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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional patent application Ser. No. 60/804,547, filed Jun. 12, 2006, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to wellbore completion. More particularly, the invention relates to a wellbore tool for selectively isolating a zone in a wellbore.
[0004] 2. Description of the Related Art
[0005] A completion operation typically occurs during the life of a well in order to allow access to hydrocarbon reservoirs at various elevations. Completion operations may include pressure testing tubing, setting a packer, activating safety valves or manipulating sliding sleeves. In certain situations, it may be desirable to isolate a portion of the completion assembly from another portion of the completion assembly in order to perform the completion operation. Typically, a ball valve, which is referred to as a formation isolation valve (FIV), is disposed in the completion assembly to isolate a portion of the completion assembly.
[0006] Generally, the ball valve includes a valve member configured to move between an open position and a closed position. In the open position, the valve member is rotated to align a bore of the valve member with a bore of the completion assembly to allow the flow of fluid through the completion assembly. In the closed position, the valve member is rotated to misalign the bore in the valve member with the bore of the completion assembly to restrict the flow of fluid through the completion assembly, thereby isolating a portion of the completion assembly from another portion of the completion assembly. The valve member is typically hydraulically shifted between the open position and the closed position.
[0007] Although the ball valve is functional in isolating a portion of the completion assembly from another portion of the completion assembly, there are several drawbacks in using the ball valve in the completion assembly. For instance, the ball valve takes up a large portion of the bore in the completion assembly, thereby restricting the bore diameter of the completion assembly. Further, the ball valve is susceptible to debris in the completion assembly which may cause the ball valve to fail to operate properly. Additionally, if the valve member of the ball valve is not fully rotated to align the bore of the valve member with the bore of the completion assembly, then there is no full bore access of the completion assembly.
[0008] There is a need therefore, for a downhole tool that is less restrictive of a bore diameter in a completion assembly. There is a further need for a downhole tool that is debris tolerant.
SUMMARY OF THE INVENTION
[0009] The present invention generally relates to a wellbore tool for selectively isolating a portion of a wellbore from another portion of the wellbore. In one aspect, a method of selectively isolating a zone in a wellbore is provided. The method includes the step of positioning a downhole tool in the wellbore. The downhole tool includes a bore with a first flapper member and a second flapper member disposed therein, whereby each flapper member is initially in an open position. The method also includes the step of moving the first flapper member to a closed position by rotating the first flapper member in one direction. Further, the method includes the step of moving the second flapper member to a closed position by rotating the second flapper member in an opposite direction, whereby each flapper member is movable between the open position and the closed position multiple times.
[0010] In another aspect, an apparatus for isolating a zone in a wellbore is provided. The apparatus includes a body having a bore formed therein. The apparatus also includes a first flapper member disposed in the bore. The first flapper member is selectively rotatable between an open position and a closed position multiple times, wherein the first flapper member is rotated from the open position to the closed position in one direction. The apparatus further includes a second flapper member disposed in the bore. The second flapper member is selectively rotatable between an open position and a closed position multiple times, wherein the second flapper member is rotated from the open position to the closed position in an opposite direction.
[0011] In yet another aspect, a method of isolating a first portion of a wellbore from a second portion of the wellbore is provided. The method includes the step of lowering a downhole tool in the wellbore. The downhole tool includes a first flapper member and a second flapper member, wherein each flapper member is initially in an open position and each flapper member is movable between the open position and a closed position multiple times. The method further includes the step of selectively isolating the first portion of the wellbore from the second portion of the wellbore by shifting the first flapper member to the closed position to hold pressure from below the first flapper member and shifting the second flapper member to the closed position to hold pressure from above the second flapper member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of 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.
[0013] FIG. 1 is a cross-sectional view illustrating a downhole tool in a run-in position, wherein a first flapper valve and a second flapper valve are in an open position.
[0014] FIG. 2 is a cross-sectional view illustrating the first flapper valve in a closed position.
[0015] FIG. 3 is a cross-sectional view illustrating the second flapper valve in a closed position.
[0016] FIGS. 4 and 5 are cross-sectional views illustrating a hydraulic chamber arrangement.
[0017] FIGS. 6 and 7 are cross-sectional views illustrating the second flapper valve being moved to the open position.
[0018] FIG. 8 is a cross-sectional view illustrating the first flapper valve in the open position.
DETAILED DESCRIPTION
[0019] FIG. 1 is a cross-sectional view illustrating a downhole tool 100 in a run-in position. The tool 100 includes an upper sub 105 , a housing 160 and a lower sub 110 . The upper sub 105 is configured to be connected to an upper completion assembly (not shown), such as a packer arrangement. The lower sub 110 is configured to be connected to a lower completion assembly (not shown). Generally, the tool 100 is used to selectively isolate the upper completion assembly from the lower completion assembly.
[0020] The tool 100 includes a first flapper valve 125 and a second flapper valve 150 . The valves 125 , 150 are movable between an open position and a closed position multiple times. As shown in FIG. 1 , the valves 125 , 150 are in the open position when the tool 100 is run into the wellbore. Generally, the valves 125 , 150 are used to open and close a bore 135 of the tool 100 in order to selectively isolate a portion of the wellbore above the tool 100 from a portion of the wellbore below the tool 100 .
[0021] The valves 125 , 150 move between the open position and the closed position in a predetermined sequence. For instance, in a closing sequence, the first flapper valve 125 is moved to the closed position and then the second flapper valve 150 is moved to the closed position as will be described in relation to FIGS. 1-3 . In an opening sequence, the second flapper valve 150 is moved to the open position and then the first flapper valve 125 is moved to the open position as will be described in relation to FIGS. 6-8 . The predetermined sequence allows the tool 100 to function properly. For example, in the opening sequence, the flapper valve 150 is moved to the open position first in order to allow the flapper valve 150 to open in a substantially clean environment defined between the flapper valves 125 , 150 , since the flapper valve 125 is configured to substantially block debris from contacting the flapper valve 150 when the flapper valve 125 is in the closed position. In the closing sequence, the flapper valve 125 is moved to the closed position first in order to substantially protect the flapper valve 150 from debris that may be dropped from the surface of the wellbore.
[0022] As illustrated in FIG. 1 , the first flapper valve 125 is held in the open position by an upper flow tube 140 and the second flapper valve 150 is held in the open position by a lower flow tube 155 . It should be noted that the flapper valves 125 , 150 may be a curved flapper valve, a flat flapper valve, or any other known flapper valve without departing from principles of the present invention. Further, the opening and closing orientation of the valves 125 , 150 may be rearranged into any configuration without departing from principles of the present invention. Additionally, the flapper valve 150 may be positioned at a location above the flapper valve 125 without departing from principles of the present invention.
[0023] The tool 100 includes a shifting sleeve 115 with a profile 165 proximate an end thereof and a profile 190 proximate another end thereof. The tool 100 also includes a biasing member 120 , such as a spring. The tool 100 further includes a shift and lock mechanism 130 . As discussed herein, the shift and lock mechanism 130 interacts with the biasing member 120 , the shifting sleeve 115 , and the flow tubes 140 , 155 in order to move the flapper valves 125 , 150 between the open position and the closed position.
[0024] As shown in FIG. 1 , the shift and lock mechanism 130 is a key and dog arrangement, whereby a plurality of dogs move in and out of a plurality of keys formed in the sleeves as the sleeves are shifted in the tool 100 as illustrated in FIGS. 1-3 . The movement of the dogs and the sleeves causes the flapper valves 125 , 150 to move between the open and the closed position. It should be understood, however, that the shift and lock mechanism 130 may be any type of arrangement capable of causing the flapper valves 125 , 150 to move between the open and the closed position without departing from principles of the present invention. For instance, the shift and lock mechanism 130 may be a motor that is actuated by a hydraulic control line or an electric control line. The shift and lock mechanism 130 may be an arrangement that is controlled by fiber optics, a signal from the surface, an electric line, or a hydraulic line. Further, the shift and lock mechanism 130 may be an arrangement that is controlled by a pressure differential between an annulus and a tubing pressure or a pressure differential between a location above and below the tool 100 .
[0025] FIG. 2 is a cross-sectional view illustrating the first flapper valve 125 in the closed position. In the closing sequence, the flapper valve 125 is moved to the closed position first in order to protect the flapper valve 150 from debris that may be dropped from the surface of the wellbore. In one embodiment, a shifting tool (not shown) having a plurality of fingers that mates with the profile 165 of the sleeve 115 is used to move the first flapper valve 125 to the closed position. The shifting tool may be a mechanical tool that is initially disposed below the tool 100 and then urged through the bore 135 of the tool 100 until it mates with the profile 165 . The shifting tool may also be a hydraulic shifting tool that includes fingers that selectively extend radially outward due to fluid pressure and mate with the profile 165 . In either case, the shifting tool mates with the profile 165 in order to pull the sleeve 115 toward the upper sub 105 .
[0026] As the sleeve 115 begins to move toward the upper sub 105 , the shift and lock mechanism 130 unlocks the flapper valves 125 , 150 . Thereafter, the shift and lock mechanism 130 moves the flow tube 140 away from the flapper valve 125 . At that time, a biasing member (not shown) attached to a flapper member in the flapper valve 125 rotates the flapper member around a pivot point until the flapper member contacts and creates a sealing relationship with a valve seat 170 . As illustrated, the flapper member closes away from the lower sub 110 . As such, the flapper valve 125 is configured to seal from below. In other words, the flapper valve 125 is capable of substantially preventing fluid flow from moving upward through the tool 100 . In addition, as the sleeve 115 moves toward the upper sub 105 , the biasing member 120 is also compressed.
[0027] As the shifting tool urges the sleeve 115 further toward the upper sub 105 , a locking mechanism 185 is activated to secure the flapper valve 125 in the closed position. The locking mechanism 185 may be any known locking mechanism, such as a ball and sleeve arrangement, pins, or a series of extendable fingers. The locking mechanism 185 is configured to allow the flapper valve 125 to burp or crack open if necessary. This situation may occur when debris from the surface of the wellbore falls and lands on the flapper valve 125 . It should be noted that the locking mechanism 185 will not allow the flapper valve 125 to move to the full open position, as shown in FIG. 1 , but rather the locking mechanism 185 will only allow the flapper valve 125 to crack open slightly. As such, the flapper valve 125 in the closed position acts a barrier member to the flapper valve 150 by substantially preventing large particles (i.e. a dropped drill string) from contacting and damaging the flapper valve 150 .
[0028] FIG. 3 is a cross-sectional view illustrating the second flapper valve 150 in the closed position. After the flapper valve 125 is in the closed position and secured in place, the shifting tool continues to urge the sleeve 115 toward the upper sub 105 . At the same time, the flapper valve 150 is moved away from the flow tube 155 , thereby allowing a biasing member (not shown) attached to a flapper member in the flapper valve 150 to rotate the flapper member around a pivot point until the flapper member contacts and creates a sealing relationship with a valve seat 180 . As illustrated, the flapper member closes away from the upper sub 105 . As such, the flapper valve 150 is configured to seal from above. In other words, the flapper valve 150 is capable of substantially preventing fluid flow from moving downward through the tool 100 . Thereafter, the sleeve 115 is urged closer to the upper sub 105 and the flapper valves are locked in place by the shift and lock mechanism 130 . Also, the biasing member 120 is in a full compressed state.
[0029] FIGS. 4 and 5 are cross-sectional views illustrating a hydraulic chamber arrangement. The flapper valves 125 , 150 in the downhole tool 100 are moved to the open position by actuating the shift and lock mechanism 130 . In the embodiment illustrated in FIGS. 4 and 5 , the shift and lock mechanism 130 is actuated when a pressure differential between an ambient chamber 210 and tubing pressure in the bore 135 of the tool 100 reaches a predetermined pressure. The chamber 210 is formed at the surface between two seals 215 , 220 . As the tool 100 is lowered into the wellbore, a hydrostatic pressure is developed which causes a pressure differential between the pressure in the chamber 210 and the bore 135 of the tool 100 . As illustrated in FIG. 5 , at a predetermined differential pressure, a shear pin 205 is sheared, thereby causing the biasing member 120 to uncompress and shift the sleeve 115 toward the lower sub 110 in order to unlock the flapper valves 125 , 150 and start the opening sequence. The shear pin 205 may be selected based upon the depth location in the wellbore that the shift and lock mechanism 130 is to be actuated.
[0030] FIGS. 6 and 7 are cross-sectional views illustrating the flapper valve 125 being moved to the open position. As previously set forth, in the opening sequence, the flapper valve 150 is moved to the open position first in order to allow the flapper valve 150 to open in a clean environment. However, prior to moving the flapper valve 150 to the open position, the flapper valves 125 and 150 are unlocked by manipulating the shift and lock mechanism 130 . Next, the pressure around the flapper valve 150 is equalized by aligning a port 230 with a slot 235 formed in the flow tube 155 as the sleeve 115 is moved toward the lower sub 110 . Thereafter, further movement of the sleeve 115 toward the lower sub 110 causes the flapper valve 150 to contact the flow tube 155 which will subsequently cause the flapper valve 150 to move from the closed position to the open position as shown in FIG. 7 . As previously discussed, the movement of the sleeve 115 toward the lower sub 110 may be accomplished by a variety of means. For instance, the sleeve 115 may be urged toward the lower sub 110 by a hydraulic or mechanical shifting tool (not shown) that interacts with the profile 190 formed on the sleeve 115 . In turn, the sleeve 115 manipulates the mechanism 130 in order to open the flapper valves 125 , 150 .
[0031] The flapper valves 125 , 150 in the downhole tool 100 are moved to the open position by manipulating the shift and lock mechanism 130 . As discussed herein, in one embodiment, the shift and lock mechanism 130 is a key and dog arrangement, whereby the plurality of dogs move in and out of the plurality of keys formed in the sleeves as the sleeves are shifted in the tool 100 as illustrated in FIGS. 1-3 . The movement of the dogs and the sleeves causes the flapper valves 125 , 150 to move between the open and the closed position. It should be understood, that the shift and lock mechanism 130 is not limited to this embodiment. Rather, the shift and lock mechanism 130 may be any type of arrangement capable of causing the flapper valves 125 , 150 to move between the open and the closed position, such as a motor that is controlled by a hydraulic or electric control line from the surface. The shift and lock mechanism 130 may also be an arrangement that is controlled by fiber optics, a signal from the surface, an electric line, or a hydraulic line. Further, the shift and lock mechanism 130 may be an arrangement that is controlled by a pressure differential between an annulus and a tubing pressure or a pressure differential between a location above and below the tool 100 .
[0032] FIG. 8 is a cross-sectional view illustrating the first flapper valve 125 in the open position. After the flapper valve 150 is opened, the flow tube 140 moves toward the flapper valve 125 as the shift and lock mechanism 130 is manipulated. Prior to the flow tube 140 contacting the flapper member in the flapper valve 125 , a slot 245 formed in the flow tube 140 aligns with a port 240 to equalize the pressure around the flapper valve 125 . Thereafter, the flow tube 140 contacts the flapper member in the flapper valve 125 and causes the flapper valve 125 to move from the closed position to the open position. Subsequently, the flapper valves 125 , 150 are locked in place by further manipulation of the shift and lock mechanism 130 . The process of moving the flapper valves 125 , 150 between the open position and the closed position may be repeated any number of times.
[0033] While the foregoing is directed to embodiments 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.
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The present invention generally relates to a wellbore tool for selectively isolating a portion of a wellbore from another portion of the wellbore. In one aspect, a method of selectively isolating a zone in a wellbore is provided. The method includes the step of positioning a downhole tool in the wellbore. The downhole tool includes a bore with a first flapper member and a second flapper member disposed therein, whereby each flapper member is initially in an open position. The method also includes the step of moving the first flapper member to a closed position by rotating the first flapper member in one direction. Further, the method includes the step of moving the second flapper member to a closed position by rotating the second flapper member in an opposite direction, whereby each flapper member is movable between the open position and the closed position multiple times. In another aspect, an apparatus for isolating a zone in a wellbore is provided.
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RELATED APPLICATIONS
[Not Applicable]
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[Not Applicable]
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
MICROFICHE APPENDIX
A microfiche appendix of the presently preferred computer program source code is included and comprises 1 sheets and a total of 91 frames.
The Microfiche Appendix is hereby expressly incorporated herein by reference, and contains material which is subject to copyright protection as set forth above.
FIELD OF INVENTION
The present invention generally relates to software compiler technology. More particularly, the present invention relates to a method for computing definition-use information for lvalues that may be aggregates and/or referenced through pointer expressions.
BACKGROUND OF THE INVENTION
Within the field of compilers, the problem of determining which definitions reach uses in a program is important to many optimizations. For the case where the left sides of definitions are scalars, the problem is well understood. One prior-art technique generalizes the analysis to definitions whose left sides are aggregates and/or pointer expressions. The generalization to aggregates is based on partitioning an aggregate into components, and tracking each component separately. The generalization to lvalues referenced through pointer expressions is based on using two data-flow solvers. A bottom level solver tracks whether a pointer expression to the lvalue changes between the point of definition and point of use, and a top level solver employs said information about said changes to determine where the lvalues reach.
This prior art technique has a number of disadvantages.
(a) It requires two data-flow solvers, which can be expensive in time and memory storage requirements. Particularly expensive in terms of space is the requirement that the results of the bottom analyzer be retained while the top analyzer runs.
(b) It requires up to 9 bits of data-flow solution per definition in the data-flow problems solved. Specifically, the bottom-level solver operates on a lattice of 3-bit vectors, and requires two such vectors for each definition analyzed, one for the address of the defined lvalue, and one for the support of the right side. Thus the bottom-level solver requires up to 6 bits per definition to represent a lattice value. The top-level solver requires yet another 3-bit vector value for each partitioned piece of the lvalue defined by the definition. Furthermore, for each bit in any said vector, there are three possible monotone lattice functions, thus two bits are required to represent each lattice function on a bit. Consequently, for a definition partitioned into n pieces, the solvers need 6+3n bits and 12+6n bits respectively to represent the lattice values and functions related to a single definition.
(c) It fails to find some opportunities for forward substitution, because the bottom solver sometimes reports changes in right sides of definitions that were actually irrelevant because the corresponding definition is no longer live along the paths for which the change occurred. FIG. 1 A and FIG. 1B show such an example. Definitions 100 and 101 both reach the use 102 of p in “q=p”. Both have the form “p=x[j]”. The support of x[j] is the set of lvalues {x,j}. If the statement 103 “j=j+1” is executed, then the support of the right side of definition 100 will have changed between its point of definition and the statement “q=p”. The prior art interprets the change as preventing forward substitution. However, along paths including “j=j+1”, definition 100 is dead, and thus would be correct to forward substitute x[j] for p in “q=p”.
(d) It fails to find some opportunities for removing dead stores or scalar replacement, because the bottom solver sometimes reports changes to the support of left sides of definitions that were actually irrelevant because the corresponding definition is no longer live along the paths for which the change occurred. The problem is similar in flavor to said problem with right sides, though the consequent inferiority is different. FIG. 2 A and FIG. 2B show such an example. Definition 200 is never used, because it is killed by either definition 201 or 202 , depending upon the path taken. The support of the left side of definition 200 includes k, and along paths through definition 201 , the value of k changes 203 . Unfortunately, when the top-level solver of said prior art inspects definition 202 to check whether it kills definition 200 , the bottom-level solver reports that k changed along some paths and consequently the top-level solver must assume that definition 202 does not kill definition 200 .
BRIEF SUMMARY OF THE INVENTION
Accordingly, the present invention provides a method and apparatus that analyzes definitions and uses of lvalues in a program. For each definition in the program, the method computes where the definition reaches, and whether the support of the definition's left side has changed while the definition is live. The method according to the present invention can also be implemented by computing where each use reaches backwards within a program, and whether the support of the use changes while the use is live. The present invention also demonstrates a novel way of representing lattice elements with binary codes. The lattice is embedded in a boolean hypercube, and binary codes are assigned corresponding to the hypercube coordinates. The codes are then compacted by removing some bit positions and duplicate codes removed by complementing a few bits in some of the codes.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 A and FIG. 1B show an example C program and its corresponding flow graph that illustrates a forward-substitution problem in the prior art.
FIG. 2 A and FIG. 2B show an example C program and its corresponding flow graph that illustrates a dead-store problem in the prior art.
FIG. 3 is a flow chart of the overall operation of a method in accordance with the present invention.
FIG. 4 A and FIG. 4B show sample C declarations and an associated partitioning of lvalues into lvalue chunks.
FIG. 5 shows the DCA value lattice.
FIG. 6 shows the DCA function lattice.
FIG. 7 is a flow chart illustrating a method for encoding a finite lattice.
FIG. 8 shows how said encoding method was used to encode the DCA function lattice.
FIG. 9 shows boolean logic for evaluating the DCA function application y=f(x).
FIG. 10 shows boolean logic for evaluating the DCA Kleene closure h=f*.
FIG. 11 shows boolean logic for evaluating the DCA function h that is the meet of DCA functions f and g.
FIG. 12 shows boolean logic for evaluating the DCA function composition h=fog.
FIG. 13 shows the OMF value lattice.
FIG. 14 shows the OMF function lattice.
FIG. 15 shows boolean logic for evaluating the OMF function composition h=fog.
FIG. 16 shows the recommended packing of bits in memory when using the “shared logic” approach to doing operations on DCA and OMF entities.
FIG. 17 is a flow chart of process ANALYZE-DEF, which analyzes the effects of an instruction on candidate definitions.
FIG. 18 is a flow chart of process ANALYZE-STORE, which is a subprocess of ANALYZE-DEF.
FIG. 19 is a flow chart of process STORE-LHS, which is a subprocess of process ANALYZE-STORE.
FIG. 20 is a flow chart of process STORE-UGLY, which is a subprocess of processes ANALYZE-STORE and STORE-LHS.
FIG. 21 is a flow chart of process TRANSFER, which accumulates transfer functions.
FIG. 22 is a flow chart for process ANALYZE-USE, which analyzes the effects of an instruction on candidate uses.
FIG. 23 is a flow chart for process ANALYZE-REF, which is a subprocess of process ANALYZE-USE.
DETAILED DESCRIPTION OF THE INVENTION
The following terms have been defined in U.S. Pat. No. 5,790,866 which is assigned to the assignee of the present application and which is incorporated herein by reference: “aggregate”, “rvalue”, “lvalue”, “lvalued-expression”, “definition”, “support”, “SUPPORT”, and “TOXIC”. The superfluous word “hand” in the terms “left-hand side” and “right-hand side” from U.S. Pat. No. 5,790,866 is omitted herein. The embodiment of the present invention illustrated herein also employs the edge-labeled control-flow graph representation described in U.S. Pat. No. 5,790,866. Said kind of flow graph simplifies minor details of the presentation of the presently preferred embodiments of the present invention.
As used herein, the term “use” means the occurrence of an lvalued expression in a program that denotes the reading (sometimes called loading) of the designated storage location's value.
Here is a brief review of the requisite lattice theory, which should be well known to implementors of data-flow analyzers. A partial ordering is a relation, here denoted by ≦, that is transitive, reflexive, and antisymmetric. A lattice is a partial ordering closed under the operations of least upper bound and greatest lower bound. The least upper bound is also called the meet. A function f that maps a lattice of values onto itself is monotone if x≦y implies f(x)≦f(y) for any two lattice elements x and y. The set of monotone functions over a lattice of values forms a lattice of functions, where f≦g if and only if f(x)≦f(x) for all lattice values x. Such a lattice is called a function lattice. A sublattice of a lattice L is a lattice whose elements are a subset of the elements of L. The operation o denotes function composition; i.e., (fog)(x)=f(g(x)). The notation f* denotes the Kleene closure of f; i.e., the limit of the infinite composition gogogogo . . . , where g is the meet of f and the identity function. The Cartesian product of two functions f and g is a function (f,g) that is defined as (f,g)(x,y)=(f(x),g(y)). The Cartesian product of two lattices L and M is a lattice of all pairs (x,y), where x is an element from L and y is an element from M. The Cartesian product of the set of monotone functions on two lattices is itself a set of monotone functions on the Cartesian product of the lattices.
FIG. 3 shows an overview of the steps of a method in accordance with the present invention. A set of candidate definitions or a set of candidate uses is constructed in step 300 . The preferred embodiment is to generate a set of candidate definitions and solve a forward data flow problem. An alternative variation is to generate a set of candidate uses and solve a similar backward data flow problem. The rest of this discussion pertains to the forward embodiment until specified otherwise. The left sides of the definitions are partitioned, step 301 , into lvalue chunks. Each chunk is tracked separately. Vector indices are allocated at step 302 , one per lvalue chunk. Transfer functions are computed at step 303 , for each instruction. A data-flow problem is constructed from the transfer functions at step 304 . A data-flow framework solves the data-flow problem at step 305 . Though the diagram shows the transfer functions being computed eagerly before the data-flow problem is solved, it should be apparent to anyone skilled in the art of data-flow frameworks that the functions can be computed lazily while the data-flow problem is being solved. The eager/lazy tradeoff is similar to that for any other sort of data-flow framework. Finally, the solutions to the flow equations are used at step 306 to guide transformations of the program, such as forward substitution, removing dead stores, scalar replacement, hoisting common subexpresssions etc. The exact transformations are not specified by the method of FIG. 3 as they include any sort of transformation that employs definition-use information. One particular innovation of the illustrated method is the speed and accuracy of the definition-use information, not its application.
FIG. 4A shows a sample declaration of some aggregate types and an lvalue v. FIG. 4B shows a pictorial view of the related lvalues, their partitioning into lvalue chunks, and the indices associated with the lvalue chunks. Notice that lvalues inserted for sake of padding are ignored. For a given definition y, the indices allocated for its chunks is denoted INDICES(LHS(y)). For example, if LHS(y) is (*v).f 2 , then INDICES(LHS(y))={ 2 , 3 }. The notation CHUNK[k] denotes the inverse mapping from indices to lvalue chunks. For instance, CHUNK[ 3 ] is the lvalue (*v).f 2 .f 4 . There is a tradeoff of time and accuracy in choosing the granularity of said partitioning. The recommended level is to partition the lvalues with the coarsest partition such that each definition's left side lvalue is covered by a set of non-overlapping chunks. It is often advantageous to let the partitioning be at bit boundaries rather than merely byte boundaries, when the lvalue chunks are bit fields that are not aligned on byte boundaries.
Data-flow frameworks are based upon value lattices, and functions that map the value lattice onto itself. The functions form a function lattice. The data-flow framework in accordance with the present invention is based on a lattice that is the Cartesian product of two value lattices, called the DCA value lattice and the OMF value lattice. Each of these lattices has an associated function lattice, which is a set of monotone functions from values to values. The set of monotone functions on the Cartesian product of the value lattices is the Cartesian product of the function lattices. From the viewpoint of implementation, this means that the DCA and OMF lattice values and their functions are orthogonal and can be considered separately within the data-flow framework.
FIG. 5, FIG. 6, FIG. 8, FIG. 13, and FIG. 14 show various lattices employed by methods in accordance with the present invention. In each drawing, the lattice elements appear as boxes, which contain the name of the lattice element (if it has a name) and its binary representation. The arrows indicate the partial ordering relation. The relation x≦y is true if and only if the box for x can be reached from the box for y by traversing zero or more of the arrows from box to box in the direction of the arrows.
The DCA value lattice is shown in FIG. 5 . The lattice has three elements called D, C, and A. For a given program location, the lattice value A indicates that a definition cannot reach the location. The lattice value C indicates that the definition might reach the location and its left-side support has not changed since the most recent execution of the definition. The lattice value D indicates that the definition might reach the location and its left-side support might have changed since the most recent execution of the definition. For discussion, it is convenient to say a definition is “absent”, “clean”, or “dirty” at a given program location, depending upon whether the corresponding lattice value is A, C, or D respectively. Absent definitions are often called “dead” or “killed” in the literature. Clean or dirty definitions are often called “live” in the literature. FIG. 5 also shows the 2-bit binary code associated with each element. These codes are used to represent the elements. Other representations are possible, though the representation shown is recommended because it has the useful property that the code for the meet of two DCA elements is the bitwise-AND of their codes.
The DCA function lattice is shown in FIG. 6 . Each function f in said lattice is a map from DCA values to DCA values, and has a name of the form xyz, where x=f(D), y=f(C), and z=f(A). For instance, the identity function is named DCA, and the function that always returns D is named DDD. Each DCA function is monotone. The set of DCA functions is closed under composition and meet, thus the functions form a function lattice. Notice that the set of DCA functions is not the set of all ten possible monotone functions on the DCA value lattice. Two possible monotone functions, namely CAA and CCA, are deliberately omitted because they are unnecessary and the omission permits representation of the functions with only 3 bits instead of 4 bits. FIG. 6 also shows how each function on the lattice is encoded as a 3-bit binary numeral.
The encoding of the DCA lattice depends upon the notion of a hypercube lattice. This lattice is well known to those skilled in the art of lattice theory. The relevant details are summarized here. Informally, a hypercube lattice is simply a lattice whose diagram is isomorphic to such a labeled hypercube, hence the name. More formally, each corner of an H-dimensional hypercube can be labeled with an H-bit binary numeral such that there is a hypercube edge between the corners if and only if the corresponding labels differ in exactly one bit position. The lattice elements of a hypercube lattice correspond to said labels on a hypercube. The partial ordering x≦y on said hypercube lattice is true if and only if the label for y has a 1 in every bit position where the label for x has a 1 in the same position. The meet operation on such a lattice corresponds to taking the bitwise AND of the labels. An H-dimensional hypercube lattice is isomorphic to a “subset lattice”, in which each lattice element corresponds to a subset of an H-element set, and the ordering x≦y is true for said subset lattice if and only if x is a subset of y. The isomorphism is mentioned here because many texts discuss the lattice from the subset viewpoint instead of the hypercube viewpoint. The two viewpoints are mathematically equivalent.
The codes for the DCA function lattice are chosen to simplify implementation of function composition, function meet, and function application. The codes are based on the following general method shown in FIG. 7 for compressing the representation of elements in a finite lattice to K bits, where K is at least large enough to permit a distinct representation of each element. The lattice is embedded, at step 700 , as a minimal sublattice of a hypercube lattice. Minimal means the hypercube lattice of smallest dimension that permits embedding. Step 700 also sets H to the dimension of said hypercube. Such hypercube lattices and embeddings are well known to mathematicians; one novel aspect of the method according to the present invention is in the compaction performed by steps 702 - 705 . Step 701 assigns expanded codes corresponding to the hypercube lattice. More precisely, step 701 sets the expanded code for each lattice element to the H-bit binary label for the element's corresponding corner in the hypercube. Step 702 chooses H-K bit positions to remove from each code. The bit positions must be the same for all codes. The best choice of which bits to remove is most likely those that cause the fewest duplicate codes after step 703 . Step 703 shortens the expanded codes by removing the bit position chosen by step 702 from each expanded code. It may be necessary to iterate over the choices allowed by step 702 and do steps 703 - 705 for each choice, to see which choice is best. Step 704 sets U to a maximal set of elements such that their shortened codes are distinct. An easy way to do this is to start with an empty set, and then for each element, add it to the set if the set does not yet contain an element with the same code. It may be necessary to iterate over the choices allowed by step 704 , and do step 705 for each choice, to see which choice is best. Step 705 assigns unique codes to represent the elements of the elements of the lattice. Step 705 does so by looking at each element not in U, and for each such element, complementing bits in it. The best choice of which bits to complement is those that minimize the total number of bits complemented. Another good heuristic is to attempt to minimize the number of positions that involve complementing. The reason is that the meet operation of the lattice elements is the bitwise-AND of their expanded codes, and thus for each position not changed by the reduced code, the corresponding logic for the meet operation is still bitwise AND.
FIG. 8 shows an example where the lattice is the DCA function lattice, with H=5 and K=3. The binary numerals in FIG. 8 are the expanded codes. The complete hypercube has 32 points, though to reduce clutter, only a 12-point subset of interest is shown. The 12 points shown correspond to the minimal sublattice that contains the elements that are DCA functions. The K bits chosen are the middle three bits; i.e. the leftmost and rightmost bits of the 5-bit codes are removed to shorten the codes. The choice was made because it minimized the number of duplicate shortened codes for the DCA lattice elements, before the next step that complements some bits. The underlined bits are those that are complemented to make the reduced codes unique. The choice was guided by the desire to minimize the number of bits complemented and the number of bit positions in which bits needed to be complemented. The shortened 3 -bit codes are shown in FIG. 6 . Notice that no flipping is required for the next to rightmost bit of the 5-bit expanded codes in FIG. 8, which corresponds to the rightmost bit of FIG. 6 . Thus the corresponding logic for the bit when computing the meet of two DCA functions is simply an AND operation (output hO of FIG. 11 ).
FIG. 9 shows logic suitable for computing function application z:=f(x) for a DCA function fto a DCA value x, where the binary code for input f is f 2 f 1 f 0 , and the binary codes for input x and output z are x 1 x 0 and z 1 z 0 respectively. FIG. 10 shows logic suitable for computing the Kleene closure h with binary representation h 2 h 1 h 0 of a DCA function f with binary representation f 2 f 1 f 0 . FIG. 11 shows logic suitable for computing the meet h of two functions f and g in the DCA function lattice, where the binary codes for h, f, and g, are respectively h 2 h 1 h 0 , f 2 f 1 f 0 , and g 2 g 1 g 0 . FIG. 12 shows logic suitable for computing the composition h of two functions f and g, where the binary codes are likewise.
The diagrams of FIGS. 9-12 are presented in the form of traditional hardware diagrams to convey the notion that the logic can be implemented with straight-line code that performs bitwise boolean operations. The implementor can think of them as parse graphs of expressions for the operations. Alternative embodiments are table lookup and explicit programming using a sequence of decisions; e.g., if-then-else statements. The bitwise approach is preferred, because the logic can be executed in parallel for many values or functions. For example, on a 64-bit machine, 64 different function compositions can be computed simultaneously at a cost of less than one machine operation per composition. There is also a tradeoff between compactness of the encoding and complexity of the logic. For instance, using 5-bit expanded codes simplifies computation of function meet, at the expense of memory storage requirements. Codes of intermediate length or redundancy are also possible.
The OMF value lattice is shown in FIG. 13 . The lattice has three elements called O, M, and F. For a given program location, the lattice value F indicates a definition can be forward-substituted at the location. The lattice value M indicates that a definition cannot be forward-substituted at the location but is not corrupted by part of the program that is not a definition. The lattice value O indicates that the definition is corrupted by part of the program that is not a definition. For discussion it is convenient to say that a definition is “forwardable”, “mixed”, or “outside” at a location, depending upon whether the corresponding lattice value is F, M or O respectively. The distinction between M and O is important, because in case M, we know that the definition-use information provided by the DCA lattice describes entirely how an lvalue is defined. The OMF value lattice is isomorphic to the DCA lattice; hence its binary encoding is isomorphic.
The OMF function lattice is shown in FIG. 14 . Each function f in said lattice has a name of the form xyz, where x=f(O), y=f(M), and z=f(F). A handy mnemonic is that both the DCA and OMF function lattices are named for their respective identity functions. Each OMF function is monotone. The set of OMF functions is closed under composition and meet. FIG. 14 also shows the 3-bit binary code associated with each function. The codes are based on the observation that the OMF function lattice is isomorphic to a sublattice of the DCA function lattice. The logic used to compute various operations on OMF functions and values can be the same logic as for DCA functions and values, permitting a “shared logic” implementation. This is advantageous to implementors because, for instance, bitwise operations on a 64-bit machine can compute 32 separate DCA function compositions and 32 separate OMF function compositions, all simultaneously.
Alternatively, implementors may want to exploit the fact that the OMF function lattice has three fewer functions than the DCA lattice, and consequently the boolean logic can be simplified by exploiting the resulting “don't care” states in the logic equations. For example, FIG. 15 shows the resulting simplified logic corresponding to FIG. 12 (function composition), which demonstrates the significant savings that may be obtained. The art of deriving such simplification is well known to computer designers, hence simplification of FIG. 9, FIG. 10, and FIG. 11 for the OMF function lattice are left to the implementor. The simplifications sometimes help, because there are fewer operations for the flow analyzer to execute; they sometimes hinder, because they prevent sharing of bitwise operations for both DCA and OMF logic. To make the best choice, the implementor should consider the typical number of lvalue chunks that are of simultaneous interest, say N, and the word size of the host machine's bitwise boolean operations, say M bits. When N does not exceed M/2, the shared implementation is superior, as the OMF calculation can be done “for free” while the DCA calculation is done. When N exceeds M/2, the simplified form may be quicker. However, if the limiting resource of the host computer is memory bandwidth and not the bitwise operations, then the simplified form might not help, since the number of inputs and outputs is still the same. A hybrid alternative is to implement both forms, and dynamically decide during analysis which to use on a case-by-case basis.
An important key component of a data-flow framework is the computation of transfer functions corresponding to each instruction in a flow graph. The total number of lvalue chunks in a given flow problem is henceforth denoted by N. The chunks are numbered 0 through N−1. The transfer function for an instruction is the Cartesian product of two functions T f and T a . The function T f is an OMF lattice function and the function T a is a DCA lattice function. Each function maps knowledge about the program's state before said instruction is executed to knowledge about the program's state after said instruction is executed. The functions T f and T a for each instruction are conceptually represented as N-element arrays of values of the OMF and DCA kind respectively. The notations T f [k] and T a [k] denote the kth element of the respective arrays. Physically, the best way to implement the arrays is in a “slicewise” packing with six bit vectors, because said packing permits evaluation of many lattice operations in parallel by using bitwise boolean operations on words of bits. An alternative is to use unpacked arrays with one lattice element per array element, though this approach makes parallel evaluation of many lattice operations less practical unless the hardware running the analyzer has suitable vector instructions.
The slicewise packing is as follows. For j in { 0 , 1 , 2 }, the jth bit of T f [k] is the kth bit within the (j+3)th bit-vector, and the jth bit of T a is the kth bit within the jth bit-vector, so that said bitwise boolean operations may be employed. If the vectors require more than one word, it is best to interlace the vectors so word i of the jth vector is the (6i+j)th word in memory.
In the “shared logic” implementation, the encodings of values for the two lattices share the same words of storage, the encodings of the functions for the two lattices share the same words of storage, and the operations on the two lattices share the same bitwise boolean operations. To do this, the arrays T f and T a are packed into three bit vectors such that the jth bit of T f [k] and jth bit of T a [k] are the (2k)th bit and (2k+1)th bit within the jth bit vector, the vectors are word-wise interlaced such that word i of the jth vector is the (3i+j)th word in memory. FIG . 16 shows the recommended packing of words for said “shared logic” implementation. DCA lattice values and DCA lattice functions are packed similarly, except that since each value requires only two bits, only two bit vectors are required. Since the OMF function lattice is a sublattice of the DCA function sublattice, the bitwise boolean operations for implementing the lattice operations on both lattices simultaneously are those for evaluating the corresponding DCA operations shown in FIG. 9 -FIG. 12 .
FIG. 17 shows a method illustrating the process ANALYZE-DEF for computing transfer functions T f and T a corresponding to an instruction x. Process ANALYZE-DEF is called when the transfer function for each instruction needs to be computed (step 303 of FIG. 3 ). Its operation is as follows. Step 1700 sets all elements of T f and T a to the respective identity functions of the OMF and DCA lattices. Step 1701 sets sequence dseq to the sequence of lvalues stored by instruction x. If an instruction conditionally stores into an lvalue, the lvalue is included in sequence dseq. The rest of the steps remove each lvalue from dseq in turn and analyze it. Step 1702 checks whether dseq is empty, and if not empty, step 1703 removes the first lvalue d from dseq. Step 1704 assigns to set yset the set of candidate definitions (from step 300 in FIG. 3.) The rest of the steps remove each definition from yset and in turn and analyze the effect on it by the store to lvalue d. Step 1705 checks whether yset is empty, and if not empty, step 1706 removes any definition y from yset, and step 1707 invokes process ANALYZE-STORE. Process ANALYZE-STORE is described in detail in conjunction with FIG. 18 .
The accuracy of the method in accordance with the present invention is enhanced by the notion of “toxic” stores into memory. U.S. Pat. No. 5,790,866 discusses the notion of “toxic” in more detail and is incorporated herein by reference. The predicate TOXIC(L,R) is true if the analyzer is permitted to ignore the effect of a store of an rvalue R on subsequent evaluations of an lvalue L. For example, the program being analyzed may be known to never store a floating-point value into memory and read the value back as a pointer. In this case, given any pointer lvalue L and floating-point value R, the predicate TOXIC(L,R) would be true.
FIG. 18 shows a method illustrating process ANALYZE-STORE, which analyzes the effects of a store to lvalue d to a definition y. Its basic operation is to inspect effects of the store, and accordingly set function-valued variables f and a to the appropriate transfer functions from the OMF and DCA function lattices respectively, and invoke process TRANSFER to apply said functions to the desired elements of T f and T a . The desired elements are specified by the indices within set-valued variable bis. Three classes of effects are considered: effects on the lvalue defined by y, effects on the support of the left side of y, and effects on the support of the right side of y. The left side and right side of definition y are respectively denoted LHS(y) and RHS(y). The order of inspecting these three classes of effects is important. For instance, if definition y were “j=j+1”, and effects on the support of the right side were handled before effects on the defined lvalue, contrary to the order shown, then the definition would be analyzed as “forwardable”, when in fact it is not. Steps 1800 , 1804 , and 1809 depend upon the well-known art of alias analysis to determine whether lvalues overlap. The implementation and quality of alias analysis are not part of the present invention, though the quality will affect the accuracy of the present invention. The detailed operation of ANALYZE-STORE follows. Step 1800 tests if lvalue d might overlap the lvalue stored by y. If so, step 1801 checks whether the store to d is the store to LHS(x) by an instruction x having the form of a definition, even if the instruction is not a candidate definition. If so, then step 1802 invokes process STORE-LHS to analyze the store in detail. Process STORE-LHS is described in conjunction with FIG. 19 . Otherwise step 1803 invokes process STORE-UGLY. Process STORE-UGLY is described in detail in conjunction with FIG. 20 . Step 1804 tests whether the store to d might change the support of the left side of y. If so, step 1805 checks if for all rvalues r in SUPPORT(LHS(y)), the predicate TOXIC(d,r) is true. If always so, then step 1806 sets variable a to DCA. If sometimes not, then step 1807 sets variable a to DDA. In either case, step 1808 sets variable f to OOO, sets variable bis to INDICES(LHS(y)), and invokes process TRANSFER. Process TRANSFER is described in detail in connection with FIG. 21 . This completes accounting for effects to the left side of y. Step 1809 tests whether the store to d might change the support of the right side of y. If so, step 1810 sets variable f to OMM, set variable a to DCA, set variable bis to INDICES(LHS(y)), and invoke process TRANSFER.
The loop structure in FIG. 17 and checks for overlap in FIG. 18 are shown as independent. It should be apparent to those skilled in the art of database design that the loop and checks are searching a database for records with certain attributes, namely various forms of overlap. Therefore clever data structures that fetch only those combinations of a definition y and lvalue d of non-trivial interest may greatly speed up operation of the present invention. Design of said clever database is not part of the present invention.
FIG. 19 is a flow diagram illustrating process STORE-LHS, which analyzes the effects on a candidate definition y of a store by an instruction x that has the form of a definition, even if it is not in the set of candidate definitions (constructed in step 300 of FIG. 3 ). Step 1900 checks whether instruction x is identical to y, i.e. is the definition itself. If said instruction is identical, step 1901 sets variable f to FFF and sets variable a to CCC, as the definition is trivially forwardable and clean at the point of its execution. Otherwise, step 1902 inspects whether the left side of x is lexically equivalent to the left side of y. Lexically equivalent means has the same structure, or same structure after algebraic rewriting. E.g., “[ 2 *i]” and “x[i+i]” are considered lexically equivalent here, since each can be rewritten as the other. The recommended implementation is to bring all left and right sides into some canonical form before invoking the invention. The design of said canonical form is not part of the invention. If lexical equivalence does not hold, then step 1903 performs process STORE-UGLY, which is illustrated in FIG. 20 . Otherwise step 1904 sets variable a to function DAA and inspects whether x is a candidate definition. If x is not a candidate definition, step 1905 sets variable f to OOO. If x is a candidate definition, step 1906 inspects whether the right sides of x and y are lexically equivalent. If so, step 1907 inspects whether the support of x is a (possibly improper) subset of the support of y. If said canonical form is used, lexical equivalence implies that the support of x is the same as the support of y, and thus is trivially a subset. If the tests in steps 1906 and 1907 are both satisfied, then step 1908 sets variable f to FFF. Otherwise step 1909 sets variable f to MMM. After any of steps 1901 , 1905 , 1908 or 1909 , step 1910 applies the functions specified by variables f and a to the relevant portions of T f and T a respectively by setting bis to INDICES(LHS(y)) and invoking process TRANSFER.
FIG. 20 shows a flow diagram illustrating process STORE-UGLY, which handles stores to left sides that process STORE-LHS cannot handle. The general idea is that part of the store will completely overwrite some lvalue chunks, and thus kill any definitions that were contained therein. These are the “neatly” killed chunks. The other part of the store might overwrite or partially overwrite some lvalue chunks, and thus damage but not kill definitions that were contained therein. These are the “sloppily” killed chunks. The implementation details follow. Variables g and h are set to the functions for neat and sloppy kills respectively by steps 2000 through 2002 . Step 2000 checks if the store to d is a store by the left side of a definition. If so, step 2001 sets variables g and h to MMM and OMM respectively. The reason for these values is that in the worst case the kill creates a “mixed” definition, except in the case of a sloppy kill to an “outside” definition. Hence step 2001 sets g and h to the function that maps all lattice values onto value M, except that h must map value O onto O. Otherwise, step 2002 sets variables g and h both to OOO. The reason is that the kill imparts an outside influence no matter what, so the values of g and h must then be the functions that maps all lattice values onto value O. Step 2003 initializes neat and sloppy to the empty set, and initializes set bis to INDICES(LHS(y)). All three said sets are sets of vector indices. Steps 2004 through 2009 partition set bis into three sets: neat, sloppy, and an unnamed set that is ignored. Step 2004 checks if set bis is empty. While it is not empty, step 2005 chooses an arbitrary element k and removes it from set bis. Step 2006 inspects whether the lvalue chunk for k overlaps d, as indicated by said alias analysis. If not, the lvalue chunk is unaffected by the store and the value of k is ignored. Otherwise, step 2007 checks whether d not only overlaps, but also strictly contains the lvalue chunk for k. If so, step 2008 adds k to set neat; otherwise step 2009 adds k to set sloppy. After all elements have been removed from set bis, step 2010 invokes process TRANSFER for the “sloppy” kills, with variable a set to DCA, variable f set to h, and set bis set to set sloppy. In likewise fashion, step 2011 invokes process TRANSFER for the “neat” kills, with variable a set to DAA, variable f set to g, and set bis set to set neat.
FIG. 21 shows process TRANSFER, which applies the functions specified by variables f and a to portions of T f and T a specified by the set bis of vector indices. Each time step 2100 determines that set bis is not empty, step 2101 removes an arbitrary vector index k from set bis. For each such index k, the functions specified by variables f and a are composed with the current contents of T f [k] and T a [k], and said contents are updated with the resulting compositions. In some data-flow frameworks, it may be advantageous to directly compute the application of the transfer functions to values rather than computing the functions themselves. In this case, merely remove step 1700 of process ANALYZE-DEF, and change step 2102 to apply f and a to the values. The net effect of said modification is merely the obvious reassociation of (hog)(x) into h(g(x)). Indeed, some forms of data-flow solvers will want both associations, in which case it is advantageous to make T f and T a polymorphic such that they are either vectors of functions or vectors of values, and step 2102 does the kind of update appropriate to the type of vector. Such polymorphism is well known to modern programmers.
Given said computation of transfer functions T f and T a for each instruction x by process ANALYZE-DEF (FIG. 17 ), a data-flow problem is constructed. The problem is to assign to each vertex v of the flow graph two solution vectors S f (v) and S a (v). The kth element of the solution vector S f (v) is denoted S f (v)[k], and is a OMF lattice value representing knowledge about the kth lvalue chunk at the program location corresponding to vertex v. The kth element of the solution vector S a (v) is denoted S a (v)[k], and is a DCA lattice value representing knowledge about the kth lvalue chunk at the program location corresponding to vertex v. The solutions must obey the following constraints. For any edge e in the graph, let w be the tail vertex of the edge and let v be the head of the edge. Let v 0 be the initial vertex of the flow graph that represents where execution of the program begins. Then for any vector index k corresponding to an lvalue chunk, the following four constraints must hold:
(a) S f (v 0 )[k]=F if the lifetime of lvalue CHUNK[k] is local to the part of the program represented by the flow graph, O otherwise.
(b) S a (v 0 )[k]=A.
(c) S f (v)[k]≦T f [k](S f (w)[k]).
(d) S a (v)[k]≦T a [k](S a (w)[k])
Such a solution (for any kind of data-flow problem) is called a fixed-point solution in the literature.
The constraints should be apparent to those skilled in the art of data-flow problems. Here is a rationale for the constraints. Constraint (a) pertains to initial conditions before the program begins. Before the program has begun, only non-local chunks could have been affected by outside influences, as local chunks are created after the program begins. Constraint (b) states that all definitions are absent when the program begins, as no definitions have yet been executed. Constraints (c) and (d) state that the solution must not violate information obtained by process ANALYZE-DEF.
As is common with data-flow problems, the maximal fixed-point solution is preferred. A data-flow framework is employed to solve the data-flow problem. The details of how the framework solves the data-flow problem delegated to the implementor, as many techniques of various power are known. What all these well-known techniques have in common is that the framework upon which they operate can be constructed from primitive operations that compute function application (FIG. 9 ), Kleene closure (FIG. 10 ), function meet (FIG. 11 ), and function composition (FIG. 12 ), or some subset of said primitives. Said primitive operations on lattice values and functions can employ bitwise boolean operations in accordance with FIG. 9, FIG. 10, FIG. 11, and FIG. 12, using said packing of bit vectors. A good primer on the general subject of data-flow frameworks is Chapter 8 of Advanced Compiler Design and Implementation, by Steven S. Muchnick, Copyright ©1997 by Morgan Kaufmann Publishers, Inc., Published by Morgan Kaufmann Publishers, Inc.
The solution to the data-flow problem yields the following information. If no partitioning is done, each lvalue chunk corresponds to the left side of a definition. Then for each definition of an lvalue, a location in the program is reached by the definition if S a (v)[k]≠A, where v is a vertex corresponding to a location and k is the vector index for the lvalue chunk representing the left side of the definition. For each such location reached, S a (v)[k]=D indicates that the support of the left side of the definition has changed since the most recent execution of the definition. Partitioning each left side into separate chunks (Step 301 of FIG. 3, as exemplified in FIG. 4B) and analyzing each chunk separately simply increases the accuracy of the information.
It is well known that for a “reaching definition” problem, there is usually a reverse “reaching use” problem. The method according to the present invention may be modified to solve the “reaching use” problem. The DCA value and function lattices remain the same, only their interpretation changes. Instead of being interpreted as assertions about definitions, they are interpreted as assertions about uses. The OMF value and function lattices are not used.
To find reaching uses, follow the method described by FIG. 3, with step 300 employed to construct a set of candidate uses instead of definitions. Step 301 partitions the lvalues used by the candidate uses, instead of partitioning left sides of definitions. The indices allocated for the chunks of use y are denoted INDICES(y).
FIG. 22 shows a method illustrating process ANALYZE-USE for computing the transfer function T a corresponding to an instruction x. Process ANALYZE-USE is called when the transfer function for each instruction needs to be computed (step 303 of FIG. 3 ). Step 2200 sets all elements of vector T a to the identity function DCA. The sequence dseq is set to the sequence of lvalues loaded or stored by instruction x, in reverse order of their occurrence. Notice that unlike for FIG. 17, sequence dseq includes loads as well as stores. Then step 2203 removes each lvalue d from sequence dseq. Step 2204 assigns to set yset the set of candidate uses (from step 300 in FIG. 3 ). The rest of the steps remove each use from yset and in turn and analyze the effect on it by the reference to lvalue d. Step 2205 checks whether yset is empty, and if not empty, step 2206 removes any definition y from yset, and step 2207 invokes process ANALYZE-REF. Process ANALYZE-REF is described in detail in conjunction with FIG. 23 .
FIG. 23 is a flow diagram illustrating process ANALYZE-REF, which updates T a to reflect the effect of the load or store to an lvalue d on a use y. Step 2300 tests whether the effect on lvalue d is a load. If so, step 2301 checks if the load of d is identical to the use y. If so, step 2302 sets variable a to CCC, sets bis to INDICES(y), and invokes process TRANSFER. If the effect on lvalue d is a store, step 2303 sets bis to INDICES(y). Then step 2304 removes each index k from bis such that CHUNK[k] does not overlap d. The point of this step is to avoid loss of information for chunks that really are not affected by the store. Notice that often d and y will be disjoint, and hence bis will end up empty after step 2304 . Then step 2305 sets variable a to DAA, sets bis to INDICES(y), and performs process TRANSFER. Step 2306 checks if d overlaps the support of y. If so, then the reaching use does not reach cleanly, and step 2307 records this fact by setting variable a to DDA, setting bis to INDICES(y), and performing process TRANSFER. Note that since the OMF lattice is not employed for the reaching uses problem, operations on T f by process TRANSFER (FIG. 21) should be omitted.
Given said computation of transfer function T a for each instruction x by process ANALYZE-USE (FIG. 22 ), a data-flow problem is constructed. The problem is to assign to each vertex w of the flow graph a solution vector S a (w). Each solution vector S a (w)[k] is a DCA lattice value representing knowledge about the kth lvalue chunk at the program location corresponding to vertex v. The solutions must obey the following constraints. For any edge e in the graph, let w be the tail vertex of the edge and let v be the head of the edge. Let w 0 be the final vertex of the flow graph that represents where execution of the program ends. Then for any vector index k corresponding to an lvalue chunk, the following two constraints must hold:
(a) S a (w 0 )[k]=A if the lifetime of lvalue CHUNK[k] is local to the part of the program represented by the flow graph; otherwise
(b) S a (w 0 )[k]=C if (a) does not apply and the support of lvalue CHUNK[k] is known not to change once the part of the program represented by the flow graph is exited.
(c) S a (w 0 )[k]=D if neither (a) nor (b) apply.
(d) S a (w)[k]≦T a [k](S a (v)[k]).
Notice that since this is a backwards data-flow problem, the roles of head and tails of edges is reversed from that of the earlier described forwards-flow problem.
The constraints should be apparent to those skilled in the art of data-flow problems. Here is a rationale for the constraints. Constraints (a)-(c) pertain to final conditions beyond the part of the program represented by the flow graph. Constraint (d) states that the solution must not violate information obtained by process ANALYZE-USE.
The solution to the backward data-flow problem yields the following information. If no partitioning is done, each lvalue chunk corresponds to a use. Then for each use of an lvalue, a location in the program is reached backwards by the use if S a (w)[k]≠A, where w is a vertex corresponding to a location and k is the vector index for the lvalue chunk representing the use. For each such location reached, S a (w)[k]=D indicates that the support of the use will change before the next execution of the use. Partitioning each use into separate chunks (Step 301 of FIG. 3) and analyzing each chunk separately simply increases the accuracy of the information.
The method according to the present invention may be extended to consider the actions of creation or destruction of an lvalue when computing the transfer functions. In either case, the lvalue becomes undefined, and any definitions of it become “absent” and “mixed” (not forwardable). If part of the support of the left side of a definition becomes undefined, then the associated transfer functions are DDA and OMM, as the definition is dirtied unless absent, and certainly no longer forwardable. If the support of the right side of a definition becomes undefined, then the associated transfer functions are DCA and OMM, as the definition's DCA-lattice value is unaffected, but it is no longer forwardable.
A method in accordance with the present invention is faster than prior art because it applies a single framework that simultaneously tracks whether a definition reaches, and whether its support has changed. Like prior art, it handles aggregates by dividing them into chunks, but requires fewer bits per chunk. For a definition partitioned into n chunks, the solver requires 4n and 6n bits respectively to represent the lattice values and functions. Said factor of 4 arises from the 2 bits required to represent a DCA lattice value and the 2 bits required to represent an OMF lattice value, which is a total of 4 bits. Said factor of 6 comes from the 3 bits required to represent a DCA lattice function and the 3 bits required to represent a OMF lattice function, which is a total of 6 bits. Though the 4n is slightly worse than the 3n+6 for prior art when n>6, it is much better in the common case of optimizing scalar variables, for which n=1. Despite a significantly more complicated lattice formulation, the framework is still implemented via classical bit-vector techniques.
The method in accordance with the present invention greatly improves over the prior art in accuracy, making possible optimizations that were previously missed. For instance, in the problem posed by FIG. 1, the method of the present invention computes that definitions 100 and 101 are forwardable into the use by “q=p”, since the solution at the tail of the latter's arrow, the OMF part of the solution is F. In the problem posed by FIG. 2, the method of the present invention computes that definition 200 is cleanly killed by definitions 201 along paths that include definition 201 , and thus it reaches cleanly at the tail of the edge with definition 202 , which cleanly kills it too. The classical algorithm for finding dead stores by taking the complement of the transitive closure of live stores is simply extended by considering a definition to reach if any lvalue chunk reaches, dirtily or cleanly.
Any optimization that employs traditional definition-use, use-definition, use-use, or definition-definition information can be extended to arbitrary lvalues by employing the more general analysis of the present invention. The extensions come in two flavors. The first extension is to aggregates, and this is straightforwardly done by examining the solution to the data-flow problem for each lvalue chunk of interest. The extension to lvalues with non-constant addressing expressions is more complicated, because the present invention introduces two flavors of reaching definitions: those that reach cleanly, i.e. their left-side support has not changed, and those that reach dirtily, i.e. their left-side support has changed.
The extension of some optimizations will obviously require that definitions reach cleanly for best effect. For example, the method of replacing lvalues by variables described by U.S. Pat. No. 5,710,927, assigned to the assignee of the present application, computes least-general-unifiers (LGU) for definition-use information. When a definition reaches a use cleanly, the LGU can be as narrow as the use, but when a definition reaches dirtily, the LGU must be as wide as the outermost lvalue that contains the definition's left side.
Predicated analyses of traditional simple scalar variables can be extended to predicated analyses of arbitrary lvalues by employing features of the present invention.
The method for compact encoding of lattice values has application wherever the meet or join of lattice values need be computed, and space is at a premium.
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A method for analyzing and optimizing programs that contain pointers or aggregates or both, such as found in the languages C, C++, FORTRAN-90, Ada, and Java is disclosed. The program is represented as a control flow graph. The method applies to storage locations (lvalues) computed by instructions in a program. The data flow analysis distinguishes when a definition might reach a use, and if so, whether the expression defining the address of the defined lvalue may have changed. The method ignores changes to the addressing expression where a definition does not reach. The lattice values and functions employed by the analysis are compactly represented as packed bit vectors, and operated upon in a parallel bitwise fashion. Despite the generality of definitions that define lvalues specified by expressions, the present invention computes the reachability of the definitions with a single data-flow framework that requires only one fixed-point solution per data-flow problem.
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The invention relates to methods of sewing, and more particularly to improvements in free form sewing, and to mechanisms for practicing those methods. Free form sewing is often used with quilting operations and thread painting, and, when quilting, is typically concerned with a multi-layered workpiece. Essentially, free form sewing is the movement of the workpiece material being sewn by moving that material with the sewing machine operator's hands in relation to the needle and thread of the sewing machine so that the patterns made by the stitching, whether doing quilting or thread painting, is free form in style and design.
BACKGROUND OF THE INVENTION
In free form sewing, the feed teeth that normally advance the material as each stitch is made are not used. All of the movements of the workpiece material are accomplished by the hands of the sewing machine operator. Some sewing machines have the ability to retract the feed teeth so that they do not engage the material being sewn. Others, usually very simple portable or even battery powered sewing machines, do not have retractable feed teeth, and it is more difficult to do free form sewing when they are in place, even if they can be disabled from movement. Even when the feed teeth are retracted or rendered inoperable there are still parts of the sewing machine that do not permit full free form sewing without any of those parts engaging the material being sewn, and the sewing machine operator has to work around them and at times lift up the material being sewn so that there is no engagement of any machine parts in the vicinity of the needle, presser foot and needle plate, which is also a bobbin cover, with the material being sewn.
Prior to the invention herein disclosed and claimed, the workpiece was just moved over the workpiece surface of the sewing machine. This is not practical unless the feed teeth are not only disabled, but are moved below the sewing machine workpiece surface so that they do not engage the workpiece material at any time during the free form sewing operation. Also, the needle plate has openings therein and one or more upper edges thereof may at times not be in perfect planar alignment with the sewing machine work surface, and the work surface itself may have a coefficient of friction which is sufficiently high to cause some resistance to easy sliding movement of the workpiece directly over the sewing machine work surface. Some unheeded deposits may be on that surface and inadvertently provide impediments to smooth workpiece movements, such as residue from various glue-like substances used in sewing at times. Any unneeded resistance to smooth free form movements of the workpiece can adversely affect results of the free form sewing of the workpiece as the sliding force exerted thereon by the operator's hands, causing the final sewn product containing the particular results thereof to be less smooth or free-flowing than desired. Therefore, it is advantageous to provide a smooth low coefficient of friction work surface on the work support sheet or panel which may be easily and inexpensively replaced by the sewing machine operator if it develops any adverse flaws after use or storage or handling, minimizing the problems that may occur with a higher coefficient of friction work surface which is typically provided on the work surface of sewing machines or the likelihood that the feed teeth can be in position to engage some part of the workpiece material, adversely affecting the smooth movements of the workpiece material being sewn as the hands of the sewing machine operator move that workpiece material while free form sewing.
BRIEF SUMMARY OF THE INVENTION
The method embodying the invention employs a thin plastic sheet or panel as a workpiece support material that has a low coefficient of friction (COF), and is preferably flexible yet somewhat stiff. It also employs a sewing machine of the type having a bobbin containing sewing thread, one or more spools containing other sewing thread, a needle mounted in a needle clamp assembly movable to move the needle manually downwardly and upwardly, a presser foot, a work surface, and a workpiece to be sewn. An example of a preferred embodiment of such a polymer sheet or panel is one that is made of Teflon® Polytetrafloroethylene (PTFE) from DuPont. This material has a low COF in the range of 0.03-0.15, depending on the load placed on the sheet or panel, the sliding speed of a particular material surface on and relative to the low COF of the sheet or panel, and the particular Teflon® finish used. This entire range of COF is satisfactory in practicing the method herein disclosed and claimed. Because of the very low loads placed on the workpiece material and therefore on the low COF surface of the sheet or panel engaged by the workpiece material, and slow sliding speeds on the interface between the Teflon® workpiece support sheet or panel and the workpiece, as well as the finish of typical commercially available thin Teflon® sheets and panels, the lower portion of the range of COF, 0.03 to about 0.08 is particularly satisfactory.
Other members of the families of Fluoropolymers, Polyimides and Acetal plastics may be used so long as they meet the workpiece support material requirements set forth above. Nylon is an example of the Polyimide family. Delrin® and Celcon® are examples of the Acetal family. It is well known that different ones of the members of these families have different ranges of COF, as well as other characteristics, and that some of them are provided in forms that do not meet these workpiece support material requirements, while other variations thereof can do so. It is only such variations that are usable in the method embodying the invention. Some may have a slightly higher COF upper range limit than 0.15, at times up to about 0.20 range. While these obviously may have a COF range which makes them less slippery than those in the lower COF range, they can perform adequately so long as the COF of the material used is lower than the COF of the standard work surfaces of sewing machines. Most of these materials can be checked out on web pages of DuPont, and the choice of the particular material is usually one that is relatively inexpensive, and has a sufficiently low COF to be able to slide the cloth workpiece around on the surface in the manner of free motion sewing. Thus, the preferred range of the COF of the material being used is from 0.02 to about 0.08, with a satisfactory COF range extending upwardly to about 0.20.
There is a distinction made between the static COF (at the point of incipient motion) and the dynamic or kinetic COF (measured at constant velocity). The difference between the static COF and the dynamic or kinetic COF is known as “slip-stick” and the numerical difference is the slip-stick value. Static friction is greater than dynamic or kinetic friction, and therefore the coefficients of friction for these two conditions are usually of different values. By way of example, with steel on steel, the static COF is 0.74 and the kinetic COF is 0.57; aluminum on steel, the static COF is 0.61 and the kinetic COF is 0.47; rubber on concrete, the static COF is 1.0 and the kinetic COF is 0.8; lubricated metal on metal, the static COF is 0.15 and the kinetic COF is 0.06; ice on ice, the static COF is 0.1 and the kinetic COF is 0.03; and Teflon®on Teflon® in both static and kinetic COF is 0.04.
Polymers such as Teflon® with a low (even 0.0) slip-stick value are industrially used for parts which undergo back-and-forth or stop-and-go movements. Typical industrial uses are under relatively much heavier loads and more stringent stop-and-go movements than are used in practicing the methods herein disclosed and claimed. The very light loads placed on the polymer sheet or panel used, being only that the weight of the workpiece material itself, which is usually very light, and the loads impressed by an operator's hands on the workpiece material. These hand-applied loads or forces are only sufficient to easily move the workpiece around on the polymer sheet or panel while the sewing machine is sewing free form stitches, render the slip-stick value of the particular polymer in relation to the typical cloth sewing materials substantially unnoticeable, even if it exists at all, to the sewing machine operator, and therefore the range of the COF, whether static or dynamic (kinetic) under such light loading and stop-and-go movements, is about the same under either type of COF. Therefore, other polymers having a similar range of COF to that of Teflon® may be used, so long as they are available in relatively thin flexible sheets or panels and are capable of being pierced by a sewing needle or a die punch and thereafter allowing the sewing needle to move into and out of the hole if such a sheet or panel formed by that piercing, as occurs during a sewing operation employing the polymer sheet or panel.
The polymer sheet or panel used in the development and reduction to practice of the invention herein disclosed and claimed has been easily rolled up onto a tube form for temporary storage, or just stored in a file folder, by way of example, without any substantial bending or rolling thereof. Also, it has been able to lie over unretracted feed teeth of a sewing machine and be sufficiently flexible to have most of its lower surface remain in contact with the work surface of the sewing machine as the sewing machine operator moves a free form sewing workpiece around while sewing on it. These characteristics are desirable in all plastic sheets or panels when practicing the invention herein disclosed and claimed.
One method embodying the invention employs the steps of: (1) placing a suitable plastic sheet or panel of workpiece support material so that it is under the sewing needle when the presser foot and the needle are positioned in their upward positions; (2) manually moving the presser foot down into engagement with the workpiece support material, holding the workpiece support material in place under the needle; (3) manually moving the needle downwardly until it has pierced through the workpiece support material and, at or near the bottom part of its sewing stroke, forming a hole therein; (4) anchoring the corners or outer edges of the workpiece support material to the flat plate of the sewing machine by use of suitable removable anchoring means such as Scotch® Tape or similar tape; (5) removing the needle upwardly out of the pierced opening in the workpiece support material; (6) placing a workpiece to be sewn by free form sewing under the needle so that it can be sewn, with the workpiece lying on the workpiece support material; and (7) operating the sewing machine to sew the workpiece in a desirable free form pattern or thread painting process, moving the workpiece by sliding it around by hand on the low coefficient-of-friction upper surface of the workpiece support material.
A modification of the method aspect of the invention herein described and claimed involves the above-numbered steps (3) and (5), in which the sewing needle may be moved downwardly to mark the position of an opening which is then formed by other means such as drilling or die punching the opening through the workpiece support material as a separate step taking place with that material having been removed from the sewing machine to perform that drilling or punching step, after which the material may serve as a pattern to make other such plastic sheets or panels having the same opening location therethrough and adapted to be used on other sewing machines on which the additionally made workpiece support materials are respectively secured with each such opening being in alignment with the sewing needle of each such other sewing machine. At times, the position of the drilled or punched opening on the plastic sheet or panel may be calculated and the opening created without requiring the needle to mark on a particular plastic sheet or panel the point where the drilling or punching to make the opening. Different patterns or measurements for the location of an opening for different other sewing machines may be made or calculated as needed, and other workpiece support materials may have openings formed therethrough to match such other sewing machines. At times, it is within the purview of the invention for one workpiece support material to have two or more such openings, each one being located to be used with a specific different machine layouts.
The mechanism embodying the invention includes the work support material, also known as the work surface slider, having a low COF in the order of about 0.03 to 0.20, with a preferred range in the order of 0.03 to about 0.08, although the higher end 0.20 of the COF range noted will work sufficiently well to be advantageous to some extent. It also includes an opening properly positioned on and through the plastic sheet or panel forming the work surface slider to allow the sewing needle and the strand of sewing thread from the bobbin to pass therethrough during the sewing operation, such opening being located by any of the several procedures set forth above and formed by any known methods of locating and forming an opening through such a plastic sheet or panel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical sewing machine, shown in simplified form, with the low COF sheet or panel constituting the work surface slider being shown in place with dashed lines.
FIG. 2 is a view taken in the direction of arrows 2 — 2 of FIG. 1 , with parts broken away and a part of the needle and presser foot ankle mount being in cross-section.
FIG. 3 is a view similar to FIG. 2 , but with the plane of view being below the lower end of the needle and the bottom of the pressure foot so that only the opening in the workpiece support and slider material made by the needle is visible, with the sewing needle extending through that opening and the presser foot engaging the upper surface of the work surface slider.
FIG. 4 is a view similar to FIG. 1 , showing the workpiece material on top of the workpiece support and slider material, and the hands of a sewing machine operator engaging the workpiece material and having moved that material around on the workpiece support and slider material to create a design being sewn in free form.
DETAILED DESCRIPTION OF THE INVENTION
The sewing machine 10 of FIGS. 1 and 4 is intended to generically represent any electric sewing machine which has been, is, or later shall be on the market, whether it is one of the high end, digitally programmed and controlled types, one of the lower end ones where relatively few if any options as to stitches and patterns, etc., are available, to the low end sewing machines such as portable ones which only sew with one type of stitch, yet are adequate for very simple sewing, and may be powered by one or more batteries, or even by a hand crank. One basic characteristic of all such machines is that they have a work surface, a needle for sewing using a thread supply, and a presser foot, and are capable of manual movement of the needle sufficient to punch a hole in the workpiece support material, or to mark the position through which an opening is to be separately formed, if that position is not otherwise determined, as will be described.
The drawing of the particular sewing machine 10 shown in FIG. 1 is a simplified drawing of the more upscale type such as a Husqvarna® Viking Series I® sewing machine, that particular sewing machine being used only for illustrative purposes. The invention is not limited td use only with that type of machine, but is usable with any sewing machine which may be operated as described. The sewing machine 10 has a housing providing a base 12 , a head 14 and a head support 16 so that a portion of the base 12 is a free arm 18 extending underneath the head 14 . The upper surface of the free arm 18 provides a work surface 20 having a needle plate 22 covering the bobbin area. A pair of parallel-positioned feed teeth 24 extend upwardly through the needle plate and are in position to move a workpiece material during normal sewing operations. When it is desired, feed teeth 24 may be moved downwardly from the position in which they may engage the workpiece material when desired to a position where they are below the surface of the needle plate. There is also a needle opening 26 in the needle plate 22 , through which a sewing needle 28 may be moved in a reciprocal manner during the sewing process to have a needle thread, not shown, pick up a thread, not shown, from a bobbin located under the needle plate 22 each time a stitch is sewn, as is well known in the art of sewing machines. A presser foot 30 is mounted on a presser foot bar and ankle 32 and the needle 28 extends through the presser bar and ankle 32 . Presser foot 30 may be moved toward and away from the needle plate 22 in vertical directions to selectively engage a workpiece material while sewing and to release the workpiece material from its being-sewn position when it is desired to move or remove or replace the workpiece material from under the needle 28 and the presser foot 30 . Needle 28 is secured to the needle bar 34 by a needle clamp screw 36 . The needle bar 34 is connected to a mechanism in the head 14 so that it is driven in a reciprocal manner as the stitches are sewn, moving the needle into and out of the needle opening 26 during each sewing stitch operation. The sewing machine 10 also includes a generally U-shaped accessory tray 38 which fits on and about the free arm 18 . Tray 38 has a top surface forming a work surface extension 40 which is in coplanar relation with the work surface 20 of the free arm 18 , thus providing a larger total work surface which directly supports the workpiece material being sewn during normal sewing operations.
FIG. 1 also shows, in dashed lines, the position of the work surface slider 42 shown in full view in FIGS. 2 , 3 and 4 . Work surface slider 42 is a sheet or panel of an appropriate plastic material have a low COF as above described. It is illustrated as being a rectangular sheet having a total area and dimensions so that it fits over the extended work surface area 44 formed by work surface 20 and work surface extension 40 , but is preferably slightly smaller than that extended work surface area in all directions. Of course, it may have shapes other than rectangular and for this reason it is also referred to as a panel. FIG. 1 also shows several fastening tapes 46 which are used to fasten the work surface slider in position as will be described below with regard to FIGS. 2 , 3 and 4 .
FIG. 2 shows the work surface 20 , which is the upper surface of the free arm 18 , and a cross section of a part of the head support portion 16 of the sewing machine housing. It also shows the work surface extension 40 of the accessory tray 38 . The work surface 20 and the work surface extension 40 combine to form the sewing machine's extended work surface area 44 . It also shows the work surface slider 42 in position over a portion of the extended work surface area 44 , with the sewing needle 28 extending through the opening 48 which has been formed with the work surface slider 42 in the position shown and secured in that position by the tapes 46 . Since the work surface slider 42 is shown in the shape of a rectangle, there is a tape 46 securing each of the four corners 50 of it to the extended work surface area 44 . Of course, the work surface slider may have other planar shapes as may be desired so long as the intent of the invention is capable of being carried out, and the tape locations are then located accordingly to secure the work surface slider 42 in the desired position. It is advantageous but not necessary to use the removable type of tapes, which have sufficient retention power but can be removed easily when desired. These tapes are preferably thin, self-sticking tape sections such as 3M's Scotch® tape. They adhere to the work surface slider corners 50 and also to portions of the extended work surface 44 , holding the work surface slider 42 in position so that, when the sewing needle 28 is retracted upwardly out of the opening 48 , the sewing needle and that opening remain in axial alignment so that the sewing needle 28 , when moved downwardly in each stitch operation, freely reenters the opening 48 , shown in FIG. 3 but not shown in FIG. 2 and located directly under the sewing needle 28 , and does not pierce through the work surface slider 42 at another point and create more, unneeded, openings through it so long as the work surface slider is being used on one sewing machine. The maintenance of this alignment of the sewing needle 28 and the opening 48 during the entire free form sewing operation is therefore important.
FIG. 3 is similar to FIG. 2 , but shows, in section, the sewing needle 28 and the presser foot ankle mount 52 , which are in position so that the presser foot 30 is in engagement with the work surface slider 42 while the sewing needle 28 is extended through the opening 48 and the needle plate opening 22 , having pierced through the work surface slider 42 to form opening 48 . Once the work surface slider 42 is secured to the extended work surface 44 and the opening 48 has been formed, the sewing needle 28 and the presser foot 30 are retracted upwardly. The upper surface 54 of the work surface slider provides a surface for supporting the workpiece material to be sewn. FIG. 3 also shows a variation of the invention wherein another opening 48 ′, similar to opening 48 , is provided so as to be located properly for use with a different make or model of sewing machine where the sewing needle is differently located relative to the machine's work surface 44 . This makes one such work surface slider 42 more versatile by having it prepared to work with another sewing machine. At times even more such openings may be provided to prepare one work surface slider 42 to work with still other makes and models of sewing machines.
A workpiece material 56 , illustrated in FIG. 4 , is then inserted under the sewing needle 28 and the presser foot 30 , located where the sewing machine operator wants to begin free form sewing, and the presser foot is lowered to engage the upper surface of the workpiece material 56 . This workpiece 56 may be a single layer or several layers of material. When it is to be a part of a quilt, it typically has a lower layer and an upper layer, with batting or other filler material between those layers. The under side of the workpiece material is in slidable engagement with the low COF work support surface 54 . When the sewing operation begins, these layers and the filler material are sewn together, and the pattern made by the sewing is formed on the material layers in free form creation by the operator placing his/her hands 58 on the workpiece material on either side of the sewing needle 28 and the presser foot 30 , and freely moving the workpiece material around relative to the sewing needle by sliding its lower surface on the low COF work support surface 54 provided by the work surface slider 42 . This low COF characteristic of the work support surface 54 allows virtually free, no-sliding-resistance movements of the workpiece material, allowing the machine operator to free form the exact stitch design desired on the workpiece material with no significant drag.
This sewing operation is illustrated in FIG. 4 , which is similar to FIG. 1 . The work surface slider 42 is shown as having been fastened by tapes 46 , located at or near its corners 50 , to the extended work surface area 44 of the sewing machine 10 , after having had the opening 48 formed therethrough by one of the methods described and claimed. The workpiece material 56 has been placed on top of the upper surface 54 of the work surface slider 42 , and the sewing machine operator, whose hands 58 are shown, has done some free form sewing, illustrated as the pattern 60 sewn on the workpiece material 56 . As is common in sewing, the workpiece material 56 is larger than the sewing machine extended surface 44 , and some part 62 of it extends over the back side of the accessory tray 38 which forms a part of surface 44 , some other part 64 of it extends over the front side of that tray and in front of the sewing machine operator. If its width is greater than the length of surface 44 , it is commonly gathered together as shown at 66 . The portion 68 in the immediate vicinity of where the sewing operation takes place is held tight and flat by the hands 58 of the sewing machine operator.
When the feed teeth 24 are not retracted, or are not even retractable, the work surface slider 42 covers them and is sufficiently flexible to engage the major portion of the typically higher COF extended work surface 44 so that the feed teeth do not interfere with the smooth sliding operation of the workpiece material on the low COF surface 54 as the free form sewing process is carried out. The work surface slider 42 is sufficiently strong that the feed teeth, if they engage the bottom surface of slider 42 , do not damage it so as to cause any crack therein which would interfere with the free sliding action of the workpiece material on the work support surface 54 .
A work surface slider 42 has been made from Teflon® sheet material having a thickness of 0.010 inch, such as is commercially available from Interplastic Inc. of Burlington, N.J. It is specifically identified by that source as “virgin PTFE film,” is available in sheet rolls of 12″ in width and various thicknesses, including 0.005, 0.010 and 0.015 inch and thicker. This is an appropriate width of the plastic stock from which the work surface slider 42 is to be made because of the dimensions of the typical sewing machine work surface 44 , and any particularly desired size sheet or panel may be cut from the roll. The 0.005 inch thickness, while having been tried and found to be usable, is relatively flimsy and not as easy to manage as a somewhat higher thickness. Therefore, it is not as desirable as a somewhat thicker sheet. Furthermore, it is to be understood that, while it is preferable to use a single layer for the flexible sheet or panel, it may be made in two or more layers, it only being required as a minimum that one outside layer thereof be made of a plastic material having its COF within the desired range. The 0.005 inch thick Teflon®PTFE material noted above could serve as the top or uppermost layer of such a multiple-layer slider 42 . Of course, a single layer sheet of the appropriate plastic material is usually desired because it is usually considerably less expensive that making a multi-layered sheet or panel, and may have the COF of both of its sides within the desired range, often permitting each of the two sides of the slider 42 to be used at various times.
As the Teflon® sheet or panel to be used as a work surface slider 42 is increased in thickness, its flexibility decreases. When its flexibility is decreased it reaches a point where it is not sufficiently useful in practicing the invention because it is then too thick to flex so as to be supported by and in engagement with most of the work surface 44 immediately under it. Thus there are practical limits to the sheet or panel thickness because of this lack of flexibility or its being overly flexible. As the sheet or panel 42 is decreased in thickness, it reaches a point that, while still usable in a single thickness, it is not preferred because it is too flimsy for easy manipulation and use. Thus, the desirable range of thickness is 0.010 to about 0.030 inch, the actual limit of such upper measurement of its thickness is to be understood to be that beyond which the material is not sufficiently flexible as above required. With different materials, these thickness ranges may be different. A particular thickness of a particular material to be used in any particular application is readily determined by simple trial using sheets of several thicknesses and selecting the one with the characteristic that best fits the purpose when practicing the invention.
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A method and mechanism for free form sewing in which the workpiece is being sewn on a sewing machine having a plastic sheet or panel secured to the sewing machine work surface which has a coefficient of friction in any of several ranges which are all considered to be low friction coefficients. Depending upon the plastic material used, the coefficient of friction of any particular material may be in the range of 0.02 to 0.20, or in smaller ranges of coefficients of friction. The objective in using the method or mechanism is to permit the workpiece being sewn by free form sewing to be moved more easily with less frictional resistance by the hands of the sewing machine operator. Various plastics usable include various types of Teflon.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention related to a first driving element, a second driving element and an enhancement mode FET for rectifier driving circuit, especially FET there is not an intrinsic body diode can be achieve rectify function.
[0003] 2. Description of Related Arc
[0004] FIG. 7 shown a structures of the prior art half-wave rectifier. In this figure, FET F 1 is responsible for rectification. In operation, when positive of AC power source in the terminal A, terminal B is negative, FET F 1 turned on, FET F 1 acts as a rectifier, the path of the current flow is from terminal A of AC power source though a load LD, FET F 1 and back to terminal B; when negative of AC power source in the terminal A, terminal B is positive, FET F 1 turned off, the path of the current flow is from terminal B of AC power source though intrinsic body diode DB of the FET F 1 , a load LD and back to terminal A, may be burnout by current of the prior art FET F 1 , and FET F 1 having no responsible for rectification.
SUMMARY OF THE INVENTION
[0005] In order to provide a first driving element, a second driving element FET having no intrinsic body diode that may elevate the efficiency of half-wave rectifier, the present invention is proposed the following object:
[0006] The first object of the present invention provide a driving circuit for a rectifier, in which the rectifier simplicity is improved.
[0007] The second object of the present invention provide a diode parallel to the FET for surge current protection.
[0008] According to the defects of the prior art technology discussed above, a novel solution, the rectifier driving circuit is proposed in the present invention, which provides simplicity and for surge current protection in rectifier circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shown the structures of a prior art N-Channel FET.
[0010] FIG. 2 shown the structures a having no intrinsic body diode N-Channel FET.
[0011] FIG. 3 shown the structures of a diode parallel to the N-Channel FET, a P-junction of the diode connected to drain of the N-Channel FET, a N-junction of the diode connected to source of the N-Channel FET.
[0012] FIG. 4 shown the structures of a prior art P-Channel FET.
[0013] FIG. 5 shown the structures a having no intrinsic body diode P-Channel FET.
[0014] FIG. 6 shown the structures of a diode parallel to the P-Channel FET, a N-junction of the diode connected to drain of the P-Channel FET, a P-junction of the diode connected to source of the P-Channel FET.
[0015] FIG. 7 is a circuit diagram of a prior art N-Channel FET for half-wave rectifier circuit.
[0016] FIG. 8 is a circuit diagram of a first embodiment of the present invention.
[0017] FIG. 9 is a circuit diagram of a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIG. 1 shows the structures of a prior art N-Channel FET, a N-junction of the intrinsic body diode DB connected to drain of the prior art N-Channel FET, a P-junction of the intrinsic body diode DB connected to source of the prior art N-Channel FET.
[0019] FIG. 2 shows the structures of a N-Channel FET having no intrinsic body diode, has a enhancement mode FET.
[0020] FIG. 3 shows the structures of a diode parallel to the N-Channel FET, a diode parallel to the N-Channel FET for surge current protection in the rectify circuit.
[0021] FIG. 4 shows the structures of a prior art P-Channel FET, a P-junction of the intrinsic body diode DB connected to drain of the prior art P-Channel FET, a N-junction of the intrinsic body diode DB connected to source of the prior art P-Channel FET.
[0022] FIG. 5 shows the structures of a P-Channel FET having no intrinsic body diode, has a enhancement mode FET.
[0023] FIG. 6 shows the structures of a diode parallel to the P-Channel FET, a diode parallel to the P-Channel FET for surge current protection in the rectify circuit.
[0024] As shown in FIG. 8 , has a AC power source input terminal, a first terminal A and second terminal B of the input terminal, a N-Channel FET Q 1 , a first driving element R 1 , a second driving element D 1 , D 2 . . . DN, and a load LD.
[0025] A inrush diode DP parallel to the N-Channel FET Q 1 shown in FIG. 8 , a driving circuit comprises a voltage drop resistor R 1 and a diode D 1 or series-connected with D 1 , D 2 . . . DN diodes; the P-junction of D 1 , D 2 . . . DN diodes connected to gate of the N-Channel PET Q 1 , the N-junction of D 1 , D 2 . . . DN diodes connected to source of the N-Channel FET Q 1 , the driving voltage is equal to the forward voltage of series-connected of D 1 , D 2 . . . DN diodes.
[0026] As shown in FIG. 8 , when positive of AC power source in the terminal A, terminal B is negative, the P-junction is positive of the series-connected D 1 , D 2 . . . DN diodes, the N-junction is negative of the series-connected of D 1 , D 2 . . . DN diodes, the N-Channel FET Q 1 is turned on, the driving voltage is equal to the forward voltage of series-connected of D 1 , D 2 . . . DN diodes, the path of the current flows is from terminal A of the AC power source though a load LD, a N-Channel FET Q 1 , and back to terminal B of the AC power source.
[0027] As shown in FIG. 8 , when negative of AC power source in the terminal A, terminal B is positive, the P-junction is negative of the series-connected of D 1 , D 2 . . . DN diodes, the N-junction is positive of the series-connected of D 1 , D 2 . . . DN diodes, the N-Channel FET Q 1 is turned off, the rectifier is open circuit.
[0028] As shown in FIG. 9 , has a AC power source input terminal, a first terminal A and second terminal B of the input terminal, a P-Channel FET Q 2 , a first driving element R 1 , a second driving element D 1 . . . DN, and a load LD.
[0029] A surge diode DP parallel to the P-Channel FET shown in FIG. 9 , a driving circuit comprises a voltage drop resistor R 1 and a diode D 1 or series-connected with D 1 , D 2 . . . DN diodes; the N-junction of D 1 , D 2 . . . DN diodes connected to gate of the P-Channel PET Q 2 , the P-junction of D 1 , D 2 . . . DN diodes connected to source of the P-Channel PET Q 2 , the driving voltage is equal to the forward voltage of series-connected of D 1 , D 2 . . . DN diodes.
[0030] As shown in FIG. 9 , when positive of AC power source in the terminal A, terminal B is negative, the P-junction of the diode D 1 is positive of the series-connected D 1 , D 2 . . . DN diodes, the N-junction of the diode DN is negative of the series-connected of D 1 , D 2 . . . DN diodes, the P-Channel FET Q 2 is turned on, the driving voltage is equal to the forward voltage of series-connected of D 1 , D 2 . . . DN diodes, the path of the current flows is from terminal A of the AC power source though a P-Channel FET Q 2 , a load LD, and back to terminal B of the AC power source.
[0031] As shown in FIG. 9 , when negative of AC power source in the terminal A, terminal B is positive, the P-junction is negative of the diode D 1 of the series-connected of D 1 , D 2 . . . DN diodes, the N-junction of the diode DN is positive of the series-connected of D 1 , D 2 . . . DN diodes, the P-Channel FET Q 2 is turned off, the rectifier is open circuit.
[0032] The operation principle of the second driving element D 1 , D 2 . . . DN of FIG. 8 and the second driving element D 1 , D 2 . . . DN of FIG. 9 is same, both of the second driving element can be use a series-connected circuit of diode and zener diode replace, the driving voltage is equal to the forward voltage of diode and zener voltage of zener.
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A rectifier driving circuit of the present invention, has a first driving element and a second driving element, switching element comprises a FET, a first driving element comprises the voltage drop resistor, a second driving element comprises the series-connected circuit of the diodes, the driving element for driving a FET, may be achieved rectify function.
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BACKGROUND OF THE INVENTION
The invention concerns a method for producing structures or contours on a workpiece in which in a moulder with at least one rotatably driven tool the structure or contour is produced by workpiece removal on the workpiece. The invention also concerns a moulder, in particular for performing such a method, comprising at least one transport path for the workpieces, along which the workpieces are transported through the moulder for machining, and comprising rotatably driven tools of which at least one tool is provided for producing a structure or contour in the workpiece.
It is known to produce by means of a tool on the surface of a workpiece structures, also referred to as relief surface. In this context, the tool is adjusted in at least two directions relative to the workpiece.
The invention has the object to design the method according of the aforementioned kind and the moulder of the aforementioned kind such that, in a simple way, the desired structures or contours can be produced on the workpiece with high precision and reliably.
SUMMARY OF THE INVENTION
This object is solved for the method of the aforementioned kind in accordance with the invention in that, as a function of the data of the workpiece and of the tool, the tool positions along the workpiece for generating the structure or contour are defined and the data are transmitted to the machine controller, which executes the CNC program that is based on the data during passage of the workpiece through the moulder and adjusts the tool into the required positions by CNC drives as a function of the workpiece position, and in that the workpiece position is detected upon passage of the workpiece through the moulder. The object is solved for the moulder of the aforementioned kind in accordance with the invention in that, for detecting the workpiece position in the moulder, in front of and behind the tool at least one measuring element is provided that is connected to the machine controller and supplies signals that describe the feeding travel of the workpiece to the machine controller, with which, in accordance with the signals, the tool is adjusted into the respective tool positions.
In the method according to the invention, the tool positions along the workpiece for producing the structure or contour are determined as a function of the data of the workpiece and of the tool. The data are transmitted to the machine controller which executes the CNC program based on these data during workpiece passage through the moulder. As a function of the workpiece position, the tool is adjusted in the feeding direction into the required positions in order to obtain the desired structure or contour on the workpiece. By means of the workpiece data, tool data, and tool position data, any structure or contour on the workpiece can be produced. Workpiece data are, for example, the length, the width, and the thickness of the workpiece.
As data of the tool, advantageously the data that determine the contour or the profile of the tool can be input and saved. The tool, depending on the kind and/or shape of the structure or contour of the workpiece, can have different contours or profiles.
A reliable and precise generation of the structure or contour results when the tool positions of the tool are determined and preset in fixed steps along the workpiece. In this way, appropriate workpiece positions can be defined and saved, for example, in millimeters steps, respectively. In this way, the structures or contours can be produced very precisely.
Advantageously, the tool positions are determined for circumferential milling in axial and/or radial direction of the tool. The axial position of the tool indicates at which location transverse to the feeding direction, i.e., relative to the width of the workpiece, the tool machines the workpiece. The radial position value indicates how deep the tool penetrates into the workpiece. In case of tool profiles that are V-shaped or circular segment-shaped, the structure is the wider the greater the penetration depth. When the tool penetrates only little into the workpiece, then the structure is correspondingly narrow. Accordingly, by means of the axial tool position, the position of the structure on the workpiece, and by the radial tool position, the depth and optionally the width of the structure can be set.
It is advantageously possible to predetermine and save also the angular position of the tool in two planes relative to the feeding direction of the workpiece. In the simplest case, the axis of rotation of the tool is perpendicular to the feeding direction and parallel to the surface of the workpiece to be machined. When the axis of rotation, on the other hand, is positioned at an angle deviating from 90° relative to the workpiece feeding direction or deviating from 0° relative to the surface, further effects of the structure or contour can be achieved.
A precise control and thus production of the structure or contour results when the tool is adjusted, as a function of the workpiece position, by CNC drives into the required axial and/or radial positions that are determined by the program as the workpiece passes through the moulder.
The workpiece position in the moulder is advantageously detected by at least one sensor. It can be, for example, part of a photoelectric barrier with which, for example, the leading end of the workpiece can be detected.
The signal of the sensor is advantageously utilized as a reference for the position detection of the workpiece by at least one measuring element. The method according to another embodiment is characterized in that several measuring elements are employed in the moulder for position detection of the workpiece. Their measured values are transmitted in a cascade fashion. For example, the first measuring element detects the position of the workpiece. At the latest when the workpiece leaves the detection area of this first measuring element, the latter transmits its measured values to the next measuring element that now, based on the received measured values, continues to detect the position values of the workpiece. When the workpiece, as it passes through the machine, leaves also the detection area of this measuring element, the latter transmits in turn its incremented values to the following measuring element at the latest at this point in time. In this way, the cascading transmission of the measured values is realized. This measured value handover or transducer changeover can be realized already when the workpiece reliably has reached the detection area of the downstream measuring element, at the latest however when it leaves the detection area of the preceding measuring element.
In a preferred embodiment, depending on the position of the workpiece relative to the machining spindles of the tools and the measuring elements, the optimally suitable measuring element is respectively utilized as active measuring element.
In this context, the measured values of the selected active measuring elements are utilized advantageously as reference variable for the axis adjustments of the respective tool.
A particularly advantageous method results when the data of the workpiece and of the tool are detected and are saved together with the tool position data determined across the length of the workpiece, wherein the generation of the structure or contour is performed in a simulation process with the saved data and wherein, after completion of simulation, the saved data are transmitted to the machine controller. The structure or contour generation is simulated first in a computer. In this way, it can be checked without problem whether the desired structure or contour is obtained. During the simulation process, the required corrections, in particular changes of the workpiece-related tool position data, can be carried out. Only when the computer simulation was successful and the simulated structure or contour matches the desired structure or contour and the machine parameters, such as maximum adjusting speed or adjusting acceleration, are complied with, the saved data are transferred to the machine controller. As a result of the preceding simulation, material expenditure is thus kept small because the desired structuring or contour on the workpiece is produced already upon passage of the first workpiece.
The moulder according to the invention is characterized in that the workpiece position in the moulder is detected in front of and downstream of the tool with the measuring element so that, as a function of the respective workpiece position, the tool can be adjusted into the defined axial and/or radial positions. The measuring element provides signals that describe or characterize the feeding travel of the workpiece to the machine controller. In this way, it is ensured that the tool is adjusted precisely into the respective positions when the workpiece has reached the precisely predetermined position relative to the tool.
In a simple and advantageous embodiment, the measuring element is a measuring roller which is contacting the workpiece upon its feeding movement through the moulder. As a result of the immediate contact between the measuring element and the workpiece, the workpiece position can be precisely determined.
In a preferred embodiment, the measuring roller is rotatably driven by the workpiece itself upon its feeding movement through the moulder.
Advantageously, the measuring element is provided with a rotary encoder which encodes the revolutions of the measuring roller into signals that are supplied to the machine controller.
Advantageously, the measuring roller is resting under pressure on the workpiece so that slipping between measuring roller and workpiece is avoided.
The measuring element is advantageously provided in a carrier that is adjustable transverse to the feeding direction of the workpiece. Accordingly, the measuring element can be adjusted such that it first projects somewhat past the workpiece and when it is engaged by the workpiece it is lifted or returned by it against a counterforce. In this way, it is ensured that the measuring element is reliably in contact with the workpiece. Moreover, in this way, the measuring element can be simply adjusted to different widths or thicknesses of the workpiece, as needed.
The adjustment of the carrier is advantageously detected by at least one sensor.
In an advantageous embodiment, along the transport path of the workpieces several measuring elements are provided, positioned at a spacing behind each other in the feeding direction of the workpiece through the moulder. By means of them, the position of the workpiece as it passes through the moulder can be reliably detected.
It is advantageous in this context when the measuring elements are signal-connected to each other by cascading. In this way, the measuring elements can transmit their measured values to the next measuring element, respectively.
Advantageously, the workpiece position in the moulder is detected by at least one sensor.
The invention results not only from the subject matter of the individual claims but also by all data and features disclosed in the drawings and in the specification.
They are claimed as being essential to the invention, even though they may not be subject matter of the claims, inasmuch as they are novel relative to the prior art individually or in combination.
Further features of the invention result from the additional claims, the specification, and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail with the aid of an embodiment illustrated in the drawings. It is shown in:
FIG. 1 a machine according to the invention in a front view;
FIG. 2 the detail A of FIG. 1 in an enlarged illustration;
FIG. 3 a detail of FIG. 1 in enlarged illustration;
FIG. 4 in schematic illustration a tool with which a vine with leaves is produced in a workpiece;
FIG. 5 in an enlarged illustration a vine and a leaf with indicated planing steps;
FIG. 6 a tool for producing the vine in FIG. 5 ;
FIG. 7 a tool for producing the leaf in FIG. 5 ;
FIG. 8 and
FIG. 9 two different surface patterns on a workpiece;
FIG. 10 in schematic illustration two tools with which a contour on the workpiece can be produced.
DESCRIPTION OF PREFERRED EMBODIMENTS
With the moulder described in the following and the disclosed method, different structures can be introduced into the surface of a workpiece of wood, plastic material and the like, or the workpiece can machined with different longitudinal contours. These structures or contours can have any shape and can be freely defined while observing possible limits of individual machine parameters. The structure is produced upon passage of the workpiece through the machine.
The moulder has a CNC control unit and CNC controlled tool axes.
The moulder according to FIG. 1 is a milling machine for four-sided machining of workpieces of wood, plastic material and the like, in which longitudinal workpieces 1 in a through-feed process in general are machined on all 4 sides. For transporting the workpieces 1 , feeding or transport rollers 2 are provided which are resting on the workpieces 1 . In the infeed area, the moulder has a straightening table 3 on which the workpieces 1 are supplied to the machine. On the right side of the straightening table 3 in the infeed direction, there is an edge jointing fence 4 on which the workpiece 1 with its right longitudinal side is resting during transport. The edge jointing fence 4 is adjustable transverse to the transport direction of the workpiece 1 in order to adjust the magnitude of chip removal at the right longitudinal side of the workpiece 1 . The straightening table 3 can be adjusted in vertical direction so that the magnitude of chip removal at the bottom side of the workpiece 1 can be adjusted.
The workpiece 1 passes via an infeed opening 5 into the machine. In the machine chamber a horizontal lower straightening spindle is provided on which a straightening tool 6 is fixedly secured with which, upon passage of the workpiece 1 , its bottom side is machined by cutting, preferably is straightened by planing. In transport direction of the workpiece 1 downstream of the straightening tool 6 , there is a vertical right spindle on which a tool 7 is seated with which in the transport direction the right longitudinal side of the workpiece 1 is machined, preferably straightened by planing. The tool 7 is a planing head with straight knives. However, a profiling tool can be provided also with which then on the right workpiece side a profile is produced.
In the transport direction of the workpiece 1 , downstream of the vertical right spindle, there is a vertical left spindle on which a tool 8 is seated that is preferably a planing head with which the left workpiece side is planed straight. By machining the right and the left longitudinal sides of the workpiece, the width of the finished workpiece is generated. The tool 8 on the left side can also be a profiling tool with which a profile on the left longitudinal side of the workpiece 1 can be produced.
Upon passage through the machine, the workpieces 1 are resting on a machine table 9 which forms a transport path on which the workpieces 1 , resting thereon, are transported through the machine. The machine table 9 is fast with the machine and forms the horizontal support and reference plane for the workpieces 1 .
In transport direction of the workpieces 1 downstream of the right tool 7 , the workpiece 1 is guided along a fence (not illustrated) father through the machine. The workpiece 1 is resting with its right machined longitudinal side on this fence which is fast with the machine and forms the vertical contact and reference plane.
In transport direction downstream of the left vertical spindle, the machine has an upper horizontal spindle on which a tool 10 is seated with which the top side of the workpiece 1 is machined upon passage through the machine. With the tool 10 , the workpiece topside can be, for example, straightened by planing.
In transport direction of the workpiece 1 at a spacing behind the upper tool 10 , a second upper tool 11 is rotatably driven about a horizontal axis.
In transport direction of the tool 1 at a spacing behind the upper horizontal tool 11 , there is a lower horizontal spindle on which a tool 12 is fixedly seated with which the bottom side of the workpiece 1 can be machined.
The workpiece 1 which has been machined on all four sides exits through an outlet opening 13 from the machine. The described tools are located within a machine cover 14 .
In the area between the two upper tools 10 and 11 , a lower horizontal table roller 15 is provided. A further horizontal lower table roller 16 is located at the level of the outlet opening 13 . The machine table 9 is interrupted for the two parallel positioned table rollers 15 , 16 . In the area of the lower tool 12 the machine table 9 is interrupted also so that machining of the workpiece bottom side by the tool 12 is possible.
With the two upper tools 10 , 11 , structures can be introduced into the workpiece topside 17 . For this purpose, the corresponding spindles or tool receptacles are axially and radially adjustable by CNC drives and control units as a function of the position of the workpiece 1 , as indicated in FIG. 3 by the corresponding double arrows.
In order for the position of the workpiece 1 in the machine to be detected at any time, before and behind the tools 10 , 11 measuring rollers 18 are provided which in the embodiment are resting on the left longitudinal side of the workpiece 1 in the transport direction and are rotated about their vertical axes in accordance with the feeding movement of the workpiece. In the illustrated embodiment, three such measuring rollers 18 are provided which are located in front of the tool 10 , between the tools 10 and 11 , and downstream of the tool 11 .
As shown in FIG. 2 , the measuring rollers 18 are supported to be freely rotatable about a vertical axis. A vertical measuring roller carrier 20 is received in a holder 21 which is provided at a free end of a support arm 22 . It is designed such that it forces the measuring roller 18 against the workpiece 1 with such a force that the measuring roller 18 is rotated reliably. The support arm 22 can be subjected to a spring force or pneumatic/hydraulic pressure so that the measuring roller 18 is always forced against the left longitudinal side of the workpiece 1 . The support arm 22 is supported so as to be slidable in its longitudinal direction in a holding tube 23 which is arranged in a suitable way fast with the machine. In the illustrated embodiment, the support arm 22 is loaded by a spring force.
The measuring roller carrier 20 comprises a rotary encoder 19 that is connected fixedly to the measuring roller and supplies by a line 25 the rotary encoder signals to a machine controller.
In order to detect the leading end of the workpiece 1 and thus its exact position in the machine, a photoelectric barrier 26 is provided in the transport direction upstream of the first upper tool 10 . When it is interrupted by the leading end of the workpiece 1 , the sensor of the photoelectric barrier 26 sends a corresponding signal to the machine controller. This represents the starting point of the position measurement by means of the first measuring roller 18 . The sensor for detecting the leading end of the workpiece is not limited to a photoelectric barrier 26 but can be any type of sensing means which is capable of detecting with the required precision and speed the leading end of a workpiece, in particular of wood, upon its transport through the machine.
As can be seen in FIGS. 4, 5, 8, and 9 , different structures 27 to 29 can be introduced by means of the machine into the workpiece topside 17 . The structures are advantageously first generated by means of a computer program and simulated in a computer. For this purpose, the axial and radial workpiece positions of the tools 10 , 11 or of their spindles along the workpiece 1 are generated in the form of a table. This procedure is explained in the following with the aid of an example that is meant to illustrate the computation process but is not to be viewed as being limiting.
In a first step, the contour of the tool to be employed is described. As can be seen in FIGS. 6 and 7 , the corresponding tools can be designed differently, depending on which structure is to be produced in the workpiece topside 17 . The two tools 30 , 31 of FIGS. 6 and 7 are used for generating the structure 27 according to FIG. 5 . This structure is comprised of a vine 32 and leaves projecting away from it. As can be seen in FIG. 4 , from the vine 32 several leaves 33 are projecting. The tool 30 according to FIG. 6 is employed for generating the vine 32 and the tool 31 according to FIG. 7 is employed for generating the leaves 33 . The tool 30 is significantly narrower than the tool 31 .
In this first step, the contour of these two tools 30 , 31 is defined by a y-coordinate and a z-coordinate. The y-coordinate represents the axial and the z-coordinate the radial size of the tool 30 , 31 , i.e., concretely the cutting circle diameter of the respective axial position.
It should be noted that the method will be explained based on the rotation-symmetrical tools 30 , 31 with which circumferential milling on the workpiece 1 is performed. The method can however also be used with other tools or machining device. Examples therefor are top spindle devices or grooving devices, fixed angle rotors in which, for example, end mill or pin routers are used, and the like. The method can also be employed on universal spindles which can be positioned at various angular positions relative to the workpiece 1 . In such tools, the angle position is also taken into account as a parameter.
In the example, two tools and two spindles are provided for producing the structures 27 to 29 . The number of tools/spindles participating in the process for producing the structures is however not limited.
After the contour of the tools 30 , 31 has been defined by means of the z- and y-coordinates, in the next step the description of the workpiece to be manufactured is realized, inter alia with the aid of the tool position data. This description is also saved in table form. In the introduced coordinate system (see FIG. 4 ), the x-axis describes the feeding and longitudinal direction of the workpiece 1 , the y-axis the width direction, and the z-coordinate the thickness direction of the workpiece 1 . Dividing the workpiece piece length along the x-axis is done, for example, in millimeter steps but can also be realized, depending on the application, in a different raster pattern. The length of the table and its number of rows depend thus on the length of the workpiece to be machined.
Each x-position of the workpiece 1 has assigned a defined tool coordinate y or z and optionally also one or several tool angles for the corresponding spindle. In the following, a section of a table is indicated in an exemplary fashion in which for the spindles of the two tools 30 , 31 the axial (y-coordinate) and the radial (z-coordinate) positional values for corresponding feeding travel (x-coordinate) of the workpiece 1 are listed.
Path table
spindle 1
spindle 2
Feed
axial
radial
axial
radial
[mm]
[mm]
[mm]
[mm]
[mm]
50
9.90
0.20
0.00
0.30
51
9.95
0.20
−0.63
0.30
52
10.00
0.20
−1.26
0.30
53
10.00
0.21
−1.88
0.31
54
10.00
0.24
−2.51
0.31
55
10.00
0.28
−3.13
0.31
56
10.00
0.34
−3.75
0.32
57
10.00
0.43
−4.36
0.33
58
10.10
0.52
−4.97
0.34
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
The axial (y-coordinate) and radial (z-coordinate) position data in the table take into consideration defined reference points of the tool, for example, the axial measure between tool contact and defined profile point and greatest cutting circle diameter, in the embodiment, for example, axial measure and cutting circle diameter of the profile tip, and of the workpiece 1 , i.e., the contact of the workpiece 1 at the fence in the machine and on the machine table 9 . In the embodiment with the tools 30 , 31 according to FIGS. 6 and 7 , the axial position of the tool tip engaging the workpiece 1 and the radial penetration depth of the tool in the workpiece in y-direction are defined in the respective x-coordinate point of the workpiece. Moreover, inasmuch as the angle position of the tool can be adjusted and is to be detected, the angle α as well as the angle β of the tool relative to the workpiece 1 can be defined so that, based on these angle values, the appropriate spindle can be positioned during machining of the workpiece in the machine.
In the described way, the coordinate values for the tools to be utilized for structuring as well as their position data at the different workpiece length positions are compiled in table form (path table). This table is saved in the memory of the computer so that subsequently a simulation can be performed by means of the computer in a way to be described in the following.
The quantity and position of the spindles or tools to be utilized for structuring the workpiece 1 is freely selectable and not limited by the employed system. Also, generating the structure is not limited to the workpiece topside as disclosed in the embodiment but, alternatively or additionally, can also be carried out at the other workpiece sides, to the right, to the left, or at the bottom. The structures 27 to 29 can be generated with all of the tools 7 , 8 , 10 , 11 , 12 that are present in the described machine. Optionally, the machine can comprise additional right, left, top or bottom tools. Moreover, also tools on universal spindles or on slanted spindles can be employed. Also, the tools of grooving devices or angled devices can be utilized for structuring the workpiece at its topside 17 or at other external sides.
The table which has been prepared as described is now utilized to link the tool geometry and the tool position data along the workpiece length in such a way with each other that the structure in the workpiece topside 17 is obtained. Since in an exemplary fashion the position and penetration depth as well as superimposing of all of the tools contributing to the process are calculated in millimeter steps row by row, the appearance of the structure in the workpiece can be pre-calculated exactly. On the computer, a simulation of the surface structuring can thus be performed by means of the values contained in the table.
The computed structure which results from the table values can also be produced visually on the screen of the computer as a 3D effect.
In the context of the simulation of the structuring process, it is checked, taking into consideration the maximum acceleration and speed limits of the machine, whether the structure can be produced with the feeding rate of the workpiece 1 defined by the user in the x-direction. The computer program can be designed such that overloading of the machine dynamics is indicated and a maximum possible feeding rate of the workpiece 1 for generating the structure is calculated.
By means of the simulation, the user is thus provided with the possibility to determine very precisely the appropriate parameters which are required later on for adjusting the tool spindles and the feeding rate of the workpiece 1 .
In the simulation, the required corrections of the path curves by which the shape of the structure is determined can be done in a simple way. As soon as the simulation has been completed successfully, based on the table that is saved in the computer, a CNC program is generated and is transmitted to the machine controller.
Generating the table with the data for the tools and the tool positions can be done by individual data input in that the appropriate data are manually input for the individual steps along the workpiece. In principle, it is however also possible to carry out the data input automatically by an upstream computation algorithm, optionally with utilization and assistance of computer programs with graphic interfaces by means of which the structure can be graphically generated.
After the CNC program has been generated and has been saved in the machine controller, for example, as a path table, structuring of the workpieces 1 in the machine can be performed. The machine feed action obtains first a defined feed rate which in the described way has been determined beforehand by the simulation in the computer or, as a function of the application, is predetermined or adjusted. The feeding rate remains constant during machining for the current workpiece 1 . The spindles or tools which are utilized for structuring are moved by the CNC drives and CNC control units as a function of the workpiece position into the appropriate axial and radial start positions. Upon passage of the workpiece 1 through the machine, the CNC program is executed whereby the desired structure in the workpiece surface 17 is generated
In the simplest embodiment of the method, the prior simulation of the structure or contour can be omitted. In this context, the tool position data, for example, in form of the path table, are transferred to the machine controller.
In a further configuration of the machine, as a function of the geometry of the structural pattern, the feeding rate can be automatically changed and adapted to the structural pattern during the workpiece passage. In this way, advantageously the predetermined acceleration and rate limits of the machine for different structural courses can be complied with, for example, for steep contour ascends in the direction transverse to the feeding direction 39 . For a change of the feeding rate, the planing step will change however, which becomes visible at the machined surfaces. When this is not acceptable depending on the application, this must be compensated by further measures, for example, by machining the relevant sides in a separate pass or by adjustment of the rotary spindle speeds of the appropriate machining spindles.
The exact workpiece position within the machine is determined by means of the photoelectric barrier 26 whose position in the machine, like the position of the machining spindles, is stationarily constructively defined and dimensionally known and serves as a reference for the remaining measuring systems. As soon as the leading end of the workpiece 1 in transport direction penetrates the photoelectric barrier 26 , the position of this leading workpiece end is known and the signal that is emitted by the photoelectric barrier 26 serves as a starting point for the position measurement by means of the first measuring roller 18 . During feeding of the workpiece 1 , at any time the workpiece position is known relative to the tools 10 , 11 utilized for structuring by utilizing the rotary encoder signals of the measuring rollers 18 so that, after the workpiece has reached the first tool 10 , 11 , the tools 10 , 11 now perform, CNC-controlled, the programmed axial and/or radial adjusting movements as a function of the travel. The measuring rollers 18 are provided, as described, before and behind the tools 10 , 11 , respectively. During passage of the workpiece, the exact workpiece position is handed over by measured value handover in a cascading fashion to the measuring wheels 18 arranged sequentially by taking into consideration their relative position. The measuring wheels 18 are entrained loosely on the workpiece 1 as it is being fed. As a function of the relative position of the workpiece 1 relative to the respective tools 10 , 11 or their spindles, the respective optimally suitable measuring roller 18 can be utilized as an active measuring system and the measured values of its rotary encoder can be employed as a reference variable for the spindles that are participating in the structuring process.
Changeover from one measuring roller 18 to another measuring roller 18 or its respective rotary encoder 19 (encoder changeover) is done “on the fly”, without interruption of the structuring process, with the corresponding measured value handover. The number of measuring systems is not limited to two measuring rollers 18 per tool 10 , 11 but, as a function of the length of the workpiece 1 , can be expanded.
The use of the measuring rollers 18 driven by the workpiece 1 has the advantage that errors, which may be caused as a result of speed differences (slip) between the workpiece 1 and the feeding drive, can be prevented.
As position transducers only those measuring rollers 18 are utilized which are resting on the workpiece 1 upon its passage through the machine. This is monitored by a sensor 24 ( FIG. 2 ). The sensor 24 is fastened to a plate-shaped holder 40 and detects the movement of the support arm 22 when the measuring roller 18 comes into contact with the workpiece 1 . The support arm 22 projects through the holding tube 23 in the direction toward the sensor 24 . The measuring roller 18 is arranged such that it is pushed back together with the support arm 22 when it contacts the workpiece 1 . The thus caused axial movement of the support arm 22 is detected by the sensor 24 which emits a corresponding signal. Since the measuring rollers 18 in transport direction are positioned at a spacing behind each other, the measuring rollers contact sequentially the workpiece and sequentially lose contact again with the workpiece when it has been transported past them. Accordingly, switching between the rotary encoders 19 of the measuring rollers 18 occurs automatically upon passage of the workpiece. The position of the measuring rollers 18 in the machine as well as their correlation to the tools 10 , 11 or their spindles and their correlation relative to each other is geometrically fixed and is taken into consideration in the evaluation and positional detection of the workpiece 1 . With the rotary encoders 19 of the measuring rollers 18 , in combination with the leading end of the workpiece exactly determined by the photoelectric barrier 26 , the position of the workpiece within the machine can be very precisely determined so that the tools 10 , 11 can produce the desired structure in the workpiece topside 17 very precisely.
In the illustration according to FIG. 1 , the workpiece 1 with its leading end face has just reached the first upper tool 10 . The leading end of the workpiece has already been detected by the photoelectric barrier 26 and the first measuring roller 18 is the only measuring roller 18 that is engaged with the workpiece 1 . This measuring roller 18 is thus the active measuring system and supplies the appropriate measured signals to the machine controller as a reference variable for the first upper tool 10 . Upon further workpiece passage through the machine, the workpiece 1 has already left the first (right) measuring roller 18 in the illustration according to FIG. 3 . For machining by the tool 10 , the central measuring roller 18 is employed and, for machining by the tool 11 , the central or left measuring roller 18 is employed; both are resting on the workpiece 1 . At the latest when the right measuring roller 18 leaves the workpiece 1 , it hands over the detected value determined by the correlated rotary encoder 19 to the central measuring roller 18 that takes over this value. Based on this value, the rotary encoder 19 of the central measuring roller 18 increments the further values. At the latest when the central measuring roller 18 leaves the workpiece 1 , it hands over its value to the left measuring roller 18 . Then, incrementing occurs, based on the received value of the central measuring roller 18 , by means of the left measuring roller. In this way, the cascading measuring value handover to the downstream measuring wheels 18 takes place. In this way, an exact knowledge of the workpiece position upon passage of the workpiece 1 through the machine is ensured. The measured value transfer or transducer changeover can already be taking place when the workpiece has reliably reached the detection area of the downstream measuring roller, at the latest however when it leaves the detection area of the preceding measuring roller so that at any time it is ensured that only one measuring roller which is in contact with the workpiece is acting as an active position indicator.
The tools 30 , 31 which are utilized for structuring have a shape or profiling that is matched to the type and/or shape of the structure as is shown in an exemplary fashion with the aid of FIGS. 6 and 7 . Depending on the kind of structure, the tools can have different widths. The circumferential surface 34 , 35 of the tools 30 , 31 are designed in axial section of such a V-shape that, at half the width, they have a circumferential edge 36 , 37 . The circumferential surface 34 , 35 can have also any other suitable shape.
Based on FIGS. 4 and 5 , in an exemplary fashion the generation of the structure 27 in the workpiece topside 17 will be explained. The employed tool 10 / 11 is arranged such that its horizontal axis of rotation 38 is perpendicular to the feeding direction 39 of the workpiece 1 and parallel to the topside of the workpiece 17 , i.e., is positioned in the x-y plane. The tool 10 / 11 is moved in accordance with the program in the z- and/or y-direction relative to the workpiece 1 in order to produce the desired structure. In FIG. 4 , for example, the vine 32 of the structure 27 has a curved, approximately sinusoidal course in the longitudinal direction of the workpiece 1 . Accordingly, the tool 10 / 11 moves along the desired vine course in the y-direction. Also, by adjustment in the z-direction the depth and width of the vine 32 is determined.
Since the vine 32 is narrow, the narrow tool 30 according to FIG. 6 is utilized as a tool 10 / 11 for its production.
For producing the leaves 33 , the wider tool 31 according to FIG. 7 is utilized. The different width of the leaf 33 is achieved in that the tool 31 penetrates more or less far in z-direction into the workpiece 1 .
In FIG. 5 , the planing steps are indicated which, upon generating the structure, are caused by the non-illustrated tool cutting edges of the tools 30 , 31 . In general, the visible planing steps are produced by the farthest projecting cutting edge of the tool 10 / 11 at each tool revolution. Their spacing is thus dependent on the rotary tool speed and the feeding rate. During machining of the structure, the workpiece 1 is transported continuously through the machine. The stepwise adjustment of the respective tool in the z- and/or y-direction is matched to the feeding speed of the workpiece 1 so that the structure can be produced in the desired way in the workpiece topside 17 . The required feeding speed and acceleration of the respective CNC adjusting axis of the tools is calculated and preset by the control unit.
In the exemplary situation, the structure 27 is produced by two tools. In principle, one tool is however sufficient when a simple structure is concerned. However, more than two tools can be utilized for generating the structure on the workpiece topside 17 .
In the illustrated embodiment, the tools rotate about horizontal axes 38 which are perpendicular to the feeding direction 39 and positioned in the x-y plane. The tool 10 , 11 can moreover be designed to be pivotable about the z-axis and/or also about the x-axis so that the axis of rotation 38 extends in deviation from 90° relative to the feeding direction 39 of the workpiece 1 , measured in the x-y plane, and/or extends in deviation from 0° relative to the workpiece surface (x-y plane), measured in the y-z plane, when corresponding structures are to be manufactured in the workpiece topside 17 .
The displacement of the planing steps that can be seen in FIG. 5 results due to the fact that during engagement of the tool 30 , 31 the workpiece 1 is moved in the feeding direction 39 and the tool 30 , 31 transverse thereto.
FIGS. 8 and 9 show further examples of structures 28 and 29 which can be produced in the described way in the workpiece topside 17 . The structure 28 with recesses adjoining each other has, for example, visually the appearance of a helical coil rope while the structure 29 represents a type of braid pattern. For generating these two exemplary structures 28 , 29 , two tools on two spindles are required. With the tools it is possible to produce in a targeted fashion the different structures wherein their adjustment in the z- and y-direction is adjusted appropriately.
With the aid of FIG. 10 , the possibility is described of providing the workpiece with a desired contour by means of the tools of the machine. The workpiece 1 is provided on its two longitudinal sides 41 , 42 with the contour 43 , 44 . The course of the contours 43 , 44 on two longitudinal sides in this case is generated by the tools 7 and 8 seated on the vertical spindles. As in case of the tools 10 , 11 , as a function of the data of the workpiece as well as of the data of the tools 7 , 8 , the tool positions along the workpiece 1 for generating the contours 43 , 44 are defined and transmitted to the machine controller. Advantageously, the data are saved and beforehand the generation of the contour 43 , 44 is performed in a simulation process with the saved data. Only after successful simulation, the saved data are transferred to the machine controller. It executes the CNC program during passage of the workpiece 1 through the machine. The respective tool 7 , 8 is adjusted into the required positions by means of the CNC drives as a function of the workpiece position. The workpiece position upon passage of the workpiece 1 through the machine is also detected. Because in this embodiment the contour is generated on the right and left longitudinal side of the workpiece, the measuring elements for detecting the workpiece position are arranged advantageously on the top or bottom side of the workpiece. Producing the contour 43 , 44 is thus in principle identical to producing the described structures 27 to 29 .
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In a molder, at least one rotatably driven tool ( 7, 8, 10, 11 ) is used to produce the structure ( 27 ) or contour on the workpiece ( 1 ) by workpiece removal. The workpiece positions along the workpiece ( 1 ) for producing the structure or contour are set depending on the data of the workpiece ( 1 ) and of the tool ( 7, 8, 10, 11 ). The data are transmitted to the machine controller which processes the CNC program based on the data during the passage of the workpiece ( 1 ) through the molder and moves the tool ( 7, 8, 10, 11 ) into the required positions via CNC drives depending on the workpiece position. The workpiece position is sensed during the passage of the workpiece ( 1 ) through the molder. In order to sense the workpiece position in the molder, at least one measuring element ( 18 ) is provided upstream and downstream of the tool ( 1 ), said measuring element ( 18 ) being connected to the machine controller and supplying signals that describe the advancing travel of the workpiece ( 1 ) to the machine controller. By way of the machine controller, the tool ( 7, 8, 10, 11 ) is moved into the respective tool positions in accordance with the signals.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to computer security systems, and, more particularly, to an occurrence level, value-based security system capable of limiting the access of some selected users and terminal locations to only some preselected, but variable, operations on selected database records and fields.
2. Description of the Related Art
As computing has evolved over the last several decades, it has become more accessible to the general public and user. The number and size of computer installations has increased dramatically over this period of time and is continuing to increase at an ever increasing rate. Single-computer, timesharing systems and remote access systems have highlighted the vulnerability of data communications as a key security issue in computing. That vulnerability today is becoming more serious with the proliferation of computer networking.
Another trend over this period of time has been to assign computers more of the chores of managing our personal and business activities. Computers are routinely handling the most sensitive correspondence. For example, electronic funds transfer systems pass our money around the globe in bit streams, and sensitive governmental communications are sent among various departments by computer networks.
There are several reasons why computer security is receiving so much attention at present. The availability of personal computers has brought computer literacy to the general public. Millions of people have taken computer courses in various schools, read computer books, purchased personal computers, or used computer systems at work. In today's highly computerized society, those who would commit fraud or a crime are often faced with penetrating a computer system's defenses to achieve their goal.
It is therefore important to implement security measures to ensure the uninterrupted and uncorrupted functioning of these systems. This problem has been approached on both a hardware and software level and various security protection schemes are currently available to provide some measure of system security.
SUMMARY OF THE INVENTION
The present invention provides an occurrence level, value-based security system that offers additional security protection to existing protection schemes that is basically transparent to the existing system.
The present invention can also be used in a "stand alone" configuration to provide system security that can be tailored to the needs and demands of the host system.
In general, in a computer system that acts to interface Input/Output requests between at least one system user, identified by a "userid" or unique user identification symbol, that is accessing the system from at least one terminal location with a terminal address, and at least one database having data records, including data fields, the invention includes a method for providing occurrence level, value based security protection, limiting the access of selected users and terminal locations to preselected, but variable, Input/Output operations on selected data records and data fields of the databases, and includes the steps of establishing a series of security data tables.
The first of these tables is a data security access table. The data security access table has, for each data record and data field selected for security protection, a first entry identifying the data record or the data field and a second data security profile entry defining the Input/Output operations permitted on the data record or the data field identified by said first data security access table entry.
A second table that is established is a user security access table that has, for each user selected to have Input/Output access to the database, a first entry identifying the user and a second user security profile entry defining the Input/Output operations permitted on the database by the user identified by said first user security access table entry.
A third table that is established is a terminal location security access table that has, for each terminal location selected to have Input/Output operation access to the database, a first entry identifying the terminal location, and a second terminal location security profile entry defining the Input/Output operations permitted on the database from the terminal location identified by said first terminal location security access table entry.
Each Input/Output request from the host system to the database is parsed, and the userid of the system user making the Input/Output request is extracted therefrom, along with the data record or data field that is the subject of the Input/Output request, the terminal location address from which the Input/Output request is being made, and the requested Input/Output operation.
A request table is built that has as its first entry the extracted userid, as its second entry the extracted subject data record and data field, as its third entry the extracted terminal location address, and, as its fourth entry, the extracted requested Input/Output operation.
The first request table entry for the userid is compared with the first entry of the user security access table and a first security condition "flag" is set to an "allowed" condition if a match is found and failing that, to a "violation" condition.
The fourth request table entry for the requested Input/Output operation is compared with the second entry of the user security access table whenever the first security condition flag is in the "allowed" condition. If no match is found, the first security condition "flag" is set to a "violation" condition.
The second request table entry for the data record or data field entry, the subject of the Input/Output request that was parsed, is compared with the first data security access table entry and a second security condition flag is set to an "allowed" condition if a match is found and, failing that, to a "violation" condition.
The fourth request table entry for the requested Input/Output operation is compared with the second entry of the data security access table whenever the second security condition flag is in the "allowed" condition but if no match is found, the second security condition flag is set to a "violation" condition.
The third request table entry for the terminal location address is compared with the first terminal location security access table entry and a third security condition flag is set to an "allowed" condition if a match is found and to a "violation" condition if otherwise.
The fourth request table entry for the requested Input/Output operation is compared with the second entry of the terminal location security access table whenever the third security condition flag is in the "allowed" condition and the third security condition flag is set to a "violation" condition if no match is found.
The request table entries are then written to a security log database whenever any of the first, second or third security condition flag is in the "violation" condition. The execution of the parsed Input/Output request is cancelled by the host system. However, the Input/Output request is passed on to the host system for processing whenever the first, second and third security condition flags are in the "allowed" condition.
After parsing all the Input/Output requests pending against the databases, control is returned to the host system to continue processing the instruction stream.
The novel features of construction and operation of the invention will be more clearly apparent during the course of the following description, reference being had to the accompanying drawings wherein has been illustrated a preferred form of the device of the invention and wherein like characters of reference designate like parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 contains an idealized diagram of the present invention as embodied in a host computer system; and
FIG. 2 contains a block diagram flowchart showing the general overall logic flow through a system incorporating the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the method of the present invention would provide a value based security system that is handles by a single global database procedure.
The method compares information in a user table and a record table against the current record to determine whether access is allowed. In some cases the procedure is capable of immediately determining that an attempted security violation has occurred. In these cases, the procedure returns a code that makes it appear as though the records were not found.
In other cases the application is routed around occurrences in the database that the user is not allowed to access with our permitting any access to these intermediate occurrences or paths.
In either of these two cases, the database procedure never allows access to secure record occurrences unless the user is specifically authorized to access these occurrences.
When an attempted violation has been detected, the procedure cuts an audit trail of attempted security or access violations. The audit trail, for maximum usefulness to security personnel, includes detailed information about the identity of the user and the nature of the attempted access.
The preferred method of the present invention keeps the maintenance of use rules to a minimum by avoiding unnecessary redundancy and duplication using the concept of shared security profiles or access tables.
In general, the invention embodies the belief that a group of system users who have common work-related interest would also have a common "need to know" or access requirements on a particular database. Therefore, the security administrator of a host computer system would be able to define the majority of access privileges by the use of profiles or data access tables, that is a aset of user access rules shared by a group of users. Moreover, the concept was extended to allow an individual user to have multiple profiles within the host system. Demographically, the present invention is based upon the concept that the user community with the host system can be described topographically by defining the set(s) of group(s) to which a user belongs.
In the preferred embodiment of the present invention described below a given user can belong to a number of different profiles or data access tables. The exact number and membership of any one given user can be changed by the security systems programmer at the installation time of the value based security system described below as embodying the present invention.
In addition to user profiles, a given user can have a set of user specific access rules. These user specific rules are preferably very narrow in scope because the vast majority of significant generalizations will be defined witin the profiles. Profile access rules are processed in preference to individual user specific rules. The present invention provides a method that will process all profiles while validating a request, and then if the request is still not satisified it will then process individual user specific access rules if they are present.
Therefore, a preferred embodiment of the method of the present invention is as a value based security system in a computer host system.
Specifically, the method of the present invention would provide a value based security system for interfacing Input/Output requests between at least one system user and a database within the host system. The system user is identified by a unique user identification symbol and is attempting to access the host system from at least one terminal location having a unique terminal address within the host system.
The host system would preferably have at least one global database having data records, including data fields.
In this environment, the invention is preferably embodied in a method for providing occurrence level, value based security protection, that limits to selected users and terminal locations, access to preselected, but variable, Input/Output operations on chosen data records and data fields of the database.
The method preferably comprises a set of procedures operating within the host system archecture, that establish, at system sign on by the user, a data security access table for the system user.
This data security access table has, for each data record and data field selected for security protection, a first entry identifying the data record and data field and, a second entry, associated with the first entry, that defines the Input/Output operations permitted on each data record and data field identified by the first data security access table entry.
Also, at system sign on by the user, a second user security access profile table is established for the subject system user.
This second user security access profile table defines, for each user selected to have authorized access for performing Input/Output operations on the database, a first entry identifying the unique user identification symbol of the selected user, and a second entry associated with the first entry that defines the Input/Output operations permitted on the database by each user identified by the first user security access profile table entry.
A terminal location security access table is further established in the system at this time.
This terminal location security access table has, for each terminal location selected to have access for performing Input/Output operations on the database, a first entry that identifies the terminal location and a second entry associated with the first entry that defines the Input/Output operations permitted on the database for each terminal location identified by the first terminal location security access table entry.
Specifically, the user access profile table and the terminal location security access table are constructed within the host system environment by parsing the system sign-on by the system user and extracting therefrom the unique user identification symbol.
After this, each of the respective tables is built by comparing the extracted unique user identification symbol against a value based security database having, for each unique user identification symbol, a first entry representing the unique user identification symbol and a second entry containing a selected set of access rules associated with the first entry for determining allowable Input/Output operations by the identified system user.
The allowable Input/Output operations associated with the unique user identification symbol detail specific allowed operations upon selected data records and fields of the database and identify selected terminal locations from which each of the Input/Output operations on the database is allowable.
In order to avoid unnecessary Input/Output operations between the present method of the invention and the main operating system of the host system, as well as to make the processing logic simpler in the database procedures, the information contained in the above created tables is created at the user's system logon and retained throughoutthe user's system session until system logoff.
Once these value tables are established in the system, the method of the present invention is ready to parse each Input/Output operation request from the host system to the database.
Using these parsed requests, an Input/Output operations request table is built having as its first entry the unique user identification symbol of the system user making the Input/Output operation request, as its second entry the data record and data field that is the object of the Input/Output operation request being parsed, as its third entry the terminal location address from which the Input/Output operation request is being made, and, as its fourth entry the entered Input/Output operation request being made.
Each of the data entry elements of the Input/Output operation request table are sequentially compared with its corresponding data entry element found in the user security access table, the data security access table, and the terminal location security access table, respectively. A corresponding "flag" is set to an "allowed" or "violation" condition in the event of a "match" or "no match" being found between corresponding data entry elements being respectively compared.
Once the comparison between elements and tables is made, the Input/Output operation request table entries are written to a security violation log database, whenever at least one of the "flags" corresponding to the Input/Output operation request table entries is in a "violation" condition.
The execution of the parsed Input/Output operation request from the host system is also cancelled in this situation.
As an additional measure of security, the preferred embodiment of the method of the present invention does not directly inform the system user that a "violation" has occurred, thereby possibly alerting the individual to the detection of the attempted unauthorized act, but returns instead a message, such as "not found" to the system user.
In this manner, a discrete investigation can be made to determine whether the unauthorized action was made in error, or as part of a calculated act to gain unauthorized access to a protected area.
Nevertheless, the method of the present invention could also include returning to the system user a message that warned of the attempted unauthorized access such as by returning a message that read, "unauthorized access".
With this latter procedure, the system user is immediately informed of the unauthorized activity and, if done in error, could inform the proper authorities.
Likewise, if the unauthorized act was done purposely, the system user would possibly be sufficiently frightened to leave the host system immediately, thus preventing any security breach at the earliest possible time.
The preferred method of the invention being described would also terminate the system user's logon, or access to the host system, after logging the unauthorized activity, with its associated identifying characteristics, after either a single or a pre-set number of unauthorized acts. In this manner, the method of the present invention provides a security system that limits any unauthorized activity by limiting the number of individual attempts made by any one system user during any one logon session.
However, the parsed Input/Output operation request is returned to the host system for processing whenever all of the "flags" corresponding to the Input/Output operation request table entries are in a "allowed" condition.
In this latter case, the system user has been determined by the method of the invention to be a valid user located at a valid terminal that is attempting to execute an authorized activity upon a permitted portion of the database being protected.
Finally, to terminate the system user session within the host system, control is returned to the host system after parsing all Input/Output operation requests received from the host system against the database.
Even after the particular system user has left the host system, the preferred method of the present invention will retain a audit trail history that will permit security personnel to examine, with particularity, each attempted unauthorized system logon and activity that occured within the host system.
In order to accomplish this, the data security access table, the user security access profile table and the terminal location security access table are retained within the host system until the system user terminates the session with the host computer system, that is logs off the system.
The invention described above is, of course, susceptible to many variations, modifications and changes, all of which are within the skill of the art. It should be understood that all such variations, modifications and changes are within the spirit and scope of the invention and of the appended claims. Similarly, it will be understood that it is intended to cover all changes, modifications and variations of the example of the invention herein disclosed for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.
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A method for providing an occurrence level, value based security protection system including the steps of building a data security table; extracting from the request to the database information concerning the system user, his terminal location, the data he wishes to access, and the operation he wishes to perform on the data; comparing these extracted pieces of information against the permitted access rules found in the data security table; returning a violation status to the host system making the request if the compared information fails to match the permitted access rules found in the data security table and logging the violation; permitting the execution of the request if the extracted data is found to match the permitted access rules found in the data security table.
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TECHNICAL FIELD
The present invention relates generally to a device for providing water or other fluids to animals or humans. Specifically, the present invention involves the use of a device that allows for attachment of a water bottle or other container to the device, attachment of the device to a belt or other convenient article, and allows for consumption of water or other fluids from the device while a pet owner is mobile.
BACKGROUND OF THE INVENTION
Providing water for household pets is usually accomplished using a stationary pet bowl. These pet bowls adequately serve the purpose of providing water for the pet in one fixed location, but are not well suited to provide water to the pet while the pet and owner are mobile. The bowl can be difficult for the owner to carry and water can spill. Owners that wish to provide water to their pets while mobile must use these existing stationary bowls or existing portable pet watering devices. These existing portable devices prevent water from spilling when mobile, but are inconvenient and bulky to carry.
Therefore, in light of the foregoing deficiencies in the prior art, the applicant's invention is herein presented.
SUMMARY OF THE INVENTION
It is an object of the present invention to facilitate the convenient carrying and dispensing of fluids to pets or humans while mobile. Preferably, the present invention comprises a shaft, a reservoir, and means for attaching a water bottle or similar container to the shaft. Depending on the embodiment, the device could have rigid bands that hold the water bottle with a friction fit, flexible or adjustable bands that wrap around the water bottle, or clip like appendages which can be spread apart to receive a water bottle.
It is preferred that the device has a mechanism to attach the device to a person or other suitable article. Depending upon the embodiment, the attachment mechanism may be a belt clip, belt slot or other similar mechanism. The attachment mechanism allows the user to detach the device when desired by a user.
The reservoir may be used to hold water dispensed from a water bottle or other source and serves as a bowl for the pet to drink from. Preferably the device also comprises a mechanism that prevents slippage of a water bottle along the shaft such as stop members along the shaft of the device. These stop members (“dimples”) are appendages along the shaft that prevent an attached water bottle from sliding along the shaft.
In operation while walking a pet, a person can detach the device from the article it is thereto attached, and dispense fluid from the water bottle. This dispensing process may take place while the water bottle is still attached to the device. Once fluid fills the fluid reservoir, the pet may then consume it. Once finished, the entire device may be re-attached to the person or otherwise stored. A further feature of the present invention is that a bottle can be conveniently removed for immediate use while one is mobile.
SUMMARY OF THE DRAWINGS
FIG. 1 is a perspective view of a preferred embodiment of a Portable Fluid Delivery Device according to the present invention.
FIG. 2 is a front elevational view of a preferred embodiment of a Portable Fluid Delivery Device according to the present invention.
FIG. 3 is a left side elevational view of a preferred embodiment of a Portable Fluid Delivery Device shown in FIG. 2 according to the present invention.
FIG. 4 is a top plan view of a preferred embodiment of a Portable Fluid Delivery Device shown in FIG. 2 according to the present invention.
FIG. 5 is a perspective view of a preferred embodiment of a Portable Fluid Delivery Device according to the present invention.
FIG. 6 is a front elevational view of a preferred embodiment of a Portable Fluid Delivery Device according to the present invention.
FIG. 7 is a left side elevational view of a preferred embodiment of a Portable Fluid Delivery Device shown in FIG. 7 according to the present invention.
FIG. 8 is a front elevational view of a preferred embodiment of a Portable Fluid Delivery Device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred Portable Fluid Delivery Device 10 is shown in FIG. 1 . The Portable Fluid Delivery Device 10 comprises a shaft 12 having a first and second end, a partial cup-shaped reservoir 28 , and at least one full annular band, 16 or 20 . The Portable Fluid Delivery Device 10 may be used to hold and dispense fluid for a pet or human while mobile. The embodiment shown also includes an optional attachment assembly 14 used to attach the Portable Fluid Delivery Device 10 to an article of clothing of the user or any other suitable article. The attachment assembly 14 facilitates quick detachment of the Portable Fluid Delivery Device for use. The attachment assembly shown comprises a belt-clip assembly located at the first end of said shaft. Other attachment assemblies are contemplated such as a fixed belt slot, a hook and loop attachment mechanism, or other attachment assemblies known in the art.
This embodiment also includes an optional means for storing the device upon a peg. The means for storing the device shown comprises an appendage 30 at the first end of the shaft having a hole through the center of said appendage. This embodiment also includes an optional means for preventing slippage of an attached water bottle along the shaft. The means for preventing slippage shown comprises a pair of dimples 24 and 26 .
In the embodiment shown in FIG. 1, an upper full annular band 16 and a lower full annular band 20 are located along the shaft 12 . The upper full annular band 16 , and lower full annular band 20 are used to selectively attach a water bottle along said shaft 12 . A water bottle may be inserted through the upper full annular band 16 and then through the lower full annular band 20 . Other means for securing a water bottle to said device are contemplated such as at least one annular band, a hook and loop attachment mechanism, at least one adjustable strap, or other means of attachment readily known in the art. It is further contemplated that a water bottle may be integrated into the Portable Fluid Delivery Device 10 in the form of a vessel located along the shaft 12 .
The dimples 24 , 26 are appendages protruding from said shaft 12 . Dimples 24 , 26 are used to prevent slippage of a water bottle that is positioned along shaft 12 . Other embodiments for preventing slippage of an attached water bottle are contemplated, such as the use of varying sized annular bands, non-slip surfaces along the shaft 12 or on the inner surface of annular bands 16 & 20 , and other slippage prevention means known in the art.
The reservoir 28 is located at the second end of said shaft. The reservoir 28 may be any shape that is capable of containing and giving access to fluid. A user may detach the Portable Fluid Delivery Device 10 from an article it is thereto attached and dispense fluid from an attached water bottle. The fluid reservoir 28 retains fluid and may serve as a water bowl for the pet. The fluid reservoir is contemplated as being made in varying sizes and shapes. Although not shown, an optional reservoir drain hole is also contemplated and could be added by one ordinarily skilled in the art.
A further preferred Portable Fluid Delivery Device 110 is described in FIG. 2, FIG. 3, and FIG. 4 having an alternate embodiment of the fluid reservoir 128 , in lieu of the fluid reservoir 28 shown in FIG. 1 .
A further preferred Portable Fluid Delivery Device 210 is described in FIG. 5 having at least one pair of gripping appendages 116 and 118 , and/or 120 and 122 in lieu of the full annular bands 16 , 20 described in FIG. 1, FIG. 2, FIG. 3, and FIG. 4 . The gripping appendages 116 , 118 , 120 , 122 are used as a means to selectively attach a water bottle to the Portable Fluid Delivery Device 210 . The gripping appendages 116 , 118 , 120 , 122 preferably are fabricated using plastic that has a “memory”, in that it will return to its original shape after being flexed. Still other attachment means could be used in lieu of the appendages 116 , 118 , 120 , 122 such as clips, straps, or other attachment means readily known to the art.
A further preferred Portable Fluid Delivery Device 310 is described in FIG. 6 and FIG. 7 . The Portable Fluid Delivery Device 310 is similar to preferred Portable Fluid Delivery Device 110 described in FIGS. 2, 3 , and 4 , with the substitution of appendages 116 , 118 , 120 , and 122 in lieu of full annular bands 16 and 20 .
A further preferred Portable Fluid Delivery Device 410 described in FIG. 8 has a slot 114 through the first end of the shaft 112 in lieu of the belt-clip assembly shown in FIGS 1 , 2 , 3 , 4 , 5 , 6 , and 7 . Said Portable Fluid Delivery Device 410 is shown with an optional reservoir 228 that is detachable from the shaft 112 . Detachment of said fluid reservoir allows for additional uses of said Portable Fluid Delivery Device such as the transportation of water for use by humans and/or the placement of the fluid reservoir on the ground or other suitable surface for use as a stationary pet bowl.
Portable Fluid Delivery Devices according to the present invention may be manufactured from any of a plurality of materials that are generally known to those ordinarily skilled in the art including, but not limited to appropriate plastics, wood, or composition material. Preferably, they may be manufactured from appropriate polypropylene plastics. They may be manufactured using techniques well known to those ordinarily skilled in the art.
The forgoing disclosure is illustrative of the present invention and is not to be construed as limiting thereof. Although one or more embodiments of the invention have been described, persons of ordinary skill in the art will readily appreciate that numerous modifications could be made without departing from the scope and spirit of the disclosed invention. As such, it should be understood that all such modifications are intended to be included within the scope of this invention. The written description and drawings illustrate the present invention and are not to be construed as limited to the specific embodiments disclosed.
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Portable Fluid Delivery Device used for transporting water or other fluids comprising a shaft, a reservoir, and a means for holding a water bottle or other container. In a preferred embodiment, the Portable Fluid Delivery Device also comprises an optional attachment assembly in order to facilitate quick removal of the device from the article it is thereto attached for use.
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FIELD OF THE INVENTION
The present invention relates generally to transmissions and more particularly, to an improved hydraulic and gear apparatus for increasing and/or reducing the output speed of a shaft as driven by a power source. Cars, buses, trucks, military vehicles, railway engines and electric motors employed for driving pumps, compressors, blowing devices, fans and mills can be supplied with variable speed transmissions for automatic vehicle speed control or the speed control of working machine shafts.
BACKGROUND OF THE INVENTION
Optimal vehicle and working machine acceleration depends on the difference between the driving engine available power and the power of total acceleration resistance. Multi-speed manual transmissions perform in a long acceleration period which affects the slow motion of vehicles and working machines, i.e., speed gain or loss provokes transmission gear shocks, so the total motion time is augmented while the general motion quality is lower. The working machine motors take the several times multiplied starting current, which affects unfavorably the electric power supply system control. Thus, the real technical problem is the optimal vehicle acceleration, optimal driving engine start, and working machine shaft revolving speed control.
DESCRIPTION OF THE PRIOR ART
All vehicles use transmission gears. They are operated by hand/foot or automatically. Their quality is developed up to the maximu, still they are not sufficiently improved. Hand operated transmissions require the driver's supplemental concentration and general vehicle speed is reduced. Turbine automatic transmissions are very good in operation, yet they are not widely used. The general opinion is that turbine transmissions with continuous shaft speed variation are not being used sufficiently.
SUMMARY OF THE INVENTION
By the present invention, an improved transmission is provided wherein the inner ends of axially aligned input and output shafts are journaled relative one another with the input shaft having a sun gear affixed thereto and in engagement with a plurality of planet gears in turn supported by a carrier affixed to the output shaft. While a ring gear engages the planet gears, it rotation is controlled by a variator gear that in turn engages the ring gear. The absence or amount of torque and its direction, as applied to the variator gear, is regulated by fluid pressure as controllably directed to a turbine gear connected to the variator gear.
Accordingly, one of the objects of the present invention is to provide an improved transmission including a variator gear engaged with a ring gear which in turn is engaged with planet gears driven by an input shaft sun gear and wherein movement and direction of the planet gears and an output shaft joined thereto, is regulated by controlling torque as applied by the variator gear.
Another object of the present invention is to provide an improved hydraulic and gear transmission employing fluid pressure as created by an input shaft pump gear, which pressure selectively operates a turbine gear to produce desired torque to a variator gear engaging a ring gear, in order to control the displacement of planet gears mounted on a carrier affixed to an output shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of the transmission according to the present invention; and
FIG. 2 is a cross-section, taken along the line A--A of FIG. 1.
Similar reference characters designate corresponding elements throughout the drawing figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The automatic variator, generally designated 100, comprises an apparatus for the automatic hydraulic and gear transmission of power from a driving engine or revolving electric motor shaft, to any desired device such as a vehicle or machinery item. FIGS. 1 and 2 illustrate the transmission construction including a main cylindrical peripheral body 1 enclosed at opposite ends by a rear hood 2 and front hood 3. The body 1 may include appropriate attachment devices to facilitate its mounting in the desired vehicle or other type of installation. Journaled within the rear hood, by means of journal bearing 16, and further supported by roller bearings 17, is an input shaft 4. An exteriorly accessible bearing cover 18a retains the bearings 17 and also serves as a seat for a seal 19a which is contained by an outermost seal cover 20. The input shaft 4 axially extends to an inner end 4a disposed in the medial area of the body 1.
Fixed to the input shaft 4, intermediate its two ends, is a main input gear 9, the teeth of which constantly engage a pump driving gear 21 affixed to a pump shaft 22. This shaft is part of a fluid pump gear 24 supported by the lower portion of the rear hood 2 by means of a rear journal bearing 25 and forward journal bearing 31a. The latter is fitted within a removable pump gear cover 30a, disposed within the interior of the main body 1 and will be seen to include a seal 26 retained by a seal cover 27a. Operation of the pump gear 24 will be understood to energize hydraulic fluid for operation of the instant apparatus. As is well practiced, a plurality of such pump gears 24 may be employed.
A sun gear 6, fixedly mounted on the inner end of the input shaft 4 will be seen to mesh with a plurality of planet gears 7 respectively mounted upon a carrier 11 with each planet gear 7 rotating on an individual shaft 12 supported by the carrier. This carrier 11 is fixedly attached to the output shaft 5, forward of its inner end 5a. A journal bearing 14 rotatably supports each planet gear 7 upon its shaft 12 while a nut 13 maintains the axial disposition of these components as shown in FIG. 1.
The output shaft 5 axially extends from the forward end 4a of the input shaft 4 with its rear end 5a supported within the input shaft end 4a, by means of first journal bearing 15. The forward or outer end of the output shaft 5 projects through the front hood 3 and is journaled therein by journal bearing 16a and further supported by roller bearings 17a. A front bearing cover 18 encloses the bearings and provides a seat for a seal 19 that is retained by a front seal cover 20a.
An internally toothed ring gear 8 surrounds the output shaft 5 and inner end 4a of the input shaft 4 and will be seen to be externally supported by a second journal bearing 39 and which is radially aligned with the plurality of planet gears 7 and is press fitted within the internal wall of the main body 1. The teeth of the planet gears 7 remain coupled with the rear portion of internal teeth on the ring gear 8.
The lower part of the front hood 3 provides a mount for a pair of adjacent, cooperating turbine gears 23 having the forward portion of their respective shafts 32,35 supported by means of journal bearings 25a while the rearward portion of the shafts are each supported by a journal bearing 31 carried by the turbine gear cover 30 disposed within the main body 1. This cover 30 also provides a seat for seals 26a retained by a seal cover 27. The turbine gear shaft 32 will be seen from FIG. 1 to extend rearwardly to support a variator gear 33 engaging the forward portion of the teeth on the ring gear 8. As the fluid pump gear 24 obviously will be driven in a constant direction of rotation upon rotation of the input shaft 4, well known switchable valve means (not shown) will be employed to selectively control and alter the delivery of hydraulic fluid output from the pump gear 24 to opposite ends of the turbine gears and thus determine the driven direction of rotation of the turbine gear shaft 32 and its variator gear 33. Typically, such fluid control is regulated by a distributor, such as a gear shift lever or the like.
The output shaft 4 carries an output gear 10 engaging with a drive gear 36, the shaft 28 of which is supported by a journal bearing 29 mounted in the upper portion of the front hood 3. As shown in FIG. 2, this drive gear 36 in turn drives a read-out gear 38 carried by a shaft 37 similarly supported by the front hood 3. As the read-out gear 38 will always be driven at a speed which is a direct function of the output shaft speed, suitable well known signal means may be controlled by this latter gear to provide the user with an indication of the current status of the RPM and direction of the output shaft 5.
The automatic transmission according to the present invention operates in four different modes. In one mode, the operator has manipulated his available distributor or mode selector lever to a neutral position and the engine or motor is rotating the input shaft 4 with its attached gear 9 and sun gear 6 obviously rotating at the same input shaft speed. Although the pump gear 24 is likewise in operation, the idle distributor setting merely recirculates the fluid output from the pump gear and thus, the pump turbine is not energized nor is the variator gear 33 subjected to torque by the turbing gear 23. With the sun gear rotating with the input shaft 4, the planet gears 7 will be rotating about their shafts 12 in an opposite direction and in view of the lack of any resistance from the variator gear 33, the ring gear 8 will in turn rotate in an opposite direction and with the output shaft 5 remaining at rest. Accordingly, in this mode it will be understood that the input shaft rotation is not being transmitted to the vehicle or device connected to the output shaft 5.
In another mode, with the associated vehicle at rest, the motor or engine driving the input shaft 4 is idling and although the operator's distributor or selector is in a drive or moving position, the pump gear 24 will be understood also to be operating at an idling RPM. The pump fluid pressure output correspondingly energizes the turbine gears 23 which transmit energy through the shaft 32 to the variator gear 33. However, as the resisting forces of the vehicle at rest are greater than the torque being applied to the variator gear 33, the vehicle remains at rest. In this mode, the sun gear 6 runs the planet gears 7 which run the ring gear 8 in the same direction.
In a third mode, the engine or motor is driving the input shaft 4 with power corresponding to the motion of the driven vehicle or the like, as in the case of a vehicle at cruise speed. The pump gear 23 is delivering fluid pressure corresponding to the vehicle motion with the turbine gears 23 operating the variator gear 33 at a torque greater than the resisting forces of the vehicle, were it at rest. Consequently, the ring gear rotation will be slowing down with the planet gears 7 beginning to move and rotate around the sun gear 6 in the same direction, while running the output shaft 5. As any additional power increases the RPM of the input shaft 4, the vehicle will accelerate. At a certain speed, when the resisting forces of motion create a resisting torque equal to the engine power torque, the vehicle will not be accelerating and the variator gear 33 will be running the planet gears 7 at a constant speed.
In a remaining mode, the output shaft 5 and thus, the vehicle, is driven in reverse. This is accomplished when the operator manipulates his distributor selector to energize the turbine gear 23 so as to run the variator gear 33 in the direction of ring gear rotation with the planet gears 7 rotating the opposite direction from the input shaft 4. Again, the speed of the associated vehicle will depend upon the supplied engine power to the input shaft 4.
It is to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the appended claims.
