution system 104, and includes communication means 121 which sends control parameters to the zone controllers to affect operation of the zone controllers and receives signals from each zone controller corresponding to operating conditions within the zone associated with the zone controller.
Typically, a control zone 102 would be an office, a classroom, a hallway, or a group of light fixtures next to windows in a common office area. There could be from one to hundreds of distinct control zones in an office building or a school. Each control zone could have from one to tens of light fixtures 101, all responding to the same control signals. Each control zone will have a zone controller 108 that may be connected to sensors 103 such as light level sensors 109 which provide a signal according to the daylight available to the zone, occupancy sensor(s) 110 that respond to the presence of people in the zone, and manually operated switch inputs 111 that provide on-off and light level requests directly from occupants in the zone. The zone controller provides power 112 and a control signal 106 to the light fixtures operatively connected to the power conductors 130, 131 on the load side of the zone controller. Dimmable Controllable Electronic Ballasts (DCEB) 113 in the light fixtures provide a starting sequence and variable power to the fluorescent lamps 114 to provide the light required in the zone.
FIG. 2 shows the relationship between the light output from a light fixture 101 and the power used by the DCEB 113. It can be seen that by selecting a lower than maximum light output from the fixture, the power consumed by the fixture will reduce proportionately. It can also be seen that, to an adequate approximation, the light output of the fixture can be approximated by measuring the power consumed by the ballast. Prior art dimmable ballasts such as described by Guisinger in U.S. Pat. No. 5,030,887 show a method of measuring lamp current and then controlling the ballast circuit to regulate the lamp current. Prior art dimmable ballasts, such as described in U.S. Pat. No. 5,172,034 by Brinkerhoff, show a method of monitoring and controlling the lamp current and lamp voltage and performing an instantaneous power calculation to determine the lamp power. Other prior art ballasts attempts to determine the light being produced by a fixture by measuring the actual light produced with a light sensor. A distinguishing feature of the present invention is to use the method of measuring and controlling the input power to the ballast to achieve a dimming function for the ballast. The preferred embodiment uses the method of controlling the power consumed from the power line to control the light level of the fixture and is described in detail in connection with FIG. 6 to follow.
FIG. 3 is an exploded view showing the elements of a light fixture 101 including the fixture frame 301, standard bi-pin rapid start fluorescent lamp(s) 114 such as industry standard part number FO32T8, standard bi-pin lamp sockets 303, and a ballast 113 which provides power to operate the lamp(s), the power originating from the mains power distribution wires 130 and 131. It is noted that the fixture wiring method is the industry standard method for bi-pin rapid start fluorescent lamps. Prior art lighting control system such as described by Luchaco et al in U.S. Pat. No. 5,357,170 requires additional control signal wiring between a programmable lamp controller and the dimming ballasts. In the referred embodiment, there are no additional control or signal wires required.
FIG. 4 is a diagram showing the functional blocks of an electronic ballast suitable for use in this lighting control system. Starting from the connection to the power distribution wires 130 and 131, the ballast has a communication signal receiver 401 that is able to detect high frequency signals being sent along the mains power distribution wires. The operative power to run the lamps is then passed through a low pass filter 402 that blocks high frequency signals from continuing into the ballast circuitry and also prevents high frequency noise generated within the circuitry of the ballast from being coupled back onto the power distribution wires. The voltage of the mains power supplying the ballast measured between point 403 and point 404 is sampled using a line voltage sensing circuit 405 to provide a reference for ballast power consumption, line current power factor control, and line current harmonic distortion control. A bridge rectifier is used to convert the 50 or 60 cycle mains voltage to a DC voltage in an AC to DC converter circuit 406. The power line current is sampled with a line current sensing circuit 407 to provide power factor control, current harmonic distortion control and to determine the power being consumed by the ballast. A DC to DC flyback boost inverter 408 is preferred to draw power from the full wave rectified but unfiltered DC voltage from the AC-DC converter to provide a second DC voltage 417 that is higher than the peak voltage of the incoming line voltage. The ballast control circuit 409 provides the signals to the power control drive circuit 410 which operates the switching transistor in the DC--DC inverter. Limit error signals 411, such as a maximum voltage limit that may be encountered if the ballast is operated without lamps, is sent from the DC--DC inverter to the ballast control circuit. A final DC to AC converter 412 is used to supply the available power from the second DC voltage 417 to the fluorescent lamp(s) 413. The DC-AC converter can be turned on and off by a Converter Drive 415 control. The ballast control circuit provides a soft starting sequence for the lamps. An independent cathode heater power circuit 414 is used to provide heat to the cathodes of the fluorescent lamp(s). The cathode heater source can be turned on and off by the ballast control circuit 409 and can be controlled by a power level control 416 to provide a variable cathode heating power during the starting phase of the lamps and during the running phase of the lamps. Prior art such as U.S. Pat. No. 5,179,326 by Nilssen shows a separate cathode heating circuit that can be turned OFF after the ballast has operated for a short time. There is no means in Nilssen for variable control of the cathode heat to optimize lamp starting or to maintain cathode heat for operation at reduced light levels.
Referring again to FIG. 4, FIG. 5a shows the detail circuitry of the control signal detector 401 and the low pass filter 402. The power source from the zone controller 108 is applied on wires 130 and 131. A modulated high frequency control signal V51-V0 as shown in FIG. 5b is added to the mains frequency power from the zone controller. It is preferred that the modulated signal have a fundamental frequency of about 100 khz and be pulse code modulated with a variable duty cycle at a modulation frequency of at least 1 khz. Inductors L51, L52 and capacitor C51 are connected as a low pass filter 402 to supply the mains frequency power to the AC-DC converter 406 of the ballast 113. The low pass filter presents a high impedance to the high frequency control signal but allows the 50 hz or 60 hz mains frequency to pass. The preferred cut off frequency of the low pass filter is 1,000 hz.
The high frequency control signal V51-V0 is passed through coupling capacitors C52 and C53 to the primary winding of a tuned transformer X51. The inductance of the primary winding of the transformer and the value of capacitor C54 is chosen to provide resonance at the fundamental carrier frequency of the high frequency control signal. The turns ratio of transformer X51 is such that the peak output voltage V51-V0 is about 5 volts. Diode D51 is used to detect the pulse coded signal amplitude and a second low pass filter comprising capacitor C55 and resistor R51 provide an amplitude envelope waveshape V52-V0 shown in FIG. 5c. The preferred time constant of the filter C55 and resistor R51 is 100 microseconds. Comparator U51 has a reference voltage of about 2.5 volts. and is used to detect the edges of the modulated waveform as shown in FIG. 5d. An output low pass filter comprising resistor R52 and capacitor C56 provides a direct current control signal V54-V0 as shown in FIG. 5e. The preferred cutoff frequency of the output low pass filter is 10 milliseconds. The ballast control circuit 409 of FIG. 4 uses the control signal V54-V0 to determine what light level is desired or if the ballast is to be turned off and the soft start sequence reset. FIG. 8 shows four phases of operation of the ballast circuit based on the duty cycle of the modulated control signal V54-V0 and is described in detail later.
FIG. 6a is a detailed schematic of the circuitry comprising several of the functional blocks of FIG. 4. The AC-DC converter 406 is comprised of diode bridge D61, D62, D63, and D64. Line voltage sense 405 is comprised of resistors R61, R62 and R63. Line current sense 407 is achieved by measuring the voltage across resistor R64. The DC--DC flyback boost inverter 408 comprises a comparator U61, switching transistor Q61, inductor L61, diode D65 and filter capacitors C61 and C62. A voltage limit signal V67-V0 is provided by a resistive divider comprising R65 and R66.
To further understand the operation of these circuit functional blocks in combination, FIG. 6b to FIG. 6f shows representative voltage waveforms that would be seen in the circuit. The AC power line input voltage measured as V55-V56 and shown in FIG. 6b, is applied to a rectifier bridge formed by diodes D61, D62, D63, and D64. Inductor L61, switching transistor Q61, diode D65, and filter capacitors C61 and C62 form a common flyback boost inverter configuration. The load across capacitor C61 and C62 represents the rest of the ballast circuit and the lamps. R61 and R62 are used to sense the input voltage waveshape. FIG. 6c and FIG. 6d show the voltages across resistors R61, R62 respectively. The value of R61 is the same as R62 and both are about 100 times the value of R63. The current through R61 and R62 is summed on resistor R63. The voltage on R63 as shown in FIG. 6e is a reference with the same waveshape and phase as the full wave rectified input line voltage V67-V0. The comparator U61 uses the voltage V63-V0 as a reference and turns the transistor switch on and off to try to make the voltage V64-V0 on R64, being representative of the line current and shown in FIG. 6f, match the reference voltage V67-V0. The value of R64 is chosen so that the desired line current drawn from the AC power line creates a voltage on R64 that is equal to the reference voltage on R63. For example, if the AC power line voltage is 120 volts and the power used by the ballast is desired to be 60 watts, then the line current would be 0.5 amps. If R61, R62 are chosen to be 120,000 ohms and R63 is 1000 ohms, then a reference of 1.0 volt rms would be created on resistor R63. Resistor R64 would be 2.0 ohms to make the voltage on R64 be 1.0 volt rms at 0.5 amps. The frequency and duty cycle of the comparator output is allowed to free-run in order to best match the line current waveform to the line voltage waveform. When the line current matches the line voltage, the Power Factor (PF) is unity and the Total Harmonic Distortion (THD) of the current waveform is minimized and will approach the THD of the line voltage waveform itself. Preferably, the comparator U61 is provided with a small amount of hysteresis to establish a maximum frequency of oscillation. The frequency of oscillation of the comparator is essentially determined by the value of inductor L61 and the amount of hysteresis in the comparator U61. The preferred frequency range would be between 20 khz to 60 khz. It will be shown later in this description that by effectively changing the value of resistor R63, the power drawn by the ballast from the AC power line can be changed. As described earlier, the power drawn by the ballast is proportional to the light produced by the fixture and this is the preferred method of providing dimming for this ballast.
Since the internal voltage V65-V0 is an independent variable, if a power level is selected and the lamps fail or are removed from the fixture as may be the case when the fixture is being re-lamped while still powered, the internal voltage would increase indefinitely and destroy circuit components in the ballast 113. A voltage divider consisting of resistors R65 and R66 is used to provide a voltage limit signal to the ballast control circuit 409 so that the DC--DC inverter can be shut off when the internal voltage reaches a preset maximum level. In the preferred embodiment, the components used in the DC--DC inverter 408 and the DC-AC converter 412 are rated for up to 800 volts so the preferred preset maximum voltage V65 is set for 700 volts.
A significant advantage of the preferred embodiment is that the functions of power line current power factor correction, minimizing the power line current harmonic distortion, and ballast power control are combined into a single circuit.
A second advantage of the preferred embodiment is that by controlling the input power to the ballast, the second internal DC voltage V65-V0 is an independent variable that will seek a level that is necessary to deliver the input power to the lamps. This feature is particularly useful to minimize the warm-up time of the lamps and minimize the effects of lamp aging and to accommodate Variations in the lamp operating voltages from lamp to lamp.
FIG. 7 is a detail schematic of the DC-AC converter 412 and the converter drive 415 connected to a pair of fluorescent lamps 413. Fluorescent lamps are a negative resistance plasma device which means that if a true voltage source was connected across a lamp, the current would increase more and more until the lamp failed. It is necessary to provide a limit to the current available to the lamp. This current limiting means is commonly referred to as the "ballasting" means or ballast and, for lamps operated on an alternating voltage, is typically accomplished with an inductive reactance in series with the lamps. "Ballasting" of the lamp in the present invention is achieved by limiting the power transfer from the first DC voltage V67-V0 to the load DC supply voltage V65-V0. Additional "ballasting" can be provided by an inductance in series with the lamps. The primary purpose of this inductance as part of the "ballasting" circuit is to provide rate-of-change-of-current control, or di/dt control. It is possible to operate the lamps without the supplementary ballasting inductance but the radiated Radio Frequency energy from the lamps may be unacceptable. It is preferred that the output drive transformer X72 have the primary and secondary windings separated horizontally on a E-type ferrite core that is provided with a gap on the center leg of the E-core. Such gap provides some uncoupled inductance for the primary and secondary windings that will provide di/dt control to provide a lamp current waveform shown in FIG. 7e.
The output voltage V65 of the DC--DC flyback inverter 408 of FIG. 6 provides the power source to deliver to the lamps. In the preferred embodiment, the filter capacitors C61 and C62 divide the voltage V65 to provide a supply voltage V66 for the primary of transformer X72. Drive transistors Q71 and Q72 are alternately switched ON and off at a fixed 50% duty cycle and a repetition rate of preferably 40 khz. The drive for the gates of the switching transistors is provided by a single drive transformer X71. The primary of the drive transformer is powered directly from the ballast control circuit 409 preferably using a full bridge drive circuit. The two secondary windings are connected in opposite polarity to the gates of the drive transistors through a circuit that provides fast turn-off through diode D71 and a delayed turn-on through resistor R71. The time constant created with resistor R71 and the gate capacitance of the FET transistor Q71 provides about one microsecond of delay on turn-on so that Q72 can turn off and the load inductance of X72 can cause the voltage V73 to commutate up to the supply rail V65. This time delay reduces switching losses in the transistors and contributes to the improved efficiency of this converter circuit.
In order to achieve the desired soft start sequence for the lamps as described in detail later in FIG. 9, the voltage applied to the lamps V75-V74 must be turned on only after the cathodes have been adequately heated. The plasma current can be turned on and off by applying or removing transformer X71 primary drive from the ballast control circuit 409.
FIG. 8 and FIG. 9 show how the preferred embodiment applies a soft start sequence to the lamps to minimize damage to the lamps with repeated ON-OFF cycles. The control voltage V54 created by the circuit of FIG. 5a is used to provide the four phases of operation shown in FIG. 8. If the duty cycle of the control signal V51-V0 shown in FIG. 8 is less than 25%, the ballast is to operate at the maximum light level. For duty cycles between 25% and 75%, the light output of the ballast will be variable and will reduce from the maximum light level to the minimum light level respectively. One reason for having the control signal seemingly reversed is so that if a ballast was used in a stand-alone application without a zone controller, it would default to being "ON" at maximum light level whenever power is applied to the ballast. A second reason for the preferred control concept is that if there was a failure of the zone controller circuit and the signal was absent, the lights in the control zone would default to being "ON". If the duty cycle is between 75% and 80% then the light level would remain at the minimum level. If the duty cycle is greater than 80% (or some other given level), then the ballast would be turned "OFF" and the soft start timer would be reset so when the ballast is turned "ON" the next time, the lamps would be provided with the proper soft start sequence. Another feature of the preferred control method is that if there was noise on the modulated waveform around the 75% duty cycle, the ballast would not turn "ON" and "OFF" since there is a noise margin about 5% of the duty cycle. The control signal generated by the zone controller 108 steps from a duty cycle of 75% to a duty cycle of 85% to ensure that the ballasts turn off cleanly. Another feature of the control signal generated by the zone controller 108 is that when the ballasts are requested to turn "ON", the duty cycle is stepped from 85% to at least 50% to ensure that when the lamps are started cold, they will be allowed to warm up quickly so that they will operate without flicker. If the light level setpoint is intended to be less than 50%, then the zone controller gradually reduces the light level by increasing the duty cycle to the setpoint level. The detail description of the operation of the zone controller follows with reference to FIG. 15 and FIG. 16.
The soft start sequence that is applicable to bi-pin rapid start fluorescent lamps is described in the IEC standard 929 and is summarized in FIG. 9. In order to minimize the damage to a fluorescent lamp during starting of the lamp, it is necessary to heat the cathodes to their emission temperature before trying to establish the plasma current through the lamp. Bi-pin fluorescent lamps have connections from transformer X1002 to the cathodes that form a means to allow the cathodes to be heated separately from the plasma current. To minimize the time that is required to preheat the cathodes, it is desirable to apply a high voltage across the cathodes. For North America, the American National Standards Institute (ANSI) standard C78.1 identifies the maximum and minimum voltages that should be used to heat the lamp cathodes. During the soft start phase it would be desirable to use the maximum value of voltage recommended by the ANSI standard. Power applied to the lamp cathodes that is above that required to keep them above the minimum emission temperature does not contribute significantly to light output from the lamp but results in additional power being consumed. During lamp operation, it is desirable to provide a minimum value of cathode heat in order to minimize the energy consumption of the lamp. Referring to FIG. 9a, the cathode heater voltage is at the maximum ANSI level starting at time zero. FIG. 9b shows that after about one second, the plasma voltage is applied to the lamps. After the plasma voltage has been applied and the lamp has started, the cathode heater voltage is reduced to the minimum ANSI level as shown in FIG. 9a. The preferred ballast provides the lamp soft start sequence as above described and also maintains the minimum ANSI heater voltage during operation of the lamp independent of the plasma current (light output) of the lamps.
FIG. 10 shows the cathode heater drive circuit. The cathode heaters are a resistive load to the heater drive circuit so a variable duty cycle can be used to effectively change the heater drive power. Because V65 is an independent variable with ballast power, it reduces when the lamp power is reduced. Since the heater drive derives its primary power from the voltage V65, the duty cycle of the heater drive must increase when the voltage V65 decreases in order to maintain the minimum cathode heating voltage. The variable duty cycle drive is accomplished similar to that shown in FIG. 12a with the circuitry shown in FIG. 13c. The triangle wave oscillator of FIG. 11b provides the ramp signal V1112 which is shown in FIG. 12a. Comparator U1305 compares a heater control voltage V1302 to the ramp signal. When the control voltage V1302 is lower than the ramp then the output voltage of comparator U1305 is at a logic high level and the output of buffers U1308 and U1310 switch at a 50% duty cycle but out of phase to provide a full bridge drive output for the primary of transformer X1001. If the control voltage V1302 is within the range of the ramp signal V1112, then comparator U1305 will provide a modified duty cycle signal as shown in FIG. 12b which results in a lower voltage being applied to the cathodes of the lamps. If the reference voltage V1302 is higher than ramp signal V1112 then the heater drive will be off. By selecting the values of a resistive divider network comprising R1302, R1303, and R1304, the duty cycle of the heater drive V1001-V1002 can be modified to maintain a constant rms value when the voltage V65 changes due to dimming of the lamps. When the ballast is in its OFF state, the cathode heater drive is turned off by holding the control voltage V1118 at a logic low level.
FIG. 11a shows how the control voltage signal V54 generated by the circuitry in FIG. 5a is decoded to provide a variable power level. Power control is effected with a means to reduce the reference signal V63 to the input power inverter. Transistor switch Q1101 is used to connect R1111 in parallel with R63 to provide a power level adjustment circuit responsive to the control voltage signal V54. If transistor Q1101 is OFF, then only R63 is used in the divider and the reference voltage is at its highest value. If transistor Q1101 is ON all the time, then R1111 is in parallel with R63 and the signal V63 is at its lowest value. The duty cycle of the signal V1110 as shown in FIG. 12b changes when the control voltage V54 is within the range of the ramp signal V1112. The duty cycle of the output of comparator U1111 changes and because of transistor Q1101, the effective resistance of R63 changes to provide a modified reference voltage as shown in FIG. 12c. Since the power consumed by the ballast relates to the square of the line voltage signal, the ballast power is shown in FIG. 12d with respect to the input control voltage V54. Capacitor C1112 is a small value that will filter the high frequency control signal V1110 but allow the 120 hz component of the fullwave rectified line voltage shown in FIG. 6e to pass with minimal distortion. It is preferred that R1111 be the same value as R63 so that the minimum power level is 25% of the maximum power level. The non-linearity of the power control is not a problem since the zone controller can output a duty cycle to compensate for such non-linearity. Also, this power level control is sensitive to changes in power line voltage but again, the zone controller measures the power line voltage and changes the power control signal to maintain relatively constant ballast power with respect to power line voltage.
FIG. 13a shows the circuitry used to implement the preferred soft start sequence. A soft start timer voltage V1301 is generated by resistor R1301 and capacitor C1301 with a time constant of about 3 seconds. If the control voltage V54 from the control signal detector or communication receiver 401 is greater than the 4 volt reference on U1112 of FIG. 11b, the output V1111 goes to a logic high level. This turns switch transistor Q61 ON and resets the voltage on C1301 to zero and all of the comparators U1301, U1302, and U1303 outputs go low which sets the ballast into a standby mode with the heaters and the plasma OFF. When the control signal V54 is below 4 volts, it signals the ballast to begin a soft start sequence and the voltage V1301 on capacitor C1301 is allowed to rise according to the curve in FIG. 13b. When V1301 passes the 1.2 volt reference, U1303 enables the heater output drive on maximum duty cycle. About one second later, voltage V1301 passes the 5 volt reference and U1302 enables the plasma drive via U1311 and U1313. About one second later, voltage V1301 passes the 7.5 volt reference and U1301 switches the heater drive to operate at in a variable duty cycle mode at less than 50% duty cycle to reduce the rms voltage applied to the lamp cathodes. FIG. 13c shows the logic circuitry used to implement the bridge output drives for the plasma inverter and the heater inverter.
In the preferred embodiment, the ballast control circuit 409 is provided by a NegaWatt Technologies (Edmonton, AB, Canada) NW120032CP ballast control integrated circuit that combines all of the required control functions into an 18 pin integrated circuit. The function of the circuitry described in FIGS. 11b U1111, U1113, and U1114, FIG. 13a U1301, U1302, and U1303, FIG. 13c, and FIG. 6 U61 are provided by the integrated circuit chip. In addition the NW120032CP integrated circuit provides a safe power-up sequence for when power is first applied to the ballast, over-voltage shutdown, under-voltage lockout, high voltage regulation during soft start and during operation without lamps, voltage references, continuous power supply to operate the communication receiver circuit, ballast over-temperature shutdown for the ballast drive circuits, the plasma output drive is designed to directly drive a FET transistor, the bridge output drives for heater and plasma are designed to directly drive transformer loads without external transistors, and the bridge output drives are protected for inductive load switching. The primary purpose of combining the functionality of all of the above circuit functions is to minimize the parts needed to manufacture the ballast and therefore minimize the production cost of the ballasts.
FIG. 14 shows the complete schematic of the preferred DCEB with a CCC receiver implemented with discrete components. By comparing the number of components required to implement this full feature ballast to prior art that does not have soft start or communications or may not have dimming capability, it can be seen that this ballast can be manufactured at a low cost, which is a primary objective of the present invention.
Although the present embodiment uses analog timing, analog power control, analog oscillators, and analog voltage comparators to provide the desired control, in another embodiment, the control functions could be provided by digital and microprocessor circuitry. There will be a requirement for analog circuitry to provide voltage references, power supply regulation, voltage comparator functions, and drive circuitry for the switching transistors.
FIG. 15 shows a block diagram of a preferred zone controller 108 to be used as a component of the lighting control system. The key elements of the zone controller include a low voltage power supply 1501 that provides power to operate the zone controller circuitry as well as to power sensors 1508, 1509, and 1510 that are connected to the zone controller through the sensor interface 115. There is a signal modulator 1504 that couples a control signal onto the power line that supplies power to the light fixtures 101 that are connected to the load side of the zone controller. The uni-directional control signal 1521 sends power level and on-off control to the DCEB 113 in the fixtures, which DCEB is therefore responsive to the control signal 1521. A second modulator/demodulator 1502 is provided to implement bi-directional data 1510 communication with a central control computer 120. Since there are two different CCC signals, it is important that they do not interfere with each other so a signal blocking low pass filter 1503 is provided to isolate the CCC signals yet pass the 60 hz power through from the power distribution system 104 to the light fixtures 101. A microprocessor 1505 forming a control means and means to operate on signals from sensors 103 to condition the signals is used to respond to transmissions from the central computer, format data packets for the central computer, read the signals from the various sensors connected to the zone controller, monitor the power line voltage, provide response timing, fade rate timing, setpoint comparisons, and format the power level control signal duty cycle to send to the ballasts. The microprocessor 1505 may be obtained from any of several commercial vendors such as Intel and Motorola and may be programmed using the flow charts in FIG. 17-19 to carry out the functions described here. The actual software will depend on the microprocessor used.
From a communications point of view, it is preferred that the zone controllers be slaves of the central control computer in that they do not initiate a transmission onto the power line unless they receive a command from the central computer to do so. Using a master-slave configuration means that there is no need to account for data transmission errors due to collisions of transmissions. The data being transmitted between the central computer and the zone controller is a packet that contains address bytes, control bytes and data bytes as is common with local area networks. In the preferred embodiment the CEBus protocol for sending data and control packets is used. The system could be made to work with other commercially available CCC methods such as GE Homenet, X10, or Echelon. Each zone controller requires a unique address within one building control system. The preferred embodiment uses binary coded decimal switches to provide up to 999 zone addresses 1506 which are set at the time of installation of the zone controller. The central computer must be programmed to know what zone addresses are installed. In another embodiment, each zone controller would be programmed with a serial number at the time of manufacture. The CEBus protocol has a very large address range available so it is unlikely that two zone controllers would have the same serial number in an installation.
FIG. 16 is a simplified schematic of the circuitry in the zone controller. The low voltage power supply 1501 is isolated from the power system using a transformer X1616. Rectifier diodes D1625, D1626 and filter capacitor C1624 supply a pair of analog voltage regulators U1627, U1628 to provide 5 volts to operate the microprocessor circuitry and 12 volts for the sensors interface 115 and CCC modulator circuits 1502, 1504. A separate 100 khz oscillator 1604 is gated ON and OFF with U1629 to by a duty cycle control signal generated the microprocessor 1505 to produce the CCC power control signal 106 for the DCEB(s) 113. The signal blocking filter 1503 is accomplished using inductor L1611, L1612 and capacitor C1613 so that CCC signals from the power distribution system do not interfere with CCC signals to the DCEB(s). It is preferred that the signal blocking filter pass frequencies below 1000 hz and block frequencies above 10,000 hz. Although the signal blocking filter provides additional surge protection to the DCEB(s) connected as a load, further surge protection or transient suppression can be provided to the lighting control system by connecting a varistor VR1620 across capacitor C1613.
In a preferred embodiment, the Intellon CEBus protocol and CCC module can be used to implement the Signal-2 107 modulator/demodulator 1502. This module will accept BCD switch 1506 inputs for address selection and will look for communication on the power line that has an address header that matches. If a transmission destined for the address of the zone controller is detected, then the module will notify the microprocessor that data is available using the control line(s) 1602. When the zone controller receives a command from the central computer, it will respond by sending information about the current status of the zone back as an acknowledgement. The sensor interface 115 is accomplished with pull up resistors R1605, R1606, R1607, and R1608 with the logic level signals being read by the microprocessor 1505. In a further embodiment of the zone controller, additional filtering can be provided on the signals from the sensors to protect the microprocessor from potentially harmful electrostatic discharge from the sensor connection terminals.
FIGS. 17, 18, and 19 show a flow chart of the software program used to operate the microprocessor in the preferred zone controller. FIG. 17 shows how switch inputs are processed to provide ON-OFF and manual dimming control of the fixtures in the zone. FIG. 18 shows how signals from occupancy sensors are processed and how the light power level can be faded from a normal value to a lower value or to zero. FIG. 19 shows how the light level can be regulated to a level being measured by a light sensor. FIG. 19 also shows that a signal from the communication receiver can be processed within the main program loop. FIG. 19 also shows that the power line voltage can be monitored and the duty cycle value being sent to the DCEB(s) in the zone can be modified to maintain a relatively constant light level independent of line voltage fluctuations.
Referring again to FIG. 1 and then to FIG. 20, the lighting control system of the present embodiment can have a light level sensor 109 connected to the zone controller 108. A light level sensor would provide an appropriate input signal for a zone that has access to daylight. At times of the day when sufficient light is available from the daylight through windows, then the artificial light produced by the lighting system could be reduced or turned off to save energy. In the preferred embodiment, a suitable light level sensor would provide an analog indication of the level of light "seen" by the sensor. Prior art light level sensors for daylight harvesting lighting controls start with an analog light level sensor but have circuitry that provides a switched output if the light level is above or below a setting. The setpoint must be adjusted at each light sensor. In the present embodiment, the light level setpoint is set in the software of the zone controller which means that the circuitry in the light level sensor can be much simpler and therefore less expensive to manufacture. The circuitry of the preferred embodiment shown in FIG. 20a is able to provide a wide range of operation from 100 to 1. Light level sensor elements such as photodiodes or photo-resistive elements LDR2001 have adequate range in sensitivity as shown in FIG. 20b. The variable current from the sensor element LDR2001 must be converted into a digital signal that can be processed by the zone controller. In the preferred embodiment, the circuit of FIG. 20a converts the variable current through the photo-resistive element to a variable frequency using a common integrated circuit such as an industry standard LM555 shown as U2001. The frequency of operation of the circuit is determined by the characteristics of the light dependent resistor LDR2001 and the timing capacitor C2001. FIG. 20c shows a typical output frequency vs light level that is achieved. For the present invention, the absolute frequency presented at the output terminal for a specific light level is not important since the setpoint frequency for controlling the light level in the zone is set in software of the zone controller. Measuring frequency accurately over a wide range is easy to do with the software in the zone controller without requiring an Analog to Digital converter.
Referring again to FIG. 1, the lighting control system of the present invention can have occupancy sensor(s) 110 connected to the zone controller 108. The purpose of occupancy sensors is to determine if people are actively working in the control zone. If no person is there, the artificial lighting can be reduced to a minimum level or could be turned off to save energy. Occupancy sensors are commercially available as inputs for security monitoring systems, for security lighting control systems, and for general lighting control systems. Such sensors containing additional circuitry is not required for application in the present lighting control system.
FIG. 21a shows a block diagram of the functions used in a conventional Passive Infra Red (PIR) occupancy sensor used to switch a line voltage lighting load. These sensors generally operate from an internal low voltage supply and provide an output switch closure for a preset duration of time. If further motion is detected within the delay time, the delay time is extended. The "ON" time is usually manually adjustable. Other occupancy sensors used for security monitoring generally operate on a low voltage power source and provide a switch output signal whenever motion is detected, when power is disconnected from the device, or when the enclosure of the sensor is opened or tampered with. The additional circuitry and components used in these types of sensors is not required for an occupancy sensor used in the present embodiment.
FIG. 21b shows a block diagram of the functions required for occupancy sensors that are suitable for the preferred embodiment using a dual element PIR sensor, bandpass amplifier and signal level detector. Suitable sensors do not require additional power supplies, line voltage switching means, an adjustable time delay or false alarm filtering.
FIG. 21c shows a basic circuit for a preferred embodiment of the occupancy detectors. The detector is a dual element PIR sensor S2101 that detects changes in light impinging on two adjacent photosensitive semiconductor junctions. When an object in the field of view of the sensor moves in front of a lens, the level of light received by each element changes and a signal is produced. An AC coupled amplifier U2101 is typically used to amplify the signal. A threshold detector U2102 and U2103 is used to provide an output signal whenever the AC signal from the sensor pair exceeds the 6V threshold. The output signal is then driven with an open collector transistor Q2101 with a pull-up being provided in the zone controller 108 sensor interface circuit 115.
Referring again to FIG. 1, the lighting control system is preferred to have a central controller 105 even though the zone controllers are capable of providing immediate response to sensor inputs connected to the zone controller. A central control computer 120 is connected to a communication modulator/demodulator 121 that allows communication to the zone controller(s) 108 that are distributed throughout the building. It is preferred that the communication method is using Current Carrier Communication (CCC) by superimposing the communication signals 107 onto the power distribution wires 117, 118 already existing in the building. A suitable CCC means is to use an Intellon (Ocala, Fla., USA) module part number CEMac-pl a CEBus Power Line Media Access Card that uses the Intellon CELinx-pl Integrated Circuit. It is preferred that the communication signal 107 be two direction so that the central controller 105 can send data to and receive data from each zone controller 108.
The central computer 120 can have a means for the operator to directly control light levels in the zone and set minimum and maximum light levels 122 that are suitable for each control zone 102. Minimum light levels may be advantageous for hallways for security lighting or after-hour general lighting. Hallways can generally be operated at 75% of the original design light level and zones that use video display monitors can generally be operated at 50% of the light level required for detail paperwork. Again, setting maximum light levels to less than full light output directly reduces the energy used by the lighting system.
The central computer 120 can also have a means for the building manager to input a schedule of occupancy 123 for each zone. In an application at school for example, the schedule for classes using a particular room can be used to reduce light levels or turn lights off when the room is to be unoccupied.
The control parameters of the zone controller 108 for light level, response times, and fade rates can be adjusted by the central control computer 120 either manually by the building manager with the zone response setpoints 124 or automatically by looking at occupancy patterns in the zones. For example, the delay times for occupancy detection can be optimized with reference to the occupancy patterns in the zone. The computer can monitor occupancy periods and set the delay time to the maximum expected occupancy period.
Another way to optimize the energy efficiency of the complete building would be to interface to the heating, ventilation, and air conditioning (HVAC) system through an HVAC interface 125. If the HVAC is also controlled in zones, when zones are not occupied, the HVAC can be reduced for that zone.
By being able to monitor the operating status of each zone, the central computer can determine the instantaneous power used by the lighting system. If there is additional information provided by a load shed and peak demand input 126, then the lighting load can be reduced at times of peak demand which will reduce the overall power cost for the building.
The central computer 120 can have means for connection to a telephone or modem interface 127. Operating parameters for the lighting system can be monitored or modified remotely via telephone modem. This is an advantage for utility companies to directly control the utility loads and achieve real-time demand side load management.
The lighting control system would preferably have occupancy sensors 110 distributed throughout the building. The central computer 120 can read the status of the occupancy sensors connected to the zone controllers and this information can be relayed to an intrusion monitoring system. With a security system interface 128 to the central computer, it is possible to enable after-hours lighting only in zones authorized for use by those working after-hours.
Since the central computer 120 is capable of obtaining operating status information from the zone controllers 108, the effective operating hours of the lamps in the fixtures 101 may be logged to provide statistical information to assist with preventative maintenance by preparing a maintenance schedule 129.
The power distribution system 104 used in the building is conventional and requires no modification to function as the CCC medium in this application. Most large buildings use independent power systems for lighting and operate at 277 volts or 347 volts from line to neutral. Most power systems are three phase which requires a 3 phase communication modulator/demodulator 121 and the zones operate on individual phases of the power system. The advantage of the preferred embodiment is that only minor changes are needed to retrofit a full feature lighting control system in existing buildings operating on any commercial power voltage.
One of the important features of the present invention and the description of a preferred embodiment is that the lighting control system is very flexible and comprehensive in scope so that it can take advantage of all aspects of minimizing energy consumption, There are many combinations of control features and capability that will become apparent to one skilled in the art when implementing a lighting control system.
______________________________________Table of component values for FIG. 14Part Reference Part Description______________________________________R1 100 Ω 5% 1/4 WR2 100 Ω 5% 1/4 WR3 47,000 Ω 5% 3 WR4 649,000 Ω 1% 1/4 WR5 680 Ω 5% 1/4 WR6 270 Ω 5% 1/4 WR7 270 Ω 5% 1/4 WR8 82,500 Ω 1% 1/4 WR9 10 Ω 5% 1/4 WR10 10,000 Ω 1% 1/4 WR11 324,000 Ω 1% 1/4 WR12 324,000 Ω 1% 1/4 WR13 4,700 Ω 5% 1/4 WR14 4,020 Ω 1% 1/4 WR15 100,000 Ω 1% 1/4 WR16 10,000 Ω 1% 1/4 WR17 10,000 Ω 1% 1/4 WR18 10,000 Ω 1% 1/4 WR19 200,000 Ω 1% 1/4 WR20 10,000 Ω 1% 1/4 WR21 10,000 Ω 1% 1/4 WR22 100,000 Ω 1% 1/4 WR23 14,300 Ω 1% 1/4 WR24 1,000,000 Ω 1% 1/4 WR25 10,000 Ω 1% 1/4 WR26 3,320 Ω 1% 1/4 WR27 21,000 Ω 1% 1/4 WR28 13,700 Ω 1% 1/4 WR29 1,000 Ω 1% 1/4 WR30 1,000,000 Ω 1% 1/4 WR31 0.81 Ω 1% 1/2 WR32 1,000,000 Ω 1% 1/4 WC1 22 uF 10% 350 VC2 22 uF 10% 350 VC3 470 uF 10% 16 VC4 10 nF 5% 50 VC5 1000 pF 2% 100 VC6 47 nF 5% 50 VC7 10 nF 5% 50 VC8 470 nF 5% 50 VC9 1500 pF 400 VC10 3300 pF 2% 100 VC11 100 nF 400 VC12 10 nF 400 VC13 560 pF 5% 50 VC14 100 nF 5% 50 VC15 10 nF 5% 50 VC16 22 uF 10% 16 VC17 1000 pF 2% 100 VC18 100 nF 5% 50 VD1 UF4002D2 UF4002D3 UF4002D4 UF4002D5 1N4007D6 1N4007D7 1N4007D8 1N4007D9 UF4002D10 UF5408Q1 BUZ80Q2 BUZ80Q3 BUZ80Q4 BUZ80Q5 BUZ80U1 NW120032CP *U2 LM393U3 TLC272F1 1.0 Amp fast fuseT1 NW120060C1 *T2 NW120060B1 *T3 NW120060A1 *T4 NW120060F1 *T5 NW120060G1 *T6 NW120060D1 *T7 NW120060D1 *______________________________________ * NW.... components available from Negawatt Technologies Inc. Edmonton, Alberta, Canada. Reference numerals in this table and FIG. 14 relate only to FIG. 14.
A person skilled in the art could make immaterial modifications to the invention described and claimed in this patent without departing from the essence of the invention.
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An energy saving lighting control system for operating fluorescent light fixtures is provided with means for controlling the light level according to the light required for the task being done in the area. Ambient light available from sources outside of the controlled area such as daylight can be harvested to reduce the amount of artificial lighting required. A method of providing sensor inputs to detect occupancy in the controlled area provides control signals to the lighting control system which are used to reduce the light level or turn light fixtures off at times when the area is not occupied. A method of providing a central .control of the operation of the lighting system can provide time-of-day scheduling, can provide minimum and maximum lighting levels, and can provide calibration and set-points for response times to various sensor inputs. In order to minimize the installation cost of the lighting control system, the system is provided with components that can be controlled using signals carried along the power conductors that provide primary operative power to the lighting fixtures. Special circuitry in the ballasts for fluorescent lamps provides a starting sequence and operating conditions that maximize the life of the lamps which therefore minimizes maintenance costs.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional application of U.S. patent application Ser. No. 09/482,467, filed Jan. 13, 2000.
BACKGROUND OF THE INVENTION
[0002] This invention relates to shower heads which allow for selection of a variety of discharge spray patterns and intensities.
[0003] There are a wide variety of shower heads which are used in conjunction with plumbing installations. They provide a variety of spray patterns with different flow rates, as well as pulsated sprays. One such apparatus is described in U.S. Pat. No. 5,201,468 where the head has three different flow paths to provide a central, outer and middle spray pattern. There is a pulsating turbine in communication with the middle spray pattern.
[0004] In U.S. Pat. No. 4,398,669 a rotatable housing is provided with a small opening and a large opening, with the large opening feeding water to rotate a valve and cause pulsing of the water from orifices. U.S. Pat. No. 5,862,985 shows pulsating spray channels for fluid communication with pulsating spray selector holes for varying flow to the pulsating spray assembly.
[0005] U.S. Pat. Nos. 5,397,064 and 5,577,664 disclose pulsating shower heads each with a pair of impellers. However, only one of the impellers causes a pulsation of water flow.
[0006] Notwithstanding this variety of options in shower heads, there is nevertheless a desire for further variety. For example, it is preferred to have a set of spray apertures which can provide an outlet of pulsed water or optionally non-pulsed water (through the same apertures), along with a second set of spray apertures which provides only non-pulsed water.
[0007] Another desired feature (the subject of this divisional) would be to provide multiple impellers that provide concentric pulsing through two sets of pathways, with the pulsing being at different rates, along with a non-pulsing separate third pathway.
[0008] Yet another desired feature would be a shower head having three concentric rings of spray options, where none are in communication with an impeller and the central spray pattern can provide a more forceful spray out any given nozzle than the outer and middle spray patterns.
BRIEF SUMMARY OF THE INVENTION
[0009] In one embodiment the invention provides a shower head. It has an inlet assembly having a portion for connection to a fluid supply at a first end, and an outlet assembly abutting the inlet assembly opposite the first end and being rotatably attached thereto.
[0010] The outlet assembly includes a housing positioned opposite the inlet assembly, and a diverter member in the housing. The diverter member includes three separate passages, the second passage being of a smaller cross section than the first passage. There is also a face plate member connected to the housing. The face plate member has two sets of fluid passageways therethrough. A first of the sets of passageways is capable of being in communication with either the first or the second passages, and the second of the sets of passageways is capable of being in communication with the third passage.
[0011] There is also an impeller positioned between the first of the sets and the first passage. When the first passage is in communication with the first set of passageways, and water is passed through the shower head, the impeller will spin. When the second passage is in communication with the first set (and water is passed through the shower head) the impeller will not spin. A consumer can therefore select a pulsing central flow at high force, or a more gentle non-pulsing central flow (e.g. to clean off the face), or a more diffuse spray to wash soap off the rest of the body.
[0012] In preferred forms flexible nozzles are positioned in the passageways, there is a seal member surrounding the first and second passages, the first set of passageways are positioned radially inward from the second set of passageways, and the diverter member includes a raceway for accommodating a detent member.
[0013] In another embodiment (the subject of this divisional) there is a shower head that has an inlet assembly with a first chamber therein, a means for coupling the first chamber to a fluid supply, and an exit from the first chamber. There is also an outlet assembly abutting the inlet assembly and being rotatably attached thereto. The outlet assembly has a body having an inlet positionable to communicate with the exit when the outlet assembly is rotated into different positions with respect to the inlet assembly. The body also has a discharge section in which outlets are positioned.
[0014] There is also a face plate member connected to the body. The face plate member has three sets of fluid passageways therethrough. The first set is a radially inward set. The second set is a radially middle set. The third set is a radially outward set.
[0015] Also provided are a first rotatable impeller positioned between a first outlet and the first set of passageways, and a second rotatable impeller positioned between a second outlet and the second set of passageways. When an outlet of the body is in communication with the first set of passageways and water is passed through the shower head, the first impeller will spin. Similarly, when an outlet of the body is in communication with the second set of passageways and water is passed through the shower head, the second impeller will spin. Water can also pass through the third set of passageways when an outlet of the body is in communication with the third set. In a preferred form the head is connected to a hand held shower handle.
[0016] In this form of the invention the two different impellers can cause pulsing at different rates. There is also the option of a non-pulsed flow. This provides increased massaging flexibility.
[0017] In yet another embodiment there is provided a shower head. It has an inlet assembly with a first chamber therein, a means for coupling the first chamber to a fluid supply, and an exit from the first chamber. There is also an outlet assembly abutting the inlet assembly and being rotatably attached thereto.
[0018] The outlet assembly has a body with an inlet positionable to communicate with the exit when the outlet assembly is rotated into different positions with respect to the inlet assembly. The body also has a discharge section in which outlets are positioned.
[0019] There is also a face plate member connected to the body. The face plate member has three sets of fluid passageways therethrough. The first set is a radially inward set constructed and arranged to provide water at a first force level for a given volume of water passing through the head. The third set is a radially outward set constructed and arranged to provide water at a third force level which is less than the first force for said given volume of water passing through the head. The second set is a radially middle set constructed and arranged to provide water at a second force level which is less than the first force level and greater than the third force level for said given volume of water passing through the shower head. The shower head is further characterized in that it does not have any impeller in fluid communication with the face plate. In judging force levels for a set for this purpose, one looks to the force of the water exiting the nozzle of the set with the highest force level.
[0020] This embodiment permits water to exit from three different concentric arrays, with varying levels of force. No impeller is required.
[0021] The invention thus provides a variety of different options for a shower head. The assembly is relatively inexpensive to produce and manufacture. Further, repair of the assembly is quite easy.
[0022] The advantages of the invention therefore include providing shower heads of the above kind which:
[0023] a. can provide a multiplicity of spray patterns;
[0024] b. can provide a variety of flow rates;
[0025] c. are easily installed and maintained;
[0026] d. are adapted to be employed in conjunction with both wall mounted fluid supplies and hand held shower outlets.
[0027] These and still other advantages of the invention will be apparent from the description which follows. In the detailed description below, preferred embodiments of the invention will be described with reference to the accompanying drawings. These embodiments do not represent the full scope of the invention. Rather the invention may be employed in other embodiments. Reference should therefore be made to the claims herein for interpreting the breadth of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] [0028]FIG. 1 is a top perspective view of a first shower head of the present invention;
[0029] [0029]FIG. 2 is an end view of the outlet end of the shower head shown in FIG. 1;
[0030] [0030]FIG. 3 is a longitudinal sectional view of the FIG. 1 shower head;
[0031] [0031]FIG. 4 is a sectional view taken along line 4 - 4 of FIG. 3;
[0032] [0032]FIG. 5 is a schematic perspective view of an inlet member and diverter of the FIG. 1 shower head;
[0033] [0033]FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 4;
[0034] [0034]FIG. 7 is a view similar to FIG. 4, but with parts shown at a different rotational position;
[0035] [0035]FIG. 8 is a sectional view taken along line 8 - 8 of FIG. 7;
[0036] [0036]FIG. 9 is a view similar to FIG. 7, albeit illustrating yet another position of the shower head;
[0037] [0037]FIG. 10 is a sectional view taken along line 10 - 10 of FIG. 9;
[0038] [0038]FIG. 11 is a view similar to FIG. 2, albeit of a second embodiment of the present invention;
[0039] [0039]FIG. 12 is a longitudinal sectional view of the shower head shown in FIG. 11;
[0040] [0040]FIG. 13 is a view taken along line 13 - 13 of FIG. 12;
[0041] [0041]FIG. 14 is a perspective view of a selector plate of the shower head;
[0042] [0042]FIG. 15 is a second perspective view of the selector plate of FIG. 14;
[0043] [0043]FIG. 16 is a view taken along line 16 - 16 of FIG. 13;
[0044] [0044]FIG. 17 is a view similar to FIG. 13, but in a rotated position;
[0045] [0045]FIG. 18 is view taken along line 18 - 18 of FIG. 17;
[0046] [0046]FIG. 19 is a view similar to FIG. 17, albeit showing the selector plate in yet another rotational position;
[0047] [0047]FIG. 20 is a view taken along line 20 - 20 of FIG. 19;
[0048] [0048]FIGS. 21 and 22 are longitudinal sectional views of a third embodiment of the present invention, in two different rotational positions; and
[0049] [0049]FIG. 23 is a view similar to FIG. 2, albeit of the embodiment shown in FIG. 21.
DETAILED DESCRIPTION OF THE INVENTION
[0050] Referring first to FIGS. 1 - 3 , a shower head generally 10 represents a first embodiment of the present invention and includes an inlet assembly 12 and an outlet assembly 14 . The head can select between two different spray patterns by rotating outlet assembly 14 with respect to the inlet assembly, and as will be described one of these can be either pulsating or not.
[0051] The inlet assembly 12 has a metal ball joint 16 to which is connected tubular member 18 by means of set screw 20 . O-ring seals 26 are placed therebetween. Tubular member 18 is internally threaded such as at 22 , and can have a screen filter 24 placed therein.
[0052] Collar 28 is connected between the ball joint 16 and the tubular member 18 . It includes a spring 30 and a closure ring 32 and provides for connection to a fluid supply. Another collar 36 surrounds the ball joint 16 and a seal 40 is placed therebetween. A pivot 42 extends into cutout 44 on the ball joint 16 to provide for a pivoting of the head 10 . Inlet member 48 is connected to collar 36 by the threads 38 and has an endwall 49 and a flange 51 .
[0053] Outer shell or housing 50 rides over inlet member 48 and is retained by flange 51 of inlet member 48 . A suitable seal 52 is placed between inlet member 48 and shell 50 . Grip rings 54 are disposed on the outside of shell 50 for the purpose of assisting rotation of shell 50 . A diverter member 56 is disposed between inlet member 48 and face plate 60 to rotate therewith. It is connected to shell 50 by the threads 62 . Face plate 60 has nozzles 63 and 64 , and there is a seal 65 placed between the face plate and the diverter 56 . An impeller 66 is rotatably mounted in chamber 67 of face plate 60 .
[0054] Referring to FIGS. 4 - 5 , it is seen that diverter 56 is connected to shell 50 by the grooves 68 on the diverter and the tongues 69 extending from the shell. A detent mechanism 70 is housed in the member 48 and includes a compartment 72 for a biased detent 73 and the spring 74 . The detent extends from inlet member 48 and into the raceway 75 on the diverter 56 . This aids in the rotation of the diverter 56 with respect to the inlet member 48 . A central locating notch is also provided at 71 .
[0055] As best seen in FIG. 4, there is a large passage 76 and a small passage 77 extending through diverter 56 , as well as a seal surrounding the passages.
[0056] [0056]FIGS. 7 and 8 represent one phase of operation of the shower head 10 . This is the passage of water out through the centrally located nozzles 64 . In this instance, water passes in through the passage 17 of the ball joint 16 and against the end wall 49 of inlet member 48 . As shown by the directional arrows, water will flow to the passage 80 of inlet member 48 and into the small passage 77 . From there, it will enter the chamber 67 and exit the nozzles 64 . As the small passage will restrict the flow of water into chamber 67 , it will not be of sufficient force to rotate the impeller 66 . In order to effect rotation of the impeller 66 , the diverter 56 will be rotated so that passage 80 of inlet member 48 will be orientated with the larger passage 76 in the diverter. This will effect rotation of the impeller.
[0057] [0057]FIGS. 9 and 10 illustrate the passage of water to the outerly disposed nozzles 63 . In this instance, the passage 80 is located away from either large passage 76 or small passage 77 . Water will then flow around these passages and be sealed therefrom by the seal 78 . Water will flow against the wall 49 and thereover until it reaches the passages 86 in the diverter 56 . From there it flows into passages 88 in the face plate 60 .
[0058] It should be noted that the nozzles 63 are preferably composed of a flexible and resilient material so as to provide a nozzle which can be flexed and thus prevent clogging.
[0059] A second embodiment of the invention is shown in the shower head 110 in FIGS. 11 - 20 . Shower head 110 comprises an inlet assembly 112 and an outlet assembly 114 . A user of the shower head 110 can adjust the spray volume, and select among three different spray patterns by rotating the outlet assembly 114 with respect to the inlet assembly 112 , as will be described.
[0060] The inlet assembly 112 has a ball joint 115 which includes an internal threaded member 117 adapted to mate with a pipe extending from a shower enclosure. The ball joint 115 has an aperture 134 extending therethrough with a conventional inlet screen 135 . The inlet assembly includes a hollow cylindrical inlet cap 116 with an aperture 118 at one end through which the ball joint 115 passes and a larger diameter 119 at the other end adjacent the outlet assembly 114 .
[0061] The outlet assembly 114 includes an annular outer shell 120 having two grip rings 121 for rotational purposes. The end of the outlet assembly 114 which is remote from the inlet assembly 112 has a large circular opening within which several components are concentrically located. These components create the different spray patterns. The first of these components is a channel ring 122 which abuts the inner surface of the outer shell 120 . A ring shaped diffuser 124 is placed between the distributor 128 and the outer shell 120 , and provides for nozzles 125 .
[0062] As seen in FIG. 12, an inlet housing 138 has a tubular portion 140 that threads onto a tubular projection 139 inside the inlet cap 116 . The inlet housing 138 has a hollow, conical section 142 extending from the tubular portion 140 and an internal wall 144 which extends across the junction of the tubular portion 140 to the conical section 142 . The internal wall 144 has a number of apertures 145 extending therethrough. A tubular member 146 extends from the wall inside the conical section 142 defining each chamber 150 therebetween.
[0063] The ball joint 115 extends through the aperture 118 in the inlet cap 116 with a sphere 137 of the ball joint located inside the tubular portion 140 of the inlet housing 138 . The sphere 137 is larger than the aperture 118 so that it will not fit therethrough. A resilient washer 147 is placed between the sphere 137 in the inlet cap 116 to prevent contact with and damage to the surface finish of the sphere. An annular gasket 148 is positioned within the tubular portion 140 between the ball joint 115 and the wall 144 and is biased against the ball by the compression spring 149 . This assembly of components within the tubular portion 140 of the inlet housing 138 forms a watertight pivoted coupling for connecting the showerhead 110 to a water supply pipe. The water flows from the ball joint 115 into the tubular portion 140 and passes through aperture 145 into chamber 150 within the conical section 142 .
[0064] Chamber 150 is closed by an annular head plate 152 which extends across the interior of the inlet housing 138 abutting the exposed end of the conical section 142 and the tubular member 146 in a manner which provides a fluid tight seal there between. The head plate 152 also forms a wall of the inlet assembly 112 which abuts the outlet assembly 114 . Two cylindrical cavities 154 are formed in the outer surface of the head plate 152 and have aperture 156 to which the chamber 150 communicates with each cavity. A separate annular inlet seal 158 lies within each cavity 154 and is biased outward by a compression spring 159 .
[0065] As shown in FIG. 16, another cavity 160 is provided in the head plate 152 in a radially spaced relationship to the two cavities 154 . A ball bearing 162 is located within the cavity 160 and is biased outwardly therefrom by the spring 164 . The ball bearing 162 rides against a selector plate 166 which forms an inner wall of the outlet assembly 114 .
[0066] As previously noted, three different spray patterns of the shower head are selected by rotating the outlet assembly 114 with respect to the inlet assembly 112 . At the centerpoint of the rotation of travel, where one of the three spray patterns is selected, the ball bearing 162 falls into a depression 163 providing a detent as a sensory feedback to the user when the spray head is in this position. The other two spray patterns are selected by rotating the assembly 114 into that extreme positions in opposite directions as will be described subsequently. Rotational stops strike the walls which form the cavities 154 and thereby define each of these extreme positions.
[0067] With reference to FIGS. 13 - 15 , the selector plate 166 of the outlet assembly 114 has two sets of three outlet apertures 167 , 168 and 169 extending therethrough. Each set of apertures is positioned to communicate with one of the rubber inlet seals 158 upon rotation of the outlet assembly. FIGS. 12 and 13 illustrate a first water passage through the selector plate 166 . One of the selector plate apertures 168 communicates with a radially transversed passage 170 on each side of the annular selector plate 166 . The outer most ends of the passages 170 are sealed by plugs 183 . The inner most ends open into a central aperture 172 .
[0068] The passages 170 permit water entering the selector plate through apertures 168 to flow toward the central aperture 172 by means of a passage 170 . From there water will enter through the apertures 174 in the central post 175 having the channel 176 . From there water flows past the flow director 178 and into the channel 179 where it will strike the impeller 180 which is mounted over the central post 186 of central housing 130 .