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A hydraulic and gear transmission includes a body having journaled therein axially aligned input and output shafts each having inner ends journaled relative one another. A carrier mounted on the output shaft supports a plurality of planet gears in engagement with a sun gear mounted on the input shaft inner end. Input motion as directed through the sun and planet gears, reacts with an outer most ring gear engaging the planet gears while the movement of this ring gear is controlled by the application of or absence of torque as applied to a variator gear also engaging the ring gear. Torque to the variator gear is regulated by a turbine gear attached thereto and which is activated by a pump gear driven by the input shaft.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present patent application is a divisional application of U.S. patent application Ser. No. 13/100,133, now U.S. Pat. No. ______, which was filed on May 3, 2011, which was a divisional application of U.S. patent application Ser. No. 12/018,421, now U.S. Pat. No. 7,980,445, which was filed on Jan. 23, 2008, and are all commonly assigned herewith to International Business Machines, and which their collective teachings are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the field of placement of conductive bonding material such as solder on electronic pads, and more particularly relates to fill techniques for injection molding of solder on integrated circuit chip pads.
BACKGROUND OF THE INVENTION
[0003] In modern semiconductor devices, the ever increasing device density and decreasing device dimensions demand more stringent requirements in the packaging or interconnecting techniques of such devices. Conventionally, a flip-chip attachment method has been used in the packaging of IC chips. In the flip-chip attachment method, instead of attaching an IC die to a lead frame in a package, an array of solder balls is formed on the surface of the die.
[0004] Controlled Collapse Chip Connection New Process (“C4NP”) is another method of depositing conducting bonding material onto molds. C4NP is a subset technology of IMS, which is further discussed in U.S. Pat. No. 5,244,143 and is commonly owned by International Business Machines Corporation, and is hereby incorporated by reference in its entirety. C4NP allows the creation of pre-patterned solder balls to be completed while a silicon wafer is still in the front-end of a manufacturing facility, potentially reducing cycle time significantly. The solder bumps can be inspected in advance and deposited onto the silicon wafer in one simple step. In this technology, a solder head with an injection aperture comprising molten solder scans over the surface of the mold. In order to fill the cavities on the mold, pressure is applied onto the reservoir of the C4NP head which comprises the molten solder as it is scanned over the cavities. The filling of the C4NP mold plate in a reliable, high speed and cost-effective manner is a challenge. Current C4NP systems use a scanning fill head which covers only a portion of the total area to be filled at any one time. This approach requires sealing elements, which must contain solder, air, and/or vacuum at significant pressure differentials while the seal is scanned across the mold plate.
[0005] Therefore a need exists to overcome the problems with the prior art as discussed above.
SUMMARY OF THE INVENTION
[0006] Briefly, in accordance with the present invention, a method for depositing conductive bonding material into a plurality of cavities in a mold is disclosed. The method includes placing a fill head in substantial contact with a mold comprising a plurality of cavities. The fill head includes a sealing member that substantially encompasses an entire area to be filled with conductive bonding material. The conductive bonding material is forced out of the fill head toward the mold. The conductive bonding material is provided into at least one cavity of the plurality of cavities contemporaneous with the at least one cavity being in proximity to the fill head.
[0007] In another embodiment, another method for depositing conductive bonding material into a plurality of cavities in a mold is disclosed. The method includes placing a fill head in substantial contact with a mold comprising a plurality of cavities. The fill head comprises a sealing member that substantially encompasses an entire area to be filled with conductive bonding material. The mold is situated on top of the fill head and the fill head is situated so that the sealing member is facing in a upward direction with respect to the plurality of cavities. The fill head and mold are transitioned so that the fill head is situated on top of the mold and so that the plurality of cavities is facing in an upward direction with respect to the sealing member. The conductive bonding material is forced out of the fill head toward the mold. The conductive bonding material is provided into at least one cavity of the plurality of cavities contemporaneous with the at least one cavity being in proximity to the fill head.
[0008] An advantage of the foregoing embodiments of the present invention is that conductive bonding material such as solder can be precisely dispensed into the mold plate using a full-field solder fill head that can cover the entire region to be filled. The present invention allows the seal(s) of the fill head to be stationary during the solder fill process steps where the highest pressure differentials occur. The fill head seals only slide over the mold surface during the solder fill process steps where relatively low pressure differentials are required. Stated differently, the present invention does not require a sealing member to withstand large pressure differentials while sliding across a mold plate. Another advantage of various embodiments of the present invention is that air can be evacuated from all cavities so that the cavities can be reliably filled with pressurized solder.
BRIEF DESCRIPTION OF THE DRAWINGS
[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 is a block diagram showing a top view of a conventional C4NP mold fill process;
[0011] FIG. 2 is a block diagram showing a cross-sectional view of the conventional C4NP mold fill process of FIG. 1 ;
[0012] FIG. 3 is a block diagram showing a cross-sectional view of an example of a full-field fill head according to one embodiment of the present invention;
[0013] FIG. 4 is a block diagram showing a top view of the full-field fill head of FIG. 3 ;
[0014] FIG. 5 is a block diagram showing a cross-sectional view of another example of a full-field fill head according to one embodiment of the present invention;
[0015] FIG. 6 is block diagram showing a top view of the full-field fill head of FIG. 5 ;
[0016] FIG. 7 is a block diagram showing a cross-sectional view of a full-field coverage system according to one embodiment of the present invention;
[0017] FIG. 8 is a block diagram showing a top view of the full-field coverage system of FIG. 7 ;
[0018] FIG. 9 is a block diagram showing a cross-sectional view of another full-field coverage system according to one embodiment of the present invention;
[0019] FIG. 10 is a block diagram showing a top view of the full-field coverage system of FIG. 9 ;
[0020] FIG. 11 is a block diagram showing a cross-sectional view of yet another full-field coverage system according to one embodiment of the present invention;
[0021] FIG. 12 is a block diagram showing a top view of the full-field coverage system of FIG. 11 ;
[0022] FIG. 13 is a block diagram illustrating a sequence of steps for depositing conductive bonding material into cavities on a mold according to one embodiment of the present invention;
[0023] FIG. 14 is an operational flow diagram illustrating an example of a process of filling molds using a full-field coverage system according to one embodiment of the present invention;
[0024] FIG. 15 is an operational flow diagram illustrating another example of a process of filling molds using a full-field coverage system according to one embodiment of the present invention;
[0025] FIG. 16 is an operational flow diagram illustrating yet another example of a process of filling molds using a full-field coverage system according to one embodiment of the present invention; and
[0026] FIG. 17 is an operational flow diagram continuing the process of FIG. 16 .
DETAILED DESCRIPTION
[0027] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.
[0028] The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
Conventional C4NP Mold Fill Process
[0029] FIGS. 1-2 illustrate a conventional C4NP mold fill process. In particular FIG. 1 shows an overhead view of a conventional fill head 102 dispensing solder into cavities 104 on a mold plate 106 . FIG. 2 shows a cross-sectional view of FIG. 1 . The conventional fill head 102 of FIGS. 1-2 dispenses molten solder into the mold plate 106 utilizing a round O-ring seal. In conventional C4NP systems the fill head 102 is heated above the melting point of the solder, for the case of Tin/Copper solder above 230 C. The liquid solder is held in a reservoir 208 inside the fill head 102 and covered by a lid (not shown). The fill head 102 rests on the mold plate 106 and O-ring seal 210 prevents the solder from leaking out the bottom of the fill head 102 . The fill process begins by first applying a nominal load or down force on the O-ring seal 210 , typically on the order of 2.5 lbs/linear inch. The fill head reservoir 208 is then pressurized, usually to 20 psi, to ensure the solder enters the mold plate cavities 104 during the fill process.
[0030] Next, the fill head 102 is moved across the mold plate surface, typically at a speed of between 0.1 to 10 mm/sec. As the fill head moves over the mold plate 106 the air in the cavities 104 is expelled and replaced by liquid solder from the fill head 102 . The mold plate 106 with the solder filled cavities 104 is then removed and passed to the next tool for transfer of the solder to a silicon wafer.
[0031] A key difficulty of this conventional approach is that the O-ring 210 is sealing against significant solder pressure at the same time that it is being dragged across the mold surface. This requires that a seal material be selected that can withstand high temperatures and solder contact and seal against substantial pressure differential, while also not experiencing mechanical failure or excessive wear as a result of contact with the cavity-filled mold plate 106 . Given that the mold plate 106 is often made of glass and the cavities often have relatively sharp edges, it can be quite difficult to find a material that can withstand the “filing action” of the mold-plate under the high compression forces needed to seal against solder leakage.
Full-Field Solder Coverage
[0032] According to an embodiment of the present invention, FIGS. 3-13 illustrate a systems and methods for C4NP full-field solder coverage according to various embodiments of the present invention. In particular FIG. 3 shows a cross-sectional view of an example of a full-field fill head 302 . FIG. 4 is a top-view of the fill head 302 of FIG. 3 . The fill head 302 , according to the present example, comprises an O-ring 310 that substantially surrounds an area of a mold 306 to be filled. The mold in one embodiment can be rectangular, non-rectangular, or any combination of shapes. In one embodiment, the conductive bonding material such as solder is forced out of the reservoir 308 and into the cavities 304 using high pressure. The high pressure is applied while the mold 306 is stationary with respect to the fill head 306 . This is advantageous because the large normal forces needed to seal against solder leakage are only needed when the seal 310 is stationary and when the seal is located above smooth parts of the mold plate 306 . After the solder is forced into the cavities 304 at high pressure, the pressure can be reduced while the mold 306 is translated out from underneath the fill head 302 . Since the sliding occurs only when the solder pressure is low, the normal force applied to the seal 310 can be low thereby reducing friction and wear occurring at the seal 310 .
[0033] FIG. 5 shows a cross-sectional view of another example of a full-field fill head 502 . FIG. 6 illustrates a top-view of the fill head 502 shown in FIG. 5 . The fill head 502 includes a rotating and/or agitating blade 512 inside the molten solder pool 514 . This blade 512 can be rotated and/or agitated vigorously during various steps of the solder filling process to improve the fill performance, which is discussed in greater detail below.
[0034] FIGS. 7-8 illustrate one embodiment of depositing a conductive bonding material into cavities in a mold using a full-field coverage process. FIG. 7 shows a cross-sectional view of a full-field coverage system 700 where a fill head 702 deposits solder into cavities 704 on a mold 706 . FIG. 8 shows a top-view of the full-field coverage system 700 of FIG. 7 . FIGS. 7-8 show a succession of the mold 706 during the solder filling process. For example, FIGS. 7-8 show the mold 706 as empty, being filled with solder, and filled with solder. As discussed above the full-field fill head 702 includes an O-ring seal 710 that substantially covers an area on the mold 706 that is to be filled with solder.
[0035] In one embodiment, unfilled mold 706 is placed in position next to the full-field solder fill head 702 . The unfilled mold 706 is slid underneath the fill head 702 while the solder is being held near ambient pressure. The seal 710 is held in contact with the mold 706 with just enough force to prevent/minimize any solder leakage during the motion. A region above the solder is filled with high-pressure gas such as nitrogen to force the solder into the mold cavities 704 .
[0036] Once the solder has been forced into the cavities 704 and contacts the cavity walls, the gas pressure above the solder can generally be reduced without affecting the solder-filled cavities 704 . The mold 706 is moved out from under the fill head 702 while the solder is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal 710 during this motion acts to squeegee the solder off of the mold surface, leaving only the solder which is in the mold cavities 704 .
[0037] FIGS. 9-10 illustrate another embodiment of depositing a conductive bonding material into cavities in a mold using a full-field coverage process. FIG. 9 shows a cross-sectional view of a full-field coverage system 900 where a fill head 702 deposits solder into cavities 704 on a mold 706 under a vacuum. The system 900 of FIG. 9 removes substantially all of the air from the cavities 904 of the mold 906 by drawing a vacuum above the molten solder before the space above the solder is pressurized to force the solder into the cavities 904 . FIG. 10 shows a top-view of the full-field coverage system 900 of FIG. 9 . FIGS. 9-10 show a succession of the mold 906 during the solder filling process. For example, FIGS. 9-10 show the mold 906 as empty, being filled with solder, and filled with solder. An unfilled mold 906 is placed in position next to the full-field solder fill head 902 .
[0038] In one embodiment, an unfilled mold 906 is slid underneath the fill head 902 while the solder is being held near ambient pressure. The seal 910 is held in contact with the mold 906 with just enough force to prevent/minimize any solder leakage during the motion. The region above the solder is evacuated, thereby causing most of the gas trapped in the cavities 904 to bubble up through the solder where it is carried away by the vacuum source 916 . The region above the solder is then filled with high-pressure gas such as nitrogen to force the solder into the mold cavities 904 . Since most of the gas in the cavities 904 was removed in the previous step, the pressurized solder is more likely to completely fill the cavities as desired.
[0039] Once the solder has been forced into the cavities 904 and it makes contact with the cavity walls, the gas pressure above the solder can generally be reduced without affecting the solder-filled cavities. The mold 906 is moved out from under the fill head 902 while the solder is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal 910 during this motion acts to squeegee the solder off of the mold surface, thereby leaving only the solder which is in the mold cavities 904 .
[0040] FIGS. 11-12 illustrate another embodiment of depositing a conductive bonding material into cavities in a mold using a full-field coverage process. FIG. 11 shows a cross-sectional view of a full-field coverage system 900 where a fill head 1102 deposits solder into cavities 1104 on a mold 1106 utilizing an agitator bar 1112 . FIG. 12 shows a top-view of the full-field coverage system 1100 of FIG. 11 . FIGS. 11-12 show a succession of the mold 1106 during the solder filling process. The agitator bar 1112 is used to help dislodge gas bubbles during (and after) the evacuation process stage discussed above. Without agitation, some of the gas trapped in the cavities 1104 can adhere to the mold as small bubbles, even when a vacuum is drawn above the solder, as discussed above. By vigorously stirring the molten solder during this phase, the heavy liquid solder can be used to dislodge such gas bubbles adhering to the mold 1106 . Thus, the combination of vacuum above the solder plus vigorous mechanical agitation can substantially improve the probability that essentially all gas is removed from all cavities 1104 in the mold 1106 .
[0041] In one embodiment, an unfilled mold 1106 is placed in position next to the full-field solder fill head 1102 . The unfilled mold 1106 is slid underneath the fill head 1102 while the solder is being held near ambient pressure. The seal 1110 is held in contact with the mold 1106 with just enough force to prevent/minimize any solder leakage during the motion. The region above the solder is evacuated, thereby causing most of the gas trapped in the cavities 1104 to bubble up through the solder, where it is carried away by the vacuum source 1116
[0042] The molten solder is vigorously stirred and/or agitated by the agitator bar 1112 to dislodge any gas bubbles which remain adhered to the mold surface. Any dislodged bubbles then rise to the surface of the solder where they are removed by the vacuum source 1116 . The region above the solder is then filled with high-pressure gas such as nitrogen to force the solder into the mold cavities 1114 . Since most of the gas in the cavities 1114 was removed in the previous step, the pressurized solder is more likely to completely fill the cavities as desired. Once the solder has been forced into the cavities 1114 and makes contact with the cavity walls, the gas pressure above the solder can generally be reduced without affecting the solder-filled cavities 1114 . The mold 1106 is moved out from under the fill head 1102 while the solder is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal 1110 during this motion acts to squeegee the solder off of the mold surface, leaving only the solder which is in the mold cavities 1104
[0043] FIG. 13 is a block diagram illustrating a sequence of steps for ensuring that substantially all gas is removed from cavities 1304 in a mold 1306 being filled with solder 1318 . In this embodiment, substantially the entire fill head 1302 plus the mold plate 1306 is mounted as one assembly in such a way that it can be rotated between a first position and second position. A rotational mounting arrangement is mechanically coupled with the fill head for rotating the fill head and the mold as one mounted assembly. The rotational mounting arrangement can include one or more mechanical and electrical components that can hold the fill head and the mold as one assembly and can rotate the fill head and the mold between the first and second positions. When the fill head and the mold are together as one assembly, a volume is defined in the fill head between an inner surface of the fill head and a surface area of the mold including a plurality of cavities to be filled. In the first position the mold 1306 is below the fill head 1302 and gravity forces the solder 1318 in contact with the mold 1306 (as discussed above). A second position is utilized where the mold 1306 is substantially at a top portion of the volume and above the fill head 1302 so that gravity holds the solder away from the mold plate 1306 . By providing a system 1300 whereby gravity holds the liquid solder away from the mold surface it is possible to evacuate (e.g., via a gas exchange port in the fill head) the cavities 1304 directly without requiring any gases to bubble up through the solder 1318 .
[0044] In this embodiment, the cavities 1304 can be fully and completely evacuated while the solder is below the mold 1306 . After the cavities 1304 (and the rest of the free volume inside the fill head 1302 ) have been evacuated substantially the entire assembly is slowly flipped over so that the solder flows across the mold surface and pools above the mold 1306 . At this point, the solder 1318 might not perfectly wet the entire cavity surface (because of surface tension effects, etc.), and any gas trapped in the cavities 1304 can cause defects. Therefore, application (e.g., via a gas exchange port in the fill head) of pressurized gas above the molten solder can now reliably force the solder completely into all cavities 1304 .
[0045] In one embodiment, an unfilled mold 1306 , at times T 0 and T 1 , is transitioned from a face-up position to a face-down position next to the full-field solder fill head 1302 . The full-field solder fill head 1302 is orientated so that the seal 1310 is upward and the solder 1318 is pooled at the bottom of the head 1302 , away from the seal 1310 . At time T 2 , the unfilled mold 1306 is slid across (above) the fill head 1302 while gravity holds the solder 1318 away from the seal 1310 and mold plate 1306 . The gas above the solder 1318 such as nitrogen is held near the ambient pressure. The seal 1310 is held in contact with the mold 1306 with just enough force to prevent/minimize any solder leakage during the motion. The region 1320 above the solder, at time T 3 , is evacuated, thereby directly removing any gas that was in the mold cavities 1306 as well as any gas above the solder 1318 or mixed into the solder 1318 . All gas in the cavities is directly carried away by the vacuum source.
[0046] The entire assembly comprising the fill head 1302 , seal 1310 , and mold plate 1306 are then slowly rotated 180 degrees at time T 4 (i.e., flipped over). This brings the mold plate 1306 underneath (substantially below) the fill head 1302 , thereby allowing gravity to force the liquid solder to pool over the entire surface of the mold 1306 as compared to the inside of the seal 1310 . The region 1320 above the solder 1318 , at time T 5 , is then filled with high-pressure gas such as nitrogen to force the solder 1318 into the previously evacuated cavities 1304 . Since essentially all of the gas in the cavities 1304 was removed in the previous step, the pressurized solder is virtually guaranteed to completely fill all of the cavities 1304 as desired.
[0047] Once the solder 1318 has been forced into the cavities 1304 and it makes contact with the cavity walls, the gas pressure above the solder 1318 , at time T 6 , can generally be reduced without affecting the solder-filled cavities. The mold 1306 , at time T 7 , is moved out from under the fill head 1302 while the solder 1318 is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal 1310 during this motion acts to squeegee the solder 1318 off of the mold surface, thereby leaving only the solder 1318 which is in the mold cavities 1304 .
[0048] As can be seen from the above discussion the various examples of the present invention are advantageous in that they improve the reliability of the mold plate fill process by using a fill head and related processes that do not require a sealing member to withstand large pressure differentials while sliding across the mold plate. The sealing element, according to various embodiments of the present invention, only has to withstand high pressure differential while stationary, and only has to withstand sliding motion while sealing against small pressure differentials. The solder fill head, according to certain examples, can be at least as large as the full mold pattern to be filled. The fill head is scanned onto a mold plate while the solder is kept near ambient pressure. A vacuum is then drawn above the pooled solder (which covers the entire mold area) in order to draw any trapped air away from the mold surface. After the air has been evacuated, the space above the pooled solder is highly pressurized with inert gas to force the solder into the cavities.
[0049] The fill head is scanned off of the mold plate while the solder pressure is held at a relatively low pressure differential with respect to ambient. Note that in this process, the seal was stationary during high-pressure-differential operations such as vacuum evacuation and pressurized solder fill, and the seal was only sliding during low-pressure-differential operations such as mold loading and final solder wiping. This approach thus allows the use of high seal loading forces during high-pressure operations which occur while stationary, and low seal loading forces during sliding motion, thereby greatly reducing seal wear and increasing the range of seal materials which can be used.
[0050] Various embodiments of the present invention, as discussed above, also utilize a rotating or oscillating agitator blade to improve the vacuum evacuation of the cavities by aggressively stirring the molten solder so as to dislodge any gas bubbles adhering to the mold cavities. Another advantage is that the entire mold plate plus solder fill head assembly can be flipped over during the process, thereby allowing some process steps (especially vacuum evacuation) to occur with the liquid solder supply below and not in contact with the mold surface. Other process steps (especially pressurized solder filling of the cavities) can occur with the liquid solder above and in contact with the mold surface.
Process Of Filling A Non-Rectangular Mold With Solder
[0051] FIG. 14 is an operational flow diagram illustrating an example of a process of filling molds using a full-field coverage system. The operational flow diagram of FIG. 14 begins at step 1402 and flows directly to step 1404 . An unfilled mold 906 , at step 1404 , is placed in position next to the full-field solder fill head 902 . The unfilled mold 906 , at step 1406 , is transitioned underneath the fill head 902 . This occurs while the solder within the fill head 902 is being held near ambient pressure. The seal 910 , at step 1408 , is held in contact with the mold 906 with just enough force to prevent/minimize any solder leakage during the motion.
[0052] A region above the solder, at step 1410 , is evacuated, causing most of the gas trapped in the cavities to bubble up through the solder, where it is carried away by the vacuum source 916 . The region above the solder, at step 1412 , is then filled with high-pressure gas such as nitrogen. The solder, at step 1414 , is then forced into the mold cavities 904 . Since most of the gas in the cavities 904 was removed in the previous step, the pressurized solder is more likely to completely fill the cavities 904 as desired. The gas pressure, at step 1416 , above the solder is reduced without affecting the solder-filled cavities 904 . The mold 906 , at step 1418 , is transitioned from under the fill head 902 while the solder is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal during this motion acts to squeegee the solder off of the mold surface, leaving only the solder which is in the mold cavities 904 . The control flow then exits at step 1420 .
Another Process Of Filling A Non-Rectangular Mold With Solder
[0053] FIG. 15 is an operational flow diagram illustrating another example of a process of filling molds using a full-field coverage system. The operational flow diagram of FIG. 15 begins at step 1502 and flows directly to step 1504 . An unfilled mold 1106 , at step 1504 , is placed in position next to the full-field solder fill head 1102 . The unfilled mold 1106 , at step 1506 , is transitioned underneath the fill head 1102 . This occurs while the solder within the fill head 1102 is being held near ambient pressure. The seal 1110 , at step 1508 , is held in contact with the mold 1106 with just enough force to prevent/minimize any solder leakage during the motion.
[0054] A region above the solder, at step 1510 , is evacuated, causing most of the gas trapped in the cavities to bubble up through the solder, where it is carried away by the vacuum source 1116 . The solder within the fill head 1102 , at step 1512 , is vigorously stirred and/or agitated to dislodge any gas bubbles which remain adhered to the mold surface. Any dislodged bubbles then rise to the surface of the solder where they are removed by the vacuum source 1116 . The region above the solder, at step 1514 , is then filled with high-pressure gas such as nitrogen. The solder, at step 1516 , is then forced into the mold cavities 1104 . Since most of the gas in the cavities 1104 was removed in the previous step, the pressurized solder is more likely to completely fill the cavities 1104 as desired. The gas pressure, at step 1518 , above the solder is reduced without affecting the solder-filled cavities 1104 . The mold 1106 , at step 1520 , is transitioned from under the fill head 1102 while the solder is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal during this motion acts to squeegee the solder off of the mold surface, leaving only the solder which is in the mold cavities 1104 . The control flow then exits at step 1522 .
Another Process Of Filling A Non-Rectangular Mold With Solder
[0055] FIGS. 16-17 are operational flow diagrams illustrating another example of a process of filling molds using a full-field coverage system. The operational flow diagram of FIG. 16 begins at step 1602 and flows directly to step 1604 . A full-field fill head 1302 , at step 1604 , is positioned so that the seal 1310 is upward and the solder 1318 is pooled at the bottom of the fill head 1302 away from the seal. An unfilled mold 1306 , at step 1606 , is placed in position next to the full-field solder fill head 1302 . The unfilled mold 1306 , at step 1608 , is transitioned across the fill head 1302 . Gravity holds the solder 1318 away from the seal and mold 1306 . The gas above the solder 1318 in the fill head 1302 , at step 1610 , is held substantially near ambient pressure. The seal 1310 , at step 1612 , is held in contact with the mold 1306 with just enough force to prevent/minimize any solder 1318 leakage during the motion.
[0056] A region above the solder 1318 , at step 1614 , is evacuated, causing most of the gas trapped in the cavities to bubble up through the solder 1318 , where it is carried away by the vacuum source 1316 . The fill head 1302 and mold 1306 , at step 1616 , are transitioned 180 degrees so that the mold 1306 is underneath the fill head, thereby allowing gravity to force the liquid solder 1318 to pool over the entire surface of the mold 1306 (inside the seal 1310 ). The control flows to entry point A of FIG. 17 . The region above the solder 1318 , at step 1704 , is then filled with high-pressure gas such as nitrogen. The solder 1318 , at step 1706 , is then forced into the mold cavities 1304 . Since most of the gas in the cavities 1304 was removed in the previous step, the pressurized solder 1318 is more likely to completely fill the cavities 1304 as desired. The gas pressure, at step 1708 , above the solder 1318 is reduced without affecting the solder-filled cavities 1304 . The mold 1306 , at step 1710 , is transitioned from under the fill head 1302 while the solder 1318 is held at a relatively low positive pressure with respect to the ambient environment. The wiping action of the seal during this motion acts to squeegee the solder 1318 off of the mold surface, leaving only the solder 1318 , which is in the mold cavities 1304 . The control flow then exits at step 1712 .
Non-Limiting Examples
[0057] The foregoing embodiments of the present invention are advantageous because they provide a technique for filling non-rectangular molds or substrates with a conductive bonding material using an IMS system. The discussed examples of the present invention allow for molds that more closely resemble their associated non-rectangular silicon wafer to be used. Furthermore, the fill heads provide a means for heating throughout the heads that melt material to be deposited into cavities of a mold and cooling gasses that solidify the material within the cavities.
[0058] Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments, and it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.
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A method and apparatus are provided to deposit conductive bonding material into cavities in a mold. A fill head is placed in substantial contact with a mold that includes cavities. The fill head includes a sealing member that substantially encompasses an entire area to be filled with conductive bonding material. The conductive bonding material is forced out of the fill head toward the mold. The conductive bonding material is provided into at least one cavity of the cavities contemporaneous with the at least one cavity being in proximity to the fill head.
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BACKGROUND
[0001] The present invention relates to a bearing structure. The present invention more particularly relates to a bearing structure for an expansion joint system and an expansion joint system including the bearing structure.
[0002] An opening or gap is purposely provided between adjacent concrete structures for accommodating dimensional changes within the gap occurring as expansion and contraction due to temperature changes, shortening and creep of the concrete caused by prestressing, seismic cycling and vibration, deflections caused by live loads, and longitudinal forces caused by vehicular traffic. An expansion joint system is conventionally utilized to accommodate these movements in the vicinity of the gap.
[0003] Bridge constructions are also subject to relative movement in response to occurrence of thermal changes, seismic events, and vehicle loads. This raises particular problems, because the movements occurring during such events are not predictable either with respect to the magnitude of the movements or with respect to the direction of the movements. Gaps or openings in the bridge deck are provided for accommodating these movements, and expansion joint systems are often installed in the gap. In many instances, bridges have become unusable for significant periods of time, due to the fact that traffic cannot travel across damaged expansion joints.
[0004] Prior art expansion joint systems include various types of bearings for absorbing loads applied to the expansion joint system and for supporting the various expansion joint system components. However, many of the bearings used in expansion joint systems cannot absorb the increased loads and rotations that are demanded by the roadway and bridge designs. Therefore, a need still exists in the art for an improved bearing structure that can accommodate increased loads and an expansion joint system including an improved bearing that can accommodate movements that occur in the vicinity of a gap having an expansion joint between two adjacent roadway sections, for example, movements that occur in longitudinal and transverse directions relative to the flow of traffic, and which are a result of thermal changes, seismic events, and deflections caused by vehicular loads.
SUMMARY
[0005] A bearing structure is provided, said bearing structure comprising a bearing substrate and an upper bearing portion disposed on a portion of said bearing substrate, said upper bearing portion including concavely curved side walls.
[0006] According to certain embodiments, the upper bearing portion includes curved side walls, a substantially curved upper bearing surface, and a flat seat region.
[0007] An expansion joint system is further provided for a roadway construction wherein a gap is defined between adjacent first and second roadway sections, said expansion joint system extending across said gap to permit vehicular traffic, said expansion joint system comprising transversely extending, spaced-apart, vehicular load bearing members, elongated support members having opposite ends positioned below said transversely extending load bearing members and extending longitudinally across said expansion joint gap, first means for accepting ends of said longitudinally extending elongated support members for controlling the movement of said ends of said support members within said first means for accepting longitudinally extending elongated support members, second means for accepting opposite ends of said longitudinally extending elongated support members for controlling the movement of said opposite ends of said support members within said second means for accepting longitudinally extending elongated support members, and bearing means disposed between said ends of said longitudinally extending elongated support members and said first and second means for accepting ends of said longitudinally extending elongated support members, said bearing means comprising a bearing substrate and an upper bearing portion disposed on said bearing substrate, said upper bearing portion including concavely curved side walls.
[0008] According to certain embodiments, the bearing includes an upper bearing portion having curved side walls, a substantially curved upper bearing surface, and a flat seat region.
[0009] In another embodiment, an expansion joint system is provided for a roadway construction wherein a gap is defined between adjacent first and second roadway sections, said expansion joint system extending across said gap to permit vehicular traffic, said expansion joint system comprising transversely extending, spaced-apart, vehicular load bearing members, elongated support members having opposite ends positioned below said transversely extending load bearing members and extending longitudinally across said expansion joint, means for movably engaging said longitudinally extending, elongated support members with at least one of said transversely extending, spaced-apart load bearing members, and bearing means disposed between lateral sides of said longitudinally extending elongated support members and surfaces of said means for movably engaging at least one of said longitudinally extending, elongated support members with said transversely extending, spaced-apart load bearing members, said bearing means comprising a bearing substrate and an upper bearing portion disposed on said bearing substrate, said upper bearing portion including concavely curved side walls.
[0010] According to certain embodiments, the bearing includes an upper bearing portion having curved side walls, a substantially curved upper bearing surface, and a flat seat region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is an exploded perspective view of the bearing structure.
[0012] FIG. 2 is a side view of the bearing structure in an uncompressed state in the absence of a load.
[0013] FIG. 3 is a side view of the bearing structure in a compressed state in response to the application of a load to the bearing.
[0014] FIG. 4 shows a top perspective view of the expansion joint system including the bearing structure
[0015] FIG. 5 is a side view of an illustrative support bar member.
[0016] FIG. 6 is a rear view of the means for permitting transverse movement of the support bar members.
[0017] FIG. 7 is a side view of an illustrative support bar member inserted into means for permitting transverse movement of the support bar member.
[0018] FIG. 8A is a side view of the means for permitting longitudinal and vertical movement of the support bar member.
[0019] FIG. 8B is an end view of the means for permitting longitudinal and vertical movement of the support bar member.
[0020] FIG. 9A is a side view of a portion of the expansion joint system including an end view of the yoke assembly for maintaining the support bar member in proximity to the bottom surfaces of the load bearing beams of the expansion joint system.
[0021] FIG. 9B is an enlarged fragmentary side view of a portion of the expansion joint system including an end view of the yoke assembly for maintaining the support bar member in proximity to the bottom surfaces of the load bearing beams of the expansion joint system.
DETAILED DESCRIPTION
[0022] An improved bearing structure is provided. Without limitation, the bearing can be utilized in connection with an expansion joint system in roadway constructions, bridge constructions, tunnel constructions, and other constructions where gaps are formed between spaced-apart, adjacent concrete sections. The expansion joint system may be utilized where it is desirable to absorb loads applied to the expansion joint systems, and to accommodate movements that occur in the vicinity of the expansion joint gap in response to the application of the applied loads to the expansion joint system.
[0023] The bearing structure includes a bearing substrate and an upper bearing portion that is disposed on, or otherwise fitted over, a portion of the bearing substrate. The upper bearing portion of the bearing includes curved side walls and a curved upper bearing surface.
[0024] The bearing structure will now be described in greater detail with reference to the FIGURES. It should be noted that the bearing structure is not intended to be limited to the illustrative embodiments shown in the FIGURES.
[0025] FIG. 1 shows an exploded side view of one embodiment of the bearing structure 10 . Bearing structure 10 comprises a substrate 11 that is manufactured from a resilient material. According to the embodiment shown in FIG. 1 , bearing substrate 11 is shown having a substantially cylindrical shape. The bearing substrate 11 includes a top surface 12 , bottom surface 13 , and side walls 14 that extend between top surface 12 and bottom surface 13 .
[0026] Bearing structure 10 also includes an upper bearing portion 15 . Upper bearing portion 15 includes a top bearing surface 16 and side walls 17 extending downwardly away from top bearing surface 16 . The side walls 17 of upper bearing portion 15 include oppositely facing inner 18 and outer 19 surfaces. The top bearing surface 16 and curved side walls 17 , together, form a cap-like structure having an inner volume 20 .
[0027] Now turning to FIG. 2 , the bearing structure 10 is shown with upper bearing portion 15 engaged with the bearing substrate 11 . Upper bearing portion 15 is engaged with bearing substrate 11 by disposing or otherwise fitting upper bearing portion 15 over a portion of bearing substrate 11 . The upper bearing portion 15 is fitted over the top surface 12 of bearing substrate 11 , and the side walls 17 of upper bearing portion 15 extend over a portion of the side walls 14 of the bearing substrate 11 .
[0028] According to FIG. 2 , the bearing structure 10 is shown under conditions where no force or load is applied to the top bearing surface 16 of the upper bearing portion 15 of the bearing 10 . The side walls 17 of the upper bearing portion 15 are constructed such that in the absence of a force or load on the upper bearing portion 15 the sides walls 17 of upper bearing portion 15 have a curved shape. That is, the side walls 17 of upper bearing portion 15 remain concavely curved and “bow in” toward the center of the upper bearing portion 15 . A portion of the upper bearing surface 16 includes a flat seat region. The flat seat region of upper bearing surface 16 may be centrally located.
[0029] Turning to FIG. 3 , the bearing structure 10 is shown under conditions where a force or load (F) is applied to the top bearing surface 16 of the upper bearing portion 15 . Under conditions where a force or load is applied to the upper bearing surface 16 of the bearing 10 , the side walls 17 of upper bearing portion 16 are urged downwardly along the outer surfaces of side walls 14 of bearing substrate 11 and upper bearing portion 16 moves into closer proximity with bearing substrate 11 . As upper bearing portion 15 is urged in a downward direction toward bearing substrate 11 , the shape of the side walls 17 of upper bearing portion 15 undergo a transition from being concavely curved toward the center of the upper bearing portion 15 to a vertical configuration. That is, as top bearing portion 15 is urged downwardly the side walls 17 change configuration from the concavely shaped side walls to a position that is perpendicular to the upper bearing surface 16 of upper bearing portion 15 and top surface 12 of bearing substrate 11 . When an out of level force or load is applied to upper bearing surface 16 at an angle, the upper bearing portion 15 of structural bearing 10 is able to transmit the vertical load such that the bottom surface of the bearing “feels” very minimal eccentricity.
[0030] Distortional stresses in response to the application of a load to a traditional bearing structure often caused damage to the bearing structure. The use of the bearing structure 10 having concavely curved side walls 17 minimizes the distortional stresses below the bearing surface in response to the application of a force or load. The optimized geometric combination of curved side walls, curved top bearing surface, and flat seat region reduces local distortional stresses directly below the applied load, and moves the maximum distortional stress region to below the surface, based on the accepted principles of elasticity.
[0031] It is known that prior art bearing structure stiffness remains nearly constant over the range of applications, as they are compressed in response to the application of a load to the bearing. The use of the bearing structure 10 having an upper bearing portion 15 with concavely curved side walls 17 provides an increasing force versus deflection spring rate. Utilizing the bearing structure 10 having an upper bearing portion 15 with curved side walls 17 permits the bearing structure to be precompressed to a significant degree, thereby mitigating bearing vibration when large vehicular impact loads are applied to the bearing. Additionally, the use of the bearing structure 10 having an upper bearing portion 15 with curved side walls 17 stabilizes large displacements in response to loads applied to the bearing 10 .
[0032] In general, the top bearing surfaces of prior art bearings expand and contract against the support bar of the expansion joint systems in response to an application of a load, which causes significant rubbing and friction between the top bearing surfaces of the bearings and the surfaces of the support bar of the expansion joint systems. In contrast, upper bearing portion 15 of the bearing structure 10 expands upward to contact the surface of the support bar of the expansion joint systems. Under these conditions, less surface rubbing and friction occur between the top bearing surface 16 and the surface of the support bars of the expansion joint system. Because there is less friction between the top bearing surface 16 of the bearing 10 and the surfaces of the support bars, there is a significant decrease in the surface wear of the bearing 10 . Thus, the overall life of the bearing is increased.
[0033] The side walls of the prior art bearings bulge outwardly upon an application of a load to the top bearing surface. These bearings, sometimes referred to as parabolic bulge bearings, are bonded on the top and bottom surfaces, and are free to bulge on their sides. These bearings produce very large surface shears at the point where the free edge of the bearing meets the bonded surfaces. In contrast to prior art parabolic bulge bearings, the side walls 17 of bearing 10 are constructed in such a manner that upon maximum compression by a load applied to the bearing, the side walls 17 of upper bearing portion 15 are vertical. This is a significant improvement over prior art parabolic bulge bearings, as shear strains at the point of the bond of the free edge to the bonded edge is minimized.
[0034] An expansion joint system incorporating the improved structural bearing 10 is further provided. The expansion joint system may be utilized in a roadway construction wherein a gap is defined between adjacent first and second roadway sections. The expansion joint system extends across the gap between adjacent concrete roadway sections to permit vehicular traffic. The expansion joint system comprises transversely extending, spaced-apart, vehicular load bearing members. Elongated support members having opposite ends are positioned below the transversely extending load bearing members and extend longitudinally across the gap in the expansion joint from a first concrete roadway section to a second concrete roadway section. According to certain embodiments, the expansion joint system also includes first means for accepting first ends of the longitudinally extending elongated support members for controlling the movement of the ends of the support members within the first means for accepting longitudinally extending elongated support members, and second means for accepting opposite ends of the longitudinally extending elongated support members for controlling the movement of the opposite ends of said support members within the second means for accepting longitudinally extending elongated support members. Bearing structures 10 are disposed between sides surfaces of the opposite first and second ends of the longitudinally extending elongated support members and inner surfaces of the first and second means for accepting ends of the longitudinally extending elongated support members to absorb loads applied to the expansion joint system. The bearing structure includes a substrate and an upper bearing portion that is disposed on, or otherwise fitted over, the substrate. The upper bearing portion of the bearing comprises curved side walls and a curved upper bearing surface.
[0035] According to other embodiments, the expansion joint system includes transversely extending, spaced-apart, vehicular load bearing members, elongated support members having opposite ends positioned below the transversely extending load bearing members and extending longitudinally across the expansion joint, and means for movably engaging the longitudinally extending, elongated support members with the transversely extending, spaced-apart load bearing members. Bearings 10 are disposed between surfaces of lateral sides of the longitudinally extending elongated support bar members and surfaces of the means for movably engaging the longitudinally extending, elongated support bar members with the transversely extending, spaced-apart load bearing members. The bearing structure 10 includes a substrate and an upper bearing portion that is disposed on, or otherwise fitted over, the substrate. The upper bearing portion of the bearing comprises curved side walls and a curved upper bearing surface.
[0036] Now referring to illustrative FIG. 4 , expansion joint system 30 includes a plurality of vehicular load bearing members 31 - 37 . The vehicular load bearing members 31 - 37 of expansion joint system 30 are positioned in the gap between the adjacent roadway sections (not shown). The vehicle load bearing members are often referred to in the art as “center beams.” While illustrative FIG. 4 shows seven transversely extending load bearing members 31 - 37 , it should be noted that the expansion joint system 30 may include any number of transversely extending load bearing members, depending on the size of the gap of the particular construction. According to certain embodiments, the load bearing members have a generally square or rectangular cross section. Nevertheless, the load bearing members 31 - 37 are not limited to members having approximately square or rectangular cross sections, but, rather, the load bearing beam members 31 - 37 may comprise any number of cross sectional configurations or shapes. The shape of the cross section of load bearing beam members 31 - 37 is only limited in that the load bearing beams 31 - 37 must be capable of permitting relatively smooth and unimpeded vehicular traffic across the top surfaces of the load bearing beam members, and the load bearing beam members must have the ability to support engaging means that are engaged to the bottom surfaces of the load bearing beam members to engage the longitudinally extending elongated support members. According to certain embodiments, the top surfaces of the load bearing beam members may, for example, also be contoured to facilitate the removal of debris and liquids, such as rainwater runoff.
[0037] The load bearing beam members 31 - 37 are positioned in a spaced apart, side-by-side relationship and extend transversely in the expansion joint gap relative to the direction of vehicle travel. That is, the load bearing members 31 - 37 extend substantially perpendicular, relative to the direction of vehicle travel across the expansion joint system 30 . The top surfaces of the load bearing beam members are adapted to support vehicle tires as a vehicle passes over the expansion joint. Compressible seals (not shown in FIG. 1 , but shown in FIG. 9 ) may be placed and extend transversely between the positioned vehicular load bearing beam members 31 - 37 adjacent the top surfaces of the beam members 31 - 37 to fill the spaces between the beam members 31 - 37 . The seals may also be placed and extend in the space between end beam member 31 and edge plate 38 and to extend between end beam member 37 and edge plate 39 . The seals are flexible and compressible and, therefore, can stretch and contract in response to movement of the load bearing beams within the expansion joint. The seals are preferably made from a durable and abrasion resistant elastomeric material. The seal members are not limited to any particular type of seal. Suitable sealing members that can be used include, but are not limited to, strip seals, glandular seals, and membrane seals.
[0038] Still referring to FIG. 4 , the expansion joint system 30 includes elongated support bar members 40 - 43 . Support bar members 40 - 43 are positioned in a spaced-apart, side-by-side relationship and extend longitudinally across the gap of the expansion joint, relative to the direction of the flow of vehicular traffic. That is, the support bar members 40 - 43 extend substantially parallel relative to the direction of vehicle travel across the expansion joint system 30 . The support bar members 40 - 43 provide support to the vehicle load bearing beams 31 - 37 as vehicular traffic passes over the expansion joint system 30 . Support bar members 40 - 43 also accommodate transverse, longitudinal and vertical movement of the expansion joint system 30 within the gap.
[0039] Opposite ends of the support bar members 40 - 43 are received into suitable means for accepting the ends of the support bar members, and several means for accepting the support bar members are disposed, or embedded in portions of respective adjacent roadway sections in the roadway construction. The expansion joint system 30 can be affixed within the “block-out” areas between two adjacent roadway sections by disposing the system 30 into the gap between the roadway sections and pouring concrete into the block-out portions or by mechanically affixing the expansion joint system 30 in the gap to underlying structural support. Mechanical attachment may be accomplished, for example, by bolting or welding the expansion joint system 30 to the underlying structural support.
[0040] In accordance with the invention, provision is made for particular types of movement of the support bar members 40 - 43 within the separate means for accepting the ends of the support bar members. In one embodiment, the means for accepting the ends of the support bar members comprise box-like structures. It should be noted, however, that the means for accepting the ends of the support bar members may include any structure such as, for example, receptacles, chambers, housings, containers, enclosures, channels, tracks, slots, grooves or passages, that includes a suitable cavity for accepting opposite end portions of the support bar members 40 - 43 .
[0041] Still referring to FIG. 4 , the expansion joint system 30 includes first means 50 for confining the first ends of the support bars 40 - 43 against longitudinal movement within the first means 50 for accepting, but permitting transverse movement of the first ends within the first means 50 for accepting. Therefore, the expansion joint system 30 includes first means for accepting first ends of the longitudinally extending elongated support members which include means for substantially restricting longitudinal movement within the first means for accepting, but permitting transverse and vertical movement within said first means for accepting.
[0042] The expansion joint system 30 includes second means 51 for accepting opposite ends of the support members 40 - 43 for confining the opposite ends of the support bars 40 - 43 against transverse movement within the second means 51 for accepting, but permitting longitudinal movement and vertical movement within the second means 51 for accepting. Therefore, the expansion joint system 30 includes second means for accepting ends of said longitudinally extending elongated support members which includes means for substantially restricting transverse movement within said second means for accepting, but permitting longitudinal movement within said second means for accepting.
[0043] FIG. 5 shows an illustrative support member 60 of the expansion joint system 30 . The support member 60 is shown as an elongated bar-like member having a square cross section. It should be noted, however, that the support member 60 is not limited to elongated bar members having square cross sections, but, rather, the support member 60 may comprise an elongated bar member having a number of different cross sectional shapes such as, for example, round, oval, oblong and rectangular. The support bar 60 includes opposite ends 61 , 62 . Illustrative support bar 60 includes a hole 63 communicating from one side 64 of the support bar 60 to the other side 65 . According to this embodiment, the hole 63 is adapted to receive a securing means. End 62 of the support bar 60 having the hole 63 therein is adapted to be inserted into first means 50 for permitting transverse and vertical movement, but substantially restricting longitudinal movement of the support member 60 of the expansion joint system 30 within the means 50 .
[0044] FIG. 6 shows a side view of means 50 , which according to the embodiment shown is a substantially rectangular box structure, and which permits transverse and vertical movement of support bars 40 - 43 of the expansion joint system 30 in response to movement within the expansion joint. The transverse and vertical movement box 50 includes top 52 and bottom 53 plates, side plates 54 , 55 and back plate (not shown). According to this embodiment, the securing means 56 is an elongated, substantially cylindrical guide rod to which a support bar 40 - 43 is engaged. The securing means 56 is substantially centrally disposed within box 50 may extend across box 50 from side plate 54 to side plate 55 . The securing means 56 may be held in place by holding plates 57 , 58 , which are attached to the inside wall surfaces 59 a , 59 b of side plate 54 and side plate 55 , respectively. The securing means 56 is inserted into the hole 63 in order to secure the support bar 40 - 43 within means 50 . The securement means 56 can be any means which permits pivotable movement of end 62 of the support bar in the vertical direction within means 50 , while further permitting transverse movement of end 62 of the support bar along the axis of the securement means. Thus, the securing means 56 substantially restricts longitudinal movement of the support bars 40 - 43 , but permits transverse and vertical movement. While the securing means 56 is shown in FIG. 6 as a cylindrical guide rod, it may, for example, include differently shaped rods, bars, pegs, pins, bolts, and the like.
[0045] FIG. 7 shows one end 62 of the support bar 60 inserted into means 50 . Bearing means 10 are disposed between the top surface of support bar member 60 and the inner surface 52 a of top plate 52 of box 50 and between the bottom surface of the support bar member 60 and the inner surface 53 a of bottom plate 53 . The rigid bearing substrate 11 of bearing structure is positioned adjacent to inside surface 52 a of top plate 52 and top bearing surface 16 of upper bearing portion 15 may contact top surface of support bar member 60 . A second bearing means 10 is positioned within box 50 . The rigid bearing substrate 11 of the second bearing structure is positioned adjacent to inside surface 53 a of bottom plate 53 and top bearing surface 16 of upper bearing portion 15 may contact bottom surface 64 of support bar member 60 .
[0046] FIGS. 8A and 8B shows longitudinal movement support box 51 . Box 51 includes means for permitting longitudinal and vertical movement of the support bars 40 - 43 within box 51 , and means for substantially preventing transverse movement of support bars 40 - 43 within the box 51 . Preferably, the upper 71 and lower 72 bearing means maintain the vertical load on the support bars perpendicular to the axis of the support bars and, permits slidable movement of the support bars in the direction of vehicular traffic flow (longitudinal movement). Upper and lower bearing means 71 , 72 are the constructed like bearing structure 10 described in FIGS. 1-3 . As shown in FIG. 8B , side bearing means 73 , 74 substantially prevent transverse movement of support bars 40 - 43 within box 51 , while not inhibiting or otherwise preventing longitudinal and vertical movement. According to the embodiment shown, side bearing means 73 , 74 are provided in the form of bearing plates that are disposed adjacent the inner surfaces of box 51 .
[0047] The use of the upper 71 and lower 72 bearings maintain the vertical load on the bearings perpendicular to the sliding surfaces. The upper and lower bearings are capable of absorbing impact from vehicular traffic moving across the expansion joint system.
[0048] The transverse movement box for receiving one end of the support bars is designed to permit transverse and vertical movement of the support bars within the boxes in response to changes in temperature changes, seismic movement or deflections caused by vehicular traffic, while restricting longitudinal movement. Longitudinal boxes for receiving the opposite ends of the support bars are designed to permit relative longitudinal and vertical movement of the support bar within the boxes, while confining the bars against relative transverse movement.
[0049] Means are provided to maintain the position of support bars 40 - 43 relative to the bottom surfaces of the load bearing beams members 31 - 37 . Also, the means permit longitudinal and limited vertical movement of the support bars 40 - 43 within the means. FIGS. 9A and 9B show one embodiment of the means, which comprises a yoke or stirrup assembly 80 for retaining the position of the support bars 40 - 43 relative to the bottom surfaces of the load bearing beams 31 - 37 of the expansion joint system 30 . As shown in FIG. 9B , the yoke assembly 80 includes spaced-apart yoke side plates 81 , 82 that are attached to and extend away from the bottom surface of the vehicular load bearing beam 31 . Bent yoke plate 83 includes leg portions 84 , 85 and spanning portion 86 that extends between legs 84 , 85 . The yoke assembly 80 also includes upper yoke bearing 87 and lower yoke bearing 88 . The yoke assembly 80 utilizes upper 87 and lower 88 yoke bearings to minimize yoke tilt and optimizes the ability of the expansion joint system 30 to absorb vehicular impact from traffic moving across the expansion joint system 30 . While the one embodiment is shown utilizing a yoke or stirrup assembly to maintain the positioning of the support bars 40 - 43 , any restraining device or the like that can maintain the position of the support bars 40 - 43 relative to the load bearing beams 31 - 37 may be utilized.
[0050] Yoke assembly 80 may further include yoke retaining rings 90 , 91 and yoke discs 92 , 93 , which are located on the inner surfaces of bent yoke legs 74 , 75 . The yoke retaining rings 81 , 82 and yoke discs 83 , 84 are provided to allow limited vertical and longitudinal movement of the support bars 40 - 43 . Furthermore, the yoke side plates 81 , 82 are spaced apart at a distance sufficient to permit bent yoke plate 83 to be inserted in the space defined by the inner surfaces of yoke side plates 81 , 82 .
[0051] The expansion joint system 30 may also include means for controlling the spacing between the transversely extending load bearing beam members 31 - 37 in response to movement in the vicinity of the expansion joint. In one embodiment, the means for controlling the spacing between beam members 31 - 37 maintains a substantially equal distance between the spaced-apart, traffic load bearing beams 31 - 37 that are transversely positioned within the gap in an expansion joint, in response to movements caused by thermal or seismic cycling and vehicle deflections.
[0052] The expansion joint system of the invention is used in the gap between adjacent concrete roadway sections. The concrete is typically poured into the blockout portions of adjacent roadway sections. The gap is provided between first and second roadway sections to accommodate expansion and contraction due to thermal fluctuations and seismic cycling. The expansion joint system can be affixed within the block-out portions between two roadway sections by disposing the system into the gap between the roadway sections and pouring concrete into the block-out portions or by mechanically affixing the expansion joint system in the gap to underlying structural support. Mechanical attachment may be accomplished, for example, by bolting or welding the expansion joint system to the underlying structural support.
[0053] While the present invention has been described above in connection with the preferred embodiments, as shown in the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function of the present invention without deviating therefrom. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired characteristics. Variations can be made by one having ordinary skill in the art without departing from the spirit and scope of the invention. Therefore, the present invention should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the attached claims.
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A bearing is provided for use in connection with expansion joint systems. The structure of the bearing permits improved motion of, and provides improved support for, the components of the expansion joint system that are supported on or engaged with the bearing. The bearing is particularly useful for expansion joint systems in roadway constructions, bridge constructions, and architectural structures.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to semiconductor packaging and, more particularly, to a method and apparatus for providing multi-chip semiconductor device (die) packages.
2. Statement of the Art
Integrated circuit devices proceed through a complicated and time consuming fabrication routine before being completed and ready for packaging. Once this integrated circuit device passes final inspection for acceptability, it is passed to packaging. The integrated circuit device (IC) then is typically encapsulated in a protective package made of plastic, metal, ceramic material, or combinations thereof. The package is sealed to insulate the semiconductor die from the effects of temperature extremes, humidity and unintentional electrical contacts. The package has a plurality of conductive leads protruding from the encapsulation material for connecting to external devices on a printed circuit board. Various types of semiconductor packages include sealed metal cans, plastic and ceramic dual in-line packages, small outlining packages, single in-line packages, surface mount packages, and various other flat packages.
One type of semiconductor device assembly is a lead-on-chip (LOC) assembly as shown in the prior art drawing FIG. 1 . In drawing FIG. 1, a strip 10 of lead frames 12 is provided. Located in a center portion of each lead frame 12 is a semiconductor die 14 attached to the lead fingers 16 , typically by way of wire bonds. An example of a single semiconductor die 14 being attached to a lead frame 12 is shown in prior art drawing FIG. 2 . The wire bonds 18 connect the semiconductor die 14 to the lead fingers 16 of the lead frame 12 . Next, the lead fingers 16 are trimmed and an encapsulant material is applied over the semiconductor die 14 and portions of lead fingers 16 to completely encapsulate and seal wire bonds 18 , portions lead fingers 16 , and semiconductor die 14 , making a single chip package.
There is a need to increase the semiconductor die density of a semiconductor package to include two or more semiconductor dice in one package. A high density package having multiple semiconductor dice therein increases the electronic component density on a printed circuit board. Such a high density semiconductor package also maximizes space utilization on a printed circuit board and further increases the number of active elements on the printed circuit board. U.S. Pat. No. 5,483,024, entitled “High Density Semiconductor Package,” issued Jan. 9, 1996, discloses a high density semiconductor package, an example of which is depicted in the prior art drawing FIG. 3 . In the '024 Patent, two semiconductor dice 14 are fixed on the lead fingers 16 of a corresponding one of two lead frames 12 . The semiconductor die 14 and the lead frames 12 are then encapsulated (not shown) wherein a portion of the lead frames protrude and extend from the package. Wire bonds 18 electrically connect each semiconductor die 14 to its respective lead frame 12 . An adhesive material 20 is used to bond the back surfaces of semiconductor dice 14 to one another. The high density semiconductor package illustrated in the '024 Patent does achieve a multi-chip package, but there are shortcomings in the manufacture of the same.
One problem is that a first semiconductor die must be attached to its lead frame and then electrically connected with the wire bonds 18 . The two or more semiconductor dice 14 are adhered one to another. Once they are attached, the semiconductor die 14 must be carried in an open basket that does not provide great rigidity that otherwise leads to poor wire bonding during the wire bonding process. A strong base support is necessary in order to provide a wire bond application that does not have weaknesses that lead to subsequent electrical or mechanical failure.
Another disadvantage with the '024 Patent disclosure is that the semiconductor device assembly must be flipped in order to do the wire bonding on the second surface. This exposes the delicate wire bonds on the first surface of the first semiconductor die to risks of detachment that may occur due to the stressing that results while wire bonding the second surface of the second semiconductor die as the assembly is held in a less than desirable open support structure. Thus, it would be desirable to be able to use a wire bonding process where the wire bonds are made between both the first semiconductor die and the second semiconductor die and their respective lead frames from the same access point.
Other types of multiple chip modules have been developed in the prior art. Another example is shown in U.S. Pat. No. 5,422,435, entitled “Stacked Multi Chip Modules and Method of Manufacturing,” issued Jun. 6, 1995. The '435 Patent discloses a circuit assembly that includes a semiconductor die having substantially parallel opposing first and second surfaces and at least one electrical contact mounted on the first surface. The multiple semiconductor dice are stacked one on top another or adjacent one another in a tandem position and then are electrically connected using wire bonds to a lead frame attached to a base substrate. The '435 Patent allows the wire bonding between multiple semiconductor dice to be performed during the same operation, but the use of a very complicated substrate with lead frame assembly requires a larger semiconductor die than otherwise desired as well as a much more complicated assembly process of attaching the semiconductor devices and any other intervening elements in a stack arrangement to the carrier substrate that includes the lead frame. No lead fingers of the lead frame are directly connected to the semiconductor die, such as in the '024 Patent previously described. Thus, the '435 Patent does not have the same advantages as using a lead-on-chip configuration as is achieved in the '024 Patent.
Another multi chip stacked device arrangement is depicted in U.S. Pat. No. 5,291,061, entitled “Multi Chip Stacked Devices,” issued Mar. 1, 1994, and commonly assigned with the present invention. The '061 Patent discloses multiple stacked die devices attached to a main substrate. Each stacked semiconductor die device is then electrically connected using wire bonds to a separate lead frame, which is not attached to the main substrate. The '061 Patent suffers from the same problem previously described in that it is not easily assembled using the improved lead-on-chip lead frame and the devices are stacked one on top another so as to make wire bonding difficult or done in stages after the addition of each subsequent die device.
SUMMARY OF THE INVENTION
The present invention is directed to a multi-chip semiconductor device package using a lead-on-chip lead frame configuration. The lead-on-chip multi-chip semiconductor device package places two or more lead-on-chip semiconductor dice into one package that are either attached to their own lead-on-chip lead frame or are mounted to the same lead-on-chip lead frame and subsequently wire bonded to provide electrical connection from the dice to the lead frame while in substantially the same arrangement without requiring the assembly of the multiple semiconductor dice and lead frame to be flipped for additional wire bonding attachment of the dice to the lead frame.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a prior art assembly of a lead frame tape;
FIG. 2 is a cross-sectional schematic diagram of a prior art package of a lead-on-chip assembly having a single semiconductor device;
FIG. 3 is a cross-sectional schematic diagram of a multi chip lead-on-chip assembly according to the prior art;
FIG. 4 illustrates a cross-sectional schematic diagram of a pair of semiconductor devices mounted in tandem according to the present invention;
FIG. 5 is an alternative embodiment of a multi-chip lead-on-chip assembly according to the present invention;
FIG. 6 is an alternative embodiment of a pair of semiconductor devices attached using lead-on-chip lead frames;
FIG. 7 is an alternative embodiment of a plurality of semiconductor devices interconnected to a lead-on chip lead frame structure;
FIG. 8 is an alternative embodiment of a pair of semiconductor devices attached to a single in-line lead-on-chip lead frame;
FIG. 9 depicts an alternative embodiment of the lead-on-chip multi-chip package according to the present invention;
FIG. 10 depicts an alternative embodiment of a lead-on-chip lead frame package according to the present invention;
FIG. 11 depicts a schematic diagram of a single in-line memory module utilizing a multi chip package according to the present invention;
FIG. 12 depicts a schematic diagram of multiple multi-chip assemblies in a lead frame tape strip according to the present invention; and;
FIG. 13 depicts a computer system incorporating the multi-chip package according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to drawing FIG. 4, illustrated is a semiconductor device assembly 100 of the present invention. The assembly 100 comprises a conductor carrying substrate 102 and a first and second semiconductor die 104 , which are both attached to the conductor-carrying substrate 102 . Each semiconductor die 104 is further attached to the leads of a lead-over-chip (LOC) lead frame 106 , the leads of the lead frame 106 being mechanically attached, by adhesive 112 bonding either directly to the active surface of the semiconductor die 104 or through the use of an adhesively coated tape 112 located between the active surface of the die 104 and the leads of the lead frame 106 , along a portion of a respective die 104 . Next, a wire bond 108 is attached to extend between a bond pad 110 on each semiconductor die 104 and a lead of the lead frame 106 . Since a plurality of bond pads 110 are located on the active surface of a semiconductor die 104 , a plurality of wire bonds 108 will thus be provided to connect to a plurality of leads of the lead frame 106 . Next, an encapsulant material, shown by dotted line 101 , is used to seal the substrate 102 , the multiple semiconductor die 104 , and wire bonds 108 . Subsequently, the leads of lead frame 106 are trimmed and formed into any variety of shapes, such as that depicted in FIG. 4 or, alternately, a J-shaped lead, a Z-shaped lead, an S-shaped lead, or the like.
Each semiconductor die 104 attaches to the carrier substrate 102 using an appropriate adhesive 112 or any other well known standard die attach processes. The adhesive 112 is selected to have an appropriate coefficient of thermal expansion (CTE) to closely match the coefficient of thermal expansion of the carrier substrate 102 and the semiconductor die 104 as well as to provide good heat-conductive properties while providing electrical insulation between the active surface of a die 104 and the substrate 102 . Adhesive 112 may alternately be an adhesively coated tape. The adhesive 112 may be composed of an electrically insulating material or a heat dissipating material such as a heat sink or combinations of both. A conductive epoxy, such as a silver type die attach epoxy, may also be employed to attach the die 104 to the substrate 102 .
After the wire bonding process, typically, the semiconductor device assembly 100 is encapsulated using a suitable encapsulation material, shown by outline 101 . One type of encapsulation material is molded plastic filled with inert material, which is commonly used for encapsulating semiconductor die and the like. Other encapsulation materials may also be used, such as ceramics or metal enclosures or combinations of both. The encapsulation material does not cover the outer ends of the leads of the lead frame 106 , which protrude from the encapsulation material. The protruding portions of outer ends of the leads of the lead frame 106 provide electrical connection of the semiconductor die 104 encapsulated in the semiconductor device assembly 100 to a printed circuit board (not shown).
Referring to drawing FIG. 5, an alternative embodiment of the semiconductor device assembly 100 is depicted. In the alternative embodiment illustrated in drawing FIG. 5 of the present invention, no carrier substrate 102 is used, but rather the two semiconductor die 104 are attached to each other with the back side of one dice 104 mating to the active surface of the other die 104 . The active surface of the semiconductor die 104 is protected by an oxide coating or other protective coating, such as the adhesive layer 112 , or adhesively coated tape 112 . This allows one semiconductor die 104 to have its active region attached to a back side of another die 104 with adhesive 112 or adhesive coated tape 112 therebetween. Wire bonds 108 are attached to individual leads of the lead frame 106 and attached to the bond pads 110 on each of the semiconductor dice 104 . The leads of the lead frame 106 are attached by adhesive 112 or adhesively coated tape 112 to an edge of the active surface of each semiconductor die 104 . The leads of the lead frame 106 are not spaced relatively close to the bond pads 110 on the semiconductor die 104 , thereby allowing for easy attachment of the wire bonds 108 during the wire bonding process. The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material as shown by outline 101 .
Referring to drawing FIG. 6, yet an alternative embodiment of the semiconductor device assembly 100 of the present invention is depicted where a portion of the leads of a lead frame 106 is attached by adhesive 112 or adhesively coated tape 112 to a portion of the active surface of a semiconductor die 104 , while another portion of the leads of lead frame 106 is attached by adhesive 112 or adhesively coated tape 112 to the back side of another semiconductor die 104 . Alternately, well known standard die attach processes using a conductive epoxy, such as a silver based epoxy, may also be used. Wire bonds 108 are then used to electrically connect the bond pads 110 of each semiconductor die 104 to the leads of the lead frame 106 . The back side of one semiconductor die 104 is attached to a portion of the active surface of another semiconductor die 104 by a suitable adhesive 112 or adhesively coated tape 112 . The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material shown by outline 101 .
Referring to drawing FIG. 7, yet another alternative embodiment of the semiconductor device assembly 100 of the present invention is illustrated. In this alternative embodiment of the semiconductor device assembly 100 of the present invention, two semiconductor dice 104 , located in a common horizontal plane, each have a portion of the active surface thereof attached to a portion of the back side of a third semiconductor die 104 located thereabove through the use of a suitable adhesive 112 or adhesively coated tape 112 . A portion of the leads of the lead frame 106 is attached using an adhesive 112 or adhesively coated tape 112 to a portion of the active surface of the semiconductor die 104 while another portion of the leads of the lead frame 106 is attached by an adhesive 112 or adhesively coated tape 112 to a portion of the adjacent semiconductor die 104 . A plurality of wire bonds 108 is then used to attach the bond pads 110 of each semiconductor die 104 to the leads of the lead frame 106 . In this case, preferably, the top semiconductor die 104 has bond pads 110 fabricated along the outside edges of the dice 104 while the bottom two die 104 have substantially center-aligned bond pads 110 formed thereon. If desired, the bond pads 110 on the top semiconductor die 104 may be at any location thereon however, the wire bonds 108 may increase in length between the bond pads 110 and the leads of the lead frame 106 . The leads of the lead frame 106 attach to the edge of the active surface of each of the semiconductor dice 104 located below the upper die 104 in the configuration. Alternatively, as illustrated in dotted lines, the leads of the lead frame 106 may be attached on the back side of the lower semiconductor die 104 with wire bonds 108 extending between the bond pads 110 of each die 104 and the leads of the lead frame 106 . The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material as shown by outline 101 .
Referring to drawing FIG. 8, yet another alternative embodiment of the semiconductor device assembly 100 of the present invention is depicted that includes two semiconductor die 104 and a plurality of leads of a lead frame 106 . A first semiconductor die 104 has a portion of the back side thereof attached to a portion of the upper surfaces of the leads of the lead frame 106 by a suitable adhesive 112 or adhesively coated tape 112 or well known standard die attach epoxies or conductive epoxy, such as a silver based epoxy, while a second semiconductor die 104 has a portion of the active surface thereof attached to the lower surfaces of the leads of the lead frame 106 by a suitable adhesive 112 or adhesively coated tape 112 . The first semiconductor die 104 is positioned so that an exposed portion of lead frame 106 extends a sufficient enough distance beneath the back side of the first die 104 to allow a plurality of wire bonds 108 to connect the bond pads 110 of each die 104 to the leads of the lead frame 106 . This is advantageous in that a single in-line module may be formed utilizing the advantage of placing two or more, any desired number of, semiconductor dice 104 in a substantially adjacent configuration with the active surface of each die 104 and their associated bond pads 110 thereon facing the same direction for forming wire bonds 108 during a wire bond process. The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material as shown by outline 101 .
Referring to drawing FIG. 9, an alternative embodiment of the semiconductor device assembly 100 of the present invention is illustrated. The semiconductor device assembly 100 includes the leads of a lead frame 106 attached through the use of a suitable adhesive 112 or adhesively coated tape 112 or other well standard die attach epoxies to the back side of the first or top semiconductor die 104 and other leads of the lead frame 106 attached through the use of a suitable adhesive 112 or adhesively coated tape 112 to a portion of the active surface of a second or bottom semiconductor die 104 . The first semiconductor die 104 has a portion of the back side thereof attached to a portion of the active surface of the second semiconductor die 104 using a suitable adhesive 112 or adhesively coated tape 112 . Such a semiconductor device assembly 100 of the present invention provides a more compact design since the profile height of the overall structure is reduced. In this embodiment of the semiconductor device assembly 100 of the present invention, preferably, the one semiconductor die 104 has bond pads 110 on the edge of the active surface thereof while the other semiconductor die 104 has generally centered or centrally oriented bond pads 110 on the active surface thereof. Wire bonds 108 extend between the bond pads 110 of the semiconductor die 104 and the leads of the lead frame 106 . The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material as shown by outline 101 .
Referring to drawing FIG. 10, another alternative embodiment of the semiconductor device assembly 100 of the present invention includes the leads of the lead frame 106 attached to the back side of each semiconductor die 104 using a suitable adhesive 112 therebetween or an adhesively coated tape 112 or well known standard die attach epoxies or conductive epoxies as described hereinbefore located therebetween while a portion of the back side of the first semiconductor die 104 is attached to a portion of the active surface of the second semiconductor die through the use of a suitable adhesive 112 or an adhesively coated tape 112 . In this manner, each semiconductor die 104 , the first semiconductor die and the second semiconductor die, preferably has edge-oriented bond pads 110 on the active surface thereof for the wire bonds 108 extending between the leads of the lead frame 106 and the bond pads 110 of the die 104 for a rapid wire bonding process during the wire bonding stage. In all but the embodiment shown in drawing FIG. 8, the resulting semiconductor device assembly 100 produces a dual in-line parallel lead configuration for the semiconductor die 104 . The semiconductor device assembly 100 is encapsulated in a suitable encapsulation material as shown by outline 101 .
Once the assembly 100 has been encapsulated, it then may be installed on a circuit board, such as shown in drawing FIG. 11 . As illustrated in drawing FIG. 11, a single in-line memory module (SIMM) 120 includes a plurality of semiconductor device assemblies 100 electrically and mechanically attached to a printed circuit board 122 . Printed circuit board 122 further includes a plurality of edge connectors 124 , which are electrically connected to the plurality of semiconductor device assemblies 100 . A pair of clip holes 126 are provided on either end of circuit board 122 , and are used to securely fasten the SIMM 120 within a memory slot on a computer system.
Referring to drawing FIG. 12, a plurality of semiconductor device assemblies 100 are illustrated in a tape array format 130 . In each semiconductor device assembly 100 includes, a pair of semiconductor dice 104 , attached one over the other denoted by the dotted line 132 . The two semiconductor dice 104 are mechanically attached to the leads of lead frames 106 , forming a portion of the tape assembly 130 . Next, the wire bonding process is performed that attaches wire bonds 108 from each semiconductor die 104 to the leads of the lead frames 106 . Then, the leads of the lead frames 106 are severed, such as shown along the dotted line 134 , during a trimming operation. The leads of the lead frames 106 are formed into a desired shape after the encapsulation of the leads of the lead frames 106 and semiconductor dice 104 .
Referring to drawing FIG. 13, a computer system 140 is illustrated. The computer system 140 includes one or more semiconductor device assemblies 100 manufactured according to the present invention as described hereinbefore. Computer system 140 includes a microprocessor unit 142 , which may utilize the multi-chip packaging semiconductor device assembly 100 . Computer 140 further comprises an input device 144 and an output device 146 , which are both attached to a bus system 150 . Bus system 150 is attached further to microprocessor unit 142 and to a memory system 148 . Memory system 148 may also incorporate the multi-chip semiconductor device assembly 100 according to the present invention.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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A multi-chip semiconductor package using a lead-on-chip lead frame. The lead-on-chip package places two or more lead-on-chip dice into one package that are either attached to their own lead-on-chip lead frame or are mounted to the same lead-on-chip lead frame and subsequently wire bonded to provide electrical connection from the dice to the lead frame while in substantially the same arrangement without requiring the assembly of the multiple semiconductor dice and lead frame to be flipped for additional wire bonding attachment of the dice to the lead frame.
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to German Patent Application No. 10 2012 024 615.3, filed Dec. 17, 2012, which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
The technical field relates to a device for influencing the passenger compartment noise in a motor vehicle.
BACKGROUND
There are various classes of such devices, on the one hand such that dampen the noise level in the passenger compartment of a vehicle, in that relative to a noise entering from the outside they emit an inversely phased offsetting noise into the passenger compartment, on the other hand such that selectively amplify or complement the noise entering from the outside in order to offer the passengers a desired auditory impression.
A preferred field of application however are devices of the latter class, such as known from EP 0469 023 B2 for example. This document describes a device for influencing the passenger compartment noise, which can be activated through a control signal representing a throttle valve movement or gear change, in order to render the operating noise of a racing car or of another high-performance road vehicle audible in the passenger compartment.
A skilled driver extracts information, often instinctively, from the cab noise, which facilitates his handling of the vehicle. The noise spectrum that is audible while driving for example makes possible drawing a conclusion regarding the travelling speed, which makes it easier for the driver to keep the travelling speed just under an approved maximum speed, without continuously having to follow the speedometer display. Unusual components of the passenger compartment noise can point to a technical malfunction. Conventional devices for influencing passenger compartment noise, regardless of whether they reduce or alienate the latter, render it more difficult for the driver to extract useful information from the passenger compartment noise.
In view of the foregoing, at least one object is to state a device for influencing passenger compartment noise, which makes it easier for the driver to extract such information instead of making it more difficult. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
SUMMARY
A device is provided for influencing the passenger compartment noise in a motor vehicle with a noise signal generator for generating an offsetting noise signal, which comprises at least one control input for receiving a control signal that is representative for the engine load of the motor vehicle, and comprises at least one loudspeaker for receiving the offsetting noise signal and emitting an offsetting noise into the passenger compartment of the motor vehicle the audio signal generator furthermore comprises at least one input for a temperature signal and is equipped to generate the offsetting noise signal as a function of a signaled temperature.
Based on the realization that the passenger compartment noise, insofar as it originates from sources within the vehicle, is also clearly determined through the temperature to which these sources are exposed, but that this temperature in general does not constitute a quantity that is relevant to the driver. In that the device makes possible adapting the offsetting noise signal to the signaled temperature, it simultaneously allows reducing the dependency of the entire passenger compartment noise, which is composed of the offsetting noise and noise transmitted via air or structure-borne sound-transmitting parts of the vehicle from the respective noise sources into the passenger compartment. In that, however, the temperature dependency of the passenger compartment noise is eliminated or at least diminished it is simpler for the driver to learn and take into account while driving the relationship between the passenger compartment noise and other parameters such as travelling speed, transmission rotational speed, etc.
The input for the temperature signal can in particular be connected to an outside temperature sensor, an oil temperature sensor or temperature sensors that are arranged on the inlet air or exhaust line of the engine, in particular on a compressor, a turbine, an exhaust gas filter or catalytic converter. The input for the temperature signal can be formed by a digital data bus such as for example a CAN-bus, which connects the temperature sensor(s) to the noise signal generator and possibly to other devices of the vehicle, which utilize such a temperature signal.
A mixer for superimposing the offsetting noise signal with an audio signal is preferentially connected upstream of the loudspeaker. This makes possible utilizing one and the same loudspeaker, preferentially simultaneously, for emitting the offsetting noise and for reproducing a sound recording. In order to minimize the dependency of the passenger compartment noise on the signaled temperature, the noise signal generator is preferentially equipped to control the volume of the offsetting noise opposite to the dependency of the volume of an operating noise passively transmitted into the passenger compartment on the signaled temperature.
In order to render not only the total volume, but also the sound spectrum of the passenger compartment noise as independent as possible from the temperature, the noise signal generator is preferentially equipped to carry out controlling the volume for various frequency ranges independently of one another.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:
FIG. 1 is a block diagram of a motor vehicle with a device according to an embodiment for influencing the passenger compartment noise; and
FIG. 2 is a diagram showing the sound pressure as a function of the temperature for a noise source of the vehicle, for the device for influencing the passenger compartment noise and for the total passenger compartment noise.
DETAILED DESCRIPTION
The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description.
FIG. 1 schematically shows a vehicle having a device for influencing the passenger compartment noise. An internal combustion engine, in particular a spark-ignition or diesel engine of the vehicle is designated 1 . On an inflow line 2 of the engine 1 , the following are arranged in series: an air filter 3 , compressor 4 , a charge air cooler 5 , a throttle valve 6 and an intake manifold 7 , which distributes the charge air over the cylinders of the engine 1 . On an exhaust line 8 of the engine 1 , a turbine 9 and an exhaust catalytic converter 14 or particle filter are arranged. The exhaust gas expanding in the turbine 9 drivers the compressor 4 via a shaft 10 in a manner known per se element.
The travelling noise that is audible in a cab 11 of the vehicle is composed of contributions of various sources, in particular of the engine 1 , of a transmission 12 driven by the engine 1 and of a drive train connected downstream and extending to driven wheels of the vehicle, of the wheels in contact with the road surface and the various components arranged on intake airline and exhaust line of the vehicle. In the case under consideration here, the operating noises of the compressor 4 and of the turbine 9 in particular are temperature-dependent, since the mass of the gas put through the converter 4 and turbine for each revolution of the shaft 10 greatly depends on the temperature of the sucked-in air, i.e. on the ambient temperature. However, other components also have a temperature-dependent noise development, which is why the invention in its applicability is not restricted to compressor vehicles. Thus, the ease of operation of the cylinders of the engine 1 and of the transmission 12 is dependent on the temperature of the lubricating oil circulating therein, which likewise has an influence on the noise development.
Temperature sensors can be provided on the vehicle in a multiplicity of locations. For sensing the ambient temperature, a temperature sensor 13 can for example be arranged directly on the air filter 3 or on a section of the intake air line 2 extending from the air filter 3 to the compressor 4 . Also conceivable is a placement between the compressor 4 and the charge air cooler 5 for sensing the charge air temperature after compression. Temperature sensors 13 can be provided on the exhaust line directly on the exhaust manifold, between engine 1 and turbine 9 . A temperature sensor 13 usually provided on the catalytic converter 14 or particle filter for monitoring the catalytic converter function or the regeneration of the particle filter can also be employed for a secondary usage within the scope of the present invention. A temperature sensor 13 cannot least be arranged also downstream of the catalytic converter 14 , for example between the latter and a muffler 15 .
Temperature sensors 13 for monitoring oil or cooling water can be placed on the engine 1 or the transmission 12 . The various temperature sensors 13 communicate with a noise signal generator 16 and if appropriate other components of the vehicle which are not shown in the figure via a digital bus, e.g. a CAN-bus 17 .
A load sensor 18 is shown arranged on an accelerator pedal 19 in FIG. 1 ; a signal supplied by this sensor 18 and indicating the position of the pedal 19 is utilized by an engine control unit 20 in a manner known per se in order to likewise via the bus 17 , control the throttle valve 6 . The noise generator signal 16 can via the bus 17 directly receive the position signals of the sensor 18 , an adjusting signal derived by the engine control unit 20 from this and addressed to the throttle valve 6 or feedbacks of the throttle valve 6 , which in each case indicates the respective set position of the throttle valve 6 , in order to draw conclusions regarding the engine load from this.
A rotational speed sensor 21 is arranged on a shaft 22 connecting the internal combustion engine 1 to the transmission 12 and connected to the bus 17 . In this way, the noise signal generator 16 can also receive information regarding the rotational speed of the engine via the bus 17 .
The noise signal generator 16 generates an offsetting noise signal with the help of the received data relating to the engine load and if applicable rotational speed and one or a plurality of measured temperatures. To this end, it can comprise various oscillators or memory modules that can be matched in frequency and range, in which digitized noise signals are stored and which, continuously read out and weighted with load-dependent amplitudes, are superimposed on one another in order to form the offsetting noise signal.
An audio or infotainment system 23 of the vehicle comprises one or a plurality of audio signal sources 24 , such as for example a car radio, a playback device for CDs, MP3-files or the like, and an amplifier 25 with a plurality of inputs for audio signals of the sources 24 and the offsetting noise signal of the noise signal generator 16 . An output of the amplifier 25 is connected to loudspeakers 26 distributed in the passenger compartment 11 in order to reproduce the offsetting noise signal and, in the event that one of the sources 24 is in operation, its audio signal which is superimposed on the offsetting noise signal.
FIG. 2 schematically shows the relationship between sound pressure p and operating temperature T for one of the abovementioned noise sources engine 1 , compressor 4 etc. as a curve a. The noise signal generator 16 is equipped in order to supply an offsetting noise signal with the same spectral composition as the operating noise of the noise source that is audible in the passenger compartment 11 but with respect to a horizontal axis, in mirrored temperature dependency, corresponding to a curve b, so that the entire passenger compartment noise that is audible in the passenger compartment 11 and formed through an incoherent superimposition of the contributions of the noise source and of the noise signal generator 16 , represented as curve c, no longer has any dependency on the temperature.
The relationship between operating temperature and sound pressure can be different for various ranges of the audible frequency spectrum. Since the spectral composition of the operating noise of the various noise sources is also variable over time in particular as a function of the engine rotational speed in general, different relationships each between operating temperature and sound pressure can apply for various spectral ranges. Accordingly, the offsetting of the temperature influence can take place in that the noise signal generator 16 initially estimates the sound pressure of the operating noise for various spectral ranges with the help of the engine load and the rotational speed, then multiplies this value by a factor which corresponds to the ratio of the curves a and b at the current temperature, synthesizes the offsetting noise with the sound pressure thus obtained, outputting it via the loudspeakers 26 .
In that the dependency of the passenger compartment noise on the temperature is thus substantially eliminated, the perceptibility of other quantities influencing the noise spectrum is rendered easier for the driver, so that in particular drawing a conclusion regarding the vehicle speed from the heard noise is facilitated.
While at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalents.
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A device is provided for influencing the passenger compartment noise in a motor vehicle includes, but is not limited to a noise signal generator for generating an offsetting noise signal, which includes, but is not limited to a control input for receiving a control signal that is representative of the engine load of the motor vehicle, and a loudspeaker for receiving the offsetting noise signal and emitting an offsetting noise into the passenger compartment of the motor vehicle. The noise signal generator furthermore includes, but is not limited to an input for a temperature signal of a temperature sensor and is equipped to generate the offsetting noise signal as a function of a signaled temperature.
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BACKGROUND OF THE INVENTION
This invention relates to novel enamine derivatives of phosphonic acid esters and to herbicidally-effective compositions containing such derivatives.
DESCRIPTION OF INVENTION
The compounds of the invention have the formula ##STR1## wherein the groups Ar are each individually selected from phenyl, halophenyl and C 1 -C 4 alkoxyphenyl groups; R is a C 1 to C 4 alkyl group; R 1 is selected from the group consisting of nitrile, --COR, --COCF 3 , and --COOR groups; and R 2 is selected from hydrogen, R 1 and COR 3 , where R 3 is a C 1 to C 4 alkyl or haloalkyl group.
The compounds of the invention are effective herbicides and the invention also comprises a herbicidal composition comprising a compound of the invention as the active ingredient and a herbicidal method which comprises applying a herbicidally effective amount of such a composition to a plant.
Among the novel compounds of the invention, those in which R 1 is a --COOR group and R 2 is a --COCF 3 or, preferably, a --COOR group, are found to have the most attractive herbicidal properties. The preferred "Ar" groups are unsubstituted phenyl radicals and generally both "Ar" groups are identical.
The preferred compounds according to the invention include 2-propenoic acid, 2-acetyl-3-{[(diphenoxyphosphinyl)-methyl]-2-(ethoxy-2-oxoethyl)amino}, ethyl ester; 2-propenoic acid, 3-{[(diphenoxyphosphinyl)methyl](2-ethoxy-2-oxoethyl)amino-}2-(trifluoroacetyl)-, ethyl ester; and 2-propanedioc acid, ({[(diphenoxyphosphinyl)methyl](2-ethoxy-2-oxoethyl)amino}methylene), diethyl ester.
The compounds of the invention can be prepared by reaction of the corresponding glyphosate derivatives such as are described in U.S. Pat. No. 4,120,689 with an appropriate 2-ethoxy ethene derivative. A typical reaction proceeds as follows: ##STR2## where Ar, R, R 1 and R 2 have the significances indicated above.
The reaction can be carried out by contacting the reactants in solution in an inert solvent, preferable under reflux conditions, for several hours. It is found that the reaction is assisted if carried out under an inert atmosphere (e.g., nitrogen) with continued agitation. The 2-ethoxy ethene derivative adds on to the nitrogen atom of the glyphosate derivative with the elimination of ethanol.
DESCRIPTION OF PREFERRED EMBODIMENTS
In the following Examples, the preparation of compounds according to the invention and the herbicidal properties of selected compounds is demonstrated. The Examples are for the purpose of illustration only and are intended to imply no limitation on the essential scope of the invention.
EXAMPLE 1
This Examples illustrates the preparation of a compound with the formula ##STR3##
A reaction mixture comprising 5.2 gm of the ethyl ester of N-(diphenoxyphosphinylmethyl)glycine and 5.58 gm of the ethyl ester of 2-acetyl-3-ethoxy-propenoic acid in 100 ml of toluene was refluxed under nitrogen for 20 hours and then concentrated by removal of the solvent. The residue was placed in a column of 120 gm of silica gel and eluted using a 60:40 cyclohexane/ethyl acetate mixture. A purified product (3.2 gm) in the form of an oil was obtained.
The above product has an empirical formula of C 24 H 28 NO 8 P. Thus, the predicted elemental proportions are: C-58.89%, H-5.77%, N-2.86%. Elemental analysis of the product showed: C-58.66%, H-5.79%, N-2.80%.
EXAMPLE 2
This Example illustrates the preparation of a compound with the formula ##STR4##
A reaction mixture comprising 6.3 gm of the ethyl ester of N-(diphenoxyphosphinylmethyl)glycine and 6.10 gm of the ethyl ester of 2-trifluoroacetyl-3-ethoxy-propenoic acid in 100 ml of toluene was refluxed under nitrogen for 41/2 hours. An NMR analysis of a sample of the reaction product showed very little of the starting material remained. After refluxing for a further 4 hours, the solvent was removed and the reaction mixture was placed in a chromatograph column containing 90 gm of silica gel. Elution using a 60:40 v/v mixture of cyclohexane and ethyl acetate gave 3.0 gm of an oil which upon standing solidified to material having a melting point 92°-94° C. The purified product weighed 2.85 gm.
The above compound has an empirical formula: C 24 H 25 F 3 NO 8 P. Theory predicts for this product: C-53.04%, H-4.64%, N-2.58%. Elemental analysis of the product showed: C-53.22%, H-4.66%, N-2.53%.
EXAMPLE 3
This Example illustrates the preparation of a compound with the formula ##STR5##
A reaction mixture comprising 5.2 g of the ethyl ester of N-(diphenoxyphosphinylmethyl)glycine and 6.48 gm of the diethyl ester of ethoxy methylene malonic acid in 100 ml of toluene was refluxed under nitrogen for 16 hours. The solvent was then removed and the product purified as described in Example 2. Elution gave first of all the malonate ester starting product (0.8 gm) and the 4.3 gm of the target product as an oil.
The above compound has an empirical formula: C 25 H 30 NO 9 P. Thus, the expected elemental proportions are: C-57.8%, H-5.82%, N-2.70%. Elemental analysis of the product showed: C-57.86%, H-5.80%, N-2.70%.
EXAMPLE 4
This Example illustrates the preparation of a compound with the formula ##STR6##
A reaction mixture comprising 7.7 gm of the ethyl ester of N-(diphenoxyphosphinylmethyl)glycine, 4.0 gm of 4-methoxy-3-butene-2-one, and 100 ml of toluene was refluxed for 18 hours under nitrogen and then concentrated by removal of toluene. The product was purified chromatographically as described in Example 2 except that the cyclohexane/ethyl acetate proportions in the elutant were 30:70. This purification resulted in 6.7 gm of product which on elemental testing was found to contain 60.37% of carbon, 5.82% of hydrogen, and 3.28% of nitrogen. The above compound has the empirical formula C 21 H 24 NO 6 P and on this basis would have predicted proportions of C-60.58%, H-5.57%, and N-3.36%.
EXAMPLE 5
This Example illustrates the herbicidal activity of the compounds of the invention described in Examples 1-4.
In each case the compound was applied in spray form to 14-day old specimens of the various plant species indicated below.
The additive was incorporated in an aqueous spray solution comprising 3 parts of cyclohexanone and 1 part of a surfactant (35 parts of the butylamine salt of dodecylbenzene-sulfonic acid and 65 parts of tall oil condensed with ethylene oxide in the ratio of 11 moles of ethylene oxide to 1 mole of tall oil).
The application rate of the spray was varied as indicated and the treated plants were placed in a greenhouse in good growing conditions. After the indicated period the effect on the plants was examined and rated according to the following index.
0 indicates 0-24% control
1 indicates 25 to 49% control
2 indicates 50 to 74% control
3 indicates 75 to 99% control
4 indicates 100% control.
The plant species tested are indicated by letter. The significances of which are as follows:
A: Canada Thistle*
B: Common Cocklebur
C: Velvetleaf
D: Morning Glory
E: Lambsquarters
F: Smartweed
G: Nutsedge* (yellow)
H: Quackgrass*
I: Johnsongrass*
J: Bromus Tectorum
K: Barnyardgrass
L: Soybean
M: Sugar Beet
N: Wheat
O: Rice
P: Sorghum
Q: Wild Buckwheat
R: Hemp Sesbania
S: Panicum spp.
T: Crabgrass.
The results obtained were as shown in Table I.
TABLE I__________________________________________________________________________Herbicidal EffectsCom-pound WAT kg/ha A B C D E F G H I J K L M N O P Q R S T__________________________________________________________________________Ex. 1 4 5.6 -- 4 4 3 4 3 -- -- -- 3 4 4 4 4 4 4 3 4 4 4 4 1.12 -- 4 4 3 4 4 -- -- -- 4 4 2 4 3 3 4 4 4 4 4 4 0.28 -- 2 3 2 4 2 -- -- -- 2 3 1 3 3 3 3 3 4 3 4 4 11.2 4 3 3 3 4 4 3 4 4 3 4 -- -- -- -- -- -- -- -- -- 4 5.6 2 4 3 3 4 4 3 4 4 3 4 -- -- -- -- -- -- -- -- --Ex. 2 4 5.6 -- 4 3 4 4 -- -- -- -- 3 3 3 4 3 3 3 2 4 4 4 4 1.12 -- 2 1 2 3 2 -- -- -- 2 3 1 1 2 1 3 1 1 3 3 4 11.2 3 3 3 3 3 3 3 3 2 3 4 -- -- -- -- -- -- -- -- -- 4 5.6 3 2 1 3 4 4 2 3 3 2 4 -- -- -- -- -- -- -- -- --Ex. 3 4 5.6 -- 2 3 2 3 -- -- -- -- 2 4 1 2 2 1 3 3 -- 3 4 4 1.12 -- 2 1 2 3 2 -- -- -- 1 3 1 1 1 1 2 2 4 2 3 4 0.28 -- 0 1 1 3 0 -- -- -- 0 3 1 1 1 1 2 0 3 1 2 4 11.2 2 2 1 2 4 2 2 0 2 1 3 -- -- -- -- -- -- -- -- -- 4 5.6 1 2 1 2 3 1 2 0 2 1 3 -- -- -- -- -- -- -- -- --Ex. 4 4 5.6 -- 3 3 3 3 3 0 3 1 2 2 2 3 3 1 3 4__________________________________________________________________________ *WAT indicates "Weeks After Treatment".
From the illustrative data presented above, it should be clear that the herbicidal response will be dependent upon the compound employed, the rate of application, the plant specie involved, and other factors well understood by those skilled in the art.
The herbicidal compositions (including concentrates which require dilution prior to application to the plants) of this invention contain at least one active ingredient and an adjuvant in liquid or solid form. The compositions are prepared by admixing the active ingredient with an adjuvant such as a diluent, extender, carrier or conditioning agent to provide composition in the form of a finely-divided particulate solid, pellet, solution, dispersion or emulsion. Thus, the active ingredient can be used with an adjuvant such as a finely-divided solid, a liquid of organic origin, water, a wetting agent, a dispersing agent, an emulsifying or any suitable combination of these. From the viewpoint of economy and convenience, water is the preferred diluent. However, it is found that not all the compounds are resistant to hydrolysis and in some cases this may dictate the use of non-aqueous solvent media.
The herbicidal compositions of this invention, particularly liquids and soluble powders, preferably contain as further adjuvant components one or more surface-active agents in amounts sufficient to render a given composition readily dispersible in water or in oil. The incorporation of a surface-active agent into the compositions greatly enhances their efficacy. By the term "surface-active agent" it is understood that wetting agents, dispersing agents, suspending agents, and emulsifying agents are included therein. Anionic, cationic, and non-ionic agents can be used with equal facility.
Preferred wetting agents are alkyl benzene and alkyl naphthalene sulfonates, sulfated fatty alcohols, amines or acid amides, long chain acid esters of sodium isothionate, esters of sodium sulfosuccinate, sulfated or sulfonated fatty acid esters petroleum solfonates, sulfonated vegetable oils, ditertiary acetylenic glycols, polyoxyethylene derivatives of alkylphenols (particularly isooctylphenol and nonylphenol), and polyoxethylene derivatives of the mono-higher fatty acid esters of hexitol anhydrides (e.g. sorbitan). Preferred dispersants are methyl cellulose, polyvinyl alcohol, sodium lignin sulfonates, polymeric alkyl naphthalene sulfonates, sodium naphthalene sulfonate, polymethylene bisnaphthalenesulfonate, and sodium N-methyl-N- (long chain acid) laurates.
Water-dispersible powder compositions can be made containing one or more active ingredients, an inert solid extender and one or more wetting and dispersing agents. The inert solid extenders are usually of mineral origin such as the natural clays, diatomaceous earth, and synthetic minerals derived from silica and the like. Examples of such extenders include kaolinites, attapulgite clay, and synthetic magnesium silicate. Water-dispersible powders of this invention usually contain from about 5 to about 95 parts by weight of active ingredient, from about 0.25 to 25 parts by weight of wetting agent, from about 0.25 to 25 parts by weight of dispersant and from 4.5 to about 94.5 parts by weight of inert solid extender, all parts being by weight of the total composition. Where required, from about 0.1 to 2.0 parts by weight of the solid inert extender can be replaced by a corrosion inhibitor or anti-foaming agent or both.
Aqueous suspensions can be prepared by mixing together and grinding an aqueous slurry of a water-insoluble active ingredient in the presence of a dispersing agent to obtain a concentrated slurry of very finely-divided particles. The resulting concentrated aqueous suspension is characterized by its extremely small particle size, so that when diluted and sprayed, coverage is very uniform.
Emulsifiable oils are usually solutions of active ingredient in water-immiscible or partially water-immiscible solvents together with a surface active agent. Suitable solvents for the active ingredient of this invention include hydrocarbons and water-immiscible ethers, esters or ketones. The emulsifiable oil compositions generally contain from about 5 to 95 parts active ingredient, about 1 to 50 parts surface active agent and about 4 to 94 parts solvent, all parts being by weight based on the total weight of emulsifiable oil.
Compositions of this invention can also contain other additaments, for example fertilizers, phytotoxicants and plant growth regulants, pesticides and the like used as adjuvants or in combination with any of the above-described adjuvants. The compositions of this invention can also be admixed with the other materials, e.g. fertilizers, other phytotoxicants, etc., and applied in a single application. Chemicals useful in combination with the active ingredients of this invention either simultaneously or sequentially include for example triazines, ureas, carbamates, acetamides, acetanilides, uracils, acetic acids, phenols, thiolcarbamates, triazoles, benzoic acids, nitriles, and the like such as:
3-amino-2,5-dichlorobenzoic acid
3-amino-1,2,4-triazole
2-methoxy-4-ethylamino-6-isopropylamino-s-triazine
2-chloro-4-ethylamino-6-isopropylamino-s-triazine
2-chloro-N,N-diallylacetamide
2-chloroallyl diethyldithiocarbamate
N'-(4-chlorophenoxy)phenyl-N,N-dimethylurea
1,1-dimethyl-4,4'-bipyridinium dichloride
isopropyl m-(3-chlorophenyl)carbamate
2,2-dichloropropionic acid
S-2,3-dichloroallyl N,N-diisopropylthiolcarbamate
2-methoxy-3,6-dichlorobenzoic acid
2,6-dichlorobenzonitrile
N,N-dimethyl-2,2-diphenylacetamide
6,7-dihydrodipyrido(1,2-a:2',1'-c)-pyrazidinium salt
3-(3,4-dichlorophenyl)-1,1-dimethylurea
4,6-dinitro-o-sec-butylphenol
2-methyl-4,6-dinitrophenol
ethyl N,N-dipropylthiolcarbamate
2,3,6-trichlorophenylacetic acid
5-bromo-3-isopropyl-6-methyluracil
3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea
2-methyl-4-chlorophenoxyacetic acid
3-(p-chlorophenyl)-1,1-dimethylurea
1-butyl-3-(3,4-dichlorophenyl)-1-methylurea
N-1-naphthylphthalamic acid
1,1'-dimethyl-4,4'-bipyridinium salt
2-chloro-4,6-bis(isopropylamino)-s-triazine
2-chloro-4,6-bis(ethylamino)-s-triazine
2,4-dichlorophenyl-4-nitrophenyl ether
alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine
S-propyl dipropylthiolcarbamate
2,4-dichlorophenoxyacetic acid
N-isopropyl-2-chloroacetanilide
2',6'-diethyl-N-methoxymethyl-2-chloroacetanilide
monosodium acid methanearsonate
disodium methanearsonate
N-(1,1-dimethylpropynyl)-3,5-dichlorobenzamide.
Fertilizers useful in combination with the active ingredients include for example ammonium nitrate, urea, potash, and superphosphate.
When operating in accordance with the present invention, effective herbicidal amounts of the compounds of the invention are applied directly or indirectly to the plants. The application of liquid and particulate solid plant regulating compositions can be carried out by conventional methods, e.g., power dusters, boom and hand sprayers, rope wick applicators, rollers, recirculating sprayers and spray dusters. The compositions can also be applied from airplanes as a dust or a spray because of their effectiveness at low dosages.
The application of a herbicidally effective amount of the compounds of this invention to the plant is essential and critical for the practice of the present invention. The exact amount of active ingredient to be employed is dependent upon the response desired in the plant as well as such other factors as the plant species, and the environmental conditions, as well as the specific compound employed. In general, the active ingredients are employed in herbicidally effective amounts equivalent to from about 0.112 to about 10.0 kg/hectare.
Although the invention is described with respect to specific modifications, the details thereof are not to be construed as limitations except to the extent indicated in the following claims.
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Novel compounds are described which are glyphosate esters having an unsaturated substituent on the nitrogen atom of the glyphosate group. The compounds are active herbicides and may provide an active ingredient of a herbicidal composition.
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This application is a continuation of International Application No. PCT/EP03/03262, filed Mar. 28, 2003, and claims the benefit of priority to German patent application 102 14 802.3, filed Apr. 4, 2002.
BACKGROUND OF THE INVENTION
The present invention concerns space-saving and easily assembled systems for guiding mechanical and variable valve controls. Each system includes a rocker and a walker. The rocker is driven by a cam by way of a follower. The rocker is articulated to and drives the walker by way of a swivel accommodated on the walker. The swivel can be shifted by a steering mechanism along the arc of a circle or along a similar curve around the axis of rotation of a follower mounted on the walker that actuates the valve. The rocker drives the walker by way of an engagement contour and by means of a follower.
The rocker can alternatively drive the walker by way of an engagement contour that arches outward in the form of an arc of a circle, in which case the rocker can be shifted along the arc of a circle or along a similar curve around the axis of the arching engagement contour.
The rocker can alternatively be driven by a cam by way of an engagement contour.
The rocker can alternatively drive one-armed and two-armed levers.
Valve controls wherein the rocker's swivel can be shifted in a circular path around the axis of rotation of a follower accommodated in the walker and engaged by the rocker are disclosed in German Application 10 136 612.4.
The valve controls disclosed in German Application 10 155 007.3 feature an engagement contour or a follower shifted along a circular path by a shift and engaged either by a rocker and a follower or by an engagement contour, whereby the rockers drive a valve-actuating walker by way of a swivel.
The valve controls disclosed in German Application 10 136 612.4 feature a shift that shifts a swivel along a circular path, whereby a rocker is articulated to the swivel and drives a valve-actuating walker by way of a follower.
The shifts in these embodiments can be complicated to install because of lack of space or of assembly problems, and can also be too delicate, in that the swivels lie along the axis of rotation of the swivel accommodated on the walker and in reach as long as the valve remains closed or along that of the follower accommodated on the walker.
SUMMARY OF THE INVENTION
The present invention accordingly concerns three different embodiments that take up little space and are easy to install. FIGS. 1 and 2 depict a mechanism for setting valve controls. A flat or sliding block has similarly curved and mutually engaging tracks inside a case. The flat is provided with an engagement contour that acts as a cam. The engagement contour is engaged by a follower mounted on a rocker. Alternatively, the flat itself can be provided with a follower that operates in conjunction with an engagement contour on the rocker that acts as a cam. The flat itself can also alternatively be provided with a swivel.
FIG. 3 depicts another embodiment of a mechanism for setting valve controls. A contoured flat is secured between two banking rollers, one on each side, or more. The rollers are provided with flanges. The flat is provided with a follower that engages an engagement contour on a rocker.
Alternatively, the flat itself can be provided with either a follower for engaging the engagement contour on a rocker or with a swivel for guiding a rocker.
FIG. 4 depicts still another embodiment of a mechanism for setting valve controls. A steering lever is supported at two points by swivels accommodated on two crankshafts or camshafts. The angled end of the lever is provided with a swivel for guiding the engagement contour of a rocker. A slide in the form of a flat must be provided in this case to position the engagement contour for engagement by a follower. The situation is more complicated in that the steering lever must be supported at two swiveling points by two contoured flats.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 show a mechanism for setting valve controls, in accordance with the present invention;
FIG. 3 shows another embodiment of a mechanism for setting valve controls; and
FIG. 4 shows still another embodiment of a mechanism for setting valve controls.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an assembly for mechanically setting variable valve controls. The assembly includes a rocker 1 , a walker 4 , and a contoured flat 11 . Rocker 1 has two arms and pivots around a swivel 2 mounted on walker 4 . Walker 4 actuates a valve 3 . Rocker 1 is driven by a cam 6 by way of a follower 5 mounted on the end of one arm. Mounted on the rocker's other arm is another follower 7 that follows the engagement contour of flat 11 . Flat 11 slides clockwise and counterclockwise inside a case 10 around the axis of swivel 2 while the swivel remains in the position it is in as long as valve 3 is closed. The flat's engagement contour is divided into two segments 8 and 9 . Segment 8 participates in maintaining valve 3 closed, and segment 9 in allowing the valve to open. Segment 8 curves inward with a radius R. Radius R is the radius of a circle centered on the axis of swivel 2 as long as valve 3 is closed. Segment 9 terminates in a spur that extends inward and considerably beyond segment 8 . The length of radius R equals the length of a radius R 1 extending from the axis of swivel 2 to the axis of follower 7 plus the length of a radius R 2 extending from the axis of follower 7 to its circumference.
FIG. 2 is a cross-section through a case 10 to be employed with a cylindrical alignment of such assemblies. Each face of each flat 11 is, in this practical illustrated version, secured in case 10 by a longitudinal polyvinyl cogged section 12 . Flat 11 is forced against the stationary cogged section 12 by an expanding component 14 . Expanding component 14 is subject to the force of a ram 13 . Expanding component 14 is maintained in the direction associated with setting the controls inside case 10 and is provided with a matching cogged section. This approach prevents play. In a cylindrical alignment, each expanding component 14 can be subject to the force of a ram 13 exerted from each side. Rams 13 derive their force mechanically from springs, from the pressure of the oil in an automotive lubrication system, or from both.
Flat 11 can alternatively be guided by other appropriate circular longitudinal cogged sections, mounted radially. Flat 11 is positioned by a cogged section 15 that engages a cogwheel 16 mounted on a rotating shaft 17 .
Valve 3 will be maintained closed as long as the spur, the segment 9 of the engagement contour of flat 11 , that is, remains in position A. Once the spur is in position B, however, the valve will be able to open with its longest and slowest stroke. As long as valve 3 is maintained closed, follower 7 will engage the circular segment 8 of the engagement contour of flat 11 without activating the valve. To actuate the valve, flat 11 will be shifted out of its valve-closed position and along the arc of a circle inside case 10 by a rotation of shaft 17 , allowing the spur to be engaged by the follower 7 mounted on rocker 1 . The extent of the engagement will determine the length and accordingly the duration of the opening stroke. Flat 11 can alternatively be positioned by an articulated rod driven for example by an eccentric shaft.
Assembly can be facilitated if case 10 and shaft 17 are integrated into bearing blocks screwed to cylinder head 18 . The bearing blocks to be employed with a specific cylindrical alignment of such assemblies can be subassembled in advance along with cases 10 , shaft 17 , and flats 11 , already accommodated inside the cases, as well as, when practical with the shaft 19 of cam 6 if they share the same bearing blocks, on a mount screwed to cylinder head 18 .
FIG. 3 illustrates another embodiment of an assembly for mechanically guiding variable valve controls. The assembly includes a rocker 20 and a walker 23 . Rocker 20 has two arms and pivots around a swivel 21 mounted on walker 23 . Walker 23 actuates a valve 22 . Rocker 20 is driven by a cam 25 by way of a follower 24 on the end of one arm. At the other end of the arm, rocker 20 is provided with an engagement contour. The engagement contour is divided into two curved segments 26 and 27 . Segments 26 and 27 are engaged by a follower 28 mounted on a steering rod in the form of a similarly curved contoured flat 31 . Contoured flat 31 is secured by two radial banking rollers 29 and 30 , one on each engagement contour. Each banking roller has a flange on each face. Segment 26 participates in maintaining valve 22 closed, and segment 27 in allowing the valve to open. The longitudinal axis of contoured flat 31 extends concentric around the axis of the swivel 21 mounted on walker 23 that is in reach as long as valve 22 is closed. The segment 26 that participates in maintaining valve 22 closed curves outward in the form of an arc of a circle with a radius R. The center of the circle coincides with the axis of the swivel 21 mounted on walker 23 . The segment 27 that participates in allowing the valve to remain open is provided with an outward-projecting spur that extends considerably beyond segment 26 .
To allow adjustment of contoured flat 31 , banking roller 30 is composed of two halves and mounted on a rotating shaft 32 . Accommodated between the two halves is a cogwheel fixed tight to rotating shaft 32 and engaging a cogged section 34 of flat 31 .
As long as the follower 28 mounted on contoured flat 31 remains in position A, valve 22 will be maintained closed. Once the follower is in position B, however, the valve will be able to open with its longest and slowest stroke. To maintain valve 22 closed, the outwardly curved segment 26 of the engagement contour will engage the follower 28 mounted on contoured flat 31 without activating valve 22 . To actuate valve 22 , shaft 32 is rotated, rotating in turn contoured flat 31 , and the follower 28 mounted on it, out of the position wherein it participates in maintaining the valve closed until the spur extending out of segment 27 engages follower 28 . The extent of engagement will determine the length and accordingly the duration of the opening stroke.
To eliminate play on the part of contoured flat 31 , banking roller 29 is accommodated on an articulated lever and provides the flat with a stabilizing moment of rotation derived from a ram.
To simplify assembly, the axes of banking rollers 29 and 30 can be accommodated in bearing blocks screwed to a cylinder head 35 . The bearing blocks associated with a particular cylindrical alignment of assemblies can be preliminarily mounted along with the shafts of the banking rollers, with the contoured flats 31 that they secure, and optionally with a camshaft 36 accommodated in the same bearing block, on a mount fastened to cylinder head 35 .
FIG. 4 illustrates a third embodiment of an assembly for mechanically guiding variable valve controls.
The upper end of a one-armed rocker 37 pivots around a swivel 39 accommodated at the end of a cantilever extending out of a steering lever 38 . Rocker 37 is driven by a cam 41 by way of a follower 40 more or less half-way along it. At its lower end, rocker 37 is provided with an engagement contour comprising segments 42 and 43 . Segments 42 and 43 engage a follower 44 mounted on a walker 46 that actuates a valve 45 . Segment 42 participates in maintaining valve 45 closed and segment 43 in allowing it to open. Steering lever 38 is controlled by two cranks 47 and 48 , the former mounted on a crankshaft 49 and the latter on a crankshaft 50 . The orientation of crankshafts 49 and 50 , the structure of steering lever 38 with its three points of articulation impossible to align, the establishment of an appropriate angle, and optionally a differentiation in the lengths of cranks 47 and 48 in the setting vicinity allow the generation of a circular motion that can accurately enough guide the axis of the swivel 39 mounted on rocker 37 around the axis of the follower 44 mounted on walker 46 and in reach as long as valve 45 remains closed.
To allow adjustment of steering lever 38 , one of the crankshafts, crankshaft 49 , also comprises a controlling shaft. As crankshaft 49 rotates, accordingly, the other crankshaft, crankshaft 50 , will be driven by way of steering lever 38 and will also execute a rotation, in that cranks 47 and 48 , both, in the adjustment area, are at an appropriate angle to the longitudinal axis of steering lever 38 .
The segment 42 of the engagement contour of rocker 37 that participates in maintaining valve 45 closed curves outward in the arc of a circle of radius R with its center coinciding with the axis of the swivel 39 mounted on steering lever 38 . The segment 43 associated with the valve's opening stroke is provided with an outward-bent spur that extends considerably beyond segment 42 .
As long as the swivel 39 mounted on steering lever 38 is in position A, the mechanism will be set to maintain valve 45 closed. With the swivel in position B, the valve will be able to open with its longest and slowest stroke. As long as valve 45 is maintained closed, outward curving segment 42 will engage the follower 44 mounted on walker 46 without activating the valve. To actuate the valve, the swivel 39 mounted on steering lever 38 will be rotated by a rotation of the controlling-shaft crankshaft 49 along with steering lever 38 out of the position associated with maintaining the valve closed until the spur associated with segment 43 engages the follower 44 mounted on walker 46 . The extent of engagement will determine the length and accordingly the duration of the stroke.
Since these mechanisms require only an acute setting angle, the crankshafts 49 and 50 employed therein can be produced from straight round structural section, without bends. Cranks 47 and 48 can be welded to the section for example. Otherwise, bushings can be fastened tight to a length of section to create crankshafts 49 and 50 . If the crankshafts are mounted on round section, the articulations for steering lever 38 can be undivided, with steering lever 38 comprising two flat bars.
To facilitate assembly, crankshafts 49 and 50 can be accommodated in bearing blocks to be screwed to a cylinder head 51 . The mechanisms intended for a single cylindrical alignment can be preliminarily assembled along with the two crankshafts, with the steering levers 38 mounted thereon, with the rockers 37 articulated to the steering levers by swivels 39 , and optionally with a camshaft 52 accommodated in the same bearing blocks, on a mount secured to cylinder head 51 .
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The invention relates to space-saving, easily-assembled guide systems for mechanical, variable value controllers, cam followers ( 1 ), driven by a cam ( 6 ) via a cam roller ( 5 ), the pivot joint ( 2 ) of which, for driving a tappet ( 4 ) which operates the value ( 3 ), is arranged in the tappet ( 4 ), or the pivot joint for the adjustment thereof runs in an arc around the axis of rotation of a roller, which is arranged on a tappet operating a value. The cam followers drive the tappets by means of the contact surface with the roller thereof. The guide systems are embodied with slide blocks ( 11 ), adjustable within slide housings ( 10 ), guide arms mounted in rollers and guide levers mounted in crank levers. According to application, the guide systems comprise contact surfaces, rollers or pivot joints.
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FIELD OF THE INVENTION
The present invention is concerned with the treatment of mixed metal waste. More specifically, the present invention relates to a process for separating and recovering metals from mixed waste by means of converting said metals to the corresponding halides, and to apparatus for carrying out said process.
BACKGROUND OF THE INVENTION
The large-scale production of waste materials, primarily in industrialized countries, has led to major ecological and economic problems on a worldwide scale. Waste materials, which may be defined as undesired substances that result from the production or use of a desirable, useful material, are of three main types: household, industrial and toxic or hazardous waste.
In the absence of efficient waste recycling plants, very large amounts of waste materials are deposited in landfill sites, which entails high cost, both to the environment and to the economy. In addition to the problems arising from pollution, fire and explosion risk, an additional concern is the loss of potentially valuable raw materials which could otherwise be recycled for use as starting materials or intermediates for many manufacturing processes.
While many different recycling technologies have been developed, these are generally applicable only to single materials or a class of materials, and hence require sorting or pre-processing of the waste.
The problem is compounded when the waste material includes highly toxic, inflammable, and potentially explosive substances. The increasingly widespread use, and hence disposal, of electrical batteries provides an example of the generation of toxic waste from industrial and household sources. Electrical batteries are a source of chemical contamination, as a result of their toxic components such as cadmium, cobalt and nickel. In addition, they may pose a fire hazard and explosion risk as a consequence of components such as Lithium and other exothermic materials.
U.S. Pat. No. 4,637,928 discloses a method for treating articles such as batteries by opening the battery casings and contacting the interiors of said batteries with an alkaline agent.
Co-owned International patent application no. PCT/IL99/00045, incorporated herein by reference, discloses a recovery process for mixed waste, in which components such as metals are separated from each other as halides, following gaseous phase halogenation. Although this process is highly efficient, for certain applications the equipment required may be relatively expensive.
It is a purpose of the present invention to provide a highly efficient process for the recovery of metals from unsorted mixed waste, in particular from electrical batteries. It is a further purpose of the present invention to convert hazardous components present in the waste to non-hazardous materials.
It is another object of the present invention to provide a process that is ecologically clean, economically advantageous and industrially convenient.
It is a further object of the present invention to provide a process for rendering electrical batteries non-hazardous, while also permitting recovery of the valuable raw materials contained therein.
Other objects and advantages of the invention will become apparent as the description proceeds.
SUMMARY OF THE INVENTION
It has now been found that it is possible to render hazardous mixed-waste materials non-hazardous by virtue of their contact with an aqueous solution of HX, wherein X is a halogen, and to recover certain valuable components, particularly metals, from said waste. Recovery of the metallic components is achieved by virtue of their conversion to the corresponding halides, said metal halides being subsequently separated from the reaction mixture and from each other. Thus, the aqueous HX solution serves two distinct purposes: firstly, to provide a medium in which hazardous material can be rendered non-hazardous, and secondly, to permit the recovery of valuable metals therefrom in the form of halides.
Thus, the present invention provides a high efficiency process for rendering hazardous materials present in multi-element waste non hazardous, and for recovering valuable components of said waste, particularly metals, comprising contacting the waste with an aqueous solution of HX, wherein X is halogen, thereby converting metals present in the waste to the corresponding halides, and subsequently separating said metal halides from other components of the reaction mixture and from each other.
According to a preferred embodiment of the present invention, the waste to be treated comprises electrical batteries, such as lithium or nickel batteries. In another embodiment, the waste comprises electrical equipment or electrical devices, e.g., cellular telephones, which may optionally be treated according to the invention together with the batteries contained therein.
A major advantage associated with the application of the present invention to the treatment of lithium batteries is that the process involves a reaction between the components of the batteries and an aqueous solution of HX, namely, a reaction in the liquid phase. This permits hazardous compressed gases such as SO 2 or SOCl 2 , that are present in said batteries as the electrolytic medium, to be absorbed by the aqueous solution. In addition, according to the present invention, hazardous lithium metal is converted in the solution to LiX.
In a preferred embodiment of the invention, oxidising agents are present in the aqueous solution of HX, to enhance the oxidation power of the solution. Preferably, the oxidising agent is hydrogen peroxide, the concentration of which in the solution is between 0.1 and 5% (w/w).
The term “the reaction” is used hereinafter to refer to the conversion of the metals present in the waste to the corresponding halides, by the reaction of said metals with HX, wherein X is a halogen, or optionally by the reaction of said metals with the above mentioned oxidising agents. In a preferred embodiment, the reaction is carried out at a temperature of between 20 and 90° C., and more preferably, at a temperature of between 50 and 80° C.
In a preferred embodiment of the invention, the aqueous solution containing HX is HCl solution or HBr solution, HCl solution being most preferred. The concentration of the solution is between 5 and 33% (w/w), more preferably between 15 and 25% (w/w). In another preferred embodiment, an aqueous solution containing a combination of HCl and HBr is used in the reaction. A preferred combination is provided by a solution of HCl, comprising between 1 and 10% (w/w) HBr.
Preferably, the reaction is performed with agitation. Preferred modes of agitation are selected from the group of mixing, vibrating, shredding, liquid circulation, and forced gaseous/air turbulent mixture aeration.
Preferably, the waste material is brought into contact with the aqueous solution of HX at a controlled rate, to allow controlled evolution of the gaseous H 2 formed in the reaction. This gas is preferably removed from the reaction mixture, together with other gases that are not dissolved by the reaction mixture, or which are only partially dissolved thereby, and are optionally recovered. Preferably, the reaction is carried out under reduced pressure in order to facilitate the removal of said gases.
The waste material may also contain various gases that are soluble in the aqueous reaction medium, for example, SO 2 and SOCl 2 , as found in lithium batteries. These gases are rendered non-hazardous by virtue of their becoming absorbed by the aqueous medium. In addition, the dissolved gases increase the acidity of the solution, and the halide-containing gases such as SOCl 2 act as a halide source for the reaction solution.
The separation of the metal halides from the reaction mixture and their subsequent separation from each other are accomplished by methods known in the art. Most of the metal halides formed in accordance with the present invention are water soluble, and therefore, in order to separate said halides from the reaction mixture, known liquid/solid separation techniques may be employed, such as, for example, filtration. Thus, in a preferred embodiment of the present invention, the reaction mixture is filtered to obtain a filtrate containing said soluble halides. Typically, the filter cake consists of plastics and carbon materials that were initially present in the raw waste, and did not undergo chemical reaction. The filter cake may also contain insoluble metal oxides, which may be recovered, if desired, by treating said cake with a base.
In a preferred embodiment of the present invention, the metals are recovered from the filtrate by causing the selective precipitation of some of the metals. Optionally, metal recovery may also be achieved by using ion exchange or selective extraction. Preferably, the selective precipitation is carried out by treating the filtrate with an alkaline agent, preferably NaOH, to allow the separation between water soluble hydroxides, particularly, LiOH, from water insoluble hydroxides, such as Fe(OH) 3 , Ni(OH) 2 , Cd(OH) 2 , Co(OH) 2 and Al(OH) 3 . Subsequently, the non soluble hydroxides are separated from the liquid phase, preferably by filtration, and the filtrate, containing Li + (and Na + ), is further treated to cause the selective precipitation of lithium, preferably in the form of LiF or LiCO 3 , generally by introducing into said filtrate Na 2 CO 3 or NaF. The water insoluble lithium salt may be separated by filtration, and the filtrate obtained is preferably evaporated to recover NaCl therefrom. The insoluble hydroxides are separable by methods known in the art.
According to the present invention, metals, the halides of which are water insoluble, may also be present in the mixed waste. These metals may be recovered from the solid phase of the reaction mixture by standard methods.
Optionally, the reaction according to the present invention is preceded by heat treatment of the raw waste material and/or mechanical processing of said waste material. In one embodiment, the heat treatment is performed prior to said mechanical processing. In a second embodiment, the waste material is subjected to simultaneous heat treatment and mechanical processing. The mechanical processing is intended to transform the waste into a particulate form, to facilitate the reaction. In one embodiment, the reaction is carried out concurrently with said processing.
The optional heat treatment stage is performed under conditions allowing the removal from the waste of gases or liquids, particularly water, and organic material, which typically constitute part of the raw waste material, preferably by evaporation in the case of water, and evaporation or carbonization in case of organic matter. The heat treatment is performed in a controlled oxygen atmosphere preferably at a temperature of less than 1000° C. Alternatively, the heat treatment may be performed in a metallic molten bath, said bath preferably being at a temperature of between 500° C. and 1600° C. According to another embodiment, the heat treatment is pyrolysis.
The optional mechanical processing of the waste, prior to the reaction with an aqueous solution of HX according to the present invention, is intended to remove the coating from the metal parts and to reduce the waste particle size, in order to provide small metallic particles which may easily react with said HX, thus facilitating both rapid reaction times and also easier handling of the partially processed waste material. The mechanical processing preferably comprises one or more of the following operations: mechanical shaping of solid waste into units of a size and shape appropriate for subsequent processing;
shredding, scraping, crushing and/or milling;
briquetting of sludge.
Preferably, the mechanical processing comprises shredding the waste material in a controlled environment. In a preferred embodiment, the controlled environment is provided by a gas such nitrogen or a noble gas, e.g., argon, or a liquid.
In another preferred embodiment of the present invention, said heat treatment and/or said mechanical processing are carried out in either order, subsequent to the reaction. In another embodiment, the mechanical processing and the reaction are carried out concurrently.
In another aspect, the invention is directed to an apparatus for rendering hazardous materials present in multi-element waste non-hazardous, and for recovering valuable components of said waste, comprising:
a reaction chamber, for reacting multi-element waste with a solution of HX, wherein X is a halogen;
means for introducing said waste into said reaction chamber at a controlled rate;
means for removing gaseous products from the reaction chamber;
means for discharging the metal halide products from the reaction chamber and means for separating said metal halides from each other.
According to a preferred embodiment, the apparatus further comprises a heating chamber comprising means of heating, a waste inlet and an outlet leading from said heating chamber to the reaction chamber. According to one preferred embodiment of the invention, the apparatus further comprises means for the mechanical processing of the waste material, which means is preferably a shredder, located between said outlet of the heating chamber and the inlet of the reaction chamber. Alternatively, the shredder may be positioned at the inlet of said heating chamber. According to another embodiment, the shredder is located within the heating chamber or in the reaction chamber.
The reaction chamber is preferably equipped with heating/cooling means and with agitation means.
Preferably, the means for introducing raw waste material into said reaction chamber at a controlled rate comprises a conveying system such as a conveyor belt, which transports the waste to the reaction chamber. In one preferred embodiment, the conveyor belt is fully enclosed in a protected atmosphere, provided by a gas such as nitrogen or argon that will not react with the hazardous components which may be part of the raw waste. When the apparatus according to the present invention comprises a shredder, the shredding rate is controlled to allow the waste material to be discharged therefrom, and to be fed into the reaction chamber, at a desired rate.
Preferably, the means for removing gaseous products from the reaction chamber comprises a scrubbing system.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more clearly understood from the detailed description of the preferred embodiments and from the attached drawings in which:
FIG. 1 is a schematic diagram of one embodiment of an apparatus for performing high efficiency treatment of mixed metal-containing wastes.
FIG. 2 is a schematic diagram of a further embodiment of an apparatus for performing high efficiency treatment of mixed metal-containing wastes.
FIG. 3 is a flow chart of one embodiment of the process according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
According to one embodiment of the present invention, which will be described with reference to FIG. 1 , the waste to be treated is inserted into a hopper 1 , which is maintained at a controlled atmosphere, provided by a gas such as nitrogen or argon, and is further provided with a means for controlling the rate of discharge of the waste therefrom. Controlled, predetermined amounts of waste pass through a gate, 1 a , to enter the heating chamber, 2 . Heating chamber, 2 , which is maintained at a controlled atmosphere, preferably rotates on wheels, 2 a , and is heated by external heating elements, 2 b , or by a burner in a controlled atmosphere. The concentrations of oxygen and/or gaseous components in the heating chamber are regulated by the gate valves, 1 a . The amount of waste being transported through the chamber is regulated by the rotating speed of the chamber or by other transporting means such as a walking beam or conveyor belt. The waste falls by gravity into the shredding chamber, 3 , which comprises known components such as jaw crushers, rotating shredding knives, etc. The size of the shredded particles vary according to the type of waste material, speed of operation and so forth. The shredder operates within a protected atmosphere, in which the levels of water and other liquid and gaseous components are controlled. The shredding rate is adjusted according to the rate of reaction in the reaction chamber, 4 , and in particular, according to the rate of gas generation and/or removal. The reaction chamber, 4 , is made of a material that will withstand a chemical reaction between metals and HX solutions at temperatures up to 140° C., such as various common polymers, for example, polyamide or PVDF. Said reaction chamber is fitted with inlets/outlets, 4 a , for the introduction of various chemicals in liquid form for the reaction and also for circulating the solution through an externally placed heat exchanger. In a preferred embodiment a solution of 15–30% HCl, 0.1–1% H 2 O 2 , 0.05–10% HBr and 0–10% sulfuric acid is used for the reaction with batteries. The reaction chamber may also be fitted with a heating or cooling jacket, 4 b , where a liquid, 6 , may be introduced from another external source. Other heating elements (for example electrical elements) can also be incorporated into the design of the reaction chamber. A mixing device, 5 , is used to mix the solution and the shredded material in order to improve the reaction between the waste material and the HX solution. The mixing speed may be adjusted according to the type of reaction mixture, particle size, and other chemical and physical parameters. In another preferred embodiment, air is injected into the lower region of the reactor in order to assist in mixing the particles and to add oxygen to the reaction. The gases that evolve during the course of the reaction, and also the gases which were already present in the waste material, such as SO 2 , will be absorbed by the solution of the reactor, or will react with said solution. The non-dissolved gases will then be bubbled upwards to be collected in the scrubbing system, 13 , through the fan blower system, 14 . The undissolved materials, mainly plastics are discharged through a conduit, 11 , at the lower end of the reaction chamber, 4 , passing through liquid filter apparatus, 7 , to be discharged to solid waste chamber 8 . The liquid phase containing the metal chlorides is delivered, by means of pump, 7 a , through valves 12 to various means, 9 and 10 , for separating the metal halides, said means being based on known technologies such as selective precipitation, extraction, absorption and ion exchange. The separating means 9 , and 10 also remove contaminants from the metal halides, thus permitting further processing of said metal halides into commercially-useful compositions.
According to a preferred embodiment of the present invention, the scrap waste to be treated comprises lithium batteries having compressed SO 2 and/or SOCl 2 as an electrolyte, or electrical equipment comprising such batteries. The batteries may still be partly or fully charged, and contain lithium metal which may easily ignite and explode if exposed to water and air, producing hydrogen gas. The process of the present invention will render the batteries non-hazardous, while also permitting recovery of the valuable raw materials contained therein. The embodiment of the present invention related to the recovery of valuable metals from electrical equipment and/or batteries will be described with reference to FIG. 2 .
The batteries, which are encapsulated in plastic film, but which have their metal leads exposed, are fed at a predetermined rate by a conveying system, 2 d , which comprises a conveyor belt which, optionally, may be enclosed in a protected atmosphere, into the reaction chamber, 4 . The rate of introduction of the batteries is partly determined by safety considerations (for example, as a function of the energy produced, efficiency of the venting system, hydrogen production and the maximum permissible temperature in the reaction chamber).
The reaction chamber 4 contains a 30% HCl water solution at 50° C. supplemented with 5% H 2 O 2 . The battery lead face, which is an iron alloy, will react with the chloride solution to emit H 2 , which is vented through the scrubber. The venting system is designed so that the flow of air and the possible H 2 production will always be at a level below the critical level for explosions to occur. Generally, H 2 concentration may not be permitted to exceed 2% of the total gas volume present in the reaction chamber, at any time.
The chloride solution causes pitting of the battery's metal casing, and eventually will produce tiny holes. The SO 2 gas and/or the SOCl 2 gas contained within the batteries will be released therefrom, as evidenced by bubbling. Due to the small size of the holes the bubbles will be correspondingly small with a very large surface area. These bubbles will mix well with the hot solution and will react to form sulfuric acid.
A battery that is fully charged will be short-circuited as soon as it contacts the solution. This may, in fact, increase the rate of reaction within the battery, the compressed SO 2 escaping from the battery explosion valve. The effect will be accommodated in the reaction chamber because of its size and also since the battery will be beneath the surface of the solution. Gaseous SO 2 will react with the water and only traces will be emitted to the surface to be vented to the scrubber ( 13 ) further to be absorbed by caustic soda. Once the compressed gas has escaped from the battery, its toxicity and hazard level is greatly reduced. The solution will seep into the battery to react slowly with the Lithium metal to produce LiCl. The reaction is exothermic but because of the slow rate of introduction of the solution through the tiny holes, the temperature level can be controlled. Furthermore, at fast reaction rates, there may be hot spots that may lead to an explosive effect. During the process the metal components will react with the solution to produce metal chlorides such as FeCl 3 , NiCl 2 , LiCl, and CuCl 2 while the plastic parts will remain largely unreacted. The SO 2 absorbed in the solution will add to the acidity and may produce other salts such as CuSO 4 and FeSO 4 .
The metal halides formed in the solution are pumped either directly from the reaction chamber, 4 a , or following shredding and/or filtration, to be further treated and separated in separation modules 9 and 10 , by known hydrometallurgy techniques. The shredder, 3 , and the heating chamber, 2 , are both optional, and in one preferred embodiment are located after the liquid/solid filter, 7 , such that the solid material that does not pass through said filter is passed on to the shredder, 3 . The shredded material leaving shredder, 3 , passes into the heating chamber, 2 . Residual solids are collected in the optional solids tank, 8 , while the gaseous products of the heat treatment are removed via scrubbers, 13 , clean air being evacuated by fans, 14 .
The unreacted components, mainly plastics, are removed, washed to remove any chloride and further processed either by incineration, land fill or by a known plastic recovery system. In a preferred embodiment the plastic parts are incinerated in order to produce steam for use by the plant.
FIG. 3 is a flow chart illustrating the process of the present invention and the recovery of the metals present in electrical batteries employing separation methods based on selective precipitation.
EXAMPLE 1
A single lithium ‘D’ battery weighing 85 grams, containing 4 g lithium, was placed in 300 mL of a 20% (w/w) solution of aqueous HCl for a period of 90 minutes. The reaction, as evidenced by the appearance of bubbling, began after 7 minutes. The temperature of the solution increased from an initial 21° C. (ambient temperature) to 50° C. after 48 minutes. The maximum temperature reached during the course of the reaction was 65° C. The color of the solution started to become yellow after 11 minutes, due to the absorption of oxides of sulfur by the solution. No explosive events were recorded. Following the reaction, the solution was filtered, and the filtrate was found to contain 3.3 g of lithium. The lithium was recovered from the reaction solution as follows:
Sodium hydroxide was added to the halide solution until a pH of 4–5 was reached, in order to permit precipitation of the hydroxides of most of the metals with the exception of lithium. This mixture was then filtered in order to achieve separation of the solid and liquid phases, the latter containing lithium hydroxide. Sodium carbonate was added to the liquid phase until, at a pH of about 8, a precipitate of lithium carbonate was obtained. This precipitate was then filtered yielding technical grade lithium carbonate, weighing 16 g.
While specific embodiments of the invention have been described for the purpose of illustration, it will be understood that the invention may be carried out in practice by skilled persons with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of the claims.
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A process for rendering hazardous materials present in multi-element waste non-hazardous, and for recovering valuable components of said waste, particularly metals, comprising contacting the waste with an aqueous solution of HX, wherein X is halogen, thereby converting metals present in the waste to the corresponding halides, and subsequently separating said metal halides from other components of the reaction mixture and from each other.
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REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a Continuation application of U.S. application Ser. No. 10/728,986, filed Dec. 8, 2003, now pending; which claims the benefit of SE 0303269-5 filed Dec. 2, 2003, both of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a medical product comprising inhalable doses of tiotropium loaded in a moisture-tight, dry container and in particular, a metered dry powder medicinal dose of tiotropium bromide being adapted for administration by a dry powder inhaler device.
BACKGROUND
[0003] Asthma and chronic obstructive pulmonary disease (COPD) affect more than 30 million people in the United States. More than 100,000 deaths each year are attributable to these conditions. Obstruction to airflow through the lungs is the characteristic feature in each of these airway diseases, and the medications utilized in treatment are often similar.
[0004] Chronic obstructive pulmonary disease (COPD) is a widespread chronic lung disorder encompassing chronic bronchitis and emphysema. The causes of COPD are not fully understood. Experience shows that the most important cause of chronic bronchitis and emphysema is cigarette smoking. Air pollution and occupational exposures may also play a role, especially when combined with cigarette smoking. Heredity also causes some emphysema cases, due to alpha1 anti-trypsin deficiency.
[0005] Administration of asthma drugs by an oral inhalation route is very much in focus today, because of advantages offered like rapid and predictable onset of action, cost effectiveness and high level of comfort for the user. Dry powder inhalers (DPI) are especially interesting as an administration tool, compared to other inhalers, because of the flexibility they offer in terms of nominal dose range, i.e. the amount of active substance that can be administered in a single inhalation.
[0006] Anticholinergic agents, e.g. tiotropium, especially tiotropium bromide, are effective bronchodilators. These medicaments have a relatively fast onset and long duration of action, especially tiotropium bromide, which may be active for up to 24 hours. Anticholinergic agents reduce vagal cholinergic tone of the smooth muscle, which is the main reversible component of COPD. Anticholinergic agents have been shown to cause quite insignificant side effects in clinical testing, dryness of mouth and constipation are perhaps the most common symptoms. Because it is often very difficult to diagnose asthma and COPD correctly and since both disorders may co-exist, it is advantageous to treat patients suffering temporary or continuous bronchial obstruction resulting in dyspnoea with a small but efficient dose of a long-acting anticholinergic agent, preferably tiotropium bromide, because of the small adverse side effects.
[0007] Tiotropium bromide is the preferred anticholinergic agent because of its high potency and long duration. However, tiotropium is difficult to formulate in dry powder form to provide acceptable performance in terms of dose efficacy using prior art DPIs. Dose efficacy depends to a great deal on delivering a stable and high fine particle dose (FPD) out of the dry powder inhaler. The FPD is the respirable dose mass out of the dry powder inhaler with an aerodynamic particle size below 5 μm. Thus, when inhaling a dose of dry medication powder it is important to obtain by mass a high fine particle fraction (FPF) of particles with an aerodynamic size preferably less than 5 μm in the inspiration air. The majority of larger particles (>5 μm) does not follow the stream of air into the many bifurcations of the airways, but get stuck in the throat and upper airways, where the medicament is not giving its intended effect, but may instead be harmful to the user. It is also important to keep the dosage to the user as exact as possible and to maintain a stable efficacy over time, and that the medicament dose does not deteriorate during normal storage. For instance, Boehringer Ingelheim KG (BI) markets tiotropium bromide under the proprietary name of SPIRIVA®. Surprisingly, in a recent investigation into the inhalability of SPIRIVA® we have found that the SPIRIVA®/HANDIHALER® system from BI for administration by inhalation of doses contained in gelatin capsules shows poor performance and has short in-use stability.
[0008] Thus, there is a need for improvement regarding a medical product comprising inhalable dry powder doses of tiotropium bromide, for instance SPIRIVA®, and suitably adapted inhaler devices for the purpose of administration.
SUMMARY
[0009] The present invention discloses a medical product for use in the treatment of respiratory disorders, and comprises a metered dose of a tiotropium dry powder formulation, directly loaded and sealed into a moisture-tight, dry container acting as a dry, high barrier seal against moisture. The container itself does not emit water, which may affect the tiotropium powder inside. Thus, the container does not release any water to the dose and ingress of moisture from the exterior into the container is thereby prevented.
[0010] The dose of tiotropium is further intended for inhalation and the container is so dry and tight that the efficacy of the dose when delivered is unaffected by moisture.
[0011] In another aspect of the invention a type of inhaler is disclosed, which may accept at least one sealed, moisture-tight, dry container of a dose of tiotropium, e.g. SPIRIVA®, and deliver said dose with a consistent FPD, over the expected shelf life of the product.
[0012] In a further aspect of the invention tiotropium may be mixed or formulated with at least one additional pharmacologically active ingredient(s) with an object of combining tiotropium with other medicament(s) to be used in the treatment of respiratory disorders. The present invention encompasses such use of tiotropium in a combination of medicaments directly loaded into a sealed, moisture-tight, dry container for insertion into a DPI, the combination adapted for inhalation by the user.
[0013] The present medical product is set forth by the independent claims 1 and 2 and the dependent claims 3 to 13 , and a pharmaceutical combination is set forth by the independent claims 14 and 15 and the dependent claims 16 to 25 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention, together with further objects and advantages thereof, may best be understood by referring to the following detailed description taken together with the accompanying drawings, in which:
[0015] FIG. 1 illustrates in a graph the results of tests S 1 to S 5 and HBS 1 to HBS 3 ;
[0016] FIG. 2 illustrates in top and side views a first embodiment of a dose deposited onto a dose bed and a high barrier seal; and
[0017] FIG. 3 illustrates in top and side views a second embodiment of a dose onto a dose bed and a high barrier seal.
DETAILED DESCRIPTION
[0018] Tiotropium is a new important anticholinergic substance for treatment of asthma and COPD but tiotropium is known in the industry to have problems maintaining in-use stability due to sensitivity to moisture. This fact is also documented in the report ‘COLLEGE TER BEOORDELING VAN GENEESMIDDELEN MEDICINES EVALUATION BOARD; PUBLIC ASSESSMENT REPORT; SPIRIVA 18 μg, inhalation powder in hard capsules; RVG 26191’ (2002-05-21) on page 6/28 under ‘Product development and finished product’ a very short in-use stability of the SPIRIVA® product (9 days) is reported and a brittleness of the capsule in the blister pack and a very low FPD: ‘about 3 ug’.
[0019] Details about an inhalation kit comprising inhalable powder of tiotropium and use of an inhaler for the administration of tiotropium may also be studied in the international publication WO 03/084502 A1. Details about tiotropium compounds, medicaments based on such compounds, the use of compounds and processes for preparing compounds may be studied in the European Patent Application 0 418 716 B1.
[0020] In the light of the above information given in the quoted report a test program was set up for the physical stability of the SPIRIVA® product with respect to the compatibility of the formulation together with the components of the device according to Food and Drug Administration (FDA) ‘Guidance for Industry; Metered Dose Inhaler (MDI) and Dry Powder Inhaler (DPI) Drug Products; Chemistry, Manufacturing, and Controls Documentation’ page 37/62 ‘Drug product stability’ lines 1209-1355. In ‘Guidance for Industry; Stability Testing of Drug Substances and Drug Products; DRAFT GUIDANCE; B. Container/Closure’ pages 35 and 36/110 lines 1127-1187, FDA states: ‘Stability data should be developed for the drug product in each type of immediate container and closure proposed for marketing, promotion, or bulk storage. The possibility of interaction between the drug and the container and closure and the potential introduction of extractables into the drug product formulations during storage should be assessed during container/closure qualification studies using sensitive and quantitative procedures.’ and further ‘Loss of the active drug substance or critical excipients of the drug product by interaction with the container/closure components or components of the drug delivery device is generally evaluated as part of the stability protocol. This is usually accomplished by assaying those critical drug product components, as well as monitoring various critical parameters (e.g., pH, preservative, effectiveness). Excessive loss of a component or change in a parameter will result in the failure of the drug product to meet applicable specifications.’
[0021] According to FDA publication ‘Guidance for Industry; Stability Testing of Drug Substances and Drug Products’ a 3 week test program in accelerated conditions (40±2°/75±5 RH) for the container closure of the SPIRIVA® product in this case the capsule and the blister pack and the impact of the capsule and the blister package on the FPD was set up and tested.
Execution of Tests
[0022] SPIRIVA® powder formulation in bulk and SPIRIVA® capsules from our local pharmacy where introduced to the laboratory together with the HANDIHALER®. The laboratory was set up to perform in-vitro tests according to European Pharmacopoeia (EP) and US Pharmacopoeia (USP) using two Andersen cascade impactors. All analytical work where then performed according to standardized methods for Physical Tests and Determinations for Aerosols, metered-dose inhalers and dry powder inhalers described in pharmacopoeias (e.g. USP 2002 <601>) using a state of the art High Performance Liquid Chromatograph (HPLC) system.
SPIRIVA® Tests
[0023] Test S 1
[0024] Aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using SPIRIVA® formulation from bulk powder loaded into originator capsules during relative humidity below 10%. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0025] Test S 2
[0026] Aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using commercial SPIRIVA® capsules purchased from our local pharmacy. Test performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0027] Test S 3
[0028] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using commercial SPIRIVA® capsules purchased from our local pharmacy. From the blister holding 5 capsules one capsule was withdrawn and the remaining 4 capsules were put 4 days into 40° C. and 75% Rh. The blister containing the 4 capsules was then put in an exicator for 2 h before tests were performed. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0029] Test S 4
[0030] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using commercial SPIRIVA® capsules purchased from our local pharmacy. From the blister holding 5 capsules one capsule was withdrawn and the remaining 4 capsules were put 13 days into 40° C. and 75% Rh. The blister containing the 4 capsules was then put in an exicator for 2 h before tests were performed. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0031] Test S 5
[0032] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using commercial SPIRIVA® capsules purchased from our local pharmacy. From the blister holding 5 capsules one capsule was withdrawn and the remaining 4 capsules were put 21 days into 40° C. and 75% Rh. The blister containing the 4 capsules was then put in an exicator for 2 h before tests were performed. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
High Barrier Seal Tests
[0033] Test HBS 1
[0034] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using SPIRIVA® formulation from bulk powder loaded during relative humidity below 10% into containers made to act as a high barrier seal, in this case aluminum foils from Alcan Singen Germany and then sealed to absolute tightness. The aluminum containers were put in an exicator for 2 h before the SPIRIVA® powder formulation was loaded from the aluminum containers into the originator capsules at a relative humidity below 10%. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0035] Test HBS 2
[0036] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using SPIRIVA® formulation from bulk powder loaded during relative humidity below 10% into containers made to act as a high barrier seal, in this case aluminum foils from Alcan Singen Germany and then sealed to absolute tightness. The sealed aluminum containers were put into climate chambers for 7 days at 40° C. and 75% Rh. The aluminum containers were put in an exicator for 2 h before the SPIRIVA® powder formulation was loaded from the aluminum containers into the originator capsules at a relative humidity below 10%. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
[0037] Test HBS 3
[0038] An in-use stability test of the aerodynamic fine particle fraction of metered and delivered dose out of HANDIHALER® using SPIRIVA® formulation from bulk powder loaded during relative humidity below 10% into containers made to act as a high barrier seal, in this case aluminum foils from Alcan Singen Germany and then sealed to absolute tightness. The sealed aluminum containers were put into climate chambers for 14 days at 40° C. and 75% Rh. The aluminum containers were then put in an exicator for 2 h before the SPIRIVA® powder formulation was loaded from the aluminum containers into the originator capsules at a relative humidity below 10%. The test was performed with 4 kPa pressure drop over the HANDIHALER® at room temperature and laboratory ambient conditions.
C-Haler DPI Tests
[0039] A test was also made outside the stability test program to evaluate our proprietary inhaler, the so-called C-haler, in comparison with the HANDIHALER® using a tiotropium formulation. The C-haler cartridge used high barrier seals made out of aluminum foils from Alcan Singen Germany and the containers where filled volumetrically with 5 mg of the SPIRIVA® powder formulation in bulk. The test was performed using a 4 kPa pressure drop over the C-haler at room temperature and laboratory ambient conditions. The results from the Andersen impactor tests were calculated on fine particle fraction based on delivered dose as well as on metered dose and converted to FPD. The results are given in Table 1 below.
[0000] The results of tests S 1 - 5 and HBS 1 - 3 are plotted in FIG. 1 . The Y-axis is designated ‘% of commercial SPIRIVA® FPD’. This relates to the FPD out from the HANDIHALER®, where 100% is the FPD from a fresh sample from the pharmacy.
[0000]
TABLE 1
Inhaled fine particle dose (FPD) <5 μm in %
Calculation
SPIRIVA ® in HANDIHALER ®,
SPIRIVA ® in
based on
commercial sample, FPD
C-haler, FPD
Metered dose
18%
47%
Delivered dose
36%
56%
Conclusion of the Tests Performed on SPIRIVA®
[0040] Surprisingly we have found and concluded in our tests that tiotropium is extremely sensitive to moisture and that a conventional packaging into gelatin capsules used for a majority of respiratory products will seriously affect the FPD. The results show that there is a need for a dry, moisture-tight high barrier seal enclosing the tiotropium formulation to preserve the original fine particle fraction. Not so surprisingly in the light of these findings, we have also found that the tiotropium formulation must be properly protected also during the in-use time if further reduction of the FPD shall be avoided. Eliminating the gelatin capsule has an unexpected, big, positive effect on the performance of the SPIRIVA® formulation.
[0041] The tests carried out show that the moisture content of the gelatin capsule reduces the FPD out of the HANDIHALER® with approximately 50% from the time of loading the dose into a capsule until the point in time when the product reaches the market. Loading SPIRIVA® doses into dry containers made of materials presenting high barrier seal properties and then storing the loaded containers in 40° C. and 75% Rh, before transferring the SPIRIVA® doses to originator capsules and performing the same tests using HANDIHALER® as before, no change can be detected in the fine particle dose (FPD), even after long periods of time. The FPD of SPIRIVA® in gelatin capsules, however, is further diminishing during the in-use time of the product and the FPD has been shown to drop up to another 20% after 5 days of storage in 40° C. and 75% Rh in an in-use stability test, due to the breaking of the moisture barrier in the opened blister secondary package. Table 1 shows that our propertiary C-haler using high barrier containers shows a 2.6 times higher performance than HANDIHALER® with respect to FPD based on metered dose.
State of the Art
[0042] Metered doses of the SPIRIVA® powder formulation are today at the originator manufacturing site loaded into gelatin capsules. A gelatin capsule contains typically 13-14% water by weight in the dose forming stage and after the capsules have been loaded they are dried in a special process in order to minimize water content. A number of dried capsules are then put in a common blister package. Details about suitable state-of-the-art capsule materials and manufacturing processes may be studied in the German Patent Application DE 101 26 924 A1. The remaining small quantity of water in the capsule material after drying is thus enclosed in the blister package and some water will be released into the enclosed air, raising the relative humidity in the air. The equilibrium between the captured air inside the package and the gelatin capsule will generate a relative humidity inside the blister package that will negatively affect the FPD of tiotropium powder out of the dry powder inhaler.
[0043] It is interesting to note that the big majority of dry powder formulations of many kinds of medicaments are not seriously affected by enclosed moisture in the capsule material or by normal storage variations in the relative humidity of the surrounding air. Surprisingly, our investigation has shown tiotropium to be very much different. Tiotropium powder is very much affected by very small amounts of water such that it tends to stick to wall surfaces and to agglomerate. By some mechanisms the FPD becomes less over time. Since the capsules are only used as convenient, mechanical carriers of SPIRIVA® doses, a solution to the moisture problem would be not to use capsules at all, but rather to directly load doses into containers made of dry packaging material with high barrier seal properties during dry ambient conditions, preferably below 10% Rh.
[0044] The present invention discloses a dry, moisture-tight, directly loaded and sealed container enclosing a metered dose of tiotropium powder or a pharmaceutically acceptable salt, enantiomer, racemate, hydrate, or solvate, including mixtures thereof, and particularly tiotropium bromide, optionally further including excipients. The term “tiotropium” is in this document a generic term for all active forms thereof, including pharmaceutically acceptable salts, enantiomers, racemates, hydrates, solvates or mixtures thereof and may further include excipients for whatever purpose. The container uses dry, high barrier seals impervious to moisture and other foreign matters and is adapted for insertion into a dry powder inhaler device or the container may be adapted to be a part of an inhaler device.
[0045] “Dry” means that the walls of the container are constructed from selected materials such that the walls, especially the inside wall of the container, cannot release water that may affect the tiotropium powder in the dose such that the FPD is reduced. As a logical consequence container construction and materials should not be selected among those suggested in the German publication DE 101 26 924 A 1.
[0046] “High barrier seal” means a dry packaging construction or material or combinations of materials. A high barrier seal is characterized in that it represents a high barrier against moisture and that the seal itself is ‘dry’, i.e. it cannot give off measurable amounts of water to the load of powder. A high barrier seal may for instance be made up of one or more layers of materials, i.e. technical polymers, aluminum or other metals, glass, siliconoxides etc that together constitutes the high barrier seal.
[0047] A “high barrier container” is a mechanical construction made to harbour and enclose a dose of e.g. tiotropium. The high barrier container is built using high barrier seals constituting the walls of the container.
[0048] “Directly loaded” means that the metered dose of tiotropium is loaded directly into the high barrier container, i.e. without first loading the dose into e.g. a gelatin capsule, and then enclosing one or more of the primary containers (capsules) in a secondary package made of a high barrier seal material.
[0049] The high barrier containers to be loaded with tiotropium should preferably be made out of aluminum foils approved to be in direct contact with pharmaceutical products. Aluminum foils that work properly in these aspects generally consist of technical polymers laminated with aluminum foil to give the foil the correct mechanical properties to avoid cracking of the aluminum during forming. Sealing of the formed containers is normally done by using a thinner cover foil of pure aluminum or laminated aluminum and polymer. The container and cover foils are then sealed together using at least one of several possible methods, for instance:
using a heat sealing lacquer, through pressure and heat; using heat and pressure to fuse the materials together; ultrasonic welding of the materials in contact.
[0053] Tiotropium in pure form is a very potent drug and it is therefore normally diluted before dose forming by mixing with physiologically acceptable excipients, e.g. lactose, in selected ratio(s) in order to fit a preferred method of dose forming or loading. Details about inhalation powders containing tiotropium in mixtures with excipients, methods of powder manufacture, use of powder and capsules for powder may be studied in the international publication WO 02/30389 A1.
[0054] In a further aspect of the invention tiotropium may be mixed or formulated with one or more other pharmacologically active ingredient(s) with an object of combining tiotropium with other medicament(s) to be used in a treatment of respiratory disorders. The present invention encompasses such use of tiotropium when a combination of tiotropium and other medicaments are deposited and sealed into a dry, moisture-tight high barrier container intended for insertion into a DPI for inhalation by the user. Examples of interesting combinations of substances together with tiotropium could be inhalable steroids, nicotinamide derivatives, beta-agonists, beta-mimetics, anti-histamines, adenosine A2A receptors, PDE4 inhibitors, dopamine D2 receptor agonists.
[0055] The sealed, dry, high barrier container of the invention that is directly loaded with a formulation of tiotropium may be in the form of a blister and it may e.g. comprise a flat dose bed or a formed cavity in aluminum foil or a molded cavity in a polymer material, using a high barrier seal foil against ingress of moisture, e.g. of aluminum or a combination of aluminum and polymer materials. The sealed, dry, high barrier container may form a part of an inhaler device or it may be a separate item intended for insertion into an inhaler device for administration of doses.
[0056] An inhaler providing a prolonged delivery of a dose during the course of a single inhalation constitutes a preferred embodiment of an inhaler for the delivery of the tiotropium powder formulation, e.g. SPIRIVA®. An Air-razor method as described in our publication US 2003/0192539 A1 is preferably applied in the inhaler to efficiently and gradually aerosolize the dose when delivered to the user. Surprisingly enough, applying an inhaler for a prolonged delivery and using the Air-razor method on a dose comprising tiotropium in SPIRIVA® formulation results in a FPD at least twice as big as that from the state-of-the-art HANDIHALER®.
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The invention discloses a medical product for use in a treatment of respiratory disorders, and comprises a metered dose of a tiotropium dry powder formulation, directly loaded and sealed into a container made to act as a dry high barrier seal to prevent the capture and ingress of moisture into the tiotropium powder. The dose of tiotropium is further adapted for inhalation and the container is so tight that the efficacy of the dose when delivered is unaffected by moisture. In a further aspect of the invention a type of inhaler is illustrated, which may accept at least one sealed, moisture-tight container of a dose of tiotropium, to deliver the dose with a consistent fine particle dose, over the expected shelf life of the product.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is based on and hereby claims priority to PCT Application No. PCT/DE2003/002187 filed on Jul. 1, 2003 and German Application No. 102 29 881.5, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
The invention relates to a plasma particulate filter.
DE 100 57 862C1 discloses a plasma particulate filter and a method for reducing the levels of carbon-containing particulate emissions from diesel engines, in which the particulates contained in the exhaust gas are deposited on filter surfaces, the deposited particles being oxidized in order to regenerate the filter, and the regeneration being effected by non-thermal, electrical sliding surface discharges at the surfaces covered with particulates.
DE 100 57 862 C1 has described various geometries for operating an arrangement of this type which are based on the principle of what are known as wall flow filters. These filters comprise parallel passages with a quadrilateral cross section which are alternately closed on the outlet side and the inlet side of the exhaust gas. This results in a division into inlet passages for the particulate-laden exhaust gas and outlet passages for the filtered exhaust gas. The particulates are deposited on the inner walls of the passages that are open on the inlet side and are oxidized there by oxygen and hydroxyl radicals which are produced in the immediate vicinity of the wall by non-thermal sliding surface discharge plasmas.
DE 100 57 862 C1 works on the basis that an electrode be arranged at each of the edges of a filter passage in order to produce sliding surface discharges. The electrodes required to produce plasma can either be embedded in the filter material or applied to the filter material, in such a way that in any event there is a layer with a high dielectric strength between an electrode connected to high voltage and the counterelectrode that is connected to ground. The embedding of the electrodes described in that document, however, means that sliding surface discharges can only be generated on both sides of the cell walls, whereas the particulates are only deposited on one side. This means that the specific energy consumption for the regeneration is twice as high as is actually necessary.
On the other hand, electrodes which are exposed to the exhaust gas and are proposed in that document in combination with embedded electrodes for the preferential operation of sliding surface discharges on one side of the wall, on account of being in contact with the exhaust gas are exposed to erosion processes which may be boosted still further by gas discharge processes. These erosion processes may not only have an adverse effect on the service life of the electrodes in particular, but also, via the formation of metal oxides, on the service life of the ceramic.
A further drawback is that the large number of electrodes—specifically four per inlet passage—significantly increases the size and weight of the plasma particulate filter compared to known filters.
The literature has disclosed geometries for the operation of dielectric barrier discharges in ceramic honeycomb bodies (cf. for example EP 0 840 838 B1), in which a cylindrical volume which includes a large number of passages could be excited by an internal high-voltage electrode and an external ground electrode. However, this means that it is not possible to differentiate between inlet and outlet passages of a particulate filter and also it is impossible to produce targeted sliding surface discharges. Moreover, the long sparking distance between the electrodes means that a high voltage amplitude of 20 kV is required, which can lead to problems in the motor vehicle.
SUMMARY OF THE INVENTION
Working on the basis of the latter related art, it is one possible object to provide a plasma particulate filter in which a suitable geometry avoids the drawbacks listed above.
The inventor proposes a wall flow filter comprising elongate passages of any desired cross section which are closed off on alternate sides, the particulate-covered walls of which wall flow filter are regenerated by sliding surface discharges. On account of the arrangement of the electrodes embedded in the filter material and thereby protected against corrosion, the sliding surface discharges now preferentially burn on the particulate-covered inlet side of the filter. The geometry indicated with two-line symmetry advantageously requires only two electrodes per inlet passage to produce the sliding surface discharges.
The wall flow filter has elongate passages with a quadrilateral cross section arranged in matrix form. The passages are closed off on alternate sides along a row or a column, so that inlet passages and outlet passages alternate.
The electrode arrangement may ensure that the distribution of the electric field in the individual cells of the plasma particulate filter allows non-thermal sliding surface discharges to be struck in individual cells. The dielectric properties of the wall material of the ceramic particulate filter are utilized to concentrate the field in cavities between the electrodes. Surprisingly, a reduction in the number of electrodes per inlet passage from four to two does not, for example, result in a deterioration of the electric field distribution with regard to the generation of sliding surface discharges. For this to be the case, it is important that the electrodes be arranged at diagonally opposite edges of the quadrilateral passage cross section, and it is necessary for inlet passages which are adjacent via their edges which are not provided with electrodes to be connected so as to have the same polarity.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 and FIG. 3 show cross sections through plasma filter elements with inlet passages and outlet passages and associated electrodes,
FIG. 2 and FIG. 4 show calculated field strength distributions in the arrangements shown in FIGS. 1 and 3 , and
FIG. 5 shows cross sections through an inlet passage with two-line symmetry and its variation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
The figures are in part described jointly below. In particular in connection with FIG. 1 , reference is made in detail to patent DE 100 57 862 C1.
The latter patent protects a method and associated arrangements for lowering the levels of carbon-containing particulate emissions from diesel engines in which sliding surface discharges are used. FIGS. 1 to 5 and 7 to 12 , which are described in detail in DE 100 57 862 C1, illustrate wall flow filters made from ceramic material composed of elongate passages which are closed off on alternate sides and have a special quadrilateral cross section with electrodes fitted at each of the corners.
FIG. 1 shows a cross section through an electrode arrangement of this type in a plasma filter element of known design with four electrodes per passage embedded in filter material.
In detail, an inlet passage is denoted by 10 and an outlet passage is denoted by 20 . Inlet passage 10 and outlet passage 20 are separated by porous walls 30 made from specific ceramic material. Electrodes are fitted in the walls 30 at each of the corners of the passages 10 , these electrodes, arranged in pairs next to one another, serving as a high-voltage electrode 41 and a grounded electrode 42 . To ensure sufficient dielectric strength, the electrodes 41 and 42 , made from electrically conductive material, are each surrounded by an electrically insulating barrier layer 31 , which to enable it to withstand high voltages has a low porosity compared to the filter material of the walls 30 .
FIG. 2 shows the distribution of the electric field strength, which is of importance to the formation of sliding surface discharges, for a voltage of 10 kV applied to the high-voltage electrodes in the case of a square passage cross section of 2×2 mm 2 in cross section through the arrangement shown in FIG. 1. 50 denotes calculated field minima in the arrangement shown in FIG. 1 . On account of the quadrupole-like arrangement of the electrodes, these minima are in each case located on the axes of symmetry of both the inlet passages and the outlet passages. Regions with an elevated electric field strength 51 , in which electric gas discharges are preferentially struck, are located in the vicinity of the passage walls of both the inlet passages and the outlet passages.
Overall, it can be seen from FIG. 2 that on account of the symmetry in the outlet passages 20 , the same electric field distribution as in the inlet passages 10 results. However, for particulate oxidation in the wall flow filter, the regions of elevated electric field strength are actually only required in the inlet passages.
FIG. 3 shows an electrode arrangement for the selective production of gas discharges in the inlet passages, in cross section. The main difference with respect to FIG. 1 is the diamond-shaped arrangement of the inlet passages 10 and the outlet passages 20 , which results from the structure shown in FIG. 1 being rotated through 45°. A further difference with respect to the related art is that electrodes 40 , which are in this case designed in pairs as a high-voltage electrode 41 and a ground electrode 42 , are in each case present at opposite corners of the diamond on the vertical at the inlet passages, which are now of diamond-shaped design. In this case too, for a porous filter material a barrier layer 31 is provided once again.
FIG. 4 shows the advantageous distribution of the electric field in the arrangement shown in FIG. 3 , which allows the preferential ignition of gas discharges within the inlet passages. It is clear from this calculated illustration that compared to FIG. 2 the inlet passages 10 have an elevated electric field strength which is sufficient to ignite gas discharges over virtually the entire cross section, whereas in the outlet passages 20 the ignition of gas discharges is only likely in the vicinity of the electrodes, on account of slightly elevated electric fields. Otherwise, field minima 50 are once again present in accordance with FIG. 2 .
Preferred attachment points for gas discharges in the inlet passages 10 are firstly in the vicinity of the electrodes on account of the elevated electric field strength being particularly pronounced there. However, since electric charge carriers are stored during operation of the gas discharge, and therefore the electric fields are reduced there, the preferred points of attachment for the gas discharges gradually slide along the walls of the inlet passages 10 toward the center region until the walls are covered with surface charges to such an extent that it is no longer possible to ignite any further gas discharges.
The latter process is associated with the formation of sliding surface discharges. Although the initial field distribution allows sliding surface and volume discharges equally, in this way, a not insignificant part of the electrical energy is converted into sliding surface discharges. At the same time, the operation of gas discharges in the outlet passages is substantially suppressed. This confirms that the arrangement shown in FIG. 3 gives an improved result, compared to FIG. 1 , which corresponds to the related art, for the implementation of a plasma particulate filter with the use of sliding surface discharges for oxidation of the particulates.
The arrangement shown in FIG. 3 , compared to FIG. 1 , not only results in an electric field distribution which is advantageous for the efficient utilization of the electrical energy, but also results in a reduction of the materials and costs outlay as a result of a reduced number of electrodes per unit filter volume and area and, at the same time, a reduced electrical capacitance, which has the effect of reducing costs on account of simplification of the design of high-voltage grid parts for electrical excitation of the plasma particulate filter. In this context, it is important for the electrodes to be arranged at diagonally opposite edges of the quadrilateral passage cross section; inlet passages which are adjacent via their edges that are not provided with electrodes must necessarily be connected so as to have the same polarity.
FIG. 5 shows, as an excerpt from FIG. 3 , on the left-hand side the diamond-shaped cross section of an individual inlet passage with electrode 41 , counterelectrode 42 and two axes 60 and 60 ′ which define a two-line symmetry. These elements are of importance for the ability of the filter to function, the electrodes 41 and 42 being connected by the axis 60 as one line of symmetry.
It will be clear that the concept described can also be transferred to other passage cross sections. Working on the basis of the overall geometry shown in FIG. 3 and the specific symmetry presented in FIG. 5 , the electrodes 41 and 42 and the connecting axis 60 between the electrodes 41 and 42 , as a first line of symmetry, are held in place and the passage cross section is deformed symmetrically with respect to this axis. When the second line of symmetry is taken into account, the result, for example, is a star shape in the right-hand part of FIG. 5 , in which the wall surface area which is active in the deposition of particulates is increased in the inlet passage compared to FIG. 3 .
If the geometry in accordance with FIG. 5 is taken into account, the outlet passages are deformed in a correspondingly complementary way, so that the cross section is once again completely covered with inlet and outlet passages. In principle, any conversion of a quadrilateral into an n×quadrilateral with n≧2 is possible.
The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” or a similar phrase as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004).
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A method for reducing the particulate emissions containing carbon of diesel motors uses surface discharges to regenerate a filter. An appropriate wall flow filter is configured from alternately closed longitudinal channels. The electrodes are embedded in the filter material and are thus protected from erosion. Two electrodes are sufficient for selectively generating the surface discharges in the inlet channel of the wall flow filter as a result of a suitable geometric arrangement.
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RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 14/020,425, filed Sep. 6, 2013 which is a continuation of: U.S. patent application Ser. No. 12/928,943, filed Dec. 21, 2010, now U.S. Pat. No. 8,542,768, issued Sep. 24, 2013, which claims the benefit of U.S. patent application Ser. No. 61/288,847, filed Dec. 21, 2009. Each of these applications is hereby incorporated by reference in its entirety for all purposes.
FIELD OF THE INVENTION
The present invention generally relates to wireless communication systems using power amplifiers and remote radio head units (RRU or RRH). More specifically, the present invention relates to RRU which are part of a distributed base station in which all radio-related functions are contained in a small single unit that can be deployed in a location remote from the main unit. Multi-mode radios capable of operating according to GSM, HSPA, LTE, and WiMAX standards and advanced software configurability are key features in the deployment of more flexible and energy-efficient radio networks. The present invention can also serve multi-frequency bands within a single RRU to economize the cost of radio network deployment.
BACKGROUND OF THE INVENTION
Wireless and mobile network operators face the continuing challenge of building networks that effectively manage high data-traffic growth rates. Mobility and an increased level of multimedia content for end users require end-to-end network adaptations that support both new services and the increased demand for broadband and flat-rate Internet access. In addition, network operators must consider the most cost-effective evolution of the networks towards 4G. Wireless and mobile technology standards are evolving towards higher bandwidth requirements for both peak rates and cell throughput growth. The latest standards supporting this are HSPA+, WiMAX, TD-SCDMA and LTE. The network upgrades required to deploy networks based on these standards must balance the limited availability of new spectrum, leverage existing spectrum, and ensure operation of all desired standards. This all must take place at the same time during the transition phase, which usually spans many years. Distributed open base station architecture concepts have evolved in parallel with the evolution of the standards to provide a flexible, cheaper, and more scalable modular environment for managing the radio access evolution, FIG. 6 . For example, the Open Base Station Architecture Initiative (OBSAI), the Common Public Radio Interface (CPRI), and the IR Interface standards introduced standardized interfaces separating the Base Station server and the remote radio head part of a base station by an optical fiber.
The RRU concept constitutes a fundamental part of a state-of-the-art base station architecture. However, RRUs to-date are power inefficient, costly and inflexible. Their poor DC to RF power conversion insures that they will have a large mechanical housing. The RRU demands from the service providers are also for greater flexibility in the RRU platform. As standards evolve, there is a need for a software upgradable RRU. Today RRUs lack the flexibility and performance that is required by service providers. The RRU performance limitations are driven in part by the poor power efficiency of the RF amplifiers. Thus there has been a need for an efficient, flexible RRU architecture that is field reconfigurable.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made in view of the above problems in the prior art, and it is an object of the present invention to provide a high performance and cost effective method of multi-frequency bands RRU systems enabled by high linearity and high efficiency power amplifiers for wideband communication system applications. The present disclosure enables a RRU to be field reconfigurable, and supports multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands, and multi-channels.
To achieve the above objects, according to the present invention, the technique is generally based on the method of adaptive digital predistortion to linearize RF power amplifiers. Various embodiments of the invention are disclosed, including single band, dual band, and multi-band RRU's. Another embodiment is a multi-band multi-channel RRU. In an embodiment, the combination of crest factor reduction, PD, power efficiency boosting techniques as well as coefficient adaptive algorithms are utilized within a PA system. In another embodiment, analog quadrature modulator compensation structure is also utilized to enhance performance.
Some embodiments of the present invention are able to monitor the fluctuation of the power amplifier characteristics and to self-adjust by means of a self-adaptation algorithm. One such self-adaptation algorithm presently disclosed is called a digital predistortion algorithm, which is implemented in the digital domain.
Applications of the present invention are suitable for use with all wireless base-stations, remote radio heads, distributed base stations, distributed antenna systems, access points, mobile equipment and wireless terminals, portable wireless devices, and other wireless communication systems such as microwave and satellite communications. The present invention is also field upgradable through a link such as an Ethernet connection to a remote computing center.
THE FIGURES
Further objects and advantages of the present invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram showing the basic form of a Remote Radio head unit system.
FIG. 2 is a block diagram showing a multi-channel Remote Radio Head Unit according to one embodiment of the present invention.
FIG. 3 is a block diagram showing polynomial based predistortion in a Remote Radio head system of the present invention.
FIG. 4 is a block diagram of the digital predistortion algorithm applied for self-adaptation in a remote radio head unit system of the present invention.
FIG. 5 illustrates an analog modulator compensation block.
FIG. 6 depicts schematically a variety of potential installation schemes for an RRU-based system architecture.
FIG. 7 depicts a three-sector arrangement of an RRU system architecture comprising optical links to a base station server.
FIG. 8 shows in block diagram form various DSP-based functions including crest factor reduction and digital predistortion.
FIG. 9 is a Digital Hybrid Module with either an RF input signal or a baseband modulated signal or an optical interface according to another embodiment of the present invention.
FIG. 10 is a Dual Channel Remote Radio head block diagram showing a digital hybrid module with an optical interface according to another embodiment of the present invention.
FIG. 11 is an alternative Dual Channel Remote Radio Head block diagram showing a digital hybrid module with an optical interface according to another embodiment of the present invention.
FIG. 12 is an 8 channel Dual Band Remote Radio Head block diagram showing a digital hybrid module with an optical interface, and further comprises a calibration algorithm for insuring that each power amplifier output is time-aligned, phase-aligned and amplitude-aligned with respect to each other.
GLOSSARY
Acronyms used herein have the following meanings:
ACLR Adjacent Channel Leakage Ratio
ACPR Adjacent Channel Power Ratio
ADC Analog to Digital Converter
AQDM Analog Quadrature Demodulator
AQM Analog Quadrature Modulator
AQDMC Analog Quadrature Demodulator Corrector
AQMC Analog Quadrature Modulator Corrector
BPF Bandpass Filter
COMA Code Division Multiple Access
CFR Crest Factor Reduction
DAC Digital to Analog Converter
DET Detector
DHMPA Digital Hybrid Mode Power Amplifier
DDC Digital Down Converter
DNC Down Converter
DPA Doherty Power Amplifier
DQDM Digital Quadrature Demodulator
DQM Digital Quadrature Modulator
DSP Digital Signal Processing
DUC Digital Up Converter
EER Envelope Elimination and Restoration
EF Envelope Following
ET Envelope Tracking
EVM Error Vector Magnitude
FFLPA Feedforward Linear Power Amplifier
FIR Finite Impulse Response
FPGA Field-Programmable Gate Array
GSM Global System for Mobile communications
I-Q In-phase/Quadrature
IF Intermediate Frequency
LINC Linear Amplification using Nonlinear Components
LO Local Oscillator
LPF Low Pass Filter
MCPA Multi-Carrier Power Amplifier
MDS Multi-Directional Search
OFDM Orthogonal Frequency Division Multiplexing
PA Power Amplifier
PAPR Peak-to-Average Power Ratio
PD Digital Baseband Predistortion
PLL Phase Locked Loop
QAM Quadrature Amplitude Modulation
QPSK Quadrature Phase Shift Keying
RF Radio Frequency
RRU Remote Radio Head Unit
SAW Surface Acoustic Wave Filter
SERDES Serializer/Deserializer
UMTS Universal Mobile Telecommunications System
UPC Up Converter
WCDMA Wideband Code Division Multiple Access
WLAN Wireless Local Area Network.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a novel RRU system that utilizes an adaptive digital predistortion algorithm. The present invention is a hybrid system of digital and analog modules. The interplay of the digital and analog modules of the hybrid system both linearize the spectral regrowth and enhance the power efficiency of the PA while maintaining or increasing the wide bandwidth. The present invention, therefore, achieves higher efficiency and higher linearity for wideband complex modulation carriers.
FIG. 1 is a high level block diagram showing the basic system architecture of what is sometimes referred to as a Remote Radio Head Unit, or RRU, which can be thought of, at least for some embodiments, as comprising digital and analog modules and a feedback path. The digital module is the digital predistortion controller 101 which comprises the PD algorithm, other auxiliary DSP algorithms, and related digital circuitries. The analog module is the main power amplifier 102 , other auxiliary analog circuitries such as DPA, and related peripheral analog circuitries of the overall system. The present invention operates as a “blackbox”, plug and play type system because it accepts RF modulated signal 100 as its input, and provides a substantially identical but amplified RF signal 103 as its output, therefore, it is RF-in/RF-out. Baseband input signals can be applied directly to the Digital Predistorter Controller according to one embodiment of the present invention. An Optical input signal can be applied directly to the Digital Predistorter Controller according to one embodiment of the present invention. The feedback path essentially provides a representation of the output signal to the predistortion controller 101 . The present invention is sometimes referred to as a Remote Radio head Unit (RRU) hereinafter.
FIG. 2 illustrates in schematic block diagram form an embodiment of an eight channel (or n channel) RRU in which an input signal 200 is provided. Depending on the implementation, the input signal can take the form of an RF modulated signal, a baseband signal, or an optical signal. The input signal 200 is fed to a plurality of channels, where each channel includes a digital predistortion (DPD) controller, indicated at 201 , 211 and 271 , respectively. The DPD can be implemented in an FPGA in at least some embodiments. For each channel, the DPD outputs are fed to associated PA's 202 , 212 and 272 , respectively, and the PA outputs 203 , 213 and 273 are fed back to that channel's DPD's.
FIG. 3 illustrates a polynomial-based digital predistorter function in the RRU system of the present invention. The PD in the present invention generally utilizes an adaptive LUT-based digital predistortion system. More specifically, the PD illustrated in FIG. 3 , and in embodiments disclosed from FIGS. 9-12 discussed hereinafter, are processed in the digital processor by an adaptive algorithm, presented in U.S. patent application Ser. No. 11/961,969, entitled A Method for Baseband Predistortion Linearization in Multi-Channel Wideband Communication Systems. The PD for the RRU system in FIG. 3 . has multiple finite impulse response (FIR) filters, that is, FIR1 301 , FIR2 303 , FIR3 305 , and FIR4 307 . The PD also contains the third order product generation block 302 , the fifth order product generation block 304 , and the seventh order product generation block 306 . The output signals from FIR filters are combined in the summation block 308 . Coefficients for multiple FIR filters are updated by the digital predistorter algorithm based on the error between the reference input signal and the amplified power output signal.
FIG. 4 shows in block diagram form additional details of an embodiment including a DPD in accordance with the present invention and is discussed in greater detail hereinafter. In general, the input 400 is provided to the DPD 401 . The output of the DPD is fed to a DAC 402 and thence to the PA 403 . A feedback signal from the output of the PA is received by ADC 406 , and the digital form is supplied to alignment logic 405 , after which the aligned signal is provided to DPD estimator logic 404 , which also receives an input from the output of the DPD 401 . The output of the DPD estimator is then fed back to the DPD 401 .
FIG. 5 illustrates an analog modulator compensation block. The input signal is separated into an in-phase component X I and a quadrature component X Q . The analog quadrature modulator compensation structure comprises four real filters {g11, g12, g21, g22} and two DC offset compensation parameters c1, c2. The DC offsets in the AQM will be compensated by the parameters c1, c2. The frequency dependence of the AQM will be compensated by the filters {g11, g12, g21, g22}. The order of the real filters is dependent on the level of compensation required. The output signals Y I and Y Q will be presented to an AQM's in-phase and quadrature ports, discussed hereinafter in connection with FIG. 9 .
FIG. 6 illustrates a plurality of possible implementations of an RRU-based system architecture, in with a base station server 600 is connected to, for example, a tower-mounted RRU 605 , a rooftop-mounted RRU 610 , and/or a wallmounted RRU 615 .
FIG. 7 illustrates an embodiment of a three-sector implementation of an RRU-based system architecture, in which a base station server 700 is optically linked to a plurality of RRU's 710 to provide adequate coverage for a site.
FIG. 8 illustrates in simplified form an embodiment of the DSP functionality of some implementations of the present invention. An input signal is fed to an interface 800 , which can take several forms including OBSAI, CPRI or IR. The incoming signal is fed to a digital up-converter (DUO) 805 and then to CFR/DPD logic 810 , such as an FPGA. The output of the CFR/DPD logic 810 is then supplied to a DAC 815 . The DAC provides an output signal to the analog RF portion 820 of the system, which in turn provides a feedback signal to a ADC 825 , and back through the DSP block in the form of inputs to the CFR/DPD and a DOC 830 . The DOC outputs a signal to the interface 800 , which in turn can provide an output.
FIG. 9 is a block diagram showing a more sophisticated embodiment of a RRU system, where like elements are indicated with like numerals. The embodiment of FIG. 9 applies crest factor reduction (CFR) prior to the PD with an adaptation algorithm in one digital processor, so as to reduce the PAPR, EVM and ACPR and compensate the memory effects and variation of the linearity due to the temperature changing of the PA. The digital processor can take nearly any form; for convenience, an FPGA implementation is shown as an example, but a general purpose processor is also acceptable in many embodiments. The CFR implemented in the digital module of the embodiments is based on the scaled iterative pulse cancellation presented in U.S. patent application Ser. No. 61/041,164, filed Mar. 31, 2008, entitled An Efficient Peak Cancellation Method For Reducing The Peak-To Average Power Ratio In Wideband Communication Systems, incorporated herein by reference. The CFR is included to enhance performance and hence optional. The CFR can be removed from the embodiments without-affecting the overall functionality.
FIG. 9 is a block diagram showing a RRU system according to one embodiment of the present invention. RRU systems typically comprise three primary blocks: power amplifiers, baseband processing and an optical interface. The optical interface contains an optical to electrical interface for the transmit/receive mode. The optical interface 901 , shown in FIG. 9 , is coupled to a FPGA. The FPGA 902 performs the functions of SERDES/Framer/DeFramer/Control and Management. This FPGA 902 interfaces with another FPGA 903 that performs the following Digital Signal Processing tasks: Crest Factor Reduction/Digital Upconversion/Digital Downconversion and Digital Predistortion. Another embodiment will be to integrate 902 with 903 in a single FPGA. The Serializer/De-serializer (SERDES) module converts the high speed serial bit stream from the optical to electrical receiver to a parallel bit stream. The De-Framer decodes the parallel bit stream and extracts the In-phase and Quadrature (I/Q) modulation and delivers this to the digital signal processing module 903 . The Control and Management module extracts the control signals from the parallel bit stream and performs tasks based on the requested information. The received I/Q data from the optical interface is frequency translated to an Intermediate Frequency in the Digital Upconverter Module (DUC). This composite signal then undergoes Crest Factor Reduction (CFR) in order to reduce the peak to average power ratio. The resultant signal is then applied to a Digital Predistorter in order to compensate for the distortion in the Power Amplifier module 905 . The RRU operates in a receive mode as well as a transmit mode. The RRU receives the signal from the output duplexer and passes this signal to the Rx path or paths, depending on the number of channels. The received signal is frequency translated to an Intermediate Frequency (IF) in the receiver (Rx1 and Rx2 in FIG. 10 ). The IF signal is further downconverted using a Digital Downconverter (DDC) module and demodulated into the In-phase and quadrature components. The recovered I/Q signal is then sent to the Framer module/SERDES and prepared for transmission over the optical interface.
The system of FIG. 9 has a multi-mode of RF or multi-carrier digital signal, which can be optical, at the input, and an RF signal at the output 910 . The multi-mode of the signal input allows maximum flexibility: RF-in (the “RF•in Mode”) or baseband digital-in (the “Baseband-in Mode”) or optical input (the “Optical-in Mode”). The system shown in FIG. 9 comprises three key portions: a reconfigurable digital (hereinafter referred as “FPGA-based Digital”) module 915 , a power amplifier module 960 , a receiver 965 and a feedback path 925 .
The FPGA•based Digital part comprises either one of two digital processors 902 , 903 (e.g. FPGA), digital-to-analog converters 935 (DACs), analog-to-digital converters 940 (ADCs), and a phase-locked loop (PLL) 945 . Since the system shown in FIG. 9 has a multi-input mode, the digital processor has three paths of signal processing. For the baseband signal input path, the digital processor has implemented a digital up-converter (DUO), CFR, and a PD. For the optical input path, SERDES, Framer/Deframer, digital up-converter (DUC), CFR, and PD are implemented. For the RF input path, analog downconverter, DUC, CFR and PD are implemented.
The Baseband-in Mode of FIG. 9 contains the I-Q signals. Digital data streams from multi-channels as I-Q signals are coming to the FPGA-based Digital module and are digitally up-converted to digital IF signals by the DUO. These IF signals are then passed through the CFR block so as to reduce the signal's PAPR. This PAPR suppressed signal is digitally predistorted in order to pre-compensate for nonlinear distortions of the power amplifier.
In either input mode, the memory effects due to self-heating, bias networks, and frequency dependencies of the active device are compensated by the adaptation algorithm in the PD, as well. The coefficients of the PD are adapted by a wideband feedback which requires a very high speed ADC. The predistorted signal is passed through a DQM in order to generate the real signal and then converted to an IF analog signal by the DACs. As disclosed above, the DQM is not required to be implemented in the FPGA, or at all, in all embodiments. If the DQM is not used in the FPGA, then the AQM Implementation can be implemented with two DACs to generate real and imaginary signals 935 , respectively. The gate bias voltage 950 of the power amplifier is determined by the adaptation algorithm and then adjusted through the DACs 935 in order to stabilize the linearity fluctuations due to the temperature changes in the power amplifier. The PLL 945 sweeps the local oscillation signal for the feedback part in order to translate the RF output signal to baseband, for processing in the Digital Module.
The power amplifier part comprises an AQM for receiving real and complex signals (such as depicted in the embodiments shown in FIG. 9 ) from the FPGA-based Digital module, a high power amplifier with multi-stage drive amplifiers, and a temperature sensor. In order to improve the efficiency performance of the DHMPA system, efficiency boosting techniques such as Doherty, Envelope Elimination and Restoration (EER), Envelope Tracking (ET), Envelope Following (EF), and Linear amplification using Nonlinear Components (LINC) can be used, depending upon the embodiment. These power efficiency techniques can be mixed and matched and are optional features to the fundamental RRU system. One such Doherty power amplifier technique is presented in commonly assigned U.S. Provisional Patent Application Ser. No. 60/925,577, filed Apr. 23, 2007, entitled N-Way Doherty Distributed Power Amplifier, incorporated herein by reference. To stabilize the linearity performance of the amplifier, the temperature of the amplifier is monitored by the temperature sensor and then the gate bias of the amplifier is controlled by the FPGA-based Digital part.
The feedback portion comprises a directional coupler, a mixer, a low pass filter (LPF), gain amplifiers and, and a band pass filter (BPF). Depending upon the embodiment, these analog components can be mixed and matched with other analog components. Part of the RF output signal of the amplifier is sampled by the directional coupler and then down converted to an IF analog signal by the local oscillation signal in the mixer. The IF analog signal is passing through the LPF, the gain amplifier, and the BPF which can capture the out-of-band distortions. The output of the BPF is provided to the ADC of the FPGA-based Digital module in order to determine the dynamic parameters of the PD depending on output power levels and asymmetrical distortions due to the memory effects. In addition, temperature is also detected by the DET 970 to calculate the variation of linearity and then adjust gate bias voltage of the PA. More details of the PD algorithm and self-adaptation feedback algorithm can be appreciated from FIG. 3 , which shows a polynomial based predistortion algorithm and from FIG. 4 , which shows the primary adaptive predistorter blocks which can be used in some embodiments of the invention.
In the case of a strict EVM requirement for broadband wireless access such as WiMAX or other OFDM based schemes (EVM<2.5%), the CFR in the FPGA-based Digital part is only able to achieve a small reduction of the PAPR in order to meet the strict EVM specification. In general circumstances, this means the CFR's power efficiency enhancement capability is limited. In some embodiments of the present invention, a novel technique is included to compensate the in-band distortions from CFR by use of a “Clipping Error Restoration Path” 907 , hence maximizing the RRU system power efficiency in those strict EVM environments. As noted above, the Clipping Error Restoration Path has an additional DAC in the FPGA-based Digital portion and an extra UPC in the power amplifier part. The Clipping Error Restoration Path can allow compensation of in-band distortions resulting from the CFR at the output of the power amplifier. Further, any delay mismatch between the main path and the Clipping Error Restoration Path can be aligned using digital delay in the FPGA.
While FIG. 9 illustrates a RRU system implemented with AQM, according to another embodiment of the present invention, the system of FIG. 9 can also comprise a digital processor which has implemented therein CFR, PD, and an analog quadrature modulator corrector (AQMC).
Still further, the system of FIG. 9 can alternatively be configured to be implemented with AQM and an AQM-based Clipping Error Restoration Path. In such an arrangement, the Clipping Error Restoration Path can be configured to have two DACs in the FPGA-based Digital part and an AQM in lieu of the UPC in the power amplifier part.
FIG. 10 is a block diagram showing a dual channel RRU implemented with two power amplifiers 1000 and 1005 , respectively, for two distinct bands provided from AQM1 1010 and AQM2 1015 . A duplexer 1020 is used to combine the two power amplifier outputs and provide the combined output to the antenna [not shown]. Switches 1025 and 1030 are used to isolate the transmit signals from the received signals as occurs in a Time Division Synchronous Code Division Multiple Access (TD-SCDMA) modulation. Feedback signals 1035 and 1040 , derived from the output of PA's 1000 and 1005 , are each provided to an additional switch 1045 , which is toggled at appropriate times to permit feedback calibration of each PA with only a single FPGA 1050 . In the embodiment shown, the FPGA 1050 comprises two blocks: SERDES Framer/Deframer and CMA, indicated at 1055 , and a block 1060 comprising DDC1/CFR1/PDC1/DUC1 as well as DDC2/CFR2/PDC2/DUC2, with block 1060 controlling the switching timing of the associated switches. The feedback signals 1035 and 1040 are fed back to the block 1060 first through adder 1065 , where they are combined with phase-locked-loop signal 1070 , and then through band pass filter 1075 , low pass filter 1080 and ADC 1085 . In addition, temperature sensor signals from PA's 1000 and 1005 are fed back to the block 1060 through toggle switch 1090 and detector 1095 so that the predistortion coefficients can include temperature compensation. The toggling of the switches 1045 and 1090 is synchronized to ensure that the output and temperature signals of each PA are provided to block 1060 at the appropriate times. Another embodiment of the RRU extends its application to multi-frequency bands. In another embodiment, a multi-frequency band (i.e., two or more bands) implementation comprises adding additional channelized power amplifiers in parallel. The output of the additional power amplifiers is combined in an N by 1 duplexer and fed to a single antenna, although multiple antennae can also be utilized in some embodiments. Another embodiment of the multi-frequency band RRU combines two or more frequency bands in one or more of the power amplifiers.
FIG. 11 is a block diagram showing another embodiment of the dual channel RRU. In this embodiment the Rx switches 1105 and 1110 are placed on the third port of circulators 1115 and 1120 , thereby reducing the insertion loss between the PA output and the duplexer 1020 . The remainder of FIG. 11 is substantially identical to FIG. 10 and is not described further.
FIG. 12 is a block diagram showing an embodiment of an 8 channel dual-band RRU. In this embodiment, the feedback path for each PA 1000 A-H and 1005 A-H comprises a receiver chain plus a wideband capture chain, indicated at 1200 A-H and 1205 A-H, respectively, receiving feedback signals from the array of associated PA's through associated circulators 1210 A-H and 1215 A-H. The receiver chain is utilized when the RRU is switched to a receive mode and corresponds to the receive (Rx) paths shown in FIG. 11 . The wideband capture chain is utilized for capturing the wideband distortion of the power amplifier, and corresponds to the Feedback Calibration path shown in FIG. 11 . In an embodiment a channel calibration algorithm is implemented to insure that each power amplifier output is time, phase and amplitude aligned to each other.
Digital Predistorter Algorithm
Digital Predistortion (DPD) is a technique to linearize a power amplifier (PA). FIG. 1 shows the block diagram of linear digitally predistorted PA. In the DPD block, a memory polynomial model is used as the predistortion function ( FIG. 3 ).
z
(
n
)
=
∑
i
=
0
n
-
1
x
i
(
n
-
i
)
(
∑
j
=
0
k
-
1
a
i
j
x
i
(
n
-
i
)
j
)
where a ii are the DPD coefficients.
In the DPD estimator block, a least square algorithm is utilized to find the DPD coefficients a ij , and then transfer them to DPD block. The primary DPD blocks are shown in FIG. 4 .
Delay Estimation Algorithm:
The DPD estimator compares x(n) and its corresponding feedback signal y(n−Δd) to find the DPD coefficients, where Δd is the delay of the feedback path. As the feedback path delay is different for each PA, this delay should be identified before the signal arrives at the coefficient estimation. In this design, the amplitude difference correlation function of the transmission, x(n), and feedback data, y(n), is applied to find the feedback path delay. The correlation is given by
c ( m ) = ∑ i = 0 N - 1 sign ( x ( i + 1 ) - x ( i ) ) sign ( y ( i + m + 1 ) - y ( i + m ) ) n (delay)=Max( C ( m ))
The delay n that maximizes the correlation C(m) is the feedback path delay.
Since the feedback path goes through analog circuitry, the delay between the transmission and feedback path could be a fractional sample delay. To synchronize the signals more accurately, fractional delay estimation is necessary. To simplify the design, only a half-sample delay is considered in this design, although smaller fractional delays can also be utilized.
To get the half-sample delay data, an upsampling approach is the common choice, but in this design, in order to avoid a very high sampling frequency in the FPGA, an interpolation method is used to get the half-sample delay data. The data with integer delay and fractional delay are transferred in parallel. The interpolation function for fractional delay is
y ( n ) = ∑ i = 0 3 c i x ( n + i )
in which c i is the weight coefficient.
Whether the fractional delay path or the integer delay path will be chosen is decided by the result of the amplitude difference correlator. If the correlation result is odd, the integer path will be chosen, otherwise the fractional delay path will be chosen.
Phase Offset Estimation and Correction Algorithm:
Phase offset between the transmission signal and the feedback signal exists in the circuit. For a better and faster convergence of the DPD coefficient estimation, this phase offset should be removed.
The transmission signal x(n) and feedback signal y(n) can be expressed as
x
(
n
)
=
x
(
n
)
ⅇ
jθ
x
and
y
(
n
)
=
y
(
n
)
ⅇ
jθ
y
,
The phase offset e j(θ x −θ y ) can be calculated through
ⅇ
j
(
θ
x
-
θ
y
)
=
x
(
n
)
y
(
n
)
*
x
(
n
)
y
(
n
)
So, the phase offset between the transmission and feedback paths is
ⅇ
j
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,
=
mean
(
x
(
n
)
y
(
n
)
*
x
(
n
)
y
(
n
)
)
The feedback signal with the phase offset removed can be calculated by
y ( n )= y ( n ) e jhe
Magnitude Correction:
As the gain of the PA may change slightly, the feedback gain should be corrected to avoid the error from the gain mismatch. The feedback signal is corrected according to the function
y _ ( n ) = y ( n ) ∑ i = 1 N x ( i ) ∑ i = 1 N y ( i )
The choice of N will depend on the accuracy desired.
QR_RLS Adaptive Algorithm:
The least square solution for DPD coefficient estimation is formulated as
F ( x ( n ))= y ( n )
F
(
x
(
n
)
)
=
∑
i
=
1
N
∑
j
=
0
K
a
i
j
x
(
n
-
i
)
x
(
n
-
i
)
j
Define h k =x(n−i)|x(n−i)| j , w k =a ij , where k=(i−1)N+j. The least square formulation can be expressed as:
∑ k = 1 N × K w k h k = y ( n )
In this design, QR-RLS algorithm (Haykin, 1996) is implemented to solve this problem. The formulas of QR_RLS algorithm are
{
d
(
i
)
=
Δ
y
(
i
)
-
h
i
w
_
w
_
i
=
Δ
w
i
-
w
_
q
i
=
Δ
ϕ
i
*
/
2
[
w
i
-
w
_
]
where φ i is a diagonal matrix, and q i is a vector.
The QR_RLS algorithm gets the ith moment φ i and q i from its (i−1)th moment through a unitary transformation:
A
=
[
ϕ
i
1
2
0
q
1
*
e
a
*
(
i
)
γ
1
2
(
i
)
h
i
Φ
1
-
*
2
γ
1
2
(
i
)
]
=
[
λ
1
2
ϕ
i
-
1
*
2
h
i
*
λ
1
2
q
i
-
1
*
d
(
i
)
*
0
1
]
θ
i
θ i is a unitary matrix for unitary transformation.
To apply QR_RLS algorithm more efficiently in FPGA, a squared-root-free Givens rotation is applied for the unitary transformation process (E. N. Frantzeskakis, 1994)
[
a
1
a
2
…
a
n
b
1
b
2
…
b
n
]
=
[
k
a
0
0
k
b
]
[
a
1
′
a
2
′
…
a
n
′
b
1
′
b
2
′
…
b
n
′
]
[
a
1
′
a
2
′
…
a
n
′
b
1
′
b
2
′
…
b
n
′
]
θ
=
[
k
a
′
0
0
k
b
′
]
[
1
a
2
″
…
a
n
″
0
b
2
″
…
b
n
″
]
k′
a
=k
a
a
1
2
+k
b
b
1
2
k b ′ = k a k b k a ′ a′ j =( k a a 1 a j +k b b 1 b j )/ k′ a b′ j =−b 1 a j +a 1 b j
For RLS algorithm, the i th moment is achieved as below:
[
λ
1
2
ϕ
i
-
1
*
2
h
i
*
λ
1
2
q
i
-
1
*
d
(
1
)
*
_
0
1
]
θ
i
=
[
ϕ
1
1
2
_
0
e
a
*
(
1
)
γ
1
2
(
1
)
q
1
*
_
h
1
Φ
1
-
1
2
γ
1
2
(
1
)
_
]
[
k
a
0
0
k
b
]
w i can be obtained by solving
Φ
*
2
_
[
w
i
-
w
_
]
=
q
1
_
In the iterative process, a block of data (in this design, there are 4096 data in one block) is stored in memory, and the algorithm uses all the data in memory s to estimate the DPD coefficient. In order to make the DPD performance more stable, the DPD coefficients are only updated after one block of data are processed. The matrix A will be used for the next iteration process, which will make the convergence faster.
To make sure the performance of the DPD is stable, a weighting factor f is used when updating the DPD coefficient as
w i =f×w i −1+(1− f ) w 1
The DPD coefficient estimator calculates coefficients w i by using QR_RLS algorithm. These w i are copied to the DPD block to linearize the PA.
Channel Calibration Algorithm
The 8 channel RRU in FIG. 12 has 16 distinct power amplifiers, indicated at PA's 1000 A-H and 1005 A-H. Half the power amplifiers are designed for one band and the other for a second band. The bands are hereafter referred to as band A and band B, and occupy two distinct frequencies. The 8 channel RRU uses eight antennas 1220 A-H and both bands will coexist on each antenna. In order to maximize performance, each power amplifier's output signal needs to be time, phase and amplitude aligned with respect to each other. The antenna calibration algorithms comprise three distinct approaches: 1) A Pilot Tone is injected into each PA; 2) a Reference Modulated signal is transmit through each PA; or 3) the Real Time I/Q data is used as the reference signal. The Pilot Tone approach injects a single carrier IF tone that is tracked in either the feedback calibration path or the individual PA's receiver. Each transmitter path for band A is time, phase and amplitude aligned with respect to each other, similarly for band B. The Reference Modulated approach utilizes a stored complex modulated signal which is transmitted through each of the band A PA's, similarly for the band B PA's. The transmitters are then time, phase and amplitude aligned with respect to each other. Either the feedback calibration path or the individual receivers can be used for obtaining the PA output signals. The Real Time approach operates on the real-time transmitted signals. This approach utilizes the DPD time alignment, phase and magnitude offset information to synchronize each PA output with respect to each other.
In summary, the RRU system of the present invention enhances the performance in terms of both the efficiency and the linearity more effectively since the RRU system is able to implement CFR, DPD and adaptation algorithm in one digital processor, which subsequently saves hardware resources and processing time. The high power efficiency of RF power amplifiers inside the RRU means that less thermal dissipation mechanism such as heat sinks is needed; therefore, significantly reducing the size and volume of the mechanical housing. This smaller RRU can then enable service providers to deploy the RRU in areas where heavy or large RRU's could not be deployed, such as pole tops, top of street lights, etc. due to lack of real estate, or weight limitation, wind factor, and other safety issues. The RRU system of the present invention is also reconfigurable and field-programmable since the algorithms and power efficiency enhancing features which are embedded in firmware can be adjusted similarly to a software upgrade in the digital processor at anytime.
Moreover, the RRU system is agnostic to modulation schemes such as QPSK, QAM, OFDM, etc. in CDMA, TD-SCDMA, GSM, WCDMA, CDMA2000, and wireless LAN systems. This means that the RRU system is capable of supporting multi-modulation schemes, multi-carriers and multichannels. The multi-frequency bands benefits mean that mobile operators can deploy fewer RRUs to cover more frequency bands for more mobile subscribers; hence significantly reducing CAPEX and OPEX. Other benefits of the RRU system include correction of PA non-linearities in repeater or indoor coverage systems that do not have the necessary baseband signals information readily available.
Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
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A remote radio head unit (RRU) system is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels. Consequentially, the remote radio head system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems.
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BACKGROUND OF THE INVENTION
This invention relates to roller assemblies for guiding panels, such as doors and the like, slidably along a railed track. More particularly, it is directed to such assemblies incorporating new and improved means for preventing roller derailment.
It is conventional to mount a sliding door in a door frame or opening having a railed track facing and parallel to the bottom edge of the door, and to provide in the bottom edge portion of the door two or more grooved rollers for riding on the rail of the track to guide the door in smooth sliding movement along the track. Advantageously, the rollers are fabricated of a relatively, low-friction material such as nylon. In one known form of construction, described for example in U.S. Pat. No. 4,064,592, each roller is rotatably mounted in a U-shaped housing member which is itself pivotally carried by an outer housing or bracket mounted in the door, so that the angular position of the U-shaped member relative to the outer housing can be adjusted (to locate the roller at the proper height for a particular installation) by means of an adjusting screw carried in the outer housing and bearing against the U-shaped member.
Roller-mounted sliding doors are susceptible to lateral displacement or derailment, e.g. under conditions of severe wind loading such as may be encountered during heavy storms, especially because the low-friction characteristics of the rollers (though desirable for smooth door movement) enable them to jump or slip quite easily off the track rails. Various expedients have accordingly heretofore been proposed to prevent derailment of sliding doors.
One such expedient involves the provision of vertical flanges on the tracks for engaging the bottom edge portions of the doors to retain the doors on the tracks. These flanges, however, constitute upwardly projecting obstacles which are hazardous to persons walking through the door openings, as well as being aesthetically unattractive and vulnerable to bending or other damage. In this regard, it may be mentioned that in a currently preferred track configuration, herein termed a "flat track," the track rail on which the rollers ride is recessed between parallel horizontal lands, thereby to protect the rail from damage, minimize hazards to walkers, and present a pleasingly unobtrusive appearance.
Since the track rail is commonly formed as an upstanding web having an enlarged lip or bead at the top for engagement by the rollers, it has also been proposed to provide derailment-inhibiting retainer elements that extend downwardly from the axle of and in overlapping relation to each roller (as described in the aforementioned U.S. Pat. No. 4,064,592, and in U.S. Pat. No. 3,033,285), or elsewhere along the bottom edge of the door (as described in U.S. Pat. No. 3,745,706), to hook under the rail lip or bead. The use of these devices tends to increase the difficulty of installing and especially of removing the doors to which they are attached; moreover, their ability to withstand door-displacing forces is limited, owing to the fact that they must be flexible in order to facilitate such installation and removal.
Additionally, elements mounted separately from the rollers along the bottom edge of a door, and having downwardly-opening grooves or notches for the rails, have been proposed and employed for retaining sliding doors on their tracks. An example of this type of device is a rigid metal lug adapted to be force-fitted into the lower end of a vertical stile of a sliding door. A structurally somewhat similar element is described in U.S. Pat. No. 3,085,298. Such devices must be individually mounted and positioned with considerable care, contributing to the complexity of door installation, and giving rise to the possibility that an installer in the field may inadvertently omit them, with the result that the installed door is unprotected against derailment.
SUMMARY OF THE INVENTION
The present invention is broadly directed to improvements in a roller assembly, for slidably mounting a panel (e.g. a door) on a horizontal guide track having a rail facing and parallel to one edge of the panel, of the type including a roller having a peripheral groove for bearingly receiving the rail, and means for rotatably mounting the roller, the mounting means being mountable in the panel with the roller positioned to receive the rail in its peripheral groove as aforesaid. In this broad sense, the invention contemplates the provision, in such a roller assembly, of a rigid stabilizer element carried by the mounting means of the assembly and having a generally U-shaped extremity positioned for overlying the rail in tandem relation to the roller. The U-shaped extremity has spaced legs respectively disposed to project on opposite sides of the rail in laterally overlapping relation thereto, for preventing lateral displacement of the roller relative to the rail, when the mounting means of the assembly is mounted in the panel and the rail is received in the roller groove.
In particular embodiments of the invention, the U-shaped extremity has a bridging portion between the legs for engaging the rail, and the stabilizer element is freely vertically movable in the mounting means at least through a substantial range of positions so as to ride floatingly on the rail, with the bridging portion engaging the rail. Advantageously, the bridging portion is constituted of a material (e.g. nylon) providing a low-friction surface for ease of sliding contact of the bridging portion with the rail, and the legs are constituted of metal with exposed metal inner side surfaces disposed to face the sides of the rail but spaced apart sufficiently to be ordinarily out of contact with the rail. Thus, in a preferred or convenient form, the stabilizer element comprises a rigid metal body and an insert of low-friction material mounted therein to constitute the bridging portion. Preferably, also, the legs and the bridging portion cooperatively define a downwardly opening groove or notch deeper than the peripheral groove of the roller, and the legs have straight horizontal lower edges.
Further in accordance with the invention, in specific embodiments thereof, the mounting means includes vertical wall portions defining an open-ended vertical passage for the stabilizer element, which is dimensioned to fit in the passage for vertical sliding movement relative to the mounting means while being restrained by the wall portions against horizontal movement in any direction relative to the mounting means. Conveniently or preferably, in such embodiments, the stabilizer element has a vertically elongated transverse opening above the U-shaped extremity, and one of the passage-defining wall portions of the mounting means bears a stop projection disposed within the transverse opening for limiting the extent of upward and downward movement of the stabilizer element by interferingly engaging lower and upper edges of the transverse opening. In roller assemblies wherein the mounting means includes a U-shaped inner housing carrying the roller and pivotally mounted in an outer housing, with an adjusting screw carried in a rear wall of the outer housing for bearing endwise against the inner housing to set the angular position of the inner housing, the rear wall of the outer housing may constitute one of the aforementioned vertical wall portions defining the passage for the stabilizer element, and the adjusting screw may be arranged to project into the passage so as to constitute the stop projection.
Directional terms such as "horizontal," "vertical," "forwardly," "rear," "rearwardly," and the like are to be understood as used herein only in a relative sense, i.e., to specify relative positions of the elements of the assembly, and not as limiting the assembly to any particular orientation in use. Also, it is to be understood that the term "low friction" is used herein to refer to materials and surfaces which slide substantially more easily (i.e. with a lower coefficient of kinetic friction) on a metal rail than do metal surfaces.
In the roller assembly of the invention, the stabilizer element, being a rigid body, provides fully effective restraint of the panel against derailment even under heavy wind loadings or other forces directed laterally against the panel, because the legs of its U-shaped extremity interferingly engage the rail to prevent such derailment even if the roller might otherwise tend to slip off the rail. The tandem arrangement of the roller and stabilizer (one behind the other along the rail) permits the stabilizer, even though mounted with the roller, to be of the type in which derailment is prevented by interfering engagement between its legs and the sides of the rail, rather than by hooking under a projecting bead or lip of the rail, and thereby facilitates installation and removal of the panel, while enabling use of a fully rigid stabilizer that can most effectively prevent derailment. The provision of the stabilizer on the roller assembly greatly simplifies mounting, because only a single operation is needed to mount and position both the stabilizer and the roller, and there is no possibility of omitting the stabilizer.
The arrangement of the stabilizer element for freefloating vertical movement relative to the mounting means, with a bridging portion of the U-shaped extremity riding on the rail, makes the stabilizer element entirely self-adjusting in position. In this arrangement, the use of a low-friction material for the bridging portion (as well as the spacing of the metal legs of the U-shaped extremity so that they are normally out of contact with the rail) minimizes frictional resistance to the desired smooth sliding movement of the panel and enables the stabilizer element to slide easily, raising and lowering itself, over humps and other irregularities in rail height. At the same time, use of metal for the legs is also beneficial because frictional forces between the metal legs and metal rail (when contact between them occurs) make the stabilizer less vulnerable than a low-friction roller to slipping off the rail. The provision, in the U-shaped extremity, of a groove deeper than the roller groove, with legs having straight horizontal lower edges, maximizes the extent of lateral overlap of the rail by the legs, thereby to enhance the resistance of the stabilizer to derailment. Positioning of the stabilizer in a vertical passage of the mounting means, with a stop projection to limit vertical movement, facilitates manufacture of the assembly and prevents the stabilizer from falling out of the assembly before or during installation. Overall, the structure and arrangement of the elements in the preferred specific embodiment provide a beneficially simple, economical and virtually foolproof construction which is easy to manufacture, to install, and to adjust.
Further features and advantages of the invention will be apparent from the detailed description hereinbelow set forth, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a roller assembly embodying the present invention in a particular form;
FIG. 2 is a side elevational view of the assembly of FIG. 1;
FIG. 3 is a top plan view of the FIG. 1 assembly;
FIG. 4 is a front elevational view of the same assembly;
FIG. 5 is as fragmentary sectional elevational view taken as along the line 5--5 of FIG. 3;
FIG. 6 is a sectional elevational view taken along the line 6--6 of FIG. 3;
FIG. 7 is an exploded perspective view of the assembly of FIG. 1;
FIG. 8 is an enlarged side elevational view of a stabilizer element suitable for use in the assembly of FIG. 1; and
FIG. 9 is a similarly enlarged front elevational view of the stabilizer element of FIG. 8.
DETAILED DESCRIPTION
Referring to the drawings, the invention will be described as embodied in a roller assembly 10 mountable in a sliding door represented in FIG. 1 by a schematic, fragmentary, phantom line showng of a corner portion of a conventional sliding door 11 including a vertical stile 12 and a bottom rail 14. As installed in a door frame or opening, the door 11 is positioned with its bottom horizontal edge 15 disposed above a straight horizontal flat track 16 of known type mounted on a floor or sill (not shown) so as to extend beneath, parallel to, and in facing relation to the bottom edge 15 of the door. This track includes two spaced, parallel, upwardly facing horizontal lands 18 and 20, between which is disposed a recessed rail 22 comprising an upstanding web 24 formed with an enlarged bead 26 at the top, the bead being essentially flush with the lands. Conveniently, the track is an extruded aluminum member.
The assembly 10 includes a nylon roller 28 having a peripheral groove 30 which, when the assembly is mounted in the door 11 adjacent the lower edge thereof, is positioned to receive and bear against the bead 26 of the rail 22 so that the roller rides on the rail, guiding the door for sliding movement along the track. In addition, the assembly includes a housing structure comprising an outer housing 32, an inner housing 34, a pivot pin 36 connecting the inner and outer housings for relative angular movement about a first horizontal axis perpendicular to the direction of sliding movement of the door, an axle 38 supporting the roller in the inner housing for rotation about a second horizontal axis parallel to but spaced forwardly from the aforementioned first axis, and an adjusting screw 40 (FIGS. 3, 6 and 7) for selectively setting the relative angular positions of the inner and outer housings.
In this assembly, the outer housing 32 is a rigid, generally U-shaped metal member having a vertical rear wall 42 and spaced vertical side walls 44 and 46, being open at the top, bottom and front. The inner housing 34 is similarly a rigid U-shaped metal member with a vertical rear wall 48 and vertical side walls 50 and 52 and is likewise open at the top, bottom, and front, being disposed between the side walls of the outer housing forwardly of the rear wall 42, i.e. in nested relation to the outer housing, and being dimensioned to fit with clearance therein. The pivot pin is located adjacent the lower rear corner of the inner housing 34 but forwardly of the rear wall thereof, extending through the inner and outer housing side walls 44, 50, 46 and 52, so as to interconnect the inner and outer housings for relative anuglar movement as described. Such angular movement is limited, however, to a few degrees (from a position in which the rear walls of the two housings are parallel), in both clockwise and counterclockwise directions as viewed in FIG. 6, by interfering engagement of the inner and outer housing rear walls. In addition, the adjusting screw 40 is threaded through an opening in the rear wall 42 of the outer housing so that its end or nose bears against the rear wall 48 of the inner housing, acting as a stop to limit clockwise anuglar movement of the inner housing (as viewed in FIG. 6) relative to the outer housing at a point determined by the extent to which the screw projects forwardly of wall 42.
The axle 38 extends between and is mounted in the inner housing side walls 50 and 52 adjacent the forward end of the assembly, i.e. forwardly of and above the level of the pivot pin 36. The roller 28, rotatably supported on this axle, projects substantially below the lower margin of the housing walls so as to be exposed for engagement with the track rail 22, the position of which (relative to the roller, in an installed door) is illustrated in section in FIG. 4 and in phantom lines in FIGS. 2, 3 and 6.
For use of the assembly, the outer housing 32 is fixedly mounted in the door 11 adjacent the bottom edge of the door, e.g. in the vertical stile 12 as shown in FIG. 1 with the roller positioned to engage and ride on the track rail 22 and the rear of the housing 32 facing the exposed vertical edge of the stile to facilitate access to the adjusting screw 40 through an opening (not shown) in the latter stile edge. The manner of mounting the housing 32 in the door may be entirely conventional, and suitable arrangements for such mounting will be readily apparent to persons of ordinary skill in the art, it being understood that the housing 32 is typically fixed in the door with its rear and side wall surfaces oriented substantially in vertical planes.
As long as the roller 28 is not bearingly engaging the track rail 22, the inner housing 34 is free to pivot downwardly (counterclockwise, as viewed in FIG. 6) relative to the outer housing 32 about pin 36 until arrestd by interfering engagement of the rear walls 42 and 48. When the roller receives the rail 22 in groove 30 and the weight of the door bears on it (through housing 32, pin 36, housing 34, and axle 38), however, the inner housing is forced clockwise (upwardly) to the upper limit of its angular travel, and there remains so long as the door rides on the track. This upper limit, determined as explained above by the position of screw 40, is adjusted during installation to vary the elevation of the roller relative to the door, or in other words to increase or decrease the distance to which the roller protrudes vertically below the door bottom edge 15, until a proper fit of the door with its rollers in the door frame or opening is achieved. Typically, each sliding door panel carries two of the roller assemblies 10, respectively adjacent opposite ends of its bottom edge, providing balanced support for the door on the track.
In this typical case, the weight of the door is borne on the two rollers, which bearingly receive the bead 26 of rail 22 in their grooves and roll therealong, when the door is pushed lengthwise of the track, to guide the door in sliding movement. The low-friction characteristic of the nylon of which the rollers are made contributes to the ease and smoothness of movement of the doors. However, owing in part to this same property, the rollers are susceptible to becoming derailed (slipping sidewise off the rail 22) when the door is subjected to strong lateral forces, such as the severe wind loading that may occur in hurricanes, gales, or even lesser storms. Derailment commonly results in complete dislodgement of the door, which is especially undesirable during heavy weather conditions, may cause damage to the door itself or other objects, and in any event necessitates awkward and inconvenient reinstallation of the door.
The assembly 10, insofar as described above, is generally conventional in construction, installation, and use. Particular features of the invention, now to be set forth, reside in the combination therewith of new and improved means for preventing derailment of the roller 28.
In the form shown, the improvement in accordance with the invention comprises the provision of a rigid stabilizer element 60 disposed within the outer housing 32 rearwardly of the rear wall 42 and between the side walls 44 and 46 thereof. Conveniently, the element 60 includes an integral body 62 of aluminum, having an upper portion 64 of vertically elongated rectangular solid configuration and a generally U-shaped extremity 66 at the lower end of the portion 64. This U-shaped extremity is formed with a pair of downwardly projecting parallel legs 68, between which there is fixedly disposed a low friction (e.g. nylon) insert 70, with a concavely arcuate lower surface 71, constituting a bridging portion between the legs and defining therewith a downwardly opening groove or notch 72 having a depth greater than the depth of the roller groove 30. The lower edges 74 of the legs are preferably straight and horizontal, and are parallel to the axis of curvature of surface 71.
The U-shaped extremity 66 is disposed to overlie the track rail 22, in tandem relation to (behind) the roller 28, such that the rail 22 lies within the groove or notch 72, engaged by the surface 71 of the nylon insert 70, and the legs 68 respectively extend downwardly, on opposite sides of the rail, in laterally overlapping relation thereto. The inner surfaces of the legs 68, respectively facing the opposite sides of the rail, are exposed bare metal surfaces. The spacing between the legs 68 is such, however, that there is ordinarily no contact between the legs 68 and the rail 22, but rather a complete though small clearance between them, as shown in FIG. 5. Thus, the sliding movement of the door on its rollers is not hindered by the frictional resistance that would result if there were metal-to-metal contact between the bare metal stabilizer legs and the rail. As the door moves, the nylon insert 70 of the stabilizer rests against and slides along the top of the rail 22, but since the insert is made of low friction material its contact with the rail does not impede desired free sliding movement of the door.
In the illustrated assembly, the upper portion 64 of the stabilizer element 60 is received within a vertical, open-ended passage 76 of uniform rectangular cross-section, defined by the planar vertical rearwardly-facing surface of the rear wall 42 of the outer housing 32, planar vertical inwardly-facing surfaces of portions 44a and 46a of the outer housing side walls which extend rearwardly of wall 42, and a pair of spaced vertical flanges 78 formed on the rear vertical edges of the outer housing wall portions 44a and 46a. The dimensions of passage 76 are such as to permit free-floating vertical sliding movement of the stabilizer element 60 in either direction (up or down) relative to the housing 32, but to restrain the element 60 against horizontal movement in any direction.
The portion 64 of element 60 has a vertically elongated front-to-rear opening 80 above the U-shaped extremity. When the adjusting screw 40 is threaded through the screw hole 82 (FIG. 7) provided in wall 42, so as to bear endwise against the rear wall 48 of the inner housing 34, the head of the screw (as best seen in FIG. 6) projects rearwardly of the wall 42, i.e. into the passage 76; with the stabilizer element 60 in place in the passage 76, the head portion of the screw is received within the opening 80, which has a greater vertical extent than the screw head. Thus, the element 60 is free to move up and down between upper and lower limits respectively established by interfering engagement of the screw head with the lower and upper edge surfaces of the opening 80. The disposition and vertical dimensions of the opening 80 are selected to locate these upper and lower limits outside the range of vertical travel through which the stabilizer element may move, with the insert 70 riding on the rail 22, in any position to which the roller 28 and housing 34 may be adjusted.
In the manufacture of the described roller assembly, the stabilizer element is first inserted in the passage 76 (with the U-shaped extremity oriented downwardly), until the opening 80 comes into register with the screw hole 82 in the wall 42. The screw 40 is then inserted forwardly through the gap between the flanges 78 and through the opening 80 and threaded in the screw hole; as will be appreciated, this gap and opening provide access both for initial insertion of the screw and for subsequent adjustment of the screw (to vary the position of the roller 28) with a screwdriver. The screw acts as a stop projection, preventing the stabilizer element 60 from dropping out of the housing 32 prior to or during installation of the roller assembly, while permitting the element 60 to move freely through the full range of vertical sliding movement necessary to enable it to continuously ride on the rail 22 at any position of roller 28.
The element 60 may conveniently be produced by extruding an elongated aluminum section having the profile of the body 62, pouring in nylon between the legs 68 to form the insert 70, and cutting the extruded section (with the contained insert) transversely into individual stabilizer elements. As best seen in FIG. 9, the gap between legs 68 is enlarged at the top (i.e. the inner surface of each leg 68 is offset outwardly in its upper portion) to assist in positively retaining the insert 70 in place.
Owing to its freedom of vertical sliding movement in the passage 76, the stabilizer element 60 is entirely self-adjusting. When the roller assembly 10 is installed in a door and a rail 22 is received in the groove of the roller 28, the element 60 simply drops (by gravity) into the position in which the surface of the nylon insert 70 engages the rail, and continues thus to rest on the rail (by virtue of its freedom to float up and down in the housing 32) regardless of any positional adjustment of the roller 28 relative to the door.
As the door is moved along the track 16, the insert surface 71 of the stabilizer element glides along and in continuous floating contact with the rail. The stabilizer simply rises or descends in the passage 76 as it passes over bumps or other irregularities of height in the rail.
In the event of high wind or other strong lateral force exerted against the door (viz. a force having a significant component in a direction transverse to the major surfaces of the door), one or the other of the stabilizer legs 68 comes into interfering engagement with a side of the track 22, thereby preventing derailment of the adjacent roller 10. Contributing to the effectiveness of the stabilizer are the rigidity and the relatively high friction characteristics of its constituent material (metal); the extended region of engagement of its upper portion 64 with the passagedefining wall portions of housing 32; and the depth of the groove 72 and the straight lower edges of the legs 68, which maximize the extent to which the legs laterally overlap the rail.
It is to be understood that the invention is not limited to the features and embodiments hereinabove specifically set forth but may be carried out in other ways without departure from its spirit.
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For slidably mounting a panel such as a door on a railed track, a roller assembly including a roller having a peripheral groove for sliding on the track rail, housing structure for mounting the roller in the panel, and a rigid metal stabilizer element carried by the housing structure and having a grooved or notched extremity for overlying the rail, in tandem relation to the roller, to prevent derailment of the roller. The stabilizer element is vertically slidable in the housing structure so as to ride smoothly along the rail, accommodating local irregularities or variations in rail height.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application, under 35 U.S.C. §120, of copending international application No. PCT/EP2011/005616, filed Nov. 9, 2011, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German patent application No. DE 20 2011 001 891, filed Jan. 25, 2011, and German patent application No. DE 10 2011 015 449, filed Mar. 30, 2011; the prior applications are herewith incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a switchgear unit for switching high DC voltages, particularly for interrupting direct current between a direct current source and an electrical device. The switchgear unit has two connections which project from a housing and which are electrically conductively coupled by a conductor path, and a mechanical contact system, arranged between the first and second connections. The switchgear unit further has two contacts which can move relative to one another and can be transferred from a closed position to an open position, and also an isolating apparatus, which can be tripped by a thermal fuse, for extinguishing an arc which is produced when the contacts are opened. In this context, a direct current source is intended to be understood to mean particularly a photovoltaic (PV) generator (solar installation), and an electrical device is intended to be understood to mean particularly an inverter.
[0003] When relatively high DC voltages up to 1,500 V (DC) are switched, the high field strengths (as a result of gas ionization) produce conductive channels in such switchgear units between the contact zones, the conductive channels being known as electrical arcs or arc plasmas. The arc produced when isolating the switching contacts needs to be extinguished as quickly as possible, since the arc releases a large amount of heat (gas temperature of several thousand degrees Kelvin) which results in severe heating of the switching contacts and of the surroundings. This severe heating can result in damage to the switchgear unit, for example burning of the switchgear unit, and also to the superordinate installation unit.
[0004] German utility model DE 20 2008 010 312 U1 discloses a PV installation or solar installation having what is known as a PV generator, which for its part comprises grouped solar modules combined to form generator elements. The solar modules are connected in series or are in parallel lanes. Whereas a generator element outputs its direct current power via two terminals, the direct current power of the entire PV generator is fed to an AC voltage system via an inverter. In order to keep down the wiring complexity and power losses between the generator elements and the central inverter in this case, what are known as generator terminal boxes are arranged close to the generator elements. The direct current power accumulated in this way is usually routed to the central inverter by a common cable.
[0005] Depending on the system, PV installations continuously deliver an operating current and an operating voltage in a range between 180 V (DC) and 1,500 V (DC). Reliable isolation of the electrical components or devices from the PV installation acting as a direct current source is desirable for installation, assembly or servicing purposes, for example, and also particularly for the general protection of persons. An appropriate isolating apparatus needs to be capable of performing interruption under load, which is to say without prior disconnection of the direct current source.
[0006] For load isolation, it is possible to use mechanical switches (switching contact). These have the advantage that when the contacts have been opened there is likewise DC isolation produced between the electrical device (inverter) and the direct current source (PV installation).
[0007] Such switchgear units are known generally from the prior art. The arcs produced when the contacts are opened under load are quickly moved to extinguishing apparatuses provided for this purpose, where the appropriate arc extinguishing takes place. The force required for this is provided by magnetic fields, what are known as blowing fields, which are typically produced by one or more permanent magnets. Special design of the contact zones and of the arc conducting piece routes the arc into appropriate extinguishing chambers, where the arc extinguishing takes place on the basis of known principles.
[0008] Such extinguishing chambers comprise arc splitter stacks, for example. The materials used for the arc splitters are usually ferromagnetic materials, since the magnetic field which accompanies the arc strives to run through the arc splitters, which exhibit better magnetic conduction, in the vicinity of a ferromagnetic material. This produces a suction effect in the direction of the arc splitters, which effect results in the arc moving toward the arrangement of the arc splitters and being split between the latter.
[0009] In simple mechanical switchgear units, numerous sources of fault arise in practice which have an adverse effect on safe switching or even render it impossible. One possible fault is the absence of an arc-extinguishing part, such as an arc splitter or a blowing magnet. In addition, incorrectly assembled parts, for example as a result of the blowing magnet being inserted with the wrong polarity, can also likewise result in the switchgear unit failing. Particularly in the case of hybrid switch systems, there are further opportunities for fault on account of missing or defective electronic parts.
[0010] In order to put the PV installation into a state which is safe for humans and the installation in the event of such instances of fault occurring, the circuit needs to be permanently isolated so that the user can identify the fault and can replace the switchgear unit. When the installation is transferred to this state, the switching housing of the appliance must not be damaged or destroyed, so that the live portions remain insulated. The transfer in such an instance of fault is affected by what is known as a failsafe element of the switchgear unit, without the need for activation measures, for example manual intervention or the like, to be taken beforehand.
[0011] Typical failsafe elements are tripped by virtue of an admissible material-dependent current density (current intensity per surface area) being exceeded. In this case, an electrical conductor is melted and the circuit is interrupted. This is a customary method of identifying and disconnecting overcurrents, as is used in safety fuses, for example. This method cannot be used in PV installations, however, since it is not possible to assume a particular current density or current level in this case. On the contrary, the tripping or fault detection needs to be effected independently of current level.
[0012] Published, non-prosecuted German patent application DE 10 2008 049 472 A1 discloses a surge arrester having at least one dissipation element, and also having a disconnection apparatus, in which it is firstly possible for the at least one dissipation element to be disconnected in a manner implementable by thermal measures. Secondly, it is possible to bring about shorting in the event of further energy-related, in particular thermal, loading. In this case, there is a thermally detachable stopping device in the path of movement of a conductor section, moved by the disconnection apparatus, between a melting location and a conductive element that forms an opposing contact. In the event of tripping and in the case of an overload, the movement of the conductor section is interrupted by the stopping device before the end position is reached. In the event of a fault in which the disconnection apparatus cannot safely interrupt the current and an arc is produced, or continues to exist, between the fixed connection of the dissipation element and the conductor section, which corresponds to an additional input of heat, the stopping action is cancelled and the moving conductor section is moved to the end position. The clearance of the short and hence the disconnection of the surge arrester from the system are undertaken in a manner which is known per se by an upstream overcurrent protection device, particularly a fuse.
[0013] A failsafe element of this kind is likewise not suitable for the application outlined above, since, in this case too, the fault detection does not take place until a particular overcurrent has been reached. An arc which is present would also arise in the electric energy range of the switchgear unit at relatively high voltages in the event of a fault.
SUMMARY OF THE INVENTION
[0014] The invention is based on the object of specifying a switchgear unit of the type cited at the outset which can switch a high DC voltage reliably and safely. In particular, the switchgear unit is intended to be suitable for performing direct current interruption between a direct current source, particularly a PV generator, and an electrical device, particularly an inverter. In addition, the switchgear unit is intended to be set up to extinguish an arc which is produced in the event of a fault and which is not automatically extinguished within the switchgear unit, without the need for activation measures, for example manual intervention or the like, to be taken beforehand.
[0015] To this end, the switchgear unit contains two connections which project from the housing and which are electrically conductively coupled by a conductor path. Arranged between the first and second connections is a mechanical contact system having two contacts which can move relative to one another and can be transferred from a closed position to an open position. An isolating apparatus which can be tripped by a thermal fuse is used for extinguishing an arc which is produced when the contacts are opened. The thermal fuse contains a melting location which is arranged in the conductor path and which is connected first to the contact system and second via a moving conductor section to the first connection.
[0016] In the event of a fault—on account of the high voltage applied between the contact areas—an arc which is not automatically extinguished can form under load when the contact system is opened. The isolating apparatus is tripped and the connection between the conductor section and the contact system at the melting location is broken when the arc has caused the melting temperature of the melting location to be reached or exceeded.
[0017] The arc produced in the event of a fault is very energy rich. In contrast to the prior art, the thermal fuse is tripped or the melting location is melted by using not the current density in the event of an overcurrent but rather the heat energy produced by the arc, which heat energy increases disproportionately in the event of a fault. This results in a failsafe for the switchgear unit, which is tripped or has a fault detected independently of current level.
[0018] The thermal fuse in the switchgear unit therefore serves as a failsafe element which is suitable particularly for use in PV installations. In addition, the backup for the switchgear unit is inexpensive to manufacture and therefore meets the requirements of economic manufacturability.
[0019] In one expedient embodiment, the melting location is, in particular, a solder point which is broken when the response temperature is reached or exceeded. The solder material used between the contact system and the conductor section may be a fusible alloy, such as an aluminum/silicon/tin alloy or other generally known low-melting-point alloys. The melting point of such alloys is usually in the range from 150° C. to 250° C. This means that during rated operation the current is carried safely without tripping the thermal fuse. Alternatively, it is conceivable for other temperature-sensitive and electrically conductive materials to be used as a melting location material, such as an electrically conductive plastic.
[0020] According to the field of application, selection of the conductive and/or insulating materials of the switchgear unit allows a corresponding variation in the response temperature and/or tripping time to be achieved. It is also conceivable for suitable dimensioning and compilation of the materials used to allow such a switchgear unit to be used for lower voltages too.
[0021] In one advantageous development, the isolating apparatus contains a prestressed spring element. The spring restoring force acts indirectly or directly on the moving conductor section in a breaking direction. If the melting location is heated inadmissibly in the event of a fault, it is melted and the switchgear unit consequently prompts a system interruption on account of the spring restoring force. In particular, the prestressed spring element therefore allows automatic system interruption without the need for an activation measure to be taken by a person in the event of a fault.
[0022] When the melting location is broken, an arc likewise forms between the contact system on the one hand and the moving conductor section on the other. On account of the spring restoring force, the conductor section is moved away from the contact system and therefore the arc or the arc plasma is artificially extended. If this arc is extinguished in this manner, the arc between the contact areas of the contact system is also extinguished. The direct current source consequently has DC isolation from the electrical device.
[0023] In one suitable embodiment, the spring element deflects the conductor section about a pivot point, which is at a distance from the melting location, when the isolating apparatus is tripped. The pivot angle covered in this case is greater than or equal to 90°, in particular. The pivoting of the conductor section artificially extends the second arc and therefore cools it further. This additional extension or cooling ensures that the distance between the contact system and the conductor section is opened as quickly and as wide as possible in order to extinguish the (second) arc produced when the conductor section is detached and also the (first) arc which is present on the contact system. In this case, the spring restoring force is chosen to be of appropriately large enough size for the conductor section to be pivoted as quickly as possible, so that damage to the switching housing by the arcs is advantageously prevented.
[0024] In one suitable embodiment, the housing of the switchgear unit has an insulating chamber which adjoins the melting location. When the isolating apparatus has been tripped, the conductor section is pushed into this insulating chamber as a result of the spring restoring force. The insulating chamber is used for the physical and hence insulating isolation of the conductor section from the contact system, which advantageously assists in extinguishing the arc.
[0025] In a similarly suitable embodiment, the isolating apparatus has an isolating element which is held in the housing so as to move and which is directed against the conductor section. The melting location is naturally sensitive to external forces acting on it. On account of the aforementioned spring restoring force of the isolating apparatus on the conductor section, the melting location is subjected to relatively intense loading. As a result of the isolating element, the restoring force can begin effectively on a relatively large contact area on the conductor section. In other words, this means that the resulting torque acting at the melting location is advantageously reduced. As a result, there is less mechanical stress applied to the melting location.
[0026] In one suitable embodiment of the invention, the isolating element also begins close to the melting location on the conductor section, as a result of which the power arm and hence the effective torque at the melting location are reduced further. This torque, or the power arm length and/or the isolating element dimensioning, can be used as an additional parameter for dimensioning the response temperature and/or the tripping time for the dropout fuse in the switchgear unit or the isolating apparatus.
[0027] In one expedient development, when the isolating apparatus has been tripped, the conductor section is covered by the isolating element so as to be at least partially insulated from the melting location, as a result of which the arc is advantageously suppressed.
[0028] In one expedient refinement of the switchgear unit, the isolating element is directed in the housing so as to move in sliding fashion and, when the isolating apparatus is tripped, is moved into the insulating chamber together with the conductor section by the spring restoring force. As a result, the conductor section is covered completely in the tripped state. When the isolating apparatus is tripped, the further arc is squeezed in between the isolating element and the insulating chamber, on account of the conductor section being pivoted. Particularly fast and safe extinguishing of the arc is ensured by virtue of it being squeezed in.
[0029] In one preferred embodiment, the spring element in this case is a compression spring which pushes the isolating element into the insulating chamber in the breaking direction. To this end, the isolating element and the insulating chamber are of geometrically complementary design, so that the arc can be squeezed into the chamber and the conductor section can be completely concealed from the contact system by the isolating element. In this case, the squeezing-in length can be expediently matched to the performance parameters of the direct current source.
[0030] In an alternative, likewise advantageous refinement of the switchgear unit, the isolating element is held in the housing so as to move in rotary fashion. When the isolating apparatus is tripped, the conductor section is pivoted by the isolating element about the pivot point, which is at a distance from the melting location. In one expedient embodiment, the spring element is a leg spring by which a pivot lever pivots the conductor section in the event of a fault.
[0031] In a simple form of the invention, the contact system contains a moving contact and a fixed contact. Arranged between the fixed contact and the melting location is an electrically conductive contact carrier which couples the fixed contact and the melting location so as to conduct heat. Instead of a moving contact and a fixed contact, two moving contacts may also be provided. In this case, the thermal capacity or the melting point of the contact carrier is higher than that of the melting location. In one expedient embodiment, the contact carrier is produced from a material which is a good conductor of heat and electricity, such as copper, so that fast and reliable tripping of the isolating apparatus is ensured. In order to support the thermal conductivity (flow of heat per cross-sectional area and temperature gradient), the contact carrier can be shaped and dimensioned accordingly, for example by virtue of a taper on the carrier.
[0032] In one suitable development, the moving contact is coupled to a rocker lever for manually operating the contact system by a trip mechanism. In one typical embodiment, the tripping mechanism, the moving contact and the fixed contact form a (mechanical) snap contact system. In the case of such snap contact, the contacts are—as a result of operation—removed from one another as quickly as possible, typically in a few milliseconds, typically by a prestressed leg spring. This normally allows a (first) arc produced to be extinguished, so that the isolating apparatus is not tripped.
[0033] In a typical embodiment of the switchgear unit, the movable conductor section is a flexible connecting element, particularly a stranded conductor, the fixed end of which is soldered nondetachably to the first connection, and the loose end of which is soldered at the melting location, preferably to the contact carrier.
[0034] In a similarly typical embodiment, the housing of the switchgear unit holds the conductor path, the mechanical contact system, the isolating apparatus and the thermal fuse. As a result, the live portions of the switchgear unit are insulated from the surroundings. In particular, this advantageously protects a person operating the switchgear unit from the high voltages and currents which are applied.
[0035] In one advantageous refinement, the housing and the isolating element are made from a thermally stable plastic material, particularly from a thermoset material. This ensures that the high level of heat generation on account of the arc does not damage or destroy the switchgear housing. As a result, the live portions continue to be insulated so as to be safe to touch in the event of a fault. In addition, it is ensured that the isolating element is not damaged or destroyed by the second arc in the region of the melting location. As a result, the isolating element can reliably isolate the switchgear unit from the system in the event of a fault.
[0036] In one suitable embodiment, the isolating element and/or the insulating chamber are made from a plastic material which degases in the event of fire, particularly from polyamide. By way of example, polycarbonate or polyoxymethylene are likewise suitable. The plastic degassing operations advantageously contribute to fast extinguishing of the (second) arc. In particular, the gases hamper ionization of the air gap in the region of the severed melting location, or help the ionization to die down faster.
[0037] The interaction with the choice of suitable plastics for housing, insulating chamber and isolating element, the shape and the material of the contact carrier and the dimensioning of the squeezing-in and also the torque acting on the melting location allow exact tripping of the isolating apparatus in the event of a fault and reliable extinguishing of the arc.
[0038] In respect of a disconnection apparatus for interrupting direct current between a direct current source and an electrical device, particularly between a PV generator and an inverter, the stated object is achieved by a live switchgear unit according to the invention.
[0039] In one expedient embodiment of the switchgear unit, the connections and the housing are, to this end, suitable and set up for a printed circuit board assembly. In the case of the preferred used of the switchgear unit, the disconnection apparatus is therefore particularly suitable for reliable and touch-safe interruption of direct current both between a PV installation and an inverter associated therewith and in connection with a fuel cell installation or an accumulator (battery), for example.
[0040] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0041] Although the invention is illustrated and described herein as embodied in a switchgear unit for switching high DC voltages, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0042] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0043] FIG. 1 is a block diagram of a switchgear unit according to the invention with a failsafe system between a PV generator and an inverter according to the invention;
[0044] FIG. 2 is a diagrammatic, sectional view of the switchgear unit in a closed switching state;
[0045] FIG. 3 is a diagrammatic, sectional view of the switchgear unit shown in FIG. 1 when a mechanical contact system is opened and when an arc is formed;
[0046] FIG. 4 is a diagrammatic, sectional view of the switchgear unit shown in FIG. 1 and in FIG. 2 after a failsafe system has been tripped;
[0047] FIG. 5 is a diagrammatic, exploded perspective view of the switchgear unit;
[0048] FIG. 6 is a detailed sectional view of the isolating apparatus;
[0049] FIG. 7 is a sectional view of details of the switchgear unit with an alternative isolating apparatus; and
[0050] FIG. 8 is a sectional view of details of the switchgear unit shown in
[0051] FIG. 6 in the tripped failsafe state.
DETAILED DESCRIPTION OF THE INVENTION
[0052] Parts and magnitudes which correspond to one another have always been provided with the same reference symbols in all figures. Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown schematically a switchgear unit 1 which, in the exemplary embodiment, is connected between a PV generator 2 and an inverter 3 . The PV generator 2 contains a number of solar modules 4 which are directed, in a situation parallel to one another, to a common generator terminal box 5 , which effectively serves as an assembly point.
[0053] In a main current path 6 representing the positive terminal, the switchgear unit 1 generally contains two subsystems for DC isolation of the PV generator 2 from the inverter 3 . The first subsystem is a manually operable mechanical contact system 7 , and the second subsystem is a failsafe system 8 which trips automatically in the event of a fault. In a return line 9 , representing the negative terminal, of the switchgear unit 1 —and hence of the overall installation—there may be further contact and failsafe systems 7 , 8 connected in a manner which is not shown in more detail.
[0054] FIGS. 2 to 6 show a variant of the switchgear unit 1 according to the invention in a detailed illustration. The switchgear unit 1 contains a housing 10 from which two connections (external connections) 11 and 12 project. The switchgear unit 1 is connected to the main current path 6 between the PV generator 2 and the inverter 3 by the connections 11 and 12 .
[0055] The contact system 7 furthermore contains a contact crossbar 15 , which can be operated manually by a rocker lever 13 and a coupling lever 14 , as a moving contact and a contact carrier 16 as a fixed contact is formed. The contacts or contact areas 17 a and 17 b between the contact crossbar 15 and the contact carrier 16 are in the form of platelet-like contact elements.
[0056] The contact crossbar 15 is electrically conductively coupled to the connection 11 by a fixed stranded conductor 18 , with both the connection between the contact crossbar 15 and the stranded conductor 18 and the connection between the stranded conductor 18 and the connection 11 being in the form of a weld joint. The contact crossbar 15 is generally hammer-shaped and made from an electrically conductive metal, the contact area 17 a being arranged at the hammer head end and resting on the contact area 17 b in a closed position of the switchgear unit 1 ( FIG. 2 ).
[0057] The contact carrier 16 is made from copper, which means that it has a high level of electrical and thermal conductivity. The contact carrier 16 has generally the shape of a step, with the contact area 17 b being arranged at the upper step edge. The step body of the contact carrier 15 has a tapered cross section in order to increase the thermal conductivity thereof. A moving stranded conductor 20 is electrically conductively coupled at the lower step edge by a solder 19 .
[0058] The stranded conductor 20 may have an electrically insulating shield 21 which has been removed at both ends of the stranded conductor. One of the conductor ends (fixed end) of the stranded conductor 20 is connected to the connection 12 nondetachably by welding, while the other conductor end (loose end) is soldered to the contact carrier 15 by the solder 19 .
[0059] In the closed position of the switchgear unit 1 , the circuit is therefore closed by virtue of the two connections 11 and 12 and the main current path 6 . The current flows through a conductor path 22 which is thus formed, containing the connection 11 , the stranded conductor 18 , the contact crossbar 15 , the contact areas 17 a and 17 b, the contact carrier 16 , the solder 19 , the stranded conductor 20 and the connection 12 . The conductor path 22 runs in an approximate U shape within the housing 10 .
[0060] The housing 10 contains an electrically insulating and heat-resistant plastic and is—as can be seen in FIG. 5 —formed from two complementary housing half-shells 10 a and 10 b. The half-shells 10 a and 10 b can be connected to one another by four holes 23 using screws or rivets (not shown further). The holes 23 are arranged in an even distribution on the housing 10 approximately at the corner points of an imaginary square.
[0061] The housing 10 has an approximately rectangular cross section, so that simple assembly of a plurality of switchgear units 1 arranged next to one another or a common printed circuit board is possible. The housing 10 has an approximately U-shaped extent, with the two U limbs being connected to one another by a horizontal portion. Projecting from this horizontal portion are the two connections 11 and 12 , and at the U base at least partially the rocker lever 13 . In addition, the half-shells 10 a and 10 b are configured to have corresponding internal profile structures into which the individual parts of the switchgear unit 1 can be inserted using the interlocking shapes or with play.
[0062] The rocker lever 13 is used not only for opening and closing the contact system 7 but also as an external visual indication of the switching state of the switchgear unit 1 , as can be seen in FIG. 4 , in which the rocker lever 13 is in the open position. When the rocker lever 13 is operated manually, an external force for toggling the switch is converted into a pivot movement for the contact crossbar 15 by an articulation system 24 .
[0063] The failsafe system 8 ensures permanent DC isolation between the PV generator 2 and the inverter 3 . The failsafe system 8 contains the contact carrier 16 , the solder 19 , the stranded conductor 20 , an isolating apparatus 27 with a spiral compression spring 28 and a slider 29 and also an insulating chamber 30 . This variant embodiment of the isolating apparatus 27 is shown in more detail in FIG. 6 .
[0064] The compression spring 28 is situated in a guide chamber 31 of the housing 10 , with a pin-like extension 32 of the guide chamber 31 being embraced at least in part by the compression spring 28 . The compression spring 28 pushes the slider 29 against the stranded conductor 20 on account of a spring restoring force F. The slider 29 has an extension which is the form of a finger 33 and which pushes directly against the stranded conductor 20 . In this case, the finger 33 begins close to the solder 19 , as a result of which the torque acting on the soldering, on account of the spring restoring force F, is as low as possible.
[0065] The guide chamber 31 and the insulating chamber 30 are at one level in a breaking direction A and are isolated from one another by the stranded conductor 20 , which runs perpendicular thereto. The guide chamber 31 and the insulating chamber 30 furthermore have the same (slider-like) cross section.
[0066] In the event of a fault, an arc 26 produced heats the contact areas 17 a and 17 b and hence also the contact carrier 16 on account of the disproportionately increasing heat generation. On account of the high thermal capacity of the contact carrier 16 , the solder 19 is heated to a comparable extent and is ultimately melted. As a result, the spring restoring force F of the compression spring 28 moves the slider 29 into the insulating chamber 30 in the breaking direction A. The slider 29 and the insulating chamber 30 are of geometrically complementary design, which means that they can be pushed into one another without difficulty. The squeezing-in length of the insulating chamber 30 expediently matches the performance parameters of the PV generator 2 in this case.
[0067] While the slider 29 is being moved into the insulating chamber 30 , the stranded conductor 20 is pivoted about a center of rotation 34 , and is ultimately bent through approximately 90° ( FIG. 4 ). When the solder 19 melts and breaks, a second arc (not shown) is formed between the contact carrier 16 and the loose end of the stranded conductor 20 , which runs approximately along the connecting line for these in the broken state. The second arc is first extended, and thereby cooled, by virtue of the slider 29 being moved and is second squeezed in between the slider 29 and the insulating chamber 30 on account of the matching shape between these, and hence extinguished. As soon as the second arc has been extinguished, the contact carrier 16 and the stranded conductor 20 are DC isolated, as a result of which the arc 26 is also simultaneously extinguished. The finger 33 promotes the breaking of the soldering and completely encapsulates or cuts off the second arc when it strikes the bottom of the insulating chamber 30 .
[0068] Both the slider 29 and the internal walls of the insulating chamber 30 may be manufactured from a degassing and electrically insulating plastic material. The heat generation in the surroundings of the second arc, particularly in the region of the isolating apparatus 27 , releases gases from these plastic materials. The gases hamper ionization of the air gap in the region of the broken solder 19 or help the ionization to die down faster. As a result, the second arc is easier for the isolating apparatus 27 to extinguish.
[0069] In the broken state ( FIG. 4 ), the conductor path 22 of the switchgear unit 1 accordingly has two DC isolation locations, namely firstly between the contact areas 17 a and 17 b and secondly between the contact carrier 16 and the loose end of the stranded conductor 20 . The materials and dimensions of the switchgear unit 1 and the isolating apparatus 27 thereof are dimensioned as appropriate in order to ensure interruption of direct current between the PV generator 2 and the inverter 3 within a few milliseconds even in the event of a fault.
[0070] A second variant embodiment of the switchgear unit 1 with an isolating apparatus 27 ′ is explained below with reference to FIG. 7 and FIG. 8 , where—as an aid to clarity—only the second half of the conductor path 22 (the contact carrier 16 , the solder 19 , the stranded conductor 20 and the connection 12 ), which is relevant to the failsafe system 8 , is shown. The isolating apparatus 27 ′ containing a prestressed leg spring 35 , an approximately hook-like pivot head or lever 36 and an insulating chamber 30 ′. The internal profile of the housing 2 is set up and shaped to correspond to the isolating apparatus 27 ′.
[0071] In this embodiment, the insulating chamber 30 ′ is essentially the lower half (starting from the top hat rail 12 ) of the housing 10 . The pivot head (pivot lever) 36 is approximately L-shaped, with both the pivot head 36 and the insulating chamber 30 ′ being manufactured from a degassing electrically insulating plastic material. The upper corner 36 a of the horizontal L-limb of the pivot head 36 begins at the litz wire 20 in a similar manner to the finger 33 in the variant described previously. Arranged at the lower end of the vertical L-limb of the pivot head 36 is the prestressed leg spring 35 . The leg spring 35 holds the pivot head 36 so as to move in pivot fashion or in rotary fashion.
[0072] When the solder 19 melts on account of the heat generation by the arc 26 , the leg spring 35 pivots the pivot head 36 on account of a spring restoring force F′. In this case, the litz wire 20 is pivoted about the center of rotation 34 ′ through an angle of approximately 90° in the direction of the lower right-hand corner of the housing 10 or of the insulating chamber 30 ′.
[0073] In contrast to the first exemplary embodiment, the arc is not squeezed in but rather is merely artificially extended, as a result of which the arc plasma can be extinguished on account of the resultant cooling. In this case, the arc is extended to a substantially greater extent in comparison with the first exemplary embodiment, since the stranded conductor 20 is not pushed in the direction of the right-hand side wall but rather is pivoted into the lower corner. The switchgear unit 1 , with the isolating apparatus 27 ′, is set up and suitable for ensuring interruption of direct current between the PV generator 2 and the inverter within a few milliseconds, both in the normal case and in the event of a fault.
[0074] When the housing size is dimensioned in suitable fashion, the horizontal contact area of the housing 10 on the top hat rail side is approximately 4 cm wide, the lateral edges of the housing are approximately 6 cm long and the housing 10 is approximately 2 cm deep. The distance between the contact areas 17 a and 17 b is approximately 1 cm in the open position, and the distance between the contact carrier 15 and the loose end of the stranded conductor 20 after the isolating apparatus 27 or 27 ′ has been tripped is at least 1.5 cm. The plastics for the housing 10 , the insulating chamber 30 / 30 ′ and the slider 29 or pivot head 35 , the shape and material of the contact carrier 16 and also the torque acting on the solder 19 are chosen such that the switchgear unit 1 has a rated voltage of approximately 1,500 V (DC).
[0075] The invention is not limited to the exemplary embodiments described above. On the contrary, it is also possible for other variants of the invention to be derived by a person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the different exemplary embodiments can, furthermore, also be combined with one another in a different way without departing from the subject matter of the invention.
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A switchgear unit switches high DC voltages, particularly for interrupting of direct current between a direct current source and an electrical device. The switchgear unit contains two connections which project from a housing and which are electrically conductively coupled by a conductor path, a contact system which is arranged between the first and second connections and an isolating apparatus that can be tripped by a thermal fuse. The thermal fuse contains a melting location which is arranged in the conductor path and which is connected first to the contact system and second via a moving conductor section to the first connection. The isolating apparatus is tripped and the connection between the conductor section and the contact system is broken at the melting location when an arc produced when the contact system is opened has caused the melting temperature of the melting location to be reached or exceeded.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally involves systems for conditioning materials during a drying operation. In particular, it relates to controlling the moisture content of clothes which are being dried in order to eliminate static electricity by preventing overdrying, while allowing adequate drying time for articles which are more difficult to dry.
2. Description of the Prior Art
A typical domestic clothes dryer uses a rotating drum to tumble clothes while exposing them to a heated stream of air. The clothes become dry by losing their moisture to the air stream. It has been difficult to determine the proper length of the drying cycle because of differences in load size and consistency. Employment of dryness sensors has been inadequate in overcoming this problem because of difficulties in sensing dryness accurately and in uniformly drying a non-homogeneous load of clothes.
In the past, the most common approach to overcoming these difficulties has been to time the drying cycle so as to assure dryness of each and every item of clothing in the load. In assuring total dryness, this procedure overdries the clothes and creates the buildup of an electrostatic charge which causes the clothes to cling to each other. There have been proposed solutions to the problem of overdrying based on preconditioning the incoming air prior to its use in the dryer. For example, conditioning the air of a dry cleaning drum in order to prevent excessive drying of goods is taught by the Fuhring U.S. Pat. No. 3,266,166.
However, heretofore known procedures have not been fully adequate in both eliminating the buildup of static electricity in clothes during a drying operation and permitting uniform drying of the clothes.
SUMMARY OF THE INVENTION
It has been discovered that, while tumbling of clothes in a dryer to an overdried state causes buildup of static electricity in the clothes, the addition of moisture to the clothes at the end of a drying cycle not only prevents the buildup of static electricity but also permits the uniform drying of all the clothes, including those that are more difficult to dry.
In accomplishing the foregoing, the present invention removes moisture from air exhausted by a clothes dryer by cooling the exhaust air and collecting the moisture in a condensate trap. After the clothes have been dried sufficiently to actuate a temperature sensor, the collected moisture is injected into the dryer drum to eliminate static electricity by increasing moisture level and permitting uniform drying of all the clothes. During moisture injection, the dryer exhaust air is recirculated through the dryer to serve as the drying air stream.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE is a schematic side elevational view of a conventional automatic clothes dryer, shown partly in section, having a preferred embodiment of the invention incorporated therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The single FIGURE shows a domestic automatic clothes dryer incorporating a preferred embodiment of the invention. Clothes dryer 10 has a conventional drying chamber 12 which tumbles clothes while they are drying in a heated stream of air. Air inlet 14 is a conduit which directs air past a conventional heating device 16 to warm the air prior to its passage through drying chamber 12. After passing through drying chamber 12, the air is directed along air exhaust 18, a conduit which contains a conventional fan 20 for powering the air flow.
A passageway 22 is provided in common wall 24 for providing communication between air inlet 14 and air exhaust 18. An air flow diverter system includes a flap valve 26 which can be positioned in two modes. In the first mode, flap valve 26 is in a horizontal position in which it blocks passageway 22 in common wall 24. This mode allows a flow pattern in which new air is drawn in through entrance 28 and in which air exhausted from drying chamber 12 leaves through exit 30.
The juxtaposition of the relatively warm air exhaust 18 and the relatively cool air inlet 14 along common wall 24 creates a heat exchanger 32 which cools and condenses the moisture in the air passing through air exhaust 18. The condensate is collected in a condensate trap 34.
A second mode of operation is commenced after a temperature sensor 36, located in the air exhaust 18, indicates that the clothes have reached a certain level of dryness. This type of sensor is conventional and works on the principle that the temperature of the air in the air exhaust is directly related to the dryness of the clothes. When the temperature in the air exhaust reaches the value which corresponds to the desired degree of dryness of the clothes, the second mode of operation begins.
In the second mode, flap valve 26 is moved to a vertical position, as shown in dotted lines, and blocks entrance 28 to air inlet 14 so that air is recirculated from air exhaust 18 through air inlet 14 to drying chamber 12. Moisture from condensate trap 34 is injected into drying chamber 12 through moisture injection tube 38 by using a conventional pump 40. Therefore, during the second mode of operation, the liquid injection raises the moisture level of the clothes to prevent electrostatic buildup and allow adequate drying time for articles of clothing which are more difficult to dry.
In operation, clothes are loaded into drying chamber 12 in a conventional way, such as through a door in the housing (not shown). The dryer is started by actuating a conventional control switch (not shown) which causes the dryer to commence its first mode of operation. Drying chamber 12 starts to spin and thereby tumble the clothes through the use of a belt drive from an electric motor (not shown). Simultaneously, heating device 16 and fan 20 are energized so that air is drawn in through entrance 28, past heating device 16 where it is heated, through the clothes in drying chamber 12 where it picks up moisture from the clothes, through air exhaust 18 and heat exchanger 32 where moisture is condensed and then collected in condensate trap 34. The air is finally expelled through exit 30. In this mode, flap valve 26 in the air flow diverter is in a horizontal position and blocks passageway 22 in common wall 24 between air inlet 14 and air exhaust 18. The clothes are quickly dried through exposure to a hot dry stream of air. This mode of operation continues until temperature sensor 36 indicates that the clothes have reached a certain level of dryness. At this point, the temperature sensor 36 automatically causes commencement of the second mode of operation.
In commencing the second mode of operation, flap valve 26 in air flow diverter 22 is automatically moved to a vertical position, as shown in the dotted lines, by a conventional valve actuator (not shown) thereby blocking entrance 28 to air inlet 14 and uncovering an opening in common wall 24 between air inlet 14 and air exhaust 18. This changes the flow path of the air in the system so that air is recirculated from air exhaust 18 through opening 22 in common wall 24 into air inlet 14 rather than exiting through exit 30 after passing through heat exchanger 32. This causes the air entering drying chamber 12 to be less dry due to the fact that recycled moist air is being used rather than the fresh drier air which was drawn through entrance 28 from outside the system in the first mode of operation.
The control system for operating flap valve 26 in the air flow diverter and moisture injector 36 is conventional in nature. It may consist of either an electronic microprocessor or an electromechanical switching arrangement.
Other arrangements for an air flow diverter may be used. They include using a double flap valve which, in the second mode of operation may be actuated to block both entrance 28 and exit 30 in establishing a recirculating air pattern.
To further increase the moisture level of the drying chamber, moisture from condensation trap 34 is injected into drying chamber 12, through moisture injection tube 38 by using a conventional pump. The increased moisture level of the clothes prevents buildup of static electricity while allowing adequate drying time for articles of clothing which are more difficult to dry. After a period of time, the second mode of operation automatically terminates and the load of clothes which are now thoroughly dry and free from electrostatic buildup may be removed from drying chamber 12.
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Buildup of static electricity and uniform drying of a clothes dryer are controlled by condensing moisture from the exiting air stream and later injecting it into a recirculating air stream before the clothes become overdried.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2013-060479 filed on Mar. 22, 2013, the entire contents of which are incorporated herein by reference.
FIELD
The embodiments discussed herein are related to a modulating device and a modulation method.
BACKGROUND
Upon receiving signals to be transmitted, conventional wireless communication devices that conduct communication with wireless signals convert, to modulation signals, signals to be transmitted received as local signals and then transmit the converted signals by using a quadrature modulation circuit to perform quadrature modulation on the local signals that become carrier waves. Modulation systems for performing quadrature modulation use quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM) and the like. However, a DC offset is produced as noise due to imperfections of the elements in the abovementioned quadrature modulation circuit and the DC offset is added to the modulation signals.
Accordingly, Japanese Laid-open Patent Publication No. 10-079693 describes a technique for calculating a DC offset of a quadrature modulation circuit, for example, by providing a feedback circuit that provides feedback by using a quadrature demodulation circuit to perform quadrature demodulation on modulation signals, and by switching inputs and non-inputs of the modulation signals to the feedback circuit. Moreover, Japanese Laid-open Patent Publication No. 2002-077285 describes a technique for calculating a DC offset of a quadrature modulation circuit by using, for example, a frequency converting circuit to convert modulation signals to IF signals and then by using an ADC to perform digital conversion to provide feedback.
SUMMARY
According to an aspect of the invention, a modulating device includes a first convertor configured to generate a converted analog signal by analog conversion on a input digital signal that is inputted to the first converter, a modulator configured to generate a modulated signal by quadrature modulation on the converted analog signal, a first phase shifter configured to generate a first phase shift signal by first phase rotation on a local signal by a phase shift quantity that changes with a period, a demodulator configured to generate a demodulated signal by quadrature demodulation on an output signal using the first phase shift signal, the output signal deriving from the modulated signal and being outputted from the modulating device, the quadrature demodulation corresponding to the quadrature modulation, a second convertor to generate a converted digital signal by digital conversion on the demodulated signal, a calculating circuit configured to estimate a the first direct current offset based on the input digital signal and the converted digital signal, the first direct current offset being a noise of digital current component generated between the input digital signal inputted to the first convertor and the output signal inputted to the demodulator, and a correcting circuit configured to correct at least one among from the input digital signal to the output signal based on the first direct current offset.
The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a baseband model for a modulating device according to an embodiment;
FIG. 2 is a block diagram of a functional configuration of the modulating device;
FIG. 3 illustrates a first embodiment of the modulating device;
FIG. 4 illustrates a correction of a signal according to the first embodiment;
FIG. 5 illustrates a second embodiment of the modulating device;
FIG. 6 illustrates a third embodiment of the modulating device;
FIG. 7 illustrates a correction of a signal according to the third embodiment;
FIG. 8 illustrates a fourth embodiment of the modulating device;
FIG. 9 illustrates a fifth embodiment of the modulating device;
FIG. 10 illustrates a correction of a signal according to the fifth embodiment;
FIG. 11 illustrates a sixth embodiment of the modulating device;
FIG. 12 illustrates a seventh embodiment of the modulating device;
FIG. 13 illustrates a correction of a signal according to the seventh embodiment; and
FIG. 14 illustrates an eighth embodiment of the modulating device.
DESCRIPTION OF EMBODIMENTS
However, in the abovementioned conventional techniques, the DC offset produced by the quadrature modulation circuit may not be detected accurately and the DC offset of the modulation signals may not be accurately compensated.
An object in one aspect of the embodiments discussed herein is to accurately compensate the DC offset of the modulation signals.
Detailed explanations of embodiments of the modulating unit and the modulation method described hereinbelow will be provided with reference to the accompanying drawings.
(Baseband Model for Modulating Device 100 According to an Embodiment)
FIG. 1 illustrates a baseband model for a modulating device 100 according to an embodiment. The modulating device 100 is a device for performing analog conversion and quadrature modulation of input digital signals and then transmitting the signals. In the example in FIG. 1 , a digital signal is, for example, a signal represented by a complex number having a real number part and an imaginary number part. The modulating device 100 performs quadrature demodulation and digital conversion of the signals to be transmitted to provide feedback.
In FIG. 1 , the modulating device 100 has, for example, a DAC and a QMOD as transmission-side circuits. The modulating device 100 has, for example, a first complex multiplier, an ADC, a QDEM, and a second complex multiplier as feedback-side circuits.
The digital to analog converter (DAC) is a circuit for performing analog conversion on signals. The quadrature modulating unit (QMOD) is a circuit for performing quadrature modulation on signals.
The first complex multiplier is a circuit for performing phase rotation of signals in phase shift quantities that change periodically. The analog to digital converter (ADC) is a circuit for performing digital conversion on signals. The quadrature demodulating unit (QDEM) is a circuit for performing quadrature demodulation on signals. The second complex multiplier is a circuit for performing phase rotation on signals in the direction opposite that of the first complex multiplier and in the same phase shift quantity as the first complex multiplier.
In FIG. 1 , a digital signal x that is to be transmitted is input into the DAC and converted to analog by the DAC in the transmission-side circuits. Next, the signal x analog-converted by the DAC is input into the QMOD and quadrature modulation is performed by the QMOD. When processed by the DAC and the QMOD, a DC offset b produced in the DAC and the QMOD is added to the signal x.
The DC offset is, for example, direct current component noise which is noise that is produced when actual circuit characteristics deviate from the ideal characteristics due to aging and production variances of circuit elements included in circuits such as the DAC, the QMOD, the QDEM, and the ADC and the like. In the following explanation, the DC offset may be referred to as a “modulating unit offset b” along with the DC offset produced by the DAC and the QDEM.
In other words, in the transmission-side circuits, the digital signal x is analog-converted as indicated by reference numeral 101 , and the modulating unit offset b is added as indicated by reference numeral 102 so that the signal x becomes modulation signal x+b, which is then transmitted and input into the feedback-side circuits.
In FIG. 1 , the modulation signal x+b in the feedback-side circuits is input into the first complex multiplier and phase-rotated by θ(t) by the first complex multiplier. In this case, θ(t) is represented, for example, by multiplying an angular speed w by a time t to produce wt. Next, the signal (x+b)×exp(jθ(t)) phase-converted by the first complex multiplier is in input into the QDEM and quadrature demodulation is performed by the QDEM. The signal (x+b)×exp(jθ(t)) quadrature-demodulated by the QDEM is input into the ADC and digitally-converted by the ADC.
When processed by the QDEM and the ADC, a DC offset c produced by the QDEM and the ADC is added to the signal (x+b)×exp(jθ(t)). In the following explanation, the DC offset may be referred to as a “demodulating unit offset c” along with the DC offset produced by the QMOD and the ADC. Next, the signal (x+b)×exp(jθ(t))+c to which was added the demodulating unit offset c, is input into the second complex multiplier and phase-rotated only θ(t)* by the second complex multiplier. Here, the * symbol indicates a conjugate.
In other words, in the feedback-side circuits, the modulation signal x+b is phase-rotated by using a signal to be phase-rotated by the θ(t) of the reference numeral 104 as indicated by reference numeral 103 . Further, the demodulating unit offset c as indicated by the reference numeral 105 is added to the modulation signal x+b and digitally-converted as indicated by the reference numeral 106 . The modulation signal x+b is phase-rotated in the opposite direction from the reference numeral 103 by using a signal to be phase-rotated by the θ(t) of the reference numeral 104 as indicated by reference numeral 107 . Consequently, the modulation signal x+b becomes the feedback signal y={(x+b)×exp(jθ(t))+c}×exp(jθ(t))*=x+b+c×exp(jθ(t))* and is fed back.
In this way, before and after the transmitted signal x+b is quadrature-demodulated, a feedback signal y=x+b+c×exp(jθ(t))* is obtained by providing feedback while performing phase rotation in the feedback-side circuits. The modulating unit offset b produced by the transmission-side circuits and the demodulating unit offset c produced by the feedback-side circuits in the feedback signal y are each elements with different frequencies.
As a result, the modulating device 100 separates the modulating unit offset b produced by the transmission-side circuits and the demodulating unit offset c produced by the feedback-side circuits on the basis of the elements with the different frequencies and is able to specify the modulating unit offset b. The modulating device 100 then sets the specified modulating unit offset b as a compensation value b′ of the modulating unit offset b and inputs the compensation value b′ into the transmission-side circuits in order to subtract the compensation value b′ from the modulation signal x+b to remove the modulating unit offset b in the transmission-side circuits. As a result, the modulating device 100 is able to erase the modulating unit offset and transmit a more accurate modulation signal.
(Example of Functional Configuration of Modulating Device 100 )
The following discusses an example of a functional configuration of the modulating device 100 with reference to FIG. 2 .
FIG. 2 is a block diagram of a functional configuration of the modulating device 100 . The modulating device 100 includes an input unit 201 , a first converting unit 202 , a modulating unit 203 , an amplifying unit 204 , an output unit 205 , a first phase shift unit 206 , a demodulating unit 207 , a second converting unit 208 , a second phase shift unit 209 , a calculating unit 210 , and a correcting unit 211 .
<Example of Transmission-Side Functions>
An example of the transmission-side functions of the modulating device 100 will be discussed first. The input unit 201 inputs digital signals. A digital signal includes, for example, two baseband signals that indicate information to be transmitted. The two baseband signals include an in-phase (I) signal for indicating a real number part of the information to be transmitted, and a quadrature-phase (Q) signal for indicating an imaginary number part of the information to be transmitted. The two baseband signals may be represented together as a “signal representing one complex number”. As a result, the first converting unit 202 is able to perform analog conversion on the signals input by the input unit 201 .
The first converting unit 202 performs analog conversion on the signals input by the input unit 201 . The first converting unit 202 uses, for example, a DAC to perform the analog conversion on the I-signal and the Q-signal input by the input unit 201 . At this time, a DC offset produced in the first converting unit 202 is added to the I-signal and Q-signal input by the input unit 201 . As a result, the modulating unit 203 is able to perform quadrature modulation on the signals having undergone analog conversion by the first converting unit 202 .
The modulating unit 203 performs quadrature modulation on the signals converted by the first converting unit 202 . The modulating unit 203 uses, for example, QMOD to perform quadrature modulation on two carrier waves that are orthogonal to each other, and produces one modulated wave for indicating the I-signal and the Q-signal converted by the first converting unit 202 . As a result, the modulating unit 203 is able to produce a modulated wave to be transmitted from an antenna.
The amplifying unit 204 amplifies the signal having undergone quadrature modulation by the modulating unit 203 . The amplifying unit 204 uses, for example, an amplifier to amplify the modulated wave having undergone quadrature modulation by the modulating unit 203 . The amplifying unit 204 is able to amplify the modulated wave to be transmitted from the antenna.
The output unit 205 outputs the signal having undergone quadrature modulation by the modulating unit 203 . The output unit 205 uses, for example, an antenna to transmit the modulated wave having undergone quadrature modulation by the modulating unit 203 . The output unit 205 may output the signal amplified by the amplifying unit 204 . The output unit 205 uses, for example, an antenna to transmit the modulated wave amplified by the amplifying unit 204 . As a result, the modulating device 100 is able to transmit the signal.
<Example of Feedback-Side Functions>
A first example of the functions of the feedback-side will be discussed next. The first phase shift unit 206 performs phase rotation on a local signal by a phase shift quantity that changes periodically. The first phase shift unit 206 uses, for example, a complex multiplier to perform the phase rotation on the local signal that becomes a carrier wave. As a result, the demodulating unit 207 is able to perform phase rotation on the modulated wave.
In this case, the demodulating unit 207 uses the local signal that has undergone phase rotation by the first phase shift unit 206 to perform quadrature demodulation on the signal having undergone quadrature modulation by the modulating unit 203 . The demodulating unit 207 uses, for example, QDEM to produce two signals that are orthogonal to each other and that have been phase-rotated by demodulating the modulated wave using the phase-rotated carrier wave. The demodulating unit 207 may perform quadrature demodulation on the signal amplified by the amplifying unit 204 . As a result, the second converting unit 208 is able to perform digital conversion on the two signals produced by the demodulating unit 207 .
The first phase shift unit 206 may perform phase rotation, by a phase shift quantity that changes periodically, on the signal having undergone quadrature modulation by the modulating unit 203 . The first phase shift unit 206 uses, for example, a complex multiplier to perform the phase rotation on the modulated wave. The first phase shift unit 206 may perform phase rotation, by the phase shift quantity that changes periodically, on the signal amplified by the amplifying unit 204 . As a result, the first phase shift unit 206 is able to perform phase rotation on the modulated wave.
In this case, the demodulating unit 207 uses the first phase shift unit 206 to perform quadrature demodulation on the signal having undergone phase rotation by the first phase shift unit 206 . The demodulating unit 207 uses, for example, QDEM to produce two signals that are orthogonal to each other by performing quadrature demodulation on the modulated wave. As a result, the second converting unit 208 is able to perform digital conversion on the two signals produced by the demodulating unit 207 .
The second converting unit 208 performs digital conversion on the signal having undergone quadrature demodulation by the demodulating unit 207 . The second converting unit 208 uses, for example, ADC to perform digital conversion on each of the two signals produced by the demodulating unit 207 . As a result, the second phase shift unit 209 is able to perform phase rotation on the signals having undergone digital conversion by the second converting unit 208 .
The second phase shift unit 209 performs phase rotation, by a phase shift quantity in a direction opposite to the direction of the phase rotation performed by the first phase shift unit 206 , on the signal converted by the second converting unit 208 . The second phase shift unit 209 uses, for example, a complex multiplier to perform phase rotation, by the same phase shift quantity as the phase shift quantity of the phase rotation performed by the first phase shift unit 206 , in the direction opposite to the direction of the phase rotation by the first phase shift unit 206 . As a result, the second phase shift unit 209 is able to change the modulating unit offset b and the demodulating unit offset c into elements having different frequencies.
The calculating unit 210 calculates an amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 , by using the signal input into the input unit 201 and the signal converted by the second converting unit 208 . The calculating unit 210 may calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 , by using the signal input into the input unit 201 and the signal having undergone phase rotation by the second phase shift unit 209 .
The calculating unit 210 may calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the phase shift units, by using the signal input into the input unit 201 and the signal converted by the second converting unit 208 . The calculating unit 210 may further calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the first phase shift unit 206 , by using the signal input into the input unit 201 and the signal having undergone phase rotation by the second phase shift unit 209 .
The calculating unit 210 obtains information indicating a relationship between, for example, the signal input by the input unit 201 , a direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 , a direct current offset produced in a signal from when the signal is input into the demodulating unit 207 until the signal is input into the calculating unit 201 , and the signal converted by the second converting unit 208 . Next, the calculating unit 210 obtains values of a signal input by the input unit 201 obtained at a plurality of points in time, and values of a signal converted by the second converting unit 208 obtained at a plurality of points in time. The calculating unit 210 uses the obtained information and the obtained values of the signals to calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 .
The calculating unit 210 may also calculate a value obtained by dividing, by periods of multiples, the results of an integration of a differential between the signal input by the input unit 201 and signal converted by the second converting unit 208 , in periods of multiples of cycles of the changes in the phase shift quantities. As a result, the calculating unit 210 calculates the amount of direct current offset produced in the signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 .
The calculating unit 210 may also calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the demodulating unit 207 , by using the signal input into the input unit 201 and the signal converted by the second converting unit 208 . Moreover, the calculating unit 210 may calculate a correction coefficient corresponding to a distortion produced in the signal in the amplifying unit 204 by using the signal input by the input unit 201 and the signal converted by the second converting unit 208 . The calculating unit 210 uses, for example, FPGA, to realize the above functions.
The correcting section 211 corrects the signal between the input unit 201 and the output unit 205 on the basis of the direct current offset amounts calculated by the calculating unit 210 . The correcting section 211 uses, for example, a subtractor to correct the signal input into the input unit 201 by subtracting the direct current offset amounts calculated by the calculating unit 210 from the signal input into the input unit 201 .
The correcting section 211 may also correct the signal between the input unit 201 and the output unit 205 on the basis of a correction coefficient and the direct current offset amounts calculated by the calculating unit 210 . The correcting section 211 uses, for example, a DPD and a subtractor to correct the signal input into the input unit 201 . As a result, the correcting section 211 is able to output a signal with high accuracy to the output unit 205 .
A second example of functions on the feedback-side will be discussed. The operations by the second converting unit 208 , the second phase shift unit 209 , and the correcting section 211 are the same as those of the first example and will be omitted from the discussion of the second example.
The first phase shift unit 206 may perform phase rotation, by a phase shift quantity that changes periodically, on the signal having undergone quadrature modulation by the modulating unit 203 . The first phase shift unit 206 uses, for example, a complex multiplier to perform the phase rotation on the modulated wave. The first phase shift unit 206 may perform phase rotation, by the phase shift quantity that changes periodically, on the signal amplified by the amplifying unit 204 . As a result, the first phase shift unit 206 is able to perform phase rotation on the modulated wave.
The demodulating unit 207 performs quadrature demodulation on the signal having undergone phase rotation by the first phase shift unit 206 . The demodulating unit 207 uses, for example, QDEM to produce two signals that are orthogonal to each other by performing quadrature demodulation on the modulated wave. As a result, the second converting unit 208 is able to perform digital conversion on the two signals produced by the demodulating unit 207 .
The calculating unit 210 uses the information indicating a relationship between the signal input by the input unit 201 , the direct current offset produced in the signal from when the signal is input into the input unit 201 until the signal is input into the first phase shift unit 206 , the direct current offset produced in the signal from when the signal is input into the first phase shift unit 206 until the signal is input into the calculating unit 210 , and the signal converted by the second converting unit 208 , and the calculating unit 210 also uses the values of the signal input by the input unit 201 obtained at the plurality of points in time, and the values of the signal converted by the second converting unit 208 obtained at the plurality of points in time, to calculate the direct current offset amount produced in the signal from when the signal is input into the input unit 201 until the signal is input into the first phase shift unit 206 .
The calculating unit 210 may also calculate the amount of direct current offset produced in the signal from when the signal is input into the input unit 201 until the signal is input into the first phase shift unit 206 by calculating the value obtained by dividing, by periods of multiples, the results of the integration of the differential between the signal input by the input unit 201 and signal converted by the second converting unit 208 , in periods of multiples of cycles of the changes in the phase shift quantities.
The calculating unit 210 may further calculate the amount of direct current offset produced in a signal from when the signal is input into the input unit 201 until the signal is input into the first phase shift unit 206 and the correction coefficient corresponding to the distortion produced in the signals in the amplifying unit 204 , by using the signal input into the input unit 201 and the signal having undergone phase rotation by the second phase shift unit 209 .
First Embodiment of Modulating Device 100
FIG. 3 illustrates a first embodiment of the modulating device 100 . As illustrated in FIG. 3 , the modulating device 100 has two subtractors 301 , a DAC 302 , a QMOD 303 , a first oscillator 304 , an amplifier 305 , an analog EPS 306 , a second oscillator 307 , a QDEM 308 , an ADC 309 , a digital EPS 310 , and a DC offset detecting unit 311 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and will be omitted.
The two subtractors 301 are two-input one-output circuits that output, as an output signal, a subtraction result of the subtraction of one of the input signals from the other. In the example in FIG. 3 , a signal line for inputting an I-signal that is a digital signal to be transmitted, a signal line for inputting a signal for correcting the I-signal from the DC offset detecting unit 311 , and a signal line for outputting the signal to the DAC 302 , are connected to one of the subtractors 301 . Moreover, a signal line for inputting a Q-signal that is a digital signal to be transmitted, a signal line for inputting a signal for correcting the Q-signal from the DC offset detecting unit 311 , and a signal line for outputting the signal to the DAC 302 , are connected to the other one of the subtractors 301 . In FIG. 3 , the subtractors 301 subtract a compensation value b′ of the modulating unit offset b input from the DC offset detecting unit 311 , from an input I-signal x to be transmitted, and output the subtraction result u=x−b′ to the DAC 302 .
The DAC 302 is a two-input two-output circuit that performs analog conversion on the two digital signals that are input signals and outputs the analog-converted signals as two output signals. In the example in FIG. 3 , signal lines for inputting the two digital signals from the subtractors 301 , and signal lines for outputting the two signals to the QMOD 303 are connected to the DAC 302 . In FIG. 3 , the DAC 302 performs analog conversion on input digital signals u and outputs the analog-converted signals to the QMOD 303 . The analog-converted signals may be referred to by “u” in the same way as the digital signals in the following explanation.
The QMOD 303 is a three-input one-output circuit that uses a local signal that is the remaining input signal to perform quadrature modulation on the analog signals that are the two input signals, and outputs the quadrature-modulated signal as an output signal. In the example in FIG. 3 , two signal lines for inputting the two analog signals from the DAC 302 , a signal line for inputting the local signal from the first oscillator 304 , and a signal line for outputting the signal to the amplifier 305 , are connected to the QMOD 303 . In FIG. 3 , the QMOD 303 uses the local signal from the first oscillator 304 to perform quadrature modulation on the input signal u, and outputs the quadrature-modulated signal to the amplifier 305 . The modulating unit offset b is added to the signal u by passing through the DAC 302 and the QMOD 303 , to become the signal u+b.
The first oscillator 304 is a one-output circuit that outputs a local signal as an output signal. In the example in FIG. 3 , a signal line for outputting the local signal to the QMOD 303 , and a signal line for outputting the local signal to the analog EPS 306 , are connected to the first oscillator 304 . In FIG. 3 , the first oscillator 304 branches one output of the local signal to output the local signal to the QMOD 303 and to the analog EPS 306 .
The amplifier 305 is a one-input one-output circuit that amplifies an analog signal that is an input signal and outputs the amplified signal as an output signal. In the example in FIG. 3 , a signal line for inputting the analog signal from the first oscillator 304 , a signal line for outputting the signal to the QDEM 308 , and a signal line for outputting the signal to the antenna, are connected to the amplifier 305 . In FIG. 3 , the amplifier 305 outputs, to the antenna and to the QDEM 308 by branching, a one-output signal that is a quadrature-modulated signal that has been amplified. For simplification at this time, the amplifier 305 amplifies the signal by one.
The analog EPS 306 is a two-input one-output circuit that performs phase rotation on a local signal that is one of the input signals by using a signal that is phase-rotated by a phase shift quantity that changes periodically and that is the other input signal, and outputs the phase-rotated signal as an output signal. In the following discussion, a signal that is phase-rotated by a phase shift quantity that changes periodically may be referred to as a “phase shift signal”. In the example in FIG. 3 , a signal line for inputting the local signal from the first oscillator 304 , a signal line for inputting the phase shift signal from the second oscillator 307 , and a signal line for outputting the signal to the QDEM 308 are connected to the analog EPS 306 . In FIG. 3 , the analog EPS 306 uses the phase shift signal to perform phase rotation on the local signal from the first oscillator 304 , and outputs the phase-rotated signal to the QDEM 308 .
The second oscillator 307 is a one-output circuit that outputs the phase shift signal as an output signal. In the example in FIG. 3 , a signal line for outputting the phase shift signal to the analog EPS 306 and a signal line for outputting the phase shift signal to the digital EPS 310 are connected to the second oscillator 307 . In FIG. 3 , the second oscillator 307 outputs by branching one output phase shift signal to the analog EPS 306 and one output phase shift to the digital EPS 310 .
The QDEM 308 is a two-input two-output circuit that uses the local signal that is phase-rotated by the phase shift signal that is one of the input signals to perform quadrature demodulation on an analog signal that is the other of the input signals, and outputs the quadrature-demodulated signal as an output signal. In the example in FIG. 3 , a signal line for inputting the signal from the amplifier 305 , a signal line for inputting the signal from the analog EPS 306 , and a signal line for outputting the signal to the ADC 309 are connected to the QDEM 308 . In FIG. 3 , the QDEM 308 uses the signals from the analog EPS 306 to perform quadrature demodulation on the analog signal from the amplifier 305 , and outputs the signal (u+b)*EXP(jwt) to the ADC 309 .
The ADC 309 is a two-input two-output circuit that performs digital conversion on the two analog signals that are input signals and outputs the digital-converted signals as two output signals. In the example in FIG. 3 , a signal line for inputting the two signals from the QDEM 308 and a signal line for outputting the signals to the digital EPS 310 are connected to the ADC 309 . In FIG. 3 , the ADC 309 performs digital conversion on the signal (u+b)*EXP(jwt) input from the QDEM 308 , and outputs the digitally converted signal to the digital EPS 310 . The demodulating unit offset c is added to the signal (u+b)*EXP(jwt) that passes through the QDEM 308 and the ADC 309 to become the signal (u+b)*EXP(jwt)+c.
The digital EPS 310 is a three-input two-output circuit that uses the phase shift signal that is the remaining input signal to perform phase rotation on the two signals that are the input signals, and outputs the phase-rotated signal as an output signal. In the example in FIG. 3 , a signal line for inputting the two signals from the ADC 309 , a signal line for inputting the phase shift signal from the second oscillator 307 , and a signal line for outputting the signal to the DC offset detecting unit 311 , are connected to the digital EPS 310 . In FIG. 3 , the digital EPS 310 uses the phase shift signal from the second oscillator 307 to perform phase rotation, by a phase shift quantity that is the same as that of the phase rotation performed by the analog EPS 306 , on the two input signals in a direction opposite the direction of the phase rotation by the analog EPS 306 . The digital EPS 310 outputs the phase-rotated signal (u+b)+c*EXP(jwt)* to the DC offset detecting unit 311 as the feedback signal y.
The DC offset detecting unit 311 is a four-input two-output circuit that uses two feedback signals that are input signals and two digital signals to be transmitted that are input signals, to output the compensation value b′ signal of the modulating unit offset b. In the example in FIG. 3 , a signal line for inputting the two feedback signals from the digital EPS 310 , a signal line for inputting the two digital signals that are to be transmitted, and a signal line for outputting the signal to the subtractor 301 are connected to the DC offset detecting unit 311 . In FIG. 3 , the DC offset detecting unit 311 produces the compensation value b′ signal of the modulating unit offset b for correcting the two digital signals to be transmitted and outputs the compensation value b′ signal to the two subtractors 310 as described below with reference to FIG. 4 .
As a result, the signal input to the amplifier 305 becomes the signal u+b=u−b′+b≈u due to the DC offset detecting unit 311 inputting the compensation value b′ that becomes the same value as the modulating unit offset b into the subtractors 301 . Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 305 and transmit a signal with high accuracy.
(Correction of Signals in First Embodiment)
FIG. 4 illustrates a correction of a signal according to the seventh embodiment. FIG. 4 illustrates the flow of a signal xi until the signal x i becomes a feedback signal y i in the circuit illustrated in FIG. 3 .
In the circuit illustrated in FIG. 3 , the compensation value b′ of the modulating unit offset b as indicated by reference numeral 401 is subtracted from the signal x i , and the modulating unit offset b as indicated by the reference numeral 402 is added to the signal x i . Further, the signal x i is phase-rotated, as indicated by reference numeral 403 , using the phase shift signal indicated by reference numeral 404 , and the demodulating unit offset c is added to the signal x i as indicated by reference numeral 405 . Further, as indicated by reference numeral 406 , the signal x i is phase-rotated in the direction opposite to that of the phase rotation indicated by reference numeral 403 , using the phase shift signal indicated by reference numeral 404 .
As a result, the signal x i is fed back as the feedback signal y i . In this case, the signal becomes u i =x i −b′. Therefore, an error ε i between the feedback signal y i theoretically calculated from the signal u i and the actually measured feedback signal y i in the circuit illustrated in FIG. 3 is expressed by the following equation (1). Here, 1 to n are natural numbers. “a” is a coefficient for indicating the level of amplification of the signal u i performed by the amplifier 305 . “b” indicates the modulating unit offset. “c” indicates the demodulating unit offset. “e −jwt ” indicates the phase rotation.
au i +b+c×e −jwt −y i =ε i (1)
The DC offset detecting unit 311 produces the signal for the compensation value b′ of the modulating unit offset b by using the signal x i in a period I of one cycle of e −jwt and the feedback signal y i to apply the least-squares method in the above equation (1). In this case, the DC offset detecting unit 311 applies the least-squares method in the above equation (1) to calculate the coefficient “a”, the coefficient “b”, and the coefficient “c” when the error ε i in the following equation (2) is the smallest.
∑
i
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(
2
)
The error ε i in the above equation (2) becomes the smallest when the following equations (3) to (5) that are equations differentiated from the above equation (2) become 0.
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The following equation (6) is obtained when the above equations (3) to (5) are expressed as a matrix.
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The following equation (7) is obtained when the above equation (6) is transformed.
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(
7
)
In this case, the DC offset detecting unit 311 calculates the modulating unit offset b by substituting the signal u i calculated from the digital signal x i that is to be transmitted in a period I of one cycle, and the feedback signal y i in a period I of one cycle, into the above equation (7). The DC offset detecting unit 311 then outputs the calculated modulating unit offset b as the compensation value b′ of the modulating unit offset b to the subtractors 301 .
The DC offset detecting unit 311 may output, as the compensation value b′, a value obtained by dividing the modulating unit offset b by the level of amplification a of the amplifier 305 when the calculated modulating unit offset b is a value amplified by the amplifier 305 .
The error ε i between the feedback signal y i theoretically calculated from the signal u i and the actually measured feedback signal y i in the circuit illustrated in FIG. 3 is expressed by the following equation (8). Therefore, the DC offset detecting unit 311 may calculate the modulating unit offset b by using an integral operator using the signal u i calculated from the signal x i in the period I of one cycle of e −jwt , and the feedback signal y i in the period I of one cycle.
ax+b+c×e −jwt −y=ε (8)
The following equation (9) is obtained when the above equation (8) is integrated.
∑
j
=
1
1
(
a
x
j
+
b
+
c
×
ⅇ
-
j
w
t
-
y
j
)
=
∑
j
=
1
1
ɛ
j
(
9
)
The following equation (10) is obtained when the above equation (9) is expanded.
a
∑
j
=
1
1
(
x
j
)
+
1
b
-
∑
j
=
1
1
(
y
j
)
=
∑
j
=
1
1
ɛ
j
(
10
)
The following equation (14) is obtained when the following equations (11) to (13) are used to transpose the above equation (10).
a
∑
j
=
1
I
(
x
j
)
=
X
(
11
)
∑
j
=
1
I
(
y
j
)
=
X
(
12
)
∑
j
=
1
I
ɛ
j
=
E
(
13
)
aX
i
+
1
b
-
Y
i
=
E
i
(
14
)
In this case, the DC offset detecting unit 311 applies the least-squares method in the above equation (14) to calculate the coefficient “a” and the coefficient “b” when an error E i in the following equation (15) is the smallest.
∑
i
=
1
n
[
(
aX
i
+
1
b
-
Y
)
(
aX
i
+
1
b
-
Y
)
*
]
=
∑
i
=
1
n
E
i
2
(
15
)
The error in the above equation (15) becomes the smallest when the following equations (16) and (17) that are equations differentiated from the above equation (15) become 0.
∑
i
=
1
n
[
X
i
*
(
aX
i
+
1
b
-
Y
i
)
]
=
0
(
16
)
∑
i
=
1
n
[
1
(
aX
i
+
1
b
-
Y
i
)
]
=
0
(
17
)
The following equation (18) is obtained when the above equations (16) and (17) are expressed as a matrix.
[
∑
i
=
1
n
X
i
2
n
1
1
∑
i
=
1
n
X
i
n
1
]
[
a
b
]
=
[
∑
i
=
1
n
Y
i
X
i
*
1
∑
i
=
1
n
Y
i
*
]
(
18
)
The following equation (19) is obtained when the above equation (18) is transformed.
[
a
b
]
=
[
∑
i
=
1
n
X
i
2
n
1
1
∑
i
=
1
n
X
i
n
1
]
-
1
[
∑
i
=
1
n
Y
i
X
i
*
1
∑
i
=
1
n
Y
i
*
]
(
19
)
In this case, the DC offset detecting unit 311 calculates the modulating unit offset b by substituting the digital signal u i to be transmitted and the input feedback signal y i , into the above equation (19). The DC offset detecting unit 311 then outputs the calculated modulating unit offset b as the compensation value b′ of the modulating unit offset b to the subtractors 301 .
Second Embodiment of Modulating Device 100
FIG. 5 illustrates a second embodiment of the modulating device 100 . As illustrated in FIG. 5 , the modulating device 100 has two subtractors 501 , a DAC 502 , a QMOD 503 , a first oscillator 504 , an amplifier 505 , an analog EPS 506 , a second oscillator 507 , a QDEM 508 , an ADC 509 , a digital EPS 510 , and a DC offset detecting unit 511 in the same way as illustrated in FIG. 3 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and will be omitted.
The two subtractors 501 are circuits that are similar to the two subtractors 301 illustrated in FIG. 3 and thus an explanation will be omitted. The DAC 502 is a circuit similar to the DAC 302 illustrated in FIG. 3 and thus an explanation will be omitted. The QMOD 503 is a circuit similar to the QMOD 303 illustrated in FIG. 3 and thus an explanation will be omitted. The modulating unit offset b is added to the signal u by passing through the DAC 502 and the QMOD 503 , to become the signal u+b.
The first oscillator 504 is a one-output circuit that outputs a local signal as an output signal. In the example illustrated in FIG. 5 , a signal line for outputting the local signal to the QMOD 503 and a signal line for outputting the local signal to the QDEM 508 are connected to the first oscillator 504 . In FIG. 5 , the first oscillator 504 branches the one output of the local signal to the QMOD 503 and to the QDEM 508 .
The amplifier 505 is a one-input one-output circuit that amplifies the analog signal that is the input signal and outputs the amplified signal as an output signal. In the example in FIG. 5 , a signal line for inputting the analog signal from the first oscillator 504 , a signal line for outputting the signal to the analog EPS 506 , and a signal line for outputting the signal to the antenna, are connected to the amplifier 505 . In FIG. 5 , the amplifier 505 outputs, to the antenna and to the analog EPS 506 by branching, the one-output signal that is the quadrature-modulated signal that has been amplified.
The analog EPS 506 is a two-input one-output circuit that performs phase rotation on the signal from the amplifier 505 that is one of the input signals by using the phase shift signal from the second oscillator 507 that is the other input signal, and outputs the phase-rotated signal as an output signal. In the example illustrated in FIG. 5 , a signal line for inputting the signal from the amplifier 505 , a signal line for inputting the phase shift signal from the second oscillator 507 , and a signal line for outputting the signal to the QDEM 508 are connected to the analog EPS 506 . In FIG. 5 , the analog EPS 506 uses the phase shift signal to perform phase rotation on the signal from the amplifier 505 , and outputs the phase-rotated signal to the QDEM 508 . The second oscillator 507 is a circuit similar to the second oscillator 307 illustrated in FIG. 3 and thus an explanation will be omitted.
The QDEM 508 is a two-input two-output circuit that uses the local signal that is one of the input signals to perform quadrature demodulation on the analog signal that is the other of the input signals, and outputs the quadrature-demodulated signal as an output signal. In the example in FIG. 5 , a signal line for inputting the signal from the analog EPS 506 , a signal line for inputting the local signal from the first oscillator 504 , and a signal line for outputting the signal to the ADC 509 , are connected to the QDEM 508 . In FIG. 5 , the QDEM 508 uses the local signal from the first oscillator 504 to perform quadrature demodulation on the analog signal from the analog EPS 506 to output the signal (u+b)*EXP(jwt) to the ADC 509 .
The ADC 509 is a circuit similar to the ADC 309 illustrated in FIG. 3 and thus an explanation will be omitted. The demodulating unit offset c is added to the signal (u+b)*EXP(jwt) that passes through the QDEM 508 and the ADC 509 to become the signal (u+b)*EXP(jwt)+c. The digital EPS 510 is a circuit similar to the digital EPS 310 illustrated in FIG. 3 and thus an explanation will be omitted. The DC offset detecting unit 511 is a circuit similar to the DC offset detecting unit 311 illustrated in FIG. 3 and thus an explanation will be omitted.
As a result, the signal input into the amplifier 505 due to the DC offset detecting unit 511 inputting the compensation value b′ that is the same value as the modulating unit offset b into the subtractors 501 , becomes the signal u+b=u−b′+b≈u. Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 505 and is able to transmit a signal with high accuracy.
(Correction of Signals in Second Embodiment)
In the circuits illustrated in FIG. 5 , the compensation value b′ of the modulating unit offset b is subtracted from the signal x i , the modulating unit offset b is added to the signal x i and then the signal x i is phase-rotated in the same way as illustrated in FIG. 4 . The demodulating unit offset c is then added to the signal x i and the signal x i is phase-rotated in the opposite direction to be then fed back as the feedback signal y i . Therefore, the DC offset detecting unit 511 in the circuits illustrated in FIG. 5 calculates the modulating unit offset b and outputs the modulating unit offset b to the subtractors 501 as the compensation value b′ of the modulating unit offset b in the same way as illustrated in FIG. 4 .
Third Embodiment of Modulating Device 100
FIG. 6 illustrates a third embodiment of the modulating device 100 . The third embodiment is a modified example of the first embodiment.
As illustrated in FIG. 6 , the modulating device 100 has two subtractors 601 , a DAC 602 , a QMOD 603 , a first oscillator 604 , an amplifier 605 , an analog EPS 606 , a second oscillator 607 , a QDEM 608 , an ADC 609 , a digital EPS 610 , and a DC offset detecting unit 611 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and will be omitted.
The two subtractors 601 are two-input one-output circuits that output, as an output signal, a subtraction result of the subtraction of one of the input signals from the other. In the example in FIG. 6 , a signal line for inputting the digital I-signal to be transmitted and a signal line for inputting the signal for correcting the I-signal from the DC offset detecting unit 611 are connected to one of the subtractors 601 . A signal line for outputting a signal to the DAC 602 and to the DC offset detecting unit 611 is connected to the other subtractor 601 .
A signal line for inputting the Q-signal that is the digital signal to be transmitted and a signal line for inputting the signal for correcting the Q-signal from the DC offset detecting unit 611 are connected to the other subtractor 601 . A signal line for outputting the signal to the DAC 602 and to the DC offset detecting unit 611 is connected to the other subtractor 601 . In FIG. 6 , the subtractors 601 subtract the compensation value b′ of the modulating unit offset b input from the DC offset detecting unit 611 , from the input I-signal x to be transmitted, and branch and output the subtraction result u=x−b′ to the DAC 602 and to the DC offset detecting unit 611 .
The DAC 602 is a circuit similar to the DAC 302 illustrated in FIG. 3 and thus an explanation will be omitted. The QMOD 603 is a circuit similar to the QMOD 303 illustrated in FIG. 3 and thus an explanation will be omitted. The first oscillator 604 is a circuit similar to the first oscillator 304 illustrated in FIG. 3 and thus an explanation will be omitted. The amplifier 605 is a circuit similar to the amplifier 305 illustrated in FIG. 3 and thus an explanation will be omitted. The analog EPS 606 is a circuit similar to the analog EPS 306 illustrated in FIG. 3 and thus an explanation will be omitted.
The second oscillator 607 is a circuit similar to the second oscillator 307 illustrated in FIG. 3 and thus an explanation will be omitted. The QDEM 608 is a circuit similar to the QDEM 308 illustrated in FIG. 3 and thus an explanation will be omitted. The ADC 609 is a circuit similar to the ADC 309 illustrated in FIG. 3 , and thus an explanation will be omitted. The digital EPS 610 is a circuit similar to the digital EPS 310 illustrated in FIG. 3 and thus an explanation will be omitted.
The DC offset detecting unit 611 is a four-input two-output circuit that uses two feedback signals that are input signals from the digital EPS 610 and two signals from the subtractors 601 that are input signals, to output the compensation value b′ signal of the modulating unit offset b. In the example in FIG. 6 , a signal line for inputting the two feedback signals from the digital EPS 610 , a signal line for inputting the two signals from the subtractors 601 , and a signal line for outputting the signals to the subtractors 601 are connected to the DC offset detecting unit 611 . In FIG. 6 , the DC offset detecting unit 611 produces the compensation value b′ signal of the modulating unit offset b for correcting the two signals to be transmitted and outputs the compensation value b′ signal to the two subtractors 601 as described below with reference to FIG. 7 .
As a result, the signal input to the amplifier 605 becomes the signal u+b=u−b′+b≈u due to the DC offset detecting unit 611 inputting the compensation value b′ that becomes the same value as the modulating unit offset b into the subtractors 601 . Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 605 and is able to transmit a signal with high accuracy.
(Correction of Signals in Third Embodiment)
FIG. 7 illustrates the correction of a signal according to the third embodiment. FIG. 7 follows a direction reverse to the flow of the signal and illustrates a flow of the feedback signal y i being returned to the signal x i in the circuits in FIG. 6 .
In the circuits in FIG. 6 , the feedback signal y i is phase-rotated, as indicated by the reference numeral 701 , by using the phase shift signal indicated by the reference numeral 702 , and the demodulating unit offset c is subtracted from the feedback signal y i as indicated by the reference numeral 703 . Further, as indicated by reference numeral 704 , the feedback signal y i is phase-rotated in the direction opposite to that of the phase rotation indicated by reference numeral 701 , using the phase shift signal indicated by reference numeral 702 , and the modulating unit offset b is subtracted as indicated by the reference numeral 705 . As a result, the feedback signal y i is returned to the signal u i . Therefore, in the circuits illustrated in FIG. 6 , an error ε i between the signal u i theoretically calculated from the feedback signal y i and the actually measured signal u i is expressed by the following equation (20).
ay i +b+c×e −jwt −u i =ε i (20)
The DC offset detecting unit 611 produces the signal for the compensation value b′ of the modulating unit offset b by using the signal x i and the feedback signal y i in a period I of one cycle of e −jwt to apply the least-squares method in the above equation (20). In this case, the DC offset detecting unit 611 applies the least-squares method in the above equation (20) to calculate the coefficient “a”, the coefficient “b”, and the coefficient “c” when the error ε i in the following equation (21) is the smallest.
∑
i
=
1
n
[
(
ay
i
+
b
+
c
×
ⅇ
j
wt
-
u
i
)
(
ay
i
+
b
+
c
×
ⅇ
j
wt
-
u
i
)
*
]
=
∑
i
=
1
n
ɛ
i
2
(
21
)
The error ε i in the above equation (21) becomes the smallest when the following equations (22) to (24) that are equations differentiated from the above equation (21) become 0.
∑
i
=
1
n
[
y
i
*
(
ay
i
+
b
+
c
×
ⅇ
j
wt
-
u
i
)
]
=
0
(
22
)
∑
i
=
1
n
[
(
ay
i
+
b
+
c
×
ⅇ
j
wt
-
u
i
)
]
=
0
(
23
)
∑
i
=
1
n
[
ⅇ
-
j
wt
(
ay
i
+
b
+
c
×
ⅇ
j
wt
-
u
i
)
]
=
0
(
24
)
The following equation (25) is obtained when the above equations (22) to (24) are expressed as a matrix.
[
∑
i
=
1
n
y
i
2
∑
i
=
1
n
y
i
*
∑
i
=
1
n
y
i
*
ⅇ
j
wt
∑
i
=
1
n
y
i
n
∑
i
=
1
n
ⅇ
j
wt
∑
i
=
1
n
y
i
ⅇ
-
j
wt
∑
i
=
1
n
ⅇ
-
j
wt
n
]
[
a
b
c
]
=
[
∑
i
=
1
n
u
i
y
i
*
∑
i
=
1
n
u
i
∑
i
=
1
n
u
i
ⅇ
-
j
wt
]
(
25
)
The following equation (26) is obtained when the above equation (25) is transformed.
[
a
b
c
]
=
[
∑
i
=
1
n
y
i
2
∑
i
=
1
n
y
i
*
∑
i
=
1
n
y
i
*
ⅇ
j
wt
∑
i
=
1
n
y
i
n
∑
i
=
1
n
ⅇ
j
wt
∑
i
=
1
n
y
i
ⅇ
-
j
wt
∑
i
=
1
n
ⅇ
-
j
wt
n
]
-
1
[
∑
i
=
1
n
u
i
y
i
*
∑
i
=
1
n
u
i
∑
i
=
1
n
u
i
ⅇ
-
j
wt
]
(
26
)
In this case, the DC offset detecting unit 611 calculates the modulating unit offset b by substituting the digital signal u i in a period I of one cycle, and the feedback signal y i in a period I of one cycle, into the above equation (26). The DC offset detecting unit 611 then outputs the calculated modulating unit offset b as the compensation value b′ of the modulating unit offset b to the subtractors 601 .
Fourth Embodiment of Modulating Device 100
FIG. 8 illustrates a fourth embodiment of the modulating device 100 . The fourth embodiment is a modified example of the second embodiment.
As illustrated in FIG. 8 , the modulating device 100 has two subtractors 801 , a DAC 802 , a QMOD 803 , a first oscillator 804 , an amplifier 805 , an analog EPS 806 , a second oscillator 807 , a QDEM 808 , an ADC 809 , a digital EPS 810 , and a DC offset detecting unit 811 , in the same way as FIG. 5 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and thus an explanation will be omitted.
The two subtractors 801 are two-input one-output circuits that output, as an output signal, a subtraction result of the subtraction of one of the input signals from the other. In the example in FIG. 8 , a signal line for inputting a digital I-signal to be transmitted and a signal line for inputting a signal for correcting the I-signal from the DC offset detecting unit 811 are connected to one of the subtractors 801 . A signal line for outputting the signal to the DAC 802 and to the DC offset detecting unit 811 is connected to one of the subtractors 801 .
A signal line for inputting a Q-signal that is a digital signal to be transmitted and a signal line for inputting a signal for correcting the Q-signal from the DC offset detecting unit 811 are connected to the other subtractor 801 . A signal line for outputting the signal to the DAC 802 and to the DC offset detecting unit 811 is connected to the other subtractor 801 . In FIG. 8 , the subtractors 801 subtract the compensation value b′ of the modulating unit offset b input from the DC offset detecting unit 811 , from the input I-signal x that is to be transmitted, and output by branching one output of the subtraction result u=x-b′ to the DAC 802 and to the DC offset detecting unit 811 .
The DAC 802 is a circuit similar to the DAC 502 illustrated in FIG. 5 and thus an explanation will be omitted. The QMOD 803 is a circuit similar to the QMOD 503 illustrated in FIG. 5 and thus an explanation will be omitted. The first oscillator 804 is a circuit similar to the first oscillator 504 illustrated in FIG. 5 and thus an explanation will be omitted. The amplifier 805 is a circuit similar to the amplifier 805 illustrated in FIG. 5 and thus an explanation will be omitted. The analog EPS 806 is a circuit similar to the analog EPS 506 illustrated in FIG. 5 , and thus an explanation will be omitted.
The second oscillator 807 is a circuit similar to the second oscillator 507 illustrated in FIG. 5 and thus an explanation will be omitted. The QDEM 808 is a circuit similar to the QDEM 508 illustrated in FIG. 5 and thus an explanation will be omitted. The ADC 809 is a circuit similar to the ADC 509 illustrated in FIG. 5 and thus an explanation will be omitted. The digital EPS 810 is a circuit similar to the digital EPS 510 illustrated in FIG. 5 and thus an explanation will be omitted. The DC offset detecting unit 811 is a circuit similar to the DC offset detecting unit 611 illustrated in FIG. 6 and thus an explanation will be omitted.
As a result, the signal input to the amplifier 805 becomes the signal u+b=u−b′+b≈u due to the DC offset detecting unit 811 inputting the compensation value b′ that becomes the same value as the modulating unit offset b into the subtractors 801 . Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 805 and is able to transmit a signal with high accuracy.
(Correction of Signals in Fourth Embodiment)
In the circuits illustrated in FIG. 8 , the feedback signal y i is phase-rotated and the demodulating unit offset c is added to the feedback signal y i in the same way as illustrated in FIG. 7 . The feedback signal y i is then phase-rotated in the opposite direction and the modulating unit offset b is added to the feedback signal y i to be returned to the signal u i . Therefore, the DC offset detecting unit 811 in the circuits illustrated in FIG. 8 calculates the modulating unit offset b and outputs the modulating unit offset b to the subtractors 801 as the compensation value b′ of the modulating unit offset b in the same way as illustrated in FIG. 7 .
Fifth Embodiment of Modulating Device 100
FIG. 9 illustrates a fifth embodiment of the modulating device 100 . The fifth embodiment is a modified example of the first embodiment.
As illustrated in FIG. 9 , the modulating device 100 has two subtractors 901 , a DAC 902 , a QMOD 903 , a first oscillator 904 , an amplifier 905 , an analog EPS 906 , a second oscillator 907 , a QDEM 908 , an ADC 909 , a digital EPS 910 , and a DC offset detecting unit 911 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and thus an explanation will be omitted.
The two subtractors 901 are circuits that are similar to the two subtractors 301 illustrated in FIG. 3 and thus an explanation will be omitted. The DAC 902 is a circuit similar to the DAC 302 illustrated in FIG. 3 and thus an explanation will be omitted. The QMOD 903 is a circuit similar to the QMOD 303 illustrated in FIG. 3 and thus an explanation will be omitted. The first oscillator 904 is a circuit similar to the first oscillator 304 illustrated in FIG. 3 and thus an explanation will be omitted. The amplifier 905 is a circuit similar to the amplifier 305 illustrated in FIG. 3 and thus an explanation will be omitted. The analog EPS 906 is a circuit similar to the analog EPS 306 illustrated in FIG. 3 and thus an explanation will be omitted.
The second oscillator 907 is a circuit similar to the second oscillator 307 illustrated in FIG. 3 and thus an explanation will be omitted. The QDEM 908 is a circuit similar to the QDEM 308 illustrated in FIG. 3 and thus an explanation will be omitted. The ADC 909 is a circuit similar to the ADC 309 illustrated in FIG. 3 , and thus an explanation will be omitted.
The DC offset detecting unit 911 is a four-input two-output circuit that uses two signals that are input signals from the ADC 909 and two signals that are input signals from the digital EPS 910 , to output the compensation value b′ signal of the modulating unit offset b. In the example in FIG. 9 , a signal line for inputting the two signals from the ADC 909 , a signal line for inputting the two signals from the digital EPS 910 , and a signal line for outputting the signal to the subtractors 901 are connected to the DC offset detecting unit 911 . In FIG. 9 , the DC offset detecting unit 911 produces the compensation value b′ signal of the modulating unit offset b for correcting the two signals to be transmitted, to output the compensation value b′ signal to the two subtractors 901 as described below with reference to FIG. 4 .
The digital EPS 910 is a three-input two-output circuit that uses the phase shift signal that is the remaining input signal to perform phase rotation on the two signals that are the input signals, and outputs the phase-rotated signal as an output signal. In the example in FIG. 9 , a signal line for inputting the two digital signals to be transmitted, a signal line for inputting the phase shift signal from the second oscillator 907 , and a signal line for outputting the signal to the DC offset detecting unit 911 are connected to the digital EPS 910 . In FIG. 9 , the digital EPS 910 performs phase rotation on the two input signals in the opposite direction and by a phase shift quantity that is the same as that of the phase rotation by the analog EPS 906 , on the two input signals, and outputs the phase-rotated signals to the DC offset detecting unit 911 .
As a result, the signal input to the amplifier 905 becomes the signal u+b=u−b′+b≈u due to the DC offset detecting unit 911 inputting the compensation value b′ that becomes the same value as the modulating unit offset b into the subtractors 901 . Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 905 and is able to transmit a signal with high accuracy.
(Correction of Signals in Fifth Embodiment)
FIG. 10 illustrates a correction of a signal according to the fifth embodiment. FIG. 10 illustrates a flow of the signal x i until the signal x i becomes a feedback signal y i in the circuits illustrated in FIG. 9 .
In the circuit illustrated in FIG. 9 , the compensation value b′ of the modulating unit offset b as indicated by reference numeral 1001 is subtracted from the signal x i , and the modulating unit offset b as indicated by the reference numeral 1002 is added to the signal x i . Further, the signal x i is phase-rotated, as indicated by reference numeral 1003 , using the phase shift signal indicated by reference numeral 1004 , and the demodulating unit offset c is added to the signal x i as indicated by reference numeral 1005 . As a result, the signal x i is fed back as the signal y i . Therefore, in the circuits illustrated in FIG. 9 , an error ε i between the signal y i theoretically calculated from the feedback signal u i and the actually measured signal y i is expressed by the following equation (27).