[0069] As the water flows therethough, it will cause the impeller to rotate, and the impeller blade 181 to momentarily block water flow through the nozzle 182 thereby effecting a pulsation of the water. It should be noted that selector plate 166 which is remote from the inlet assembly 112 abuts and is welded or cemented to the inner ends of the channel ring 122 and the distributor 128 so as to rotate with the outlet assembly 114 .
[0070] [0070]FIGS. 17 and 18 represent the flow of water to the intermediate outlets 131 . The flow of water from apertures 156 in head plate 152 is directed to the outlet apertures 167 in selector plate 166 . From there the water flows through the passages 171 in the selector plate and into chamber 184 . Chamber 184 has rotatably mounted therein the impeller 185 and the passage of water therein will effect a rotation of the impeller in the same manner as impeller 180 in chamber 165 .
[0071] [0071]FIGS. 19 and 20 show the passage of water to the outer nozzles 125 . In this instance, the selector plate 166 is positioned such that water will pass from apertures 156 in head plate 152 into aperture 169 . From there it will flow through passages 177 and through outlets 173 . From outlet 173 water will flow into chamber 188 , through passage 189 and into chamber 190 , as well as passage 190 and ultimately out through nozzles 125 .
[0072] It should be noted that outlet assembly 114 is rotatably connected to inlet assembly 112 by the post member 175 . A threadable connection is provided at 191 for engagement with tubular member 146 . The flange 192 engaging distributor 128 provides for the rotation.
[0073] An important feature of shower head 110 is that it affords concentric pulsating spray options while also permitting regular spray aperture 182 which are centrally located as well as the outlets 131 .
[0074] A third embodiment of a shower head is shown at FIGS. 21 - 23 . Similar components are shown with similar numbers as in embodiment 110 except they are in the 200 series. The main difference between the two embodiments is that shower head 210 has no impellers. Instead, the flow from the central chamber 265 is out through the nozzles 293 which are joined by base member 294 . Also, it will be seen that the flexible nozzles 295 are placed in distributor 228 .
[0075] As may be appreciated from FIG. 23, the overall cross sectional area of the passageway holes of the radially innermost set is less than that of the second set, which in turn is less than that of the third set. Thus, for any given volume of water passing through the head water will at least in part be more forcefully expelled through the center set than the set next to that. Similarly, water expelled from the middle set will be more forceful through any given hole than water expelled from the outside holes.
[0076] Industrial Applicability
[0077] The present invention provides shower heads with settings for varying the type of flow and force of flow through various outlets.
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Shower heads are disclosed providing for varying types of spray. One spray head provides three different spray patterns, with two of the patterns having pulsing impellers which can pulse at different speeds from each other.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part to a non-provisional application Ser. No. 09/848,492 titled, “Controlled Engine Shutdown for a Hybrid Electric Vehicle” filed May 3, 2001. The entire disclosure of Ser. No. 09/848,492 is incorporated herein by reference in its entirety.
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates generally to a hybrid electric vehicle (HEV), and specifically to a method and system to control an HEV engine shutdown.
2. Discussion of Prior Art
The need to reduce fossil fuel consumption and emissions in automobiles and other vehicles predominately powered by internal combustion engines (ICEs) is well known. Vehicles powered by electric motors attempt to address these needs. Another alternative solution is to combine a smaller ICE with electric motors into one vehicle. Such vehicles combine the advantages of an ICE vehicle and an electric vehicle and are typically called hybrid electric vehicles (HEVs). See generally, U.S. Pat. No. 5,343,970 to Severinsky.
The HEV is described in a variety of configurations. Many HEV patents disclose systems where an operator is required to select between electric and internal combustion operation. In other configurations, the electric motor drives one set of wheels and the ICE drives a different set.
Other, more useful, configurations have developed. For example, a series hybrid electric vehicle (SHEV) configuration is a vehicle with an engine (most typically an ICE) connected to an electric motor called a generator. The generator, in turn, provides electricity to a battery and another motor, called a traction motor. In the SHEV, the traction motor is the sole source of wheel torque. There is no mechanical connection between the engine and the drive wheels. A parallel hybrid electrical vehicle (PHEV) configuration has an engine (most typically an ICE) and an electric motor that work together in varying degrees to provide the necessary wheel torque to drive the vehicle.
Additionally, in the PHEV configuration, the motor can be used as a generator to charge the battery from the power produced by the ICE.
A parallel/series hybrid electric vehicle (PSHEV) has characteristics of both PHEV and SHEV configurations and is sometimes referred to as a “powersplit” configuration. In one of several types of PSHEV configurations, the ICE is mechanically coupled to two electric motors in a planetary gear-set transaxle. A first electric motor, the generator, is connected to a sun gear. The ICE is connected to a carrier. A second electric motor, a traction motor, is connected to a ring (output) gear via additional gearing in a transaxle. Engine torque can power the generator to charge the battery. The generator can also contribute to the necessary wheel (output shaft) torque if the system has a one-way clutch. The traction motor is used to contribute wheel torque and to recover braking energy to charge the battery. In this configuration, the generator can selectively provide a reaction torque that may be used to control engine speed. In fact, the engine, generator motor and traction motor can provide a continuous variable transmission (CVT) effect. Further, the HEV presents an opportunity to better control engine idle speed over conventional vehicles by using the generator to control engine speed.
The desirability of combining an ICE with electric motors is clear. There is great potential for reducing vehicle fuel consumption and emissions with no appreciable loss of vehicle performance or drive-ability. The HEV allows the use of smaller engines, regenerative braking, electric boost, and even operating the vehicle with the engine shutdown. Nevertheless, new ways must be developed to optimize the HEV”s potential benefits.
One such area of HEV development is implementing a controlled engine shutdown in an HEV. If the engine shuts down in an uncontrolled manner, its starts and stops throughout a given HEV drive cycle can increase tailpipe emissions from inconsistent amounts of residual fuel (vapor and puddles) in the intake manifold from one shutdown to the next. The amount of residual fuel depends on the amount of liquid fuel flow from the injectors, as well as the amount of fuel vapor introduced by the vapor management valve (VMV) and exhaust gas recirculation valve (EGR) prior to the shutdown.
Vapor management valves (VMV) are widely used in evaporative emission control systems to reduce the fuel vapor build up in the fuel system. Fuel vapor in the fuel tank and lines is captured in a vapor storage canister (typically a charcoal material), and then drawn out into the engine's intake manifold via the VMV. The amount of fuel vapor introduced into the intake manifold, and thus into the engine cylinders to be combusted, is proportional to how much the VMV is opened and how much intake manifold vacuum is available.
Exhaust gas recirculation valves (EGR) are widely used in tailpipe emission control systems to recirculate a portion of the hot exhaust gases back into the intake manifold, thereby diluting the inducted air/fuel mixture and lowering combustion temperatures to reduce the amount of NOx (oxides of nitrogen) that are created. The amount of exhaust gases re-circulated into the intake manifold, and thus into the cylinders, is proportional to how much the EGR valve is opened and how much intake manifold vacuum is available. Though mostly made up of inert byproducts of the previous combustion event, the exhaust gases partially contain some unburned fuel vapor.
During engine shutdown in an HEV drive cycle, the fuel injectors, VMV, and EGR valves may be flowing at different rates depending on when the shutdown occurs, and thus may contribute fuel vapor and puddle amounts to the intake manifold that vary from one engine shutdown to the next. This, in turn, leads to inconsistent amounts of residual fuel left in the intake manifold from one subsequent engine restart to the next. Because of the many engine shutdowns and starts in an HEV, it is important to minimize the amount of tailpipe emissions during these events.
Nevertheless, with an inconsistent amount of residual fuel vapor and puddles, it becomes difficult to deliver the proper amount of fuel through the injectors from one engine start to the next during the course of a drive cycle. Thus, tailpipe emissions may vary from one engine start to the next during a drive cycle.
A controlled engine shutdown routine can also reduce evaporative emissions following a “key-off” engine (and vehicle) shutdown at the end of a drive cycle. One significant contributor to evaporative emissions in conventional vehicles during a “soak” (i.e., the time between drive cycles where the vehicle is inactive and the engine is off) is residual fuel vapor that migrates to the atmosphere from the intake manifold through the vehicle's air induction system. By reducing the residual fuel from the intake manifold, evaporative emissions can be reduced during the vehicle “key-off” soak periods following a drive cycle.
To accomplish this, a “power sustain” function is needed to continue to provide power to HEV controllers, ignition system, and fuel system (pump and injectors) for a period of time after “key-off.” This allows the generator to continue to spin the engine (after injectors are ramped/shut off) while the spark plugs continue to fire until residual fuel (vapor and liquid) is flushed from the intake manifold into the combustion chamber to be combusted (even if partially), and then moved on (delivered) into the hot catalytic converter to be converted.
Although controlled engine shutdowns are known in the prior art, no such controlled engine shutdown strategy has been developed for an HEV. U.S. Pat. No. 4,653,445 to Book, et al., discloses a control system for engine protection to different threatening conditions. Examples of such conditions include fire, the presence of combustible gas or fuel, rollover or excessive tilt, low oil pressure, low coolant level, engine overheating, or engine overspeed.
Book”s engine shutdown system receives warning signals for fault conditions that initiate engine shutdown. Book also includes a method to divide fault signals into either a fast shutdown response or a delayed shutdown response. This method only applies to convention ICE vehicles.
U.S. Pat. No. 4,574,752 to Reichert, Jr., et al., also discloses an engine shutdown device for a conventional ICE and is particularly suited to stationary engine applications. It describes a controlled timed shutdown to reduce engine wear or system damage if problems arise in an external device powered by the engine. When Reichert”s method detects a fault in a peripheral device driven or controlled by the engine, it uses a relay, a fuel shutoff control, an engine throttle control, and a timer to shutdown the engine.
Prior art also reveals other developments to reduce fuel waste, emissions and dieseling during controlled engine shutdown for a conventional ICE. U.S. Pat. No. 4,366,790 to DeBoynton, discloses a by-pass system that stops fuel flow to an engine when combustion is not required. When this normally open by-pass valve is closed during events such as deceleration or engine shutdown, only filtered air at a reduced vacuum is allowed into the engine manifold. This prevents fuel waste. See also generally, U.S. Pat. No. 5,357,935 to Oxley, et al. Other systems have developed to maximize the amount of exhaust gas recirculation when an ICE is switched off to reduce emissions and dieseling. U.S. Pat. No. 4,367,720 to Miyoshi, et al.
U.S. Pat. No. 4,312,310 to Chivilo, et al., discloses an emissions prevention control system that stops engine fuel intake during idle conditions or deceleration and continues to spin the ICE with an auxiliary power unit such as an electric motor or hydraulic pressure. The motor keeps the engine spinning to allow subsequent fast start-up when normal driving conditions resume.
Although the prior art discloses engine shutdown systems for conventional ICEs, they do not meet the engine shutdown needs of an HEV. Thus, a system is needed that controls HEV engine shutdowns to preserve the HEV goal of reduced emissions.
SUMMARY OF INVENTION
Accordingly, an object of the present invention is to provide a controlled engine shutdown process for a hybrid electric vehicle (HEV).
It is a further object of the present invention to provide a method and system to control HEV engine shutdowns so as to achieve the HEV goal of reduced emissions (tailpipe and evaporative).
It is a further object of the present invention to provide a method and system to control HEV engine shutdowns that have specific controllers within a vehicle system controller and/or engine controller to: shut (“ramp”) off fuel injectors; control engine torque via a throttle plate; control engine speed; stop spark delivery by disabling an ignition system; stop purge vapor flow by closing a VMV; stop exhaust gas recirculation flow by closing an EGR valve; and flush or clean out an engine intake manifold of residual fuel (vapor and puddles) once all sources of fuel are halted (injectors, VMV, and EGR valve).
It is a further object of the present invention to abort engine shutdown if the engine is commanded to run and the fuel injector ramping has not yet begun.
It is a further object of the present invention to shut off spark by disabling the ignition system when engine speed is less than a calibratable threshold.
It is a further object of the present invention to shut (“ramp”) off fuel injectors in a calibratable manner, such as all injectors off at once, one injector off at a time, or two injectors off at a time.
It is a further object of the present invention to provide a power sustain system for controlled engine shutdown to complete in a “key-off” shutdown.
Other objects of the present invention will become more apparent to persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing objects, advantages, and features, as well as other objects and advantages, will become apparent with reference to the description and figures below, in which like numerals represent like elements and in which:
FIG. 1 illustrates a general hybrid electric vehicle (HEV) configuration.
FIG. 2 illustrates a possible strategy of the controlled engine shutdown sequence for an HEV.
FIG. 3 illustrates stage one of the controlled engine shutdown sequence for an HEV.
FIG. 4 illustrates a basic schematic of the vehicle system control, engine control unit, and a transaxle management unit.
FIG. 5 illustrates stage two of the controlled engine shutdown sequence for a hybrid electric vehicle.
DETAILED DESCRIPTION
The present invention relates to electric vehicles and, more particularly, hybrid electric vehicles (HEVs). FIG. 1 demonstrates just one possible configuration, specifically a parallel/series hybrid electric vehicle (powersplit) configuration.
In a basic HEV, a planetary gear set 20 mechanically couples a carrier gear 22 to an engine 24 via an one way clutch 26 . The planetary gear set 20 also mechanically couples a sun gear 28 to a generator motor 30 and a ring (output) gear 32 . The generator motor 30 also mechanically links to a generator brake 34 and is electrically linked to a battery 36 . A traction motor 38 is mechanically coupled to the ring gear 32 of the planetary gear set 20 via a second gear set 40 and is electrically linked to the battery 36 . The ring gear 32 of the planetary gear set 20 and the traction motor 38 are mechanically coupled to drive wheels 42 via an output shaft 44 .
The planetary gear set 20 , splits the engine 24 output energy into a series path from the engine 24 to the generator motor 30 and a parallel path from the engine 24 to the drive wheels 42 . Engine 24 speed can be controlled by varying the split to the series path while maintaining the mechanical connection through the parallel path. The traction motor 38 augments the engine 24 power to the drive wheels 42 on the parallel path through the second gear set 40 . The traction motor 38 also provides the opportunity to use energy directly from the series path, essentially running off power created by the generator motor 30 . This reduces losses associated with converting energy into and out of chemical energy in the battery 36 and allows all engine 24 energy, minus conversion losses, to reach the drive wheels 42 .
A vehicle system controller (VSC) 46 controls many components in this HEV configuration by connecting to each component”s controller. An engine control unit (ECU) 48 connects to the engine 24 via a hardwire interface. The ECU 48 and VSC 46 can be based in the same unit, but are actually separate controllers. The VSC 46 communicates with the ECU 48 , as well as a battery control unit (BCU) 50 and a transaxle management unit (TMU) 52 through a communication network such as a controller area network (CAN) 54 . The BCU 50 connects to the battery 36 via a hardwire interface. The TMU 52 controls the generator motor 30 and traction motor 38 via a hardwire interface.
It is in the VSC 46 and ECU 48 that coordination of a controlled engine 24 shutdown takes place to meet the objects of the present invention. At a predetermined moment when the VSC 46 determines it is best for the vehicle to run without the engine, such as low torque demand or a “key-off” from an operator, the VSC 46 initiates engine 24 shutdown by issuing a command to the ECU 48 .
One possible engine 24 shutdown routine, that is the preferred embodiment of the present invention, is illustrated in FIGS. 2, 3 and 5 . FIG. 2 shows a general strategy of the controlled engine shutdown sequence for an HEV.
In FIG. 2 at Step 102 , the VSC 46 determines whether the engine 24 is needed. If the engine 24 is not needed (such as during a low-torque demand or a “key-off” from the operator) the strategy generates a command at Step 104 to the VSC 46 to begin stage one 106 of the engine 24 shutdown sequence. Stage one 106 controls engine 24 speed and engine 24 torque. Once stage one 106 is determined complete at step 108 , the strategy issues a command for the ECU 48 to begin stage two 110 of the engine 24 shutdown sequence.
In stage two 110 , the strategy generates a command for the ECU 48 to shut-off a purge valve at Step 112 to stop purge flow from a vapor management valve. Next, the strategy generates a command for the ECU 48 to shut-off an exhaust gas recirculation (EGR) valve at Step 114 to stop exhaust gas recirculation. Next, the strategy generates a command for the ECU 48 to an injector stop timer to shut (“ramp”) off injectors based on a calibratable delay at Step 116 . Once the strategy determines that all the injectors are off at Step 118 , the strategy generates a command for the ECU 48 to flush an intake manifold of residual fuel at Step 120 when all sources of fuel are halted. Once the strategy determines that the intake manifold is flushed at Step 122 , the strategy generates a command for the ECU 48 to shut-off the engine 24 at Step 124 . This can be accomplished by disabling the ignition system so that no sparking occurs from the spark plugs (not shown).
FIG. 3 specifically illustrates stage one 106 of a HEV engine shutdown routine, and deals with the overall coordination of the engine shutdown by controlling the engine speed and torque (via electronic throttle control) prior to invoking stage two 110 of the engine shutdown sequence, while power is sustained to the controllers, ignition system, and fuel system (pump and injectors) if an optional “power sustain” feature is implemented for “key-off” engine shutdowns. FIG. 5 illustrates stage two 110 , that is a more specific control of the engine components, such as fuel injectors, vapor management valve (VMV), and exhaust gas recirculation (EGR) valves, as well as the ability to “flush” the intake manifold of residual fuel if the optional “power sustain”feature is implemented for “key-off” engine shutdowns. Stage one 106 is illustrated in this preferred embodiment as being handled in the VSC 46 , while stage two 110 is handled in the ECU 48 . These “stages” do not necessarily need to be located in the controllers used in this illustrative example.
FIG. 3 (stage one 106 ) is a timeline going from left to right, as follows: DES_ENG_TORQUE 98 =the desired engine 24 torque command from the VSC 46 to the ECU 48 ; control of desired engine torque directly controls engine throttle position, if a torque based electronic throttle controller system is used; in this case, with a known engine 24 map, a desired engine 24 brake torque can be broken down into desired engine 24 indicated torque, then to desired engine 24 airflow, and then finally to desired engine 24 throttle position.
ACTUAL_ENG_SPEED 94 =the actual engine 24 speed as measured by a crankshaft position sensor (not shown), read by the ECU 48 , and sent to the VSC 46 .
DES_ENG_SPEED 90 =the desired engine 24 speed command from the VSC 46 to the TMU 52 ; the TMU 52 has the generator motor 30 in “speed” control for most driving and the VSC 46 sets the target speed of the generator motor 30 via this DES_ENG_SPEED 90 command. Generator motor 30 and engine 24 speed are always proportional to each other because they are mechanically coupled in the planetary gear set 20 .
ENGINE_MODE 72 =the mode command from VSC 46 to ECU 48 ; 0=engine 24 commanded to be off, 1=engine 24 commanded to be on; this is what starts stage two 110 of the engine shutdown routine as illustrated in FIG. 5 .
ENGINE_RUNNING 64 =flag indicating whether the engine 24 is running (i.e., making combustion and torque); 0=engine 24 not running (off), 1=engine 24 is running (on). This flag is set to 0 in stage two 110 of the engine shutdown routine as illustrated in FIG. 5 when conditions are met, and then sent from the ECU 48 to the VSC 46 .
Stage two routine indicator 110 =this routine begins when ENGINE_MODE 72 =0. Illustrated with specificity in FIG. 5 .
GEN_MODE 92 =the mode command from the VSC 46 to the TMU 52 ; 1=speed control, 0=spin engine to a stop (0 speed).
POWER_SUSTAIN_TMR 74 =timer that begins when the key is turned “OFF” and then runs until a calibratable power sustain delay time is met (POWER_SUSTAIN_DLY 78 ) or when ENGINE_RUNNING 64 =0, depending on which option is implemented.
POWER_SUSTAIN_FLG 76 =flag set inside the VSC 46 that, when=1, sustains power to all the controllers, the ignition system, and the fuel system (pump and injectors); flag is set to 1 when the key is turned “OFF”, and cleared to 0 when POWER_SUSTAIN_TMR 74 exceeds POWER_SUSTAIN_DLY 78 or when ENGINE_RUNNING 64 =0, depending on which option is implemented.
FIG. 4 shows schematically the interaction of the VSC 46 with the TMU 52 and the ECU 48 as described above.
FIG. 5 (Stage two 110 ) is also a timeline read from left to right, as follows: ENGINE_MODE 72 =the mode command from VSC 46 to ECU 48 that is set in stage one 106 , as illustrated in FIG. 3; 0=engine 24 commanded to be off, 1=engine 24 commanded to be on; this is what starts stage two 110 of the engine shutdown routine as illustrated in FIG. 5 .
INJ_STOP_TMR 56 =(IF OPTION A 58 )=timer that begins when the command to do the shutdown is given (ENGINE_MODE 72 =0) and then runs until all the injectors are shut (“ramped”) off; each injector is shut off based on a calibratable delay relative to when the shutdown command was given.
(IF OPTION B 60 )=timer that begins when the command to do the shutdown is given (ENGINE_MODE 72 =0) and then gets reset each time one of the injectors is shut off; each injector is shut off based on a calibratable delay relative to when the last injector was shut off.
SHUTDOWN_PG_DIS 66 =flag requesting that a purge valve be unconditionally shut off for the shutdown process.
SHUTDOWN_EGR_DIS 68 =flag requesting that the exhaust gas recirculation (EGR) valve be unconditionally shut off for the shutdown process.
INJON 126 =actual number of fuel injectors commanded ON (maximum is 4 for this 4-cylinder illustrative example).
MAN_FLUSH_TMR 62 =timer that begins when all the injectors have been COMMANDED OFF (via INJON 126 =0) to allow for the intake manifold to be flushed of residual fuel (vapor and liquid).
ENGINE_RUNNING 64 =flag indicating whether the engine 24 is running (i.e., making combustion and torque); 0=engine 24 not running (off), 1=engine 24 is running (on). This flag is set to 0 when a manifold “flushing” process is complete (MAN_FLUSH_TMR 62 >MAN_FLUSH_DLY 88 ) and then sent from the ECU 48 to the VSC 46 .
SPK_ENG_MODE 70 =spark shutoff command; 0=disable ignition system (i.e., do not allow spark plugs to fire), 1=enable ignition system (i.e., allow spark plugs to fire). This command is set to 1 when ACTUAL_ENG_SPEED 94 falls below a calibratable threshold (SPK_SPD_THRESHOLD 96 ).
Stages one 106 and two 110 of the engine 24 shutdown routine have the following calibratable parameters (Note: While this example applies only to a four cylinder engine 24 , it can easily be adapted to other engines with different cylinder configurations using the same type of parameters.): INJDLY43 80 =time delay from receiving the engine 24 shutdown command (ENGINE_MODE 72 =0) to when ONE injector is shut off (either OPTION A 58 or OPTION B 60 ).
INJDLY32 82 =time delay from receiving the engine 24 shutdown command (ENGINE_MODE 72 =0) to when TWO injectors are shut off (OPTION A 58 ), or=time delay from one injector having been shut off (INJON 126 =3) to when TWO injectors are shut off (OPTION B 60 ).
INJDLY21 84 =time delay from receiving the engine 24 shutdown command (ENGINE_MODE 72 =0) to when THREE injectors are shut off (OPTION A 58 ), or=time delay from two injectors having been shut off (INJON 126 =2) to when THREE injectors are shut off (OPTION B 60 ).
INJDLY10 86 =time delay from receiving the engine 24 shutdown command (ENGINE_MODE 72 =0) to when ALL FOUR injectors are shut off (OPTION A 58 ), or =time delay from three injectors having been shut off (INJON 126 =1) to when ALL FOUR injectors are shut off (OPTION B 60 ).
MAN_FLUSH_DLY 88 =time delay from when the engine 24 has stopped fueling (INJON 126 =0) to when the intake manifold has been sufficiently cleaned of residual fuel (vapor and liquid); the engine 24 will continue to be spun by the VSC 46 until this calibratable delay has expired.
SPK_SPD_THRESHOLD 96 =engine speed below which the ignition system is disabled (i.e., spark plugs are not fired).
POWER_SUSTAIN_DLY 78 =time delay from when POWER_SUSTAIN_TMR 74 begins counting to when POWER_SUSTAIN_FLG 76 is cleared to 0.
The engine 24 shutdown routine of the present invention accomplishes the HEV objectives described in the prior art review. First, the routine unconditionally disables purge and EGR (i.e., shuts the valves immediately) via SHUTDOWN_PG_DIS 66 and SHUTDOWN_EGR_DIS 68 to close off these sources of fuel. Second, the routine shuts (“ramps”) off the fuel injectors (the primary source of fuel) in a controlled and calibratable manner (e.g., all injectors shut off at once, or two at a time, or one at a time) via INJON 126 . Additionally, an abort command is added to the shutdown process if injector shut off (“ramping”) has not yet begun. For example, the shutdown would abort if INJON 126 >=4 (or the total number of engine cylinders) and ENGINE_MODE 72 is not=0. Again, shutting off these three sources of fuel helps to create a repeatable and consistent fuel condition in the intake manifold (vapor and liquid) at the end of engine shutdown so that it is easier to control the amount of fuel for optimal air/fuel ratio during the following engine restart.
And finally, if engine shutdown is implemented with a power sustain system (POWER_SUSTAIN_TMR 74 , POWER_SUSTAIN_FLG 76 , and POWER_SUSTAIN_DLY 78 ) to the controllers, the ignition system, and the fuel system (pump and injectors), the VSC 46 can continue to spin the engine 24 even though the injectors are off (INJON 126 =0) to “flush” residual fuel out of the intake manifold into the cylinders, combust the fuel (even if partially) in the combustion chamber by the continued firing of the spark plugs, and then converting the combustion byproducts once delivered to the hot catalytic converter.
The ENGINE_RUNNING 64 flag is set to 0 once the flushing process is complete and the routine shuts off engine 24 spark completely once ACTUAL_ENG_SPEED 94 has fallen below a calibratable level (SPSPD_THRESHOLD 96 ). Typically, even with the “power sustain” option active, the engine 24 will continue to spin for only a few seconds (2 or 3) after “key-off” so that the driver does not perceive a problem with the engine 24 continuing to run when not expected.
The above-described embodiment(s) of the invention is/are provided purely for purposes of example. Many other variations, modifications, and applications of the invention may be made.
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A method and system to control engine shutdown for a hybrid electric vehicle (HEV) is provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.
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BACKGROUND OF THE INVENTION
This invention deals with an improved method of controlling a high speed electric motor, which has a front-end Electromagnetic Interference (EMI) filter attached. By extracting estimated voltage and current values of the motor windings based on sensed power inverter output values, a controls scheme that is more accurate than the prior art controls schemes is obtained.
In industrial applications, regular electric motors are often driven by variable frequency power source. A variable frequency power source is used because in many motors the frequency of the input power controls the speed of the motor. A variable frequency power inverter converts Direct Current (DC) power into Alternating Current (AC) power. Variable frequency power inverters have the capability to adjust the frequency and voltage of the AC power. This allows the power inverter to control the speed and torque of an AC motor attached to it by adjusting both the frequency and voltage of its power output. In most applications the power inverter is connected directly to the motor with no intermediate EMI filter connections. This practice is common for motors of all sizes in most operations and provides the motor with standard power, though not clean power. Clean power is the power that is provided relatively free of electronic and electromagnetic noises and is typically achieved through the use of an EMI (Electro-Magnetic Interference) filter.
Some operations, for example aerospace and aircraft applications among others, have very limited electrical tolerances and thus require clean power. Clean power is achieved once a filter has been applied and electrical noise has been filtered off of the power transmission. To achieve clean power in the present setting it is necessary to introduce an EMI filter between the power inverter and the motor winding terminals. Since EMI filters are often set up in complicated inductance-capacitance formats, the electrical values (such as current, voltage, and impedance) of the EMI filter in high power, high frequency, and high speed applications become complex issues as the power level output of the power inverter increases. Simultaneously the electrical values of the motor parameters decrease as the power level output of the power inverter increases. As a result the electrical values of the EMI filter become substantially large relative to the electrical values of the motor parameters. This results in the output voltage and current of the power inverter being significantly affected by the EMI filter.
In the prior art methods of controlling motors in this configuration the voltage and current values at the output of the power inverter have been sensed and then erroneously used to control the motor by assuming them to be the voltage and current values at the input of the motor windings. Feedback controls, such as the ones used in the prior art, work by measuring the value of the voltage and current at the power inverter output and assuming them to be the voltage and current values of the motor, ignoring the effect that the EMI filter has on the voltage and current values. The controller then adjusts the input to the power inverter accordingly using the normal pulse-width modulation switching methods (i.e. depending on the load demands, the power inverter switching pattern can be varied to increase or decrease the output voltage and frequency applied into the motor inputs) The influence of the EMI filter on the voltage and current values increases the amount of time it takes to correct any improper voltage and current values in the motor control system, and it may give some disturbance response during transient due to an imbalance between the supply and demand sides of the electric machine. The duration of time necessary to correct the values is referred to as the response time. Erroneously assuming the power inverter output values to be the actual motor winding values results in a controls scheme that is slowed down or sluggish, as well as less accurate than desired.
SUMMARY OF THE INVENTION
It would be desirable for both the power inverter output values and the actual motor winding voltage and current to be sensed. This would allow for accurate feedback control, eliminate the need for estimating the values, and dramatically hasten the response time of the controllers.
When an EMI filter is placed between the power inverter and the motor it is often economically or technologically impractical to sense the actual motor winding voltage and current. This invention discloses the use of an estimator circuit to extract an estimated motor winding input voltage and input current from an actual power inverter output voltage and output current. The feedback time of the estimator circuit is slower than directly sensing the motor winding voltage and current. However, the estimator circuit is a vast improvement over the prior art method of assuming the power inverter values to be the motor winding values. The feedback this embodiment gives is more accurate and results in a quicker response time than the prior art method of using the power inverter output values for its control signal.
If the situation permits a voltage reading at the EMI filter output to be taken, in addition to voltage and current readings at the power inverter output, a second embodiment may be used. In the second embodiment of the invention the motor winding current is estimated using the sensed power inverter voltage and output current, and the sensed EMI filter voltage. Under this embodiment a simpler estimator circuit is used to extract the motor winding voltage and current from the EMI filter output voltage and the power inverter output voltage and current.
These embodiments provide for a faster response time then the prior art methods because a more accurate estimate of the motor winding voltage and current outputs is determined than the prior art method of using the voltage and current values of the power inverter output.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a power circuit with an attached EMI filter in a typical configuration.
FIG. 2A is the general circuit layout of a three phase EMI filter with no specified component values.
FIG. 2B is an example of potential component values of one phase path of a typical three phase EMI filter together with the motor impedance in a single phase form; the back-EMF voltage is not included in the figure for simplicity.
FIG. 3 is a block diagram of an estimator used to estimate the motor voltage and current when the power inverter input and output voltages and currents are sensed.
FIG. 4 is a block diagram of a simplified estimator in the case that the inverter voltage, the inverter output current and the EMI filter voltage can be sensed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the disclosed embodiments of the invention a power inverter 10 is connected to an EMI filter 20 which is then connected to a motor 30 as seen in FIG. 1 . The EMI filter 20 has a general three phase construction as shown in FIG. 2A with each phase having an inductor 22 , which has an equivalent serial resistance 21 , a capacitor 23 connected to ground in a Y format, and connections to capacitors 24 arranged in a delta pattern connecting all three phases. A specific example of a sample EMI filter single phase layout is shown in FIG. 2B with sample component values in the first inductor (35 μH) 25 and capacitor (35 μF) 27 . The inductor 26 and resistor 30 represent the motor impedance in a single phase format assuming that the internal back EMF is inherently present but not shown. The single phase layout of the EMI Filter is constructed in FIG. 2B by just a simple inductance-capacitance format.
Because of the high inductance and capacitance values of a typical EMI filter such as the EMI filter illustrated in FIGS. 2A and 2B compared to the motor's internal impedance, the power inverter output current and voltage values are not accurate estimates of the AC motor winding input values. If it is not possible to measure the values of the EMI filter output, then it is desirable to introduce an estimator to achieve a more accurate estimate of the actual AC motor winding input values than is achieved using the prior art method.
FIGS. 3 and 4 illustrate estimator circuits 41 and 42 . In both estimator circuit 41 and estimator circuit 42 the value “RL” in gain block 121 refers to the ESR (equivalent serial resistance) of the overall filter inductor 20 , the value “L” in gain blocks 121 and 122 , refers to the overall inductance of the EMI filter 20 , the value “RC” in gain blocks 222 , and 321 refers to the ESR of the filter capacitor and the value “C” in gain blocks 222 , 221 , 321 , and 322 refers to the overall capacitance of the EMI filter 20 .
Estimator circuit 41 estimates both the motor voltage, in the voltage estimator 100 , and the motor current, in the current estimator 200 . In the voltage estimator 100 the voltage drop across the EMI filter 20 is estimated. In the illustrated circuit this estimated voltage drop is based on the EMI filter 20 input current and the rate of change of the EMI filter 20 input current, however any method to determine an accurate estimate of the voltage drop could be used. Once the voltage drop estimate has been determined it is then subtracted from the actual power inverter output voltage to obtain the estimated motor winding input voltage. In the illustrated circuit this is done in a summation block 132 .
In order to obtain the estimated motor winding input voltage in the illustrated embodiment the following steps should be performed. First the voltage estimator 100 accepts the output current value of the power inverter at an input 111 , and the output voltage value of the power inverter at an input 110 . The value at input 111 is then multiplied by RL in a gain block 121 , and sent to a summation block 131 . The value at input 111 is also sent to a derivative block 190 where its derivative is taken. This value is then multiplied by L in a gain block 122 , and the output value is passed to summation block 131 . Summation block 131 sums the output of gain blocks 121 and 122 . The input value 110 is sent to a summation block 132 . The output of summation block 131 is then subtracted from the input value 110 in summation block 132 . Finally the voltage estimator 100 outputs an estimated motor winding voltage 140 . Once an estimated motor winding voltage is determined it is the output at output terminal 140 . This output may be connected to the power inverter controller input terminals and the value may then be used to control the power inverter 10 .
The current estimator 200 works by estimating the effect the EMI filter 20 has on the overall current and subtracting the value of the estimated effect from the power inverter 10 output current. In the embodiment illustrated in Figure the output of gain block 222 is an estimate of the affect the EMI filter 20 has on the current. This estimate is based on the estimated voltage from the voltage estimator 100 and on the overall resistance and capacitance of the EMI filter 20 . The estimated change in current from gain block 222 is subtracted from the actual power inverter output current from input 111 to obtain an estimated motor winding input current.
In order to obtain the estimated motor winding current using the method summarized above the following steps should be followed. Summation block 231 accepts the estimated motor voltage from the voltage estimator 100 then subtracts the output of integrator block 290 . The output of gain block 231 is multiplied by 1/RC in gain block 222 . The output of gain block 222 is then multiplied by 1/C in gain block 221 and passed to integrator block 290 . The output of gain block 222 is also sent to summation block 232 . Summation block 232 accepts the power inverter output current from input 111 . Then summation block 232 subtracts the output of gain block 222 from the value of input 111 . The resultant value is the estimated motor current 240 . Once an estimated motor winding current is obtained, it is sent to output terminal 240 . Output terminal 240 may be connected to the power inverter controller inputs and the estimated value may then be used to control the power inverter 10 .
While an estimated motor winding input voltage and current can be achieved utilizing the above system, a system where only the motor winding input current is estimated would provide a faster feedback and better controls for the motor. Such a system is possible when the EMI filter output voltage, the power inverter output voltage, and the power inverter output current are measured. Estimator circuit 42 illustrates such a system. Estimator circuit 42 works in the same way as the current estimator 200 from estimator circuit 41 , described above, with one difference. In estimator circuit 42 the voltage value used to make the estimate is not an estimated voltage value, as in estimator circuit 41 , but instead the voltage value used is an actual measured input voltage value 311 of the motor windings.
The specific operations of estimator circuit 42 as shown in the illustrated embodiment are as follows. The output of integrator block 390 is subtracted from the EMI filter output voltage in summation block 331 . The output of summation block 331 is multiplied by 1/RC in gain block 321 . The output of gain block 321 is then multiplied by 1/C in gain block 322 and then sent into integrator block 390 where it is integrated. The output of gain block 321 is additionally passed to summation block 322 where it is subtracted from input 310 (the power inverter output current). Summation block 332 then outputs an estimated motor current to output terminal 340 . Output terminal 340 may be connected to the power inverter controller inputs and the estimated current value from output terminal 340 may be used to control the power inverter.
The estimator circuit can be in the form of a microcomputer, a digital signal processor (DSP), software or an analog control. This invention extends to any such implementation.
Although multiple embodiments of this invention have been disclosed, a worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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A system and method for extracting estimated input voltage and input current values of an AC motor based on sensed power inverter output voltage and output current when the AC motor is connected to a front-end EMI filter and the EMI filter is connected to a power inverter. Where the system includes a current estimator portion, and a voltage estimator portion. The estimated input values are used by a feedback controller in the power inverter to control the motor. A second system and method for extracting estimated an input current of an AC motor based on the actual motor input voltage, and the output voltage of the power inverter.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a Continuation-in-Part of commonly assigned U.S. application Ser. No. 947,137 filed Sept. 29, 1978, now abandoned.
BACKGROUND OF THE INVENTION
a. Field of the Invention
The present invention relates to method and apparatus for manufacturing wrapped yarns and relates, more particularly, to methods and apparatus for manufacturing wrapped yarns formed of a central core of roving or the like drafted yarn which is helically wrapped with a binder strand.
In the following specification, the terms "yarn" and "strand" are used in a general sense to apply to all kinds of strand material, either textile or otherwise, and the terms "package" and "spool" are intended to mean the product of a winding machine, whatever its form. The term "balloon" refers to the path defined by the rotating portion of a rotated advancing strand irrespective of the shape or diameter of said path, and sometimes refers to the yarn in said path, according to the context in which the term is employed.
b. Problem of the Invention
In the art of manufacturing wrapped yarn in which a cover or binder strand is helically wrapped around a drafted core strand or strands to form such wrapped yarn, a tendency for loose fibers escaping from the drafting system and other airborne waste to collect on the binder strand can be observed. When such waste does collect on the binder strand it eventually forms enlarged areas on the binder strand which can ultimately become wrapped into the final yarn product, thereby reducing the quality of that yarn and product. Alternatively, such collections or airborne waste on the binder strand contribute to high tensions in the binder strand especially in the area where the balloon is formed and lead to eventual breakage of the binder strands of the wrapped yarn.
It is, therefore, a primary object of the invention to provide an improved method and apparatus for obtaining high quality wrapped yarns while substantially reducing or eliminating loss in product quality due to the ballooning binder strand picking up airborne fiber waste thereon while being wrapped around a core strand.
Most wrapped or covered yarns are formed by directing a core strand through a hollow spindle as a ballooning binder strand is being withdrawn from a rotating package on the spindle and is being wrapped around the core strand. In some instances it is particularly desirable, if not necessary, that the wrapping of the core strand be effected closely adjacent to the entrance of the hollow spindle in which the core strand is being directed since the hollow spindle then aids in better controlling wrapping of the binder strand about the core strand and in guiding the core strand during the wrapping process. This is particularly the case in the formation of a wrapped yarn having a core strand formed of drafted, generally untwisted staple fibers about which a binder strand is being wrapped.
Typical apparatuses for forming wrapped yarns are disclosed in U.S. Pat. Nos. 3,328,946; 3,831,369, and 4,018,042.
As is well known, substantial amounts of fiber waste in the form of fine airborne waste fibers, or, in the parlance of the textile industry, "fly", are generated by textile machines which process staple fibers and form textile strands therefrom. It has been observed that a substantial amount of this fly is actually derived from the roving being drafted, and this, a substantial amount of the fly proximate any given wrapping station is probably generated by the roving or core strand being processed at that station. It can be appreciated, therefore, that substantial amounts of fiber waste generally are present in the ambient air adjacent machines for wrapping binder strands about core strands formed of untwisted staple fibers. It is also well known that, during the formation of a wrapped yarn in the manner indicated in the above, the binder strand inherently balloons outwardly its path of travel from the package to the core strand being wrapped, i.e., a rapidly rotating ballooning binder strand is present between each binder strand package and the end of the corresponding spindle adjacent which the binder strand is being wrapped around the rest of core strand. Such rapidly rotating ballooning binder strand attracts fiber waste from the ambient air during rotation thereof and while some of the picked up fiber waste is likely thrown off the ballooning binder strand by centrifugal force, much of the fiber waste adheres to the rotating ballooning strand.
Heretofore, in many instances, the fiber waste picked up by the rotating ballooning binder strands stays adhered thereto and grows in size until substantial masses or wads of fiber waste, i.e., so called "flags", are formed on the binder strands. Frequently, the flags are continuously "skinned" back along the binder strand by centrifugal forces and collect in the ballooning area of the binder strand until the ballooning binder strand eventually breaks. Alternatively, some of such wads of accumulated fiber waste would eventually cling to the binder strand and no longer be "skinned" back but, rather, would be carried along with the binder strand and wrapped about the core strand, thus resulting in objectionable slubs or enlarged places in the wrapped yarn being formed. Such defects, of course, reduce the quality of the wrapped yarn. Also, such defects would often cause breakage of the wrapped yarn in subsequent processes such as during passage of the wrapped yarn through the yarn guides and needles of knitting machinery or through stop motions, heddles and reeds of weaving machinery. Further, in rewinding operations, where the wrapped yarn is rewound in cones, it is usual to advance the yarn through a slub catcher during the rewinding operation where the detected slubs are cut out of the yarn then being retied and the rewinding operation continued. Obviously, if the wrapped yarn possesses numerous slubs or flags of objectionable size, the rewinding equipment is going to result in reduced production as it is stopped to tend to removal of the flags. Further, the rewound yarn will have a knot therein where each flag has been cut out thus reducing the quality of the wrapped yarn.
It has been determined that an important cause of end-down conditions in wrapping machines of the character under discussion is the fact that picked-up fiber waste accumulated on the ballooning binder strand would increase to such a mass and weight that centrifugal forces acting thereon would increase beyond the tensile strength of the binder strand. Such end-down condition is a particularly serious problem with the wrapped yarns in accordance with the afore-mentioned commonly assigned U.S. Pat. No. 3,831,369 because, when the binder strand breaks, wrapping about the drafted core strand ceases, the core strand cannot then sustain its own integrity and moves away from the delivery rolls toward the hollow spindle in the form of an uncontrolled mass of open fibers. Such uncontrolled fibers quickly disseminate in the air currents and often times will settle on other yarns being processed on the machine, thus degrading the quality of these other yarns or causing them to break and thereby aggravate the ends-down problem. A further problem arises when the binder strand ruptures and the core strand, rather than breaking immediately, continues to issue from the drafting system and becomes caught within the rapidly rotating spindle supporting the supply of binder strand. With the core yarn so trapped it eventually billows out of the top of the spindle either as a balloon still held at one of its ends by the spindle and still issuing out of the drafting system, or the core strand may break near the drafting system and the loose end held in the rotating spindle can flail about. In either event, the core yarn can then entangle with adjacent core strands, resulting in the break-out of these adjacent core strands in a domino effect.
c. Discussion of Prior Art
In commonly assigned U.S. Pat. No. 3,899,867 method and apparatus are disclosed and claimed for mechanically intermittently and partially collapsing the normal path of travel of the ballooning binder strand so as to impart a delaying movement thereto with consequential vibration of the balloon to cause most fiber waste picked up by the binder strand to be cast off by the same. While the method and apparatus of the -867 patent are effective for the objects just mentioned, it is always desirable to avoid any mechanical contact with a rapidly revolving yarn balloon. Furthermore, it has been found that in practice, particularly where the core strand is comprised of fibers of very short staple the amount of fly in the ambient air may be so great that it is advantageous to completely isolate the zone wherein the binder strand is ballooning to further insure that the binder strand is substantially free of any collections of fiber waste.
In a more recent addition to the prior art, U.S. Pat. No. 4,018,042, which is specifically concerned with a special combination of wrapped yarn properties as well as with the peculiar processing conditions needed to produce them, there is incidentally shown a balloon limiting cylinder approximately coextensive in length with the binder strand package supported on a driven hollow inner spindle, all rotating as an integral unit, and in an alternative embodiment a hollow package held within an external cylindrical container fixed on its bottom wall to the spindle and its upper wall projecting flange-like inwardly to a point spaced from the hollow spindle periphery and below the upper end of the spindle. In such arrangements, a binder balloon of considerable magnitude would necessarily develop in the open region outside the confines of these enclosures and especially in the immediate proximity of the entrance to the spindle bore, and thus to the wrapping zone itself. Consequently, the problems caused by the entrainment of airborne waste by the binder balloon are neither addressed nor resolved by the system of this patent.
STATEMENT OF OBJECTS
Accordingly, it is one object of the present invention to provide method and apparatus for insuring that the zone containing the ballooning binder strand being delivered for wrapping about a core strand is maintained essentially free of fly and other airborne waste by isolating said zone from such fly and airborne waste.
It is a further object of the present invention to provide method and apparatus for obtaining high quality wrapped yarn wherein the zone containing the ballooning binder strand being wrapped about a core strand to form the wrapped yarn is isolated by enclosure means including means for adjusting the binder strand egress gap therefrom to permit free advance of the ballooning binder strand from its source of supply to be helically wrapped about the core strand while substantially precluding entry into the isolated zone of fly and other airborne waste.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a vertical sectional view of a yarn forming unit of the yarn wrapping machine of the present invention including a drafting unit, hollow spindle and yarn take-up means, and illustrating a preferred embodiment of apparatus in association therewith for generally isolating the zone wherein the advancing binder strand is ballooning so as to substantially preclude the entry of fly and other airborne waste into the binder strand ballooning area;
FIG. 2 is a view looking at the left-hand side of FIG. 1 substantially along lines II--II, but illustrating three of the yarn forming units of the machine;
FIG. 3 is an enlarged elevational view of the central portion of FIG. 1 and particularly illustrating details of the enclosure surrounding the supply of binder strand and the binder strand balloon which is formed as the binder strand advances off its supply source to be helically wrapped about a core strand advancing vertically downward from the drafting system;
FIG. 4 is an enlarged fragmentary view of the upper end of the binder strand enclosure illustrating details of the arrangement for adjusting the width of gap between the upper end of the enclosure and the uppermost end of the hollow spindle;
FIG. 5 is a top plan view illustrating details of the upper surface of the binder strand enclosure;
FIG. 6 is a block diagram comparing the effectiveness in reducing the breakage rate during wrapped yarn production of the improvement of the present invention, both in its broad and preferred embodiments, with conventional modes of wrapped yarn production;
FIGS. 7 and 8 are graphs for a mixed polyester cotton core yarn and all cotton core yarn, respectively, of the rate of breakage as a function of the gap dimension in the preferred embodiment of the invention.
FIG. 9 is a graph similar to FIGS. 7 and 8 for a mixed core yarn showing the effect of creating suction within the wrapping zone correlated with the gap dimension in the preferred embodiment of the invention;
FIGS. 10 and 11 are plots of an analysis of the wrapped yarn product, obtained with a mixed and all cotton core yarn, respectively, for the occurrence of excessively thick regions therein as a function of the gap dimension in the preferred embodiment of the invention; and
FIGS. 12 and 13 are grahs showing the variation in yarn tension during a production cycle with the preferred apparatus of the invention versus a conventional apparatus processing a mixed core yarn; while FIGS. 14 and 15 are similar graphs for an all cotton core yarn.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With specific attention now to the drawings, suitable apparatus for forming wrapped yarn in accordance with the present invention is best shown in FIG. 1 as being of the general type disclosed in commonly assigned U.S. Pat. No. 3,831,369. One of the yarn forming units of a yarn wrapping machine is illustrated in FIG. 1, and three such units are partially illustrated in FIG. 2. It is to be understood that the yarn forming units are ganged in side-by-side relationship spaced along the length of a common supporting frame and are normally driven through a common drive belt from a single power source such as an electrical motor (not shown). As shown in FIG. 1, a strand of staple fiber such as roving R is taken off from a package or other suitable source 10. The roving R is directed downward through a trumpet guide 11 and drafted through a suitable drafting unit 12 shown extending in a generally vertical position and provided with a pair of delivery rolls 14 for delivering the drafted core strand S derived from roving R to the yarn covering or wrapping station generally designated 20.
The yarn covering or wrapping station 20 is located adjacent the upper or ingress end 24 of a hollow wrapping spindle 22 which may be of same construction as that disclosed in U.S. Pat. No. 3,831,369 capable of rotatably supporting thereon a removable spool 30 or other suitable package of a binder strand 32 which is wound on the spool 30. Binder strand 32 preferably is continuous and may be in the form of a continuous multi-filament synthetic thread such as nylon. As illustrated, each spool 30 may have flanges at opposite ends thereof. The upper end 24 of spindle 22 is desirably formed as a flat surface for purposes to be discussed hereinafter.
The machine is equipped with a suitable spindle driving member or belt 36 common to all of the spindles 22 along the machine and engaged by the spindles so as to rotate each of said spindles 22 during the forming of a related wrapped yarn Y. A binder strand 32 extends upwardly from each spool 30 and, due to high speed rotation of spool 30, centrifugal force causes the binder strand 32 to form a rapidly rotating balloon B as it travels from the periphery of spool 30 to the region of the wrapping station 20 adjacent the upper free end 24 of spindle 22 where commencement of the wrapping of the binder strand about the drafted core strand S occurs.
The binder strand 32 is wrapped about the core strand S, in the form of spaced apart helices as the core strand, in substantially untwisted condition, passes from the delivery rolls 14, downwardly through an axial yarn passageway 40 extending centrally through spindle 22 from one end to the other and to take-up rolls 44 or any other suitable take-up means. In a preferred embodiment, the hollow spindle 22 is constructed with the usual tubular body 46 having the axial passage or bore 40 extending therethrough and a whorl portion 48 for engagement by drive belt 36. The spindle 22 is supported in a bearing 50 supported in a stationary bearing housing 52 which, in turn, is affixed in a bracket 54, in turn, is pivotally mounted as at 56 to fixed frame member F which constitutes a portion of the wrapping machine support.
The lower end portion of the tubular body 46 of each spindle 22 extends through its associated supported bracket 54 and related bearing 50 as shown in FIG. 1, and has suitable means associated therewith constituting an air flow passageway. Thus, with reference to FIG. 1, the air flow passageway is defined by a respective air flow suction tube or conduit 60 having one end connected to the lower neck-like end 61 of bearing housing 52, and, consequently, to the axial passage 40 extending through spindle 22 and having the other end thereof extending to a suitable suction and collecting device schematically shown at 62 in FIG. 1. It will be appreciated that suction and collecting device 62 extends along the full length of the wrapping machine and is common to all of the wrapping positions along that side of the machine.
Accordingly, a continuous suction air flow is induced along the axial passageways 40 of the plurality of hollow spindles 22, this suction air flow being in the direction of movement of the wrapped yarn through each spindle to prevent waste material, such as lint and other airborne waste, from accumulating in the hollow spindles and interfering with passage of the wrapped yarn therethrough. The suction air flow also aids in directing the fibers of the drafted strand S into the upper end of passage 40 of each spindle 22 during the wrapping of the binder strand 32 about the drafted strand. It will be observed in FIG. 1 that the lower portion of the wall of the suction tube 60 is provided with a suitable eyelet or egress opening 66 therethrough for passage of the helically wrapped yarn Y from the lower end of spindle 22 through the suction tube 60 to take-up means 44.
It has already been mentioned that each spindle 22 and its related parts are supported in a pivotable bracket 52. Each bracket 52 is provided with a generally upstanding operating level 70 by which means the machine operator can exert a generally downward pressure to pivot spindle 22 and its associated parts mounted on bracket 52 downwardly and outwardly to provide access to spindle 22 as when donning and doffing packages of binder strand 32 onto spindle 22. Such position is illustrated by the left-hand yarn forming unit in FIG. 2. Suction tube 60 is formed of flexible material such as plastic to permit ready flexing of the tube during the pivoting motion of bracket 52 and spindle 22. When spindle 22 is pivoted downwardly to the position of the left-hand station in FIG. 2, whorl 48 is withdrawn from engagement with drive belt 36 to thereby halt rotation of the spindle. Similarly, when spindle 22 is returned to its vertical position as shown in FIG. 1, whorl 48 once again engages belt 36 to thereby impart rotation to the spindle.
For further features of the covering or wrapping machine just described reference should be had to the disclosure appearing in commonly assigned U.S. Pat. No. 3,831,369 which is incorporated herein by reference.
As has been stated earlier herein, substantial amounts of airborne fiber waste in the form of rather fine fibers, generally known in the trade as fly, are generated by textile machines which process staple fibers and form textile yarns therefrom. In the absence of any means for controlling the presence of fly in the area of the ballooning binder strand, the fly will be picked up by and will adhere to the balloon B and will continue to accumulate on the balloon until a large fiber waste mass or wad or, as it is sometimes called, "flag", is accumulated thereon. The flag increases the outward or centrifugal force acting on the ballooning binder strand so that, if the flag does not break away from the binder strand or is not otherwise released therefrom, the flag continues to increase in size and results in rupture of the binder strand. As has already been discussed, this ruptured condition, in turn, might release the core strand to rotate rapidly and become engaged with adjacent core strands thus causing a cascading effect breaking out a plurality of further core strands along the wrapping machine. Also, if the wads of fiber waste adhere to and are caused to move upwardly along the binder strand, such wads or flags are wrapped around the binder strand to form objectionable slubs in the wrapped yarn being formed.
According to the present invention, in order to obtain a high quality wrapped yarn and to reduce the occurrence of ends-down conditions, there is provided an improved method and apparatus for isolating the binder strand ballooning zone, i.e., that region which contains the binder strand balloon up to its limit of where the binder strand enters the wrapping station 20 and thereby insuring that most of the fiber waste generated during drafting or present in the ambient air surrounding each wrapping station is excluded from the binder strand ballooning zone during formation of the wrapped yarns. To this end, an enclosure 76 is provided which, except for a necessary ingress or entrance opening for the drafted roving S encloses the upper end of spindle 22 defining the wrapping station 22 and extends in surrounding relation about substantially the supply of binder strand 32. As will be discussed further hereinafter, enclosure 76 is disposed outwardly from supply to permit the formation of balloon B as the binder strand advances to be wrapped about the core strand S. As best seen in FIGS. 1-3, enclosure 76 is stationarily supported on a rigid base 78 having a central aperture therethrough to permit free rotation of spindle 20. Base 78 is secured on an upright member 80 affixed at its lower end to bracket 54. Base 78 has a generally cylindrical, rigid wall 82 attached thereto and extending upwardly around the supply package of binder strand 32 and terminating in a generally frusto-conical section 84 situated somewhat above and adjacent to the upper end 24 of spindle 20. Wall 82 is spaced radially outward from spool 30 to delimit with the periphery of binder package 32 a sheltered zone 86 in which binder strand 32 can balloon as that strand advances for wrapping around drafted strand S. In the preferred embodiment, frusto-conical section 84 of enclosure 76 is hinged as at 90 to permit the frusto-conical section 84 to be opened, as shown in the left-hand spindle position illustrated in FIG. 2, to thereby provide easy access for attending to the supply of binder filament 32 positioned within enclosure 76.