( au i +b ) e jwt +c−y i ×e jwt =ε i (27)
The following equation (28) is obtained when the above equation (27) is expanded.
au i e jwt +be jwt +c−y i ×e jwt =ε i (28)
The following equation (29) is obtained when the above equation (28) is transformed.
au i +b+c×e −jwt −y i =ε×e −jwt (29)
The DC offset detecting unit 911 produces the signal for the compensation value b′ of the modulating unit offset b by using the signal x i and the feedback signal y i in a period I of one cycle of e −jwt to apply the least-squares method in the above equation (29). In this case, the DC offset detecting unit 911 applies the least-squares method in the above equation (29) to calculate the coefficient “a”, the coefficient “b”, and the coefficient “c” when the error ε i in the following equation (30) is the smallest.
∑
i
=
1
n
[
(
a
u
i
+
b
+
c
×
ⅇ
-
j
wt
-
y
i
)
(
a
u
i
+
b
+
c
×
ⅇ
-
j
wt
-
y
i
)
*
]
=
∑
i
=
1
n
ɛ
i
×
ⅇ
-
j
wt
2
(
30
)
The subsequent processing is similar to the processing described with reference to FIG. 4 and thus an explanation will be omitted.
Sixth Embodiment of Modulating Device 100
FIG. 11 illustrates a sixth embodiment of the modulating device 100 . The sixth embodiment is a modified example of the second embodiment.
As illustrated in FIG. 11 , the modulating device 100 has two subtractors 1101 , a DAC 1102 , a QMOD 1103 , a first oscillator 1104 , an amplifier 1105 , an analog EPS 1106 , a second oscillator 1107 , a QDEM 1108 , an ADC 1109 , a digital EPS 1110 , and a DC offset detecting unit 1111 . A processing flow of the I-signal among the I-signals and the Q-signals will be discussed hereinbelow. The processing flow of the Q-signal is the same as the processing flow of the I-signal and thus an explanation will be omitted.
The two subtractors 1101 are circuits that are similar to the two subtractors 501 illustrated in FIG. 5 and thus an explanation will be omitted. The DAC 1102 is a circuit similar to the DAC 502 illustrated in FIG. 5 and thus an explanation will be omitted. The QMOD 1103 is a circuit similar to the QMOD 503 illustrated in FIG. 5 and thus an explanation will be omitted. The first oscillator 1104 is a circuit similar to the first oscillator 504 illustrated in FIG. 5 and thus an explanation will be omitted. The amplifier 1105 is a circuit similar to the amplifier 505 illustrated in FIG. 5 and thus an explanation will be omitted. The analog EPS 1106 is a circuit similar to the analog EPS 506 illustrated in FIG. 5 , and thus an explanation will be omitted.
The second oscillator 1107 is a circuit similar to the second oscillator 507 illustrated in FIG. 5 and thus an explanation will be omitted. The QDEM 1108 is a circuit similar to the QDEM 508 illustrated in FIG. 5 and thus an explanation will be omitted. The ADC 1109 is a circuit similar to the ADC 509 illustrated in FIG. 5 and thus an explanation will be omitted. The digital EPS 1110 is a circuit similar to the digital EPS 910 illustrated in FIG. 9 and thus an explanation will be omitted. The DC offset detecting unit 1111 is a circuit similar to the DC offset detecting unit 911 illustrated in FIG. 9 and thus an explanation will be omitted.
As a result, the signal input to the amplifier 1105 becomes the signal u+b=u−b′+b≈u due to the DC offset detecting unit 1111 inputting the compensation value b′ that becomes the same value as the modulating unit offset b input into the subtractors 1101 . Therefore, the modulating device 100 is able to remove the modulating unit offset b from the signal to be amplified and transmitted by the amplifier 1105 and is able to transmit a signal with high accuracy.
(Correction of Signals in Sixth Embodiment)
In the circuits illustrated in FIG. 11 , the compensation value b′ of the modulating unit offset b is subtracted from the signal x i , the modulating unit offset b is added to the signal x i , and then the signal x i is phase-rotated in the same way as illustrated in FIG. 10 . The demodulating unit offset c is then added to the signal x i and the signal x i is then fed back as the signal y i . Therefore, the DC offset detecting unit 1111 in the circuits illustrated in FIG. 11 calculates the modulating unit offset b and outputs the modulating unit offset b to the subtractors 1101 as the compensation value b′ of the modulating unit offset b in the same way as illustrated in FIG. 10 .
Seventh Embodiment of Modulating Device 100
FIG. 12 illustrates a seventh embodiment of the modulating device 100 . The seventh embodiment is one in which a further function for compensating a distortion produced in an analog signal in the amplifier is added to the modulating device 100 according to the first embodiment.
As illustrated in FIG. 12 , the modulating device 100 has a digital pre-distortion (DPD) 1201 , an adder 1202 , a DAC 1203 , a QMOD 1204 , a first oscillator 1205 , an amplifier 1206 , an analog EPS 1207 , a second oscillator 1208 , a QDEM 1209 , an ADC 1210 , a digital EPS 1211 , an identifier 1212 , and a subtractor 1213 . In the following explanation, the signal x is described as a signal representing a complex number formed by combining the I-signal and the Q-signal.
The DPD 1201 is a two-input one-output circuit that compensates a signal to be transmitted that is one of the input signals by using a signal for correcting distortion that is produced in the analog signal in the amplifier 1206 and that is the other of the input signals, and outputs the compensated signal as an output signal. In the example illustrated in FIG. 12 , a signal line for inputting a digital signal to be transmitted and a signal line for inputting, from the identifier 1212 , a signal for compensating the distortion produced in the analog signal in the amplifier 1206 , are connected to the DPD 1201 . A signal line for outputting the signal to the adder 1202 is also connected to the DPD 1201 . In FIG. 12 , the DPD 1201 uses values a1 and a3 that have nonlinear reverse characteristics, that are input from the identifier 1212 , and that become signals for compensating the distortion produced in the analog signal in the amplifier 1206 , to compensate the input signal x that is to be transmitted. The DPD 1201 then outputs a compensation result x′ to the adder 1202 .
The adder 1202 is a two-input one-output circuit that outputs, as an output signal, an addition result of the addition of one of the input signals to the other. In the example illustrated in FIG. 12 , a signal line for inputting signals from the DPD 1201 and a signal line for inputting the compensation value −b′ signal of the modulating unit offset b for compensating the DC offset from the identifier 1212 , are connected to the adder 1202 . A signal line for outputting the signal to the DAC 1203 and to the subtractor 1213 is also connected to the adder 1202 . In FIG. 12 , the adder 1202 adds the compensation value b′ of the modulating unit offset b input from the identifier 1212 to the signal xi′ and outputs the one output addition result u=x′+b′ by branching the result to the DAC 1203 and to the subtractor 1213 .
The DAC 1203 is a one-input one-output circuit that performs analog conversion on a digital signal that is an input signal, and outputs the analog-converted signals as an output signal. In the example in FIG. 12 , a signal line for inputting the digital signal from the adder 1202 , and a signal line for outputting the signal to the QMOD 1204 are connected to the DAC 1203 . In FIG. 12 , the DAC 1203 performs analog conversion on the input digital signal u and outputs the analog-converted signal to the QMOD 1204 . The analog-converted signal may be referred to by “u” in the same way as the digital signal in the following explanation.
The QMOD 1204 is a two-input one-output circuit that uses the local signal that is the remaining input signal to perform quadrature modulation on the analog signal that is the input signal, and outputs the quadrature-modulated signal as an output signal. In the example illustrated in FIG. 12 , a signal line for inputting the analog signal from the DAC 1203 , a signal line for inputting the local signal from the first oscillator 1205 , and a signal line for outputting the signal to the amplifier 1206 are connected to the QMOD 1204 . In FIG. 12 , the QMOD 1204 performs quadrature modulation on the input signal u by using the local signal from the first oscillator 1205 and outputs the quadrature-modulated signal to the amplifier 1206 . The modulating unit offset b is added to the signal u by passing through the DAC 1203 and the QMOD 1204 , to become the signal u+b.
The first oscillator 1205 is a circuit similar to the first oscillator 304 illustrated in FIG. 3 and thus an explanation will be omitted. The amplifier 1206 is a circuit similar to the amplifier 305 illustrated in FIG. 3 and thus an explanation will be omitted. The analog EPS 1207 is a circuit similar to the analog EPS 306 illustrated in FIG. 3 and thus an explanation will be omitted. The second oscillator 1208 is a circuit similar to the second oscillator 307 illustrated in FIG. 3 and thus an explanation will be omitted.
The QDEM 1209 is a two-input one-output circuit that uses the local signal that is phase-rotated by the phase shift signal that is one of the input signals to perform quadrature demodulation on the analog signal that is the other of the input signals, and outputs the quadrature-demodulated signal as an output signal. In the example illustrated in FIG. 12 , a signal line for inputting the signal from the amplifier 1206 , a signal line for inputting the signal from the analog EPS 1207 , and a signal line for outputting the signal to the ADC 1210 are connected to the QDEM 1209 . In FIG. 12 , the QDEM 1209 uses the signal from the analog EPS 1207 to perform quadrature demodulation on the analog signal from the amplifier 1206 and outputs the signal (u+b)*EXP(jwt) to the ADC 1210 .
The ADC 1210 is a one-input one-output circuit that performs digital conversion on the analog signal that is the input signal, and outputs the digital-converted signal as an output signal. In the example in FIG. 12 , a signal line for inputting the signal from the QDEM 1209 , and a signal line for outputting the signal to the digital EPS 1211 are connected to the ADC 1210 . In FIG. 12 , the ADC 1210 performs digital conversion on the signal (u+b)*EXP(jwt) input from the QDEM 1209 , and outputs the digitally converted signal to the digital EPS 1211 . The demodulating unit offset c is added to the signal (u+b)*EXP(jwt) that passes through the QDEM 1209 and the ADC 1210 to become the signal (u+b)*EXP(jwt)+c.
The digital EPS 1211 is a two-input one-output circuit that uses the phase shift signal that is the remaining input signal to perform phase rotation on the signal that is one of the input signals, and outputs the phase-rotated signal as an output signal. In the example illustrated in FIG. 12 , a signal line for inputting the signal from the ADC 1210 , a signal line for inputting the phase shift signal from the second oscillator 1208 , and a signal line for outputting the signal to the identifier 1212 , are connected to the digital EPS 1211 . In FIG. 12 , the digital EPS 1211 uses the phase shift signal from the second oscillator 1208 to perform phase rotation on the input signal in the opposite direction and by a phase shift quantity that is the same as that of the phase rotation by the analog EPS 1207 , and outputs the phase-rotated signal to the identifier 1212 .
The identifier 1212 is a two-input three-output circuit that uses the signal from the digital EPS 1211 that is an input signal, and a signal from the subtractor 1213 that is an input signal, to output the nonlinear reverse characteristic values a1 and a3 and the compensation value b′ signal of the modulating unit offset b. In the example illustrated in FIG. 12 , a signal line for inputting the signal from the digital EPS 1211 , a signal line for inputting the signal from the subtractor 1213 , and a signal line for outputting the signal to the DPD 1201 , the adder 1202 , and to the subtractor 1213 , are connected to the identifier 1212 . In FIG. 12 , the identifier 1212 produces signals of the nonlinear reverse characteristic values a1 and a3 for compensating the distortion produced on the analog signal in the amplifier 1206 and outputs the produced signals to the DPD 1201 as described below in reference to FIG. 13 . The identifier 1212 produces the compensation value b′ signal of the modulating unit offset b for correcting the digital signal to be transmitted and outputs the compensation value b′ signal to the adder 1202 and to the subtractor 1213 as described below with reference to FIG. 13 .
The subtractor 1213 is a two-input one-output circuit that outputs, as an output signal, a subtraction result of the subtraction of one of the input signals from the other. In the example illustrated in FIG. 12 , a signal line for inputting the signal from the adder 1202 , a signal line for inputting the signal from the identifier 1212 , and a signal line for outputting the signal to the identifier 1212 , are connected to the subtractor 1213 . In FIG. 12 , the subtractor 1213 subtracts the signal input from the identifier 1212 from the signal u input from the adder 1202 , and outputs the subtraction result to the identifier 1212 . As a result, the modulating device 100 is able to compensate the distortion of the signal in the amplifier 1206 and the modulating unit offset b, and is able to transmit a signal with high accuracy.
(Correction of Signal in Seventh Embodiment)
FIG. 13 illustrates a correction of a signal according to the seventh embodiment.
In the circuits in FIG. 12 , the feedback signal y i is phase-rotated, as indicated by the reference numeral 1301 , by using the phase shift signal indicated by the reference numeral 1302 , and the demodulating unit offset c is subtracted from the feedback signal y i as indicated by the reference numeral 1303 . Further, as indicated by reference numeral 1304 , the feedback signal y i is phase-rotated in the direction opposite to that of the phase rotation indicated by reference numeral 1301 , by using the phase shift signal indicated by reference numeral 1302 . The feedback signal y i is then amplified in the negative direction as indicated by the reference numeral 1305 and the modulating unit offset b is subtracted as indicated by the reference numeral 1306 . As a result, the feedback signal y i is returned to the signal u i . Therefore, in the circuits illustrated in FIG. 12 , an error ε i between the signal u i theoretically calculated from the feedback signal y i and the actually measured signal u i is expressed by the following equation (31).
a 1 ( y i +c×e jwt )+ a 3 |y i +c×e jwt | 2 ( y i +c×e jwt )+ b−u i =ε i (31)
Since the offset is a small value with respect to the signal, the above equation (31) approximates the following equation (32).
a 1 y 1 +a 1 c×e jwt +a 3 |y i | 2 y i +b−u i =ε i (32)
The identifier 1212 produces the signal for compensating the two digital signals that are to be transmitted, by applying the least-squares method to the above equation (32). In this case, the identifier 1212 applies the least-squares method in the above equation (32) to calculate the coefficient “a 1 ”, the coefficient “a 3 ”, the coefficient “b”, and the coefficient “c” when the error ε i in the following equation (33) is the smallest.
∑
i
=
1
n
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(
a
1
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i
+
a
3
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+
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1
c
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t
-
u
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(
a
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i
+
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=
∑
i
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(
33
)
The error ε i in the above equation (33) becomes the smallest when the following equations (34) to (37) that are equations differentiated from the above equation (33) become 0.
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i
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35
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37
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The following equation (38) is obtained when the above equations (34) to (37) are expressed as a matrix.
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[
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(
38
)
The following equation (39) is obtained when the above equation (38) is transformed.
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a
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3
b
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(
39
)
In this case, the coefficient c is found with the following equation (40).
c
=
a
1
c
a
1
(
40
)
In this case, the identifier 1212 calculates the coefficients a 1 and a 3 and the compensation value b′ of the modulating unit offset b by substituting the digital signal u i in the period I of one cycle and that is to be transmitted and the feedback signal y i in the period I of one cycle, into the above equation (39). The identifier 1212 then outputs the calculated coefficients a 1 and a 3 to the DPD 1201 and outputs the calculated compensation value b′ of the modulating unit offset b to the adder 1202 . A further function for compensating the distortion produced in an analog signal in the amplifier 1206 may be further added to the modulating device 100 according to the third and fifth embodiments in the same way as illustrated in FIG. 12 .
Eighth Embodiment of Modulating Device 100
FIG. 14 illustrates an eighth embodiment of the modulating device 100 . The eighth embodiment is one in which a further function for compensating the distortion produced in an analog signal in the amplifier is added to the modulating device 100 according to the second embodiment.
As illustrated in FIG. 14 , the modulating device 100 has a DPD 1401 , an adder 1402 , a DAC 1403 , a QMOD 1404 , a first oscillator 1405 , an amplifier 1406 , an analog EPS 1407 , a second oscillator 1408 , a QDEM 1409 , an ADC 1410 , a digital EPS 1411 , an identifier 1412 , and a subtractor 1413 . In the following explanation, the signal x is described as a signal representing a complex number formed by combining the I-signal and the Q-signal.
The DPD 1401 is a circuit similar to the DPD 1201 illustrated in FIG. 12 and thus an explanation will be omitted. The adder 1402 is a circuit similar to the adder 1202 illustrated in FIG. 12 and thus an explanation will be omitted. The DAC 1403 is a circuit similar to the DAC 1203 illustrated in FIG. 12 and thus an explanation will be omitted. The QMOD 1404 is a circuit similar to the QMOD 1204 illustrated in FIG. 12 and thus an explanation will be omitted.
The first oscillator 1405 is a circuit similar to the first oscillator 504 illustrated in FIG. 5 and thus an explanation will be omitted. The amplifier 1406 is a circuit similar to the amplifier 505 illustrated in FIG. 5 and thus an explanation will be omitted. The analog EPS 1407 is a circuit similar to the analog EPS 506 illustrated in FIG. 5 , and thus an explanation will be omitted. The second oscillator 1408 is a circuit similar to the second oscillator 507 illustrated in FIG. 5 and thus an explanation will be omitted.
The QDEM 1409 is a two-input one-output circuit that uses the local signal that is one of the input signals to perform quadrature demodulation on the analog signal that is the other of the input signals, and outputs the quadrature-demodulated signal as an output signal. In the example in FIG. 14 , a signal line for inputting the signal from the analog EPS 1407 , a signal line for inputting the local signal from the first oscillator 1405 , and a signal line for outputting the signal to the ADC 1410 , are connected to the QDEM 1409 . In FIG. 14 , the QDEM 1409 uses the local signal from the first oscillator 1405 to perform quadrature demodulation on the analog signal from the analog EPS 1407 to output the signal (u+b)*EXP(jwt) to the ADC 1410 .
The ADC 1410 is a circuit similar to the ADC 1210 illustrated in FIG. 12 and thus an explanation will be omitted. The digital EPS 1411 is a circuit similar to the digital EPS 1211 illustrated in FIG. 12 and thus an explanation will be omitted. The identifier 1412 is a circuit similar to the identifier 1212 illustrated in FIG. 12 and thus an explanation will be omitted. The subtractor 1413 is a circuit similar to the subtractor 1213 illustrated in FIG. 12 and thus an explanation will be omitted. As a result, the modulating device 100 is able to compensate the distortion of the signal in the amplifier 1406 and the modulating unit offset b, and is able to transmit a signal with high accuracy.
(Correction of Signal in Eighth Embodiment)
In the circuits illustrated in FIG. 14 , the feedback signal y i is phase-rotated, the demodulating unit offset c is subtracted from the feedback signal y i , and the feedback signal y i is then phase-rotated in the reverse direction in the same way as illustrated in FIG. 13 . The feedback signal y i is then amplified in the negative direction and the modulating unit offset b is subtracted from the feedback signal y i to obtain the signal u i . Therefore, in the circuits illustrated in FIG. 14 , the identifier 1412 calculates the coefficients a 1 and a 3 in the same way as in FIG. 13 and outputs the coefficients to the DPD 1401 . The identifier 1412 also calculates the compensation value b′ of the modulating unit offset b and outputs the compensation value b′ to the adder 1402 in the same way as in FIG. 13 .
As described above, based on the modulating device 100 according to the embodiments discussed herein, the modulation signal may be fed back while being phase-rotated, and the DC offset produced in the quadrature modulation circuit may be calculated on the basis of the signal to be transmitted and the fed back signal. As a result, the modulating device 100 according to the embodiments discussed herein removes the calculated DC offset from the modulation signal and is able to transmit the modulation signal with high accuracy.
Similarly, based on the modulating device 100 according to the embodiments discussed herein, the modulation signal is phase-rotated, demodulated, and then fed back so that the DC offset produced in the quadrature modulation circuit may be calculated on the basis of the signal to be transmitted and the fed back signal. As a result, based on the modulating device 100 according to the embodiments discussed herein, the modulating unit offset is set as a direct current element and the demodulating unit offset is set as a periodically changing element so that the time desired for calculating the modulating unit offset may be reduced. Moreover, based on the modulating device 100 according to the embodiments discussed herein, a coefficient for compensating the distortion produced on the modulation signal in the amplifier may be calculated. As a result, the modulating device 100 according to the embodiments discussed herein uses the calculated coefficient to compensate the modulation signal and thus is able to transmit the modulation signal with high accuracy.
Moreover, for example, a conventional modulating device may have a feedback circuit that provides feedback by performing quadrature demodulation on the modulation signal with a quadrature demodulation circuit. In this case, the conventional modulation device inputs the modulation signal into the feedback circuit to calculate an average value of the sum of the modulating unit offset and the demodulating unit offset within the time period of the input. Further, the conventional modulation device does not input the modulation signal into the feedback circuit to calculate an average value of the sum of the demodulating unit offset within the time period of the non-input. Thus in the conventional modulating device, the modulating unit offset is calculated by subtracting the average value of the demodulating unit offset from the average value of the sum of the modulating unit offset and the demodulating unit offset. However, at the point in time that the modulation signal is compensated, the actual modulating unit offset and the calculated modulating unit offset are different and the accuracy of the calculated modulating unit offset may be poor. Conversely, based on the modulating device 100 according to the embodiments discussed herein, the calculation of the modulating unit offset may be performed continuously and the accuracy of the modulating unit offset may be improved.
Similarly, a conventional modulating device may calculate the modulating unit offset by using a frequency converting circuit to convert the modulation signal to an IF signals and then use an ADC to perform digital conversion to provide feedback. However, in this case, the conventional modulating device uses a quadrature demodulation circuit realized by a high-speed ADC and digital signal processing thus resulting in an increase in cost and an increase in power consumption. Conversely, the modulating device 100 according to the embodiments discussed herein exhibits a lower cost and reduced power consumption in comparison to the case of using the quadrature demodulation circuit realized by the high-speed ADC and the digital signal processing.
All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.
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A modulating device including: a first convertor configured to generate a converted analog signal by analog conversion on a input digital signal, a modulator configured to generate a modulated signal by quadrature modulation, a phase shifter configured to generate a phase shift signal by phase rotation, a demodulator configured to generate a demodulated signal by quadrature demodulation, a second convertor to generate a converted digital signal by digital conversion, a calculating circuit configured to estimate a the first direct current offset based on the input digital signal and the converted digital signal, the first direct current offset being a noise of digital current component generated between the input digital signal inputted to the first convertor and the output signal inputted to the demodulator, and a correcting circuit configured to correct at least one among from the input digital signal to the output signal based on the first direct current offset.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to hospital curtains and, more specifically, to a quick release hospital curtain consisting of a ventilated narrow upper portion slideably attached along an existing ceiling track. A wide lower portion of the curtain fabricated out of an antimicrobial fabric is removably attached to the narrow upper portion by a breakaway longitudinally extending zipper placed therebetween. A vertical flap secured by VELCRO can be lifted up to access a cover strip to expose a starting point of the zipper on one side of the curtain, so that the wide lower portion can be pulled away from the narrow upper portion.
2. Description of the Prior Art
There are other hospital curtains which provide for an enclosure utilized for hospital beds, surgical facilities, emergency rooms, intensive care units and recovery rooms. While these hospital curtains may be suitable for the purposes for which they where designed, they would not be as suitable for the purposes of the present invention as heretofore described.
It is thus desirable to provide a quick release hospital curtain comprising a narrow ventilated upper portion that is slideably mounted by curtain carriers to an existing ceiling track. A wide antimicrobial lower portion is removably attached by a zipper to the narrow upper portion. A vertically disposed VELCRO flap can access a cover strip to expose a starting point of the zipper allowing the wide lower portion to be pulled away or removed from the narrow upper portion.
SUMMARY OF THE PRESENT INVENTION
A primary object of the present invention is to provide a quick release hospital curtain, in which an antimicrobial lower portion can be easily removed from a thinner upper portion.
Another object of the present invention is to provide a quick release hospital curtain, in which the lower portion is fabricated out of an antimicrobial fabric.
Yet another object of the present invention is to provide a quick release hospital curtain, in which the narrow upper portion is ventilated.
Still yet another object of the present invention is to provide a quick release hospital curtain, in which a top segment of the narrow upper portion is fabricated out of a mesh material
Another object of the present invention is to provide a quick release hospital curtain having a breakaway longitudinally extending zipper between the narrow upper portion and the wide lower portion.
Yet another object of the invention is to provide a quick release hospital curtain wherein the breakaway longitudinally extending zipper may additionally be manufactured with an antimicrobial material.
Yet another object of the present invention is to provide a quick release hospital curtain containing a vertical VELCRO flap on one side of the curtain affixed at a top end to the narrow upper portion and removably attached at a bottom end to the wide lower portion.
Still yet another object of the present invention is to provide a quick release hospital curtain further containing a cover strip secured by the vertical VELCRO flap affixed to a lower end of the narrow upper portion that can be pulled up to expose the zipper.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing a quick release hospital curtain consisting of a ventilated narrow upper portion slideably attached along an existing ceiling track. A wide lower portion of the curtain fabricated out of an antimicrobial fabric is removably attached to the narrow upper portion by a breakaway longitudinally extending zipper therebetween. A vertical VELCRO flap can be lifted up to access a cover strip to expose a starting point of the zipper on one side of the curtain, so that the wide lower portion can either be unzipped from or be pulled away from the narrow upper portion.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which:
FIG. 1 is a perspective view of the present invention suspended from a track, showing a wide lower portion starting to be separated from a narrow upper portion;
FIG. 2 is a perspective view of the present invention fully assembled;
FIG. 3 is a front view of the present invention;
FIG. 4 is a front view of the present invention similar to FIG. 3 , showing the wide lower portion starting to be separated from the narrow upper portion;
FIG. 5 is an enlarged partial front view of the present invention with parts broken away;
FIG. 6 is an enlarged partial front view of the present invention similar to FIG. 5 , showing the VELCRO flap and the cover strip lifted up; and
FIG. 7 is an enlarged partial front view of the present invention similar to FIG. 6 , showing the zipper being opened and the wide lower portion being pulled away from the narrow upper portion.
DESCRIPTION OF THE REFERENCED NUMERALS
Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the figures illustrate the use of the present invention. With regard to the reference numerals used, the following numbering is used throughout the various drawing figures.
10 hospital curtain 12 curtain track 14 wide lower portion 16 narrow upper portion 18 elemental silver threads 20 upper portion top section mesh 22 curtain carriers 24 eyelets 26 cover strip 28 upper portion top edge 30 upper portion lower edge 32 breakaway zipper 34 upper zipper track 36 lower zipper track 38 interengaged zipper teeth 40 vertically disposed cover strip securing flap 42 curtain left edge 44 curtain right edge 46 zipper handle 48 cooperating VELCRO patches A 1 , A 2 , A 3 directional arrows N user
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following discussion describes in detail one embodiment of the invention (and several variations of that embodiment). This discussion should not be construed, however, as limiting the invention to those particular embodiments, practitioners skilled in the art will recognize numerous other embodiments as well. For definition of the complete scope of the invention, the reader is directed to appended claims.
FIG. 1 is a perspective view of the present invention 10 suspended from a track 12 , showing a wide lower portion 14 starting to be separated from a narrow upper portion 16 . The present invention is a quick release hospital curtain 10 comprising a wide lower portion fabricated out of an antimicrobial fabric that includes a plurality of silver threads 18 incorporated into its construction. The elemental silver 18 serves to aid in the antimicrobial protection already provided by the lower portion 14 . The invention 10 also includes a narrow ventilated upper portion 16 . The upper portion 16 has a top segment 20 made of a mesh material for ventilation and is slideably attached along an existing ceiling track using a plurality of curtain carriers 22 coupled to spaced apart eyelets 24 on a top edge 28 of the narrow upper portion 16 . As seen in the following Figures and described more completely below, a cover strip 26 is attached to a lower edge 30 of the narrow upper portion to hide a breakaway zipper 32 . The cover strip 26 is held in place by a vertically disposed cover strip securing strap 40 . The breakaway zipper 32 extends longitudinally between the wide lower portion 14 and the narrow upper portion 16 of the hospital curtain 10 . The breakaway zipper 32 has upper and lower zipper tracks 34 , 36 with matingly interlocking teeth 38 that are separable for removing the wide lower portion 14 from the narrow upper portion 16 of the hospital curtain 10 when desired.
FIG. 2 is a perspective view of the present invention fully assembled. Shown is the quick release curtain 10 of the present invention comprising the wide lower portion 14 fabricated out of an antimicrobial material and, further, having a plurality of silver threads incorporated therethrough. Also seen is the narrow ventilated upper portion 16 . A number of different materials may be used to provide the antimicrobial attributes of the lower portion 14 . These various antimicrobial materials may be topically applied periodically or they may be impregnated within the curtain material during the manufacturing process. This, along with the elemental silver threads 18 incorporated in the lower portion 14 , provides an impediment to germs in the environment surrounding the bed or examination area by denying a surface where the organisms can multiply. The breakaway zipper 32 (discussed further below) extends fully from the left edge of the hospital curtain to the right edge of the hospital curtain. The breakaway zipper has upper and lower zipper tracks 34 , 36 with matingly interlocking teeth 38 that are separable for removing the wide lower portion 14 from the narrow upper portion 16 when the matingly interlocking teeth 38 are disengaged from one another.
FIG. 3 is a front view of the present invention. The quick release hospital curtain 10 of the present invention provides the cover strip 26 affixed to the lower edge 30 of the narrow upper portion 16 of the hospital curtain 10 to hide the breakaway zipper 32 which extends from the left edge 42 of the hospital curtain 10 to the right edge 44 of the hospital curtain 10 . A vertically disposed VELCRO cover strip securing flap 40 is provided and is located on the left hand side 42 of the hospital curtain in the illustrated embodiment.
FIG. 4 is a front view of the present invention similar to FIG. 3 , showing the wide lower portion 14 starting to be separated from the narrow upper portion 16 . The quick release hospital curtain 10 of the present invention provides the cover strip 26 affixed to the lower edge 30 of the narrow upper portion 16 of the hospital curtain 10 to hide the breakaway zipper 32 which extends from the left edge 42 of the hospital curtain 10 to the right edge 44 of the hospital curtain 10 . This breakaway zipper provides a combined breakaway and engagement means that allows a user to remove the antimicrobial lower potion 14 from the upper portion 16 when desired, as will be discussed below. A vertically disposed VELCRO cover strip 40 is provided and is located on the left hand side 42 of the hospital curtain 10 in the embodiment described herein. The vertically disposed VELCRO cover strip 40 is lifted to access and move the cover strip 26 thus exposing the zipper 32 starting point and the zipper handle 46 which may then be used to disengage the interlocking teeth 34 , 36 (as indicated by directional arrow A 1 in the Figure) to release the wide lower portion 14 from the narrow upper portion 16 of the hospital curtain 10 . In the preferred embodiment described herein, the interlocking teeth 34 , 36 would be made of a polymer substance and would also be impregnated or infused with an antimicrobial compound similar to the lower portion 14 of the hospital curtain 10 . Note also that it is contemplated that in the case of an emergency, if the curtain needed to be removed quickly, the interlocking zipper teeth 34 , 36 could be disengaged from one another by simply pulling downwardly as indicated at directional arrow A 2 in the Figure, which would also cause the teeth 34 , 36 to detach from one another.
FIG. 5 is an enlarged partial front view of the present invention with parts broken away. Shown is a detailed view of the quick release curtain 10 of the present invention with the vertically disposed VELCRO cover strip 40 in a closed position and the cover strip 26 covering the breakaway zipper 32 . Breakaway zipper 32 is shown with the upper zipper track 34 and the lower zipper track 36 engaged with one another. Also shown is the interengaging VELCRO patch 48 disposed on both the VELCRO cover strip 40 and the lower portion 14 (both placements seen in FIG. 4 ).
FIG. 6 is an enlarged partial front view of the present invention similar to FIG. 5 , showing the vertically disposed VELCRO cover strip 40 and the cover strip 26 lifted up. Shown is a detailed view of the quick release hospital curtain 10 of the present invention comprising the wide lower portion 14 fabricated out of antimicrobial material having the plurality of silver threads 18 incorporated therethrough (as seen in FIGS. 1 and 3 ). The breakaway zipper 32 extends from the left edge of the hospital curtain to the right edge of the hospital curtain. The breakaway zipper 32 has the upper and lower zipper tracks 34 , 36 with the matingly interlocking teeth that are separable for removing the wide lower portion 14 from the narrow upper portion 16 when the matingly interlocking teeth are disengaged.
FIG. 7 is an enlarged partial front view of the present invention similar to FIG. 6 , showing the zipper 32 being opened and the wide lower portion 14 being pulled away from the narrow upper portion 16 as indicated by directional arrow A 3 . The breakaway zipper 32 has the upper and lower zipper tracks ( 34 and 36 , respectively) with matingly interlocking teeth that are separable for removing the wide lower portion from the narrow upper portion when the matingly interlocking teeth are disengaged as shown. As mentioned above, the user N (seen in FIGS. 1 and 4 ) may either use the zipper handle, indicated at 46 in the Figures, or may, in case of urgency, simply pull the interengaged teeth apart as shown.
A wide variety of antimicrobial agents are available and would present themselves to the skilled practitioner. In combination with the elemental silver threads 18 the present invention provides a privacy curtain foe hospital room or examination room use. With the rise of infections contracted in hospitals, some of these being partially or substantially resistant to antibiotic treatment, the present invention addresses a real need by denying any airborne organisms or germs unknowingly carried by a person in the environment a surface proximate the patient where the pathogens can rest or multiply. As mentioned above, the antimicrobial material that makes up part of the lower portion 14 of the curtain 10 may be impregnated within the curtain material during the manufacturing process, be topically applied on a predetermined schedule, or both. Additionally, the elemental silver threading 18 incorporated into the lower portion 14 of the present invention increases the antimicrobial properties thereof. It is contemplated that the lower portion 14 of the invention 10 would be easily washable and able to undergo sterilization procedures (high temperatures, chemical treatment, or the like) in case of being badly soiled.
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 methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it is not intended to be limited to the details above, 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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A quick release antimicrobial hospital curtain is disclosed. The curtain is made up of a ventilated top portion attached by curtain carriers and eyelets to the existing curtain track, and a bottom portion, the bottom portion being impregnated with an antimicrobial material and woven through with elemental silver threads. The quick release mechanism is a breakaway zipper, also preferably made of an antimicrobially impregnated polymer that may be unfastened either with a conventional zipper handle or simply pulled to detach the bottom portion from the upper.
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[0001] The present application is based on Japanese Patent Application No. 2007-019749 filed on Jan. 30, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an assembling method of an electric steering lock device, to be applied to vehicles such as automobiles.
[0004] 2. Related Art
[0005] As conventional electric steering lock devices, for example, JP-A-2004-231123 and JP-A-2006-36107 disclose, respectively, an electric steering lock device comprising a warm gear which rotates by a rotary motor, a helical gear which rotates by rotation of the warm gear, a lock arm and a cam which operate in association with rotation of this helical gear, a lock stopper which moves between a lock position and an unlock position with respect to a steering shaft, a lock bar, and a lock body housing these parts has been known.
[0006] This electric steering lock device has a configuration, in which the lock bar is moved between the lock position and the unlock position with respect to the steering shaft by mutually rotating the rotary motor in opposite directions.
[0007] However, according to the electric steering lock device of JP-A-2004-231123 etc., when assembling the electric steering lock device, it was necessary to build, for example, the lock bar, the helical gear and the lock stopper etc. into the lock body from different directions. Accordingly, it was impossible to assemble these parts from the same direction. Therefore, there is a disadvantage in that it was difficult to realize the automatic assembling of the electric steering lock device, and there was a limit to reduce the cost of manufacturing by shortening the assembling time.
THE SUMMARY OF THE INVENTION
[0008] It is an object of the invention to provide an assembling method of an electric steering lock device, in which various components can be built into the lock body from the same direction when assembling the electric steering lock device, thereby realizing the automatic assembling.
[0009] [1] According to one aspect of the invention, an assembling method of an electric steering lock device comprises:
[0010] a built-in step of building a drive part which generates a rotation drive power, a rotation shaft to be rotated by the rotation drive power of the drive part through a gear mechanism, a lock stopper to be screwed with the rotation shaft to move axially by rotating of the rotation shaft, a lock bar which moves between a lock position for locking a steering shaft by movement of the lock stopper and an unlock position for unlocking the steering shaft, and a first spring interposed between the lock stopper and the lock bar for giving a bias load, into a lock body to be installed in a mounting hole part of a steering column post of a vehicle from the same direction; and
[0011] a screwing step for screwing the rotation shaft and the lock stopper after the built-in step.
[0012] [2] In the assembling method of an electric steering lock device described in above-mentioned [1], the built-in step may comprise a step of previously building the lock bar, the first spring, and the lock stopper into the lock body from the same direction in a temporary assembled state as a sub-assay.
[0013] [3] In the assembling method of an electric steering lock device described in above-mentioned [1], the screwing step may comprises a step of applying a load on the lock stopper in a direction to screw with the rotation shaft through the first spring by applying a load on the lock bar from outside, and rotating the rotation shaft, to screw the lock bar with the rotation shaft.
[0014] [4] The assembling method of the electric steering lock device described in above-mentioned [1] may further comprise a bush insertion step of press fitting a bush to each of holes of the lock body and a lock body lid until a middle of each of the holes in a temporally assembled state, prior to the built-in step.
[0015] [5] In the assembling method of the electric steering lock device described in above-mentioned [1], it is preferable that a male screw part of the rotation shaft and a female screw part of the lock stopper are not screwed with each other yet as a spinning state, prior to the screwing step.
[0016] [6] In the assembling method of the electric steering lock device described in above-mentioned [4], the built-in step may be conducted in a state that no clearance is provided between an edge of the rotation shaft and a load receiving part of the bush.
[0017] [7] In the assembling method of the electric steering lock device described in above-mentioned [1], the built-in step and the screwing step may be conducted by an automatic assembling.
EFFECT OF THE INVENTION
[0018] According to embodiments of the present invention, it is possible to provide the assembling method of the electric steering lock device, in which various components can be built into the lock body from the same direction when assembling the electric steering lock device, thereby realizing the automatic assembling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Next, the present invention will be explained in more detail in conjunction with appended drawings, wherein:
[0020] FIG. 1 is an exploded perspective view showing an assembly relation of each components of an electric steering lock device 10 to be installed in a steering column post 1 of a vehicle such as an automobile in a preferred embodiment according to the present invention;
[0021] FIG. 2 is a cross section of the steering lock device 10 installed in the steering column post 1 , which shows a cross section including a centerline of a rotation shaft 30 etc. in which the steering lock device 10 is assembled as shown in FIG. 1 ;
[0022] FIGS. 3A to 3E are diagrams of a bush 40 , wherein FIG. 3A is a plan view thereof, FIG. 3B is a side view thereof, FIG. 3C is a cross sectional view thereof along A-A line in FIG. 3A , FIG. 3D ) is an enlarged view of a part A in FIG. 3B , and FIG. 3E is a plan view showing a state in which the bush 40 is press fitted into holes 21 a, 22 a of a main lock body 21 or a lock body lid 22 ;
[0023] FIGS. 4A and 4B are cross sectional views of the electric steering lock device 10 in the preferred embodiment according to the present invention, wherein FIG. 4A shows a state in which each components are built in from the same direction and the lock body lid 22 is not connected or fixed to the main lock body 21 , and FIG. 4B shows a state in which the main lock body 21 and the lock body lid 22 are pushed from both sides to have a predetermined positional relation and assembled by fixing with springs etc. in the state in which each components are built in as shown in FIG. 4A ; and
[0024] FIG. 5 is a cross sectional view of the electric steering lock device 10 in the preferred embodiment according to the present invention showing a non-connecting state, in which a lock bar 60 is not connected with a groove part 5 a of a steering shaft 5 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment of this Invention
[0025] FIG. 1 is an exploded perspective view showing an assembly relation of each components of an electric steering lock device 10 to be installed in a steering column post 1 of a vehicle such as an automobile in a preferred embodiment according to the present invention.
[0026] FIG. 2 is a cross section of the steering lock device 10 installed in the steering column post 1 , which shows a cross section including a centerline of a rotation shaft 30 etc. in which the steering lock device 10 is assembled as shown in FIG. 1 .
[0027] The steering lock device 10 comprises a lock body 20 , a rotation shaft 30 , a warm wheel 31 , a bush 40 , a lock stopper 50 , a lock bar 60 , a motor 70 and a warm gear 71 etc.
[0028] The lock body 20 comprises a main lock body 21 and a lock body lid 22 . The main lock body 21 and the lock body lid 22 comprise a predetermined material, for instance, magnesium die-cast or aluminum die-cast. The main lock body 21 is installed in a predetermined position of the steering column post 1 . In the state that this main lock body 21 is installed in the steering column post 1 , a lock bar 60 (to be described later) projected from a substantial central part of the main lock body 21 moves between a lock position for locking a rotation of a steering shaft 5 and an unlock position for unlocking the steering shaft 5 , to switch a connecting state and a non-connecting state with a groove part 5 a of the steering shaft 5 .
[0029] Holes 21 a and 22 a to which the bush 40 (to be described later) is fitted respectively by press fitting are formed on the main lock body 21 and the lock body lid 22 . These holes 21 a and 22 a are formed deeply enough so that a load receiving part 40 a of the bush 40 does not reach to a bottom of the holes 21 a and 22 a at the time of completion of assembly.
[0030] In the rotation shaft 30 , an external screw part 30 a, which is screwed with a female screw part 50 a formed on the lock stopper 50 (to be described later), is formed in an intermediate part, and the warm wheel 31 on which a gear is formed is installed. An edge 30 b is supported to be slidably rotatable by each of the main lock body 21 and the lock body lid 22 at both sides through the bush 40 .
[0031] FIGS. 3A to 3E are diagrams of the bush 40 , wherein FIG. 3A is a plan view thereof, FIG. 3B is a side view thereof, FIG. 3C is a cross sectional view thereof along A-A line in FIG. 3A , FIG. 3D is an enlarged view of a part A in FIG. 3B , and FIG. 3E is a plan view showing a state in which the bush 40 is press fitted into holes 21 a, 22 a of a main lock body 21 or a lock body lid 22 .
[0032] The bush 40 comprises a material having a spring property such as stainless steel, and is installed by fitting the main lock body 21 and the lock body lid 22 into the holes 21 a and 22 a with a predetermined fit. The bush 40 is provided with the load receiving part 40 a, an installation claw part 40 b, and a bearing claw part 40 c. The load receiving part 40 a functions as a contact face with the edge 30 b of the rotation shaft 30 , and three installation claw parts 40 b and three bearing claw parts 40 c are respectively provided to protrude alternately in a substantially vertical direction from this contact face side.
[0033] The installation claw part 40 b is configured to be opened from the load receiving part 40 a to a top of an installation claw part 40 d, so that the installation claw part 40 b can be fixed to the holes 21 a and 22 a formed on the main lock body 21 or the lock body lid 22 by press fitting. For instance, each of the top of installation claw parts 40 d is inclined by only 0.2 mm outward with respect to a dimension in the load receiving part 40 a. Furthermore, as shown in FIG. 3D , the installation claw part 40 b is such configured that a surface press fitted to the holes 21 a and 22 a functions as a burr side by adjusting a draft direction to a direction indicated by an arrow at the time of press work, and a sharp edge part 40 e is embedded into the holes 21 a and 22 a, not to be dropped off easily.
[0034] The bearing claw part 40 c is configured to be narrowed from the load receiving part 40 a to a top of a bearing claw part 40 f, in order to support the rotation shaft 30 to be slidably rotatable. The bearing claw part 40 c supports an outer circumference of the rotation shaft 30 by three claws. For instance, each of the top of bearing claw parts 40 f is inclined by only 0.1 mm inward with respect to a dimension of the load receiving part 40 a. For facilitating an assembly work with the rotation shaft 30 , each of the top of bearing claw parts 40 f is inclined by, for instance, only 0.2 mm outward.
[0035] In the rotation shaft 30 , the outer circumference of the rotation shaft 30 is supported to be slidably rotatable by the three bearing claw parts 40 c without any clearance, and the edge 30 b contacts to the load receiving part 40 a of the bush 40 to be slidably rotatable without any clearance by the main lock body 21 and the lock body lid 22 through the bush 40 respectively. As a result, the rotation shaft 30 is supported to be slidably rotatable without any clearance in both radial and thrust directions.
[0036] The lock stopper 50 is screwed with an external screw part 30 a of the rotation shaft 30 at the female screw part 50 a, and is movable in an axial direction of the rotation shaft 30 by the rotation of the rotation shaft 30 . The lock stopper 50 is connected to the lock bar 60 (to be described later) through the first spring 80 . Furthermore, a controller case 84 is provided with a second spring 81 , so as to give a bias load to the lock stopper 50 in a direction opposite to the bias load given by the first spring 80 , so that the external screw part 30 a of the rotation shaft 30 can be screwed with the female screw part 50 a of the lock stopper 50 , even if the lock stopper 50 moves too much in the non-connecting direction (the unlock direction) between the lock bar 60 and the steering shaft 5 . A magnet 83 is installed under the lock stopper 50 to detect the position of the lock stopper 50 by a hole IC 82 .
[0037] The lock bar 60 is connected with the lock stopper 50 through the first spring 80 and is movable between the lock position and the unlock position, so as to switch the connecting or non-connecting state with the groove part 5 a of the steering shaft 5 by the rotation of the rotation shaft 30 .
[0038] The motor 70 as a driving actuator is installed in the main lock body 21 through the controller case 84 and a spacer 85 , and the warm gear 71 is installed around an axis of the motor 70 . The warm gear 71 is screwed with a warm wheel 31 installed around the rotation shaft 30 . As a result, the rotation of the motor 70 is transmitted to the rotation shaft 30 through the warm gear 71 and the warm wheel 31 .
[0039] (Assembling Method of the Electric Steering Lock Device in the Preferred Embodiment of the Present Invention)
[0040] The bush 40 , the lock bar 60 , the first spring 80 , the lock stopper 50 , the rotation shaft 30 , the controller case 84 , the second spring 81 , the motor 70 , the spacer 85 , the bush 40 , and the lock body lid 22 are built into the main lock body 21 from the same direction (from a right side in FIG. 1 ).
[0041] Here, the warm wheel 31 is previously installed around the rotation shaft 30 . Furthermore, it is preferable to provide a bush insertion process, in which the bush 40 is press fitted into the main lock body 21 and the holes 21 a, 22 a of the lock body lid 22 until a halfway of the installation claw part 40 b, as a temporary assembled state. Furthermore, it is preferable to previously prepare a temporary assembly of the lock bar 60 , the first spring 80 and the lock stopper 50 , as a sub-assay.
[0042] FIGS. 4A and 4B are cross sectional views of the electric steering lock device 10 in the preferred embodiment according to the present invention.
[0043] FIG. 4A shows a state in which each components are built in from the same direction and the lock body lid 22 is not connected or fixed to the main lock body 21 , and FIG. 4B shows a state in which the main lock body 21 and the lock body lid 22 are pushed from both sides to have a predetermined positional relation and assembled by fixing with springs etc. in the state in which each components are built in as shown in FIG. 4A .
[0044] According to this step, the edge 30 b of the rotation shaft 30 is press fitted to the holes 21 a, 22 a while pushing the load receiving part 40 a, and assembled without any clearance (thrust) between the edge 30 b of the rotation shaft 30 and the load receiving part 40 a of the bush 40 (the rotation shaft built-in step). Even after this rotation shaft built-in step, the load receiving part 40 a of the bush 40 does not reach to the bottom of the holes 21 a and 22 a.
[0045] In the above-mentioned step ( FIG. 4B ), the external screw part 30 a of the rotation shaft 30 and the female screw part 50 a of the lock stopper 50 are not screwed with each other yet, i.e. in a spinning state. Here, by applying a load on a front edge of the lock bar 60 from the outside, a load is applied to the lock stopper 50 in a direction to screw with the rotation shaft 30 through the first spring 80 . By rotating the motor 70 so as to move the lock bar 60 in the direction to be the non-connecting state with the groove part 5 a of the steering shaft 5 under this condition, the external screw part 30 a of the rotation shaft 30 and the female screw part 50 a of the lock stopper 50 are screwed with each other to be an assembled state as shown in FIG. 2 (the screw step).
[0046] According to the respective steps mentioned above, the assembling of the electric steering lock device 10 is completed, and it is possible to install the electric steering lock device 10 to the steering column post 1 in this state.
[0047] (Function of the Electric Steering Lock Device in the Preferred Embodiment of the Present Invention)
[0048] In the state that the lock bar 60 is connected with the groove part 5 a of the steering shaft 5 ( FIG. 2 ), when operating a switch of the vehicle to a position such as “ACC”, “ON” and “START”, the motor 70 rotates in a predetermined rotational direction, the lock bar 60 is activated through the warm wheel 31 , the rotation shaft 30 and the lock stopper 50 , and the connection of the lock bar 60 and the steering shaft 5 are unlocked, to provide the non-connecting state. In a process of this operation, the motor 70 rotates at high speed (for instance, 9600 rpm). As a result, the rotation shaft 30 receives a strong force between the edge 30 b and the load receiving part 40 a of the bush 40 as a reaction. However, the edge 30 b and the load receiving part 40 a contact with each other in a state of being sidably rotatable without clearance and without backlash, abnormal noise such as impact sound etc. is not generated in the operation as mentioned above. Furthermore, it is similar in the radial direction. Furthermore, since the bush 40 comprises, for instance, the stainless steel, problems of scraping or abrasion by the rotation of the rotation shaft 30 do not occur in a long-term use.
[0049] FIG. 5 is a cross sectional view of the electric steering lock device 10 in the preferred embodiment according to the present invention showing a non-connecting state, in which a lock bar 60 is not connected with a groove part 5 a of a steering shaft 5 .
[0050] In the state that the lock bar 60 is not connected with the groove part 5 a of the steering shaft 5 , when operating the switch of the vehicle to a position of “LOCK”, the motor 70 rotates in a rotational direction opposite to the rotational direction in the operation as mentioned above, the lock bar 60 is activated through the warm wheel 31 , the rotation shaft 30 , the lock stopper 50 and the first spring 80 , and the lock bar 60 and the groove part 5 a of the steering shaft 5 are unlocked, to provide the connecting state. In this case, similarly to the above, the rotation shaft 30 receives the strong force between the edge 30 b and the load receiving part 40 a of the bush 40 as a reaction. However, the edge 30 b and the load receiving part 40 a contact with each other in the state of being slidably rotatable without clearance and without backlash, the abnormal noise such as the impact sound etc. is not generated in the operation as mentioned above. When the position of the groove part 5 a does not coincide with the position of the lock bar 60 , the connecting state is realized by connecting the lock bar 60 and the groove part 5 a of the steering shaft 5 with the bias load of the first spring 80 at the stage that the position of the groove part 5 a coincides with the position of the position of the lock bar 60 by the rotation of the steering shaft 5 .
[0051] (Effect of the Preferred Embodiment According to the Present Invention)
[0052] Since the moving direction of the lock bar 60 , the axial direction of the rotation shaft 30 , the moving direction by screwing with the external screw part 30 a of the rotation shaft 30 and the female screw part 50 a of the lock stopper 50 , the bias direction of the first spring 80 and the second spring 81 , and the press fitting direction of the bush 40 to the holes 21 a, 22 a are determined to be the same direction, these components can be built into the lock body 20 (the main lock body 21 and the lock body lid 22 ) from the same direction. As a result, the automatic assembling of the electric steering lock device 10 can be facilitated.
[0053] In the state that the rotation shaft 30 and the lock stopper 50 are built into the main lock body 21 from the same direction, the external screw part 30 a of the rotation shaft 30 and the female screw part 50 a of the lock stopper 50 are not screwed with each other yet, i.e. at the spinning state. However, in the state of applying the load on the front edge of the lock bar 60 and applying the load on the lock stopper 50 in the direction to screw with the rotation shaft 30 through the first spring 80 , by rotating the motor 70 , so as to move the lock bar 60 in the direction to be the non-connecting state with the groove part 5 a of the steering shaft 5 , the external screw part 30 a of the rotation shaft 30 and the female screw part 50 a of the lock stopper 50 can be screwed with each other. Namely, when building the components into the main lock body 21 , it is enough to build the rotation shaft 30 and the lock stopper 50 into the main lock body 21 from the same direction, without rotating the rotation shaft 30 . It is sufficient to provide the screw step of screwing the external screw part 30 a of the rotation shaft 30 with the female screw part 50 a of the lock stopper 50 , after building all necessary components into the lock body 20 . As a result, it is possible to realize the automatic assembling of the electric steering lock device 10 .
[0054] Although the invention has been described with respect to the specific embodiments for complete and clear disclosure, the appended claims are not to be therefore limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth.
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A built-in step is conducted by building a drive part which generates a rotation drive power, a rotation shaft to be rotated by the rotation drive power of the drive part through a gear mechanism, a lock stopper to be screwed with the rotation shaft to move axially by rotating of the rotation shaft, a lock bar which moves between a lock position for locking a steering shaft by movement of the lock stopper and an unlock position for unlocking the steering shaft, and a first spring interposed between the lock stopper and the lock bar for giving a bias load, into a lock body to be installed in a mounting hole part of a steering column post of a vehicle from the same direction. Thereafter, a screwing step for screwing the rotation shaft and the lock stopper after the built-in step is conducted to assemble an electric steering lock device.
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[0001] This application is a continuation of U.S. patent application Ser. No. 10/286,107, filed Oct. 31, 2002, which claims the benefit of Japanese Patent Application No. 2001-333933 filed on Oct. 31, 2001. The present invention relates to an agent and method for treating biodegradable synthetic yarns.
FIELD OF THE INVENTION
Background of the Invention
[0002] Synthetic fibers fabricated primarily from polyamide, polyester, vinylon, polyolefin, etc. are now used as industrial synthetic fibers for fishery, agricultural, and construction uses, because improved tenacity and weatherproof are demanded in such applications. For lack of self-degradability, however, such synthetic fibers, if left undisposed at hills and fields and in the sea after use, offer problems that not only are they detrimental to landscapes, but also they cling to birds, oceanic life, divers or the like, killing them or to marine engines, leading to shipwrecks. These problems may be solved if used-up synthetic fibers are disposed by incineration, landfilling or regeneration; however, they are still left undisposed at hills and fields or in the sea because much labor and cost are taken for such disposals. To provide a solution to those problems, the use of synthetic fibers fabricated from biodegradable polymers is now taken up for consideration, and so a variety of biodegradable synthetic fibers are under development. In particular, efforts are focused on making fibriform lactic acid polymers because they are biodegradable polymers from which articles having practical mechanical properties and heat resistance can be formed at relatively low costs. The present invention relates to improvements in an agent and method for treating biodegradable synthetic yarns fabricated from lactic acid polymers.
[0003] For agents for treating biodegradable synthetic yarns fabricated from lactic acid polymers, there have so far been proposed (1) an agent comprising water, ethylene glycol, polyethylene glycol, silicone oil, etc. (JP-A's 10-110332 and 2000-154425), (2) an agent in which mineral oil lubricants are used as a lubricant (JP-A 2000-192370), and (3) an agent comprising an anionic surfactant such as potassium laurylphosphate, an cationic surfactant such as a quaternary ammonium salt, a nonionic surfactant such as an aliphatic higher alcohol and a higher fatty acid ethylene oxide adduct, a polyalkylene glycol such as polyethylene glycol, block copolymer of polyethylene glycol and polypropylene glycol, and a silicone oil such as dimethylsiloxane, polyether-modified silicone oil and higher alcohol-modified silicone (JP-A's 7-118922 and 7-126970). However, problems with those prior art agents are that they cannot impart any sufficient lubricity, cohesion or the like to biodegradable synthetic yarns fabricated from lactic acid polymers, and so fuzzing and yarn breakage are often found at every step from spinning to down-stream step, especially at a false twisting step. These factors, combined with poor bulkiness, then interact one another, resulting in a failure in producing yarns having satisfactory mechanical properties in a stable fashion.
[0004] An object of the present invention is to provide an agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component (hereinafter called the lactic acid polymer), which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns that the yarns can be prevented from fuzzing and breaking at every step from spinning to down- stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner.
[0005] The inventors have now found that for treating biodegradable synthetic yarns fabricated from the lactic acid polymer it is reasonably preferable to use an agent comprising a specific functional agent at a given proportion and having a friction coefficient in a predetermined range.
SUMMARY OF THE INVENTION
[0006] Thus, the present invention provides an agent for treating biodegradable synthetic yarns produced from the lactic acid polymer, characterized by comprising 0.1 to 30% by weight of the following functional agent and a lubricant and a surfactant in a total amount of 70 weight % or greater and having the following friction coefficient in the range of 0.04 to 0.35. The present invention also provides a method for treating biodegradable synthetic yarns produced from the lactic acid polymer, characterized in that such an agent for treating biodegradable synthetic yarns is provided in an aqueous solution form, and the yarns are then applied with that aqueous solution in an amount of 0.1 to 3 weight % as calculated on the basis of said agent.
[0007] The functional agent comprises one or more compounds selected from the following polyether compound having an average molecular weight of 3,000 to 20,000, the following polyether polyester compound having an average molecular weight of 3,000 to 50,000 and a polyolefin wax having an average molecular weight of 1,000 to 10,000, wherein:
[0008] said polyether compound is represented by formula 1 (A−B) n T (formula 1) where A is a hydrogen atom, a monovalent hydrocarbon group or an acyl group, B is residual group obtained by removing hydrogen atoms in all hydroxyl groups from polyoxyalkylene glycol containing a polyoxyalkylene group of which the oxyalkylene unit have 2 to 4 carbon atoms, T is a monovalent to tetravalent hydrocarbon group or a hydrogen atom, and n is an integer of 1 to 4 when T is a monovalent to tetravalent hydrocarbon group and 1 when T is a hydrogen atom, and
[0009] said polyether polyester compound comprises one or more compounds selected from a polyether polyester compound obtained by the polycondensation of the following component D and the following component E and a polyether polyester compounds obtained by the polycondensation of the following component D, the following component E and the following component F, wherein:
[0010] said component D comprises one or more compounds selected from an aliphatic dicarboxylic acid having 4 to 22 carbon atoms, an ester-forming derivative of said aliphatic dicarboxylic acid, an aromatic dicarboxylic acid and an ester-forming derivative of said aromatic dicarboxylic acid,
[0011] said component E comprises one or more compounds selected from a polyoxyalkylene monol, a polyoxyalkylene diol and a polyoxyalkylene triol, each containing a polyoxyalkylene group having as a constitutional unit an oxyalkylene unit having 2 to 4 carbon atoms, and
[0012] said component F comprises an alkylene diol having 2 to 6 carbon atoms.
[0013] The friction coefficient of the agent is defined by a value as found in a 25° atmosphere having a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester.
ADVANTAGES OF THE INVENTION
[0014] As can already be understood from the foregoing and the specification and claims which follow, the advantages of the present invention are that improved lubricity, cohesion, etc. are so imparted to the biodegradable synthetic yarns fabricated from the lactic acid polymer that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner.
[0015] It is therefor an object of the invention is to provide an agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component.
[0016] It is an additional object of the invention to provide such an agent and method which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns and that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step.
[0017] It is a further object of this invention to provide improve yarns so treated in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of this invention.
[0019] FIG. 1 depicts Table 1, showing the compositions, etc. of the agents for treating biodegradable synthetic yarns according to the specification.
[0020] FIG. 2 depicts Table 2 which shows the results of various testing of the embodiments of the device and method herein disclosed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The functional agent used with the agent for treating biodegradable synthetic yarns according to the present invention comprises (1) a polyether compound having an average molecular weight of 3,000 to 20,000 and represented by formula 1, (2) a polyether polyester compound having an average molecular weight of 3,000 to 50,000, which is obtained by the polycondensation of the components D and E, (3) a polyether polyester compound having an average molecular weight of 3,000 to 50,000, which is obtained by the polycondensation of the components D, E and F, and (4) a polyolefin wax having an average molecular weight of 1,000 to 10,000.
[0022] The polyether compound used as the functional agent and represented by formula 1 includes (1) a polyether compound wherein all A's in formula 1 are hydrogen atoms (hereinafter called the polyether compound (a)), (2) a polyether compound wherein some of A's in formula 1 are hydrogen atoms with the rest being monovalent hydrocarbon groups (hereinafter called the polyether compound (b)), (3) a polyether compound wherein all A's in formula 1 are monovalent hydrocarbon groups (hereinafter called the polyether compound (c)), (4) a polyether compound wherein some of A's in formula 1 are hydrogen atom with the rest being acyl groups (hereinafter called the polyether compound (d)), (5) a polyether compound wherein all A's in formula 1 are acyl groups (hereinafter called the polyether compound (e)), (6) a polyether compound wherein some of A's in formula 1 are hydrogen atoms with the rest being monovalent hydrocarbon and acyl groups (hereinafter called the polyether compound (f)), and (7) a polyether compound wherein some of A's in formula 1 are monovalent hydrocarbon groups with the rest being acyl groups (hereinafter called the polyether compound (g)).
[0023] The polyether compounds (a) through (g) may all be synthesized by methods known in the art. For instance, the polyether compound (a) may be synthesized by the successive addition of an alkylene oxide having 2 to 4 carbon atoms to the monovalent to tetravalent hydroxy compound having a hydrocarbon group, which corresponds to T in formula 1. The polyether compounds (b) and (c) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the hydrocarbon groups corresponding to A in formula 1 by means of etherification. The polyether compounds (d) and (e) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the acyl groups corresponding to A in formula 1 by means of acylation. The polyether compounds (f) and (g) may each be synthesized by hindering the whole or a part of terminal hydroxyl groups in the polyether compound (a) with the hydrocarbon groups corresponding to A in formula 1 by means of etherification and with the acyl groups corresponding to A in formula 1 by means of acylation.
[0024] The monovalent to tetravalent hydroxy compounds used for the synthesis of polyether compound (a) include (1) monovalent, aliphatic hydroxy compounds having 1 to 40 carbon atoms such as methyl alcohol, butyl alcohol, octyl alcohol, lauryl alcohol, stearyl alcohol, ceryl alcohol, isobutyl alcohol, 2-ethylhexyl alcohol, isododecyl alcohol, isohexadecyl alcohol, isostearyl alcohol, isotetracosanyl alcohol, 2-propanol, 2-hexanol, 12-eicosanol, vinyl alcohol, butenyl alcohol, hexadecenyl alcohol, oleyl alcohol, eicosenyl alcohol, 2-methyl-2-propylene-1-ol, 6-ethyl-2-undecen-1-ol, 2-octen-5-ol and 15-hexadecen-2-ol; (2) monovalent hydroxy compounds having an aromatic ring such as phenol, propylphenol, octylphenol and tridecylphenol; and (3) divalent to tetravalent, aliphatic hydroxy compounds such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane and pentaerythritol. Among these, monovalent, aliphatic hydroxy compounds having 1 to 6 carbon atoms and divalent, aliphatic hydroxy compounds having 2 to 4 carbon atoms are preferred, although particular preference is given to propyl alcohol, butyl alcohol, ethylene glycol, propylene glycol and trimethylolpropane.
[0025] The alkylene oxides having 2 to 4 carbon atoms used for the synthesis of polyether compound (a), for instance, include ethylene oxide, propylene oxide, 1,2-butylene oxide and 1,4-butylene oxide, which may be used alone or in admixture. When the alkylene oxides are used in admixture, they may be added to the hydroxy compound in random addition, block addition, and blockrandom addition forms.
[0026] In the polyether compounds (b) and (c), the monovalent hydrocarbon group corresponding to A in formula 1, for instance, includes (1) monovalent, aliphatic hydrocarbon groups having 1 to 8 carbon atoms such as methyl, ethyl, propyl, butyl, octyl, vinyl, butenyl and hexadecenyl groups and (2) monovalent hydrocarbon groups having an aromatic ring such as phenoxy, propylphenoxy, octylphenoxy and benzyl groups; however, preference is given to methyl groups. Known processes may be applied to the synthesis of such polyether compounds (b) and (c). For instance, use may be made of a process wherein an alkyl halide reacts with a metal complex salt of the polyether compound (a).
[0027] In the polyether compounds (d) and (e), the acyl group corresponding to A in formula 1, for instance, includes (1) aliphatic acyl groups having 2 to 22 carbon atoms such as acetyl, propanoyl, butanoyl, hexnoyl, heptanoyl, oxtanoyl, nonanoyl, decanoyl, hexadecanoyl, octadecanoyl, hexadecenoyl, eicosenoyl and octadecenoyl groups and (2) acyl groups having an aromatic ring such as benzoyl, toluoyl and naphthoyl groups, among which decanoyl and octadecenoyl groups are preferred. Known processes may be applied to the synthesis of such polyether compounds (d) and (e). For instance, use may be made of a process wherein an acyl halide reacts with a metal complex salt of the polyether compound (a).
[0028] For the hydrocarbon group corresponding to A in formula 1 in the polyether compounds (f) and (g), the same as referred to in conjunction with the polyether compounds (b) and (c) may hold true, and for the acyl group corresponding to A in formula 1, the same as referred to in conjunction with the polyether compounds (d) and (e) may go true. Known processes may be applied to the synthesis of such poylyether compounds (f) and (g). For instance, use may be made of processes wherein an alkyl halide reacts with a metal complex salt of the polyether compound (a) and an acyl halide reacts with the resulting reaction product.
[0029] All the polyether compounds as mentioned above and represented by formula 1 have an average molecular weight of 3,000 to 20,000, and preferably 3,500 to 18,000.
[0030] The polyether polyester compound used as the functional agent includes (1) a polyether polyester compound obtained by the polycondensation of component (D) and component (E), and (2) a polyether polyester compound obtained by the polycondensation of component (D), component (E) and component (F).
[0031] The component (D) used for the synthesis of the polyether polyester compound, for instance, includes (1) aliphatic dicarboxylic acids having 4 to 22 carbon atoms such as succinic acid, adipic acid, azelaic acid, sebacic acid, α,ω-dodecane dicarboxylic acid, dodecenylsuccinic acid, octadecenyl dicarboxylic acid and cyclohexane dicarboxylic acid, (2) aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, 5-sulfoisophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid and 1,4-naphthalene dicarboxylic acid, (3) ester-forming derivatives of said (1) such as dimethyl succinate, dimethyl adipate, dimethyl azelate and dimethyl sebacate, and (4) ester-forming derivatives of said (2) such as dimethyl phthalate, dimethyl isophthalate, dimethyl terephthalate, 5-sulfoisophthalic acid dimethyl ester salt, 2,6-bis(methoxycarbonyl)-naphtalene, 2,6-bis(ethoxycarbonyl)-naphthalene and 1,4-bis(methoxycarbonyl)-naphthalene. Among these, preference is given to the aliphatic dicarboxylic acids having 6 to 12 carbon atoms, e.g., adipic acid, azelaic acid and sebacic acid, the aromatic dicarboxylic acid, e.g., phthalic acid, terephthalic acid and 5-sulfoisophthalic acid dimethyl ester salt, and the ester-forming derivatives thereof. Such organic dicarboxylic acids and ester-forming derivaties thereof, when used for polycondensation, may be used alone or in combination of two or more.
[0032] The component (E) used for polyether polyester synthesis contains polyoxyalkylene monols, polyoxyalkylene diols and polyoxyalkylene triols or any desired mixtures thereof, wherein an oxyalkylene unit having 2 to 4 carbon atoms is used as the constitutional unit.
[0033] The polyoxyalkylene monols, for instance, include those wherein one terminals of such polyoxyalkylene diols as mentioned below are hindered by monovalent hydrocarbon groups. Such monovalent hydrocarbon groups, for instance, include (1) aliphatic hydrocarbon groups having 1 to 22 carbon atoms, e.g., methyl, ethyl, butyl, n-octyl, lauryl, stearyl, isopropyl and 2-ethylhexyl groups and (2) hydrocarbon groups having an aromatic ring, e.g., phenyl, monobutylphenyl, octylphenyl and nonylphenyl groups, among which the phenyl group is preferred.
[0034] The polyoxyalkylene diols, for instance, include reaction products obtained by the addition of an alkylene oxide having 2 to 4 carbon atoms to alkylene diols having 2 to 6 carbon atoms, e.g., ethylene glycol, 1,2-propane-diol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and neopentyl glycol. Preference is given to polyoxyalkylene diols having an average molecular weight of 500 to 5,000, and particular preference is given to polyoxyalkylene diols having such an average molecular weight, wherein the oxyalkylene unit comprises an oxyethylene unit or an oxyethylene unit and an oxypropylene unit and the oxyethylene unit/oxypropylene unit proportion is in the range of 100/0 to 50/50 (mol %).
[0035] The polyoxylalkylene triols include reaction products obtained by the addition of an alkylene oxide having 2 to 4 carbon atoms to an alkylene diol having 2 to 6 carbon atoms, e.g., glycerol and trimethylolpropane. Preference is given to polyoxyalkylene triols having an average molecular weight of 500 to 5,000, and particular preference is given to polyoxyalkylene diols having such an average molecular weight, wherein the oxyalkylene unit comprises an oxyethylene unit or an oxyethylene unit and an oxypropylene unit and the oxyethylene unit/oxypropylene unit proportion is in the range of 100/0 to 50/50 (mol %).
[0036] The component (F) used for polyether polyester synthesis includes an alkylene diol having 2 to 6 carbon atoms, e.g., ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and neopenthyl glycol, among which ethylene glycol, 1,2-propanediol and 1,3-propanediol are preferred.
[0037] When the polyether polyester compound used as the functional agent is a reaction product obtained by the polycondensation of component (D) and component (E), it should preferably contain a constitutional unit formed from component (D) at a proportion of 40 to 60 mol %, preferably 48 to 52 mol %, and a constitutional unit formed from component (E) at a proportion of 40 to 60 mol %, preferably 48 to 52 mol %. When that polyether polyester compound is a reaction product obtained by the polycondensation of component (D), component (E) and component (F), it should preferably contain a constitutional unit formed from component (D) at a proportion of 20 to 40 mol %, preferably 20 to 25 mol %, a constitutional unit formed from component (E) at a proportion of 5 to 30 mol %, preferably 15 to 20 mol %, and a constitutional unit formed from component (F) at a proportion of 40 to 70 mol %, preferably 50 to 60 mol %.
[0038] Known processes may be applied to the synthesis of the polyether polyester compound used as the functional agent. For instance, reliance is on a direct poly-condensation process wherein an organic dicarboxylic acid that is component (D), a polyoxylalkylene diol that is component (E) and an alkylene diol that is component (F) are subjected to polycondensation in the presence of an anionic polymerization catalyst, a cationic polymerization catalyst, a coordination anionic polymerization catalyst or the like known in the art and under high-temperature, high-vacuum conditions while low-molecular-weight compounds are distilled off, thereby obtaining a polyether polyester compound.
[0039] Referring to the polyether polyester compounds as explained above, both the polyether polyester compound obtained from component (D) and component (E) and the polyether polyester compound obtained from component (D), component (E) and component (F) should have an average molecular weight of 3,000 to 50,000, and preferably 3,500 to 40,000.
[0040] The polyolefin wax used as the functional agent, for instance, includes oxidized polyethylene wax and copolymers of α-olefin and unsaturated fatty acids. The α-olefin used for the synthesis of such copolymers, for instance, includes ethylene, 1 propylene, 1 butene, 1 decene, 1 dodecene and 1 octadodecene. The unsaturated fatty acids, for instance, include acrylic acid, methacrylic acid, 4-pentenoic acid and 5-hexenoic acid. Preferable polyolefin waxes are oxidized polyethylene wax, and copolymers of ethylene and/or 1 propylene and acrylic acid and/or methacrylic acid. The waxes used should all have an average molecular weight of 1,000 to 10,000.
[0041] In the agent for treating biodegradable synthetic yarns according to the present invention, one or two or more compounds selected from such polyether compounds, polyether polyester compounds and polyolefin waxes as explained above is or are used as the functional agent or agents. However, it is preferable to use one or two or more compounds selected from the polyether compounds having an average molecular weight of 3,500 to 18,000 and the polyether polyester compounds having an average molecular weight of 3,500 to 40,000.
[0042] The agent for treating biodegradable synthetic yarns according to the present invention contains, in addition to the functional agent as explained above, a lubricant and a surfactant. For such a lubricant, lubricants that are known per se, for instance, aliphatic esters, polyether compounds and mineral oils or any desired mixtures thereof may be used.
[0043] The aliphatic ester used as the lubricant is obtained by the esterification of an aliphatic alcohol and a fatty acid, wherein carbon atoms of a hydrocarbon group in the aliphatic alcohol moiety and carbon atoms of a hydrocarbon group in the fatty acid moiety preferably adds up to 17 to 60, and more preferably 22 to 36. The aliphatic alcohols used for the synthesis of such aliphatic esters, for instance, include (1) aliphatic monohydric alcohols such as methyl alcohol, ethyl alcohol, butyl alcohol, 2-ethylhexyl alcohol, lauryl alcohol, palmityl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol and behenyl alcohol and (2) aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, glycerol, trimethylolpropane, sorbitol and pentaerythritol. The fatty acids, for instance, include (1) saturated aliphatic monocarboxylic acids such as acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, cerotic acid, montanic acid and mellisic acid, (2) aliphatic monoenoic monocarboxylic acids such as linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, (3) aliphatic nonconjugated polyenoic monocarboxylic acids such as linolic acid, linoleic acid and arachidonic acid, and (4) aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. More specifically, fatty acid esters obtained from aliphatic monohydric alcohols and aliphatic monocarboxylic acids, for instance, include lauryl oleate, stearyl oleate, oleyl oleate, octyl oleate, tridecyl oleate, methyl oleate, butyl oleate, 2-ethylhexyl oleate, octyl stearate, oleyl stearate, oleyl palmitate, oleyl laurate, oleyl isostearate and oleyl octanate, with lauryl oleate and octyl stearate being preferred. Exemplary fatty acid esters obtained from aliphatic polyhydric alcohols and aliphatic monocarboxylic acids are ethylene glycol dilaurate, propylene glycol distearate, butanediol palmitate, hexanediol dilaurate, glycerol tri(12-hydroxystearate), glycerol trioleate, glycerol palmitate distearate, trimethylolpropane tripalmitate, sorbitan tetraoleate and pentaerythritol tetralaurate, with glycerol tri(12-hydroxystearate) and soribtan tetraoleate being preferred. Exemplary fatty acid esters obtained from aliphatic monohydric alcohols and aliphatic dicarboxylic acids are distearyl succinate, distearyl glutarate, dicetyl adipate, dibehenyl pimelate, dibehenyl suberate, disteary azelate and distearyl sebacate, with dicetyl adipate being preferred.
[0044] Preferable for the polyether compound used as the lubricant are those represented by the aforesaid formula 1 and having an average molecular weight in the range of 700 to 2,900.
[0045] The mineral oil used as the lubricant should have a viscosity at 30° of preferably 2×10 −6 to 2×10 −4 m 2 /s, and more preferably 2×10 −6 to 2×10 −5 m 2 /s. The more preferable mineral oil is a liquid paraffin oil.
[0046] The surfactant used may be those that are known per se, e.g., nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants or any desired mixtures thereof.
[0047] The nonionic surfactants used, for instance, include (1) oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, (2) fatty acid esters of oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, (3) fatty acid esters of aliphatic polyhdric alcohols having 2 to 6 carbon atoms, (4) fatty acid esters of oxyalkylene adducts of aliphatic polyhydric alcohols having 2 to 6 carbon atoms, (5) oxyalkylene adducts of aliphatic amines having 6 to 22 carbon atoms, and (6) oxyalkylene adducts of aliphatic amides having 6 to 22 carbon atoms.
[0048] Referring to the oxyalkylene adducts of the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the nonionic surfactant, the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the synthesis material for the same, include hexyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, hexadecenyl alcohol, heptadecyl alcohol, octadecyl alcohol, octadecenyl alcohol, nonadecyl alcohol, eicosyl alcohol, eicosenyl alcohol, docosayl alcohol, 2-ethylhexyl alcohol, 3,5,5-trimethylhexyl alcohol, etc. Among these, aliphatic monohydric alcohols having 8 to 18 carbon atoms are preferred, although 2-ethylhexyl alcohol and dodecyl alcohol are particularly preferred. Oxyalkylene adducts of such aliphatic monohydric alcohols having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts as well as any desired mixtures thereof; however, preference is given to oxyalkylene adducts wherein oxylalkylenes are added at a proportion of 3 to 30 moles per mole of the aliphatic monohydric alcohol having 6 to 22 carbon atoms.
[0049] Referring to the fatty acid esters of oxyalkylene adducts of the aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the nonionic surfactant, the same as explained previously holds for the oxyalkylene adducts of aliphatic monohydric alcohols having 6 to 22 carbon atoms, used as the synthesis material for one of the same. In this case, however, it is preferable to add the oxyalkylene at a proportion of 1 to 10 moles per mole of the aliphatic monohydric alcohol having 6 to 22 carbon atoms. The fatty acid used as another synthesis material, for instance, includes (1) saturated aliphatic monocarboxylic acids having 2 to 22 carbon atoms such as acetic acid, butyric acid, caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, cerotic acid, montanic acid and mellisic acid, (2) aliphatic monoenemonocarboxylic acids such as linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, (3) aliphatic nonconjugated polyenoic acids having 18 to 22 carbon atoms such as linolic acid, linoleic acid and arachidonic acid, and (4) aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid.
[0050] Referring to fatty acid esters of aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the nonionic surfactant, the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the synthesis material for one of the same, for intance, include ethylene glycol, propylene glycol, butanediol, hexanediol, glycerol, trimethylolpropane, sorbitol and pentaerythritol. The same as explained previously goes true for the fatty acids used as another synthesis material. Exemplary fatty acid partial esters of such polyhydric alcohols are ethylene glycol monolaurate, propylene glycol monostearate, butanediol monopalmitate, hexanediol monolaurate, glycerol di(12-hydroxystearate), glycerol dioleate, glycerol monopalmitate monostearate, trimethylolpropane dipalmitate, sorbitan monooleate and pentaerythritol dilaurate, with glycerol di(12-hydroxystearate) and sorbitan monooleate being preferred.
[0051] Referring to the fatty acid esters of oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the nonionic surfactant, the same as set forth previously holds true for the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, used as the synthesis material for one of the same. Such oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 3 to 40 moles per mole of the aliphatic polyhydric alcohol having 2 to 6 carbon atoms. The same as mentioned previously goes true for the fatty acids used as another synthesis material. Examples of such fatty acid esters of oxyalkylene adducts of the aliphatic polyhydric alcohols having 2 to 6 carbon atoms are polyoxyethylene glycol dilaurate, polyoxypropylene glycol distearate, 1,4-di(polyoxyethylene)butanediol palmitate, 1,6-di(polyoxyethylene-polyoxypropylene)hexanediol dilaurate, and 1,2,3-tri(polyoxyethylene)glycerol tri(12-hydroxystearate), although polyoxyethylene glycol dilaurate and 1,2,3-tri(polyoxyethylene)glycerol tri(12-hydroxystearate) are preferred.
[0052] Referring to the oxyalkylene adducts of aliphatic amines having 6 to 22 carbon atoms, used as the nonionic surfactant, the aliphatic amines having 6 to 22 carbon atoms, used as the synthesis material for the same, include (1) saturated aliphatic amines such as hexylamine, octylamine, nonylamine, laurylamine, myristylamine, cetylamine, stearylamine and arachinylamine, (2) unsaturated aliphatic amines scuh as 2-tetradecenylamine, 2-pentadecenylamine, 2-octadecenylamine, 15-hexadecenylamine, oleylamine, linolenylamine and eleostearylamine, and so on, among which laurylamine, palmitylamine and stearylamine are preferred. Such oxyalkylene adducts of the aliphatic amines having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 2 to 20 moles per mole of the aliphatic amines having 6 to 22 carbon atoms.
[0053] Referring to the oxyalkylene adducts of aliphatic amide compounds having 6 to 22 carbon atoms, used as nonionic surfactant, the aliphatic amide compounds having 6 to 22 carbon atoms, used as the synthesis material for the same, includes those obtained by the amidation of polyalkylene polyamines and fatty acids. In such amidation, the proportion of fatty acids to the polyalkylene polyamines should be such that at least one of terminal amino groups of polyalkylene polyamine has to be amidated; however, that proportion should preferably be such that amino groups at both terminals of polyalkylene polyamine be amidated. The polyalkylene polyamines that form such fatty acid amides, for instance, include diethylenetriamine, triethylenetetramine, di(trimethylene)triamine and tri(trimethylene)tetramine, among which diethylenetriamine is preferred. The fatty acids used, for instance, include caproic acid, caprylic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, cerotic acid, montanic acid, mellisic acid, linderic acid, palmitoleic acid, oleic acid, elaidic acid and vaccenic acid, among which laruic acid and oleic acid are preferred. Such oxyalkylene adducts of the aliphatic amide compounds having 6 to 22 carbon atoms, for instance, include oxyethylene adducts, oxypropylene adducts and oxyethylene-oxypropylene adducts or any desired mixtures thereof. However, it is preferable to use adducts wherein the oxyalkylene is added at a proportion of 1 to 15 moles per mole of the aliphatic amide compound having 6 to 22 carbon atoms.
[0054] The anionic surfactant used herein, for instance, include fatty acid salts, organic sulfonic acid salts, organic sulfuric acid salts and organic phosphoric acid ester salts. The fatty acid salts used as the anionic surfactant include (1) alkaline metal salts of fatty acids having 6 to 22 carbon atoms, and (2) amine salts of fatty acids having 6 to 22 carbon atoms. Such fatty acids having 6 to 22 carbon atoms, for instance, include capric acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, erucic acid, linolic acid and dodecenylsuccinic acid. The alkaline metals that form such alkaline metal salts of fatty acids having 6 to 22 carbon atoms, for instance, are sodium, potassium and lithium, and the amines that form the amine salts, for instance, are (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, butylamine, dibutylamine, tributylamine and octylamines, (2) aromatic or heterocyclic amines such as aniline, pyridine, morphorine and piperazine or derivatives thereof, (3) alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, butyldiethanolamine, octyldiethanolamine and lauryldiethanolamine, and (4) ammonia. Among these, potassium dodecenylsuccinate is preferred.
[0055] The organic sulfonic acid salts used as the anionic surfactant used herein, for instance, include (1) alkaline metal alkylsulfonates such as sodium decylsulfonate, sodium dodecylsuflonate, lithium tetradecylsulfonate and potassium hexadecylsulfonate, (2) alkaline metal alkylarylsulfonates such as sodium butylbenzenesulfonate, sodium dodecylbenzenesulfonate, potassium octadecyl-benzenesulfonate and sodium dibutylnaphthalenesulonate, and (3) alkaline metal ester sulfonates such as sodium 1,2-bis(dioctyloxycarbonyl)-ethanesulfonate, lithium 1,2-bis(dibutyloxycarbonyl)-ethanesulfonate, sodium 2-(dodecyloxy)-2-oxoethane-1-sulfonate and potassium 2-(nonylphenoxy)-2-oxoethane-1-sulfonate. Among these, alkaline metal alkylsulfonates and alkaline metal alkylarylsufonates, especially with 12 to 18 carbon atoms, are preferred.
[0056] The organic sulfates used as the anionic surfactant, for instance, include (1) alkaline metal alkylsuflates such as sodium decylsulfate, sodium dodecylsulfate, lithium tetradecylsulfate and potassium hexadecylsulfate, and (2) alkaline metal salts of sulfides of natural fats and oils such as sulfated tallow oil and sulfated castor oil. In particular, sodium dodecylsulfate is preferred.
[0057] The organic phosphoric acid ester salts used as the anionic surfactant include (1) alkyl phosphoric ester salts containing an alkyl group having 4 to 22 carbon atoms, and (2) (poly)oxyalkylene alkyl ether phosphoric ester salts in which an alkyl group has 4 to 22 carbon atoms and the number of an oxyalkylene unit that forms a (poly)oxy-alkylene group is 1 to 5.
[0058] The alkyl phosphoric ester salts containing an alkyl group having 4 to 22 carbon atoms, for instance, include butyl phosphoric ester salt, pentyl phosphoric ester salt, hexyl phosphoric ester salt, octyl phosphoric ester salt, isooctyl phosphoric ester salt, 2-ethylhexyl phosphoric ester salt, decyl phosphoric ester alkali metal salt, lauryl phosphoric ester alkali metal salt, tridecyl phosphoric ester salt, myristyl phosphoric ester salt, cetyl phosphoric ester salt, stearyl phosphoric ester salt, eicosyl phosphoric ester salt and behenyl phosphoric ester salt. These alkyl phosphoric ester salts also include a pure form of monoester and a pure form of diester or mixtures thereof. The diester includes a diester having identical alkyl groups (symmetric diester) and a diester having different alkyl groups (asymmetric diester). The alkyl phosophoric ester salt as explained above is formed from an acidic alkyl phosphoric ester, and a base compound for which an alkali metal hydroxide, an organic amine compound, an ammonium compound or the like are mentioned.
[0059] The (poly)oxyalkylene alkyl phosphoric ester salt, in which the alkyl group has 4 to 22 carbon atoms and the number of an oxyalkylene unit that forms a (poly)oxyalkylene group, includes polyoxyalkylene butyl ether phosphoric ester salt, polyoxylalkylene hexyl ether phosphoric ester salt, polyoxylalkylene octyl ether phosphoric ester salt, polyoxyalkylene isooctyl ether phosphoric ester salt, polyoxyalkylene decyl ether phosphoric ester salt, polyoxyalkylene lauryl ether phosphoric ester salt, polyoxyalkylene tridecyl ether phosphoric ester alkali metal salt, polyoxyalkylene myristyl ether phosphoric ester alkali metal salt, polyoxyalkylene cetyl ether phosphoric ester salt, polyoxyalkylene stearyl ether phosphoric ester salt, polyoxyalkylene behenyl ether phosphoric ester salt, etc. The (poly)oxyalkylene group in such (poly)oxyalkylene alkyl ether phosphoric ester salts, for instance, includes (poly)oxyethylene group, (poly)oxypropylene group and (poly)oxyethylene-oxypropylene group. These polyoxyalkylene alkyl ether phosphoric ester salts also include a pure form of monoester and a pure form of diester or mixtures thereof. The diester includes a diester having identical alkyl groups (symmetric diester) and a diester having different alkyl groups (asymmetric diester). The (poly)oxyalkylene alkyl ether phosphoric ester salt as explained above is formed from an acidic (poly)oxyalkylene alkyl ether phosphoric ester, and a base compound for which an alkali metal hydroxide, an organic amine compound, an ammonium compound or the like are mentioned.
[0060] The cationic surfactant used includes a quaternary ammonium salt and an organic amine oxide. The quaternary ammonium salts used as the cationic surfactant, for instance, includes tetramethylammonium salt, triethylmethylammonium salt, tripropylethylammonium salt, tributylmethylammonium salt, tetrabutylammonium salt, triisooctylethylammonium salt, trimethyloctylammonium salt, dilauryldimethylammonium salt, trimethylstearylammonium salt, dibutenyldiethylammonium salt, dimethyldioleyl-ammonium salt, trimethyloleylammonium salt, tributylhydroxyethylammonium salt, dipropyl bis(2-hydroxyethyl)ammonium salt, octyl tris(2-hydroxyethyl)ammonium salt, and methyl tris(3-hydroxpropyl)ammonium salt.
[0061] The organic amine oxide used as the cationic surfactant, for instance, includes hexylamine oxide, octylamine oxide, nonylamine oxide, laurylamine oxide, myristylamine oxide, cetylamine oxide, stearylamine oxide, arachinylamine oxide, dihexylamine oxide, dioctylamine oxide, dinonylamine oxide, dilaurylamine oxide, dimyristylamine oxide, dicetylamine oxide and distearylamine oxide.
[0062] Various amphoteric surfactants may be used; however, it is preferable to use betaine type amphoretic surfactants such as octyl dimethyl ammonioacetate, decyl dimethyl ammonioacetate, dodecyl dimethyl ammonioacetate, hexadecyl dimethyl ammonioacetate, octadecyl dimethyl ammonioacetate, nonadecyl dimethyl ammonioacetate and octadecenyl dimethyl ammonioacetate.
[0063] As the surfactant used with the agent for treating biodegradable synthetic yarns according to the present invention, the nonionic, anionic, cationic and amphoteric surfactants may be used alone or in admixture of two or more; however, it is preferable to use the nonionic and anionic surfactants in admixture. More preferably in this case, a fatty acid salt and/or an organic sulfonic acid salt is used as the anionic surfactant.
[0064] The agent for treating biodegradable synthetic yarns according to the present invention comprises a functional agent in an amount of 0.1 to 30 weight %, preferably 0.5 to 20 weight %, and a lubricant and a surfactant in a total amount of 70 weight % or greater, preferably 80 weight % or greater. In one preferable embodiment of the invention, the agent comprises 20 to 80 weight % of lubricant and 10 to 70 weight % of surfactant, and in one more specific embodiment, that agent should more preferably comprise 1 to 18 weight % of functional agent, 34 to 75 weight % of lubricant and 15 to 65 weight % of surfactant.
[0065] Besides the functional agent, lubricant and surfactant as explained above, the agent for treating biodegradable synthetic yarns according to the present invention may contain other components such as antioxidants, antiseptic agent and rust preventives with the proviso that their contents are reduced as much as possible.
[0066] The agent for treating biodegradable synthetic yarns according to the present invention should have a friction coefficient in the range of 0.04 to 0.35, and preferably 0.05 to 0.16. The “friction coefficient” used herein is understood to be indicative of a value as measured in an atmosphere of 25° and a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester.
[0067] Referring to how to treat biodegradable synthetic yarns according to the present invention, the aforesaid agent for treating biodegradable synthetic yarns according to the present invention is first prepared in an aqueous solution form. Then, biodegradable synthetic yarns fabricated from the lactic acid polymer are oiled with that aqueous solution in an amount of 0.1 to 3% by weight, and preferably 0.5 to 1.5% by weight as calculated on the basis of said agent for treating biodegradable synthetic yarns. Known oiling methods such as a roller oiling method, a guide oiling method using a measuring pump, a dip oiling method and a spray oiling method may be used. Oiling may be carried out at the step of spinning biodegradable synthetic yarns fabricated from the lactic acid polymer or at the step of carrying out spinning and drawing simultaneously. It is here noted that the present invention can most efficiently be applied to biodegradable synthetic yarns that are subjected to false twisting.
[0068] The agent and method for the treatment of biodegradable synthetic yarns according to the present invention may be applied to biodegradable synthetic yarns that are fabricated from (1) polylactic acid that is a homopolymer of lactic acid, (2) a lactic acid copolymer obtained from lactic acid and a cyclic lactone such as ε-caprolactone, γ-butyrolactone and γ-valerolactone, (3) a lactic acid copolymer obtained from lactic acid and a hydroxy acid such as hydroxybutyric acid, hydroxy-isobutyric acid and hydroxyvaleric acid, (4) a lactic acid copolymer obtained from lactic acid and a glycol such as ethylene glycol, propylene glycol and 1,4-butanediol, (5) lactic acid and a dicarboxylic acid such as succinic acid, sebacic acid and adipic acid, and (6) mixtures of two or more of (1) to (5) above.
PREFERRED EMBODIMENTS OF THE INVENTION
[0069] Set out below are eight embodiments (1) to (8) of the agent for treating biodegradable synthetic yarns according to the present invention.
First Embodiment
[0070] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 10 weight % of the following functional agent (K-1), 75 weight % of the following lubricant (L-1) and 15 weight % of the following surfactant (S-1), and has a friction coefficient of 0.09:
[0000] Functional Agent (K-1)
[0071] A polyether compound having an average molecular weight of 10,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
[0000] Lubricant (L-1)
[0072] A 1/1 by-weight mixture of a polyether monol having an average molecular weight of 1,100, which is obtained by the random addition of ethylene oxide and propylene oxide to butyl alochol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and a polyether monol having a number-average molecular weight of 2,400, which is obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
[0000] Surfactant (S-1)
[0073] A 67/27/6 by-weight mixture of polyoxyethylene (with the number of repetition of oxyethylene unit being 5, hereinafter mentioned n=5) lauryl ether/sorbitan monooleate/sodium dodecylsulfonate.
Second Embodiment
[0074] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 16 weight % of the following functional agent (K-2), 62 weight % of the following lubricant (L-2), 21 weight % of the aforesaid surfactant (S-1) and 1 weight % of the following subordinate component (E-1), and has a friction coefficient of 0.07.
[0000] Functional Agent (K-2)
[0075] A polyether compound having an average molecular weight of 6,000, which is obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol are substituted by methyl groups.
[0000] Lubricant (L-2)
[0076] A 1/2 by-weight mixture of polyether monol having an average molecular weight of 2,500, which is obtained by the random addition of ethylene oxide and propylene oxide to dodecyl alcohol at an ethylene oxide-to-propylene oxide proportion of 40/60 by mole and polyether diol having a number-average molecular weight of 1,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 80/20 by mole.
[0000] Subordinate Component (E-1)
[0077] A polyether-modified silicone.
Third Embodiment
[0078] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 11 weight % of the following functional agent (K-3), 74 weight % of the aforesaid lubricant (L-1) and 15 weight % of the aforesaid surfactant (S-1), and has a friction coefficient of 0.10.
[0000] Functional Agent (K-3)
[0079] A polyether compound having an average molecular weight of 3,500, which is obtained by the random addition of ethylene oxide and butylene oxide to ethylene glycol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether diol are substituted by decanoyl groups.
Fourth Embodiment
[0080] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the aforesaid functional agent (K-3), 40 weight % of the aforesaid lubricant (L-1) and 55 weight % of the following surfactant (S-2), and has a friction coefficient of 0.11.
[0000] Surfactant (S-2)
[0081] A 14/85/2 by-weight mixture of polyoxyethylene (n=5) lauryl ether/decanoic ester of polyoxyethylene (n=4) lauryl ester/dipotassium dodecenylsuccinate.
Fifth Embodiment
[0082] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 1 weight % of the following functional agent (K-6), 42 weight % of the aforesaid lubricant (L-1) and 57 weight % of the aforesaid surfactant (S-2), and has a friction coefficient of 0.08.
[0000] Functional Agent (K-6)
[0083] A polyether polyester compound having an average molecular weight of 20,000, which is obtained from a 1/1 by-mole mixture of dimethyl terephthalate and polyethylene glycol having an average molecular weight of 1,000.
Sixth Embodiment
[0084] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 3 weight % of the aforesaid functional agent (K-6), 66 weight % of the aforesaid lubricant (L-2), 30 weight % of the aforesaid surfactant (S-1) and 1 weight % of the aforesaid subordinate component (E-1), and has a friction coefficient of 0.06.
Seventh Embodiment
[0085] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the following functional agent (K-7), 74 weight % of the aforesaid lubricant (L-1), 19 weight % of the aforesaid surfactant (S-1) and 2 weight % of the following subordinate component (E-2), and has a friction coefficient of 0.08.
[0000] Functional Agent (K-7)
[0086] A polyether polyester compound having an average molecular weight of 8,000, which is obtained from dimethyl terephthalate/dimethyl 5-sulfoisophthalate/polyethylene glycol having an average molecular weight of 600/ethyelene glycol at a proportion of 0.95/0.05/0.9/0.1 by mole.
[0000] Subordinate Component (E-2)
[0087] Ethylene glycol.
Eighth Embodiment
[0088] An agent for treating biodegradable synthetic yarns fabricated from the lactic acid polymer, which comprises 5 weight % of the aforesaid functional agent (K-7), 40 weight % of the following lubricant (L-3) and 55 weight % of the aforesaid surfactant (S-2), and has a friction coefficient of 0.10.
[0000] Lubricant (L-3)
[0089] Octyl stearate.
Ninth Embodiment
[0090] The ninth embodiment of the present invention is directed to a method for the treatment of biodegradable synthetic yarns.
[0091] According to this method the agent for treating biodegradable synthetic yarns according to any one of the 1st to 8th embodiments of the present invention is first provided in a 10 weight % aqueous solution form. Then, the biodegradable synthetic yarns spun from the lactic acid polymer are applied with that aqueous solution in an amount of 0.8 weight % as calculated on the basis of said agent.
[0092] By way of example but not by way of limitation, the present invention will now be explained with reference to working examples, etc., in which “part” means “part by weight” and “%” is given % by weight.
EXAMPLE
Experimentation 1
Preparation of the Agent for Treating Biodegradable Synthetic Yarns
Example 1
[0093] 10 parts of the following functional agent (K-1), 75 parts of the following lubricant (L-1) and 15 parts of the following surfactant (S-1) were uniformly mixed together to prepare the following agent (P-1) for treating biodegradable synthetic yarns, with a friction coefficient of 0.09.
[0000] Functional Agent (K-1)
[0094] A polyether compound having an average molecular weight of 10,000, which was obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
[0000] Lubricant (L-1)
[0095] A 1/1 by-weight mixture of a polyether monol having an average molecular weight of 1,100, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and a polyether monol having a number-average molecular weight of 2,400, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
[0000] Surfactant (S-1)
[0096] A 10/4/1 by-weight mixture of polyoxyethylene (with the number of repetition of oxyethylene unit being 5 and having an alkyl group having 12 carbon atoms) alkyl ether/sorbitan monooleate/sodium laurylsulfonate.
[0097] The friction coefficient of that agent was found in a 25° atmosphere having a relative humidity of 65% under a counter weight condition of 40 g/80 g, using a pendulum type oiliness friction tester manufactured by Shinko Zoki Co., Ltd.
Examples 2-19 & Comparative Examples 1-3
[0098] As in Example 1, the agents for treating biodegradable synthetic yarns according to Examples 2 to 19 and Comparative Examples 1 to 3 (P-2 to P-19 and R-1 to R-3) were prepared. Tabulated in Table 1 are the compositions, etc. of the agents for treating biodegradable synthetic yarns according to the examples inclusive of Example 1.
[0099] In Table 1, the amounts of the agent components used are given by part.
[0100] K-1 is a polyether compund having an average molecular weight of 10,000, which was obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 50/50 by mole.
[0101] K-2 is a polyether compound having an average molecular weight of 6,000, which was obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol were substituted by methyl groups.
[0102] K-3 is a polyether compound having an average molecular weight of 3,500, which was obtained by the random addition of ethylene oxide and butylene oxide to ethylene glycol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether diol were replaced by decanoyl groups.
[0103] K-4 is a polyether compond having an average molecular weight of 3,300, which was obtained by the random addition of ethylene oxide and butylene oxide to butyl alcohol at an ethylene oxide-to-butylene oxide proportion of 70/30 by mole.
[0104] K-5 is a polyether compound having an average molecular weight of 19,000, which was obtained by the random addition of ethylene oxide and propylene oxide to trimethylolpropane at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole and in which hydrogen atoms in all hydroxyl groups of resulting polyether triol were substituted by octadecanoyl groups.
[0105] K-6 is a polyether polyester compound having an average molecular weight of 20,000, which was obtained from a 1/1 by-mole mixture of dimethyl terephthalic acid and polyethylene glycol having an average molecular weight of 1,000.
[0106] K-7 is a polyether polyester compound having an average molecular weight of 8,000, which was obtained from a 0.95/0.05/0.9/0.1 by-mole mixture of dimethyl terephthalate, dimethyl 5-sulfoisophthalate, polyethylene glycol having an average molecular weight of 600 and ethylene glycol.
[0107] K-8 is a polyether polyester compound having an average molecular weight of 15,000, which was obtained from a 1/1/2/1 by-mole mixture of terephthalic acid, adipic acid, polyethylene glycol having an average molecular weight of 1,000 and polyethylene glycol monophenyl ether having an average molecular weight of 1,000.
[0108] K-9 is a polyether polyester compound having an average molecular weight of 45,000, which was obtained from a 3/3/1 by-mole mixture of dimethyl terephthalate, polyethylene glycol monophenyl ether having an average molecular weight of 600 and polyoxyethylene glycol triol having an average molecular weight of 500 obtained by adding ethyleneoxide to glycerin.
[0109] K-10 is an oxidized polyethylene wax having an average molecular weight of 2,400.
[0110] L-1 is a 1/1 by-weight mixture of polyether monol having an average molecular weight of 1,100, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 60/40 by mole and polyether monol having a number-average molecular weight of 2,400, which was obtained by the random addition of ethylene oxide and propylene oxide to butyl alcohol at an ethylene oxide-to-propylene oxide proportion of 75/25 by mole.
[0111] L-2 is a 1/2 by-weight mixture of polyether monol having an average molecular weight of 2,500, which is obtained by the random addition of ethylene oxide and propylene oxide to dodecyl alcohol at an ethylene oxide-to-propylene oxide proportion of 40/60 by mole and polyether diol having a number-average molecular weight of 1,000, which is obtained by the random addition of ethylene oxide and propylene oxide to ethylene glycol at an ethylene oxide-to-propylene oxide proportion of 80/20 by mole.
[0112] L-3 is octyal stearate.
[0113] L-4 is a 60/40 by-weight mixture of glycerol tri(12-hydroxystearate) and a mineral oil of 5×10 −6 m 2 /s.
[0114] S-1 is a 67/27/6 by-weight mixture of polyoxyethylene (n=5) lauryl ether, sorbintan monooleate and sodium dodecysulfonate.
[0115] S-2 is a 14/85/2 by-weight mixture of polyoxyalkylene (n=5) lauryl ether, decanoic ester of polyoxyethylene (n=4) lauryl ether, and dipotassium dodecenylsuccinic acid.
[0116] S-3 is a 70/10/20 by-weight mixture of polyoxyethylene (n=4) lauryl aminoether, lauryl dimethyl ammonioacetate and lauryl phosphate-octyltrimethyl-ammonium.
[0117] S-4 is a 27/67/6 by-weight mixture of polyoxyethylene (n=5) lauryl ether, polyoxyalkylene (n=20) hardened castor oil and polyoxyethylene (n=3) lauryl ether phosphoric ester potassium.
[0118] S-5 is a 40/40/20 by-weight mixture of polyoxyethylene (n=5) lauryl ether, polyoxyalkylene (n=4) diethylenetriamineisostearylamide and lauryl dimethylamine oxide.
[0119] E-1 is polyether-modified silicone.
[0120] E-2 is ethylene glycol.
Experimentation II
Oiling and Evaluation of each Agent with Respect to Biodegradable Synthetic Yarns
[0000] Oiling of each agent with respect to biodegradable synthetic yarns:
[0121] Lactic acid polymer chips having an average molecular weight 100,000, a melt flow rate of 25 g/10 min. at 210°, a glass transition temperature of 64° and a specific gravity of 1.26 were fed into an extruder type melt spinning machine where they were melted at 210°. After the hot melt was extruded from a spinneret and hardened by cooling, the resultant traveling yarns were oiled with a 10% aqueous solution obtained by diluting the agent for treating biodegradable synthetic yarns obtained in Experimentation 1 with water at an oiling amount as indicated in Table 2 on the basis of the agent for treating biodegradable synthetic yarns by means of a guide oiling method using a measuring pump. Thereafter, the yarns were bundled together on a guide, and wound at a speed of 2,800 m/min. without any mechanical drawing, thereby obtaining a plurality of 10 kg cakes comprising partially drawn yarns of 154-dtex 36-filaments. The obtained partially drawn yarns were found to have a tenacity of 2.8 g/dtx and an elongation of 78%.
[0000] Measurement of the coverage of the agent for biodegradable synthetic yarns:
[0122] According to JIS-L1073 (for synthetic yarn testing), the coverage of the agent for treating biodegradable synthetic yarns with respect to biodegradable synthetic yarns was measured using a mixed solvent of n-hexane/ethanol (50/50 by volume) as an extraction solvent. The results are enumerated in Table 2.
[0000] Evaluation of bulkiness:
[0123] Using a twisting system (employing a hard polyurethane rubber disk), the obtained partially drawn yarns were subjected to drawing and false twisting at a yarn traveling speed of 400 m/min. and a drawn ratio of 1.5 with a 2 m long heater on a twist side (at surface temperatures of 100 and 140° but without a heater on an untwisting side. The intended number of twisting was set at 2,800 T/m. Prior to winding, the obtained false-twisted yarns of 100 dtx 36 filaments were measured in terms of the number of twisting, using a twist monitor (Model TM-501 manufactured by Toray Industries, Inc.), and evaluated in terms of bulkiness on the following criteria. The results are set out in Table 2.
AA: the intended number of twisting, say 2,800 T/m, was achieved. A: greater than 2,700 T/m but less than 2,800 T/m. B: greater than 2,500 T/m but less than 2,700 T/m. C: less than 2,500 T/m.
Evaluation of fuzzes:
[0128] Prior to winding, the obtained false-twisted yarns of 100 dtx 36-filaments were measured in terms of the number of fuzzes per hour using a fray counter (DT-105 manufactured by Toray Engineering Co., Ltd.), and evaluated on the following criteria. The results are set out in Table 2.
AA: no fuzz was found. A: Five or less fuzzes were found. B: greater than five but less than 10 fuzzes were found. C: Ten or more fuzzes were found.
Evaluation of breaks:
[0133] After subjected to drawing and false twisting continuously over 10 days under the aforesaid conditions, the number of breaks per hour was evaluated on the following criteria. The results are shown in Table 2.
AA: no break was found. A: one break was found per hour. B: three breaks were found per hour. C: five or more breaks were found per hour.
Measurement of tenacity of false-twisted yarns:
[0138] According to JIS-L1013, the tenacity of the obtained false-twisted yarns was evaluated as tensile tenacity-elongation property. The results are shown in Table 2.
AA: tenacity of 5.4 g/dtx or greater. A: tenacity of greater than 5.0 g/dtx but less than 5.4 g/dtx. B: tenacity of greater than 4.0 g/dtx but less than 5.0 g/dtx. C: tenacity of less than 4.0 g/dtx.
[0143] In Table 2, the coverage of the agent, given in %, is defined with respect to biodegradable synthetic yarns.
[0000] Condition 1: heater temperature of 100°.
[0000] Condition 2: heater temperature of 140°.
[0144] While all of the fundamental characteristics and features and method of the present invention have been described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instance, some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should be understood that such substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. Consequently, all such modifications and variations are included within the scope of the invention as defined by the following claims.
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An agent and method for treating biodegradable synthetic yarns fabricated from a polymer comprising lactic acid as a main component, which enable improved lubricity, cohesion, etc. to be so imparted to the biodegradable synthetic yarns that the yarns can be prevented from fuzzing and breaking at every step from spinning to down-stream step, especially at a false twisting step and improved in terms of bulkiness, providing yarns having improved mechanical properties in a stable manner. The agent of the invention comprises 0.1 to 30 weight % of a specific functional agent, and a lubricant and a surfactant in the total amount of 70 weight % or greater, and has a friction coefficient in the range of 0.04 to 0.35.
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This application is a continuation-in-part application of U.S. Ser. No. 09/135,034, filed Aug. 17, 1998, now U.S. Pat. No. 6,064,970 which is a continuation of U.S. Ser. No. 08/592,958, filed Jan. 29, 1996, now U.S. Pat. No. 5,797,134. A related application is U.S. Ser. No. 09/364,803 filed Jul. 30, 1999.
FIELD OF THE INVENTION
The present invention relates to data acquisition, processing and communicating systems, and particularly to a system for acquiring and handling relevant data for an insured unit of risk for purposes of providing a more accurate determination of cost of insurance for the unit of risk and for communicating or quoting the so determined cost to an owner of the unit of risk. Although the invention has its principal applicability to motor vehicles such as automobiles, the invention is equally applicable to other units of risk such as, without limitation, motorcycles, motor homes, trucks, tractors, vans, buses, boats and other water craft and aircraft. The invention especially relates to a system for monitoring and communicating units of risk operational characteristics and operator actions for implementing the operational characteristics, to obtain increased amounts of data relating to the safety or risk of use for a subject unit, for purposes of providing a more accurate determination of the cost of insurance corresponding to a real time usage of the risk unit, and for making such data and computed costs accessible to a customer or insured or others on hardcopy, over the Internet or by other electronic means for convenient communication. The invention relates to electronic commerce, particularly where insurance and related information is marketed, sold or communicated via the Internet or other interactive network.
BACKGROUND OF THE INVENTION
Conventional methods for determining costs of motor vehicle insurance involve gathering relevant historical data from a personal interview with the applicant for the insurance and by referencing the applicant's public motor vehicle driving record that is maintained by a governmental agency, such as a Bureau of Motor Vehicles. Such data results in a classification of the applicant to a broad actuarial class for which insurance rates are assigned based upon the empirical experience of the insurer. Many factors are relevant to such classification in a particular actuarial class, such as age, sex, marital status, location of residence and driving record.
The current system of insurance creates groupings of vehicles and drivers (actuarial classes) based on the following types of classifications.
Vehicle:
Age;
manufacturer, model; and
value.
Driver:
Age;
sex;
marital status;
driving record (based on government reports),
violations (citations);
at fault accidents; and
place of residence.
Coverage:
Types of losses covered,
liability,
uninsured motorist,
comprehensive, and
collision;
liability limits; and
deductibles.
The classifications, such as age, are further broken into actuarial classes, such as 21 to 24, to develop a unique vehicle insurance cost based on the specific combination of actuarial classes for a particular risk. For example, the following information would produce a unique vehicle insurance cost.
Vehicle:
Age
1997 (three years old)
manufacturer, model
Ford, Explorer XLT
value
$18,000.
Driver:
Age
38 years old
sex
male
marital status
single
driving record
(based on government reports)
violations
1 point (speeding)
at fault accidents
3 points (one at fault accident)
place of residence
33619 (zip code)
Coverage:
Types of losses covered
liability
yes
uninsured motorist
no
comprehensive
yes
collision
yes
liability limits
$100,000./$300,000./$50,000.
deductibles
$500./$500.
A change to any of this information would result in a different premium being charged, if the change resulted in a different actuarial class for that variable. For instance, a change in the drivers' age from 38 to 39 may not result in a different actuarial class, because 38 and 39 year old people may be in the same actuarial class. However, a change in driver age from 38 to 45 may result in a different premium because of the change in actuarial class.
Current insurance rating systems also provide discounts and surcharges for some types of use of the vehicle, equipment on the vehicle and type of driver. Common surcharges and discounts include:
Surcharges:
Business use.
Discounts:
Safety equipment on the vehicle
airbags, and
antilock brakes;
theft control devices
passive systems (e.g. “The Club”), and
alarm system; and
driver type
good student, and
safe driver (accident free).
group
senior drivers
fleet drivers
A principal problem with such conventional insurance determination systems is that much of the data gathered from the applicant in the interview is not verifiable, and even existing public records contain only minimal information, much of which has little relevance towards an assessment of the likelihood of a claim subsequently occurring. In other words, current rating systems are primarily based on past realized losses. None of the data obtained through conventional systems necessarily reliably predicts the manner or safety of future operation of the vehicle. Accordingly, the limited amount of accumulated relevant data and its minimal evidential value towards computation of a fair cost of insurance has generated a long-felt need for an improved system for more reliably and accurately accumulating data having a highly relevant evidential value towards predicting the actual manner of a vehicle's future operation.
Many types of vehicle operating data recording systems have heretofore been suggested for purposes of maintaining an accurate record of certain elements of vehicle operation. Some are suggested for identifying the cause for an accident, others are for more accurately assessing the efficiency of operation. Such systems disclose a variety of conventional techniques for recording vehicle operation data elements in a variety of data recording systems. In addition, it has also been suggested to provide a radio communication link for such information via systems such as a cellular telephone to provide immediate communication of certain types of data elements or to allow a more immediate response in cases such as theft, accident, break-down or emergency. It has even been suggested to detect and record seatbelt usage to assist in determination of the vehicle insurance costs (U.S. Pat. No. 4,667,336).
The various forms and types of vehicle operating data acquisition and recordal systems that have heretofore been suggested and employed have met with varying degrees of success for their express limited purposes. All possess substantial defects such that they have only limited economical and practical value for a system intended to provide an enhanced acquisition, recordal and communication system of data which would be both comprehensive and reliable in predicting an accurate and adequate cost of insurance for the vehicle. Since the type of operating information acquired and recorded in prior art systems was generally never intended to be used for determining the cost of vehicle insurance, the data elements that were monitored and recorded therein were not directly related to predetermined safety standards or the determining of an actuarial class for the vehicle operator. For example, recording data characteristics relevant to the vehicle's operating efficiency may be completely unrelated to the safety of operation of the vehicle. Further, there is the problem of recording and subsequently compiling the relevant data for an accurate determination of an actuarial profile and an appropriate insurance cost therefor.
Current motor vehicle control and operating systems comprise electronic systems readily adaptable for modification to obtain the desired types of information relevant to determination of the cost of insurance. Vehicle tracking systems have been suggested which use communication links with satellite navigation systems for providing information describing a vehicle's location based upon navigation signals. When such positioning information is combined with roadmaps in an expert system, vehicle location is ascertainable. Mere vehicle location, though, will not provide data particularly relevant to safety of operation unless the data is combined with other relevant data in an expert system which is capable of assessing whether the roads being driven are high-risk or low-risk with regard to vehicle safety.
On-line Web sites for marketing and selling goods have become common place. Many insurers offer communication services to customers via Web sites relevant to an insured profile and account status. Commonly assigned application U.S. Ser. No. 09/135,034, filed Aug. 17, 1998, now U.S. Pat. No. 6,064,970 discloses one such system. Customer comfort with such Web site communication has generated the need for systems which can provide even more useful information to customers relative to a customer's contract with the insurer. Such enhanced communications can be particularly useful to an insured when the subject of the communications relates to real time cost determination, or when the subject relates to prospective reoccurring insurable events wherein the system can relate in the existing insured's profile with some insurer provided estimates of a future event for deciding an estimated cost of insuring the event.
The present invention contemplates a new and improved monitoring, recording and communicating system for an insured unit of risk, which primarily overcomes the problem of determining cost of vehicle insurance based upon data which does not take into consideration how a specific unit of risk is operated. The subject invention will base insurance charges with regard to current material data representative of actual operating characteristics to provide a classification rating of an operator or the unit in an actuarial class which has a vastly reduced rating error over conventional insurance cost systems. Additionally, the present invention allows for frequent (monthly) adjustment to the cost of coverage because of the changes in operating behavior patterns. This can result in insurance charges that are readily controllable by individual operators. The system is adaptable to current electronic operating systems, tracking systems and communicating systems for the improved extraction of selected insurance related data. In addition, the system provides for enhanced and improved communication of the relevant acquired data, cost estimates of insuring events and customer insured profiles through an Internet/Web site.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is disclosed a method of determining a cost of automobile insurance based upon monitoring, recording and communicating data representative of operator and vehicle driving characteristics, whereby the cost is adjustable by relating the driving characteristics to predetermined safety standards. The method is comprised of steps of monitoring a plurality of raw data elements representative of an operating state of a vehicle or an action of the operator. Selected ones of the plurality of raw data elements are recorded when they are determined to have an identified relationship to the safety standards. The recorded elements are consolidated for processing against an insured profile and for identifying a surcharge or discount to be applied to a base cost of automobile insurance. The total cost of insurance obtained from combining the base cost and surcharges or discounts is produced as a final cost to the operator.
In accordance with another aspect of the present invention, the recording comprises identifying a trigger event associated with the raw data elements which has an identified relationship to the safety standards so that trigger information representative of the event is recorded.
In accordance with a more limited aspect of the present invention, the method comprises a step of immediately communicating to a central control station via an uplink, information representative of the trigger event and recording response information generated by the control station.
In accordance with yet another aspect of the present invention, the method comprises steps of generating calculated data elements and derived data elements from the raw data elements, and accumulating the calculated and derived data elements in a recording device.
In accordance with the present invention, there is provided a method and system for Internet on-line communicating, between an insurer and an insured, of detected operating characteristics of a unit of risk, (e.g., a vehicle) for a selected period, and the cost of insuring the unit for the selected period, as decided by the insurer in consideration of the detected operating characteristics. A Web site system is provided for selectively communicating the operating characteristics and the cost between the insurer and the insured. A monitoring system monitors the operating characteristics. A storage system stores the operating characteristics and is accessible to the Web site system. A processing system decides the cost of insuring the unit for a period based upon the operating characteristics monitored during that period. The processing system is also accessible to the Web site system.
One benefit obtained by use of the present invention is a system that will provide precise and timely information about the current operation of an insured motor vehicle that will enable an accurate determination of operating characteristics, including such features as miles driven, time of use and speed of the vehicle. This information can be used to establish actual usage based insurance charges, eliminating rating errors that are prevalent in traditional systems and will result in vehicle insurance charges that can be directly controlled by individual operators.
It is another benefit of the subject invention that conventional motor vehicle electronics are easily supplemented by system components comprising a data recording process, a navigation system and a communications device to extract selected insurance relevant data from the motor vehicle.
It is another object of the present invention to generate actuarial classes and operator profiles relative thereto based upon actual driving characteristics of the vehicle and driver, as represented by the monitored and recorded data elements for providing a more knowledgeable, enhanced insurance rating precision.
It is another aspect of the present invention that an on-line Web site is provided for communicating data, services, and estimates to customers via an Internet Web Site, including estimated costs for expected operating usage for a particular unit of risk. Accordingly, the real time cost determination and communication through the Web site provides the type of enhanced communications between a customer and an insurer that can be particularly useful in limiting costs, and enhancing safety.
It is another benefit of the invention that a user of a unit of risk may be authenticated as a proper user of the unit, and a more accurate rating for the authenticated user may be implemented for the computation of insurance costs.
The subject new insurance rating system retrospectively adjusts and prospectively sets premiums based on data derived from motor vehicle operational characteristics and driver behavior through the generation of new actuarial classes determined from such characteristics and behavior, which classes heretofore have been unknown in the insurance industry. The invention comprises an integrated system to extract via multiple sensors, screen, aggregate and apply for insurance rating purposes, data generated by the actual operation of the specific vehicle and the insured user/driver.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and steps and arrangements of parts and steps, the preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:
FIG. 1 is a block diagram/flowchart generally describing data capture methods within a unit of risk for insurance in claims processing;
FIG. 2 is a block diagram generally illustrated in the communication network design the unit of risk including a response center of the insurer and a data handling center;
FIG. 3 is a suggestive perspective drawing of a vehicle including certain data elements monitoring, recording and communication devices;
FIG. 4 is a block diagram of a vehicle onboard computer and recording system implementing the subject invention for selective communication with a central operations control center and a global positioning navigation system;
FIG. 5 is a block diagram illustrating use of acquired data including communication through Internet access; and,
FIG. 6 is a block diagram/flowchart illustrating an underwriting and rating method for determining a cost of insurance in conjunction with the system of FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following terms and acronyms are used throughout the detailed description:
Internet. A collection of interconnected (public and/or private) networks that are linked together by a set of standard protocols (such as TCP/IP and HTTP) to form a global, distributed network. While this term is intended to refer to what is now commonly known as the Internet, it is also intended to encompass variations which may be made in the future, including changes and additions to existing standard protocols.
World Wide Web (“Web”). Used herein to refer generally to both (i) a distributed collection of interlined, user-viewable hypertext documents (commonly referred to as Web documents or Web pages) that are accessible via the Internet, and (ii) the client and server software components which provide user access to such documents using standardized Internet protocols. Currently, the primary standard protocol for allowing applications to locate and acquire Web documents is HTTP, and the Web pages are encoded using HTML. However, the terms “Web” and “World Wide Web” are intended to encompass future markup languages and transport protocols which may be used in place of (or in addition to) HTML and HTTP.
Web Site. A computer system that serves informational content over a network using the standard protocols of the World Wide Web. Typically, a Web site corresponds to a particular Internet domain name, such as “progressive.com,” and includes the content associated with a particular organization. As used herein, the term is generally intended to encompass both (i) the hardware/software server components that serve the informational content over the network, and (ii) the “back end” hardware/software components including any non-standard or specialized components, that interact with the server components to perform services for Web site users.
Referring now to the drawings, wherein the showings are for purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting same, the FIGURES show an apparatus and method for monitoring, recording and communicating insurance related data for determination of an accurate cost of insurance based upon evidence relevant to the actual operation and in particular the relative safety of that operation. Generally, a unit of risk, e.g., vehicle, user is charged for insurance based upon statistical averages related to the safety of operation based upon the insurer's experience with other users who drive similar vehicles in a similar geographic area. The invention allows for the measure of the actual data while the motor vehicle is being driven. Such data measurement will allow the vehicle user to directly control his/her insurance costs by operating the vehicle in a manner which he/she will know will evidence superior safety of operation and a minimal risk of generation of an insurance claim. Examples of data which can be monitored and recorded include:
1. Actual miles driven; 2. Types of roads driven on (high risk vs. low risk); and, 3. Safe operation of the vehicle by the vehicle user through:
A. speeds driven, B. safety equipment used, such as seat belt and turn signals, C. time of day driven (high congestion vs. low congestion), D. rate of acceleration, E. rate of braking, F. observation of traffic signs.
4. Driver identification
With reference to FIG. 3 , an exemplary motor vehicle is shown in which the necessary apparatus for implementing the subject invention is included. An on-board computer 300 monitors and records various sensors and operator actions to acquire the desired data for determining a fair cost of insurance. Although not shown therein, a plurality of operating sensors are associated with the motor vehicle to monitor a wide variety of raw data elements. Such data elements are communicated to the computer through a connections cable which is operatively connected to the vehicle data bus 304 through an SAE-J1978 connector, or OBD-II connector or other vehicle sensors 306 . A driver input device 308 is also operatively connected to the computer 300 through connector 307 and cable 302 . The computer is powered through the car battery 310 , a conventional generator system, a battery or a solar based system (not shown). Tracking of the vehicle for location identification can be implemented by the computer 300 through navigation signals obtained from a GPS (global positioning system) antenna, a differential GPS or other locating system 312 . The communications link to a central control station is accomplished through the cellular telephone, radio, satellite or other wireless communication system 314 .
FIG. 4 provides the block diagram of the in-vehicle computer system. The computer 300 is comprised of several principal components, an on-board data storage device, an input/output subsystem for communicating to a variety of external devices, a central processing unit and memory device and a real time operating kernel for controlling the various processing steps of the computer 300 . It is known that all of these functions can be included in a single dedicated microprocessor circuit 300 . The computer 300 essentially communicates with a number of on-board vehicle devices for acquisition of information representative of various actual vehicle operating characteristics. A driver input console 410 allows the driver to input data representative of a need for assistance or for satisfaction of various threshold factors which need to be satisfied before the vehicle can be operated.
For example, a driver authentication system is intended, such as where several individual drivers (same family, etc.) may properly use the vehicle but each may have different ratings for insurance computations.
The physical operation of the vehicle is monitored through various sensors 412 in operative connection with the vehicle data bus, while additional sensors 414 not normally connected to the data bus can be in direct communication with the computer 300 as will hereinafter be more fully explained.
The vehicle is linked to an operation control center 416 by a communications link 418 , preferably comprising a conventional cellular telephone interconnection, but also comprising satellite transmission, magnetic or optical media, radio frequency or other known communication technology. A navigation sub-system 420 receives radio navigation signals from a positioning device 422 which may include, but is not limited to GPS, radio frequency tags, or other known locating technology.
The type of elements monitored and recorded by the subject invention comprise raw data elements, calculated data elements and derived data elements. These can be broken down as follows:
Raw Data Elements:
Power train sensors
RPM, transmission setting (Park, Drive, Gear, Neutral), throttle position, engine coolant temperature, intake air temperature, barometric pressure,
Electrical sensors
brake light on, turn signal indicator, headlamps on, hazard lights on, back-up lights on, parking lights on, wipers on, doors locked, key in ignition, key in door lock, horn applied;
Body sensors
airbag deployment, ABS application, level of fuel in tank, brakes applied, radio station tuned in, seat belt on, door open, tail gate open, odometer reading, cruise control engaged, anti-theft disable, occupant in seat, occupant weight;
Other sensors
vehicle speed, vehicle location, date, time, vehicle direction, IVHS data sources pitch and roll, relative distance to other objects.
Calculated Data Elements:
rapid deceleration;
rapid acceleration;
vehicle in skid;
wheels in spin;
closing speed on vehicle in front;
closing speed of vehicle in rear;
closing speed of vehicle to side (right or left);
space to side of vehicle occupied;
space to rear of vehicle occupied;
space to front of vehicle occupied;
lateral acceleration;
sudden rotation of vehicle;
sudden loss of tire pressure;
driver identification (through voice recognition or code or fingerprint recognition);
distance traveled; and
environmental hazard conditions (e.g. icing, etc.).
Derived Data Elements:
vehicle speed in excess of speed limit;
observation of traffic signals and signs;
road conditions;
traffic conditions; and
vehicle position.
This list includes many, but not all, potential data elements.
With particular reference to FIG. 1 , a flowchart generally illustrating the data capture process of the subject invention within the vehicle for insurance and claims processing, is illustrated. Such a process can be implemented with conventional computer programming in the real time operating kernel of the computer 300 . Although it is within the scope of the invention that each consumer could employ a unique logic associated with that consumer's unit of risk, based on the underwriting and rating determination (FIG. 6 ), as will be more fully explained later, FIG. 1 illustrates how the data capture within a particular consumer logic is accomplished. After the system is started 100 , data capture is initiated by a trigger event 102 which can include, but is not limited to:
Ignition On/Off Airbag Deployment Acceleration Threshold Velocity Threshold Elapsed Time Battery Voltage Level System Health User Activation/Panic Button Traction Location/Geofencing Driver Identification Remote Activation
Trigger event processing 104 essentially comprises three elements, a flow process for contacting a central control 106 , contacting a claims dispatch, and/or recording trigger event data 110 . If the trigger event is one that does not require contacting central control or contacting a claims dispatch, then processing proceeds to merely record the event as trigger event data 110 . Trigger event processing can include, but is not limited to:
Contact External Entities EMT (Emergency Medical Transport), claims Dispatch, Other External Entity Takes Appropriate Action Record Sensor Information Transmission of Data Recalibration Load Software
If trigger event processing comprises contact central control, the inquiry is made, and if affirmative, the central control is contacted 112 , the central control can take appropriate action 114 , and a record is made of the action taken by the central control 116 . For the process of claims dispatch 108 , the system first contacts 120 the claims dispatch service department of the insurer, the claims dispatch takes appropriate action 122 and a recording 124 of the claims dispatch action information is made.
The recording of trigger event data can include, but is not limited to:
The Trigger Latitude Longitude Greenwich Mean Time Velocity Acceleration Direction Vehicle Orientation Seatbelt Status
Data capture processing concludes with end step 130 .
The recording thus comprises monitoring a plurality of raw data elements, calculated data elements and derived data elements as identified above. Each of these is representative of an operating state of the vehicle or an action of the operator. Select ones of the plurality of data elements are recorded when the ones are determined to have an identified relationship to the safety standards. For example, vehicle speed in excess of a predetermined speed limit will need to be recorded but speeds below the limit need only be monitored and stored on a periodic basis. The recording may be made in combination with date, time and location. Other examples of data needed to be recorded are excessive rates of acceleration or frequent hard braking.
The recording process would be practically implemented by monitoring and storing the data in a buffer for a selected period of time, e.g., thirty seconds. Periodically, such as every two minutes, the status of all monitored sensors for the data elements is written to a file which is stored in the vehicle data storage within the computer 300 . The raw, calculated and derived data elements listed above comprise some of the data elements to be so stored.
“Trigger events” should be appreciated as a combination of sensor data possibly requiring additional action or which may result in a surcharge or discount during the insurance billing process. Certain trigger events may require immediate upload 106 to a central control which will then be required to take appropriate action 114 . For example, a trigger event would be rapid deceleration in combination with airbag deployment indicating a collision, in which case the system could notify the central control of the vehicle location. Alternatively, if the operator were to trigger on an emergency light, similarly the system could notify the central control of the vehicle location indicating that an emergency is occurring.
Trigger events are divided into two groups: those requiring immediate action and those not requiring immediate action, but necessary for proper billing of insurance. Those required for proper billing of insurance will be recorded in the same file with all the other recorded vehicle sensor information. Those trigger events requiring action will be uploaded to a central control center which can take action depending on the trigger event. Some trigger events will require dispatch of emergency services, such as police or EMS, and others will require the dispatch of claims representatives from the insurance company.
The following comprises an exemplary of some, but not all, trigger events:
Need for Assistance:
These events would require immediate notification of the central control center.
1. Accident Occurrence. An accident could be determined through the use of a single sensor, such as the deployment of an airbag. It could also be determined through the combination of sensors, such as a sudden deceleration of the vehicle without the application of the brakes.
2. Roadside assistance needed. This could be through the pressing of a “panic button” in the vehicle or through the reading of a sensor, such as the level of fuel in the tank. Another example would be loss of tire pressure, signifying a flat tire.
3. Lock-out assistance needed. The reading of a combination of sensors would indicate that the doors are locked but the keys are in the ignition and the driver has exited the vehicle.
4. Driving restrictions. The insured can identify circumstances in which he/she wants to be notified of driving within restricted areas, and warned when he/she is entering a dangerous area. This could be applied to youthful drivers where the parent wants to restrict time or place of driving, and have a record thereof.
Unsafe Operation of the Vehicle
These events would be recorded in the in-vehicle recording device for future upload. Constant trigger events would result in notification of the driver of the exceptions.
1. Excessive speed. The reading of the vehicle speed sensors would indicate the vehicle is exceeding the speed limit. Time would also be measured to determine if the behavior is prolonged.
2. Presence of alcohol. Using an air content analyzer or breath analyzer, the level of alcohol and its use by the driver could be determined.
3. Non-use of seatbelt. Percent of sample of this sensor could result in additional discount for high use or surcharge for low or no use.
4. Non-use of turn signals. Low use could result in surcharge.
5. ABS application without an accident. High use could indicate unsafe driving and be subject to a surcharge.
With particular reference to FIG. 2 , a general block diagram/flowchart of the network design for gathering appropriate information for insurance billing on a periodic basis is illustrated. Each unit of risk 200 , which as noted above, can just as easily be an airplane or boat, as well as a automobile, includes the data storage 202 and data process logic 204 as described more in detail in FIG. 4 . The insured 206 responsible for each unit of risk communicates within the insuring entity 208 or its designee (by “designee” is meant someone acting for the insurer, such as a dedicated data collection agent, data handler or equipment vendor 210 and/or a value added service provider 212 .) The data handler can be a third party entity verifying that the operating equipment of the system is in proper working order, and as such, will usually be a subcontractor to the insurer. A value added service provider is another third party entity, such as a directional assistance service, or telephone service provider, also part from the insurer, whose communications with the units of risk may be important or useable to the insurance computation algorithms.
Another important feature of FIG. 2 is that the insured 206 may not only communicate with the insurer 208 through the communications link 418 (FIG. 4 ), but also through an Internet 218 communications path. Such communication will occur through a Webserver 220 and the insurer's Web site so that an insured 206 may get on-line with the insurer 208 to observe and verify recorded data, claims processing, rating and billing 222 , as well as acquire improved insurance cost estimations, as will hereinafter be more fully explained.
With particular reference to FIG. 5 , a more detailed description of system use of data acquired from the unit of risk is explained with particular attention to advantageous Internet communications. The unit of risk 200 is primarily concerned with transferring three classes of data between it and the insurer. The event data 500 and stored sensor data 502 have been discussed with reference to FIG. 1 . Data process logic 504 is particular processing logic that can be transferred from the insurer to the unit of risk that is adapted for acquiring data especially important for assessing the particular unit's insurance costs. For example, if a particular unit has a special need for providing information about brake pedal application, special data process logic will be provided to that unit to store data related to this activity. On the other hand, for many other units such data may not be necessary and so the unit may operate with standard data process logic 204 . The important feature of special data process logic 504 is that the data process logic 204 for a unit of risk can be regularly updated as either the insured, the insurer or events warrant. One easily foreseeable special data process logic would be related to breathalyser analysis.
The process flowchart starting at Begin 506 more generally describes the communication activity between the insurer and the unit of risk. The insurer will acquire event data 508 , sensor data 510 , may update 512 the data process logic and then process 514 the raw data elements to generate either the calculated or derived data elements. All relevant data is stored 516 in a conventional data storage device 518 . If the stored item is an event 524 , then the insurer needs to cause some sort of response to the event. For example, if there is an airbag deployment, the insurer may actually try to communicate with the vehicle, and upon failure of communication, may initiate deployment of emergency medical or police service. If this specific event processing and/or alerts 526 occurs, the system may have to initiate a charge per use event. For instance, charges can also include immediate response claims, EMS contact charges or police dispatch charges. The data or events which are stored in stored device 518 are accessed by a billing algorithm 530 to generate a cost for the unit of risk in consideration of all the relevant data and events occurring in that period. It is a special feature of the subject invention that the cost of insurance is based upon the real time data occurring contemporaneously with the billing so that the system provides an insurance use cost, as opposed to an estimation based upon historical data. After a relevant cost is computed, periodic bills are produced 532 and typically mailed to a customer as an account statement 534 .
Another important feature of the subject invention illustrated in FIG. 5 is that the insurer provides a Webserver 220 to allow a customer to access via Internet 218 communication, the relevant sensor data and event data associated with the customer.
Two different types of on-line services interfaces are illustrated; a prospective on-line services interface 550 , or an interface 552 for reporting acquired data. The data reports through the acquired service interface may comprise all of the stored event and sensor data, along with enhanced processing maps showing travel routes during the billing period, or even a map showing current location of the unit of risk. By Geofencing is meant to identify when the unit travels outside of a certain geographical area. It is even possible to determine whether automobile maintenance service is appropriate by diagnostic analysis of the sensor and event data.
The prospective interface relates to “what if” gaming where a customer can project certain usages of the unit of risk, and the system can, in combination with similar occurring usage in the past or, based upon the overall customer profile or matrix, project a estimated cost for such usage. In effect, a user can determine in advance what particular usage of the unit will incur as insurance cost with a very reliable associated insurance estimate.
Lastly, enhanced on-line account statements 554 can also be communicated on-line wherein maps with usage, or service usage details can be provided as a more detailed explanation of the resulting costs of an account statement.
With particular reference to FIG. 6 , the subject invention is particularly useful for generating improved rating algorithms due to the improved acquisition and amount of relative data for assessing insurance costs for a unit of risk. In the manner as discussed above, the database 518 has the benefit of the data from a plurality of customers 206 . An insurer can over time use the accumulated underwriting and rating information from individual customers 520 to develop improved rating algorithms 522 . Such improved algorithms can be regularly communicated to the units of risk 200 for improved insurance cost computation accuracies. The improved rating algorithms can be communicated 524 to the units of risk on-board computer 300 (FIG. 4 ).
The subject invention is also applicable as a process for collecting data to be used for the following non-insurance related purposes: advertising and marketing, site selection, transportation services, land use planning, determining road design, surface or composition, traffic planning and design, and road conditions.
The invention has been described with reference to the preferred embodiments. Obviously modifications and alterations will occur to others upon a reading and understanding of this specification. The present invention is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or equivalents thereof.
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A method and system for communicating insurance related services between an insured and an insurer through an Internet communication scheme includes a processing system for processing acquired event and sensored data to compute the cost of insurance for the same period as the data is acquired. An enhanced Internet communication scheme provides an insured access to the acquired data and its processing through enhanced presentation systems (e.g., maps with usage, service or special event processing or even automobile service diagnostics.) In addition, communication packages can provide estimates based upon user-supplied information identifying projected usages.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my co-pending application U.S. Ser. No. 07/439,321 filed Nov. 21, 1989 now U.S. Pat. No. 5,046,448 issued Sep. 10, 1991. for Railroad Tie Treating Method and Apparatus.
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention generally relates to a railroad tie treating apparatus and more specifically to injection heads for such an apparatus by which a flowable treating material can be injected through unused or unoccupied spike holes in railroad rail tie plates which anchor the bottom flange of a railroad rail to the wooden ties. Each of the injection heads includes a structure enabling the injection head to be sealingly engaged with the tie plate in order to prevent leakage of the treating material between the injection head and tie plate with several embodiments of the invention being disclosed to assure efficient discharge of the flowable treating material between the bottom surface of the tie plates and the adjacent surface areas of the wooden ties.
2. Description of the Prior Art
My prior U.S. Pat. No. 4,746,553 issued May 24, 1988 discloses a vehicular apparatus having flanged wheels movable on railroad rails and discloses the basic concept of injecting a treating material through one or more unoccupied spike holes in the rail supporting tie plate. This patent and the prior art of record therein is made of record in this application by reference thereto. In addition, co-pending application U.S. Ser. No. 07/439,321 now U.S. Pat. No. 5,046,448 discloses portable embodiments of a treating apparatus and the references of record in that application are incorporated herein by reference thereto.
None of the prior art discloses an injection head having specific structural characteristics that enable quick, easy and extremely effective sealing engagement with a peripheral portion of an unoccupied spike hole in a railroad rail tie plate which supports the rail from the wood tie in order to inject fluid treating material between the bottom surface of the tie plate and the upper surface of the wooden tie in an efficient manner without leakage of the treating material around the periphery of the upper end of the unoccupied spike hole.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an injection head for a railroad tie treating apparatus constructed of resilient material and incorporating structural features enabling a portion of the injector head to engage an unoccupied spike hole in the tie plate and to be sealingly engaged with the tie plate to prevent leakage of flowable treating material between the injection head and tie plate.
Another object of the invention is to provide an injection head of resilient construction including several embodiments some of which include a portion telescopically related to the unoccupied hole and several engaging the upper end of the unoccupied hole in sealing relation with each embodiment of the injection head including a passageway receiving pressurized flowable treating material that is mounted on the lower end of a tubular wand with a manual control valve being provided to control the discharge of treating material through the injection head.
A further object of the invention is to provide injection heads in accordance with the preceding objects including structural features in certain embodiments which enable the portion of the injection head inserted into the unoccupied hole to be expanded radially into sealing engagement with the inner surface of the unoccupied hole.
Still another object of the invention is to provide injection heads in accordance with the preceding objects which are relatively inexpensive to manufacture, easy to operate and effective in providing a seal between the injection head and the tie plate to discharge flowable treating material between the tie plate and the wooden tie and prevent leakage of liquid treating material between the injection head and tie plate.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional view illustrating the manner of using the injection heads of the present invention in association with a railroad rail, tie plate and wooden tie.
FIGS. 2, 3 and 4 are vertical sectional, side elevational and bottom plan views of one embodiment of the invention.
FIGS. 5, 6 and 7 are vertical sectional, side elevational and bottom plan views of a second embodiment of the invention.
FIGS. 8, 9 and 10 are vertical sectional, side elevational and bottom plan views of a third embodiment of the invention.
FIGS. 11, 12 and 13 are vertical sectional, side elevational and bottom plan views of a fourth embodiment of the invention.
FIGS. 14, 15 and 16 are vertical sectional, side elevational and bottom plan views of a fifth embodiment of the invention.
FIGS. 17, 18 and 19 are vertical sectional, side elevational and bottom plan views of a sixth embodiment of the invention.
FIGS. 20, 21 and 22 are vertical sectional, side elevational and bottom plan views of a seventh embodiment of the invention.
FIGS. 23, 24 and 25 are vertical sectional, side elevational and bottom plan views of an eighth embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 of the drawings illustrates the injection head designated by reference numeral 30 mounted on the lower end of a tubular pipe or wand 32 having the lower end in the form of a discharge tube 34 telescopically received in a passageway 36 in the injection head 30. A valve structure 38 is provided at the lower end of the wand 32 and includes an actuator 40 in the form of a laterally extending arm connected to an operating rod 42 that extends upwardly to a control lever all as generally disclosed in co-pending application Ser. No. 07/439,321. This enables a flowable treating material to be injected through an unoccupied spike hole 44 in a tie plate 46 conventionally employed to secure the bottom flange 48 of a railroad rail 50 to a wooden tie 52 in which an anchoring spike is normally driven through at least one of the holes in the tie plate and at least one hole in the tie plate is left unoccupied in order to receive the injection head 30. In FIGS. 2-25 the tie plate 46, the hole 44 therethrough and the wooden tie 52 are designated by the same reference numerals. Each embodiment of the injection head will be provided with different reference numerals even though there are similarities in the various embodiments.
FIGS. 2-4 disclose one embodiment of the injection head generally designated by reference numeral 54 and which includes a resilient body 56 having downwardly converging flat side surfaces 58 defining a square upper end 60 and a square lower end 62. Projecting axially from the lower end 62 of the body 56 is a projection 64 which is also of square configuration as illustrated in FIGS. 3 and 4 but of a smaller perimeter than the perimeter of the bottom edge 62 of the body 56 thus defining a horizontally disposed peripheral shoulder 66 which will engage the top surface of the tie plate 46 peripherally of the hole 44 when the projection 64 is inserted downwardly into the hole 44. A passageway 68 of circular transverse configuration extends through the body 56 and the projection 64 which are of one piece construction with the upper end of the passageway 68 telescopically receiving and being anchored to the discharge tube 34 on the wand 32. As illustrated in FIG. 2, the length of the projection 64 is slightly less than the vertical dimension of the hole 44 thus spacing the bottom edge 70 of the projection 64 from the upper surface of the tie 52 and above bottom surface of the tie plate 46 with this space being designated by reference numeral 72 thus assuring that material discharged through the passageway 68 will have access to the upper surface of the wooden tie 52 in order for it to migrate laterally outwardly between the wood tie 52 and the tie plate 56 with downward pressure being exerted on the wand to provide a positive seal between the shoulder 66 and the upper surface of the tie plate 44 peripherally of the hole 44 to prevent leakage therebetween.
FIGS. 5-7 illustrate a second embodiment of the invention generally designated by reference numeral 74 and including a square, downwardly tapering body 76 identical to the body 56 in FIGS. 2-4 and including a depending square projection 78 integral with the lower edge 80 of the body 76 with the square configuration of the projection being smaller than the lower edge 80 of the body 76 to define a peripheral horizontal shoulder 82 to sealingly engage with the upper surface of the tie plate 46 when the projection 78 is inserted into the tie plate hole 44 as illustrated in FIG. 5. The lower end 84 of the projection includes a pair of diametrically opposed, generally semi-circular notches 86 oriented in opposed relation and intersecting a vertical passageway 88 extending through the body 76. The notches 86 assure free flow of treating material from the passageway 88 laterally outwardly to the periphery of the projection 78. The vertical height of the projection 78 may be substantially the same as or slightly less than the thickness of the plate 46 to assure sealing engagement between the shoulder 82 and the upper surface of the tie plate 46. In this embodiment, as well as in the embodiment in FIGS. 2-4, the peripheral dimensions of the projection is slightly less than the internal perimeter of the hole 44 to facilitate insertion of the projection.
FIGS. 8-10 illustrate another embodiment of the injection head generally designated by reference numeral 90 which includes a square tapering body 92 provided with a projection 94 of square configuration but of less peripheral dimensions as compared to the bottom edge 96 of the body 92 thus forming a horizontal shoulder 98 which engages the upper surface of the tie plate 46 peripherally of the hole 44. A vertical passageway 100 extends through the body 92 and projection 94. In this embodiment of the invention, the projection 94 includes an annular passageway 102 positioned outwardly of and concentric with the lower end of the passageway 100 with the distance between the outer surface of the projection 94 and the annular recess 102 being relatively thin, flexible and resilient. This outer portion of the projection is designated by reference numeral 104 and is spaced below the shoulder 98 and above the bottom edge 106 of the projection 94 as illustrated in FIGS. 8 and 9. A vertical passageway 108 of less cross-sectional dimension than the passageway 100 extends vertically from the annular passageway 102 to the upper end of the body 92 in adjacent but spaced relation to the passageway 100. The passageway 108 is communicated with the pressurized supply of flowable treating material in order to pressurize the passageway 108 and the annular passageway 102 which forms a bladder which is expanded radially outwardly into sealing engagement with the inner surface of the hole 44 in the tie plate 46 thus forming a seal between the periphery of the projection 94 and the internal surface of the hole 44 in the tie plate 46. The shoulder 98 sealingly engages the upper surface of the tie plate and the vertical length of the projection is slightly less than the height of the hole 44 in the tie plate thus assuring sealing engagement of the shoulder with the tie plate and providing a space 110 between the lower end of the projection 94 and the wooden tie 52 to assure flow of material outwardly between the tie plate 46 and the wood tie 52. When the treating operation has been completed and the pressurized supply of treating material cut-off by the valve structure, the pressure will be released from the passageway 102 and passageway 108. In this arrangement, the valve structure will pressurize the passageway 108 and passageway 102 just prior to the pressurized treating material being introduced into the passageway 100 and likewise, the pressure through the passageway 100 will be released just prior to the pressure in the passageway 108 and 102.
FIGS. 11-12 illustrate a fourth embodiment of the invention designated by reference numeral 112 and includes a body 114 of square tapering configuration similar to the previously disclosed embodiments. The lower end of the body 114 is provided with a projection 116 and a horizontally disposed shoulder 118 with the projection 116 extending into the hole 44 in the tie plate 46 with the height of the projection 116 being less than the vertical height of the hole 44 thus providing a space 120 between the lower end of the projection 116 and the wooden tie 52 to enable treating material to flow outwardly. A vertical passageway 122 is provided through the body and projection and adjacent the lower end of the projection, an annular recess or groove 124 is formed in the passageway 122 to form a very thin, resilient, flexible expandable sealing bladder 126 which is expanded when pressure is supplied through the passageway 122 with expansion of the bladder 126 providing a seal between the projection 116 and the inner surface of the hole 44 in the tie plate with the shoulder 118 also sealingly engaged with the upper surface of the tie plate. In this embodiment, the pressurized treating material will enter the peripheral groove or recess 124 and expand the flexible, resilient bladder forming the outer wall of .the groove into sealing engagement with the hole 44.
FIGS. 14-16 disclose a fifth embodiment of the invention designated by reference numeral 128 which includes a downwardly tapering square body 130 similar to those disclosed in FIGS. 2-13 but in this form of the invention, a peripheral horizontal flange 132 is provided at the lower edge of a body 130 with the flange being of circular cross-sectional configuration and forming a downwardly facing shoulder 134 of circular external perimeter together with a depending square projection 136 of integral construction therewith with the body 130 flange 132 and projection 136 including a passageway 137 therethrough for receiving pressurized treating material. The length of the projection 136 below the shoulder 134 is less than the vertical height of the hole 44 in the tie plate 46 to provide a space 138 between the lower end of the projection 136 and the upper surface of the wooden tie 52 to facilitate migration of fluid treating material between the tie plate and wood tie. The shoulder 134 engages the upper surface of the tie plate 46 as illustrated in FIG. 14 thus forming an effective seal for the periphery of the hole 44 to prevent leakage between the injection head 128 and the tie plate 46.
FIGS. 17-19 illustrate a sixth embodiment of the injection head generally designated by reference numeral 140 and which includes a generally spherical body 142 having a flat lower end defining a downwardly facing horizontally disposed shoulder 144 having a centrally disposed depending square projection 146 formed integrally with the body 142. A vertical passageway 147 extends through the body 142 and through the projection 146 which is telescopically received in the hole 44 in the tie plate 46. The length of the projection 146 is slightly less than the vertical height of the hole 44 to provide a space 148 for passage of the treating material when the shoulder 144 sealingly engages the upper surface of the tie plate 46 as illustrated in FIG. 17.
FIGS. 20-22 illustrate a seventh embodiment of the invention generally designated by reference numeral 150 and including a spherical body 152 having a vertical passageway 154 therethrough. In this embodiment of the invention, the spherical peripheral surface of the body 152 sealingly engages the upper end of the hole 42 at 156 that is peripherally spaced from the lower end of the passageway 154 thus communicating the passageway 154 with the hole 44 and forming a seal between the upper end of the hole 44 and the body 152 as indicated by reference numeral 156 thus preventing leakage between the body 152 and the tie plate 46.
FIGS. 23-25 illustrate another embodiment of the injection head generally designated by reference numeral 160 which includes a spherical ball 162 having a vertical passage 164 therethrough. Where the vertical passage 164 communicates with the lower surface of the spherical body 162, there is a peripheral recess 166 to provide an enlargement of the passageway 164 and to increase the resiliency and flexibility of the portion of the body 162 between the periphery of the recess 166 and the adjacent periphery of the spherical body 162 where the spherical body 162 engages the upper edge of the hole 44 as indicated by reference numeral 168 thereby providing a more flexible and resilient engagement between the ball 162 and the tie plate 46 thereby preventing leakage between the body 162 and the tie plate 46.
In each embodiment of the invention, the body is of one piece construction of solid, resilient material that will sustain its shape but yet be sufficiently resilient and flexible to sealingly engage with the tie plate to provide an effective seal between the body and tie plate thereby preventing leakage of the treating material past the interface between the external surface of the body and the tie plate thereby assuring that all of the pressurized material passing through the injection head will be discharged in the lower end of the tie plate hole 44 with the pressurization of the treating material forcing the treating material outwardly between the upper surface of the wooden tie and the lower surface of the tie plate. The projection in each form of the invention is square to conform with the configuration of the tie plate hole 44 with the external dimensions of the projection being slightly less than the internal dimensions of the tie plate hole for ease in telescopic engagement. In each embodiment of the invention, the passageway through the body has direct communication with the tie plate hole with the peripheral sealing engagement of the body with the tie plate hole providing an effective seal that is maintained by downward thrust being exerted on the wand which is being manually manipulated and controlled by an operator.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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Injection heads for a railroad tie treating apparatus by which a flowable treating material can be injected through unused or unoccupied spike holes in railroad rail tie plates which anchor the bottom flange of a railroad rail to the wooden ties. Each of the injection heads include a structure enabling the injection head to be sealingly engaged with tie plate in order to prevent leakage of the treating material between the injection head and tie plate with several embodiments of the invention being disclosed to assure efficient discharge of the flowable treating material between the bottom surface of the tie plates and the adjacent surface areas of the wooden ties.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to movable switch points for railway switches and, more particularly, to devices for compensating for lost motion between the throw of the switch machine and the movement of the switch point.
2. Description of the Prior Art
A "frog" is the location at which one rail crosses over or intersects another rail. In instances of high speed turnouts (i.e., where a railway vehicle switches from one track onto another track), the actual degree of switch or turnout may be very long because at higher speeds it is desirable that the train make the transition from one track to the other at a slower rate. Because of the long length of turnout, means have been devised in which to separate the rails.
One means to separate the rails is to make the frog section of the track a movable point. Thus, the frog which lies between and separates two sections of rail is connected to a means for moving the frog called a switch machine. An operating rod (also referred to as a "throw rod") is connected to and caused to be translated by the switch machine. The switch machine and operating rod, together with a second operating rod and a switch point adjuster (as described in more detail below), cause the switch point to move.
The distance by which the frog must be moved (i.e., the "throw") is typically between two inches and five inches. However, switch machines per AAR (Association of American Railroads) recommendations and standards, will always throw six inches, regardless of the type of switch machine utilized. Therefore, if the switch machine throw is six inches and is connected to the frog through a rigid connection, the frog also must be moved six inches. However, if the frog is only to be moved somewhere between two to five inches, a means must be used to compensate for the lost motion of the switch machine. For this reason, the switch machine is connected through an operating rod to a switch point adjuster.
A switch point adjuster is a device that compensates for switch machine operating lost motion and maintains switch point pressure on the frog or switch point as a train travels through. The switch point adjuster takes up the lost motion between the switch machine throw and the switch point displacement. This is done by allowing the switch operating rod to move a given distance before making contact with the opposite end of the switch point adjuster. Only after this given distance of travel does the machine begin to drive the switch points. Pressure between the extended sleeves of the operating rod and the switch point adjuster is present on one side of the adjuster--the side keeping the switch point closed. By adjusting the sleeves on the threaded operating rod, the point opening can therefore be adjusted to ensure that the point is closed and has adequate pressure on it when the train travels over the rail switch.
Referring to FIG. 1, a prior art switch point adjuster 2 is schematically depicted. As can be seen, the prior art switch point adjuster 2 utilizes two separate rods 3, 4. Two separate rods are used because maintenance personnel were unable to easily access the bottom of the switch point 16, therefore, there was no way of easily making any adjustments to the switch point adjuster 2 right at the point, as the track 14 itself would prevent access to the switch point adjuster 2. Thus, the switch point adjuster 2 was located at the center of the track 14 where maintenance personnel could access it. In order to do that, a two rod configuration was utilized: a first rod 3 connects the switch point adjuster 2 to the frog and a second rod 4 connects the switch point adjuster 2 to the switch machine 12. Thus, when the switch machine 12 throws six inches, the slack is taken up in the switch point adjuster 2 so that the frog is only moved its required amount. Both operating rods 3, 4 are supported by support rollers.
There are several drawbacks associated with this prior configuration. For example, if there is a problem with either of the operating rods, the amount of throw at the switch point may vary. Also, the flexure or lateral movement of both rods must be accounted for in designing the switch point adjuster. Furthermore, adjustments made to the switch point adjuster are more difficult when two operating rods have to be adjusted.
SUMMARY OF THE INVENTION
This invention provides an improved switch point adjuster for moving a movable switch point a selected distance as a result of the throw of a switch machine. A present preferred switch point adjuster mounts directly to the bottom of a swing nose frog switch point. This direct connection of the adjuster to the switch point eliminates the use of an additional throw rod such as is utilized in prior art swing nose frog switch point adjusters.
In addition to utilizing a switch point adjuster mounted directly to the switch point, the apparatus includes a single operating rod connected to and movable by the switch machine which engages with and moves the switch point adjuster. The switch point adjuster has an elongated housing with a bore provided therethrough, in which the operating rod is disposed through the housing bore. The switch point adjuster also has first and second adjusting nuts that are adjustably secured to the operating rod on opposed sides of the housing, preferably by mated threading.
The operating rod is movable bidirectionally through the housing until one of the adjusting nuts contacts the housing. In this way, lost motion of the switch machine may be compensated for at the switch point adjuster. The adjusting nuts preferably have a head portion and a body portion, in which the head portion has a width greater than the width of the body portion. Thus, the head portions of the adjusting nuts are contactable with respective opposed ends of the housing. Alternatively, or in addition, the housing may have an interior ledge provided within the housing bore, and leading edges of the adjusting nuts which are disposable within the housing may contact the interior ledge.
Use of a single throw rod that directly connects the switch machine to the switch point provides a more rigid connection and decreases the amount of lateral movement of the operating rod. Furthermore, indirect switch point adjustment (i.e., adjustment of the switch point position at a location remote from the switch point) is eliminated. The switch point adjuster is mounted directly to the bottom of the switch point, thus any adjustments of the adjusting nut that are made will directly effect the point opening. Because the length of the adjusting nuts may be varied, adjusting nuts can be selected that are long enough such that they extend out beyond the base of the rail. In this way, maintenance personnel can access and adjust the position of the adjusting nuts. This eliminates the need for two separate adjusting points in the assembly.
The connection of the switch machine directly to the switch point by a single operating rod eliminates the use of an additional rod in the assembly. The elimination of this rod then decreases the allowable lateral movement of the operating rod. The proposed switch point adjuster design simplifies assembly thereby reducing the required time for installation, maintenance and adjustment. Reducing the amount of material required in the assembly directly reduces the cost of the rail connection. Furthermore, the adjusting nuts are preferably coupled to the operating rod within a housing, thus the device is weather resistant. Also, because two adjusting nuts are provided, an offset in the adjustment may be made. Therefore, lost motion from the switch throw may be compensated for at the beginning of the throw toward the switch machine or the throw away from the switch machine.
The switch point adjuster is preferably constructed of a cast iron plug used in cooperation with steel adjusting nuts or sleeves mounted on the switch operating rod. However, any suitable material may be used to facilitate the components of the switch point adjuster. High strength steel hardware is preferably used to mount the adjuster to the track work. A lug is affixed to the frog and a mounting portion of the adjuster housing connects to the lug. The mounting portion is configured so that the cylindrical portion of the housing is provided below and spaced apart from the lug and the frog.
Other objects and advantages of the invention will become apparent from a description of certain presently preferred embodiments thereof shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic depiction of a prior art switching configuration, showing a switch machine and a switch point adjuster utilizing two operating rods.
FIG. 2 is a schematic depiction of a present preferred switching configuration, showing a switch machine and the present switch point adjuster utilizing a single operating rod.
FIG. 3 is a top plan view of a present preferred switch point adjuster.
FIG. 4 is a top view taken in cross section of the housing of a present preferred switch point adjuster.
FIG. 5 is a top view taken in cross section of a present preferred switch point adjuster.
FIG. 6 is a side elevational view of the present preferred switch point adjuster showing the offset of the housing mounting portion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring next to FIG. 2, the present preferred switch point adjusting mechanism is shown. As can be seen, a switch machine 12 is situated wayside of two sets of rail track 14. A swing nose frog type switch point 16 is situated at the intersection of the two sets of rail track 14. The switch point adjuster 18 is mounted to the switch point 16. An operating rod 22 connects the switch point adjuster 18 to the switch machine 12. Other switch point equipment used at a switch site has been omitted.
When activated, the switch machine 12 has an operating bar 24 which moves, causing the operating rod 22 to translate bidirectionally either towards or away from the switch machine 12. When the switch machine 12 is placed into a first position of operation, the operating rod 22 is moved away from the switch machine 12, carrying the switch point adjuster 18 and thus the switch point 16 away from the switch machine 12 as well. When the switch machine 12 is placed in a second position of operation, the operating rod 22 is moved in a direction towards the switch machine 12 carrying the switch point adjuster 18 and thus the switch point 16 in a direction towards the switch machine 12.
As described above, the distance in which the operating rod 22 is caused to travel under either position of operation of the switch machine 12 is an industry standard distance of six inches per AAR recommendations and standards, regardless of the type of switch machine utilized. However, the switch point 16 must often be moved less than six inches, with the switch point movement required being dependent upon the design of the switch. Thus, the difference between the amount that the switch point 16 must be moved and the standard six inch travel (or "throw") of the switch machine 12 must be taken up by the switch point adjuster 18.
Referring next to FIGS. 3, 4 and 5, the present preferred switch point adjuster mechanism will be described in more detail. The principle components of the switch point adjuster 18 are a housing 26 having a single operating rod 22 disposed therethrough and a pair of adjusting nuts 28, 29 adjustably engaged to the operating rod 22 on opposed sides of housing 26.
Referring particularly to FIG. 4, the switch point adjuster housing 26 is shown. As can be seen in the figure, the housing 26 has an axial bore 30 extending along a longitudinal axis 31 of housing 26. The longitudinal axis 31 of the housing 26 is coincident with the axis of movement of the operating rod 22 (as will be described in more detail below). The housing bore 30 opens at openings 32, 33 which are provided at respective opposed ends 34, 35 of the housing 26. The housing bore 30 is preferably cylindrical, however, any suitable configuration of the bore 30 may be utilized.
It is further preferred that an internal ledge 36 be provided within the housing bore 30. Internal ledge 36 is also preferably annular, thus having opposed sides 37 and a cylindrical surface connecting the opposed sides. The internal ledge 37 also preferably has a transverse dimension (which is a diameter when the internal ledge 36 is annular) relative to the longitudinal axis 31 of the housing bore 30 which is less than the transverse dimension of the remaining portions of the housing bore 30. The housing 26 further has a mounting portion 38 for mounting the switch point adjuster 18 to the switch point 16.
Referring again to FIGS. 3, 4 and 5, a single operating rod 22 is disposed through the bore 30 of housing 26. Thus, the operating rod 22 extends outward from the housing 26 through the openings 32, 33 at respective opposed ends 34, 35 of the housing 26. Two adjusting nuts 28, 29 are secured to the operating rod 22, in which the position of the adjusting nuts 28, 29 along the operating rod 22 is adjustable. The preferred means by which the adjusting nuts 28, 29 are adjustably secured to the operating rod 22 is by being threadably mated to the operating rod 22. Thus, internal threading 42 which is provided within the adjusting nuts 28, 29 mates with threading 40 that is provided along the operating rod 22. The internal threading 42 may be provided along the entire inner surface of the adjusting nuts 28, 29 or only along some portion of the interior surface of the adjusting nuts 28, 29.
The adjusting nuts 28, 29 preferably have a head portion 44 and a body portion 46. It is preferred that the transverse dimension of the adjusting nut head portion 44 is greater than the transverse dimension of the adjusting nut body portion 46. It is further preferred that the adjusting nuts 28, 29 are generally sleeve-shaped. Thus, the adjusting nut body portion 46 is generally cylindrical and extends outward from the head portion 44. It is further preferred that the adjusting nut head portion 44 be five sided or six sided so as to be engagable with a wrench.
As can be seen best in FIGS. 3, 5 and 6, the housing mounting portion 38 preferably has a bolt opening 48 provided therethrough. In this way, a bolt 50 is preferably disposed through the bolt opening 48, engaging a portion of the switch point 16 (preferably a lug, 56, extending from the switch point), and thus securing the switch point adjuster 18 to the switch point 16.
Referring to FIG. 6, mounting portion 38 is preferably disposed at an angle from the remainder of housing 26. Preferably, the mounting portion 38 is disposed at a dog leg-type angle, i.e., the mounting portion 38 extends outward and upward from the remainder of housing 26. Thus, a bolt (shown in dotted line as 50 in FIG. 6) disposed through bolt opening 48 generally lies in a horizontal plane X that is a distance above a horizontal plane X' that the longitudinal axis of the housing and the operating rod 22 (shown in dotted line in FIG. 6) substantially lies. Bolt 50 then connects to a lug 56 that is affixed to the track of the switch point. Bolt 50 and plane X lie generally parallel with the track of the switch point. Therefore, the operating rod and the cylindrical portion of the housing may be disposed below the level of the track of the switch point. Similarly, bolt 50 lies in a vertical plane Y that is separated a distance from a vertical plane Y' in which the operating rod 22 lies. In this way, the present preferred switch point adjuster will not contact or otherwise have its movement inhibited by the track.
In operation, the adjusting nuts 28, 29 are secured to the operating rod 22 and the position of the adjusting nuts 28, 29 is adjusted until the adjusting nuts 28, 29 are at a desired location along the operating rod 22 relative to one another and relative to the housing 26. The operating rod 22 is then caused to move bidirectionally along the longitudinal axis 31 by the switch machine. Thus, the operating rod 22 moves either in the direction indicated by the arrow marked A in FIG. 5 or in the opposite direction indicated by the arrow marked B in FIG. 5.
Once the operating rod 22 has moved a sufficient distance in the direction indicated by the arrow marked A, the adjusting nut 29 will eventually contact the housing 26 carrying the housing 26, and thus the switch point 16, upon any further movement of the operating rod 22 in this direction. Similarly, when the operating rod 22 is then moved a sufficient distance in the direction indicated by the arrow marked B, the adjusting nut 28 will eventually contact the housing 26, causing any further movement of the operating rod 22 in this direction to move the housing 26, and thus the switch point 16, in this direction as well.
There will be some initial movement of the adjusting nuts 28, 29 before one of the adjusting nuts 28, 29 contact the housing 26. This distance of movement of the adjusting nuts 28, 29 prior to contact with the housing 26 is determined by the positioning of the adjusting nuts 28, 29 relative to one another and to the housing 26. Therefore, if the switch machine throws six inches (i.e., the operating rod 22 is caused to translate six inches) but the switch point is to move only four inches, then the adjusting nuts 28, 29 are positioned so as to move two inches before contacting the housing 26. If any adjustment is required in the amount of movement compensated for by the switch point adjuster 18, an operator need only adjust the position of either or both of the adjusting nuts 28, 29 along the operating rod 22 by rotating the adjusting nut 28, 29. As with any threadably engaged pieces, the rotation of the adjusting nuts 28, 29 causes the adjusting nuts 28, 29 to travel the threading of the operating rod 22 in either axial direction along the operating rod 22, depending upon the direction of rotation applied to the adjusting nuts 28, 29 (i.e., clockwise or counterclockwise).
In the preferred embodiments, the contact between the adjusting nuts 28, 29 and the access housing 26 occurs by a leading edge 54 of each adjusting nut 28, 29 contacting a side 37 of the internal ledge 36 of the housing 26. In this embodiment, the adjusting nut body portions 46 enter the housing bore 30 but are stopped by contact with the side 37 of the internal ledge 36. Thus, in this embodiment, the respective diameters of the adjusting nut body portions 46, the housing bore 30 and the internal ledge may be varied but the diameter of the adjusting nut body portions 46 must be less then the diameter of the housing bore 30 but greater than the diameter of the internal ledge 36.
Moreover, although the bore 30, the internal ledge 36 and the adjusting nut body portions 46 are each preferably cylindrical surfaces, any suitable configuration for these elements may be utilized so long as the adjusting nut body portions 46 may be disposed within and rotated along the operating rod 22 within the bore 30, but may not travel past the internal ledge 36. Furthermore, in the case in which the internal ledge 36 is configured as a cylindrical surface, it need not be a continuous cylinder. Thus, the internal ledge 36 may be semicylindrical or any segment of a cylinder or may be constructed of a number of separate segments.
In this way, the adjusting nuts 28, 29 are at least partially disposed within the housing 26. The internal threading 42 of the adjusting nuts 28, 29 is preferably provided along the end of the adjusting nut body portions 46 distal to the head portions 44. Thus, the internal threading 42 and the portion of the operating rod threading 40 upon which the adjusting nuts 28, 29 travel, are located within housing 26 and are thus protected from the elements and from foreign matter being caught in the threading 40, 42. The adjusting nut body portions, although having a diameter less than that of the housing bore 30, are preferably not much less in diameter, so that the space in the radial direction between the adjusting nut body portion and the portion of the housing 26 adjacent the axial bore 30 is sufficiently small so as to reduce the chance that foreign matter will enter the housing 26. The collars 52 provided along the opposed ends 34, 35 of the housing 26 may be designed to extend down very nearly into contact with the adjusting nut body portions so as to further prevent foreign matter from entering the housing bore 30.
It is understood that other means of contact between the adjusting nuts 28, 29 and the housing 26 are contemplated. For example, because it is preferred that the head portions 44 have a greater transverse dimension than the body portions 46, if the body portions 46 of adjusting nuts 28, 29 have a sufficiently small length, the head portions 44 of the adjusting nuts 28, 29 will contact the opposed ends 34, 35, respectively, of housing 26. It is preferred that collars 52 are secured to the housing 26 at opposed ends 34, 35 of the housing 26, thus, such contact between the head portions 44 of the adjusting nuts 28, 29 and the ends 34, 35 of the housing may occur either directly at the opposed ends 34, 35 or through contact with the collars 52. The collars 52 may be secured to the opposed ends 34, 35 by any convenient means.
It is also possible that the head portions 44 and the body portions 46 of the adjusting nuts 28, 29 be of a uniform dimension in the transverse direction. In this way, the adjusting nuts 28, 29 need only be long enough in the longitudinal direction to contact the internal ledge 36 and still be accessible exterior to the openings 32, 33 of the housing.
Alternatively, when the head portions 44 and the body portions 46 of the adjusting nuts 28, 29 are of uniform dimension in the transverse direction, the adjusting nuts 28, 29 need only have a sufficient dimension in the transverse dimension so as to be greater than the transverse dimensions of the openings 32, 33 so that the adjusting nuts 28, 29 contact the opposed ends 34, 35 around openings 32, 33 and are thus not able to enter the housing bore 30.
In any of the embodiments in which contact between the adjusting nuts and the housing is not made at the internal ledge 36, the internal ledge would not be required. Thus, the housing bore 30 may be of uniform dimensions in such embodiments.
In any of the embodiments, it is preferred that the length of the adjusting nuts 28, 29 in the longitudinal direction be sufficient so that the adjusting nut head portions 44 extend out beyond the base of the rail when the switch point adjuster 18 is mounted to the bottom of the switch point. Thus, the adjusting nuts 28, 29 are readily accessible by an operator despite being mounted directly to the switch point.
While certain presently preferred embodiments have been shown and described, it is distinctly understood that the invention is not limited thereto but may be otherwise embodied with the scope of the following claims.
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An apparatus is provided for moving a movable switch point a selected distance as a result of the throw of a switch machine. The apparatus includes an operating rod connected to and movable by the switch machine and a switch point adjuster mounted directly to the switch point and movable by the operating rod. The switch point adjuster has an elongated housing with a bore provided therethrough, in which the operating rod is disposed through the housing bore. The switch point adjuster also has first and second adjusting nuts that are adjustably secured to the operating rod on opposed sides of the housing, preferably by mated threading. The operating rod is movable bidirectionally through the housing until one of the adjusting nuts contacts the housing. In this way, lost motion of the switch machine may be compensated for. The adjusting nuts preferably have a head portion and a body portion, in which the head portion has a width greater than the width of the body portion. Thus, the head portions of the adjusting nuts are contactable with respective opposed ends of the housing. Alternatively, or in addition, the housing may have an interior ledge provided within the housing bore, and leading edges of the adjusting nuts which are disposable within the housing may contact the interior ledge.
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FIELD OF INVENTION
[0001] This invention relates to a blind rivet, and more especially to a peel type blind rivet.
BACKGROUND OF INVENTION
[0002] Blind rivets are set in an aperture in one or more application pieces from one side of the application piece. A blind rivet typically comprises an outer tubular shell flanged at one end, and a mandrel, having a stem and a radially enlarged head at one end of the shell. The periphery of the radially enlarged head of the mandrel is the same size or slightly smaller than the periphery of the rivet shell, so that both parts can be inserted together into the application piece(s) from the front side. The rivet shell is positioned in the aperture of the application piece(s) with the flanged end on the operator side, and the mandrel stem extends into the tubular shell so that its enlarged head is on the blind side of the application piece(s). During the rivet setting process, the flange of the rivet shell is supported by a setting tool, and the stem of the mandrel is subjected to tensile loading by the tool, and thereby pulled through the shell of the rivet until the enlarged head of the mandrel contacts the remote end face of the tubular shell of the rivet. Further tensile loading of the mandrel stem then causes the remote end of the shell to collapse in some way into contact with the blind side of the application piece(s). The manner of collapse of the remote end of the shell depends on the type of rivet. The application piece(s) are thereby firmly gripped between the collapsed remote end of the rivet shell and the front flange of the rivet shell.
[0003] In a known peel type blind rivet, the enlarged mandrel head is typically provided with a number of edges, typically four edges, beneath the mandrel head. The effect of this is that during the setting process the remote end of the rivet shell is split into segments or petals (the number of segments or petals corresponding to the number of edges beneath the mandrel head). The segments or petals spread out on the blind side of the application piece(s) to make a broad bearing area onto the back face of the application piece(s). Therefore in peel type rivets the manner of collapse of the remote end of the shell is by splitting into segments or petals, which peel back into contact with the blind side of the application piece(s).
[0004] In known peel type blind rivets, on completion of the setting process the tensile loading is at its highest causing the mandrel stem to break (it is usually necked to enhance this break). This results in a release of strain energy. The release of energy causes the mandrel head part, which was temporarily lodged in the end of the peeled back shell, to be dislodged from its position, and to move in the opposite direction to that which it was previously pulled. Therefore the mandrel head and the remaining part of the mandrel shank are ejected from the rivet shell.
[0005] There are instances where the ejection of the mandrel head from the peel type blind rivet is undesirable. For example ejection would be undesirable where the rivet is being installed in the proximity of moving parts, or where electrical equipment is installed.
[0006] It is known from GB-A-2351538, in another type of blind rivet (a self plugging blind rivet), to provide a means to retain the mandrel head in the set blind rivet. According to this reference the stem of the mandrel is provided with a plurality of axial recesses, and each recess has a protrusion or bar member formed on it. When the rivet is set the shell deforms in a region adjacent the recess and surrounds each protrusion or bar member.
[0007] The present invention aims to provide a peel type blind rivet with means substantially to prevent the ejection of the mandrel head portion from the set shell, and means for retaining the mandrel head in the rivet shell body.
SUMMARY OF THE INVENTION
[0008] The present invention provides a peel type blind rivet for securement in an aperture in one or more application pieces, the rivet comprising:
[0009] a tubular shell having a flanged front face and a remote end;
[0010] a mandrel having an enlarged head end having a plurality of edges beneath the head, and a stem extending from the enlarged head, the stem being arranged to pass through the tubular shell so that the enlarged head of the mandrel is on the blind side of the application piece(s),
[0011] the stem comprising one or more protrusions from a surface thereof;
[0012] wherein during the setting process of the rivet the stem of the mandrel is subjected to tensile load whereby the edges beneath the enlarged head of the mandrel cause the remote end of the shell to split into a plurality of segments that engage the blind side of the application piece(s), and the shell of the rivet body deforms around the protrusion(s).
[0013] The deformation of the rivet body shell around the protrusion means that the mandrel head is retained in the shell.
[0014] Preferably a plurality of protrusions spaced around the periphery of the mandrel are provided. These may be at the same longitudinal location along the mandrel stem or spaced longitudinally along the stem. Preferably one or more pairs of diametrically opposed protrusions are provided.
[0015] Preferably the mandrel stem comprises a pre-necked portion, whereby during the setting process of the rivet the stem of the mandrel is subjected to tensile load and the stem breaks at the said pre-necked portion. In this case there is an ensuing release of strain energy at the instant of mandrel break time, and it is an advantage of the invention that the mandrel head can be retained by the protrusions in the shell against the opposing force generally operating to urge it against the direction it was previously pulled prior to mandrel break.
[0016] Preferably the portion of the mandrel stem between its enlarged head portion and its pre-necked portion defines a head-shaft portion, and the protrusion(s) are located on a surface of the head-shaft portion. Such a head-shaft portion is typically 3-5 mm long, preferably about 4 mm long. Such a head-shaft portion may be any shape in cross-section. In one preferred embodiment the head shaft portion is circular in cross-section. The remainder of the stem may be any shape in cross-section, but is preferably circular in cross-section. Where both the head-shaft portion and the remainder of the mandrel stem is circular in cross-section the head-shaft portion is preferably the same diameter as the remainder of the mandrel stem, but could be smaller, or even larger. In another preferred embodiment the head-shaft portion is rectilinear, preferably square, in cross-section. Advantages of a rectilinear, especially square cross-sectioned head shaft portion is lower cost tooling to manufacture the mandrel, and the fact that the edges of the rectilinear cross-sectioned head-shaft portion help to keep and guide the mandrel head in a central position in the rivet during setting. Where a square cross-sectioned head-shaft portion is used in combination with a remaining stem portion that is cylindrical, the longitudinal edges of the head-shaft portion are preferably in line with the sides of the cylindrical remaining stem portion.
[0017] The protrusion on the stem of the mandrel may be any shape, as would be apparent to the man skilled in the art, to retain the mandrel head in the rivet body. In one embodiment the protrusion(s) comprises a bulge on a surface of the stem of the mandrel. Bulged protrusions are particularly appropriated for use with circular cross-sectioned mandrel stems, but can be used on any shaped mandrel stem. In another embodiment the protrusion(s) comprise a bar member extending across a surface of the mandrel head shaft or, stem, preferably in a direction perpendicular to the axis of the rivet. Bar-shaped protrusions are particularly appropriate for use with rectilinear-, especially square-cross-sectioned mandrel stems, but can be used on any shaped mandrel stem. Combinations of different shaped protrusions may also be used.
[0018] Preferably two protrusions are provided, located in opposed positions around the mandrel stem periphery, for example in diametrically opposed positions.
[0019] In another embodiment four protrusions are provided; a first pair of protrusions being located in opposed positions around the mandrel stem periphery in a first plane, and a second pair of protrusions being located in opposed positions around the mandrel stem periphery in a second plane, the second plane being 90° from the first plane. In this embodiment the second pair of protrusions is preferably longitudinally spaced from the first pair of protrusions along the stem of the mandrel.
[0020] Indentations may also be provided around the periphery of the rivet mandrel stem, preferably between the protrusions. These preferably accept deformed shell material during the setting process.
[0021] Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1A is a longitudinal section through a peel type blind rivet according to the prior art, prior to setting;
[0023] [0023]FIG. 1B is a longitudinal section through the rivet of FIG. 1A, after setting;
[0024] [0024]FIG. 2A is a longitudinal section through a first embodiment of peel type blind rivet according to the invention, prior to setting;
[0025] [0025]FIG. 2B is a longitudinal section through the rivet of FIG. 2A, after setting;
[0026] [0026]FIG. 2C is a cross-sectional view along line A-A of FIG. 2B;
[0027] [0027]FIG. 3A is a longitudinal section through a second embodiment of peel type blind rivet according to the invention, prior to setting;
[0028] [0028]FIG. 3B is a longitudinal section through the rivet of FIG. 3A, after setting;
[0029] [0029]FIG. 3C is a cross-sectional view along line A-A of FIG. 3B;
[0030] [0030]FIG. 3D is a cross-sectional view along line B-B of FIG. 3B;
[0031] [0031]FIG. 4A is a longitudinal section through a third embodiment of peel type blind rivet according to the invention, prior to setting;
[0032] [0032]FIG. 4B is a longitudinal section through the rivet of FIG. 4A, after setting;
[0033] [0033]FIG. 4C is a cross-sectional view along line A-A of FIG. 4B;
[0034] [0034]FIG. 5A is a longitudinal section through a fourth embodiment of peel type blind rivet according to the invention, prior to setting;
[0035] [0035]FIG. 5B is a longitudinal section through the rivet of FIG. 5A, after setting;
[0036] [0036]FIG. 5C is a cross-sectional view along line A-A of FIG. 5B; and
[0037] [0037]FIG. 5D is a cross-sectional view along line B-B of FIG. 5B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Referring to FIGS. 1A and 1B, these show a peel type rivet according to the prior art, before and after setting respectively. From FIG. 1A, it can be seen that the known rivet 2 comprises an outer cylindrical shell 4 having a flanged head 6 . The flanged head 6 is on the front operator side of the application pieces when the rivet is set. The rivet 2 also comprises a mandrel having a solid cylindrical stem 8 terminating at its remote end with an enlarged head 10 . The underside of the enlarged head 10 of the mandrel has four cut edges 12 (two are visible in FIG. 1). The stem 8 of the mandrel is pre-necked by the inclusion of four indented portions 14 around the circumference of the stem at a predetermined distance along the length of the stem 8 .
[0039] [0039]FIG. 1B shows the rivet 2 of FIG. 1 after setting. The rivet 2 comprising the shell and mandrel is placed from the front into aligned apertures in two application pieces 16 and 18 , and then during the setting process a tensile load is applied to the mandrel stem 8 pulling it towards the front of the application pieces (i.e. downwards in the Figures). During this process the edges 12 beneath the mandrel head 10 cause the remote end of the shell 4 to split into four segments or petals 20 , which spread out against the blind side of the application pieces 16 , 18 , whereby the pieces 16 and 18 are held together between the spread petals 20 and the shell flange 6 . On completion of the setting process, when the tensile loading is at its maximum, the mandrel stem 8 breaks at the pre-necked portion 14 , and the ensuing release of energy causes the mandrel head 10 to be ejected from the rivet body.
[0040] FIGS. 2 to 5 show peel type blind rivets according to the invention.
[0041] In FIG. 2A a blind rivet 22 according to a first embodiment is shown prior to setting. It comprises a tubular shell 24 having a flanged end 26 . A mandrel having a stem 28 , with a pre-necked portion 34 , and an enlarged head 30 the underside of which presents four cut edges 32 , is provided. The length of the mandrel stem between the enlarged head 30 and the pre-necked portion 34 defines a head-shaft portion 35 , which is about 4 mm long. The head shaft portion 35 is generally cylindrical, i.e. circular in cross-section and includes two protrusions in the form of diametrically opposed bulges 36 on the cylindrical surface of the head-shaft portion, and two diametrically opposed recesses 38 in the form of flat planes cut into the outer surface of the cylindrical head-shaft portion 35 . The two bulges 36 and the two recesses 38 are at the same longitudinal point along the head-shaft portion 35 circumferentially spaced between each other. The cylindrical head-shaft portion has the same diameter as the rest of the mandrel stem 28 .
[0042] [0042]FIGS. 2B and 2C show the blind rivet of FIG. 2A after setting. As in the prior art rivet of FIG. 1, the edges 32 of the head 30 of the mandrel cause the remote end of the shell 24 to split into four petals 40 to spread along the blind side of the application pieces 16 , 18 . In this case, however, the applied tensile force has also caused the material of the shell 24 to be deformed around each of the bulges 36 and into each of the indented recesses 38 . This deformation of the material of the shell 24 can be seen by comparing the forward sloping hashed section of FIG. 2C with the dotted outline. In FIG. 2C, and also in FIGS. 3C, 3D, 4 C, 5 C, and 5 D the forward sloping hashed section show the shell position after setting, and the dotted outline shows the shell position prior to setting.
[0043] In contrast to the prior art, in this case, on completion of the setting process, when the tensile loading is at its maximum, the mandrel stem 28 breaks at the pre-necked portion 34 as before, but the ensuing release of energy is not able to eject the mandrel head 30 from the rivet body 24 since the head shaft portion connected to the mandrel head 30 is held firmly in place by the deformed shell material that has moved around the bulges 36 and into the indentations 38 of the mandrel stem 28 . Also the radially outward deformation at points 39 urges the shell 24 into close conformity with at least part of the inner surface of the apertures in application pieces 16 , 18 .
[0044] [0044]FIGS. 3A to 3 D show a second embodiment of rivet according to the invention. Like parts are given like reference numerals compared to the first embodiment of FIG. 2. In common with the FIG. 2 embodiment, the head-shaft portion 35 ′ of the mandrel stem 28 is generally cylindrical, i.e. circular in cross-section, and has the same diameter as the rest of the mandrel stem 28 . However, in addition to the bulges 36 and indentations 38 present in the first embodiment of rivet according to FIG. 2, the head shaft portion 35 ′ of the FIG. 3 embodiment also comprises a second pair of diametrically opposed bulges 46 and diametrically opposed indentations 48 . The second pair of bulges and indentations 46 , 48 are longitudinally spaced from the first pair of bulges and indentations 36 , 38 . Also the bulges 36 are in the same plane as the indentations 48 and the indentations 38 are in the same plane as the bulges 46 . Looking in particular at the cross-sectional views of FIGS. 3C and 3D it can be seen that material from the shell 24 is therefore urged outwards, and hence into conformity with the apertures in the application pieces 16 , 18 , at four points 41 around the circumference of the head shaft portion 35 ′, and that shell material is urged around four bulges and into four indents. Securement of the mandrel head portion 30 and head shaft portion 35 ′ in the shell, and the rivet in the application pieces 16 , 18 , is therefore enhanced compared to the embodiment of FIG. 2.
[0045] FIGS. 4 A-C show a third embodiment of blind rivet according to the invention. As before like reference numerals refer to like parts compared to the earlier embodiments. In this case the head-shank portion 35 ″ of the mandrel is square in cross-section. It comprises two protrusions in the form of diametrically opposed bars 50 extending across opposed faces 51 of the square cross-sectioned head shank 35 ″. The bars 50 extend across the faces 51 , in a direction perpendicular to the axis of the mandrel. The two intervening faces of the square cross-sectioned head shank portion 35 ″ are referenced 52 in FIGS. 4 A-C. During the setting process shell material is deformed around the bars 50 and into the recesses presented by the faces 51 around the bars 50 and into the recesses presented by faces 52 . This material deformation thereby prevents ejection of the mandrel head 30 during the setting process. The material also deforms outwards at points 54 (see FIG. 46). The deformation at points 54 causes the rivet shell 24 to be urged into contact with the inner surface of the apertures in the application pieces 16 , 18 .
[0046] FIGS. 5 A-D show a fourth embodiment of blind rivet according to the invention. As before like reference numerals refer to like parts compared to the earlier embodiments. As in the embodiment of FIG. 4, the head-shank portion 35 ′″ of the mandrel is square in cross-section. However in this case it comprises not only the two diametrically opposed bars 50 extending across opposed flat faces 51 of the square cross-sectioned head shank 35 ′″, but also a second pair of diametrically opposed bars 56 extending across the other diametrically opposed flat faces 52 of the square cross-sectioned head shank 35 ′″ in a direction perpendicular to the rivet axis. Each pair of bars 50 , 56 is longitudinally spaced from the other pair of bars 54 , 56 . Looking in particular at the cross-sectional views of FIGS. 5C and 5D. it can be seen that material from the shell 24 is therefore urged outwards, and hence into conformity with the apertures in the application pieces 16 , 18 , at four points 62 around the circumference of the head shaft portion 35 ′″, and that shell material is urged around four bars 50 , 56 , and against the flat faces 51 and 52 around and between the bars 50 and 56 . Therefore securement of the mandrel head portion 30 and head shaft portion 35 in the shell 24 , and securement of the rivet shell 24 in the application pieces 16 , 18 is enhanced compared to the embodiment of FIG. 4.
[0047] While the above description constitutes the preferred embodiment(s), those skilled in the art will appreciate that the present invention is susceptible to other modifications and changes without departing from the proper scope and fair meaning of the following claims.
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There is provided a peel type blind rivet ( 22 ) for securement in an aperture of a workpiece, the rivet comprising a tubular shell ( 24 ) having a flange ( 26 ) at one thereof, this shell housing a mandrel stem ( 28 ) with a mandrel head ( 30 ) disposed at one end of the mandrel stem so as to abut a remote end of the tubular shell, the mandrel head ( 30 ) having a plurality of edges extending radially outwards therefrom which, in operation when the mandrel is subjected to a tensile load engage with the remote end of the shell so as to split the shell into a plurality of segments ( 40 ) to engage the blind side of the workpiece, whereby the stem of the mandrel further comprises at least one protrusion ( 38 ) about which the shell of the rivet body deforms during setting to retain the mandrel head ( 30 ) within the set rivet.
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TECHNICAL FIELD
[0001] The present invention relates to a metal organic compound, in particular to an organotin compound catalyst and the preparation method thereof.
BACKGROUND TECHNOLOGY
[0002] Organotin compounds are metal organic compounds formed by the direct combination of tin and carbon. They are widely used in the fields including agriculture, catalytic chemistry, pharmaceutical chemistry, stabilizing agent, antifouling coating, material anticorrosive and textile, and are also important organic synthetic intermediates. It is an important application of organotin compounds to act as a catalyst in the organic reaction, as it has the characteristics of high yield, high selectivity and non-corrosive to reactors. However, there are two major shortcomings when it is applied to the curing of thermosetting resins, one of which is the high activity under low concentration, this feature usually makes the catalytic curing of thermosetting resin runs so fast that is difficult to be controlled, so that the cross-linked structure of the cured product is inhomogeneous, and it is difficult to obtain a cured product with good comprehensive properties as expected. Therefore, the organotin used for the curing of the thermosetting resin should have appropriate reactivity, not high activity. Secondly, the homogeneous dispersion in the resin is a prerequisite for obtaining a cured product having excellent comprehensive properties, whereas the conventional organotin catalyst does not have an active group capable of interacting with the resin.
[0003] It is worth mentioning that the toxicity of organotin compounds has been fully confirmed, this shortcoming restricts the wide applications of organotin compounds. The research of low toxic organotin-based initiator has become a common concern. Previous researches showed that the introduction of silicon atom could reduce the toxicity of organotin compounds (literature: Patai S, Rappoport Z. Bioorganosilicon Chemistry [M]. John Wiley and Sons: 1989, 1143-1168.). However, the content of silicon in available silicon-containing organotin is very low and the tin loading is still high.
[0004] In summary, there is important application value to develop a new low-toxic organotin that can be used for the curing reaction of thermosetting resins.
SUMMARY OF THE INVENTION
[0005] The present invention provides a new low-toxic organotin suitable for applying in curing of thermosetting resins, to overcome the deficiencies of high toxicity and no reactive bases for reacting with resins of the common organic tin. The preparation method thereof is also provided.
[0006] In order to achieve the above-mentioned object, the present invention provides the technical scheme as:
[0007] A preparation method of organotin containing hyperbranched polysiloxane structure, comprising following steps:
[0008] (1) by weight, 0.5-1.5 portions of hyperbranched polysiloxane with reactive functional groups is dissolved in 50-100 portions of alcohol solvent, to obtain a solution A;
[0009] (2) by weight, 0.5-0.9 portions of a tin-based initiator and 50-100 portions of an alcohol solvent are mixed to obtain a solution B, said tin-based initiator is selected from dihydroxy butyl tin chloride, butyl tin trichloride, or dibutyl tin dichloride;
[0010] (3) dropping the solution B into the solution A at the temperature of 0° C.-60° C., reacting for 3-6 h, filtering and drying to obtain an organotin containing hyperbranched polysiloxane structure.
[0011] In the present invention, the molecular weight of the hyperbranched polysiloxane with reactive functional groups is 3500 to 9312; and the active functional group is selected from an amino group, an epoxy group, a vinyl group, or a combination thereof. Said alcohol is isopropanol, ethanol, or a combination thereof.
[0012] The invention also provides an organotin containing hyperbranched polysiloxane structure obtained by the preparation method described before.
[0013] Compared with the prior arts, the present invention has following beneficial effects:
[0014] 1. Amino-terminated hyperbranched polysiloxane, which has good biocompatibility, was introduced into the molecule of organotin-based initiator, and then the content of tin is only 0.09-0.32 wt %; besides, there is no halogen in the new organotin-based initiator prepared herein. The unique structure of the new organotin-based initiator has low toxicity.
[0015] 2. The hyperbranched polysiloxane introduced in the new organotin-based initiator has amino-terminal groups, these amino groups can react with a variety of functional groups, so this provides the new organotin-based initiator with effective dispersion in resins.
[0016] 3. The introduction of hyperbranched polysiloxane decreases the catalytic activity, and it is beneficial to get suitably catalyzing effect on curing resins.
[0017] 4. The reactivity of organotin-based initiator can be adjusted through controlling the molecular weight of hyperbranched polysiloxane as well as the proportion ratio between hyperbranched polysiloxane and organotin-based initiator, and thus a series of organotin-based initiators with different chemical reactivity were obtained.
[0018] 5. The structure of hyperbranched polysiloxane can help the thermosetting resins get better performances, such as toughness and thermal stability.
[0019] 6. In the invention, the preparation method is simple and has a great application prospect.
DESCRIPTION OF FIGURES
[0020] FIG. 1 illustrates the structure of the organotin with hyperbranched polysiloxane.
[0021] FIG. 2 is the fourier transform infrared (FTIR) spectra of 3-triethoxysilylpropylamine, amino-terminated hyperbranched polysiloxane, dihydroxy butyl tin chloride, and organotin with hyperbranched polysiloxane prepared in Example 1.
[0022] FIG. 3 shows the 1 H NMR spectrum of amino-terminated hyperbranched polysiloxane prepared in Example 1.
[0023] FIG. 4 shows 29 Si NMR spectra of amino-terminated hyperbranched polysiloxane and the new organotin (HSiSn) prepared in Example 1.
[0024] FIG. 5 gives DSC curves of cyanate ester prepolymer with dihydroxy butyl tin chloride (BCD/CE), and that with the organotin (HSiSn/CE) prepared in Example 1.
[0025] FIG. 6 shows TG and DTG curves of cured cyanate ester resin with dihydroxy butyl tin chloride (BCD/CE), and that with the new organotin (HSiSn/CE) prepared in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The technical solution of the present invention will be described in further details with reference to the drawings and examples.
EXAMPLE 1
[0027] The synthesis of an organotin with amino-terminated hyperbranched polysiloxane follows the steps described below.
[0028] 1. The synthesis of amino-terminated hyperbranched polysiloxane.
[0029] 22.1 g 3-triethoxysilylpropylamine (APTES) and 2.0 g distilled water are homogeneously mixed at room temperature. After 15 min of magnetic stirring, the solution is slowly heated to 60° C. and reacting for 4 h. After the reaction is completed, through vacuum drying to steam out ethanol, a transparent viscous amino-terminated hyperbranched polysiloxane is obtained. Its molecular weight is 6918.
[0030] 2. The synthesis of organotin with amino-terminated hyperbranched polysiloxane.
[0031] 1.34 g amino-terminated hyperbranched polysiloxane obtained in step 1 is dissolved in 50 mL isopropanol to form a solution; the solution is slowly heated to 55° C., and then into which 50 mL isopropanol containing 0.7 g dihydroxy butyl tin chloride (BCD) is dropped, then the solution is remained at 55° C. while stirring for 5 h. After filtering and drying, an organotin containing amino-terminated hyperbranched polysiloxane is obtained, in which the tin content is 0.121 wt %. The synthesis procedure, infrared spectroscopy, 1 H NMR and 29 Si NMR spectra of the organotin is shown in FIGS. 1, 2, 3 and 4 .
[0032] Referring to FIG. 1 , which is a schematic representation of the synthesis of organotin with amino-terminated hyperbranched polysiloxane provide in this example. It can be seen that the organotin with amino-terminated hyperbranched polysiloxane is halogen-free.
[0033] FIG. 2 gives the FTIR spectra of 3 -triethoxysilylpropylamine (APTES), amino-terminated hyperbranched polysiloxane (AHBSi), dihydroxy butyl tin chloride (BCD) and organotin with amino-terminated hyperbranched polysiloxane (HsiSn). There is a broad and overlapped absorption band attributing to Si—O—Si groups from 1000 to 1200 cm −1 in the spectrum of AHBSi; meanwhile, a broad and overlapped absorption band appeared at 3419 cm −1 indicating the hydrolysis of ethoxy to form silanol.
[0034] In addition, the absorption peaks at 926 cm −1 (for Si—OH of AHBSi and Sn—OH of BCD) and 554 cm −1 (Sn—Cl of BCD) are not observed, instead, a new absorption peak at 770 cm −1 (Si—O—Sn) appears, clearly manifesting the synthesis of HsiSn.
[0035] FIG. 3 shows the 1 H NMR spectrum of AHBSi, the chemical shift at 3.7 ppm is assigned to the —OH group, this further validates the polycondensation. In addition, the chemical shift of amine at 1.5 ppm is also observed.
[0036] FIG. 4 shows the 29 Si NMR spectra of AHBSi and HsiSn obtained in this example, the spectrum of HSiSn shows the chemical shifts representing dendritic unit, linear unit and terminal unit, suggesting that HSiSn has hyperbranched structure. Especially, compared with the T shift (−53.60 ppm ) in the spectrum of AHBSi, that of HSiSn appears at −48.71 ppm due to the condensation between AHBSi and butyltin chloride dihydroxide. The degree of branch (DB) of AHBSi was calculated to be 0.80.
[0037] From the results of FIG. 2-4 , it is confirmed that AHBSi was successfully synthesized.
[0038] From the results of FIGS. 2 and 4 , it can be confirmed that HSiSn was obtained.
[0039] On the base of successful synthesis of HSiSn, the modified cyanate ester (CE) resin was prepared according to following process. Specifically, 100 g 2,2′-bis(4-cyanatophenyl)propane (commercial CE monomer of bisphenol A type) was heated to 90° C. to get completely molten CE, into which 0.064 g HSiSn obtained above was added; after stirring at 90° C. for 20 min, a modified CE prepolymer (HSiSn/CE) was obtained. The DSC curve of HSiSn/CE prepolymer with a heating rate of 10° C./min under a nitrogen atmosphere is shown in FIG. 5 . The prepolymer was put into a preheated mold and thoroughly degassed to remove entrapped air at 120° C. in a vacuum oven, and then the mold was put into an oven for curing and postcuring following the protocol of 150° C./2 h+180° C./2 h+200° C./2 h+220° C./2 h+240° C./4 h, successively, to obtain a cured resin. FIG. 6 shows the TG and DTG curves of the cured HSiSn/CE resin with a flow rate of 100 mL/min and a heating rate of 10° C./min. The temperature at which the weight loss of a sample reaches 5 wt % is regarded as the initial decomposition temperature (T di ) the char yield at 800° C. is coded as Y c .
[0040] The CE resin modified by BCD was also prepared using following steps. 100 g 2,2′-bis(4-cyanatophenyl)propane is heated to 90° C. to get a completely molten liquid CE, into which 0.032 g BCD was added; after stirring at 90° C. for 20 min, a BCD/CE prepolymer was obtained. FIG. 5 gives the DSC curve of BCD/CE prepolymer with a heating rate of 10° C./min under a nitrogen atmosphere. The BCD/CE prepolymer was put into a preheated mold and thoroughly degassed to remove entrapped air at 120° C. in a vacuum oven, and then the mold was put into an oven for curing and postcuring following the protocol of 150° C./2 h+180° C./2 h+200° C./2 h+220° C./2 h+240° C./4 h, successively, to obtain a cured resin. FIG. 6 shows the TG and DTG curves of cured BCD/CE resin with a flow rate of 100 mL/min and a heating rate of 10° C./min.
[0041] By contrast the curves in FIG. 5 , it can be seen that in the curve of BCD/CE prepolymer, a curing peak appears just behind the melting peak, so the gap between the melting and curing temperatures is narrow, and this phenomenon means a relatively poor processing feature because it is generally to get cured structure without uniform structure and good performance. In addition, the curve of BCD/CE prepolymer shows multiple curing peaks, indicating that BCD has poor dispersion in CE resin, so there are different parts that have different curing reactivity. While attractively, this poor phenomenon does not appear in the DSC curve of HSiSn/CE prepolymer. In detail, the temperature gap between the curing peak and the melting peak is wide, so there is a wide processing window for HSiSn/CE prepolymer. In addition, compared with the curing peak in the DSC curve of CE, that of HSiSn/CE prepolymer shows an obvious shift toward lower temperature, demonstrating that HSiSn has an appropriate and good catalytic reactivity.
[0042] FIG. 6 gives TG and DTG curves of cured BCD/CE and HSiSn/CE resins. The two cured resins have almost same initial decomposition temperatures (T di , 420° C.), but they have an obviously different char yields, the char yields of HSiSn/CE and BCD/CE resins are 45.6 wt % and 40.8 wt %, respectively. The temperature at which showing the maximum decomposition rate of HSiSn/CE resin is 437° C. and that of BCD/CE resin is 443° C. All these results demonstrate that HSiSn/CE resin has better thermal stability than BCD/CE resin. This attractive result can be contributed to the outstanding thermal stability and catalytic reactivity of hyperbranched polysiloxane.
EXAMPLE 2
[0043] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0044] 47.3 g 3-glycidoxypropyltrimethoxysilane, 4.0 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at 50° C. with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 7500.
[0045] 2. The synthesis of new organotin.
[0046] 1.34 g epoxy-terminated hyperbranched polysiloxane was dissolved in 50 mL isopropanol to form a solution A; after being maintained at room temperature for 15 min, the solution A was heated to 55° C., and then into which 50 mL isopropanol which contained 0.7 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at 55° C. with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.26 wt %.
EXAMPLE 3
[0047] The synthesis of the new organotin follows the steps described below.
[0048] 1. The synthesis of vinyl-terminated hyperbranched polysiloxane.
[0049] 28.0 g vinyltris(2-methoxyethoxy)silane, 1.98 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was vinyl-terminated hyperbranched polysiloxane, and the molecular weight is 4200.
[0050] 2. The synthesis of the new organotin.
[0051] 0.5 g vinyl-terminated hyperbranched polysiloxane was dissolved in 50 mL isopropanol; after being maintained at room temperature for 15 min, the solution was heated to 55° C., and then into which 50 mL isopropanol which contained 0.5 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at 55° C. with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.32 wt %.
EXAMPLE 4
[0052] The synthesis of the new organotin follows the steps described below.
[0053] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0054] 45.3 g 3-glycidoxypropyltrimethoxysilane, 4.0 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 7140.
[0055] 2. The synthesis of the new organotin.
[0056] 1.25 g epoxy-terminated hyperbranched polysiloxane was dissolved in 60 mL isopropanol; after being maintained at room temperature for 15 min, the solution was heated to 55° C., and then into which 50 mL isopropanol which contained 0.5 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.11 wt %.
EXAMPLE 5
[0057] The synthesis of the new organotin follows the steps described below.
[0058] 1. The synthesis of amino-terminated hyperbranched polysiloxane.
[0059] 17.9 g 3-triethoxysilylpropylamine, 2.2 g distilled water, and 100 mL methanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution. After being maintained at room temperature for 15 min, the solution was heated to 60° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off methanol. Finally, a transparent and viscous liquid was obtained, which was amino-terminated hyperbranched polysiloxane, signed as AHBSi, and the molecular weight is 5120.
[0060] 2. The synthesis of the new organotin.
[0061] 0.90 g AHBSi was dissolved in 50 mL ethanol; after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 100 mL ethanol which contained 0.9 g dibutyl tin dichloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.3 wt %.
EXAMPLE 6
[0062] The synthesis of the new organotin follows the steps described below.
[0063] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0064] 47.3 g 3-glycidoxypropyltrimethoxysilane, 3.5 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 7630.
[0065] 2. The synthesis of the new organotin.
[0066] 1.4 g epoxy-terminated hyperbranched polysiloxane was dissolved in 80 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 100 mL ethanol which contained 0.6 g dibutyl tin dichloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.256 wt %.
EXAMPLE 7
[0067] The synthesis of the new organotin follows the steps described below.
[0068] 1. The synthesis of vinyl-terminated hyperbranched polysiloxane.
[0069] 27.0 g vinyltris(2-methoxyethoxy)silane, 1.98 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was vinyl-terminated hyperbranched polysiloxane, and the molecular weight is 3800.
[0070] 2. The synthesis of the new organotin.
[0071] 0.5 g vinyl-terminated hyperbranched polysiloxane was dissolved in 50 mL ethanol; after being maintained at room temperature for 15 min, the solution was heated to 60° C., and then into which 50 mL isopropanol which contained 0.7 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.24 wt %.
EXAMPLE 8
[0072] The synthesis of the new organotin follows the steps described below.
[0073] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0074] 40.3 g 3-glycidoxypropyltrimethoxysilane, 4.0 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 6930.
[0075] 2. The synthesis of the new organotin.
[0076] 1.1 g epoxy-terminated hyperbranched polysiloxane was dissolved in 50 mL ethanol; after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 100 mL ethanol which contained 0.8 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product.
[0077] The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.189 wt %.
EXAMPLE 9
[0078] The synthesis of the new organotin follows the steps described below.
[0079] 1. The synthesis of amino-terminated hyperbranched polysiloxane.
[0080] 22.1 g 3-triethoxysilylpropylamine, 1.9 g distilled water, and 100 mL methanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution. After being maintained at room temperature for 15 min, the solution was heated to 60° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off methanol. Finally, a transparent and viscous liquid was obtained, which was amino-terminated hyperbranched polysiloxane, signed as AHBSi, and the molecular weight is 6708.
[0081] 2. The synthesis of the new organotin.
[0082] 1.3 g AHBSi was dissolved in 100 mL ethanol; after being maintained at room temperature for 15 min, the solution was heated to 55° C., and then into which 90 mL isopropanol which contained 0.6 g dihydroxy butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.145 wt %.
EXAMPLE 10
[0083] The synthesis of the new organotin follows the steps described below.
[0084] 1. The synthesis of amino-terminated hyperbranched polysiloxane.
[0085] 19.7 g 3-triethoxysilylpropylamine, 2.6 g distilled water, and 100 mL methanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution. After being maintained at room temperature for 15 min, the solution was heated to 60° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off methanol. Finally, a transparent and viscous liquid was obtained, which was amino-terminated hyperbranched polysiloxane, signed as AHBSi, and the molecular weight is 9312.
[0086] 2. The synthesis of the new organotin.
[0087] 1.27 g AHBSi was dissolved in 70 mL ethanol; after being maintained at room temperature for 15 min, the solution was cooled to 0° C., and then into which 100 mL isopropanol which contained 0.6 g butyl tin chloride 0.90 g AHBSi was dissolved in 50 mL ethanol, after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 100 mL ethanol which contained 0.9 g dibutyl tin dichloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.135 wt %.
EXAMPLE 11
[0088] The synthesis of the new organotin follows the steps described below.
[0089] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0090] 50.3 g 3-glycidoxypropyltrimethoxysilane, 4.0 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 7800.
[0091] 2. The synthesis of the new organotin.
[0092] 1.4 g epoxy-terminated hyperbranched polysiloxane was dissolved in 100 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 90 mL ethanol which contained 0.8 g dibutyl tin dichloride 0.90 g AHBSi was dissolved in 50 mL ethanol, after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 100 mL ethanol which contained 0.9 g dibutyl tin dichloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.142 wt %.
EXAMPLE 12
[0093] The synthesis of the new organotin follows the steps described below.
[0094] 1. The synthesis of vinyl-terminated hyperbranched polysiloxane.
[0095] 29.0 g vinyltris(2-methoxyethoxy)silane, 1.98 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was vinyl-terminated hyperbranched polysiloxane, and the molecular weight is 5000.
[0096] 2. The synthesis of the new organotin.
[0097] 1.4 g vinyl-terminated hyperbranched polysiloxane was dissolved in 100 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 0° C., and then into which 50 mL isopropanol which contained 0.7 g butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.171 wt %.
EXAMPLE 13
[0098] The synthesis of the new organotin follows the steps described below.
[0099] 1. The synthesis of vinyl-terminated hyperbranched polysiloxane.
[0100] 24.0 g vinyltris(2-methoxyethoxy)silane, 1.98 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was vinyl-terminated hyperbranched polysiloxane, and the molecular weight is 3500.
[0101] 2. The synthesis of the new organotin.
[0102] 1.2 g vinyl-terminated hyperbranched polysiloxane was dissolved in 50 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 5° C., and then into which 50 mL isopropanol which contained 0.5 g dibutyl tin dichloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 3 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.175 wt %.
EXAMPLE 14
[0103] The synthesis of the new organotin follows the steps described below.
[0104] 1. The synthesis of epoxy-terminated hyperbranched polysiloxane.
[0105] 47.3 g 3-glycidoxypropyltrimethoxysilane, 3.5 g distilled water, and 100 mL ethanol were put into a three-necked flask equipped with a thermometer and condenser to form a solution, and then 1 mL HCl (36.5%) was added into the flask. After being maintained at room temperature for 15 min, the solution was heated to 50° C. and maintained at that temperature with stirring for 4 h, and then the resultant product was put into a vacuum oven to give off ethanol. Finally, a transparent and viscous liquid was obtained, which was epoxy-terminated hyperbranched polysiloxane, and the molecular weight is 7630.
[0106] 2. The synthesis of the new organotin.
[0107] 1.4 g epoxy-terminated hyperbranched polysiloxane was dissolved in 80 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 0° C., and then into which 100 mL ethanol which contained 0.6 g butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.184 wt %.
EXAMPLE 15
[0108] 0.7 g epoxy-terminated hyperbranched polysiloxane from the Example 14 and 0.7 g vinyl-terminated hyperbranched polysiloxane from the Example 12 were dissolved in 80 mL isopropanol; after being maintained at room temperature for 15 min, the solution was cooled to 0° C., and then into which 100 mL ethanol which contained 0.6 g butyl tin chloride was added to get a mixture B. The mixture B was stayed at that temperature with stirring for 5 h to get a crude product. The crude product was filtrated, and the resultant filter cake was dried in vacuo to obtain a new organotin containing hyperbranched polysiloxane, which was designed as HSiSn. The tin content of HSiSn is 0.126 wt %.
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A method of preparing an organotin containing hyperbranched polysiloxane structure includes the following steps: (1) by weight, 0.5-1.5 portions of hyperbranched polysiloxane with reactive functional groups is dissolved in 50-100 portions of an alcohol solvent, to obtain a solution A; (2) by weight, 0.5-0.9 portions of a tin-based initiator and 50-100 portions of the alcohol solvent are mixed to obtain a solution B, wherein said tin-based initiator is selected from dihydroxy butyl tin chloride, butyl tin trichloride, and dibutyl tin dichloride; and (3) dropping the solution B into the solution A at the temperature of 0° C.-60° C., reacting for 3-6 h, filtering and drying to obtain the organotin containing hyperbranched polysiloxane structure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. patent application Ser. No. 11/780,828, filed Jul. 20, 2007, a continuation-in-part of U.S. patent application Ser. No. 11/475,759, filed Jun. 27, 2006, which claims the benefit of U.S. Provisional Application No. 60/718,945, filed Sep. 20, 2005; and a continuation-in-part of U.S. patent application Ser. No. 10/961,813, filed Oct. 8, 2004; and a continuation-in-part of U.S. patent application Ser. No. 11/475,756, filed Jun. 27, 2006 which claims the benefit of U.S. Provisional Application No. 60/718,579, filed Sep. 19, 2005; a continuation-in-part of U.S. patent application Ser. No. 11/440,916, filed May 25, 2006 which claims the benefit of U.S. Provisional Application No. 60/717,310, filed Sep. 15, 2005; a continuation-in-part of U.S. patent application Ser. No. 11/554,234, filed Oct. 30, 2006.
TECHNICAL FIELD
[0002] The field to which the disclosure generally relates includes products and components thereof including means for damping and methods of making and using the same.
BACKGROUND
[0003] Product parts may produce undesirable noise when vibrated, or may vibrate at an undesirable amplitude for an prolonged period when struck or set in motion.
SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0004] Various embodiments of the invention include products and parts including a frictional damping means and methods of making and using the same.
[0005] Other exemplary embodiments of the invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while disclosing 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
[0006] Exemplary embodiments of the invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0007] FIG. 1 is a sectional view with portions broken away of one embodiment of the invention including an insert.
[0008] FIG. 2 is a sectional view with portions broken away of one embodiment of the invention including two spaced apart frictional surfaces of a cast metal body portion.
[0009] FIG. 3 is a sectional view with portions broken away of one embodiment of the invention including an insert having a layer thereon to provide a frictional surface for damping.
[0010] FIG. 4 is a sectional view with portions broken away of one embodiment of the invention.
[0011] FIG. 5 is an enlarged view of one embodiment of the invention.
[0012] FIG. 6 is a sectional view with portions broken away of one embodiment of the invention.
[0013] FIG. 7 is an enlarged sectional view with portions broken away of one embodiment of the invention.
[0014] FIG. 8 is an enlarged sectional view with portions broken away of one embodiment of the invention.
[0015] FIG. 9 is an enlarged sectional view with portions broken away of one embodiment of the invention.
[0016] FIG. 10 illustrates one embodiment of the invention.
[0017] FIG. 11 is a sectional view with portions broken away of one embodiment of the invention.
[0018] FIG. 12 is a sectional view with portions broken away of one embodiment of the invention.
[0019] FIG. 13 is a plan view with portions broken away illustrating one embodiment of the invention.
[0020] FIG. 14 is a sectional view taken along line 14 - 14 of FIG. 13 illustrating one embodiment of the invention.
[0021] FIG. 15 is a sectional view with portions broken away illustrating one embodiment of the invention.
[0022] FIG. 16 is a sectional view, with portions broken away illustrating another embodiment of the invention.
[0023] FIG. 17 is a schematic perspective view of an electric drive motor housing including an insert according to one embodiment of the invention.
[0024] FIG. 18 is a schematic perspective view of a transmission housing including an insert according to one embodiment of the invention.
[0025] FIG. 19 is a schematic perspective view of a combustion engine exhaust gas manifold including an insert according to one embodiment of the invention.
[0026] FIG. 19 is a schematic perspective view of a combustion engine cylinder head including an insert according to one embodiment of the invention.
[0027] FIG. 21 is a schematic perspective view of a differential including an insert according to one embodiment of the invention.
[0028] FIG. 22 is a schematic perspective view of a combustion engine block including an insert according to one embodiment of the invention.
[0029] FIG. 23 is a schematic perspective view of a rear end housing including an insert according to one embodiment of the invention.
[0030] FIG. 24 is a sectional view of the head of a golf club according to one embodiment of the invention.
[0031] FIG. 25 is a perspective view of a baseball bat including an insert according to one embodiment of the invention.
[0032] FIG. 26 illustrates an archery bow including stabilizers including an insert.
[0033] FIG. 27 is a sectional view of a shaft including a frictional damping means, an insert as a core and a surrounding metal layer.
[0034] FIG. 28 is a sectional view illustrating a shaft having a metal core and a frictional damping means including an insert surrounding the core.
[0035] FIG. 29 is a sectional view of a bearing including a frictional damping means including an insert surrounded by a metal body.
[0036] FIG. 30 is a sectional view illustrating a bearing including a three lobe insert frictional damping means.
[0037] FIG. 31 is a sectional view of a bearing including a five lobe insert frictional damping means.
[0038] FIG. 32 is a schematic perspective view of a vehicle brake rotor including a frictional damping means according to one embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0039] The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0040] Referring to FIGS. 1-16 , one embodiment of the invention includes a product or part 500 having a frictional damping means. The frictional damping means may be used in a variety of applications including, but not limited to, applications where it is desirable to reduce noise associated with a vibrating part or reduce the vibration amplitude and/or duration of a part that is struck, dynamically loaded, excited, or set in motion. In one embodiment the frictional damping means may include an interface boundary conducive to frictionally damping a vibrating part. In one embodiment the damping means may include frictional surfaces 502 constructed and arranged to move relative to each other and in frictional contact, so that vibration of the part is dissipated by frictional damping due to the frictional movement of the surfaces 502 against each other.
[0041] According to various illustrative embodiments of the invention, frictional damping may be achieved by the movement of the frictional surfaces 502 against each other. The movement of frictional surfaces 502 against each other may include the movement of: surfaces of the body 506 of the part against each other; a surface of the body 506 of the part against a surface of the insert 504 ; a surface of the body 506 of the part against the layer 520 ; a surface of the insert 504 against the layer 520 ; a surface of the body 506 of the part against the particles 514 or fibers; a surface of the insert 504 against the particles 514 or fibers; or by frictional movement of the particles 514 or fibers against each other or against remaining binder material.
[0042] In embodiments wherein the frictional surface 502 is provided as a surface of the body 506 or the insert 504 or a layer 520 over one of the same, the frictional surface 502 may have a minimal area over which frictional contact may occur that may extend in a first direction a minimum distance of 0.1 mm and/or may extend in a second (generally traverse) direction a minimum distance of 0.1 mm. In one embodiment the insert 504 may be an annular body and the area of frictional contact on a frictional surface 502 may extend in an annular direction a distance ranging from about 20 mm to about 1000 mm and in a transverse direction ranging from about 10 mm to about 75 mm. The frictional surface 502 may be provided in a variety of embodiments, for example, as illustrated in FIGS. 1-16 .
[0043] Referring again to FIG. 1 , in another embodiment of the invention one or more of the outer surfaces 522 , 524 of the insert 504 or surfaces 526 , 528 of the body 506 of the part 500 may include a relatively rough surface including a plurality of peaks 510 and valleys 512 to enhance the frictional damping of the part. In one embodiment, the surface of the insert 504 or the body 506 may be abraded by sandblasting, glass bead blasting, water jet blasting, chemical etching, machining or the like.
[0044] As shown in FIG. 2 , in one embodiment one frictional surface 502 (for example extending from points A-B) may be a first surface of the body 506 of the part 500 positioned adjacent to a second frictional surface 502 (for example extending from points C-D) of the body 506 . The body 506 may include a relatively narrow slot-like feature 508 formed therein so that at least two of the frictional surfaces 502 defining the slot-like feature 508 may engage each other for frictional movement during vibration of the part to provide frictional damping of the part 500 . In various embodiments of the invention, the slot-like feature 508 may be formed by machining the cast part, or by using a sacrificial casting insert that may be removed after the casting by, for example, etching or machining. In one embodiment a sacrificial insert may be used that can withstand the temperature of the molten metal during casting but is more easily machined than the cast metal. Each frictional surface 502 may have a plurality of peaks 510 and a plurality of valleys 512 . The depth as indicated by line V of the valleys 512 may vary with embodiments. In various embodiments, the average of the depth V of the valleys 512 may range from about 1 μm-300 μm, 50 μm-260 μm, 100 μm-160 μm or variations of these ranges. However, for all cases there is local contact between the opposing frictional surfaces 502 during component operation for frictional damping to occur.
[0045] In another embodiment of the invention the damping means or frictional surface 502 may be provided by particles 514 or fibers provided on at least one face of the insert 504 or a surface of the body 506 of the part 500 . The particles 514 may have an irregular shape (e.g., not smooth) to enhance frictional damping, as illustrated in FIG. 10 . One embodiment of the invention may include a layer 520 including the particles 514 or fibers which may be bonded to each other or to a surface of the body 506 of the part or a surface of the insert 504 due to the inherent bonding properties of the particles 514 or fibers. For example, the bonding properties of the particles 514 or fibers may be such that the particles 514 or fibers may bind to each other or to the surfaces of the body 506 or the insert 504 under compression. In another embodiment of the invention, the particles 514 or the fibers may be treated to provide a coating thereon or to provide functional groups attached thereto to bind the particles together or attach the particles to at least one of a surface of the body 506 or a surface of the insert 504 . In another embodiment of the invention, the particles 514 or fibers may be embedded in at least one of the body 506 of the part or the insert 504 to provide the frictional surface 502 ( FIGS. 5-6 ).
[0046] In embodiments wherein at least a potion of the part 500 is manufactured such that the insert 504 and/or the particles 514 or fibers are exposed to the temperature of a molten material such as in casting, the insert 504 and/or particles 514 or fibers may be made from materials capable of resisting flow or resisting significant erosion during the manufacturing. For example, the insert 504 and/or the particles 514 or fibers may include refractory materials capable of resisting flow or that do not significantly erode at temperatures above 1100° F., above 2400° F., or above 2700° F. When molten material, such as metal, is cast around the insert 504 and/or the particles 514 , the insert 504 or the particles 514 should not be wet by the molten material so that the molten material does not bond to the insert 504 or layer 520 at locations wherein a frictional surface 502 for providing frictional damping is desired.
[0047] Illustrative examples of suitable particles 514 or fibers include, but are not limited to, particles or fibers including silica, alumina, graphite with clay, silicon carbide, silicon nitride, cordierite (magnesium-iron-aluminum silicate), mullite (aluminum silicate), zirconia (zirconium oxide), phyllosilicates, or other high-temperature-resistant particles. In one embodiment of the invention the particles 514 may have a length along the longest dimension thereof ranging from about 1 μm-350 μm, or 10 μm-250 μm.
[0048] In embodiments wherein the part 500 is made using a process wherein the insert 504 and/or the particles 514 or fibers are not subjected to relatively high temperatures associated with molten materials, the insert 504 and/or particles 514 or fibers may be made from a variety of other materials including, but not limited to, non-refractory polymeric materials, ceramics, composites, wood or other materials suitable for frictional damping. For example, such non-refractory materials may also be used (in additional to or as a substitute for refractory materials) when two portions of the body 506 of the part 500 are held together mechanically by a locking mechanism, or by fasteners, or by adhesives, or by welding 518 , as illustrated in FIG. 4 .
[0049] In another embodiment of the invention, the layer 520 may be a coating over the body 506 of the part or the insert 504 . The coating may include a plurality of particles 514 which may be bonded to each other and/or to the surface of the body 506 of the part or the insert 504 by an inorganic or organic binder 516 ( FIGS. 3-4 , 9 ) or other bonding materials. Illustrative examples of suitable binders include, but are not limited to, epoxy resins, phosphoric acid binding agents, calcium aluminates, sodium silicates, wood flour, or clays. In another embodiment of the invention the particles 514 may be held together and/or adhered to the body 506 or the insert 504 by an inorganic binder. In one embodiment, the coating may be deposited on the insert 504 or body 506 as a liquid dispersed mixture of alumina-silicate-based, organically bonded refractory mix.
[0050] In another embodiment, the coating may include at least one of alumina or silica particles, mixed with a lignosulfonate binder, cristobalite (SiO 2 ), quartz, or calcium lignosulfonate. The calcium lignosulfonate may serve as a binder. In one embodiment, the coating may include IronKote. In one embodiment, a liquid coating may be deposited on a portion of the insert and may include high temperature Ladle Kote 310B. In another embodiment, the coating may include at least one of clay, Al 2 O 3 , SiO 2 , a graphite and clay mixture, silicon carbide, silicon nitride, cordierite (magnesium-iron-aluminum silicate), mullite (aluminum silicate), zirconia (zirconium oxide), or phyllosilicates. In one embodiment, the coating may comprise a fiber such as ceramic or mineral fibers.
[0051] When the layer 520 including particles 514 or fibers is provided over the insert 504 or the body 506 of the part the thickness L ( FIG. 3 ) of the layer 520 , particles 514 and/or fibers may vary. In various embodiments, the thickness L of the layer 520 , particles 514 and/or fibers may range from about 1 μm-400 μm, 10 μm-400 μm, 30 μm-300 μm, 30 μm-40 μm, 40 μm-100 μm, 100 μm-120 μm, 120 μm-200 μm, 200 μm-300 μm, 200 μm-250 μm, or variations of these ranges.
[0052] In yet another embodiment of the invention the particles 514 or fibers may be temporarily held together and/or to the surface of the insert 504 by a fully or partially sacrificial coating. The sacrificial coating may be consumed by molten metal or burnt off when metal is cast around or over the insert 504 . The particles 514 or fibers are left behind trapped between the body 506 of the cast part and the insert 504 to provide a layer 520 consisting of the particles 514 or fibers or consisting essentially of the particles 514 or fibers.
[0053] The layer 520 may be provided over the entire insert 504 or only over a portion thereof. In one embodiment of the invention the insert 504 may include a tab 534 ( FIG. 3 ). For example, the insert 504 may include an annular body portion and a tab 534 extending radially inward or outward therefrom. In one embodiment of the invention at least one wettable surface 536 of the tab 534 does not include a layer 520 including particles 514 or fibers, or a wettable material such as graphite is provided over the tab 534 , so that the cast metal is bonded to the wettable surface 536 to attach the insert 504 to the body 506 of the part 500 but still allow for frictional damping over the remaining insert surface which is not bonded to the casting.
[0054] In one embodiment of the invention at least a portion of the insert 504 is treated or the properties of the insert 504 are such that molten metal will not wet or bond to that portion of the insert 504 upon solidification of the molten metal. According to one embodiment of the invention at least one of the body 506 of the part or the insert 504 includes a metal, for example, but not limited to, aluminum, steel, stainless steel, cast iron, any of a variety of other alloys, or metal matrix composite including abrasive particles. In one embodiment of the invention the insert 504 may include a material such as a metal having a higher melting point than the melting point of the molten material being cast around a portion thereof.
[0055] In one embodiment the insert 504 may have a minimum average thickness of 0.2 mm and/or a minimum width of 0.1 mm and/or a minimum length of 0.1 mm. In another embodiment the insert 504 may have a minimum average thickness of 0.2 mm and/or a minimum width of 2 mm and/or a minimum length of 5 mm. In other embodiments the insert 504 may have a thickness ranging from about 0.1-20 mm, 0.1-6.0 mm, or 1.0-2.5 mm, or ranges therebetween.
[0056] Referring now to FIGS. 7-8 , again the frictional surface 502 may have a plurality of peaks 510 and a plurality of valleys 512 . The depth as indicated by line V of the valleys 512 may vary with embodiments. In various embodiments, the average of the depth V of the valleys 512 may range from about 1 μm-300 82 m, 50 μm-260 μm, 100 μm-160 82 m or variations of these ranges. However, for all cases there is local contact between the body 506 and the insert 504 during component operation for frictional damping to occur.
[0057] In other embodiments of the invention improvements in the frictional damping may be achieved by adjusting the thickness (L, as shown in FIG. 3 ) of the layer 520 , or by adjusting the relative position of opposed frictional surfaces 502 or the average depth of the valleys 512 (for example, as illustrated in FIG. 2 ).
[0058] In one embodiment the insert 504 is not pre-loaded or under pre-tension or held in place by tension. In one embodiment the insert 504 is not a spring. Another embodiment of the invention includes a process of casting a material comprising a metal around an insert 504 with the proviso that the frictional surface 502 portion of the insert used to provide frictional damping is not captured and enclosed by a sand core that is placed in the casting mold. In various embodiments the insert 504 or the layer 520 includes at least one frictional surface 502 or two opposite friction surfaces 502 that are completely enclosed by the body 506 of the part. In another embodiment the layer 520 including the particles 514 or fibers that may be completely enclosed by the body 506 of the part or completely enclosed by the body 506 and the insert 504 , and wherein at least one of the body 506 or the insert 504 comprises a metal or consists essentially of a metal. In one embodiment of the invention the layer 520 and/or insert 504 does not include or is not carbon paper or cloth.
[0059] Referring again to FIGS. 1-4 , in various embodiments of the invention the insert 504 may include a first face 522 and an opposite second face 524 and the body 506 of the part may include a first inner face 526 adjacent the first face 522 of the insert 504 constructed to be complementary thereto, for example nominally parallel thereto. The body 506 of the part includes a second inner face 528 adjacent to the second face 524 of the insert 504 constructed to be complementary thereto, for example parallel thereto. The body 506 may include a first outer face 530 overlying the first face 522 of the insert 504 constructed to be complementary thereto, for example parallel thereto. The body 506 may include a first outer face 532 overlying the second face 524 of the insert 504 constructed to be complementary thereto, for example parallel thereto. However, in other embodiments of the invention the outer faces 530 , 532 of the body 506 are not complementary to associated faces 522 , 524 of the insert 504 . When the damping means is provided by a narrow slot-like feature 508 formed in the body 506 of the part 500 , the slot-like feature 508 may be defined in part by a first inner face 526 and a second inner face 528 which may be constructed to be complementary to each other, for example parallel to each other. In other embodiments the surfaces 526 and 528 ; 526 and 522 ; or 528 and 524 are mating surfaces but not parallel to each other.
[0060] Referring to FIGS. 11-12 , in one embodiment of the invention the insert 504 may be an inlay wherein a first face 522 thereof is not enclosed by the body 506 of the part. The insert 504 may include a tang or tab 534 which may be bent downward as shown in FIG. 11 . In one embodiment of the invention a wettable surface 536 may be provided that does not include a layer 520 including particles 514 or fibers, or a wettable material such as graphite is provided over the tab 534 , so that the cast metal is bonded to the wettable surface 536 to attach the insert 504 to the body of the part but still allow for frictional damping on the non-bonded surfaces. A layer 520 including particles 514 or fibers may underlie the portion of the second face 524 of the insert 504 not used to make the bent tab 534 .
[0061] In another embodiment the insert 504 includes a tab 534 which may be formed by machining a portion of the first face 522 of the insert 504 ( FIG. 12 ). The tab 534 may include a wettable surface 536 having cast metal bonded thereto to attach the insert 504 to the body of the part but still allow for friction damping by way of the non-bonded surfaces. A layer 520 including particles 514 or fibers may underlie the entire second face 524 or a portion thereof. In other embodiments of the invention all surfaces including the tabs 534 may be non-wettable, for example by way of a coating 520 thereon, and features of the body portion 506 such as, but not limited to, a shoulder 537 may be used to hold the insert 504 in place.
[0062] Referring now to FIG. 13 , one embodiment of the invention may include a part 500 having a body portion 506 and an insert 504 enclosed by the body part 506 . The insert 504 may include through holes formed therein so that a stake or post 540 extends into or through the insert 504 .
[0063] Referring to FIG. 14 , which is a sectional view of FIG. 13 taken along line 14 - 14 , in one embodiment of the invention a layer 520 including a plurality of particles 514 or fibers (not shown) may be provided over at least a portion of the insert 504 to provide a frictional surface 502 and to prevent bonding thereto by cast metal. The insert 504 including the layer 520 may be placed in a casting mold and molten metal may be poured into the casting mold and solidified to form the post 540 extending through the insert 504 . An inner surface 542 defining the through hole of the insert 504 may be free of the layer 520 or may include a wettable material thereon so that the post 540 is bonded to the insert 504 . Alternatively, in another embodiment the post 504 may not be bonded the insert 504 at the inner surface 542 . The insert 504 may include a feature such as, but not limited to, a shoulder 505 and/or the post 540 may include a feature such as, but not limited to, a shoulder 537 to hold the insert in place.
[0064] Referring now to FIG. 15 , in another embodiment, the insert may be provided as an inlay in a casting including a body portion 506 and may include a post 540 extending into or through the insert 504 . The insert 504 may be bonded to the post 540 to hold the insert in place and still allow for frictional damping. In one embodiment of the invention the insert 504 may include a recess defined by an inner surface 542 of the insert 504 and a post 540 may extend into the insert 504 but not extend through the insert 504 . In one embodiment the post 504 may not be bonded to the insert 504 at the inner surface 542 . The insert 504 may include a feature such as, but not limited to, a shoulder 505 and/or the post 540 may include a feature such as, but not limited to, a shoulder 537 to hold the insert in place.
[0065] Referring now to FIG. 16 , in another embodiment of the invention, an insert 504 or substrate may be provided over an outer surface 530 of the body portion 506 . A layer 520 may or may not be provided between the insert 504 and the outer surface 530 . The insert 504 may be constructed and arranged with through holes formed therethrough or a recess therein so that cast metal may extend into or through the insert 504 to form a post 540 to hold the insert in position and still allow for frictional damping. The post 540 may or may not be bonded to the insert 504 as desired. The post 540 may extend through the insert 504 and join another portion of the body 506 if desired.
[0066] The frictional damping means as described herein may be used in a variety of applications, for example, in automotive parts such as brake rotors, brackets, pulleys, brake drums, transmission housings, gears, engines and engine components and other parts may undergo unwanted or undesirable vibrations, and may even produce noise that is transmitted into the passenger compartment of a vehicle. The frictional damping means may also be used to address undesirable vibrations in parts or components including, but not limited to, sporting equipment, housing appliances, manufacturing equipment such as lathes, mill/grinding/drilling machines, earth moving equipment, and other non-automotive applications, and components that are subject to dynamic loads and vibration. FIG. 17-32 are illustrative examples of such applications.
[0067] Referring now to FIG. 17 , one embodiment of the invention includes a product which may include an electric drive motor housing including a body portion 506 formed from a cast metal. An insert 504 may be included in the housing as an inlay, or completely enclosed in a wall of the housing. The insert 504 may include tabs 534 as desired. The body portion 506 may be bonded to the tabs 534 as described above.
[0068] Referring now to FIG. 18 , one embodiment of the invention may include a product 500 which may be a transmission housing including inserts 504 which may be completely enclosed by a wall of the transmission housing or may be provided as an inlay in the wall of the transmission housing according to various embodiments of the invention.
[0069] Referring now to FIG. 19 , one embodiment of the invention may include a product 500 which may be a combustion exhaust gas manifold including inserts 504 which may be completely enclosed or may be provided as an inlay in a wall forming the combustion engine exhaust gas manifold.
[0070] Referring now to FIG. 20 , one embodiment of the invention may include a product 500 which may be a combustion engine cylinder head including inserts 504 which may be completely enclosed or provided as an inlay in a wall of the cylinder head.
[0071] Referring now to FIG. 21 , one embodiment of the invention may include a product 500 which may be a differential case including inserts 504 which may be completely enclosed or provided as an inlay in a wall of the differential case.
[0072] Referring now to FIG. 22 , one embodiment of the invention may include a product 500 which may be an engine block including inserts 504 which may be completely enclosed or provided as an inlay in a wall of the engine block.
[0073] Referring now to FIG. 23 , one embodiment of the invention may include a product 500 which may be a rear end housing for a rear wheel drive vehicle including at least one insert 504 which may be completely enclosed or may be provided as an inlay in a wall of the rear end housing.
[0074] Referring now to FIG. 24 , one embodiment of the invention may include a product 500 which may include a head of a golf club iron which may include an insert 504 therein for providing frictional damping according to one embodiment of the invention. The golf club may include a shaft attached to the head and the insert 504 may be provided in the shaft in addition to or alternatively to providing the insert 504 in the head of the golf club. The insert 504 may provide a frictional damping means to reduce vibration of the head and/or the shaft when the club strikes a golf ball or the ground.
[0075] Referring now to FIG. 25 , one embodiment of the invention may include a product 500 which may be in the form of a metal baseball bat including an insert 504 as a frictional damping means. The frictional damping means may reduce the vibration of the baseball bat upon striking an object such as a baseball.
[0076] Referring now to FIG. 26 , one embodiment of the invention may include a stabilizer(s) 600 for an archery bow 602 which may comprise a metal and may include a frictional damping means such as an insert 504 in the body portion 506 of the stabilizer 600 to reduce the vibration of the bow and/or the bow string (not shown) which may occur when shooting an arrow with the bow.
[0077] Referring now to FIG. 27 , one embodiment of the invention may include a shaft 500 including a frictional damping means which may include an insert 504 as a central core and concentric metal layer as a body portion 506 . The insert 504 and the body portion 506 may be keyed to each other so that they rotate together.
[0078] Referring now to FIG. 28 , one embodiment of the invention may include a shaft 500 having a central metal core as a body portion 506 and a frictional damping means which may include a concentric insert 504 surrounding the body portion 506 . The insert 504 and the body portion 506 may be keyed to each other so that they rotate together.
[0079] Referring now to FIG. 29 , one embodiment of the invention may include a bearing 500 including a frictional damping means which may include a cylindrical insert 504 surrounded by an inner and outer concentric body portion 506 which may be made of a metal. The bearing 500 may have a bore 604 extending therethrough to receive a shaft therein. A shaft rotating in the bearing 500 may have a destructive resonance frequency which could result in damage to the part in which the bearing 500 is located. The insert 504 provides a frictional damping means to dissipate undesirable vibration or osculation of the shaft.
[0080] Referring now to FIG. 30 , another embodiment of the invention may include a bearing 500 including a frictional damping means which may include three lobe inserts 504 which may be positioned at 60 degrees with respect to each other or at an equal distance from each other. The inserts 504 may serve to reduce the vibration or osculation of a shaft spinning in the bore 604 of the bearing. Similarly, as illustrated in FIG. 31 , another embodiment may include a bearing 500 having five lobe inserts 504 equally spaced from each other.
[0081] Referring now to FIG. 32 , one embodiment of the invention may include a vehicle brake rotor 500 which may include a body portion 506 which may be a brake rotor cheek 606 having a first flat face 608 and an opposite flat face 610 for engagement with a brake pad. The brake rotor includes a frictional damping means which may include an insert 504 received in the brake cheek 606 . The vehicle brake rotor 500 may include a hub portion 612 attached to the cheek 606 . The hub portion 612 may include a central aperture 614 and a plurality of bolt holes 616 for attaching the brake rotor to a vehicle drive system.
[0082] Another embodiment of the invention includes a machine such as a stamping machine, band saw, drill or the like which includes a wall comprising a metal which is vibrated during operation of the machine, and wherein the wall includes a friction damping means including but not limited to an insert, as described above.
[0083] When the term “over,” “overlying,” “overlies,” “under,” “underlying,” or “underlies” is used herein to describe the relative position of a first layer or component with respect to a second layer or component such shall mean the first layer or component is directly on and in direct contact with the second layer or component or that additional layers or components may be interposed between the first layer or component and the second layer or component.
[0084] The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.
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Various embodiments of the invention include products and parts including a frictional damping means and methods of making and using the same.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a U.S. nonprovisional patent application of, and claims priority under 35 U.S.C. §119(e) to, U.S. provisional patent application Ser. No. 61/683,106, filed Aug. 14, 2012.
COPYRIGHT STATEMENT
All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.
COMPUTER PROGRAM LISTING
Submitted concurrently herewith via the USPTO's electronic filing system, and incorporated herein by reference, are computer program files including instructions, routines, and/or other contents of several computer program. A table setting forth the name and size of files included in the computer program listing is included below.
File Name
Creation Date
File Size (bytes)
readme.txt
Aug. 14, 2012 18:06
2745
ASCIFY.txt
Aug. 14, 2012 13:18
37473
main-zip1.txt
Aug. 14, 2012 13:22
22478848
main-zip2.txt
Aug. 14, 2012 13:22
22478848
main-zip3.txt
Aug. 14, 2012 13:22
22478848
main-zip4.txt
Aug. 14, 2012 13:22
22478848
main-zip5.txt
Aug. 14, 2012 13:22
22478848
main-zip6.txt
Aug. 14, 2012 13:22
22478848
main-zip7.txt
Aug. 14, 2012 13:22
22478848
main-zip8.txt
Aug. 14, 2012 13:22
8867045
One of these files, “readme.txt”, contains instructions for extracting information from other of the files. These other files are compressed binary files that have been converted to ascii format. These files can be converted back to a compressed .zip archive utilizing an assembly conversion program source code for which is contained in “ascify.txt”. The readme file includes instructions for compiling and running this conversion program, and instructions for converting the other text files to compressed, binary files, as well as instructions for recreating a directory structure for these compressed files.
Some of these compressed, binary files include source code written in C Sharp that can be compiled utilizing Microsoft Visual Studio 2008. The target environment for implementations utilizing such source code is 32-bit or 64-bit Windows XP, Vista, or 7.
BACKGROUND OF THE INVENTION
The present invention generally relates to the visual presentation of data. Data, and in particular temporal data, such as task data or event data, is commonly displayed in a visual format for viewing. Such a visual format may include, for example, a scheduled view or a horizontal display. However, for example with respect to tasks, if there are a lot of tasks due to be done across a span of hours, viewing this data can involve a lot of scrolling and it can be difficult to visualize how time should be distributed throughout the time interval.
A need exists for improvement in the visual presentation of data. This, and other needs, are addressed by one or more aspects of the present invention.
SUMMARY OF THE INVENTION
The present invention includes many aspects and features. Moreover, while many aspects and features relate to, and are described in, the context of healthcare, the present invention is not limited to use only in this context, as will become apparent from the following summaries and detailed descriptions of aspects, features, and one or more embodiments of the present invention.
Accordingly, one aspect of the present invention relates to a graphical user interface configured to display temporal data, such as tasks, events, or alerts, in a clock view designed to facilitate easy review and comprehension.
In a feature of this aspect, the clock view is divided up into hour intervals for twelve hours at a time.
In a feature of this aspect, the clock view is further configured to change coloring based on a time of day, so as to allow for easy differentiation between day time and night time clock views.
In a feature of this aspect, the clock view can include different rings for display of different types or groups of temporal data.
In a feature of this aspect, the method comprises displaying the radial graphical user interface element as part of a nursing dashboard.
In a feature of this aspect, the method additionally comprises displaying, to the user via the display screen of an electronic device, a second radial graphical user interface element configured for use as a medication clock, the second radial graphical user interface element displaying a plurality of icons representing tasks having an associated time falling over a displayed twelve hour period.
In a feature of this aspect, the display screen comprises a touchscreen.
In a feature of this aspect, the display screen comprises a monitor.
In a feature of this aspect, the electronic device comprises a desktop computer.
In a feature of this aspect, the electronic device comprises a laptop.
In a feature of this aspect, the electronic device comprises a workstation.
In a feature of this aspect, the display screen comprises a television.
In a feature of this aspect, the electronic device comprises a mobile device.
In a feature of this aspect, the electronic device comprises a smart phone.
Another aspect relates to a method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension, the method comprising after midnight, displaying, to a user via a display screen of an electronic device, a first radial graphical user interface element comprising a plurality of icons representing tasks having an associated time falling between midnight and noon; after noon, displaying, to a user via a display screen of an electronic device, a second radial graphical user interface element comprising a plurality of icons representing tasks having an associated time falling between noon and midnight; wherein each of the icons is displayed on its respective radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
In a feature of this aspect, display screen comprises a touchscreen.
In a feature of this aspect, the display screen comprises a monitor.
In a feature of this aspect, the electronic device comprises a desktop computer.
In a feature of this aspect, the electronic device comprises a laptop.
In a feature of this aspect, the electronic device comprises a workstation.
In a feature of this aspect, the electronic device comprises a mobile device.
In a feature of this aspect, the electronic device comprises a smart phone.
Another aspect relates to a computer readable medium containing computer executable instructions for performing a method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension, the method comprising after midnight, displaying, to a user via a display screen of an electronic device, a first radial graphical user interface element comprising a plurality of icons representing tasks having an associated time falling between midnight and noon; after noon, displaying, to a user via a display screen of an electronic device, a second radial graphical user interface element comprising a plurality of icons representing tasks having an associated time falling between noon and midnight; wherein each of the icons is displayed on its respective radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
Another aspect relates to a method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension that includes displaying, to a user via a display screen of an electronic device, a radial graphical user interface element configured to display the return of results, the radial graphical user interface element displaying a plurality of icons positioned in one or more circumferential rings of the radial graphical user interface element, the icons representing abnormal readings or measurements having an associated time falling over a displayed twelve hour period, and an indication, in a central area of the radial graphical user interface element, of a total number of abnormal readings or measurements falling over a certain period; wherein each of the icons is displayed on the radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
In a feature of this aspect, the certain period comprises a day.
In a feature of this aspect, the certain period comprises twelve hours.
In a feature of this aspect, the certain period comprises the displayed twelve hour period.
In a feature of this aspect, the displayed indication comprises a number.
In a feature of this aspect, the method comprises displaying the radial graphical user interface element as part of a nursing dashboard.
In a feature of this aspect, the method additionally comprises displaying, to the user via the display screen of an electronic device, a second radial graphical user interface element configured for use as a medication clock, the second radial graphical user interface element displaying a plurality of icons representing tasks having an associated time falling over a displayed twelve hour period.
In a feature of this aspect, the display screen comprises a touchscreen.
In a feature of this aspect, the display screen comprises a monitor.
In a feature of this aspect, the electronic device comprises a desktop computer.
In a feature of this aspect, the electronic device comprises a laptop.
In a feature of this aspect, the electronic device comprises a workstation.
In a feature of this aspect, the display screen comprises a television.
In a feature of this aspect, the electronic device comprises a mobile device.
In a feature of this aspect, the electronic device comprises a smart phone.
Another aspect relates to a method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension that includes after midnight, displaying, to a user via a display screen of an electronic device, a first radial graphical user interface element comprising a plurality of icons positioned in one or more circumferential rings of the radial graphical user interface element, the icons representing abnormal readings or measurements having an associated time falling between midnight and noon, and an indication, in a central area of the radial graphical user interface element, of a total number of abnormal readings or measurements falling over a first certain period after noon, displaying, to a user via a display screen of an electronic device, a second radial graphical user interface element comprising a plurality of icons positioned in one or more circumferential rings of the radial graphical user interface element, the icons representing abnormal readings or measurements having an associated time falling between noon and midnight, and an indication, in a central area of the radial graphical user interface element, of a total number of abnormal readings or measurements falling over a second certain period wherein each of the icons is displayed on its respective radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
In a feature of this aspect, the first and second certain periods both comprise a day.
In a feature of this aspect, the first certain period comprises the period between midnight and noon, and the second certain period comprises the period between noon and midnight.
In a feature of this aspect, each displayed indication comprises a number.
Another aspect relates to a computer readable medium containing computer executable instructions for performing a method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension, the method comprising displaying, to a user via a display screen of an electronic device, a radial graphical user interface element configured to display the return of results, the radial graphical user interface element displaying a plurality of icons positioned in one or more circumferential rings of the radial graphical user interface element, the icons representing abnormal readings or measurements having an associated time falling over a displayed twelve hour period, and an indication, in a central area of the radial graphical user interface element, of a total number of abnormal readings or measurements falling over a certain period; wherein each of the icons is displayed on the radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
In addition to the aforementioned aspects and features of the present invention, it should be noted that the present invention further encompasses the various possible combinations and subcombinations of such aspects and features. Thus, for example, any aspect may be combined with an aforementioned feature in accordance with the present invention without requiring any other aspect or feature.
BRIEF DESCRIPTION OF THE DRAWINGS
One or more preferred embodiments of the present invention now will be described in detail with reference to the accompanying drawings, wherein the same elements are referred to with the same reference numerals, and wherein,
FIG. 1 illustrates the exemplary use of a plurality of radial controls as medication clocks as part of a nursing dashboard that provides an overview of assigned patients;
FIGS. 2-5 illustrate exemplary clock views; and
FIG. 6 illustrates use of a clock view display to display data related to abnormal readings or measurements for a patient.
DETAILED DESCRIPTION
As a preliminary matter, it will readily be understood by one having ordinary skill in the relevant art (“Ordinary Artisan”) that the present invention has broad utility and application. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the invention and may further incorporate only one or a plurality of the above-disclosed features. Furthermore, any embodiment discussed and identified as being “preferred” is considered to be part of a best mode contemplated for carrying out the present invention. Other embodiments also may be discussed for additional illustrative purposes in providing a full and enabling disclosure of the present invention. As should be understood, any embodiment may incorporate only one or a plurality of the above-disclosed aspects of the invention and may further incorporate only one or a plurality of the above-disclosed features. Moreover, many embodiments, such as adaptations, variations, modifications, and equivalent arrangements, will be implicitly disclosed by the embodiments described herein and fall within the scope of the present invention.
Accordingly, while the present invention is described herein in detail in relation to one or more embodiments, it is to be understood that this disclosure is illustrative and exemplary of the present invention, and is made merely for the purposes of providing a full and enabling disclosure of the present invention. The detailed disclosure herein of one or more embodiments is not intended, nor is to be construed, to limit the scope of patent protection afforded the present invention, which scope is to be defined by the claims and the equivalents thereof. It is not intended that the scope of patent protection afforded the present invention be defined by reading into any claim a limitation found herein that does not explicitly appear in the claim itself.
Thus, for example, any sequence(s) and/or temporal order of steps of various processes or methods that are described herein are illustrative and not restrictive. Accordingly, it should be understood that, although steps of various processes or methods may be shown and described as being in a sequence or temporal order, the steps of any such processes or methods are not limited to being carried out in any particular sequence or order, absent an indication otherwise. Indeed, the steps in such processes or methods generally may be carried out in various different sequences and orders while still falling within the scope of the present invention. Accordingly, it is intended that the scope of patent protection afforded the present invention is to be defined by the appended claims rather than the description set forth herein.
Additionally, it is important to note that each term used herein refers to that which the Ordinary Artisan would understand such term to mean based on the contextual use of such term herein. To the extent that the meaning of a term used herein—as understood by the Ordinary Artisan based on the contextual use of such term—differs in any way from any particular dictionary definition of such term, it is intended that the meaning of the term as understood by the Ordinary Artisan should prevail.
Regarding applicability of 35 U.S.C. §112, ¶6, no claim element is intended to be read in accordance with this statutory provision unless the explicit phrase “means for” or “step for” is actually used in such claim element, whereupon this statutory provision is intended to apply in the interpretation of such claim element.
Furthermore, it is important to note that, as used herein, “a” and “an” each generally denotes “at least one,” but does not exclude a plurality unless the contextual use dictates otherwise. Thus, reference to “a picnic basket having an apple” describes “a picnic basket having at least one apple” as well as “a picnic basket having apples.” In contrast, reference to “a picnic basket having a single apple” describes “a picnic basket having only one apple.”
When used herein to join a list of items, “or” denotes “at least one of the items,” but does not exclude a plurality of items of the list. Thus, reference to “a picnic basket having cheese or crackers” describes “a picnic basket having cheese without crackers”, “a picnic basket having crackers without cheese”, and “a picnic basket having both cheese and crackers.” Finally, when used herein to join a list of items, “and” denotes “all of the items of the list.” Thus, reference to “a picnic basket having cheese and crackers” describes “a picnic basket having cheese, wherein the picnic basket further has crackers,” as well as describes “a picnic basket having crackers, wherein the picnic basket further has cheese.”
Referring now to the drawings, one or more preferred embodiments of the present invention are next described. The following description of one or more preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its implementations, or uses.
An aspect in accordance with a preferred embodiment of the present invention relates to a graphical user interface for displaying temporal data, such as tasks, events, or alerts, in a radial, or clock, view designed to facilitate easy review and comprehension.
For example, in one or more preferred implementations, a radial graphical user interface element, or control, is configured for use as a medication clock. FIG. 1 illustrates exemplary use of a plurality of such controls as medication clocks as part of a nursing dashboard that provides an overview of assigned patients.
Providing medication to a patient is merely one example of a task that could be displayed via such a radial control. In one or more preferred implementations, a clock view of tasks provides a user a high level view of how many tasks are due to be performed by the hour. In some implementations, this is implemented for a subset of tasks, such as medications due or nursing treatments to be given, but in at least some implementations this is expanded to include different tasks. Similarly, in some implementations displayed tasks are all tasks for a single user, person, or entity, while in at least some implementations displayed tasks may be tasks for different users, persons, or entities.
In a preferred implementation, a clock view, or radial control, is divided up into hour intervals for twelve hours at a time, as illustrated in FIG. 2 . In some preferred implementations, the radial control is configured such that the control will change based on the time of day. In a preferred implementation, a day time view will display from 0:01-12:00 and have a lighter shading, as illustrated in FIGS. 2-3 , while a nighttime view will display from 12:01-24:00 and have a darker shading for easier distinction, as illustrated in FIGS. 4-5 . In one or more preferred implementations, day and night styling allows for easy facilitation between shifts and ensures that there is no confusion in what time something is due to be completed.
In one or more preferred implementations, such as those illustrated in FIGS. 2-5 , the rings inside a clock view represent different types of tasks. In some implementations, there is one main section, while in other implementations, such as that illustrated in the referenced figures, there are multiple sections.
In one or more preferred implementations, a current hour is highlighted so as to allow a user to see where it is in the current cycle. In some preferred implementations, a radial control is configured to display related tasks, and the number of related tasks is calculated and displays in the section for that task type and the scheduled hour. Preferably, hovering over the indication of the number of tasks gives you a list of tasks to be completed, as illustrated in FIG. 3 . In one or more preferred implementations, clicking on one of the tasks effects navigation to the source of the task for task completion.
FIGS. 2-5 specifically illustrate a radial control configured to display tasks associated with medications due for a patient. It will be appreciated that this is only an exemplary implementation, and that aspects and features disclosed herein are applicable in other contexts as well.
In these figures, each number indicates the number of medications due at that specific interval. As illustrated, the radial control includes three rings. The outer ring relates to scheduled medications; the middle ring relates to IVs and drips; and the inner ring relates to PRN medications.
One or more aspects in accordance with a preferred embodiment of the present invention relate to methodologies for using a clock view display. In one or more methodologies, use of a clock view of data allows a user to easily get a sense of when tasks need to be completed and allows the user to plan his or her day around them.
In one or more preferred implementations, a clock view control is used in a larger summary screen.
For example, if a clock view control is utilized to present data related to medications due for a particular patient over a twelve hour shift, this control can be incorporated into a larger patient summary, which would allow a clinician to hand-off or accept the patient for his or her shift and not only see general patient information but also get a sense of what kind of care they will need throughout the shift. Preferably, provision of the ability to navigate to the source of a task allows a user to obtain more detailed information when desired without requiring them to sift through it when it is not desired.
In one or more preferred implementations, a radial control is configured not just for display of tasks, but for display of any type of temporal data, or for another type of temporal data, such as for display of events, alerts, or reminders.
In one or more preferred implementations, rather than displaying tasks in need of completion, a radial control is configured to show the return of results, such as, for example, the returns of laboratory tests, procedures, or other medical or healthcare actions that provide new information to a provider upon their completion. For example, FIG. 6 illustrates use of a clock view display to display data related to abnormal readings or measurements for a patient.
It is believed that, in some implementations, methodologies of use of such differing radial controls by a medical professional differ based on such difference, and the resultant information is used and applied differently by the medical professional. In one or more preferred implementations, different rules and interaction procedures are utilized for abnormal versus normal results. Further, in one or more preferred implementations, a central area of a radial control is utilized for showing daily (or periodic, e.g. 12 hour) totals.
In one or more preferred implementations, a radial control is configured for: the display of medications due for a patient over a shift; the display of nursing treatments due throughout a shift; the display of non-patient specific activities due on a unit or location (such as, for example, blood draws, respiratory therapies, vital signs, etc); the tracking of tasks completed over time by an administrator (in a preferred implementation, for example, an outer ring shows completed items and an inner ring shows outstanding items); the display of patients moving through an office by appointment time (in a preferred implementation, for example, rings represent checked-in, in-room, and seen-by-MD statuses); and/or the distribution of work among clinicians throughout a shift (in a preferred implementation, each ring represents a clinician).
One or more aspects disclosed herein enable clinicians to get a high level view of what is required for their patients to plan accordingly. It is believed that in at least some circumstances this will improve efficiency and ensure that vital tasks are not missed, thereby improving patient care. Notably, however, although described herein largely with respect to a healthcare context, aspects and features disclosed herein are not limited in use to only in such a context. The use of a clock view graphical user interface is contemplated for use in other applications, settings, and contexts as well, such as, for example, in any application for tracking tasks within a shift or hourly time interval.
Based on the foregoing description, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those specifically described herein, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing descriptions thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to one or more preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended to be construed to limit the present invention or otherwise exclude any such other embodiments, adaptations, variations, modifications or equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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A method for displaying temporal data via a graphical user interface in a manner designed to facilitate easy review and comprehension includes displaying, to a user via a display screen of an electronic device, a radial graphical user interface element configured to display the return of results, the radial graphical user interface element displaying a plurality of icons positioned in one or more circumferential rings of the radial graphical user interface element, the icons representing abnormal readings or measurements having an associated time falling over a displayed twelve hour period, and an indication, in a central area of the radial graphical user interface element, of a total number of abnormal readings or measurements falling over a certain period; wherein each of the icons is displayed on the radial graphical user interface element in a position corresponding to the time associated with the icon it represents.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an N-bit constant coefficient adder/subtractor.
2. Description of the Related Art
A constant coefficient adder/subtractor circuit has one operand that is a constant. In field programmable gate arrays (FPGAs) based on look-up tables (LUTs), generally two techniques are used for the implementation of such adder/subtractor. The first technique uses an arithmetic mode for implementation, as shown in FIG. 1 , and the second uses LUTs in normal mode.
In LUT based FPGAs, for the implementation of adder/subtractor and likewise circuits, a special mode called arithmetic mode is supported. A 4-input LUT configured in arithmetic mode is capable of generating two specific functions as output (LUT out and Carry Out). Generally one function is used for computation of sum/difference bit and the other one for the computation of carry/borrow. In this mode, three inputs arrive through normal routing and one through carry chain (i.e. carry out of previous LUT in the LUT array).
This technique uses a ripple carry implementation of an adder as shown in FIG. 2 . The delay of the circuit is directly dependant on the number of stages through which the carry is propagated. Hence, the delay is directly proportional to the size of inputs and the delay of carry chains. Since, these carry chains are extremely fast, this implementation is well suited for LUT based FPGAs. Thus, the delay encountered in the implementation of an N-bit adder/subtractor is proportional to N+1. The same approach is used for a constant coefficient adder/subtractor.
However, the approach suffers with a drawback. Many of the post mapping optimization algorithms that can be run on LUT level net list for area/delay reduction cannot be applied on LUTs that are configured in arithmetic mode, due to the simultaneous generation of two functions from a single LUT. Thus, the advantage that could be achieved in terms of area/delay by the optimization algorithm is not obtained.
Further, the arithmetic mode uses extra logic besides the LUT. It also employs a dedicated carry chain to connect the carry output of one LUT with the carry input pin of the next LUT in the LUT array. Thus, two of the three inputs arrive through normal routing and one arrives through the carry chain (i.e. carry out of the previous LUT in the LUT array). This approach implements N-bit constant coefficient adder/subtractor in N LUTs, if carry tap out is available and in N+1 LUTs in absence of a carry tap out feature.
FIG. 3 shows another approach that implements constant coefficient addition/subtraction without using arithmetic mode while supporting post-mapping optimization. The delay encountered in this implementation for an N-bit adder/subtractor is proportional to an N/3 delay of routing resources used. This technique however, suffers from a serious drawback. The number of 4-input LUTs required to implement an N-bit adder/subtractor, is at least (N+N/3). Thus, this kind of implementation requires almost 33% more LUTs as compared to the previous approach. Hence, even if this implementation leaves scope for optimization, no significant gain can be achieved in terms of area.
Besides, the LUT logic is not fully utilized, as N/4 LUTs use only 2 of their inputs and another N/4 LUTs use only 3 of their inputs.
Moreover, for implementation of N-bit dynamic addition/subtraction as shown in FIG. 4 , the number of 4-input LUTs requirement reaches to (N+ceil (N/2)-1). Besides this, the implementation makes non-uniform utilization of LUT logic (one third of the LUTs are underutilized).
BRIEF SUMMARY OF THE INVENTION
One embodiment of the present invention eliminates the need to embed extra logic in a logic cell to support the generation of two functions from a single LUT, i.e. support of arithmetic mode.
One embodiment of the invention eliminates the requirement of carry chains to propagate carry output.
One embodiment of the invention enables post-mapping optimization algorithms that can be run on an LUT level net list generated by the proposed method.
One embodiment of the invention reduces the delay involved in-bit propagation.
One embodiment of the invention provides an area efficient n-bit constant adder/subtractor comprising a plurality of LUTs interconnected to each other such that a first input of each LUT is coupled to a i data input bit, a second input of each LUT is coupled to a i-1 data input bit and a third input of each LUT is coupled to the output of the previous LUT O i-1 .
The previous data input bit of first LUT is carry input Cin.
A fourth input bit of each said LUT is coupled to a dynamic add/sub select bit.
Addition/subtraction is implemented in an FPGA.
The constant adder/subtractor is configured for the case of dynamic addition/subtraction comprising the steps of:
setting a defined bit pattern corresponding to the least significant bit output for the first LUT;
for each of the remaining output bits O i performing the steps of:
selecting a first output column from first truth table based on the value of K i and K i-1 of input constant K; selecting a second output column from either a second or third truth table depending upon whether said K i is a minuend or subtrahend based on the value of K i and K i-1 of input constant K; concatenating said first and second columns to construct the input bits for the i th LUT.
The constant adder/subtractor is configured for the case of addition comprising the steps of:
setting a defined bit pattern corresponding to the least significant bit output for the first LUT;
for each of the remaining output bits O i performing the step of selecting an output column from first truth table based on the value of K i and K i-1 of input constant K.
The constant adder/subtractor is configured for the case of subtraction comprising the steps of:
setting a defined bit pattern corresponding to the least significant bit output for the first LUT;
for each of the remaining output bits O i performing the step of:
selecting an output column from either a second or third truth table depending upon whether said K i is a minuend or subtrahend based on the value of K i and K i-1 of input constant K.
The defined bit pattern is implemented using an XOR truth table.
A delay minimized n-bit constant adder/subtractor comprising a plurality of LUTs interconnected to each other such that a first input of each LUT is coupled to a i data input bit, a second input of each LUT is coupled to the a i-1 data input bit, a third input of each LUT is coupled to a i-2 data input bit and a fourth input of each LUT is coupled to the output of the previous LUT O i-1 .
The said constant adder/subtractor is configured for the case of addition comprising the steps of:
setting a defined first bit pattern corresponding to the least significant bit output of even bits for the first LUT;
setting a defined second bit pattern corresponding to the penultimate bit output of odd bits for the second LUT;
for each of the remaining even output bits O i performing the steps of:
selecting an output column from fourth truth table based on the value of K i , K i-1 and K i-2 of input constant K;
for each of the remaining odd output bits O i performing the steps of:
selecting an output column from fourth truth table based on the value of K i , K i-1 and K i-2 of input constant K.
The constant adder/subtractor is configured for the case of subtraction comprising the steps of:
setting a defined first bit pattern corresponding to the least significant bit output of even-bits for the first LUT;
setting a defined third/fourth bit pattern corresponding to the penultimate bit output of odd bits depending upon whether said K i is a minuend or subtrahend for the second LUT;
for each of the remaining even output bits O i performing the steps of:
selecting an output column from fifth or sixth truth table depending upon whether said K i is a subtrahend or minuend respectively based on the value of K i , K i-1 and K i-2 of input constant K;
for each of the remaining odd output bits O i performing the steps of:
selecting an output column from fifth or sixth truth table depending upon whether said K 1 is subtrahend or minuend respectively based on the value of K i , K i-1 and K i-2 of input constant K.
The first bit pattern is implemented using an XOR truth table.
The second bit pattern is calculated in accordance with:
O 1 =XOR ( A 1 , K 1 , ( A 0 K 0 +A 0 Cin+K 0 Cin )), where:
A 0 is the first non-constant input;
K 0 is the first constant input;
A 1 is the second non-constant input;
K 1 is the second constant input; and
Cin is the carry input.
The third bit pattern is calculated in accordance with:
O 1 =XOR ( A 1 , K 1 , ((˜ A 0 ) K 0 +(˜ A 0 ) Cin+K 0 Cin )), where:
A 0 is the first non-constant input;
K 0 is the first constant input;
A 1 is the second non-constant input;
K 1 is the second constant input; and
Cin is the carry input.
The fourth bit pattern is calculated in accordance with:
O 1 =XOR ( A 1 , K 1 , ( A 0 (˜ K 0 )+ A 0 Cin+ (˜ K 0 ) Cin )), where:
A 0 is the first non-constant input;
K 0 is the first constant input;
A 1 is the second non-constant input;
K 1 is the second constant input; and
Cin is the carry input.
The proposed implementation integrates the benefits of both above explained approaches. It eliminates the need for special arithmetic mode and carry-chains and still implements an N-bit constant coefficient adder/subtractor in N+1 LUTs. Since only one bit of output is generated from a single LUT, at least N+1 LUTs are used for N-bit addition/subtraction, thus, the approach provides an area optimal solution as shown in FIG. 5 .
During design synthesis of FPGAs, when constant addition/subtraction is inferred, the value of the constant operand is extracted from the design file. This approach realizes a one bit constant adder/subtractor in each LUT, where the truth table value to be stored in the i th LUT is decided by the synthesis tool based upon the value of i th and i-1 th bits of the constant operand in one embodiment and the value of i th , i-1 th , i-2 th bits of the constant operand in another embodiment.
Here, each LUT, except the first LUT, takes three inputs for the implementation of the adder or subtractor. The inputs to the i th LUT are: i-1 th output bit, i-1 th non-constant input bit and i th non-constant input bit. The functions implemented in LUTs in the case of adder and subtractor are shown in Tables 1-3
Since, FPGAs generally contain 4-input LUTs, the fourth unused input is used to enhance the concept by incorporating the provision of dynamic addition/subtraction.
Another embodiment in accordance with the invention eliminates the need for generation of two functions simultaneously from one LUT, thus eliminating the need for arithmetic mode. The LUTs in this implementation are configured in normal mode, i.e. only one function of four inputs is generated at the output of the LUT. It thus facilitates the scope of optimization by the use of post-mapping optimization algorithms. The number of LUTs used to implement an N-bit constant coefficient adder/subtractor with the proposed technique is N+1, which is the minimum number of LUTs used to generate N+1 bits of outputs from single output LUTs.
Yet another embodiment makes the implementation more efficient with the use of cascade chains. It refers to a particular implementation of cascade chains in which LUT-out of one LUT can be given as one of the inputs to the next LUT in the LUT array through cascade chains as shown in FIG. 6 since the cascade chains are as fast as carry chains. Thus the delay that could be encountered due to the use of normal routing resources is minimized.
Besides, a LUT in cascade mode still implements a single function at the output of the LUT, thus facilitating optimization through post-mapping optimization algorithms.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows an arithmetic mode LUT with three external inputs, and one implicit input as carry in.
FIG. 2 shows an N-bit constant coefficient adder/subtractor using technique 1.
FIG. 3 illustrates an N-bit constant coefficient adder/subtractor using technique 2
FIG. 4 shows an N-bit constant coefficient adder/subtractor, with dynamic add/sub using technique 2.
FIG. 5 illustrates an N-bit constant adder/subtractor according to one embodiment of the invention.
FIG. 6 shows the cascade chain.
FIG. 7 illustrates LUT connectivity of an N-bit constant coefficient dynamic adder/subtractor.
FIG. 8 shows the flowchart in accordance with one embodiment.
FIG. 9 shows LUT connectivity of a delay optimized N-bit constant coefficient adder/subtractor.
FIG. 10 shows an algorithm flow for implementing a constant coefficient adder/subtractor.
DETAILED DESCRIPTION OF THE INVENTION
One proposed implementation of the present invention integrates the benefits of prior art approaches. It also eliminates the need for special arithmetic mode and carry-chains and still implements N-bit constant coefficient adder/subtractor in N+1 LUTs. Since only one bit of output is generated from a single LUT, at least N+1 LUTs are used for N-bit addition/subtraction, thus, the approach provides an area optimal solution.
FIG. 5 illustrates an N-bit constant adder/subtractor according to one embodiment of the present invention. During design synthesis of FPGAs, when the constant addition/subtraction is inferred, the value of the constant operand is extracted from the design file. This approach realizes a one bit constant adder/subtractor in each LUT, where the truth table value to be stored in the ith LUT is decided by the synthesis tool based upon the value of ith and i-1th bits of the constant operand. Here, each LUT, except the first LUT, takes three inputs for the implementation of adder or subtractor. The inputs to the i th LUT are: the i-1 th output bit, the i-1 th non-constant input bit and the i th non-constant input bit. FIG. 6 shows a cascaded version of the instant invention.
The proposed method works by calculating one bit of sum/difference in every 4-input LUT, where one of the inputs is constant. FIG. 7 shows the interconnection of n LUTs in accordance with one embodiment of the invention. Each LUT 1 [ 1 :N] has four inputs with the first input connected to the i-1 th non-constant input bit; the second input is connected to the i th non-constant input bit, the third input connected to the i-1 th output while the last input is connected to a dynamic add/sub selection line for performing i th bit addition/subtraction. The first input of LUT 1 [ 1 ] is an external carry-in bit. The LUT 1 [ 1 ] performs the function of an ordinary one bit dynamic adder/subtractor with carry-in. The output of LUT 1 [ 1 ] gives the least significant bit (LSB) of the sum or difference depending on the value of the dynamic add/sub selection line.
All the remaining LUTs have a different configuration and are connected to each other as shown in the figure with said inputs. The last LUT 1 [n+1], which is used to generate a carryout (C out ), considers the i th non-constant input to be zero. Depending on the value of constant bits K i and K i-1 , different functions are implemented in different LUTs, which are decided by the synthesis tool at run time.
Truth table values for the functions f 0 to f 7 are given in the tables 1, 2 and 3 for the adder and subtractor. All the functions f 0 . . . f 7 used for the generation of output bits O i (i=0, LSB) are functions of the three inputs O i-1 , a i-1 and a i . The functions as represented in Boolean form are as follows:
f 0 =( O i-1 *a i-1 *a i )+( O i-1 *(˜ a i-1 )*(˜ a i ))+((˜ O i-1 )* a i-1 *a i )+((˜ O i-1 )*(˜ a i-1 )* a i )
f 1 =( O i-1 *a i-1 *a i )+( O i-1 *(˜ a i-1 )*(˜ a ))+((˜ O i-1 )* a i-1 *(˜ a i ))+((˜ O i-1 )*(˜ a i-1 )* (˜ a i ))
f 2 =( O i-1 *a i-1 *(˜ a i ))+( O i-1 *(˜ a i-1 )* a i )+((˜ O i-1 )* a i-1 *(˜ a i ))+((˜ O i-1 )*(˜ a i-1 )*(˜ a ))
f 3 =( O i-1 *a i-1 *(˜ a i ))+( O i-1 *(˜ a i-1 )* a i )+((˜ O i-1 )* a i-1 *a i )+((˜ O i-1 )*(˜ a i-1 )* a i )
f 4 =( O i-1 *a i-1 *(˜ a i ))+( O i-1 *(˜ a i-1 )*(˜ a i ))+((˜ O i-1 )* a i-1 *a i )+((˜ O i-1 )*(˜ a i-1 )*(˜ a i ))
f 5 =( O i-1 *a i-1 *a i )+( O i-1 *(˜ a i-1 )* a i )+((˜ O i-1 ) a i-1 *a i )+((˜ O i-1 )*(˜ a i-1 )*(˜ a i ))
f 6 =( O i-1 *a i-1 *a i )+( O i-1 *(˜ a i-1 )* a i )+((˜ O i-1 )* a i-1 *(˜ a i ))+((˜ O i-1 )*(˜ a i-1 )* a i )
f 7 =( O i-1 *a i-1 *(˜ a i ))+( O i-1 *(˜ a i-1 )*(˜ a i ))+((˜ O i-1 )* a i-1 *(˜ a i ))+((˜ O i-1 )*(˜ a i-1 )* a i ),
where:
O i-1 is the output of the i th bit (i!=0) addition/subtraction,
a i-1 is the i-1 th bit of a non-constant input,
a i is the i th bit of the non-constant input,
˜ is NOT,
* is AND, and
+ is OR operator, with precedence relation as: ˜>*>+.
In Tables 1-3:
K i is the i th bit of a constant operand.
K i-1 is the i-1 th bit of the constant operand.
a−K/K−a, is the selection line for constant coefficient subtraction, which specify whether the constant is subtractor or subtrahend.
In FIG. 7 , add/sub is the dynamic addition/subtraction selection line.
FIG. 8 shows the flowchart that highlights the functioning of one embodiment of the invention. In step 80 , synthesis infers a constant coefficient adder/subtractor/dynamic adder/subtractor from a design file and calls a macro generator system for its implementation. The macro generator checks if it's a call for dynamic adder/subtractor, or for adder or subtractor, step 81 . If dynamic addition or subtraction is to be performed, then the flow proceeds in accordance with the steps 82 , 85 , 89 , 93 , 94 , 95 , 99 and 101 , else a decision is made on whether addition or subtraction is to be performed, step 83 . In case subtraction is to be performed, the constant is checked as to whether it is minuend or subtrahend, step 84 . If the constant is subtrahend, flow proceeds through steps 87 , 91 , 97 , 100 , 102 while if the constant is minuend, flow proceeds through steps 88 , 92 , 98 , 100 , 102 . If addition is to be performed flow proceeds in accordance with the steps 86 , 90 , 96 , 100 , and 102 .
The first step in the dynamic adder/subtractor implementation is calculation of the LSB output (O 0 ) in LUT 1 [ 1 ], step 82 . The LSB bit of input and external carry in (if exists) is connected at the input of the LUT 1 [ 1 ] and the function that is implemented is O 0 =XOR (A 0 , K 0, Cin). A loop is run (n−1) number of times to implement n-bit dynamic addition/subtraction, step 85 . The function for adder is g 0 and the function for subtractor is g 1 . The function value for adder g 0 for the penultimate bit to the MSB is selected from the functions f 0 , f 2 , f 4 , f 6 depending on value of K i and K i-1 listed in the Table 1, step 89 , i.e. a column corresponding to the values of K i and K i-1 from Table 1 is selected. The function value g 1 for subtractor is selected, based on whether the constant is subtrahend or minuend, from the tables 2 or 3, step 94 or 95 i.e. a column corresponding to the values of K i and K i-1 from tables 2 or 3 is selected. The final function g is calculated as (˜add/sub) g 0 +(add/sub) g 1 to be implemented for dynamic add-sub, step 99 , i.e. the two columns are concatenated to yield the final function. Once the output function is calculated, the inputs a i , a i-1 , O i-1 and add/sub are connected to the inputs of respective LUT and O i with its output, step 101 . The process is repeated for n-bit addition/subtraction.
In case addition/subtraction is performed, the LSB output (O 0 ) in LUT 1 [ 1 ] is calculated, step 86 , 87 or 88 . The LSB bit of input and external carry in (if exists) is connected at the input of the LUT 1 [ 1 ] and the function that is implemented is O 0 =XOR (A 0 , K 0, Cin). A loop is run n number of times to implement n-bit addition/subtraction, step 90 , 91 or 92 . In case of addition, a function value for g for the penultimate bit to the MSB is selected from the functions f 0 , f 2 , f 4 , f 6 depending on value of K i and K i-1 as listed in the table 1, step 96 , i.e. a column corresponding to the values of K i and K i-1 from table 1 is selected. In case of subtractor a function value g for penultimate bit to MSB is selected from the functions f 0 , f 2 , f 4 , f 6 (if constant is subtrahend) or f 1 , f 3 , f 5 , f 7 (if constant is minuend) depending on the value of K i and K i-1 listed in the tables 2 or 3, step 97 or 98 , i.e. a column corresponding to the values of K i and K i-1 from tables 2 or 3 is selected. The output function thus obtained is stored in the LUT, step 100 and the inputs a i , a i-1 and O i-1 are connected to the inputs of respective LUT and O i with its output, step 102 . The process is repeated for n-bit addition/subtraction.
The approach is illustrated with the help of an example for A+K, where K is a constant coefficient as shown in Table 1,
A=0110 1101, C in =1,
K=1101 0001, and
O=0011 1111.
Here, LSB O 0 is calculated by simple addition logic in the LUT:
O 0 =XOR ( A 0 , K 0 , Cin ).
There onwards, O i is calculated through the function that is based on value of constant coefficient bits (K i , K i-1 ). O i is located in the corresponding row of a i-1 , O i-1 and a i.
TABLE 1
A + K
Ki, Ki − 1
00
01
10
11
a i−1
O i−1
a i
F6
F2
F4
F0
0
0
0
0
1
1
0
0
0
1
1
0
0
1
0
1
0
0
0
1
1
0
1
1
1
1
0
0
1
0
0
1
1
0
0
1
0
1
0
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
0
1
An example for A−K, where K is a constant coefficient is shown in table 2, where:
A=0110 1011, B in =0,
K=0001 1001, and
O=0101 0010,
Here, LSB O 0 is calculated by simple subtractor logic in the LUT:
O 0 =XOR ( A 0 , K 0 , Cin ).
There onwards, O i is calculated through the function that is based on the values of constant coefficient bits (K i , K i-1 ). O i is located in the corresponding row of a i-1 , O i-1 and a i.
TABLE 2
A − K
Ki, Ki − 1
00
01
10
11
a i−1
O i−1
a i
F0
F4
F2
F6
0
0
0
0
1
1
0
0
0
1
1
0
0
1
0
1
0
1
1
0
0
0
1
1
0
0
1
1
1
0
0
0
0
1
1
1
0
1
1
1
0
0
1
1
0
0
1
1
0
1
1
1
1
0
0
1
An example for K-A, where K is constant coefficient is shown in table 3, where:
K=0110 1011, B in =0,
A=0001 1001, and
O=0101 0010.
Here, LSB O 0 is calculated by simple subtractor logic in the LUT:
O 0 =XOR ( A 0 , K 0 , Cin ).
There onwards, O i is calculated through the function that is based on the values of constant coefficient bits (K i , k i-1 ). O i is located in the corresponding row of a i-1 , O i-1 and a i .
TABLE 3
K − A
Ki, Ki − 1
00
01
10
11
a i−1
O i−1
a i
F7
F3
F5
F1
0
0
0
0
0
1
1
0
0
1
1
1
0
0
0
1
0
1
0
0
1
0
1
1
0
1
1
0
1
0
0
1
0
0
1
1
0
1
0
1
1
0
1
1
0
1
1
0
0
1
1
1
0
0
1
1
Another embodiment of the invention works by calculating one bit of sum/difference in every LUT, where, one of the inputs is constant. The connectivity is as shown in FIG. 9 .
The LUT 2 [ 1 ] is connected with only two inputs: external carry-in, and the LSB of the non-constant input a 0 . This LUT performs the function of an ordinary one bit adder/subtractor with carry-in. Similarly, LUT 2 [ 2 ] takes three inputs: external carry-in, LSB and penultimate LSB of the non-constant input to generate the penultimate LSB of the output.
All the remaining LUTs have a different configuration and take four inputs. The inputs to the LUT performing the i th bit addition/subtraction are the i-2 th output, i-2 th , i-1 th and i th non-constant input bits. The last LUT, which is used to generate carryout, considers the i th non-constant input to be zero. Depending on the value of constant bits, different functions are implemented in different LUTs, which are decided by the synthesis tool at run time.
Truth table values for the functions F 0 to F 23 are given in the tables 4, 5 and 6 for adder and subtractor below. All the functions F 0 . . . F 23 are four input functions of O i-2 , a i-2 , a i-2 , and a i . The functions in the Boolean expression form can be expressed as follows:
F 0 =F 22 =(˜ a i )*((˜ a i-1 )*( a i-2 )* O i-2 )+ a i *( a i-2 +a i-1 +(˜ O i-2 ))
F 1 =F 20 =(˜ a i )*( a i-2 +a i-1 +(˜ O i-2 ))+ a i *((˜ a i-1 )*(˜ a i-2 )*O i-2 )
F 2 =F 18 =(˜ a i )*((˜ a i-1 )+(˜ a i-2 )* O i-2 )+ a i *a i-1 *( a i-2 +(˜O i-2 ))
F 3 =F 16 =(˜ a i )* a i-1 *( a i-2 +(˜ O i-2 ))+ a i *((˜ a i-1 )+(˜ a i-2 )*O i-2 )
F 4 =F 14 =(˜ a i )*(˜ a i-1 )*((˜ a i-2 )+ O i-2 ))+ a i *( a i-1 +( a i-2 *(˜ O i-2 )))
F 5 =F 12 =(˜ a i )*( a i-1 +( a i-2 *(˜ O i-2 )))+ a i *(˜ a i-1 )*((˜ a i-2 )+O i-2 )
F 6 =F 10 =(˜ a i )*((˜ a i-2 )+(˜ a i-1 )+O 1-2 )+ a i *a i-1 *a i-2 *(˜ O i-2 )
F 7 =F 8 =(˜ a i )* a i-1 *a i-2 *(˜ O i-2 )+ a i *((˜ a i-2 )+(˜ a i-1 )+ O i-2 )
F 9 =(˜ a i )*((˜ a i-1 )+(˜ a i-2 )+(˜ O i-2 ))+ a i *( a i-1 *a i-2 *O i-2 )
F 11 =(˜ a i )*( a i-1 *a i-2 *O i-2 )+ a i *((˜ a i-1 )+(˜ a i-2 )+(˜ O i-2 ))
F 13 =(˜ a i )*(˜ a i-1 )*((˜ a i-2 )+(˜ O i-2 ))+ a i *( a i-1 +( a i-2 *O i-2 ))
F 15 =(˜ a i )*( a i-1 +( a i-2 *O i-2 ))+ a i *( a i-1 )*((˜ a i-2 )+(˜ O i-2 ))
F 17 =(˜ a i )*((˜ a i-1 )+(˜ a i-2 )*(˜ O i-2 ))+ a i *( a i-1 *( a i-2 +O i-2 ))
F 19 =(˜ a i )*( a i-1 *( a i-2 +O i-2 ))+ a i *((˜ a i-1 )+(˜ a i-2 )*(˜ O i-2 ))
F 21 =(˜ a i )*((˜ a i-1 )*(˜ a i-2 )*(˜ O i-2 ))+ a i *( a i-1 +a i-2 +O i-2 )
F 23 =(˜ a i )*( a i-1 +a i-2 +O i-2 )+ a i *((˜ a i-1 )*(˜ a i-2 )*(˜ O i-2 )),
where:
O i-2 is the output of the i-2 th bit addition/subtraction,
a i-2 is the i-2 th bit of non constant input,
a i-1 is the i-1 th bit of non constant input,
a i is the i th bit of non constant input,
˜ is NOT,
* is AND, and
+ is OR operator,
with precedence relation as: ˜>*>+.
In tables 4-6:
a−K/K−a is the selection line for constant coefficient subtraction, which specify whether the constant is subtractor or subtrahend;
K i is the i th bit of the constant operand;
K i-1 is the i-1 th bit of the constant operand; and
K i-2 is the i-2 th bit of the constant operand.
FIG. 10 shows the flowchart that highlights the functioning of the proposed embodiment. In step 104 , synthesis infers a constant coefficient adder/subtractor from a design file and calls macro generator system for its implementation. The macro generator checks if it's a call for adder or subtractor, step 105 . In case subtraction is to be performed, it checks if the constant is minuend or subtrahend. Accordingly, one of the 3 flows is selected.
LSB output (O 0 ) in LUT 2 [ 1 ] is calculated, step 106 , 107 or 108 . The LSB bit of input and external carry in (if exists) is connected at the input of the LUT 2 [ 1 ] and the function that is implemented is O 0 =XOR (A 0 , K 0, Cin). In case of addition, a loop is run to implement n-bit addition for even bits, step 109 . A function value for g is selected from the functions F 0 , F 1 , F 2 , F 3 , F 4 , F 5 , F 6 , F 7 depending on the values of K i , K i-1 and K i-2 by selecting a column from table 4, step 112 . The output function thus obtained is stored in the LUT and the inputs a i , a i-1 , a i-2 and Oi- 2 are connected to the inputs of respective LUT and Oi with its output, step 115 . The process is repeated for n-bit addition.
LSB output (O.) in LUT 2 [ 2 ] is calculated in accordance with O 1 =XOR (A 1 , K 1 , (A 0 K 0 +A 0 Cin+K 0 Cin)), step 118 . Another loop is run to implement n-bit addition for odd bits, step 121 . A function value for g is selected from the functions F 0 , F 1 , F 2 , F 3 , F 4 , F 5 , F 6 , F 7 depending on the values of K i , K i-1 and K i-2 by selecting a column from table 4, step 124 . The output function thus obtained is stored in the LUT and the inputs a i , a i-1 , a i-2 and O i-2 are connected to the inputs of respective LUT and Oi with its output, step 127 . The process is repeated for n-bit addition.
In the case of a subtractor, a loop is run to implement n-bit subtraction for even bits, step 110 or 111 , a function value g for all the even bits is selected from the functions F 22 , F 20 , F 18 , F 16 , F 14 , F 12 , F 10 , F 8 (if constant is subtrahend) or F 23 , F 21 , F 19 , F 17 , F 15 , F 13 , F 11 , F 9 (if constant is minuend) depending on the values of K i , K i-1 and K i-2 by selecting a column from tables 5 or 6, step 113 or 114 . The output function thus obtained is stored in the LUT and the inputs a i , a i-1 , a i-2 and Oi- 2 are connected to the inputs of respective LUT and Oi with its output, step 116 or 117 . The process is repeated for all the even bits.
LSB output (O 1 ) in LUT 2 [ 2 ] is calculated in accordance with O 1 =XOR (A 1 , K 1 , ((˜A 0 ) K 0 +(˜A 0 ) Cin+K 0 Cin)) or O 1 =XOR (A 1 , K 1 , (A 0 (˜K 0 )+A 0 Cin+(˜K 0 )Cin)) if constant is subtrahend or minuend respectively, step 119 or 120 . Another loop is run, step 122 or 123 to select a function value g for all the odd bits from the functions F 22 , F 20 , F 18 , F 16 , F 14 , F 12 , F 10 , F 8 (if constant is subtrahend) or F 23 , F 21 , F 19 , F 17 , F 15 , F 13 , F 11 , F 9 (if constant is minuend) depending on the value of K i , K i-1 and K i-2 by selecting a column from the tables 5 or 6, step 125 or 126 . The output function thus obtained is stored in the LUT and the inputs a i , a i-1 , a i-2 and Oi- 2 are connected to the inputs of respective LUT and Oi with its output, step 128 or 129 . The process is repeated for all odd bits.
Addition of A and K is explained with the help of an example. Let
Cin=0,
A=10101010,
K=11001100, and
O=01110110.
The LSB O 0 and O 1 are calculated by the following formulae:
O 0 =XOR ( A 0 , K 0, Cin ),
O 1 =XOR ( A 1 , K 1 , ( A 0 K 0 +A 0 Cin+K 0 Cin )).
There onwards, O i is calculated through the function that is based on the values of constant coefficient bits (K i , K i-1 , K i-2 ). O i is located in the corresponding row of a i-2 , O i-2, a i-1 and a i as given in table 1.
TABLE 4
A + K
Ki − 2 Ki − 1 Ki
000
001
010
011
100
101
110
111
a i−2
O i−2
a i−1
a i
F7
F6
F5
F4
F3
F2
F1
F0
0
0
0
0
0
1
0
1
0
1
1
0
0
0
0
1
1
0
1
0
1
0
0
1
0
0
1
0
0
1
1
0
1
0
1
0
0
0
1
1
1
0
0
1
0
1
0
1
0
1
0
0
0
1
0
1
0
1
0
1
0
1
0
1
1
0
1
0
1
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
0
0
1
1
0
0
1
1
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
1
0
1
0
1
0
1
1
1
0
0
0
1
0
1
0
1
1
0
1
1
0
1
1
0
1
0
1
0
0
1
1
1
1
0
0
1
1
0
1
0
1
0
1
1
1
1
1
0
0
1
0
1
0
1
Table 5: Function values for Subtractor (A−K).
An example for A−K where:
Bin=0,
A=10101010,
K=11001100,
O=11011110.
The LSB O 0 and O 1 are calculated by the following formulae.
O 0 =XOR ( A 0 , K 0 , Cin )
O 1 =XOR ( A 1 , K 1 , ((˜ A 0 ) K 0+(˜ A 0 ) Cin+K 0 Cin ))
There onwards, O i is calculated through the function that is based on the values of constant coefficient bits (K i , K i-1 , K i-2 ). Oi is located in the corresponding row of a i-2 , O i-2 , a i-1 and a i as given in table 2.
TABLE 5
A − K
Ki − 2 Ki − 1 Ki
000
001
010
011
100
101
110
111
a i−2
O i−2
a i−1
a i
F22
F20
F18
F16
F14
F12
F10
F8
0
0
0
0
0
1
1
0
1
0
1
0
0
0
0
1
1
0
0
1
0
1
0
1
0
0
1
0
0
1
0
1
0
1
1
0
0
0
1
1
1
0
1
0
1
0
0
1
0
1
0
0
1
0
1
0
1
0
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
0
0
1
1
0
0
1
1
0
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
0
1
0
1
0
1
0
1
1
0
1
1
1
0
1
0
1
0
1
0
1
1
0
0
0
1
1
0
1
0
1
0
1
1
0
1
1
0
0
1
0
1
0
1
1
1
1
0
0
1
0
1
0
1
1
0
1
1
1
1
1
0
1
0
1
0
0
1
An example for K-A where:
Bin=0,
K=10101010,
A=11001100,
O=11011110.
The LSB O 0 and O 1 are calculated by the following formulae:
O 0 =XOR ( A 0 , K 0, Cin ).
O 1 =XOR ( A 1 , K 1 , ( A 0 (˜ K 0 )+ A 0 Cin+ (˜ K 0 ) Cin )).
There onwards, O i is calculated through the function that is based on the values of constant coefficient bits (K i , K i-1 , K i-2 ). O i is located in the corresponding row of a i-2 , O i-2 , a i-1 and a i as given in table 6.
TABLE 6
K − A
Ki − 2 Ki − 1 Ki
000
001
010
011
100
101
110
111
a i−2
O i−2
a i−1
a i
F23
F21
F19
F17
F15
F13
F11
F9
0
0
0
0
0
1
0
1
0
1
0
1
0
0
0
1
1
0
1
0
1
0
1
0
0
0
1
0
1
0
0
1
1
0
0
1
0
0
1
1
0
1
1
0
0
1
1
0
0
1
0
0
1
0
0
1
0
1
0
1
0
1
0
1
0
1
1
0
1
0
1
0
0
1
1
0
1
0
1
0
1
0
0
1
0
1
1
1
0
1
0
1
0
1
1
0
1
0
0
0
1
0
0
1
0
1
0
1
1
0
0
1
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
1
1
0
1
1
0
1
0
1
0
1
1
0
1
1
0
0
1
0
0
1
1
0
0
1
1
1
0
1
0
1
1
0
0
1
1
0
1
1
1
0
1
0
1
0
1
0
1
0
1
1
1
1
0
1
0
1
0
1
0
1
W/o dynamic add/sub
With dynamic add/sub
4-LUT
Post Mapping
4-LUT
Post Mapping
Count
LUT mode
Optimization
Count
LUT mode
Optimization
Technique 1
N + 1
Arithmetic
Not Possible
N + 1
Arithmetic
Not Possible
Technique 2
N + N/3
Normal
Possible
N + N/2
Normal
Possible
Proposed
N + 1
Normal
Possible
N + 1
Normal
Possible
Technique
LUT
Routing
Post Mapping
Count
Delay
Resource
LUT mode
Optimization
Technique 1
N + 1
N + 1
Carry Chain
Arithmetic
Not Possible
Technique 2
N + N/3
N/3
*Direct
Normal
Possible
Interconnect/
Feedback
Proposed
N + 1
N/2
*Cascade
Normal
Possible
Technique
Chain
*Since the delay of the cascade chain/carry chain is extremely less as compared to other routing resources, including direct interconnect, the proposed technique using cascade chain yields a delay-optimized implementation compared to technique 2.
Advantages over Prior Art
The method discussed above eliminates the need to embed extra logic in logic cell to support the generation of two functions from a single LUT, i.e. support of arithmetic mode. Besides need for arithmetic mode, it also eliminates the requirement of carry chains to propagate carry output.
The LUTs used for implementation are single output LUTS, therefore for N-bit addition/subtraction at least N+1 LUTs are used, N LUTs for N-bit addition and one LUT for generation of carry out bit. Thus, an important advantage of this approach is that without even support of arithmetic mode, an N-bit constant coefficient adder/subtractor can still be implemented in N+1 LUTs. The proposed technique also makes 100% utilization of LUT logic, i.e. except the first LUT, all the four inputs of every LUT are utilized.
Since all LUTs are used in normal mode, post-mapping optimization algorithms can be run on an LUT level net list generated by the proposed method. Thus, it still leaves scope for optimization algorithms to merge the logic of adder/subtractor with additional logic.
Since the calculation is performed in two parallel chains, the drawback of carry propagation in a single chain posed by technique 1 is eliminated. And the output can be generated within a maximum delay of N/2. As cascade chains are being used in the proposed technique, it gives far better reduction in delay than technique 2.
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.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
|
An area efficient realization of an N-bit constant coefficient adder/subtractor implemented on FPGAs, utilizing N LUTs with single output generation capability. It includes three inputs from every LUT for addition/subtraction, without any requirement for extra logic for support of arithmetic mode and carry chains. For FPGAs supporting 4-input LUTs, the concept is further enhanced with the capability to perform addition and subtraction dynamically, by exploiting the fourth unused input of the LUTs. Another embodiment involves delay-optimized realization of an N-bit constant coefficient adder/subtractor implemented on FPGAs with 4-input LUTs. LUTs in the implementation have single output generation capability without any carry generation and propagation. The implementation utilizes N+1 LUTs and gives a delay proportional to N/2 of routing resource used. However, the implementation becomes more efficient by the use of cascade chains. The delay optimization is achieved by doing computation in two parallel chains.
| 6
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to reduction of power consumption. More specifically, the invention relates to reducing power consumption of an integrated microprocessor in a USB device to satisfy USB enumeration power requirements for bus powered devices.
2. Related Art
The Universal Serial Bus follows a protocol defined in Universal Serial Bus Specification, Version 1.0 (USB Spec). Modification of this specification can be expected from time to time. However, the USB Spec provides a standardized approach for peripheral interconnection with a host computer. The USB is set up in a tiered topology with a host on the top tier and USB hubs and functions on subsequent tiers. Each USB device, whether it be a hub or a function, has associated therewith a serial interface engine (SIE) which provides an interface between the hub or function and the transceiver which transmits or receives signals across the serial line. Generally, the SIE takes care of all the USB low level protocol matters such as bit stuffing, cyclic redundancy checks (CRCs), token generation, and handshaking.
From a power perspective, two types of USB devices exist, bus powered devices and self-powered devices. As the name implies, bus powered devices receive their required power supply from the USB. The USB Spec mandates that no bus powered device shall draw more than 1 unit current (100 mA) during enumeration. This extreme power limitation has precluded the integration of general purpose high performance microcontrollers into the USB module. Instead, stand alone USB controllers have been used to implement USB devices. This reduces a flexibility of the devices and requires increased technical support as multiple products must be maintained and supported instead of a single general purpose high performance microcontroller.
In view of the foregoing, it would be desirable to be able to reduce the power consumption of a general purpose high performance microcontroller integrated into a USB module so as to satisfy the USB specification during enumeration.
BRIEF SUMMARY OF THE INVENTION
An apparatus and method of reducing power consumption in an integrated device having a first module with a mandatory operating frequency and a second module with a flexible frequency requirement is disclosed. The integrated device is powered by a serial bus. The first module is segregated from the second module in the time domain by a frequency independent interface. The second module is then operated at a lower frequency when power conservation is needed. The operating frequency of the second module can be dynamically changed to improve performance of the second module when a power budget for the device permits.
In one embodiment, the first module is a serial interface engine, and the second module is a processor core logic. The frequency independent interface (client interface) acts as a client for all transactions between the SIE and downstream endpoints. The SIE is always the master. The SIE provides a triggering event indicating a valid command is available. The client interface captures the command and provides an expected response within a predefined window before a next triggering event occurs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a system of one embodiment of the invention.
FIG. 2 is a block diagram of an example of synchronization logic employed by one embodiment of the invention.
FIG. 3 is a timing diagram of a transmit/receive window of one embodiment of the invention.
FIG. 4 is a table of commands in which receive commands are shown paired with their corresponding transmit response.
FIG. 5 is a diagram of signaling of both a SETUP and an OUT command in one embodiment of the invention.
FIG. 6 is a diagram of an IN command of one embodiment of the invention.
FIG. 7 is a diagram of a start-of frame (SOF) command of one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of a system of one embodiment of the invention. A Universal Serial Bus (USB) host 10 is coupled to a repeater 11. The host 10 could be any prior art or future developed host complying with the USB Spec. The repeater 11 has external ports 2-5 and an embedded port 1. A serial interface engine (SIE) 12 is coupled to embedded port 1 and provides a serial interface with a hub and/or function coupled to the embedded port. The client interface 14 is coupled to the SIE by a transmit bus (TX bus) and a receive bus (RX bus). The client interface may also be referred to as a backend interface. To allow for low power operation, a frequency independent interface is required to permit segregation between a frequency mandated by the USB Spec and a low power frequency for modules not required to operate at the mandated frequency. In one embodiment, the client interface 14 is a frequency independent interface and serves as the point of segregation between the two time domains.
A layer of transmit data buffering 15 and receive data buffering 16 is provided between the client interface 14 and the local bus 20. The transmit data buffering layer 15 provides a FIFO for each endpoint, the FIFOs for buffering data to be transmitted upstream, i.e., in the direction of the host. Similarly, the receive data buffering layer 16 also provides a FIFO for each endpoint. The FIFOs buffering data directed downstream, i.e., to the hub or function endpoints within the device. A multiplexor 23 is provided to select between the function endpoint FIFOs 24. Similarly, a multiplexor 26 is provided to select between the function receive FIFOs 27 and hub receive FIFOs 25. A processor core and peripherals reside on the internal bus (IB) 20. Additionally, a random access memory (RAM) 18 and a read only memory (ROM) 19 are also coupled to the IB 20. Clocking for the circuits below the client interface 14 is provided by the clocks and reset unit 21.
Assuming that the device is a full speed device, the USB operates at 12 MHz, and the data stream coming from repeater 11 to SIE 12 is a serial stream at 12 Mb/sec. When the various modules 14 through 19 are integrated on a single chip and operating at 12 MHz, it is not possible to satisfy the USB enumeration current requirements. Moreover, merely shutting off, for example, the processor core and peripherals 17, is not an acceptable solution because enumeration is not a purely hardware event. Rather, the core 17 must be active to run some software to tell the host 10 the transfer mode desired, bandwidth, and expected power requirements, among other things. Moreover, it is important that the core and peripheral 17 are active so that they can wake up very rapidly in response to an incoming transaction. To satisfy both of these requirements, in one embodiment of the invention, the frequency at which the processor core and peripherals 17 operates during enumeration is reduced. Because the core and peripherals 17 conduct transactions in bytes or words, while the SIE 12 receives a bit stream at 12 MHz, a theoretical minimum clock speed for the processor core is 1.5 MHz. This is because 12 MHz bit stream implies 1.5 M bytes/sec. Since the client interface 14 receives bytes, it need only receive a transaction 1/8th as fast as the SIE. As a practical matter, it has been found that redundancy makes a 3 MHz clock speed desirable to ensure reliability, and to meet turn-around response timing required by the repeater 11. Repeater 11 in turn is required to meet response timing of the USB protocol.
As noted above, to operate the backend (e.g., everything downstream of the client interface) at a different clock frequency than the serial interface engine and the rest of the USB system requires a frequency independent interface. In one embodiment of the invention, the frequency independent interface is provided by client interface 14. Client interface 14 segregates the device into two time domains. The first time domain 31 is applicable, the repeater 11 and the SIE 12. The second time domain 30 applies to all units downstream of the client interface 14. In one embodiment of the invention, a software settable control register is provided to dictate the operating frequency in the second time domain 30. It is preferred that the control register always defaults to low power mode on reset or when the device becomes unconfigured so that enumeration power requirements will be met. In one embodiment, low power mode implies a clock frequency of 3 MHz. The software settable nature of the clock mode is particularly desirable because it permits the core to change the frequency and, therefore, the power requirements of the device at any time under firmware control. Once enumeration is complete, the frequency of the core can be adjusted upward to improve performance by merely resetting the control register appropriately to select another supported frequency. It is still necessary for the device to remain within the power budget granted by the host. It is expected that the core can be operated at 6 MHz, 12 MHz, or possibly even 24 MHz, and satisfy USB power requirement after enumeration.
In the prior art, the SIE was fully synchronized with the backend interface, the SIE was required to tell the backend interface that the buffer was full, and the backend interface was required to handshake to tell the SIE that it had read the buffer. This required a minimum speed of 12 MHz to perform all the required handshaking. To permit operation of the backend at a lower frequency, this protocol must be discarded.
One embodiment of the invention such as that described with reference to FIG. 3 below employs a pseudo-handshaking system in which the SIE 12 is always the master and the client interface 14 is always the client. All communication on the client interface is initiated by and controlled by the SIE. The client receives command or data from the SIE on the RX bus, and an appropriate response is transmitted to the SIE on the TX bus. Each new command from the SIE is signaled by a strobe signal (STRB). Bus throughput is maximized by using toggle signaling, and by not requiring an acknowledge to the STRB. Therefore, the client is required to recognize the STRB, latch the command, and provide the appropriate response before the next STRB, and in time to meet valid_token/token-error and data setup time requirements. The STRB serves as a triggering event, and data on the RX bus remains valid until the next STRB (triggering event). If buffering is required to maintain the throughput, then it is the responsibility of the client to provide such buffering.
A digital-phase-locked-loop (DPLL) is employed to extract a clock (CLK1X) from the asynchronous data stream. The DPLL operates from a clock (CLKnX) which runs at "n" times the data rate (in the embodiment "n"=4). The DPLL detects transitions on the input data stream, and produces an output clock CLK1X which is at the data rate, and in phase with the data. Due to jitter and small differences in frequency between CLKnX and the transmitters clock it is occasionally necessary to adjust the phase of output clock CLK1X. This requires "growing" or "shrinking" one CLK1X period to retard or advance the phase of CLK1X. The minimum distance between adjacent STRBs is eight CLKlXs (because of, this can be as little as thirty-one CLK4Xs). This is also the earliest that the SIE will sample the client response. This provides a window within which the client must respond. Therefore, the client must drive the TX bus in time to be setup on the ninth CLK1X pulse after the strobe was toggled. Because the SIE may sample TX later than this, the client must hold TX valid until the next STRB. There is no maximum distance between adjacent STRBs. A critical feature of the toggling employed is that the client interface must be able to readily identify the toggle and synchronize responses and incoming data with the local clock (LCLK).
FIG. 2 is a block diagram of an example of synchronization logic employed by one embodiment of the invention. The synchronization logic exists within the client interface and has the purpose of detecting strobe toggles. The strobe signals input to a flip-flop 40 which is enabled by a phase shift of the local clock. Flip-flop 40 is coupled to flip-flop 41 which is enabled by the local clock. The output of flip-flop 41 simultaneously drives flip-flops 42 and 43, as well as one input of exclusive OR gates 44 and 45. Flip-flop 42 is enabled by the local clock, while flip-flop 43 is enabled by 180° phase shift of the local clock. Flip-flops 42 and 43 provide, respectively, the second input for exclusive OR gates 44 and 45. The outputs of exclusive OR gate 44 is a pulse (RXE) used to latch data into the client interface from the RX bus. The output of exclusive OR gate 45 (TXE) is used to latch in data from the FIFOs and place it on the TX bus. In this manner, a strobe signal which is toggled by the SIE is readily detected by the client interface and incoming data and outgoing data is appropriately synchronized with the local clock.
FIG. 3 is a timing diagram of a transmit/receive window of one embodiment of the invention. On the rising edge of a 1× clock, the STRB is asserted. The STRB signal is defined to be a toggle signal so it is deemed asserted any time it changes from high to low or from low to high. After the STRB is asserted, the receive data is maintained valid for a minimum of eight lx clock pulses or, equivalently, thirty-one 4×clock pulses (until the next STRB toggle). Sometime during this guaranteed window between STRB toggles, valid transmit data must be applied to the TX bus lines. What is meant by valid transmit data is described more fully in connection with FIGS. 4-8 below which show examples of one implementation of the transaction protocol of one embodiment of the invention.
FIG. 4 is a table of commands in which receive commands are shown paired with their corresponding transmit response. Communication between the SIE and the client is encoded onto the RX bus and TX bus. The command type is encoded onto upper RX, and is similar to the USB packet ID (PID) from which the command is generated. A "-" in the table indicates a don't-care, i.e., no valid information is present in the field at that time. The commands include IN, OUT, SETUP, start of frame (SOF), data receive (DATA RX), data transmit (DATA TX), acknowledge (ACK), and end of data receive (EO RX). For IN, OUT, and SETUP commands, the client is required to decode address and endpoint information and return a subset of flags as described below in connection with FIGS. 5-7. For the SOF command, the client is required to capture the frame number designated "F" in the table and the "C" flag which receives an error flag indicating a CRC or bit stuff error.
The remaining nomenclature of this table is as follows: "A" corresponds to the address of a targeted function. "EP" corresponds to the endpoint of the targeted function. As is well-known in the art, a function may have up to 16 endpoints. Thus, a four bit field is used to designate the endpoint. Similarly, a 7 bit field is used for the address, since up to 128 USB devices may reside under one host. RxD is the next byte of received data. TxD is the next byte of transmit data. L is a last data flag. When returned to the SIE by the client in response to an IN, L indicates a zero length data packet. When returned to the SIE by the client in response to a DATA TX, L indicates that the byte being sent is the last byte of transmit data. C is a received error flag. OK is an endpoint okay flag indicating whether the address and endpoint are within this function. T, RE, N, and S are all force error flags corresponding to forcing a transmit error, forcing a receive error, sending a NAK and sending a STALL, respectively. No more than one of these flags may be asserted at any time. ISO is an isochronous flag indicating that a decode of an address/endpoint expects isochronous data and, therefore, no handshakes should be expected on a current transaction. T is a data toggle flag.
FIG. 5 is a diagram of signaling of a SETUP or an OUT command in one embodiment of the invention. The first row 110 of the diagram shows the signaling on the USB wire. Both the SETUP and OUT commands include a token packet 123, and a data packet 124 both originating from the host and an acknowledge packet 125 originating from the device. The remaining rows 111-114 are signals between the SIE and client interface. Row 111 shows the strobe signaling (STRB) which, as previously mentioned, is a toggle signal. Row 112 shows valid token signaling which is a sideband signal corresponding to the outcome of the CRC within the SIE. Row 113 shows signaling on the RX bus, and row 114 shows signaling on the TX bus.