While the exact region along the length of bore 40 of spindle 22 at which the actual wrapping of the binder strand takes place has not been precisely identified, and may well in any event be varying due to the dynamic conditions of the wrapping operation, clearly the ingress end opening of bore 40 is the earliest point where wrapping could be initiated, and this end opening can, therefore, be taken as the beginning or starting point of the wrapping station 20, i.e., the section of the apparatus within which the wrapping operation occurs. The end opening locus also defines for practical purposes the downstream end (in the direction of binder strand travel) of the binder strand balloon (the other end of that balloon lying on the package periphery and moving axially to and fro between the package ends as the binder windings are removed from the package). In approaching the end opening of bore 40, the binder strand necessarily runs in contact with the inner edge of spindle end face 18 which delimits bore 40 (and most likely with more extensive contact with end face 18 marginal to bore 40), and once such contact is made, the free ballooning condition of the strand terminates.
In accordance with the broad concept of the invention, the ballooning zone of the binder strand is sheltered within an enclosure or housing such as enclosure 76 formed of material impervious to ambient textile fly or lint and extending over substantially the entirety of that zone and particularly the portion of the ballooning zone adjacent the wrapping station 20. Hence, the downstream limit of the enclosure should project at least adjacent the entrance to the wrapping zone as defined by the entrance opening of bore 40 to insure the surrounding of the adjacent portion of the ballooning zone.
While, as will be subsequently documented, an enclosure meeting this broad requirement has proved effective to achieve substantial protection of the binder strand balloon from entrainment of airborne fiber waste, it is preferred that the downstream limit of the enclosure define with the upper end of the spindle 22 a constriction, desirably adjustable in dimension, which establishes restricted communication between the ballooning zone allowing free passage of the binder strand therethrough while maximally restraining fly from entering the ballooning zone therethrough and can, at the same time, define an entrance opening for core strand S to the wrapping zone. Such a construction has been found uniquely effective in excluding substantially all of the airborne waste from entering the zone 86 defined within enclosure 76, i.e., that zone in which balloon B is formed as the binder 32 advances to be wrapped around the core strand up to the point of proximity with the wrapping station entrance.
Thus, with particular attention at this point to FIG. 4 it will be seen that the upper end of frusto-conical enclosure section 84 has a threaded bushing 104 secured thereto in generally coaxial relation to the upper end of spindle 22 with the bore through the bushing being threaded to accomodate a mating sleeve 106. The shank 108 of sleeve 106 is threaded along substantially its full length and is provided with a mating check nut 110. The lower end 112 of shank 108 is extended radially as a flange or lip generally parallel to the upper end face 24 of spindle 22 and the overall length of the shank is sufficient to extend downwardly into zone 86 to a point where its lower end 112 can, if sleeve 106 is fully lowered, actually bear against the upper face 24 of spindle 22. In operation, a gap 116 defined between the mutually adjacent surfaces of flange 112 and spindle face 24 is created by elevating sleeve 106 a predetermined distance above the upper end face 24 of spindle 22 to afford passage through said gap of binder strand 32. In working tests of the present invention, it has been found that the amount of airborne waste entering zone 86, at least as manifested by the operational consequences of such waste, is generally proportional to the dimension of gap 116. That is to say, the greater the size of gap 116, the greater the operating difficulties which are considered attributable to the accumulation of airborne waste within zone 86. In these tests the roving was 50/50 cotton-polyester, 11/2 in. staple length, or all cotton, 1 in. ave. staple length, and the binder yarn was polyester, 20 denier monofilament. The drafting system was an SKF-PK-235 manufactured by SKF Kugellagerfabriken GMBH of Stuttgart, Germany, and the draft was 36.6. Spindle 22 was operated at 20,000 RPM inserting 13 T.P.I. into strand S, the core yarn was 30 S cotton count.
A first series of tests had, for its objectives, the determination of the magnitude of the basic problem encountered in the conventional yarn wrapping process, as a control, and then the comparative effectiveness in reducing this problem of (1) the improvement of prior art U.S. Pat. No. 3,899,867, (2) the balloon sheltering enclosure of the invention without the special gap adjusting feature, and (3) the balloon sheltering enclosure of the invention with the special gap adjusting feature. In these tests, a group of spindles constructed according to each of these arrangements 1-3 plus the control was operated for a given period of time and the number of breaks or ends down of any kind which occurred during the given operating period were recorded and converted to a common basis corresponding to the total number of breaks for 1,000 hours of spindle operation. The results of these tests are summarized in block diagram fashion in FIG. 6. From the data in FIG. 6, one learns that a tremendous number of breaks or ends down does, in fact, occur during the operation of the conventional yarn wrapping system, exceeding 6,000 breaks per 1,000 spindle hours. Translating this figure into practical terms, it follows that approximately 6 breaks would occur for each spindle hour or about one per spindle every 10 minutes. Assuming the aggregation in a commercial machine frame of a total of only 100 individual wrapping units or stations, it follows that a total of 600 breaks or ends down could be expected per hour of operation of the frame or 10 breaks per minute. It would be humanly impossible for a single operator to repair so high a frequency of breaks and maintain even one commercial frame in full operating condition which, obviously, would greatly add to the expense of operating this type of machine.
The improvement of the prior art -867 patent wherein the yarn ballon is intermittently intercepted on each revolution and vibrated to dislodge entrained fly does achieve a very substantial improvement in operation, reducing the extent of breakage by slightly over 90%. The binder strand sheltering enclosure of the invention, without the special gap adjusting feature, is roughly equally effective with the prior art -867 patent but without the necessity for physically intercepting the balloon during each rotation thereof with consequential potential degradation in the quality of the final wrapped yarn product or other undesirable results. Where, however, in the ideal practice of the invention the special gap adjusting feature is added to the balloon sheltering enclosure, the number of yarn breaks or ends down is reduced by more than 99% over a range of gap dimensions of about 0.004-0.112 in.
To provide specific indication of the effect on yarn breakage rate of varying the gap dimension according to the special feature of the invention within the just specified range of 0.004-0.112 in., an additional series of tests was carried out using, first, a core yarn constituted of a 50/50 mixture of polyester and cotton, and second, an all cotton core yarn, and the number of breaks occurring for each of these two types of core yarns is plotted in FIGS. 7 and 8 with the gap being set with a clearance dimension of 0.004, 0.008, 0.016, 0.032, 0.064, and 0.112 respectively, the last figure representing the maximum retracted position for the sleeve 106 that was possible with the test apparatus. The curves of FIGS. 7 and 8, show that for the "mixed" core yarn, the break rate with the gaps at the small end of this range is in the order of 20 or less per 1,000 spindle hours which virtually equals the ideal operation of the machine, while with gaps toward the upper limit, the break rate increased to only about 50 per 1,000 spindle hours. The break rate increases somewhat more rapidly with the all cotton core yarn, stabilizing at about 50 per 1,000 hours for a gap of about 0.016 and remaining virtually constant about that level, while the "mixed" core yarn varied essentially linearly between the two gap limits. This contrasting behavior cannot be reasonably explained with currently available information, although it would appear likely that if the gap were increased above the stated limit for the "mixed" core yarn, the break rate would likewise tend to stabilize at a maximum value. Even a break rate of 50/1000 spindle hours is within the limit of commercially acceptable operation, amounting to approximately 5 breaks per hour for a 100 position machine frame which means that a single operator could effectively tend to several of such frames with relative ease.
The inducement of an air flow current through the wrapping zone, by connecting the lower end of the spindle to a suction source, is already among the measures employed in the prior art, as evidenced by the same -867 patent. To illustrate the influence of this measure upon practical operation, tests similar to those above were carried out in a system utilizing the balloon sheltering enclosure of the invention in its preferred form incorporating the adjustable gap feature with and without this suction current, and the results of this comparison appear in FIG. 9. From these results, one observes that the suction current is an important adjunct to the features of the present invention as it presumably is to the system of the -867 patent as well.
Mention was made in the introductory description of this specification of the possibility of the airborne fly entrainment becoming manifested in the creation of enlarged regions or slubs along the length of the ultimate wrapped yarn product even when such entrainment was not sufficiently serious as to bring about complete rupture in the strand being processed. To gauge the magnitude of this aspect of the problem, samples of wrapped yarn product which had been actually produced and collected independently of any breaks, were scanned for the occurrence of excessively thick regions or slubs along its length, by means of a suitable apparatus known in itself in the art for this purpose, namely, an Uster Model B Evenness Tester equipped with an Imperfection Indicator Attachment operated at a "sensitivity setting" of 3. The number of thick regions or slubs projected on the basis of 1,000 yards of yarn length is plotted in FIG. 10 and FIG. 11 for the mixed polyester/cotton core yarn and all cotton core yarn, respectively, over the gap range of 0.004-0.112. For the polyester core yarn, the number of thick regions was at a minimum with the narrower gap dimensions, while for the all cotton core yarn, the number of thick yarns remained essentially constant throughout the gap range, the apparent slight increase for the smaller gap dimensions being probably statistically insignificant.
Finally, during experimental testing of the preferred embodiment of the invention, high and low tension readings were taken in the running wrapped yarn product at a point intermediate the lower end of the hollow spindle and the wrapped yarn collection package at periods during the test operation and these values plus an average are plotted in FIGS. 12 and 14 for both the "mixed" core yarn and the all cotton core yarn, respectively, in relation to the change in the wrapper filament package diameter during an operating cycle. Similar tension readings were taken periodically during a production cycle for the same yarns but processed in the conventional manner and these values likewise related to the wrapper filament package diameter at the time of measurement appear in FIGS. 13 and 15. As is evidenced from these four graphs, the operating tension in the product yarns produced in accordance with the ideal version of the present invention exhibit a high level of uniformity with beginning to end of the wrapping operation irrespective of the kind of core yarn being processed. In distinct contrast, the operating tensions for yarns produced in the conventional way, without any enclosure according to the invention, show drastic varition, rising sharply particularly near the end of the cycle. This means that the windings of the product yarn collected near the end of a cycle are under maximum tension and thus tend to cause packing or compression of the previously collected windings which were applied under much lower tension. Such a result is undesirable in the textile art particularly for a rather bulky yarn product as in the present invention, causing this product to lose some of its desirable loftiness. In addition, the application of later windings at high tension can cause these windings to become embedded in previous soft windings, leading to possible complications when the yarn product is unwound for fabrication into consumer goods or occasional rewinding prior to fabrication.
It is not understood at the present time why the running yarn shows such major tension variations when the wrapping operation is carried out in the conventional way, but these results confirm the general instability of the conventional wrapping operation because of the accumulation of lint or fly.
It was earlier pointed out that the upper end face 24 of spindle 20 is desirably a flat surface, and similarly, that the lower surface of shank end 112 is provided as a flat surface at least roughly coextensive with face 24 so that their surfaces are parallel as seen in FIG. 4. Thus, gap 116 is preferably an elongated radially directed passage extending between the end face 18 and flange 112, with a radial dimension or length which can conveniently approximately equal the annular thickness of spindle end face 24.
As is more fully discussed in the afore-mentioned U.S. Pat. No. 3,831,369, it is desirable that individual fibers of the roving constituting strand S have a staple length such as to be engaged at one end by the nip of delivery rolls 14 while their leading ends are being wrapped by binder strand 32. Consequently, since, as is apparent from FIG. 4, the wrapping of strand S occurs downstream of sleeve 106, it is desirable that this sleeve be of a length somewhat shorter than the average staple length of the fibers making up strand S so that the individual fibers have entered the spindle bore at their leading ends before being released at their trailing end from the nip of the delivery rolls 14.
It is thus seen that the present invention provides an improved method and apparatus for obtaining a high quality wrapped yarn Y by means of a wrapping operation wherein the balloon B formed by binder strand 32 as it is advanced to be helically wrapped around the core strand S is isolated virtually up to its entry to the wrapping station by the zone 86 from the ambient conditions surrounding the machine as well as from the path of the core strand itself to thereby prevent the formation of flags on binder strand 32 by accumulation of the fiber waste which otherwise tends to adhere to the balloon binder strand. The provision of an air flow passageway 60 connecting the hollow spindle 22 to the source of suction 62 to induce an air flow into and through the spindle in the direction of movement of the wrapped yarn therethrough aids in directing the core strand S into the hollow spindle 20 and, as already indicated, in inducing any fly entering the aperture through sleeve 106 downwardly through passage 40 of the spindle. Moreover, and more importantly, the isolation of zone 86 can be optimized to the requirement of a particular set of operating conditions by the provision of gap 116 of adjustable dimension between the upper end face 24 of spindle 22 and the lower end of sleeve 106 for emergence of the binder strand therefrom so that, while binder strand 32 remains free to advance for helical wrapping about the core strand S, the communication between zone 86 and the ambient atmosphere is controlled and confined so as to increase the resistance to fly entering zone 86. It follows that by precluding the entry of significant fly into zone 86 the opportunity for flag formation on binder strand 32 is essentially minimized or even virtually eliminated and the substantial disadvantages attending flag formation on the ballooning binder strand, which have been discussed earlier herein, are avoided.
It has been observed that during the operation of a single spindle unit or position under controlled laboratory conditions where the presence of randomly airborne fly or lint in the ambient atmosphere surrounding that spindle unit generally was virtually nonexistent, the spindle nevertheless suffered the problem of lint accumulation on the binder strand balloon with the consequential formation of flags and a high rate of ends-down due to yarn breakage to a series extent when operated in the conventional way without the improvement of the present invention. Since the ambient atmosphere during operation under these conditions itself contained virtually no lint or fly which could have been entrained by the ballooning binder strand, it follows logically that the source of the fly or lint which did, in fact, accumulate during such operation must have been the fly or lint generated during the drafting and related handling of the core strand of this unit itself. This conclusion suggests that an important, and possibly critical function, performed by the improvement of the invention is the containment of the fly or lint generated in the region between the nip of the drafting delivery rollers and the ingress end of the wrapping zone, as a consequence of the drafting operation and the movement of the strand through this region, and prevention of the fly or lint from escaping or being dispersed away from the path of the advancing core strand into the region of the ballooning binder strand. This being the case, the lower limit of the enclosure 76 may well serve a less necessary role in achieving the objectives of the invention so that it might well not be required that the lower limit of such enclosure be fully coextensive in length with the binder strand package or that the lower skirt of the enclosure be entirely impervious to textile lint or fly. However, the provision of a full enclosure, as shown in the drawings, may well have practical advantages from the standpoint of design and constructional simplicity if not from the standpoint of operating effectiveness directly.
In the drawings and specification there has been set forth a preferred embodiment of the invention and where specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.
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Method and apparatus for producing high quality wrapped yarn by a wrapping operation wherein a binder strand, carried by a supply package supported by a rotatably driven hollow spindle, is fed to the free end of the hollow supply spindle and wrapped around a core strand moving through the hollow spindle. The binder strand inherently balloons outwardly in its path of travel from its rotating supply package to the core strand being wrapped. The zone in which the binder strand balloons is enclosed to isolate it from the ambient air about the wrapping apparatus to thereby substantially preclude pick up of fiber waste on the binder strand. Suction means communicates with the hollow spindle to attract the core yarn and facilitate passage of the wrapped yarn therethrough. Isolation of the zone in which the binder strand balloons is obtained by enveloping the package and balloon-forming region of the binder strand with an enclosure. The top of the enclosure is provided with an aperture to permit the delivery of core strand through the enclosure to the hollow spindle. Preferably, the inside margins around the enclosure aperture are designed to define with the adjacent end face of the hollow spindle an annular radially extending passageway for passage of the binder yarn, and means are provided to adjust the spacing between the hollow spindle end face and the aperture margins to optimize the exclusion of fiber waste from the ballooning zone.
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FIELD OF THE INVENTION
[0001] The present invention relates to an improved and more efficient method of producing aqueous buffers and other aqueous solutions used for various unit operations such as chromatography in the processing of biopharmaceuticals or other applications by utilizing continuous generation from common stocks of concentrated constitutive acids and bases, as well as salts and other needed reagents.
BACKGROUND OF THE INVENTION
[0002] The present invention is directed to a method of producing solutions which require pH-controlled buffers either for product processing operations or as the final product. These processes or products have in common the need to control pH, which is done through the use of a buffer compound containing ionizable groups, and adjusting the pH of the solution to within approximately 1 pH unit above or below the pKa of the ionizable groups. In this pH range, the ionization equilibrium of the ionizing groups has a buffering effect, making the pH of the solution reasonably stable to small changes in pH from chemical reactions to which it may be exposed that add or remove hydrogen ions from the solution. In current industry practice, these pH buffer solutions are usually created by making an aqueous solution of a purified salt form of the buffering compound, adding any additional solution components required for the application (such as other salts, surfactants microbial inhibitors, and the like) and then adjusting the pH of the solution up or down by the controlled addition of either acid or base (often HCl or NaOH) as required. The buffering compound and additives are most often in the form of dried (often crystalline) salts, which are relatively expensive. The acid or base forms of the buffering compound are often supplied as a concentrated liquid, and are most often substantially less expensive than the corresponding dried salt.
[0003] Applications for pH buffered solutions include all of the unit operations used in production and downstream purification of biopharmaceuticals, including those produced by fermentation of microbes, fungus or yeast, mammalian or insect cell culture and transgenic animal and plant sources. The unit operations which use pH buffered solutions include filtration, centrifugation, precipitation, crystallization and chromatography. Chromatography operations in particular utilize different pH buffered solutions for loading the column, washing, eluting the product, regenerating, and re-equilibrating the column. Every unit operation is achieved in discrete sub-batches or cycles, with a product batch comprised of one or more unit operation cycles. Other applications for the invention might include products which themselves are pH buffered solutions. Examples of such products include ophthalmic solutions and infusion solutions.
[0004] In these applications for this invention, the final use of the buffered solutions often requires that the solutions be aseptic, and in some cases sterile. The final blended buffer solution is often quite supportive of microbial growth. Practical production, handling and storage of aseptic or sterile solutions requires very careful, specialized and expensive design and construction of all the equipment which contacts the solution. In addition, the equipment must be subjected to rigorous clean-in-place (CIP) procedures following usage to insure no chance of microbial contamination being present for the next batch, and may also require steam-in-place (SIP) procedures to insure sufficiently clean conditions. The water used for these applications is produced to very high purity requirements (most often water-for-injection or WFI), and is costly to utilize. These requirements for aseptic or sterile system make both the capital and operating costs of such processes very high.
[0005] The concentrated acids and bases, and in many cases other ingredients in highly concentrated forms (such as salts) do not themselves support microbial growth. In fact, the highly concentrated acids and bases are often themselves used as the primary cleaning solutions for CIP operations, because of their ability to at least partially sanitize process systems. Thus the storage tanks and distribution systems for these ingredient feeds in the present invention do not necessarily need to be designed, constructed and operated to meet aseptic or sterile standards, and can thus be far less expensive and much simpler.
[0006] In many modernized plants tasked to the production of biopharmaceuticals, the systems designed for unit operations require both large capital outlays and a large labor force. The state of the art is such that the current processes provide to the combination of multiple buffers, eluents, regenerants, and other solutions employed in the unit operations individually. The components for each of these numerous and various solutions are mixed with the appropriate pharmaceutical grade water (such as water for injection or “WFI”) in large, shared solution blending tanks. Thereafter, the resulting solution is microfiltered, tested, and transferred to individual, dedicated holding tanks before the commencement of the processing which utilizes a specific batch of a reagent. Subsequent to the usage of the batch of solution, the transfer piping system and the blending tank need to be meticulously cleaned in place “CIP” and often SIP procedures prior to the production of the next solution.
[0007] Also, according to the prior art, synchronizing the solution preparation operations to enable the equipment to be utilized well and to ensure the accessibility of all solutions when needed can amount to a substantial challenge and incurs substantial cost. In an ordinary biopharmaceutical and pharamaceutical production facility of the prior art, a significant portion of the space and capital investment is reserved for solution preparation, a distribution system, and a multitude of solution storage tanks. In addition, with batch-wise blending, the span of scales that can be managed by a specific dimension of tanks and distribution systems is restricted. If the tanks are too limited in volume, they will lack the capacity required for a whole batch or cycle of production. If they are too large, the solutions will remain stationary for too long sometimes allowing inappropriate or economically undesirable chemical changes, and capital investment will be excessive for small scales, leading to a lack of commercial flexibility.
[0008] In more recent years, some biopharmaceutical production facilities have been designed using the concept of producing and storing concentrates of the solutions, which are then diluted online with the appropriate pharmaceutical-grade water at the point of use. This approach can reduce the size of the required solution storage tanks, and significantly reduce the number of times batches of solutions must be produced and the storage tanks and distribution systems cleaned. However, the number of storage tanks and the complexity of the distribution systems is not reduced with this approach. Also, the ultimate concentration factor of the storage form of the solution is limited by the solubility of the least soluble component.
[0009] As the scale of biopharmaceutical processing operations is increasing, plants are being designed and built with continuous unit operations instead of the conventional batch operations. Continuous cell culture approaches, for example, are becoming quite commonplace. Transgenic production systems are either semi-continuous (as for example with transgenic dairy animals, which produce milk 2-3 times every day) or can be treated as such (as for example with transgenic crops, which can be stored for long periods as a feed for continuous downstream processing). Increasingly, continuous downstream purification unit operations are also being developed. An example of such a unit operations is simulated moving bed or SMB chromatography.
[0010] Although maintaining batch integrity involves less difficulty to comply with the regulatory requirements of strict traceability of all procedures and materials employed in the production of a given lot of final drug product, there are disadvantages and problems to batch design. The most paramount is the inefficient utilization of equipment capacity. For a significant portion of the time, any given tank or other piece of equipment in the plant is simply waiting for the execution of the antecedent steps, for the unit operations, or for the following batch. Meticulous succession and staggering of cycles can aid in the enhancement of capacity utilization; however, the stepwise sequence within the unit operations places a restriction on this approach. There is a viable need to notably enlarge the capacity utilization, particularly for products manufactured on a relatively substantial scale (hundreds of kilograms to tons per year).
[0011] Continuous processes place particular demands upon the solution preparation systems within a production plant. Because the solutions must be supplied continuously, it is not possible to stop to clean the storage/feed tanks, produce new batches of needed solutions and then refill the tanks. Therefore, in such plants each solution must have two storage tanks with associated distribution systems—one for supply of the operation itself and a second which is being cleaned and refilled while the first is being utilized. This requirement significantly increases the cost of such facilities, and negates some of the benefits of continuous operations.
[0012] With regard to the prior art, individual patents are discussed below, U.S. Pat. No. 4,907,892 entitled “Method and Apparatus for Filling, Blending, and Withdrawing Solid Particulate Material from a Vessel” discloses a method for blending solid, particulate material with liquids to form a suspension, with an apparatus with a continuous blending unit. This method, however, neither blends solutions to create aqueous buffers nor allows for the production of biopharmaceuticals. Moreover, the apparatus contains a sensor to monitor the quantity of material in the vessel by its height or weight plus a controller that responds to the sensor for regulating the particulate material feed rate or the material withdrawal rate in order for the material supply rate and blended substance withdrawal rate to be balanced to direct the material level inside the vessel to a preferred level. In FIG. 3 of this application, in the blending unit, positive displacement chemical metering pumps are utilized to proportion the ingredient streams, entering the processing plant, not to regulate or to measure the amount of solution in the blending unit. The blend for each solution is regulated by the combination of the pump head sizes and adjustable stroke lengths.
[0013] In U.S. Pat. No. 6,180,335 entitled “Apparatus for Detecting Contamination in Food Products” the food sample is combined with a buffer solution and a blending buffer. According to the claims of this patent, the purpose of the mixing event with a buffer solution is to ultimately quantify the amount of bacterial contamination in a food sample. The claims do not disclose a method of producing pH buffered solutions themselves in a continuous or automated way. Moreover, the solution does not appear to be involved in any pharmaceutical production, but rather a diagnostic application.
[0014] In U.S. patent application Ser. No. 20020156336 entitled “Method for Continuous Detoxification of Poisonous Agent or Toxic Chemical Compound, or Soil Contaminated by Said Poisonous Agent and/or Toxic Chemical Compound” discloses a method for continuous detoxification of substances by blending of reagents with the feedstream to be detoxified, but does not contemplate or disclose the production of biopharmaceuticals.
[0015] In U.S. Pat. No. 6,186,193 entitled “Continuous Liquid Stream Digital Blending System,” this invention is directed to a method and an apparatus for continuous stream blending. The approach taught in this patent is to blend an appropriate number of small-volume “digital slugs” of fluid in a tank as a convenient way of producing a blended stream. It does not teach the specific use of blending constitutive acids and bases to produce a pH buffered solution, particularly for the use of biopharmaceuticals.
[0016] U.S. Pat. No. 6,162,392 entitled “Method and Apparatus for Super Critical Treatments of Liquids,” this invention is directed to a method to sterilize a liquid in a continuous, pressurized system consisting of de-pressurizing and cooling steps, not related to producing biopharmaceuticals. This patent utilizes pumps for controlled flow rate and increases and decreases in the temperature of a treated solution, but does not involve blending of chemicals.
[0017] In U.S. Pat. No. 5,823,669 called “Method for Blending Diverse Blowing Agents” discloses a method for continuously and precisely blending multiple gaseous or volatile liquids at low pressures, not buffering solutions.
[0018] U.S. Pat. No. 5,552,171 entitled “Method of Beverage Blending and Carbonation” discloses a method and an apparatus to procure a very precise control of the blend, but it does not involve the blending of buffer solutions for pharmaceutical purposes.
[0019] In U.S. Pat. No. 5,340,210 referred to as “Apparatus for Blending Chemicals with a Reversible Multi-Speed Pump” discloses an apparatus to blend substances with a pump for each type of chemical such as water-based and oil-based. This invention discloses multi-speed pumps which do not pertain to proportioning the ingredient streams.
[0020] The prior art (both within patents and in industry practice) teaches numerous methods of using continuous blending to produce various types of chemical solutions from mixes of solids, liquids and gases. However, the prior art does not teach a continuous, automated blending from constitutive acids and bases of pH buffered solutions used for the production of biopharmaceuticals or other products, according to the method of the current invention. Moreover, the current invention provides advances in biopharmaceutical production that allow processing of compounds, especially biopharmaceutical, on a more efficient and economically flexible basis. The invention can reduce the material costs for these products through the utilization of less expensive acids and bases rather than the more expensive dried salt forms of the buffering compounds. In addition, the current invention, according to a preferred embodiment, is much more suitable for continuous (instead of batchwise) production methods fermentation. Such production methods can be used with continuous perfusion cell culture and the production of proteins from the milk of transgenic dairy animals or from transgenic plant extracts, where the seed or plant form may provide very long term storage of the raw material, enabling continuous unit operations for purification.
SUMMARY OF THE INVENTION
[0021] According to the current invention, the batchwise, manual blending of pH buffered solutions is improved upon through the use of an automated solution blending technique of the current invention. This method utilizes concentrated acids and bases to form the primary buffer solution, and concentrated solutions of salts, surfactants or other additives blended in to form the final solution. In a preferred embodiment of the current invention, a small number of feed solutions is used to make a variety of reagent compositions improving efficiency of operation, decreasing error, and lowering cost. Moreover, the operation may be, in a preferred embodiment, continuous.
[0022] The buffering compounds can include inorganic acids (such as phosphoric or boric acid), simple organic acids (such as acetic or citric acids), organic bases (such as tris-hydroxymethyl amino methane (TRIS), and so-called Good's buffers including HEPES, MOPS, MES, etc.). The buffering compound is usually combined with a strong base (such as sodium or potassium hydroxide), or a strong acid (such as hydrochloric) as appropriate to produce the final pH desired. The acid and base are supplied to the system as liquid concentrates, usually at a very high concentration. Other ingredients are also supplied as pure liquids or concentrated solutions. These other solution ingredients can include salts (such as sodium, potassium or magnesium chloride, sodium or ammonium sulfate,, and the like), surfactants (such as Tween), chaotropic or solvophobic agents (such as ethylene glycol, urea, sodium thiocyanate, or guanadinium hydrochloride), mild reducing agents (such as cysteine or mercaptoethanol), microbial or proteolytic inhibitors (such as thimerosol, sodium azide, and the like), precipitation or extraction agents (such as polyethylene glycol, dextran, and the like), etc.
[0023] Once the ingredients are properly loaded into the processing plant, the individual ingredients are blended. In one embodiment the ingredients are continuously blended on demand by pumping the various streams (water, acid, base and other additives) at controlled flow rates into a mixing device (static or active mixer), and the resulting pH buffered solution is then used directly and immediately in the process. Control of the pH may be implemented by placing a pH sensor downstream of the mixing point and using the value to control the relative flow rates of the acid and base streams.
[0024] In a second embodiment, the individual ingredients are pumped either simultaneously or sequentially into a small, stirred tank with sensors for pH, conductivity, temperature, and level. When this small tank is filled and mixed, the solution characteristics are reviewed (either automatically or manually) against specifications. If the results are approved, the individual solution is released. A second small buffer tank can be employed to permit time for blending and checking. This practice ensures that the same Good Manufacturing Practices (GMP) quality standards can be satisfied as with batchwise solution blending.
[0025] Utilization of this method results in reduction in cost for buffer solutions by employing concentrated buffer acids and bases instead of more expensive buffer compound salts. Moreover, a considerable reduction of costly sanitary design tankage and piping proceeds from this method. A very broad scale range is able to be accomplished without more capital expenditures. The approach used in the invention is also highly advantageous for continuous processes and unit operations. Other features and advantages of this invention will become apparent in the following detailed description of preferred embodiments of this invention, taken with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 shows a downstream processing plant with the conventional batchwise solution blending of the prior art.
[0027] [0027]FIG. 2 shows a downstream plant demonstrating continuous solution blending from acids and bases.
[0028] [0028]FIG. 3 shows a buffer blending unit design for direct online blending.
[0029] [0029]FIG. 4 shows a buffer blending unit according an embodiment utilizing an inline mixing tank.
[0030] [0030]FIG. 5. shows a model of the facility elements of a typical of a biopharmaceutical production plant
[0031] [0031]FIG. 6 shows a transgenic human serum albumin process scheme.
[0032] [0032]FIG. 7. shows a chart comparing the cost of the current invention relative to conventional batchwise processing.
[0033] [0033]FIG. 8 shows human serum albumin process scheme utilizing a simulated moving bed design.
[0034] [0034]FIG. 9 shows an alternate and simplified transgenic human serum albumin process scheme.
[0035] [0035]FIG. 10 shows a downstream plant demonstrating continuous solution blending from acids and bases and SMB.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The following abbreviations have designated meanings in the specification:
[0037] Abbreviation Key:
[0038] SMB An abbreviation for simulated moving bed chromatography.
[0039] pH A term used to describe the hydrogen-ion activity of a chemical or compound according to well-known scientific parameters.
[0040] WFI An abbreviation for water for injection.
[0041] CIP An abbreviation for cleaned in place.
[0042] GMP An abbreviation for Good Manufacturing Practices.
[0043] Explanation of Terms:
[0044] Biopharmaceutical
[0045] shall mean any medicinal drug, therapeutic, vaccine or any medically useful composition whose origin, synthesis, or manufacture involves the use of microorganisms, recombinant animals (including, without limitation, chimeric or transgenic animals), nuclear transfer, microinjection, or cell culture techniques.
[0046] Buffers
[0047] a system that acts to minimize the change in concentration of a specific chemical species in a solution against the addition or depletion of this species.
[0048] Cell Culture
[0049] general term referring to the maintenance of cell strains or lines in the laboratory.
[0050] Chromatography
[0051] any of a multitude of techniques for the separation of complex mixtures that are dependent upon the differential affinities of substances for a gas or liquid mobile medium and for a stationary absorbing medium.
[0052] Feedstream
[0053] the raw material or raw solution provided for a process or method and containing a protein of interest.
[0054] Simulated Moving Bed Chromatography
[0055] a continuous solid-liquid dissociation method that purifies two components of a feedstock. Both components are generated at a superlative yield and purity.
[0056] The method of the current invention provides an efficient process to produce pH buffered solutions that will ultimately be converted into or used as pharmaceutical products. The primary ingredients that compose a mixture are water, and a buffer acid and base at a particular concentration and in a particular ratio to produce a desired final pH. In addition, the solution may include other solution ingredients, such as salts, surfactants, inhibitors etc., see detailed listing above. The individual ingredients are blended at the point of use using an automated blending unit.
[0057] In one preferred embodiment of the invention, as shown in FIG. 3, reciprocating, positive displacement chemical metering pumps are used to regulate the flow of the ingredient streams. The precise blend for a particular solution is fixed by the combination of pump head sizes and flexible stroke lengths. The various streams are simultaneously pumped into a mixing unit of either a static or active type. If required, sensors for pH and conductivity can be placed inline after the mixer and their output utilized to control the relative ratios of the acid, base and other ingredients. In this embodiment, the solution is utilized immediately by the process being supplied.
[0058] In a second preferred embodiment, the solution ingredients (water, acid, base and any other ingredients) are metered out by pumps and mixed in a small tank. The metering operation can be done simultaneously for all ingredients (using the same type of positive displacement chemical metering pumps utilized in the first embodiment). Alternatively, the metering can be done sequentially for each ingredient, using either metering pumps or control through the use of a level sensor or load cell placed on the mixing tank. The mixing tank would be equipped with sensors for pH, conductivity, level and possibly other parameters. When the blending operation in the small mixing tank is completed, the sensor measurements would be compared to a release specification, and the solution would be released for use in the process if the specifications are met. If the solution is required to be supplied continuously to the process, two small mixing tanks could be used, one of which would supply released solution while the other is being used to blend a new tank of solution.
[0059] The first preferred embodiment of the invention is simpler and less expensive to construct, and may be truly continuous, according to a preferred embodiment of the invention. This would be the embodiment used for a large fraction of the applications. The second embodiment incorporates some of the current elements of good manufacturing practice (GMP) for pharmaceutical manufacturing, and may be required for some particularly critical process steps.
[0060] Turning to FIG. 7, the design and testing data on the human serum albumin downstream purification process shown in FIG. 5 were used as input to a detailed process cost modeling software system (Paradigm One, Applied Process Technologies, Wilmington, Mass.). The software package estimates detailed capital and operating costs based upon specific process parameters, selected equipment, utility and space requirements, etc. For this model, a facility was designed to produce 25 tons per year of purified bulk active pharmaceutical ingredient (bulk API) from transgenic milk containing human serum albumin. For the comparison, all unit operations (see FIG. 6) were kept constant, and only the solution preparation and storage system and process utilities were modified to reflect the blending of buffers directly from acids, bases and additives. Moreover, due to the process of the current invention the facility (building) costs were reduced significantly, due to the reduction in space requirements by the elimination of many solution storage tanks and distribution piping. This also is reflected in the reduction in costs for the equipment needed for solution prep and CIP. There was also some reduction in the size and cost of the required water system. Overall, the estimated capital cost for the plant was reduced by $6.1 million (˜16%) through the introduction of the use of the methods of the invention.”
[0061] Although plentiful literature exists regarding the structure, function, and diseases associated with human serum albumin and alpha fetoprotein, the prior art does not disclose an efficient, automated, and continuous method of blending buffers and other solutions to process these proteins. With regard to alpha fetoprotein, U.S. Pat. No. 5,384,250 entitled “Expression and Purification of Cloned Alpha Fetoprotein,” explains a method for making human alpha fetoprotein in prokaryotic cells only. In addition, U.S. Pat. No. 5,206,153 entitled “Method of Producing Human Alpha-Fetoprotein and Product Produced Thereby” discloses a method to make human alpha fetoprotein whereby a DNA sequence for rat alpha fetoprotein is combined with the DNA for human alpha fetoprotein. These methods, however, do not yield a supply of human alpha fetoprotein by the use of the continuous, automated blending of buffers and other solutions.
[0062] As mentioned previously, this method may be employed to process human serum albumin and alpha fetoprotein for therapeutic applications. Serum albumin, the most well-known plasma protein, is responsible for a variety of physiological functions such as sustaining the osmotic pressure in the blood and transporting fatty acids and bilirubin (Peters 1995). Testing levels of serum albumin from feedstreams may be conducted to see if the subject has liver or kidney diseases or if an insufficient amount of protein is consumed by the blood. Decreased levels of serum albumin may signal such diseases as well as ascites, bums, glomerulonephritis, malabsorption syndrome, malnutrition, and nephritic syndromes.
[0063] In addition to measuring levels of serum albumin to detect disorders, synthesizing this protein is beneficial for therapeutic purposes. Albumin products are employed to maintain the plasma colloid oncotic pressure and to remedy severe edema by enabling intracavital and interstitial fluids to travel into the blood vessels. Albumin products may be administered to alleviate acute hypoproteinemia and pathological conditions stemming from chronic hypoproteinemia. Albumin products may be utilized to treat hypovolemic shock, severe bum injury, adult respiratory distress syndrome, ascites, liver failure, and pancreatitis. (Cochrane et al., 1998). Albumin may also be administered to remedy hyperbilirubinemia, hypoproteinemia, and nephrotic syndrome. (Vermeulen et al., 1995).
[0064] Alpha fetoprotein is another protein that may be processed for beneficial reasons. It is a protein assembled by the liver and yolk sac of a fetus. Throughout pregnancy, heightened levels may signal the following fetal abnormalities: spina bifida, anencephaly, omphalocele, tetralogy of Fallot, duodenal atresia, Turner's syndrome, and intrauterine death.
[0065] In addition to fetal diseases, monitoring increased levels of alpha fetoprotein may be useful in pinpointing cancers of the stomach, pancreas, biliary tract, testes, and ovaries, and recuperation from hepatitis.
[0066] According to an embodiment of the current invention when multiple or successive rounds of transgenic selection are utilized to generate a cell or cell line homozygous for more than one trait such a cell or cell line can be treated with compositions to lengthen the number of passes a given cell line can withstand in in vitro culture. Telomerase would be among such compounds.]
[0067] Accordingly, it is to be understood that the embodiments of the invention herein providing for an increased efficiency and speed in the production of chemical, biochemical, or biopharmaceutical processing are merely illustrative of the application of the principles of the invention.
[0068] It will be evident from the foregoing description that changes in the form, methods of use, and applications of the elements of the disclosed method for the improved buffer blending and development technology are novel and may be modified and/or resorted to without departing from the spirit of the invention, or the scope of the appended claims.
[0069] Prior Art Citations Incoprorated by Reference
[0070] 1. Cochrane et al., Human Albumin Administration In Critically III Patients: Systematic Review Of Randomized Controlled Trials, BR MED J. (1998); 317:235-240.
[0071] 2. Gibney M W, et al., Method of Beverage Blending and Carbonation, U.S. Pat. No. 5,552,171.
[0072] 3. Jones, C, et al., Method for Blending Diverse Blowing Agents, U.S. Pat. No. 5,823,669.
[0073] 4. Pak, Zinovy Petrovich—Chemical Compound, Or Soil Contaminated By Said Poisonous Agent and/or Toxic Chemical Compound, U.S. application Ser. No. 20020156336.
[0074] 5. Patel M, et al., Apparatus for Blending Chemicals with a Reversible Multi-Speed Pump, U.S. Pat. No. 5,340,210.
[0075] 6. Paul K D, et al., Method and Apparatus for Filling, Blending, and Withdrawing Solid Particulate Material From a Vessel, U.S. Pat. No. 4,907,892.
[0076] 7. Phallen U, et al., Continuous Liquid Stream Digital Blending System, U.S. Pat. No. 6,186,193.
[0077] 8. Platz G M, et al., Method and Apparatus for Super Critical Treatment of Liquids, U.S. Pat. No. 6,162,392.
[0078] 9. Wilkins E, et al., Apparatus for Detecting Contamination in Food Products, U.S. Pat. No. 6,180,335.
[0079] 10. Vermeulen L C, et al., Guidelines of or the Use of Albumin, Nonprotein Colloids, and Crystalloid Solutions, ARCH INTERN MED. (1995) 155:373-379.
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The present invention relates to an improved method to process, purify and/or produce biopharmaceuticals or other products involving automated blending of pH buffered solutions from water and common stocks of concentrated acids and bases, and other components. This approach reduces the cost and complexity of the solution preparation systems required for producing these solutions under aseptic or sterile conditions, and reduces the material costs of the solutions themselves. This approach is particularly beneficial to use with continuously-produced feedstocks and with continuous separation operations.
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This application is a divisional patent application claiming priority to U.S. Nonprovitional patent application Ser. No. 10/080,365, filed on Feb. 21, 2002, now abandoned, which claims priority to United Kingdom (GB) Patent Application Number 0105120.0 filed on 2, Mar. 2001.
BACKGROUND OF THE INVENTION
The present invention relates to mechanism, for a vehicle door latch.
Known vehicle door latches are lockable using a “free wheeling” principle. Thus, with the door unlocked, lifting of an outside door handle causes the door latch to open. Conversely, with the door locked, lifting of the outside door handle is still possible but a transmission path between the outside door handle and components of the door latch that retains the door in the closed position is broken. Essentially, a break is created in the transmission path. The components on the door handle side of the break are caused to move with the door handle while the components on the other side of the break do not move. A problem with this type of locking is that a space has to be provided for the components on the handle side of the break to move when the handle is lifted.
SUMMARY OF THE INVENTION
An inventive latch mechanism has an input member and an output member. The latch mechanism has a first condition at which the input and output member are coupled such that movement of the input member from its first position to its second position causes movement of the output member from its first position to its second position. The latch mechanism also has a second condition at which the input member is not coupled to the output member. The latch mechanism further has a blocking member, which, with the mechanism in its second condition, further prevents one of the input or output members from moving to its respective second position.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, with reference to the accompanying drawings in which:
FIGS. 1A to 1D show a first embodiment of the present invention in various positions;
FIGS. 2A to 2D show a second embodiment of the present invention in various positions;
FIG. 3 shows an isometric exploded view of FIG. 2A ; and
FIGS. 4A to 4D and 5 A and 5 D show isometric views of FIGS. 2A to 2D , respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1A to 1D , there is shown a latch mechanism 10 mounted on a chassis 12 (only shown in FIG. 1A ). A latch mechanism 10 includes an input member in the form of an input lever 20 , an output member in the form of a pin 30 , a clutch in the form of a link 40 and a blocking member 50 .
The input lever 20 is pivotally mounted at an input pivot 21 to the chassis 12 . The link 40 is pivotally mounted at pivot 41 to an end 20 B of the input lever 20 . The blocking member 50 is fixed in a stationary position on the chassis 12 .
The pin 30 is movable between the positions as shown in FIG. 1A and FIG. 1C . The latch mechanism 10 typically forms part of a vehicle door latch arrangement. An inside door handle 300 and an outside door handle 302 are connected by a transmission path to an end 20 A of the input lever 20 . The pin 30 is connected to a pawl, which is capable of retaining a latch bolt (e.g., a rotating claw) in a closed position. The claw in turn can releasably retain a latch striker in order to retain an associated door in a closed position. Movement of the pin 30 from the position shown in FIG. 1A to the position shown in FIG. 1C causes the pawl to disengage the claw and allow the door to open. Thus, with the latch mechanism 10 in the position as shown in FIG. 1A , the door is in an unlocked condition. Operation of the inside door handle 300 or the outside door handle 302 will cause the end 20 A of the input lever 20 to lift (i.e., the input lever 20 will rotate in counter-clockwise direction), causing the end 20 B to lower. This movement of the end 20 B results in an abutment 42 contacting and then moving the pin 30 to the position shown in FIG. 1C . It should be noted that in FIGS. 1A and 1C , the pivot 41 , the abutment 42 and the pin 30 are all aligned.
The latch mechanism 10 can be put into a locked condition as shown in FIG. 1B by rotating the link 40 so that it aligns with the blocking member 50 and no longer aligns with the pin 30 . Thus, when an attempt is made to lift the outside door handle 300 , the abutment 42 moves into contact with the blocking member 50 , and the outside door handle 300 cannot be fully lifted. The door therefore remains fully closed.
Thieves tend to apply excessive force to outside door handles 300 in the expectation of causing components of the door latch to fail in an attempt to gain entry to the vehicle. However, the present invention mitigates this problem. In the event that the blocking member 50 fails (e.g., it breaks off the chassis 12 ), the abutment 42 will bypass the pin 30 . Thus, the door still remains closed.
Under normal circumstances, the abutment 42 does not enter the space occupied by the blocking member 50 . Consequently, this space is available for other components of the latch, enabling a more compact latch design. Preferably, the blocking member 50 is not solely dedicated to acting just as a blocking member, but fulfills another function within the latch to further save space.
With reference to FIGS. 2A to 5C , there is shown a further embodiment of the invention. The latch mechanism 110 has components that fulfill substantially the same function as those in the latch mechanism 10 .
The input lever 120 includes a hole 122 , which mounts on an input pivot pin 121 , which in turn is mounted on a chassis 112 . The input lever 120 includes an L shaped hole 123 and a further hole 124 for connection to an inside door handle 200 or an outside door handle 202 .
In this case, the output member is in the form of an output lever 130 having a pivot hole 131 , which is mounted on the input pivot pin 121 . Thus, it can be seen that the input lever 120 and the output lever 130 lie adjacent to one another and pivot about the same axis. The output lever 130 includes a slot 132 , which in the position shown in FIG. 2A , substantially aligns with arm 123 A of an L shaped hole 123 . The output level 130 further includes an abutment 133 and an arm 134 .
A blocking member 150 is in the form of a link being pivotally mounted on the chassis 112 at a pivot 152 and having a abutment 153 . Adjacent the abutment 153 , there is a hole 154 in which is mounted a pin 161 of a link 160 . The link 160 includes a clutch at an end 160 A in the form of a pin 140 . The pin 140 engages in L shaped hole 123 of the input lever 120 and also in the slot 132 of the output lever 130 .
A pawl arm 170 is connected at an end 170 A to a pawl (not shown), which releasably retains a latch bolt (e.g., a rotating claw) to secure the door. Movement of the pawl arm 170 from the position shown in FIG. 4A to the position shown in FIG. 4C causes the pawl to rotate and allow the door to open.
Operation of the mechanism is as follows. With the mechanism in the position as shown in FIGS. 2A , 3 and 4 A, the pin 140 is located at the end 132 A of the slot 132 and hence at an end 125 of an L shaped hole 123 . As such, the input lever 120 and the output lever 130 are coupled together for rotation. Further, as seen from FIG. 2A , the abutment 133 of the output lever 130 is not aligned with the abutment 153 of the blocking member 150 (i.e., the abutment 133 , the abutment 153 and the pivot 152 are not aligned). Thus, operation of the inside door handle 200 or the outside door handle 202 causes a hole 124 to move in the direction of arrow A of FIG. 2A to the position as shown in FIG. 2C , which results in the arm 134 rotating the pawl arm 170 and thus opening the door. It should be noted that the abutment 133 has bypassed the abutment 153 , as shown in FIG. 2C .
With the input lever 120 and the output lever 130 in the position shown in FIG. 2A , the block member 150 can be rotated to the position as shown in FIG. 2B . This has two effects, namely a) the abutment 153 aligns with the abutment 133 (i.e., the abutments 153 and 133 and the pivot 152 are aligned) to prevent movement of output lever 130 and b) the pin 140 is moved (by the link 160 ) to the end 132 B of the slot 132 and hence to the confluence of arms 123 A and 123 B of the L shape hole 123 , i.e., to position 126 (see FIG. 3 ).
In the event that the inside door handle 200 or the outside door handle 202 is operated, movement of the input lever 120 causes the arcuate arm 123 B of the L shaped hole 123 to move past the pin 140 , which remains stationary. Compare FIGS. 2B and 2D ). Accordingly, if the input lever 120 and the outside lever 130 corrode or otherwise stick together, then the door is still prevented from opening by engagement between the abutments 133 and 153 . Under these circumstances, it is not possible to move the associated door handle and this acts as an indicator that the mechanism is malfunctioning. Such an indicator is useful since a malfunction can be determined simply by attempting to operate the door handles. No internal examination of the door is required.
The mechanism can be used in the transmission path between an outside door handle and a latch bolt (i.e., it can be used to lock the door). Alternatively, the mechanism can be used between both the inside and outside door handles and the latch bolt, i.e., it can be used to superlock (or deadlock) the door. Alternatively, it can be used between an inside door and a latch bolt, especially on a rear door of a vehicle, i.e. 4 to provide a child safety function of the door latch.
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A latch mechanism has an input member and an output member. The mechanism has a first coupled condition at which the input and output members are coupled such that movement of the input member from its first position to its second position causes movement of the output member from its first position to its second position. The mechanism has a decoupled condition at which the input member is not coupled to the output member. The mechanism further includes a block member, which, with the mechanism in the decoupled condition, further prevents at least one of the input and output member from moving to its respective second position.
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This is a continuation of allowed application Ser. No. 988,251, filed Dec. 10, 1992, now U.S. Pat. No. 5,420,763, which is a continuation-in-part of application Ser. No. 961,777, filed Oct. 15, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates in general to cornice lighting fixtures for use in public transit vehicles, and more particularly, to an improved lighting fixture for installation in a cove or cornice of a vehicle and which provides access to the air duct region between the fixture and vehicle body, while illuminating and retaining an advertising car card in place.
Several card-carrying cornice lighting fixtures are known in the art. One type of cornice lighting fixture for public transit vehicles is disclosed in U.S. Pat. No. 4,387,415. This fixture is of unitary pultrusion construction and includes a trim panel for holding a car card, integral with a light housing. While this construction is said to satisfy a need for economy of manufacture, this fixture must, however, be custom cut to provide necessary apertures or removed entirely from the vehicle to provide access to an air duct behind the fixture, and such access is generally only available after removing the advertising card.
Another vehicle lighting fixture designed for use in public transit vehicles such as railway cars is disclosed in U.S. Pat. No. 3,035,161. This type includes through-running beams, one on each side of the vehicle, upon which advertising card receptacles are anchored. A card backing plate of this type of fixture is secured by screws at one edge and by a flange at an opposite edge. Access to an enclosed duct behind the card backing plate is provided by removing an advertising card supported on the card backing plate and unfastening the plate.
Yet another vehicle lighting system for illuminating an advertising card as well as for general vehicle illumination is disclosed in U.S. Pat. No. 2,587,807 which is adapted to be installed in the vehicle cornice. The fixture is mounted to a vehicle ceiling surface and to a deck member. The deck member and ceiling define a duct for cables or ventilation.
These references recognize the need to access the fluorescent lamps of the fixtures for replacement purposes and the like, by providing removable lenses or bezels, but they generally do not provide ready access to an enclosed air plenum above the fixture.
Today's public transit vehicles are equipped with sophisticated electrical apparatus to operate lights, bells, buzzers, air conditioners and other complex equipment, all of which must be placed in spaces which do not interfere with the passengers' safety and comfort. The cove formed by the adjacent sidewall and ceiling of such vehicles is uniquely suited to house air ducts, cables, and electrical and mechanical devices. There exists a need to provide ready access to these spaces with minimal delay.
Furthermore, it is desirable to provide such access without resorting to customizing panels with access doors and the like. Additionally, it is desirable to provide such access without disturbing an advertisement card held in the fixture.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved lighting fixture, especially designed for installation in a cove formed by the ceiling and sidewall of a passenger vehicle interior.
Another object is to eliminate the need to customize particular lighting fixture units to provide access to a duct or plenum defined by a combination of the installed lighting fixture and the cove.
Yet another object is to provide a lighting fixture which is pre-wired and shipped as a complete modular unit ready for installation into a bus.
Still another object is to provide a lighting fixture with the foregoing advantages with minimal cost and complexity.
A further object is to provide a lighting fixture with a means for retaining an electrical connector which advantageously permits maintenance and replacement of a plug-in ballast adapted to mate with the connector.
The present invention provides a lighting fixture for passenger vehicles providing ready access to a space behind it, without requiring a variety of specially designed fixtures for special access requirements. Instead, the fixtures of the present invention may be made uniformly for installation and electrical connection throughout the vehicle, permitting access to the air plenum everywhere in the vehicle. Thus, only a single design need be produced instead of a variety of special designs, contributing to lower costs of production.
These and other objects are achieved according to the present invention by providing a lighting fixture of the type designed to support an advertisement card, for use with a fluorescent lamp, which comprises: a pair of battens or supporting struts extending generally vertically to support the fixture; a longitudinally extending card-holder panel supported at each end by the battens in a movable relationship to the battens, the panel having a groove adapted to mount an advertisement card; a socket connected to each of the battens cooperating to mount a fluorescent lamp; and a bezel supported by the battens and supporting a lens or other light distributor covering the mounted lamp. In accordance with an aspect of the present invention, the card panel is pivotally mounted on the battens. As a further feature of the present invention, the bezel is also pivotally mounted on the battens and may assist in retaining the advertisement card. As an additional feature of the present invention, the battens may include a mounting for an electrical connector for engaging a ballast and means for retaining the ballast. A single ballast may be used for two adjoining fixtures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of a lighting fixture according to the present invention;
FIG. 2 is a sectional view along line 2--2 of FIG. 1;
FIG. 3 is a sectional view of a second embodiment of a lighting fixture constructed in accordance with the present invention;
FIG. 4 is a sectional view of a third embodiment of a lighting fixture constructed in accordance with the present invention showing a card panel in a closed position or operating state;
FIG. 5 is an enlarged view of the device of FIG. 4 showing the card panel in an open position.
FIG. 6 is a lateral view of a batten constructed in accordance with the present invention.
FIG. 7 is an enlarged view of one end of a pair of battens of two adjoining lighting fixtures constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to an improved lighting fixture, especially designed for installation in a cove formed by a ceiling and sidewall of a passenger vehicle interior. The present vehicle lighting system is formed by of a plurality of individual elongated lighting fixtures, each fixture being pre-wired and shipped as a complete modular unit ready for installation, which may be installed in a continuous end-to-end or longitudinally spaced manner along opposed sides of a central passenger aisle of a vehicle compartment. An air plenum or air duct is often defined between the lighting fixture and the vehicle wall. This space may be employed to house electrical cables or as a duct to distribute heated or cooled air, or to house mechanisms such as door closures.