The SIE receives the token packet 123 including an eight bit synchronization value, an 8 bit PID, 11 bits of address and endpoint information, and five bits for a cyclic redundancy check (CRC). The first strobe toggle 140 is delayed until the data PID is available. This supports prioritization of NAK versus toggle sequence mismatches. In response to strobe 140, a valid address and endpoint packet 145 is asserted on the RX bus. The client is required to capture this data and within the minimum window will provide a response on the TX bus as shown in row 114. As discussed above, the window is guaranteed to be at least eight 1XCLK pulses wide. As indicated in FIG. 4, the appropriate response to a SETUP command is a valid OK and RE signaling. If the address and endpoint are within the function served by the client interface, OK will be asserted, and the SIE will interact with the host to complete the transaction. If not, the received data packet will not be forwarded to the client, and the SIE will not transmit an ACK to the host. If RE is asserted, a receive error is forced meaning the SIE does not send an acknowledge to the host. For the OUT command, the client must then assert valid OK, RE, N, S and ISO signals before the next STRB toggle 141. Here, OK and RE have the same effect as in the SETUP command, but assertion of the N or S flags cause the SIE to send a NAK or STALL, respectively, to the host. Assertion of ISO indicates that the endpoint is an isocronous endpoint in such case hard shake packet 125 is not required to be sent by the SIE.
In response to strobe toggle 140, as shown in row 111, a valid SETUP address and endpoint data 145 is asserted on the RX bus. The client will sample this data and within the minimum window will provide a response on the TX bus as shown in row 114. The data on the TX bus is valid after point 147 and remains valid until strobe toggle 141 at which point this information is latched into the SIE. There is no maximum distance between strobe toggles. Therefore, the client must hold the TX bus valid indefinitely until the next strobe arrives. Also, on strobe toggle 141 the packet corresponding to a DATA RX command 146 has been encoded onto the RX bus. The client latches in this packet, and then asserts the valid RE signal at point 148.
FIG. 6 is a diagram of an IN command of one embodiment of the invention. Rows 200-204 are analogous to rows 100-104, respectively. The host drives a token packet 150 to the SIE indicating that a particular address and endpoint may transmit data upstream. The SIE then drives the data packet 151 upstream and ACK packet 152 is returned by the host to the SIE. The SIE forwards the ACK to the client. In the case of the IN transaction, as soon as the address and end point information is received, the strobe is toggled 160 and the valid command and address packet 165 is asserted on the RX bus. The client responds at 167 with OK, TE, L, N, S, ISO, and T. In the IN transaction, failure to assert OK causes the SIE not to fetch any data from the client, and it does not transmit anything to the host. Assertion of TE causes the SIE to generate a bit stuff error by transmitting a series of 1's to the host. The other signals function as discussed above. Immediately following this, the data TX command is asserted on the RX lines at strobe 161 and the client supplies valid data beginning at 168. As indicated before, the data must be held valid until a next strobe toggle 162 occurs. Strobe toggle 162 corresponds to the forwarding of the ACK at 166 on the RX bus.
FIG. 7 is a diagram of a start-of frame (SOF) command of one embodiment of the invention. Rows 210-211 and 213-214 correspond to 100-101 and 103-104 of FIG. 4. Unlike the IN, OUT, and SETUP transactions the SOF is not forwarded to the client until after the CRC has been received and checked. This allows the SIE to include the result of the CRC (the C-flag in the command). Thus, the single strobe toggle occurs in line 211 indicating a valid SOF packet. The client must capture the F and C flags, but no response is required.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. Therefore, the scope of the invention should be limited only by the appended claims.
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An apparatus and method of reducing power consumption in an integrated device having a first module with a mandatory operating frequency and a second module with a flexible frequency requirement. The integrated device is powered by a serial bus. The first module is segregated from the second module in the time domain by a frequency independent interface. The second module is then operated at a lower frequency when power conservation is needed. The operating frequency of the second module can be dynamically changed to improve performance of the second module when a power budget for the device permits.
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This is a divisional of application Ser. No. 886,776, filed Mar. 15, 1978.
BACKGROUND OF THE INVENTION
This invention relates to apparatus with which manual knitting operations can be performed to produce diverse types of knit fabrics.
It is an object of the invention to provide apparatus of a simple and economical construction which can be used with a minimum of instruction to perform diverse types of knitting operations and produce various different types of knitted fabrics.
It is another object of the invention to provide a knitting apparatus on which different forms of stitches and different knitting patterns can be produced by suitable manual manipulation of hooked needles used in conjunction with stationary knitting supports.
It is still another object of the invention, in one of its aspects, to provide a simple apparatus on which knit fabrics can be readily produced by manual operation, utilizing a plurality of yarns of different color and/or character while minimizing the possibility of such yarns becoming entangled during the knitting process.
It is a further object of this invention, in another of its aspects, to provide an apparatus on which knit fabrics can be produced having different spacing between selected stitches.
It is a still further object of the invention to provide apparatus on which a knitted fabric can be produced and into which velour or like staples can be incorporated to provide a pile fabric.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention, apparatus for use in producing knit fabrics comprises a plurality of upright supports with axially slotted upper end sections on which stitches are produced and on which the knitted fabric is supported and at least one hooked knitting needle having a pair of threading eyes for carrying a knitting thread or yarn and which is used to manipulate the yarn in conjunction with the stationary supports to produce the stitches.
One preferred embodiment of the invention, particularly useful in producing multi-colored knit fabrics comprises a pair of upright supports of rod-like form mounted on a base frame which has a series of holder devices on each side of the supports for a plurality of hooked needles, each of which needles can carry a thread or yarn from a different yarn supply. In use, the needles are all initially positioned in the holder devices on one side of the supports. When a particular yarn is required for knitting, its needle is manipulated in conjunction with the supports to form the requisite stitches and stitch rows and the needle is then placed in a holder device on the other side of the supports. The process can then be repeated with other selected needles and when all required needles have been moved across from one side to the other, the entire procedure can be reversed.
In another preferred embodiment of the invention particularly useful for producing knit pile fabrics or knit fabrics with variable stitch spacing, the apparatus comprises a series of relatively squat slotted supports arranged in line or around the circumference of a circle. This arrangement is primarily intended for use with a single hooked yarn-carrying needle which is manipulated in conjunction with selected supports in turn to form and support rows of stitches into which velour or like staples can be incorporated if required to form a pile fabric.
BRIEF DESCRIPTION OF DRAWINGS
In the accompanying drawings, which illustrate the invention by way of example:
FIG. 1 is a perspective, semi-diagrammatic view of a first form of knitting apparatus shown in the course of stitch production;
FIGS. 2, 3 and 4 are detailed perspective views of part of the apparatus of FIG. 1 shown in different stages of stitch production;
FIG. 5 is a side view of the forward end of one of the yarn-carrying needles of the FIG. 1 apparatus;
FIGS. 6 and 7 are respectively a plan view and an elevation of a support structure of a second form of knitting apparatus;
FIGS. 8-12 are perspective views of a support shown in progressive stages of stitch production;
FIG. 13 is a perspective view of a further form of knitting apparatus of the type shown in FIGS. 6 and 7; and
FIGS. 14-17 are perspective views of one of the supports showing progressive stages in the incorporation of a velour or like staple into a stitch to produce a pile fabric.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The apparatus shown in FIGS. 1-5 comprises two suitably shaped support rods 1 and 2 which act in a similar manner to conventional knitting needles. At their upper ends, the two rods have longitudinal notches or slots 5 and 6, 2 to 3 centimeters long. The rods themselves are about 30 to 40 centimeters long and pass through two collets 9 and 10 attached to a base member 3. The rods themselves are secured to a downwardly depending extension of the base member at locations 7 and 8. The two collets are open at the front as shown and have a diameter greater than the rods so that the rods can slide in the collets when they hold a knit fabric. The dimensions of the longitudinal openings 17 of the collets are such as to let the manufactured knitting on the rods pass through the collets while preventing the rods themselves from passing through the openings. The support 3 has an elongate form in the horizontal plane and to the right and left of the rods, the support has an equal number of grooves forming holders for a plurality of hooked needles 11-16 each of which carries the yarn from a separate cone or ball as diagrammatically shown in FIG. 1.
The hooked needles 11-16 as shown in FIG. 5 are curved at their forward ends and have a pair of eyes 30 and 32, eye 30 being located at a forward tip of the needle and eye 32 being located at the rear of the curved forward end on a projecting portion of the needle 33. Further, the needles are channelshaped in cross section up to a point approximately at the crest of the curved portion and the remainder of the curved portion up to the tip is an extension of one wall only of the channel. The needles are threaded with the yarn 18 from a yarn supply first through eye 32, the yarn then extending along the needle channel and passing through eye 30 onto the rods 1 and 2.
In operation, as shown in FIG. 1, there are six needles, 11, 12, 13, 14, 15 and 16 which can be used with different yarns as to color and/or quality. For knitting, each needle is manipulated with the rods 1 and 2 in turns according to the pattern and the type of knitting fabric to be obtained. When one needle has completed a knitting operation, it is deposited in a groove on the support 3, on the side opposite that from which it was taken before starting the knitting operation. In FIG. 1 needle 11 is shown with the yarn which has already been used and put down in groove 29. While this needle was in operation, the other needles 12, 13, 14, 15 and 16 were deposited in grooves on the right of the rods 1 and 2.
FIG. 1 shows needle 16 in the process of forming a stitch, the needle being shown in the position it occupies when taking over a loop 19 present on rod 2. To do this, the needle must be introduced by its tip into notch 6 of rod 2, and to carry out this operation it should be noted that before the tip of the needle goes beyond the notch, the loop 19 has been moved upwardly, so that the tip of the needle can hook the loop in question. Then, the needle is raised so that the loop 19 leaves the rod 2 and remains on the needle held by the needle projection 33. In FIG. 2, the stitch has been passed onto needle 16 and the needle with stitch 19 is then moved over to rod 1 so that the rod is introduced between the curve of the needle and the section of the yarn 18 coming from the ball. Then the needle is pulled in the direction indicated by arrow 23, so that section of thread 18 remains hooked on rod 1 and loop 19, previously from rod 2, leaves the needle and is cast off into the knit fabric. The needle, having formed the stitch, is free to carry out the same operation on loop 20, and then on loop 21 and all the way down the row of stitches on rod 2. When the hook has completed the row, it is deposited in the groove next to needle 11 and the same operation is repeated with one of the needles 12, 13, 14 or 15. When all of the needles have been used to take stitches from rod 2 and cast them off onto rod 1, the needles have been deposited into grooves on the side of rod 1. The work is then turned around and the operation is repeated taking stitches from rod 1 and casting them off onto rod 2 and passing the needles into the grooves on the side of the rod 2.
It will be understood that the apparatus can be operated with more or less needles than the six shown in FIG. 1 (depending on the number of different yarns to be used) and if only a single yarn is to be used, knitting can be performed with a single needle.
A method of joining two adjacent loops formed by two threads coming from different supplies of different color or quality is shown in FIG. 3. Thread 25 has already made loops 27 and 28 and the respective needle is not shown in the drawing. The thread 24 carried by needle 16 must, before it takes up loop 26, be passed under thread 25, then the operation of casting on and off of the stitch is carried out, taking loop 26 and then casting off the section of thread 18 on rod 1 in the same manner as explained above. After this operation has been carried out, needle 16 is brought back by pulling it from below thread 25 and in executing this operation the hand should not let go of the needle. Stitches formed by threads 24 and 25 are thus joined while the respective threads have not crossed but have remained parallel down to the thread supplies. This operation is repeated whenever needles are changed.
Forming a purl stitch as shown in FIG. 4 differs from the formation of a plain stitch as described above in only one detail, which is that the tip of needle 16 takes the loop 19 not from above, but from below.
To reduce the number of stitches in a row by one stitch a needle must take two loops together and cast only its own thread onto the other rod. To increase the number of stitches in the row by one stitch, the hook must not take any loop off the rod from which it casts off, but with its thread must form a new loop on the loading rod.
FIGS. 6-17 illustrate an alternative form of apparatus in accordance with the invention which employs a series of knitting support members 50 arranged in spaced relation on a support surface 51 1 , 51 either around the periphery of a circular base member 55 as shown in FIGS. 6 and 7 to produce tubular knit fabrics, or in line along base member 53 as shown in FIG. 13 to produce knit fabric in sheet form. Each support member will be seen to have an outward-facing surface and an inward-facing surface relative to the outer edge of the base member, a pair of side surfaces, a free upper end and a lower end disposed along said outer edge, with the support surfaces disposed on the base member adjacent the inward-facing surfaces of the support members. This type of apparatus is primarily intended for use with a single hooked needle 56 and can be operated to produce fabrics having a variable stitch spacing by omitting one or more supports as shown in FIG. 13 or to produce pile fabrics by the incorporation of staples as shown in FIGS. 14-17.
The support members 50 again have longitudinal slots 61 and the outer faces are longitudinally grooved at 70 as shown to facilitate needle insertion as shown for example in FIG. 9. As shown in FIG. 7, the support surface 51 has surface portions 51a between each pair of adjacent support members 50, which surface portions are at a higher level than the bottom walls 61a of the slots in the supports. Needle 56 is similar in form to the needles described with reference to FIGS. 1-5 and has a curved forward end with a pair of spaced eyes and with yarn from a ball being threaded in use through the rear eye 71 and then through the forward eye 72 as shown. In this embodiment, however, the rearward eye 71 of the needle is shown as being located substantially on the crest of the arch or curved forward end of the needle. With this configuration, eyes 71 and 72 define a straight imaginary line extending continuously along the body of the needle. Thus, inherently, snagging of the yarn on the support members is avoided as the needle is passed thereover.
In use, stitches are formed successively on individual support members 50 by suitable manipulation of yarn-carrying needle 56, with the needle 56 carrying thread 60 from a supply having the function of taking loops off the support members 50 and discharging them into the fabric, at the same time preparing on the support members 50 a new row of stitches for the next course. To take loops from the support members, one or other of two different operating modes may be used.
In FIG. 8, for example, needle 56 has been introduced in notch 61 with the needle tip under loop 58 of a previously formed stitch. Alternatively, (FIG. 9) the needle can be introduced into slot 70 under loop 58 but upside down and on the outside of the support. After having operated by one of these two modes, the needle is raised from the support member together with loop 58 (FIG. 10) leaving the support member empty. In FIG. 11 the needle has been lowered again so that its thread 59 coming out of the tip of the needle is arranged around the perimeter of the support. Subsequently, FIG. 12, the needle is pulled back so that loop 58 leaves the needle and is released into the already formed knit fabric and the section of thread 59 forms a new loop around the perimeter of the support. This operation is then repeated on selected succeeding supports returning to the support first operated on. As shown in FIG. 13, the central support member has been excluded from the operation to obtain greater spacing between a pair of stitches. In the arrangement shown in FIGS. 6 and 7, there are thirty-six supports to form a row with a maximum of thirty-six stitches. This operation can be operated leaving one or more support members idle in order then to return to them in the same row or in one of the following rows, or one can operate several times on the same supports. Also circular knitting can be effected. To produce pile fabrics, the procedure for adding pile staples to the knit fabric is shown in FIGS. 13-17. In FIGS. 13 and 14 a staple 62/63 has been placed on a support member 50 above loop 59 which forms part of the fabric already knitted. In FIG. 15 a separate hook 57, not carrying other yarn, has been introduced with its tip under loop 59. Then the two ends of the staple are hooked to the hook. In FIG. 16 the hook protected by the two walls of notch 61 has been pulled above the support together with the two ends of the staple, without running into the loops to be protected which are present on the outside of the walls of the support. In FIG. 17 the part of the staple 62 which forms a loop 63 has been raised and hence freed from the support, so that a knot can be formed held only by loop 59. The knot having been formed, knitting is resumed as in FIGS. 8-12 thereby incorporating a pile staple into the knit fabric.
While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications can be made by those skilled in the art without departing from the scope of the invention as defined in the appended claims.
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Apparatus for manually producing knitted fabrics comprises a base member having a series of upright knitting support members arranged around an outer edge of the base member and a support surface disposed inwardly of and adjacent to the support members. Slots are provided either along the sides of or through the middle of the support members, the slots extending downward to a location below the support surface. A needle includes an arched portion and two yarn-threading eyes, one eye located at the forward end of the needle, the other located at the crest of the arched portion, and is adapted to be inserted into the slot such that a loop of yarn supported by the support surface and surrounding the support member can be forced to ride onto the needle beyond the crest of the arch from a location on the inward-facing side of the support member, the needle being inserted into the slot from the outward facing side of the support member.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to well tools, and more particularly to foot valves, especially such foot valves as may be used in pumping wells, for instance.
2. Description of Related Art
It has been common practice to use well pumps which are actuated by sucker rods moved up and down by a surface unit (pump jack, or the like), thus stroking the piston in the pump barrel to pump well liquids from the well. Such pumps commonly are seated in a pump seating nipple. The sucker rod string, being attached to the pump, is utilized in retrieving and re-running the pump for replacement or repairs.
Some wells may have sufficient surface pressure at times that the pump cannot be removed therefrom safely. Thus, it may be necessary to "kill" the well in order that the replacement operation may be carried out safely. It is desirable to have the ability to shut-in the well below the pump in order that the well pressure may be bled off, thus making it safe to open the well to the atmosphere before removing the pump. For this operation, a spring-loaded flapper valve has been used below the pump, and this valve has been held open by an extension or probe on the lower end of the pump which extends past the flapper valve when the pump is seated in its seating nipple. Upon lifting the pump a few inches, the flapper valve is allowed to close, after which the well pressure may be bled off. Great difficulties have arisen in pumping wells in this manner where such wells have steam injected thereinto at a temperature of about 600 degrees Fahrenheit (316 degrees Celsius). At such elevated temperature, the flapper valve spring has been unreliable, having a very short life. When the spring fails, the flapper valve will not move to closed position when the pump is lifted. This, then, creates a very expensive problem since it requires killing the well.
Flapper valves have been used on well packers for closing the bore therethrough upon withdrawal of the seal mandrel from its normal position in which it holds the flapper valve open. This is clearly disclosed in U.S. Pat. No. 2,189,703 which issued to Clarence E. Burt and Eugene Graham, Jr. on Feb. 6, 1940.
Applicant is aware of the just-mentioned U.S. Pat. No. 2,189,703 as well as U.S. Pat. Nos. 2,180,605 and 2,384,192.
U.S. Pat. No. 2,180,605 issued to Herbert C. Otis on Nov. 21, 1939 and discloses a plug (or closing tool) for plugging the lower end of a well tubing so that such tubing can be run into a well under pressure control. After the tubing has been run to depth, the tubing is pressured to move the plug from its seat and allowing it to drop to a bull plug below a plurality of perforations. Well fluids may then enter the tubing through such perforations and flow to the surface in the usual manner. Should it thereafter become necessary to remove the tubing from the well, a lifting tool is run into the tubing on a wire line or cable, the plug is engaged and lifted to its plugging position, pressure is bled from above it and the lifting tool disengaged therefrom, leaving the lower end of the tubing plugged.
U.S. Pat. No. 2,384,192 issued to Herbert C. Otis and John C. Luccous on Sept. 4, 1945. This patent shows a flapper valve like that of U.S. Pat. No. 2,189,703 and a plug (or closing tool) like that of U.S. Pat. No. 2,180,605.
None of the prior art with which applicant is familiar discloses a plug for use below a well pump, which plug is held in a non-plugging position when the pump is seated in its pump seating nipple and then is bodily lifted to its plugging position to plug the well below the pump when the pump is lifted from its pump seating nipple.
The device of the present invention is ideally suited to applications such as that described above.
SUMMARY OF THE INVENTION
The present invention is directed toward a plugging device for plugging a pumping well below a well pump to enable the well pressure to be bled off thereabove and the pump removed from the well, the device comprises a housing attachable to the well tubing below the pump seating nipple, the housing having lateral ports intermediate its ends, an internal annular seat surface above such ports and internal support shoulder means below said ports, a foot valve in said housing normally supported on said support shoulder and having an annular seat surface thereon engageable with the seat surface of said housing to plug the tubing, the foot valve having a stem extending upwardly therefrom, and operating means attachable to the well pump and latchable onto the stem of said foot valve when said pump is placed in engagement with its seating nipple, said foot valve being liftable from its lower position wherein it is supported upon said support shoulder in said housing to its plugging position wherein it is in engagement with said seating surface when said well pump is lifted a short distance, then after the well prssure is reduced, the operator means on the pump is disengaged from the stem of the foot valve responsive to a predetermined upward pull, thus releasing the pump from the foot valve for withdrawal from the well.
The present invention is also directed toward methods for plugging a well below a well pump using a foot valve which is lifted to plugging position automatically as the pump is unseated and lifted a short distance after which well pressure is reduced and the pump disconnect from the plug withdrawn from the well.
It is therefore one object of this invention to provide a valve for plugging a well below a well pump to permit removal of the pump from the well.
Another object is to provide such valve in the form of a poppet-type foot valve having a stem projecting from its upper end, and a foot valve nipple for housing the foot valve, the nipple having lateral inlet ports, an annular seat surface above the ports and a support shoulder below the ports, the foot valve being engageable with the annular seat surface to plug the foot valve nipple above the ports but resting upon the support shoulder when it is in its lower, non-plugging position.
Another object is to provide such a foot valve having its stem extending upwardly therefrom a sufficient distance to project beyond said annular seat surface in said nipple when the foot valve is resting upon said support shoulder.
A further object is to provide such a plugging device wherein the position of the support shoulder in the nipple is adjustable as desired, and further wherein the support shoulder is an annular ring threadedly held in the landing nippl, the thread being of adequate length for proper adjustment of the ring's position.
Another object of this invention is to provide an operator for moving the foot valve between its lower, open position and its upper, plugging position, this operator mechanism being connectable to the lower end of a well pump and having a portion thereof latchable onto the foot valve.
A further object is to provide such an operator mechanism wherein the latch mechanism automatically engages the foot valve stem when the well pump is installed in the well.
Another object is to provide such an operator mechanism wherein when the pump is lifted, the foot valve will be lifted to its plugging position.
Another object is to provide such an operator mechanism wherein the latching portion includes collet means slidable between upper latching and lower releasing positions in a housing attached to the lower end of a well pump, wherein when the collet is in its lower, releasing position its dependent fingers spread outwardly, then when the collet is pushed down over the stem of the poppet valve, the collet is moved under a predetermined axial load to its upper position wherein the collet fingers are held in a contracted position with their internal bosses engaged below a downwardly facing fishing shoulder near the upper end of the foot valve stem.
Another object is to provide such an operator mechanism wherein the collet mechanism includes a detent mechanism for detaining the collet in its upper position but is releasable for movement toward its lower position in response to a predetermined tensile load for releasing the well pump from the poppet valve to leave the same in plugging position so that the pump may be removed from the well, the well pressure being reduced after the foot valve is in its upper, closed position and before the well pump is unlatched therefrom.
Another object is to provide methods for plugging a well below a well pump so that well pressure may be reduced above the plug and the well pump thereafter removed.
Another object is to provide such methods for reinstalling such pump by lowering it into the well with the foot valve operator mechanism in released condition, engaging the latching mechanism with the foot valve and seating the pump in its seating nipple, the well being pressurized to equalize pressures across the poppet valve just prior to seating the pump.
Other objects and advantages of this invention will become apparent from reading the description which follows and from studying the accompanying drawing wherein:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematical view of the lower portion of the tubing of a pumping well showing a well pump and plugging mechanism installed therein in accordance with the present invention;
FIGS. 2A and 2B together, constitute a fragmentary longitudinal sectional view, with some parts in elevation and some parts broken away, showing the device of this invention to the lower end of a well tubing;
FIG. 3 is a fragmentary longitudinal view, partly in elevation and partly in section, showing the lower portion of the latch mechanism of this invention as it would appear just before latching onto the upper end of the foot valve stem or just after bein therefrom; and
FIG. 4 a schematical view, similar to FIG. 1, but showing the lower portion of the well tubing with the foot valve in position plugging the tubing above the lateral ports, and with the well pump removed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, it will be seen that the well tubing 10 is provided with a pump seating nipple 12 and that a well pump 14 is seated and sealed in said pump seating nipple in the usual and well-known manner. While the pump 14 is shown to have its upper end seated as at 16, it could as well have its lower end seated instead, which is the case with many other well-known pumps. Pump 14 is operated by a string of sucker rods 18 which are lifted and lowered to stroke the piston 20 in the usual manner for pumping well fluids to the surface.
Spaced below the pump seating nipple 12 by a pup joint or spacer pipe 23 is a ported foot valve nipple 24 which is provided with lateral ports 26 through which well fluids may enter the tubing. Such fluids then flow upwardly, enter the inlet 30 near the lower end of the pump, then flow upwardly past the standing valve 32 and into the pump barrel 34 to be lifted toward the surface on the next up-stroke of the piston 20.
The foot valve nipple 24 has a bore 40 which is reduced as at 42 providing a downwardly facing internal annular seat surface 46 to be engaged by a corresponding seat surface 48 on the poppet type foot valve 50 when the foot valve is lifted from its lower position (shown in FIG. 1) to its upper position seen in FIG. 4. The seat surface 46 of the foot valve nipple obviously limits upward movement of the poppet valve. Downward movement of the foot valve is limited by the stop shoulder 54 at the lower end of the plug seating nipple. Stop shoulder 54, while shown in the schematical views (Figures 1 and 4) to be an internal flange formed integral with the foot valve nipple, is preferably a threaded ring screwed into a long thread so that its position relative to the pump seating nipple and, therefore, the pump, may be adjusted rather closely. Thus, the adjustment will make allowance for variations in the longitudinal dimensions of the various parts of the apparatus.
The foot valve 50 is preferably formed with one or more bypass grooves or slots 56 extending longitudinally thereof and inclined downwardly and inwardly to run out at its lower end, as shown, to permit fluids to pass the poppet valve in either an upwardly or a downwardly direction as needed. Such fluid flow past the poppet valve will tend to prevent sand and/or other solids from setting thereon or being deposited therearound.
A foot valve operator is provided for releasably connecting the pump 14 to the upper end of stem 60 of the foot valve 50 and is indicated generally by the reference numeral 65. The upper end portion of the stem 60 is formed with a downwardly facing shoulder 61 provided by the external annular groove 62, thus forming what is commonly termed a fishing neck.
The foot valve operator 65 comprises a latch housing 70 which is connected to the lower end of the pump 14 by the adapter 72. The adapter 72, rather than being screwed onto the normal barrel cage bushing (which would need to be threaded), is preferably formed as shown in FIG. 2A and is screwed to the lower end of the pump, as shown, in the place of the normal barrel cage bushing. The standing valve 32 (shown) and its seat (not shown) would be supported on the upper end of the adapter 72. Thus, fluids entering the fluid inlets 30 of adapter 72 have free passage up through the standing valve seat (not shown) and past standing valve 32 into the pump barrel beneath the piston 20. The piston 20 carries the traveling valve 76 in the usual manner.
The adapter 72, shown in FIG. 2A, has a bore 78 which is preferably blind in that it stops short of the lower end thereof. The bore 78 could extend completely through the adapter, but this would likely encourage sand or other debris to settle into and foul the latch mechanism immediately therebelow.
The latch mechanism 70 of the foot valve operator 65 includes a latch housing 82 having a bore 84 which is enlarged as at 85 and is threaded as at 86 for attachment to the lower end of adapter 72. It is readily seen that an internal annular recess 85 is provided by the enlargement of bore 84. Bore 84 is decreased near its lower end as at 87, providing an upwardly facing shoulder 88 which is inclined inwardly and downwardly.
Inside the latch housing 82 there is disposed a latch and detent arrangement which will now be described. The collet 90 is shown to be a double-ended collet and is formed with a plurality of dependent collet fingers 100, each having an internal boss providing an upwardly facing shoulder 102. These dependent collet fingers 100 are inherently sprung outwardly for a purpose to be explained.
To deform the collet fingers 100 so that they flare, or assume a greater span when not confined by restricted bore 87 of housing 82 as they are shown to be in FIG. 2A, a plug (not shown) of predetermined size is wedged between them to hold them in the desired position during the heat-treating process. (FIG. 3 shows these fingers in their flared position.)
The collet 90 has its lower portion reduced in outside diameter to provide an inclined downwardly facing shoulder as at 106, which shoulder is engageable with upwardly facing shoulder 88 in the housing 82 to limit downward movement of the collet as shown in FIG. 3.
The collet 90 is also formed with upstanding fingers 120 each having an external boss 122 thereon which engage in the internal annular recess 85 of latch housing 82 when the collet 90 is in its upper position, shown in FIG. 2A. These external bosses 122 thus engaged in internal recess 85 detain the collet in its illustrated upper position and a predetermined, downwardly acting axial load is required to displace the collet from such upper position. Thus, if the pump 14, as seen in FIGS. 2A-2B, is lifted until the seat surface 48 the foot valve 50 is seated against seat surface 46 of the foot valve nipple. Pessure is then vented from the tubing above the foot valve 15 and the greater pressure therebelow will hold the foot valve firmly seated, The lifting force is increased until it reaches the predetermined axial load just mentioned, at which time the detent power of the upstanding collet fingers will be overcome and the pump will be lifted relative to the collet until the dependent collet fingers 100 spring outward and release their hold of the upper end of foot valve stem 60. Thus, the upwardly facing shoulders 102 of the internal bosses of dependent collet fingers 100 move radially outwardly sufficiently far to permit the collet to be lifted free. Thus, the foot valve operator 65 is released from the foot valve stem, which disconnects the pump from the plug, as seen in FIG. 3, leaving the tubing bore plugged as seen in FIG. 4.
In making ready the foot valve, foot valve seating nipple, operator, and pump for installation for the first time, the foot valve 50 is placed in the foot valve nipple 24 with the upper end of its stem 60 extending considerably above the restricted bore 42 which provides seat surface 46. The foot valve seating nipple is then screwed to the pump seating nipple with a spacer pipe or pup joint 23 of proper length therebetween.
The foot valve operator 65 and the adapter 72 are screwed together and then, having the standing valve ball 32 and seat (not shown) in the lower end of the pump, the adapter 72 is attached and tightened. It is imperative that the collet 90 be in its lower position as seen in FIG. 3 with the dependent collet fingers 100 flared to receive the upper end of the foot valve stem. The pump is then inserted into the pump seating nipple and is seated thereagainst and held in that position.
The threaded ring 55 which provides the stop shoulder 54 is screwed into thread 55a of the foot valve seating nipple and may be run up a short distance toward the upper end thereof. The pump and the foot valve are then connected together by pushing the foot valve toward the pump while making certain that the upper end of the stem is received between the dependent collet fingers. Considerable force will be required to force the collet fingers 100 into restricted bore 87 of the latch housing. When the pump and foot valve are connected together as shown in FIGS. 1-2B, they can be separated only by overcoming the resistance provided by the bosses 122 of upper collet fingers 120 engaged in the internal recess 85 of the latch housing 82, as before explained.
The position of ring 55 must be adjusted. With the tubular parts (foot valve seating nipple 24, spacer 23, and pump seating nipple 16) made up tightly, the stop ring 55 is adjusted upwardly to engage the lower end of the poppet valve and push it upwardly until the stem 60 pushes the collet mechanism upwardly in the latch housing 82 so far that it abuts or jams against the lower end of the adapter 72. The stop ring is then backed off about one-sixteenth inch (about 1.5 to 1.8 millimeters). This adjustment assures that the pump will latch to the stem when the poppet valve is in its lowermost position being supported by the support ring and that the pump will not pound the collet, stem, or foot valve. However, if the stop ring is too far below the pump, the pump will not be latched to the foot valve when the pump is seated again because the collet will not be pushed high enough for collet finger bosses 122 to enter the internal recess of the latch housing. The proper position of the stop ring 55 is now fixed by some suitable means such as placing a roll pin, or the like, in a hole drilled through the walls of the ring and nipple as shown in FIG. 2B, or by using a second threaded ring and jamming it tightly against stop ring 55. In FIG. 3, the pin used for this purpose is indicated by the reference numeral 125.
It is preferable that the foot valve seating nipple 24 be so dimensioned as to provide about 36 to 40 inches (0.9 to 1 meter) between the seating surface 46 of the nipple and the seating surface 48 of the foot valve to provide adequate vertical space for proper operation of the device which is now to be described.
In installing the device in a well, the foot valve seating nipple with the stop ring properly adjusted and secured and with the spacer pipe 23 and pump seating nipple 24 assembled thereto as previously described, is attached to the lower end of the well tubing and run into the well. After the tubing is installed, the well pump, with the foot valve operator, that is, the adapter and latching mechanism attached to its lower end and with the dependent collet fingers extending downwardly from the housing and in flared position, is run into the well on the rod string. As the pump is lowered into the pump seating nipple, the dependent fingers 100 will telescope over the upper end of the foot valve stem 60. The upper end of the stem will stop the descent of the collet mechanism and further lowering of the pump causes the confined bore 87 of the latch housing 82 to force the dependent collet fingers 100 radially inwardly so that their internal bosses engage beneath the downwardly facing fishing shoulder 61 of the poppet valve stem 60. The pump 14 will at that time become fully seated in the pump seating nipple 12, and the upper ends of the upstanding collet fingers will be engaged in the internal recess 85 of the latch housing 82 and will be spaced from the lower end of the adapter 72 about one-sixteenth inch, as previously adjusted. The pump is then in pumping position.
When it is desired to remove the pump from the well, it is lifted about 40 inches, or until resistance is noticed, to lift the foot valve to its plugging position. Bleeding some pressure from the well will indicate whether or not the foot valve is plugging the nipple. It should be understood here that the restricted bore 42 which provides the downwardly facing seating surface 46 of the foot valve seating nipple is a fairly close fit with that portion 57 of the foot valve 50 which is immediately below its seating surface 48, so that if the pump does not lift the foot valve quite high enough, relieving well pressure above the poppet valve will lift the poppet valve the remainder of the way to full plugging position. This close fit greatly restricts the flow therethrough and prevents throttling across the seating surfaces, protecting them from flow-cutting action.
After the foot valve 50 has been seated as just described and pressure thereabove has been reduced somewhat below the magnitude of the pressure therebelow, the difference between these two pressures will act upwardly to hold the foot valve 50 in its thus seated position. The pump at this time will be pulled free of the foot valve to effect a disconnect, after which the pump may be lifted to the surface. It should be understood, however, that it will generally be preferable to bleed the well pressure to equal atmospheric as soon as it has been determined that the foot valve has been seated. Then the pump and sucker rods can be pulled from the well without the necessity of pulling them under pressure control as through use of a stripper or other type of blowout prevention equipment.
The device of this invention is particularly suitable for use in wells which are stimulated by steam injection. In the operation of such wells, steam at high temperature is injected into the oil production zone through the well tubing for a period of several days, and maybe 30 days, or more. The hot steam increases both the pressure and the temperature of the formation. Wells requiring such steam stimulation usually produce heavy oil, and the high temperature of the steam greatly reduces the oil's viscosity, making it much more flowable.
Generally, after steam has been injected into the producing formation for a substantial period of time, the increased bottom hole pressure and the increased flowability of the oil permit the well to be flowed for several days, and possibly a month. After the period of free flow, the well may be pumped for a month or more. Occasionally the pump will need to be removed, as for servicing. The present invention is useful for plugging such wells below the pump to enable the well pressure thereabove to be released to permit opening up the well to remove the pump, as was explained earlier.
In a well of the type just described and being equipped with the apparatus of this invention as described earlier, the operation thereof may be carried out according to the cycle now to be described, starting with re-running of the pump.
The pump having the latch mechanism on the lower end thereof in the ready condition, as seen in FIG. 3, is lowered into the well and latched onto the stem of the foot valve which is seated in the foot valve seating nipple and plugging the well so that the pump and sucker rod string can be installed. The pump is lowered to its fully seated position. The pump becames connected automatically to the foot valve when the pump is seated in the pump seating nipple.
Next, the pump is unseated and lifted to lift the foot valve to its plugging position, and lifted beyond that position to unlatch it from the foot valve and lifted yet higher so that it will clear the pump seating nipple. Steam is then injected into the well. Pressures are equalized across the poppet valve, and it is moved to its lowermost position. Steam flows down around the pump, through the pump seating nipple and into the foot valve seating nipple and out through its lateral ports, and eventually into the producing formation. Some of the steam will flow down around the foot valve and through its bypass grooves then out the lower end of the foot valve nipple. Injection continues for the desired period.
At the end of the injection period, the well is allowed to flow as long as it will while the pump remains suspended above its seating nipple. The well may flow for quite a period, perhaps 30 to 60 days.
When the well will no longer flow at a satisfactory rate, the pump is lowered and seated again in the pump seating nipple and at the same time reconnected with the poppet valve. The pump is then operated to pump the well as long as an acceptable production rate can be maintained.
At the end of the pumping period, the pump is unseated, disconnected from the foot valve, lifted clear of the pump seating nipple, and steam is injected again to repeat the cycle just described.
When it is desired to remove the pump from the well, the pump is lowered to its seating position to assure that it is connected to the foot valve, and then lifted in order to lift the foot valve to its plugging position. The foot valve should be clean, but if desired, it may be lifted to a position just short of entering the restricted bore of the foot valve nipple. In this position the seating surface of the foot valve and the cylindrical surface immediately therebelow will be just above the lateral ports of the foot valve nipple. If at this time steam is injected for a short period, the foot valve will be washed by the steam, after which it may be lifted to its plugging position. Once the poppet valve is in plugging position, the well pressure thereabove may be reduced to see if the plug is holding. If it is, well pressure may be bled off completely and the rods and pump lifted further to disconnect the pump from the foot valve while well pressure beneath the foot valve 60 holds it in plugging position. The sucker rods and pump may then be removed from the well in the usual manner.
When it is desired to reinstall the pump, it is lowered into the well and latched onto the foot valve as before. The pressure beneath the foot valve should continue to maintain the foot valve plugged in its plugging position. The pump is then lifted until the pump disconnects from the foot valve and then further lifted until it clears the pump seating nipple. This being accomplished, steam can once again be injected as before.
It is readily seen that the operation of a well equipped with the device of this invention involves methods of plugging the well below the well pump to allow well pressure to be released so that the pump can then be removed, and for reinstalling the pump.
Thus, it has been shown that the device and methods of this invention fulfill all of the objects set forth early in this application.
The foregoing description is presented herein by way of explanation only, and changes in materials, arrangement of parts or elements, or sizes thereof, as well as variations in the methods and equipment, may be had within the scope of the appended claims without departing from the true spirit of this invention.
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Methods of and apparatus for plugging a well below a rod pump to permit bleeding off the pressure thereabove so that the pump can be removed from the well for replacement or repairs and reinstalled for further pumping operations, the pump being connected to a valve mechanism in the well in a manner which permits the valve to be closed as a result of lifting the pump, this connection being releasable to permit the pump to be pulled free of the valve and withdrawn from the well after the well pressure has been bled from above the closed valve. When the pump is installed again, the pump automatically reconnects to the valve. This invention is particularly useful in wells which are stimulated by the injection of steam.
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This application is a continuation of application Ser. No. 08/570,180 filed on Dec. 7, 1995, now abandoned.
TECHNICAL FIELD
This invention pertains to improved methods for oxygen delignification and brightening of medium consistency pulp slurry. This method utilizes a two phase reaction design with hydrogen peroxide enhancement.
BACKGROUND OF THE INVENTION
The known methods and apparatii for oxygen delignification of medium consistency pulp slurry consist of the use of high shear mixers and single reactors with retention times of twenty to sixty minutes. These are operated at consistencies of ten to fourteen percent (o.d.) at an alkaline pH of from 10 to 12.5. Oxygen gas and hydrogen peroxide are contacted with the pulp slurry in a turbulent state lasting less than one second. The oxygen gas and hydrogen peroxide are both added prior to the high shear mixer, either simultaneously, or the hydrogen peroxide is added prior to the oxygen by 10-300 seconds. To date, sulfite pulp systems of the aforementioned design have resulted in 60-70% Kappa number reduction and a brightness increase of 20-25% ISO. It has been reported that over half of the Kappa number reduction can occur at the high shear mixer, after the oxygen gas is introduced. Final brightness of 84-86% ISO can be achieved with additional hydrogen peroxide bleaching steps.
The disadvantages of the known methods is that high total dosages of hydrogen peroxide, often in excess of 5.0% are required to achieve a mid-80's ISO brightness, and this often requires two separate hydrogen peroxide bleaching stages following the oxygen delignification stage.
It is understood that oxygen delignification reaction proceeds under two distinct orders of reaction kinetics. The first reaction occurs rapidly, and is responsible for lignin fragmentation (delignification). It is a radical bleaching reaction that is dependent on alkali concentration or pH to proceed. It also consumes alkali (e.g., NaOH) as it proceeds and generates organic acids, causing pH to drop by one-half to one point. This is consistent with prior noted field observations. The second reaction occurs slowly, at a rate estimated to be twenty times slower than the first reaction. This reaction is responsible for the destruction of chromophoric structures (brightness development). It is an ionic bleaching reaction that is dependent on alkali concentration, and pH, to proceed. It also will consume alkali as it proceeds and generate organic acids, causing the pH to drop by one to two points during the reaction time.
The addition of hydrogen peroxide (H 2 O 2 ) to an oxygen delignification stage will increase both orders of the reaction kinetics, resulting in increased delignification and brightness. It will, for sulfite pulps, have the largest impact on the first rapid, delignification reaction. The impact of the peroxide slows dramatically during the second brightening reaction. This may be due to the applied hydrogen peroxide reacting as both a delignification and a brightening agent in the first reaction. This will consume hydrogen peroxide and increase alkali consumption during the first order reaction. Corrections in hydrogen peroxide and alkali will be required for the second reaction to proceed efficiently.
SUMMARY OF THE INVENTION
It is a purpose of this invention to set forth a method for delignification and brightening of pulp in a slurry at medium consistency to a level that will improve subsequent totally chlorine free (TCF) brightness response with minimal bleach chemical usage. This invention utilizes a two phase oxygen delignification concept with hydrogen peroxide being added only to the second reaction phase The invention can be utilized for retrofits to existing medium consistency oxygen delignification systems as well as for new systems.
To effectively accomplish this objective (OOp), the oxygen delignfication system will be designed with two reactors, each with a dedicated mixer. The first mixer will be a high shear or extended time gas mixer for oxygen gas and alkali and the first reactor will have a retention time of 5-10 minutes (O). The second mixer will be an extended time or high shear mixer for oxygen gas, hydrogen peroxide and alkali and will have a retention time of 30-180 minutes (Op).
The aforesaid, and further purposes and features of the invention will become apparent by reference to the following description, taken in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical depiction of an O/Op Reaction Flow Diagram for the delignification and brightening for wood pulp;
FIG. 2 is a plot of Kappa vs. time (min.) showing the effect of 60 minute oxygen delignification (O), in comparison to 60 minute oxygen delignification with the addition of 0.5% H 2 O 2 (Op), and 10 minute oxygen delignification followed by 50 minute (Op) stage with the addition of 0.5% H 2 O 2 (OOp); and
FIG. 3 is a plot of %ISO vs. time (min.) making the same comparison as described for FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein the showings are for purposes of illustrating the preferred embodiment of the invention only and not for purposes of limiting the same, FIG. 1 shows a reaction schematic which would be used in a preferred embodiment of this invention. In this schematic, the apparatus 10 shows two mixers, a higher shear mixer 18 and an extended contact gas mixer 28 installed in series. Each mixer has a retention time of from less than one second to 5 minutes. The operating pressure of the apparatus 10 and the method which it practices is preferably from approximately 20 to 200 psig. A source 12 of pulp slurry is fed to the high shear or extended time contact gas mixer 18 having a consistency of from approximately 10 to 16%, at a temperature of from approximately 170-240° F., preferably from 190-220° F. A source of alkali 14 is communicated with the mixer 18 either directly or prior to for thorough mixing thereof with the slurry to effect a pH of the slurry from approximately 11.0 or higher, more preferably 12.0 or higher. A source of oxygen gas 16 is provided to communicate with the mixer 18 either directly or prior to for inclusion in the mixing process. The contents of the first mixer 18 are kept agitated for from less than one second to 5 minutes with subsequent transfer to pressurized reactor 20. A source of steam 34 in communication with mixer 18 will insure that the slurry is maintained in the temperature range described. Downstream of this pressurized reactor is a second mixer 28 with associated inlets for alkali 22, oxygen 26 and peroxide 24. The alkali will return the pH of the slurry to at least 11.0, more preferably 12.0, while the oxygen source will replenish depleted oxygen consumed or partially consumed in the first reaction. Another source of steam 36 or the same source identified previously 34 is provided and communicated with the product to bring the slurry temperature back to approximately 170 to 240° F., more preferably 190 to 220° F. The slurry is then agitated in the mixer 28 for less than one second to five minutes. The product is conducted to a second reactor 30 wherein the slower ionic bleaching reaction takes place at a temperature of from 170° F. to 240° F., preferably from 190 to 220° F. The pressure in the first reactor will range from 60-180 psig, and more preferably from 85-140 psig. The pressure in the second reactor will range from 0-180 psig and in one case, preferably from 85-140 psig.
A series of autoclave reactions were performed on Sulfite pulp (brownstock) which was characterized in having a Kappa number of 10.7, a viscosity of 33.4 cps, a brightness of 51% ISO and a Z-span of 18.7 psi. This material served as the baseline case for all testing, the results of which are summarized in the row designated "base" in Table I.
The laboratory work described below utilized an autoclave type oxygen reactor. Sequences labeled 1 and 2 show the effects of oxygen delignification (O stage), under constant conditions shown in Table 1, after 10 and 60 minutes. The final pHs are 11.7 and 9.9, respectively. Note that 64% of the total Kappa number drop and less than 45% of the total %ISO gain occur in the first 10 minutes of the total 60 minute reaction. These results are also shown in FIGS. 2 and 3. This is typical of the initial radical delignification reactions.
TABLE 1__________________________________________________________________________Oxygen Delignification & Bleaching.sup.(a) Resid. Time Kappa Final Visc Z-span T NaOH NaOH H.sub.2 O.sub.2 H.sub.2 O.sub.2 NaOHStage (min) # ISO pH cps (psi) °C. #1.sup.b #2.sup.c #1.sup.b #2.sup.c (gpl)__________________________________________________________________________0 base 0 10.7 51.0 33.4 18.71 0 10 6.6 57.0 11.7 32.7 14.3 100 2.5% -- -- -- 0.502 0 60 4.3 64.9 9.9 33.1 13.9 100 2.5% -- -- -- 0.303 Op 10 3.8 65.0 11.4 32.0 12.2 100 3.0% -- 0.5% -- 0.724 Op 60 3.4 68.8 9.5 32.5 14.0 100 3.0% -- 0.5% -- 0.365 O/Op 10/50 2.7 74.4 10.0 30.2 13.7 100 Z5% 05% -- 0.5% 0.256 O/Op 10/50 3.0 71.5 10.0 29.7 12.4 90 2.5% 0.5% -- 0.5% 0.37__________________________________________________________________________ .sup.(a) Conditions included 100 psig 02 and 0.5% MgSO.sub.4 .sup.(b) First Reaction (˜10 min.) .sup.(c) Second Reaction (˜50 min.)
Sequences 3 and 4 show the effects of oxygen delignfication, after 10 and 60 minutes, with the addition of 0.5% H 2 O 2 and an incremental 0.5% NaOH to the 2.5% NaOH base charge (Op), under conditions shown in Table 1. The final pH values were 11.4 and 9.5 respectively. The level of delignification and %ISO gain was enhanced by the addition of H 2 O 2 and NaOH, after 10 and 60 minutes. Lower final pH values, compared to Sequences 1 & 2, indicate increased NaOH consumption. Note that 88% of the total Kappa number drop and 78% of the total ISO gain occur in the first 10 minutes of the total 60 minute reaction.
Both the delignification and brightness gain in the second 50 minutes diminished with the addition of H 2 O 2 , when compared to the second 50 minutes with only O 2 (see the slope of the Op curve of FIGS. 2 and 3). This may be due, in part, to attempting to both delignify and brighten during the first rapid delignification reaction. This results in increased NaOH consumption during the initial phase, decreasing the NaOH level and pH during the second phase (11.7 pH for (O) vs. 11.4 pH for (Op) after the initial 10 minutes). This initial phase, with H 2 O 2 added, competed for available NaOH and H 2 O 2 to both brighten and delignify, and the kinetics overlapped. Although the end results were improved, (see Sequences 1 & 2 for comparison of final Kappa and %ISO values), this was due to reaction kinetics improvement during the rapid initial phase, (the easy part). Due to NaOH and H 2 O 2 depletion, the second brightening phase slowed down considerably as shown in Sequence 4 and graphically shown by the essentially flat slope of the final 50 minute part of the Op curve.
H 2 O 2 is primarily a strong alkali dependent, brightening agent. It is best applied, with additional NaOH, to complement the chemistry of the slower second brightening reaction. The rapid initial delignification is efficient without a significant H 2 O 2 boost.
Sequences 3,4 and 5 compare the effects of single stage chemical addition in comparison to splitting the two phases of oxygen delignification, i.e., adding 0.5% H 2 O 2 and the incremental 0.5% NaOH to the second phase only. The total Kappa number drop was increased by 0.7 and the brightness gain was increased by 5.6% ISO. Table 2 shows that single stage peroxide addition in the Op stage reduced the NaOH residual concentration to 0.72 gpl after 10 minutes (Sequence 3), slowing down the secondary reaction to a final 3.4 Kappa number and 68.8% ISO (Sequence 4). The O/Op phase split results in a 1.26 gpl NaoH concentration entering the second 50 minute Op stage. This results in a final Kappa number of 2.7 and 74% ISO (Sequence 5). It can also be concluded from Table 2 that it is beneficial for the final pH after 60 minutes to be above 10.0. It is also noted that Sequences 3,4 and 5 all had overall chemical charges of 3.0% NaOH and 0.5% H 2 O 2 .
TABLE 2______________________________________ Initial Final Final Time NaOH NaOH Final Kappa FinalSeq. Stage (min) (gpl) (gpl) pH No. % ISO______________________________________3 OP 10 4.10 0.72 11.4 4.3 64.94 Op 60 0.72 0.34 9.8 3.4 68.85 O 10 3.40 0.30 11.7 6.6 57.05 Op 50 1.26 0.25 10.0 2.7 74.4______________________________________
Sequence 6 shows that smaller, but significant, gains in delignification and brightness can be made by operating even at a lower temperature of 90° C. Laboratory studies on oxygen delignification of softwood Kraft pulp have shown this method of peroxide reinforcement to be equally as powerful.
TABLE 3______________________________________Delignification response of northern softwood pulp.sup.(1)for O, Op and Op delignification sequences. Time Kappa Visc. Z-spanSeq..sup.(2) Stage(s) (min) nbr. % ISO (cps) (psi)______________________________________base.sup.(1) 17.4 31.3 39.7 381 O 5 15.4 32.5 28.7 29.42 O 60 10.9 36.6 23.2 263 Op 5 13.8 33.9 27.8 30.84 Op 60 10.5 36.1 23.2 27.45 O 5 15.4 32.5 28.7 29.46 OOp 5/55 9.8 37.2 20.9 26.6______________________________________ .sup.(1) Pulp baseline characteristics .sup.(2) Process variables were:
O.sub.2 press. 100 psigConsistency 12.0%NaOH 1.4%H.sub.2 O.sub.2 0.5% (Op only)Temp. 95° C.MgSO.sub.4 0.5%
This two phase design provides for separate delignification and brightening phases, each with independent chemical controls, results in a second phase enhancement that will improve the overall delignification and brightening results.
Peroxide has typically not been considered as an economical method of enhancement for Kraft oxygen delignification. This conclusion was based on evaluations using conditions similar to those shown in Sequences 3 & 4. This is only a 0.4 Kappa drop improvement over the oxygen delignification Sequences 1 & 2 where no peroxide was added, a performance increase which is too small to be of economic value.
Adding peroxide to the second mixer, allowing the first phase delignification reaction to progress on its own, enhances the delignification by 0.7 Kappa drop (10.5 vs. 9.8) for the same chemical charges. This is an overall Kappa drop improvement of 1.1 (10.9 vs. 9.8) from the oxygen delignification (Sequences 1 and 2).
Table 4 shows that the brightness and delignification gains from utilizing the OOp hardwood sulfite pulp sequence are transferable in the subsequent Z(ozone) P(peroxide) TCF(total chlorine free) bleaching sequence for hardwood sulfite pulp. These benefits result in significantly lower H 2 O 2 usage in the final P(peroxide) stage to attain an 88% ISO brightness (0.5% vs. 1.5%) and a higher final brightness ceiling above 92% ISO.
TABLE 4______________________________________Brightness (% ISO) response of hardwood acid sulfite pulpfor Op/Z/P and O/Op/Z/P sequences. Op/Z/P O/Op/Z/P______________________________________Brownstock 51.0 51.0O and/or Op stages 68.8 71.5Z stage (0.4%) 80.0 82.7P stage (0.5%) 88.7 91.0P stage (1.5%) 91.2 92.6______________________________________
The Op and O/Op stages were the same as stated in Table 1, 12.0% cs (od); the Z stage had a pH=2.7, ambient temperature, 40% cs (od) whereas the P stage had a pH=10.2-10.3, 90° C., 3.5 hrs. 0.5% DPTA, 1.0% Na 2 SiO 3 , and 12.0% cs (od).
From these studies, it is concluded that OOp sequence allows optimum control of the second Op stage. For sulfite with no filtrate recycle to the OOp stage, it is initially recommended that the Op stage following a 10 minute O stage operate at a minimum 1.25 gpl NaOH controlled to a final pH≧10.0. Alkali and pH are also critical for control of the OOp sequence for Kraft, but due to the filtrate recycle of these systems, extrapolations are more difficult.
While I have described my invention in connection with specific embodiment thereof, and specific steps of performance, it is to be clearly understood that this is done only by way of example, and not as a limitation to the scope of the invention, as set forth in the purposes thereof and in the appended claims.
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The invention described a method of oxygen delignification of medium consistency pulp slurry, which includes the steps of providing a pulp slurry of from approximately ten percent to sixteen percent consistency, at a temperature of from approximately 170-240° F., preferably from 190 to 220° F., thoroughly impregnating the slurry with oxygen gas, and with alkali to bring the slurry to a pH of at least 11, more preferably 12, introducing the slurry to oxygen gas in a high shear mixer, for agitating mixing therein, reacting the slurry in a first pressurized reactor for between 5 to 10 minutes, returning the pH of the slurry to at least 11, more preferably 12, with a residual alkali concentration of at least 1.25 gpl, thoroughly impregnating the slurry with H 2 O 2 and oxygen gas, and reacting the slurry in a second reactor for between 30 to 180 minutes. By only employing the hydrogen peroxide during the slower bleaching reaction, a lower Kappa number with higher %ISO is obtained in the product, these beneficial characteristics being retained in subsequent processing steps.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to electronic signaling. More particularly, the present invention relates to data transmission from a first component to a second component over a signaling bus, the data transmission accompanied by one or more strobe signals normally used by the second component for the purpose of latching data received on the signaling bus.
2. Description of the Related Art
Historically, the density of circuits on silicon chips has increased exponentially and is forecasted to continue to do so for some time. “Moore's Law”, an observation by Gordon Moore, co-founder of Intel Corporation, projects that the number of transistors per square inch of silicon doubles every 18 months. Although cost of processing silicon wafers has also increased to some degree, the overwhelming density of the circuitry has dramatically reduced the cost of many electronic products, such as computers, Personal Digital Assistants (PDAs), communication devices, and the like.
In contrast to on-chip circuitry, packaging interconnections used to drive signals from a chip or to receive signals onto a chip are relatively expensive, and the number of such interconnections has not increased greatly over time. Such interconnections are called pins. In “low-cost” chip packaging, pins cost approximately 0.5 cents per pin. In “high-performance” chip packaging, used for many ASICs (Application Specific Integrated Circuits) and processors, pins cost approximately 2.0 cents per pin. Pins in memory products cost approximately 1.0 cent per pin.
As a result, many techniques have been used to reduce the number of pins required. For example, DRAMs (Dynamic Random Access Memories) have for year's time multiplexed address lines. A Row Address is transmitted by a chip such as a processor over a group of signal conductors called an address bus and is strobed into a DRAM chip by a RAS (Row Address Strobe) signal. Subsequently, a Column Address is transmitted over the same address bus and is strobed into the DRAM chip by a CAS (Column Address Strobe) signal. Use of the same signal conductors for the row address and the column address dramatically reduces the number of pins required by the DRAM chip, as well as the processor.
Although “chip” is used for simplicity in the remaining discussion, those skilled in the art will recognize that the teachings of this invention apply to interconnections at any level of packaging, including, but not limited to, multi-chip modules, printed wiring boards (PWBs), and computer enclosures. The invention applies to any electrical component coupled to another electrical component coupled by a signaling bus accompanied by one or more strobe signals.
Because signal pins need to be kept to a low number, time multiplexing data over busses is a common technique. For example, a 32-byte bus is commonly used to interconnect one chip to another. The first chip may be a processor chip; the second may be another processor chip, a chip that communicates with a memory subsystem, or an I/O (Input/Output) subsystem. Commonly, blocks of data larger than the bus width need to be transferred. For example, a 128-byte block of data would require four bus cycles, or “beats”, on the 32-byte bus for transmission. A bus cycle is the time period allocated for placing data the signal conductors of a bus and transmitting it before additional data is placed on the bus. Note that in many modern systems, another transmission begins before the previous transmission has physically reached the receiving chip. In the example, 32 bytes are transferred on a first bus cycle; 32 bytes more are transferred on a second bus cycle; 32 bytes more are transferred on a third bus cycle; and the final 32 bytes are transferred on a fourth bus cycle. Data in each bus cycle must arrive at the receiving chip within a known window of time. Such busses typically have strobe signals sent with the data to assist the receiver in determining when in the window of time the data from a particular bus cycle of data should be latched. Some busses are embodied with a single strobe for the entire bus. Some busses are embodied with a separate strobe for each byte of the bus.
The possibility of errors or malfunction on a chip or data transmission must be planned for by those designing the chip and the system in which the chip is used. Often, separate, expensive, additional busses are implemented to communicate status, errors, and diagnostics. In chips where cost is of utmost importance, and pins are kept at an absolute minimum, transmission of status, errors, and diagnostics is limited to “hard fails”, either by incorrect data being sent, or an extra (and costly) signal pin being driven to a logic level that indicates an error has occurred, with no further diagnostics being transmitted on the extra signal wire. When such an event occurs, the system utilizing the chips may be forced into a shutdown or a complex diagnostic sequence, perhaps involving scanning of chip diagnostic through LSSD (Level Sensitive Scan Design) pins.
Therefore, a need exists to transmit timely error, status, or diagnostic information without the use of additional signal conductors.
SUMMARY OF THE INVENTION
The present invention generally provides methods and apparatus to transmit diagnostic, error, or status messages over one or more strobe signal conductors associated with a signaling, or data bus. The signaling bus is used to transfer a block of data that is larger than the signaling bus width, with multiple bus cycles used to transfer the block of data over the signaling bus.
In an embodiment, a method is disclosed, where, if there is no diagnostic, error, or status message to report, one or more strobe edges are transmitted in an expected encoded message by a driving chip and received by the receiving chip, identifying the proper times in expected timing windows to latch the incoming data. When there is a diagnostic, error, or status message to report, the diagnostic, error, or status message is encoded into an encoded message pattern, and transmitted on the one or more strobe conductors, causing the one or more strobe edge to differ from the expected pattern. The receiving chip then decodes the encoded message to determine the diagnostic, error, or status message sent.
In an embodiment, apparatus is disclosed that encodes a message pattern that is transmitted, by a sending chip, on one or more strobe signal conductors. The encoded message pattern differs from an expected encoded message pattern, in which transitions on the one or more strobe signal conductors are used on a receiving chip to cause data on a data bus to be latched.
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. 1A shows a block diagram of a unidirectional, single data rate (SDR) data bus and an accompanying strobe coupling a first chip and a second chip.
FIG. 1B shows representative waveforms on signals associated with the block diagram of FIG. 1A .
FIG. 2A shows a block diagram of a unidirectional, double data rate (DDR) data bus and an accompanying strobe coupling a first chip and a second chip.
FIG. 2B shows representative waveforms on signals associated with the block diagram of FIG. 2A .
FIG. 3A shows a block diagram of a unidirectional, double data rate (DDR) data bus, with an accompanying strobe that is a differential signal, coupling a first chip and a second chip.
FIG. 3B shows representative waveforms on signals associated with the block diagram of FIG. 3A .
FIG. 3C shows alternative waveforms on signals associated with the block diagram of FIG. 3A , illustrating an alternative embodiment of the invention, using independent signaling on each of the signal conductors of the differential strobe.
FIG. 4A shows a block diagram of a bidirectional, double data rate data bus with a separate unidirectional strobe for each direction of data transfer, coupling a first chip and a second chip.
FIG. 4B shows representative waveforms on signals associated with the block diagram of FIG. 4A .
FIG. 5A shows a block diagram of a bidirectional, double data rate, data bus with a single, bidirectional strobe, coupling a first chip and a second chip.
FIG. 5B shows representative waveforms on signals associated with the block diagram of FIG. 5A .
FIG. 6 shows a block diagram of a sending chip having ability to encode messages on a unidirectional strobe signal and a receiving chip having ability to decode and interpret messages on the strobe signal.
FIG. 7 shows a block diagram of coupled chips having ability to encode messages on one or more strobe signals associated with a bidirectional data bus, and to decode and interpret the messages.
FIG. 8 shows a block diagram of two chips coupled by a bidirectional signaling bus and a bidirectional strobe signal; each chip having ability to encode and transmit a message via the bidirectional strobe signal and ability to receive, decode and interpret the message.
FIG. 9 shows a flow chart of a preferred method embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides methods and apparatus to send encoded messages via one or more strobe signal conductors relevant to data transmitted on an associated signaling bus. The strobe signal transitions sent on the one or more strobe signal conductors normally provide a receiving chip with timing information regarding when, within a window of time, data on the signaling bus should be latched.
Having reference now to the figures, and having provided above a discussion of the art, the present invention will be described in detail.
FIG. 1A shows an electronic system generally referenced as 110 comprising a first chip 10 coupled to a second chip 11 via a signaling bus 13 and an SDR strobe 12 . Chip 10 and chip 11 may be similar chips (e.g., one processor chip communicating with another processor chip). Chip 10 and chip 11 may be different chips (e.g., a processor chip and a memory chip). As stated earlier, although “chip” is used for exemplary purposes, the teachings of this invention apply equally to any level of interconnection between one electronic component and another.
Signaling bus 13 is any conductor of signals, including, but not limited to, electrically conducting wiring on a printed wiring board (PWB), electrically conducting cable conductors, electrically conducting wiring on a multi-chip module (MCM), or optically conducting signal fibers. Typically, signaling bus 13 comprises a number of signal conductors, and signaling bus 13 can simultaneously carry, for example, 8 bits, 16 bits, 32 bits, 64 bits of data, depending on how many signal conductors are in signaling bus 13 . Similarly, SDR strobe 12 is likewise one or more conductor of signals. Typically, a block of data having more bits than can be transmitted over signaling bus 13 at one time needs to be sent. For example, a 128-byte block of data would require four bus cycles if signaling bus 13 has 32 bytes in an embodiment of signaling bus 13 . Thirty-two bytes of data in such an example would be transmitted during each of four bus cycles, also called “beats”. Data from each beat is expected within a window of time on chip 11 . A voltage transition on SDR strobe 12 defines the proper time for chip 11 to latch data received from signaling bus 13 . “SDR” in electronic system 110 means “single data rate”. When data is sent at a single data rate, data from signaling bus 13 is latched only on single transition directions on SDR strobe 12 , for example, data is only latched when the signal on SDR strobe 12 transitions from a low logic level to a high logic level. Signaling bus 13 and SDR strobe 12 are shown to be unidirectional busses in FIG. 1A , that is, chip 10 drives information that is received by chip 11 . Even though the bus is “unidirectional”, bi-directional I/O (input/output) circuitry on both chip 10 and chip 11 having both a driver and a receiver is often used, typically for test purposes. For example, during a bring-up test, chip 10 may cause its I/O circuits for signaling bus 13 and SDR Strobe 12 to go to a high impedance state and activate its receivers; chip 11 would then activate its I/O circuits as drivers. Chip 11 drives one or more known data patterns and chip 10 would verify that the known data patterns are received.
FIG. 1B shows exemplary waveforms that appear on signaling bus 13 and SDR strobe 12 . An exemplary clock is also shown in FIG. 1B . Chip 10 has one or more internal clocks that cause processing to happen in an orderly manner as are understood by those skilled in the art. Chip 11 also has one or more internal clocks. Chip 10 sends data on signaling bus 13 and strobe transitions on SDR strobe 12 based upon the internal clocking of chip 10 . Although chip 11 also has one or more internal clocks, those clocks may not be in perfect phase alignment with the one or more internal clocks of chip 10 . Whereas chip 11 knows a window of time in which to expect data to arrive on signaling bus 13 , chip 11 relies on transitions on SDR strobe 12 to latch data in latches or registers on chip 11 . The clock waveform is included for explanatory reasons only, and may or may not be in perfect phase alignment with data or strobe signals. The clock signal only shows an exemplary clock waveform such as may appear on chip 10 or chip 11 . Data-A and Data-B are two beats of data on signaling bus 13 . Any particular signal conductor in signaling bus 13 may be at a high logic level or a low logic level, except during transitions from a low logic level to a high logic level, or from a high logic level to a low logic level. The openings wherein “Data-A” and “Data-B” are placed in the figure show stable logic levels. Those skilled in the art understand that sampling (latching) data at or near the center of these openings, rather than at or near the ends of the openings provides a lower rate of data transmission errors, or, in many cases, error-free operation. SDR strobe 12 as shown, has a transition at the receiver 14 A at or near the center of the opening, or window, where Data-A appears at the receiver. Chip 11 uses this transition to latch Data-A from signaling bus 13 . Similarly, transition 14 B is used to latch Data-B.
Chip 10 , may have detected an error in the data, or may have other critical information to convey to chip 11 . For example, chip 10 may be an SRAM chip (static random access memory) that has determined that the data being sent is corrupt, perhaps having more errors than ECC (Error Correcting Code) circuitry can correct. Chip 10 may be detecting thermal problems to the degree that validity of data being transferred is in doubt, even though parity or ECC does not show a problem. If chip 10 is an SRAM chip, an address transmitted by chip 11 to chip 10 over an address bus (not shown) may have been found to be corrupted or otherwise unusable.
In the following examples a particular pattern on a strobe line, as identified in FIGS. 1B , 2 B, 3 B, 3 C, 4 B, and 5 B, is identified in parentheses. For example, in FIG. 1B , SDR strobe ( 11 ) means that an encoded message “11” is transmitted on the exemplary strobe line, SDR strobe 12 in the example of FIG. 1 .
The normal data transmission of electronic system 110 occurs when SDR strobe 12 rises at or near the center of the expected data windows, as explained above, and can be considered to be an encoded message “11” (i.e., two transitions, consisting of transition 14 A and transition 14 B). Encoded message “11” is shown as SDR strobe ( 11 ) in FIG. 1B . The present invention encodes another message and transmits that encoded message on SDR strobe 12 if such alternate message is determined to be necessary. In FIG. 1B , encoded message SDR Strobe ( 10 ) has transition 15 A at the same timing position as transition 14 A discussed earlier, but lacks a transition 15 B in the expected data window. Chip 11 notes the lack of the second transition and recognizes that encoded message “10” has been sent. Similarly, encoded messages SDR Strobe ( 01 ) and SDR Strobe ( 00 ) can be sent, each recognized by chip 11 as abnormal conditions. Chip 11 takes appropriate predetermined action based upon the message received. A response of “00” (no transitions), as shown in example SDR Strobe ( 00 ) often means that chip 10 is “dead” and unable to respond at all, so encodings of messages having less serious meaning should have a value other than “00”. Table 1 shows exemplary messages sent by chip 10 and predetermined actions taken by chip 11 responsive to each message. In general, a message could be any string of bits that represent a condition. In an embodiment, encoded messages are identical to the associated messages; however that is not a requirement of the present invention. For example, many systems use a bit for each condition possible, wherein one and only one condition can occur at a particular time. For example, in an embodiment, “1000” encodes to “00”; “0100” encodes to “01”; “0010” encodes to “10”; and “0001” encodes to “11”. “Message” and “encoded message” are assumed to be identical (i.e., a direct map) for simplicity in table 1. This simplification (i.e., message is identical to encoded message) is also made in discussion of FIGS. 2A and 2B ; 3 A, 3 B, and 3 C; 4 A and 4 B; and 5 A and 5 B. Table lookup or logic circuitry is used in alternate embodiments to map a message into an encoded message.
TABLE 1
Message
Meaning
Action taken by chip 11
00
Fatal Error
Do not use data;
Terminate operation of
electronic system 110
electronic system 110
01
Received request from chip
Retransmit request
11, but data was corrupt
10
Significant problem on chip
Quarantine chip 10;
10; associated data is suspect
do not rely on chip 10
for future communication.
11
Normal Strobe
Latch data in; use the data
FIG. 2A shows an electronic system 120 comprising a first chip 20 a second chip 21 , a signaling bus 23 , and a DDR strobe 22 . The difference between electronic system 120 and electronic system 110 is that “double data rate” (DDR) transmission is employed in electronic system 120 . In DDR, data is normally latched by chip 21 on each transition (i.e., both the rising transition and the falling transition) of DDR strobe 22 .
FIG. 2B shows a four-beat signaling transfer of data over signaling bus 23 . When the strobe message (normal strobe) is “1111” as shown in FIG. 2B , Data- 0 , Data- 1 , Data- 2 , and Data- 3 are latched into chip 21 by transitions 24 A, 24 B, 24 C, and 24 D, respectively.
As in the examples of FIG. 1B , FIG. 2B shows several of the encoded messages possible. Since there are four transitions, with each transition either occurring or not occurring, there are 16 possible messages (including the normal “1111” message). Exemplary encodings of “1000”, “1100”, “1110”, and “1010” are shown as waveforms, besides the normal “1111”. Chip 21 takes predetermined action, based upon the particular message received, as taught in Table 1 for the simple, two-beat data transfer.
In some embodiments of electronic system 120 (as well as electronic system 110 , 130 , 140 and 150 of FIGS. 1A , 3 A, 4 A, and 5 A), not all encodings are allowable. For example, in an embodiment, the strobe must be at a low logic level at the start of a number of beats on the signaling bus. In this embodiment, there must be an even number of transitions, since an odd number of transitions would leave the strobe signal at an invalid logic level at the end of the transfer of the beats.
Many data transfers involve far more than the two-beat or four-beat transfers discussed in the examples above, and a huge number of potential messages are contemplated. For example, where a 128-beat data transfer is implemented, each beat strobe with a transition on the associated strobe signal, in an embodiment, a transition means that the associated data beat is valid; a missing transition means that the associated data beat should not be used. The receiving chip (chip 21 in FIG. 2A ) then repeats its request for the data in an embodiment; in another embodiment wherein receipt of all data beats is not critical, the receiving chip simply proceeds with the data that was reported as “valid”, and discards or does not use the data reported as “not valid” (i.e., did not have an accompanying transition in the expected window).
FIG. 3A shows electronic system 130 , comprising chip 30 , chip 31 , signaling bus 33 , and differential strobe 32 . As shown, signaling bus 33 is unidirectional, as is differential strobe 32 . Differential strobe 32 is a differential signal, further comprising phase 32 T (a “true” phase) and phase 32 C (a “compliment” phase).
FIG. 3B shows the encoding of messages similarly to that described in electronic system 120 of FIG. 2A . In FIG. 3B , phase 32 T and phase 32 C always carry the same information, but in a complimentary fashion. Transitions 34 A, 34 B, 34 C, and 34 D normally result in Data- 0 , Data- 1 , Data- 2 , and Data- 3 being latched into chip 31 . The normal message is “1111” (every transition occurs). A alternate message “1011” is shown to be sent as DIFF Strobe ( 1011 ) (transition 35 A, 35 C, and 35 D occur, but transition 35 B does not occur), with that message being received, decoded, and interpreted in a manner similar to that described in the previous examples, with chip 31 taking a predetermined action, such as, for example, repeating its request for the data, ignoring the data, or termination operation of electronic system 130 .
If electrical constraints and tolerances allow, additional messages can be encoded by driving phase 32 T and phase 32 C independently as shown in FIG. 3C , resulting in a message having twice as many bits. For example, DIFF Strobe ( 1011 0111 ) transmits “1011” on phase 32 T (transitions 36 A, 36 C, and 36 D occur; transition 36 B does not occur), and “0111” on phase 32 C (transitions 37 B, 37 C and 37 D occur, but transition 37 A does not occur). A further example in FIG. 3C shows DIFF strobe (0011 0101) with exemplary waveforms.
FIG. 4A shows electronic system 140 , comprising chip 40 , chip 41 , signaling bus 43 , unidirectional strobe A 42 A, and unidirectional strobe B 42 B. Signaling bus 43 is a bidirectional bus. Typically when two or more chips are coupled together with a bidirectional bus, chips time-multiplex their use of the bidirectional bus. For example, chip 40 drives signaling bus 43 at a time when chip 41 is receiving data. At a later time, chip 41 drives signaling bus and chip 40 receives data. Many protocols are known in the art regarding deciding which chip can drive signaling bus 43 at a particular time. In the exemplary electronic system 140 , unidirectional strobe A 42 A is normally driven by chip 40 and received by chip 41 to latch data into chip 41 from signaling bus 43 . Unidirectional strobe B 42 B is normally driven by chip 41 and received by chip 40 to latch data into chip 40 from signaling bus 43 . FIG. 1B shows unidirectional strobe A 42 A (1111) having transitions 44 A, 44 B, 44 C, and 44 D, which normally are used to latch Data- 0 , Data- 1 , Data- 2 , and Data- 3 into chip 41 . During this transfer, in previous systems, unidirectional strobe B 42 B is driven to a particular logic level (i.e., high or low) by chip 41 . However, in an embodiment of the present invention, chip 41 leaves unidirectional strobe B 42 B in a high impedance state and allows chip 40 to drive unidirectional strobe B 42 B. Two exemplary messages unidirectional strobe B “0000” and unidirectional strobe B “0110” are shown as waveforms. Sixteen different messages can be transmitted on unidirectional strobe B 42 B in the 4-beat data transfer of the example. As before, the number of messages that can be transferred goes up as more beats are in the data transfer. Unidirectional strobe A 42 A can also carry messages, as taught in the discussion of previous electronic systems 110 , 120 , and 130 .
The various examples given above are exemplary only. The present invention contemplates encoding messages on any embodiment of a strobe associated with a signaling bus.
FIG. 5A shows an electronic system 150 , comprising chip 50 , chip 51 , signaling bus 53 , and bidirectional strobe 52 . Signaling bus 53 is bidirectional, as is bidirectional strobe 52 .
Encoding, transmission, reception, and response of messages are similar to those discussed before, however, as shown in FIG. 5B , a bidirectional strobe typically has to be driven to a known logic level prior to the beginning of data transfer, in order that all transitions that occur are intended to occur, and not simply transitions from where the voltage on the strobe conductor was prior. Often such strobe lines are left in a high impedance condition for some time and may “float” to an unknown logic level, or be at an indeterminate logic level. FIG. 5B shows the bidirectional strobe message “1111” (normal message with a transition for each beat of data on signaling bus 53 ). Bi-directional strobe 52 has an undetermined logic level 54 A, which is driven to a known logic level 54 B (i.e., low, in the example) prior to transmission of the message. Transitions then occur as before, allowing chip 51 (assuming data is being sent by chip 50 and is being received by chip 51 ) to latch data from signaling bus 53 using transitions 54 C, 54 D, 54 E, and 54 F to latch in data- 0 , data- 1 , data- 2 , and data- 3 , respectively. FIG. 5B shows an alternate message BIDI strobe ( 1001 ) (i.e., message “1001”) being sent (transitions 54 C and 55 F occur, but transitions 55 D and 55 E do not occur). Following transmission of the 4-beat data transfer, strobe signal 52 is allowed to return to a high impedance state, as shown as 54 H or 55 H.
FIG. 6 shows a block diagram of an exemplary embodiment of chips 20 and 21 . SDR strobe 22 and signaling bus 23 are shown coupling chip 20 and chip 21 . This exemplary embodiment assumes a 4-beat data transfer as discussed earlier for electronic system 120 , featuring chips 20 and 21 .
Chip 20 has data bank 60 , further divided into banks 60 - 1 , 60 - 2 , 60 - 3 , and 60 - 4 . Banks 60 - 1 , 60 - 2 , 60 - 3 , and 60 - 4 are groups of storage elements, such as latches or registers, each with a data width equal to the width of signaling bus 23 . For example, if signaling bus 23 can carry 32 signals simultaneously, the widths of banks 60 - 1 , 60 - 2 , 60 - 3 , and 60 - 4 are each 32 bits. During each beat of transfer, one of banks is driven onto signaling bus 23 .
Chip status unit 61 is logic on chip 20 that can report any information relevant to data transfer over signaling bus 23 . For example, chip status unit 61 , in embodiments, detects errors that have occurred on chip 20 such as thermal problems, data errors too numerous to correct with ECC, unavailability of data to transmit, or one or more errors in data bank 60 , or uncertainties regarding prior transmissions received from chip 21 . Many chips are self initialized at power up, or are initialized by commands from other chips. Chip status unit 61 in an embodiment verifies proper initialization. Many chips depend on Phase Lock Loop (PLL) lock or Delay Lock Loop (DLL) lock for proper operation. In an embodiment, chip status unit 61 verifies proper PLL lock or DLL lock. Dynamic Random Access Memory chips (DRAMs) depend on periodic refreshes. In an embodiment in which chip 10 is a DRAM chip, chip status unit 61 verifies that a specified refresh interval has not been exceeded. Those skilled in the art will recognize that many conditions on a chip may result in a requirement to communicate a message indicative of that condition to another chip that receives data from the sending chip. The current invention contemplates all such conditions. Chip status unit 61 is also coupled to data bank 60 in order to detect any errors that may exist in banks 60 - 1 , 60 - 2 , 60 - 3 , or 60 - 4 that causes a condition for which a message must be encoded and sent over SDR strobe 22 . Any condition relevant to data transmission over signaling bus 23 is contemplated in the present invention.
Message determination unit 62 receives status information from chip status unit 61 and determines which of a plurality of messages, needs to be transmitted over SDR strobe 22 . Examples are “normal”, “fatal error”, “uncertainty of request” (e.g., a parity error in a prior request, an unsupported request, and similar uncertainties), and “data in bank 60 - 2 ″ is corrupt.” The present invention contemplates any message relevant to data transfer on the associated data bus.
Message encoder 63 receives a message from message determination unit 62 and encodes it for transmission on SDR strobe 22 . For example, in an embodiment, message determination unit 62 provides a 16-bit message, where one and only one bit is “active”, and encodes that information into a 4-bit encoded message.
Those skilled in the art will understand that the division of function shown in FIG. 6 is only exemplary. For example, in an embodiment, message determination unit 62 , is designed with the function of message encoder 63 included.
Chip 21 , in FIG. 6 comprises a message decoder 63 A, a message interpretation unit 62 A, a chip status unit 61 A, data bank 60 A, and communication 64 A coupling chip status unit 61 A to data bank 60 A.
Message decoder 63 A receives messages transmitted over SDR strobe 22 and decodes the message sent. Message decoder 63 A is coupled to message interpretation unit 62 A, which determines (e.g., by logic circuits, table look up, or other known technique) what the message is. Message interpretation unit 62 A is coupled to chip status unit 61 A, which determines a response based on the message received from chip 20 . Responses are determined using table lookup (e.g., as in the example of table 1), by logic circuitry, or by any other technique. Responses, as before include, but are not limited to, discarding some or all of the data block received into data bank 60 A; re-requesting the data block; and terminating operation of electronic system 120 . Chip status unit 61 A in an embodiment also considers status information on chip 21 (e.g., temperature, voltage, validity of the data being received) in determining a response, including such information as input to the technique used in a particular embodiment (e.g., table look up). Data bank 60 A is a storage area used to receive data transmitted, and, in the embodiment shown, comprises banks 60 A- 1 , 60 A- 2 , 60 A- 3 , and 60 A- 4 , to receive the four beats of data in the data transmission assumed for the illustrated example.
Typically, accurate timing of strobe transitions is critical to latching in data. Although FIG. 6 shows that a strobe transition must go through message decoder 63 A, message interpretation unit 62 A, and chip status unit 61 A prior to arrival at data bank 60 A, a preferred embodiment allows the transitions to flow through those units relatively undelayed, with interpretation of non-normal messages (i.e., where the receiving chip must take some action other than simply latching the incoming data) being processed in parallel, and at a somewhat reduced speed. For example, if chip 20 has sent a message that it was uncertain of a prior request from chip 21 , any data sent over signaling bus 23 is either suspect or, more likely, is default data (such as “all zeroes”), rather than data needed by chip 21 . The units (e.g., message decoder 63 A, message interpretation unit 62 A, and chip status unit 61 A) in chip 21 typically have all or most of the time required to transmit the four beats of data before action must be taken.
The exemplary structure of FIG. 6 illustrates the present invention using chips 20 and 21 , signaling bus 23 , and SDR strobe 22 . Those skilled in the art will understand that the teaching of FIG. 6 also applies to all other electronic systems using unidirectional busses with associated strobe signals.
FIG. 7 shows a more detailed block diagram of chips 40 and 41 . Signaling bus 43 is bidirectional in this exemplary figure, and two strobe lines are shown; strobe 42 A is used by chip 41 to latch data into chip 41 ; strobe 42 B is used by chip 40 to latch data into chip 40 . Since either chip can, at a given time be either a driver or receiver, Message encoder/decoders 73 and 73 A each must contain the total function described for message encoder unit 63 and message decoder 63 A. Message determination unit & interpretation units 72 and 72 A each must contain the total function described for message determination unit 62 and message interpretation unit 62 A. Chip status units 71 and 71 A must each contain the functions of chip status unit 61 and chip status unit 61 A. Storage banks 70 and 70 A must be able to both drive and receive data over bidirectional signaling bus 43 . As described earlier, in an embodiment where a message is to be transmitted by a first chip over a strobe signal not being used to strobe data into the first chip, message encoder/decoder units 73 and 73 A each must be capable of not actively driving the particular strobe signal so that the message encoder/decoder unit on a second chip does not actively drive the particular strobe when the first chip is driving the strobe. For example, if chip 40 is driving data over bidirectional signaling bus 43 , message encoder/decoder 73 A must not actively drive strobe 42 B at the same time.
FIG. 8 shows a more detailed block diagram of chip 50 and chip 51 . Signaling bus 53 is bidirectional, and strobe 52 is also bidirectional. Since data can be transmitted in either direction of bidirectional signaling bus 53 , message encoder/decoder 83 and 83 A must each have the combined function of message encoder 63 and message decoder 63 A. Message determination unit & interpretation units 82 and 82 A must each have the combined function of message determination unit 62 and message interpretation unit 62 A. Chip status units 81 and 81 A must each have the combined function of chip status unit 61 and chip status unit 61 A. Storage 80 and 80 A must both be able to store data from and send data to bidirectional bus 53 . When chip 50 is sending data to chip 51 over signaling bus 53 , chip 51 must not be driving signaling bus 53 at the same time. Similarly, strobe 52 is bidirectional. When chip 50 is sending a message on strobe 52 , chip 51 must not be driving strobe 52 at the same time.
Those skilled in the art understand that, in another embodiment, using recent advances in signal driving and receiving, some electronic systems have signaling busses and strobe signals that are capable of simultaneous bidirectional data transmission. In an embodiment using such techniques in chips 50 and 51 , chip 50 could simultaneously drive data to chip 51 on signaling bus 53 and receive data from chip 51 on signaling bus 53 . Strobe 52 , in such embodiment would transfer encoded message simultaneously from chip 51 to chip 52 and from chip 52 to chip 51 .
FIG. 9 is a flowchart illustrating a preferred method embodiment of the present invention.
Step 90 begins the method used to encode and transmit information messages from a first chip to a second chip that contain information via a strobe signal that is relevant to data being transferred over an associated signaling bus.
In step 91 , if any condition (errors, information, or problems) relevant to transmission of a block of data is found on the first chip, control passes to step 93 . Such errors, information, or problems include, but are not limited to, detection of thermal problems; detection of voltage problems; one or more errors in the block of data; uncertainty of validity of data in the block of data; one or more errors associated with portions of the first chip that might jeopardize validity of the data to be sent; lack of PLL lock, lack of DLL lock; improper self or external chip initialization; failure to meet refresh timing specifications; unavailability of data to transmit to the second chip; and uncertainty regarding a prior request made from the second chip.
In step 92 , data to be transmitted is examined for errors. Although any error (e.g., errors correctable by ECC) is of interest, errors that cannot be corrected are of particular interest. If errors are found, control passes to step 93 .
If no errors have been found in step 91 or 92 , control flows to step 96 , which encodes a message to be sent on a strobe signal as an encoded message. This encoded message simply contains the transitions needed by the second chip to latch transmitted data into the second chip. Control then flows to step 97 , where the encoded message is transmitted on the strobe signal.
Step 93 determines a message to transmit over the strobe signal. Step 93 was reached after determination of a condition on the first chip that needs to be sent to the second chip. Step 93 determines a message, using logic circuitry, table lookup, or other technique to select a particular message among a number of predetermined messages.
Step 94 encodes the message determined by step 93 into an encoded message. A table lookup is used to encode the message into the encoded message in one embodiment. In a second embodiment, logic circuitry is used to encode the message into the encoded message. In a third embodiment, the message is used directly as the encoded message. Step 95 transmits the encoded message on the strobe signal.
Step 98 is the end of the method.
While the foregoing is directed to embodiments 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.
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Methods and apparatus are disclosed for use in an electronic system where data is transmitted over signaling conductors from one electronic component to another using strobe signals accompanying the data. The edge or transition of the strobe signals identifies when, in a window of time, the receiving electronic component should latch the data. In many such systems, data is transmitted over the signaling conductors in the form of a plurality “beats”, of data, proper timing to latch each beat of data being identified by a transition of the strobe signal. Faults in components or errors in transmission must be handled. The present invention discloses apparatus and methods to communicate conditions relevant to data transmitted without requiring additional signaling conductors. The present invention discloses selecting a message from a plurality of messages, encoding the selected message, and transmitting the encoded message on existing strobe lines to communicate the condition encountered.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a cleaning device for a dust filter, having a flow duct which extends between an entry opening and an exit opening, and having an annular chamber which surrounds the flow duct and which is provided with gas-inlet connectors for the inflow of pressurized gas into the annular chamber and, towards the flow duct, is provided with nozzle gaps which are delimited by nozzle-gap walls. The annular chamber is composed of an upper annular shell and a lower annular shell which on the radial outside in a connection region are interconnected in a pressure-tight manner. The gas-inlet connectors are moulded on the upper annular shell; the lower annular shell is designed so as to be predominantly flat, extends horizontally or downwardly towards the nozzle gap and, at the same time, forms the lower nozzle-gap wall.
[0002] Cleaning devices of this type are known from KR 20/0321528 Y1 and from WO 2009/043332. Said cleaning devices operate based on the Coand{hacek over (a)} principle and are employed for cleaning the filter hoses and filter candles of dust filters, to which end the cleaning device is disposed above the filter hose which is open towards the top, or above the filter candle. A flow duct which is surrounded by an annular chamber extends between an entry opening and an exit opening. The annular chamber is supplied from above from a compressed-air reservoir. Said annular chamber is closed on the external wall and is provided on the internal wall thereof with nozzle gaps which open into the flow duct. The nozzle gaps are upwardly and downwardly delimited by nozzle gap walls.
[0003] The annular wall is formed and enclosed by two walls which in a connection region which extends along the external periphery are interconnected in a pressure-tight manner. The lower wall runs horizontally or slightly downwardly towards the nozzle gap and, at the same time, forms the lower nozzle gap wall; the upper wall determines substantially the spatial shape of the annular chamber and the volume of the annular chamber.
[0004] The potential of use of cleaning devices of this type covers all sectors in which dust filters are industrially employed. One of these sectors is the foodstuff industry, for example, the industry processing milk to milk powder. Particularly stringent hygiene requirements apply to the foodstuff industry and also to the pharmaceutical industry. An infestation with germs may arise in the case of cleaning devices for dust filters when, following wet cleaning, residues of cleaning fluid mixed with residue of product remain in individual parts of the plant. It has been observed that in the case of cleaning devices of the generic type, even where these are conceived for increased hygiene requirements, an infestation with germs may still arise under unfavourable circumstances involving tight cavities and in particular gaps. Small residues of cleaning fluid, possibly mixed with residue of product, may remain there for a prolonged time after the cleaning process.
[0005] Therefore, the object of the invention is to provide a cleaning device for a dust filter which meets even the highest hygiene requirements.
SUMMARY OF THE INVENTION
[0006] This object is achieved by a cleaning device wherein, in the connection region, the angle (W) at which the annular shells mutually abut in the annular chamber is at least 90°.
[0007] In such a cleaning device the angle at which the periphery of the upper annular shell abuts the periphery of the lower annular shell inside the annular chamber is at least 90°. In this manner, the cleaning device is capable of meeting even the highest hygiene standards since an infestation with germs cannot arise in the annular chamber, for instance following preceding wet purging. This is so because the interior of the annular chamber is free of gaps or regions of constriction, in which in the case of the known cleaning devices minimal residues of fluid may accumulate, thus giving rise to an environment which is conducive to the formation of germs.
[0008] Advantageous design embodiments of the cleaning device are stated in the dependent claims. Gaps and constrictions in the interior of the annular chamber may be avoided when in the connection region the annular zone of the lower annular shell has a curvature towards the upper annular shell, wherein this curvature is preferably of quarter-circular shape. It is furthermore advantageous when the annular zone of the upper annular shell has a curvature towards the lower annular shell.
[0009] It is furthermore proposed for the connection region that the peripheries of the two annular shells mutually abut by way of the end faces thereof. In this case, the end faces of the two walls are preferably machined, for example, ground, to be planar, wherein the common end-face plane in which said end faces are located extends perpendicularly to the central axis of the annular chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further details and advantages are derived from the following description with reference to the drawings.
[0011] FIG. 1 shows in a perspective view a cleaning device as is known from the prior art.
[0012] FIG. 2 shows in a sectional view a cleaning device according to the invention.
[0013] FIG. 3 a shows the right part of FIG. 2 in an enlarged view and FIG. 3 b shows an even more enlarged detail illustration of the connection region.
[0014] FIG. 4 shows a horizontal section through the cleaning device.
[0015] FIG. 5 shows an enlarged section view along section line V-V indicated in FIG. 4 .
DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] The basic construction and the basic operating mode of the compressed-air cleaning device which operates according to the Coand{hacek over (a)} principle is described in U.S. Pat. No. 6,604,694 B1, and reference is being had to the explanations provided therein.
[0017] FIG. 1 shows a cleaning device for a dust filter according to the prior art, specifically according to KR 20/0321528 A. A Coand{hacek over (a)} injector 1 is connected at two points to a compressed-gas line 2 which is disposed above the Coand{hacek over (a)} injector 1 . The Coand{hacek over (a)} injector 1 is designed so as to be substantially annular such that the central axis A thereof intersects perpendicularly the central axis of the compressed-gas line 2 . An annular chamber 7 which is disposed about the central axis A is a component part of the Coand{hacek over (a)} injector 1 . The annular chamber 7 by way of gas-inlet connectors 10 a, 10 b is connected to the interior of the compressed-gas line 2 at two locations which in relation to the central axis A are oppositely positioned at 180°. Compressed air may flow into the annular chamber 7 by way of the two gas-inlet connectors 10 a, 101 e at these two locations. During operation, this inflow is performed abruptly since the compressed-gas line 2 by way of a very rapidly switching valve is connected to a compressed-air source having a capacity for very high pressure. When the rapid-action valve is opened, compressed air or another compressed gas abruptly enters the compressed-gas line 2 , enters by way of the two gas-inlet connectors 10 a, 10 b the annular chamber 7 , and is distributed across the annular chamber 7 .
[0018] Self-evidently, a plurality of Coand{hacek over (a)} injectors 1 are simultaneously connected to one and the same compressed-gas line 2 , for example, 10 to 20 Coand{hacek over (a)} injectors of this type, depending on the size of the dust filter. Moreover, a plurality of compressed-gas lines 2 are disposed parallel to each other in the filter housing, so as to direct in this way compressed air also into adjacent rows of Coand{hacek over (a)} injectors of this type. In this manner an entire “field” in the housing of the dust filter may be equipped with Coand{hacek over (a)} injectors of identical type, each such injector being disposed above a filter element of the dust filter.
[0019] The annular chamber 7 of the Coand{hacek over (a)} injector 1 is assembled from two wall parts 11 , 12 , which in a connection region 13 which extends along the external periphery of the annular chamber 7 , are interconnected in a pressure-tight manner. The first wall is an annular shell 12 and the already mentioned gas-inlet connectors 10 a, 10 b for the connection to the compressed-gas line 2 are moulded thereon. This upper shell 12 is of pronounced three-dimensional shape, having a dome-shaped cross section. The gas-inlet connectors 10 a, 10 b are moulded thereon at locations which are located opposite each other at 180°.
[0020] The other wall is an annular shell 11 which, in radial inward direction, transitions into a tubular piece 30 having a central axis A.
[0021] As can be seen in FIG. 1 showing the prior art device, the two annular shells 11 , 12 in the connection region 13 are interconnected by a flange connection. While a flange connection on the external periphery of the annular chamber 7 is indeed a connection which in terms of production technology is advantageous, small gaps or cavities may form where the peripheral zones of the annular shells 11 , 12 close in on one another; in Such gaps or cavities, following operation of the cleaning device, residues of cleaning fluid mixed with residues of product may deposit. Therefore, the risk of an infestation with germs cannot be completely excluded.
[0022] This risk does not exist in the embodiment according to the invention, which is shown in FIGS. 2 to 5 . This embodiment will be explained in more detail in the following using the reference characters already used in the context of the prior art device shown in FIG. 1 . Therefore, the explanations which have already been given in the context of the prior art device also apply to the cleaning device according to the invention to the extent that they do not pertain to the connection region 13 .
[0023] Both walls 11 , 12 are shells which, in relation to the axis A, are shaped so as to be of annular design and which each are preferably integral press-moulded sheet-metal panel parts.
[0024] When viewed radially from the outside to the inside, the lower annular shell 11 , which thus is closer to the exit opening 18 , can be subdivided into a total of four portions. The external peripheral zone 20 is a component part of the connection region 13 and is designed so as to be connectible in a pressure-tight manner to the other annular shell 12 by welding. This peripheral zone 20 is adjoined radially inwardly by a larger wall portion 21 , the upper side 24 of which, facing the annular chamber 7 , extends almost horizontally and flat. This flat wall portion 21 extends up to a nozzle gap 25 where the compressed air or the compressed gas, respectively, exits from the annular chamber 7 . The flat upper side 24 of the wall portion 21 at the same time forms the lower nozzle-gap wall of the nozzle gap 25 .
[0025] Downstream of the nozzle gap 25 , a transition portion 22 is integrally formed in the shape of a rounded portion that establishes the connection to the tubular piece 30 . The tubular piece 30 forms the beginning of a cylindrical flow duct 27 which extends all the way to the exit opening 18 . The flow duct 27 is welded to the transition portion 22 or to the short tubular piece 30 of the wall 11 .
[0026] The transition portion 22 has a quarter-circular shape in cross section so as to enable an interference-free deflection of the gas jet, exiting from the nozzle gap 25 at high velocity, in the direction toward the exit opening 18 of the flow duct 27 .
[0027] Corresponding to the pressure supply by way of the valve-controlled compressed-gas line 2 , the exit of gas from the nozzle gap 25 is also performed in a pulsated manner and at high velocity. The gas, after leaving the nozzle gap 25 , follows the profile of the wall (Coand{hacek over (a)} effect) in the region of the curved transition portion 22 resulting in negative pressure at the center of this polydirectional gas flow. Due to the negative pressure, secondary air is drawn in from above by way of the entry opening 17 into the flow duct 27 such that an increased amount of gas exits from the exit opening 18 at a correspondingly high velocity. The inflow of the entrained secondary air into the entry opening 17 of the Coand{hacek over (a)} injector 1 is visualized by means of the flow arrows S in FIG. 2 .
[0028] Since the upper side 24 of the lower annular shell 11 , facing the annular chamber 7 , extends substantially horizontally or slightly downwardly at least up to the end of the nozzle gap 25 , fluid cannot accumulate on the upper side 24 and formation of an atmosphere conducive to an infestation with germs is prevented. Rather, any potential residues of fluids can always run off by way of the nozzle gap 25 and thus escape. In order for this effect to be amplified, the wall portion 21 in a radially inward direction, that is to say toward the central axis A, extends slightly downward, e.g. at an angle of less than 3° relative to the horizontal. It is crucial in this context that there is no location within the annular chamber 7 that is disposed lower than the nozzle gap 25 .
[0029] In order to avoid gaps, joints, or constrictions that bear the risk of an infestation with germs, on the external periphery of the annular chamber, the angle W at which the periphery 12 A of the upper annular shell 12 on the internal side of the annular chamber 7 meets the periphery 11 A of the lower annular shell 11 is at least 90°. This angle W is preferably approximately 180°, as is the case with the embodiment of FIGS. 2 to 5 .
[0030] An angle W of approximately 180° in the connection region 13 may be achieved in that the peripheral zone 11 A of the annular shell 11 has a curvature or a bend toward the other annular shell 12 , on the one hand, and the peripheral zone 12 A of the annular shell 12 also has a curvature or bend toward the annular shell 11 on the other hand. In this way, the end faces of the two annular shells 11 , 12 in the connection region 13 mutually abut in a straight line. In order to provide a connection without gaps or constricting regions, the mutually bearing end faces of the two annular shells 11 , 12 are moreover ground so as to be planar. Said end faces are located in a common end-face plane E which extends perpendicularly to the central axis A of the annular chamber 7 .
[0031] For pressure-tight attachment, a weld seam 35 is produced externally on the connection region 13 so as to be level with the end-face plane E, in this way, complete pressure-tightness of the annular chamber 7 is achieved. There are thus no gaps, constrictions, or other small cavities on the inside of the annular chamber wall in which residues of cleaning fluid mixed with residues of product could be deposited following operation of the cleaning device.
[0032] The nozzle gap 25 may indeed be a single nozzle gap which extends across the entire circumference. However, in order to calibrate the height of the nozzle gap in a simpler and more reliable manner, preferably a plurality of individual nozzle gaps 25 are provided which are regularly distributed across the circumference and from which the pressurized gas exits radially inwardly. The shells 11 , 12 are directly supported on one another along short circumferential portions 26 between mutually successive nozzle gaps 25 . On account thereof, it is possible for the height of the nozzle gaps 25 to be precisely dimensioned.
[0033] The specification incorporates by reference the entire disclosure of German priority document 10 2015 111 825A having a filing date of Jul. 21, 2015.
[0034] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
LIST OF REFERENCE CHARACTERS
[0035] 1 Coand{hacek over (a)} injector
[0036] 2 Compressed-gas line
[0037] 5 Central axis
[0038] 7 Annular chamber
[0039] 10 a Gas-inlet connector
[0040] 10 b Gas-inlet connector
[0041] 11 Lower wall, annular shell
[0042] 11 A Periphery
[0043] 12 Upper wail annular shell
[0044] 12 A Periphery
[0045] 13 Connection region
[0046] 17 Entry opening
[0047] 18 Exit opening
[0048] 20 Peripheral zone
[0049] 21 Rat portion
[0050] 22 Transition portion
[0051] 24 Upper side
[0052] 25 Nozzle gap
[0053] 26 Circumferential portion
[0054] 27 Row duct
[0055] 30 Tubular piece
[0056] 35 Weld seam
[0057] A Central axis
[0058] S Flow
[0059] E End-edge plane
[0060] W Angle
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A cleaning device for a dust filter has a flow duct extending between an entry opening and an exit opening. An annular chamber surrounds the flow duct. Gas-inlet connectors are provided for inflow of pressurized gas into the annular chamber. Nozzle gaps delimited by nozzle-gap walls open toward the flow duct. The annular chamber has an upper annular shell and a lower annular shell interconnected pressure-tightly in a connection region. The gas-inlet connectors are molded on the upper annular shell. The lower annular shell is predominantly flat, extends horizontally or downwardly toward the nozzle gaps, and forms the lower nozzle-gap wall. In order to meet highest demands in terms of hygiene, in the connection region the angle at which the annular shells mutually abut in the annular chamber is at least 90°. Gaps and constrictions are thus avoided.
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FIELD OF THE INVENTION
The present disclosure relates to energy storage systems, and more particularly to energy storage systems for high-voltage applications.
BACKGROUND OF THE INVENTION
Batteries are energy storage devices that are well-known for use as an autonomous supply of energy for a desired application through a chemical reaction. Batteries are an energy dense technology (kWh/kg). Ultra-capacitors are increasingly used for supplying energy. Ultra-capacitors are designed to be very power dense (kW/kg) and are capable of delivering very high instantaneous current. Ultra-capacitors have a very simple construction when compared to batteries which leads to lower cost per unit of energy. Ultra-capacitors have an order of magnitude reduced internal resistance compared to batteries.
Hybrid energy storage systems using, for example, batteries and ultra-capacitors have been developed in order to take advantage of the strengths of each technology to provide high power density solutions. Such hybrids can be better optimized when compared to a single energy storage technology, like adding batteries in parallel to achieve peak power points of particular applications. The outcome of the combined design is that the total weight, volume and cost can be reduced over battery-only designs. In such previous hybrid energy storage systems, voltage control between the battery and ultra-capacitor sub-systems has been by active circuits (see FIG. 9A ). Such previous designs commonly use a bi-directional DC/DC converter or an active current management control strategy.
The active controllers used in such hybrid energy storage systems add to the weight and complexity of the overall system. Additionally, the controllers are susceptible to electrical design risks common in space/aerospace applications.
BRIEF SUMMARY OF THE INVENTION
The present disclosure is directed to an energy storage device using a combination of battery and ultra-capacitor storage components and having passive voltage control. An inductor is placed inline between the batteries and ultra-capacitors of the hybrid module. The disclosed device is suitable for use in high-power applications where high-currents can have adverse effects on impedance-matching components—i.e., causing saturation in inductors. Additionally, inductors of some embodiments of the present invention are designed to better dissipate heat generated in such high-power applications.
The present passive hybridization technique differs from previous systems in that there is no need for complicated electronics to regulate system voltage, thereby reducing the electrical design risk and other environmental risks inherent when using active electronics. As such, the use of passive voltage control allows the hybrid systems to be used in applications—in particular, space, aerospace, defense, and industrial applications—in which electronics are restricted through specification, environment, or end use. Systems according to embodiments of the present disclosure advantageously have lower complexity, for example, eliminating the need for a DC/DC converter. And, such passively-controlled systems benefit from lower-weight than the conventional alternatives. Passive voltage control is also more reliable than active voltage control because of the reduction in active electronics, which is advantageous for space and aerospace applications.
The application space is a primary driver in systems according to the present disclosure. In applications with harsh environments, solutions are difficult to design and have often have additional restrictions such as, for example, common design practices, required to meet military standards and avoid electrical design risks. Systems according to the present disclosure are particularly suited for applications such as, for example, sub-sea vehicles, unmanned aerial vehicles, aerospace systems, deep space systems, military vehicles and turret drive systems, and industrial systems. The high current demand nature of these applications necessitates more than common commercial electrical design practices and component selection.
Compared to battery-only solutions, (see FIG. 10 ), hybrid systems allow for more optimal sizing of the energy module to the duty cycle (the power requirements of a load over time). It can be seen that while both systems come close to maximizing the capability of the respective modules in maximum power draw, the hybrid system can be better optimized to the duty cycle for energy. The difference between the two systems in performance is that the ultra-capacitor takes a significant portion of power load on high current transients in the hybrid module. Additionally, the battery-only solution will be oversized in energy because it is sized to peak current. As such, hybrid modules save in both cost and weight when compared to battery-only options.
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.
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a circuit diagram of an ultra-capacitor module according to an embodiment of the present disclosure;
FIG. 2 is a circuit diagram of an energy storage apparatus according to another embodiment of the present disclosure;
FIG. 3 is a circuit diagram of an energy storage apparatus according to another embodiment of the present disclosure, having multiple batteries and multiple ultra-capacitors;
FIG. 4A is a diagram of an energy storage apparatus configured to be connected to a power bus;
FIG. 4B is a circuit diagram of an embodiment of the energy storage apparatus configured to be connected to a power bus;
FIG. 5 is a circuit diagram of another embodiment of an energy storage apparatus according to the present disclosure;
FIG. 6 is a circuit diagram of another embodiment of an energy storage apparatus according to the present disclosure;
FIG. 7 is a circuit diagram of an energy storage apparatus shown of the present disclosure connected to a testing apparatus;
FIG. 8 is a circuit diagram of another embodiment of an ultra-capacitor module according to the present disclosure;
FIG. 9A is a diagram of an active hybridization system according to embodiments of the present disclosure;
FIG. 9B is a diagram of a passive hybridization system according to embodiments of the present disclosure;
FIG. 9C is a diagram of a passive hybridization system according to another embodiment of the present disclosure;
FIG. 10 is a graph depicting the improved sizing (i.e., sized to the duty cycle of a load) of a hybrid module as compared to a battery-only module;
FIGS. 11A and 11B are graphs showing the performance of an embodiment of a hybrid module according to the present disclosure, compared to a battery-only system;
FIG. 12 is a set of graphs showing the regen characteristics of components of an embodiment of a hybrid module according to the present disclosure;
FIG. 13 is a set of graphs showing the response of a 12 VDC test system and comparing the test system to a modeled system;
FIG. 14 is a block diagram depicting exemplary applications for a high-voltage apparatus of the present disclosure;
FIG. 15 is a set of graphs depicting the swept frequency response of a 300 VDC exemplary system;
FIG. 16 is a set of graphs depicting the response of the 300 VDC exemplary system to a portion of the conducted duty cycle;
FIG. 17 is a set of graphs depicting the response of the 300 VDC exemplary system to another portion of the conducted duty cycle; and
FIG. 18 is a set of graphs depicting the 6 Hz frequency response of the 300 VDC exemplary system.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , the present disclosure may be embodied as an ultra-capacitor module 10 for an energy storage apparatus. Such a module 10 may be used to supplement an existing battery-only system. The ultra-capacitor module 10 comprises a battery positive terminal 12 configured to be connected to a positive terminal of a rechargeable battery and a battery negative terminal 14 configured to be connected to a negative terminal of the rechargeable battery. The ultra-capacitor module 10 further comprises a load positive terminal 16 and a load negative terminal 18 , configured such that a load connected to the load terminals 16 , 18 is electrically in parallel with the at least one ultra-capacitor 30 .
The module 10 comprises an inductor 20 having a first lead 22 , a second lead 24 , and a core made from a low-permeability material (further described below). The first lead 22 of the inductor 20 is in electrical communication with the battery positive terminal 12 . At least one ultra-capacitor 30 is provided. The at least one ultra-capacitor 30 has a positive lead 32 and a negative lead 34 . The positive lead 32 is in electrical communication with the second lead 24 of the inductor 20 , and the negative lead 34 being in electrical communication with the battery negative terminal 14 .
To handle high power applications the inductor 20 is designed not to succumb to saturation, which typical inductors (i.e., ferromagnetic-core inductors) are susceptible to. A saturated inductor will not properly regulate the balance of current between the two energy sources—ultra-capacitor and battery—and, therefore, will not be suitable for the passive hybrid control design of the present disclosure. Inductors 20 of the present disclosure are designed with the goal of reducing or eliminating the susceptibility to saturation by using low-permeability materials for the inductor 20 core (sometimes referred to as “air-core” inductors). Suitable low-permeability materials may have a permeability of approximately 1.2367×10 −6 (H/m). For example, suitable materials include, without limitation, steel, aluminum, and platinum. Other materials will be apparent to those having skill in the art, in light of the present disclosure. In some embodiments, the core material is also selected to have high thermal conductivity in order to dissipate thermal concerns driven by the high currents of high-power applications. This allows the present inductor 20 to survive a high-power environment and maintain functionality. Such low permeability-core inductors would not be used in more common low-power applications due to the additional size and cost of the low permeability-core inductors compared to ferromagnetic-core inductors.
In some embodiments of an ultra-capacitor module 10 , the low permeability-core inductor 20 further comprises one or more thermal pads disposed between the high thermal conductivity material core and the windings of the inductor 20 to aid in heat transfer. Because of the high-power application, the generalized material selection guideline developed for the inductor 20 advantageously accounts for thermal issues that are present in such high-power applications. Thermal heating is present primarily due to the large currents (e.g., in excess of 100 A) that are passed through the inductor. The inductor 20 is designed to reduce the line resistance of the component to assist with lower heating but is not enough to eliminate the issue. The material used for the inductor 20 may be selected to have high thermal conductivity such that thermal heating may be mitigated within the design of the inductor 20 . The inductor 20 may be thermally sunk to the packaging of the ultra-capacitor module 10 through thermal pads on the core, sink, and plate. Sinking the generated heat helps reduce the necessary wire gauge of the inductor 20 coil and overall size and weight of the inductor 20 . Such reduction in volume and weight is advantageous in the aerospace industry and other industries due to volume and weight restrictions and also reduces any additional volume and weight required by systems of the present disclosure when compared to single energy storage cell designs.
Embodiments may have more than one ultra-capacitor 30 arranged in series to accommodate total higher voltage across the series components, and/or arranged in parallel, to provide higher total capacitance. For example, FIG. 8 depicts an exemplary embodiment of an ultra-capacitor module 10 having fourteen ultra-capacitors 30 arranged in series.
In another embodiment, the present disclosure (depicted in FIG. 2 ) may be an energy-storage apparatus 50 for providing energy to an electrical load. Such an apparatus 50 comprises at least one ultra-capacitor 30 having a positive terminal 32 and a negative terminal 34 . The positive and negative terminals 32 , 34 being configured to be connected to the electrical load. For example, the positive and negative terminals 32 , 34 may be in electrical communication with load terminals 16 , 18 .
The apparatus 50 further comprises a battery 60 having a battery positive lead 62 and a battery negative lead 64 . The battery negative lead 64 is coupled to the negative terminal 34 of the ultra-capacitor 30 . The apparatus 50 may comprise more than one battery 60 connected in series with one another, to provide higher voltage, and/or in parallel with one another, to provide higher peak current draw. FIGS. 3 and 4B depict embodiments wherein multiple battery cells are connected in series. FIG. 5 depicts an embodiment of an energy-storage apparatus wherein a four-cell string of batteries (i.e., in series) is connected in parallel with another four-cell strong of batteries.
An inductor 20 is provided having a first lead 24 coupled to the positive terminal 32 of the at least one ultra-capacitor 30 . A second lead 22 of the inductor 20 is coupled to the battery positive lead 62 of the battery 60 . The inductor 20 has a low-permeability core material. In some embodiments, the core of the inductor 20 is made from steel, aluminum, or platinum. The inductor 20 may further comprise one or more thermal pads disposed between the core and the windings to aid in heat transfer.
Devices of the present disclosure may be adapted to accept power from a power bus (see, for example, FIG. 4A ). In the embodiment of an bus-attached energy-storage apparatus 90 depicted in FIG. 4B , battery positive lead 92 is connected to a bus positive terminal 98 of a power bus 91 and battery negative lead 94 is connected to a bus negative terminal 96 of the power bus 91 . In this way, the apparatus 90 may act as an autonomous energy pack (e.g., a regen buffer to a central bus line) or can be used as a low power bus booster pack (providing high power to a load without having to upgrade a low power bus rail). Such a power bus-attached embodiment may include a clamping circuit between the apparatus 90 and the power bus 91 . In this way, power from the apparatus 90 would not be output back onto the bus.
Ultra-Capacitors
The ultra-capacitor(s) may preferably be capable of supplying a majority of load current demands and regen current capability. The capacitance rating of the selected ultra-capacitor will determine current supply capability. In this way, the higher the capacitance, the higher the energy and therefore the larger the current load the ultra-capacitor can take in the system. The higher capacitance ultra-capacitors may advantageously be paired with low power/higher energy battery cells or matched with a higher current load duty cycle (vice-versa with lower capacitance cells). Ultra-capacitor selection may be based off of overall system sizing with regard for weight.
Batteries
The battery(ies) may preferably be capable of supplying charge current for the ultra-capacitor(s) as well as providing secondary load current. Additionally, the battery should be capable of maintaining itself without violating safe cell charge/discharge practices.
Inductor
The inductor size is tuned for each application and done in view of the whole system because the inductor is the passive control element. The inductor selection is first based on selectivity, which is a ratio between the inductance and capacitance of a filter system. This selectivity, with some augmentation for the peak currents and voltage seen by the inductor, drive the inductor sizing. Based on the inductor sizing, the design is then driven to make the inductor work without any ill-effects (current saturation) while being volume efficient, all while being capable of use in a high-power environment. To handle such high power applications (e.g., in excess of 100 A), the low permeability-core inductor reduces concerns related to inductor saturation. Additional thermal considerations and winding size considerations are discussed above.
Exemplary Embodiments
The functionality of the passive hybridization scheme was demonstrated in the model and using a low-voltage (12 VDC) test circuit. Through this testing, the desired results were demonstrated: the ultra-capacitor supplied a large portion of the initial current demand, the current output capability increased with the size of the ultra-capacitor, as current was supplied from the ultra-capacitor, the available voltage decreased, which led to decreases in the contribution to total output current from the ultra-capacitor. A library of cells (both battery and ultra-capacitor) was developed for a mathematical model and for use in simulating the presently disclosed passive hybridization techniques. The testing library was developed using low-voltage (12 VDC) test data. Based on the testing, the model was considered to be correlated (see, e.g., FIG. 13 ).
FIG. 14 depicts two typical high-current applications—an electromechanical actuator and an electrohydrostatic actuator—having loads that can range anywhere within the described application space. Systems of the present disclosure are suitable for use in such applications as power sources connected to what is noted in the figures as the “control electronics and variable speed motor.”
A 300 VDC passive hybridization system was built to demonstrate the functionality of the disclosed apparatus in a high-voltage application, such as, for example, an electromechanical actuator or an electrohydrostatic actuator, shown in FIG. 14 , and other applications within the described application spaces. The 300 VDC demonstration system was also used to show the extreme discharge and regen capabilities of the presently disclosed techniques.
FIG. 15 depicts the swept frequency response of the 300 VDC demonstration system; FIGS. 16 and 17 depict the response of the system to portions of the duty cycle; and FIG. 18 depicts the 6 Hz frequency response of the system. It can be seen that the system maintains an acceptable level of voltage during pulsed discharge. The battery output (voltage/current) is kept to a more steady level, which is advantageous for battery selection. The ultra-capacitor is taking transient current demand. In the case of the 6 Hz response, it is noted that the ultra-capacitor is taking all of the regen current (see circled portion).
Through this testing of a hybrid module, the concept of load sharing between battery and ultra-capacitor component was validated and used for model correlation. In simulation, the hybrid module was capable of accepting 350 A of regenerative current in a is pulse (see FIG. 12) and 500A of regenerative current in a 0.1 s pulse. This compares to 180 A @ 1 s and 190 A @ 0.1 s for the battery-only module.
The present application may be embodied as a method for passive voltage control in a hybrid energy module having at least one battery and at least one ultra-capacitor. Each of the at least one battery and at least one ultra-capacitor having a respective positive terminal and negative terminal. The method comprises the step of providing an inductor connected between positive terminals of the battery and ultra-capacitor, the inductor having a low-permeability-core.
Although the present invention has been described with respect to one or more particular embodiments, it will be understood that other embodiments of the present invention may be made without departing from the spirit and scope of the present invention. Hence, the present invention is deemed limited only by the appended claims and the reasonable interpretation thereof.
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The present disclosure is directed to an energy storage system using a combination of battery and ultra-capacitor storage components and having passive voltage control. An inductor is placed inline between the batteries and ultra-capacitors of the hybrid module. In another embodiment, the inductor/ultra-capacitor module is configured to be connected to a battery. The disclosed device is suitable for use in high-power applications where high-currents can have adverse effects on impedance-matching components.
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FIELD OF THE INVENTION
[0001] This invention relates to pouches for holding medical instruments and medical devices such as implants. These articles may be loaded into the pouch either as separate items or within holding trays or baskets.
BACKGROUND TO THE INVENTION
[0002] Traditionally, the purpose of a medical pouch has been to provide a sterile barrier for instruments and devices up to the point of use. After use, the soiled articles are sent to a washing/disinfecting facility in bags or containers which allow protein to dry on the instruments, thereby rendering them difficult to clean.
[0003] Statements of the Invention
[0004] According to the present invention there is provided a pouch formed from one or more webs of material providing at least one absorbent surface, the pouch having an integral flap which may be folded over the entrance of the pouch so as to maintain the contents of the pouch in place and help to retain moisture within the pouch, and the interior of the pouch being defined at least partly by the or each absorbent surface. In use therefore, an item, such as a medical instrument will be located within the pouch along with the absorbent surface or surfaces.
[0005] A pouch in accordance with the present invention is intended to provide a moist environment for the bag contents at and beyond the point of use. Such an environment reduces the drying of protein and other debris on the instruments, thus facilitating easier cleaning prior to sterilisation.
[0006] To achieve and maintain a moist environment within the pouch, liquid is introduced into the pouch and is allowed to permeate the absorbent surfaces prior to use. The liquid may be a sterile liquid and/or it may contain one or more additives. The liquid is preferably an aqueous liquid.
[0007] Preferably, the pouch comprises first and second substantially rectangular webs of material, at least one of which has an absorbent surface on one side thereof, the webs being of the same length but of different width and being sealed together along respective three edges of each web so that the web of greater width extends beyond the free edge of the web of lesser width to provide a flap for folding over the web of lesser width and also for facilitating ease of entry of the instruments or trays into the pouch.
[0008] Alternatively, the pouch may comprise first and second substantially rectangular webs of material and a third web located between said first and second webs and having at least one absorbent surface, the first and second webs being of the same length but of different width and being sealed together along respective three edges of each web so that the web of greater width extends beyond the free edge of the web of lesser width to provide a flap for folding over the web of lesser width and also for facilitating ease of entry of the instruments or trays into the pouch.
[0009] Preferably, the pouch is formed by at least one web of absorbent material.
[0010] Preferably, the pouch is provided with at least one web of water imperious plastics film.
[0011] One or both of the flaps and the outer surface of the web of lesser width is provided with means for securing the flap to the outer surface of the web of lesser width. Preferably, such securing means is provided on the flap.
[0012] Preferably, the securing means is double sided tape.
[0013] The first and second webs may be provided by a single piece of folded over material or alternatively by separate pieces of material.
[0014] Preferably, the webs are additionally joined together at one or more positions along the length of the pouch to provide pockets for accommodating medical instruments.
[0015] For example, the webs may be joined together at two positions along the length of the pouch to provide three pockets.
[0016] The present invention also provides a method of storing a medical instrument or component in a moist environment, the method comprising locating the instrument or component within a pouch as claimed in any of the preceding claims, the or each absorbent surface being permeated with liquid.
[0017] The pouch may be provided in “wet” condition, that is to say, with the or each absorbent surface permeated with liquid. Alternatively, it may be in “dry” form with liquid supplied in a separate container, from which it is added to the pouch. As a further alternative, the pouch may be supplied dry and the user may make up a suitable liquid for addition to the pouch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are as follows:
[0019] FIG. 1 is a perspective view of a medical pouch in accordance with the present invention; and
[0020] FIGS. 2 to 4 are, in each case, front and longitudinal sectional views of three further embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention will now be described, by way of examples only, with reference to the accompanying drawings.
[0022] Referring to FIG. 1 of the accompanying drawings, a medical pouch 1 is for use in holding surgical instruments in a moist environment both during and after use.
[0023] Pouch 1 includes a web of material 3 which may consist of two separate pieces of material 5 , 7 or a single piece of material folded at 9 . The surface or surfaces which provide the inner surfaces of the pouch are liquid absorbent.
[0024] As shown in the drawing, the webs 5 and 7 are rectangular and of the same length but of different width. They are connected together at 9 (or folded about 9 ) and also along edges 11 and 13 . Because of the different widths, web 7 extends beyond the edge 15 of web 5 to form a flap 17 which extends from the open edge of the pouch. Flap 17 may be provided with a strip of double sided tape 19 which extends along the length of the flap at a position close to its free edge.
[0025] Pouch 1 may be divided into sealed compartments by means of seals 21 which extend parallel to edges 11 and 13 . As a result there are provided three compartments for holding instruments 23 .
[0026] With instruments in place in the pouch, the release liner may be removed from tape 19 and the flap folded over to retain the instruments within the pouch, and also to help retain the moist atmosphere within the pouch. When access to the instruments is required, the flap can be easily detached from the body of the pouch.
[0027] The above described pouch allows instruments to be maintained in a moist environment both during and after use. Material, such as protein, adhering to the instruments may be kept moist thereby allowing for easy cleaning prior to sterilisation of the instruments.
[0028] Sterile liquid may be introduced into the pouch to achieve and maintain a moist environment.
[0029] It should be appreciated that the above described pouch can be modified in many ways within the scope of the present invention. For instance, the webs may be of equal length, tape to hold the flap down may be omitted and the pouch may be made of three (or more) webs.
[0030] Various pouches, within the scope of the present invention, are illustrated in FIGS. 2 to 4 . In each case, the pouch makes use of at least one web of absorbent material 25 . This web may be, for instance, of 100% viscose material, made of viscose rayon and binder (73% viscose rayon fibre/27% binder). The material may be impregnated with an absorbency increasing agent. The material has low linting, that is to say, it has a low level of loose fibres and does not disintegrate easily as a result of instrument abrasion.
[0031] Referring to FIG. 2 , a pouch 27 comprises a layer of absorbent material 25 having a backing of a transparent plastics film 29 . A shorter layer of plastics film 31 is provided at the front of absorbent layer 25 . The three layers are secured together by sealing about a substantial portion of the edges as indicated at 33 . The absorbent layer 25 is shorter than both plastics film layers 29 and 31 .
[0032] The plastics film 31 may be made of any suitable transparent, translucent or opaque material. Examples are a polyester/polypropylene or polyester/polyethylene film which might be a laminate, or a non-laminate. A film containing polypropylene might be used if the pouch and its contents are to be subjected to a steam sterilisation process. A film containing polyethylene might be used where the pouch and its contents are to be subjected to EB (electron beam radiation) or γ radiation.
[0033] The film 31 may or may not be provided with small holes to allow steam to escape from the pouch.
[0034] The flap 37 , which is that portion of webs 29 extending above web 31 , may be folded over the front of web 31 when the pouch is loaded with an instrument. Flap 37 is provided with a strip 39 of double sided adhesive tape.
[0035] Referring to FIG. 3 of the accompanying drawings, a pouch 41 is formed from two webs of absorbent material 43 and 45 . The webs are connected together by means of seals indicated at 47 . As a result, pockets are provided at 49 and these pockets may accommodate surgical instruments or associated components.
[0036] Rear web 45 extends beyond front web 43 and the flap 51 may be folded over the web when the instruments are contained within the pouch.
[0037] Referring to FIG. 4 of the accompanying drawings, a further embodiment of a pouch in accordance with the present invention has a layer of absorbent material 53 backed by a layer of transparent plastics film 55 . Located at the front of web 53 is a further layer of transparent plastics film 57 and the three layers are sealed together as indicated by sealing 59 . The result is that two pockets 61 are provided and these can accommodate instruments located between the plastics film 57 and absorbent layer 53 .
[0038] Fixed to plastics film 57 , at a position above the sealing areas 59 is a strip of double sided adhesive tape 63 . Tape 63 is provided with a protective backing (on its front side) which may be peeled off. The flap 65 , above the upper edge of layer 57 may then be folded over the front of layer 57 and secured to the adhesive layer 63 in order to maintain the instruments within the pockets 61 of the pouch 57 .
[0039] It should be appreciated that pouches may be made in various combinations of absorbent and non-absorbent layers. A plastics film located on the front side of an absorbent layer provides visibility of the contents of the pockets and has some effect on water retention. If a plastic film is provided on both sides of the absorbent film, such as is the case in the FIG. 2 embodiment, then there is both visibility of instruments within the pouch and also a better water retention.
[0040] Tests have been carried out on various embodiments as follows:
[0041] 1. An embodiment in which there is no plastics film (such as is shown in FIG. 3 ). In this case, a time interval of about two hours elapsed before the water had completely evaporated from the moistened pouch.
[0042] 2. Film is provided on both sides of an absorbent layer (such as is shown in FIG. 4 ). In this case, a period of two days elapsed before the water has evaporated from the moistened pouch.
[0043] 3. The pouch is similar to that of FIG. 4 except that the front plastics layer is perforated to allow for steam sterilisation. In this case a period of four hours elapsed before water evaporated from the moistened pouch.
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A pouch is formed from one or more webs of material that provide at least one absorbent surface. The pouch further includes an integral flap, which may be folded over the opening, or entrance, of the pouch so as to maintain the contents of the pouch in place and to help retain moisture within the pouch. The interior of the pouch is defined, at least partially, by its absorbent faces.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to systems for providing steamed video on demand to end users. More specifically the present invention relates to the provision of enhanced features to viewers of digital video on demand over Internet Protocol (IP) based networks.
BACKGROUND
[0002] Prior art streamed video on demand (SVOD) systems and an growing body of developing international standards exist for the provision of digital video content to end users. Current implementations of these systems are expensive, rely upon proprietary or inaccessible networks or cable systems and creating the net result of systems that do not provide the combination of attractive price, meaningful functionality and dependable delivery over existing networks. The present invention offers an inexpensive, scalable, modular and dependable system that brings meaningful and attractive features to end users.
BRIEF DESCRIPTION OF THE FIGURES
[0003] Table 1 sets out the technical specifications of the present invention.
[0004] FIG. 1 illustrates the general structure of present invention.
[0005] FIG. 2 is a block diagram of the general structure of present invention.
[0006] FIG. 3 is a block diagram of movie production using the present invention.
[0007] FIG. 4 is a block diagram of the user account module of the present invention.
[0008] FIG. 5 is a block diagram of on-line intelligent retrieval of the present invention.
[0009] FIG. 6 . 1 is a block diagram of the process of streaming movie content to clients in the present invention.
[0010] FIG. 6 . 2 is a block diagram of the data communication between the media server an the client in the present invention.
[0011] FIG. 7 is a block diagram of the movie playback and control mechanism of the present invention.
[0012] FIG. 8 illustrates a streaming sequence in the present invention.
[0013] FIG. 9 illustrates a streaming sequence in the present invention.
[0014] FIG. 10 illustrates a streaming sequence in the present invention.
[0015] FIG. 11 illustrates a coding strategy in the present invention.
[0016] FIG. 12 illustrates a coding strategy in the present invention.
[0017] FIG. 13 illustrates a coding strategy in the present invention.
[0018] FIG. 14 illustrates a coding strategy in the present invention.
[0019] FIG. 15 illustrates a streaming sequence in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 illustrates the general structure of the present invention. Initially, the end user issues an HTTP GET command to the web server to start a Real Time Streaming Protocol (RTSP) session. The web server, after receiving and processing the connection request will send back to the end user a session description. If the web server agrees to establish the connection, it will start a client player, which will issue a SETUP request to the media server and a connection is established between the client player and the media server. As a result, data communication is ready and the user may choose to play/pause the media subsequently streamed from the media server. Simultaneously, the client player in the present invention may send back some Real-time Transport Control Protocol (RTCP) packets to give quality of service (QoS) feedback and support the synchronization of different media streams that exist in the preferred embodiment of the present invention. It will convey information such as the session participant and multicast-to-unicast translators. At the conclusion of the session or upon user request, the client player will close the connection by sending a TERADOWN command to the media server; the media server will then close the connection.
[0021] For the streaming control, the preferred embodiment of the present invention may use the Real Time Streaming Protocol (RTSP). Considering its popularity and quality, it is a good protocol to set up and control media delivery. For the actual data transfer, Internet Engineering Task Force (IETF) authored Real-time Transport Protocol (RTP) may be used. RTP is layered on top of TCP/IP or UDP and is effective for real-time data transmission.
[0022] For resources control, Resource ReserVation Protocol (RSVP) may be used to provide the QoS services to end users. When a client sends a request to the web server for a movie with some quality requirements, the server will decide if the resources for the requirements are available or not. If the resources are available, they will be reserved for media transmission from the server to the client; otherwise, the server will notify the client that there are not enough resources to meet its requested requirements.
[0023] FIG. 2 illustrates the overall flow chart of the streaming video on demand system of the present invention. The system is composed of five modules: movie production, intelligent movie retrieval, movie streaming, movie playback, and user account management processes.
[0024] Movie production is the process used to generate a movie database for playback and a feature database for movie retrieval. When new movies come, they will go through two processes. One is encoding process, where the movie content is encoded and converted to a bit-stream suitable for streaming. The other is a preprocessing step, where some semantic contents of the movie are extracted, such as keywords, movie category, scene change information, story units, important objects, and so on.
[0025] Another important module is the user account management, which consists of a user registration control and a user account information database. User registration provides an interface for new users to register and existing users to log on. User account information database saves all the user information, including credit card number, user account number, balance, and so on. This information is very important and must be secured against intrusion during both transmission and storage.
[0026] After movie encoding production, a movie database is available for customers to browse. However, if the database contains tens of thousands of movies, it is difficult to find a wanted movie. Therefore, a search engine is necessary for the efficiency of the system. The search can be based on movie title, movie features, and/or important objects. Movie title search is quite obvious and can be implemented easily. Movie feature search means searching the feature database to find movies with certain, fundamental features. The features may include color, texture, motion, shape, and so on. A third search criteria may be to find movies with certain important objects, such as featured performers, director or other criteria.
[0027] Once an end user selects a movie, the movie streaming and data communication module will be started. Streaming and data communication is a process to open a connection between the client and media server and send the compressed movie file to the client for playback. The file is in a format suitable for streaming. By using streaming, the client can start to play the movie after buffering a certain number of frames, which is much more user friendly than downloading and playing.
[0028] The next module is responsible for playing and controlling the movie. Movie playback will be performed while streaming continues. At the same time, another thread will be maintained for the control information from the customer. The control information includes play/stop/pause, fast forward/backward, and exit.
[0029] When a user chooses a movie to watch, the web server should activate the corresponding player, which will communicate with the media server for the specific movie. Some configuration is required to enable the web server to recognize appropriate file extensions and call the corresponding player.
[0030] The media server is of key importance within the system and its responsibilities include setting up connections with clients, transmitting data, and closing the connections with clients.
[0031] All movie files saved in the media server are in streaming format. The data communication between client and media server will use RTSP for control and RTP for actual data transmission. SDKs from Real Network are available to convert files coded for the present invention into the standard streaming format. At the decoder side, the same SDKs can be used to convert the streaming data into a multiplexed bit stream.
[0032] Movie production is a procedure to create stream video files. The production process of the present invention includes a video coding and conversion process and a content extraction process. The first process encodes a raw movie and converts the encoded file into a format suitable for streaming. For video coding, the preferred embodiment of the present invention uses H.263+, for audio, MP3. The multiplexing scheme is from available MPEG standards. After encoding and multiplexing, the bit-stream is converted to a streaming format. The present invention may use some Real Producer SDKs to convert the bit-stream to a file in streaming format and the file is saved in a movie database.
[0033] The content extraction process starts with video segmentation, where the scene changes are detected and a long movie is cut into small pieces. Within each scene change, one or more key frames are extracted. Key frames can be organized to form a storyboard and can also be clustered into units of semantic meaning, which correspond to some stories in a movie. Visual features of the key frames are computed, such as color, texture, and shape. The motion and object information within each scene change can also be computed. All this information will be saved in a movie feature database for movie database indexing and retrieval.
[0034] User account management module, as illustrated in FIG. 4 is responsible for user registration and user account information management. User registration is realized via a Java interface, where the new users are required to provide some information and the existing users can just type in the user name and password. For a new user, the new account information needs to be entered and sent to the media server for confirmation. If the account information is ok, then an account name and password will be generated and sent to the user. Otherwise, the user will be asked to reenter the account information. If the user fails three times, the module will exit. For an existing user, a logon interface will appear for the user name and password. If the user name and password are ok, the user is allowed to browse the movie database and choose the movies to watch. Otherwise, the user is informed that the user name and/or password are not correct. The user can reenter the user name and password. If the user fails three times, the module will exit.
[0035] FIG. 5 illustrates the flow chart of online intelligent retrieval module. This module displays the thumbnails of a selected set of movies. If a customer wants to search for a movie, several search criteria are available, such as movie title, keywords, important objects, feature-based search, and audio feature search. A feature database will be searched against the user-specified criteria and the thumbnails of the best matches in the movie database will be returned as the search result. The customer can then browse the thumbnails to get more detailed information or click them to playback a short clip. This module allows users to find a set of movies that they like in a short time.
[0036] FIG. 6 . 1 shows the streaming process between the media server and client player. After video and audio coding, multiplexing is applied to generate a multiplexed bit-stream with timing information. Then the bit-stream is converted to the streaming format and sent to the client. When the client receives the bit-stream, it will convert it back to the multiplexed bit-stream, which will be de-multiplexed and sent to audio and video decoder for playback.
[0037] FIG. 6 . 2 shows the data communication between the media server and client player. If the media server does not receive a stop command, it will always check the incoming connection requests from the client players. When a new connection request comes in, the media server will check the available resources to see if it can handle this new request. If so, it will open a new connection and stream the requested movie to the client; otherwise, it will inform the client that the server is unable to process the request. After the movie is streamed to the client, the connection between the media server and the client will be closed so that the network bandwidth can be saved for other uses.
[0038] The movie playback and control module as illustrated in FIG. 7 . has two threads A and B. Thread A decodes the compressed movie and play it, and thread B accept the control information from the customers. The control information includes play, stop/pause, fast forward/backward, and exit command. Thread checks if the current playback mode is set to on or not. If it is on, then thread A will decode the current movie file and play back the movie; otherwise, it will do nothing. When the decoding and playback continue, some reconstructed P frames will be saved for fast backward function. After finish playback, the playback mode will be set to off. The right side of FIG. 7 shows the work of thread B, which accepts control information from the customers. When a play command is received, it will call play function of thread A and play the movie. When a stop command is received, the current movie will be stopped and the file pointer will be moved to the start of the movie. When a pause command is received, the current movie is paused at the current position. When a fast forward command is received, if the customer wants to fast forward to an I frame, then the information is available in the local disk. However, if the customer wants to fast forward to a P or B frame, then the client player needs to fetch one or two reconstructed frames from the media server. When a fast backward command is received, a reconstructed P frame or an I frame is obtained to start the decoding process. When an exit command is received, thread A and B are killed and client player exits.
[0039] Random frame search is the ability of a video player to relocate to a different frame from the current frame. Since the video frames are typically organized in a one-dimensional sequence, random frame search can be classified into fast forward (FF) and fast backward (or rewind REW).
[0040] If every frame in a video sequence is independently encoded (I-frame), then the player (decoder) would have no difficulty to jump to an arbitrary frame and resume the decoding and play from there. In a video sequence with all frames as I-frames, every frame can serve as a starting point of a new video sequence in FF and REW functions. However, due to its low compression, very few systems, such as MJPEG, use this scheme.
[0041] In MPEG family, predicted frames (P-frame) and bi-directional frames (B-frame) are used to achieve higher compression. Since the P-frames and B-frames are encoded with the information from some other frames in the video sequence, they can not be used as the starting point of a new video sequence in FF and REW functions.
[0042] MPEG family supports the FF and REW functions by inserting I-frames at fixed intervals in a video sequence. Upon a FF or REW request, the player will locate to the nearest I-frame prior to the desired frame and resume the playing from there. The following figure shows a typical MPEG video sequence, where the interval between a pair of I-frames is 16 frames:
I BBBPBBBPBBBPBBB I BBBPBBBPBBBPBBB I...
However, I-frames usually have lower compression ratio than P and B frames. MPEG family provides a tradeoff between the compression performance and VCR functionality.
[0043] The new method, the DRFS, is realized by keeping two sequences for a given video archive on the media server. One sequence, called streaming sequence, provides the data for normal transmission purpose. Another sequence, the index sequence, provides the data for realizing FF and REW functions.
[0044] The streaming sequence starts with an I-frame, and contains I-frames only at places where scene changes occur. This is shown in FIG. 8 :
[0045] The index sequence contains search frames (S-frame) to support the FF and REW functions, as shown in FIG. 9 . The interval between a pair of S-frames can be variable, and is determined by the requirement of the accuracy of random search.
[0046] During the encoding process, the streaming sequence is coded as the primary sequence, and the index sequence is derived from the streaming sequence. An S-frame in the index sequence can be derived either from an I-frame or from a P-frame of the streaming sequence, but not from a B-frame. This is illustrated in FIG. 10 .
[0047] The process of deriving an S-frame from an I-frame is trivial as illustrated in FIG. 11 . The present invention simply copies the compressed I-frame data into the buffer of the S-frame.
[0048] The following diagram shows how an S-frame is derived from a P-frame. Firstly, the reconstructed form of this P-frame is needed, and it can be acquired from the feedback loop of the normal P-frame encoding routine. Secondly, an I-frame encoding routine is called to encode this same frame as an I-frame, and one must keep both its compressed form and its reconstructed form.
[0049] Then, the difference between the reconstructed P-frame and the reconstructed I-frame is calculated. This difference is encoded through a lossless process. The lossless-encoded difference, together with the compressed I-frame data, forms the complete set of data of the S-frame.
[0050] Similar to the encoding process, the decoder needs to derive an index sequence while decoding the streaming sequence. Same as the encoding process, an S-frame in the index sequence can be derived either from an I-frame or from a P-frame of the streaming sequence, but not from a B-frame. Notice that in theory, the decoder does not necessarily need to produce the S-frames at the same locations in the sequence as the encoding process.
[0051] FIG. 13 shows the derivation of an S-frame from I-frame in decoding while FIG. 14 illustrates the derivation of an S-frame from a P-frame.
[0052] Notice that the S-frame derived from an I-frame is saved in compressed form, whereas the S-frame derived from a P-frame is saved in reconstructed form. Since the reconstructed form requires much larger storage space than the compressed form does, this system uses two approaches to save the space required by P-frame derived S-frames: (1) use a lossless compression step to save the reconstructed S-frames, which can in average reduce the required space by 50%. (2) Produce a sparser index sequence than the encoding process.
[0053] In streaming process, the encoded streaming sequence stored on the media server is transmitted to the client player.
[0054] The client player decodes the received streaming sequence, and at the same time produces an index sequence and stores it in a local storage associated with the player.
[0055] FIG. 15 illustrates the method by which the FF and REW functions are achieved with the DRFS technology. Suppose the decoding process is currently at the place of ‘Current Frame’. Because this is a streaming application, the current frame is placed somewhere within the buffered data range. In general, this situation defines two searching zones for random frame access. The Valid REW Zone starts with the first frame and ends at the current frame, and the Valid FF zone is from the current frame to the front end of the buffered data range. In practice, the present invention defines a Dean Zone at the front end of the buffered data range for the sake of smooth play after the FF search operation.
[0056] When the client player receives a user request for FF operation, it first checks to see if the wanted frame is within the valid FF zone. If yes, the wanted frame number is sent to the media server. The server will locate the S-frame that is nearest to the wanted frame and send the data of this S-frame (compressed) to the client. Once this data is received, the player decodes this S-frame and plays it. The playing process will continue with the data in the buffer.
[0057] When a REW request is received by the player, it will first check the local index sequence to see if a ‘close-enough’ S-frame can be found. If yes the nearest S-frame will be used to resume the video sequence. If no, a request is issued to the server to download an S-frame that is nearest to the wanted frame.
[0058] In both FF and REW operations, the downloaded S-frame is stored in client's local storage after it is used to resume a new video sequence.
[0059] This random search technique is referred to as being ‘distributed’ because both the server and the client provide partial data for the index sequence. Given a specific FF or REW request, the wanted S-frame could be found either in the local index sequence or in the server's index sequence. At the end of the play process, the user will have a complete set of S-frames for later review purposes. Therefore, when the viewer watch the same video content for the second time, all FF and REW functions will be available locally.
[0060] A storyboard is a short—usually 2 or 3 minute—summary of a movie, which shows the important pictures of a feature length movie. People usually want to get a general idea of a movie before ordering. The SVOD system allows the viewers to preview the storyboard of a movie to decide whether to order it or not. Another advantage of the storyboard is to allow viewers to fast forward/backward by storyboard unit instead of frame by frame. Moreover, some indexing can be utilized based on the storyboard and intelligent retrieval of movies can be realized.
[0061] The generation of a storyboard involves three steps. First of all, some scene change techniques are applied to segment a long movie into shorter video clips. After that, key frames are chosen from each video clip based on some low or medium level information, such as color, texture, or important objects in the scene. Later on, some higher-level semantic analysis can be applied to the segmented clips to group them into meaningful story units. When a customer wants to get a general idea of a certain movie, he can quickly browse the story units and if he is interested, he can dig into details by looking at key frames and each video clips.
[0062] Scalability is a very desirable option in streaming video application. The current streaming systems allow temporal scalability by dropping frames, and cut the wavelet bit-stream at a certain point to achieve spatial scalability. The present invention offers another scalability mode, which is called SNR and spatial scalability. This kind of scalability is very suitable for streaming video, since the videos are coded in base layer and enhancement layers. The server can decide to send different layers to different clients. If a client requires high quality videos, the server will send base layer stream and enhancement layer streams. Otherwise, when a client only wants medium quality videos, the server will just send the base layer to it. The video player is also able to decode scalable bit-stream according to the network traffic. Normally, the video player should display the video stream that the client asks for. However, when the network is really busy and the transmission speed is very slow, the client should notify the upstream server to only send the base layer bit-stream to relieve the network load.
[0063] After processing of the movie clips, scene change information and key frames are available, which can be used to popularize the movie database. Keywords, as well as visual content of key frames, can be used as indices to search for the movies of interest. Keywords can be assigned to movie clips by computer processing with human interaction. For example, the movies can be categorized into comedy, horror, scientific, history, music movies, and so on. The visual content of key frames, such as color, texture, and objects, should be extracted by automatic computer processing. Color and texture are relatively easy to deal with and the difficult task is how to extract objects from the natural scene. At present, the population process can be automatic or semi-automatic, where human operator may interfere.
[0064] After popularization, another embodiment of the present invention may allow customers to search for the movies they would like to watch. For example, they can specify the kind of movies, such as comedy, horror, or scientific movies. They can also choose to see a movie with certain characters they like, and so on. Basically, the intelligent retrieval capability allows them to find the movies they like in a much shorter time, which is very important for the customers.
[0065] Multicasting is an important feature of streaming video. It allows multiple users to share the limited network bandwidth. There are some scenarios that multicasting can be used with another embodiment of the present invention. The first case is a broadcasting program, where the same content is sent out at the same time to multiple customers. The second case is a pre-chosen program, where multiple customers may choose to watch the same program around the same time. The third case is when multiple customers order movies on demand, some of them happen to order the same movie around the same time. The last case may not happen frequently and another embodiment of the present invention shall focus on the first cases for the multicasting utilization. Basically, multicasting allows us to send one copy of encoded movie to a group of customers instead of sending one copy to each of them. It can greatly increase the server capability and make full use of network bandwidth.
[0066] Due to the combination of the present invention's DRFS technology and proprietary video compression performance, very high compression ratio can be achieved for high-quality content delivery. The following table gives an estimation of compression performance. (The estimation is based on frame size of 320×240 at 30 frames/sec.)
100-min DVD quality VCD quality DAC quality Movie (20:1) (40:1) (80:1) (Raw Down- Down- Down- Data Data load Data load Data load Size) Size Time Size Time Size Time 19775 M 989 M 3956 Sec 495 M 1980 Sec 248 M 992 Sec Note: 2 Mbps channel bandwith is assumed.
[0067]
TABLE 1
System Specifications
Bandwidth
Server
Presentation
Server
Transfer Control
Transfer
(Client)
Capability
Delay
Network
Protocol
Protocol
1.5 Mbps
1.5 Gbps
6 Minutes
Fiber/ATM
RTSP
RTP
Fast
Pause/
Intelligent
High quality,
Forward/
Stop/
Movie
smooth
Backward
Play
Storyboard
Scalability
Retrieval
playback
Multicasting
Yes
Yes
Yes
Yes
Yes
Yes
Yes
[0068]
TABLE 2
100-min
DVD quality
VCD quality
DAC quality
Movie
(20:1)
(40:1)
(80:1)
(Raw
Down-
Down-
Down-
Data
Data
load
Data
load
Data
load
Size)
Size
Time
Size
Time
Size
Time
19775 M
989 M
3956 Sec
495 M
1980 Sec
248 M
992 Sec
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The present invention discloses a method and system for the provision of enhanced features in streamed video on demand (SVOD) over a network.
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BACKGROUND OF THE INVENTION
This application relates to the art of driving a nail, or other comparable fastener, into a piece of material. It has particular application to the art of driving roofing nails, or the like, for securing insulation to a roof deck.
It has been customary in applying insulation to a roof deck to manually hammer the roofing nails through the insulation and deck. This is a fairly time consuming operation. There has been a need in the roofing art for a nail applicator which reduces the amount of manual labor involved in the application of the roofing nails, and yet which is safe, easy to operate, and which is capable of effectively driving roofing nails through insulation and roof deck.
SUMMARY OF THE PRESENT INVENTION
According to the preferred embodiment of the present invention, there is provided a roofing nail applicator which is safe, easy to manipulate, which minimizes the expenditure of energy, and which is capable of effectively driving roofing nails through insulation and into a roof deck.
Moreover, the principles of the present invention may be readily applied for driving fasteners into various types of materials in addition to roof insulation and decks.
Briefly, the present invention provides a weight which is designed to apply the driving force to a nail or fastener by means of a gravity drop of the weight over a predetermined distance. Means are provided for supporting the weight a predetermined vertical distance above an area through which the nail or fastener is to be driven and for releasing the weight to enable it to drop from that first position almost exclusively under the unfluence of gravity.
The preferred embodiment further provides a weight supporting mechanism which is also designed to brake the downward dropping of weight if it drops further than said predetermined distance, and thereby provides an important safety feature when employed in the roofing nail application art.
Accordingly, the primary object of the present invention is to provide a nail or fastener applicator which is safe, easy to operate and maneuver, and which basically functions under and principle of providing a driving force to a nail or fastener by means of the fall of a weight under the influence of gravity.
Other objects and advantages of this invention will become further apparent from the following detailed description and the accompanying drawings wherein:
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a roofing nail applicator according to the present invention, with portions cut away;
FIG. 2 is a view taken from the direction 2--2 of FIG. 1;
FIG. 3 is a perspective view of a roofing nail with which the preferred embodiment of the present invention is used;
FIG. 4 is an enlarged view, with portions broken away of the area marked 4 in FIG. 1;
FIG. 5 is a sectional view of the area labeled 5--5 in FIG. 1;
FIG. 6 is an enlarged sectional view on lines 6--6 of FIG. 1;
FIG. 7 is a schematic illustration of the pneumatic circuitry for practicing the preferred embodiment of the present invention; and
FIG. 8 is an enlarged perspective view of the mechanism for inserting a nail into engagement with the weight.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As set forth above, the preferred embodiment of the present invention relates to an apparatus for driving roofing nails through insulation and roof decking. It is believed that from the description which follows, the manner in which the principles of the present invention may be applied for driving nails or comparable fasteners into numerous types of materials will be readily apparent to those of ordinary skill in the art.
Referring to the drawings, in FIG. 1, a substantially horizontal roof deck 10 has a layer of insulation 12 placed thereover. The nails which are used to secure the insulation to the deck 10 are shown in FIG. 3 and comprise bent metallic sheets 14 having a plurality of tabs 16 bent to form teeth for retaining the nail against dislodgment from the roof deck. Each nail protrudes through a circular washer 20 which is disposed adjacent the head 22 of the nail. The washer may be preformed with a rectangular slot and the nail inserted therethrough manually, or mechanical means may be provided for piercing a washer with a nail for combining the two.
The nail applicator 24 includes a frame or carriage 26 which is designed to traverse the roof under the hand guidance of an operator. The carriage 26 includes a base plate 27 having a pair of spaced front wheels 28 mounted thereto, and a single rear caster 29 which is mounted to swivel relative to the base plate 27 to help steer the carriage. A pair of frame members 30, 32 extend upwardly from the base plate 27, and include a plurality of recesses 34 at the upper ends thereof. The recesses adjustably support a pair of brackets 36 and a cross-bar 38 is supported between the upper ends of the brackets. The crossbar 38 provides a gripping member for an operator desiring to move the carriage 26 in any desired direction over a roof deck. The adjustability of the brackets enables the crossbar height to be adjusted to accommodate operators of varying heights.
Thus, from the foregoing description, it should be clear that the present invention basically contemplates a carriage which is designed so that an operator can conveniently maneuver the carriage over a roof deck or other surface upon which nails or fasteners are to be applied.
The leading ends of the carriage include a pair of spaced metal cylinders 40. Each cylinder 40 acts as a guide for a weight 42 which is contained within the cylinders and which is designed to be released for gravity fall therein while guided basically by the confines of the cylinder.
Each weight 42 comprises one or more sections 44 which are detachable from one another for varying the magnitude of the weight 42. The upper portion of each weight 42 has detachably mounted thereto the end portion of a chain 46 which is entrained over a sprocket 48 (see FIG. 4) and which is detachably connected at its other end (such as through a conventional threaded block B) to the reciprocable piston 65 (FIG. 7) of an air cylinder 50. As shown in FIG. 4, the sprocket shaft 49 is removably supported by clamp 59 and spring 61.
Referring to FIGS. 1, 2, and 7, the reciprocable piston of the air cylinder 50 is supported in a first position by air pressure which is directed to the cylinder from compressor 51. Compressor 51 is driven by engine 53, and communicates with the cylinder 50 through spool valve 80. The spool valve includes an axially movable spool which is spring biased to a first position at which it communicates high pressure fluid to the upper chamber of the air cylinder 50 and exhausts the air from the lower chamber of the air cylinder, to support the piston 65 in its first position and thereby support the weight in a raised position.
In order to permit the weight to drop from its raised position the air cylinder is "fired," i.e. the piston 65 is rapidly driven upwardly to create an almost instantaneous slack in the chain 46. In the preferred embodiment each cylinder is fired by actuating a respective lever operated air valve 56 supported by the carriage 24. Actuation of a lever operated air valve 56 directs a pulse of air to its respective spool valve, which overcomes the bias of the spring and drives the spool to a second position. In the second position the spool valve ports high pressure fluid to the lower chamber of the air cylinder and begins to exhaust fluid from the upper chamber of the cylinder. A quick exhaust valve 57 is designed to open as the upper chamber begins to exhaust, and to immediately exhaust the upper chamber of the cylinder to atmosphere. This results in a rapid movement of the piston 65 in an upward direction to create slack in the chain. When the lever operated air valve 56 is released, the spool valve is permitted to return, under its spring bias, to its first position to slowly raise the weight to its raised position. The return velocity of the weight is controlled by a conventional flow control valve 67.
The aforementioned elements (i.e. air cylinder, spool valve, quick exhaust valve, flow control valve, compressor and engine) for controlling the movement of the weight as set forth above can all be conventional. In the preferred embodiment the following elements have provided satisfactory results: a 3 h.p., single cylinder engine with horizontal crankshaft, made by Briggs & Stratton, Milwaukee, Wisc.; a compressor of the opposed twin piston type, model PCD-10, made by Gast Manufacturing Corp., Denton Harbor, Michigan; model 5340-07 spool valves by Aro Corp., Bryan, Ohio; Aro model 5040-01 lever operated air valves; Aro model EV-375, quick exhaust valves; Aro F-25b flow control valves and air cylinder of any type qualified to style MS1 under the National Fluid Power Association. Other forms of these elements are contemplated, but should require no further explanation to those of ordinary skill in the art.
In the preferred embodiment of this invention a combined nail and washer are attached to the weight before the air cylinder is fired, so that the dropping of the weight serves to drive the nail through the insulation 12 and into the roof deck 10. The nail and washer may be preassembled by manual or mechanical means and may be, therefore, accessible to an operator in a precombined state. Alternatively, as shown in FIG. 6, it is contemplated that the upper portion of the carriage may be provided with a mechanism for combining the nail and washer. One or more reciprocating plungers are reciprocable in a respective cylinder 52 supported by the members 33 each carrying a magnet 63 at its lower end for engaging the head of a nail. Vertically aligned therebelow for supporting a circular washer 20 is a circular member 54 having a central cavity. The plunger is reciprocated to drive the nail through the washer to combine the two. The movement of each plunger is operator controlled by a suitable valving arrangement actuated by a respective handle 55 on the upper portion of the carriage. The same valve also operates the insertion prongs 66. It is contemplated that the number of such mechanism carried by the carriage correspond to the number of weight means.
Once a nail and washer have been assembled, they are placed along a downwardly sloping track 58 which is comprised of a pair of cylindrical bars 60, and which serves to guide the nail under the influence of gravity into position at an inserting station 62. There is a track 58 associated with each of the cylinders.
At the inserting station, a washer rests on a reciprocating inserting member 64 (see FIGS. 1, 2 and 5). The member pg,10 64 appears in top view (FIG. 5) as a fork-shaped member for supporting the washer with the nail extending downwardly between a pair of prongs 66. The inserting member 64 is designed for reciprocating motion under the control of an air cylinder 68 which is also controlled by the handle 55 through conventional valving. Separate handles and controls are associated with each inserting member. In addition to the positions shown, it is contemplated that for operator convenience, the handles may be disposed in other locations relative to bar 38. Where the nail is to be punched by the mechanism shown in FIG. 6, the valving is such that in the preferred mode of control, as one nail is driven through a washer, a nail and washer positioned at the inserting station is inserted into the metallic cylinder 40.
When an inserting member is driven towards its respective cylinder it passes through appropriate slots in the cylinder. The nail and washer are thereby carried into the cylinder, and the nail head and the washer are attached to the weight by means of a permanent magnet 72 secured to the weight.
In the preferred embodiment, the magnet 72 is insulated (by means of insulation 73) from the remainder of the weight and a stainless steel non-magnetic plate 74 is secured over the magnet. The stainless steel plate 74 further includes a recess in its lower surface. When the nail and washer are inserted into the metallic cylinder the magnet 72 serves to attract the nail and washer and hold the same fast to the underside of the weight. The recess in the stainless steel plate receives the head of the nail to avoid the nonsymmetrical portion of the head from misaligning the nail as it is driven through the insulation and roof deck.
After the nail and washer have been attached to the weight, and with the carriage positioned so that cylinders have been suitably aligned with the areas through which the nail is to be driven, each weight 42 is released and permitted to fall solely under the influence of gravity for driving the nail through the insulation and the deck. As set forth above, this is accomplished by positively firing the air cylinder 50 which is attached to the sprocket chain 46 to rapidly move the piston 65 of the air cylinder to the second position.
Upon the firing of the air cylinder 50 there is virtually an instantaneous slack provided in the sprocket chain 46. This permits the weight 42 to fall from a raised preset distance solely under the influence of gravity. As the weight falls it drives the nail through the insulation and roof deck. The weight is then raised to its initial position and the nail teeth, which securely engage the deck, release the nail and washer from the weight. As set forth above, the spool-type valve 80 is effective, after the weight has driven the nail through the roof deck, to slowly drive the piston 65 of the air cylinder to its first position to raise the weight into its initial position for subsequent application of another roofing nail. Since the firing of the air cylinder is at a very high speed, there is the danger that in such firing the slack in the chain could release it from its sprocket wheel, a guard 82 is provided suitably close to the sprocket wheel in order to block any tendency of the chain to disengage from the wheel.
Since the chain 46 is always attached to the weight and to the air cylinder 50, even while the weight is dropping, the chain serves to brake the fall of the weight by limiting the downward travel of the weight, which could otherwise fall completely through the insulation of a steel deck. An additional feature resides in the annular guard 84 (FIG. 5) provided on the metallic cylinder. This guard is spaced just vertically below the lowermost portion of the slot through which the inserting element 64 moves. This prevents undue damage to the machine in the unlikely event that the inserting mechanism and the weight release mechanism are inadvertently simultaneously triggered.
The disclosed embodiment contemplates a weight of 50 pounds designed to drop approximately 11 inches for driving 21/4 inch to 31/4 inch roofing nails through 1-2 inch insulation. It will be readily obvious to those of ordinary skill in the art how the present invention can be modified for numerous sizes of nails and numerous insulation thicknesses.
While the preferred embodiment discloses a pair of spaced cylinders, it is contemplated that more or less numbers of cylinders (and associated controls and tracks) may be employed, if desired. It is also contemplated that while the air supply and air pressurizing mechanism are preferably mounted on the carriage, the present invention can be operated off of any comparable source of pressurized air.
In operation, the carriage is manipulated by an operator in order to align one or both of the weight guiding cylinders with a desired spot (or spots) at which a nail is to be driven into the roof insulation and roof deck. If a nail has already been magnetically attached to the weight the operator simply actuates the appropriate lever 56 to fire the air cylinder 61 to drive the nail into the desired portion of the roof deck. After driving the roofing nail into the roof deck the weight is then returned to a raised position to await insertion of a subsequent nail. Either during movement, or with the apparatus at rest, an operator can place a nail into position to be connected to magnet 63, and the operator can then actuate lever 55 which both reciprocates magnet 63 to drive the nail into engagement with its appropriate washer, and also to reciprocate prongs 66 to insert any nail which is resting thereon into engagement with the weight. The apparatus is then in a condition to drive the inserted nail into any desired location on the roof deck.
With the foregoing description in mind, numerous applications and advantages of this invention, using the concepts of the present invention, will become readily apparent to those of ordinary skill in the art.
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An apparatus for driving roofing nails into a roof deck or the like. A carriage is movable with respect to the surface of a roof deck, and carries one or more weights for movement therewith. Means are provided for raising a weight to a raised position a predetermined distance above the roof deck and for aligning a roofing nail below said weight with the head of said nail facing said weight. Control means are provided for releasing said weight means to enable said weight means to accelerate under the influence of gravity for imparting a force to said nail in a direction tending to drive said nail into said roof deck.
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This application is a 371 of PCT/EP2014/066016 filed 25 Jul. 2014
BACKGROUND OF THE INVENTION
Field of the Invention
The invention pertains to a fabric for use in a machine for producing a fiber web such as a paper, board or tissue web, and also to a method for producing such a fabric.
Fabrics can be found in a large number of forms in a papermaking machine. Depending on the position, different tasks are assigned to the fabrics which, in addition to supporting and guiding the paper web, are used in particular for dewatering. The water present in the paper web in a decreasing amount as said web passes progressively through the machine must be carried away in a suitable form without the paper web being damaged in the process or suffering marking as a result of mechanical or hydraulic processes during the dewatering.
In particular in the press section, gentle dewatering is of central importance, since here the switches for the smoothing of the paper web are already set. After the initial dewatering in the forming section, the paper web is not yet dry enough to run through the machine in free draws, instead is usually guided and pressed on at least one felt or between two felts, depending on configuration.
Accordingly, the requirements on corresponding press felts in relation to the quality of the surface, the water absorption and re-discharge capacity, the tendency to re-wetting and the permeability to air and water are very high.
Press felts nowadays normally have a load-absorbing base structure, optionally one or more additional layers to reinforce or to improve the aforementioned properties and one or more layers of staple fibers. The latter constitute a bottleneck in the production, since the staple fiber layers can firstly be numerous and secondly pass through a multistage and partially operationally intensive production process before they are connected to the base structure. This connection is made via needling, in which a needle matrix acts on the staple fiber layer resting on the base structure and forces the individual fibers into the base structure and draws said fibers through the same and, as a result, permits a firm connection between base structure and staple fiber layers.
Current machines for producing paper or board often have a large working width, which can be up to 12 m. It is therefore obvious that the fabrics must have just such a width. The production of the fabrics in these dimensions becomes ever more complicated and expensive, however. In addition to the width of the weaving machines, the width of the needling machines and thus the high investment costs are a factor limiting the production.
It is thus in the interests of the paper machine operator and the fabric industry to look for solutions to producing fabrics in a simpler and more economical way and nevertheless in any desired dimension.
Various approaches thereto have already been developed a long time ago.
For example, from DE102011007291 A1 and DE 102008000915 A1 it is known to apply a reinforcing layer made of a knitted fabric or another nonwoven flat textile onto a base structure, transversely with respect to the machine direction, and to add the individual parts to one another until the full length of the base structure is covered. However, the latter is formed in a familiar manner in the full length and width of the fabric.
The disadvantage here is in particular the fact that the reinforcing layer cannot be used on its own, since it does not offer sufficient stability, but only in conjunction with the base structure. In addition, the yarns are not crimped or curled, so that separation of the structure during the use of the fabric is to be feared.
EP 1209283 B1 discloses a fabric which, as seen in the transverse direction, has a plurality of partial webs extending parallel to one another in the longitudinal direction and arranged beside one another, the side edges of which are connected via connecting means. Adjacent side edges have a meandering course with alternating protrusions and recesses. The partial webs are meshed with one another via the protrusions and recesses.
The disadvantage with this prior art is to be seen in particular in the length of the connecting regions which, on account of the spiral winding of the partial webs, extend over a multiple of the length of the paper machine fabric. The production of such a felt is extremely complicated both in relation to the time factor and in relation to handling. In addition, when seam regions extend in the machine longitudinal direction, there is always the danger that these will lengthen to different extents when absorbing load and the felt will thus be damaged, which can result in an increased tendency to marking and in malfunctions as far as felt breakages with danger to the operating personnel and damage to following machine parts.
Furthermore, U.S. Pat. No. 4,842,905 discloses a paper machine fabric which is produced from individual panels, which have protrusions and recesses in the manner of a puzzle and can be connected together. Here, the panels can be extruded, punched out, laminated or produced in similar suitable methods.
The disadvantage with this prior art is the complex production, which requires many steps. Furthermore, the durability of the connections is questionable if only a small projection is available on a long edge. Multiple projections are once more associated with increased outlay on production of the individual panels. In general, it is difficult to produce a seam which is marking-free and operates with adequate stability. The structure of the aforementioned fabrics has seams or connections in multiple directions—machine direction and machine transverse direction—which increases the tendency to marking still further. The crossing points of the seams constitute particular weak points, both in relation to the stability and in relation to the tendency to marking.
U.S. Pat. No. 5,879,777 reveals a paper machine fabric which is produced from modular panels which are connected to one another by a touch and close strip or the like. Here, the individual panels are arranged to overlap in at least two layers and are connected both within the layer and also with the layer lying underneath by the aforementioned touch and close strips.
The stability of the paper machine fabrics thus produced, their suitability in particular in relation to the tendency to marking and the practicability in production may be doubted.
BRIEF SUMMARY OF THE INVENTION
It is thus an object of the invention to specify a fabric which avoids the aforementioned disadvantages of the prior art and which can be produced firstly in a simple and economical way and secondly with reliable high quality.
With regard to the fabric, the object is achieved by the characterizing features as claimed and, with regard to the method, by the characterizing features as claimed, in each case in combination with the generic features.
The fabric according to the invention, which in particular can be embodied as a press felt for use in a press section of a machine for producing a fiber web such as a paper, board or tissue web, has the following features: the fabric consists of multiple strips which are arranged beside one another and extend substantially parallel to one another in a machine direction; the strips together form a width of the fabric in the machine transverse direction; each strip is formed as a double-layer sheet material; strips each arranged beside one another in pairs are connected to one another by means of a connecting strip; a part of the width of each of the connecting strips extends in a machine transverse direction into the two adjacent strips; the strips are connected to the connecting strips.
The method according to the invention for producing the fabric has the following steps: i) producing a double-layer strip; ii) laying a single-layer or multilayer connecting strip in or on the double-layer strip over a sub region of the width of the connecting strip; iii) covering the strip with at least one staple fiber layer; and iv) needling the at least one staple fiber layer with the strip and the partial width of the connecting strip extending in the strip; v) repeating steps i) to iv) as far as the overall width of the fabric as seen in the machine transverse direction.
By means of the measures according to the invention, it is possible to ensure that the fabric can be produced stably and nevertheless particularly simply, since it is produced modularly, so that it is possible to dispense with equipment of full fabric width. This manifests itself primarily in the area of the needling machines which, with increasing fabric width, are both considerably more expensive to procure and also operate in a manner that requires intensive maintenance and is time-consuming.
Further advantageous aspects and developments of the invention emerge from the sub claims.
According to an advantageous aspect of the invention, provision can be made for the part of its width in the machine transverse direction by which each of the connecting strips extends into the two adjacent strips to be at least 5%, preferably at least 25%, particularly preferably 50%. As a result, a reliable connection can be achieved between the strips and the connecting strips.
The sheet material for strips and connecting strips can be chosen from: woven fabrics, laid fabrics, knitted fabrics, crocheted fabrics, spiral structure, tapes, films. By means of a suitable choice, the properties of the fabric can be modified and thus optimized to the respective running position and type of machine.
Advantageously, the sheet materials can have a width of 30 to 600 cm in a machine transverse direction. The maximum value results from about half of the width of modern fabrics, so that the needling sections accordingly have to have at most half the width of the fabric or less.
Advantageously, end edges of the double-layer sheet materials can be connected to one another to make the same endless, forming a tube-like material.
Preferably, the end edges can be connected by ultrasonic welding, laser welding, high-frequency welding, thermal welding, in particular by using a monofilament, adhesive bonding, in particular by using hot melt adhesives, filling with a resin or needling.
According to preferred design variants, the connecting strips can either be inserted between the layers of the double-layer strips or positioned on or under the layers of the double-layer strips.
According to one advantageous embodiment, the connecting strips can have the same width as the strips, as seen in the machine transverse direction. This results in a simple structure and the ability to position the connecting strips simply, which merely have to be laid so as to overlap the strips by approximately 50% and edge to edge with one another.
According to an advantageous embodiment that is an alternative hereto, the connecting strips can have a different width than the strips, as seen in the machine transverse direction. The connecting strips can be wider or narrower.
Auxiliary strips can preferably be provided if the extension of the connecting strips into the strips is less than 50%, said auxiliary strips being dimensioned such that a layer formed from the auxiliary strips and the connecting strips is formed without gaps in the machine transverse direction.
Advantageously, at least one layer of staple fibers can be arranged on one or both sides of the strips or between the layers of the strips.
Also preferably, it is possible to provide multiple staple fiber layers which have the same or different weights per unit area and/or the same or different fiber thicknesses.
According to one aspect of the invention, multiple strips can also be provided with at least one common staple fiber layer.
The at least one layer of staple fibers can usually be needled with the strips.
According to a further advantageous aspect of the invention, one or more functional layers can be arranged on the strips and/or on the connecting strips and/or between the layers of the strips and/or on the at least one staple fiber layer and/or between staple fiber layers and/or on the uppermost staple fiber layer as a covering layer.
The one or more functional layers can preferably be chosen from: films, foils, woven fabrics, laid fabrics, crocheted fabrics, knitted fabrics, nonwovens, impregnations.
The method according to the invention can advantageously provide for method step i) to have the following partial steps: i.i) providing a sheet material; i.ii) cutting a section of the sheet material to length to approximately four times the length of the fabric ( 1 ) to be produced; i.iii) connecting end edges of the section to produce an endless tube-like material; i.iv) laying the section on itself to produce a double-layer strip; i.v) positioning the connecting point of the end edges at a distance from the ends of the strip.
According to a further preferred aspect of the invention, method step ii) can have the following partial steps: ii.i) cutting a section of the sheet material to length to at least approximately twice the length of the fabric to be produced in order to produce a connecting strip; ii.ii) laying the total length of the connecting strip in or on the strip in a sub region of the width of the strip, the sub region being at least 5%, preferably at least 25%, particularly preferably 50%.
Particularly preferably, also provided as a further partial step of method step ii) can be laying auxiliary strips in or on if the extension of the connecting strips into the strips is less than 50%, which auxiliary strips are dimensioned such that a layer formed from the auxiliary strips and the connecting strips has no gaps in the machine transverse direction.
Preferably, step v) can be followed by a further step vi) for making the fabric endless, which step comprises the following partial steps: vi.i) forming terminal seam loops at both ends of the strips, which are formed in one piece with the strips or are connected detachably or non-detachably thereto; vi.ii) laying the seam loops of the ends in one another; vi.iii) connecting the seam loops by means of a push-in wire.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The invention will be described in more detail below with reference to the drawings, without restricting generality, by using preferred exemplary embodiments. In the figures:
FIG. 1 shows a plan view of a fabric according to the invention,
FIG. 2 shows a highly schematic lateral illustration of the fabric according to FIG. 1 , and
FIG. 3 shows a schematic lateral illustration of the fabric according to FIG. 2 with the viewing direction rotated through 90°.
DESCRIPTION OF THE INVENTION
It should be pointed out that the invention is not restricted to the embodiments of the examples described but is determined by the scope of the appended patent claims. In particular, the individual features in embodiments according to the invention can be implemented in a different number and combination than in the examples listed below. In the figures, the same or similar designations are used for functionally equivalent or similar characteristics, irrespective of specific embodiments.
FIG. 1 shows a fabric 1 in a schematic illustration. The fabric 1 can in particular be embodied as a press felt but also other fabric types such as forming and drying fabrics, and transport belts produced by means of the addition of polymer components can be imagined embodied in the manner of the invention.
Here, the fabric 1 comprises a plurality of substantially parallel strips 2 . 1 , 2 . 2 . . . 2 . n , which overall form the total width of the fabric 1 . Here, the strips 2 . 1 , 2 . 2 . . . 2 . n are produced in the way described below. First of all, a sheet material is produced which, for example, can be produced in a known way as a flat fabric made of mutually crossing warp and weft threads in any desired weaving patterns. Alternatively, it is also possible to use spiral structures which have a number of plastic spirals which are laid down so as to interengage and are connected to one another by push-in wires. In addition, prefabricated tapes, laid fabrics, knitted fabrics, crocheted fabrics can be used, as can flat structures in the form of films. The sheet material can preferably have a width between 30 cm and 600 cm.
Following the production of the sheet material in any desired length, which is possible quickly and economically on familiar weaving machines, a piece is severed therefrom which corresponds approximately to four times the length of the subsequent fabric 1 as seen in a machine direction MD plus an addition for overlaps. The severed piece is folded and laid on itself, so that a material is produced which has double layers and is half the length of the severed piece. As a result, a first double-layer strip 2 . 1 has been produced. End edges are connected to form an endless tube-like material by fraying out some terminal yarns oriented in the machine transverse direction CD and subsequently interlacing and connecting the yarn ends oriented in the machine direction. Here, the connection can preferably be made by means of ultrasonic welding, laser welding, adhesive bonding, sewing or similar suitable methods. The connecting point between the end edges is not terminal, however, but is preferably arranged in approximately one third of the length of the strip 2 . 1 .
The first of the double-layer strips 2 . 1 produced in this way is combined in a next step with a first connecting strip 3 . 1 , having one layer in the exemplary embodiment, by the latter being laid between the layers of the double-layer strip 2 . 1 . The first one-layer connecting strip 3 . 1 is likewise severed from the endless sheet material and has substantially the same length as the double-layer strip 2 . 1 , that is to say twice the length of the fabric 1 to be produced. The positioning is carried out in such a way that the one-layer connecting strip 3 . 1 , as seen in the machine transverse direction, is pushed in approximately as far as the center of the two-layer strip 2 . 1 . The second half of the one-layer connecting strip 3 . 1 thus initially remains visible.
The thus combined semi-finished product comprising a double-layer strip 2 . 1 and a connecting strip 3 . 1 laid halfway in the latter is covered with at least one layer of staple fiber layers and, by using a needling machine, which advantageously has to have only the width of the double-layer strip 2 . 1 , with which the at least one staple fiber layer is needled. In a known way, multiple staple fiber layers can be applied to one or both sides of the strip 2 . 1 . The staple fiber layers can have different weights per unit area and fiber thicknesses. Furthermore, it is possible to introduce additional functional layers in the form of foils, membranes, films or else impregnations on the strip 2 . 1 or between the staple fiber layers. It is possible for further method steps of fusing the functional layers on, injecting and subsequently fusing particles on, etc, to be carried out. The number and type of these steps depends on the desired range of properties and on the position of use of the fabric 1 . Since these steps are known per se, it is possible to dispense with an extensive description at this point.
Following the needling, a further double-layer strip 2 . 2 , which has been produced in the above-described way, is positioned beside the first double-layer strip 2 . 1 and lying edge to edge with the latter, by the still visible part of the first connecting strip 3 . 1 being inserted into the newly arrived double-layer strip 2 . 2 . From the other side, a second one-layer connecting strip 3 . 2 is added, being positioned between the layers of the second double-layer strip 2 . 2 . After the material has been pushed into the needling machine in the machine transverse direction by the width of a strip 2 . 1 , 2 . 2 , . . . 2 . n , the needling step is repeated following the addition of the desired number of staple fiber and/or functional layers.
The steps described above are then repeated until the complete width of the fabric 1 , as seen in the machine transverse direction, is reached.
The strips 2 . 1 , 2 . 2 , . . . 2 . n each lie beside one another edge to edge, the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n lie in the interior of the strips 2 . 1 , 2 . 2 , . . . 2 . n , likewise edge to edge. The result is thus an overall three-layer structure formed without gaps. This is illustrated highly schematically in FIG. 2 in a section in the machine transverse direction.
It is also possible to see in FIG. 2 how marginal regions 4 can be formed. Here, either half the width of the marginal strips 2 . 1 and 2 . n can remain empty without the third layer made of the part of a connecting strip 3 . x being added, which is generally not a problem, since the marginal regions 4 always have somewhat of a protrusion with respect to a fiber web resting on the fabric 1 . Alternatively, as can be seen from FIG. 2 , half a connecting strip 3 . x can be inserted, then terminating flush with outer edges 5 of the first strip 2 . 1 and of the last strip 2 . n.
In FIG. 3 , the fabric 1 according to the invention is illustrated in the region of terminal seam loops 6 , likewise in a side view but in a viewing direction rotated through 90° with respect to FIG. 2 .
As already explained above, each of the strips 2 . 1 , 2 . 2 , . . . 2 . n has a length which corresponds substantially to twice the length of the subsequent fabric 1 . In order to make the fabric 1 endless, some of the yarns oriented in the machine transverse direction are removed at end edges 7 of the strips 2 . 1 , 2 . 2 , . . . 2 . n . In the case of a spiral structure, a spiral additionally provided for this purpose or a seaming element can be attached. Films must likewise be equipped with a seaming element.
As a result of the removal of the yarns, seam loops 6 are formed which, with seam loops 6 which are formed in the same way at the other end of the strips 2 . 1 , 2 . 2 , . . . 2 . n , can be connected to one another in the fiber web machine by the insertion of a push-in wire 8 , forming an endless fabric 1 .
In order to prevent a gap from occurring in the staple fiber layers in the region of the seam loops 6 , here a slight excess length of the staple fiber layers needled onto the strips 2 . 1 , 2 . 2 , . . . 2 . n can provide a remedy.
It should be noted that above, the exemplary embodiment illustrated in the figures was viewed in more detail at the point where the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n are formed in one layer, the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n are inserted between the layers of the strips 2 . 1 , 2 . 2 , . . . 2 . n , the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n have the same width as the strips 2 . 1 , 2 . 2 , . . . 2 . n and the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n are produced from the same type of sheet material as the strips 2 . 1 , 2 . 2 , . . . 2 . n.
Alternatively, the further exemplary embodiments described below can be provided.
The connecting strips 3 . 1 , 3 . 2 , . . . 3 . n can likewise be formed with multiple layers. If, for example, the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n are formed in an identical way to the strips 2 . 1 , 2 . 2 , . . . 2 . n , as described above, the result that follows, after combination of the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n with the strips 2 . 1 , 2 . 2 , . . . 2 . n , is an overall four-layer material.
It is likewise possible not to arrange the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n between the two layers of the strips 2 . 1 , 2 . 2 , . . . 2 . n but on or under the strips 2 . 1 , 2 . 2 , . . . 2 . n , and in each case such that a continuous surface is formed.
In a further conceivable embodiment, provision can be made for the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n to have a width which is lower than the width of the strips 2 . 1 , 2 . 2 , . . . 2 . n . As a result, the overlap between the strips 2 . 1 , 2 . 2 , . . . 2 . n and the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n is correspondingly lower than 50%. The gaps produced as a result could be closed by auxiliary strips, not illustrated further, the auxiliary strips being dimensioned such that a layer formed from the auxiliary strips and the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n is formed without gaps in the machine transverse direction CMD.
Alternatively, the width of the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n can also be greater than the width of the strips 2 . 1 , 2 . 2 , . . . 2 . n . A preferred embodiment here would provide a width of the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n which is an integer multiple of the width of the strips 2 . 1 , 2 . 2 , . . . 2 . n . As a result, it is possible to avoid butt joints without overlaps occurring.
Finally, it is further possible to make the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n from a different type of sheet material than the strips 2 . 1 , 2 . 2 , . . . 2 . n . For example, the strips 2 . 1 , 2 . 2 , . . . 2 . n can comprise a flat woven textile with longitudinal and transverse threads, as described above, and the connecting strips 3 . 1 , 3 . 2 , . . . 3 . n of a film or a crocheted fabric, for example.
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A fabric, in particular a press felt, is provided for use in a press section of a machine for producing a fiber web such as a paper, cardboard, or tissue web. The fabric is formed of multiple strips which are arranged adjacent one another and extend substantially parallel to one another in a machine direction. The strips together form a width of the fabric in the machine transverse direction. Each strip is designed as a double-layered sheet material. Strips arranged adjacently in respective pairs are connected by way of a connecting strip. A part of the width of each of the connecting strips extends in the machine transverse direction into the two adjacent strips. The strips are connected to the connecting strips.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/500,669 filed on Feb. 9, 2000, now U.S. Pat. No. ______.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to the stimulation of crude oil reservoirs to enhance production using a combination of pulsed power electrohydraulic and electromagnetic methods and the processing of the recovered crude oil into its components. In particular, the present invention provides a method and apparatus for recovery of crude oil from oil bearing soils and rock formations using pulsed power electrohydraulic and electromagnetic discharges in one or more wells that produce acoustic and coupled electromagnetic-acoustic vibrations that can cause oil flow to be enhanced and increase the estimated ultimate recovery from reservoirs.
BACKGROUND OF THE INVENTION
[0004] The stimulation of crude oil reservoirs to enhance oil production from known fields is a major area of interest for the petroleum industry. One of the single most important research goals in fossil fuels is to recover more of the hydrocarbons already found. At present, approximately 66% of discovered oil is left in the ground due to the lack of effective extraction technology for secondary and tertiary Enhanced Oil Recovery (EOR). A EOR technology that can be deployed easily and at low cost in onshore and offshore field locations would greatly improve the performance of many oil fields and would increase significantly the world's known recoverable oil reserves.
[0005] Methods that are widely used for the purpose rely on the injection of fluid at one well, called the injection well, and use of the injected fluid to flush the in situ hydrocarbons out of the formation to a producing well. In one mode of secondary recovery, a gas such as CO 2 that may be readily available and inexpensive, is used. In other modes, water or, in the case of heavy oil, steam may be used to increase the recovery of hydrocarbons. One common feature of such injection methods is that once the injected fluid attains a continuous phase between the injection well and the production well, efficiency of the recovery drops substantially and the injected fluid is unable to flush out any remaining hydrocarbons trapped within the pore spaces of the reservoir. Addition of surfactants has been used with some success, but at high cost, both economic and environmental.
[0006] Many methods have been developed that try address the problem of driving out the residual oil. They can be divided into a number of broad categories.
[0007] The first category uses electrical methods. For example, U.S. Pat. No. 2,799,641 issued to Bell discloses a method for enhancing oil flow through electrolytic means. The method uses direct current to stimulate an area around a well, and uses the well-documented effect known as electro-osmosis to enhance oil recovery. Another example of electro-osmosis is described in U.S. Pat. No. 4,466,484 issued to Kermabon wherein direct current only is used to stimulate a reservoir. U.S. Pat. No. 3,507,330 issued to Gill discloses a method for stimulating the near-wellbore volume using electricity passed upwards and downwards in the well using separate sets of electrodes. U.S. Pat. No. 3,874,450 issued to Kern teaches a method for dispersing an electric current in a subsurface formation by means of an electrolyte using a specific arrangement of electrodes. Whitting (U.S. Pat. No. 4,084,638) uses high-voltage pulsed currents in two wells, a producer and an injector, to stimulate an oil-bearing formation. It also describes equipment for achieving these electrical pulses.
[0008] A second category relies on the use of heating of the formation. U.S. Pat. No. 3,141,099 issued to Brandon teaches a device installed at the bottom of a well that causes resistive heating in the formation though dielectric or arc heating methods. This method is only effective within very close proximity to the well. Another example of the use of heating a petroleum bearing formation is disclosed in U.S. Pat. No. 3,920,072 to Kern.
[0009] A third category of methods relies on mechanical fracturing of the formation. An example is disclosed in U.S. Pat. No. 3,169,577 to Sarapuu wherein subsurface electrodes are used to cause electric impulses that induce flow between wells. The method is designed to create fissures or fractures in the near-wellbore volume that effectively increase the drainage area of the well, and also heat the hydrocarbons near the well so that oil viscosity is reduced and recovery is enhanced.
[0010] It has long been documented that acoustic waves can act on oil-bearing reservoirs to enhance oil production and total oil recovery. A fourth category of methods used for EOR rely on vibratory or sonic waves, possibly in conjunction with other methods. U.S. Pat. No. 3,378,075 to Bodine discloses a method for inducing sonic pumping in a well using a high-frequency sonic vibrator. Although the sonic energy generated by this method is absorbed rapidly in the near wellbore volume, it does have the effect of cleaning or sonicating the pores and fractures in the near-wellbore area and can reduce hydraulic friction in the oil flowing to the well. Another example of a vibratory only technique is disclosed by U.S. Pat. No. 4,049,053 to Fisher et al. wherein several low-frequency vibrators are installed in the well and are driven hydraulically using surface equipment. U.S. Pat. No. 4,437,518 issued to Williams describes the design for a piezoelectric vibrator that can be used to stimulate a petroleum reservoir. U.S. Pat. No. 4,471,838 issued to Bodine teaches a method for using surface vibrations to stimulate oil production. The surface source defined in this patent is not sufficient to produce significant enhanced recovery of crude oil.
[0011] Turning next to methods that use vibratory or sonic waves in conjunction with other methods, U.S. Pat. No. 3,754,598 to Holloway, Jr. discloses a method that utilizes at least one injector well and another production well. The method imposes oscillating pressure waves from the injector well on a fluid that is injected to enhance oil production from the producing well. U.S. Pat. No. 2,670,801 issued to Sherborne discloses the use of sonic or supersonic vibrations in conjunction with fluid injection methods: the efficiency of the injected fluids in extracting additional oil from the formation is improved by the use of the acoustic waves. U.S. Pat. No. 3,952,800, also to Bodine teaches a sonic treatment in which a gas is injected into the well and is used to treat the wellbore surface using sonic wave stimulation. The method causes the formation to be heated through the gas by heating from the ultrasonic vibrations. U.S. Pat. No. 4,884,634 issued to Ellingsen uses vibrations of an appropriate frequency at or near the natural frequency of the formation to cause the adhesive forces between the formation and the oil to break down. The method calls for a metallic liquid (mercury) to be placed in the wells to the level of the reservoir and the liquid is vibrated while also using electrodes placed in the wells to electrically stimulate the formation. Apart from the potential environmental hazards associated with the handling and containment of mercury, this method faces the problem of avoiding formation damage due to an excess of borehole pressure over the formation fluid pressure caused by the presence of a dense liquid. U.S. Pat. No. 5,282,508, also issued to Ellingsen et al. defines an acoustic and electrical method for reservoir stimulation that excites resonant modes in the formation using AC and/or DC currents along with sonic treatment. The method uses low frequency electrical stimulation.
[0012] The success of the existing art in stimulating reservoirs has been spotty at best, and the effective range of such methods has been limited to less than 1000 feet from the stimulation source. A good discussion on wettability, permeability, capillary forces and adhesive and cohesive forces in reservoirs is provided by the Ellingsen '508 patent. These discussions fairly represent the state of knowledge on these subjects and are not repeated herein. These discussions do not, however, address the limitations on the current state of the art in acoustic stimulation.
[0013] Existing acoustic stimulation methods have demonstrated clearly that they are limited to a range of about 1000 feet from the stimulation point. This limit is caused by the natural attenuation properties of the reservoir, which absorb high frequencies preferentially and reduce the effective frequency range to less than a few hundred Hertz at distances beyond about 1000 feet from the acoustic source. This same limit has plagued seismic imaging in cross-borehole studies for many years and is a fundamental physical limitation on all acoustic methods.
[0014] Effective acoustic stimulation of oil-bearing reservoirs requires support at greater distances from the stimulation source than possible with most of the prior art. In addition, there is some empirical evidence suggesting that higher frequencies than direct acoustic methods can generate may be more effective in stimulation of oil-bearing reservoirs. Accordingly, it is desirable to have a stimulation source that has a greater range of effectiveness than the prior art discussed above. Such a source should preferably be able to provide stimulation at higher frequencies than the 10-500 Hz typically attainable using prior art methods.
[0015] U.S. Pat. No. 4,345,650 issued to Wesley teaches a device for electrohydraulic recovery of crude oil using by means of an electrohydraulic spark discharge generated in the producing formation in a well. This method presents an elegant apparatus that can be placed in the producing interval and can produce a shock and acoustic wave with very desirable qualities. The present invention will build on the teachings of this patent and will extend the effective range of Wesley's method through new and novel equipment designs and field configurations of Wesley's apparatus and new apparatus designed to enhance the effect on oil reservoirs.
[0016] Hydrocarbons recovered from a wellbore may include a number of components. The term “crude oil” is used to refer to hydrocarbons in liquid form. The API gravity of crude oil can range from 6° to 50° API with a viscosity range of 5 to 90,000 cp under average conditions. Condensate is a hydroacarbon that may exist in the producing formation either as a liquid or as a condensable vapor. Liquefaction of the gaseous components occurs when the temperature of the recovered hydrocarbons is lowered to typical surface conditions. Recovered hydrocarbons also include free gas that occurs in the gaseous phase under reservoir conditions, solution gas that comes out of solution from the liquid phase when the temperature is lowered, or as condensable vapor. Recovered hydrocarbons also commonly include water that may be in either liquid form or vapor (steam). The liquid water may be free or emulsified: free water reaches the surface separated from liquid hydrocarbons whereas the emulsified water may be either water dispersed as an emulsion in liquid hydrocarbons or as liquid hydrocarbons dispersed as an emulsion in water. Produced well fluids may also include gaseous impurities including nitrogen, helium and other inert gases, CO 2 , SO 2 and H 2 S. Solids present in the recovered wellbore fluids may include sulphur. Heavy metals such as chromium, vanadium or manganese may also be present in the recovered fluids from a wellbore, either as solids or in solution as salts. In all enhanced EOR operations, it is desirable to separate these and other commercially important materials from the recovered fluids.
SUMMARY OF THE INVENTION
[0017] The present invention is a pulsed power device and a method of using the pulsed power device for EOR. Pulsed power is the rapid release of electrical energy that has been stored in capacitor banks. By varying the inductance of the discharge system, energies from 1 to 100,000 Kilojoules can be released over a pulse period from 1 to 100 microseconds. The rapid discharge results in a very high power output that can be harnessed in a variety of industrial, chemical, or medical applications. The energy release from the system can be used either in a direct plasma mode through a spark gap or exploding filament, or by discharging the energy through a single- or multiple-turn coil that generates a short-lived but extremely intense magnetic field.
[0018] When electricity stored in capacitors is released across a spark gap submerged in water, a plasma channel is created that vaporizes the surrounding water. This plasma ionizes the water and generates very high pressures and temperatures as it expands outward from the discharge point. In a plasma, or electrohydraulic (EH) mode, the pulse may be used in a wide range of processes including geophysical exploration, mining and quarrying, precision demolition, machining and metal forming, treatment and purification of a wide range of fluids, ice breaking, defensive weaponry, and enhanced oil recovery which is the purpose of the present invention. The basic physics of the shock wave that is generated by the EH discharge is well understood and is documented in U.S. Pat. No. 4,345,650 issued to Wesley, and incorporated herein by reference.
[0019] In the electromagnetic (EM) mode, the coil is designed to produce controlled flux compression that can be used to generate various physical effects without the coupled effect of the EH strong acoustic wave. In both systems, however, typical systems require about 0.5 to 1 seconds to accumulate energy from standard power sources. The ratio of accumulation time to discharge time (100,000 to 1,000,000) allows the generation of pulses with several gigawatts of peak power using standard power sources.
[0020] Given the physical limitations on direct acoustic stimulation caused by attenuation in natural materials, acoustic stimulation must be generated using wide band vibrations in these materials at distances much greater than the current limitation of about 1000 feet. The present invention addresses this issue in a new and innovative way using pulsed power as the source. The Wesley '650 patent teaches a method for generating strong acoustic vibrations for reservoir stimulation that has been shown in the field to have an effective limit of about 1000 feet. What was not recognized in the Wesley teachings was that the pulsed power method also has a unique ability to generate high-frequency acoustic stimulation of the reservoir separately from the direct acoustic response of the EH shock wave generated by the plasma discharge in the wellbore. In addition to the direct shock wave effect claimed in the Wesley patent, the pulsed power discharge also generates a strong electromagnetic pulse that travels at the speed of light across the reservoir. As this electromagnetic pulse transits the reservoir, it induces a coupled acoustic vibration at very high frequencies in geologic materials like quartz that causes stimulation at multiple scales in the reservoir body. This induced acoustic vibration acts for a short period of time after the pulse is discharged, usually on the order of about 0.1 to 0.3 seconds, but is induced everywhere that the electromagnetic pulse travels. Thus, it is not limited by the natural acoustic attenuation that limits the effectiveness of a direct acoustic pulse source because it is induced at all locations in-situ by the electromagnetic pulse. At the same time, the lower-frequency direct acoustic pulse travels through the reservoir at the velocity of sound. This direct acoustic pulse assists the electromagnetically-induced vibrations in stimulating the reservoir, but has a clearly limited range due to the finite speed that it can travel before the EM-induced vibrations decay and become ineffective.
[0021] Effective acoustic stimulation of oil-bearing reservoirs requires higher frequencies than direct acoustic methods can generate and support at great distances from the stimulation source. Every rock formation can be modeled as a uniform equivalent medium with imbedded inclusions. These inclusions can be present at the pore scale, grain scale, crack scale, lamina scale, bedding scale, sand body scale, and larger scales. Each of these inclusions, or features, of the formation act as scatterers that absorb acoustic energy. The frequency of the energy absorbed is directly correlated to the scale of the inclusions and the contrast in physical properties between the inclusion and the surrounding matrix, and this absorption provides the energy for enhanced oil recovery that is required at a specific scale of inclusion. Hence, an effective acoustic stimulation program can be designed to optimize the energy absorption and effective stimulation if the scale of the inclusions and their physical properties are known, and if the acoustic stimulation frequencies can be targeted at these inclusion scales over a large volume of the reservoir. The limitations and variations in the effectiveness of existing acoustic methods are directly correlated to the narrow band of seismic frequencies from 10-500 hertz used to stimulate and whether there are inclusions at those frequencies within the effective range of the stimulation method in question. When this physical understanding of the role of acoustic absorption by scale dependent features in reservoirs is included, it becomes readily apparent why existing acoustic methods with a frequency band limited to a few hundred hertz are not capable of stimulating most reservoirs effectively. The existing technology has demonstrated a spotty record because the narrow band of frequencies used are often not the right ones for stimulating the critical inclusions of a particular reservoir. The scale of the inclusions that are critical to effective stimulation exist at the Dore scale, grain scale, flat-crack scale, and fracture scale, all of which are activated by much higher frequencies (kilohertz and higher) than the band pass of the low-frequency direct acoustic wave.
[0022] The present invention differs from all of the prior art in several ways. First, it uses a coupled process of direct EH acoustic vibrations that propagate outward into the formation from one or more wells, and electromagnetically-induced high-frequency acoustic vibrations that are generated using both EH and EM pulsed power discharge devices that takes advantage of the acoustic coupling between the electromagnetic pulse and the formation. This is significantly different from the prior art which relies on acoustic vibrations only, or a combination of acoustic vibrations and low-frequency AC or DC electrical stimulation.
[0023] The present invention also recognizes that these two effects must occur together to effectively mobilize the oil and increase production of the oil. The problem that arises is that the EM-induced vibrations only occur for a short time after the electrohydraulic or electromagnetic pulse is initiated. The electrohydraulic acoustic pulse travels at a finite speed from the well where the pulse originates, so that the effective range of the technique is defined by how far the acoustic wave can travel before the electromagnetically-induced vibration in the reservoir ceases. Hence, a single pulse source has a range that is limited by the pulse characteristics employed.
[0024] In a preferred embodiment of the present invention, the technique can be applied using a multi-level discharge device that allows sequential firing of several sources in one well in a time sequence that is optimized to allow continuous electromagnetic-coupled stimulation of a large reservoir volume while the electrohydraulic acoustic pulse travels further from the pulse well than it could before a single source electromagnetic vibration would decay. This approach can be used to extend the effective range of the stimulation by a factor of 5-6 from about 1000 feet as claimed and proven in the Wesley patent, i.e., up to distances of 5000 to 6000 feet claimed in the present invention. This allows the technique to be applied effectively to a wide range of oil fields around the world. This concept can be extended to the placement of multiple tools in multiple wells to achieve better stimulation of a specific volume of the reservoir.
[0025] In another embodiment of the invention, the range of the technique is extended by using multiple pulse sources in multiple wells that allow the electromagnetically-induced vibrations to continue for a longer time, thus allowing the acoustic pulse to travel further into the formation, effectively extending the range of coupled stimulation that can be achieved. This embodiment utilizes a time-sequential discharge pattern that produces a series of electromagnetically-induced vibrations that will last up to several seconds while the direct acoustic pulse travels further from the discharge source to interact with the electromagnetically-induced vibrations at much greater distances in the reservoir.
[0026] In another embodiment of the present invention, multiple EH and EM sources can be placed in multiple wellbores and discharged to act as an array that will stimulate production of the oil in a given direction or specific volume of the reservoir.
[0027] In another aspect of the invention, the discharge characteristics of the pulse sources can be customized to produce specific frequencies that will achieve optimal stimulation by activating specific scales of inclusions in the reservoir. In this embodiment, the discharge devices can have their inductances modified to achieve a variety of pulse durations and peak frequencies that are tuned to the specific reservoir properties. This allows for the design of a multi-spectral stimulation program that can activate those inclusions that are critical to enhanced production, while preventing activation of those inclusions that might inhibit enhanced production. Once the desired inclusions for stimulation are defined by conventional geophysical logging methods, a reservoir model is constructed and the optimal frequencies for the stimulation are determined. The pulse tool can be adapted to a wide range of pulse durations and peak frequencies by adjusting the induction of the capacitor circuits in the pulse tool. Where multiple frequencies are desired to achieve stimulation at several scales, the multi-level tool in a single well or multiple tools placed in multiple wells can be tuned to the reservoir to optimize the desired stimulation effect and produce a multi-spectral stimulation of the reservoir.
[0028] The present invention also differs from the previous art in that it includes the use of EM pulse sources that do not generate a direct acoustic shock pulse like the plasma shock effect caused by the spark gap in the electrohydraulic device defined by Wesley. These pulse sources replace the conventional spark gap discharge device defined by Wesley with a single-turn magnetic coil that produces a magnetic pulse with no acoustic pulse effect. This tool can be placed in more sensitive wells that will not tolerate the strong shock effect of an EH pulse generator. They also allow a wider range of discharge pulse durations that will extend the effective frequency range of induced vibrations that can be applied to a given reservoir.
[0029] In another embodiment of the present invention, the EH pulse source can be directed using a range of directional focusing and shaping devices that will cause the acoustic pulse to travel only in specific directions. This reflector cone allows the operator to aim the pulses from one or multiple wells so that they can effect the specific portion of the formation where stimulation is desired.
[0030] In another embodiment of the present invention, the pulse source is placed in an injector well that is being used for water injection, surfactant injection, diluent injection, or CO2 injection. The tool can be configured to operate in a rubber sleeve to isolate it, where appropriate, from the fluids being injected. The tool can be deployed in a packer assembly suspended by production tubing, and can be bathed continuously in water to maintain good coupling to the formation. Gases generated by the electrohydraulic discharge can be removed from the packer assembly by pumping water down the well and allowing the gases to be flushed back up the production tubing to maintain optimal coupling and avoid the increase in compressibility that would occur if the gases were left in the well near the discharge device.
[0031] A chronic problem with electrohydraulic discharge devices is that the electrodes are prone to wear and must be replaced from time to time. In another embodiment of the present invention, the electrodes designed for electrohydraulic stimulation have been improved using several methods including (1) improved alloys that withstand the pulse discharge better and last longer, (2) two new feeding devices for exploding filaments, one with a hollow electrode using a pencil filament, and one with a rolled filament on a spool, that allows the exploding filament to be threaded across the spark gap rapidly between discharges so that the pulse generator can operate more efficiently, and (3) gas injection through a hollow electrode that acts as a spark initiation channel.
[0032] In another embodiment of the invention, the fluids produced from the wellbore are separated into its components. These components may include one or more of associated gas, condensate, liquid hydrocarbons, helium and other noble gases, carbon dioxide, sulphur dioxide, pyrite, paraffins, heavy metals such as chromium, manganese and vanadium.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] [0033]FIG. 1 is a diagram of the basic configuration of the tool as deployed in a wellbore, including the surface equipment, winch truck and control panel, and showing the activation of various scales of the reservoir in a blow-up insert to the diagram.
[0034] [0034]FIG. 2 is a diagram showing improvements in the basic one-level tool from U.S. Pat. No. 4,345,650 of Wesley.
[0035] [0035]FIG. 3 is a diagram showing the design of a multi-level tool allowing time sequential and variable inductance discharges with both EH and EM discharge devices under user control.
[0036] [0036]FIG. 4 is a schematic diagram showing the design of a single-turn coil EM discharge device for the tool with rubber sleeve for electrical isolation
[0037] [0037]FIG. 5 is a schematic diagram showing the activation of a reservoir adjacent to the tool with a multi-level discharge device.
[0038] [0038]FIG. 6 is a schematic diagram showing the deployment of multiple tools in multiple wells to act as a source array.
[0039] [0039]FIG. 7 is a schematic diagram showing the deployment of a tool contained in a packer assembly in an injector well with tubing to feed water and electrical and control leads.
[0040] [0040]FIG. 8. is a schematic diagram showing the design of the tool incorporating a sleeve exploder configuration for non-packer applications.
[0041] [0041]FIG. 9 is a schematic diagram showing the design of the directional energy cone for the EH discharge device.
[0042] [0042]FIG. 10 is a schematic diagram showing the design of hollow EH electrodes with a pencil exploding filament device.
[0043] [0043]FIG. 11 is a schematic diagram showing the design of hollow EH electrodes with a spooled feeding device for an exploding filament.
[0044] [0044]FIG. 12 is a schematic diagram showing the design of hollow electrodes with a gas-injection device for improving electrode wear.
DETAILED DESCRIPTION OF THE INVENTION
[0045] [0045]FIG. 1 shows a wellbore 1 drilled in the subsurface of the earth penetrating formations 7 , 9 , 11 , 13 , 15 . . . . The wellbore 1 is typically filled with a drilling fluid 5 known in the art as “drilling mud.”. The sonde 21 that forms part of the present invention is conveyed downhole, in the preferred embodiment of the present invention, on an armored electrical cable, commonly called a wireline 3 .
[0046] The wireline is supported by a derrick 19 or other suitable device and may be spooled onto a drum (not shown) on a truck 25 . By suitable rotation of the drum, the downhole tool may be lowered to any desired depth in the borehole. In FIG. 1, for illustrative purposes, the downhole tool is shown as being at the depth of the formation 11 . This is commonly a hydrocarbon reservoir from which recovery of hydrocarbons is desired. An uphole power source 33 and a surface control unit 23 provide electrical power and control signals through the electrical conductors in the wireline to the sonde 21 . In FIG. 1, the sonde is depicted as generating energy pulses 35 into one of the subsurface formations.
[0047] The control unit 23 includes a power control unit 25 that controls the supply of power to the sonde 21 . The surface control unit also includes a fire control unit 27 that is used to initiate generation of the energy pulses 35 by the sonde. Another component of the surface control unit 23 is the inductance control unit 29 that controls the pulse duration of the energy pulses 35 . Yet another component of the surface control unit is the rotation control 31 that is used to control the orientation of components of the sonde 35 . The functions of the power control unit 25 , the fire control unit 27 , the inductance control unit 29 and the rotation control unit 31 are discussed below in reference to FIG. 3.
[0048] One embodiment of the invention is a tool designed for operation at a single level in a borehole. This is illustrated in FIG. 2 that is a view of the sonde 21 and the major components thereof as adapted to be lowered into the well. The basic EH sonde is an improvement over that disclosed in U.S. Pat. No. 4,345,650 issued to Wesley and the contents of which are fully incorporated here by reference.
[0049] One set of modifications relates to the use of processors wherever possible, instead of the electronic circuitry. This includes the surface control unit 23 and its components as well as in the downhole sonde.
[0050] In a preferred embodiment of the invention, the sonde 21 is used within a cased well, though it is to be understood that the present invention may also be used in an uncased well. The sonde 21 comprises an adapter 53 that is supported by a cable head adapter 55 for electrical connection to the electrical conductors of the wireline 3 . The sonde 21 includes a gyro section 57 that is used for establishing the orientation of the sonde and may additionally provide depth information to supplement any depth information obtained uphole in the truck 25 based upon rotation of the take-up spool. The operation of the gyro section 57 would be known to those versed in the art and is not discussed further. The gyro section 57 here is an improvement over the Wesley device and makes it possible to controllably produce energy pulses in selected directions.
[0051] The other main components of the sonde 21 are a power conversion and conditioning system 59 , a power storage section 63 , a discharge and inductance control section 65 , and the discharge section 67 . A connector 69 couples the power conversion and conditioning section to the power storage section 63 . The power storage section 63 , as discussed in the Wesley patent, comprises a bank of capacitors for storage of electrical energy. Electrical power is supplied at a steady and relatively low power from the surface through the wireline 3 to the sonde and the power conversion and conditioning system includes suitable circuitry for charging of the capacitors in the power storage section 63 . Timing of the discharge of the energy in the power from the power storage section 63 through the discharge section 67 is accomplished using the discharge and induction control section 65 on the basis of a signal from the fire control unit ( 27 in FIG. 1). Upon discharge of the capacitors in the power storage section 63 through the discharge section 67 energy pulses are transmitted into the formation. In one embodiment of the invention, the discharge section 67 produces EH pulses. Refinements in the design of the discharge section 67 over that disclosed in the Wesley patent are discussed below with reference to FIGS. 9 - 12 .
[0052] Turning now to FIG. 3, an embodiment of the invention suitable for use with multiple levels of energy stimulation into the formation is illustrated. The downhole portion of the apparatus comprises a plurality of sondes 121 a , 121 b , . . . 121 n . For illustrative purposes, only three sondes are shown. The coupling between two of the sondes 121 a and 121 b is illustrated in detail in the figure. Eyehooks 141 and 143 enable sonde 121 b to be suspended below sonde 121 a . This eyehook arrangement allows for a limited rotation of sonde 121 b relative to sonde 121 a . Flexible electrical leads 153 carry power and signals to the lower sonde 121 b and the eyehooks ensure that the leads 153 are not subjected to stresses that might cause them to break. The leads are carried within support post 151 in the upper sonde 121 a . A similar arrangement is used for suspending the remaining sondes.
[0053] Each of the sondes 121 a , 121 b . . . 121 n has corresponding components in the surface control unit 123 . Illustrated are power control units 125 a , 125 b . . . 125 n for power supply to the sondes; inductance control units 127 a , 127 b . . . 127 n for inductance control; rotation control units 129 a , 129 b . . . 129 n for controlling the rotation of the various sondes relative to each other about the longitudinal axes of the sondes (see rotation bearing 71 in FIG. 2); and inclination control unites 131 a , 131 b , . . . 131 n for controlling the inclination of the discharge sections (see 67 in FIG. 2) of the sondes relative to the horizontal. In addition, the surface control unit also includes a fire control and synchronization unit 135 that controls the sequence in which the different sondes 121 a , 121 b , . . . 121 n are discharged to send energy into the subsurface formations.
[0054] Turning next to FIG. 4, an EM pulse source is depicted. This is a single-turn magnetic coil that produces a magnetic pulse with no significant acoustic pulse. This tool can be placed in more sensitive wells that will not tolerate the strong shock effect of an EH pulse generator. It also allows a wider range of discharge pulse durations that will extend the effective frequency range of induced vibrations (up to 100 microseconds) that can be applied to a given reservoir.
[0055] The input electrical power is supplied by a conductor 161 . The EM discharge device comprises a cylindrical single-turn electromagnet 179 having an annular cavity 174 filled with insulation 175 . The electromagnet body is separated by rubber insulation 173 from the steel top plate 164 and the steel base plate 181 . Steel support rods 171 couple the steel top plate 164 and the steel base plate 181 . The whole is within a nonconductive housing 163 with an expansion gap between the steel base plate 183 . Optionally, provision may be made for circulating a cooling liquid between the electromagnet body 179 and the rubber insulation 173 . The electromagnet does not allow current to flow back out of the device, which results in dissipative resistive heating of the magnet from each pulse, hence the potential need for a cooling medium if rapid discharge is desired.
[0056] Turning next to FIG. 5, the different scales at which the flow of reservoir fluids in the subsurface is depicted. Depicted schematically are four energy sources 211 , 213 , 215 and 217 within a borehole 201 . Waves 200 a from source 211 are depicted as propagating into formations 221 , 223 and 225 to stimulate the flow of hydrocarbons therein. The frequency of these waves is selected to stimulate flow on the scale of bedding layers: typically, this is of the order of a few centimeters to a few meters.
[0057] The energy source 217 is shown propagating waves 200 d into the subsurface to stimulate flow of hydrocarbons from fractures 227 therein. As would be known to those versed in the art, these fractures may range in size from a few millimeters to a few centimeters. Accordingly, the frequency associated with the waves 200 d would be greater than the frequency associated with the waves 200 a.
[0058] Also shown in FIG. 5 are waves 200 b and 200 c from sources 213 and 215 are depicted as propagating into the formation to stimulate flow of hydrocarbons on the scale of grain size 229 and pore size 231 . Typical grain sizes for subsurface formations range from 0.1 mm to 2 mm. while pore sizes may range from 0.01 mm to about 0.5 mm, so that the frequency for stimulation of hydrocarbons at the grain size scale is higher than for the fractures and the frequency for stimulation of flow at the pore size level is higher still.
[0059] As would be known to those versed in the art, the discharge of a capacitor is basically determined by the inductance and resistance of the discharge path. Accordingly, one function of the inductance control units ( 27 in FIG. 1; 65 in FIG. 2; 127 a . . . 127 n in FIG. 3) in the invention is to adjust the rate of discharge (the pulse duration) and the frequency of oscillations associated with the discharge.
[0060] [0060]FIG. 6 a is a plan view of an arrangement of wells using the present invention. Shown is a producing well 253 and a number of injection wells 251 a , 251 b , 251 c . . . 251 n . Each of the wells includes a source of EH or EM energy. Shown in FIG. 6 a are the acoustic waves 255 a , 255 b . . . 255 n propagating from the injection wells in the formation towards the producing well. When sources in all the injection wells 251 a , 251 b , 251 c . . . 251 n are discharged simultaneously, then the acoustic wavefronts, depicted here by 257 a . . . 257 n propagate through the subsurface as shown and arrive at the producing well substantially simultaneously, so that the stimulation of hydrocarbon production by the different sources occurs substantially simultaneously.
[0061] One or more of the wells 251 a , 251 b , 251 c . . . 251 n may be used for water injection, surfactant injection, diluent injection, or CO2 injection using known methods. The tool can be configured to operate in a rubber sleeve to isolate it, where appropriate, from the fluids being injected. The tool can be deployed in a packer assembly suspended by production tubing, and can be bathed continuously in water to maintain good coupling to the formation. Gases generated by the electrohydraulic discharge can be removed from the packer assembly by pumping water down the well and allowing the gases to be flushed back up the production tubing to maintain optimal coupling and avoid the increase in compressibility that would occur if the gases were left in the well near the discharge device. This is discussed below with reference to FIGS. 7 and 8.
[0062] [0062]FIG. 6 b shows a similar arrangement of injection wells 251 a , 251 b . . . 251 n and a producing well 253 . However, if the sources in the injection well are excited at different times by the surface control unit, then the acoustic waves 255 a ′, . . . 255 n ′ appear as shown and the corresponding wavefronts 257 a ′, . . . 257 n ′ arrive at the producing well at different times. In the example shown in FIG. 6 b , the acoustic wave 257 c ′ from well 251 c is the first to arrive.
[0063] In both FIG. 6 a and 6 b , the injection wells have been shown more or less linearly arranged on one side of the producing well. This is for illustrative purposes only and in actual practice, the injection wells may be arranged in any manner with respect to the producing well. Those versed in the art would recognize that with the arrangement of either 6 a or 6 b , the frequencies of the acoustic pulses may be controlled to a limited extent by controlling the pulse discharge in the sources using the inductance controls of the surface control unit. As noted in the background to the invention, these acoustic waves will have a limited range of frequencies. However, when combined with the large range of frequencies possible with the EM waves, the production of hydrocarbons may be significantly improved over prior art methods.
[0064] Turning now to FIG. 7, a tool of the present invention is shown deployed in a cased borehole within a formation 301 . The casing 305 and the cement 303 have perforations 307 therein. An upper packer assembly 309 and a lower packer assembly 311 serve to isolate the source and limit the depth interval of the well over which energy pulses are injected into the formation. In addition to the power supply 313 , provision is also made for water inflow 315 and water outflow 317 . The outflow carries with it any gases generated by the excitation of the source 319 . With the provision of the water supply, the borehole between the packers 309 , 311 is filled with water or other suitable fluid and is in good acoustic coupling with the formation. This increases the efficiency of generation of acoustic pulses into the formation.
[0065] An alternate embodiment of the invention that does not use packer assemblies is schematically depicted in FIG. 8 wherein a tool of the present invention is shown deployed in a cased borehole within a formation 351 . The casing 355 and the cement 353 have perforations (not shown). As in the embodiment of FIG. 7, in addition to the power supply 363 , provision is also made for water inflow 365 and water outflow 367 . The outflow carries with it any gases generated by the excitation of the source 369 . The tool is provided with a flexible sleeve 373 that is clamped to the body of the tool by clamps 371 and 375 . The sleeve isolates the fluid filled wellbore 357 from the water and the explosive source within the sleeve while maintaining acoustic coupling with the formation.
[0066] Turning now to FIG. 9, an embodiment of the invention allowing for directional control of the outgoing energy is illustrated. The tool 421 includes a bearing 403 that allows for rotation of the lower portion 405 relative to the upper portion 401 . This rotation is accomplished by a motor (not shown) that is controlled from the surface control unit. By this mechanism, the energy may be directed towards any azimuth desired. In addition, the tool includes a controller motor that rotates a threaded rotating post 409 . Rotation of the post 409 pivots a pulse director 412 in a vertical plane, and a substantially cone-shaped opening in the pulse director directs the outgoing energy in the vertical direction.
[0067] A common problem with prior art spark discharge devices is damage to the electrodes from repeated firing. One embodiment of the present invention that addresses this problem is depicted in FIG. 10. Shown are the electrodes 451 and 453 between which an electrical discharge is produced by the discharge of the capacitors discussed above with reference to FIG. 2. The electrode 451 connected to the power supply (not shown) is referred to as the “live” electrode. In such spark discharge devices, the greatest amount of damage occurs to the live electrode upon initiation of the spark discharge. In the device shown in FIG. 10, the live electrode is provided with a hollow cavity 454 through which a pencil electrode 457 passes. The pencil electrode 457 is designed to be expendable and initiation of the spark discharge occurs from the pencil electrode while the bulk of the electrical discharge occurs from the live electrode 451 after the spark discharge is initiated. This greatly reduces damage to the live electrode 451 with most of the damage being limited to the end 459 of the pencil electrode from which the spark discharge is initiated. The device is provided with a motor drive 455 that feeds the pencil electrode 457 through the live electrode upon receipt of a signal from the control unit received through the power and control leads 455 . In one embodiment of the invention, this signal is provided after a predetermined number of discharges. Alternatively, a sensor (not shown) in the downhole device measures wear on the pencil electrode and sends a signal to the control unit.
[0068] Another embodiment of the invention illustrated schematically in FIG. 11 uses a filament for the initiation of the spark discharge. The power leads (not shown) are connected to the live electrode 501 as before, and the return electrode 503 is positioned in the same way as before. The filament 511 is wound on a spool 509 and is carried between rollers 513 into a hole 504 within the live electrode. The spark is initiated at the tip 515 of the filament 511 . The filament 511 gets consumed by successive spark discharges and additional lengths are unwound from the spool 509 as needed using the power and control leads 505 .
[0069] [0069]FIG. 12 shows another embodiment of the invention wherein a gas 561 is conveyed through tubes 563 and 565 to the hollow lower electrode 553 via a threaded pressure fitting 569 . The lower electrode is coupled by means of a thread to the bottom plate 567 . The flowing gas gets ionized by the potential difference between the lower electrode 553 and the upper electrode 551 . The initiation of the spark takes place in this ionized gas, thereby reducing damage to the electrodes 551 and 553 .
[0070] There are a number of different methods in which the various embodiments of the device discussed above may be used. Central to all of them is the initiation of an electromagnetic wave into the formation. The EM wave by itself produces little significant hydrocarbon flow on a macroscopic scale; however, it does serve the function of exciting the hydrocarbons within the formation at a number of different scales as discussed above with reference to FIG. 5. This EM wave may be produced by an electromagnetic device, such as is shown in FIG. 4, or may be produced as part of an EH wave by a device such as described in the Wesley patent or described above with reference to FIGS. 10, 11 or 12 . This EM wave is initiated at substantially the same time as the arrival of the acoustic component of an earlier EH wave at the zone of interest from which hydrocarbon recovery is desired. Any suitable combination of EH and EM sources fired at appropriate times may be used for the purpose as long as an EM and an acoustic pulse arrive at the region of interest at substantially the same time.
[0071] For example, a single EH source as in FIG. 1, may be fired in a repetitive manner so that acoustic pulses propagate into the layer 11 : the EM component of later firings of the EH source will then produce the necessary conditions for stimulation of hydrocarbon flow at increasing distances from the wellbore 1 . Also by way of example, a vertical array of sources such as is shown in FIG. 5 may be used to propagate EM and acoustic pulses into the formation to stimulate hydrocarbon flow from different formations and from different types of pore spaces (fractures, intragranular, etc.). EH and/or EM sources may be fired from a plurality of wellbores as shown in FIG. 6 a , 6 b to stimulate hydrocarbon flow in the vicinity of a single production well. The sources may be oriented in any predetermined direction in azimuth and elevation using a device as shown in FIG. 9. In any of the arrangements, additional materials such as steam, water, a surfactant, a diluent or CO 2 may be injected into the subsurface. The injected material serves to increased the mobility of the hydrocarbon, and/or increase the flow of hydrocarbon.
[0072] The primary purpose of using electrohydraulic stimulation as described above is the recovery of hydrocarbons from the subsurface formations. However, as noted above in the Background of the Invention, the fluids recovered from a producing borehole may include a mixture of hydrocarbons and water and additional material such as, solids, CO 2 , H 2 S, SO 2 , inert gases
[0073] H. Vernon Smith in Chapter 12 of the Petroleum Engineering Handbook (Society of Petroleum Engineers), and the contents of which are fully incorporated herein by reference, reviews devices known as Oil and Gas Separators, that are normally used near the wellhead, manifold or tank battery to separate fluids produced from oil and gas wells into oil and gas or liquid and gas. In one embodiment of the present invention, any of the devices discussed in Smith may be used to separate fluids produced by the electrohydraulic stimulation discussed above. Favret (U.S. Pat. No. 3,893,918), the contents of which are fully incorporated herein by reference, teaches a fractionation column for separation of oil from a fluid mixture containing oil. Kjos (U.S. Pat. No. 5,860,476), the contents of which are incorporated herein by reference, teaches an arrangement in which a first cyclone separator is used to separate gas and liquid, a second cyclone separation is used to separate condensate/oil from water, and a membrane separation us used to separate gases including H 2 S, CO 2 , and SO 2 . U.S. Pat. No. 4,805,697 to Fouillout et al, the contents of which are fully incorporated herein by reference, teaches a method in which recovered fluids from the wellbore are separated into an aqueous and a light phase consisting primarily of hydrocarbons and the aqueous phase is reinjected into the producing formation.
[0074] U.S. Pat. No. 6,085,549 to Daus et al., the contents of which are fully incorporated herein by reference, teaches a membrane process for separating carbon dioxide from a gas stream. U.S. Pat. No. 4,589,896 to Chen et al, the contents of which are fully incorporated herein by reference, discloses the use of a membrane process for separation of CO 2 and H 2 S from a sour gas stream. One embodiment of the present invention uses a membrane process such as that taught by Daus and Chen et al to separate CO 2 , H 2 S, He, Ar, N 2 , hydrocarbon vapors and/or H 2 O from a gaseous component of the recovered fluids from the borehole: Perry's Chemical Engineers' Handbook, 7 th Ed., by Robert H. Perry and Don W. Green, 1997, Chapter 22, Membrane Separation Processes, page 22-61, Gas-Separation Processes the contents of which are incorporated herein by reference, teaches further methods for accomplishing such separation.
[0075] U.S. Pat. No. 5,983,663 to Sterner , the contents of which are fully incorporated herein by reference, discloses a fractionation process for separation of of CO 2 and H 2 S from a gas stream. One embodiment of the invention uses a fractionation process to separate CO 2 and H 2 S from the recovered formation fluids.
[0076] Another embodiment of the invention uses a solvent method for removing H 2 S from the recovered formation fluids using a method such as that taught by Minkkinen et al in U.S. Pat. No. 5,735,936, the contents of which are incorporated herein by reference.
[0077] Cryogenic separation may also be used to separate carbon dioxide and other acid gases from the recovered formation fluids. Examples of such methods are disclosed in Swallow (U.S. Pat. No. 4,441,900) and in Valencia et al (U.S. Pat. No. 4,923,493) the contents of which are fully incorporated herein by reference. Those versed in the art would recognize that removal of carbon dioxide from the recovered formation fluids is particularly important if, as discussed above with reference to FIG. 6 a , CO 2 injection is used in conjunction with electrohydraulic stimulation.
[0078] Another embodiment of the invention uses a process of cryogenic separation such as that taught by Wissoliki (U.S. Pat. No. 6,131,407), the contents of which are fully incorporated here by reference, for recovering argon, oxygen and nitrogen from a natural gas stream. Optionally, Helium may be recovered from a natural gas stream using a cryogenic separation such as that taught by Blackwell et al (U.S. Pat. No. 3,599,438), the contents of which are incorporated herein by reference. In another embodiment of the invention, a combination of cryogenic separation and solvent extraction, such as that disclosed in Mehra (U.S. Pat. No. 5,224,350) may be used for recovery of Helium.
[0079] As discussed above, a heavy liquid portion of the recovered formation fluids may include vanadium, nickel, sulphur and asphaltenes. In an alternate embodiment of the present invention, these may be recovered by using, for example, the method taught by UedaI et al (U.S. Pat. No. 3,936,371), the contents of which are incorporated herein by reference. The process disclosed in Ueda includes bringing the liquid hydrocarbon in contact with a red mud containing alumina, silica and ferric oxide at elevated temperatures in the presence of hydrogen. Another method for recovery of heavy metals disclosed by Cha et al (U.S. Pat. No. 5,041,209) includes mixing the heavy crude oil with tar sand, heating the mixture to about 800° F. and separating the tar send from the light oils formed during the heating. The heavy metals are then removed from the tar sand by pyrolysis.
[0080] While the foregoing disclosure is directed to the preferred embodiments of the invention, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope and spirit of the appended claims be embraced by the foregoing disclosure.
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Pulsed power sources are installed in one or more wells in the reservoir interval. The pulse sources include (1) an electrohydraulic generator that produces an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir, and an acoustic pulse from the plasma vaporization of water placed around the source that propagates through the reservoir at the speed of sound in the reservoir and (2) an electromagnetic generator that produces only an intense and short lived electromagnetic pulse that travels at the speed of light through the reservoir. The combination of electrohydraulic and electromagnetic generators in the reservoir causes both the acoustic vibration and electromagnetically-induced high-frequency vibrations occur over an area of the reservoir where stimulation is desired. Single generators and various configurations of multiple electrohydraulic and electromagnetic generators stimulate a volume of reservoir and mobilize crude oil so that it begins moving toward a producing well. The method can be performed in a producing well or wells, an injector well or wells, or special wells drilled for the placement of the pulsed power EOR devices. The method can be applied with other EOR methods such as water flooding, CO2 flooding, surfactant flooding, diluent flooding in heavy oil reservoirs. The recovered formation fluids may be separated into various constituents.
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PRIOR APPLICATION
[0001] This is a continuation application of Ser. No. 09/024,688, filed Feb. 17, 1998, which is a continuation-in-part application of U.S. patent application Ser. No. 08/908,285, filed Aug. 7, 1997 now U.S. Pat. No. 6,123,807.
TECHNICAL FIELD
[0002] The present invention relates to a novel top separator and a method for producing pulp, preferably sulphate cellulose, with the aid of a continuous digester system.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] Environmental demands has forced our industry to develop improved cooking and bleaching methods. One recent breakthrough within the field of cooking is ITC™, which was developed in 1992-1993. ITC™ is described in WO-9411566, which shows that very good results concerning the pulp quality may be achieved. ITC™ is mainly based on using almost the same temperature (relatively low compared to prior art) in all cooking zones in combination with moderate alkaline levels. The ITC™-concept does not merely relate to the equalization of temperatures between different cooking zones, but a considerable contribution of the ITC™-concept relates to enabling an equalized alkaline profile also in the lower part of the counter-current cooking zone.
[0004] Moreover, it is known that impregnation with the aid of black liquor can improve the strength properties of the fibers in the pulp produced. The aim of the impregnation is, in the first place, to thoroughly soak each chip so that it becomes susceptible, by penetration and diffusion, to the active cooking chemicals which, in the context of sulphate cellulose, principally consist of sodium hydroxide and sodium sulphide.
[0005] If, as is customary according to prior art, a large proportion of the white liquor is supplied in connection with the impregnation, there will exist no distinct border between impregnation and cooking. This leads to difficulties in optimizing the conditions in the transfer zone between impregnation and cooking.
[0006] Now it has been found that surprisingly good results can be achieved when:
[0007] 1. Keeping a low temperature but a high alkali content in the beginning of a concurrent cooking zone of the digester;
[0008] 2. Withdrawing a substantial part of a highly alkaline spent liquor that has passed through at least the concurrent cooking zone; and
[0009] 3. Supplying a substantial portion of the withdrawn spent liquor that has a relatively high amount of rest-alkali, to a point that is adjacent the beginning of an impregnation zone.
[0010] This leads to a reduced H-factor demand, reduced consumption of cooking chemicals and better heat-economy. Additionally, the novel method leads to production of pulp that has a high quality and a very good bleachability, which means that bleach chemicals and methods can be chosen with a wider variety than before for reaching desired quality targets (brightness, yield, tear-strength, viscosity, etc.) of the finally bleached pulp.
[0011] Furthermore, we have found that these good results can also be achieved when moving in a direction opposite the general understanding of the ITC™-teaching, in connection with digesters having a counter-current cooking zone. Instead of trying to maintain almost the same temperature levels in the different cooking zones, we have found that when using a digester that has both a concurrent and a counter-current cooking zone, big advantages may be gained if the following basic steps are used:
[0012] 1. Keeping a low temperature but a high alkali content in the concurrent zone of the digester;
[0013] 2. Keeping a higher temperature but a lower alkali content in the counter-current zone;
[0014] 3. Withdrawing a substantial part of the highly alkaline spent liquor that has passed through at least one digesting zone; and
[0015] 4. Preferably supplying almost all of the withdrawn spent liquor, that has a relatively high amount rest-alkali, to a position that is adjacent the beginning of the impregnation zone.
[0016] Also, in connection with digesters of the one-vessel type (without a separate impregnation vessel), surprisingly good results are achieved when the basic principles of the invention are used.
[0017] Moreover, preliminary results indicate that the preferred manner of using the invention may be somewhat modified also in other respects but still achieving very good result, e.g., by excluding the counter-current cooking zone. Additionally, expensive equipment might be eliminated, e.g., strainers in the impregnation vessel, hanging central pipes, etc., making installations much easier and considerably less expensive.
BRIEF DESCRIPTION OF THE FIGURES
[0018] [0018]FIG. 1 is a schematic flow diagram of a preferred first embodiment of a digester system according to the present invention;
[0019] [0019]FIG. 2 is a cross-sectional view of a preferred first embodiment of a top separator to be used in an impregnation vessel or a single vessel digester according to the present invention;
[0020] [0020]FIG. 2A is a cross-sectional view of a preferred second embodiment of a top separator to be used in a digester according to the present invention;
[0021] [0021]FIG. 3 is a schematic flow diagram of a preferred second embodiment of a digester system according to the present invention;
[0022] [0022]FIG. 4 is a schematic flow diagram of a preferred third embodiment of a digester system according to the present invention;
[0023] [0023]FIG. 5 is a schematic flow diagram of a preferred fourth embodiment of a digester system according to the present invention;
[0024] [0024]FIG. 6 is a schematic flow diagram of a preferred fifth embodiment of a digester system according to the present invention;
[0025] [0025]FIG. 7 is a schematic flow diagram of a preferred sixth embodiment of a digester system according to the present invention;
[0026] [0026]FIG. 8 is a schematic flow diagram of a preferred seventh embodiment of a digester system according to the present invention;
[0027] [0027]FIG. 9 is a schematic flow diagram of a preferred eighth embodiment of a digester system according to the present invention;
[0028] [0028]FIG. 10 is a schematic flow diagram of a preferred ninth embodiment of a digester system according to the present invention;
[0029] [0029]FIG. 11 is a schematic flow diagram of a preferred tenth embodiment of a digester system according to the present invention;
[0030] [0030]FIG. 12 is a schematic flow diagram of a preferred eleventh embodiment of a digester system according to the present invention;
[0031] [0031]FIG. 13 is a schematic flow diagram of a preferred twelfth embodiment of a digester system according to the present invention; and
[0032] [0032]FIG. 14 is a cross-sectional view of a preferred third embodiment of a top separator of the present invention.
DETAILED DESCRIPTION
[0033] The preferred embodiments of the present invention are described with reference to FIGS. 1 - 14 . FIG. 1 shows a preferred first embodiment of a two vessel hydraulic digester for producing chemical pulp according to the present invention. The main components of the digesting system consist of an impregnation vessel 1 and a hydraulic digester 6 . It is to be understood that both the digester and the impregnation vessel may be hydraulic vessels that are totally filled with, among other things, a liquid.
[0034] The impregnation vessel 1 , which normally is totally liquid filled, includes a feeding-in device 2 at the top. The feeding-in device may be of a conventional type, i.e., a top separator having a screw-feeding device that feeds the chips in a downward direction at the same time as a transport liquid is drawn off. Other types of top separators may also be used. At the bottom, the impregnation vessel 1 has a feeding-out device 3 comprising a bottom scraper. In addition to this, there is a conduit 17 that extends from the digester 6 to the impregnation vessel 1 for adding hot black liquor. As seen in FIG. 1, the black liquor is preferably supplied to the top of the impregnation vessel 1 . In contrast to conventional impregnation vessels, no draw-off screen is located inside the impregnation vessel. However, such draw-off screen may be provided if desired.
[0035] The chips are fed from the chip bin 20 A, through the steaming vessel 20 B and the chip chute 20 C. A feeding device, preferably a high-pressure feeder 19 , feeds the chips suspended in a transport liquid via a conduit 18 to the top of the impregnation vessel 1 . The feeder 19 is cooperating with the chute 20 C, and is connected to the necessary liquid circulations and replenishment.
[0036] A conduit 21 , for transporting chips and a transport liquid D, extends from the bottom of the impregnation vessel 1 up to the top 5 of the digester 6 . Conduit 21 opens up at the top of a top separator 7 which feeds by means of a screw in an downwardly moving direction.
[0037] The screen of the separator may be used to draw off the transport liquid D (which is then returned in line 15 ) together with which the chips are transported from the impregnation vessel 1 up to the top 5 of the digester. Below the top separator 7 there are inlet openings 37 defined that are in operative engagement with a conduit 24 which (preferably via a heat-exchanger 13 ) leads to a cooking liquor supply such as a white-liquor container (not shown). The heat-exchanger 13 is connected to a high pressure steam conduit 102 and heats up the white liquor to a suitable temperature before the white liquor enters the top 5 . As best seen in FIG. 1, approximately 95% of the total supply of the white liquor in the conduit 24 is supplied to the top 5 of the digester and the remaining 5% is supplied to the high pressure feeder 19 via a conduit 132 and a conduit 134 to lubricate the high pressure feeder 19 . About 90% of the white liquor in the conduit 24 is supplied to the top of the digester, the remaining 10% is supplied to the counter-current zone D via a conduit 123 .
[0038] A first screen girdle section 8 may be arranged in conjunction with a step-out approximately in the middle of the digester 6 . If the digester 6 is an MCC digester, the screen section may be used to withdraw spent liquor that is conducted to a recovery unit. Draw-off from this screen girdle section 8 can also be conducted directly via the conduit 17 to the impregnation vessel 1 . A second screen girdle section 104 may be arranged below the first screen girdle section 8 (in an MCC digester, the screen girdle section 104 would normally be called the MCC screen). Draw-off from the second screen section 104 , such as spent liquor, i.e., black liquor, may be conducted via a conduit 106 to a first flash tank 108 to recover steam and let pressure off before the liquor is conducted to a recovery unit 110 . Preferably, the spent liquor is also conducted through a second flash tank 112 via a conduit 114 to further reduce the pressure and temperature of the spent liquor before the liquor is conducted to the recovery unit 110 . In the preferred embodiment, a conduit 124 conducts the spent liquor from the return conduit 15 (preferably at least 3 m 3 /ADT) to the second flash tank 112 . The spent liquor from both flash tanks 108 , 112 is then conducted with a conduit 126 to the recovery unit 110 . Conduits 128 and 130 may be connected to the flash tanks 108 , 112 , respectively, to supply steam to the chip bin 20 A and the steaming vessel 20 B.
[0039] At the bottom 10 of the digester, there is a feeding-out device including one scraping element 22 . A third lower screen girdle section 12 is disposed at the bottom 10 of the digester 6 . The girdle section 12 may, for example, include three rows of screens for withdrawing liquid, which is heated and to which some white liquor, preferably about 10% of the total amount of the white liquor in conduit 24 , is added via a branch conduit 117 before it is recirculated by means of a central pipe 123 , which opens up at about the same level as the lowermost strainer girdle 12 .
[0040] The draw-off from the screen girdles 12 and the white liquor from the branch conduit 117 are preferably conducted via a heat exchanger 120 back to the bottom 10 of the digester 6 . The temperature of this draw off is about 140° C. since it is a mix of washing liquid and black liquor. The white liquor is supplied in a counter-current direction via the central pipe 123 to the screen girdle section 12 . The white liquor provides fresh alkali and, in the form of counter-current cooking, further reducing the Kappa number. A conduit 122 is connected to the high pressure steam conduit 102 to provide the heat exchanger with steam to regulate the temperature of the liquid supplied via the standpipe 123 . A blow line 26 is connected to the bottom 10 of the digester for conducting the digested pulp away from the digester 6 .
[0041] A preferred installation according to the present invention, as shown in FIG. 1, may function as follows. The chips are fed in a conventional manner into the chip bin 20 A and are subsequently steamed in the vessel 20 B and, thereafter, conveyed into the chute 20 C. The high-pressure feeder 19 , which is supplied with a minor amount of white liquor (approximately 5% of the total amount to lubricate the feeder), feeds the chips into the conduit 18 together with the transport liquid. The slurry of chips and transport liquid are fed to the top of the impregnation vessel 1 and may have a temperature of about 110° C. to 120° C. when entering the impregnation vessel (excluding recirculated transport liquor).
[0042] In addition to the actual fibers in the wood, the latter also conveys its own moisture (the wood moisture), which normally constitutes about 50% of the original weight, to the impregnation vessel 1 . Over and above this, some condense is present from the steaming, i.e., at least a part of the steam (principally low-pressure steam) which was supplied to the steaming vessel 20 B is cooled down to such a low level that it condenses and is then recovered as liquid together with the wood and the transport liquid.
[0043] Inside the top of the impregnation vessel 1 , the screw feeder 2 pushes the chips in a downward direction. No liquid is necessarily recirculated within the impregnation vessel 1 . Instead, spent liquor, such as black liquor, from the screen girdle section 8 is preferably supplied to the impregnation vessel 1 . However, it is to be understood that liquid may be recirculated within the impregnation vessel 1 .
[0044] The chips which are fed out from the bottom of the top screen 2 of the impregnation vessel 1 then move slowly downwards in a plug flow through the impregnation vessel 1 in a liquid/wood ratio between 2/1-10/1 preferably between 3/1-8/1, more preferred of about 4/1-6/1. Hot black liquor, which is drawn off from the screen girdle section 8 , may be added, via the conduit 17 , to the top of the impregnation vessel 1 . The black liquor may also be added to other sections of the impregnation vessel such as to an intermediate section of the impregnation vessel. The high temperature of the black liquor (100° C. to 160° C.), preferably exceeding 130° C., more preferred between 130° C. to 160° C., ensures rapid heating of the chips flowing through the impregnation vessel 1 . In addition, the relatively high pH, exceeding pH 10 , of the black liquor neutralizes acidic groups in the wood and also any acidic condensate accompanying the chips, thereby, i.e., counteracting the formation of encrustation, so-called scaling.
[0045] An additional advantage of the method of the present invention is that the black liquor supplied into the impregnation vessel 1 has a high content of rest alkali, (effective alkali EA as NaOH), at least 13 g/l, preferably about or above 16 g/l and more preferred between 13-30 g/l at the top of the impregnation vessel 1 . This alkali mainly comes from the black liquor due to the high amount of alkali in the concurrent zone B of the digester 6 . Furthermore, the strength properties of the fibers are positively affected by the impregnation because of the high amount of sulphide. A major portion of the black liquor may be directly (or via one flash) fed into the impregnation vessel 1 . A minor amount of the black liquor may be used for transferring the chips from the high pressure feeder 19 to the inlet of the impregnation vessel 1 .
[0046] The minor flow of the black liquor should be cooled (not shown) before it is entered into the feeder 19 . The two flows of black liquor are preferably used to regulate the temperature within an impregnation zone A disposed inside the impregnation vessel 1 . In the preferred embodiment, the temperature should not exceed 140° C. However, it should be understood that the temperature may exceed 140° C. The total supply of black liquor to the impregnation vessel 1 may exceed 80% of the amount drawn off from the draw-off strainers 8 , preferably more than 90% and most preferred about 100% of the total flow, which normally is about 8-12 m 3 /ADT.
[0047] The retention time in the impregnation zone A should be at least 20 minutes, preferably at least 30 minutes and more preferred at least 40 minutes. However, a shorter retention time than 20 minutes, such as 15-20 minutes may also be used. The volume of the impregnation vessel 1 may be larger than {fraction (1/11)}, preferably larger than {fraction (1/10)} of the volume of the digester 6 . Additionally, in the preferred embodiment, the volume V of the impregnation vessel 1 should exceed 5 times the value of the square of the maximum digester diameter, i.e., V=5D 2 , where D is the maximum diameter of the digester 6 .
[0048] From tests made in lab-scale, we have found indications that it is desirable to keep the alkaline level at above at least 2 g/l, preferably above 4 g/l, in the impregnation vessel 1 in connection with black liquor, which would normally correspond to a pH of about 11. If not, it appears that dissolved lignin precipitates and even condenses.
[0049] The chips, which have been thoroughly impregnated and partially delignified in the impregnation vessel 1 , may be fed to the top of the digester 6 and conveyed into the downwardly-feeding top separator 7 . The chips are thus fed downwards through the screen, meanwhile free transport liquid may be withdrawn outwardly through the separator screen. Before the chips enter the concurrent cooking zone B, the chips pieces are drained with cooking liquor, such as white liquor, which is supplied by means of the annular openings 37 at the top separator 7 (see FIG. 2).
[0050] The quantity of white liquor that is added at the top separator 7 depends on how much white liquor possibly is added else where, but the total amount corresponds to the quantity of white liquor that is required to achieve the desired delignification of the wood chips. Preferably, a major part of the white liquor is added here, i.e., more than 60%, which also improves the diffusion velocity, since it increases in relation to the concentration difference (chip-surrounding liquid). The thoroughly impregnated chips very rapidly assimilate the active cooking chemicals by diffusion, since the concentration of alkali (EA as NaOH) is relatively high, at least 20 g/l, preferably between 30 g/l and 50 g/l and more preferred about 40 g/l.
[0051] The chips then move down in the concurrent zones B, C through the digester 6 at a relatively low cooking temperature, i.e., between 130° C. to 160° C., preferably about 140° C. to 150° C. The major part of the delignification takes place in the first and second concurrent cooking zones B, C.
[0052] The liquid-wood ratio should be at least 2/1 and should be below 7/1, preferably in the range of 3/1-5.5/1, more preferred between 3.5/1 and 5/1. (The liquid wood-ratio in the counter-current cooking zone should be about the same as in the concurrent cooking zones.)
[0053] The temperature in a lower counter-current zone D is preferably higher than in the concurrent zones B, C, i.e., preferably exceeding 140° C., preferably about 145° C. to 165° C., in order to dissolve remaining lignin. The alkali content in the lowermost part of the concurrent cooking zone C should preferably be lower than in the beginning of the concurrent zone B, above 5 g/l, but below 40 g/l. Preferably less than 30 g/l and more preferred between 10-20 g/l. Expediently, the conduit 116 may be charged with about 5-20%, preferably 10-15%, white liquor from the conduit 24 via the conduit 117 . Below the draw-off screen section 104 is the counter-current zone D that is defined between the section 104 and the section 12 .
[0054] The temperature of the liquid which is recirculated via the pipe 123 up to the screen girdle section 12 is regulated with the aid of the heat exchanger 120 so that the desired cooking temperature is obtained at the lowermost part of the counter-current cooking zone D.
[0055] At the lowermost part of the digester, cool wash liquid is added in order to displace, in counter-current, hot liquid which is subsequently withdrawn at the lowermost screen girdle 12 .
[0056] [0056]FIG. 2 shows a preferred embodiment of a separator that may be used together with an impregnation vessel that is part of a digester system, such as the digester system shown in FIG. 1, where there is a need for a heat seal. The advantage of providing the heat seal in the separator is to enable the injection of hot black liquor into the separator without risking to operate the high pressure feeder at too high of a temperature. The heat seal reduces or even eliminates the risk of any hot liquor being inadvertently conducted back to the high pressure feeder which may damage the feeder. It is to be understood that the separator may also be used in an impregnation vessel that is connected to a steam/vapor phase digester and the separator may be used in a single-vessel hydraulic digester.
[0057] Only a portion of a an impregnation vessel 1 is shown. The non-impregnated slurred fiber material is transferred to the top of the digester by means of the transfer line 21 and enters an in-let space 30 of a screw-feeder 31 . The screw-feeder 31 is attached to a shaft 32 connected to a drive-unit 33 which is attached to a mounting-plate 34 at the top of the digester shell 6 . The drive-shaft 32 is rotated in a direction so as to force the screw to feed the chips and the transport fluid in a downward direction.
[0058] A cylindrical screen-basket 35 surrounds the screw-feeder 31 . The screen-basket 35 is arranged within the digester shell 6 so as to define a liquid collecting space 36 between the digester shell and the outer surface of the screen-basket 35 . The liquid collecting space 36 , which preferably is annular, communicates with a conduit 15 for withdrawing liquid from the liquid collecting space 36 , which in turn is replenished by liquid from the slurry within the screen basket 35 . The major part of the free liquid within the slurry entering the screen basket is withdrawn into the liquid collecting space 36 , but a small portion of free liquid, at least about 0.5 m 3 /ADT should not be withdrawn from the slurry.
[0059] A set of level sensors 60 are positioned along a side wall of the digester 6 to sense the level in the digester. The level sensors are disposed below the screw-feeder 31 but above the pair of liquid supply devices 37 . A top section 62 of the digester 6 has a diameter (d) that is less than a diameter (D) of the digester at a mid-portion and bottom portion thereof. The diameter (d) is small to reduce or even avoid any substantial heat transfer to the T-C lines so that the T-C lines may maintain a temperature that is slightly above 100° C. In this way, a heat lock zone 64 is formed between the liquid supply devices 37 and the top of the level sensors 60 . Preferably, the heat lock zone 64 has a length h that is greater than the diameter d where h is the distance between the lower edge of the screen 35 and the transition zone and d is the diameter of the separator at its upper end, as described earlier. It is to be understood that the heat lock zone may have any other suitable length.
[0060] The liquid supply device 37 preferably comprises an annular distribution ring 38 which has a number of supply conduits 37 disposed between the ring and the impregnation vessel 1 . The supply conduits 37 open up into the chips pile for supply of liquid into the fiber material moving down into the impregnation vessel 1 . The annular distribution ring 38 is replenished by means of the conduit 24 wherein a desired amount of liquid is supplied. The liquid supplied through the liquid supply device 37 and ring 38 may be hot black liquor having a relatively high amount of effective alkaline, in order to provide for the possibility of establishing a concurrent impregnation zone (B) having a desired temperature of about 120° C. to 145° C., and a desired content of effective alkaline, of about 10-20 g/l.
[0061] In FIG. 2A, there is shown a simpler separation device intended for a two-vessel hydraulic digester. If the separator shown in FIG. 2A is used in an impregnation vessel (that is part of a two vessel steam/vapor phase digester system) the separator works exactly in the same way. The heat-seal eliminates any risk of obtaining any hot return-liquid in return line 15 which could cause problems with the operation of the high pressure feeder. Only a part of the top of the digester 6 s is shown. The slurred fiber material is transferred to the top of the digester by means of a transfer line 21 s and enters an in-let space 30 s of a screw-feeder 31 s . The screw-feeder 31 s is attached to a shaft 32 s connected to a drive-unit 33 s which is attached to a mounting-plate 34 s on the top of the digester shell 6 s . The drive-shaft 32 s is rotated in a direction so as to force the screw to feed in a down-ward direction.
[0062] A cylindrical screen-basket 35 s surrounds the screw-feeder 31 s . The screen-basket 35 s is arranged within the digester shell 6 s so as to form a liquid collecting space 36 s between the digester shell and the outer surface of the screen-basket 35 s . The liquid collecting space 36 s , which preferably is annular, communicates with a conduit 15 s for withdrawing liquid from the liquid collecting space 36 s , which in turn is replenished by liquid from the slurry within the screen basket 35 s . The major part of the free liquid within the slurry entering the screen basket is withdrawn into the liquid collecting space 36 s , but a small portion of free liquid, at least about 0.5 m 3 /ADT should not be withdrawn from the slurry.
[0063] Below the outlet end of the screen basket 35 s there is arranged a pair of liquid supply devices 37 s , each preferably comprising an annular distribution ring which opens up into the chips pile for supply of liquid into the fiber material moving down into the digester 6 s . The liquid supply devices 37 s are replenished by means of lines 24 s wherein a desired amount of liquid is supplied. If it is a two-vessel hydraulic digester system, the liquid supplied through the liquid supply devices 37 s would be hot cooking liquor having a relatively high amount of effective alkaline, in order to provide for the possibility of establishing a concurrent cooking zone (B) having a desired temperature of about 145-150° C., and a desired content of effective alkaline, e.g. about 45 g/l.
[0064] A major advantage with both kinds of the shown separation devices is that they provide for establishing a distinguished change of zones (they enable almost a total exchange of free liquid at this point), which means that the desired conditions in the beginning of the concurrent zone (B) can easily be established.
[0065] [0065]FIG. 3 illustrates an second embodiment of the hydraulic digester system of the present invention. This embodiment is almost identical to the embodiment shown in FIG. 1. Only the main differences are therefore described. It relates to a two-vessel hydraulic digester which, accordingly, has a downwardly feeding separator at the top of the digester. A screen girdle section 38 a is disposed at the bottom of an impregnation vessel 1 a . Spent liquor is withdrawn at the girdle section 38 a and conducted via a conduit 34 a to a second flash tank 112 a to be further conducted to a recovery unit, as described in FIG. 1. A conduit 36 a extends between a return conduit 15 a and a conduit 24 a so that a portion of the white liquor in the conduit 24 a is conducted via the conduit 36 a to the return line 15 a . Instead of conducting the white liquor in the conduit 24 a up to the top of a digester 6 a , the conduit 24 a is connected to the conduit 116 a so that about 90% of the white liquor in the conduit 24 a is conducted to the conduit 116 a . The remaining parts of this embodiment operates in a way that is very similar to the embodiment described in FIG. 1.
[0066] [0066]FIG. 4 also shows a hydraulic digester, being the third embodiment of the present invention. Only the new features of this embodiment compared to the first embodiment are described. A conduit 106 b attached to a digester 6 b conducts spent liquor that has been withdrawn from a screen section 104 b to the top of an impregnation vessel 1 b . A portion of the spent liquor withdrawn in the conduit 106 b is diverted via a conduit 107 b to a first flash tank 108 b and then via a conduit 114 b to a second flash tank 112 b . It should be noted that the third embodiment does not have a screen girdle section at the upper end of the digester 6 b.
[0067] [0067]FIG. 5 describes a fourth embodiment of the present invention. A digester 6 c has a first screen girdle section 8 c disposed therein. Spent liquor is withdrawn from the girdle section 8 c via a conduit 109 c to a second flash tank 112 c . The spent liquor withdrawn from the girdle section 8 c has a low effective alkali value that is below 12 g/l.
[0068] The digester 6 c also has a second screen girdle section 11 c immediately below the first screen girdle section 208 d . Liquor is withdrawn from the second screen girdle section via a conduit 113 c . A conduit 24 c conducts white liquor so that approximately 5% to 15% of the white liquor in the conduit 24 c is diverted via a conduit 117 c to a conduit 116 c that is connected to a lower screen girdle section 12 c . The remaining amount of white liquor in the conduit 24 c is conducted up to the conduit 113 c . The liquor withdrawn from the screen girdle section 11 c together with the white liquor from the conduit 24 c is via a central pipe conducted back into the digester at about the same level as the screen girdle section 8 c . With this embodiment, the impregnation zone is prolonged to also include the upper zone of the digester, i.e., to the screen 8 c . Below the screen 8 c , the cooking zone commences at the point there the conduit 113 c opens up. The cooling liquor is then radially, uniformly displaced/mixed into the chips column by means of withdrawing and recirculating liquor with the screen 11 c.
[0069] In the preferred fourth embodiment, the conduit 113 c is associated with a heat exchanger 115 c to regulate the temperature of the black liquor and the white liquor which is to be reintroduced by the conduit 113 c . The heat exchanger is adapted to receive steam via a conduit 217 c that is connected to a main high pressure steam conduit 102 c . Similar to the embodiment shown in FIG. 1, spent liquor is also withdrawn from a screen girdle section 104 c and conducted back to an impregnation vessel 1 c via a conduit 17 c . The effective alkali of the spent liquor that is conducted in the conduit 17 c is about 13 g/ 1 .
[0070] [0070]FIG. 6 illustrates an fifth embodiment of the present invention. White liquor is supplied to a digester 6 d via a conduit 24 d . The temperature of the white liquor may be regulated by a heat exchanger 13 d that is adapted to receive steam from a high pressure steam conduit 102 d . About 5% to 15% of the total amounts of the white liquor in the conduit 24 d is diverted via a conduit 117 d to a conduit 116 d . The remaining portion is conducted up to a top portion of the digester 6 d . Spent liquor may be withdrawn from a screen girdle section 11 d via a conduit 113 d . A major portion of the spent liquor in the conduit 113 d is diverted and conducted via a conduit 121 d back to an impregnation vessel 1 d . The addition of a small amount of black liquor to the top of the digester 6 d prevents the white liquor from flowing back into the separator. Accordingly, the black liquor addition takes place above the white liquor addition so that the black liquor creates a barrier between the white liquor and the separator.
[0071] [0071]FIG. 7 describes a sixth embodiment of the present invention. In general, the sixth embodiment is very similar to the fifth embodiment shown in FIG. 6. The sixth embodiment has the advantage of including a liquid exchanger to completely eliminate the risk of any undesirable back flow of white liquor that is particularly difficult problem with most hydraulic digesters. However, the separator shown in FIG. 2 has features to reduce the risk of back flow.
[0072] A conduit 24 e conducts white liquor to a return line 15 e . The temperature of the white liquor may be controlled by a heat exchanger 13 e that is adapted to receive steam from a high pressure steam conduit 102 e . The temperature of the white liquor may be about 140-150° C. depending on the type of wood pulp that is used. The return line 15 e terminates at a liquid exchanger 31 e , which fulfills the same function as a top separator, i.e., it provides a very distinct exchange of treatment zones by almost totally withdrawing a first liquid from the chips and, subsequently, adding a second liquid so that any undesired mixing is avoided, the liquid changer 31 e , in turn, has a mid-portion that is connected via a return line 33 e to a bottom portion of an impregnation vessel 1 e . A slurry of the chips and transport liquid may be conducted from the bottom portion of the impregnation vessel 1 e via a conduit 35 e to a bottom end of the liquid exchanger 31 e after exchange of liquid the chips are transported in a conduit 21 e to the top of a digester 6 e . A portion of the spent liquor in the return line 33 e is diverted and conducted to a second flash tank 114 e via a conduit 137 e for recovery.
[0073] Black liquor is withdrawn from a girdle section 8 e of the digester 6 e and conducted via a conduit 17 e back to a top portion of the impregnation vessel 1 e . Spent liquor is also drawn off from a screen girdle section 104 e and is conducted to a first flash tank 108 e via a conduit 106 e.
[0074] [0074]FIG. 8 shows a seventh embodiment of the present invention. This embodiment is similar to the sixth embodiment. In some instances, the seventh embodiment is preferred over the sixth embodiment because there is often no need for a screen between the top of the digester and the draw-off screen girdle 104 . This is because the liquid exchanger and the transport to the digester often provide sufficient and homogenous mixing of the cooking liquor so that a perfect condition can be established in the long concurrent cooking zone. If the conditions are optimally adjusted in the seventh embodiment, almost all or all the black liquor withdrawn from the screen 104 may be supplied to the impregnation vessel and therefore all or almost all of the liquid for the recovery may be taken from the liquid that is separated in the liquid exchanger.
[0075] Only some of the most important differences compared to the other embodiments are described. This embodiment has a digester 6 f that does not have a screen girdle section at the top of the digester. Most of the spent liquor is therefore withdrawn from the digester 6 f at a screen girdle section 104 f and a portion of the spent liquor withdrawn is conducted via a conduit 17 f back to an impregnation vessel if. The remaining portion of the spent liquor is conducted to a first flash tank 108 f via a conduit 106 f.
[0076] [0076]FIG. 9 illustrates a eighth embodiment of the present invention. This embodiment is similar to the embodiment shown in FIG. 7. Only some of the main differences are described. In general, when a liquid exchanger is used, there is no longer any need for a heat seal at the top of the impregnation vessel (contrary to the embodiments shown in FIGS. 6 - 8 ). In fact, even less expensive cupped gables can be used in the impregnation vessel. Therefore, the eighth embodiment may be an attractive way of retrofitting existing two vessel hydraulic digester systems. Also, the slurry of pulp and transport liquid is heated to a cooking temperature before the introduction into the digester by heating the transport liquid in the return line that is associated with a heat exchanger. It is to be understood that several advantages are gained by not only eliminating the heat seal in the impregnation vessel but also design the separator so that there is no back flow in the digester because a simple and inexpensive cupped gable design may be used at the top of both the impregnation vessel and the digester.
[0077] A high pressure feeder 19 g feeds a slurry of chips to a bottom portion of a liquid exchanger 31 g . The object of this liquid exchanger is to ensure safe operation of the high pressure feeder at the same time as a high temperature (e.g., 130° C.) is maintained at the top of an impregnation vessel 1 g , which is achieved by supplying hot black liquor to a conduit 21 g via a conduit 17 g . After exchange of liquid, the slurry is further conducted to a top of the impregnation vessel 1 g via a conduit 18 g . Relatively cool transport fluid is returned to the high pressure feeder 19 g via a conduit 23 g . The temperature of the transport liquid can be kept low thanks to the total exchange of free liquid.
[0078] [0078]FIG. 10 illustrates a ninth embodiment of a single vessel hydraulic digester system of the present invention. The chips are fed from a chip bin 20 Ah, through a steaming vessel 20 Bh and a chip chute 20 Ch. A feeding device, preferably a high-pressure feeder 19 h feeds the chips suspended in a transport liquid D via a conduit 18 h to the top of a digester 6 h . The feeder 19 h is cooperating with the chute 20 Ch, and is connected to the necessary liquid circulations and replenishment.
[0079] The conduit 18 h extends from the feeder 19 h up to a top 5 h of the digester 6 h . The conduit 18 h may open up at the top of a top separator 7 h that feeds by means of a screw in a downwardly moving direction. The separator 7 h is preferably identical or very similar to the top separator 7 that is shown in FIG. 2 and described in detail above. The screen of the separator may be used to draw off the transport liquid D (which is then returned in a return line 15 h ) together with which the chips are transported from the feeder 19 h up to the top 5 h of the digester 6 h . A first screen girdle section 8 h may be arranged in conjunction with a step-out approximately in the middle of the digester 6 h . Draw-off of spent liquor from this screen girdle section 8 may be conducted via the conduit 17 h to an impregnation zone A that is defined between the screen girdle section 8 h and the top 5 h of the digester 6 h . A portion of the spent liquor may be withdrawn from the screen girdle section 8 h via a conduit 111 h that conducts the spent liquor to a second flash tank 112 h.
[0080] A cooking liquor conduit 24 h is operatively attached to the conduit 17 h to supply a major part of the cooking liquor, such as white liquor, to the conduit 17 h . A heat-exchanger 13 h may heat up the white liquor and the spent liquor to a suitable temperature before the liquor enters the top 5 h . The heat exchanger 13 h may be in operative engagement with a high pressure steam line 102 h . The effective alkali of the liquor in the conduit 17 h is at least about 35 g/l; more preferably at least about 40 g/l; and, most preferably, between about 45 g/l and about 55 g/l.
[0081] Approximately 95% of the total supply of the white liquor in conducted in the conduit 24 h and the remaining 5% is supplied to the high pressure feeder 19 h via a conduit 132 h and a conduit 134 h to lubricate the high pressure feeder 19 h.
[0082] A second screen girdle section 104 h may be arranged below the first screen girdle section 8 h . Draw-off from the second screen section 104 h , such as spent liquor, i.e., black liquor, may be conducted via a conduit 106 h back to a top portion of the impregnation zone A. The effective alkali of the spent liquor conducted in the conduit 106 h is about 10-20 g/l. A portion of the black liquor in the conduit 106 h may be conducted to a first flash tank 108 h via a conduit 107 h to cool the spent liquor before the liquor is conducted to a recovery unit 110 h . Preferably, the spent liquor is also conducted through a second flash tank 112 h via a conduit 114 h to further reduce the temperature and pressure of the spent liquor before the liquor is conducted to the recovery unit 110 h . The spent liquor from both flash tanks 108 h , 112 h are then conducted with a conduit 126 h to the recovery unit 110 h . Conduits 128 h and 130 h may be connected to the flash tanks 108 h , 112 h , respectively, to provide steam that is sent to the chip bin 20 Ah and the steaming vessel 20 Bh.
[0083] At a bottom 10 h of the digester 6 h , there is a feeding-out device including a scraping element 22 h . A third lower screen girdle section 12 h is disposed at the bottom 10 h of the digester 6 h . The girdle section 12 h may, for example, include three rows of screens for withdrawing liquid, which is heated and to which some white liquor, preferably about 10% of the total amount of the white liquor in the conduit 24 h , is added via a branch conduit 117 h before it is recirculated by means of a central pipe 123 h , which opens up at about the same level as the lowermost strainer girdle 12 h.
[0084] The draw-off from screen girdles 12 h and the white liquor from the branch conduit 117 h are preferably conducted via a heat exchanger 120 h back to the bottom 10 h of the digester 6 h . The high pressure steam conduit 102 h is connected to the heat exchanger 120 h to provide the heat exchanger 120 h with steam to regulate the temperature of the white liquor in the conduit 116 h . The temperature of this draw off is about 130-150° C. The temperature may depend on how much washing-liquor that has penetrated to the screen is withdrawn. The white liquor is supplied in a counter-current direction via the central pipe 123 h to the screen girdle section 12 h . The white liquor provides fresh alkali and, in the form of counter-current cooking, further reducing the kappa number. A blow line 26 h may be connected to the bottom 10 h of the digester for conducting the digested pulp away from the digester 6 h.
[0085] A preferred installation according to the present invention, as shown in FIG. 10, may be described as follows. The chips are fed into the chip bin 20 Ah and are subsequently steamed in the vessel 20 Bh and, thereafter, conveyed into the chute 20 Ch. The high-pressure feeder 19 h , which is supplied with a minor amount of white liquor (approximately 5% of the total amount to lubricate the feeder), feeds the chips into the conduit 18 h together with the transport liquid. The slurry of chips and the liquid are fed to the top of the digester 6 h and may have a temperature up to 110-120° C. when entering the digester 6 h (excluding recirculated transport liquor).
[0086] Inside the top of the digester 6 h , there is the top separator 7 h that pushes chips in a downward direction then the chips move slowly downwards in a plug flow through the impregnation zone A in a liquid/wood ratio between 2/1-10/1 preferably between 3/1-8/1, more preferred of about 4/1-6/1. Hot black liquor, which is drawn off from the screen girdle section 104 h , may be added, via the conduit 106 h , to the top of the impregnation zone A of the digester 6 h . The black liquor may also be added to other sections of the digester such as to an intermediate section thereof. The high temperature of the black liquor (100-160° C.), preferably exceeding 130° C., more preferred between 130-160° C., ensures rapid heating of the chips flowing through the impregnation zone A. In addition, the relatively high pH, exceeding pH 10 , of the black liquor neutralizes acidic groups in the wood and also any acidic condensate accompanying the chips, thereby, i.e., counteracting the formation of encrustation, so-called scaling.
[0087] An additional advantage of the method of the present invention is that the black liquor supplied into the impregnation zone A has a high content of rest alkali, (effective alkali EA as NaOH), at least 13 g/l, preferably about or above 16 g/l and more preferred between 13-30 g/l in the top of the impregnation zone A. This alkali mainly comes from the black liquor due to the high amount of alkali in the concurrent zone B of the digester 6 h . Furthermore, the strength properties of the fibers are positively affected by the impregnation because of the high amount of sulphide. A major portion of the black liquor may directly (or via one flash tank) be fed into the impregnation zone A.
[0088] The total supply of black liquor to the impregnation zone A may exceed 80% of the amount drawn off from the draw-off screen girdle section 104 h , preferably more than 90% and optimally about 100% of the total flow, which normally is about 8-12 m 3 /ADT.
[0089] The retention time in the impregnation zone A should be at least 20 minutes, preferably at least 30 minutes and more preferred at least 40 minutes. However, a shorter retention time than 20 minutes, such as 15-20 minutes may also be used. The volume of the impregnation zone A may be larger than {fraction (1/11)}, preferably larger than {fraction (1/10)} of the volume of the digester 6 h . Additionally, in the preferred embodiment, the volume V of the impregnation zone A should exceed 5 times the value of the square of the maximum digester diameter, i.e., V=5D 2 , where D is the maximum diameter of the digester 6 h.
[0090] The chips, which have been thoroughly impregnated and partially delignified in the impregnation zone A, may be fed to the top of the digester 6 h and conveyed into the downwardly-feeding top separator 7 h . The chips are thus fed upwards through the screen, meanwhile free transport liquid may be withdrawn outwardly through the separator screen and finally the chips fall down into the digester 6 h . Before or during their free fall, the chips pieces are drained with cooking liquor, such as white liquor, which is supplied at the top separator 7 h.
[0091] The quantity of white liquor that is added at the top separator 7 depends on how much white liquor possibly is added else where. The thoroughly impregnated chips very rapidly assimilate the active cooking chemicals by diffusion, since the concentration of alkali (EA as NaOH) is relatively high, at least 20 g/l, preferably between 30 g/l and 50 g/l and more preferred about 40 g/l.
[0092] The chips then move down in the concurrent zone B through the digester 6 h at a relatively low cooking temperature, i.e., between 130-160° C., preferably about 140-150° C. The major part of the delignification takes place in the first concurrent cooking zone B.
[0093] The liquid-wood ratio should be at least 2/1 and should be below 7/1, preferably in the range of 3/1-5.5/1, more preferred between 3.5/1 and 5/1. (The liquid wood-ratio in the counter-current cooking zone should be about the same as in the concurrent cooking zone.)
[0094] The temperature in the lower counter-current zone C is preferably higher than in the concurrent zone B, i.e., preferably exceeding 140° C., preferably about 145-165° C., in order to dissolve remaining lignin. The alkali content in the lowermost part of the counter-current cooking zone C should preferably be lower than in the beginning of the concurrent zone B, above 5 g/l, but below 40 g/l. Preferably less than 30 g/l and more preferred between 10-20 g/l. In the preferred case, the aim is to have a temperature difference of about 10° C. between the concurrent zone B and the counter-current cooking zone C. Expediently, the conduit 116 h may be charged with about 5-20%, preferably 10-15%, white liquor from the conduit 24 h via the conduit 117 h.
[0095] The temperature of the liquid which is recirculated via the pipe 123 h up to the screen girdle section 12 h is regulated with the aid of the heat exchanger 120 h so that the desired cooking temperature is obtained at the lowermost part of the counter-current cooking zone.
[0096] From tests made in lab-scale, we have found indications that it is desirable to keep the alkaline level at above at least 2 g/l, preferably above 4 g/l, in the impregnation zone A in connection with black liquor, which would normally correspond to a pH of about 11 . If not, it appears that dissolved lignin precipitates and even condenses.
[0097] [0097]FIG. 11 illustrates a tenth embodiment of the present invention. This embodiment is substantially similar to the embodiment shown in FIG. 10. Chips and a transport fluid is pumped up in a conduit 18 i and a conduit 119 i to a top section 5 i of a digester 6 i via a liquid exchanger 33 i . The operation of the liquid exchanger is similar to the liquid exchanger 33 i described for the sixth embodiment shown in FIG. 7 and its function is similar to the eighth embodiment shown in FIG. 9. As described earlier, liquid is exchanged in the liquid exchanger 33 i before the chips enter the top section 5 i of the digester 6 i.
[0098] A portion of the transport liquid may be returned in return line 15 i that leads from the top portion 5 i to a mid-section of the liquid exchanger 33 i and then back to a feeder 19 i via a conduit 25 i . The conduit 106 i conducts the spent liquor withdrawn from a screen girdle section 104 i to the liquid from 117 i and to the conduit 15 i . A portion of the liquor in the conduit 106 i may be sent to a flash tank 108 i.
[0099] [0099]FIG. 12 shows a eleventh embodiment of the present invention. The eleventh embodiment is similar to the ninth embodiment shown in FIG. 10. Some of the more important differences are described herein. The eleventh embodiment has a digester 6 j having a return line 15 j attached to a top portion 5 j of the digester 6 j . A recirculation line 101 j is in fluid communication with the return line 15 j so that a portion of the liquid in the return line 15 j may be diverted back to the top portion 5 j via the line 101 j . The temperature of the liquid in the recirculation line 101 j may be regulated with a heat exchanger 113 j that is operatively engaged with a high pressure steam line 102 j . The recirculation line is used to heat the liquid from the return line 15 j before the liquid is introduced. The temperature in the return line 15 j must not exceed about 100° C. to avoid undesirable flashing in the high pressure feeder.
[0100] Similar to the above described embodiments, a flash tank 108 j is in fluid communication via a conduit 106 j to a screen girdle section 104 j so that spent liquor from the section 104 j may be conducted to the flash tank 108 j . A bottom portion of the flash tank 108 j has a conduit 103 j connected thereto to conduct a portion of the spent liquor back to a conduit 134 j that carries some white liquor from the cooking liquor conduit 24 j.
[0101] [0101]FIG. 13 describes a twelfth embodiment of the present invention. This embodiment is similar to the embodiment shown in FIG. 12 but it does not have the recirculation line 101 j that is associated with the return line. Instead the twelfth embodiment includes a digester 6 k having an additional screen girdle section 200 k that is disposed immediately below a top section 5 k . The girdle section 200 k has a recirculation line 201 k in fluid communication therewith. The recirculation line 201 k withdraws cooking liquor from the girdle section 200 k and recirculates it back up to a point that is immediately below a top separator 7 k disposed inside the top portion 5 k . The temperature of the liquor in the line 201 k may be controlled by a heat exchanger 203 k that is in operative engagement with a high pressure steam line 102 k . The main reason for using the recirculation line 201 k is to improve the distribution of the white liquor that is withdrawn from the girdle section 200 k . The method of recirculating the cooking liquor is often called quench circulation. The remaining sections of this twelfth embodiment are similar to the embodiments shown in FIGS. 10 - 12 .
[0102] [0102]FIG. 14 is a cross-sectional view of a preferred third embodiment of a top separator 300 of the present invention. In contrast to previously downwardly feeding top separators, this third embodiment is peripherally supplied with chips/slurry. The top separator 300 has a rotating source 333 that is attached to a top of the top separator 300 . The rotating source 333 may rotate a rotor 332 that is in operative engagement therewith and disposed inside the top separator 300 . A plate or lid 334 is disposed adjacent the top of the top separator. The lid may be made of a suitable material such as a standard steel plate. The lid 334 extends diametrically across the top separator 300 and has a central opening defined therein to receive the rotor 332 . A screen 335 is disposed below the lid 334 inside the top separator 300 . The screen 335 extends vertically from about a mid-point of the top separator to a bottom portion of the top separator. The screen 335 is in operative engagement with the rotor 332 . A supply conduit 321 for supplying chips into the top separator is disposed between the lid 334 and the screen 335 . The supply conduit 321 extends through a side wall of the top separator. An important feature of this embodiment is that the supply conduit 321 does not extend through the lid 334 which makes the lid 334 expensive to manufacture such as by casting. Another important feature of this alternative embodiment that is solved by this embodiment is that it is often difficult to adjust, inspect and maintain the screen and the screw member because there is only a very limited space defined between the inner wall of the vessel and the screen. This makes is particularly difficult to adjust and center the screw member relative to the screen once the installation is completed.
[0103] A top of the screen 335 of the top separator 300 is integral with a cylindrical shell 338 that has a flange 339 resting on a support member 340 of the impregnation vessel. The screen 335 has a mid-segment collar 341 that is radially and tightly fitted within a supporting ring 342 at the top separator. This is to provide additional support of the screen 335 due to the large forces that are created at the top portion of the screen 335 . A similar support device is disposed at a bottom portion of the screen 335 . An adjustment mechanism 344 is attached to a support plate 343 at the bottom of the screen 335 . The adjustment mechanism has an adjustment screw so that the position of the screen 335 relative to the wall of the top separator may be adjusted. In other words, the axial position of the bottom of the screen 335 may be adjusted with the adjustment mechanism 344 . Similarly, a second adjustment mechanism 345 is in operative engagement with the bottom of the screen. It is an important advantage to be able to made the adjustment from below the screen 335 . In fact, the adjustment can be made by standing on a platform within the vessel. The support plate 343 also ensures that the lower part of the screen 335 is lifted thanks to protruding pieces that bear against a sliding ring. Four U-beams 346 are disposed at the upper portion of the screen 335 to prevent the screen 335 from be rotated because the U-beams 346 are in operative engagement with a protruding segment 347 that is attached to the collar 341 .
[0104] The invention is not limited to that which has been shown above but can be varied within the scope of the subsequent patent claims. Thus, instead of the shown separator used with the hydraulic digester many alternatives may be used, e.g., instead of an annular supply arrangement a central pipe (as shown in WO-9615313) for supply of liquid at distance downstream of the separator device within chip pile adjacent the top of the digester.
[0105] Moreover, there are many ways of optimizing the conditions even further, e.g., new on-line measuring systems (for example using NIR-spectroscopy) provide for the possibility of exactly measuring specific contents of the fiber material and the liquids entering the digesting system, which will make it feasible to more precisely determine and control the supply/addition of specific fluids/chemicals and also their withdrawal in order to establish optimized conditions. Different kind of additives can be very beneficial to use, especially for example poly-sulphide which has a better effect in a low temperature environment than in high temperatures. Also AQ (Anthraquinone) would be very beneficial since it combines very well with high alkaline environments.
[0106] Furthermore, there are a multiplicity of alternatives for uniformly drenching the chips with white liquor at the top of the digester. For example, a centrally arranged inlet (as described in WO 95/18261) having a spreading device can be contrived, which device, provides a mushroom-like film of liquid, as can a centrally arranged showering element or an annular pipe with slots, etc.
[0107] In addition, the number of screen girdles shown is in no way limiting for the invention but, instead, the number can be varied in dependence on different requirements. The invention is in no way limited to a certain screen configuration and it is understood that bar screens can be exchanged by, for example, such as screens having slots cut out of sheet metal. Also in some installations moveable screens are preferred.
[0108] The shown system in front of the digester is in no way limiting to the invention, e.g., it is possible to exclude the steaming vessel 20 and have a direct connection between the chip bin (for example, a partly filled atmospheric vessel) and the chip chute. Furthermore, other kind of feeding systems than an high pressure feeder may be used, e.g., DISCFLO-pumps).
[0109] 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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A new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.
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BACKGROUND OF THE INVENTION
Clustered munitions have been used to deliver a variety of small weapons which are separated in an air burst to cover a wide target area. The individual weapons known as submunitions are usually bomblets, pyrotechnic devices, or the like, but do not have individual guidance to selected targets, the cluster technique being used primarily for area saturation of a target. Guidance systems have been utilized in some recent submunitions but the designs of these weapons have not included effective wing surfaces nor any propulsion means. Such lack requires that the seeker ranges be excussive and the area of coverage small. Guided weapons are usually individually launched and carry a large warhead, since the complexity and cost of the guidance system makes it impractical for large numbers of small missiles.
Targets such as tanks or other armored vehicles are not easily damaged by randomly scattered small munitions. However, if a direct hit can be made, a small shaped charge of explosive can destroy or incapacitate a tank. In an attack on a group of armored vehicles it would be a distinct advantage to use multiple small missiles capable of homing on individual targets, while keeping the unit cost to a minimum.
SUMMARY OF THE INVENTION
In the weapons system described herein, a delivery canister or other appropriate holder contains or holds a cluster of small rocket propelled missiles, which are normally stored with aerodynamic surfaces folded. The canister, for example, is launched from an aircraft at low altitude, preferably by a lofting maneuver which enables the aircraft to stay clear of the target area. At a predetermined altitude the canister bursts and the missiles fall free. The aerodynamic surfaces extend and the missiles level out at a preset cruise altitude, controlled by a simple aneroid device in each missile. The missiles are propelled toward the target area each having a simple seeker system for detecting a target. It has been found that a radiometric detector operating in the millimeter wavelength band, at 35 GHz for example, can detect a metal or similarly reflective target against the terrain background. When a target is identified by signal discrimination the scanning antenna of the radiometric seeker system is driven in a tracking pattern which enables the missile to be steered to a direct hit on the target. A small shaped charge warhead carried in the missile is thus delivered in the most effective manner for destroying the target.
The primary object of this invention, therefore, is to provide a new and improved multiple target seeking clustered munition adapted for aerial delivery at a safe distance from the target.
Another object of this invention is to provide a multiple target seeking clustered munition in which the individual munitions have means for detecting and homing on a target.
Still another object of this invention is to provide a new and improved multiple target seeking clustered munition which, with its versatility of operation, is simple and low in cost.
Other objects and advantages will be apparent in the following description and with reference to the accompanying drawings, in which:
FIG. 1 is a diagram of a typical delivery operation of the clustered munition.
FIG. 2 is a perspective view of a typical individual missile or vehicle.
FIG. 3 is a top plan view of the missile with the aerodynamic surfaces folded.
FIG. 4 is a front elevation view of four such missiles clustered for installation in a canister.
FIG. 5 is a diagram, in side elevation, of the cruise mode of the target seeking missile.
FIG. 6 is a diagram from above, illustrating the scanning pattern of the seeker means.
FIG. 7 is a diagram of the scanning pattern in the tracking and homing mode.
FIG. 8 is a block diagram of a radiometer seeker system.
FIG. 9 is a function diagram of the target seeking and homing action.
FIG. 10 is a diagram illustrating a typical target pulse occurring in the radiometer system.
FIG. 11 is a diagram illustrating the small signal occurring from a change in background character.
FIG. 12 is a perspective view of an alternative missile configuration.
FIG. 13 is a side elevation view of a further missile type for delayed target detection after delivery.
FIG. 14 is a diagram of the operation of the missile shown in FIG. 13.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the typical mission illustrated in FIG. 1, an aircraft 10 flies a conventional lofting maneuver, indicated by flight path 12, to release a conveyance device, such as a canister 14, for example, which follows a ballistic path 16 to a target point 18. At the target point the canister bursts and releases a cluster of missiles 20, which are spread out across the target front by the bursting action, by aerodynamic trim or any other suitable separation means. Typically the aircraft, which could be some other type of flying vehicle, approaches at about 500 feet altitude and releases the canister about 20,000 feet from the target point, which may be from 1,000 to 1,500 feet in altitude. It should be understood that the missiles could also be clustered in or around a separable rack-like conveyance (not shown) which may have an ejectable protective cover if desired.
One form of the missile illustrated in FIGS. 2-4, has a generally cylindrical body 24 with a domed nose section 26 and a tapered tail section 28. Mounted on a short pylon 30 above the body 24 are wings (control surfaces) 32, hinged on pivots 34 to fold back along the body. On the tail section 28 are horizontal control surfaces 36 and a vertical control surface 38, mounted on hinges 40 to fold back. The wings and control surfaces may be extended upon release by simple springs, or by any other suitable means, self-extending aerodynamic surfaces on missiles being well known. It should be understood that none of the wings or other control surfaces need be the foldable type but some or all could be permanently fixed in the extended position, depending upon missile size, number desired, storage factors, mission requirements, etc., and the degree of complexity and sophistication involved.
In the central portion of the body is a conventional shaped charge warhead 42, actuated by a suitable crush switch or impact type detonator. The missile is guided by a radiometer 44, having an antenna 46 within nose section 26, with an antenna scanning drive 48. Behind the warhead is a battery 50 and a guidance electronics package 52, included an aneroid unit 54 or other altitude control means. In the tail section 28 is a rocket motor 56, for example, preferably capable of providing 15 to 20 seconds sustaining power. The control surfaces 36 and 38 are rotatably driven about spanwise axes by servo motors 58. It must be emphasized that by designing a missile having an airframe and control surfaces which provide a high glide ratio, the rocket motor 56 may be deleted. However, there would be a decrease in the overall range and a decrease in effectiveness, that is, the number of target encounters would be less.
As is understood by those skilled in the art, the basic techniques of scanning for and tracking a target, and controlling the flight path of a missile to intercept the target are well known. Many off-the-shelf antenna drive and vehicle guidance circuits and packages, and control servo systems, are readily available, and adaptable to the vehicle illustrated.
Upon release from the canister, the missile is activated by switching on the seeker and guidance systems. This can be accomplished by static lines or lanyards 59 tied to the canister, or by the spring erection of the aerodynamic surfaces. The aneroid unit 54 can be preset or can be set on release with reference to altitude sensing means carried in the canister, to cause the guidance package to level the missile out at the predetermined cruise altitude. At this altitude the rocket motor 56 is fired to sustain the missile in cruising flight.
During the cruise portion of the flight, the antenna 46 is directed at 45 degrees, for example, downwardly from the longitudinal axis of the missile, as indicated in FIG. 5, and is swept from side to side by the drive means 48 to produce the scan search pattern, the beam spot traverses a forwardly progressing arcuate path which sweeps the terrain ahead of the missile. When a target 22 is detected, the antenna scan is switched to an identification and track pattern centered on the target, as in FIG. 7, producing a signal pulse each time the beam crosses the target 22. The missile is then controlled by the guidance system to home on the target. From the cruise altitude indicated and the relative position of the missile to the target due to the initial look-down angle, the missile will impact the target from a near vertical approach.
The radiometer 44 is essentially a passive receiver of well known circuitry, sensitive to energy in a millimeter waveband. A frequency of 35 GHz has been found particularly suitable. The receiver in solid state form is small enough to permit mounting directly on the antenna 46, thus eliminating flexible waveguides. One form of millimeter wave radiometer 44 uses a millimeter wave oscillator or added into the radiometer circuitry whereby the radiometer functions as an active radiometer. The added illuminator utilizes a silicon IMPATT type diode, for example, in an adjustable holder. A Cassegrainian antenna having a rotating secondary reflector is connected to the illuminator and to a transmit-receive switch (which is preferably a PIN diode switch) through a duplexer, which may be a ferrite circulator. A balanced mixer is connected to the output of the switch and to a local oscillator operating with a Gunn type diode, for example. The mixer output is fed to an IF/video amplifier whose output in turn is fed to a tracking circuit having a range gate. The tracking circuit accepts video and timing reference pulses and delivers detected scan modulation and a dc acquisition indicator voltage to a gimbal servo control circuit. The servo control circuit controls the position and motion of the gimbaled antenna during search and track modes. The antenna mount is a two-axis direct drive gimbal, powered by two dc torque motors. Potentiometers mounted within the motor housings provide closure of the servo loops. A modulator/synchronizer circuit network is connected to the illuminator, the switch and to the tracking circuit. The modulator/synchronizer circuit performs three functions. It generates a train of rectangular pulses that controls the illuminator output waveform, it protects the mixer against power overload by turning off the switch for the duration of each transmitted pulse of energy and it sends synchronizing pulses to the tracking circuit to control the start of each range sweep.
In the millimeter wavelength region, terrain background, being effectively a lossy dielectric, has an average radiometric "temperature" of about 280° K. A metal target, such as a tank, reflects a sky temperature of about 50° K. The sky temperature actually varies with reflectivity of the target and the angle of reflection from the zenith, but the generalized figures indicate the large difference which facilitates picking a target out of the background. Certain backgrounds such as asphalt, and water in particular have effective temperatures which differ from the background average. However, by selective filtering the radiometer can be made sensitive to the particular target signal range required.
In FIG. 10, the beam spot is represented as passing over a target. The reflectivity will undergo a sharp change as the target enters the beam spot, as indicated by leading edge slope 60, the reflectivity remaining at a peak value 62 while the target is within the spot and returning to nominal background value 64 as the spot passes beyond the target. The resultant radiometer signal pulse 66 is sufficient to trigger recognition circuitry.
In FIG. 11 a more gradual change 68 in reflectivity is indicated as the beam spot passes through one terrain type to another, such as from rocks to heavy brush. The resultant signal change 70 is small and the output remains at the new level until the beam encounters another change in terrain. Such changes do not affect the radiometer output sufficiently to initiate any action. It will be obvious that there will also be fluctuations in the signal due to irregularities in the terrain being scanned, but these will not normally be sufficient to trigger a reaction.
Referring now to FIG. 8, the output of the radiometer 44 is fed to an amplitude discriminator 72, which determines when a sufficient amplitude change occurs to suggest a target. The amplitude discriminator provides a signal to a pulse width discriminator 74 and to a mode selector logic circuit 76. A pulse counter 78 is connected to the pulse width discriminator 74 and provides a second signal to the mode select logic circuit 76. When no significant changes are occurring in the radiometer output, the mode select logic commands the antenna drive 48 to operate in the search mode, with the sweeping action of FIG. 6.
If a pulse of sufficient amplitude is received, the mode select logic switches to an identification mode and commands the antenna drive 48 to operate in the identification and track pattern of FIG. 7. If the pulse width and number of pulses meet the predetermined requirements, the mode select logic switches to track mode. The antenna scan pattern continues in the same type pattern, but switch 80 is actuated to start the track guidance package 52, which controls servos 58 to guide the missile to the target. If the pulse width and number of pulses do not meet requirements, the mode select logic reverts to the search mode to continue target seeking.
The functions involved in the operation are diagrammed in FIG. 9. At the start the radiometer signals are those received from the search pattern scan. In the amplitude discrimination circuit an upper threshold (UT) is set at a constant and the lower threshold of pulse amplitude is variable. This allows processing small signals which may be of interest, such as received from grazing contact of the beam with a target. If the signal (S) is within limits equal to or greater than the lower threshold and equal to or less than the upper threshold, the signal is passed to the pulse width circuitry. If the signal is not within the set amplitude limits, the search pattern continues.
In the pulse width circuitry based on the known scanning speed and the average width of a target of interest, which avoids reaction to a significant pulse from a wide target such as a body of water. If the signal pulse width is equal to or less than the preset pulse width (PW) the track pattern is initiated. If the pulse width is equal to or greater than the preset value, the search pattern continues. The pulse counter now determines if the target signal is present for three consecutive scans, to ensure that the target is within the effective strike zone of the missile. If not the search pattern is resumed. If the target signal is present as required, the pulse counter determines how many times the pulse occurs in each side to side scan. If the number is more than two, as from multiple targets which could cause indecision and a miss, the search pattern is resumed. If, however, the number of target pulses is not more than two per scan, the guidance to the target is initiated.
Also in the circuitry is a flight timer which is set to a time sufficient to allow the missile to reach a target within the range of its propulsion means. The timer is activated at the start of the function sequence and, when the preset time is reached, the missile is commanded to self destruct by any suitable means.
An alternative missile configuration, particularly suitable for high speed operation, is illustrated in FIG. 12. The body 82 contains all of the equipment used in missile 20, and the tail section carries horizontal control surfaces 84 and vertical control surfaces 86 in a cruciform arrangement. The wings are also in cruciform arrangement and are offset 45 degrees in rotation from the tail surfaces, all the surfaces being foldable. In flight the upper pair of wings 88 would be extended for cruising, the lower wings 90 being folded as indicated in broken line. Upon initiation of final tracking on a target, the lower wings would be extended, making the missile aerodynamically symmetrical to simplify directional control in the final approach to the target.
A further missile configuration is illustrated in FIGS. 13 and 14. The body 92 again contains all of the equipment as described above. Wings 94 are shown extended and the tail surfaces 96 retracted, in which configuration the vehicle is implanted vertically nose up in the ground. The missile can be air dropped or may be manually implanted in an area known to be frequented by target vehicles. The extended wings act as stabilizing means to support the missile.
At the base of the body is a sensor 98, which may be of a seismic type to detect vibrations of an approaching target 22. Acoustic, thermal, or other such sensors may also be used at appropriate positions on the missile. When an approaching target is detected, the rocket motor 100 is fired to propel the missile upwardly until burnout of the motor. The missile will then turn over at the peak 102 of the flight path, stabilized by the now extended tail surfaces, so that the seeker system can detect and home on the target.
If the missile is equipped with a more sophisticated guidance system, such as inertial type guidance, the missile may be programmed to a lower and faster flight path 104. At the close range at which the missile attacks the target, other seeker or sensor means may be suitable such as acoustic or thermal types.
The missile system is thus primarily effective against a dispersed group of targets and is delivered by an aircraft from a safe distance. The missiles seek out individual targets with simple detection and guidance means and attack from above on the vulnerable portions of the targets.
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A clustered munition in a system for low altitude aerial delivery, which releases multiple rocket powered missiles, each having the capability to cruise at a constant altitude and search for a target. Once a target is identified, the missile homes on and strikes the target. In the preferred form the target seeking means is a radiometric seeker operating in the millimeter wavelength range, in which metal or similarly reflective targets stand out against the background and provide a significant signal which is used to program the terminal action of the missile.
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BACKGROUND OF THE INVENTION
In the feeding or supply of metal sheet-like articles or blanks to a machine or press where one or more operations are performed on each article, it is commonly desirable to supply or transfer the articles to the press in a successive manner and at a high rate of speed so that optimum performance can be obtained from the press. It is also desirable for the feeding or transfer mechanism to operate in a continuous and dependable manner without interruption so that there is no down time of the press which receives the articles.
Frequently, it is necessary to supply or feed sheet-like articles such as flat blanks to a press by picking up each sheet from the top of a supply stack, moving the sheet laterally or horizontally to a predetermined location and then lowering the sheet onto a feeding mechanism which successively feeds the blanks or sheets into the press. Furthermore, it is usually desirable for the articles or sheets to be transferred from the supply stack to the press in precise timed relation with the operation of the press.
SUMMARY OF THE INVENTION
The present invention is directed to improved apparatus for successively transferring articles from a storage or supply station to another station where the article receives one or more operations. Apparatus of the invention is particularly adapted for successively transferring articles at a high speed and in timed sequence with another power driven machine and is also adapted for dependable operation so that the articles are transferred without skipping or interruption. In addition, the apparatus of the invention provides for precision movement of each article along a predetermined path and for precisely positioning the article at a receiving station.
Other advantages and features of the invention and the specific construction of one embodiment will be apparent from the following description, the accompanying drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of apparatus constructed in accordance with the invention for successively transferring articles from supply stacks to a receiving station;
FIG. 2 is an enlarged perspective view of the hopper forming part of the apparatus shown in FIG. 1;
FIG. 3 is a diagramatic vertical section of the lower portion of the apparatus shown in FIG. 1;
FIG. 4 is a diagramatic vertical section of the upper portion of the apparatus shown in FIG. 1; and
FIG. 5 is a fragmentary section taken generally on a line 5--5 of FIG. 4 and showing the indexing mechanism used in the apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus illustrated in FIG. 1 is adapted for successively transferring articles A in the form of flat oval metal blanks or sheets from a supply stack S to a mechanism (not shown) for feeding a press having a die set for forming each sheet into an end wall of a muffler. However, while each article A is illustrated in the form of a flat oval blank or sheet, it is to be understood that the article may be of a different shape or configuration.
As shown in FIGS. 2 and 3, the stack S of flat ferrous metal sheets A are confined within a hopper 15 formed by two sets or pairs of vertical guide rods 16 positioned at opposite ends of the stack. Each pair of guide rods 16 is supported by an L-shaped bracket 18 which is mounted on a horizontal support plate or platform 19 for lateral or horizontal adjustment by a set of screws 21 extending through corresponding slots within the base portion of the bracket. A set of four rectangular permanent magnets 25 are supported in horizontally spaced generally opposing relation on opposite sides of the stack S by corresponding L-shaped brackets 26 which are also secured to the platform 19 by sets of screws 27 extending through corresponding slots within the base of the brackets 26.
Preferably, the magnets 25 are of the type manufactured and marketed by Bunting Magnetics Co., Franklin Park, Ill. and are effective to induce a magnetic field within the sheets A so that the sheets within the upper portion of the stack are separated and spaced vertically apart in a logarithmic manner and the sheets remain in parallel vertically spaced relation. This magnetic separation of the sheets within the upper portion of the stack assures that two adjacent sheets do not stick together as a result of oil or other forms of surface adhesion.
A set of four dogs or pawls 32 are positioned adjacent the bottom of the hopper 15, and each pawl 32 is pivotally supported by a corresponding horizontal pin 33 secured by a bracket 34 depending from the stationary platform 19. The pivot pins 33 are located so that the weight of each pawl 32 normally positions the pawl as shown in FIG. 3 where the pawl engages the bottom article or sheet A within the stack S and rests against a corresponding stop pin 36.
A rotary indexing transport member or table 40 is positioned below the hopper 15 and includes sets of upwardly projecting rods 42 which are interconnected by cross-members 43, 44 and 46 to form nests for receiving a plurality of supply stacks S of sheets A. The stacks S are angularly arranged in a spoke-like manner on the annular table 40, and are successively located or positioned directly under the hopper 15 in response to indexing of the table 40 by a suitable power indexing drive (not shown).
A mechanical elevator or jack actuator 50 (FIG. 3) is positioned below the transport table 40 and under the hopper 15, and includes a circular head member 52 secured to the upper end of a helical ball screw 53 which receives recirculating balls (not shown) confined within a rotary nut driven by a reversible drive motor 55. Preferably, the jack actuator 50 is of the ball screw actuator type, for example, as manufactured and marketed by Duff-Norton Company, Charlotte, N.C. A set of circular holes 56 are formed within the indexing table 40 directly under the centers of the stacks S of sheets A, and each hole 56 is adapted to receive the head 52 of the jack actuator 50 when the head member 52 is raised for elevating a stack of articles on the table 40 into the hopper 15.
Referring to FIGS. 1 and 4, a rotary indexing unit or mechanism 60 includes a housing 62 which is mounted on a frame (not shown) and supports a rotatable input shaft 64 and a rotatable tubular output shaft 66. Preferably, the general construction of the indexing unit or mechanism 60 is similar to that shown in U.S. Pat. No. 2,986,949 which issued to Commercial Cam and Machine Company, Chicago, Ill. The indexing mechanism 60 provides for indexing the output shaft 66 in angles of predetermined degrees in response to continuous rotation of the input shaft 64. A double cam member 68 is secured to the input shaft 64 for rotation therewith and has outer peripheral cam surfaces 69. A cam follower 72 includes a plurality of axially spaced sets of roller 63 for engaging the outer cam surfaces 69 of the cam members 68. THe cam member 68 and the cam follower member 72 cooperate to prevent back lash or relative play when the follower member 72 is rotatably indexed in response to continuous rotation of the cam member 68 and thus provides for precision rotation of the output shaft 66.
The output shaft 66 includes an enlarged cylindrical lower portion 76 which supports an elongated upper plate 77. A pair of parallel spaced vertical guide rods 81 have their upper end portions rigidly secured to the plate 77 and project downwardly into corresponding antifriction sleeve-type ball bearings 82 which are supported by an elongated lower plate 84. Thus the plates 77 and 84 rotate with the output shaft 66 of the indexing mechanism 60, and the lower plate 84 is supported for vertical movement relative to the upper plate 77. Preferably, the plates 77 and 84 are constructed of aluminum to minimize their mass.
An elongated transfer member or arm 90 has its center portion rigidly secured to the lower plate 84, and a pair of oval shaped suction units 92 (FIG. 1), having resilient oval lips 93, are secured to the opposite end portions of the transfer arm 90. Compressed air is supplied to the transfer arm 90 through an air supply tube 94 (FIG. 1) and a rotary union 96 located on the axis of rotation, and the compressed air is passed through a venturi to generate a suction within each suction unit 92 when it is positioned over the hopper 15. The pressurized air supply is also alternately supplied directly to each suction unit 92 when it is positioned 180° from the hopper 15, as will be explained later.
Referring to FIG. 4, an elongated vertical rod 102 extends through the tubular output shaft 66 of the indexing mechanism 60 and has its lower end portion connected to the lower plate 84 through an anti-friction thrust bearing 103 and a nut 104. A linear actuating unit or mechanism 110 includes a box-like housing 112 which is secured to the housing 62 of the indexing mechanism 60 and encloses a cylindrical barrel-type cam member 114 which has a peripherally extending cam groove or surface 116. The cam member 114 is rigidly secured or connected to the input shaft 64 of the indexing mechanism 60 and is driven with the cam member 68 at a constant rpm by a drive unit 120.
The housing 112 of the linear actuating mechanism 110 also supports a pair of horizontally spaced vertical guide rods 122 which receive a corresponding pair of sleeve-type anti-friction ball bearings (not shown) retained within a follower block 124 rigidly connected to the upper end portion of the actuating rod 102. The block 124 supports a roller-type cam follower member or element 126 which projects horizontally into the cam groove 116 of the cam member 114.
In operation of the article transfer apparatus described above, the input shaft 64 is driven at a constant speed by the drive 120 which may be an extension from the drive of another machine such as a punch press. The cam members 68 and 114 are designed so that the output shaft 66 is indexed in increments of 180° with a dwell between each indexing movement. The cam member 114 produces vertically reciprocating movement of the plate 84 and the transfer arm 90 during each dwell of the indexing mechanism 60. When the transfer arm 90 descends, the suction unit 92 overlying the hopper 15 is effective to pick up the uppermost blank or sheet A on the stack S within the hopper 15. After the transfer arm 90 ascends to the position where the lower plate 84 is substantially adjacent the upper plate 77, the transfer arm is rotated or indexed 180° by the mechanism 60 so that the blank or sheet A is carried to a receiving station, for example, above a feed mechanism (not shown) which successively feeds the sheets into a punch press.
When the transfer arm 90 again descends, air pressure is created within the suction unit 92 at the receiving station so that the transferred sheet A is released from the suction unit and deposited on the sheet feeding mechanism. Simultaneously, the suction unit 92 on the opposite end of the transfer arm 90 picks up the uppermost sheet A within the stack S within the hopper 15 as a result of a suction created in the suction unit, and the cycle is repeated. As mentioned above, successive stacks of blanks or sheets A are supplied to the hopper 15 in response to a proximity sensor 130 which senses the level of the sheets A within the hopper 15 and controls the operation of the indexing drive for the table 40 and the drive 55 for operating the jack actuator 50.
From the drawings and the above description, it is apparent that transfer apparatus constructed in accordance with the present invention, provides desirable features and advantages. For example, the combination of the rotary indexing unit or mechanism 60 and the linear actuating unit or mechanism 110 provides for a precision high speed transfer of a succession of articles when it is desirable to transfer each article along a path which requires vertical or "X" movement as well as horizontal or "Y" movement. Furthermore, the combined mechanisms produce the X-Y transfer path at a high speed in response to continuous rotation of the input shaft 64. For example, it has been found that the combined mechanisms provide for easily transferring metal blanks or sheets A at a speed of one sheet per second and for depositing each sheet in a precise position at the receiving station. In addition, the two separate cam members 68 and 114 provide for conveniently and independently selecting or changing the "X" path and the "Y" path to produce a desired transfer path. It is also understood that the rotary indexing mechanism 60 may be constructed to produce intermittent rotary oscillatory movement as well as intermittent rotary indexing movement.
As another important advantage, the mechanisms 60 and 110 cooperate with the article supply hopper 15 and article spacing magnets 25 to assure that the articles or sheets are successively transferred in a rapid manner without interruptions and with optimum dependability so that continuous operation of the press which receives the articles is assured.
While the indexing mechanism 60 and the linear actuating mechanism 110 are illustrated in a machine for successively transferring flat sheets A from the supply hopper 15, it is apparent that the combined mechanisms may be used in other machines or apparatus which require X-Y transferring or advancement of one or more articles. Furthermore, while the form of transfer apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.
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A rotary transfer member carries means for picking up a sheet-like article from the top of a supply stack supported within a hopper having an open top and an open bottom. An indexing mechanism includes means for intermittently rotating an output shaft in response to a continuously driven input shaft, and the transfer member is supported for rotation with the output shaft and also for axial movement relative to the output shaft. The transfer member is moved axially in response to linear movement of a follower which engages a cam connected for continuous rotation with the input shaft. Supply stacks of articles are successively elevated into the hopper from an index table by a power driven jack mechanism, and a set of magnets are positioned adjacent the hopper for magnetically spreading and spacing the articles within the upper portion of the supply stack within the hopper.
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The present invention relates generally to a seat adjustment mechanism which is especially suitable for enabling adjustment of the position of the seat of a motor vehicle. More particularly, the invention is related to a mechanism which includes a seat member supported on an adjustable seat underframe with at least one adjustment motor being provided which is connected with the seat member through at least one drive connection having two mutually engaging drive or transmission parts.
In a seat adjustment mechanism of the type to which the present invention relates, an audible, perceptible rattling will occasionally occur during operation of the adjustment mechanism. It has become apparent that the rattling phenomenon occurs when the weight of the seat, combined with the weight of a passenger occupying the seat, acts in a direction abetting the force through which the adjusting movement of the seat member is effected by the motor of the adjusting mechanism. In a situation where the force exerted by the motor during the adjustment operation is of the same order of magnitude as a seat force, which may be defined as a force deriving from the weight of the seat itself and the weight of a person occupying the seat, which seat force acts in a direction abetting the force applied for adjusting the seat by the motor, it is possible that one of the parts of the drive mechanism may act relative to a mating part with which it engages, to alternately operate as a driving member and as a driven member. Thus, an alternating change of load application may occur which can involve a rather high frequency of occurrence. This could lead to extremely disturbing vibrations and noises unless the entire drive connection mechanism, and in particular the two mutually engaging drive parts, are manufactured with close tolerances so as to be free from play.
However, such precision in manufacturing generally tends to increase the cost of the parts involved and moreover renders the mechanism unsuitable for conventional mass production techniques.
In view of the foregoing, the present invention is directed toward providing a seat adjustment mechanism of the type mentioned above which will operate more quietly than devices presently known.
SUMMARY OF THE INVENTION
Briefly, the present invention may be defined as a seat adjustment mechanism particularly adapted for use in motor vehicles comprising a seat member, motor means for adjustably moving the seat member, transmission means including at least two mutually engaging transmission parts operatively interposed between the seat member and the motor means, and braking means for applying a braking force against adjusting movement of the seat member by the motor means in one direction, the direction of adjusting movement of the seat during which the braking force is applied being a direction in which the movement of the seat member by the motor means is in a direction abetted by a seat force exerted by the seat member.
As previously indicated, this seat force generally may be defined as a force generated by the weight of the seat itself and the weight of a passenger occupying the seat.
Thus, the objectives of the invention are achieved by providing a braking device which counteracts the adjusting movement of the seat member, when the adjusting movement is made in a first direction with the force moving the seat being abetted by the seat force which the seat exerts upon the underframe. As a result of the braking action, an effect is achieved whereby the drive connection, and therefore also the two mutually engaging drive parts, are maintained constantly under a defined tension which does not change. Hence, it will always be the same tooth surfaces which engage each other so that operation free from vibration may be ensured even when the drive parts which engage each other are formed so that there is play therebetween.
In a first embodiment of the braking device in accordance with the invention, when adjusting movement of the seat occurs in a first direction, a braking effect is created of such a type on the drive connection in the power path between the adjustment motor and the drive parts, that one of the drive parts which is nearer to the adjustment motor in the power path is acted upon by the adjustment motor with an adjusting force which is less than the seat force which is acting on the other of the drive parts. As a result of this, an effect is achieved whereby no load change of the drive connection occurs even at the beginning and at the end of the adjusting movement in the first direction because when the seat adjustment is stationary as well as while the adjusting movement is being effected, the other drive part under the effect of the dominant seat force will press against the one drive part always with the same tooth surfaces.
Another advantage involved is that the adjustment motor for the adjusting movement of the seat in the first direction may be dimensioned to be relatively smaller since the adjusting movement itself will be abetted by the force generated by the seat.
In another embodiment of the braking device in accordance with the present invention, when the adjusting movement of the seat is effected in the first direction, a braking effect is created on the drive connection in the power path between the drive parts and the seat member whereby one drive part which is nearer the adjustment motor in the power path is acted upon by the adjustment motor with an adjusting force greater than the seat force which is acting upon the other drive part and which is reduced by the braking action. This embodiment is especially advantageous under circumstances where it is simpler to brake the other of the two drive parts which are in engagement. A change of load occurs only at the beginning and at the end of the adjusting movement During the adjusting movement, the braking mechanism operates such that the adjusting power is dominant and such that the drive connection is therefore maintained constantly under a defined tension.
In accordance with the invention, the braking device is constructed as a frictional brake thereby permitting the braking mechanism to be formed of a simple construction which is economical to produce.
In accordance with one aspect of the invention, at least one plastic or rubber friction ring is provided between the outer circumference of a drive shaft and the inner circumference of a brake housing mounted on the seat underframe. Friction rings of this type are generally obtainable in many different dimensions.
In a further aspect of the invention, the drive shaft is embraced by a one-part or multi-part prestressed brake head of plastic or the like which is mounted on the seat underframe, rigidly connected for rotation. For setting a desired brake force, the brake head formed with a bifurcated construction may be provided with mutually engaging notched teeth on the ends of the bifurcated structure. It is, however, also possible to prestress the brake head by means of at least one screw connection.
When an adjusting movement is made in a second direction contrary to the first direction, the seat force will be applied in a direction opposing the motor drive force applied for adjustment of the seat. Under such circumstances, it is not necessary for a braking force to be applied and in order to eliminate the necessity for such a braking force to be overcome, the present invention is structured so that a freewheeling operation which renders the braking device inoperative may occur when the adjusting movement is made in a direction which must overcome the seat force, i.e., in a direction where the seat force does not abet the driving force for seat adjustment.
As a freewheeling system which is found more reliable in operation and yet economical to produce, a freewheeling system, and preferably a needle-bearing sleeve, is provided which in one rotational direction rotates with the drive shaft and which in the other rotational direction is freewheeling.
This freewheeling sleeve, in a suitable embodiment of the invention, can be mounted on the outer circumference of the drive shaft either inside a plastic or rubber friction ring or inside of a brake head.
When the seat is adjusted linearly in a forward or rearward direction, the seat having at least one upper rail furnished with a rack supported so as to be movable forwardly and rearwardly on a lower rail, the seat also having a drive pinion which meshes with the rack, a seat force occurs which on occasion will cause rattling in the adjusting movement as soon as the rail runs in a direction inclined to the horizontal. In this case, there is obtained a component of the seat force which corresponds to this inclination and which is directed in the longitudinal direction of the rails. If a low friction, ball track rail is used, there is no significant reduction in the power component by the force of any friction which develops between the rails. In order to avoid rattling during operation, the invention provides that the drive pinion be constructed as the one of the two drive parts and that the rack be constructed as the other of the two drive parts. As has been previously explained, the braking device may be formed to produce a braking effect either on the drive connection between the adjustment motor and the drive pinion or on the drive connection between the rack and the seat member.