As illustrated in FIGS. 1 and 2, the lighting fixture 10 of the present invention comprises a pair of left and right hand battens 20a, 20b, respectively, for pivotally mounting both a card panel 60, which selectively covers or provides access to the air plenum or cove 118 formed by vehicle ceiling 110 and sidewall 112, and a bezel 84 disposed above the card panel 60, which selectively covers or provides access to a light socket and lamp assembly 12,14. Bezel 84 is formed to hold a lens or diffuser 52 which diffuses or directs light from the light tube into the vehicle passenger compartment and onto the card carded by the card panel 60. The light fixture is formed by a unitary assembly of a left hand batten 20a and a fight hand batten 20b, each carrying a light socket 12, and a pivotally secured card panel 60 and bezel 84. A reflector 106 may also be part of the assembly. This assembly may then be secured to the vehicle merely by affixing the battens to the vehicle ceiling and side wall, with an air plenum 118 formed by the space between the vehicle and fixture. The right hand batten of one fixture and the left hand batten of another fixture may be installed in the vehicle adjacent to each other to provide a longitudinally continuous cornice lighting fixture structure along the length of the vehicle.
Left hand batten 20a may be formed with an extension 21 having a mounting for an electrical connector 17b which is wired to the light socket and lamp assembly 12, 14, as shown in FIG. 7. Where two fixtures are juxtaposed end to end, a dual lamp ballast 16 having a mating connector 17a may engage connector 17b to serve both adjoining fixtures. Such an arrangement offers the advantages of fewer ballasts per vehicle resulting in decreased weight and fewer electrical interconnections, resulting in increased electrical reliability. Battens 20a and 20b are otherwise symmetrical and are referred to hereinafter more generally as batten 20.
In a first embodiment shown in FIGS. 1 and 2, access to air plenum 118 is provided by pivoting the card panel 60 outward from the cove formed by the ceiling 110 and the sidewall 112. Card panel 60 has a concave front surface 60a for receiving a car card 56 and a convex rear surface 60b which faces the cove. At each end of card panel 60 is a boss or projection 71 extending rearward from a rib or flange 61 on rear surface 60b and having a pivot hole 72, near its upper edge, adapted to receive a pivot pin or trunnion 36 formed on batten 20.
Card panel 60 is further formed with a resiliently flexible extension flap 74 which is generally planar with front surface 60a and extends beyond boss 71. This extension 74 has a slightly enlarged rounded or bulbous edge 76 adapted, in a manner described below, to support the card panel 60 in an open position to provide access to the air plenum 118.
Panel 60 is supported from each batten 20 by the batten pivot pin 36 which engages the panel boss 71 of an upper edge of the panel 60 and by a screw 66 or other removable securing means passing through a hole in a lower edge of the panel 60 to engage the batten 20 at 44.
In accordance with the invention, access to air plenum 118 is obtained by releasing the lower edge of card panel 60 from the batten 20 and rotating it about pivot pins 36 to an open position shown in phantom lines in FIG. 2. As card panel 60 is pivoted, the bulbous edge 76 of extension flap 74 travels freely through an arc generally defined by the length of flap 74 and pivot pin 36, along an arched surface 32 of batten 20 as shown by arrow A in FIG. 2. Arched surface 32 is formed generally coaxial with pivot pin 36 and has a protuberance 34 formed thereon. As card panel 60 is pivoted to near its fully open position, extension 74 flexes slightly and may be manually urged past one side of protuberance 34 toward an adjacent vertical wall 38 of batten 20, permitting extension 74 to return to its natural unflexed shape. Once extension 74 has passed protuberance 34, bulbous edge 76 is held between projection 34 and wall 38 to support card panel 60 in an open position. Panel 60 may be closed by reversing this operation, allowing extension 74 to flex as it passes over protuberance 34 to return to an unflexed state as the panel 60 is secured at its lower edge to the batten 20.
A car card 56 inserted in card panel 60 is retained by the card panel 60 throughout the panel's pivotal displacement. At an edge of card panel 60 opposite the flexible extension 74, card panel 60 is formed with a connection portion 62 for securing the panel 60 to a batten 20 at each panel end. The panel is formed with a card holder tab or lip 68 forming a groove to hold one edge of the card 56. Thus, as card panel 60 is pivoted about pivot pin 36, a car card 56 placed in the groove 68 is retained on front surface 60a of panel 60 at its bottom edge.
Bezel 84 supports the car card 56 at its top edge. Bezel 84 is formed with a flat edge 98 which overlaps extension 74 of card panel 60, leaving a gap between panel 60 and bezel edge 98 to retain the upper edge of the card 56. When both the card panel 60 and bezel 84 are closed, a car card 56 may be placed in groove 68 at a bottom edge of card 56 and in the cavity formed between panel extension 74 and bezel edge 98 at a top edge of card 56.
Bezel 84 has a boss with a pivot hole 90 formed in each end of its edge opposite the flat edge 98. The pivot hole 90 is arranged to receive a pivot pin or trunnion 22 formed on batten 20. Thus, when bezel 84 is pivoted to an open position, edge 98 separates from card panel 60 and provides access to a lamp 14 and to the top edge of car card 56. When bezel 84 is in a closed position, it can be secured in place by screws 92 inserted into screw holes formed in edge 98 which are arranged to align with and engage threads 50 formed on batten 20.
The lighting fixture of the present invention is further provided with a pair of light sockets 12, preferably of the type described in U.S. Pat. No. 5,261,831, issued Nov. 16, 1993, in the names of M. J. Vendal and L. B. Ruth and assigned to the assignee of the present invention, which cooperate to mount a fluorescent light tube 14. Each batten 20 is formed with a flange 26 having threaded projections or holes 28 for mounting socket 12 to flange 26. A reflector 106 is disposed behind the light tube 14 at a section 30 of batten 20 to direct light from the light tube through the bezel. Reflector 106 may be formed in a concave or double concave shape, as illustrated in FIG. 2. Preferably, reflector 106 is formed with a double generally ellipsoidal trough so that light from light tube 14 focuses onto the car card 56, and also onto the passenger reading plane and floor aisle of the vehicle. Reflector 106 is supported at each end by batten 20. The reflector and the bezel prevent light emanating from the light fixture 10 through apertures 86 from travelling directly onto the vehicle ceiling 110. This reduces one source of driver glare.
The concave inner surface 96 of bezel 84 is formed with longitudinally extending walls 88 projecting inwardly from the inner surface 96. A pair of gasket strips 108 are disposed, respectively, upon each longitudinally extending edge of reflector 106. The outer edges of walls 88 engage gasket strips 108 in the closed position of the bezel to form a seal against dust. Bezel 84 also has a plurality of lens openings or apertures 86 fitted with a transparent or translucent lens or diffuser 52 for appropriately distributing light onto the car card 56 below light tube 14 and generally throughout the passenger vehicle. The bezel may be provided with a single opening extending nearly its full length or with a number of such openings along its length, separated by strips 87 extending between the upper and lower portions of the bezel opening. A separate lens may be associated with each opening, or alternatively, a single lens may overlie the entire sequence of openings. The lenses are preferably extruded of transparent or translucent material with a cross-sectional configuration adopted to distribute light as may be desired over the vehicle passenger compartment and advertising card. The strips or webs 87 between the apertures 86 also function like a louver to baffle linear glare, another source of driver glare, which may otherwise be obtrusive to driver visibility.
As shown in FIGS. 1 and 2, batten 20 is formed with a rectangular sleeve 24a defined by sleeve walls 24 adjacent batten section 30 and is adapted to hold a lamp ballast 16. Where two fixtures are juxtaposed end-to-end, the sleeves 24a of their battens are in register (i.e. in alignment) and may hold a dual-lamp ballast to serve both adjoining fixtures. The ballast may be retained in the sleeve 24a in any suitable manner, such as one or more set screws, or as described more fully in connection with FIG. 7. A longitudinal lip or flange 58 is formed on batten 20 extending beyond sleeve 24a for mounting batten 20 to a bracket or frame member 114 of the vehicle ceiling 110.
As seen in FIG. 1, the lower connection portion 62 of card panel 60 is further formed with a hole for a screw 66 and a slot 64 at each end overlying batten 20. Screws 66 are arranged so that when card panel 60 is in its closed position, each screw 66 is aligned with an opening 44 formed on one end of batten 20. Card panel 60 may thereby be secured to batten 20 by suitable securing means, to form a single unit with the bezel and reflector for shipping or installation purposes. Slots 64 are provided to expose screws 48 in batten 20 to permit securing the batten to the vehicle structure, for installing a lighting fixture 10 or an adjoining pair of fixtures as a single unit. Batten 20 is provided with screws 46,48 at upper flange 58 and lower horizontal portion 42, respectively, for attaching the lighting fixture 10 to a pair of frame members or brackets 114,116 mounted to the vehicle ceiling and sidewalls, respectively. Additionally, batten 20 may be formed with a groove 41 at its lower horizontal portion 42 adapted to seat the batten upon bracket 116, as shown in FIG. 6.
FIG. 3 shows a second embodiment of the present invention, in which features common to the first embodiment are given corresponding reference numerals. Otherwise than as specifically described below, the fixture of FIG. 3 is essentially the same as in FIGS. 1-2.
As in the embodiment of FIGS. 1 and 2, access to air plenum 118 is obtained by pivoting card panel 60 about pivot pin 36 to an open position. Card panel 60 is formed at its upper edge with a loop 80 engaging pivot pin 36 and having a projection 82 extending outwardly from it. As card panel 60 is pivoted, projection 82 rotates about pin 36 toward a generally vertical wall portion 38 of batten 20. Wall 38 is generally perpendicular to card panel 60. Card panel 60 may be pivotally rotated as shown by arrow B until projection 82 bears against wall 38 to provide a stop for panel 60.
As before, a car card 56 inserted in card panel 60 may be retained throughout the pivotal displacement of the panel. A card-holding tab 68 is provided to retain the car card 56 on a bottom edge of the front surface 60a of the card panel 60. The card panel 60 is further provided with an upper card holding tab forming a groove 78 to hold an upper edge of a car card 56.
As shown by arrow C in FIG. 3, bezel 84 is pivotally supported by a pivot pin 22a formed on batten 20 permitting downward swinging of the bezel toward the card panel 60 about the lower edge of the bezel. Bezel 84 is formed with a boss on each end having a pivot hole 90a disposed on a rear surface 96 between lens openings 86 and the bezel left edge as seen in the drawing. A projection 104 extends beyond pivot hole 90 to provide a close fit, when closed, between the card panel 60 and the bezel 84, and also to engage the batten wall in the open bezel position to provide a stop for the pivoting of the bezel. The bezel flange 102 overlaps a flange 58 of batten 20 when the bezel 84 is in a closed position. These flanges are removably secured together, as by screws, to retain the bezel closed.
As before, a reflector 106 is supported at each end by batten 20 and is disposed behind the light tube 14 at a section 30 of batten 20 to direct light from the light tube 14 through the bezel. Reflector 106 is preferably formed with a pair of generally ellipsoidal troughs to direct light and reduce driver glare, as discussed in connection with the previous embodiment.
FIGS. 4 and 5 show a third embodiment of the present invention, in which features common to both the first and second embodiments are denoted with corresponding reference numerals. Otherwise than as specifically described below, the fixture of FIGS. 4 and 5 is essentially the same as in FIGS. 1-3.
Referring to FIGS. 4 and 5, card panel 60 is formed with a boss or projection 171 adjacent each end. Boss 171 has a bore or hole 172 of generally oval cross-section extending generally parallel to the card panel 60 and adapted to receive a pivot pin or trunnion 36 formed on batten 20. The pivot pin 36 may slide in the groove 172 between one edge 172a of the groove 172 and another edge 172b while still permitting panel 60 to pivot.
Card panel 60 is further formed with an extension 174 which is generally co-planar with the front surface 60a of card panel 60 and extends beyond boss 171. This extension 174 has a shoulder portion 175 as well as a flange 176 at its distal end adapted, in a manner described below, to support the card panel 60 in both an open and a closed position.
A concave bezel 84 is formed at each end and adjacent its lower edge with an extension 90a having a bore or groove adapted to receive a pivot pin 20a of a batten 20. Bezel 84 at its opposite edge is (in its closed position) secured to an end of batten 20 by a screw 83 or other suitable removable securing means. Bezel 84 is formed with an inwardly extending wall 88a terminating in a flange 181 forming a seat in the edge of wall 88a which receives one edge of a reflector 106a.
The reflector 106a is formed with a double concave surface 180 preferably in the shape of a double generally ellipsoidal trough having a small extension flange 182 at one edge. Flange 182 is adapted to engage the terminal edge of wall 88a of bezel 84 when the bezel 84 is in a closed position as seen in FIG. 4. Reflector 106a is further formed at its other edge with a T-shaped termination 184. One leg of the T-shaped termination 184 forms a ledge 186 which engages a flange 105 of bezel 84, disposed on the distal edge of a continuation 104a of the bezel 84. The reflector termination 184 also has a second leg 188 spaced from the upper edge of panel 60 (when in the closed position) which forms a groove 187 adapted to hold a top edge of a car card 56 as shown in FIG. 4. Leg 188 of reflector termination 184 has a ridge or rib 190 extending upwardly which, as described below, engages the upper edge of the card panel 60 in combination with a bump or rounded ridge 192 extending along reflector 106a.
In use, by removing screw 83, bezel 84 is permitted to swing about pivot 22a to the open position shown in dotted lines in FIG. 4. It will be maintained in that position by its weight hanging from the pivot pins. In this way, ready access is given to the fluorescent tube and sockets, for maintenance when needed.
The bezel 84 is formed also with longitudinal grooves 193 into which may be slid the edges of a diffuser or lens 195, which is retained in the bezel 84, both in its open and closed positions.
As seen in FIG. 4, when the lower edge of card panel 60 is engaged by a screw or other removable securing means, pivot pin 36 is adjacent edge 172a of pivot bore 172. At the same time, the flange 176 of card panel 60 supports an upper edge of card panel 60 on rib 190 formed in reflector 106a.
In accordance with this embodiment of the invention, access to an air plenum 118 above card panel 60 is obtained by releasing the lower edge of card panel 60 from the batten 20, as in the previous embodiments. Then, by sliding the panel leftward so that pivot pin 36 engages edge 172b of bore 172, the flange 176 is withdrawn from between rib 190 and rounded ridge 192 permitting rotation of the card panel 60 about pivot pin 36 to an open position as shown in FIG. 5.
As card panel 60 is pivoted, the flange 176 of extension 174 travels through an arc, along an arched surface 32 of batten 20 toward a groove 34a. As card panel 60 is pivoted near its fully open position, flange 176 flexes slightly in arched surface 32 and snaps into groove 34a, permitting flange 176 to return to its natural unflexed shape. Once flange 176 has entered groove 34a, flange 176 will support card panel 60 in an open position, with pivot pin 36 bearing against edge 172b of groove 172. Panel 60 may be closed by reversing this operation, by causing flange 176 to flex as it exits groove 34a and return to an unflexed state within arched surface 32. By pivoting the panel 60, its flange will engage rib 190. Then by sliding the panel over pivot pin 36, it is engaged between rib 190 and rounded ridge 192. By securing the lower edge of panel 60 to batten 20 (not shown in this figure), the panel 60 is secured in this position.
The reflector 106a is secured at each end to a respective batten 20 and extends longitudinally between the two battens, generally coextensive with the card panel 60 and bezel 84. Batten 20 may be further formed with a lip 200 to hingeably secure one margin of each end of reflector 106a. An opposite margin of reflector 106a may have a stub 206 secured in a groove formed by a lip or tab 204. As shown in FIG. 6, reflector 106a may be adapted to hingeably mount on batten 20 and have its stub 206 flexibly urged into a slot formed by tab 204 or may be positioned in slot 204 and around lip 200 upon assembly. Once inserted, stub 206 serves to resist withdrawal of reflector 106a from the slot. Reflector 106a may additionally be secured in any other suitable manner, such as by one or more screws.
FIG. 7 shows an enlarged view of a portion of two adjoining battens 20a,20b of two adjoining fixtures. The left-hand batten 20a is formed with an extension 21 having a mounting for an electrical connector 17b formed at the outer end of extension 21. The mounting is formed so that connector 17b having a groove 25 in its side may be securely retained on extension 21 by means of a pair of locking fingers (not shown) which engage groove 25. The locking fingers are elastically flexible and arranged so that as connector 17b is inserted into the mounting, the fingers are urged apart until connector 17b is fully inserted at which point the fingers engage groove 25 and thereby return to their unbiased state while retaining the connector. Connector 17b is arranged to mate with a connector 17a formed on one end of a ballast 16 when inserted in the direction of arrow E in the batten sleeves 24a. One of the connector 17a and connector 17b is a male-type connector while the other is a female-type connector. This provides for ready connection, maintenance and replacement of the ballast 16.
Extension 21 is formed with a length sufficient so that a single-lamp ballast with a connector 17a will have an opposite end substantially contained within sleeve 24a. This permits an end lighting fixture in an odd-numbered series of such fixtures to hold a ballast. Where a dual lamp ballast is used to serve adjoining light fixtures 10, the ballast may extend beyond sleeve 24a of one lighting fixture into a second sleeve 24a of an adjoining lighting fixture. Although the dual lamp ballast may extend beyond one fixture into another, it would still be contained in an air plenum defined by the adjoining fixtures. Both adjoining light fixtures may be electrically connected by wires 23 to the dual lamp ballast.
The connector 17b is wired at certain terminal locations to select one of two lamp output options provided by ballast 16. One output option provides full current to the lamps for maximum light intensity. A second output option provides reduced current to the lamps to save power.
Sleeve 24a may be further formed with a locking finger 27 extending away from one of its sleeve walls 24 adapted to lockably engage an end of ballast 16 opposite connector 17a when the ballast is inserted into sleeve 24a in the direction of arrow E. This would secure ballast 16 in sleeve 24a. Alternatively, ballast 16 could be retained in sleeve 24a by locking means associated with each of connectors 17a, 17b or could be retained in any other suitable manner, such as one or more set screws.
It will be readily appreciated that the pivot pins 36 and pivot holes 72,80, and the pivot pins 36 and pivot holes 172, could readily be interchanged, putting the hole in the batten and pin on the panel 60 or bezel. Other pivot arrangements may be used, such as a metal pin extending between a hole or recess in the batten and in the bezel or card holder panel. Also, the boss on the panel containing the pivot hole (or pin) may extend from either the front or the rear surface of the panel or bezel or be intermediate those surfaces. The boss may extend the entire length of the panel. Similarly, the pivot boss on the bezel may extend for its entire length.
Enhanced structural integrity may be achieved by including braces or webs about the pivot holes or pins and on various flanges such as flange 26 as shown in FIG. 6. The card panel 60 is provided with ribs or flanges 61 spaced along its length extending rearward from a rear surface 60b to enhance the strength of the panel. A boss 71 is formed on ribs 61 near an upper edge of card panel 60. At each end of card panel 60, boss 71 is formed with a pivot hole 72 adapted to receive a pivot pin or trunnion 36 formed on batten 20.
Card panel 60 is of a length sufficient to accommodate standard length light tubes 14 between the sockets mounted on the battens including, for example, four foot tubes. Shorter length tubes can be accommodated by a secondary cut and punch operation where the panel is cut along the outside margin of a rib 61 and a hole is punched in boss 71 for receiving pivot pin 36. Ribs 61 are generally spaced one foot apart to facilitate cutting panel 60 to house shorter length light tubes, such as a three foot tube.
While FIG. 1 shows three openings in the bezel, in any of the forms of the invention, the bezel may be formed either with a single opening or with a plurality of openings along its length. The strips 87 joining the upper and lower edges of the bezel openings will serve to provide increased strength and rigidity for the bezel and to baffle linear glare. The spacing between adjoining strips 87 is selected to give a desired glare reduction effect in the longitudinal direction. This spacing may, for example, be 4 to 8 inches. In any of the forms of the invention, the lens may, for convenience, extend for substantially the entire length of the bezel, or alternatively, there may be a separate lens element for each bezel opening or group of openings.
The battens, panel, and bezel may be formed by compression or injection molding from plastic materials of suitable strength. Alternatively, the bezel and panel may be extruded or pultruded, in which case the pivot hole bosses may extend the length of the bezel and panel, with pivot holes formed in their ends. The lens or bezel opening or openings may be formed thereafter.
From the foregoing description, it will be clear that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and not limited to the foregoing description.
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A fighting fixture disclosed is designed for installation in a cove of a public transit vehicle providing ready access to a space behind it, without requiring a variety of specially designed fixtures for special access requirements. The fixture comprises a pair of battens extending generally vertically to support the fixture, a longitudinally extending card panel supported in movable relationship by the battens and having a groove adapted to mount an advertisement card, a socket connected to each of the battens cooperating to mount a fluorescent lamp, and a bezel supported by the battens and supporting a lens covering the mounted lamp. Access to the space is obtained by releasing a lower edge of the card panel and rotating it about pivot pins to an open position. Similarly, the bezel is pivoted to provide access to the mounted lamp. An advertisement car card placed on the card panel is retained at a lower edge by the card panel throughout the pivotal displacement of the panel. An elongated lighting fixture may be formed by supporting additional panels by the battens in movable relationship thereto.
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BACKGROUND OF THE INVENTION
This application is a continuation in part of U.S. application Ser. No. 507,494 filed Sept. 19, 1974, and now U.S. Pat. No. 3,994,489.
The subject invention relates to sheet feeding systems such as those utilized in the corrugated blank feeding industry wherein sheets of material or blanks are stacked and subsequently fed to the processing equipment.
In particular, the subject invention has direct application in feeding systems such as disclosed in co-pending application, now U.S. Pat. No. 3,994,489.
In U.S. Pat. No. 3,994,489 as in similar types of feeding systems, blanks are stacked on feeding equipment preparatory to being fed to processing machinery. The lowermost blank of the stack is engaged by a feed bar and advanced singularly to the processing machinery. Since feeding equipment must accommodate blanks of different sizes and different operation times, an adjustable back stop member is utilized against which the stack of blanks is confined in a position to be engaged in turn by the feed bar mechanism.
As the adjustable back stop is adjusted to different locations dependent upon the size of blanks to be processed, it is also desirable to adjust the vacuum system beneath the feed bed by closing off portions of the vacuum chamber not utilized due to the positioning of the adjustable back stop.
As disclosed in my co-pending application now, U.S. Pat. No. 3,994,489, several different systems for adjusting the vacuum source by effectively adjusting the size of the vacuum chamber are disclosed. In one embodiment, the back stop member was shown being provided with a vacuum close-off member which was lowered to within the chamber to restrict the vacuum to that portion of the chamber above which blanks were being transported. As shown in FIG. 9 of my co-pending application, now U.S. Pat. No. 3,994,489, the vacuum close-off member 126 was a plate-like member extending widthwise across the chamber. A handle 128 which served as a locking member was shown. In another embodiment, in place of the vertical close-off member 126, an extendable roll-out curtain member 132 was shown in FIGS. 10 and 11 which could be extended from a storage roll 134.
While either of these above systems may be utilized, many additional advantages are associated with the use of the improved construction as disclosed in the subject disclosure.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the subject invention to provide in corrugated blank feeding equipment, an improved vacuum system in which an adjustable back stop member can be adjusted without decreasing the efficiency of the vacuum system.
It is a related object of the subject invention to provide in corrugated blank feeding equipment, a vacuum system, adjustable in nature, which is uniquely suited to automation and which does not have to be adjusted by personnel during changes in blank feeding operations.
It is another object of the subject invention to provide an adjustable vacuum system in which a more effective seal can be created without lessening the adjustability of the system.
It is still another object of the subject invention to provide an improved vacuum system for the specific type of rolling vacuum feed table structure as disclosed in co-pending application, now U.S. Pat. No. 3,994,489.
In accordance with the above objects, improved apparatus for feeding sheets or blanks of material from stacks is disclosed herein. The invention in its preferred form is utilized with feeding apparatus such as disclosed in U.S. Pat. No. 3,994,489. In this type of system, vacuum chambers are utilized over which are positioned a plurality of rotatable rollers axially mounted in the direction perpendicular to the travel of blanks of material. A series of chambers are disclosed being located in strip-like fashion with blank engaging means alternatively depressed in strips located therebetween. Adjustable back stop means is disclosed which is positioned to confine blanks of different sizes at different times. Associated with the adjustable back stop means is adjustable structure which serves to redefine the size of the vacuum chamber depending upon the size of blanks being processed, i.e., the positioning of the adjustable back stop means.
More specifically, in the structure of the subject invention , a vacuum chamber is disposed beneath the roller members so that the vacuum supply serves to hold down the lowermost board on the top of the rollers. The chamber is defined by the location of the rollers and is preferably constructed with the rollers forming the top portion of the chamber.
As the back stop member is moved forward or to the rear above the rolling members, a sealing member comprised of flexible material and which is connected to the back stop member moves within the chamber and engages individual roller members in turn to form a tight seal within the chamber. To enable the sealing member to move with the back stop member, the sealing member is connected to structure which moves beneath the vacuum chamber. A linking arm extends from the structure beneath the chamber to the sealing member as permitted by a slot which extends along the base of the chamber. The slot is normally closed by a deflection member which is held in position by the vacuum within the chamber, however, the linking arm must interrupt the closure formed by the deflection member. This linking arm structure associated with the sealing member is positioned remotely from the operation area where the vacuum is utilized and accordingly, the linking arm does not interfere with vacuum supply.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial top view disclosing a rolling vacuum feed bed in which the feeding mechanism with the blank engaging means is positioned in alternate strips across the width of the feed bed area;
FIG. 2 is a side sectional view taken along the lines 2--2 of FIG. 1; and
FIG. 3 is a cross-sectional end view taken along the lines 3--3 of FIG. 2.
DETAILED DESCRIPTION
With reference to FIG. 1, the rolling vacuum feed bed is shown having strip-like divisions positioned across the width of the machine. FIG. 1 is only a partial view, however, it is to be understood that the rolling vacuum feed bed is on the order of that disclosed in my co-pending application, now U.S. Pat. No. 3,994,489.
Alternating vacuum chamber strips 10 are shown with blank advancing means disposed within the remaining strip chamber 12. The blank advancing means comprises a feed bar 14 which extends widthwise across the feed bed yet below the alternating vacuum chambers 10. Blank engaging members 16 are shown mounted on the feed bar 14 which engage the lowermost sheet of a stack of blanks.
The vacuum chambers 10 have side walls 18 within which are mounted rollers 20, mounted to be freely rotatable. A vacuum manifold 22 extends widthwise across the feed bed and is connected to the vacuum chambers 10 via orifices 24. An adjustable back stop mechanism 26 is shown which will be described in detail in subsequent paragraphs.
With reference to FIG. 2, a stack of blanks B are shown with the lowermost blank LB being advanced to processing equipment (not shown). Blank advancing equipment is shown which may be on the order of the air cushioned kicker feed assembly which has been fully described in my U.S. Pat. No. 3,675,918 and which may be positioned as shown in my co-pending application, now U.S. Pat. No. 3,994,489. On feed bar 14, mounted actuator mechanism 28 is shown having a piston projection 30 which engages member 32 joined to rear roller 34. The rear roller 34 engages plate member 36 of a spring finger which is pivotally mounted as shown at 38 on mounting member 40. Both the mechanism 28 and the mounting member 40 are rigidly secured to feeder bar 14. A feed clip 42 is mounted on the curved extremity of plate member 36 and engages the lowermost blank LB.
As can be appreciated by jointly viewing FIGS. 1 and 2, the feeder bar reciprocates with the feeder clips 42 shifting rearwardly of back stop structure 26 in the alternating strips as shown in FIG. 1 to engage the lowermost blank and advance it in the direction of arrow 43 of FIG. 2.
With further reference to FIG. 2 and with reference to FIG. 3, the adjustable back stop structure will now be described in detail. A base plate 45 extends widthwise across the feed bed extending beneath the vacuum chambers (see FIG. 1). A top plate 47 extends widthwise across the machine above the rollers and is secured to the lower plate 45 by adjustment means comprising adjusting bolt 49 which extends through shaft 51. The shaft 51 is shown as a steel roller comprised of frictionless material on the outside. The back stop is secured in position by tightening nut 49.
The back stop is further comprised of upright plate members 53 and 55 which are joined by bolts 57 and 59. A stacking roller 61 is freely rotatable about bolt 63. The side plates 53 and 55 are joined to a cross member 65 by connecting means or bolts 67,69. The cross member 65 along with the upright structure comprising upright plates 53 and 55 is in turn bolted to the top plate 47 by means of bolt 71. In such a manner, the adjustable back stop is firmly secured to top and bottom plates 45 and 47 which when adjusted by adjusting means 49 is secured at desired positions along the vacuum feed table. The front connecting plate 73 extends between plates 53 and 55.
The vacuum sealing means which is connected to the adjustable back stop structure can be seen in FIGS. 2 and 3. It will be noted from FIG. 3 that the vacuum chamber bottom is comprised of angles 75 and 77, the sides of which are secured to chamber sides 18 by screw or rivet means 79. A tight fitting resilient seal member 81 which may be constructed of rubber, neoprene, silicone, or other closed cell material is positioned within the vacuum chamber and abuts tightly against chamber side structure 18 and the sides of angle bases 75 and 77 as well as against the top sides of the bottom portions of angle bases 75 and 77. As shown in FIG. 2, the seal member 81 is resilient and will follow the curvature of rollers 20 at its top portion. The resilient seal member 81 is secured to support structure 83 by screw or other means 85. The support structure 83 in turn is bolted to linking arm or connecting structure 87 of generally angular configuration by means of bolts 89 and 91. The linking arm or connecting structure 87 extends downwardly through a slot 93 which is formed between angle bases 75 and 77. With reference to FIG. 1, it will be noted that the slot 93 is shown terminating near the forward edge of the vacuum chambers. It will be appreciated that the back stop will never have to be adjusted fully to the right since blanks of at least minimal size will always be loaded and accordingly, the slot may be terminated short of the processing equipment. The connecting member 87 terminates in a horizontal cross plate 95 which is secured within base plate structure 45 by means of screws or other means 97 and 99. Also, as best seen in FIG. 3, a deflectable member 101 extends below slot 93 which serves as a sealing closure for slot 93 along those areas where vacuum is being applied. The deflectable member 101 may be a piece of vinyl having good memory characteristics. Thus, as seen in FIG. 2, the chamber is sealed by deflectable member 101 being engaged against the chamber bottom (angle base 75 and 77) beneath and to the right of the sealing member so that the vacuum chamber remains air tight along its base. The vacuum created in the chamber to the right of the seal sucks or draws against deflectable member 101 causing the member 101 to be drawn flush against the chamber bottom structure 75, 77. By this structure, it will be appreciated that the adjustability of the back stop is maintained despite a sealing member 81 being positioned within the vacuum chamber yet connected to the adjustable back stop structure outside of the vacuum chamber. It will be appreciated that the back stop may be moved forward or to the rear to enable blanks of different sizes to be processed once the back stop has been adjusted. In this manner, vacuum will be limited to where it is directed through those rollers 20 serving as a feed bed where it will assist in maintaining the desired level of lowermost board which will be driven to processing equipment by the engaging clip 42 as previously described.
The present invention may be embodied in other specific forms without departing from the spirit or essentail attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.
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Apparatus for feeding corrugated blanks to processing machinery which comprises roller members mounted above a vacuum chamber which enables each advancing blank to be held flat while minimizing friction between the advancing blank and the feed bed comprised of the rollers. Improved vacuum chamber construction is utilized in which an adjustable back stop includes improved sealing means to minimize vacuum loss.
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CROSS-REFERENCE T RELATED APPLICATION
[0001] The present application claims priority from copending, commonly assigned U.S. patent application Ser. No. 60/368,667, filed Mar. 28, 2002, entitled Novel Tetrablock Copolymer and Compositions Containing Same (W-0003 prov.).
FIELD OF THE INVENTION
[0002] The present invention relates to a novel tetrablock copolymer and to compositions containing such tetrablock copolymer. More particularly the tetrablock copolymer is a selectively hydrogenated SBSB block copolymer having a particular molecular weight distribution and microstructure, resulting in a polymer having a unique set of property advantages. Also claimed are blends of the tetrablock copolymer and other constituents including styrene polymers, olefin polymers and tackifying resins
BACKGROUND OF THE INVENTION
[0003] The preparation of block copolymers of mono alkenyl arenes and conjugated dienes is well known. One of the first patents on linear ABA block copolymers made with styrene and butadiene is U.S. Pat. No. 3,149,182. These polymers in turn could be hydrogenated to form more stable block copolymers, such as those described in U.S. Pat. No. 3,595,942 and Re. 27,145. A number of other variations for block copolymer structures have been found since then. One of the types of block copolymers that has found limited utility in the past have been tetrablock copolymers having the structure ABAB or BABA, where the A block is a styrene block and the B block is a conjugated diene block, typically either an isoprene block or a butadiene block. These polymers in turn have sometimes been hydrogenated. Such tetrablock copolymers are disclosed in a variety of patents, including U.S. Pat. Nos. 4,874,821; 5,378,760; 5,492,967; 5,549,964; 5,554,697; 6,106,011; and 6,239,218.
[0004] One of the many end uses for block copolymers and tetrablock copolymers is in fibers and films. See, for example, U.S. Pat. Nos. 5,549,964 and 5,705,556. However, during film and fiber formation, breaks are a common problem for highly elastic rubber compounds. Many of the existing block copolymers and formulations based on such block copolymers continue to have problems with breaks. What is needed is a polymer and compound that possesses enhanced strength to produce tougher films and fibers that are much less likely to break during processing. In addition, highly elastic compounds have a tendency to orient during injection molding in long or complex molds. This orientation leads to warpage and non-uniform shrinkage during de-molding or heating. What is needed then is a material with good elastic properties that can be easily injection molded into a part with isotropic properties. It is also desirable to produce a polymer with a higher modulus thus providing a stiffer rubber. A stiffer, stronger rubber allows the use of less polymer to achieve a desired stretching force, and is therefore, more economical.
SUMMARY OF THE INVENTION
[0005] The inventors have discovered a linear hydrogenated block copolymer possessing a unique balance of properties. In particular, the inventors have discovered a linear hydrogenated block copolymer consisting of four alternating blocks having the block arrangement of A 1 -B 1 -A 2 -B 2 wherein:
[0006] a. the two polymer blocks B 1 and B 2 comprise hydrogenated butadiene monomer units in which at least 90% of the olefinically unsaturated double bonds contained in the unhydrogenated polymer block are hydrogenated, and in which the unhydrogenated polymer block have a 1,2-vinyl bond content of greater than 25% and less than 60%;
[0007] b. the two polymer blocks A 1 and A 2 comprise mono alkenyl arene monomer units;
[0008] c. the number average molecular weights of the blocks are between 6,000 and 8,000 for the S 1 block, between 55,000 and 70,000 for the B 1 block, between 7,500 and 9,000 for the S 2 block and between 5,000 and 12,000 for the B 2 block; and
[0009] d. wherein said linear hydrogenated block copolymer has an order-disorder temperature of less than 240° C., a melt flow rate of less than 2.0 g/10 minutes as measured at 200° C. under a load of 5 kg in accordance with ASTM D1238 and a melt flow rate of between 4.0 and 20.0 g/10 minutes as measured at 250° C. under a load of 5kg in accordance with ASTM 1238D.
[0010] The B 1 and B 2 blocks resemble ethylene/butylene copolymers due to the control of the 1,2-content of the butadiene polymer. These are therefore alternatively termed “EB” blocks.
[0011] The inventors have found that the particular combinations of molecular weights for the blocks claimed herein leads to outstanding elastic properties, and that the molecular weight of the B 2 block, or the “EB-tail”, can be used to control the processability of the polymer.
[0012] In another aspect, the inventors have discovered that such linear hydrogenated block copolymers may be compounded with other components into certain elastomeric compositions that have great utility for injection molding and extrusion. Injection molding can be used to make articles such as overmolded handles and soft panels. Extrusion can be used to prepare films, ribbons, tapes and fibers. These compositions comprise the linear hydrogenated block copolymer, a styrene polymer, an ethylene polymer and a tackifying resin. The tetrablock copolymer of the present invention allows a balance of processability, strength and elasticity not achievable in any other film and fiber compound. Compounds for these film and fiber applications normally have strengths in the range of 2,000 to 3,000 psi. The combination of this particular tetrablock copolymer with tackifying resin, polyethylene, and polystyrene yields strengths in the range of 4,500 to 6,000 psi while retaining the balance of processability and elasticity of existing compounds. It is commonly accepted in the art that addition of commercial polystyrene to block copolymers does not affect the end-blocks of these polymers. However, the inventors have found that the addition of between 5 and 10% commercial polystyrene strikingly increases the tensile strength and modulus of these compounds, far beyond the small effect that would arise if the polystyrene were present as filler. The compounds of the present invention are much stiffer than previous compounds with comparable elasticity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 shows stress-strain curves for various compounds of one of the tetrablock copolymers of the present invention with varying amounts and types of polystyrene. FIG. 2 shows stress-strain curves for various compounds of the present invention, including tetrablock copolymer, polystyrene, polyethylene and tackifying resin. FIG. 3 shows stress-strain curves comparing compounds of the present invention against a compound based on a selectively hydrogenated styrene-isoprene tetrablock copolymer.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The tetrablock copolymers of the present invention are linear polymers prepared by contacting the monomers to be polymerized sequentially with an organoalkali metal compound in a suitable solvent at a temperature within the range from about −150° C. to about 300° C., preferably at a temperature within the range from about 0° C. to about 100° C. Particularly effective anionic polymerization initiators are organolithium compounds having the general formula RLi n where R is an aliphatic, cycloaliphatic, aromatic, or alkyl-substituted aromatic hydrocarbon radical having from 1 to 20 carbon atoms; and n is an integer of 1 to 4. Preferred initiators include n-butyl lithium and sec-butyl lithium. See generally, U.S. Pat. Nos. 4,039,593 and Re 27,145 for typical synthesis.
[0015] The tetrablock is a selectively hydrogenated A 1 -B 1 -A 2 -B 2 block copolymer where the A blocks are polymer blocks of mono alkenyl arenes, preferably polymer blocks of styrene. The B blocks prior to hydrogenation are polymer blocks of 1,3-butadiene, where between about 25 and 60 percent of the units have a 1,2-vinyl bond content, preferably between about 30 and about 55 1,2-vinyl bond content. The control of microstructure in the synthesis of the polymer is through the addition of a control agent during polymerization of the butadiene. A typical agent is diethyl ether. See U.S. Pat. No. Re 27,145 and U.S. Pat. No. 5,777,031, the disclosure of which is hereby incorporated by reference.
[0016] The tetrablock copolymer is selectively hydrogenated using any of the several hydrogenation processes know in the art. For example the hydrogenation may be accomplished using methods such as those taught, for example, in U.S. Pat. Nos. 3,494,942; 3,634,594; 3,670,054; 3,700,633; and Re. 27,145, the disclosures of which are hereby incorporated by reference. The methods known in the prior art and useful in the present invention for hydrogenating polymers containing ethylenic unsaturation and for selectively hydrogenating polymers containing aromatic and ethylenic unsaturation, involve the use of a suitable catalyst, particularly a catalyst or catalyst precursor comprising an iron group metal atom, particularly nickel or cobalt, and a suitable reducing agent such as an aluminum alkyl. Also useful are titanium based catalyst systems. In general, the hydrogenation will be accomplished in a suitable solvent at a temperature within the range from about 20° C. to about 100° C., and at a hydrogen partial pressure within the range from about 100 psig to about 5,000 psig. Catalyst concentrations within the range from about 10 ppm wt to about 500 ppm wt of iron group metal based on total solution are generally used and contacting at hydrogenation conditions is generally continued for a period of time with the range from about 60 to about 240 minutes. After the hydrogenation is completed, the hydrogenation catalyst and catalyst residue will, generally, be separated from the polymer.
[0017] An important aspect of the present tetrablock copolymer is control of the molecular weights of the individual blocks. This is accomplished by controlling the monomer and the initiator ratios according to known techniques. The following are the preferred and more preferred molecular weights of the blocks:
Block Preferred Range More Preferred Range A 1 6,000 to 8,000 6,500 to 7,250 B 1 55,000 to 70,000 55,000 to 65,000 A 2 7,500 to 9,000 8,000 to 9,000 B 2 5,000 to 12,000 5,000 to 8,000
[0018] Molecular weights of linear block copolymers are conveniently measured by Gel Permeation Chromatography (GPC) in tetrahydrofuran, where the GPC system has been appropriately calibrated. Polymers of known molecular weight are used to calibrate the GPC and these must be of the same molecular structure and chemical composition as the unknown linear polymers that are to be measured.
[0019] Another important aspect of the tetrablock copolymers is the melt flow, measured at 200° C. and at 250° C. The measurement is according to ASTM D-1238. The melt flow for the neat polymer must be between 4.0 and 20.0 grams per 10 minutes as measured at 250° C. under a load of 5 kg, preferably between 5.0 and 15 grams per 10 minutes. In addition the melt flow must be less than 2.0 grams per 10 minutes as measured at 200° C. under a load of 5 kg, preferably under 1.5. These melt flow rates are important because they are measures of the rheological properties that control the balance of performance and processability for these polymers. Products that have melt flow rates at 200° C. greater than 2.0 grams per 10 minutes will have poor mechanical properties in the application. Products that have melt flow rates at 250° C. that are less than 4.0 grams per 10 minutes will be difficult to melt fabricate into a useful article. Preparing polymers having the desired melt flow rates will allow the preparation of compounds having good melt processing characteristics and excellent performance in the final fabricated article.
[0020] Still further, the order-disorder temperature (ODT) must be less than 240° C., preferably between 210° C. and 240° C. This is important because when the ODT is below 210° C. the polymer will exhibit excessive creep. Polymers with ODT's above 240° C. may not be easily formulated into effective elastic compounds with common ingredients. The order-disorder temperature is defined as the temperature above which a zero shear viscosity can be measured by capillary rheology or dynamic rheology.
[0021] As mentioned above, another aspect of the present invention relates to blends or compounds of the tetrablock copolymers of the present invention with other polymers selected from the group consisting of certain styrene polymers, certain olefin polymers, and certain tackifying resins.
[0022] The styrene polymers are selected from crystal polystyrene and anionic polystyrene, and are included to increase strength and modulus of the compound. High impact polystyrene is not useful because the rubber dispersed in the HIPS would reduce the strength of the compound. It is preferred that the anionic polystyrene have a molecular weight of about 5,000 to about 100,000, since lower molecular weights would be too volatile and higher molecular weights could be obtained as easily from commercial polymers. As for the crystal polystyrene, it is preferred that it have a melt flow greater than 8 and about 15. Preferred polystyrenes include anionic polystyrene having a molecular weight of 7,000, and crystal polystyrene having a melt flow of about 15. Suitable polystyrenes are available from many manufacturers such as Nova Chemicals.
[0023] The olefin polymers include both crystalline and elastomeric polyolefins. Polyolefins utilized in the present invention must be those that form a mechanically compatible blend when blended with the tetrablock copolymers of the present invention. The olefin polymer is added to the compound in order to increase the modulus (stiffness) of the compound and improve the flow properties. In particular, preferred olefin polymers include polyethylene, polypropylene, and polybutylene, including ethylene copolymers, propylene copolymers and butylene copolymers. Also useful are metallocene catalyzed olefin polymers, such as those available from Dow Chemical Company under the trademark AFFINITY or ENGAGE and from Exxon/Mobil Chemical Company under the trademark EXACT. Blends of two or more of the polyolefins may be utilized. Much preferred polyolefins include low density polyethylene and linear low density polyethylene having densities less than 0.93 grams per cubic centimeter. In addition it is preferred that the LDPE or LLDPE have a high melt flow, preferably greater than about 100. A much preferred polyolefin is Petrothene NA 601 from Quantum Chemical, having a density of about 0.903 grams per cubic centimeter and a Melt index of 2,000 grams per 10 minutes when measured in accordance with ASTM D 1238. Waxes, such as Epolenes, available from Eastman Chemical are also suitable polyolefins. The waxes may be branched ethylene waxes or copolymer waxes.
[0024] Various tackifying resins can be used in the present invention in order to 1 0 increase tack and reduce viscosity. Any tackifying resin can be used which is compatible with the tetrablock copolymer and the polyolefin, and can withstand the processing temperatures. Generally, hydrogenated hydrocarbon resins are preferred tackifying resins, because of their better temperature stability. Suitable resins are available from a number of companies such as Arkon resins from Arakawa, Rextac from Huntsman Chemical, Escorez from Exxon Chemical and Estotac , Regalite, and Regalrez resins from Eastman.
[0025] Preferred tackifying resins are hydrogenated α-methyl styrene, low molecular weight hydrocarbon resin, such as REGALREZ® resins 1126 and 1139 from Eastman Chemical.
[0026] The compounds of the present invention include those having the following formulations, where the total of the various components in any one formulation equals 100 percent:
Component Preferred Range, % w More Preferred Range, % w Tetrablock 50 to 80% 65 to 75% Styrene Polymer 4 to 15% 5 to 10% Olefin Polymer 5 to 20% 5 to 15% Tackifying Resin 0 to 25% 10 to 25%
[0027] While the principal components of the extrudable, elastomeric composition have been described in the foregoing, such composition is not limited thereto, and can include other components not adversely affecting the composition attaining the stated objectives. Exemplary materials which could be used as additional components would include, without limitation, pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, solvents, particulates, and materials added to enhance processability and handling of the composition.
[0028] Any of the techniques known in the art for blending polymeric components may be used to combine the components of the composition of this invention. Suitable blending techniques include roll milling, screw extrusion and the like.
[0029] The compositions of the present invention may be used in a variety of applications such as molded and extruded goods. Preferred applications are overmolding on various polymer substrates and extrusion into elastic films and fibers having improved processing and/or bonding properties. Molded products provide a soft, high friction surface either alone or overmolded onto polymer substrates to improve the surface feel of a wide range, of products.
[0030] The following examples are intended to be illustrative only, and are not intended to be, nor should they be construed as being, limiting in any way of the scope of the present invention.
[0031] Illustrative Embodiment #1
[0032] In Illustrative Embodiment #1 various tetrablock copolymers were prepared—some according to the present invention, and some outside the present invention. In all cases the tetrablock copolymers were prepared according to the following process scheme:
[0033] 1. In the first step styrene was polymerized in a reactor in the presence of a cyclohexane diluent and a sec-butyl lithium initiator to form the S 1 block;
[0034] 2. in the second step, 1,3-butadiene was added to the reactor along with diethyl ether as a microstructure modifier to form the B 1 block;
[0035] 3. in the third step styrene was added to form the S 2 block;
[0036] 4. in the fourth step 1,3-butadiene was added to form the B 2 block;
[0037] 5. methanol was then added to terminate the polymerization;
[0038] 6. the resulting S 1 -B 1 -S 2 -B 2 polymer was then hydrogenated under standard conditions with a nickel octoate/aluminum triethyl catalyst to selectively hydrogenate the butadiene units. The residual unsaturation of the olefin portion of the block copolymer was under 0.3 millequivalents per gram, equivalent to a conversion of over 95% of the olefin unsaturation.
[0039] The 1,2-vinyl content of the butadiene blocks prior to hydrogenation was about 38% for all the polymers.
[0040] The various polymers prepared in Illustrative Embodiment #1 are listed in Table #1. The polymers marked with an asterisk are those according to the present invention. —those not marked with an asterisk are outside the present invention.
[0041] Illustrative Embodiment #2
[0042] In Illustrative Embodiment #2 Polymer 1000 from Illustrative Embodiment #1 was compounded with varying amounts and types of polystyrene. The various polystyrenes tested include:
[0043] PS 6700, an anionic polystyrene having a molecular weight of 6700
[0044] Nova 555, a crystal polystyrene having a melt flow of 15
[0045] PS 15000, an anionic polystyrene having a molecular weight of 15,000
[0046] Nova EA 3000, a crystal polystyrene having a melt flow of 1.5
[0047] In all cases the compound contained 0.2 percent of an antioxidant.
[0048] It is well known in the industry that high molecular weight polystyrene is not effective in improving the properties of block copolymers because it does not interact with the polystyrene domains of the block copolymers. With the polymer of the present invention, however, the inventors have found that the addition of 5% to 10% polystyrene provides a very large improvement in tensile strength and 500% modulus. Table 2 and FIG. 1 details the formulations and properties of various compounds. These compounds were melt mixed in a small Brabender mixing head at 225° C. for 5 minutes. The resulting mixture was removed and compression molded into a film for testing. Table 2 and FIG. 1 show that the addition of 5% to 10% polystyrene produces a significant improvement in tensile strength, but more importantly in the modulus values at 300% and 500% strain. This provides the compound with a more linear stress strain curve and less of a rubbery plateau from 150-500% elongation. Typical block copolymers have a relatively slow increase in stiffness from 150-500% elongation. This slow increase in stiffness allows typical block copolymers to be stretched to high elongation without the use of significantly greater forces. In injection molded parts, the stiffer elastomer will provide better tear and bite resistance.
[0049] Illustrative Embodiment #3
[0050] In Illustrative Embodiment #3 Polymer 1000 from Illustrative Embodiment #1 was compounded with a tackifying resin and a low-density polyethylene. The tackifying resin was Regalrez 1126, which is a fully hydrogenated a-methyl styrene hydrocarbon resin having a softening point of 125° C. The low-density polyethylene was NA-601, having a density of 0.903. Samples D-1 through D-5 were compounded in a similar manner to that of Illustrative Embodiment #2. The benefit of increased strength and modulus can be see from Table #3 and FIG. # 2 . Sample D-3, which contains polystyrene, tackifying resin and polyethylene has a substantially improved tensile strength and modulus at 500% elongation over any of the other formulations, without sacrificing other properties such as permanent set and hysteresis.
[0051] The formulation of Sample D-3 was compounded in larger volumes on a Berstorff twin screw extruder, then cast on a Davis Standard cast film line. The formulation is labeled F-1in Table 3 and FIG. 2. The film version has substantially improved tensile strength and modulus at high elongations compared to formulations without polystyrene. The improvement is particularly noted in the machine direction (“md”) of the extruded film, compared to the transverse (“td”) direction. For applications where elongation is in the machine direction, such as fibers and some films, this is highly advantageous. The properties shown in Table 3 are relatively isotropic compared to traditional compounds where the difference in properties between the MD and TD directions is often more than a factor of 2. This is advantageous for molding thin parts with long flow paths. A material such as the F-1 compound would show very little tendency to warp or shrink non-uniformly because the properties are very similar in all directions.
[0052] Illustrative Embodiment #4
[0053] In Illustrative Embodiment #4 formulation F-1 from Illustrative Embodiment #3 is compared with other similar formulations with varying amounts of polymer and other ingredients. As shown in Table #4 the variation in tackifying level and polystyrene level results in materials which can have a range of modulus and surface tack without losing their high strength. Table 4 shows that this formulation can be very tacky and can be adjusted as desired.
[0054] In addition, formulations with KRATON™ polymers G-1657 and G-1730 were prepared in a similar manner to the F-1 formulation, and the particular formulations are shown in Table 5. G-1657 is a selectively hydrogenated SBS block copolymer having a styrene content of about 13% w and also containing about 30% uncoupled diblock copolymer. G-1730 is a selectively hydrogenated S-I-S-I tetrablockcopolymer having a styrene content of about 22% w. As shown by comparing the results in Tables 4 and 5 and in FIG. 3, the ultimate tensile strength of the current invention is substantially improved over the existing commercial compounds. The modulus at all elongation levels is improved resulting in a more powerful elastic.
TABLE #1 Tetrablock Copolymers-Block Sizes, Melt Flow and Order-Disorder Temperatures Actual Block Size (×1000) Melt flow ODT Polymer S 1 EB 1 S 2 EB 2 @ 250° C. @ 200° C. (° C.) 1000* 6.7 65.2 8.4 6.7 5.0 0.5 210 1001* 6.8 59.2 8.1 6.6 8.4 210 1002* 6.9 61.0 8.4 6.6 8.4 220 1003 23.4 83.4 25.0 8.8 300+ 1004 27.0 90.4 27.4 12.1 300+ 1005 21.4 83.5 28.7 11.0 300+ 1006 7.4 67.7 9.6 6.9 2.0 250 1007 7.3 65.8 9.2 7.7 2.9 240 1008 7.4 64.8 9.1 6.7 2.9 240 1009 6.7 59.2 8.6 7.3 5.0 240 1010 6.8 58.4 8.6 6.5 7.0 0.7 240 B-6 6.6 66.1 9.5 6.6 4.7 250 B-7 6.9 60.7 9.5 6.0 5.3 240 B-8* 6.9 60.3 8.9 5.8 9.5 0.7 230 B-9* 6.8 59.4 14.3 1.7 210 B-10* 6.8 59.9 7.8 6.3 12.8 1.3 210 B-11* 6.8 59.7 8.8 5.8 7.7 230 B-12* 6.8 60.6 8.2 6.1 9.4 1.1 230
[0055] [0055] TABLE #2 Sample No. D11 D12 D13 D17 D14 D15 D16 D18 Formulation 1000, % 99 95 90 95 99 95 90 95 PS 6700, % 1 5 10 0 0 0 0 0 Nova 555, % 0 0 0 0 1 5 10 0 PS 1500, % 0 0 0 5 0 0 0 0 EA 3000, % 0 0 0 0 0 0 0 5 Properties Stress-Strain Max Stress, psi 4792 5561 5433 5773 4896 5734 6035 5719 Strain at Break, 921 915 843 882 989 905 860 877 % Stress at 50%, 172 151 183 165 159 165 179 170 psi Stress at 100%, 218 193 241 212 203 209 229 216 psi Stress at 200%, 290 264 342 286 271 286 324 301 psi Stress at 300%, 392 362 482 398 364 402 472 426 psi Stress at 500%, 799 806 1176 921 713 919 1249 1059 psi ODT (° C.) 210- >280 >280 200- 200- 200- >280 200- 260 280 260 280 280
[0056] [0056] TABLE #3 Sample No. D1 D2 D3 D4 D5 F-1 F-1 1000, % 68 80 75 63 74 75 75 PE 601, % 12 7 7 20 13 7 7 Regalrez 1126, 20 13 13 17 13 13 13 % Nova 555, % 0 0 5 0 0 5 5 Properties Stress-Strain md trans Max Stress at 4461 4482 5648 4771 4758 5628 5834 Break, psi Strain at Break, 1019 1008 969 1064 1019 787 914 % Stress at 50%, 166 176 179 199 173 182 176 psi Stress at 100%, 208 221 224 242 215 233 216 psi Stress at 200%, 272 288 305 313 281 336 284 psi Stress at 300%, 360 382 423 409 371 485 380 psi Stress at 500%, 688 732 951 745 704 1262 817 psi ODT (° C.) 225 230 240 225 240 240
[0057] [0057] TABLE #4 Sample No F-1-1 F-1-2 F-1-3 Polymer 1000 1000 1000 Formulation Polymer, % 75 68 60 PE 601, % 7 7 7 Reg. 1126, % 13 20 23 PS 555, % 5 5 10 Tack Very slight Slightly tacky Tacky Properties Stress-Strain md td md td Max Stress at Break, psi 5628 5834 5700 5400 4360 Strain at Break, % 787 914 830 985 945 Stress at 50%, psi 182 176 170 140 135 Stress at 100%, psi 233 216 220 170 180 Stress at 200%, psi 336 284 310 230 260 Stress at 300%, psi 485 380 430 300 390 Stress at 500%, psi 1262 817 980 560 1050
[0058] [0058] TABLE #5 Sample No F-2 F-3 F-4 Polymer Type G-1657 G-1730 G-1730 Formulation Polymer, % 63 68 80 PE 601, % 20 12 7 Reg. 1126, % 17 20 13 PS 555, % 0 0 0 Tack Very slight Very slight Very slight Properties Stress-Strain md td md td md Td Max Stress at Break, psi 2037 2050 3213 1924 2100 1990 Strain at Break, % 1000 1066 888 787 930 900 Stress at 50%, psi 146 122 106 Stress at 100%, psi 190 222 158 139 150 154 Stress at 200%, psi 236 211 189 276 Stress at 300%, psi 294 281 255 270 554 Stress at 500%, psi 478 535 498 563 Sample No F-5 F-6 Polymer Type G-1730 G-1730 Formulation Polymer, % 70 85 PE 601, % 30 15 Reg. 1126, % 0 0 PS 555, % 0 0 Tack Very slight Very slight Properties Stress-Strain Md Td Md Td Max Stress at Break, psi 1970 1840 2485 2310 Strain at Break, % 795 788 830 800 Stress at 50%, psi Stress at 100%, psi 330 284 263 260 Stress at 200%, psi Stress at 300%, psi 520 520 485 480 Stress at 500%, psi 950 1020 1040 1020
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A novel tetrablock copolymer having the general configuration of A 1 -B 1 -A 2 -B 2 is claimed, where the A 1 and A 2 blocks are blocks of mono alkenyl arene and the B 1 and B 2 blocks are blocks of hydrogenated butadiene, having a 1,2-vinyl content of between 25% and 60%. The blocks have well defined molecular weight ranges, resulting in a polymer having a unique set of property advantages. Also disclosed and claimed are elastomeric compositions containing the linear hydrogenated block copolymer, a styrene polymer, an ethylene polymer and a tackifying resin. These elastomeric compositions have particular utility in injection molded parts and in extruded parts such as extruded films and fibers.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/539,331 entitled “HAND GRENADE”, Sep. 26, 2011, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to fuzed devices, and, more particularly, fuzed hand grenades.
2. Description of the Related Art
A hand grenade is a small bomb that can be thrown by hand. There are at least three types of hand grenades—explosive grenades, chemical grenades, and gas grenades. Explosive hand grenades are the most common used in modern warfare, and they detonate after impact or after a predetermined time after the detonator of the hand grenade is armed. Chemical and gas grenades do not explode, rather they burn or release a gas.
Typically grenades explode, projecting shrapnel consisting of pieces of the casing, serrated wire, or an incendiary material. Grenades are manufactured having an explosive or chemical filler with an opening for a fuze. Modern hand grenades have a fuze that is lit by an internal device rather than an external flame typically used in older grenades.
Hand grenades manufactured for US forces, such as that shown in FIG. 1 , typically have a safety handle or lever 4 (which is known by some as the spoon, due to its size and shape) and a removable safety pin 1 that prevents the safety lever 4 from being released. Some grenade types, such as the one shown in FIG. 1 , also have a safety clip 3 to further prevent the handle from inadvertently coming off in transit.
To use a grenade of FIG. 1 , the soldier grips it with the throwing hand, ensuring that his thumb holds the safety lever 4 in place. This is called the death grip, because releasing the lever could make the grenade detonate, killing the thrower. Left-handed soldiers are advised to invert the grenade, so the thumb is still the digit that holds the safety lever. The soldier then grabs the pull ring 1 with the index or middle finger of the other hand and removes it with a pulling and twisting motion. He then throws the grenade towards the target.
Once the soldier throws the grenade, safety lever 4 releases, the striker throws safety lever 4 away from the grenade body 5 as it rotates to detonate the primer (not specifically shown). The primer explodes and ignites the fuze (which serves as a delay element). The fuze burns down to the detonator, which explodes the main charge in body 5 .
Several problems exist with the prior art hand grenades, among them the difficulty in operating the system with one hand. Another problem is that the pull ring can catch on something and be inadvertently pulled out. Another problem is that it is difficult to reinsert the pin of the pull ring once it is removed.
What is needed in the art is an effective device to overcome these problems with the prior art hand grenades.
SUMMARY OF THE INVENTION
The present invention provides an effective locking mechanism for a hand grenade that is easily removable when removal is intended, yet does not come out inadvertently.
The present invention in one form is directed to a hand-throwable grenade including a detonator initiating mechanism, a detonator and a locking key. The detonator initiating mechanism is activatable by an operator before the grenade is thrown. The detonator is associated with the detonator initiating mechanism. The locking key interacts with the detonator initiating mechanism to preclude an arming of the detonator until the locking key is removed from the detonator initiating mechanism. The locking key has at least one notch therein.
An advantage of the present invention is that the key is easily removable by the hand that is holding the grenade.
Another advantage of the present invention is that the key is positively locked to the safety lever until the safety clip is removed.
Yet another advantage of the present invention is that the key can be easily reinserted into the opening in the safety lever and the opening in the detonator to re-safe the grenade.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a side view of a prior art hand grenade;
FIG. 2 is a partial side view of an embodiment of a hand grenade of the present invention;
FIG. 3 is another partial side view of the hand grenade of FIG. 2 showing the alignment of slots;
FIG. 4 is another partial side view of the hand grenade of FIGS. 2 and 3 with an embodiment of a key of the present invention installed with the safety lever in the position shown in FIG. 3 ;
FIG. 5 is another partial side view of the hand grenade of FIGS. 2-4 with the key installed with the safety lever in the position shown in FIG. 2 ;
FIG. 6 is a partial perspective view of another side of the hand grenade of FIGS. 2-5 ;
FIG. 7 is another perspective view of the hand grenade of FIGS. 2-6 ;
FIG. 8 is a side view of the hand grenade of FIGS. 2-7 ;
FIG. 9 is another view of the hand grenade of FIG. 2-8 ;
FIG. 10 is a top view of the hand grenade of FIGS. 2-9 ;
FIG. 11 is a partial view of the hand grenade of FIGS. 2-10 , with the key of the present invention nearly removed;
FIG. 12 is a view of the key used in the hand grenade of FIGS. 2-11 ; and
FIG. 13 is a view of another embodiment of a key of the present invention that can be used with the hand grenade of FIGS. 2-11 .
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings and more particularly to FIG. 1 there is shown a prior art hand grenade having a pull ring pin 1 , a confidence clip 2 , a safety clip 3 , a safety lever 4 and a grenade body 5 . Confidence clip 2 is provided to hold pull ring pin 1 in place in an attempt to prevent a premature removal of pull ring pin 1 . An operator has to clear pull ring pin 1 from confidence clip 2 , flip safety clip 3 off, remove pull ring pin 1 , let safety lever 4 come off to activate the fuze of the grenade. These operations are typically carried out with two hands. A disadvantage of this configuration is that the ring of pull ring pin 1 can get caught on something inadvertently causing pull ring pin 1 to be removed.
Now referring to FIGS. 2-13 there is illustrated a new fuzed device 10 in the form of a hand grenade 10 including a bomb portion 12 , a fuze assembly 14 , a safety lever 16 , an opening 18 , a safety clip 20 , an opening 22 , a key 24 and an opening 26 . Key 24 includes notches 28 and a clip 30 . As can be seen in FIG. 2 opening 18 and opening 26 are not fully aligned while opening 22 is visible beside safety lever 16 . Several of the subsequent figures illustrate the insertion of key 24 and safety clip 20 , which is the reverse of what a fuzed device 10 would normally do in the use of fuzed device 10 .
Fuze assembly 14 contains a detonator, which for the ease of explanation fuze assembly 14 can be considered a detonator 14 that is activated when safety lever 16 is removed. Safety lever 16 is a detonator initiating mechanism 16 that is prepared for activation by the removal of clip 30 and key 24 as discussed herein. The detonation process initiates when lever 16 is removed, which may be by the operator releasing lever 16 , or as is often the case the separation of lever 16 from the rest of grenade 10 during the throwing process.
In FIG. 3 , safety lever 16 is pressed closer to bomb portion 12 to cause openings 18 and 26 to substantially align. Movement of lever 16 in direction D has allowed openings 18 and 26 to align. This action causes opening 22 to be obscured from view by the position of safety lever 16 . The movement of safety lever 16 and a spring in fuze assembly 14 (not shown) allows this movement to occur. In FIG. 4 , key 24 has been inserted through openings 18 and 26 and some of the force, which is applied in direction D, has been released from safety lever 16 allowing a view of a part of opening 22 . In FIG. 5 , safety lever 16 has been released and key 24 is preventing safety lever 16 from leaving fuze assembly 14 . Additionally referring to FIGS. 12 and 13 , notches 28 can be seen in key 24 , which are what allows opening 18 to once again not align fully with opening 26 as notches 28 allow a portion of safety lever 16 to enter therein to thereby lock key 24 in position and fully exposing opening 22 . Notches 28 allow a portion of lever 16 to enter thereinto so as to preclude the sliding removal of key 24 from openings 18 and 26 .
In FIG. 6 , safety clip 20 has been inserted into opening 22 and is clipped over a portion of the outer surface of safety lever 16 . Safety clip 20 then prevents safety lever 16 from being depressed enough to remove key 24 . This is an interaction that does not exist in the prior art, with safety clip 20 precluding the removal of key 24 . In contrast the prior art hand grenade as illustrated in FIG. 1 , allowed the pin 1 to be removed with the safety clip installed. In the present invention the coacting of safety clip 20 , safety lever 16 and key 24 require a prescribed sequence of operations to arm fuze assembly 14 . That sequence is the removal of safety clip 20 , the depressing of safety lever 16 , the pressing of clip 30 outwardly, the sliding of key 24 from openings 18 and 26 , and the release of safety lever 16 .
In FIG. 7 there is shown another view of fuzed device 10 illustrating an opposite side of safety lever 16 from that shown in FIG. 6 . FIG. 8 is yet another view of fuze device 10 , which clearly shows key 24 , which not only extends through openings 18 and 26 , but also wraps around safety lever 16 having a clip 30 which additionally serves to secure the position of key 24 . It is also contemplated that key 24 may not wrap around safety lever 16 . FIG. 9 is a top view of fuzed device 10 with key 24 and safety clip 20 in there normal installed positions.
FIGS. 10 and 11 illustrates a method of arming fuzed device 10 with safety clip 20 being removed by pushing with a finger or thumb (not shown) in direction S, then as safety lever 16 is grasped and pressure being applied in direction D, key 24 is pressed upward and in direction L over and across safety lever 16 . Once key 24 is removed fuzed device 24 is armed by the releasing of safety lever 16 in a conventional manner.
FIGS. 12 and 13 illustrate possible configurations of key 24 each having notches 28 that interact with elements of fuze assembly 14 and/or safety lever 16 to secure key 24 until safety lever 16 is depressed and key 24 is removed.
The present invention was conceived whereby a key 24 with positive locking features, aka “PosiKey”, replaces the existing pull ring 1 and split pin in current hand grenade technologies. Advantageously, the present invention negates the need to control the pull force associated with pull ring pin 1 of the prior art. The present invention further exploits the existing components to create an interlocking system allowing existing inventory to be retrofitted with the PosiKey system. In and of itself, the locking aspect of the new system that exploits the current technology fuze body, safety lever, spring-loaded striker and the innovative key negates the need for confidence clip 2 for the pull ring 1 inasmuch as a pull ring 1 does not exist in the present invention. While with the current technology confidence clip 2 acts as an additional component to defeat extraction of the pull ring 1 and the associated split pin from the grenade, the innovative PosiKey system acts singularly to prevent removal of the key in the normally stowed position. The PosiKey system further exploits the use of a safety clip with an added loop 32 to prevent compression of the spring-loaded striker/safety lever 4 , 16 , i.e., the ready position when gripped by the operator. Loop 32 performs two functions, it provides a stop for holding safety clip 20 in a proper position relative to lever 16 as loop 32 rests against the face of fuze assembly 14 , and loop 32 adds a spring element to clip 20 so that clip 20 pushes against lever 16 toward the body of grenade 10 . Once the grenade with the PosiKey system is gripped and the safety clip 20 is removed, the safety lever 4 , 16 can be compressed to the ready position and the key 24 easily removed. The PosiKey further incorporates a tab 30 that latches across the width of the safety lever such that no compression is imparted to the spring-loaded striker/lever. This feature is provided to present a final mode of intent to function the grenade once the grenade is gripped, safety clip removed, and lever compressed. With this latching feature, the PosiKey must be extracted with intent, but unlike the current technology that necessitates two hand operation, the key 24 can be extracted either with thumb action of the throwing hand, which is also used to remove the safety clip, or with the hand alternate to the throwing hand, much like the current technology pull ring. Unlike the current technology, the invention provides for multiple opportunities to abort the intended function of the grenade. Most importantly, the key 24 can be re-inserted after removal, and the safety clip re-inserted to completely and readily re-safe the grenade, while the current technology pull ring and pin cannot be readily re-safed due to deformation of the split pin.
Primary motivation for the present invention emanated from observed problems for hand grenades from manufacturing production acceptance and inventory testing for low pull pin retention force. Secondary motivation emanated from operators' practice of taping the pull ring current technology in place, causing a more hazardous scenario for the retrograde of grenades back into the supply chain. To mitigate this, grenades are now being produced by the U.S. Government that adds a confidence clip 2 shown in FIG. 1 to the grenade. The shortcoming with this technology is that the pull ring 1 still exists and can become snagged by external objects, i.e., even in the stowed position, opportunity can arise that causes the pull ring 1 to detach from confidence clip 2 and further cause the pin 1 to extract from the grenade thereby leaving only the easily sprung safety clip 3 to prevent grenade function if the clip has been left in place. Additional shortcoming is that the confidence clip 2 reduces fuze thread engagement into the grenade body. Calculations are that only three-quarters of a thread is engaged when using the confidence clip 2 .
All known prior art hand grenades use a pull ring and pin 1 through the safety lever 4 and fuze body with or without a safety clip trapping the lever to the fuze body. The prior art technology uses a safety clip 3 as a secondary safety feature in the event that the pull ring and pin 1 are inadvertently removed. However, common practice through training is to remove this clip prior to pulling the safety pin. Neither the safety clip 3 nor the confidence clip 2 positively prevents the pull pin 1 from being removed in current technology.
Aside from the inherent safety advantages of the multiple detent PosiKey of the present invention, the innovation further allows the grenade to be retrofitted and eliminate the confidence clip 2 , thereby reclaiming the advantages of the original mating assembly configuration of the fuze to grenade body with proper compression of the gasket and proper original design engagement of the threads. By eliminating the confidence clip 2 , modes of failure introduced by the confidence clip's physical characteristics to control removal of the pull pin 1 are also eliminated. By eliminating the pull ring 1 and its intricately formed safety pin, additional failure modes are eliminated, most notably “pull force” that is a recurring barrier to product acceptability in fuze and grenade manufacturing. Pull pin force continues to be a controlled characteristic in spite of the addition of the confidence clip 2 . Instead of adding components to secure the safety pin and complicating the technology, the PosiKey system reduces the number of components and associated failure modes from current technology.
The improved safety clip 20 in the PosiKey system truly serves a safety function by preventing the PosiKey from being removed from the fuze/grenade assembly, prior to the removal of safety clip 20 .
With the safety lever 16 in the compressed and unlocked position, the PosiKey can be extracted using a thumb action of the throwing hand similar to that used to remove the safety clip 20 , which theoretically allows one hand operation in extreme combat conditions, e.g., non-throwing hand is incapacitated.
Unlike the current technology wherein components can result in pin extraction through material deformation, the PosiKey system of interlocking component feature interfaces cannot be extracted. Even if a portion of key 24 were to suffer from a material failure, the portion of the key internal to the grenade would continue to lock the grenade until the lever is compressed. Should such an event occur, the grenade can still be functioned by compressing the safety lever and allowing the locking residual to fall out. If material failure ever occurred with the PosiKey system, the primary failure mode of the locking key would occur external to the grenade and the residual key internal to the grenade would continue to lock the system.
Advantageously, existing inventory can be retrofitted with the PosiKey system as proven by the construction of a working model using surplus materiel.
The present invention consists of a system of current technology components with the addition of improvement features that accommodate the PosiKey system locking interface. The system has slots or openings 18 and 26 through the safety lever and fuze body. Slots 18 and 26 are directed towards the grenade inward along a line perpendicular to the safety lever pivot point. These slots are aligned when the safety lever 16 is in the fully compressed position as when gripped and squeezed by the operator's hand. The required compressing force is not altered from that required for the current technology's baseline. Interfacing key 24 is made from spring steel and is formed according as illustrated in FIG. 12 or 13 and machined to create multiple standoffs and recesses, cut-outs or notches 28 , which align respectively with the fuze body and safety lever 16 material in the area of their slots. The standoffs and recesses allow the safety lever 16 to close the slots when the compressing force is removed, allowing the current technology spring-loaded striker to move the safety lever 16 and current technology striker into a locked position with key 24 . Key 24 includes aligned portions of material that is not removed and serves as standoffs in the improved fuze body slots and to lock against the inside and outside of the improved safety lever 16 side material. A shoulder is created on key 24 to serve as a positive stop and to properly align the standoffs and recesses with the improved fuze body and safety lever 16 when key 24 is fully inserted. A third recess is also cut in key 24 to correspond with the striker that also creates an interfacing locking function. Once in the locked position, a total of three interfaces prevent key 24 from being removed from the improved fuze/grenade assembly. These multiple recesses are what create multiple opportunities for the operator to reconsider a decision to function the grenade. As can be seen in the figures notches 28 extend from an edge of key 24 in a direction which is generally perpendicular to the direction in which key 24 is removed from the fuzed device. A portion of lever 16 is positioned in notches 28 when key 24 is precluding the arming of the detonation device.
The remaining material of key 24 in the area of the recesses/cut-outs prevents the current technology spring-loaded striker and improved safety lever from further movement, having a material cross section with yield strength greater than that of the current technology split pin used for the same purpose.
On the operator side of the key's positive stop shoulder, the protruding flat steel is further formed to create an external tab that wraps back 180 degrees as shown in several of the figures and traverses the width of safety lever 16 , ending in a catch formed from the tab (shown as clip or tab 30 ) that detents on the opposite side of safety lever 16 . This external tab is formed to not compress the improved safety lever when in the locked position. The tab is also sufficiently formed to catch on the opposite side of safety lever 16 when safety lever 16 is in the fully compressed position. The catch serves to retain key 24 when lever 16 is in the compressed and unlocked position wherein slots 18 and 26 in the fuze body and safety lever 16 , and the current technology striker are aligned to otherwise allow the free extraction of key 24 . This catch feature adds a mode of safety for key extraction. The wrap around tab also includes a narrowing of its cross section to reduce bending stress on the shoulder area of key 24 and allows the catch to spring into place around safety lever 16 .
Alternately, a key 24 may be formed with recesses to lock on the fuze body. In this manner, the key is shown in FIG. 13 . However, this alternative reduces the number of locking interfaces by not providing a locking interface with the striker.
To prevent safety lever 16 from being inadvertently compressed from its locked position during stowage, i.e., the environment of transported loose cargo storage or temporary handling trays or pouches, a new safety clip hole 22 is created on the insertion side of the improved fuze body that traps the end of the improved safety clip 20 and creates an opposing force as the improved safety clip 20 latches on the opposite side of safety lever 16 . An improved safety clip 20 is created by culminating in a blunt tip that is inserted into the hole. The improved safety clip 20 is formed to conform to the mating side surfaces of the safety lever and create an interference/spring fit around the safety lever 16 sides when inserted into the said safety clip hole 22 .
Once the improved safety clip 20 is inserted into hole 22 in the improved fuze body, the edge of the improved safety lever 16 is constrained and lever 16 is prevented from inadvertent compression, thereby preventing key 24 from being removed and ultimately locking the improved fuze/grenade assembly until clip 20 is removed and lever 16 is compressed.
Should the PosiKey not become fully extracted from the grenade for any circumstance or reason, such as operator incapacitation, the improved system will relock the grenade upon release of the safety lever 16 . This cannot be accomplished with current technology.
With the improved safety lever 16 in the compressed and unlocked position, the PosiKey allows one-handed operation using the thumb catch on the external tab.
This invention may be implemented into any hand grenade that uses a spring-loaded striker under a safety lever without requiring radical modification of current technology to implement. Most grenades in the world use a split pin through the fuze and across the striker to impede grenade function. The PosiKey not only impedes grenade function, but also eliminates the characteristic of pull force associated with current technology pull rings and split pins.
Advantageously, this PosiKey system can be implemented into new production as well as retrofitted into existing inventory for both grenade assemblies and practice fuze assemblies.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
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A hand-throwable grenade including a detonator initiating mechanism, a detonator and a locking key. The detonator initiating mechanism is activatable by an operator before the grenade is thrown. The detonator is associated with the detonator initiating mechanism. The locking key interacts with the detonator initiating mechanism to preclude an arming of the detonator until the locking key is removed from the detonator initiating mechanism. The locking key has at least one notch therein.
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FIELD OF THE INVENTION
This invention relates to a marine propulsion unit for use in boats such as pleasure boats including yachts and motor boats.
More particularly, the present invention relates to a marine propulsion unit of the type comprising an engine mounted in the hull of a boat at a stern portion with the output end directed towards the stern, an inclined propeller shaft extending downwardly and backwardly from the hull and carrying at its terminal end a propeller, and a reversing clutch mechanism disposed between said engine and propeller shaft and having an input shaft drivenly connected to said engine and an output shaft drivingly connected to said propeller shaft.
DESCRIPTION OF PRIOR ART
In general, marine propulsion unit of the type set forth above is called an angle drive system. A standard type of such angle drive system is fashioned so that the whole of propulsion unit from engine to propeller shaft via a reversing clutch mechanism is mounted in a posture inclined downwardly and backwardly by an angle equal to an inclination angle to be given to the propeller shaft. Such standard type propulsion unit is disclosed in, by way of examples, British Pat. No. 1,226,358 and German Offenlegungsschrift No. 2,303,723.
It is always required or preferred to enlarge crew space in a boat such as pleasure boat. In a boat having an angle drive system of the standard type, height of engine room is enlarged due to the inclined posture of engine corresponding to the downward and backward inclination of propeller shaft so that crew space is reduced correspondingly. From this, there have been proposed some propulsion units of angle drive type in which engine is mounted horizontally so as to enlarge crew space within the hull of a boat.
One of such structures according to the prior art is such in that, as shown in, for example, FIGS. 3 and 6 of JP, A (Japanese Patent Publication under Art. 65 bis of the Japanese Patent Law) No. 51,76793, engine and reversing clutch mechanism are disposed horizontally and the inclined propeller shaft is drivenly connected to the output shaft of reversing clutch mechanism by means of transmission shaft having at both ends thereof universal joints. According to this prior art, however, the whole of propulsion unit is enlarged considerably in length in the longitudinal direction of boat due to the use of not only an intermediate transmission shaft but a pair of universal joints at the ends of such shaft. This drawback is enhanced when a pair of universal joints of constant velocity type are employed for a smooth drive of the propeller shaft, because such constant velocity universal joints provide bulky joint structures. Constant velocity universal joint is relatively expensive so that use of a pair of such universal joints is not preferred.
Another use of constant velocity universal joint in an angle drive system is shown in FIGS. 13 and 14 of JP, A No. 55-51698. In the propulsion unit according to this prior art engine and reversing clutch mechanism are disposed horizontally, too. A transmission shaft extending downwardly and backwardly as from a position below the rear end portion of output shaft of the reversing clutch mechanism is provided coaxially with propeller shaft and is fixedly connected to such propeller shaft. This intermediate transmission shaft mounts rotatably at its front end portion a spur gear which is meshed with another spur gear fixedly mounted on the rear end portion of clutch output shaft. A constant velocity universal joint of Birfied-type is disposed within the former spur gear and on the intermediate transmission shaft for connecting operatively such spur gear and transmission shaft. The marine propulsion unit according to this prior art employs a single constant velocity universal joint which is disposed within a gear so that the propulsion unit is made compact and may be manufactured with a relatively low cost. On the other hand, the intermediate transmission shaft having a downward and backward inclination is located below the clutch output shaft so that power transmission path includes a step or stepped portion at a bend from which such path is inclined. Such step or stepped portion which lowers the level of transmission path at the bend thereof requires to highten the level of clutch output shaft and, therefore, the level of reversing clutch mechanism and engine so that crew space is reduced correspondingly.
As another prior art which provides an inclination in the power transmission path from engine to propeller shaft for the angle drive system while the engine is mounted horizontally, use of bevel gears has been proposed.
An example of such prior art is shown in FIGS. 14 and 15 of JP, A No. 55-156796. In a marine propulsion unit according to this prior art, engine and reversing clutch mechanism are mounted horizontally but the clutch mechanism is disposed so that output shaft extends vertically and is projected downwardly from the clutch mechanism. An inclined intermediate shaft which is aligned coaxially with propeller shaft and is fixedly connected to such propeller shaft is provided and is drivenly connected to the clutch output shaft by meshing a pair of bevel gears fixedly mounted on these shafts. In the propulsion unit according to this prior art, the reversing clutch mechanism and transmission located below such clutch mechanism and having the pair of bevel gears occupy a large space in the vertical direction so that level of the clutch mechanism and, therefore, the level of engine are hightened. This will result in a reduction of crew space, too.
Use of conical gear for providing a downward and backward inclination in the power transmission path is shown in FIGS. 1 to 6 of U.S. Pat. No. 3,570,319. In the marine propulsion unit according to this U.S. patent, output shaft of fluid-actuated reversing clutch mechanism which is powered from a horizontally mounted engine is inclined so as to align coaxially with propeller shaft and is fixedly connected to such propeller shaft. On the clutch output shaft is fixedly mounted a conical gear which is in constant mesh with forward direction and backward direction gears respectively mounted on forward direction and backward direction shafts. The forward direction and backward direction gears are connected selectively to forward direction and backward direction shafts by an operation of fluid-actuated forward direction and backward direction clutches, respectively. This structure will reduce mounting space for the propulsion unit in the longitunal direction of a boat as well as in the vertical direction of such boat so that an enlarged crew space may be secured. With respect to pleasure boats and similar boats, it is, however, often true that mounting positions and postures of the engine and clutch as well as the inclination angle of propeller shaft are decided when designing the hull of a boat. From this, there are various boats to be equipped with angle drive system. That is, some boats are predetermined to mount the engine and reversing clutch mechanism in an inclined posture and another boats are predetermined to mount the engine in a horizontal posture. Further, the inclination angle of propeller shaft is predetermined variously. In the marine propulsion unit disclosed in the above-stated U.S. Pat. No. 3,570,319, the clutch output shaft is inclined downwardly and backwardly by an angle while the forward direction shaft which also acts as clutch input shaft and the backward direction shaft are disposed horizontally. It is thus seen that a reversing clutch mechanism having the structure according to this U.S. patent may be equipped only in a boat which is designed to mount the engine horizontally and to incline the propeller shaft by a given angle corresponding to the inclination angle of clutch output shaft. This means that such reversing clutch mechanism must be designed from boat to boat having predetermined various layouts, that is disadvantageous in economical respects. Clutch casing which journals the inclined output shaft must be varied when the inclination angle of such output shaft is varied.
OBJECT
Accordingly, a primary object of the present invention is to provide a novel marine propulsion unit of the type set forth at the beginning which permits to mount engine in the hull of a boat at a low level horizontally and may be manufactured with a low cost while permitting to employ a reversing clutch mechanism in boats having different layouts with respect to the inclination angle of propeller shaft as well as the mounting posture of engine.
SUMMARY OF THE INVENTION
The present invention relates to a marine propulsion unit comprising an engine mounted in the hull of a boat at a stern portion with the output end directed towards the stern, an inclined propeller shaft extending downwardly and backwardly from the hull and carrying at its terminal end a propeller, and a reversing clutch mechanism disposed between said engine and propeller shaft and having an input shaft drivenly connected to said engine and an output shaft drivingly connected to said propeller shaft, and is characterized in that an intermediate shaft located outside said reversing clutch mechanism is incorporated in the power transmission path between said engine and propeller shaft in a fashion such that, among said intermediate shaft and one of said input shaft and output shaft, a second shaft taking a rearer position extends relative to a first shaft taking a fronter position downwardly and backwardly as from the front end of said second shaft which end is located at a level substantially same with that of the rear end of said first shaft, said first shaft being connected drivingly to said second shaft by meshing a first bevel gear fixedly mounted on a rear end portion of said first shaft with a second bevel gear fixedly mounted on a front end portion of said second shaft.
That is, the marine propulsion unit according to the present invention is fashioned such that an intermediate shaft is disposed between the clutch output shaft and propeller shaft so as to provide a bend towards a downward and backward direction to the power transmission path between such output shaft and intermediate shaft or such that an intermediate shaft is disposed between the engine and clutch input shaft so as to provide a bend towards a downward and backward direction to the power transmission path between such intermediate shaft and input shaft. In the case when the intermediate shaft is disposed between the engine and clutch input shaft, the inclination to be given to the clutch input shaft which is now the above-recited second shaft relative to the intermediate shaft which is now the above-recited first shaft may be given by disposing the reversing clutch mechanism in a posture downwardly and backwardly inclined by an angle equal to the inclination angle to be given to the input shaft.
When the first shaft is disposed horizontally and the second shaft is inclined downwardly and backwardly by an angle equal to the inclination angle to be given to the propeller shaft, the inclination angle to be given to the propeller shaft is provided between the first and second shafts so that engine is mounted in a horizontal posture. It is thus seen that the marine propulsion unit according to the present invention permits to mount the engine horizontally.
Because the front end of second shaft taking a rearer position is located at a level substantially same with the level of first shaft taking a fronter position and because the required connection between such first and second shafts is achieved by meshing first and second bevel gears fixedly mounted on these shafts at the opposed end portions thereof, a bend in the power transmission path is located approximately at the rear end of the first shaft the level of which end is substantially equal to that of the front end of the second shaft. It is thus seen that the power transmission path does not include at such bend a step or stepped portion which lowers the level of the transmission path than the level of first shaft. Owing to such bend which provides substantially no step or stepped portion in the power transmission path, the marine propulsion unit according to the present invention does not require to give a large difference in levels between the engine and propeller shaft so that it permits to mount engine in the hull of a boat at a low level.
In the marine propulsion unit according to the present invention, a required inclination in the transmission path corresponding to the inclination of propeller shaft is provided outside the reversing clutch mechanism by using a single intermediate shaft and a pair of bevel gears. This structure is simpler than a structure that a required inclination in the power transmission path is provided by a pair of constant velocity universal joints which are large in number of parts. The structure according to the present invention that a required inclination or bend in the power transmission path is provided outside the reversing clutch mechanism permits to employ a reversing clutch mechanism in a boat in which engine is mounted horizontally or approximately horizontally and in another boat in which engine is mounted in a posture inclined by an angle equal to the inclination angle of propeller shaft. Adjustment or change of the inclination angle of propeller shaft to a given or predetermined value may be achieved by varying holder means for the intermediate shaft as well as the pair of bevel gears while the reversing clutch mechanism is used as it is.
The pair of meshing bevel gears mounted on the first and second shafts which are opposed with each other at their ends are in face to face relationship with other. Each of such bevel gears may have a small cone distance so that these bevel gears may be manufactured by using a conventional machine with a low cost. A pair of bevel gear each having a large distance such that are used for bending the power transmission path in a marine V-drive system disclosed in, for example, U.S. Pat. Nos. 2,130,125 and 2,282,612 requires a very large machine for manufacturing such gears and are expensive.
As described before, the engine may be mounted horizontally by disposing the second shaft in a posture inclined by an angle equal to the inclination angle to be given to the propeller shaft while the first shaft is disposed horizontally. A required inclination of the propeller shaft may, however, also be given by a combination of an inclination of the engine and an inclination or bend provided in the power transmission path.
An embodiment of the present invention is thus fashioned such in that the engine is mounted in a posture inclined downwardly and backwardly by an inclination angle, said inclination angle of engine and inclination angle of the second shaft relative to the first shaft being predetermined so that sum of these inclination angles is equal to the inclination angle to be given to the propeller shaft. According to this structure, the inclined engine will enlarge the engine room resulting in a reduction of crew space in a boat. In a case where such structure is employed in a boat having a propeller shaft of relatively large inclination angle, however, the inclination angle of engine may be much smaller than that of the propeller shaft so that reduction of crew space due to the inclined engine may be much smaller when compared to the standard type propulsion unit in which engine is inclined by an angle equal to the inclination angle of propeller shaft.
In the marine propulsion unit according to the present invention, an inclination or bend in the power transmission path is provided between either of the clutch output shaft or input shaft and the intermediate shaft and, for providing such inclination or bend, a bevel gear is fixedly mounted on an end portion of the clutch output shaft or input shaft. It is preferred that such bevel gear on either of clutch output shaft or input shaft is formed separately from the shaft and is fixedly mounted on the shaft using a removable fastening means, because this kind of bevel gear permits to mount a coupling means on the end portion of the shaft immediately in place of the bevel gear when a reversing clutch is intended to be employed in a boat having another layout of propulsion unit.
On the other hand, the second or first bevel gear fixedly mounted on the intermediate shaft is preferred to be such that is formed integrally with the intermediate shaft. This is because such integral bevel gear contributes not only to an easier assemblage by omitting a fastening process but to a closer arrangement of the clutch output or input shaft and intermediate shaft by eliminating fastening means for the bevel gear between such two shafts. Such closer arrangement of the two shafts in turn contributes to a reduction of axial thickness of the meshing first and second bevel gears which are mounted on the opposed end portions of the two shafts.
BRIEF DESCRIPTION OF THE DRAWINGS
Another features of the present invention and its attendant advantages will become readily apparent from the descriptions of the embodiments shown in the drawings in which:
FIG. 1 is a schematic side elevational view of a boat in which a first embodiment of the marine propulsion unit according to the present invention is employed;
FIG. 2 is a sectional side view showing an essential part of the propulsion unit shown in FIG. 1;
FIG. 3 is a sectional view, partially omitted, taken along line III--III of FIG. 2, showing a part of reversing clutuch mechanism shown in FIG. 2;
FIG. 4 is a side elevational view of a pair of meshing bevel gears shown in FIG. 2;
FIG. 5 is a schematic side elevational view of part of a boat in which a second embodiment of the marine propulsion unit according to the present invention is employed;
FIG. 6 is a sectional side view showing an essential part of the propulsion unit shown in FIG. 5;
FIG. 7 is a schematic side elevational view of a third embodiment of the marine propulsion unit according to the present invention, showing also part of a boat in which the third embodiment is employed; and
FIG. 8 is a schematic side elevational view similar to FIG. 7, but showing schematically a fourth embodiment of the marine propulsion unit according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings in which like numerals designate like parts throughout, there is shown in FIGS. 1 to 4 a first preferred embodiment of the marine propulsion unit according to the present invention.
In a yacht or pleasure boat shown in FIG. 1 having a center board 10 at the bottom for stabilizing the boat, a mast 11 on the deck and a rudder 12 at the stern for steering the boat, an engine 13 is mountd at a stern portion substantially in a horizontal posture so that its output end is directed towards the stern. Propeller 14 which directly propels the boat is carried by an inclined propeller shaft 15 extending downwardly and backwardly from the bottom of the hull. The propeller shaft 15 is journaled at a portion adjacent to the terminal end thereof by a shaft bracket 16 on the bottom of the hull. To the output end of engine 13 is attached a reversing clutch mechanism 17 to which a transmission casing 18 of a small size is in turn attached at the output end of such clutch mechanism. Power from the engine 13 is transmitted to the propeller shaft 15 through the reversing clutch mechanism and through transmission within the transmission casing 18.
As shown in FIG. 2, the reversing clutch mechanism 17 comprises an input shaft 20 extending forwardly from a clutch casing 19 for the clutch mechanism, an output shaft 21 extending backwardly from the clutch casing 19 and an idler shaft 22 shown in FIG. 3 which is journaled within the casing 19. These shafts 20, 21 and 22 are arranged in parallel with one another. In the first embodiment shown in FIGS. 1 to 4, reversing clutch mechanism 17 is attached at its casing 19 to the engine 13 so that the clutch mechanism takes a horizontal posture whereby shafts 20, 21 and 22 extend horizontally. As is usual, the input shaft 20 is connected at the front end thereof to the fly wheel 25 of engine 13 through a damper coupling 24. Within the clutch casing 19, the input shaft 20 is integrally formed with a forward direction gear 26 and backward direction gear 27. On the output shaft 21 are rotatably mounted a forward direction gear 28 and backward direction gear 29 through bearing means. The forward direction gears 26 and 28 are directly meshed with each other, whereas the backward direction gears 27 and 29 are operatively connected by meshing these gears with an idler gear 30 shown in FIG. 3 which is mounted rotatably on the idler shaft 22 through bearing means. The clutch mechanism 17 shown includes a mechanically actuated friction clutch 31 of the type known from, for example, British Pat. No. 1,266,840 which is operated by a selective engagement of forward direction frictional elements 31a or backward direction frictional elements 31b. Such clutch may be any of another types such as fluid-actuated friction clutch well known to the art. The clutch 31 operates to connect the forward direction gear 28 or backward direction gear 29 selectively to the output shaft 21 so that the shaft 21 is driven to rotate selectively into forward or backward propelling direction.
As also shown in FIG. 2, an intermediate shaft 32 is provided outside the reversing clutch mechanism 17. This intermediate shaft 32 is rotatably supported by a cylindrical rear end portion of the transmission casing 18 through a pair of bearings 33 so that it is inclined backwardly and downwardly by an angle θ equal to the angle of inclination of the propeller shaft 15 so as to be aligned coaxially with such propeller shaft. On the rear end portion of intermediate shaft 32 is fixedly mounted a coupling half 35 using a spline connection and a nut 34 screwed on the shaft 32. The intermediate shaft 32 is fixedly coupled to the propeller shaft 15 by fastening the coupling half 35 to another coupling half 36 fixedly mounted on the front end portion of propeller shaft 15 by means of fastening means 37.
The intermediate shaft 32 is disposed relative to the horizontally disposed output shaft 21 of reversing clutch mechanism 17 so that the front end of such intermediate shaft 32 is substantially located at a level equal to the level of the rear end of output shaft 21 so as to be faced substantially to such rear end of the shaft 21. These output shaft 21 and intermediate shaft 32 are operatively connected with each other within the transmission casing 18 by meshing a first bevel gear 38 fixedly mounted on a rear end portion of the shaft 21 with a second bevel gear 39 fixedly mounted on a front end portion of the shaft 32. The first and second gears 38 and 39 a side view of which is shown in FIG. 4 are formed to helical bevel gears so as to reduce noise generated from co-rotation of the meshing gears.
Among the bevel gears 38 and 39, the first bevel gear 38 is mounted on the output shaft 21 using a spline connection 40 and is fixedly fastened to the shaft 21 using a nut means 41 screwed on the output shaft 21. Contrarily, the second bevel gear 39 is formed integrally with the intermediate shaft 32. The transmission casing 18 is formed by a fronter case 18a fixedly secured to the rear of clutch casing 19 and a rearer case 18b fixedly secured to the former case 18a by fastening means 42. The rearer case 18b has an inclination along the intermediate shaft 32 and is fitted at the front end thereof into the fronter case 18a.
In the marine propulsion unit shown in FIGS. 1 to 4, power is transmitted from the fly wheel 25 of engine 13 to the input shaft 20 of reversing clutch mechanism 17 through damper coupling 24 so that the input shaft 20 is driven to rotate into a direction. By a selective operation of the reversing clutch mechanism 17, the output shaft 21 thereof is driven to rotate selectively into forward or backward propelling direction. Rotation of this output shaft 21 is transmitted from the first bevel gear 38 to the second bevel gear 39 so as to rotate the intermediate shaft 32 so that the propeller shaft 15 and propeller 14 are driven to rotate to cause a propulsion of the boat towards the forward or backward direction.
Owing to the fact that the engine 13 is mounted horizontally and owing to the fact that bend in the transmission path between the clutch output shaft 21 and the intermediate shaft 32 does not have any step which lowers the level of transmission path at such bend so that the level of engine 13 is lowered, a large crew space is secured within the hull. For varying the angle of propellor shaft 15, intermediate shaft 32 and transmission casing 18 supporting such shaft as well as a pair of bevel gears 38, 39 are exchanged in accordance with such inclination angle of propeller shaft and the reversing clutch mechanism 17 shown may be used as it is. Because the second bevel gear 39 is formed integrally with the intermediate shaft 32 so that there is provided between the output shaft 21 and intermediate shaft 32 no fastening means for fastening the second gear 39 to intermediate shaft 32, the rear end of output shaft 21 and the front end of intermediate shaft 32 may be positioned relative to each other as closely as possible whereby it is not required to shape each of the bevel gears 38, 39 to have a large thickness so that these gears project largely towards each other for meshing.
As can be seen from FIG. 2, angle α between axes of the mutually meshed first and second bevel gears 38 and 39 is not equal to the inclination angle θ to be given to the intermediate shaft 32 but has a value deducted such inclination angle θ from 180° due to the face to face arrangement of two bevel gears to be meshed. Cone distance D of each of such bevel gears 38, 39 is thus small, as shown in FIG. 2. From this, a pair of bevel gears 38, 39 employed in the propulsion unit according to the present invention may be manufactured with a low cost.
In a boat which is designed previously so as to be equipped with a standard type propulsion unit in which engine 13 is mounted in a posture inclined downwardly and backwardly by an angle equal to the inclination angle of propellor shaft 15, the reversing clutch mechanism 17 may be employed as it is by removing the first bevel gear 38 on the clutch output shaft 21 and by fixedly mounting the coupling half 35 onto the rear end portion of output shaft 21 by means of nut means 34 or 41.
Turning to a consideration of FIGS. 5 and 6, there is shown in these figures a second preferred embodiment of the marine propulsion unit according to the present invention.
In this second embodiment, a transmission casing 18 which corresponds to the transmission casing 18 employed in the first embodiment is disposed between engine 13 and reversing clutch mechanism 17. An intermediate shaft 32 which corresponds to the intermediate shaft 32 employed in the first embodiment is horizontally arranged within such transmission casing 18 and is journalled by the casing 18 through a pair of bearings 33. This intermediate shaft 32 is drivenly connected at the front end portion thereof to the fly wheel 25 of horizontally mounted engine 13 through damper coupling 24.
As shown in FIG. 6, the reversing clutch mechanism 17 is inclined downwardly and backwardly by an angle θ equal to the inclination angle of propeller shaft 15. This clutch mechanism 17 has a structure similar to that of the clutch mechanism 17 employed in the first embodiment except that a coupling half 35 is fixedly mounted on a rear end portion of the clutch outputshaft 21 using a spline connection and nut means 34. The output shaft 21 is aligned coaxially with the propeller shaft 15 and is fixedly connected to such propeller shaft 15 by fastening the coupling half 35 to another coupling half 36 fixedly mounted on the front end portion of propeller shaft 15 by means of fastening means 37.
The horizontally disposed intermediate shaft 32 and the clutch input shaft 20 which is inclined by an angle θ equal to the inclination angle of clutch mechanism 17 are disposed relative to each other so that the rear end of intermediate shaft 32 and the front end of input shaft 20 are located substantially at a same level and are opposed with each other. A first spiral bevel gear 38 is formed integrally with the rear end portion of intermediate shaft 32, whereas a second spiral bevel gear 39 is fixedly mounted on a front end portion of the input shaft 20 using a spline connection 40 and a nut 41. These first and second bevel gears 38 and 39 are meshed with each other, as is the case in the first embodiment.
The transmission casing 18 comprises a fronter case 18a which also covers the rear end opening of engine casing 23 and a rearer case 18b which also covers the front end opening of clutch casing 19. These cases 18a, 18b are fitted and fixedly connected at their ends.
Compared to the propulsion unit shown in FIGS. 1 to 4, the marine propulsion unit shown in FIGS. 5 and 6 will reduce crew space within the hull by an extent such that the inclined clutch mechanism 17 having a relatively large height will highten the position of engine 13. It is, however, to be noted that the propulsion unit shown in FIGS. 5 and 6 will also enlarge crew space owing to a horizontal mounting of engine 13 and owing a structure for giving a required inclination of propeller shaft 15 which structure includes therein substantially no stepped bend portion. For varying the inclination angle of propeller shaft 15, intermediate shaft 32 and the rearer case 18b of transmission casing 18 supporting such shaft as well as a pair of bevel gears 38, 39 are exchanged correspondingly.
For a boat to be equipped with a standard type propulsion unit, the reversing clutch mechanism 17 may be employed as it is by removing the second bevel gear 39 on the clutch input shaft 20 and by fitting the splined front end portion of such shaft 20 into the center hub of damper coupling 24 for a spline connection.
In the two embodiments having been detailed hereinbefore, a required downward and backward inclination is given to the propeller shaft 15 only by providing a bend in the power transmission path from engine 13 to the propeller shaft 15. The present invention may, however, be embodied in a fashion such that a required inclination of the propeller shaft 15 is given by a combination of an inclination of the engine 13 and a bend in the transmission path. FIG. 7 and FIG. 8 show a third and fourth embodiments which concern such combination, respectively.
In the marine propulsion unit shown in FIG. 7, propeller shaft 15 is inclined with a relatively large angle θ. Engine 13 is mounted in a posture inclined downwardly and backwardly by a relatively small angle θ 1 . To the output end of reversing clutch mechanism 17 is provided a transmission casing 18 which includes a transmission similar to that employed in the first embodiment shown in FIGS. 1 to 4 so as to provide a bend of angle θ 2 between clutch output shaft (not shown) and intermediate shaft 32. The inclination angle θ 1 of engine 13 and the angle θ 2 at the bend of power transmission path are predetermined so that sum of these angles θ 1 and θ 2 is equal to the inclination angle θ of the propeller shaft 15 (θ 1 +θ 2 =θ).
In the fourth embodiment shown in FIG. 8 in which propeller shaft 15 is inclined with a relatively large angle θ, engine 13 is inclined by a small angle θ 1 . Between the engine 13 and reversing clutch mechanism 17 is disposed a transmission casing 18 which includes a transmission similar to that employed in the second embodiment shown in FIGS. 5 and 6, whereby a bend of angle θ 2 is provided in the power transmission path. The required inclination angle θ of propeller shaft 15 is given by a sum of the angle θ 1 and angle θ 2 .
Compared to a standard type propulsion unit in which engine is mounted with a posture inclined by an angle equal to the inclination angle of propeller shaft, each of the marine propulsion units shown in FIGS. 7 and 8 is fashioned so that the engine 13 is inclined by a smaller angle θ 1 . Accordingly, such propulsion unit will also enlarge crew space within the hull.
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A marine propulsion unit having an engine (13) mounted with the output end directed toward the stern of a boat is disclosed in which a required inclination of propeller shaft (15) is provided outside a reversing clutch mechanism (17) by an intermediate shaft (32) and a pair of meshing bevel gears (38, 39) incorporated in the transmission path. The bevel gears (38, 39) are fixedly mounted on either of output shaft (21) or input shaft (20) of the clutch mechanism (17) and the intermediate shaft (32) among which one of the shafts taking a rearer position is inclined relative to the other shaft downwardly and backwardly. These two shafts are disposed relative to each other so that opposed ends thereof take substantially a same level. The propulsion unit permits a low level mounting of engine and may be manufactured with a low cost while permitting to employ a reversing clutch mechanism in boats having different layouts of propulsion unit.
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to the field of dyeing textiles. More specifically, the present invention is related to using vat dyes in a continuous process to produce a variety of colors during the production of denim.
2. Discussion of Prior Art
“The older, the better look” has been the philosophy of the blue jean industry. Blue jeans are dark blue when they are first produced. As they are worn and washed, the abraded places become a different color than the rest. Today there are numerous techniques to produce this natural washout look in denim. Some of these techniques include stone washing, enzyme washing, bleaching, acid washing, resin treatment, ozone washing, neutralization, tinting and garment dyeing, local tinting, chemical spraying, local bleaching, sand blasting, brushing, laser, moustache or whiskers, damage and cutting. However, this natural worn-out or washout effect only happens with fabric produced with yarn that has ring effect dyeing (i.e., perimeter dyeing), or specifically in blue jean denim, dyed with Indigoid vat dye. Ring effect in yarn is defined when dye does not penetrate into the yarn and only perimeter/external dyeing is achieved.
Today, the production of yarns with ring effect dyeing is feasible only through a few continuous processes. The most popular continuous processes used for dyeing yarns are rope (long chain) dyeing, slasher (sheet) dyeing, and loop dyeing (looptex). In these processes, indigo-derived vat dye is added in reduced form or in mixture with reducing agents to a dye tank. FIGS. 1-4 illustrate prior art for continuous dyeing cotton yarns or fabric.
Indigo is a water insoluble organic substance that can be reduced to a water-soluble form and used to dye yarns or fabrics. Following dyeing, the dye is oxidized, which returns the dye to its water insoluble form on the yarn. Indigoid vat dyes have been primarily used for cotton yarns, which have given rise to the popularity of denim fabric today.
It is known, in the continuous dyeing of yarns, to add the dye in the form of a concentrated stock vat. FIGS. 1 and 2 illustrate 2-16 dip-dye tanks equipped with squeezing/skying apparatus used for applying the vat dyes. A minimum of 2 dip-dye tanks is required for rope and slasher dyeing. Squeezing and skying takes place between the dipping steps and the dye is oxidized by air passage. To avoid dye depletion of the dip vats, the dye is replenished from stock vat dyes having a concentration greater than 80 g/l or concentration of at least 20% stock vat. These reduced stock vat dyes are introduced in the circulation line at the dye tank. FIG. 3 illustrates loop-dyeing process wherein direct beam is introduced to at least one dip-dye tank and squeezing/skying apparatus. The direct beam is recycled or looped several times in the same dip-dye tank. FIG. 4 shows continuous dyeing process for fabric where “ready-to-dye” fabric is added to a series of dip dye tanks squeezing/skying apparatus.
Similar to indigo, other vat dyes (indigoid or anthraquinonoid) also have excellent all-round fastness properties on cotton. However, unlike indigo, most vat dyes have high molecular weight, high substantivity, and low solubility. Hence, for most vat dyes no reduced stock solution is available in the market to use in denim fabric production. Additionally, adding reducing agents to high concentration of most vat dyes in feeder dye tank results in precipitations due to their poor solubility.
It is desired to produce textile material with ring effect dyeing using different colors, such as, but not limited to: orange, red, violet, pink, green, yellow, black, brown, blue, khaki, gray, purple, navy, beige, or other vat dye colors or combinations thereof. However, the production of textile material with ring effect dyeing has been limited to vat dyes with high solubility, limiting the color of denim fabric. Vat dyes, in particular anthraquinonoid vat dyes, have a wide range colors. However most these different color dyes have low solubility.
U.S. Pat. No. 5,518,508 (hereinafter referred to patent '508) discloses a method for continuous dyeing of yarn. Patent '508 uses dye dispersion instead of stock vat to solve the problem of supersaturation and insufficient concentrated stock vat. However, the circulating concentration of dyes is usually low (approximately 50:1 ratio from stock vat to circulating dye) which results in low reduction rate of vat dye. It is known that the vatting rate is a function of dye and reducing agent concentration. The prior art requires a high concentration of reducing agent for reduction of dyes in the circulating liquor. Increased unreduced dye in the circulating dip-dye tank results in poor dyeing and finished yarn has poor rubbing and washing fastness.
Whatever the precise merits, features, and advantages of the above cited references, and none of them achieve or fulfill the purposes of the present invention.
SUMMARY OF THE INVENTION
In the present invention, all vat dyes may be used individually or in combination with other dyes in a continuous process for production of yarn or fabric with ring effect dyeing. Vat dyes are introduced to a treatment unit comprised of at least one reaction unit where the reducing agent is added to a mixture comprising a dye composition, caustic soda and/or other components or additives known in the art of textile dyeing. The dye concentration in the reaction unit is lower than feeding dye concentration so that dye precipitation does not occur, but significantly higher than the circulating dye concentration so that the dye is reduced efficiently. Although the preferred location for the reaction unit is before the circulation line, any location before the dip-dye tank is within the scope of the present invention.
The present invention enables the production of textile material of different colors, such as orange, red, violet, pink, green, yellow, black, brown, blue, khaki, gray, purple, navy, beige, and/or other vat dye colors or combination thereof. In particular, the different color denim of this invention can be embodied in clothing garments such as pants, skirts, shirts, hat, or jacket. Specific examples of colors or garments should not limit the scope of the invention.
The present invention further enables the production textile material of different shades of colors, such as different shades of orange, red, violet, pink, green, yellow, black, brown, blue, khaki, gray, purple, navy, beige, and/or other vat dye colors or combination thereof. In particular, the darker shades of textile material of this invention may be used to produce clothing garments such as pants, skirts, shirts, hat, or jacket.
In one embodiment of the present invention, the treatment unit has at least one reaction unit where unreduced dye composition, caustic soda, and reducing agent are mixed and the reaction started. Each reaction unit has a residence/retention time (hereinafter referred to as RT) that is a function of reaction unit volume, flow rate, and mixing parameters depending on reaction unit design. Each vat dye requires a different RT depending on the vat dye half-life, solubility, and other chemical properties.
In another embodiment of the present invention, the treatment unit has several reaction units in parallel with each unit containing a different dye composition, wherein each dye composition has a different half-life, solubility, and other chemical properties.
In yet another embodiment of the present invention, the treatment unit may further include milling and/or an ultrasound apparatus.
In a further embodiment of the present invention, a continuous dyeing process for textile material to produce ring effect dyeing comprises at least one treatment unit used at a location before the dip-dye tank.
In yet another embodiment of the present invention, the continuous textile material dyeing process used in conjunction with the treatment unit is rope-dyeing, slasher-dyeing, loop-dyeing, or continuous fabric dyeing.
According to the invention, all vat dyes can be used individually or in combination. The desired vat dye or combination of vat dyes can be added at the desired concentration to the treatment unit to achieve a desired reduced dye concentration.
Suitable substrates for dyeing are all cellulose type and/or blend yarns including, but not limited to, cotton, wool, linen, or viscous. These yarns are, in a preferred embodiment, subsequently predominantly made into denim articles.
The present invention embodiments produce denim with ring effect. The denim fabric may be further processed to produce washout or worn-out look jeans with different colors.
The present invention embodiments include the production of clothing garments such as pants, skirts, shirts, hats, or jackets from denim from the present invention dyeing techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee
FIG. 1 illustrates prior art rope dyeing with reduced stock vat dyes.
FIG. 2 illustrates prior art slasher dyeing with reduced stock vat dyes.
FIG. 3 illustrates prior art loop dyeing with reduced stock vat dyes.
FIG. 4 illustrates prior art continuous dyeing for fabric with reduced stock vat dyes.
FIG. 5 illustrates treatment unit of the present invention.
FIGS. 6 a and 6 b , collectively, illustrate yarn and denim fabric produced from yarn dyed in a continuous process with Vat Red 10 (C.I. 67000).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is illustrated and described in a preferred embodiment, the invention may be produced in many different configurations. There is depicted in the drawings, and will herein be described in detail, a preferred embodiment of the invention, with the understanding 5 ′ that the present disclosure is to be considered as an exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the invention to the embodiment illustrated. Those skilled in the art will envision many other possible variations within the scope of the present invention.
FIG. 1 illustrates a rope-dyeing method common in the prior art. In this method, yarn is first introduced to a warping process 1 a . Next, warped yarn is introduced to a series of n dip dye tanks (where n is preferably from 2-16) and m squeezing/skying apparatus (where m=n) for applying the vat dyes to warp yarns. The warp yarn is then introduced in sequence to a re-beaming apparatus 2 , sizing/slashing apparatus 3 , weaving apparatus 4 , and finally to a finishing step.
FIG. 2 illustrates a slasher-dyeing method common in the prior art. In this method, yarn is introduced to a beaming process 1 b . Next, direct beam is introduced to series of n dip dye tanks (where n is preferably from 2-16) and m skying apparatus (where m=n) for applying the vat dyes. The beam is then fed through weaving apparatus 4 and finally to a finishing step.
FIG. 3 illustrates a loop-dyeing method common in the prior art. In this method, yarn is introduced to a beaming process 1 b . Next, the direct beam is introduced to series of n dip dye tanks (where n is at least 1) and m squeezing/skying apparatus (where m=n) for applying the vat dyes. In a loop dye process, the direct beam may be recirculated in each dip dye tank several times. The beam is then fed through weaving apparatus 4 and finally to a finishing step.
FIG. 4 illustrates a continuous fabric dyeing method common in the prior art. Ready for dyeing fabric is rolled in 5 . Next, the fabric is introduced to series of n dip dye tanks (where n is at least 1) and m squeezing/skying apparatus (where m=n) for applying the vat dyes. In a continuous process, the fabric may be recirculated in each dip dye tank several times.
The n dip-dye tanks illustrated in FIGS. 1-4 are connected in parallel via a circulation line. However other configurations such as a series configuration or a combination of both series and parallel are with the scope of this invention. An example series/parallel combination configuration is when n dip-dye tanks are in a parallel configuration in the circulation line with respect to one another, while each tank is also connected in series via a leveling pipe. The circulation line may further comprise non-limiting additional elements, such as suction unit at end of each dip-dye tank, circulation pipe, circulation pump or other elements known in the art of dyeing textiles.
FIG. 5 illustrates the treatment element of the present invention. This unit may be at any location before the dip-dye tanks. However the treatment unit 500 is preferably located between the dye tank 6 and the circulation line, in a pre-circulation configuration. The treatment unit has at least one reaction tank 10 . The additives 9 , including but not limited to, caustic soda, may be added at any location before to the reaction unit. The volume of reactor or pipe and/or a combination thereof where the reducing agent 8 is first introduced to a mixture of dye and additives and the volume of pipe before the mixture enters the circulation line; defines the reaction unit. Additives 9 may also be simultaneously added with the reducing agent 8 to the reaction unit 10 . Alternatively, additive 9 can be added to the dye tank 6 .
An unreduced dye composition located in tank 6 comprising of at least one vat dye may be first introduced to a milling and/or dispersion apparatus 7 and further introduced to a reaction unit 10 (or in an alternative configuration: 7 may be by-passed or it may proceed or be combined with 6 ). Several dye mixtures (dye composition, plus additives 9 ) may enter the reaction unit 10 or alternately each mixture enters a different reaction unit. Where several reaction units exist, the units may be arranged in a parallel and/or series configuration. The reduced dye from each reaction units may be mixed before entering the circulating unit or alternatively each reduced dye may enter independently to the circulation unit.
Reaction unit 10 has an RT that is a function of reaction volume, flow rate, and mixing parameters-depending on reaction unit design. Each vat dye requires a different RT depending on the vat dye half-life, solubility, and other chemical properties. Hence RT for each reaction unit can be determined based on chemical and physical properties of each vat dye. Where a mixture of vat dyes is used; the properties of the least soluble or mixture may be used for RT design.
The treatment unit may have several parallel reaction units. Each reaction unit may have a different RT and/or temperature. This configuration provides for use of vat dyes of different solubility in a continuous process. Each reaction unit may be specifically designed for a particular vat dye (based on RT, temperature, or other parameters to control reaction rate) to achieve a desired reduced dye composition.
Alternatively, it may be desired to reach a specific mixture of reduced or unreduced dye. The RT and temperature maybe adjusted to achieve any desired ratio of reduced-to-unreduced dye.
FIG. 6 a illustrates two configuration of desired ring effect dyeing of yarn dyed with Vat Red 10 (C.I. 67000) in the continuous rope-dyeing process used in conjunction with the treatment unit of the present invention. FIG. 6 b illustrates various garment samples made from the yarn of FIG. 6 a further rinse washed, stonewashed, or stone-bleached.
In these processes, the number of dip dye tanks is at least 2, preferably from 8 to 16. Depending on the dye and the reducing agent, dyeing temperatures are 20 to 90° C., preferably from 35-45° C.
Suitable reducing agents are any of, or a combination of the following: sodium dithionite, thiourea dioxide, hydroxyacetone, or mixtures or equivalents thereof.
The anthraquinonoid vat dye is any of, or a combination of, the following or their equivalents: Vat Brown 3 (C.I. 69015), Vat Black 25 (C.I. 69525), Indanthren Direct Black 5589, Vat Violet 1 (C.I. 60010), Vat Red 13 (C.I. 70320), Vat Red 10 (C.I. 67000), Vat Yellow 2 (C.I. 67300), Vat Orange 15 (C.I. 69025), Vat Blue 6 (C.I. 69825), or Vat Brown 1 (C.I. 70800).
EXAMPLE 1
Cotton yarn dyed with darker shades of Vat Red 10 (C.I. 67000):
Anthraquinonoid vat dye was used in pilot plant operation using treatment unit of the present invention in conjunction with rope-dyeing process.
Feeding Preparation:
Dye Composition in Dye Tank
The dye composition in the dye tank was made in the following order. A solution 5 g/l of dispersing agent (Setamol WS, commercially available) was made. Next, complexing agent (Trilon TB) was added to a final concentration of 2 g/l. Next, Vat Red 10 (C.I. 67000) was added to the solution to make a final concentration of 150 g/l of dye. Finally, the wetting agent was added to the solution to a final concentration of 3 g/l. This composition was introduced to the reaction unit at a rate of 0.10 l/min.
Caustic Feeding
Caustic composition of the additive tank was made as follows. Prepared 40 Be caustic solution (494 g/l of sodium hydroxide) with 47 Be caustic (668 g/l sodium hydroxide, commercially available). This composition was introduced to the reaction unit at a rate of 0.40-0.45 l/min.
Reduction Agent Composition
Reducing agent composition of tank was made in the following order. Prepared 25 g/l of caustic from 47 Be (668 g/l sodium hydroxide, commercially available). Add sodium dithionite to a final concentration of 150 g/l. This composition was introduced to the reaction unit at a rate of 0.40-0.45 l/min.
Treatment Unit:
Reaction Unit Composition
Dye composition, caustic composition, and reducing agent with above-mentioned rates were mixed in the reaction unit with a volume of 2.5-3.0 liters. The RT of the treatment unit under this condition was approximately 2.7-3 minutes. The reduced dye was introduced to the circulation unit at a rate of 0.90-1.00 l/min.
Pilot Continuous Rope-Dyeing Process with Treatment Unit:
10 dip-dye tanks, with total volume of 2400 liters were used for rope dyeing. The circulation rate was 100-120 l/min. Dip-dye tank temperatures were 40-45° C. The process had output of 1128 gram-yarn/min. The process had a pH of 12.5-12.7.
The produced red warp yarn was further processed by standard rebeaming apparatus, sizing/slashing apparatus, weaving apparatus, and finally finished to produce red denim. The fabric was made into a garment wherein the garment is further processed by rinse washing, local scraping, stonewashing, and stonewashing plus bleaching. FIGS. 6 a and 6 b illustrate dyed yarn and garment produced using these conditions.
EXAMPLE 2
Higher Indanthren Direct Black 5589 concentrations in the treatment unit yields higher dyeing performance.
Equipment
Spectral reflectance measurements for estimation of color strength were done with Datacolor Spectroflash SF600. Concentrations measurements were made with Metrohm Titroprocessor 726, Dosimat 685 and Stirrer 728 by red-ox titration method. Relative dye concentration (herein after C*) is defined as dye concentration (hereinafter C) divided by factor k, where k is defined as the ratio of formula weight of Indathren Direct Black 5589 (hereinafter FWb) divided by formula weight of Indigo (hereinafter FWi).
C*=C/k
(where k=FWb/Fwi)
Solution Preparation
C=3 g/l
0.75 g Indanthren Direct Black 5589
2.75 ml Caustic soda (48%)
1.13 g Hydrosulphite
250 ml volume solution is prepared by adding these chemicals to distilled water. 10 ml of this solution was fed used for solubility measurement.
C=30 g/l
7.5 g Indanthren Direct Black 5589
27.5 ml Caustic soda (48%)
11.3 g Hydrosulphite
250 ml volume solution is prepared by adding these chemicals to distilled water. 1 ml of this solution was diluted with 9 ml weak hydrosulphite-caustic soda solution and used for solubility measurement.
C=60 g/l
15 g Indanthren Direct Black 5589
55 ml Caustic soda (48%)
22.6 g Hydrosulphite
250 ml volume solution is prepared by adding these chemicals to distilled water. 5 ml of this solution was diluted to 100 ml using weak hydrosulphite-caustic soda solution and 10 ml of the diluted solution was used for solubility measurement.
Weak Hydrosulphite-Caustic Soda Solution (4, 7×10-3 M)
0.5 ml Caustic soda (48%)
0.82 g Hydrosulphite
Distilled water
Solubility Measurement
Tables 1-3 show that increase in dye input to the treatment unit increases the amount of solved dye. For comparison purposes, measurements of the samples from the treatment unit were done with the appropriate dilution with weak hydrosulphite-caustic soda solution.
TABLE 1
C = 3 g/l
t (minutes)
3
15
C*
0.578
0.583
(C* was directly measured)
TABLE 2
C = 30 g/l
t (minutes)
3
17
C*
0.597
0.657
0.605
0.638
(C* was measured with 1:10 dilution)
TABLE 3
C = 60 g/l
t (minutes)
3
16
C*
0.631
0.643
(C* was measured with 1:20 dilution)
Dyeing Performance
Conditions in Tables 1-3 were used for the treatment unit to investigate dyeing performance. The feed rate for the treatment unit for the three conditions depicted in Tables 1-3 was adjusted so that the dip-dye tank concentration (hereinafter Cb) remained at 3 g/l. The color strength of the dyed fabric was measured using a Datacolor Spectroflash SF600. Table 4 shows the result of these measurements.
TABLE 4
Dyeing results
C (g/l)
Cb (g/l)
Color Strength (CMC 2:1)
3
3
100
30
3
123.76
60
3
143.20
The examples provided in this application are for the exemplification of the principles of the invention and the associated functional specifications for its construction and is not intended to limit the scope of the invention.
CONCLUSION
The present invention provides for a method and apparatus to use all vat dyes, regardless of the solubility, in a continuous process for textile material. The invention is useful for production of denim with ring effect dyeing. In particular the invention provides for a method and apparatus to produce different colored denim, such as orange, red, violet, pink, green, yellow, black, brown, blue, khaki, gray, purple, navy, beige, and/or other vat dye colors or combination thereof.
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A process for using reduced vat dyes in a continuous dyeing process for production of dyed yarns and fabrics of different colors. In the process, dye composition is introduced to a treatment unit for reduction to desired dye composition. The dye concentration in the treatment unit is lower than feeding dye concentration so that dye precipitation does not occur, but significantly higher than the circulating dye concentration so that the dye is reduced efficiently. Although the preferred location for the treatment unit is before the circulation line, it may be at any location before the dip-dye tank.
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BACKGROUND OF THE INVENTION
This is a Continuation-In-Part of application, Ser. No. 08/733,127 filed Oct. 17, 1996, abandoned, which is a Continuation of application, Ser. 08/085,724 filed Jul. 6, 1993, and now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to infection control and personal protection devices provided in a novel kit form. More particularly, the invention concerns a compact, first-aid-type kit which contains various infection control, personal protection and injury treatment items, including novel glove-like devices that can be conveniently used for the cleanup, containment and disposal of infectious and hazardous materials
DISCUSSION OF THE INVENTION
In recent years, there has been an ever increasing need for new and innovative methods and devices for use in providing emergency aid to accident victims while at the same time protecting the care giver from direct contact with dangerous materials capable of spreading infectious diseases. More particularly, the need has grown in direct proportion to the public's expanding knowledge that infectious diseases such as AIDS and Hepatitis "B" can be contracted not only from direct contact with an infected person but also from indirect contact through exposure to contaminated materials used in the treatment of infected persons.
In the last year alone, statistics reveal that there have been many thousands of cases of infectious disease transfer between patients and medical care givers. These substantial problems and the prior art attempts to deal with them are discussed in greater detail in co-pending U.S. application, Ser. No. 08/733,127, which application is hereby incorporated by reference as though fully set forth herein. As pointed out in this incorporated-by-reference application, in serious accident situations it is important to provide the care giver with various types of emergency treatment devices which are designed to remain with the patient rather than with the care giver. These emergency treatment items need to be relatively small so as to be convenient to carry, they need to be simple to use, and they need to be designed to provide positive protection to the care giver while at the same time enabling the adequate performance of initial treatment at the accident site. Importantly, the treatment and personal protection devices available to the care giver must effectively block the transfer of fluids, viruses, spores, bacteria, or microorganisms from the patient to the care giver, and at the same time must function in widely varying weather conditions. Further, they must enable prompt direct medical assistance to be provided to the patient and be appropriate for use in the treatment of a wide range of injuries.
While a number of types of so-called "first aid kits" have been suggested in the past, these prior art kits typically are incomplete and fail to give adequate consideration to providing necessary protection to the care giver and to the environment proximate the accident site. A number of the prior art devices, of which the inventor is aware, are discussed in greater detail in incorporated-by-reference application Ser. No. 08/733,127.
As will be better understood from the descriptions which follow, the unique design of the apparatus of the present invention gives to the care giver ready access to essential items needed to provide adequate emergency treatment, such as cardiopulmonary resuscitation (CPU) masks and gloves or protective mits of novel design which can be used by the care giver to apply a dressing to a wound in a manner so as to substantially avoid cross-contamination between the patient and the care giver. The apparatus accident-victim-emergency-treatment kit of the invention also uniquely permits containment clean-up and removal of a myriad of different types of unwanted and dangerous material without the danger of spread of contamination. After clean up, the novel protective mits apparatus of the invention also can be used to accomplish the safe transport of the contaminates to a final disposal site without risk of cross-contamination.
As will be better appreciated from the description that follows, the apparatus of the invention is compact, light weight and readily transportable. Further, it specially designed for use in the home, at sporting events or on the road and represents a significant step forward in the contamination-free treatment of accident victims.
In one form of the invention, the treatment apparatus comprises a novel fold-out kit that includes a mask for use in cardiopulmonary resuscitation, a supply of tape and bandages and one or more first-aid mits which are uniquely designed to permit the use of one or more hands of one or more individuals and also to provide means for safe containment and disposal of the mit after use. More particularly, the mits are designed so that after the treatment has been completed, the mit can be turned inside out to safely enclose the contaminants thereon.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a compact, easy-to-carry and easy-to-use accident victim emergency treatment kit which includes the essential items necessary to provide emergency treatment to accident victims. More particularly, it is an object of the invention to provide a novel, easy-to-use, fold-out-type kit which includes a number of personal protection treatment devices that effectively protect the patient and the care giver as well as bystanders and clean-up personnel from exposure to hazardous material of the character often encountered when medical care is provided at accident sites and in emergency situations.
Another object of the invention is to provide an apparatus of the character described that provides the care giver quick and easy access to essential first-aid implements including a small CPR mask, a number of bandages and dressings and adhesive tape as well as the novel gloves or protective mits which can be used to treat the victim in a safe and contamination-free manner. More particularly, the novel protective units included in the emergency treatment kit prevent the transfer of blood and body fluids between the care giver and the patient while at the same time providing effective means for the control and containment of bleeding.
Another object of the invention is to provide a treatment kit of the class described in which the protective mits of the kit can be used for applying a sterile dressing in a manner that protects the entire hand of the care giver from any contact with any elements or microorganisms outside the protective exterior of the pouch, thereby preventing cross-contamination between patients, care givers, clothing and equipment.
Another object of the invention is to provide a novel emergency treatment kit which is self-contained, provides a convenient and substantially sterile transport medium for the various items and implements normally required in providing emergency first-aid treatment.
her objects of the invention are set forth in the incorporated by reference application Ser. No. 08/733,127.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally perspective view of one form of the of the emergency treatment glove or mit of the present invention.
FIG. 2 is an enlarged, side-elevational, cross-sectional view of the mit shown in FIG. 1.
FIG. 3 is a generally perspective view of one form of the emergency treatment kit of the invention.
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 3.
FIG. 5 is a generally perspective view of the kit shown in FIG. 3 but showing the kit in an open configuration with one of the protective units being withdrawn therefrom.
FIG. 6 is a generally perspective view of the kit shown in FIG. 3, but showing the kit in a fold-out configuration.
DESCRIPTION OF THE INVENTION
Referring to the drawings and particularly to FIGS. 3, 4, and 5 one form of the accident-victim-emergency-treatment kit of the invention is there shown. As previously mentioned, the kit contains a number of treatment items, the details of which will presently be described. Among these treatment items are the important combined treatment, clean-up, transport and disposal treatment mits of the invention. The manner in which these novel mits are stowed within the kit is illustrated in FIGS. 4 and 5 wherein the mits are generally designated by the numeral 12.
In the form of the invention shown in the drawings, each of the treatment mits comprises a barrier member 14 constructed from a thin film of microporous material that prohibits the passage therethrough of contaminants including infectious disease, micro-organisms, bacteria, viruses, spores and other hazardous contaminants.
As best seen in FIGS. 1 and 2, the barrier member, can take the shape of a pouch, a glove, a gauntlet or a mitten. Each barrier member 14 includes a front surface 14a and a back surface 14b which cooperate to define a hand receiving chamber 14c (FIG. 2). In one form of the invention, the barrier member 14 comprises a seamless, pouch-like enclosure which is free of pin holes and is constructed of a thin film of a suitable microporous, non-latex material that has pores smaller in size than 90 nanometers.
Affixed to the front surface, or face 14a of the barrier member, is engaging means for engagement with sources of contamination including burn areas, wound areas and contaminated surfaces of various kinds. The engaging means here comprises a plurality of discrete layers of material superimposed over one another. The various layers of the assemblage which comprises the engaging means are collectively identified in FIGS. 1 and 2 by the numeral 16. The individual layers can exhibit various special characteristics depending upon the use that is to be made of the device. For example, some layers can comprise an absorbent material that may be a gel, a hydrogel, a hydrophobic web or a natural or synthetic fibrous material. By way of illustration, the first layer 17, which is here shown as adhesively bonded to surface 14a of the barrier member by a suitable adhesive, can comprise a layer of gauze. Alternatively, the layer can comprise a puncture resistant, protective padding material such as an elastomer which is adapted to protect the user's hands from puncture by sharp articles such as bits of glass and the like. The next layer 18, which is shown as being adhesively bonded to layer 17, can comprise an absorbent powder packet constructed from an absorbent material such as a sponge or fabric pad. Layer 18 here contains a powdered medicament. However, other powdered materials can also be carried by layer 18 including various beneficial agents, disinfectants, drugs and pharmaceuticals of several types. Additional material layers can be interconnected with layer 18, such as a layer which comprises a porous, cellular mass which may, for example, be an elastomer, a sponge, or a polymeric foam. Attached to this layer may be a backing member to which a wound dressing such as hydrogel wound dressing can be affixed in any appropriate manner.
In summary, assemblage 16 can be made up of a wide variety of different types of material so that the device can be used to effectively treat burns, to treat a particular type of wound, to serve as an applicator of topical medications, to clean up numerous types of contamination and to retrieve and safely dispose of various kinds of contaminated articles.
Assemblage 16 can be constructed and arranged to safely deal with a number of different types of contaminants in differing media, including liquids, solids, semi-solids, pastes, micro-organisms, bacteria, viruses, tissue samples and the like.
The protective pouch or barrier member 12 can also be constructed in a number of different ways using a number of different types of materials. For example, the barrier can comprise a single layer of film or a combination of one or more layers of film individually layered or bonded together by heat, adhesive, chemical reaction, or numerous other attachment methods. The film itself can be of various thicknesses and can be of metallic origin, polymeric origin, or it may be nylon, latex, rubber, natural or synthetic composites or any combination of these materials. In summary, the materials used to construct the barrier member can be any material or combination of materials that has the property to substantially limit permeability of liquids, viruses, spores, bacteria, or micro-organisms, so long as it is acceptable for human use and preferably is lint free and flexible under extreme temperature variations. An example of one type of film material suitable for use in constructing the barrier member, is a material made by E. I. duPont de Nemours and Company, and sold under the name and style HYTREL. Another suitable material is a material manufactured and sold by Exxon under the name and style of TPE. Other basic materials acceptable for use in construction of the barrier member for certain applications include neoprene, polyethylene and copolyester films, polypropylenes, polythylenes, polystyrenes, polysophones, polyisopene, polyvinyl, polyamide and numerous polymers including biodegradable polymers such as mylar, latex, nylon, butyl, silicone and acetate. Materials of the character identified should preferably be of a character to provide resistance to penetration and tearing, flexibility in extreme temperature regimes, and, as previously discussed, be micro-organism impermeable. Additionally, for certain applications, it is preferable that the material be transparent or translucent and be substantially resistant to ultraviolet radiation.
It is also understood that the films used to construct the barrier member may be films or components that are coated, or impregnated with one or more chemical or pharmaceutical agents or substances capable of neutralizing or adjusting the acid or pH levels, disinfecting, deodorizing and delivering a pharmaceutical agent to the patient.
With these materials in mind and referring once again to FIG. 3, the first layer 17 can comprise a single layer or a plurality of layers of various types of natural or synthetic materials including materials such as polyester, hydrogel, cotton, rayon, wool, nylon, silicone and like materials. Layer 17 can be bonded to either face or both faces of the barrier member 14 by any suitable means including heat bonding, chemical bonding, adhesive bonding, electrical charge and the like. Similarly, member 18 can be constructed from a wide variety of materials including sponge,elastomers, cellular foam and like cellular structures and can be affixed to assemblage 17 by any suitable means.
Turning once again to FIGS. 3 through 6, the important emergency treatment kit of the invention of which the treatment mits form a part, can be seen to comprise a container 20 having a first body portion 22 defining a first chamber 24 (FIG. 4). Chamber 24 is formed from flexible front and back panels which are suitably interconnected. Stowed within first chamber 24 is a flexible fold-out flap portion 26 (FIG. 6) which has a plurality of individual compartments 28, 30 and 32 for storage of treatment materials and components. Fold-out flap portion can be conveniently stowed within chamber 24 in the manner shown in FIG. 4 and can be unfurled therefrom into a generally planar configuration of the character shown in FIG. 6.
As indicated in FIG. 3, compartment 24 is normally closed by a closure means comprising a top flap 34 which is interconnected with body portion 22 by a zipper 36 mechanism which also forms a part of the closure means. As shown in FIG. 6, flap 34 is preferably hingeably connected along its rearward edge with body portion 22 so that when the zipper 36 is unzipped, flap 34 can be folded into the upward position shown in FIG. 6 thereby permitting easy access to internal chamber 24.
Provided on the front face of first body portion 22 is a front body portion 40 which also has an inner or second chamber 42 that is normally closed by a closure means including an upper flap 44 which is hingeably connected to front body portion 22 and can be opened and closed by a second zipper mechanism 46 which also forms a part of the closure means (FIG. 3).
To enable easy portability of the emergency treatment safety kit, an adjustable carrying strap assembly 50 is interconnected with one of the panels which make up body portion 22 in the manner best seen in FIG. 3. Strap assembly 50 comprises an elongated carrying strap having an adjustable end portion 52, the length of which can be varied by manipulation of a buckle member 54. The carrying strap also includes a second strap portion 56 which is interconnected with strap member 52 by a conventional type of finger release buckle mechanism 58. With this construction, the emergency treatment kit can easily be carried over the user's shoulder, or alternatively, can be carried by hand in the same manner as a small purse.
Various treatment materials and components can be strategically stowed within body portion 22, front body portion 40, and within the compartment of fold-out flap 26. One of the extremely important emergency treatment items stowed within chamber 24 of first body portion 22 is the previously identified treatment mit 12. In the form of the invention shown in the drawings, two treatment mits 12 are stowed within chamber 24 in the rolled up configuration shown in FIG. 4 of the drawings. Each of these treatment mits 12 are of the construction previously described can be conveniently removed from chamber 24 in the manner illustrated in FIG. 5. More particularly, by grasping the open end 12a of the safety mit, the mit can be unrolled and removed from chamber 24 by exerting a force in the direction of the arrow in FIG. 5. With this construction, treatment mits 12 remain in a protected, sterile environment within chamber 24 until time of use.
At the accident site, the safety kit can be removed from the transport vehicle and, using strap assembly 50 can conveniently be carried directly to a location adjacent the accident victim. At this location, access to chamber 24 can be obtained using zipper mechanism 36. Once the zipper mechanism is opened, flap 34 can be moved into a chamber access position and one of the treatment mits 12 can be removed from the chamber in the manner shown in FIG. 5. Once removed from chamber 24, the care giver can insert one hand into interior compartment 14c of the treatment mit and the nit can effectively be used to stop the bleeding of the accident victim or to wipe blood or other body fluids from the patient. Once the engaging means 16 of the mit is saturated, the treatment mit can be turned inside out so as to safely encapsulate the body fluids or other materials which have been absorbed by the engaging means. A convenient tie means or strap 53 is provided proximate opening 14c of the treatment mit in the manner shown in FIG. 1. After the treatment mit has been turned inside out to contain the contaminated materials captured by the on engaging means 16, strip 53 can be removed from the safety mit and used to secure the neck of the treatment mit in a manner to effectively encapsulate the engaging means and contaminants thereon within the interior of the inside out barrier member 14.
Another important treatment component stowed within the emergency kit is a small cardio-pulmonary resuscitation mask 54. As best seen in FIG. 56, pouch or compartment 28 provided on fold-out panel 26 is specially designed to hold the important CPU mask 54. In an emergency situation, once chamber 24 is opened, panel 26 can be removed therefrom and placed in the generally planar configuration shown in FIG. 6. In this configuration, the CPU mask is exposed to view and is readily accessible by the care giver.
Other emergency treatment components such as adhesive tape or the like can be conveniently stowed within compartment 30 while small bandages, gauze and like treatment materials can be stowed within compartment 32.
As illustrated in FIG. 4, still other safety treatment components such as latex gloves, larger bandages, gauze strips and the like can be stowed within compartment 42 of front body portion 40.
With the novel construction of the accident-victim-emergency-treatment kit 20, thus described, the kit can be readily transported to the vicinity of the accident victim. At that location, chamber 24 can be quickly opened by the care giver so as to at once gain access to the treatment mits 12 and to also gain access to fold-out panel 26. By folding panel 26 into the planar configuration shown in FIG. 6, the care giver is given immediate convenient access to additional treatment components such as the CPR mask, adhesive tape and a variety of bandages and other treatment materials. Similarly, the care giver can quickly gain access to chamber 42 of front pouch 40 so as to retrieve therefrom other emergency treatment components such as latex gloves, larger gauze bandages and the like.
In summary, the novel accident-victim-treatment kit of the invention for the first time provides to the care giver a means for treating the accident victim in a prompt, professional manner while at the same time protecting against the spread of infectious disease microorganisms and other contaminants which may be contained within the body fluids of the patient.
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
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A compact, easy-to-carry and easy-to-use accident victim emergency kit which includes the essential items necessary to provide emergency treatment to accident victims. The kit is in the nature of a fold-out-type apparatus which includes a number of personal protection treatment devices including a specially designed treatment mit that effectively protects the patient and the care giver as well as bystanders and clean-up personnel from exposure to hazardous material of the character often encountered when medical care is provided at accident sites and in emergency situations.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from provisional patent application Ser. No. 60/610,777, filed Sep. 17, 2004, which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
This invention generally relates to medical devices that are implantable within a human subject and that have occlusion capabilities that are especially suitable for use as medical device plugs for defective or diseased body vessels. These types of devices have pores which, upon deployment, reverse configuration from open to closed or vice versa for enhanced occlusion, fixation, or other therapeutic capabilities.
DESCRIPTION OF RELATED ART
Medical devices that can benefit from the present invention include those that are characterized by hollow interiors and that are introduced endoluminally and expand when deployed so as to plug up a location of concern within the patient. These are devices that move between collapsed and expanded conditions or configurations for ease of deployment through catheters and introducers. The present disclosure focuses upon occlusion devices for diseased locations within vessels of the body, especially devices sized and configured for implantation within the vasculature, as well as devices for neurovascular use.
A number of technologies are known for fabricating implantable medical devices. Included among these technologies is the use of thin films. Current methods of fabricating thin films (on the order of several microns thick) employ material deposition techniques. These methods are known to make films into basic shapes, such as by depositing onto a mandrel or core so as to make thin films having the shape of the mandrel or core, such as geometric core shapes until the desired amount has built up. Traditionally, a thin film is generated in a simple (oftentimes cylindrical, conical, or hemispherical) form and heat-shaped to create the desired geometry. One example of a known thin film vapor deposition process can be found in Banas and Palmaz U.S. Patent Application Publication No. 2005/0033418, which is hereby incorporated herein by reference.
Methods for manufacturing three-dimensional medical devices using planar films have been suggested, as in U.S. Pat. No. 6,746,890 (Gupta et al.), which is hereby incorporated herein by reference. The method described in Gupta et al. requires multiple layers of film material interspersed with sacrificial material. Accordingly, the methods described therein are time-consuming and complicated because of the need to alternate between film and sacrificial layers.
For some implantable medical devices, it is preferable to use a porous structure. Typically, the pores are added by masking or etching techniques or laser or water jet cutting. When occlusion devices are porous, especially for intercranial use, the pores are extremely small and these types of methods are not always satisfactory and can generate accuracy issues. Approaches such as those proposed by U.S. Patent Application Publication No. 2003/0018381, which is hereby incorporated herein by reference, include vacuum deposition of metals onto a deposition substrate which can include complex geometrical configurations. Microperforations are mentioned for providing geometric distendability and endothelialization. Such microperforations are said to be made by masking and etching or by laser-cutting.
An example of porosity in implantable grafts is Boyle, Marton and Banas U.S. Patent Application Publication No. 2004/0098094, which is hereby incorporated by reference hereinto. This publication proposes endoluminal grafts having a pattern of openings, and indicates that different orientations thereof could be practiced. Underlying stents support a microporous metallic thin film. Also, Schnepp-Pesch and Lindenberg U.S. Pat. No. 5,540,713, which is hereby incorporated by reference hereinto, describes an apparatus for widening a stenosis in a body cavity by using a stent-type of device having slots which open into diamonds when the device is radially expanded.
A problem to be addressed is to provide an occlusion device with portions having reversible porosities that can be delivered endoluminally in surgical applications, while implanting and locating same at the proper site of an occlusion, wherein the porosities reverse in order to provide an at least generally closed portion with an immediate occlusive function to “plug” the vessel defect and control or stop blood flow into the diseased site and an at least generally open portion with filtration or tissue integration properties.
Accordingly, a general aspect or object of the present invention is to provide an occlusion device having portions with varying porosity properties which separately perform a plugging function and a filtration or fixation function upon deployment at or near a diseased site.
Another aspect or object of this invention is to provide a method for plugging a vessel defect that can be performed in a single endoluminal procedure and that positions an occlusion device for effective blood flow control into and around the area of the diseased location.
Another aspect or object of this invention is to provide an improved occlusion device that incorporates thin film metal deposition technology in preparing occlusion devices which exhibit regions of opposing porosity during deployment, which porosity is substantially reversed when properly positioned for occlusion.
Other aspects, objects and advantages of the present invention, including the various features used in various combinations, will be understood from the following description according to preferred embodiments of the present invention, taken in conjunction with the drawings in which certain specific features are shown.
SUMMARY OF THE INVENTION
In accordance with the present invention, an occlusion device is provided that has a thin film structure that has a contracted or collapsed configuration which facilitates endoluminal deployment as well as an expanded or deployed configuration within the body. When in at least the deployed configuration, the thin film is shaped with a converging end of reduced cross-sectional extent when compared with the rest of the deployed device.
Porosity is provided in at least a first portion of the occlusion device in the radially contracted configuration in the form of pores that are generally open when the device is stretched longitudinally. These pores close substantially or fully upon deployment, when the thin film device longitudinally foreshortens and expands radially to shrink the pores to a smaller profile. This slot closure upon expansion provides a porosity that is low enough to fully or partially occlude blood flow to a vessel being treated.
In contrast to these pores, an area having opposing porosity is provided in at least a second portion of the occlusion device. When the term “opposing porosity” is used herein, this refers to an area having pores that are generally closed when the device is in a collapsed configuration for delivery. These pores open upon implantation when the device is deployed to a target occlusion site and expanded. Depending on their location and profile when open, these pores can provide for passage of blood flow to perforator vessels while occluding a diseased location, for body fluid filtration, and/or for tissue fixation (i.e. endothelialization) at or adjacent to the occlusion site. Hence, it will be understood that these two pore areas can be considered to essentially reverse porosities upon deployment, moving from open to closed and vice versa when implanted within the body.
In making the thin film mesh, a core or mandrel is provided which is suited for creating a thin film by a physical vapor deposition technique, such as sputtering. A film material is deposited onto the core or mandrel to form a seemless or continuous three-dimensional layer. The thickness of the film will depend on the particular film material selected, conditions of deposition and so forth. Typically, the core then is removed by chemically dissolving the core, or by other known methods. Manufacturing variations allow the forming of multiple layers of thin film mesh material or a thicker layer of deposited material if desired.
Special application for the present invention has been found for creating porous occlusion devices which have a thin film structure and automatic porosity reversal upon deployment as occlusion devices, and methods also are noted. However, it will be seen that the products and methods described herein are not limited to particular medical devices or methods of manufacture or particular surgical applications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of an occlusion device according to the present invention, in a collapsed configuration;
FIG. 2 is a front elevational view of the occlusion device of FIG. 1 in a deployed configuration;
FIG. 3 is a front elevational view of an occlusion device according to an alternate embodiment, in a collapsed configuration adjacent to a branched body vessel;
FIG. 4 is a front elevational view of the occlusion device of FIG. 3 , in a deployed configuration at a body vessel branch;
FIG. 5 is a cross-sectional view of the occlusion device of FIG. 1 in a collapsed configuration within a catheter or introducer;
FIG. 6 is a cross-sectional view of the occlusion device of FIG. 5 in a deployed configuration within a body vessel prior to removal of the catheter;
FIG. 7 is a front elevational view of a tube used to form support struts of an alternate embodiment;
FIG. 8 is a front elevational view of the occlusion device of FIG. 1 , with a support structure according to an alternate embodiment;
FIG. 9 is a front elevational view of an occlusion device in a collapsed configuration according to an alternate embodiment, with portions broken away for clarity; and
FIG. 10 is a front elevational view of the occlusion device of FIG. 9 according to an alternate embodiment, with portions broken away for clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate manner.
FIG. 1 illustrates an occlusion device 10 in a collapsed position. The occlusion device 10 preferably comprises a thin film mesh formed by physical vapor deposition onto a core or mandrel, as is well-known to those skilled in the art. Most preferably, a thin film of nitinol, or other material which preferably has the ability to take on a shape that had been imparted to it during manufacture, is formed. When nitinol material is used in forming the thin film, the thin film can be at the martensite state. In addition, the thin film when made of nitinol or materials having similar shape memory properties may be austenite with a transition from martensite to austenite, typically when the device is raised to approximately human body temperature, or in the range of about 95 F. to 100 F.
In making the thin film mesh, this selected material is sputter-deposited onto a core, which core is then removed by chemical etching or the like. Examples of this type of deposition are found in US Published Patent Application No. 2003/0018381, No. 2004/0098094 and No. 2005/0033418, incorporated herein by reference. Nitinol, which encompasses alloys of nickel and titanium, is a preferred film material because of its superelastic and shape memory properties, but other known biocompatible compositions with similar characteristics may also be used.
The thickness of the thin film mesh depends on the film material selected, the intended use of the device, the support structure, and other factors. A thin film of nitinol is preferably between about 0.1 and 250 microns thick and typically between about 1 and 30 microns thick. More preferably, the thickness of the thin film mesh is between about 1 and 10 microns or at least about 0.1 micron but less than about 5 microns. A supported mesh may be thinner than a self-supported mesh.
The occlusion device 10 is shown in FIG. 1 in a collapsed configuration in which a plurality of pores or slots 12 disposed along end portions 14 and 16 are substantially open, while a set of generally longitudinal slits 18 located along a body portion 20 between the end portions 14 and 16 are substantially closed. The slots 12 and slits 18 may be formed by any known means, but are preferably formed using laser-cutting. The illustrated slots 12 are shown in FIG. 1 with generally identical rectangular openings which are arranged in a uniform pattern along the end portions 14 and 16 , but they may assume other open profiles, e.g. diamond-shaped openings, and be arranged randomly or in selected non-uniform patterns, depending on the intended use. The slits 18 may also assume differing profiles, e.g. curvilinear, and be arranged randomly or in selected non-uniform patterns, according to the intended use. The occlusion device 10 preferably includes a proximal end 14 having a shape that is generally closed, which can culminate in a plasma weld and include an engagement member or hook 22 , and a distal end 16 of a shape that is generally closed and that is atraumatically sealed shut by a plasma weld 24 or other suitable seal.
In use, the slots 12 and slits 18 assist in allowing the associated portions of the occlusion device 10 to expand radially. For example, FIG. 2 shows the occlusion device of FIG. 1 when same assumes a longitudinally foreshortened and radially expanded deployed configuration 26 within a body vessel V. When implanted in the body, the occlusion device 10 moves from the elongated, collapsed configuration of FIG. 1 to the foreshortened, deployed configuration 26 of FIG. 2 , while the slots move from the open configuration 12 of FIG. 1 to the generally closed configuration 12 a of FIG. 2 . Compared to the open configuration 12 , the slots in the generally closed configuration 12 a resemble the closed slits 18 of FIG. 1 , but are disposed transversely or generally circumferentially along the end portions 14 and 16 . In this closed configuration 12 a , the slots provide a decreased porosity and are intended to prevent the flow of blood and other bodily fluids through the associated portion of the occlusion device. Thrombus development occurs and/or occlusion results as generally appreciated in the art.
In contrast to the slots 12 , the slits 18 move from the generally closed configuration of FIG. 1 to the generally open configuration 18 a of FIG. 2 when the occlusion device has been deployed to the target area. While the slots 12 telescope to cause longitudinal foreshortening and radial expansion, the slits 18 are compressed by the force of the occlusion device moving to its deployed configuration, causing them to narrow and open, thereby contributing to having the associated body portion 20 foreshorten and radially expand. In the open configuration 18 a , the slits generally resemble the open slots 12 of FIG. 1 , but they may assume other open profiles, such as diamond-shaped openings, depending on their initial closed profile. The open slits 18 a abut the walls of the body vessel V and can allow for tissue ingrowth and endothelialization for permanent fixation of the occlusion device.
The configuration of the device 26 as deployed in FIG. 2 is typically achieved by heating a nitinol thin film mesh or other shape memory material when on a shaping core or mandrel until it reaches an austenite condition, whereby it is heat-set into the desired shape. This set shape can be offset when cooled and removed from the mandrel and stretched down to a configuration such as shown in FIG. 1 .
Typically, such memory “setting” is adequate to achieve the desired expanded shape of the device. It can be possible to assist this expanded shaping by varying slot or slit size, shape, and location. For example, the elasticity of the mesh can be supplemented in the end portions 14 and 16 adjacent to the body portion 20 by overlaying those portions with relatively large slots that telescope to allow for enhanced radial expansion when the occlusion device moves from a collapsed configuration to a deployed configuration. In contrast, less radial expansion is desired adjacent to the hook 22 and plasma weld 24 , so smaller slots that telescope to a lesser extent may be used. Alternatively, if even less radial expansion is required, selected regions may be devoid of slits and slots, which means that the amount of expansion which results is due to the characteristics of the thin film material unaided by slots or slits in the material.
The occlusion device is configured and sized for transport within a catheter or introducer 28 in a collapsed configuration 10 , as illustrated in FIGS. 1 and 5 . In general, the occlusion device 10 is placed at a downstream end 30 of a catheter 28 , which catheter 28 is introduced to the interior of a blood vessel V. The downstream end 30 is positioned adjacent to a region of the blood vessel V which is to be occluded, and then a plunger or pusher member 32 ejects the occlusion device 10 into the target region. This may be achieved by moving the pusher member 32 distally, moving the catheter 28 in a retrograde direction, or a combination of both types of movement.
Preferably, the occlusion device 10 is comprised of a shape memory material, such as nitinol, which will move to a deployed configuration 26 upon exposure to living body temperatures, as shown in FIG. 6 . When the occlusion device has been placed, the catheter 28 and plunger 32 are thereafter removed from the vessel V, and the occlusion device is left at its deployed location, as shown in FIG. 2 .
FIGS. 5 and 6 illustrate deployment of the occlusion device 10 to a blood vessel V, but the described method can be applied to other body locations, such as to a location in a vessel V that is in the vicinity of a branch B and a diseased area D, as shown in FIGS. 3 and 4 . However, for such a treatment site, an alternate occlusion device geometry is preferable. In particular, FIGS. 3 and 4 illustrate an occlusion device 34 suitable for implantation adjacent to a branch B of a body vessel V.
The “branch”-type occlusion device 34 of FIG. 3 is a variation of the occlusion device 10 of FIG. 1 . The principal difference is that the proximal end portion 14 of the device 34 of FIG. 3 includes a plurality of generally open slots 12 instead of generally closed slits 18 . In all other respects, the “branch”-type occlusion device 34 can be structurally similar to the occlusion device 10 of FIG. 1 .
In use, the “branch”-type occlusion device 34 is delivered to the vessel V in an elongated, collapsed configuration, where it is released from a catheter or introducer and allowed to move to a foreshortened, deployed configuration 36 , as in FIG. 4 . In the illustrated deployed configuration 36 , the slots 12 close, as described previously, which causes the distal end portion 16 to radially expand to engage the walls of the vessel V. The deployed configuration with generally closed slots 12 b has a decreased porosity and prevents the flow of blood into the diseased area D, which fosters thrombosis and occlusion.
In moving to the deployed configuration 36 , the slits 18 of the proximal end portion 14 and body portion 20 move to a generally open configuration 18 b , as described previously, which causes the end portion 14 and body portion 20 to radially expand to engage the walls of the vessel V. The open slits 18 b define a generally open flow path, which allows blood to flow between the vessel V and the branch B. The slits 18 b abutting the walls of the vessel V allow for endothelialization and fixation of the device 36 within the vessel V. Depending on the open profile of the slits 18 b , they may also provide a filtering function to prevent the flow of undesirable material between the vessel V and the branch B. They also allow for blood flow to perforator vessels in the vicinity of where the open slits 18 b engage the vessel wall.
As described previously with regard to the occlusion device 10 of FIG. 1 , the slots 12 and slits 18 of the “branch”-type occlusion device 34 may be of different sizes, configuration, and locations. Although in typical application this variation is not required, it may facilitate the desired expanded shaping, depending on the desired amount of radial expansion and longitudinal foreshortening required at any particular location of the device.
If the occlusion device includes a hook 22 , as illustrated in FIGS. 1-4 , the device can be removed from the body or readjusted within the vessel V after deployment. The distal end 16 of the occlusion device is inserted into the target region prior to full removal of the proximal end 14 from the distal catheter end 30 in order to minimize the risk of damage to the vessel V and to facilitate removal or location adjustment if needed. To remove or adjust the location of the occlusion device, the process of FIGS. 5 and 6 is essentially reversed, by replacing the pusher member 32 with a pulling member 33 of known construction to engage the hook 22 or the like and to pull the occlusion device into the catheter 28 and engage its walls to reduce its size. When the occlusion device is back in the catheter 28 , the catheter 28 is then removed from the vessel V or used to reposition the occlusion device.
According to an alternate embodiment of the present invention, the described occlusion devices may be provided with a support structure, similar to that described in U.S. Pat. No. 6,428,558 (Jones and Mitelberg), which is hereby incorporated herein by reference. FIG. 7 shows a generally hollow tube 38 which may be used to make an internal support structure for an occlusion device as illustrated in FIG. 8 , or for other devices such as the occlusion device of FIG. 4 . The tube 38 is preferably comprised of nitinol or another shape memory material having a wall between about 70 and 250 microns thick, most preferably between about 175 and 225 microns thick. The tube 38 also has at least one region with a plurality of longitudinal cuts 40 and two uncut end portions 42 .
In assembling the tube 38 , a compressive force is applied to the end portions 42 of the tube 38 until the cuts 40 buckle outwardly to define the struts 46 of FIG. 8 . A thin film mesh 44 , as illustrated in FIG. 8 , may thereafter be laid over the struts 46 and sealed at least along the end portions 42 . Alternatively, the tube 38 may be returned to the configuration of FIG. 7 and inserted into the thin film mesh 44 before the sealing step. In another embodiment, the thin film mesh 44 can be positioned inside the tube 38 to provide a device having an external support structure. As a further option, the tube can be positioned between thin film mesh layers to provide an occlusion device having an encapsulated support structure.
The mesh 44 is preferably a biocompatible, flexible material and may be thinner than the thin film of FIGS. 1-4 , because it is not required to support itself. The mesh 44 does include a pore structure similar to the self-supporting embodiments, whereby the slots move to a generally closed configuration and the slits move to a generally open configuration when the occlusion device 26 a is deployed, as illustrated in FIG. 8 . It will be appreciated that, while this aspect of the present invention is shown and described with reference to the occlusion device of FIG. 2 , the shape and configuration of the cuts along the tube can be varied so that it can be applied to other occlusion devices according to the present invention. For example, if the cuts 40 are interrupted by an uncut section, a waist will form at the uncut section. In other words, the absence of the cut aspect at a given area will minimize radial expansion thereat while the cut lengths will radially expand upon axial compression.
According to another alternative embodiment of the present invention, the described occlusion devices may be created with an additional outer thin film layer 48 , as illustrated in FIG. 9 . An occlusion device 10 according to FIG. 1 is nested within a porous thin film layer 48 , which is partially broken away in FIG. 9 . These layers 10 and 48 operate according to the principles described above. Preferably the two layers 10 and 48 have differing slot patterns or at least slot patterns that are out of phase with each other, such that the slots 12 of the inner layer 10 are misaligned with the slots 50 of the outer layer 48 , thereby decreasing the effective slot size S of the layered occlusion device 52 . As a result, the layered occlusion device 52 will have substantially the same radially expansive properties according to the present invention, while providing an even lower porosity along the end portions in the deployed configuration, which improves the occlusive properties. This embodiment is useful when cutting technology does not provide slot sizing as small as may be desired in some circumstances.
Unless the slits 18 of the inner layer 10 are substantially aligned with the slits 54 of the outer layer 48 , the effective open slit size along the body portion will be diminished in the deployed configuration. Typically, this diminishment will not be complete and blood flow therethrough, even though diminished, can supply perforator vessels with blood flow, oxygen, and the like to maintain these vessels in a healthy condition.
In another embodiment of the device, substantially the same effect of FIG. 9 may be achieved using an outer layer having only longitudinal slits, as illustrated in FIG. 10 . Some slits 54 of the outer layer 56 can be aligned with those slits 18 of the inner layer 10 which are to be open in a deployed configuration, while other slits 54 a of the outer layer 56 are generally out of phase or misaligned with the slots 12 of the inner layer 10 , which are to be closed in a deployed configuration. Accordingly, in a deployed configuration, the aligned slits 18 and 54 of the respective two layers 10 and 56 will define openings, while the misaligned slits 54 a and slots 12 will be generally closed. It will be seen that the inner layer may also be provided with only longitudinal slits, and substantially the same pattern of alignment and misalignment may be practiced in order to define open and closed portions of the deployed device. The exclusive use of slits may be preferred in some instances where it is difficult to provide adequate slots for the collapsed configuration.
It will be understood that the embodiments of the present invention which have been described are illustrative of some of the applications of the principles of the present invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention, including those combinations of features that are individually disclosed or claimed herein.
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Thin film devices implantable within a human subject for occlusion of an aneurysm or body vessel are provided. The devices are movable from an elongated, collapsed configuration for delivery to a deployed configuration within the body. Open slots in selected portions of the device telescope as the device moves to its deployed configuration, which causes the associated portions to longitudinally foreshorten and radially expand, while also decreasing in porosity for preventing blood flow. Closed slits in other portions of the device open as the device moves to its deployed configuration, which causes the associated portions to longitudinally foreshorten and radially expand, while remaining open for fluid flow or endothelialization. The occlusion devices may be either self-supporting or supported by a strut structure. Additionally, the occlusion devices may comprise a plurality of mesh layers having unaligned pore systems which further reduce porosity in desired portions of the deployed configuration.
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CLAIM FOR PRIORITY
This non-provisional application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/180,348, of the same title, filed Feb. 4, 2000.
TECHNICAL FIELD
The present invention relates generally to papermaking fiber processing and more particularly to a method and apparatus useful for cleaning secondary pulp by way of a multistage forward cleaner system with an integrated flotation cell which cooperates with the forward cleaners to boost efficiency of the system.
BACKGROUND
Processing of papermaking fibers to remove contaminants is well known in the art, including the use of forward cleaners and flotation cells. Such technology is used, for example, to treat secondary (recycle) fiber sources for re-use in paper products such as towel and tissue, paperboard, coated writing and printing papers and so forth. Following is a brief synopsis of some patents of general interest.
According to U.S. Pat. No. 4,272,315 to Espenmiller waste paper containing materials, e.g., commercial “waste paper”, are treated for recovery of reusable paper therefrom by slushing in a pulper from which two fractions are continuously extracted—a first fraction through small holes, e.g. {fraction (3/16)} inch in diameter, and a second fraction through substantially larger holes, e.g., 1 inch in diameter. The second fraction is screened, preferably after a centrifugal cleaning operation, in a screen having small perforations sized to accept only substantially defibered paper, and the accepts flow is mixed directly with the first extracted fraction. The reject flow from this screen is conducted, with or without an intermediate deflaking operation, to a tailing screen from which the accepts are recycled to the pulper and the rejects are eliminated from the system. Advantages of this method and system include the continuous elimination of plastic and other floating trash from the pulper, a high degree of essentially complete defibering in the pulper, and minimal recycling of adequately defibered stock.
U.S. Pat. No. 4,983,258 to Maxham discloses a process for the production of papermaking fiber or pulp from waste solids emanating from pulp and paper mills, particularly waste solids in process water streams containing fibrous solids that cannot be directly recycled by paper mill “saveall” devices, from pulp and paper mill process water streams conveyed by the sewerage system to wastewater treatment plant facilities, and from “sludge” emanating from the underflow of a primary clarifier or sedimentation basin at pulp and paper mill wastewater treatment facilities either before or after the “sludge” is thickened and dewatered. The said process comprises a defibering stage to release individual fibers from bundles, a screening stage to separate long fiber and debris from short fiber and clay, a centrifugal cleaning stage to separate debris from the long fiber, a bleaching stage to increase the brightness of the fiber, a dewatering stage to remove excess water from the pulp, a sedimentation stage to separate the short fiber-clay-debris from the defibering effluent which is substantially recycled, and a biological treatment process to remove dissolved organic materials from the excess water generated which can be either discharged from the process or recycled as process water.
U.S. Pat. No. 5,240,621 to Elonen et al. discloses a method of separating an aqueous solids containing suspension which includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a). An apparatus for the separation of gas and lightweight material from a gas and lightweight material containing aqueous solids suspension is also described and includes a centrifugal pump for separating the gas and lightweight material from the solids suspension with a suspension inlet and an outlet for the lightweight material; a flotation cell for separating the lightweight material from a solids suspension; and a circulation loop connecting the outlet of the centrifugal pump, the flotation cell and the suspension inlet of the pump.
In U.S. Pat. No. 5,693,222 to Galvan et al. a dissolved gas flotation tank system is disclosed which is configured to provide educted gas or air into recirculated effluent fluid from the tank which includes a pump system which increases the dissolution rate of gas into the effluent fluid thereby eliminating the need for retention tanks and related equipment which adds to high equipment costs. The dissolved gas flotation tank system also provides a pre-contact chamber for assuring immediate and intimate contact between the suspended solids in an influent feed stream and the recirculated effluent fluid in which gas is dissolved, as well as flocculant when used, to produce a better agglomerate structure for improved flotation and separation. The dissolved gas flotation tank also provides an improved means of removing and processing float from the tank, and employs a dewatering system enhanced by the addition of chemicals or flocculants into the float removal system.
The disclosures of the foregoing patents are hereby incorporated for reference.
While flotation and separation technologies are fairly advanced, there is an ongoing need to increase overall fiber-cleaning system performance and to reduce the amount of waste and capital investment in the plant.
SUMMARY OF INVENTION
The present invention provides a hybrid system for processing papermaking fibers and includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.
One advantage of feeding the second accepts stream forward is that it does not have to be returned to the first bank of cleaners for re-cleaning. This reduces the size of the first bank of cleaners or allows an existing installation to operate at a lower consistency. (The cleaners operate more efficiently at a low consistency of 0.5% than at 0.8 or 1%). Another advantage is that the flotation cell operates at greater than 60% efficiency on removing hydrophobic contaminants from the first cleaner rejects, while another cleaner stage removes less than 50% of the hydrophobic contaminants. As a result a large quantity of hydrophobic contaminants are removed in the flotation stage, which makes the remaining cleaner stages work more efficiently with less good fiber loss.
Investigation showed that the number of hydrophobic contaminants in the second cleaner accepts after the flotation stage was lower than the number of hydrophobic contaminants in the first cleaner accepts. Without the flotation stage the number of hydrophobic contaminants in the second accepts is much higher than the first accepts, so that the second accepts have to be returned to the first bank of cleaners for more cleaning.
As will be appreciated from the discussion which follows, the size and cost of a flotation stage for treating secondary fiber can be reduced by up to 75% if it is installed in centrifugal cleaner system as compared to a full scale treatment of the stock by flotation. The centrifugal cleaner system modeling indicates a 34% reduction in ink speck area of total centrifugal cleaner system accepts by removing ink specks from the first stage rejects with 80% efficiency in a flotation stagc and then feeding the flotation accepts forward after centrifugal cleaning of the second stage. (24% reduction if second stage rejects are treated in a similar manner). The ability to feed the centrifugal cleaner rejects forward (after the flotation stage and additional centrifugal cleaning in the next stage) reduces the stock consistency in the first stage, thereby improving the efficiency of He first stage. The capacity of the system is also increased by feeding the second stage centrifugal cleaner accepts forward. The other centrifugal cleaner ages can also be operated more efficiently since more than 50% of the ink in the first stage centrifugal cleaner rejects has been removed in the flotation stage. When the centrifugal cleaner accepts are thickened in a press, a large amount of ink ends up in the pressate. This ink can also be removed by using the ink-laden pressate as dilution water for the centrifugal cleaner rejects going to the flotation stage.
A conventional centrifugal cleaner system (as shown in FIG. 1) normally consists of several stages, whereby the rejects of each centrifugal cleaner stage are diluted for cleaning in the next stage and the centrifugal cleaner accepts are fed backwards to the feed of the previous stage. The ink speck removal efficiency of the centrifugal cleaner is usually much less than 50% on toner inks in office waste paper. As a result the total centrifugal cleaner system ink speck removal efficiency can drop to 30% or less on a furnish containing a large proportion of office waste.
By sending the first or second stage centrifugal cleaner rejects to a flotation stage (as shown in FIG. 2) it is possible to remove a much higher percentage of the ink specks in office waste. (It was possible to obtain 80% removal of ink specks during a pilot plant trial with a flotation cell operated on second stage centrifugal cleaner rejects.) If the accepts of the flotation cell are cleaned in the next centrifugal cleaner stage, the centrifugal cleaner accepts from that stage can then be fed forward to the thickener. Sending centrifugal cleaner accepts forward reduces the load and improves the efficiency of the previous centrifugal cleaner stage.
The present invention is particularly useful in connection with removing stickies from the recycle fiber product stream; likewise, it is believed pitch removal is enhanced. Stickies are generally a diverse mixture of polymeric organic materials which can stick on wires, felts or other parts of paper machines, or show on the sheet as “dirt spots”. The sources of stickies may be pressure-sensitive adhesives, hot melts, waxes, latexes, binders for coatings, wet strength resins, or any of a multitude of additives that might be contained in recycled paper. The term “pitch” normally refers to deposits composed of organic compounds which are derived form natural wood extractives, their salts, coating binders, sizing agents, and defoaming chemicals existing in the pulp. Although there are some discrete characteristics, there are common characteristics between stickies and pitch, such as hydrophobicity, low surface energy, deformability, tackiness, and the potential to cause problems with deposition, quality, and efficiency in the process. Indeed, it is possible with the present invention to reduce stickies by 50%, 80% or even more by employing a flotation cell in a multistage forward cleaner system as hereinafter described in detail.
The rejects from the flotation stage are so full of ink and ash that they can be rejected without any further treatment.
There is provided in one aspect of the present invention, a method of processing papermaking fibers with a multistage array of forward cleaners including a plurality of centrifugal cleaners configured to generate accepts streams and rejects streams which concentrate heavy waste, the method including (a) feeding a first aqueous feed stream including papermaking fibers to a first stage bank of centrifugal cleaners of the multistage array; (b) generating a first accepts aqueous stream and a first rejects aqueous stream in the first stage bank of centrifugal cleaners, the first aqueous rejects stream being enriched in heavy waste with respect to said first aqueous feed stream; (c) supplying the first rejects aqueous stream to a flotation stage; (d) treating the first rejects aqueous stream in the flotation stage to remove hydrophobic waste from the first aqueous rejects stream and produce an intermediate aqueous purified feed stream; and (e) feeding the aqueous purified intermediate feed stream to a second stage bank of centrifugal cleaners of the multistage array, the second centrifugal cleaner being configured to generate a second accepts aqueous stream, wherein the second rejects aqueous stream is enriched in heavy waste with respect to said aqueous purified intermediate feed stream. The method may further include feeding the first accepts aqueous stream and said second accepts aqueous stream to another cleaning device or a thickening device. Suitable additional cleaning devices include screening devices, reverse cleaners and the like. In a preferred embodiment, the first aqueous feed stream comprises a preliminary accepts stream generated by way of a preliminary bank of centrifugal cleaners dividing a preliminary feed stream into a preliminary accepts stream and a preliminary rejects stream. A preferred method may include feeding the preliminary rejects stream to the flotation stage and treating the preliminary rejects stream along with the first rejects aqueous stream to remove hydrophobic waste therefrom whereby the aqueous purified intermediate stream includes treated components from both the preliminary rejects stream and the first rejects aqueous stream.
In other preferred embodiments, the process may include feeding the second rejects aqueous stream to a third centrifugal cleaner operative to generate a third accepts aqueous stream and a third rejects aqueous stream.
Preferably, the multistage array of forward cleaners comprises at least 3 banks of centrifugal cleaners, and still more preferably, the multistage array of forward cleaners comprises at least 5 banks of centrifugal cleaners. The first aqueous feed stream generally has a consistency of from about 0.3% to about 0.9%, whereas the first aqueous stream more typically has a consistency of from about 0.4% to about 0.7%. The hydrophobic waste removed from the first aqueous stream by the flotation stage often includes an ink and stickies composition, toner ink compositions being typical in office waste and stickies compositions frequently being obtained from pressure sensitive adhesives in office waste.
In another aspect of the invention there is provided a hybrid apparatus for processing papermaking fibers with a multistage array of forward cleaners including (a) a first bank of centrifugal cleaners configured to generate a first accepts stream and a first rejects stream upon operating on a first aqueous feed stream, the first rejects stream being enriched with respect to heavy hydrophobic contaminants with respect to the first aqueous feed stream; (b) a flotation cell connected to the first bank of centrifugal cleaners so as to receive the first rejects stream and adapted to remove hydrophobic contaminants such as ink, stickies and the like from the first rejects stream, the flotation cell being constructed and arranged so as to generate a flotation rejects stream and a flotation accepts stream which is purified with respect to hydrophobic contaminants in said first rejects stream; and (c) a second bank of centrifugal cleaners coupled to the flotation cell so as to receive the flotation accepts stream as a second feed stream, the second bank of centrifugal cleaners being likewise configured to generate an accepts stream hereinafter referred to as a second accepts stream and a second rejects stream respectively. In a preferred embodiment, a preliminary bank of centrifugal cleaners is provided upstream of the first bank of centrifugal cleaners and coupled thereto whereby the accepts stream of the preliminary bank of centrifugal cleaners is fed to the first bank of centrifugal cleaners. The banks of centrifugal cleaners are typically hydrocyclone type cleaners.
Unless otherwise indicated, terminology appearing herein is given its ordinary meaning; %, percent or the like refers, for example, to weight percent and “consistency” refers to weight percent fiber or solids as that term is used in papermaking.
BRIEF DESCRIPTION OF DRAWINGS
The invention is described in detail below with reference to numerous examples and the appended Figures wherein like numbers designate similar parts throughout and wherein:
FIG. 1 is a schematic of a conventional multistage forward centrifugal cleaner system wherein each bank of cleaners are designated by a conical element;
FIG. 2 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention, wherein a flotation stage is provided to treat the second stage rejects stream;
FIG. 3 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention wherein a flotation stage is provided to treat the first stage rejects stream;
FIG. 4 is a schematic diagram of a hybrid multistage forward cleaner/flotation apparatus and process of the present invention wherein a flotation stage is provided to treat the first stage rejects and third stage accepts; and
FIG. 5 is a schematic diagram illustrating an apparatus and process of the present invention wherein the hybrid system has dual forward cleaner banks in series and the rejects stream from both of the forward cleaner banks are provided to a flotation cell.
DETAILED DESCRIPTION
The invention is described in detail below for purposes of illustration and exemplification only. Such explanation of particular embodiments in no way limits the scope of the invention which is defined in the appended claims. Referring to FIG. 1, there is shown a conventional forward cleaner system 10 of the type employed at a paper mill, for instance, as part of the cleaning process for processing secondary pulp into paper products. System 10 has five stages 12 , 14 , 16 , 18 and 20 of banks of centrifugal cleaners interconnected in the manner shown. Such connections may include suitable piping, mixing tanks, holding vessels and the like (not shown) as may be convenient for operating the system. Pulp is fed at low consistency to the system at 22 to the first bank of cleaners 12 through inlet 24 and centrifugally treated in the first stage by a bank of hydrocyclones, for example, such that the accepts are fed forward at 26 to a thickener (or another cleaning device) at 28 whereas the rejects, concentrating the heavy, hydrophobic waste in the system are fed to second stage 14 at 28 for further treatment in a second stage made up of a second bank of centrifugal cleaners 14 . Diluent water is added to the rejects stream from the first stage as indicated at 30 in an amount suitable for the particular system or operating conditions. Stream 28 (first stage rejects) is thus fed to the second stage cleaners whereupon bank 14 of cleaners generates an accepts stream 32 and a rejects stream 34 . Stream 32 is a recycled to the feed 22 and makes up a portion of the material fed to the first stage bank of cleaners 12 . The first bank of cleaners may be made up of 50 or more hydrocyclones depending on capacity and performance desired. Subsequent stages will each contain fewer cleaners than the previous stage depending upon the amount of rejects, until the final stage contains less than 10 cleaners.
Stream 34 is again enriched with respect to heavy components (with respect to stream 32 ) and is fed to the third stage 16 bank of cleaners for further processing. Diluent water may again be added at 36 if so desired to stream 34 . Stage 16 generates another accepts stream 38 which is fed back to the second stage (stream 28 ) and another rejects stream 40 enriched in heavy hydrophobic components.
In like fashion, stream 40 is fed to the fourth stage 18 bank of cleaners at 42 where diluent water may again be added. The fourth stage generates another accepts stream 44 and another rejects stream 46 . These streams have the rejects/accepts characteristics noted above.
Stream 46 is fed to yet another stage 20 of forward cleaners at 48 wherein stream 46 is divided into an accepts stream 50 and a rejects stream 52 as indicated on the diagram. Accepts stream 50 is recycled to the fourth stage as shown and rejects stream 52 is discarded or further processed if so desired. There is thus described a conventional forward cleaner system utilizing centrifugal cleaners in cascaded/refluxing fashion to concentrate the waste material and purify the pulp which is fed forward at a papermaking process to a thickening device or a cleaning device such as screens or a reverse cleaner.
In accordance with the present invention, a flotation stage is advantageously integrated into a multistage forward cleaner system to remove hydrophobic material and increase the cleaning efficiency. Flotation utilizes the phenomenon that the minerals which are present in the ground ore can partially be wetted, i.e., they are hydrophilic, while other parts of the minerals are hydrophobic. Hydrophobic particles have a clear affinity to air. Accordingly, finely distributed air is introduced into the solid-water-mixture so that the air will attach to the hydrophobic particles causing them to rise to the surface of the mixture or suspension. The hydrophobic particles, such as valuable minerals or the above-mentioned contaminants present in repulped stock suspensions, collect as froth at the surface of the suspension and are skimmed off with a suitable means such as a paddle or weir. The hydrophilic particles of the ore or stock suspension remain in the flotation vat. It is also possible to separate two or more useful minerals selectively by the flotation method, for example, in the separation of sulfidic lead/zinc ores. For controlling the surface properties of the minerals small amounts of additives of chemical agents are introduced such as, for example, foaming agents which will help to stabilize the air bubbles, so-called collecting agents which actually cause the hydrophobic effect and prepare the mineral particles for attachment to the air bubbles, and floating agents which temporarily impart hydrophilic properties to the hydrophobic minerals and later return the hydrophobic properties for selective flotation, as mentioned above. The latter are generally inorganic compounds, mostly salts, while the collectors are mostly synthetic organic compounds, and the foaming agents are oily or soapy chemicals such as fatty acid soap.
The apparatus of the present invention may utilize a variety of readily available components. The centrifugal cleaners, for example, are available from Ahlstrom (Noormarkku, Finland) or Celleco (Model 270 series) (Lawrenceville, Ga. USA) and are arranged in banks as shown in FIGS. 2-5. The flotation stage, which may be multiple cells, are likewise readily available from Comer SpA (Vicenza, Italy). Comer Cybercel® models FCB1, FCB3 and FCB4 are suitable as discussed further herein.
There is illustrated in FIG. 2 an apparatus 100 and method in accordance with the present invention. Apparatus 100 operates similarly to apparatus 10 in FIG. 1 . Like parts are given like numbers for purposes of brevity and only differences noted from the discussion above. The system 100 of FIG. 2 operates as described in connection with system 10 of FIG. 1 and is so numbered in the drawing except that system 100 has a flotation stage 75 for treating the rejects stream 34 of second stage cleaner 14 . Diluent water may be added at 36 as before, and hereafter, stream 34 is treated in the flotation stage to remove hydrophobic material. The accepts from the flotation stage, that is purified as shown by removing hydrophobic waste from stream 34 , is then fed in stream 34 ′ to third stage cleaner 16 . Instead of refluxing the accepts from the third stage back to the second stage, the accepts material is fed forward in a product stream 26 ′ for downstream processing. The hydrophobic rejects ( 31 ′) from flotation stage ( 75 ) are removed from system 100 .
In FIG. 3 there is illustrated another apparatus 200 and method of the present invention. Here again similar functioning parts are numbered as in FIGS. 1 and 2, the discussion of which is incorporated by reference here. Apparatus 200 of FIG. 3 differs from apparatus 10 of FIG. 1 in that a flotation stage 75 is added to treat the first stage rejects stream 28 to remove hydrophilic waste to produce an intermediate purified stream 28 ′ which is fed to the second stage bank of cleaners 14 . Bank 14 generates a purified accepts stream 32 ′ which is fed forward to the thickening or other device 28 along with stream 26 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 200 .
In FIGS. 4 and 5 there are illustrated alternate embodiments of the present invention. Like components are numbered as in FIGS. 1-3 above, the discussion of which is incorporated by reference. In the apparatus 300 of FIG. 4, there is provided a flotation cell 75 which treats rejects stream 28 from the first centrifugal cleaning stage along with accepts stream 38 ′ from the third centrifugal cleaning stage. Stream 38 ′ is combined with rejects stream 28 and fed to the flotation stage where hydrophobic material is removed and an intermediate purified stream 28 ′ is produced. Stream 28 ′ is fed to the second stage 14 of centrifugal cleaners. The accepts stream from stage 14 is fed forward as stream 32 ″ and combined with stream 26 in thickening device 28 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 300 .
Apparatus 400 of FIG. 5 resembles apparatus 200 of FIG. 3 except that there is provided a preliminary stage 12 ′ of centrifugal cleaners, the accepts stream 26 ″ of which is utilized as the feed to stage 12 . Rejects stream 28 ″ of stage 12 ′ is combined with rejects stream 28 of stage 12 and fed to flotation stage 75 . Accepts stream 32 ′ of the second stage cleaners is fed forward with accepts stream 26 of stage 12 . The hydrophobic rejects ( 21 ′) from flotation stage ( 75 ) are removed from system 400 .
EXAMPLE
Pilot plant trials showed that flotation cells such as the Comer Cybercel® can successfully deink secondary centrifugal cleaner rejects, with better results obtained if the consistency is kept close to 0.6%. Consistency refers to weight percent fiber or associated solids such as ash unless the context indicates otherwise. Results on 42% office waste (Grade A) and 100% office waste (Grade B) are shown in Table 1.
TABLE 1
Pilot Plant Results for Brightness Gain, Dirt + Ash Removal Efficiency
on Grades A and B at Halsey and Results Used in Simulation Models
Grade:
A
B
Model
Consistency:
0.69%
0.90%
0.62%
Brightness Gain:
18.5%
5.3%
Dirt Removal:
77-89%
65-87%
80%
Ash removal:
63%
64%
64%
A simulation model was used to calculate the impact of a Comer Cybercel® flotation cell to deink forward cleaner rejects on solids loss, ash removal and on removal efficiency of mid-dirt (>150 microns) from a 1 st washer to the deinked pulp (while running grade B at 336 tpd at the 1 st washer):
TABLE 2
Impact of Flotation Cell on Solids Loss, Ash Loss, and Mid-dirt
Removal Efficiency
(according to the Simulation Model for 6 different configurations on
Grade B)
Example
Solids loss
Ash loss
Mid-dirt Eff.
1
No Flotation cell
8.9 tpd
0.8 tpd
96.1%
2
Flotation cell on 2 nd
2.7 tpd
0.9 tpd
97.0%
stage Rejects
3
Flotation cell on
6.7 tpd
1.9 tpd
97.4%
1 st stage Rejects
4
As 3 with 50% eff. in
6.7 tpd
1.9 tpd
97.7%
1 st stage
5
Flotation cell on 1 st
8.9 tpd
1.9 tpd
97.7%
stage Rejects +
3 rd stage accepts, 44%
eff. in 1 st stage
6
Flotation cell on two
11.8 tpd
2.8 tpd
98.5%
1 st stages
The following indicators were used to evaluate the performance of the pilot plant:
feed consistency.
brightness gain of handsheets from accepts compared to feed.
Dirt removal efficiency of small dirt (<150 microns), mid-dirt (>150 microns) and large dirt (>200 microns).
Ash removal efficiency.
The results in Table 3 below for examples 7-14 (duplicate runs) show that even at 0.90% feed consistency it was possible to obtain 5.3% points brightness gain, 73% mid-dirt removal efficiency and 64% ash removal on Grade B. Operating the flotation cell at 0.69% consistency on Grade A, it was possible to obtain 8.1% points brightness gain, 79% mid-dirt removal efficiency and 63% ash removal.
TABLE 3
Comer Pilot Plant Results on 2 nd stage Cleaner Rejects
Feed
Brightness
Dirt + Ash Removal %
Example
Anal.
Cons. %
Ash %
Gain
Small
Mid
Large
Ash
Comments
Grade B
7
1
0.86
3.3
88
71
64
2
4.4%
5.8
87
74
65
59
Accepts = 90% > 200 m.
8
1
0.88
5.4
87
74
67
2
3.9%
4.6
86
69
57
52
Accepts = 99% > 200 m.
9
1
0.88
6.3
88
78
74
2
5.9%
5.0
87
73
66
68
10
1
0.98
5.9
89
74
61
3.8%
5.7
86
69
63
77
Average
0.90
4.5%
5.3
87
73
65
64
Grade A
11
1
0.53
7.3
—
—
—
2
15.9%
9.4
92
78
72
Accepts = 95% > 200 m.
12
1
0.83
4.2
88
70
60
70
2
17.8%
8.2
87
70
64
Accepts = 90% > 200 m.
13
1
0.70
8.6
89
88
92
53
2
16.5%
8.0
89
80
80
Accepts = 74% > 200 m.
14
1
—
8.7
91
85
87
67
2
23.8%
10.4
89
85
85
Average
0.69
18.5%
8.1
89
79
77
63
The effect of incorporating a flotation stage in accordance with the present invention into a multistage forward cleaner system was evaluated with a computer model with respect to the systems illustrated in FIGS. 1-5. Results are summarized in the tables below. DIP refers to deinked pulp and DRE refers to dirt removal efficiency.
TABLE 4
System of FIG. 1 - Conventional Multi-Stage Cleaner System
SUMMARY
Flow
Cons.
Ash
Ash
Dirt > 150
Dirt > 150
gpm
%
STPD
%
STPD
ppm/1.2 g
m 2 /day
Washer
Thick Stock
540
10.37
335.7
2.53
8.5
720
3310
DWw
4272
0.03
7.7
7
0.5
1504
158
Gyro
Accept
4812
1.19
343.4
2.63
9.0
738
3468
Gyro
Accept
4812
1.19
343.4
2.49
8.55
738
3468
Dil. Water
4741
0.03
8.5
7.00
0.60
1504
176
Total in
9553
351.9
9.15
3644
1 st Stage Cleaner
Accept
9492
0.60
343.0
2.43
8.34
596
2798
Total out
Accept
9492
343.0
8.34
596
2798
Diff.
In-out
60
8.9
0.8
846
5 th Stage Cleaner
Rejects
60
2.46
8.9
9.04
0.80
6957
847
Total
Rejects
60
8.9
0.8
847
Cleaner to Press DRE:
30.0% DRE
Dil. Water
Out
9334
0.03
16.8
Press
Out
158.5
35.1
326.2
1.9
6.2
417
1863
Press to DIP DRE:
93.3% DRE
DIP
28
PROCESS
WASHER - DIP
96.1% DRE
TABLE 5
System of FIG. 2 - Multi-Stage Cleaner System with Flotation Cell on 2 nd Stage Rejects
SUMMARY
Flow
Cons.
Ash
Ash
Dirt > 150
Dirt > 150
gpm
%
STPD
%
STPD
ppm/1.2 g
m 2 /day
Washer
Thick Stock
540
10.37
335.7
2.53
8.5
720
3310
DWw
4272
0.03
7.7
0.7
0.1
150.4
16
Gyro
Accept
4812
1.19
343.4
2.49
8.5
708
3326
Gyro
Accept
4812
1.19
343.4
2.49
8.55
708
3327
Dil. Water
5666
0.03
10.2
0.70
0.07
150
21
Total in
10478
353.5
8.62
3348
1 st Stage Cleaner
Accept
9492
0.57
327.0
2.25
7.34
461
2063
3 rd Stage Cleaner
Accept
927
0.43
23.8
1.39
0.33
373
121
Total out
Accept
10419
0.56
350.8
7.68
455
2185
Diff.
In-out
58
2.7
0.9
1164
Comer
Rejects
42
0.93
2.3
34.77
0.81
32762
1050
5 th Stage Cleaner
Rejects
16
0.36
0.3
32.88
0.11
23680
113
Total
Rejects
58
2.7
0.9
1163
Cleaner to Press DRE:
30.0% DRE
Dil. Water
Out
10261
0.03
18.5
Press
Out
158.5
35.1
332.4
1.9
6.3
318
1449
Press to DIP DRE:
93.3% DRE
DIP
21.3
PROCESS
WASHER - DIP
97.0% DRE
TABLE 6
System of FIG. 3 - Multi-Stage Cleaner System with Flotation Cell on 1 st Stage Rejects
SUMMARY
Flow
Cons.
Ash
Ash
Dirt > 150
Dirt > 150
gpm
%
STPD
%
STPD
ppm/1.2 g
m 2 /day
Washer
Thick Stock
540
10.37
335.7
2.53
8.5
720
3310
DWw
4272
0.03
7.7
0.7
0.1
150.4
16
Gyro
Accept
4812
1.19
343.4
2.49
8.5
708
3326
Gyro
Accept
4812
1.19
343.4
2.49
8.55
708
3327
Dil. Water
7449
0.03
13.4
0.70
0.09
150
28
Total in
12261
356.8
8.64
3355
1 st Stage Cleaner
Accept
9492
0.50
282.9
2.13
6.04
443
1715
2 nd Stage Cleaner
Accept
2679
0.42
67.1
1.12
0.75
191
175
Total out
Accept
12171
0.48
350.1
6.79
394
1890
Diff.
In-out
90
6.7
1.85
1465
Comer
Rejects
74
1.45
6.4
25.91
1.66
15279
1337
5 th Stage Cleaner
Rejects
16
0.28
0.3
69.31
0.19
34056
128
Total
Rejects
89
6.7
1.85
1465
Cleaner to Press DRE:
30.0% DRE
Dil. Water
Out
12012
0.03
21.6
Press
Out
158.5
35.1
328.5
1.9
6.2
276
1241
Press to DIP DRE:
93.3% DRE
DIP
18.5
PROCESS
WASHER - DIP
97.4% DRE
TABLE 7
System of FIG. 4 - Multi-Stage Cleaner System with Flotation on 1 st St. Rejects + 3 rd St. Accepts
SUMMARY
Flow
Cons.
Ash
Ash
Dirt > 150
Dirt > 150
gpm
%
STPD
%
STPD
ppm/1.2 g
m 2 /day
Double-dirt
Washer
Thick Stock
546
10.37
339.5
2.51
8.52
1489
6921
DWw
4266
0.015
3.8
0.7
0.0
300
16
Gyro
Accept
4812
1.19
343.4
2.49
8.55
1476
6937
Gyro
Accept
4812
1.19
343.4
2.49
8.55
1476
6937
Dil. Water
7543
0.015
6.8
0.70
0.05
300
28
Total in
12355
350.1
8.60
6965
1 st Stage Cleaner
Accept
10100
0.46
279.2
2.15
6.01
816
3118
2 nd Stage Cleaner
Accept
2104
0.50
62.9
1.16
0.73
346
298
Total out
Accept
12204
0.47
342.2
1.97
6.74
729
3416
Diff.
In-out
151
8.0
1.9
3549
Comer
Rejects
143
0.91
7.8
23.75
1.85
31464
3347
5 th Stage Cleaner
Rejects
8
0.41
0.2
7.68
0.02
72988
202
Total
Rejects
151
8.0
1.9
3549
Cleaner to Press DRE:
30.0% DRE
Dil. Water
Out
12045
0.015
10.8
Press
Out
158.5
35.1
331.3
1.9
6.3
511
2316
double-dirt
Press to DIP DRE:
93.3% DRE
DIP
34
double-dirt
PROCESS
WASHER - DIP
97.7% DRE
Note:
Mid-dirt level at the Gyro was doubled from 738 to 1476 ppm in this simulation, which results in double-dirt figures at the press and in the DIP. (Divide by 2 for comparison with simulations in Tables 4-6).
TABLE 8
System of FIG. 5 - Multi-Stage Cleaner System with Flotation Cell on both 1 st Stage Rejects.
SUMMARY
Flow
Cons.
Ash
Ash
Dirt > 150
Dirt > 150
gpm
%
STPD
%
STPD
ppm/1.2 g
m 2 /day
double-dirt
Washer
Thick Stock
546
10.37
339.5
2.51
8.5
1489
6920
DWw
4266
0.015
3.8
0.7
0.0
300
16
Gyro
Accept
4812
1.19
343.3
2.49
8.5
1476
6935
Gyro
Accept
4812
1.19
343.4
2.49
8.55
1476
6937
Dil. Water
7431
0.015
6.7
0.70
0.05
300
27
Total in
12243
350.0
8.60
6964
1 st Stage Cleaner
Accept
8417
0.44
223.0
1.89
4.21
523
1596
2 nd Stage Cleaner
Accept
3619
0.53
115.3
1.36
1.56
388
612
Total out
Accept
12036
0.47
338.3
5.77
477
2208
12036
0.55
400.0
Diff.
In-out
208
11.8
2.8
4756
Comer
Rejects
192
0.99
11.4
24.65
2.81
28167
4389
5 th Stage Cleaner
Rejects
16
0.39
0.4
8.54
0.03
71490
367
Total
Rejects
208
11.8
2.8
4756
Cleaner to Press DRE:
30.0% DRE
Dil. Water
Out
11856
0.015
10.7
0.70
0.1
Press
Out
180.0
35.16
327.6
1.74
5.7
334
1497
379.5
double-dirt
Press to DIP DRE:
93.3% DRE
DIP
22
double-dirt
PROCESS
WASHER - DIP
98.5% DRE
Note:
Mid-dirt level at the Gyro was doubled from 738 to 1476 ppm in this simulation, which results in double-dirt figures at the press and in the DIP. (Divide by 2 for comparison with simulations in Tables 4-6).
|
A hybrid system for processing papermaking fibers includes a multistage array of forward cleaners coupled with a flotation cell which increases overall efficiency of the system. In a typical embodiment, a first rejects aqueous stream from a first stage bank of centrifugal cleaners is treated in a flotation cell before being fed to a second stage bank of centrifugal cleaners.
| 3
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims the priority of provisional U.S. Patent application Ser. No. 60/025,187, filed Sep. 10, 1996.
BACKGROUND
This invention was made in part with support from the National Science Foundation Grant Number DMR 9315914.
The present invention relates to a process for forming high quality crystalline refractory materials, particularly gallium (Ill) nitride (GaN), from solid precursors. GaN is a material newly available for use in the optoelectronics industry fur the fabrication of light-emitting diodes (LEDs) and blue lasers. It is also possible that doped GaN crystals may have utility as semiconductors. A particularly suitable application is the replacement of standard light bulbs in large outdoor displays, traffic lights and street lighting by GaN LEDs. GaN crystals, when properly activated, fluoresce producing a bright blue glow which is about 60 times brighter than the best GaP based yellow-green LEDs and many times brighter than a standard light bulb which it would replace. Further, a GaN LED display would have an operating life far in excess of the standard light bulb.
Currently, bulk quantities of high purity, polycrystalline gallium nitride are not available. Current techniques to produce such materials require maintaining reactants at high temperatures and pressures for long periods of time. Prior attempts to manufacture GaN by reacting gallium iodide with lithium nitride, which appears to be a suitable approach, produces elemental Ga, nitrogen and Lil and not GaN. Thus there is a need for a low cost, rapid process to produce large quantities of powdered crystalline materials for use in such applications as lighting, signal displays, and flat screen displays for computers and television screens.
SUMMARY
These needs are met by the present invention which comprises a low temperature process for directly forming crystals of refractory nitrides by blending dry reactants in an oxygen and moisture free environment, placing the reactants in a sealed vessel, pressurizing the reactants to in excess of 5 kilobars (5000 atmospheres) and rapidly exposing the reactants to a temperature in excess of about 225° C. The soluble salt by-products are then extracted from the resultant mixture, leaving high purity crystals of the nitride in the form of a fine powder.
The invention can be used for preparing a wide variety of refractory materials. However, it is particularly suitable for preparing gallium nitride (GaN). In a first embodiment Gal 3 is mixed with Li 3 N, the mixture is placed in a pressure vessel and heated by exposure to a resistively heated wire. It was discovered that performing this reaction at pressures in excess of 5 kbar resulted in GaN instead of elemental gallium and nitrogen.
DRAWINGS
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and accompanying drawings, where:
FIG. 1 is a front schematic view of an apparatus used to perform the process embodying features of the invention.
FIG. 2 is an enlarged exploded front schematic view of a first type of reaction chamber used with the apparatus of claim 1.
FIG. 3 is an enlarged exploded front schematic view of a second type of reaction chamber used with the apparatus of claim 1.
FIG. 4 is an X-ray diffraction pattern elicited from the solid products of the solid-state metathesis reaction at ambient conditions of Gal 3 and Li 3 N.
FIG. 5 is an X-ray diffraction pattern elicited from the solid products of the solid-state metathesis reaction at 45 kbar of Gal 3 and Li 3 N.
FIG. 6 shows the photoluminescence spectra at 298 K and 20 K of a GaN sample produced at 45 kbar.
DESCRIPTION
It has been discovered that high quality, pure, refractory crystalline materials, particularly refractory nitrides and more particularly gallium nitride, can be produced by a solid-state exchange (metathesis) reaction when conducted in a controlled environment at high pressures with initial temperatures being ambient. FIG. 1 shows an apparatus 10 used for performing this reaction. The apparatus 10 is a hydraulic press which includes an upper and lower piston 12, 14 capable of applying pressure on a reactant mixture placed within a reaction fixture 16 positioned between the juxtaposed faces 18, 20 of the upper and lower pistons 12, 14.
FIG. 2 is a first example of a reaction fixture 16 suitable for use to perform the process of the invention. The reaction fixture 16 consists of upper and lower anvils 22, 24, commonly referred to as Bridgman anvils, and washer 26 placed therebetween. The anvils 22, 24 generally include a centrally located tungsten carbide core or pin 28 of a high strength metal which, for a particular embodiment of the invention, is electrically conductive. In use, the anvils 22, 24 are arranged with an exposed end 30 of each facing each other, the washer 26 being placed with the hole 32 between and in the center of the anvil pins 28 to define a space therebetween which functions as a reaction chamber 34. The assembled reaction fixture 16, with the reactants 50 placed in the reaction chamber 34, is then placed between the pistons 12, 14 so that application of pressure to the pistons 12, 14 exerts pressure on the pins 28 and, in turn, the reactants placed within the hole 32 in the washer (ie, the reaction chamber 34).
Typical dimensions for relevant portions of the reaction fixture 16 using the Bridgman anvils 22, 24 are an anvil pin exposed end 30 of 3/8 inches diameter and an Inconel washer 26 having a thickness of 0.393 inches (1 mm), the centrally located hole 32 having a diameter of 3/16 inch (0.1875 inch).
In a second version of the reaction fixture 16, shown in FIG. 3, the anvil exposed ends 30 have a diameter of 0.5 inch. In place of the washer 26, a thick retaining ring 36 with a central opening having upper and lower tapered surfaces 38, 40 and a circular, vertical central portion 42 of 0.560 inch in diameter is used. The upper and lower tapered surfaces 38, 40 mate with similarly tapered surfaces on the upper and lower anvils 22, 24. Prior to assembly, electrically insulating, pressure sealing tapered rings made of pyrophillite 46 are placed between the surfaces to be mated and an insulator 48 is placed between the upper and lower surface of the assembly and the pistons 12, 14 of the press 10. When the fixture is assembled a circular reaction chamber 34 of 0.560 inch in diameter and 0.150 inch thickness is created between the components.
Using prior art techniques, in which the reactants are reacted under ambient conditions for extended periods of time, TaCl 5 has been reacted with Li 3 N to produce hexagonal phase TaN with only a trace of the cubic phase.
3TaCl.sub.5 +5Li.sub.3 N→3TaN+15LiCl+N.sub.2
Using the process and apparatus described above and operating at approximately 30 kbar or greater the same reaction produces primarily cubic phase TaN with only a trace of the hexagonal phase.
It has been found that the process and apparatus described above can also be used to synthesize products which are not thermodynamically favored using the same reactants at ambient conditions. GaN can not be formed by solid-state metathesis reactions under ambient conditions. Instead, elemental Ga and nitrogen gas are produced according to the formula:
Gal.sub.3 +Li.sub.3 N→Ga+1/2N.sub.2 +3Lil
along with various soluble compounds of gallium, such as oxides. The solid reaction product of the ambient reaction, all of which are soluble in aqueous or acid solutions, has the X-ray diffraction pattern shown in FIG. 4. This is consistent with the absence of GaN in the product.
It has been found that when this reaction is performed using the apparatus and process described above under high pressure conditions (25-40 kbar), GaN is preferentially produced instead of Ga and N 2 gas. FIG. 5 shows the X-ray diffraction pattern for the nonsoluble reaction product. This material, which has been determined to be pure crystalline GaN, fluoresces with an intense blue violet glow, the photoluminescence spectra thereof being shown in FIG. 6.
The high quality of the gallium nitride produced by metathesis under 4.5 GPa confining pressure is apparent in the photoluminescence spectra shown in FIG. 6. The excitation source is 5 ns, 20 μJ pulse of 266 nm radiation. The room temperature 298 K spectrum (FIG. 6, bottom) reveals only the 3.38(3) eV band gap characteristic of bulk gallium nitride. The low temperature (20 K) spectrum (FIG. 6 upper curve) is also consistent with high quality bulk GaN with a sharp excitonic transition at 3.45(3) eV and lower energy features originating from known donor-acceptor pair recombination. The photoluminescence measurements do not show either size effects or surface states, consistent with micron-scale, rather than nano-scale, crystallites. This is confirmed by scanning electron microscopy and a negligible amount of line broadening measured in the X-ray diffraction pattern (FIG. 5) when compared to an external silicon standard.
The high pressure solid-state metathesis process incorporating features of the invention, has also been shown to produce Si 3 N 4 according to the formula:
3Sil.sub.4 +4Li.sub.3 N→Si.sub.3 N.sub.4 +12Lil
These reactants produce a totally different product under ambient conditions.
EXAMPLE 1
GaN was prepared using the apparatus shown in FIGS. 1 and 2 and described above. The Inconel washer 26 was coated with a paste 52 composed of magnesia (MgO) and alumina (Al 2 O 3 ) in an epoxy binding material to electrically insulate the washer from the two anvils 22, 24. A pellet of reactants 50 was prepared by intimately mixing 0.08353 g of Gal 3 and 0.00646 g of Li 3 N in a moisture free helium atmosphere and the mixture was placed within the hole 32 in the washer 26 with a conductive fine gauge iron wire 54 vertically arranged through the center of the pellet 50 such that when placed between the anvils 22, 24 the anvils are in contact with the opposite ends of the wire 54. While maintaining the inert atmosphere around the pellet 50 the reaction fixture 16 was assembled, placed in the press 10 with the ends of the hydraulic pistons 18, 20 in the press electrically insulated from the anvils by a PVC sheet 48 (see FIG. 3), and 45,227 lbs force was applied to the 3/8 inch anvils 12, 14, resulting in approximately 28.2 kbar being applied to the pellet 50. An electrical current (0.5 to 1 amp) was then applied to the anvils via copper leads 56 (see FIG. 3), the current flowing through the iron wire 54 in the center of the pellet 50 causing the wire 54 to heat to greater than 227° C., the reaction occurring and being complete in a few seconds. The fixture was then disassembled, the powdered product washed with water and acid to remove all soluble salts produced in the reaction and the insoluble material collected, which was approximately 30% w of the reaction product, and analyzed. The X-ray diffraction pattern and photoluminescence spectra of the collected insoluble material is shown in FIGS. 5 and 6.
EXAMPLE 2
GaN was prepared using the apparatus 10 shown in FIGS. 1 and 3 and described above. The upper and lower tapered surfaces 38, 40 of the thick retaining ring 36 were electrically insulated from the twn anvils 22, 24 by tapered pyrophyllite insulating rings 46. A pellet of reactants 50 was prepared by intimately mixing 1.6059 g of Gal 3 and 0.1241 g of Li 3 N in a moisture free helium atmosphere and the mixture was placed within the central vertical portion of the ring 36 with a 1.5 cm length of a conductive fine gauge iron wire 54 vertically arranged through the center of the pellet 50 such that when placed between the anvils the anvils 22, 24 are in contact with the opposite ends of the wire 54. The pellet 50 had a volume of about 0.0369 in 3 . While maintaining the inert atmosphere around the pellet 50 the reaction fixture 16 was assembled, placed in the press 10 with the ends of the hydraulic pistons 18, 20 in the press electrically insulated from the anvils by a PVC sheet 48, and force was applied to the anvils 22, 24. Several different experiments were run with pressures of from 84,530 to 127,000 pounds of force applied to the 1/2 inch diameter anvils, creating a force on the pellet 50 of from 29.7 to 44.8 kbar. An electrical current (0.5 to 1 amp) was then applied to the anvils 22, 24, the current flowing through the iron wire 54 in the center of the pellet 50 causing the wire 54 to heat to greater than 227° C., the reaction occurring and being complete in a few seconds. The fixture was then disassembled, the powdered product washed with water and acid to remove all soluble salts produced in the reaction and the insoluble material collected, which was approximately 30% w of the reaction product, and analyzed. The X-ray diffraction pattern and photoluminescence spectra of the collected insoluble material in each experiment was substantially as shown in FIGS. 5 and 6.
To demonstrate the potential for device fabrication, pulsed laser deposition (PLD) of the resultant GaN powder was used to grow thin polycrystalline GAN films on MgO substrates. A pressed pellet of GaN powder was used as a rotating target in a vacuum chamber with a pressure ≦5×10 -8 Torr during growth. The target was preablated to remove any surface contaminants. A 50 ml pulsed Eximer laser (248 nm) with a fluence of˜211/cm 2 at a pulse repetition rate of 1 Hz for 4 hours enable films of 800 Å thickness to be grown on a MgO substrate heated to 580° C. A bright blue photoluminescence generated is a secondary reflection from the GaN. The primary, bright reflection is a white spot. Although the high energy pulsed laser caused irreversible damage to the thin film after 1,000 laser shots, the photoluminescence spectrum (FIG. 6) reveals the signature of GaN with a good signal to noise ratio.
It is believed that the process described above can be used to produce the preferred forms of many other crystalline refractory materials such as rhombohedral or cubic BN rather than the more thermodynamically favored phases (under ambient conditions) of these materials.
Although the present invention has been described in considerable detail with reference to certain preferred versions and uses thereof, other versions and uses are possible. Therefore, the spirit and scope of the invention should not be limited to the description of the preferred versions contained herein.
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A process for forming high quality crystalline refractory materials, particularly gallium (Ill) nitride (GaN), from solid precursors. By blending dry reactants in an oxygen and moisture free environment, placing the reactants in a sealed vessel, pressurizing the reactants to in excess of 5 kilobars (5000 atmospheres) and rapidly exposing the reactants to a temperature in excess of about 225° C. The soluble salt by-products are then extracted from the resultant mixture, leaving high purity crystals of the nitride in the form of a fine powder.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the means and procedure for storage, dispensing, inventorying and patient charting of medications and other medical treatments and equipment. More particularly, this invention relates to a computerized system of integrated means for medication control and inventory, as well as the visual linkage of a patient's image to his or her medical record.
2. Description of the Prior Art
Medical dispensing machines are well-known in the art. In medicine, the existence and use of dangerous narcotics and other medications have led to the development of machines and systems that allow for safe and effective control and monitoring of hospital medications with the least amount of time and inconvenience to the nursing, pharmacy, and physician staff of the facility. Nurses working in a hospital or other care facility must always be careful to record every use and application of medicine or other treatment to the patient. Even with care-giver diligence, there are circumstances which create the potential for error and omission of information in the patient record. In addition, the hospital staff must continually monitor levels of medications and communicate with the hospital pharmacy for resupply of medications.
These same problems exist in long-term care facilities along with additional problems specific to this setting. Whereas medicine supplies are generally owned by the hospital until administered, patients in long-term care facilities individually own all medications which are used on a regular basis. Furthermore, whereas resupply in a hospital generally occurs from one central store e.g. the hospital pharmacy, patients in long-term care facilities obtain their medicines from the supplier of their choosing. In the extreme case, this supplier may be different for each medication they require. At the long-term care facility these medications have to be monitored and reordered in a timely fashion. This creates three distinct problems for the long-term care facility. The first is the proper timing for reordering a medication. The second is the direction of an order to the correct source of resupply. The third is the segregation and control of patient-owned supplies and medications. These three problems differ from distribution and control problems in hospitals and require different automation systems to address them.
Whether a person is a short-term hospital patient or a long-term resident in a care facility, the potential for medication error is always a factor with which care facilities struggle. The potential for patients to receive the wrong medication is always an issue. Some patients may receive improper medications because they have changed rooms and their chart has not yet moved, or the chart has been misplaced, or mixed up with another patient's medical record. Although this is not an overwhelming cause of hospital error the potential for error is great enough to require further minimization of risk.
One such attempt to control the dispensing and storage of medication can be seen in U.S. Pat. No. 4,967,928 to Carter. This patent sets forth a means and a method for dispensing medicines including narcotics on the nursing unit floor. Carter discloses a cart wherein a computer is positioned. The computer has memory and various input devices such as a card reader, a keyboard, and a barcode reader. The cart has a cabinet linked to it which is divided into two sections, a locked section which houses narcotics and a second which houses other medications. The computer controls the output of medications, including narcotics, and maintains a tally on the used medicines. This system is effective to control access to medications and to reduce theft or loss of controlled substances, but its capabilities do not rise to the level of those of the claimed invention. Carter does not allow for monitoring of medications owned by the patient as would be required in an extended-care facility. Further, there is no mechanism of control or charting between the patient's record and the automated system. No automatic reordering exists in Carter's invention and there is no identifiable way to connect or reduce error in dispensing medicine to the patient.
In U.S. Pat. No. 3,917,045 to Williams et al., the invention includes a locked cabinet housing a plurality of removable and refillable cartridges. Each cartridge has the ability to store a plurality of individual, identical drug doses which can be sequentially dispensed on demand. The doses are dispensed in response to information input into the machine. Although Williams et al. discloses an apparatus which is effective in storing and dispensing, there is no mechanism to accurately protect against the error problems such as incorrect patient identification and reordering.
Thus, there remains a need for a medication dispensing system which not only controls the dispensing of dangerous narcotics, but controls the proper timing for reordering a medication, directs the order to the correct source of resupply, and segregates and controls patient-owned supplies and medication.
SUMMARY OF THE INVENTION
The invention is an automated medication monitoring, dispensing and reordering system which incorporates the ability to reduce error by presenting patient images on the system. Further, the invention includes the capability of monitoring and evaluating the medication inventories, to automate and optimize the reorder process, thereby reducing the financial burden on the user. The system includes a plurality of computers which are linked together to form a network. Said computers are capable of communicating together to provide the best and most effective method of monitoring a patient's medication needs as well as reducing the potential for human error and maintaining an accurate record of the patient's treatment and progress.
The system includes a mobile charting center computer which accompanies the nurse and mobile stores of patient-owned medications and supplies on medication or treatment rounds. This mobile charting center stays in communication with other system computers via a radio frequency data link. The mobile charting center computer is the primary input center for all patient activity such as medication usage. When a nurse extracts and administers medications or treatments, the activity is recorded in a mobile charting center memory and is communicated to other system computers. This electronic record allows the patient-owned medication stocks to be debited. The automated reorder process is triggered by a decrease in stock below a preset threshold level.
The system includes a site computer. This site computer has two main functions. First, it acts as an intermediary in the processing of prescriptions, and second as an archiving system for patient pictures and wound images. The site computer routes data including prescriptions and pictures to all devices within the network.
The system includes a supplier computer. It is capable of serving multiple facilities and is generally located at a supplier warehouse. The supplier computer receives resupply orders communicated from the charting center computers or site computers. Additionally, it provides a means for the supplier to input progress toward satisfying orders. Said progress is communicated to the charting center and site computers thereby eliminating the need for costly and time consuming telephone follow-up.
Any single system component is able to integrate with numerous other complementary components. This provides a system able to solve the complex resupply problems associated with the long-term care health delivery system.
Activity, usually by a nurse, at the charting center activates the reorder monitoring process by reducing the level of medication with each dosage. When a medication has been reduced below a predetermined point then the reorder process is activated. The system has been programmed to determine what that point is for each medication based on the type of prescription and the patient's requirement for that medication. When the charting activity brings a medication below said point, a reorder transaction is generated and is transmitted to the site computer. The site computer receives the order and routes that order to the correct supplier computer as well as the other charting centers in its area. The appropriate supplier is determined by factors, such as the patient's insurance provider, preferred vendor, type of supply or medication, and cost variance.
The supplier computer receives the request from the site computer and forwards the information to the supplier's host system. When the order is sent the supplier computer immediately receives the order status back from the supplier system and informs the correct facility of the order status so that the facility will know the order status at all times. When an order is filled the supplier's host informs the supplier computer of the impending delivery of the product. This information is forwarded to the site computer by the supplier computer. When the medication or supply is received by the facility, the nurse or other appropriate person, checks in the supply using the charting computer or site computer and closes out the request system-wide.
Images of the patient are incorporated into the system to reduce the potential for error when providing medication, as well as providing a tool whereby care-givers can quickly familiarize themselves with their patients and thereby promote a more comfortable and secure atmosphere for the patient. Such a system improves the overall experience of the patient in a facility. A digital camera is intermittently connected to the site computer to download patient images taken upon admission to the facility. The site computer then routes the image to all devices located within the network which maintains or has access to patient information. Thereafter, whenever a patient's record is brought to the screen the patient's photograph is displayed on the screen as well. Therefore, when a nurse or physician treats the patient he has a visual representation of that patient, on the charting computer, for reference.
In much the same way, a physician or nurse can use a digital camera attached to a charting computer to document a wound or injury. The care-giver takes a photograph using the digital camera. The time-stamped electronic photograph becomes part of the patient's record on the charting computer and is sent along to the site computer. The site computer similarly makes the photograph part of the patient's record. Such a system allows a care-giver to monitor the progress of a wound as it heals or conversely as it develops. Another benefit is that a nurse or doctor working an evening shift will be able to accurately document any changes that may occur to a patient throughout the night so that another doctor or nurse may view the exact change which occurred.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features of the invention.
These and other objects of the invention will become more apparent when reading the description of the preferred embodiment along with the drawings that are appended hereto. The protection sought by the inventor may be gleaned from a fair reading of the claims that conclude this specification.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of the preferred embodiment of this invention;
FIG. 2 is a schematic diagram of the various parts of a typical charting center of this invention;
FIG. 3 is a flow chart of activities relating to inventory maintenance;
FIG. 4 is a flow chart of actions undertaken by nursing or physician personnel to dispense medicines or treatments during rounds according to the practices of this invention; and,
FIG. 5 is a flow chart of activities relating to the image linkage to patient records according to the practices of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, where like items are identified by like numerals and labels throughout the five figures, FIG. 1 shows the overall system of this invention to comprise at least one mobile charting computer 1, linked to a site computer 3 by radio telemetry, wherein said site computer 3 has attached thereto a digital camera 5 for use as will be hereinafter more fully explained. A plurality of supplier computers 7 are located, usually one in each warehouse or administration office of a medicine supplier, for the purpose of handling ordering and reordering of medicines to the particular system. Supplier computers 7 are preferably connected to site computer 3 by land lines or satellite communications.
In its preferred embodiment, one site computer 3 is located in the main office of an extended-care facility. Its function is to act as an intermediary in the processing of medicine prescriptions and as an archiving system for patient pictures and wound images. Upon admittance of a patient to an extended-care facility, all existing prescribed medicines are entered into the memory of site computer 3 along with the identification of patient-chosen medicine and supply sources, if any. Digital camera 5 is used to take a picture of the new patient and store the digitized picture in its memory unit along with transmitting the medicine and treatment schedule and picture to charting computer 1.
This invention is therefore embodied in a medication inventory, dispensing and reordering system which incorporates the use of visual images of the patient to provide more accurate care with a decreased possibility of dangerous care-giver error.
Charting computer 1 is shown in FIG. 2 to comprise a central processing unit (CPU) 9 that is fed information through a radio frequency data exchange unit 13, and includes a computer keyboard 15, a display monitor 17 and a touch screen input device 19 that allows the user to touch the screen at various locations to activate CPU 9 to undertake various operations such as mark a patient's chart as having a treatment completed or as having given the patient a dose of certain prescribed medicine. CPU 9 also includes a memory (not shown) integral therewith for retaining the appropriate patient photograph, patient prescriptions and medical inventory/order status that was inputted thereto through a radio frequency data link with site computer 3.
Charting computer 1 accompanies the nurse and mobile stores of patient-owned medications and supplies on medication or treatment rounds in the extended care facility. Mobile stores of patient-owned medications and supplies are already known in the art and a well-known example of such is disclosed in U.S. Pat. No. 5,014,875. This mobile store is computer-controlled and retains the medicines and supplies in locked storage to be dispensed under strict control and monitoring thereby providing greater accountability and more timely reordering.
According to generally accepted standards of care, when medications or supplies are administered to a patient the nurse makes a notation onto the patient's paper chart or record, indicating the exact nature of the medication or supply that was administered. Using the present invention, a nurse who provides a medication or supply to a patient, uses charting computer 1. Charting computer 1 requires certain information from the nurse namely nurse identification, password, and patient name before permitting access to the system's charting functions. After providing said required information the nurse may then review, administer, and document the required medication as directed by the patient's chart. Upon completion of this process, charting computer 1 enters the patient care information into the patient's file to indicate the medication was administered, and then updates the inventory list for that particular medication.
Within the aforementioned process, the nurse will note that upon accessing the patient's file there will be a photograph of the patient displayed on monitor 17 for proper identification. The photo identification will eliminate error particularly in the case of a new patient or when a nurse is new to that particular unit. The patient's photograph becomes part of the file when the patient is admitted into the hospital or long-term care facility. During the admission process digital camera 5 is used to take a photograph of the patient. Digital camera 5 is briefly connected to site computer 3 at the facility to transfer the digital image of the patient. Said site computer 3 thereafter routes said patient's photograph to other system components that communicate with said computer. Thereafter, whenever that patient's chart is called to the screen, at any of the charting computers 1 or site computer 3, the patient's photograph is displayed.
In much the same manner, the nurse or physician is able to use digital camera 5 to chart and monitor the treatment of a wound, injury or area of interest. The nurse may take a photograph of the wound using digital camera 5. To do so, digital camera 5 is briefly connected to charting computer 1 to download the image into the patient's record. Said charting computer 1 will first record the photograph and then communicate the photograph to site computer 3. Site computer 3 stores the image in the patient's file and communicates it to all other computers servicing that patient. Thereafter, anytime the file is displayed, the patient's photograph as well as the wound photograph may be displayed for viewing by the medical staff administering treatment at that time. Such a system can create an accurate history of the treatment a patient is given and the progress a wound makes as it is treated.
The benefits of such a system are numerous. Such a system will decrease the likelihood of malpractice claims because it will create an undisputed record of care as well as the development of a wound or injury. Similarly, a nurse or doctor is able to maintain an accurate record on which to seek other opinions by medical professionals who are called in to assist in a particular matter. The benefits to the patient are especially pronounced because a photographic monitoring system relieves the nurse or physician from a written description which can often be vague and may create confusion among care-givers as to what benefit a treatment is having or as to what progress has been made in the patient's care.
As shown in FIG. 3, this invention also contains a system for monitoring and reordering patient supplies and prescriptions. As shown, the physician writes an order for medicine to be administered to the patient. A clerk or other personnel enters this order in detail into site computer 3 where it remains in the memory subject to recall by appropriate personnel. A predetermined reorder point is set for each medication based upon the patient's needs, the type of medication, the quantity of reorder, and the specific supplier chosen by the patient or by the facility. Each time the nurse or administering personnel enters the data into charting computer 1, that accompanies the nurse along with a mobile medication store, and follows that with actually administering the medication, a software program in site computer 3 creates an entry which decreases the medication level toward the predetermined and programmed reorder point.
When the reorder point is reached, site computer 3 automatically places an order through land lines to supplier computer 7, located in the warehouse of the appropriate supplier. Supplier computer 7 notifies the appropriate personnel to fill the order while, at the same time, communicating with charting computer 1 to confirm the order and provide charting computer 1 with a status report on the order.
Upon receipt of the order of medicine at the facility, charting computer 1 notifies the nurse or person in charge and the medicine is loaded into the medications carried on the mobile store. The nurse signifies when the order has been loaded and charting computer 1 updates site computer 3 which updates supplier computer 7 that the order is received and terminating further reordering activity.
The nurse, doctor or other treating personnel then dispenses the medication to the patient according to prescriptions and instructions contained in charter computer and the patient is treated. The system begins monitoring anew and the process is repeated.
When a reorder message is sent by site computer 3 it is done so by radio telemetry. This method of data transmission is important in this part of the system for a number of reasons. First there is the rapidity at which the transmission is made. There may be other charting computers used in the facility and without such rapid transmission of data, there is a chance that another charting computer 1 will be moved into the same area with a different nurse who will re-administer the same medicine resulting in over-medication which has been the cause of some tragic accidents. The radio telemetry is instantaneous and does not require any sort of wires or plugs that would delay it on its rounds. In addition, there are no wires to drag on the floor when using radio telemetry so that the mobile store and charting computer 1 will be handled more safely.
When reorder information is sent to a specific supplier, previous arrangement has already been made to provide only certain information. This results in a savings of time and cost in not having to send a large amount of information that has to be processed into useful information and extraneous information that may cause a mix-up in the order. Extraneous information is not sent because the software program in the site computer already knows what information to send and what not to send.
The use of land lines to transmit these orders over radio telephone is for the purpose of saving costs in transmission. Many calls or orders can be made automatically at times when telephone service costs are minimized such as at night or during off-hours of operation. In addition, a plurality of orders to a specific supplier may be made with the resulting savings to the patient because of bulk ordering. This is important as many facilities are frequently geographically distant from suppliers making telecommunication costs important.
Site computer 3 informs all other charting computers 1 in its service area of the reorder procedure and can inform the facility's host administrative computer as well; this administrative computer may be tied into one or more health maintenance organizations that wish to be provided with up-to-date data on all of its clients in the facility. In this way, the entire network is updated with the reorder information, thereby reducing any likelihood of double ordering. When site computer 3 obtains the reorder request from charting computer 1, it forwards the information to the supplier's computer 7 and receives an order status back from the supplier. The order status is then transmitted from site computer 3 to site computer 3. Site computer 3 then updates all charting computers 3 within its network with the reorder status.
The system is capable of updating all orders status whenever it communicates with the supplier and subsequently transmits that information to site computer 3 which updates the complete network. Previous to this invention, nursing personnel checking on the status of reorders made numerous telephone calls to suppliers and, depending on the time zone in which the supplier was located, found it was difficult for accurate updating. This invention allows the nurse or other personnel at the charting computer to know the latest information on the status of the reorder at any given time and maintain his or her full attention on the patients.
When an order of medication or supplies is actually received in the facility, the nurse who restocks the mobile store accompanying charting computer 1 inputs the delivery information into the system and closes out the reorder request. That information is then routed to site computer 3 which updates the entire system.
As shown in FIG. 4, the nurse brings or rolls the mobile stores cabinet and charting computer 1 up to a patient's bedside. She selects the patient he or she will treat and brings up that patient's status on display monitor 17. Charting computer 1 then brings up the patient's digitized photograph and presents it on monitor 17 so that the nurse can cross-check that he or she has the appropriate chart for the selected patient.
The nurse then verifies the patient's identity and is prompted with the treatments scheduled for that period. He or she may then select the treatment he or she will administer to patent and enter any ancillary clinical data such as temperature, heart rate, etc.
The nurse then administers the appropriate medicine, taking it and whatever supplies he or she requires from the mobile store. As each treatment is completed, the nurse touches monitor 17 to engage touch screen input device 19 and provide an entry that this particular treatment is completed. Each dose of medicine administered at this time causes a debit on the balance of medicine on hand for this patient and begins to drive the inventory downward toward the previously set reorder point.
Charting computer 1 monitors the inputs from the nurse for compliance with all orders of the physician. Should the nurse attempt to close out the patient's chart without completing his or her duties, computer 1 provides him or her with an electronic warning that all administrations are not done and for him or her to continue until they are completed. Should the patient require a treatment not previously programmed, the nurse may use his or her own professional training to determine to provide this treatment and enter it into the record so that the facility, the doctor and any health maintenance organization may become aware of this added treatment and cost. Close control of medication and supplies provided to this patient is maintained while allowing the nurse to utilize his or her nursing skills for the betterment of the patient.
As shown in FIG. 5, the electronic photograph is a very important component in this inventive system. As shown, upon entry of the patient into the facility, he or she is photographed with digital camera 5 and the photo digitized into a stream of electronic bits that are sent to storage in the camera. At the present time, digital cameras are about the size of cellular telephones and use room lighting to take the picture. They are unobtrusive and the patient is not placed in any stressful situation.
Digital camera 5 then is temporarily connected to site computer 3 by a cable where the stored bits of energy making up the digitized picture are transmitted for storage. Camera 5 may be stored on site computer 3 or kept with charting computer 1. Site computer 3 then forwards the digitized photograph to each charting computer 1 by radio frequency data link. This means of transferring the image is necessary because the patient may already have been placed in a room and a nurse is standing by to proceed with an initial treatment. It has occurred that the wrong treatment is given to a patient. This radio frequency data link is instantaneous and will provide the nurse with a quick and efficient way of verifying the identity of the new admittee so that these mistakes do not occur.
When a patient is suffering from a wound, such as a bed sore, camera 5 is useful in taking pictures of the wound so that an accurate picture and history of pictures may be made and fed into charting computer 1 and maintained in the memory so that a real-time analysis may be made of the history of the development or treatment of the wound over time.
While the invention has been described with reference to a particular embodiment thereof, those skilled in the art will be able to make various modifications to the described embodiment of the invention without departing from the true spirit and scope thereof. It is intended that all combinations of elements and steps which perform substantially the same function in substantially the way to achieve substantially the same result are within the scope of this invention.
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A system for monitoring, dispensing and reordering medication to patients who use patient-owned medication, including, in combination, a central site computer including device for receiving and storing therein data relevant to specific patients, their medical needs and the reorder sources of medication they require, at least one mobile charting computer, connected by radio frequency data link to the central site computer and including a central process unit to receive, store and process data received from the central site computer, an electronic camera for obtaining a picture of the patient and joining it with the patient's specific medical needs and his or her reorder sources of medication for storing in the central site computer and transmitting it on demand to the charting computer, and a monitor device connected to the charting computer to display the pertinent data on a specific patient as well as his or her electronic picture so that identification of the specific patient and his or her personal medical needs is confirmed.
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[0001] This invention was made with U.S. Government support under grant NAS 1-20579 awarded by the National Aeronautics and Space Administration. The U.S. Government has certain rights in this invention. The current invention applies to the field of fiber-optic sensors, wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.
FIELD OF THE INVENTION
Background of the Invention
[0002] There are several modern methods for fabricating optical waveguides for the low-loss containment and delivery of optical waves. One such wavequide is optical fiber which slightly higher index of refraction than the surrounding cladding. Typical values for the core diameter are of order 10μm for single-mode fiber operating at communications wavelengths of 1300-1550 nm, and 50 μm or 62.5 μm for highly multi-mode fiber. Whether single-mode or multi-mode, the cladding diameter has most commonly an overall diameter of 125 μm, and a plastic jacket diameter is typically 250 μm for standard telecommunications fiber. The glass core is generally doped with germanium to achieve a slightly higher index of refraction than the surrounding cladding by a factor of roughly 1.003. The jacket is generally plastic and is used to protect the core and cladding elements. It also presents an optically discontinuous interface to the cladding thereby preventing coupling modes in the cladding to other adjacent fibers, and usually plays no significant part in the optical behavior of the individual fiber other than the usually rapid attenuation of cladding modes in comparison with bound core modes.
[0003] As described in the book by Snyder and Love entitled “Optical Waveguide Theory” published by Chapman and Hall (London, 1983), under the assumptions of longitudinal invariance and small index differences for which the scalar wave equation is applicable, the modal field magnitudes may be written.
Ψ( r,φ,z )=ψ( r ,φ) exp{ i (β z -ω t )}
[0004] where
[0005] β is the propagation constant
[0006] ω is the angular frequency
[0007] t is time
[0008] z is the axial distance
[0009] r,φ is the polar trans-axial position along the fiber.
[0010] Single-mode fibers support just one order of bound mode known as the fundamental-mode which we denote as ψ 01 , and which is often referred to in the literature as LP 01 . The transverse field dependence for the fundamental-mode in the vicinity of the core may be approximated by a gaussian function as
ψ 01 ( r ,φ)=exp{−( r/r 01 ) 2 }
[0011] where r 01 is the fundamental-mode spot size.
[0012] Optical fiber couplers, also known as power splitters, are well known in the art, and generally comprise two fibers as described above having their jackets removed and bonded together with claddings reduced so as to place the fiber cores in close axial proximity such that energy from the core of one fiber couples into the core of the adjacent fiber. One such coupler is a fused coupler, fabricated by placing two fibers in close proximity, and heating and drawing them. The finished fused coupler has the two cores in close proximity, enabling the coupling of wave energy from one fiber to the other. A further subclass of fused coupler involves a substantially longer coupling length, and is known as a wavelength discriminator. The characteristics of a wavelength discriminator include wavelength-selective coupling from an input port to a first output port, as well as a second output port. As the wavelength is changed over the operating range of the wavelength discriminator, more energy is coupled into the first output port, and less is coupled into the second output port. The operation of a wavelength discriminator is described in “All-fibre grating strain-sensor demodulation technique using a wavelength division coupler” by Davis and Kersey in Electronics Letters, Jan. 6, 1994, Vol. 30 No. 1.
[0013] Fiber optic filters are well known in the art, and may be constructed using a combination of optical fiber and gratings. Using fiber of the previously described type, there are several techniques for creating fiber optic gratings. The earliest type of fiber grating-based filters involved gratings external to the fiber core, which were placed in the vicinity of the cladding as described in the publication “A single mode fiber evanescent grating reflector” by Sorin and Shaw in the Journal of Lightwave Technology LT-3:1041-1045 (1985), and in the U.S. patents by Sorin U.S. Pat. No. 4,986,624, Schmadel U.S. Pat. No. 4,268,116, and Ishikawa U.S. Pat. No. 4.622,663. All of these disclose periodic gratings which operate in the evanescent cladding area proximal to the core of the fiber, yet maintain a separation from the core. A second class of filters involve internal gratings fabricated within the optical fiber itself. One technique involves the creation of an in-fiber grating through the introduction of modulations of core refractive index, wherein these modulations are placed along periodic spatial intervals for the duration of the filter. In-core fiber gratings were discovered by Hill et al and published as “Photosensitivity in optical fiber waveguides: Application to reflected filter fabrication” in Applied Physics Letters 32:647-649 (1978). These gratings were written internally by interfering two counter propagating electromagnetic waves within the fiber core, one of which was produced from reflection of the first from the fiber end face. However, in-core gratings remained a curiosity until the work of Meltz et al in the late 1980s, who showed how to write them externally by the split-interferometer method involving side-illumination of the fiber core by two interfering beams produced by a laser as described in the publication “Formation of Bragg gratings in optical fibers by a transverse holographic method” in Optics Letters 14:823-825 (1989). U.S. patents Digiovanni U.S. Pat. No. 5,237,576 and Glenn U.S. Pat. No. 5,048,913, also disclose Bragg gratings, a class of grating for which the grating structure comprises a periodic modulation of the index of refraction over the extent of the grating. Short-period gratings reflect the filtered wavelength into a counter-propagating mode, and, for silica based optical fibers, have refractive index modulations with periodicity on the order of a third of the wavelength being filtered. Long-period gratings have this modulation period much longer than the filtered wavelength, and convert the energy of one mode into another mode propagating in the same direction, i.e., a co-propagating mode, as described in the publication “Efficient mode conversion in telecommunication fibre using externally written gratings” by Hill et al in Electronics Letters 26:1270-1272 (1990). The grating comprises a periodic variation in the index of refraction in the principal axis of the core of the fiber, such variation comprising a modulation on the order of 0.1% of the refractive index of the core, and having a period associated with either short or long-period gratings, as will be described later.
[0014] The use of fiber-optics in temperature measurement is disclosed in U.S. Pat. No. 5,015,943 by Mako et al. A laser source is beam split into two fibers, one of which is a sensing fiber exposed to an elevated temperature, and one of which is a reference fiber in an ambient environment. The optical energy from the two fibers is summed together, and an interference pattern results. As the temperature changes, the physical length of the sensing fiber optic cable changes, which causes the interference pattern to modulate. Each modulation cycle represents one wavelength change in length. Counting these interference patterns over time enables the measurement of temperature change.
SUMMARY OF THE INVENTION
[0015] The present invention is directed to an apparatus for the measurement of sensor grating pitch, wherein the change in grating pitch can originate from a strain applied to the sensor grating, or it may originate from a temperature change wherein the sensor grating expands or contracts due to the coefficient of thermal expansion of the optical fiber enclosing the sensor grating. A pair of fibers, each having a sensor grating, is illuminated by a pair of broadband sources coupled through a pair of optical power splitters, and this sensor grating reflects wave energy over a narrow optical bandwidth. Reflected wave energy from the narrow-band sensor grating is passed through a wavelength discriminator, comprising a long-drawn optical coupler. A normalized power ratio comprises the difference in first and second detector power levels divided by the sum of the first and second power level. This intensity ratio is compared to the wavelength discriminator characteristic stored in a controller to look up the wavelength from a normalized power ratio value, and hence the pitch of the sensor grating. As the characteristic of the wavelength discriminator is essentially temperature invariant, this very accurately yields the sensor grating pitch. Comparing this reflected wavelength to the known wavelength of the grating indicates a change in wavelength brought about by either a temperature change or by the presence of a strain. In the case where a second sensor is also monitored, one sensor may be used as a reference to monitor the temperature of the second sensor, which is used to measure applied strain. In this manner, the temperature effect of the strain gauge may be cancelled by using the measured result of the reference sensor. Commutating the two sources in separate non-overlapping intervals enables the independent measurement of temperature, or strain, or any combination of the two.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 a is a prior art grating.
[0017] [0017]FIG. 1 b,c,d show the spectral behavior of the prior art grating of FIG. 1 a.
[0018] [0018]FIG. 1 e is a prior art coupler/wavelength discriminator
[0019] [0019]FIG. 1 f is a section view of the fused area of FIG. 1 e.
[0020] [0020]FIG. 2 is a block diagram of the fiber optic sensor system.
[0021] [0021]FIG. 3 is a block diagram of the controller of FIG. 2.
[0022] [0022]FIG. 4 is a wavelength discriminator.
[0023] [0023]FIG. 5 is a graph of the response of a wavelength discriminator including reflected grating power applied to this wavelength discriminator.
[0024] [0024]FIG. 6 is a graph of the output function of the wavelength discriminator normalized power ratio (P 1 −P 2 )/(P 1 +P 2 ).
[0025] [0025]FIG. 7 is the dynamic state of various internal nodes of the fiber optic sensor system during operation.
[0026] [0026]FIG. 8 is a three-wavelength, temperature/strain sensor.
[0027] [0027]FIG. 9 shows the wavelength detection properties of FIG. 8.
[0028] [0028]FIG. 10 is a multi-wavelength strain/temperature measurement system.
[0029] [0029]FIG. 11 is an alternate wavelength detector for FIG. 10.
[0030] [0030]FIG. 12 is a multi-wavelength strain/temperature measurement system using tunable gratings.
[0031] [0031]FIG. 13 shows the voltage waveforms for FIG. 12.
[0032] [0032]FIG. 14 shows a temperature/strain measurement system having an alternate wavelength discriminator comprising a broadband grating and a splitter.
[0033] [0033]FIG. 15 shows the block diagram of the measurement controller of FIG. 14.
[0034] [0034]FIG. 16 shows the input to the first and second detectors versus wavelength for the measurement system of FIG. 14.
[0035] [0035]FIG. 17 shows a temperature/strain measurement system using a wavelength discriminator comprising a coarse wavelength discriminator and a fine wavelength discriminator.
[0036] [0036]FIG. 18 shows the characteristic transfer function for the fine wavelength discriminator and the coarse wavelength discriminator of FIG. 17.
DETAILED DESCRIPTION OF THE INVENTION
[0037] [0037]FIG. 1 a shows a prior art internal grating filter, comprising an optical fiber having a core 1 , a cladding 2 , and a grating 3 fabricated within the extent of the core 1 . The grating 3 comprises a modulation of the index of refraction of core 1 having a regular pitch 4 , where the grating 3 is used to create short-period grating behavior. For reflection of waves through the grating at wavelength λ b , the short-period grating function is as follows:
Λ b =λ b /2 n
[0038] where
[0039] Λ b =pitch of the desired Bragg grating,
[0040] λ b =conversion wavelength: For short period gratings, λ b is the wavelength for which incident fundamental mode wave energy is converted to counter-propagating (traveling in the opposite direction) wave energy.
[0041] n=effective index of refraction of the fiber, which is dependant on the mode of the propagated wave.
[0042] Examining now the transfer curves for a short-period grating 3 , FIG. 1 b shows the-input source spectrum 7 applied to port 5 , and FIG. 1 c shows the reflected spectrum 8 and grating peak 9 reflected back to port 5 . FIG. 1 d shows the remaining optical energy continuing to port 6 . Filter notch 11 represents wave energy reflected by the short period Bragg grating back to the input port 5 , and is represented as spectrum 8 having peak 9 corresponding to the Bragg wavelength. The use of reflected wave energy at peak 9 is generally not available without the use of an optical coupler or some other device sensitive to the propagating direction of this wave.
[0043] [0043]FIG. 1 e shows a prior art optical coupler. First fiber having a core 12 and cladding 13 is placed in proximity with a second fiber having a core 15 and a cladding 14 . Together, these fibers are heated and drawn to fuse the two fibers into one having a coupling length 16 . FIG. 1 f shows a section view of this fused middle section. Coupling length 16 and separation 17 determine the coupling characteristics of the coupler. If the coupling length 16 is short, a broadband coupler having a coupling coefficient related to separation 17 is formed. This is the typical construction for power splitter configurations. If the length 16 is many wavelengths long, a narrowband coupler is formed, also known as a wavelength discriminator. The characteristics of a wavelength discriminator are similar to those of a coupler, with an additional wavelength dependence, as shown in FIG. 5, which is described later.
[0044] [0044]FIG. 2 shows the present fiber-optic sensor. Measurement system 20 is coupled to fibers 45 and 51 . Each of fibers 45 and 51 has a Bragg grating 46 and 52 respectively. Measurement system 20 further comprises a controller 22 having a first source enable output 24 coupled to first source 36 , which may be any source of optical energy having a spectrum which includes the wavelength of the grating 46 on fiber 45 . A broadband light-emitting diode (LED) would provide an inexpensive broadband source. Similarly, second source enable output 26 is coupled to second source 40 , which has the same requirement of including in its output spectrum the wavelengths of the grating 52 of fiber 51 . Broadband sources 36 and 40 respectively couple energy through standard power splitters 42 and 44 , which provide optical energy to gratings 46 and 52 respectively. The gratings 46 and 52 may be internal Bragg gratings or external short period gratings. The short-period grating has the property of reflecting optical energy at the grating wavelength back to couplers 42 and 44 , where it is split into optical energy provided to cables 41 and 43 to wavelength discriminator 38 , the operation of which will be discussed later in FIG. 4. Output wave energy from wavelength discriminator 38 is separated into a first output on fiber 31 travelling to first detector 30 , which provides a voltage 28 proportional to the input optical level delivered on fiber 31 . Similarly, optical wave energy from the second output 33 of wavelength discriminator 38 is delivered to the second detector 34 , which produces a voltage 32 to controller 22 proportional to the input optical level delivered on fiber 33 .
[0045] [0045]FIG. 3 describes in detail the controller 22 of FIG. 2. Controller 22 further comprises a microprocessor 78 which produces first source enable output 24 and second source enable output 26 . In addition, first detector input 28 and second detector input 32 are processed by buffer amplifiers 62 and 64 respectively, which isolate the detector element from the following electronics, and produce respectively outputs 82 and 84 . These are processed by a difference amplifier 66 to produce a difference output at 86 , which is converted from an analog signal to a digital signal by A/D converter 74 , delivering a digital representation 90 of this signal to microprocessor 78 . Amplifier 68 produces a detector sum output 88 , which is similarly converted to a digital signal 92 by A/D converter 76 , which is also input to microprocessor 78 . A keypad 72 for input and a display 70 are also coupled to the microprocessor 78 , as is an auxiliary interface 80 . Microprocessor 78 may be chosen from several available units, including the PIC16C71 from Micro-Chip. Inc. of Chandler, Ariz., which has the A/D converters 74 and 76 incorporated internally. As is clear to one skilled in the art, many microprocessor choices are available for 78 , including devices with internal or external ROM, RAM, A/D converters, and the like, of which many candidates from the Micro-Chip PIC- 16 family would be suitable. While a particular microprocessor is shown for illustrative purposes, it is clear to one skilled in the art that other units could be substituted for these devices without changing the operation of the sensor. The principal requirements of microprocessor 78 are the ability to control the first and second sources, and to process the values provided by the first and second detectors in a manner which determines the wavelength of the sensor grating.
[0046] [0046]FIG. 4 shows the wavelength discriminator 38 . The wavelength discriminator has a first splitter input port 41 , a second splitter input port 43 , a first detector output port 31 , and a second detector output port 33 . FIG. 5 shows the normalized output of wavelength discriminator 38 for the case where a swept-wavelength input is applied to first splitter input 41 , and no input is provided to second splitter input 43 . Curve 100 shows the output level of first detector output 31 , while curve 104 shows the output level of second detector output 33 . As can be seen from the graph, as the wavelength is varied from 1300 nm to 1316 nm, the first detector and second detector outputs vary in a complimentary manner, such that the sum of the first detector output and second detector output is nearly constant. The wavelength discriminator is a symmetric device, so if no optical signal were applied to first input 41 and a swept wavelength optical signal were applied to second input 43 , curve 100 would show the level of second output port 33 , while curve 104 would show the level of first output port 31 .
[0047] [0047]FIG. 6 shows a plot for normalized power ratio derived from first output curve 100 and second output curve 104 . If these two complimentary curves 100 and 104 are plotted as (P 1 −P 2 )/(P 1 +P 2 ), then the plot of FIG. 6 results, and we may now determine wavelength over monotonic regions such as from 1304 nm to 1312 nm by simply looking up the wavelength given the (P 1 −P 2 )/(P 1 +P 2 ) normalized power ratio. Curve 114 represents the response to first source 36 , and curve 112 represents the response to second source 40 . The advantage of performing this lookup in this ratiometric manner of FIG. 6 as opposed to the absolute output level on the curve 100 of FIG. 5 is that variations in source power are normalized out of the result. Specifically, changes in the output power of sources 36 and 40 would modulate the values shown in plots 100 and 104 of FIG. 5, but not the normalized power ratio shown in the plot of FIG. 6.
[0048] Further examining the operation of the measurement system of FIG. 2, the first measurement is performed with only first source 36 enabled. Optical energy travels through first coupler 42 to fiber 45 , and to grating 46 . Optical energy at the wavelength λ 1 of grating 46 is reflected through fiber 45 back to first coupler 42 , through fiber 41 , where it is presented to wavelength discriminator 38 . No input is present on fiber 43 because second source 40 is not enabled. Optical energy from grating 46 is reflected, for example, at λ 1 =1309 nm, as shown in curve 102 of FIG. 5, and 0.4 volts is generated at 28 by first detector 30 . The second output 33 of wavelength discriminator 38 is applied to the second detector 34 , producing 0.6 volts at 32 as shown in curve 103 of FIG. 5. By now finding the normalized power ratio of (0.4−0.6)/(0.4+0.6)=−0.20, it can be seen that this corresponds to 1309 nm wavelength on curve 114 at point 109 in FIG. 6.
[0049] An entirely separate measurement can be made by disabling first source 36 and enabling second source 40 . In this case, optical energy would leave second splitter 44 through fiber 51 to grating 52 . Optical energy at wavelength λ 2 52 would be returned to second splitter 44 through fiber-optic cable 51 , leave second splitter 44 through fiber-optic cable 43 , entering wavelength discriminator 38 . Analogous to the earlier described processing, first source 36 would be disabled, hence no optical energy would be present in fiber 41 . In the case of wave energy input to fiber 43 instead of fiber 41 , the output characteristic of FIG. 5 would be reversed such that curve 100 would be the output energy on fiber 33 , and curve 104 would represent the output energy of fiber 31 . If the grating 52 were reflecting at λ 2 =1306 nm, then second detector 34 would produce 0.75 volts as shown in curve 108 of FIG. 5. First detector 30 would produce 0.25 volts as shown in curve 106 of FIG. 5. The normalized power ratio of FIG. 6 would be (0.25−0.75)/(0.25+0.75)=−0.5, corresponding to 1306 nm on curve 112 of FIG. 6 at point 107 .
[0050] [0050]FIG. 7 shows the sensor measurement system operating in the earlier-described case where the wavelength of first sensor 46 is λ 1 =1309 nm and the wavelength of second sensor 52 is λ 2 =1306 nm. First, the detector offsets are determined by turning both first source 36 and second source 34 off. This produces the detector offset values OS 1 and OS 2 , which will be necessary to subtract from the power difference and power sum before calculation of the normalized power ratio (P 1 −P 2 )/(P 1 +P 2 ). Thereafter, first source 36 and second source 40 are alternately enabled as shown in FIG. 7. First detector 30 and second detector 34 produce the P 1 and P 2 values shown, and the difference, sum, and the normalized power ratio value of difference/sum are computed as shown, wherein the power difference (P 1 −P 2 ) and the sum (P 1 +P 2 ) represent power quantities after removal of offsets OS 1 and OS 2 , which thereafter form the normalized power ratio (P 1 −P 2 )/(P 1 +P 2 ). If the plot of FIG. 6 normalized power ratio were kept in the memory of the microprocessor, either as a series of interpolated points, or as a power series wherein only the coefficients f 0 , f 1 , f 2 , f 3 . . . fn of a polynomial are stored, and the power
λ ( P1 , P2 ) = f 0 + f 1 [ P1 - P2 P1 + P2 ] + f 2 [ P1 - P2 P1 + P2 ] 2 + f 3 [ P1 - P2 P1 + P2 ] 3 + … + f n [ P1 - P2 P1 + P2 ] n series is of the form
[0051] where
[0052] λ(P 1 ,P 2 )=wavelength as a function of detector power ratio (P 1 −P 2 )/(P 1 +P 2 ).
[0053] It would be possible to convert the given normalized power ratio(P 1 −P 2 )/(P 1 +P 2 ) back to a wavelength λ 1 =1309 nm for the first sensor, and λ 2 =1306 nm for the second sensor. This determination could be done using either a look-up table derived from the normalized power ratio, or by storing the coefficients of a power series based on the normalized power ratio, and thereafter calculating for wavelength based on this power series.
[0054] If the sensors were operating either as temperature sensors or strain sensors, the applied strain or temperature could be computed from the following relationship:
Δλ=α 1 ΔT+α 2 ΔS
[0055] where
[0056] Δλ=change in sensor wavelength
[0057] α 1 =coefficient of thermal change for sensor
[0058] ΔT=change in sensor temperature
[0059] α 2 =coefficient of strain change for sensor
[0060] ΔS=change in sensor strain
[0061] In this equation, the change in sensor wavelength is expressed as the sum of a temperature related change and a strain related change. The coefficients α 1 and α 1 would be stored in the controller along with initial condition values to solve for total strain and total temperature. In this manner, any combinations of strain and temperature could be determined given a change in sensor wavelength and the wavelength discriminator characteristic curve, and first and second detector inputs.
[0062] [0062]FIG. 8 shows a strain/temperature measurement system having a 3-way wavelength discriminator 162 . This system is analogous to the system described in FIG. 2, however, for an n-way wavelength discriminator, the output port associated with the excited port has the response shown in plot 186 , while the remaining ports have the characteristic shown in plot 188 . For example, in the case of FIG. 8, first source 134 sends broadband excitation through first splitter 136 , and wave energy at the example grating wavelength λ 1 =1300 nm is reflected through splitter 136 to wavelength discriminator port 167 . For this case, the output at port 168 has the characteristic shown in plot 186 , while the second output 174 and third output 180 have the responses shown by curve 188 . For λ 1 =1300 nm, the response of the first detector is shown as point 192 , while the second the third detectors have the response shown by point 194 . As before, a normalized plot of the response of curves 186 and 188 is shown in plot 190 . For the case of an n-way wavelength discriminator, the output curve 190 would be
P ( normalized ) = [ P det ( a ) - { P det ( b ) + P det ( c ) … + P det ( n ) } P det ( a ) + { P det ( b ) + P det ( c ) … + P det ( n ) } ]
[0063] Where
[0064] Pdet(a)=output power from excited channel
[0065] Pdet(b) through Pdet(n)=output power from non-excited channel.
[0066] A lookup table constructed from the values of curve 190 would produce the value for λ=1300 nm as shown at point 196 . Similarly, when second source 144 excites grating 150 , wave energy at the exemplar wavelength λ 2 =1305 nm would return through splitter 146 , fiber 173 , and now fiber 174 would contain the response shown in plot 186 . Fibers 168 and 180 would contain wave energy shown in plot 188 , corresponding to point 200 . The normalized power ratio for λ 2 =1305 nm is represented by point 204 of the plot 190 . The case where third source 154 excites grating 160 is shown in third detector response 186 , and first and second detector responses 188 . For the case where third grating wavelength is 1310 nm, the responses of the third detector, first and second detectors, and normalized power ratio are shown in points 206 , 208 , and 210 . It is clear to one skilled in the art that this system is extendable to n ports of measurement, where each port has a source, a splitter, and each splitter port is connected to an input port of an n-way wavelength discriminator. Each output port of the n-way wavelength discriminator is coupled to a detector, and the response of each detector is measured, and the normalized power ratio is formed from the ratio of the difference between the response of an excited port and the responses of all of the non-excited ports, divided by the sum of all of the responses of excited and non-excited ports.
[0067] [0067]FIG. 10 shows a strain/temperature sensor system 211 attached to a fiber 220 comprising a plurality of gratings 224 , 226 , and 230 . These sensors operate as earlier described, but are sequentially applied to various parts of a fiber 220 . Each sensor 224 , 226 , and 230 reflects wave energy at respective unique wavelengths λ 1 , λ 2 , and λ n . Since gratings 224 and 226 have no effect on out-of-band waves at λ n , splitter 218 delivers to fiber 268 the superposition of reflected unique wavelengths λ 1 through λ n . Wavelength separator 236 has broadband outputs which respond only to the range of reflected wavelengths for that given output. For example, output 235 is responsive only to the range of λ 1 , and output 243 is only responsive to the range of λ 2 , and output 249 is only responsive to the range of λ n . This requires that the sensor wavelengths and wavelength separator characteristics be chosen such that isolated response of a given wavelength separator to a given sensor grating wavelength occur. In this manner, output 235 represents exclusively the range of wavelengths of sensor 224 , output 243 represents exclusively the range of wavelengths of sensor 226 , and output 249 represents exclusively the range of wavelengths of sensor 230 . The conversion of the outputs of separator 236 into a detected wavelength occurs as was earlier described in FIGS. 4, 5, and 6 . In this manner, multiple sensors can share a single fiber, as long as each produces a unique wavelength.
[0068] An alternate wavelength measurement apparatus 318 is shown in FIG. 11, which performs the same function as 270 of FIG. 10. While the wavelength measurement apparatus 270 uses a wavelength separator 236 followed by narrowband wavelength discriminators 234 , 242 , and 248 , the wavelength measurement apparatus 318 of FIG. 11 utilizes a broadband wavelength discriminator 316 followed by wavelength separators 312 and 314 . These produce complimentary outputs 296 and 304 for λ 1 , complimentary outputs 298 and 306 for λ 2 , and complimentary outputs 300 and 308 for λ n . Detectors 232 , 240 , 246 , 238 , 244 , and 250 operate in a manner identical to those of FIG. 10.
[0069] [0069]FIG. 12 shows a measurement system 340 connected to fiber 350 , which has a series of sensors 352 , 354 , and 358 , which operate the same as those described earlier in FIG. 10. A single broadband source excites fiber 350 through splitter 348 . Splitter 348 returns aggregate reflected waves from sensors 352 , 354 , and 358 on fiber 356 . A series of tunable filters 362 , 364 , and 368 is coupled to detector 360 . Each of these filters is tuned over a narrow range through the application of a control voltage 372 , 374 , and 378 . In operation, filters 364 and 368 have a voltage applied which reflects wave energy out of the range reflected by the sensors 354 and 358 , enabling the passage of waves reflected by sensor 352 to pass through and on to tunable filter 362 . Tunable filter 362 is swept over its tuning range, and produces a minimum output at detector 360 at the point where the grating 352 matches the tuned filter 362 . Controller 380 has the characteristic of tunable filter 362 stored in memory such that the voltage 372 producing a minimum detected output 370 enables the extraction of corresponding wavelength for λ 1 , Next, tunable filters 362 and 368 are tuned out of the band of grating 352 and 358 , and tunable filter 364 is swept over its range until a detector minimum is found. As earlier, this minimum voltage corresponds to the wavelength λ 2 . This process continues for as many sensor gratings and tunable filters that are present in the system. In practice, there are many ways of fabricating tunable gratings, including the application of a material with an index of refraction which varies with an applied voltage, the application of a tensile force to a fiber having a grating, or the application of a magnetic field to a grating in close proximity to a material having an index of refraction which changes with an applied magnetic field. It should be clear to one skilled in the art that there are many different ways of practicing such tunable filters, wherein an applied control voltage changes the wavelength of reflection of the tunable filter.
[0070] [0070]FIG. 13 shows the waveforms for the system of FIG. 12. Tunable filter control voltage points 390 , 392 , and 394 correspond to the detector minima 396 , 398 , and 400 shown, and therefore enable the recovery of sensor wavelengths λ 1 , λ 2 , and λ n .
[0071] While the foregoing description is drawn to specific implementations, it is clear to one skilled in the art that other embodiments are available. For example, the earlier described functions SUM and DIFF, which relate to the normalized power ratio, could be implemented using operational amplifiers computing these measurements as analog values, or they could be implemented digitally, operating on digitized detector values. These converters could be either integral to the microprocessor, or external, and the sum and difference values could either be computed through direct reading of the values of the detectors, or through reading sum and difference voltages of alternate circuitry. While the multiple sensor system of FIGS. 10 and 12 are drawn to a 3 sensor system, it is clear to one skilled in the art that these could be drawn to arbitrary numbers of channels operating as strain sensors, temperature sensors, or both. There are also many ways of extracting sensor wavelength from the systems described. For clarity, time division processing has been shown, wherein at a particular time, only a single channel of the system is active, and only one particular wavelength value is recovered. In addition to the explicitly described method of time division processing, there are many modulation schemes wherein each of the sensor values is modulated in frequency or amplitude, and later demodulated to recover the desired value. In this manner, all of the channels of the system could operate simultaneously, rather than sequentially. The use of specific examples for illustration and understanding of the operation of the system does not imply an exclusive manner in which these systems could be implemented.
[0072] [0072]FIG. 14 shows a strain/temperature measurement system 20 similar to that of FIG. 2, but with a different wavelength discriminator. In the alternate embodiment of FIG. 14, the elements having the same numbering as those of FIG. 2 perform the same function as earlier described, but the wavelength discriminator now comprises third splitter 400 which has as inputs the previously described fibers 41 and 43 , and has a normalizing output 406 which is wavelength-invariant compared to wavelength determining output 405 . The wavelength-determining output 405 is formed from broad-bandwidth grating 404 , which has an output amplitude varying with wavelength over the tuning range of the sensor gratings, as will be described later. First detector 408 and second detector 410 accept optical inputs 405 and 406 , respectively, and produce electrical outputs 412 and 414 which are proportional to the respective optical inputs 405 and 406 .
[0073] [0073]FIG. 15 shows the controller 401 of FIG. 14, which is similar to the controller of FIG. 3, and has similarly-functioning elements numbered the same as those of FIG. 3, as was described earlier. First detector output 412 drives buffer 416 and produces output 420 , which is digitized by analog-digital converter 424 and is presented as a digital input 428 to microprocessor 78 . Second detector output 414 drives buffer 418 to produce signal 422 which is converted to a digital input 430 by analog-digital converter 426 and delivered to microprocessor 78 .
[0074] [0074]FIG. 16 shows the characteristic response of the wavelength discriminator having a normalizing input 406 , represented by response curve 464 , and wavelength-determining input 405 , represented by response curve 450 . As the reflected wave from grating 46 or grating 52 passes through third splitter 400 , equal amounts of energy are presented into grating 404 , and to normalizing input 406 . As the wavelength applied to third splitter 400 is varied, normalizing output 406 follows the response of curve 464 , while the wavelength-determining input 405 follows the response of curve 450 , in accordance with the characteristic response of broadly tuned grating 404 , whose characteristics are chosen to include a monotonic region from first discrimination wavelength 452 to final discrimination wavelength 454 . In the case where grating 46 is reflecting a wavelength of 1306 nm, curve 460 represents the spectral energy of reflected energy from grating 46 , which is applied to curve 460 to produce an output of approximately 1.0 units. This same reflected response 456 applied to grating 404 having the response of curve 450 and produces an output of approximately 0.25 units. As can be seen from FIG. 16, as long as the range of input wavelength is between first discrimination wavelength 452 and final discrimination wavelength 454 , it is possible to recover the wavelength from curve 450 . By using the ratio of response 450 to response 464 , the effect of intensity variations in first source 36 and second source 40 is removed, as was discussed for the system of FIG. 2. By keeping a copy of the characteristic curve of this normalized function of curve 450 divided by curve 464 in the microprocessor 78 , it is possible to resolve any input wavelength in the range first discrimination wavelength 452 to final discrimination wavelength 454 when given the first detector output 412 and second detector output 414 . As described earlier, this determination can be made by storing the response of curves 450 and 452 in a look-up table, or by specifying the curve as the coefficients of a polynomial, or in many other ways, all of which form representations of the characteristic curves of 450 or the ratio of curve 450 divided by curve 452 .
[0075] [0075]FIG. 17 shows another embodiment 503 of a temperature/strain sensor comprising the old elements of FIG. 2 with a new wavelength discriminator circuit. This new wavelength discriminator comprises third splitter 470 , fourth splitter 488 , a coarse wavelength discriminator 474 , and a fine wavelength discriminator 492 , coarse wavelength first and second detectors 478 and 484 , and fine wavelength discriminator first and second detectors 504 and 498 . The operation of the coarse wavelength discriminator comprising coarse wavelength discriminator 474 , first detector 478 , and second detector 484 is similar to that described in FIGS. 4, 5, and 6 , and has a usable wavelength range matched to that of the sensor grating operating range. However, in addition to the coarse wavelength discriminator, a fine wavelength discriminator comprising fine wavelength discriminator 492 , and first detector 504 and second detector 498 are used, Third splitter 470 and fourth splitter 488 produce the signals for simultaneous delivery to the coarse and fine wavelength discriminators, as all 4 detectors are used simultaneously, although as described earlier, the first source 36 and second source 40 operate during different intervals, or have orthogonal modulation functions which enable the discrimination of the two detector outputs through the use of a modulation function applied to the sources and a demodulation function applied to the detectors.
[0076] [0076]FIG. 18 shows the details of the fine and coarse wavelength discriminators. Curves 516 and 510 represent the optical response of the wavelength discriminator, as measured at fibers 476 and 482 , as well as the detected electrical responses of 480 and 486 to changes in wavelength of sensor 46 or 52 , all of which function as earlier described in the system of FIG. 2. For the case of sensor 46 reflecting optical energy at 1302 nm, fiber 472 carries optical wave energy which is provided to coarse wavelength discriminator 474 . First output optical fiber 476 carries the energy of curve 512 , while second output optical fiber 482 carries the energy of curve 514 . Fine wavelength discriminator 492 has many more cycles in the same monotonic range of coarse wavelength discriminator 474 , as is seen by the periodicity of curves 510 and 516 of the coarse wavelength discriminator, compared to curves 522 and 524 of the fine wavelength discriminator. The monotonic curve of 510 and 516 is necessary over the tuning range of the reflecting gratings 46 and 52 to ensure single-wavelength resolution. The multiple cycles of discriminator 522 and 524 enable the more precise measurement of wavelength when used in combination with the coarse wavelength discriminator 474 . Fine wavelength discriminator is fed by fiber 491 , and has a first output 502 which carries the energy of curve 522 and a second output 496 which carries the energy of curve 524 when excited by the signal of fiber 491 . When the input signal is provided by fiber 493 , the characteristic of the first and second outputs reverse, as was described earlier in FIGS. 4, 5, and 6 . In this manner, sensor 46 reflecting a 1302 nm wavelength produces a first coarse detector response of 512 , a second coarse detector response of 514 , a first fine detector response of 526 , and a second fine detector response of 528 . Sensor 52 reflecting a wavelength of 1311 nm produces a first coarse detector response of 518 , a second coarse detector response of 520 , a first fine detector response of 532 , and a second fine detector response of 530 . As is clear to one skilled in the art, any combination of curve storage methods for maintaining the characteristic curves of 510 , 516 . 522 , and 524 or the difference divided by the sum of curves 510 to 516 , or curves 522 and 524 could be stored using the previously described look-up tables, polynomial coefficients, or interpolated points for use by the microprocessor 78 of the controller 501 of FIG. 17.
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A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.
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INTRODUCTION
[0001] The present invention provides a method of modifying the surface of contact lenses to reduce bacterial, fungal or viral adherence and presence. The method of the invention comprises the coating of a contact lens surface with a sulfated polysaccharide such as heparin to reduce the concentration of microbiological flora as well as the level of bacterial, fungal or viral adherence. The invention further relates to compositions comprising contact lenses for correcting vision deficiencies of the eye coated with a sulfated polysaccharide such as heparin. Contact lens surfaces as provided in accordance with this invention have a coating of sulfated polysaccharide which reduces the adjacent microbiological flora and prevents the adherence of bacteria, fungi or viruses to the lens surface thereby reducing the potential for infection.
BACKGROUND OF THE INVENTION
[0002] Eye care products, such as contact lenses, are susceptible to contamination by ocular pathogens. Such pathogens, including bacteria, fungi, protozoans and viruses, have been found to cause diseases of the eye including infectious keratitis, conjunctivitus and uveitis. Of the approximately 20 million contact lens wearers in the United States, over 12,000 infections are estimated to occur yearly. Thus, wearing of contact lenses poses a risk of serious, painful complications, including corneal ulceration from infection, which can lead to blindness.
[0003] Various agents have been found to be effective in killing or reducing the growth of pathogens. For example, U.S. Pat. No. 4,499,077 discloses an antimicrobial composition for treatment of soft contact lenses comprising an oxidizing agent such as an oxyhalogen compound; and U.S. Pat. No. 4,654,208 discloses an antimicrobial composition for contact lenses including a germicidal polymeric nitrogen compound. In addition, contact lenses may be manufactured to incorporated specific compounds having antimicrobial activities into the lens material. For example, U.S. Pat. No. 5,770,637 discloses contact lenses prepared from polymers that contain metal chelators that make such metals unavailable to pathogens such as bacteria.
[0004] Intraocular lenses have been coated with sulfated polysaccharides, such as heparin, for prevention of coagulation, inflammation and activation of complement as described in U.S. Pat. No. 4,240,163.
[0005] Despite quality manufacturing and sterilizing methods that have reduced inflammation due to mechanical and chemical causes and surface coatings that have reduced inflammation, microbial contamination of contact lenses remains a serious and ever present problem. Thus, methods that lead to the creation of a barrier to preventing bacterial, fungal or viral adherence or penetration of the lens surface are desirable for reducing the potential for ocular infection.
SUMMARY OF THE INVENTION
[0006] The present invention relates to a method of modifying the surface of a contact lens to reduce concentration of adjacent pathogens as well as to reduce bacterial, fungal or viral adherence. The method of the invention comprises the coating of a contact lens surface with a sulfated polysaccharide such as heparin. The invention further provides compositions comprising contact lenses coated with a sulfated polysaccharide such as heparin for reducing the potential of infection. Lens surfaces as provided in accordance with this invention have a coating of sulfated polysaccharide such as heparin which reduces microbial organism concentration and reduces the adherence of bacteria, fungi or viruses to the lens surface.
[0007] Other objects and advantages of the invention will be apparent to those skilled in the art, from a reading of the following detailed description of the preferred embodiments, and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The present invention relates to the coating of the surface of a contact lens with a sulfated polysaccharide such as heparin to reduce bacterial, fungal or viral presence and adherence to said contact lens. The surface of contact lenses including but not limited to soft, hydrophilic hydrogels, soft hydrophobic elastomers, rigid, gas permeable or hard PMMA lenses, may be coated with sulfated polysaccharide to enhance their safety. Further, coating of contact lenses with such sulfated polysaccharides will enhance their hydrophilicity thereby creating a more lubricious surface resulting in a more comfortable contact lens.
[0009] The present invention is directed to a method of preparing contact lenses coated with a sulfated polysaccharide, such as heparin, comprising the steps of first activating the surface of the lens, for example, by exposing an uncoated lens to a plasma to generate a plasma-treated lens having a surface containing amines, carboxylic acids, active free radicals or passive free radicals, and thereafter bonding the sulfated polysaccharide to the plasma-treated lens surface.
[0010] Contact lenses of this invention include hard poly (methylmethacrylate), rigid gas permeable lenses, soft hydrogel lenses and gas permeable silicon based hydrogels. In addition, hydrophobic materials such as silicone elastomers can also be utilized. All these lenses may be coated with a surface polysaccharide such as heparin. Lenses containing collagen can also be treated in the same fashion.
[0011] The coating of the present invention may be bonded to the surface of the lens by any method of bonding well known by those skilled in the art, preferably in such a manner that the coating is bonded to the surface of the lens by means of covalent bonding, ionic attraction, or hydrogen bonding, with covalent bonding being particularly preferred. Either end point and/or midpoint attachment of the sulfated polysaccharide may be accomplished for effective reduction of adhesion. In one particularly preferred embodiment of this invention, heparin is covalently bonded to the surface of the lens by means of an end-group attachment of heparin to the lens surface.
[0012] In another particularly preferred embodiment, the lens surface is first treated with a plasma to generate an amine-containing surface, a carboxylic acid containing-surface, or an active or passive free radical-containing surface, and heparin compounds or derivatives thereof are thereafter employed to coat the lens surface.
[0013] In one embodiment, plasma treating is accomplished by setting the lens in a gaseous atmosphere such as an oxygen rarefied atmosphere, and subjecting the lens to an electromagnetic field for a given period of time. In one embodiment the lens may be subjected from 1-10 minutes, for example 2 minutes to an electromagnetic field having a frequency in the range of 1-50 MHZ, for example about 10-15 MHZ with a corresponding power range of 10-500 W/cm 2 , for example about 100 W/cm 2 .
[0014] In another embodiment, in accordance with techniques well known to those skilled in the art, plasma treating is accomplished by applying a voltage between electrodes wherein the uncoated lens resides between the electrodes in the presence of a gas, thereby causing a highly ionized gas to bombard the lens surface so as to cause the desired constituent (i.e. amine, carboxylic acid, active free radical, or passive free radical) to reside in the lens surface. The gas employed may comprise a carrier gas, either alone or in combination with other gases. The carrier gas may be any gas, but argon or air are preferred, with argon gas typically being used. The pressure of the gas is typically between 1.0 and 3,000 torr. Equipment which may be employed to achieve such plasma treating is well known to those skilled in the art, such as the equipment described in U.S. Pat. No. 4,780,176 (Sudarshan et al.) for plasma cleaning and etching a metal substrate, which is incorporated herein by reference. In the present invention, a power input to the electrode of 10-500 W may be employed to achieve a corresponding potential difference across the gap between the electrode and lens.
[0015] To generate an amine-containing surface, a plasma containing ammonia or a primary amine-containing material is used. A carboxylic acid-containing surface is generated by an oxidative reaction occurring at the surface or by having residual water in the plasma under inert conditions. In such an embodiment, argon is typically used as the carrier gas. Exposing the surface to argon gas plasma at sufficiently high power causes bond fission, yielding an active free radical-containing surface, whereas exposing the surface to oxygen or air plasma under oxidizing conditions results in a passive free radical-containing surface.
[0016] The method of coating the contact lens of this invention may be any appropriate well known coating technique, such as immersion coating, spray coating and the like, using a suitable solution or dispersion of the medicament dissolved or dispersed in an appropriate solvent or dispersant, such as water, ethanol, and the like, with the solvent not affecting the optics of the lens material. The coating solution or dispersion has a conventional concentration of polysaccharide corresponding to the particular coating technique selected. Typically, after the coating is applied to the lens, it is dried, for example, by drying at room temperature or above. The coating may be repeatedly applied, if necessary, to achieve the desired coating weight or thickness. The coating should not affect the transmission of visual light, and typically has a thickness in the range of from about {fraction (1/100,000)} mm to {fraction (1/100)} mm, and constitutes from about {fraction (1/10,000)}% to about {fraction (1/10)}% by weight of the implant.
[0017] The sulfated polysaccharide coating employed in conjunction with the contact lens in this invention is preferably selected from the group consisting of heparin, heparin sulfate, chondroitin sulfate, dermatan sulfate, chitosan sulfate, xylan sulfate, dextran sulfate, and sulfated hyaluronic acid. Heparin is particularly preferred for use as the coating, with heparin having a molecular weight in the range of about 2,500-15,000 daltons. If low molecular weight heparins are employed they can be prepared by enzymatic hydrolysis or depolymerization of heparin with heparinase as disclosed, for example, by U.S. Pat. No. 3,766,167 (Lasker et al.), or by depolymerizing either heparin residues or commercial porcine or bovine heparin by reacting the heparin material with a blend of ascorbic acid and hydrogen peroxide, the reaction products then being isolated and fractionated by precipitation using an organic solvent, such as ethanol, methanol, acetone, or methyl ethyl ketone. Commercially available heparin may also be cleaved chemically using nitrous acid to yield lower molecular weight heparin, including heparin having a molecular weight in the range of about 2500-10,000 daltons, preferably 2500-5300 daltons.
[0018] Additional compounds may also be employed in conjunction with the compatible sulfated polysaccharide coating of the present invention, for example, compounds that inhibit fogging or beading may also be utilized.
EXAMPLE 1
[0019] Lenses fabricated of poly (methylmethacrylate) were obtained. Heparin (10 g) was dissolved in distilled water (200 ml) with sodium periodate (1 g). The solution was stirred in the dark at room temperature for 12 hours. After addition of glycerol (10 ml), the solution was dialized for 12 hours against distilled water (15 l). The water changed every second hour. The oxidized heparin was further processed by lyophilization (yield 8.2 g). The lenses were thoroughly rinsed with water and etched by treatment with a aqueous solution of ammonium peroxidisulphate (5% w/v) for 30 min at 60° C. After rinsing in water, the lenses were treated with an aqueous solution of polyethyleneimine (0.05% w/v) at pH 3.9 at room temperature for 10 min. After rinsing with water, the treatment was repeated as described above with the modification that the etching procedure was omitted and that the treatment with oxidized heparin was preformed for 120 min the generated Schiff base is induced and finally the heparinized lenses were rinsed first with borate buffer pH 9.0, then with water and left to dry at room temperature. The presence of heparin coating may be established semiquantitatively by staining with toluidine blue (0.02% w/v in water) and quantitatively with the MBTH (3-methyl-2-benzothiazoloine hydrzone) method (Risenfeld J. et al., 1990, Analyt Biochem 188:383-389).
EXAMPLE 2
[0020] An uncoated contact lens in accordance with this invention and containing surface carboxyl groups is surface coated with low molecular weight heparin (i.e. about 2,500-5,300 daltons) by the following procedure. The carboxyl group-containing surface of the contact lens may preferably be made by initially incorporating about 5 weight percent methacrylic acid into the monomer formulation used in preparing the lens. Alternatively, surface hydrolysis of pendant acrylate or methacrylate groups residing on the surface of the lens may be employed, in a manner well known to those skilled in the art. The pendant carboxylic acid groups on the surface of the lens are then reacted with a commercially available diamine, such as hexamethylene diamine or a polymeric di amine such as those commercially available under the JEFFAMINE series trade name from Texaco Chemical Company, in the presence of a water-soluble carbodimide coupling agent, to generate an amine grafted surface (through amide bond formation) where the non-attached portion of the amine resides as a free primary amine. To the free primary amine grafted surface is added the low molecular weight heparin that contains a terminal aldehyde group, and the aldehyde group is then coupled with the primary amine on the surface of the lens by a water-soluble carbodimide to yield a Schiff base, which is then reduced to give a secondary amine linkage to which is attached the low molecular weight heparin.
EXAMPLE 3
[0021] In another preferred embodiment, an uncoated lens in accordance with this invention and containing surface carboxyl groups, is obtained in accordance with Example 1. However, instead of reacting the surface carboxylic groups with a diamine, as in Example 1, an aldehyde-terminated heparin is first coupled with a diamine. This reaction utilizes an excess of diamine, such as a low molecular weight, water-soluble diamine, that reacts with the aldehyde-terminated heparin through one of its amine groups, generating an amido-bonded heparin derivatized with a free, pendant amino group. This water-soluble compound is then purified by dialysis to eliminate the excess, unreacted diamine, and the product obtained by lyophilization. The aminated heparin is then reacted with the hydrolyzed surface of the contact lens through its surface carboxyl groups in the presence of a water-soluble carbodiimide coupling agent. In contrast to the previously described embodiment of Example 1, this process involves only one coupling reaction on the surface of the lens rather than two.
EXAMPLE 4
[0022] In yet another preferred embodiment, an uncoated lens in accordance with this invention is treated with a plasma in accordance with methods as previously described to generate an amine-containing surface, a carboxylic acid-containing surface, or an active or passive free radical-containing surface. If an amine-containing surface is obtained, aldehyde-terminated heparin may be employed to coat the surface of the lens in accordance with Example 1. If a carboxylic acid-containing surface is obtained, aminated heparin may be employed to coat the surface of the lens in accordance with Example 2. If an active or passive free radical-containing surface is obtained, amine or carboxylic acid-containing compounds of low or high molecular weight may be reacted with the surface to yield a covalently attached amine or carboxylic acid-containing lens surface, respectively, to which the designated aldehyde-terminated or aminated heparin compounds set forth in Examples 1 and 2, respectively, are employed to coat the surface of the lens with heparin. In a particularly preferred embodiment, the plasma treatment employed will act in such a manner as to permit trace surface moisture residing in the uncoated lens to be converted into passive free radical coupling agents via the formation of peroxide groups.
[0023] Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made which clearly fall within the scope of this invention.
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The present invention provides a method of modifying surfaces of contact lenses to reduce bacterial, fungal or viral concentration and adherence. The method of the invention comprises the coating of a contact lens surface with a sulfated polysaccharide such as heparin to reduce the concentration of microorganisms, as well as bacterial, fungal or viral adherence. The invention further relates to compositions comprising contact lenses for correcting vision deficiencies of the eye coated with a sulfated polysaccharide such as heparin. Contact lens surfaces as provided in accordance with this invention have a coating of sulfated polysaccharide which reduces the concentration of microorganisms of all types and prevents the adherence of bacteria, fungi or viruses to the lens surface thereby reducing the potential for infection.
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