At the same time, the braking device can also be constructed to work directly upon the drive pinion or upon the rack.
Preferably, the braking device is structured to engage a pinion shaft of a drive pinion of the driving mechanism since, in this case, the braking device may be built in an especially simple manner and may also be readily combined with the aforementioned freewheeling sleeve.
It is proposed that the drive pinion be connected with a worm gear arranged in a drive unit housing and be driven by a worm and that the brake housing be formed as part of the drive unit housing. A special brake housing for the purpose is consequently not necessary.
In an especially stable arrangement, there may be provided two upper rails running parallel with each other upon which the adjustable seat member is mounted. Each of these rails is provided with a rack and two lower rails are also provided with two drive pinions being connected with each other by means of a connector shaft, the drive pinions operating to engage the rack. In such a case, the braking device of the invention is provided in the area of one of the ends of the connector shaft or in the area of both ends of the connector shaft.
In the case where a seat adjustment mechanism is provided with at least one swivel lever constructed with a toothed sector and a drive pinion which operate for raising or inclining the seat member, with the drive pinion meshing with the toothed sector of the swivel lever, it is proposed in accordance with the invention that the drive pinion be constructed as one of the drive parts with the toothed sector being constructed as the other of the drive parts. By this approach, frequent change of load on lowering of the seat is prevented. If as proposed, the braking device engages a pinion shaft of the drive pinion, the effect will be achieved in that the adjusting power with which the drive pinion acts upon the toothed sector will always be less than the seat force conveyed from the toothed sector to the drive pinion so that no change of load will occur at any time.
In another embodiment of the invention, the braking device is structured to engage the swivel lever, an action which under certain circumstances is structurally easier to achieve, especially when two swivel levers rigidly connected for rotation with each other are provided and when at least one of the swivel levers is constructed with a toothed sector. In this case, the braking device may be made to engage the outer circumference of the connector shaft. Here, again, the braking device may be combined with a freewheeling sleeve.
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. 1 is a side view partially in section of a first embodiment of a braking device in accordance with the invention taken along a line I--I of FIG. 2;
FIG. 2 is a top view of the arrangement shown in FIG. 1;
FIG. 3 is a sectional view showing a second embodiment of a braking device in accordance with the invention; and
FIG. 4 is a sectional view a third embodiment of a braking device in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 wherein there is depicted a first preferred embodiment of the invention, a seat adjustment mechanism 10 is depicted which is basically composed of a seat underframe 12 adapted to be movably adjusted by operation of a motor. The assembly shown in FIG. 1 includes two bottom rails 14, one of which is visible in FIG. 1, by means of which the seat underframe 12 is fastened onto sheet metal holders 16 on the floor of the motor vehicle.
The motor vehicle seat member itself is designated by the reference numeral 18 and is shown in FIG. 1 in dotted line form. The seat member 18 is mounted upon two upper rails 20 which extend parallel with each other and which are, in turn, supported upon the two lower rails 22 so as to movable lengthwise relative thereto.
In order to accomplish motorized shifting of the two upper rails 20 which support the vehicle seat member 18 relative to the lower rails 22, a rack 24 is mounted on each of the upper rails 20. Additionally, an end piece 26 is fastened at both ends of each of the upper rails 20 with this end piece 26 including a lug 28 protruding downwardly and to the side which is bolted by a pin 30 to a corresponding end of the rack 24.
A drive pinion 32, which is shown in dotted line form in FIG. 2, is in meshing engagement with the rack 24. The drive pinion 32 is connected upon a drive shaft 34 indicated by dash-dot line, with the drive shaft 34 being driven by a worm gear drive 36 which is, in turn, connected with an electrical adjusting motor by means of a flexible connector shaft 38.
The adjusting motor is part of a motor unit 40 which includes besides the adjusting motor for driving the rack 24, thereby serving for lengthwise shifting of the seat member 18, two additional adjusting motors which operate to effect inclination and raising of the motor vehicle seat 18.
The basic construction of a worm gear drive of the type which may be used with the present invention and which represents a second embodiment of the invention is shown in FIG. 3. The embodiment of FIG. 3 is different from the embodiment shown in FIGS. 1 and 2 in that it, for example, involves a different construction of the upper rail, and the FIG. 3 embodiment will be described in greater detail hereinafter.
Referring now to the embodiment shown in FIGS. 1 and 2, the worm gear drive 36 is attached by means of screws 44 to a mounting plate 42. The mounting plate 42 is, in turn, attached by means of screws 46 to the lower rail 22. The mounting plate 42 is formed with reinforcing rings 48. A corresponding mounting plate 50 is also mounted on the lower rail 22 on the right side of the assembly, as seen in FIG. 2. The motor unit 40 is attached by screw and bolt connections 54 onto a fastening bracket 52 which is rigidly attached by screws 56 to the mounting plate 50.
In order to achieve an exactly simultaneous movement of the two upper rails 20, a drive pinion 58 corresponding to the drive pinion 32 is provided on the right side of the assembly as viewed in FIG. 2. The drive pinion 58 meshes with the rack 24 located on the right hand side, as seen in FIG. 2, of the assembly and it is connected for rotation by means of a tubular connecting shaft 60 with the drive pinion 32. The drive pinion 58 is indicated in FIG. 2 in dotted line form.
The two mounting plates 42 and 50 are connected at their left ends, as seen in FIG. 1, with a corresponding bottom rail 14, each by means of a swivel lever 62 which is pivotally supported on each of these parts.
Additionally, a connector shaft 64 welded with both swivel levers penetrates a corresponding bearing bore hole on a fastening lug 66 which extends upright on the respective ends of both of the bottom rails 14. The fastening lugs 66 are located within the swivel levers 62 which are formed with a bifurcated configuration best viewed in FIG. 2. The corresponding swivel lever 62 is pivotally supported on the mounting plate 42 by means of a pin 68 which additionally serves to fasten a worm gear drive 70. A drive pinion 72, indicated in dashed line in FIG. 1, of the worm gear drive 70 meshes with a toothed sector 74 of the swivel lever 62. A flexible drive shaft 76 connects the worm gear drive 70 with an adjustment motor part of the motor unit 40. This adjustment motor part is assigned to operate the worm gear drive 70. The swivel lever 62 shown on the right in FIG. 2 is articulated to the mounting plate 50 by means of a swivel pin 78. The connector shaft 64 ensures synchronous movement of both the swivel levers 62.
In order to facilitate raising of the left ends of the lower rails 22, as seen in FIG. 1, a spirally shaped prestressed leaf spring 80 is provided having one end resting against the connector shaft 64 with the other end extending into a transverse slit of a locking bolt or holding pin 82. The locking bolt 82 in turn protrudes from a holding plate 84 which is fixed on the worm gear drive 70 by means of screws 86. The right end of the mounting plates 42 and 50, as viewed in FIG. 1, are each connected by means of a dual lever joint 88 with the corresponding ends of the bottom rails 14. A first swivel lever 90 of each of the joints 88 is articulated at one end to the bottom rails 14 by means of bearing pins 92 and at its other end to an end of a second swivel lever 94. The second swivel lever 94 is in turn articulated to the mounting plate 42, 50 by means of bearing pins 96, 98. The two second swivel levers 94 are connected with each other for mutual rotation by means of a connector shaft 100 having several bends formed therein so that, just as in the case of the swivel levers 62, it is sufficient to drive one of the two second swivel levers 94 in order that both may be simultaneously driven. Additionally, the second swivel lever 94, like the swivel lever 62, is constructed with a toothed sector 102 which meshes with a drive pinion 104, indicated with a dashed line, of a worm gear drive 106. Fastening screws 108 hold the worm gear drive 106 on the mounting plate 42. The driving connection with a corresponding adjustment motor part of the motor unit 40 is established by means of a flexible drive shaft 110.
By suitable actuation of one or more of the adjusting motor parts of the motor unit 40, the motor vehicle seat member 18 can be optionally moved forwardly or rearwardly in a two-way direction indicated by the arrow A or it can be adjusted in its inclination or elevation by suitable pivoting of the swivel levers 62 and 94 in a two-way direction, as indicated by the double arrows B and C.
In the uppermost position of the seat member 18, the rails 20 and 22 will be inclined at an angle α relative to the horizontal. The total overall weight of the seat member 18 and of a person or passenger occupying the seat member 18 may be defined as a seat force F, which seat force is directed in the lengthwise direction of the seat assembly of the upper rail 20. Due to the low frictional mounting existing between the upper rail 20 and the lower rail 22, whereby ball bearings are utilized, friction between the upper and lower rails is relatively negligible. Accordingly, the rack 24 attached with the upper rail 20 engages with the drive pinion 32 under the influence of a force equivalent to the seat force F.
When the seat member 18 is adjusted toward the rear of the seat assembly--that is, when the upper rail 20 is moved from the left to the right as viewed in FIG. 1--an audible and perceptible rattling may occur if the power or motorized force which is applied for moving the seat member 18 is on the same order of magnitude as the seat force F. That is, the rattling will generally occur when the motorized drive force applied through the drive pinion 32 which is in engagement with the rack 24, is of about the same order of magnitude as the force F. Because play, caused by manufacturing and mounting tolerances, will occur between the rack 24 and the drive pinion 32, one or the other of the toothed surfaces 112, 114, shown to the left in FIG. 1, of the rack 24 will rest against corresponding toothed surfaces of the drive pinion 32 depending upon whether the seat force or the motorized adjusting force is greater. Depending upon the particular conditions, it may occur that rapid alternation between the two described types of engagement may occur and therefore very frequent changes of load can also occur. This rapid load change generates unpleasant vibrations and noises which will be quite noticeable as part of the rattling occurrences previously discussed.
In order to avoid this, the invention provides a braking device 116 which is shown in FIGS. 1 and 2 which operates a apply a force to prevent the occurrence of rattling or noise. The braking device 116 is composed of a brake head 118 which embraces a freewheeling sleeve 120 which, in turn, encompasses the drive shaft 34 (see also FIG. 2).
The brake head 118 shown in FIG. 1 is secured against clockwise rotation by a holding lug 122 which projects from the worm gear drive 36. In order to also exclude counterclockwise rotation, the brake head 118 is screw fastened to the holding lug 122. In this rotational direction, however, substantially less torque occurs than when rotation is in the counterclockwise direction due to the freewheeling sleeve 120, which will be discussed hereinafter.
The brake head 118 is constructed in the approximate shape of a fork with two thickened bifurcated ends 124 and 126 and with a middle section 128 which rests against an outer sleeve 130 of the freewheeling sleeve 120 with a frictional force engagement.
The middle section 128 is formed in an annular configuration and thus embraces the outer sleeve 130 along a circumferential line which is only slightly broken in the region of the fork ends 124, 126. Corresponding in size is the effective frictional surface between the outer sleeve 130 and the middle section 128.
The frictional force between the brake head 118 and the outer sleeve 130 of the freewheeling sleeve 120 may be varied in that the two fork ends 124, 126 which protrude generally radially from the outer sleeve 130 are spaced from each other in a circumferential direction. In the particularly simple embodiment shown in FIG. 1, the two fork ends 124, 126 are attached with each other by means of a counterhook tooth system 132 which permits one of the fork ends 124 to be engaged with the other fork end 126 at several locations. For this purpose, corresponding counterhooks are mounted at a frontal area of the fork end 124 which is distant from the freewheeling sleeve 120 as well as on a shoulder 134 which projects from the fork end 126 and which covers or overlaps this frontal area. As shown in FIG. 1, prestressing of the brake head 118 and therefore occurrence of a frictional force can be increased in a simple manner by moving the fork end 124 toward the fork end 126 until the counterhooks of the toothed system 132 engage each other. To loosen the prestressing frictional force, it is only necessary for the shoulder 134 to be bent radially outwardly until the teeth of the counterhook tooth system 132 no longer engage each other.
The construction of the freewheeling sleeve 120 is indicated schematically in FIG. 1. This freewheeling sleeve 120 is composed of a previously mentioned outer sleeve 130 and an inner sleeve 136 which is mounted on the drive shaft 34 rigidly connected for rotation therewith, with bearing needles 138 running between the inner sleeve 136 and the outer sleeve 130 at locations distributed over the circumference thereof. Because of the special curvature (not shown in FIG. 1) of one of the mutually facing circumferential surfaces of the outer sleeve 130 and the inner sleeve 136, the outer sleeve 130 can rotate freely in one rotational direction relative to the inner sleeve 136. In the case depicted herein, the outer sleeve 130 rotates freely relative to the inner sleeve 136 in the counterclockwise direction. When the outer sleeve 130 rotates in a direction opposite to said one rotational direction, however, a braking action of the outer sleeve 130 in relation to the inner sleeve 136 occurs.
In the case of a motor driven, rearward shifting of the seat member 18, i.e., when the seat member 18 and the upper rail 20 are to be moved in a direction indicated by the arrow F, the freewheeling sleeve 120 performs a blocking action so that the force exerted on the drive pinion 32 by the corresponding adjustment motor part through the drive shaft 38 and the worm gear drive 36 is diminished to a degree corresponding to the friction between the freewheeling sleeve 120 and the brake head 118. In this connection, the frictional force is set to a degree so that the resultant driving power with which the drive pinion 32 is driven by the adjusting motor part will always be perceptibly less than the seat force F which derives from the weight of the seat and the weight of the person sitting in the seat which operates to affect the rack 24. As a result, an effect is ensured such that when the adjusting motor is switched off as well as when it is running, the tooth surfaces 112 of the rack 24 always rest against the orresponding surfaces of the drive pinion 32. Change of load will not occur during operation.
An alternative embodiment of the braking device of the invention is shown in FIG. 3 wherein there is depicted a braking device 216. The braking device 216 is integrated into the worm gear drive 236 which corresponds to the worm gear drive 36 shown in the embodiment of FIGS. 1 and 2. In the embodiment of FIG. 3, a pinion 232 is provided supported upon a drive shaft 234. Here again, a connector shaft 260 is provided which corresponds with the connector shaft shown in FIG. 2 and which is engaged rigidly for rotation onto a correspondingly splined end of the drive shaft 234 in order to make a connection to the opposite drive pinion (not shown). The drive pinion 232 meshes with a rack 224 which is constructed in one piece with the upper rail 220. A ball 221 between the upper rail 220 and the corresponding lower rail 222 is provided in order to assure easy movement and proper ball track guidance.
The worm gear drive 236 is composed of a drive unit housing 237 in which a worm gear 239 and a drive worm 241 are arranged, the worm 241 meshing with the worm gear 239. The worm gear 239 is nonrotatably joined by casting with a flange 243 which is, in turn, rigidly connected for rotation on a drive shaft 234. In the axial direction (to the right in FIG. 3), the drive unit housing 237 is closed by a bearing cover 245 in which a bearing bushing 247 is pressed for the drive shaft 234. The bearing cover 245 is screwed or fastened in a manner not shown on the drive unit housing 237, with a plate 249 being interposed therebetween. The plate 249 which is composed of plastic supports two bearing shoulders 251 (only one being shown in FIG. 3) which project in the axial direction or to the left as seen in FIG. 3.
The drive worm 241 arranged between the bearing shoulders 251 with its two axial ends is rotatably supported at each end on one of the bearing shoulders 251.
In accordance with the device shown in FIG. 3, the braking device 216 is composed of a freewheeling sleeve 320 shown in simplified form upon which there is provided an inner sleeve (not shown) mounted rigidly for rotation on the outer circumference of the drive shaft 234. For receiving the freewheeling sleeve 320, the drive unit housing 237 is constructed with a cylindrical neck 253 projecting axially to the left as seen in FIG. 3. An edge 255 of the cylindrical neck 253 is bent over toward the drive shaft 234 and forms a stop for the left end of the freewheeling sleeve 320. At the right end of the freewheeling sleeve 320 there is provided a disc 257 having an enlarged diameter which braces itself to the right in FIG. 3 against an enlarged diameter section 259 of the drive shaft 234.
The inner diameter of the neck 253 is greater than the outer diameter of the freewheeling sleeve 320 so that a cylindrical annular space 259a is formed between the freewheeling sleeve 320 and the neck 253. The cylindrical annular space 259a is bounded in an axial direction on one side by the bent edge 255 and on the other side by the disc 257. Inserted in this annular space 259a are, for example, four rubber rings 261 being dimensioned to be somewhat larger than the dimensions of the annular space 259a so that the rings 261, when in a prestressed condition, will press against the outer circumferential surface of the freewheeling sleeve 320 as well as against the inner circumferential surface of the neck 253.
When the drive shaft rotates, if the freewheeling sleeve or its outer sleeve rotates therewith, the friction between the rubber rings 261 and the outer or inner circumferential surfaces of the freewheeling sleeve 320 or of the neck 253 will lead to a deceleration or braking of the turning movement and therefore to a lessening of the adjusting power with which the drive pinion 232 tends to adjust the rack 224. By suitable dimensioning of the rubber rings 261, the braking power of the brakng device 216, in a manner similar to that which may be accomplished with the embodiment according to FIGS. 1 and 2, is provided with a size such that the resultant adjusting force of the drive pinion 232 will always be less than the seat force with which the rack 224 is acted on by the weight of the seat and the driver. The pinion 232 thus is constantly pushed by the rack 224 whether the adjusting motor is in motion or deactivated. Hence, there will never arise a condition in which the drive pinion is rotated by the adjusting motor at a speed faster than it would be turned by the rack 224 alone.
FIG. 4 shows another embodiment of a braking device in accordance with the invention. In FIG. 4, a braking device 416 is provided with rubber rings 461 between a freewheeling sleeve 520 mounted on a drive shaft 434 and a cylindrical section 453 of a housing. The functional mode of the embodiment of FIG. 4 is generally the same as in the case of the braking device 216 in accordance with FIG. 3, the basic difference being that the cylindrical section 453 in the FIG. 4 embodiment is part of its own brake housing 463 and is thus not integrated into the worm gear drive. Hence, the braking device 416 may, for example, be arranged on the end of the connector shaft 260 which is distant from the worm gear drive 236 shown in FIG. 3. A drive pinion 458 is rigidly connected for rotation on a drive shaft 434 which would then correspond to the drive pinion 58 shown in FIG. 2. A rack with which the drive pinion 458 engages or interacts is indicated at 424. The brake housing 463 is provided with a fastening flange 465 which extends radially outwardly, the flange operating to enable mounting of the brake housing 463 on the seat adjustment mechanism, for example on the mounting plate 50 such as is shown in FIG. 2.
The braking devices 116, 216, and 416 shown, respectively, in FIGS. 2, 3, and 4 may also be suitably altered or be integrated into or built into the worm gear drive 70 and/or 106 in order to exert a braking effect upon the drive pinion 72 or 104. The freewheeling sleeve is then so adjusted in each case that it has a braking effect on the corresponding drive pinion when the seat is lowered. Since here again a force corresponding to the seat force F is exerted on the swivel levers 62 or 94, a correspondingly effective braking force on the drive pinion 72 or 104 will prevent an undesired change of load which can very often occur between the toothed sector 74 or 102 and the corresponding pinion teeth.
The braking devices described above may, however, also be built into the seat adjustment mechanism 10 in such a manner that they have a direct effect upon the connector shaft 64 and/or upon the connector shaft 100 which would therefore enable provision of a relatively simple structure. In this case, the freewheeling sleeve is again connected in such a way that the braking device, by a corresponding rotation of the connector shaft, will counteract lowering of the seat. The braking force in this action can be high enough so that it will exclude automatic adjustment of the seat when the drive pinion is freewheeling. If now the seat is lowered by the corresponding adjustment motor being switched on, the drive pinion will drive the toothed sector of the corresponding swivel lever in a positive manner without the danger of shifting load effects.
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 seat adjustment mechanism especially suited for motor vehicle seats is composed of at least one motor mechanism for adjustably moving a seat member through a drive connection having at least two mutually engaging force transmission parts. In order to avoid rattling of the adjustment mechanism when adjusting movement of the seat is to be effected in a direction where the adjusting movement is abetted by the weight of the seat member itself, a braking device is provided which counteracts the adjusting force of the motor mechanism applied in that direction.
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[0001] This application claims the benefit of U.S. Provisional Application No. 60/839,785 filed on Aug. 24, 2006.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of geophysical prospecting and reservoir delineation, and more particularly to interpretation of electromagnetic data. Specifically, the invention is a computer software program for aiding interpretation of electromagnetic data and resistivity mapping of a subterranean region.
BACKGROUND OF THE INVENTION
[0003] Controlled-source electromagnetic (“CSEM”) surveying is a powerful tool for hydrocarbon exploration. To map resistivity anomalies that can be related to hydrocarbon fields, raw survey data (measurements of one or more components of the electric or magnetic fields) are processed, then interpreted. Interpreting CSEM data consists of developing a model of the earth's resistivity that is consistent with the measured CSEM data and with any other available geophysical or geological information. While they are not necessarily practiced in this order, interpretation typically includes the steps of:
Understanding which features of the data may properly be regarded as signal and which features as noise; Understanding how the signal varies in space; Understanding how the signal varies with frequency; Understanding how the signal varies among the x, y, z components of the data, in both amplitude and phase; Constructing approximate resistivity models of the earth in 1, 2 and 3 dimensions; Constraining those models with additional information, such as well logs or seawater resistivity profiles; or structural information derived from seismic or gravimetric or magnetic data. Forward-modeling synthetic electromagnetic field data based on those earth models and the source-receiver configurations in the measured data; Comparing those actual and synthetic data to understand how the anomalies or misfits vary in space, among frequencies, or among data components; Comparing synthetic data to synthetic data to understand how changes in the earth model impact synthesized data; Modifying the earth model and re-synthesizing data; Inverting the measured data; and, Evaluating the resistivity models together with other geophysical measurements for evidence of hydrocarbon accumulations.
[0016] Typically, CSEM data is collected by individual receivers (laid on the sea floor) that record the signal emitted by a transmitter towed a few meters above the sea floor (however, in some experiments, the transmitter can also be fixed). CSEM surveys can be large and complex. For example, a survey might involve 7 tow lines, 90 receivers, and 10 or more discrete frequencies. Each receiver may record up to 6 electric and magnetic field components. In addition, the CSEM data may have been processed in more than one way in order to improve some signals at the expense of others or to convey uncertainties present in the data. Furthermore, many synthetic data sets may be produced as part of the iteration cycle for reconciling the measured data with an earth resistivity model. Therefore, the CSEM interpreter faces the daunting bookkeeping challenge in ensuring that all of the measured data are explained in terms of a single resistivity model of the earth.
[0017] Some recent publications and patents address one or another part of these problems, or present final results with little discussion of the tools employed. Often, literature only presents final results. See, for instance U.S. Patent Publication 2005/0077902; and S. Ellingsrud et al., The Leading Edge 21, 972-982 (2002). There is a need for a tool that integrates the full process of interpreting the CSEM data.
SUMMARY OF THE INVENTION
[0018] In one embodiment with reference to FIG. 10 , the invention is a computer implemented method 1000 for interpreting data from a controlled-source electromagnetic survey of a subsurface region, comprising:
[0019] (a) providing a graphical user interface allowing selection of electromagnetic data and their manipulation or display by one or more selected tools;
[0020] (b) providing a plurality of data manipulation and display tools 1005 , each accessible from a graphical user interface;
[0021] (c) providing layered data storage 1004 for frequency-domain electromagnetic field data volumes, each layer corresponding to a certain survey source line, frequency and receiver, and being allocated to receive at least the following types of data or information:
(A) frequency; (B) type of processing used for actual data, or identification of resistivity model assumed for synthetic data; (C) receiver identification and geometry information for survey receivers, including (x,y,z) coordinates and 3D orientation angles; (D) source information including (x,y,z) location and data specifying source antenna shape as a function of time; and (E) electromagnetic data, either actual ( 1001 ) or simulated ( 1002 ), corresponding to parameters (A)-(D);
wherein the electromagnetic data in each layer, whether real data or synthetic data, are stored with the same internal structure; and
[0027] (d) using a software program comprising the features provided in steps (a)-(c) to interpret the electromagnetic data to predict whether the subsurface region contains hydrocarbons.
[0028] In some embodiments of the invention, computer data storage is also provided for resistivity data in connection with inversion operations ( 1003 ).
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The present invention and its advantages will be better understood by referring to the following detailed description and the attached drawings in which:
[0030] FIG. 1 shows the control panel display, the primary graphical user interface, for one embodiment of the present invention;
[0031] FIG. 2 shows a monitor display of a parametric plot from one embodiment of the present invention;
[0032] FIG. 3 shows a mirror plot display from one embodiment of the present invention;
[0033] FIG. 4 shows a display from one embodiment of the present invention of a plot of receivers along a tow line;
[0034] FIG. 5 shows a display from one embodiment of the present invention of a relative amplitude map;
[0035] FIG. 6A shows a resistivity depth log from a 1D simulation module, and FIG. 6B shows a graphical user interface in one embodiment of the present invention in which a resistivity log can be edited into a form suitable for the resistivity model in a 1D simulation of electromagnetic field values;
[0036] FIG. 7 shows a graphical user interface in one embodiment of the present invention for defining an initial resistivity model for a 1D inversion computation;
[0037] FIG. 8 is a flow chart of an example work flow using the present invention;
[0038] FIG. 9A shows a parametric plot display with graphical user interface from one embodiment of the present invention, and FIG. 9B shows the result of a bulk horizontal shift operation; and
[0039] FIG. 10 is a programming flow chart for certain embodiments of the present invention.
[0040] The invention will be described in connection with its preferred embodiments. However, to the extent that the following detailed description is specific to a particular embodiment or a particular use of the invention, this is intended to be illustrative only, and is not to be construed as limiting the scope of the invention. On the contrary, it is intended to cover all alternatives, modifications and equivalents that may be included within the spirit and scope of the invention, as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] The present invention addresses the integrated interpretation (of EM survey data) problem by means of a structured computer program, which may be referred to herein as EMIM (Electro-Magnetism Interpretation and Mapping), that in certain embodiments of the invention includes mechanisms for:
Managing and selecting actual CSEM Data (processed common-receiver gathers); Creating, managing and selecting synthetic CSEM Data and for maintaining its identification with the Earth Resistivity Models on which it is based; Co-displaying any combination of actual and synthetic data by means of one or more display tools (such as amplitude and phase versus offset, cross-section, relative amplitude pseudo-section, or relative amplitude map); Applying Data Adjustment tools (such as muting, smoothing or phase correction) to the actual CSEM Data prior to display or inversion; Developing earth resistivity models from inversion of actual CSEM Data; Editing or modifying earth resistivity models for the purpose of creating additional synthetic data; and, Constraining those earth resistivity models based on non-CSEM data. Input/output links to simulation and inversion packages. Input/output links to 3D visualization packages. Input/output of resistivity logs (1 dimension) or resistivity profiles (2 dimensions) or resistivity cubes.
[0052] EMIM is a user-friendly tool based on graphical user interfaces. The main panel, which may be called the EMIM Control Panel, allows the input/output and the selection of the CSEM data and their display or manipulation through command buttons. An example of a control panel for the present invention is shown in FIG. 1 . Various CESM data interpretation operations are described in the following paragraphs with reference to the actuating locations in FIG. 1 . Each feature described does not necessarily appear in all embodiments of the invention.
Loading Data
[0053] Actual data are loaded from the processing package 101 . Actual data may have been recorded and processed in a geodetic coordinate system different than the coordinate system to be used at the interpretation stage. In this case, the program performs the coordinate transform “on the fly.” The horizontal components of the electric and magnetic fields of each receiver are also, at the user's option, re-oriented into the components parallel and perpendicular to the average tow line direction. Several versions of processed data can be loaded together. They are labeled by a processing version name provided by the user.
[0054] 3D simulation results (from an external software program) may be loaded from 3D forward-modeling output files 102 . Usually, they are in the interpretation geodetic system in which case no coordinate transformation is required. They are labeled by a scenario name provided by the user. The horizontal components of the electric and magnetic fields of each receiver are also, at the user's option, re-oriented into the components parallel and perpendicular to the average tow line direction. Where actual data exist, simulation data may be mapped to actual data based on the direction of the tow line and the receiver location.
[0055] Simulations corresponding to the 3D inversion results may be loaded from an external 3D inversion package 103 . They are normally in the interpretation geodetic system in which case no coordinate transformation is required. They are labeled by the inversion name as provided by the user. The horizontal components of the electric and magnetic fields of each receiver may also be re-oriented into the components parallel and perpendicular to the average tow line direction. Simulation data corresponding to the 3D inversion results may be mapped to actual data based on the direction of the tow line and the receiver location.
[0056] 1D inversion results (simulations and resistivity profiles) are loaded from the output files of the 1D inversion package 104 which, in some embodiments, is part of the present invention.
[0057] Data editing functions are also provided 105 ; for example, the survey name and general comments can be modified, actual or simulated data can be renamed or deleted (on a receiver or frequency basis), or entire simulation datasets can be removed.
Managing CSEM Data (as Common-Receiver Gathers)
[0058] Actual CSEM data, 1D, 2D and 3D simulated data (generically known to as synthetic data) can be found in very different formats because of the different computer programs used to generate them. They also can represent electric or magnetic fields. The present invention has a feature called “EM Data Layer” where these different types of data are structured in the same way which makes it very easy to display or combine them together.
[0059] The structure of the EM Data Layer (sometimes referred to herein as internal structure) may vary, from one embodiment of the invention to another, depending upon the program designer's preferences, but a typical choice for common internal structure features might be:
Name of the survey Area of the survey (i.e. country, license number) Miscellaneous comments (i.e. operator, contractor) Type of the data (actual or synthetic, electric or magnetic fields). Version. For actual data, this is typically the kind of processing. For synthetic data, it is typically the name of the scenario. For instance, in the case of a 3D simulation, the entry in the version field will typically make reference to the resistivity cube the synthetic was generated from. Unique name of the receiver Unique name of the transmitter line. X, Y, Z coordinates of the receiver and the orientation of its horizontal and vertical antenna with respect to the geographic North (azimuth) and the vertical (tilt). X, Y, Z coordinates of the transmitter locations and their signed distance away from the receiver (signed offset). Conventionally, the offset is negative where the transmitter is towed toward the receiver; it is positive where it is towed away. Also stored at the same location (in some embodiments of the invention) are the azimuth, pitch, length and altitude above the sea floor of the transmitter, the conductivity of the sea water measured at the transmitter, the Julian date and the current intensity at the different transmitter locations. More accurate interpretations of CSEM data require keeping track and taking into account the shape of the transmitter. As used herein, the terms source and transmitter are used interchangeably, and refer to the (usually flexible) dipole antenna (in the case of an electric dipole source) by which a selected current signal is transmitted (into sea water in most applications) rather than to the signal generator, sometimes called a power waveform synthesizer, that is connected to the transmitting antenna. Average line through the transmitter positions (characterized by its azimuth and the coordinates of one point). The transmitter positions are generally located along a line that can be somewhat crooked. The program feature of approximating the geometry of each transmitter gather by an average line proved very powerful in tests of the present invention, particularly in the data loading process and in displaying or manipulating CSEM data. The average line may be characterized by an angle (direction in the horizontal plane) and an average point (X, Y, Z coordinates). Bulk horizontal shift (commands 119 in FIG. 1 ). Depending on the contractor and the processing, experience in developing the present invention has shown that the fit between the actual data and the synthetic is often improved if the locations of the transmitter are shifted by a constant amount (usually between 0 and 100 m). The underlying theory is not presently understood, but this optional shift can often significantly help interpretation. Of course, the horizontal shift of synthetic data is always zero. Electric or magnetic field values at a given frequency. These complex numbers (in the frequency domain) are stored. The data will consist of however many components of the vector field were measured (or simulated). For 3D data, the typical three components into which the data are resolved are: parallel to the average tow line direction, perpendicular to the average tow line direction, and vertical. Original values of the electric or magnetic fields. A user can interactively alter the values of the electromagnetic field (for instance by smoothing). Preserving the original values makes the ‘undo’ function possible. Mute code. With this feature, any part of the gather can be muted out. The mute code keeps track of what is active or inactive (muted out). Phase shift. CSEM transmitters and receivers each have their own built-in clocks, and their synchronizations are imperfect. Usually, phase corrections are done during the processing steps that precede use of the present invention, but additional correction may be useful during the interpretation. This field keeps track of any such corrections. Miscellaneous weights. For example, data for inversion may be weighted, for instance by a quality factor. Resistivity. A resistivity model to be used in the 1D simulation module of the present invention would be stored here for example; or a resistivity profile along the average tow line direction.
[0077] CSEM is a rapidly evolving technology; additional parameters can be easily added to or existing parameters can be changed or removed from the “EM Data Layer”.
Selecting Data
[0078] A significant feature in many embodiments of the invention is the ability to co-render or combine any gather of any kind from anywhere in the survey. For instance, a gather from a receiver on a north-south line in the south-west corner of a survey can be displayed with a gather from a receiver on an east-west line located in the middle of the survey. First, the user selects a “base dataset” [ 100 in FIG. 1 ]. This data will lie within a particular layer in the EM Data Layer. This dataset can for example be a version of actual CSEM data or any 3D simulation. In balancing computer utilization with desirability of particular features, a preferred embodiment of the invention may be one in which only the base dataset can be edited interactively. Other processing versions or 3D simulations of different scenarios and various 1D synthetics can be added to the displays (i.e. co-rendered) with selected colors and symbols, but they cannot be edited in this embodiment. The program might be designed to not limit the amount of data that can be plotted together. Instead, the only limitation would be the ability of the user to interpret the data. The EM Data Layer can be so flexible that it is easy to display data even from two different areas in the world. In the Control Panel of FIG. 1 , such foreign data points are extracted from an existing EMIM database (having been read into memory and converted to the common internal structure as a separate layer in EM Data Layer) through the command FromProj 106 .
[0079] The aforementioned co-rendering and editing operations are all implemented by the user through the EMIM Control Panel ( FIG. 1 ), which is the graphical user interface that allows such flexibility. Particular features for selecting data in an embodiment of the invention might include sub-setting the data.
[0080] CSEM surveys can be large and complex. They can involve hundred of receivers, lines and frequency combinations. General operations or data combinations can be performed on the whole datasets, but for detail analysis, it is usually required to work on more manageable sub-datasets. At the beginning of a session, or through the “Subset” command 107 , a user can select part of a survey by sorting by receiver names or line names or graphically on a base-map. It is also possible with the control panel of FIG. 1 to select (using the buttons 120 ) only the data corresponding to one or more desired frequencies in the frequency spectrum of the particular source waveform used in the survey data acquisition. A pre-selection between all the available processing versions, 3D synthetic data or 1D synthetic data can also be done through commands 108 , 109 , 110 , respectively.
[0081] As stated previously, the EMIM Control Panel of FIG. 1 enables the user to select actual or synthetic CSEM data gathers, data components, frequencies, and offsets. (A gather is the electromagnetic data corresponding to one particular receiver and one particular tow line. It is the data that were recorded at the particular receiver when the source was emitting electromagnetic signal along the particular tow line.) The first column of buttons 111 specifies the color, the symbols and the line thickness of a gather, in the embodiment illustrated by FIG. 1 . Gathers are uniquely identified by their line name in the second column 112 and their receiver name in the third column 113 . The fourth column of buttons 114 permits the selection of positive offsets and those of the fifth column 115 the selection of negative offsets. (Offset is horizontal distance between source and receiver when the particular data point was recorded by the receiver.) Horizontal inline components (parallel to the average tow-line), horizontal cross-line components (perpendicular to the average tow-line) and vertical components are respectively selected from the sixth to the eighth columns 116 , 117 , 118 . That is, the program has a tool that resolves the measured EM field components into inline, cross-line and vertical components, and these buttons enable the program user to select the desired components. A horizontal bulk shift of the transmitter locations can be entered in the ninth column 119 . Columns 10 and beyond enable the selection of frequencies available in the base dataset 120 . Column-wise selections (selection of every button in a column) are permitted by the buttons on the lowest row 121 . The buttons in the lower right corner of FIG. 1 permit the selection of an absolute offset range 122 and of an amplitude range 123 . Button 124 controls the phase display of selected data. The phase can be displayed explicitly (raw or unwrapped) or implicitly through its sine, cosine or other trigonometric functions.
[0082] Available processing versions are selected at 125 . They may be uniquely defined by their version name. Color, symbols and line thickness can be defined for each selected processing version.
[0083] Available 3D-simulations are selected in at 126 . They may be uniquely defined by their scenario name. The scenario name will likely make reference to the resistivity model the simulation was generated from. Color, symbols and line thickness can be defined for each selected 3D-simulation.
[0084] Available 1D-simulations are selected at 127 . They may be uniquely defined by their scenario name. Color, symbols and line thickness can be defined for each selected 1D simulation. Moreover, selecting the 1D Simulation option 127 can be programmed to bring up a Resistivity Log (or resistivity profile) editing and display panel.
[0085] Information about processing versions and simulations can be browsed from button 128 : receiver and line coordinates and depths, base-map and available frequencies for actual data and simulated data.
[0086] Command 129 saves the editing that has been done since the last save. It can also save the settings of the EMIM Control Panel: the selection of lines and receivers, the selection of the processing versions and the simulations and their selected color, symbol and line thickness. These settings allow the user to re-start the application at the same point at a later date.
[0087] Command 130 terminates the session. It allows the user to save the project and the configuration of the EMIM Control Panel before exiting.
Editing Data
[0088] All selected data are plotted together in the Parametric Display window (command 131 of FIG. 1 ). FIG. 2 shows another graphical user interface in one embodiment of the present invention. The amplitude and phase of the CSEM data (electric field or magnetic field) are plotted in the same display versus the absolute offsets between the receiver location and the transmitter locations. Negative and positive offset data are plotted with different symbols to allow each offset to be identified. The type of field (electric, magnetic or both) is selected from a popup menu 201 .
[0089] Such a parametric plot is independent of the actual geographic location of the gathers. It is a convenient way to compare the positive and negative offsets of the same receiver and show if the earth is more resistive or more conductive right or left of a given receiver. It is also the best place to compare actual or simulated data from different locations. The user can zoom, un-zoom or edit the picture using the 202 commands. The names (line and receivers) of the gathers selected in the EMIM Control Panel are visible in a scrollable box 203 . The selected frequencies are visible in another scrollable box 204 . From these boxes, the user can activate or deactivate any gather and any frequency. By default, all the gathers and all the frequencies that were first selected in the EMIM Control Panel are active. In this embodiment of the invention, active data are highlighted in the scrollable boxes and are displayed with thicker lines on the parametric plot. Editing is applied to the components and offsets of the active gathers and frequencies from the base dataset. Available editing features in the embodiment of the invention illustrated by FIG. 2 are:
Rotate 205 . The receiver orientation is determined by polarization analysis or other method at the processing stage. The rotate feature allows the user to test the sensitivity of the CSEM data to the orientation of the active receiver. At the user's choice, additional rotation can be applied and the corresponding values are changed in the EM Data Layer fields. Mute 206 . The user can graphically mute out undesired transmitter locations (usually noisy points) of the active gathers at the active frequencies. UnMute 207 . The un-mute command re-activates the muted transmitter points of the active gathers at the active frequencies in a graphically designed range of offsets. Smooth 208 . The command stacks transmitter points in a user-specified sliding window along the offset axis (a kind of smoothing). It is to be noted that the stacking needs to be performed on complex numbers of the active gathers at the active frequencies. UnSmooth 209 . This command restores the original data values (before re-stacking). PhaseCorr 210 . This command allows the parallel and perpendicular components of the “base dataset” to have their phases adjusted to a selected simulation dataset. The adjusted data can be written out (for example) to a dataset for input into an external 3D inversion package.
Displaying Data
[0096] Additional commands in the EMIM Control Panel ( FIG. 1 ) co-render data in many different ways.
Mirror 132 displays selected data receiver by receiver, as illustrated in FIG. 3 for a receiver located at zero on the offset scale. Data curves for two frequencies (0.25 and 1.25 Hz) are displayed. Curves 301 represent a simulation based on an initial resistivity model. Curve 302 represents the actual (measured) data at 0.25 Hz and 303 the actual data corresponding to 1.25 Hz. The initial simulation is very close to the actual data at the higher frequency but not at the lower frequency where a second simulation is performed after adjusting the resistivity model. The second simulation curve falls on top of the actual data curve. AlongLine 133 displays data belonging to a common tow line along the line, as illustrated in FIG. 4 . The solid lines represent actual data and the dashed lines represent simulated data. Transmitter offsets can be scaled by a user-specified value. RAsec 134 displays relative amplitude or phase sections. For instance, actual data are normalized by a selected simulation dataset. For example, a vertical section using a color scale to display relative magnitude can be generated to indicate resistivity anomalies in the actual data with respect to the simulated data. See U.S. Patent Publication No US 2006/0197534 (“Method for Identifying Resistivity Anomalies in Electromagnetic Survey Data”). The sections can be exported to a commercial visualization package. RAmap 135 displays relative amplitude or relative phase maps, as illustrated in FIG. 5 , where horizontal (x,y) position is the quantity displayed on the two axes. Actual data are normalized by a reference dataset (for instance a selected simulation dataset). For each receiver, the relative amplitude (or phase) data at a given transmitter location is displayed along the tow-line at the corresponding offset (or at an offset scaled by a factor specified by the user) as a bar perpendicular to the tow line. Four tow lines, 503 - 506 , are shown in the drawing. The length of the bar is proportional to the relative amplitude (or phase). Positive anomalies (the actual data are more resistive than the reference data) are displayed in black on one side of the line. Three regions 501 are indicated that exhibit prominent, mostly positive resistive anomalies. Negative anomalies (the actual data are less resistive than the reference data) are displayed in gray on the other side of the line with; for instance, region 502 . In actual practice, a color coding might be preferred for displaying positive and negative relative amplitudes. At a glance, a relative amplitude (or phase) map such as FIG. 5 shows the resistivity anomalies in the actual data with respect to the reference data. The maps can be exported to a commercial visualization package. BaseMap 136 displays a base map of the selected receivers and lines or of the whole survey. ClearPlot 137 clears all the plots of displayed data.
Creating 1D Synthetic Data
[0103] Only 1D-simulations are performed in many embodiments of the present inventive program because 2D and 3D simulations currently require too much computing resources. Nevertheless, this program enables the user to prepare data as input to the simulation software and provides the link to import 2D or 3D simulation results.
[0104] In some embodiments of the invention, the 1D Simulation command ( 127 in FIG. 1 ) enables the user to:
select existing 1D models and display their simulation results in the Parametric Display window, allow editing of existing 1D models allow creation of new models, and run the corresponding simulations through the Resistivity Log window.
[0109] The selected 1D model is displayed in FIG. 6A as a depth-profile of resistivity, also known as a resistivity log. It is possible in this embodiment of the invention to import resistivity information from an existing well through an external file in the standard LAS format 601 and use it as a guide. The user can also import measured sea-water conductivity profiles 602 or enter their own profile (linear or exponential profile). Then, the user can graphically edit or add resistivity sediment layers 603 . The SaveLayer Command 604 opens the Check and Save Log window, shown in FIG. 6B . Fields 605 define the new model name and display parameters (which can be changed later). The user can check and manually edit the resistivity and depth of the layers in fields 606 , define the source and receiver geometry 607 , set the desired frequencies 608 and launch the 1D simulation 609 . The source and receiver geometry can be automatically retrieved from the EMIM database with the name of the receiver and the name of the tow-line 607 . The results are automatically displayed in the Parametric Display window (command 131 in FIG. 1 ).
Creating Pseudo-Simulations
[0110] At the user's choice, 1D-simulations can be attached to a selected receiver in the example embodiment of the invention. However, it may be convenient to duplicate the simulation at the location of several (or all) receivers for both the positive and the negative offset legs. In particular, it helps co-rendering 1D-simulations with the display commands 132 to 135 . The command GenBkgdSim 138 on the EMIM Control Panel of FIG. 1 generates such pseudo-simulations at the selected locations and the selected frequencies. In the same way, the command GenBkgdSim can duplicate a selected positive or negative offset leg of real data or 3D-simulated data.
Link to Visualization and Modeling Packages
[0111] In the example embodiment of FIG. 1 , SurvGeom 139 exports the CSEM survey coordinates, the receiver orientation and the transmitter information to commercial visualization packages (e.g., Gocad, Geoframe, Petrel, VoxelGeo, Jason Geophysical Benchmark). Commands like RaSec 134 or RaMap 135 can also export relative sections or maps to commercial visualization packages. 1DItoViz 140 reformats the resistivity models resulting of 1D inversion into a file that can be read by commercial visualization packages. 3DItoViz 141 reformats the resistivity model resulting from 3D inversion into a file that can be read by commercial visualization packages.
Link to Inversion Packages
[0112] The command To — 1Dinv 142 prepares the data selected in the EMIM Control Panel for 1D inversion. The selected data are displayed in the Parametric Plot window, and the Define Initial Model window is displayed as illustrated in FIG. 7 . In this window the user defines:
A sea-water resistivity profile 701 . The default is the sea-water of the most recently selected 1D simulation. A transition zone between sea-water and sediment 702 The thickness of the sediment layers to be inverted 703 The inversion bounds and the initial resistivity in the layers 704 A lower half-space 705 If the data need to be decimated 706 The convergence criteria 707
The sea-water zone, the transition zone, the half-space and some of the sediment layers can be fixed and kept constant during the inversion process. The selected data and the corresponding initial models are written in a format suitable to the 1D inversion package, which may be an external program but could possibly be a tool within the present invention. The command To — 3Dinv 143 writes the data selected in the EMIM Control Panel into a format suitable to a 3D inversion package.
Typical Work Flow
[0120] FIG. 8 shows a typical workflow of a CSEM interpretation study using the example embodiment of the invention suggested by FIG. 1 . The choices made by the user in the example work flow that follows are intended to illustrate the capabilities of one embodiment of the invention.
[0121] 1. Actual data is loaded first, at step 801 . Several processing versions 800 can be loaded at the same time for comparison into different layers of EM Data Layer, each layer being converted to a common internal structure, preferably during the loading process.
[0122] 2. At step 802 , from the EMIM Control Panel, using button 131 in FIG. 1 , the user displays all receivers in the Parametric Display window ( FIG. 2 ) for several frequencies, typically the lowest, the highest and selected intermediate ones. The receivers with bad channels are obvious 211 . The general noise level 212 is estimated for each frequency. The user can delete bad receivers with the data-base editing tools (command 105 in FIG. 1 ) or simply deselect them in the Parametric Display window. Then, the offsets where the amplitude is below the noise level are usually muted (command 206 ). This muting makes subsequent plots much simpler and clearer. For instance, in FIG. 2 , the offsets greater than 10 km will be muted 213 . Once the data have been cleaned, an assessment can be made of the resistivity variability in the displayed data.
[0123] 3. At step 803 , again using button 131 on the Control Panel, the user displays positive and negative offsets receiver by receiver in another Parametric Display window, illustrated in FIG. 9A . (The horizontal axis is offset, and one of the curves is for positive offsets, and the other for negative offsets.) Because very near offsets are mainly sensitive to sea water conductivity, near positive and negative offsets should overlap. If there is a slight mismatch, as there is at 901 , it may be due to some imperfection in the processing stream or a navigation error. Typically, a small horizontal bulk shift of the transmitter location in the towing direction (less than 100 m) will fix the problem. The required bulk shift is typed in the EMIM Control Panel (column 119 in FIG. 1 ). In this instance, a shift of 30 m in the towing direction produces the improved result shown in FIG. 9B . If the discrepancy between positive and negative near offsets is greater than 100 m, it is either caused by an abrupt change in the transmitter elevation close to the receiver or by an abrupt change in the resistivity of the very shallow sediment at the receiver location. These effects will be taken into account in the later 3D modeling step.
[0124] 4. At step 804 , the user applies additional muting 804 based on the phase stability. Experience has shown that a convenient way to check the phase stability is to display its cosine versus offset. The curve should be smooth. For instance the spike 902 of the phase cosine curve in FIG. 9A between offset 5 and 6 km will be graphically muted out through command 903 . The user can improve the phase stability (especially at far offsets) by locally restacking the data within a larger, user-defined, stacking window, typically 300 to 600 m (command 904 ). Spikes in the electric field such as 902 (probably caused by lightning) should be muted before restacking.
[0125] 5. The user can now prepare the cleaned data for 1D inversion in step 805 . The user selects receivers from the EMIM Control Panel. The command To — 1DInv ( 142 in FIG. 1 ) prompts the user to define a starting model: sea water resistivity, transition zone between water and sediment, initial resistivity values, resistivity bounds (fields 701 to 705 in FIG. 7 ). It has been found to be preferable to use a measured sea water resistivity profile and relatively thick a priori layers in the sediment (typically 300 m). The survey parameters (antenna length, receiver and transmitter depths) and the actual data are automatically retrieved from the information stored in EMIM. However, because the data are usually smooth, it is a good practice to decimate the data to save computation time. It is sufficient to keep an electric field value every 200 m (field 706 ). Finally, the residual error at which the inversion process stops is defined in field 707 . The default value of 0.1 has proven to be very consistent to ensure an excellent fit to the actual data if a 1D model can be found to explain them.
[0126] 6. At step 806 , 1D-inversions are performed, in an external inversion package, independently on each positive and negative offset leg of each receiver. In this embodiment of the invention, the 1D inversion package is an external tool (indicated by the dashed-line box 806 ) because of its demands on computer resources. However, the selected frequencies are inverted together. If the data were adequately decimated and the initial layering was not too thin, 1D inversion can be a relatively quick process. Generally, close to the edge of a resistivity anomaly, the inversion program cannot find a 1D model that fits the observed data due to failure of the earth to satisfy the 1D assumption. The residual criterion defined in 707 cannot be reached and the inversion stops after a pre-specified number of iteration (15 iterations is a typical stopping point). (Inversion involves iterative simulations, with an automated adjustment to the resistivity model, based on closeness to measured data, made between iterations.) The external inversion package may, but does not have to, use an internal 1D simulation pkg. to perform its simulation steps.
[0127] 7. Then, at step 807 , the results of the 1D-inversions (resistivity profiles and the corresponding 1D-simulations) are loaded into EMIM for quality control, display and manipulation (command 104 in FIG. 1 ).
[0128] 8. Sometimes, the results of 1D-inversion show some inconsistency in the data and it may be necessary (step 808 ) to return to the processing stage 800 to correct processing mistakes.
[0129] 9. 1D-inversion assumes a perfectly layered earth and its results are only a first step in a thorough interpretation process. However, 1D-inversion results can show meaningful variations in the regional resistivity. Also, the discrepancy between what was modeled by the 1D-simulation and the actual data shows potential 3D effects to the experienced interpreter. With the command 1D to Viz ( 140 in FIG. 1 ), the user can create resistivity sections by combining the results of the 1D-inversions along the same tow line and load them into commercial visualization packages or model building packages (e.g., Gocad, GeoFrame or Petrel). These results, combined with well information, seismic data, magneto-telluric survey and any other available information are the basis to build an initial 3D-resistivity model at step 809 .
[0130] 10. Then, the electro-magnetic response of the resistivity model is simulated at step 810 with the appropriate codes using an external 3D simulation package. (The embodiment of the invention assumed for this example recognizes that with present computer resources, a capability such as a 3D simulation (or inversion) package may need to be external to EMIM.)
[0131] 11. The results of the 3D simulations are loaded at step 811 into EMIM (command 102 in FIG. 1 ).
[0132] 12. They can be compared 812 at different frequencies to the actual data:
receiver by receiver (using FIG. 3 displays) with the command Mirror ( 132 in FIG. 1 ), along tow lines (as in FIG. 4 ) with the command AlongLine ( 133 in FIG. 1 ), in relative amplitude cross-sections with the command RaSec 134 , in relative amplitude maps ( FIG. 5 ) with the command RaMap 135 .
[0137] Such comparison shows where the actual data are more resistive or less resistive than the simulated earth model. The process then revisits step 809 where the user then modifies the earth model accordingly to better fit the observed data, and the loop 809 to 812 is repeated until a good agreement is reached (a convergence criterion or other stopping point). For more detail on performing this part of the work flow, see, for instance, U.S. Patent Publication US 2006/021788, “A Method for Spatially Interpreting Electromagnetic Data Using Multiple Frequencies.”
[0138] 13. The actual data can also be prepared for 3D-inversion (step 813 ). Usually, some additional editing or phase correction is required (step 804 ). In a typical work flow where 3D inversion is to be used, steps 805 through 812 might be skipped.
[0139] 14. The 3D-inversion (step 814 ) would probably be run outside EMIM under present day computer constraints. It is a very compute-intensive step.
[0140] 15. At step 815 , the synthetic results are loaded back into EMIM for quality control and for reformatting of the final resistivity model into a file that can be read by an external visualization package (step 816 ).
[0141] FIG. 10 is a flow chart for guiding a programmer to write or put together a software program 1000 for some embodiments of the present invention.
[0142] The foregoing application is directed to particular embodiments of the present invention for the purpose of illustrating it. It will be apparent, however, to one skilled in the art, that many modifications and variations to the embodiments described herein are possible. All such modifications and variations are intended to be within the scope of the present invention, as defined in the appended claims.
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A food making process comprises starting with Lupin legumes with minimum levels of alkaloids, dehulling the Lupin legumes to produce split seed kernels, mixing the split seed kernels with hot water to hydrate them into a slurry, grinding the slurry to blend and smooth it into a product base, cooking the product base to achieve a particular flavor and aroma consistent with a target food product, cooling the product base to stop cooking, and further processing the product base into a target food product like soups and beverages. In particular, the Lupinus Angustifolius variety produces the best results, but other sweet lupin varieties can be used if they have been leached of their bitter tasting alkaloids. The products produced have high levels of protein, vitamins, and other nutritional values. Both batch and continuous processes are possible.
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FIELD OF THE INVENTION
The present invention relates generally to sensor systems, and more particularly, to a reconfigurable array of signal sensors.
BACKGROUND OF THE INVENTION
Many conventional techniques exist for transmitting or detecting electromagnetic radiation signals. However, changing operational requirements render many of them unsuitable for certain applications. For example, it is believed to be desirable to provide high altitude airships with sophisticated sensor arrays. These ships are desired to remain on station for substantial periods of time and at very high altitudes for upwards of one year, without refueling.
It is desirable to provide a reconfigurable radiator array suitable for extended service that is relatively lightweight and flexible, and having relatively reduced power requirements as compared to conventional arrays.
SUMMARY OF THE INVENTION
A reconfigurable array including: a plurality of imaging layers including an array of software addressable pixels; a conductive/non-conductive layer including a material that is selectively conductive and positioned with respect to corresponding ones of the pixels such that addressing of corresponding ones of the pixels causes corresponding portions of the conductive/non-conductive layer to be conductive; a radiator layer including a plurality of elements suitable for actively transmitting or receiving signals in a first mode and being passive in a second mode, the radiator layer being positioned with respect to corresponding ones of the pixels such that the addressing of the corresponding ones of the pixels causes the elements to define at least one radiator array; a switching and summing layer including a plurality of elements suitable for selectively switching and summing the signals, the switching and summing layer being positioned with respect to corresponding ones of the pixels such that the addressing of the corresponding ones of the pixels causes corresponding portions of switching and summing layer to switch and sum the signals; and, a plurality of inputs coupled to the imaging layers and being under software control to selectively activate the pixels.
BRIEF DESCRIPTION OF THE DRAWINGS
Understanding of the present invention will be facilitated by consideration of the following detailed description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which like numerals refer to like parts, and:
FIG. 1 illustrates a platform according to an aspect of the present invention;
FIG. 2 illustrates an array according to an aspect of the present invention;
FIG. 3 illustrates various operational configurations of an array according to an aspect of the present invention;
FIG. 4 illustrates a conductive/non-conductive layer according to an aspect of the present invention;
FIG. 5 illustrates a pixel configuration for an imaging layer according to an aspect of the present invention;
FIG. 6 illustrates variable tuning material layers according to an aspect of the present invention;
FIG. 7 illustrates an imaging layer according to an aspect of the present invention;
FIG. 8 illustrates transmit, receive and summing layers according to an aspect of the present invention;
FIGS. 9 and 10 illustrate an array according to an aspect of the present invention;
FIG. 11 illustrates different operational modes of an array according to an aspect of the present invention;
FIG. 12 illustrates an inter-relation between conductive/non-conductive layer and pixels of an imaging layer according to an aspect of the present invention;
FIG. 13 illustrates a high power switch suitable for use with an array according to an aspect of the present invention;
FIGS. 14A and 14B illustrate a functional switch according to an aspect of the present invention; and,
FIG. 15 illustrates an array according to an aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding, while eliminating, for the purpose of clarity, many other elements found in typical sensor systems and methods of making and using the same. Those of ordinary skill in the art may recognize that other elements and/or steps may be desirable in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein.
According to an aspect of the present invention, sensors and sensor arrays may be integrated into a platform structure itself. These arrays may be conformal and flexible in nature. These arrays may be well suited for sensing relatively low, slow, small and erratic targets of interest, such as people, rocket propelled grenade launchers, ground vehicles and ultra-lights, by way of non-limiting example.
According to an aspect of the present invention, it may be desirable that such systems support real beam imaging, spherical coverage and VHF & X-Band Radars. According to an aspect of the present invention, large area, low power density arrays may be provided. Such an array may be a reconfigurable array and/or support simultaneous sensor operations (e.g. high and low frequency radar, broadband ESM, Comm, etc.), and may have a range of about 600 km, all by way of non-limiting example only.
Arrays utilized according to an aspect of the present invention may be large as compared to traditional radar arrays. For example, the area of an array according to the present invention may be on the order of thousands of square meters (m 2 ), as opposed to tens of square meters, in size. In an exemplary embodiment, the array may be on the order of about 1600 m 2 in area.
Referring now to FIG. 1 , there is shown a platform 10 suitable for use as a platform for an array according to the present invention. Platform 10 is shown as a high altitude air ship, by way of non-limiting example only. Platform 10 may be greater than about 150 m long and 50 m tall, also by way of non-limiting example.
Arrays according to the present invention may operate as multifunctional sensors by supporting two or more radars (e.g., AMTI/GMTI; ESM; Comms). They may be operable with a broadband electromagnetic radiation spectrum and provide interleaved/shared/reconfigurable/reprogrammable RF sensor apertures.
According to an aspect of the present invention, a hardware array that can be programmed and controlled by software during operations may be provided. Radiator type, including radiator shape, size, and placement within the array may be programmed. Electronic circuitry, such as DC supply circuitry and RF circuitry, like stripline, microstrip and MMIC components, may be programmed. According to an aspect of the present invention, a ground plane configuration may be programmed. Various layer material characteristics may be programmed to optimize/adapt array operational performance, as a function of frequency, space, time and/or power, for example.
According to an aspect of the present invention, an array may be programmed for desired frequency coverage (narrow band or broadband; VHF to Ku or higher, for example). According to another aspect of the present invention, an array may be programmed for desired functionality (radar, electronic support measures, communications and/or electronic attack, for example).
The array performance may be controlled to adapt to changing environments and threats, and to improve array performance where traditional sensor performance may tend to degrade. According to an aspect of the present invention, material layers may be varied to tune array performance for changes in frequency, beam steer angle, temperature and array surface deflections, for example.
According to an aspect of the present invention, a controllable multi-layered approach may be used that includes antenna elements, and transmit and receive amplification functionality. Other circuit components may be added as well—for example, other RF components in both transmit and receive chains may be incorporated.
According to an aspect of the present invention, the layers may be thin and flexible, so that the array can be made for 3-D conformal applications requiring the surface to be flexible during operation (e.g., airship 10 of FIG. 1 ).
Referring now also to FIG. 2 , there is shown a diagrammatic representation of an array 100 according to an aspect of the present invention. Generally, array 100 includes one or more radiator array layers 110 , one or more variable tuning layers 120 , one or more ground plane layers 130 , one or more transmit power amplification layers 140 , one or more receive limiter layers 150 , one or more summing layers 160 , one or more imaging layers 170 and radiator input/outputs (I/O's) 180 . System 100 may be flexible and conformal in nature, and may be thin, such as on the order of 1 mm or less in thickness. In general, imaging layers 170 may be controllable, such that layers 110 – 160 may be controlled. Control may be effected by means of computer software, by way of non-limiting example only.
Referring now also to FIG. 3 , radiator array layer(s) 110 may take the form of selectively conducting/non-conducting (CNC) layers as will be described. Layer(s) 110 may define a plurality of arrays. For example, layers 110 may provide for a variety of programmable array features, such as radiator shape, size, and spacing. FIG. 3 illustrates a variety of radiator configurations. Configuration 110 A is illustrative of a low frequency radar array. Configuration 110 B is illustrative of a high frequency radar array. Configuration 110 C is illustrative of a low periodic broadband ESM (Electronic Surveillance Measures) array. And, configuration 110 D is illustrative of a dual band radar array having interleaved elements. As will be understood by those possessing an ordinary skill in the art, configurations 110 A– 110 D are periodic homogeneous arrays that represent non-limiting examples of possible configurations of layer(s) 110 ; other configurations are possible as well.
Referring now also to FIG. 4 , according to an aspect of the present invention, where an electromagnetic field is applied to the layer 110 , corresponding portions 410 of layer 110 are conductive in nature. Where no field is applied, corresponding portions 420 of layer 110 act as an insulator or dielectric. According to an aspect of the present invention, conducting and non-conducting portions 410 , 420 may be selectively arranged by selectively applying an electromagnetic field to layer 110 to selectively provide different functionality. That is, an array according to the present invention may be operated in different modes, each corresponding to a different functionality (e.g., configurations 110 A– 110 D) by selectively applying different electromagnetic fields to layer 110 . Referring now also to FIG. 5 , the resolution of selectability may be based upon the smallest addressable radiator or circuit dimension.
Referring now to FIGS. 2 and 6 , array 100 may include one or more variable tuning layers 120 . According to an aspect of the present invention, material properties may be varied across material layers (as is shown in illustration 610 ). According to an aspect of the present invention, material properties may be varied from layer to layer (as is shown in illustration 620 ). Properties that may be varied include the electrical and/or magnetic properties, such as conductivity, dielectric constant and magnetic permeability. Other properties that may be varied include physical properties, such as thickness and the introduction of deformities such as cavities. Other properties that may be varied include ferro-, magneto-, piezo- and optical properties.
As will be understood by one possessing an ordinary skill in the pertinent arts, by varying materials in these manners, an array according to an aspect of the present invention may be suitable for providing tunability from around 100 MHz to around 18 GHz, by way of non-limiting example. It may further support operations up into the W-band, for example. The variation in properties may also provide controllable isolation, impedance matching, and frequency and thermal response tuning between individual radiating elements.
Referring now also to FIGS. 2 and 7 , there are shown imaging layers 170 . Each imaging layer 170 is controllable. For example, each imaging layer 170 may be software controlled. This controllability may be used to form desired images that may be used to control the material properties of others of the layers of array 100 . Imaging layers 170 may create fields that impinge other layers, to control material properties thereof. For example, imaging layers 170 may define the antenna shape and spacing of layer 110 . Imaging layers 170 may define conductive areas, and/or areas having other properties, in ground plane layers 130 . Imaging layers 170 may define areas having desired material characteristics in material layers 120 , such as dielectric constant, permeability, E-field and H-field. Imaging layers 170 may selectively activate and/or deactivate functional transistors in layers 140 , 150 . Imaging layers 170 may also control switching in summing layer 160 .
According to an aspect of the present invention, each layer 170 may be composed of an array of pixels, or areas. Each pixel may serve as a control switch to selectively provide material control functionality. Such a switch may be a simple two position switch or a variable switch, for example. Each pixel may be selectively activated under software control, for example.
According to an aspect of the present invention, each pixel may include an array of nanowire transistors. In addition, nanowire edge electronics (not shown) can be used to control nanowire column, row and pixel transistors. Nanowire edge electronics can also be used to drive column, row and pixel transistors that are now made using nanowires. Nanowire edge electronics can include nanowire shift registers, nanowire level shifters and nanowire buffers, for example. Nanowire shift registers refer to a shift register implemented using nanowire transistors. Nanowire level shifters refer to level shifters implemented using nanowire transistors while nanowire buffers refer to a buffer implemented using nanowire shifters. Other types of edge electronics can be implemented using nanowire transistors. In one configuration, a voltage is applied to a nanowire column transistor for the column in which the pixel is located. The nanowire row transistor for the row in which the pixel is located will be turned on to allow current to flow to the nanowire pixel transistor. When the nanowire pixel transistor is on, current flows through the nanowire pixel transistor to make the voltage across the pixel, approximately the same as the voltage applied on the column to generate the desired signal being transmitted through the pixel. According to another aspect of the present invention, each pixel may include an array of quantum dots. According to an aspect of the present invention, each pixel may further include an array of light emitting devices or LEDs. Reference can be made to U.S. published Patent Application 20040135951 entitled “Integrated Displays Using Nanowire Transistors” published on Jul. 15, 2004 for illustration of exemplary switch circuitry and fabrication techniques useful in implementing the present invention, the teachings and subject matter thereof incorporated herein by reference in its entirety.
Regardless of the specific configuration, each pixel may be fed by an array of nanowires to selectively supply power. The array of nanowires may be used to selectively activate pixels under software control, for example. In an exemplary embodiment, a configurable nanowire transistor array may be implemented to carry out the principles of the invention as comprising one or more pairs of crossed nanowires, wherein one set of nanowires include a semiconductor material having a first conductivity and the other set of nanowires include either a metal or a second semiconductor material, and (b) a dielectric or molecular species to trap and hold hot electrons. The nano-scale wire transistors either form a configurable transistor or a switch memory bit that is capable of being set by application of a voltage that is larger in absolute magnitude than any voltage at which the transistor operates. The pair of wires may cross at a closest distance of nanometer scale dimensions and at a non-zero angle. Reference can be made to U.S. published Patent Application 20040041617 entitled “Configurable Molecular Switch Array” published on Mar. 4, 2004 for illustration of exemplary switch circuitry and fabrication techniques useful in implementing the present invention, the teachings and subject matter thereof incorporated herein by reference in its entirety.
The pixel density of a layer 170 may define the smallest radiator feature and hence the achievable image quality or resolution.
Referring now also to FIGS. 2 and 8 , there are shown amplification, receive and summing layers 140 , 150 , 160 for providing transistor functionality. That is, they may be thought of as providing a plurality of transistors. In the case of layer 140 , these transistors may be used to amplify signals to handle high power levels to effectuate transmission from array 100 . In the case of layer 150 , they may be used to amplify signals with a low noise figure to effectuate receiving signals using array 100 . Layer 150 may also provide a limiting functionality to prevent burnout during reception, as will be understood by those possessing an ordinary skill in the pertinent arts. In the case of layer 160 , the transistors may be used as switches for combining or summing signals going to or coming from radiator element layer 110 . They may be used to form one signal input in a transmit mode and to form one signal output in a receive mode. According to an aspect of the present invention, each of layers 140 , 150 and 160 may take the form of a physically separate layer to enable enhanced frequency coverage.
Referring now also to FIGS. 9 and 10 , there is shown a diagrammatic view of a non-limiting example of an array 900 according to an aspect of the present invention. Consistently with array 100 , array 900 includes summing layers 160 , tuning layers 120 , ground layers 130 and radiator layer 110 .
Array layer 110 includes nanostructures 112 . In the illustrated case of FIG. 9 , nanostructures 112 take the form of carbon nanotubes. As is understood in the pertinent arts, carbon nanotubes are a variant of crystalline carbon. Carbon nanotubes are structurally related to cagelike, hollow molecules composed of hexagonal and pentagonal groups of carbon atoms, or carbon fullerene “buckyballs”, or C60. Generally, there are three types of nanotubes: zigzag, armchair and chiral tubes of different diameters. Carbon nanotubes may generally be single or multi-walled. Single walled carbon nanotubes may have diameters on the order of about 1.2 to 1.4 nm. Multi-walled carbon nanotubes have diameters up to about 50 nanometers, by way of non-limiting example. Carbon nanotubes may have lengths that can be greater than 1 micron (μm), and even around 10 μm, for example.
Referring still to FIGS. 9 and 10 , nanotubes 112 may be formed into an array using a patterned catalyst. For example, iron or nickel may be patterned using conventional methodologies to provide a patterned substrate for nanotube growth, such as by using plasma enhanced, high frequency chemical vapor deposition. The present invention, in many embodiments may be implemented to include nanoscopic wires, each of which can be any nanoscopic wire, including nanorods, nanowires, organic and inorganic conductive and semiconducting polymers, nanotubes, semiconductor components or pathways and the like. Other nanoscopic-scale conductive or semiconducting elements that may be used in some instances include, for example, inorganic structures such as Group IV, Group III/Group V, Group II/Group VI elements, transition group elements, or the like, as described below. For example, the nanoscale wires may be made of semiconducting materials such as silicon, indium phosphide, gallium nitride and others. The nanoscale wires may also include, for example, any organic, inorganic molecules that are polarizable or have multiple charge states. For example, nanoscopic-scale structures may include main group and metal atom-based wire-like silicon, transition metal-containing wires, gallium arsenide, gallium nitride, indium phosphide, germanium, or cadmium selenide structures. Reference can be made to U.S. published Patent Application 20030089899 entitled “Nanoscale Wires and Related Devices” published on May 15, 2003 for illustration of exemplary circuitry and fabrication techniques useful in implementing the present invention, the teachings and subject matter thereof incorporated herein by reference in its entirety.
Referring still to FIGS. 9 and 10 , an array 114 may serve as an imaging layer (i.e., imaging layer 170 of FIG. 2 ), and take the form of a matrix of quantum dots or nanotransistors and nanowires, and may provide for selective operability of nanotubes 112 . Nanotubes 112 may be semiconductive in nature. By activating select pixels of array 114 , corresponding portions of nanotubes 112 may be activated, or excited into an energy emitting/receiving state, while other portions 110 off remain inactivated. By energizing select pixels of array 114 via software control, such as by using a matrix addressing scheme, specific portions (i.e., 110 on) may be selectively energized using a voltage to energize different radiator patterns.
Referring now also to FIG. 11 , different ground planes 130 may be selected for operation. According to an aspect of the present invention, a series of alternating imaging layers 170 and ground layers 130 may be provided. Hundreds of such layers may be provided. The imaging layer material property (e.g., dielectric constant) may be graded down the stack (e.g., a lower value at the top and increasing in value as one progresses down the stack). A ground layer may be selected, under software control, to become an active ground plane for enabling the desired electrical response from radiator array 110 . By alternating ground layers 130 with variable tuning layers 120 , a programmable tuner with incremental selection (e.g. bits) of both material property (e.g., dielectric constant or magnetic permeability) and thickness may be used to provide frequency and impedance tuning.
According to an aspect of the present invention, ground layers 130 may be analogously configured of carbon nanotubes. By activating select pixels of corresponding imaging layers 170 , corresponding portions of ground layers 130 may be activated or excited into a conductive state, while other portions remain inactivated and hence non-conductive in nature. Referring now also to FIG. 12 , there is shown an exploded view of a ground layer 130 and corresponding imaging layer 170 . In application, layers 130 and 170 may be very close to or in contact with one another.
According to another aspect of the present invention, real-time electrical circuitry configuration may be effected through software control. Analog and digital circuit components associated with signal routing, such as signal and supply lines, may be effected by selectively activating portions of ground layers. RF circuitry (e.g., stripline, microstrip, MMIC components, and signal routing) may also be effected.
As set forth, imaging layer 170 may take the form of a lattice of quantum dots or nanotransistors, and may provide control voltages to ground layer 130 to form desired circuitry. As select areas of imaging layer 170 are activated, corresponding nanotubes of ground layer 130 become excited and transition from a non-conducting to a conducting state. That is, ground layer 130 becomes conducting where imaging layer 170 provides a control voltage and non-conducting where no control voltage is supplied.
Referring now also to FIG. 13 , there is shown an exemplary configuration of a high isolation/high power switch controlling selection of transmit or receive functionality in an array according to the present invention. Referring now also to FIGS. 14A and 14B , there is shown an embodiment to the switch of FIG. 13 using the re-programmability of conductive paths in individual layers 130 over time to eliminate the need for a physical switch. As will be understood by one possessing an ordinary skill in the pertinent arts, this may serve to eliminate loss and isolation problems associated with the switch.
Referring now to FIG. 15 , there is shown an exploded representation of an array 1000 according to an aspect of the present invention. Array 1000 is well suited for transmitting and receiving electromagnetic signals in the general directions 1005 . Array 1000 may provide for single or dual functionality. As shown in FIG. 15 , a first portion 1010 may perform as a receiver, while a second portion 1015 performs as a transmitter.
Array 1000 may include one or more radiator layers 110 , a plurality of variable tuning layers 120 , a plurality of ground layers 130 , transmit, receive and summing layers 140 , 150 , 160 , and a plurality of imaging layers 170 . By selectively controlling the imaging layers 170 and material properties of variable tuning layers 120 , conducting and non-conducting regions of ground planes 130 may be selectively operated. Also by selectively controlling the imaging layers 170 , the shape and dimensions of radiator elements in array 110 may be defined. Also by selectively controlling imaging layers 170 , the operation of layers 140 , 150 , 160 may be controlled, such as to provide for the dual-functionality illustrated, for example.
Those of ordinary skill in the art may recognize that many modifications and variations of the present invention may be implemented without departing from the spirit or scope of the invention. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A reconfigurable array including: a plurality of imaging layer including an array of software addressable pixels; a conductive/non-conductive layer being positioned with respect to corresponding ones of the pixels such that addressing them causes corresponding portions of the conductive/non-conductive layer to be conductive; a radiator layer being positioned with respect to corresponding ones of the pixels such that addressing them defines at least one radiator array; a switching and summing layer positioned with respect to corresponding ones of the pixels such that the addressing them causes corresponding portions of switching and summing layer to switch and sum the signals; and, a plurality of inputs coupled to the imaging layers and being under software control to selectively activate the pixels.
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BACKGROUND OF THE INVENTION
In the specific assay methods based on bioaffinity the analytes are usually measured at very small concentrations, which require the use of labelling agents that are detectable by a very sensitive method. Such bioaffinity assays include inter alia immunochemical assays, nucleic acid hybridizations, lectin reactions as well as receptor assays. Various labelling agent methods are usually used in the analytical applications of all these reactions. The radioisotopes are conventional labelling agents used for example in radio immunological (RIA) and immonoradiometric (IRMA) assays, which are the most sensitive specific analytical methods used in the practice. The detection sensitivity of the RIA assays is ca. 10 -14 M and the corresponding sensitivity limit of the IRMA assays is ca. 10 -16 M. Despite the common usage, the radioisotopes as labelling agents present some drawbacks such as a limited lifetime as well as handling problems. For this reason, active research has been directed to possibilities to replace the radio active labelling agents with other alternatives.
The fluorescence methods are more and more widely used in chemical, biochemical and medicinal analytics. Fluoroimmunological and immunofluorometric assays that are based on time-resolved fluorometrics and on lanthanide chelates as labelling agents give at least the same or even better sensitivity compared with RIA and IRMA assays.
Fluorescent Labelling Agents
The sensitivity of fluorescent labelling agents is high in theory for example in immunoassays, but in the practice the background of the fluorescence forms a factor limiting the sensitivity. Background fluorescence is emitted both by the components contained in the sample and by the appliances and instruments used in the measurement. In some cases where a very high sensitivity is not needed the use of fluorescent labelling agents has been possible, but the intensity of the background fluorescence often imposes real problems. For example various components contained in the serum cause often a problem of this type. The scattering caused by the sample causes also some interference especially when labelling agents with a small Stoke's shift (<50 nm) are used. Because of a high background and scattering the sensitivity of the labelling agents is about 50 to 100 times lower compared with the sensitivity of the same labelling agent in a pure buffered solution.
Time-Resolved Fluorometry and Lanthanide Fluorescence
The time-resolved fluorescence (vide Soini, E., Hemmila, I., Clin. Chem. 1979, 25, 353-361) gives a possibility to separate the specific fluorescence of the labelling agent from the interfering non-specific fluorescence of the background. The use of the time-resolved fluorescence for assays based on bioaffinity reactions are described in U.S. Pat. Nos. 4,058,732 and 4,374,120. In the time-resolved fluorescence the fluorescing labelling agent is excited by a short-time light pulse and the fluorescence is measured after a certain time from the moment of excitation. During the interval between the excitation moment and measurement moment the fluorescence of the interfering components becomes extinguished to such an extent that only the fluorescence emanating from the labelling agent will be measured. A labelling agent of this type should have a high fluorescence intensity, relatively long wavelength of emission, large Stoke's shift, sufficiently long half-life of fluorescence and further, the labelling agent should be capable of binding covalently to an antibody or antigen in such a way that it has no effect on the properties of these immunocomponents.
Some lanthanide chelates such as certain europium, samarium and terbium chelates have a long half-life of fluorescence and hence they are very suitable labelling agents for time-resolved fluorometry. The emission wavelength is relatively long (terbium 544 nm, europium 613 nm, samarium 643 nm) and the Stoke's shift is very large (230 to 300 nm). The most important property is, however, the long half-time of fluorescence, ca. 50-100 μs, which makes the use of time-resolved techniques possible. The fluorescence of the labelling agent can be measured when the labelling agent is bound to an antigen or antibody, or the lanthanide can be separated from them in properly chosen circumstances by dissociating the bond between the lanthanide and the chelate. After the dissociation the fluorescence of the lanthanide is measured in a solution in the presence of a beta-diketone, synergistic compound and detergent that together with the lanthanide form a micellar structure together with the lanthanide where the fluorescence intensity of the lanthanide is very high (U.S. Pat. No. 4,545,790). A solution that contains beta-diketone, a synergistic compound and detergent at a low pH-value is called a fluorescence developer solution.
In year 1967 it was proved that the fluorescence of a europium- (or samarium)-TTA-collidine complex is enhanced very strongly when Gd 3+ or Tb 3+ is added (Melanteva et al. (1967), Zh. Anal Khim. 22, 187). The phenomenon was not, however, studied in more detail. During the last few years in course of studies of europium and samarium chelates in the presence of TTA and a synergistic ligand it has been found out that the strong enhancement of the fluorescence is based on internal fluorescence effect that is called cofluorescence. Several studies have been published on the subject recently (Yang Jinghe et al. (1987) Anal. Chim. Acta, 198, 287; Ci Yunxiang et al. (1988), Analyst (London), 113, 1453; Ci Yunxiang et al. (1988), Anal. Lett., 21, 1499; Ci Yunxiang et al. (1989), Anal. Chem., 61, 1063; Yang Jinghe (1989), Analyst (London), 114, 1417). All studies up to present have employed only one beta-diketone (TTA), two fluorescent lanthanides (Eu 3+ and Sm 3+ ) and the determinations have been carried out in the presence of lanthanide and yttrium ions for determining trace amounts of Eu and Sm in lanthanide and yttrium oxides.
SUMMARY OF THE INVENTION
The present invention is based on a method which increases the fluorescence of lanthanide chelates when they are used as labelling agents for fluorometric assay of biologically active substances. The lanthanide is converted to a highly fluorescent form before the measurement based on a time-resolved fluorescence by forming aggregated particles that contain a lanthanide chelate as well as a chelate that contains an ion increasing the fluorescence. The specific fluorescence of lanthanides in the above-mentioned fluorescent aggregates is considerably increased. The fluorescence intensity of the lanthanide chelate is thereby enhanced when biologically active substances are measured. Europium, terbium, samarium or dysprosium are used as the lanthanides of the lanthanide chelates.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings,
FIG. 1 shows standard curves of Eu and Sm obtained with the solutions used in the method,
FIGS. 2a and 2b show the results of an immunoassay by the method of the invention and a commercial immunoassay method, respectively, and
FIG. 3 shows the results of an immunoassay by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention has proved the fact that the beta-diketones presented in table I give a good cofluorescence effect. The aromatic beta-diketones shown in table I are well applicable to the measurement of europium and samarium in a cofluorescence method, whereas the aliphatic beta-diketones of the table are applicable to the measurement of europium, terbium, samarium and dysprosium by another method based on the cofluorescence. The invention proves the fact that the fluorescence intensity of europium and samarium, and in addition terbium and dysprosium, is greatly enhanced when other lanthanides and yttrium are used in the cofluorescence. It should be mentioned that terbium, which has an unusual cofluorescence effect, can be used as a fluorescence -enhancing ion when the cofluorescence of europium and samarium is to be enhanced when an aromatic beta-diketone is used. It can be also used as a fluorescent ion whose fluorescence is enhanced by another lanthanide ion or yttrium ion when an aliphatic beta-diketone is used in the cofluorescence.
The beta-diketones of table 1 form the chelates both with the fluorescent lanthanide ion and with the ion enhancing the fluorescence, when used in accordance with the invention.
For increasing the fluorescence further, synergistic compounds must be used in the cofluorescence method. Such compounds are
1,10-phenanthroline (Phen)
4,7-dimethyl-1,10-phenanthroline (4,7-DMphen),
4,7-diphenyl-1,10-phenanthroline (4,7-DPphen),
5,6-dimethyl-1,10-phenanthroline (5,6-DMphen),
2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DMDPphen),
2,2 1 -dipyridyl (DP),
2,2 1 -dipyridylamine (DPA),
2,4,6-trimethylpyridine (TMP),
2,2 1 :6 1 ,2 11 -terpyridine (TP),
1,3-diphenylguanidine (DPG).
The synergistic compounds form a structure completing the chelate structure of the lanthanide chelates and they are at the same time hydrophobic, thus inhibiting the action of water tending to quench fluorescence.
The strong fluorescence of the lanthanide chelates is based on the fact that the ligand absorbs the excitation energy, whereafter the energy is transferred from the triplet level of the ligand to the resonance level of the lanthanide. The consequence is a very sharp emission peak whose wavelength is characteristic of the lanthanide ion. In addition, the emission has a long half-life. The cofluorescence is based on an intermolecular energy transfer that occurs from the chelate of the ion increasing fluorescence, the energy donor, to the chelate of the fluorescent ion, the energy acceptor, provided that the cofluorescence complex is in the solution as a suspension or in solid form as aggregated particles and that the solution contains a large excess of the chelate containing the ion increasing the fluorescence. In aggregated particles the chelate containing the fluorescent lanthanide ion is in a close contact with several lanthanide chelate complexes increasing fluorescence so that the energy can effectively be transferred from the latter to the former.
Ions increasing the fluorescence that are suitable for cofluorescence are Gd 3+ , Tb 3+ , Lu 3+ , La 3+ and Y 3+ . The ion must always be used in a large excess so that the ion increasing the fluorescence influences the fluorescent ion (Eu 3+ , Tb 3+ , Sm 3+ or Dy 3+ ) to increase its intensity 10 to 1000 fold. In some cases fluorescence was not at all detected without a cofluorescence complex increasing the fluorescence, but the presence of said complex caused a strong fluorescence by the fluorescent ion.
In most of the cofluoresence complexes the presence of a detergent, such as TRITON X-100, TRITON X-100, TRITON N-101 and TRITON X-405 has an effect on the fluorescence intensity and its stability. The micelles formed protect the fluorescent chelates from the quenching action by the water and at the same time keep the cofluorescence complex in suspension.
Water-soluble organic solvents such as ethanol, propanol, dimethylsulfoxide, 2-metoxyethanol or ethyleneglycol increase often the fluorescence of the fluorescent ion in the cofluorescent complex.
The determination based on cofluorescence can be used in various ways when assaying biological substances. The biological substance can be labelled with the lanthanide chelate using a chelating compound such as some EDTA analogue. After the immunochemical assay the lanthanide ion is dissociated from the labelled biological substance into a solution, whereafter the very strongly fluorescent aggregated particle is formed (cofluorescent complex), consisting of the lanthanide chelate and the chelate of the ion increasing fluorescence. The biological substance can also be labelled directly with very strongly fluorescent particles by using a chemical bond or adsorption. After the immunochemical reaction the fluorescence of the particles is measured either in suspension in a solution or directly on the surface of a solid support. Alternatively, the biological substance can be labelled only with a beta-diketone derivative or with a synergistic compound that have a group that enables their coupling to an immunocomponent such as to a protein. After the immunochemical assay, a strongly fluorescent aggregated particle is created that contains the lanthanide chelate as well as the excess of the chelate of the ion increasing fluorescence. In this case, also an excess of the chelate of the fluorescent ion is used, whereby a lanthanide contamination will not interfere, and the fluorescence can be measured directly from the surface of a solid support, if desired. Homogeneous assays excluding the separation stage can utilize factors that influence the cofluorescence by increasing or quenching the intensity, for example. Such factors are for example antigen-antibody reactions and compounds affecting the energy transfer. The assay based on cofluorescence can be commonly used in methods based on bioaffinity reactions, such as immunochemical assays, nucleic acid hybridization assays, receptor assays as well as lectine reactions, which all use lanthanide chelates or components forming cofluorescence complexes as the labelling agents.
Because the lanthanide determinations based on the cofluorescence complex are very sensitive, these complexes can be used for a simultaneous determination of several lanthanides. Hence, several analytes can be determined in one single sample incubation in the analytical applications.
The developer solution used in the cofluorescence is usually made before the use. It consists of two different solutions, Ea and Eb, which are kept separately. When it is necessary to dissociate the lanthanide ion from the labelled biological substance, Ea contains A) the beta-diketone that chelates the fluorescent ion and the fluorescence-increasing ion, said beta-diketone being in excess compared with the ions to be chelated, B) the fluorescence-increasing ion, and C) the detergent, all in an aqueous solution whose pH is adjusted to a value below 4 with acetic or hydrochloric acid, whereas Eb contains D) the synergistic compound and E) a buffer with a pH above 6. When using the developer solutions, first the solution Ea is added, whereafter shaking is applied during 1-5 minutes to dissociate the lanthanide ion. Thereafter Eb is added and the shaking is continued for 1 to 15 minutes. During the second shaking stage a suspension containing the aggregated, very fluorescent particles is formed. The fluorescence is measured using time-resolved fluorometry.
The invention is illustrated by means of the following examples:
EXAMPLE 1
Cofluorescence developer solution for the determination of Eu 3+ and Sm 3+ , containing TTA, phenanthroline, Y 3+ and TRITON X-100 surfactant.
The developer solution consists of two parts, Ea, that contains 60 μM TTA, 7,5 μM Y 3+ , 0.06% (w/v) TRITON X-100 surfactant in an aqueous solution with a pH adjusted to 3.2 by means of acetic acid, as well as Eb, which contains 1.15 mm phenanthroline in 0.21M Tri-buffer. The developer solutions Ea and Eb were used in the ratio of 10:1. FIG. 1 shows the standard curves for Eu 3+ and Sm 3+ when cofluorescence has been applied. Commercial developer solution DELFIA® has been used as the reference (En). A clearly better result is obtained with cofluorescence compared with the DELFIA® method.
EXAMPLE 2
Developer solution based on cofluorescence for determination of Eu 3+ and Sm 3+ , containing BTA, phenanthroline, Y 3+ and TRITON X-100 surfactant.
The developer solution consists of two parts, solution Ea, which contains 50 μM BTA, 7.5 μM Y 3+ and 0.02% (w/v) TRITON X-100 surfactant in an aqueous solution with a pH adjusted to 3.2 by means of acetic acid, as well as solution Eb, which contains 500 μM phenanthroline in 0.2M Tris-buffer. The solutions Ea and Eb are used in the ratio 10:1. The fluorescence results obtained with the developer solution are presented in table II.
EXAMPLE 3
Developer solution based on cofluorescence for simultaneous determination of Eu 3+ , Tb 3+ , Sm 3+ and Dy 3+ in a solution that contains PTA, Y 3+ , TRITON X-100 surfactant and ethanol.
The developer solution consists of two parts, Ea, which contains 50 μM PTA, 7.5 μM Y 3+ , 0.06% (w/v) TRITON X-100 surfactant and 25% (v/v) ethanol in an aqueous solution with a pH adjusted to 3.45 by means of acetic acid, and Eb, which contains 500 μM phenanthroline in 0.2M Tris-buffer. The solutions Ea and Eb are used in the ratio 10:1. The fluorescence results obtainable with the developer solution are presented in table III.
EXAMPLE 4
A developer solution based on cofluorescence for simultaneous determination of Eu 3+ , Tb 3+ , Sm 3+ and Dy 3+ in a solution containing PTA, DP, Y 3+ and TRITON X-100 surfactant.
The developer solution consists of two parts, solution Ea which contains 100 μM PTA, 3 μM Y 3+ and 0.0006% (w/v) TRITON X-100 surfactant in an aqueous solution with a pH adjusted to 3.0 by means of acetic acid, and solution Eb, which contains 5 mM DP and 80% (v/v) ethanol in 0.375M Tris-buffer. The solutions Ea and Eb are used in the ratio of 10:1. The fluorescence results obtainable with the developer solution are presented in table IV.
EXAMPLE 5
The determination of FSH by an immunofluorometric method based on time-resolved fluorescence using the cofluorescence development (solutions Ea and Eb of Example 1).
A monoclonal anti-alfa-FSH antibody was labelled using N 1 -(p-isothiocyanatebenzyl)-diethylenetriamine-N 1 ,N 2 ,N 3 ,N.sup.4 -tetra-acetic acid as the labelling agent. The labelling was carried out at pH 9.5 by using a 50 fold molaric excess of the Eu-chelate. The free labelling agent was separated from the labelled antibody by gel filtration (Sepharose 6B+Sephadex G 50). The labelling ratio was 17 Eu 3+ /IgG. The wells of microtiter plates were coated with a monoclonal anti-beta-FSH antibody. The coating was carried out in 0.1M NaH 2 PO 4 buffer, pH 4.5, overnight at room temperature, using 1 μg antibody per well. The wells were washed and saturated with 0.1% BSA and stored wet at +4° C.
The immunoassay was carried out in 0.05M Tris-HCl buffer, pH 7.7, which contained 9 g/l NaCl, 0.05% NaN 3 , 0.5% BSA, 0.05% bovine globulin and 0.01% Tween 40. The first incubation (1 hour at room temperature) was carried out in different FSH contents and the second incubation (1 hour at room temperature) was carried out by using 5 ng per well of the anti-alfa-FSH antibody labelled with Eu-chelate, whereafter the wells were washed six times.
After the washing the europium ion was dissociated by adding 200 μl of solution Ea per well, whereafter shaking was applied during 1 to 2 minutes. The fluorescence of the used labelling agent (Eu 3+ ) was developed by increasing 20 μl of solution Eb per well, whereafter shaking was applied for 8 to 10 minutes. The fluorescence was measured by using a time-resolved fluorometer with a cycle length of 2 ms, delay between the excitation and the measurement of 0.5 ms and the measurement time of 1.5 ms. The results are presented in FIG. 2a. FIG. 2b shows the results of the same immunoassay when a commercial DELFIA® developer solution has been used for the measurement. By using the cofluorescence, a much better result is obtained at low FSH-concentrations compared with DELFIA®.
EXAMPLE 6
The determination of FSH by an immunofluorometric method based on time-resolved fluorescence using the solutions Ea and Eb of Example 2 in the development of cofluorescence.
The components and methods used in the immunoassay were the same as in Example 5. The dissociation of Eu 3+ and the development of fluorescence after the immunoassay took place in the following manner. The dissociation was carried out by adding 200 μl of solution Ea per well, whereafter shaking was applied for 1 to 2 minutes. The fluorescence of the labelling agent (Eu 3+ ) was developed by adding 20 μl of solution Eb per well, whereafter shaking was applied for 1 minute. The fluorescence was measured as in Example 5. The standard curve of the determination is presented in FIG. 3.
TABLE 1__________________________________________________________________________Beta-diketone R.sub.1 COCH.sub.2 COR.sub.2 R.sub.1 R.sub.2__________________________________________________________________________Thenoyltrifluoroacetone (TTA) ##STR1## CF.sub.3Pivaloyltrifluoroacetone (PTA) (CH.sub.3).sub.3 C CF.sub.31,1,1-trifluoro-6methyl-2,4- (CH.sub.3).sub.2 CHCH.sub.2 CF.sub.3heptanedione (TFMH)Dipivaloylmethane (DPM) (CH.sub.3)C C(CH.sub.3).sub.3Benzoylitrifluoroacetone (BTA) C.sub.6 H.sub.5 CF.sub.31,1,1,2,2,-pentafluoro-5-phenyl- C.sub.6 H.sub.5 CF.sub.2 CF.sub.33,5-pentanedione (PFPP)2-furoyltrifluoroacetone (FTA) ##STR2## CF.sub.3p-fluorobenzoyltrifluoroacetone (FBTA) ##STR3## CF.sub.31,1,1,2,2-pentafluoro-6,6-dime- (CH.sub.3).sub.3 C CF.sub.2 CF.sub.3thyl-3,5-heptanedione (PFDMH)1,1,1,2,2,3,3-heptafluoro-7,7- CF.sub.2 CF.sub.2 CF.sub.3 (CF.sub.3).sub.3 Cdimethyl-4,6-octanedione (HFDMO)1,1,1,5,5,5-hexafluoroacethyl- F.sub.3 C CF.sub.3acetone (HFAcA)1,1,1,2,2,-pentafluoro-3,5-hexane- CH.sub.3 CF.sub.2 CF.sub.3dione (PFH)p-isothiocyanatebenzoyltrifluoro- acetone (ICBTF) ##STR4## CF.sub.3Di-p-fluorobenzoylmethane (D.sub.p FBM) ##STR5## ##STR6##Dibenzoylmethane (DBM) C.sub.6 H.sub.5 C.sub.6 H.sub.5__________________________________________________________________________
TABLE II__________________________________________________________________________ Excitation Emission Fluorescence ofFluorescent (max) (max) Delay Enchancement 1 nM of the ion Background Sensitivityion nm nm us factor* counts/s counts/s pM__________________________________________________________________________Eu.sup.3+ 333 612 764 208 4194 × 10.sup.4 1860 0.0043Sm.sup.3+ 337 647 79 358 231 × 10.sup.3 204 0.11__________________________________________________________________________ *Fluorescence enchancement factor calculated on the measurement readings with and without the presence of Y.sup.3+-
TABLE III__________________________________________________________________________ Excitation Emission Fluorescence ofFluorescent (max) (max) Delay Enchancement 1 nM of the ion Background Sensitivityion nm nm us factor* counts/s counts/s pM__________________________________________________________________________Eu.sup.3+ 315 612 820 130 2.740.000 580 0.035Tb.sup.3+ 312 544 323 1078 956.000 2770 0.34Sm.sup.3+ 315 647 88 61 5.330 370 7.9Dy.sup.3+ 316 574 27 102 16.400 6980 46__________________________________________________________________________
TABLE IV__________________________________________________________________________ Excitation Emission Fluorescence ofFluorescent (max) (max) Delay Enchancement 1 nM of the ion Background Sensitivityion nm nm us factor* counts/s counts/s pM__________________________________________________________________________Eu.sup.3+ 312 612 948 >1000 6.846.000 1000 0.019Tb.sup.3+ 312 545 239 >1000 2.983.000 2400 0.27Sm.sup.3+ 312 647 48 309 11.200 100 3.8Dy.sup.3+ 312 575 11 985 24.500 6720 100__________________________________________________________________________
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The invention relates to a method based on fluorescence, especially time-resolved fluorescence for quantitative assay of a bioaffinity reaction involving bioaffinity components. The method comprises the labelling of one or several of the bioaffinity components participating in the reaction with a lanthanide chelate, forming of a lanthanide chelate for a fluorescence measurement after the reaction, and measuring the fluorescence of the chelate. The lanthanide (Eu, Tb, Sm or Dy) is brought to a strongly fluorescent form before the fluorescence measurement by incorporating the lanthanide in an aggregated particle that comprises the lanthanide chelate and a chelate of a fluorescence-increasing ion (Y, Gd, Tb, Lu or La) to bring about a cofluorescence effect. An aliphatic or aromatic beta-diketone is used as the chelating compound in the aggregate.
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[0001] This application is a continuation of application Ser. No. 11/035,374 filed Jan. 13, 2005, entitled “Method and system for providing electrical pulses for neuromodulation of vagus nerve(s) using rechargeable implanted pulse generator”, which is a continuation of application Ser. No. 10/841,995 filed May 8, 2004, which is a continuation of application Ser. No. 10/196,533 filed Jul. 16, 2002, which is a continuation of application Ser. No. 10/142,298 filed on May 9, 2002. The prior applications being incorporated herein in entirety by reference, and priority is claimed from these applications.
FIELD OF INVENTION
[0002] This invention relates generally to providing electrical pulses for blocking/stimulation therapy for medical disorders, more specifically to neuromodulation therapy comprising vagal blocking with or without vagal stimulation, for providing therapy for obesity and other gastrointestinal (GI) disorders, utilizing rechargeable implantable pulse generator.
Background of Obesity and Relation to Vagus Nerve
[0003] Obesity is a significant health problem in the United States and many other developed countries. Obesity results from excessive accumulation of fat in the body. It is caused by ingestion of greater amounts of food than can be used by the body for energy. The excess food, whether fats, carbohydrates, or proteins, is then stored almost entirely as fat in the adipose tissue, to be used later for energy. Obesity is not simply the result of gluttony and a lack of willpower. Rather, each individual inherits a set of genes that control appetite and metabolism, and a genetic tendency to gain weight that may be exacerbated by environmental conditions such as food availability, level of physical activity and individual psychology and culture. Other causes of obesity also include psychogenic, neurogenic, and other metabolic related factors.
[0004] Obesity is defined in terms of body mass index (BMI), which provides an index of the relationship between weight and height. The BMI is calculated as weight (in Kilograms) divided by height (in square meters), or as weight (in pounds) times 703 divided by height (in square inches). The primary classification of overweight and obesity relates to the BMI and the risk of mortality. The prevalence of obesity in adults in the United States without coexisting morbidity increased from 12% in 1991 to 17.9% in 1998, and is still increasing.
[0005] Treatment of obesity depends on decreasing energy input below energy expenditure. Treatment has included among other things various drugs, starvation, and even stapling or surgical resection of a portion of the stomach. Surgery for obesity has included gastroplasty and gastric bypass procedure. Gastroplasty which is also known as stomach stapling, involves constructing a 15- to 30 mL pouch along the lesser curvature of the stomach. A modification of this procedure involves the use of an adjustable band that wraps around the proximal stomach to create a small pouch. Both gastroplasty and gastric bypass procedures have a number of complications.
[0006] The vagus nerve (which is the 10 th cranial nerve) plays a role in mediating afferent information from the stomach to the satiety center in the brain. The vagus nerve arises directly from the brain, but unlike the other cranial nerves extends well beyond the head. At its farthest extension it reaches the lower parts of the intestines. This is shown schematically in FIG. 1 , and in more detail in FIG. 2 .
[0007] In 1988 it was reported in the American Journal of Physiology , that the afferent vagal fibers from the stomach wall increased their firing rate when the stomach was filled. One way to look at this regulatory process is to imagine that the drive to eat, which may vary rather slowly with the rise and fall of hormone Leptin, is inhibited by satiety signals that occur when we eat and begin the digestive process (i.e., the prandial period). As shown schematically in FIG. 3 , these satiety signals both terminate the meal and inhibit feeding for some time afterward. During this postabsorptive (fasting) period, the satiety signals slowly dissipate until the drive to eat again takes over.
[0008] The regulation of feeding behavior involves the concentrated action of several satiety signals such as gastric distention, the release of the gastrointestinal peptide cholecystokinin (CCK), and the release of the pancreatic hormone insulin. The stomach wall is richly innervated by mechanosensory axons, and most of these ascend to the brain via the vagus nerve(s) 54 . The vagus sensory axons activate neurons in the Nucleus of the Solitary Tract in the medulla of the brain. These signals inhibit feeding behavior. In a related mechanism, the peptide CCK is released in response to stimulation of the intestines by certain types of food, especially fatty ones. CCK reduces frequency of eating and size of meals. As depicted schematically in FIG. 4 , both gastric distension and CCK act synergistically to inhibit feeding behavior.
Vagal Blocking and/or Stimulation
[0009] In commonly assigned disclosures, application Ser. No. 10/079,21 now U.S. Pat. ______, and U.S. Pat. No. 6,611,715, pulsed electrical neuromodulation therapy for obesity and other medical conditions is obtained by providing electrical pulses to the vagus nerve(s) via an implanted lead comprising plurality of electrodes. In those disclosures, the electrical pulses are provided by at least one electrode on the lead. This patent application is directed to system and method for neuromodulation of vagal activity, wherein vagal block with or without selective vagal stimulation may be used to provide therapy for obesity, weight loss, eating disorders, and other gastrointestinal disorders such as FGIDs, gastroparesis, gastro-esophageal reflex disease (GERD), pancreatitis, ileus and the like. Even though the invention is disclosed in the context of vagal blocking, the nerve blocking methodology can also be used to provide therapy for other ailments, and to provide electric pulses for blocking of other nerves such as sympathetic nerve(s), sacral nerves, or other cranial nerves or their branches or part thereof.
[0010] The gastrointestinal tract and central nervous system (CNS) engage each other in two-way communication. This has both parasympathetic and sympathetic components. Of particular interest in this disclosure is the parasympathetic component or the vagal pathway, which is shown in conjunction with FIG. 5 .
[0011] In some gastrointestinal (GI) disorders, to provide therapy, stimulation of the vagus nerve(s) is adequate and is the preferred mode of providing therapy. For other GI disorders, to provide therapy, stimulation and selective block is the preferred mode of therapy. For some GI disorders, vagal nerve(s) blocking only is the preferred mode of providing therapy. Advantageously, the method and system disclosed in this patent application can provide vagal blocking with or without vagal stimulation to provide therapy for obesity and other gastrointestinal disorders.
[0012] As is shown in conjunction with FIG. 6 when vagal pathway is stimulated, the stimulation is conducted both in the Afferent (towards the brain) and Efferent (away from the brain) direction. Shown in conjunction with FIG. 7 , by placing blocking electrodes proximal to the stimulating electrodes, and supplying blocking pulses, the conduction in the Afferent direction (towards the brain) can be blocked or significantly reduced. The blocking pulses may be 500 Hz or other frequency, as described later in this disclosure. This is useful for certain GI disorders, for example ileus and the like.
[0013] Shown in conjunction with FIG. 8 , the blocking electrodes may be placed distal to the stimulating electrodes. If the stimulator provides blocking pulses to the blocking electrode, then the vagus nerve(s) impulses in the Efferent direction are either blocked or are significantly reduced. As the vagus nerves are involved in pancreatitus, the down-regulating of vagal activity can be used to treat pancreatitus and the like.
[0014] It will be clear to one of ordinary skill in the art, that by selectively placing the blocking electrode, selective block can be obtained when the stimulator applies blocking pulses to the blocking electrode. Selective Efferent block is depicted in conjunction with FIG. 9 . As shown in the figure, because of the selective placement of blocking electrode(s), only the impulses to visceral organ 2 are blocked or significantly reduced, and impulses to visceral organ- 1 and visceral organ- 2 continue unimpeded. Selective Afferent block can also be achieved, and is depicted in conjunction with FIG. 10 . Here the nerve impulses to visceral organ and visceral organ- 5 are selectively blocked. An example would be where Afferent vagal pulses are desired, but impulses to the heart and vocal cords would be blocked. Thus, advantageously providing the desired therapy without the side effects of voice or cardiac complications such as bradycardia. Similarly other side effects can be alleviated or minimized with nerve blocking.
Background of Neuromodulation
[0015] Most nerves in the human body are composed of thousands of fibers of different sizes. This is shown schematically in FIG. 11 . The different sizes of nerve fibers, which carry signals to and from the brain, are designated by groups A, B, and C. The vagus nerve, for example, may have approximately 100,000 fibers of the three different types, each carrying signals. Each axon or fiber of that nerve conducts only in one direction, in normal circumstances. In the vagus nerve sensory fibers outnumber parasympathetic fibers four to one.
[0016] In a cross section of peripheral nerve it is seen that the diameter of individual fibers vary substantially, as is also shown schematically in FIG. 12 . The largest nerve fibers are approximately 20 μm in diameter and are heavily myelinated (i.e., have a myelin sheath, constituting a substance largely composed of fat), whereas the smallest nerve fibers are less than 1 μm in diameter and are unmyelinated.
[0017] The diameters of group A and group B fibers include the thickness of the myelin sheaths. Group A is further subdivided into alpha, beta, gamma, and delta fibers in decreasing order of size. There is some overlapping of the diameters of the A, B, and C groups because physiological properties, especially in the form of the action potential, are taken into consideration when defining the groups. The smallest fibers (group C) are unmyelinated and have the slowest conduction rate, whereas the myelinated fibers of group B and group A exhibit rates of conduction that progressively increase with diameter.
[0018] Nerve cells have membranes that are composed of lipids and proteins, and have unique properties of excitability such that an adequate disturbance of the cell's resting potential can trigger a sudden change in the membrane conductance. Under resting conditions, the inside of the nerve cell is approximately −90 mV relative to the outside. The electrical signaling capabilities of neurons are based on ionic concentration gradients between the intracellular and extracellular compartments. The cell membrane is a complex of a bilayer of lipid molecules with an assortment of protein molecules embedded in it, separating these two compartments. Electrical balance is provided by concentration gradients which are maintained by a combination of selective permeability characteristics and active pumping mechanism.
[0019] A nerve cell can be excited by increasing the electrical charge within the neuron, thus increasing the membrane potential inside the nerve with respect to the surrounding extracellular fluid. The threshold stimulus intensity is the value at which the net inward current (which is largely determined by Sodium ions) is just greater than the net outward current (which is largely carried by Potassium ions), and is typically around −55 mV inside the nerve cell relative to the outside (critical firing threshold). If however, the threshold is not reached, the graded depolarization will not generate an action potential and the signal will not be propagated along the axon. This fundamental feature of the nervous system i.e., its ability to generate and conduct electrical impulses, can take the form of action potentials, which are defined as a single electrical impulse passing down an axon. This action potential (nerve impulse or spike) is an “all or nothing” phenomenon, that is to say once the threshold stimulus intensity is reached, an action potential will be generated.
[0020] To stimulate an excitable cell, it is only necessary to reduce the transmembrane potential by a critical amount. When the membrane potential is reduced by an amount ΔV, reaching the critical or threshold potential. When the threshold potential is reached, a regenerative process takes place: sodium ions enter the cell, potassium ions exit the cell, and the transmembrane potential falls to zero (depolarizes), reverses slightly, and then recovers or repolarizes to the resting membrane potential (RMP). For a stimulus to be effective in producing an excitation, it must have an abrupt onset, be intense enough, and last long enough.
[0021] Cell membranes can be reasonably well represented by a capacitance C, shunted by a resistance R as shown by an electrical model in FIG. 13 , where neuronal process is divided into unit lengths, which is represented in an electrical equivalent circuit. Each unit length of the process is a circuit with its own membrane resistance (r m ), membrane capacitance (c m ), and axonal resistance (r a ).
[0022] When the stimulation pulse is strong enough, an action potential will be generated and propagated. As shown in FIG. 14 , the action potential is traveling from right to left. Immediately after the spike of the action potential there is a refractory period when the neuron is either unexcitable (absolute refractory period) or only activated to sub-maximal responses by supra-threshold stimuli (relative refractory period). The absolute refractory period occurs at the time of maximal Sodium channel inactivation while the relative refractory period occurs at a later time when most of the Na + channels have returned to their resting state by the voltage activated K + current. The refractory period has two important implications for action potential generation and conduction. First, action potentials can be conducted only in one direction, away from the site of its generation, and secondly, they can be generated only up to certain limiting frequencies.
[0023] A single electrical impulse passing down an axon is shown schematically in FIG. 15 . The top portion of the figure (A) shows conduction over mylinated axon (fiber) and the bottom portion (B) shows conduction over nonmylinated axon (fiber). These electrical signals will travel along the nerve fibers.
[0024] The information in the nervous system is coded by frequency of firing rather than the size of the action potential. In terms of electrical conduction, myelinated fibers conduct faster, are typically larger, have very low stimulation thresholds, and exhibit a particular strength-duration curve or respond to a specific pulse width versus amplitude for stimulation, compared to unmyelinated fibers. The A and B fibers can be stimulated with relatively narrow pulse widths, from 50 to 200 microseconds (μs), for example. The A fiber conducts slightly faster than the B fiber and has a slightly lower threshold. The C fibers are very small, conduct electrical signals very slowly, and have high stimulation thresholds typically requiring a wider pulse width (300-1,000 μs) and a higher amplitude for activation. Because of their very slow conduction, C fibers would not be highly responsive to rapid stimulation. Selective stimulation of only A and B fibers is readily accomplished. The requirement of a larger and wider pulse to stimulate the C fibers, however, makes selective stimulation of only C fibers, to the exclusion of the A and B fibers, virtually unachievable inasmuch as the large signal will tend to activate the A and B fibers to some extent as well.
[0025] As shown in FIG. 16 , when the distal part of a nerve is electrically stimulated, a compound action potential is recorded by an electrode located more proximally. A compound action potential contains several peaks or waves of activity that represent the summated response of multiple fibers having similar conduction velocities. The waves in a compound action potential represent different types of nerve fibers that are classified into corresponding functional categories as shown in the Table one below,
TABLE 1 Conduction Fiber Fiber Velocity Diameter Type (m/sec) (μm) Myelination A Fibers Alpha 70-120 12-20 Yes Beta 40-70 5-12 Yes Gamma 10-50 3-6 Yes Delta 6-30 2-5 Yes B Fibers 5-15 <3 Yes C Fibers 0.5-2.0 0.4-1.2 No
[0026] Vagus nerve blocking and stimulation, performed by the system and method of the current patent application, is a means of directly affecting central function, as well as, peripheral function. FIG. 17 shows cranial nerves have both afferent pathway 19 (inward conducting nerve fibers which convey impulses toward the brain) and efferent pathway 21 (outward conducting nerve fibers which convey impulses to an effector). Vagus nerve (the 10 th cranial nerve) is composed of 80% afferent sensory fibers carrying information to the brain from the head, neck, thorax, and abdomen. The sensory afferent cell bodies of the vagus reside in the nodose ganglion and relay information to the nucleus tractus solitarius (NTS).
[0027] The vagus nerve spans from the brain stem all the way to the splenic flexure of the colon. Not only is the vagus the parasympathetic nerve to the thoracic and abdominal viscera, it also the largest visceral sensory (afferent) nerve. Sensory fibers outnumber parasympathetic fibers four to one. In the medulla, the vagal fibers are connected to the nucleus of the tractus solitarius (viceral sensory), and three other nuclei. The central projections terminate largely in the nucleus of the solitary tract, which sends fibers to various regions of the brain (e.g., the thalamus, hypothalamus and amygdala).
[0028] This application is also related to co-pending applications entitled “METHOD AND SYSTEM FOR PROVIDING ELECTRICAL PULSES TO GASTRIC WALL OF A PATIENT WITH RECHARGEABLE IMPLANTABLE PULSE GENERATOR FOR TREATING OR CONTROLLING OBESITY AND EATING DISORDERS” and “METHOD AND SYSTEM TO PROVIDE THERAPY FOR OBESITY AND OTHER MEDICAL DISORDERS, BY PROVIDING ELECTRICAL PULSES TO SYMPATHETIC NERVES OR VAGAL NERVE(S) WITH RECHARGEABLE IMPLANTED PULSE GENERATOR.
PRIOR ART
[0029] Prior art is generally directed to adapting cardiac pacemaker technology for nerve stimulation, where U.S. Pat. Nos. 5,263,480 (Wernicke et al.) and 5,188,104 (Wernicke et al.) are generally directed to treatment of eating disorders with vagus nerve stimulation using an implantable neurocybernetic prosthesis (NCP), which is a “cardiac pacemaker-like” device. There is no disclosure for vagal blocking.
[0030] U.S. Pat. No. 5,540,730 (Terry et al.) is generally directed to treating motility disorders with vagus nerve stimulation using an implantable neurocybernetic prosthesis (NCP), which is a “cardiac pacemaker-like” device.
[0031] U.S. Pat. No. 6,553,263B1 (Meadows et al.) is generally directed to an implantable pulse generator system for spinal cord stimulation, which includes a rechargeable battery. In the Meadows '263 patent there is no disclosure or suggestion for combing a stimulus-receiver module to an implantable pulse generator (I PG) for use with an external stimulator, for providing modulating pulses to sympathetic nerve(s), as in the applicant's disclosure.
[0032] U.S. Pat. No. 6,505,077 B1 (Kast et al.) is directed to electrical connection for external recharging coil. In the Kast '077 disclosure, a magnetic shield is required between the externalized coil and the pulse generator case. In one embodiment of the applicant's disclosure, the externalized coil is wrapped around the pulse generator case, without requiring a magnetic shield.
[0033] U.S. Pat. No. 6,600,954 B2 (Cohen et al.) is generally directed to selectively blocking propagation of body-generated action potentials particularly useful for pain control.
[0034] U.S. Pat. No. 6,684,105 B2 (Cohen et al.) is generally directed to an apparatus for unidirectional nerve stimulation.
[0035] U.S. Pat. No. 6,611,715 B1 (Boveja) is generally directed to a system and method to provide therapy for obesity and compulsive eating disorders using an implantable lead-receiver and an external stimulator.
SUMMARY OF THE INVENTION
[0036] The method and system of the current invention overcomes many shortcomings of the prior art by providing a system for neuromodulation with extended power source either in the form of rechargeable battery, or by utilizing an external stimulator in conjunction with an implanted pulse generator device, to provide therapy for obesity, motility disorders, eating disorders, inducing weight loss, FGIDs, gastroparesis, gastro-esophageal reflex disease (GERD), pancreatitis, and ileus.
[0037] Accordingly, in one aspect of the invention, electrical pulses are provided utilizing a rechargeable implantable pulse generator for nerve blocking, with or without selective electrical stimulation of vagus nerve(s) or its branches or part thereof for treating obesity and other GI disorders.
[0038] In another aspect of the invention, the electrical pulses are provided for at least one of afferent block, efferent block, or organ block.
[0039] In another aspect of the invention, the nerve blocking comprises at least one from a group consisting of: DC or anodal block, Wedenski block, and Collision block.
[0040] In another aspect of the invention, a coil used in recharging said pulse generator is around the implantable pulse generator case, and in a silicone enclosure.
[0041] In another aspect of the invention, the rechargeable implanted pulse generator comprises two feedthroughs.
[0042] In another aspect of the invention, the rechargeable implanted pulse generator comprises only one feed-through for externalizing the recharge coil.
[0043] In another aspect of the invention, the implantable rechargeable pulse generator comprises stimulus-receiver means such that, the implantable rechargeable pulse generator can function in conjunction with an external stimulator, to provide nerve blocking with or without selective electrical stimulation of vagus nerve(s) or its branches or part thereof.
[0044] In another aspect of the invention, the rechargeable battery comprises at least one of lithium-ion, lithium-ion polymer batteries.
[0045] In another aspect of the invention, the external programmer or the external stimulator comprises networking capabilities for remote communications over a wide area network for remote interrogation and/or remote programming.
[0046] In yet another aspect of the invention, the implanted lead comprises at least two electrode(s) which are made of a material selected from the group consisting of platinum, platinum/iridium alloy, platinum/iridium alloy coated with titanium nitride, and carbon.
[0047] This and other objects are provided by one or more of the embodiments described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] For the purpose of illustrating the invention, there are shown in accompanying drawing forms which are presently preferred, it being understood that the invention is not intended to be limited to the precise arrangement and instrumentalities shown.
[0049] FIG. 1 is a diagram depicting vagal nerves in a patient.
[0050] FIG. 2 is a diagram showing vagal nerve innervation to the viceral organs.
[0051] FIG. 3 is a schematic diagram showing the relationship of meals and satiety signals.
[0052] FIG. 4 is a schematic diagram showing impulses traveling via the vagus nerve in response to gastric distention and CCK release.
[0053] FIG. 5 is a diagram depicting two-way communication between the gut and central nervous system (CNS).
[0054] FIG. 6 is a diagram showing conduction of nerve impulses in both afferent and efferent direction with artificial electrical stimulation.
[0055] FIG. 7 is a diagram depicting blocking in the afferent direction, but conducting in the efferent direction with electrical stimulation.
[0056] FIG. 8 is a diagram depicting electrical stimulation with conduction in the afferent direction and blocking in the efferent direction.
[0057] FIG. 9 is a diagram depicting electrical stimulation with conduction in the afferent direction and selective organ blocking in the efferent direction.
[0058] FIG. 10 is a diagram depicting electrical stimulation with conduction in the efferent direction and selective organ blocking in the afferent direction.
[0059] FIG. 11 is a diagram of the structure of a nerve.
[0060] FIG. 12 is a diagram showing different types of nerve fibers.
[0061] FIG. 13 is a schematic illustration of electrical circuit model of nerve cell membrane.
[0062] FIG. 14 is an illustration of propagation of action potential in nerve cell membrane.
[0063] FIG. 15 is an illustration showing propagation of action potential along a myelinated axon and non-myelinated axon.
[0064] FIG. 16 is a diagram showing recordings of compound action potentials.
[0065] FIG. 17 is a schematic diagram of brain showing afferent and efferent pathways.
[0066] FIG. 18 is a diagram of implanted components of stimulation/blocking system with multiple electrodes around anterior and posterior vagal nerves.
[0067] FIG. 19A is a diagram showing the implanted components (rechargeable implantable pulse generator), and an external stimulator coupled to implanted stimulus-receiver.
[0068] FIG. 19B is a diagram showing placement of the external (primary) coil in relation of the implanted stimulus-receiver.
[0069] FIG. 20 is a simplified general block diagram of an implantable pulse generator.
[0070] FIG. 21A shows energy density of different types of batteries.
[0071] FIG. 21B shows discharge curves for different types of batteries.
[0072] FIG. 22 shows a block diagram of an implantable stimulator which can be used as a stimulus-receiver or an implanted pulse generator with rechargeable battery.
[0073] FIG. 23 is a block diagram highlighting battery charging circuit of the implantable stimulator of FIG. 22 .
[0074] FIG. 24 is a schematic diagram highlighting stimulus-receiver portion of implanted stimulator of one embodiment.
[0075] FIG. 25 depicts externalizing recharge and telemetry coil from the titanium case.
[0076] FIG. 26A depicts coil around the titanium case with two feedthroughs for a bipolar configuration.
[0077] FIG. 26B depicts coil around the titanium case with one feedthrough for a unipolar configuration.
[0078] FIG. 26C depicts two feedthroughs for the external coil which are common with the feedthroughs for the lead terminal.
[0079] FIG. 26D depicts one feedthrough for the external coil which is common to the feedthrough for the lead terminal.
[0080] FIGS. 27A and 27B depict recharge coil on the titanium case with a magnetic shield in-between.
[0081] FIG. 28 shows a rechargeable implantable pulse generator in block diagram form.
[0082] FIG. 29 depicts in block diagram form, the implanted and external components of an implanted rechargable system.
[0083] FIG. 30 depicts the alignment function of rechargable implantable pulse generator.
[0084] FIG. 31 is a block diagram of the external recharger.
[0085] FIG. 32A is a schematic diagram of an implantable lead with three electrodes.
[0086] FIG. 32B is a schematic diagram of an implantable lead with multiple electrodes.
[0087] FIG. 32C is a schematic diagram of an implantable lead with two electrodes.
[0088] FIG. 33 is a schematic diagram of the pulse generator and two-way communication through a server.
[0089] FIG. 34 is a diagram depicting wireless remote interrogation and programming of the external pulse generator.
[0090] FIG. 35 is a schematic diagram of the wireless protocol.
[0091] FIG. 36 is a simplified block diagram of the networking interface board.
[0092] FIGS. 37A and 37B are simplified diagrams showing communication of modified PDA/phone with an external stimulator via a cellular tower/base station.
DESCRIPTION OF THE INVENTION
[0093] To provide vagal blocking and/or vagal stimulation therapy to a patient, blocking and stimulation electrodes are implanted at the appropriate sites. In one preferred embodiment, without limitation, multiple electrodes comprising both blocking and stimulation electrodes are placed in a band. As shown in conjunction with FIG. 18 , the band comprising multiple electrodes is wrapped around the esophagus, close to the junction of esophagus and the stomach 5 (just below the diaphragm). Alternatively, the individual electrodes do not have to be in a band, and may be individual electrodes, connected to the body of the lead via insulated conductors (shown in FIG. 32B ). In such a case, the portion of the electrode contacting the nerve tissue would be exposed and the rest of the electrode being insulated with a non-conductive material such as silicone or polyurethane. Such electrodes are well known in the art.
[0094] The electrodes may be implanted using laproscopic surgery or alternatively a surgical exposure may be made for implantation of the electrodes at the appropriate site to be stimulated and/or blocked. After placing the electrodes, the terminal portion of the lead is tunneled to a subcutaneous site where the electronics package is to be implanted. The terminal end of the lead is connected to the rechargeable implantable pulse generator. The patient is surgically closed in layers, and electrical pulse delivery can begin once the patient has fully recovered from the surgery.
[0095] In the method and system of this invention, stimulation without block may be provided. Additionally, stimulation with selective block may be provided. Furthermore, block alone (without stimulation) may be provided, which would be functionally equivalent to reversible vagotomy.
[0096] Blocking of nerve impulses, unidirectional blocking, and selective blocking of nerve impulses is well known in the scientific literature. Some of the general literature is listed below and is incorporated herein by reference. (a) “Generation of unidirectionally propagating action potentials using a monopolar electrode cuff”, Annals of Biomedical Engineering , volume 14, pp. 437-450, By Ira J. Ungar et al. (b) “An asymmetric two electrode cuff for generation of unidirectionally propagated action potentials”, IEEE Transactions on Biomedical Engineering , volume BME-33, No. 6, June 1986, By James D. Sweeney, et al. (c) A spiral nerve cuff electrode for peripheral nerve stimulation, IEEE Transactions on Biomedical Engineering , volume 35, No. 11, November 1988, By Gregory G. Naples. et al. (d) “A nerve cuff technique for selective excitation of peripheral nerve trunk regions, IEEE Transactions on Biomedical Engineering , volume 37, No. 7, July 1990, By James D. Sweeney, et al. (e) “Generation of unidirectionally propagated action potentials in a peripheral nerve by brief stimuli”, Science , volume 206 pp. 1311-1312, Dec. 14, 1979, By Van Den Honert et al. (f “A technique for collision block of perpheral nerve: Frequency dependence” IEEE Transactions on Biomedical Engineering , MP-12, volume 28, pp. 379-382, 1981, By Van Den Honert et al. (g) “A nerve cuff design for the selective activation and blocking of myelinated nerve fibers” Ann. Conf. of the IEEE Engineering in Medicine and Biology Soc ., volume 13, No. 2, p 906, 1991, By D. M Fitzpatrick et al. (h) “Orderly recruitment of motoneurons in an acute rabbit model”, “ Ann. Conf. of the IEEE Engineering in Medicine and Biology Soc ., volume 20, No. 5, page 2564, 1998, By N. J. M. Rijkhof, et al. (i) “Orderly stimulation of skeletal muscle motor units with tripolar nerve cuff electrode”, IEEE Transactions on Biomedical Engineering , volume 36, No. 8, pp. 836,1989, By R. Bratta. (j) M. Devor, “Pain Networks”, Handbook of Brand Theory and Neural Networks, Ed. M. A. Arbib, MIT Press, page 698, 1998.
[0097] Blocking can be generally divided into 3 categories: (a) DC or anodal block, (b) Wedenski Block, and (c) Collision block. In anodal block there is a steady potential which is applied to the nerve causing a reversible and selective block. In Wedenski Block the nerve is stimulated at a high rate causing the rapid depletion of the neurotransmitter. In collision blocking, unidirectional action potentials are generated anti-dromically. The maximal frequency for complete block is the reciprocal of the refractory period plus the transit time, i.e. typically less than a few hundred hertz. The use of any of these blocking techniques can be applied for the practice of this invention, and all are considered within the scope of this invention.
[0098] FIGS. 19A and 19B depict the implantable components of the system. A rechargeable implantable pulse generator 391 R is connected to the lead 40 for delivering pulses via multiple electrodes in contact with nerve tissue. The selective blocking and/or stimulation to the vagal nerve tissue 54 can be performed by “pre-determined” programs stored in the memory, or by “customized” programs where the electrical parameters are selectively programmed for specific therapy to the individual patient. The electrical parameters which can be individually programmed, include variables such as pulse amplitude, pulse width, frequency of stimulation, type of pulse (e.g. blocking pulses may be sinusoidal), stimulation on-time, and stimulation off-time. Table two below defines the approximate range of parameters,
TABLE 2 Electrical parameter range delivered to the nerve for stimulation and/or blocking PARAMER RANGE Pulse Amplitude 0.1 Volt-10 Volts Pulse width 20 μS-5 mSec. Stim. Frequency 5 Hz-200 Hz Freq. for blocking DC to 5,000 Hz On-time 5 Secs-24 hours Off-time 5 Secs-24 hours
[0099] The parameters in Table 2 are the electrical signals delivered to the nerve tissue via the two stimulation electrodes 61 , 62 (or blocking electrodes) at the nerve tissue 54 .
[0100] Shown in conjunction with FIG. 20 , is an overall schematic of a general implantable pulse generator system to deliver electrical pulses for modulating the vagus nerve(s) (selective stimulation and/or blocking) and providing therapy. The implantable pulse generator unit 391 is a microprocessor based device, where the entire circuitry is encased in a hermetically sealed titanium can. As shown in the overall block diagram, the logic & control unit 398 provides the proper timing for the output circuitry 385 to generate electrical pulses that are delivered to a pair of electrodes via a lead 40 . Timing is provided by oscillator 393 . The pair of electrodes to which the stimulation energy is delivered is switchable. Programming of the implantable pulse generator (IPG) 391 is done via an external programmer 85 . Once programmed via an external programmer 85 , the implanted pulse generator 391 provides appropriate electrical blocking and/or stimulation pulses to the vagal nerve(s) 54 via the blocking/stimulating electrodes 61 , 62 , 63 .
[0101] Because of the high energy requirements for the pulses required for blocking and/or selective stimulation of vagal nerve tissue 54 , there is a real need for power sources that will provide an acceptable service life under conditions of continuous delivery of high frequency pulses. FIG. 21A shows a graph of the energy density of several commonly used battery technologies. Lithium batteries have by far the highest energy density of commonly available batteries. Also, a lithium battery maintains a nearly constant voltage during discharge. This is shown in conjunction with FIG. 21B , which is normalized to the performance of the lithium battery. Lithium-ion batteries also have a long cycle life, and no memory effect. However, Lithium-ion batteries are not as tolerant to overcharging and overdischarging. One of the most recent development in rechargable battery technology is the Lithium-ion polymer battery. Recently the major battery manufacturers (Sony, Panasonic, Sanyo) have announced plans for Lithium-ion polymer battery production.
[0102] For preferred method of the current invention, two embodiments of implantable pulse generators may be used. Both embodiments comprise re-chargeable power sources, such as Lithium-ion polymer battery.
[0103] In one embodiment of this invention, the implanted stimulator comprises a stimulus-receiver module and a pulse generator module. Advantageously, this embodiment provides an ideal power source, since the power source can be an external stimulator in conjunction with an implanted stimulus-receiver, or the power source can be from the implanted rechargable battery 740 . Shown in conjunction with FIG. 22 is a simplified overall block diagram of this embodiment. A coil 48 C which is external to the titanium case may be used both as a secondary of a stimulus-receiver, or may also be used as the forward and back telemetry coil. The coil 48 C may be externalized at the header portion 79 C of the implanted device, and may be wrapped around the titanium case, eliminating the need for a magnetic shield. In this case, the coil is encased in the same material as the header 79 C. Alternatively, the coil may be positioned on the titanium case, with a magnetic shield.
[0104] In this embodiment, as disclosed in FIG. 22 , the IPG circuitry within the titanium case is used for all stimulation pulses whether the energy source is the internal rechargeable battery 740 or an external power source. The external device serves as a source of energy, and as a programmer that sends telemetry to the IPG. For programming, the energy is sent as high frequency sine waves with superimposed telemetry wave driving the external coil 46 C. The telemetry is passed through coupling capacitor 727 to the IPG's telemetry circuit 742 . For pulse delivery using external power source, the stimulus-receiver portion will receive the energy coupled to the implanted coil 48 C and, using the power conditioning circuit 726 , rectify it to produce DC, filter and regulate the DC, and couple it to the IPG's voltage regulator 738 section so that the IPG can run from the externally supplied energy rather than the implanted battery 740 .
[0105] The system provides a power sense circuit 728 that senses the presence of external power communicated with the power control 730 , when adequate and stable power is available from an external source. The power control circuit controls a switch 736 that selects either implanted rechargeable battery power 740 or conditioned external power from 726 . The logic and control section 732 and memory 744 includes the IPG's microcontroller, pre-programmed instructions, and stored changeable parameters. Using input for the telemetry circuit 742 and power control 730 , this section controls the output circuit 734 that generates the output pulses.
[0106] Shown in conjunction with FIG. 23 , this embodiment of the invention is practiced with a rechargeable battery 740 . This circuit is energized when external power is available. It senses the charge state of the battery and provides appropriate charge current to safely recharge the battery without overcharging. Recharging circuitry is described later.
[0107] The stimulus-receiver portion of the circuitry is shown in conjunction with FIG. 24 . Capacitor C 1 ( 729 ) makes the combination of C 1 and L 1 sensitive to the resonant frequency and less sensitive to other frequencies, and energy from an external (primary) coil 46 C is inductively transferred to the implanted unit via the secondary coil 48 C. The AC signal is rectified to DC via diode 731 , and filtered via capacitor 733 . A regulator 735 set the output voltage and limits it to a value just above the maximum IPG cell voltage. The output capacitor C 4 ( 737 ), typically a tantalum capacitor with a value of 100 micro-Farads or greater, stores charge so that the circuit can supply the IPG with high values of current for a short time duration with minimal voltage change during a pulse while the current draw from the external source remains relatively constant. Also shown in conjunction with FIGS. 23 and 24 , a capacitor C 3 ( 727 ) couples signals for forward and back telemetry.
[0108] In another embodiment, existing implantable pulse generators can be modified to incorporate rechargeable batteries. As shown in conjunction with FIG. 25 , in both embodiments, the coil is externalized from the titanium case 57 . The RF pulses transmitted via coil 46 and received via subcutaneous coil 48 A are rectified via a diode bridge. These DC pulses are processed and the resulting current applied to recharge the battery 694 / 740 in the implanted pulse generator. In one embodiment the coil 48 may be externalized at the header portion 79 C of the implanted device, and may be wrapped around the titanium case, as shown in FIGS. 26A and 26B . Shown in FIG. 26A is a bipolar configuration which requires two feedthroughs 76 , 77 . Advantageously, as shown in FIG. 26B unipolar configuration may also be used which requires only one feedthrough 75 . The other end is electronically connected to the case. In both cases, the coil is encased in the same material as the header 79 . Advantageously, as shown in conjunction with FIGS. 26C and 26D , the feedthrough for the coil can be combined with the feedthrough for the lead terminal. This can be applied both for bipolar and unipolar configurations.
[0109] In one embodiment, the coil may be positioned on the titanium case as shown in conjunction with FIGS. 27A and 27B . FIG. 27A shows a diagram of the finished implantable stimulator 391 R of one embodiment. FIG. 27B shows the pulse generator with some of the components used in assembly in an exploded view. These components include a coil cover 13 , the secondary coil 48 and associated components, a magnetic shield 9 , and a coil assembly carrier 11 . The coil assembly carrier 11 has at least one positioning detail 80 located between the coil assembly and the feed through for positioning the electrical connection. The positioning detail 80 secures the electrical connection in this embodiment.
[0110] A schematic diagram of the implanted pulse generator (IPG 391 R), with re-chargeable battery 694 of one preferred embodiment of this invention, is shown in conjunction with FIG. 28 . The IPG 391 R includes logic and control circuitry 673 connected to memory circuitry 691 . The operating program and stimulation parameters are typically stored within the memory 691 via forward telemetry. Blocking/stimulation pulses are provided to the nerve tissue 54 via output circuitry 677 controlled by the microcontroller.
[0111] The operating power for the IPG 391 R is derived from a rechargeable power source 694 . The rechargeable power source 694 comprises a rechargeable lithium-ion or lithium-ion polymer battery. Recharging occurs inductively from an external charger to an implanted coil 48 B underneath the skin 60 . The rechargeable battery 694 may be recharged repeatedly as needed. Additionally, the IPG 391 R is able to monitor and telemeter the status of its rechargeable battery 691 each time a communication link is established with the external programmer 85 .
[0112] Much of the circuitry included within the IPG 391 R may be realized on a single application specific integrated circuit (ASIC). This allows the overall size of the IPG 391 R to be quite small, and readily housed within a suitable hermetically-sealed case. The IPG case is preferably made from titanium and is shaped in a rounded case.
[0113] Shown in conjunction with FIG. 29 are the recharging elements of the invention. The recharging system uses a portable external charger to couple energy into the power source of the IPG 391 R. The DC-to-AC conversion circuitry 696 of the recharger receives energy from a battery 672 in the recharger. A charger base station 680 and conventional AC power line may also be used. The AC signals amplified via power amplifier 674 are inductively coupled between an external coil 46 B and an implanted coil 48 B located subcutaneously with the implanted pulse generator (IPG) 391 R. The AC signal received via implanted coil 48 B is rectified 686 to a DC signal which is used for recharging the rechargable battery 694 of the IPG, through a charge controller IC 682 . Additional circuitry within the IPG 391 R includes, battery protection IC 688 which controls a FET switch 690 to make sure that the rechargable battery 694 is charged at the proper rate, and is not overcharged. The battery protection IC 688 can be an off-the-shelf IC available from Motorola (part no. MC 33349N-3R1). This IC monitors the voltage and current of the implanted rechargable battery 694 to ensure safe operation. If the battery voltage rises above a safe maximum voltage, the battery protection IC 688 opens charge enabling FET switches 690 , and prevents further charging. A fuse 692 acts as an additional safeguard, and disconnects the battery 694 if the battery charging current exceeds a safe level. As also shown in FIG. 29 , charge completion detection is achieved by a back-telemetry transmitter 684 , which modulates the secondary load by changing the full-wave rectifier into a half-wave rectifier/voltage clamp. This modulation is in turn, sensed by the charger as a change in the coil voltage due to the change in the reflected impedance. When detected through a back telemetry receiver 676 , either an audible alarm is generated or a LED is turned on.
[0114] A simplified block diagram of charge completion and misalignment detection circuitry is shown in conjunction with FIG. 30 . As shown, a switch regulator 686 operates as either a full-wave rectifier circuit or a half-wave rectifier circuit as controlled by a control signal (CS) generated by charging and protection circuitry 698 . The energy induced in implanted coil 48 B (from external coil 46 B) passes through the switch rectifier 686 and charging and protection circuitry 698 to the implanted rechargable battery 694 . As the implanted battery 694 continues to be charged, the charging and protection circuitry 698 continuously monitors the charge current and battery voltage. When the charge current and battery voltage reach a predetermined level, the charging and protection circuitry 698 triggers a control signal. This control signal causes the switch rectifier 686 to switch to half-wave rectifier operation. When this change happens, the voltage sensed by voltage detector 702 causes the alignment indicator 706 to be activated. This indicator 706 may be an audible sound or a flashing LED type of indicator.
[0115] The indicator 706 may similarly be used as a misalignment indicator. In normal operation, when coils 46 B (external) and 48 B (implanted) are properly aligned, the voltage V s sensed by voltage detector 704 is at a minimum level because maximum energy transfer is taking place. If and when the coils 46 B and 48 B become misaligned, then less than a maximum energy transfer occurs, and the voltage V s sensed by detection circuit 704 increases significantly. If the voltage V s reaches a predetermined level, alignment indicator 706 is activated via an audible speaker and/or LEDs for visual feedback. After adjustment, when an optimum energy transfer condition is established, causing V s to decrease below the predetermined threshold level, the alignment indicator 706 is turned off.
[0116] The elements of the external recharger are shown as a block diagram in conjunction with FIG. 31 . The charger base station 680 receives its energy from a standard power outlet 714 , which is then converted to 5 volts DC by a AC-to-DC transformer 712 . When the recharger is placed in a charger base station 680 , the rechargable battery 672 of the recharger is fully recharged in a few hours and is able to recharge the battery 694 of the IPG 391 R. If the battery 672 of the external recharger falls below a prescribed limit of 2.5 volt DC, the battery 672 is trickle charged until the voltage is above the prescribed limit, and then at that point resumes a normal charging process.
[0117] As also shown in FIG. 31 , a battery protection circuit 718 monitors the voltage condition, and disconnects the battery 672 through one of the FET switches 716 , 720 if a fault occurs until a normal condition returns. A fuse 724 will disconnect the battery 672 should the charging or discharging current exceed a prescribed amount.
[0118] Referring now to FIG. 32A , the implanted lead component of the system is similar to cardiac pacemaker leads, except for distal portion (or electrode end) of the lead. This figure depicts a lead with tripolar electrodes 62 , 61 , 63 for stimulation and/or blocking. FIG. 32B shows a lead with multiple pairs of electrodes ( 63 , 62 , 61 ). Different electrodes or electrode pairs are used for blocking or for stimulation, as directed by logic and control unit 673 of rechargeable implantable pulse generator 691 R. An alternative embodiment with a pair of electrodes 61 , 62 is also shown in FIG. 32C . The lead terminal preferably is linear bipolar, even though it can be bifurcated, and plug(s) into the cavity of the pulse generator means. The lead body 59 insulation may be constructed of medical grade silicone, silicone reinforced with polytetrafluoro-ethylene (PTFE), or polyurethane. The electrodes 61 , 62 , 63 for stimulating/blocking the vagus nerve 54 may either wrap around the nerve or may be adapted to be in contact with tissue to be blocked/stimulated. These stimulating electrodes may be made of pure platinum, platinum/Iridium alloy or platinum/iridium coated with titanium nitride. The conductor connecting the terminal to the electrodes 61 , 62 is made of an alloy of nickel-cobalt. The implanted lead design variables are also summarized in table four below.
TABLE 4 Lead design variables Proximal Distal End End Conductor (connecting Lead body- proximal Lead Insulation and distal Electrode - Electrode - Terminal Materials Lead-Coating ends) Material Type Linear Polyurethane Antimicrobial Alloy of Pure Wrap-around bipolar coating Nickel- Platinum electrodes Cobalt Bifurcated Silicone Anti- Platinum- Standard Ball Inflammatory Iridium and Ring coating (Pt/Ir) Alloy electrodes Silicone with Lubricious Pt/Ir coated Steroid Polytetrafluoroethylene coating with Titanium eluting (PTFE) Nitride Carbon
[0119] Once the lead is fabricated, coating such as anti-microbial, anti-inflammatory, or lubricious coating may be applied to the body of the lead.
Telemetry Module
[0120] Shown in conjunction with FIG. 33 , in one embodiment of the invention the external stimulator 42 and/or programmer 85 may comprise two-way wireless communication capabilities with a remote server, using a communication protocol such as the wireless application protocol (WAP). The purpose of the telemetry module is to enable the physician to remotely, via the wireless medium change the programs, activate, or disengage programs. Additionally, schedules of therapy programs, can be remotely transmitted and verified. Advantageously, the physician is thus able to remotely control the stimulation therapy.
[0121] FIG. 34 is a simplified schematic showing the communication aspects between the external stimulator 42 and or programmer 85 , and the remote hand-held computer. A desktop or laptop computer can be a server 130 which is situated remotely, perhaps at a health-care provider's facility or a hospital. The data can be viewed at this facility or reviewed remotely by medical personnel on a wireless internet supported hand-held device 140 , which could be a personal data assistant (PDA), for example, a “palm-pilot” from PALM corp. (Santa Clara, Calif.), a “Visor” from Handspring Corp. (Mountain view, CA) or on a personal computer (PC) available from numerous vendors or a cell phone or a handheld device being a combination thereof. The physician or appropriate medical personnel, is able to interrogate the external stimulator 42 device and know what the device is currently programmed to, as well as, get a graphical display of the pulse train. The wireless communication with the remote server 130 and hand-held device (wireless internet supported) 140 can be achieved in all geographical locations within and outside the United States (US) that provides cell phone voice and data communication service. The pulse generation parameter data can also be viewed on the handheld devices 140 .
[0122] The telecommunications component of this invention uses Wireless Application Protocol (WAP). WAP is a set of communication protocols standardizing Internet access for wireless devices. Previously, manufacturers used different technologies to get Internet on hand-held devices. With WAP, devices and services inter-operate. WAP promotes convergence of wireless data and the Internet. The WAP Layers are Wireless Application Environment (WAE), Wireless Session Layer (WSL), Wireless Transport Layer Security (WTLS) and Wireless Transport Layer (WTP).
[0123] The WAP programming model, which is heavily based on the existing Internet programming model, is shown schematically in FIG. 35 . Introducing a gateway function provides a mechanism for optimizing and extending this model to match the characteristics of the wireless environment. Over-the-air traffic is minimized by binary encoding/decoding of Web pages and readapting the Internet Protocol stack to accommodate the unique characteristics of a wireless medium such as call drops. Such features are facilitated with WAP.
[0124] The key components of the WAP technology, as shown in FIG. 35 , includes 1) Wireless Mark-up Language (WML) 400 which incorporates the concept of cards and decks, where a card is a single unit of interaction with the user. A service constitutes a number of cards collected in a deck. A card can be displayed on a small screen. WML supported Web pages reside on traditional Web servers. 2) WML Script which is a scripting language, enables application modules or applets to be dynamically transmitted to the client device and allows the user interaction with these applets. 3) Microbrowser, which is a lightweight application resident on the wireless terminal that controls the user interface and interprets the WML/WMLScript content. 4) A lightweight protocol stack 402 which minimizes bandwidth requirements, guaranteeing that a broad range of wireless networks can run WAP applications. The protocol stack of WAP can comprise a set of protocols for the transport (WTP), session (WSP), and security (WTLS) layers. WSP is binary encoded and able to support header caching, thereby economizing on bandwidth requirements. WSP also compensates for high latency by allowing requests and responses to be handles asynchronously, sending before receiving the response to an earlier request. For lost data segments, perhaps due to fading or lack of coverage, WTP only retransmits lost segments using selective retransmission, thereby compensating for a less stable connection in wireless. The above mentioned features are industry standards adopted for wireless applications, and well known to those skilled in the art.
[0125] The presently preferred embodiment utilizes WAP, because WAP has the following advantages, 1) WAP protocol uses less than one-half the number of packets that the standard HTTP or TCP/IP Internet stack uses to deliver the same content. 2) Addressing the limited resources of the terminal, the browser, and the lightweight protocol stack are designed to make small claims on CPU and ROM. 3) Binary encoding of WML and SMLScript helps keep the RAM as small as possible. And, 4) Keeping the bearer utilization low takes account of the limited battery power of the terminal.
[0126] In this embodiment two modes of communication are possible. In the first, the server initiates an upload of the actual parameters being applied to the patient, receives these from the stimulator, and stores these in its memory, accessible to the authorized user as a dedicated content driven web page. The web page is managed with adequate security and password protection. The physician or authorized user can make alterations to the actual parameters, as available on the server, and then initiate a communication session with the stimulator device to download these parameters.
[0127] The physician is also able to set up long-term schedules of stimulation therapy for their patient population, through wireless communication with the server. The server in turn communicates these programs to the neurostimulator. Each schedule is securely maintained on the server, and is editable by the physician and can get uploaded to the patient's stimulator device at a scheduled time. Thus, therapy can be customized for each individual patient. Each device issued to a patient has a unique identification key in order to guarantee secure communication between the wireless server 130 and stimulator device 42 .
[0128] In this embodiment, two modes of communication are possible. In the first, the server initiates an upload of the actual parameters being applied to the patient, receives these from the stimulator, and stores these in its memory, accessible to the authorized user as a dedicated content driven web page. The physician or authorized user can make alterations to the actual parameters, as available on the server, and then initiate a communication session with the stimulator device to download these parameters.
[0129] Shown in conjunction with FIG. 36 , in one embodiment, the external stimulator 42 and/or the programmer 85 may also be networked to a central collaboration computer 286 as well as other devices such as a remote computer 294 , PDA 140 , phone 141 , physician computer 143 . The interface unit 292 in this embodiment communicates with the central collaborative network 290 via land-lines such as cable modem or wirelessly via the internet. A central computer 286 which has sufficient computing power and storage capability to collect and process large amounts of data, contains information regarding device history and serial number, and is in communication with the network 290 . Communication over collaboration network 290 may be effected by way of a TCP/IP connection, particularly one using the internet, as well as a PSTN, DSL, cable modem, LAN, WAN or a direct dial-up connection.
[0130] The standard components of interface unit shown in block 292 are processor 305 , storage 310 , memory 308 , transmitter/receiver 306 , and a communication device such as network interface card or modem 312 . In the preferred embodiment these components are embedded in the external stimulator 42 and can also be embedded in the programmer 85 . These can be connected to the network 290 through appropriate security measures (Firewall) 293 .
[0131] Another type of remote unit that may be accessed via central collaborative network 290 is remote computer 294 . This remote computer 294 may be used by an appropriate attending physician to instruct or interact with interface unit 292 , for example, instructing interface unit 292 to send instruction downloaded from central computer 286 to remote implanted unit.
[0132] Shown in conjunction with FIG. 37A the physician's remote communication's module is a Modified PDA/Phone 140 in this embodiment. The Modified PDA/Phone 140 is a microprocessor based device as shown in a simplified block diagram in FIGS. 37A and 37B . The PDA/Phone 140 is configured to accept PCM/CIA cards specially configured to fulfill the role of communication module 292 of the present invention. The Modified PDA/Phone 140 may operate under any of the useful software including Microsoft Window's based, Linux, Palm OS, Java OS, SYMBIAN, or the like.
[0133] The telemetry module 362 comprises an RF telemetry antenna 142 coupled to a telemetry transceiver and antenna driver circuit board which includes a telemetry transmitter and telemetry receiver. The telemetry transmitter and receiver are coupled to control circuitry and registers, operated under the control of microprocessor 364 . Similarly, within stimulator a telemetry antenna 142 is coupled to a telemetry transceiver comprising RF telemetry transmitter and receiver circuit. This circuit is coupled to control circuitry and registers operated under the control of microcomputer circuit.
[0134] With reference to the telecommunications aspects of the invention, the communication and data exchange between Modified PDA/Phone 140 and external stimulator 42 operates on commercially available frequency bands. The 2.4-to-2.4853 GHz bands or 5.15 and 5.825 GHz, are the two unlicensed areas of the spectrum, and set aside for industrial, scientific, and medical (ISM) uses. Most of the technology today including this invention, use either the 2.4 or 5 GHz radio bands and spread-spectrum technology.
[0135] The telecommunications technology, especially the wireless internet technology, which this invention utilizes in one embodiment, is constantly improving and evolving at a rapid pace, due to advances in RF and chip technology as well as software development. Therefore, one of the intents of this invention is to utilize “state of the art” technology available for data communication between Modified PDA/Phone 140 and external stimulator 42 . The intent of this invention is to use 3G technology for wireless communication and data exchange, even though in some cases 2.5G is being used currently.
[0136] For the system of the current invention, the use of any of the “3G” technologies for communication for the Modified PDA/Phone 140 , is considered within the scope of the invention. Further, it will be evident to one of ordinary skill in the art that as future 4G systems, which will include new technologies such as improved modulation and smart antennas, can be easily incorporated into the system and method of current invention, and are also considered within the scope of the invention.
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Method and system to provide therapy for obesity and gastrointestinal disorders such as FGIDs, gastroparesis, gastro-esophageal reflex disease (GERD), pancreatitis and ileus comprises vagal blocking and/or vagal stimulation, utilizing implanted and external components. Vagal blocking may be in the afferent or efferent direction, and may be with or without selective stimulation. Blocking may be provided by one of a number of different electrical blocking techniques. The implantable components are a lead and an implantable pulse generator (IPG), comprising re-chargeable lithium-ion or lithium-ion polymer battery. The external components are a programmer and an external recharger. In one embodiment, the implanted pulse generator may also comprise stimulus-receiver means, and a pulse generator means with rechargeable battery. In another embodiment, the implanted pulse generator is adapted to be rechargeable, utilizing inductive coupling with an external recharger. Existing nerve stimulators may also be adapted to be used with rechargeable power sources as disclosed herein. The implanted system comprises a lead with two or more electrodes, for vagus nerve(s) modulation with selective stimulation and/or blocking. In another embodiment, the external stimulator and/or programmer may comprise an optional telemetry unit. The addition of the telemetry unit to the external stimulator and/or programmer provides the ability to remotely interrogate and change stimulation programs over a wide area network, as well as other networking capabilities.
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CROSS REFERENCE
My prior and co-pending application Ser. No. 07/644,554 filed Jan. 23, 1991, U.S. Pat. No. 5,122,624 date Jun. 16, 1992.
BRIEF SUMMARY OF THE INVENTION
The present invention resides in the same general field as that of my prior application identified above. Specifically, the invention finds most effective use in the case where a plurality of circuit breakers are involved, and it is desired to open, or block out, certain ones. This particular arrangement is found most often in industrial and commercial establishments, where such plurality of circuit breakers are used, and many times a large number of them. As in the case of the previous invention, when a plurality of circuit breakers are involved, it is usually necessary and desired to block out only certain ones of them. The device of that invention is adaptable to be applied to individual circuit breakers very effectively, and the device of the present invention is more flexible in being so applied.
A principal object of the present invention is to provide a circuit breaker block out that is more readily adaptable to circuit breakers of a great variety of kinds and sizes, than any devices heretofore known.
Another object is to provide such a block out that is easily locked in place, on a circuit breaker that is blocked out, and that can be very securely so locked in place.
Still another object is to provide such a block out having novel special form which adapts it to a plunger type circuit breaker.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a top edge view of one form of the circuit breaker, of the invention.
FIG. 2 is a view oriented according to FIG. 2, showing the device in partially folded form, in a step of its application to the circuit breaker.
FIG. 3 is a side view of a plunger type circuit breaker with which the device of FIGS. 1 and 2 is adapted to be used.
FIG. 4 is a face view of a panel or board having a plurality of circuit breakers thereon, of the type illustrated in FIG. 3.
FIG. 5 is a view oriented according to FIG. 3, showing the upper part of the circuit breaker of FIG. 3, and the block out in open position in a step of applying it to the circuit breaker.
FIG. 6 is a view oriented according to FIG. 5 showing the block out in folded position and applied to the circuit breaker.
FIG. 7 is a view oriented to line 7--7 of FIG. 2.
FIG. 8 is a view taken at line 8--8 of FIG. 6.
FIG. 9 is a perspective view of a second form of block out, in a partially folded position.
FIG. 10 is a top view of the block out of FIG. 9, applied to a circuit breaker.
FIG. 11 is a view similar to FIG. 8 but showing the latching finger in an opposite location.
FIG. 12 is a perspective view of another form of block out, oriented in the same direction as in FIG. 9.
FIG. 13 is a side view of the device of FIG. 12, oriented by the arrow 13 in FIG. 12, and with the device applied to a circuit breaker.
FIG. 14 is a top view of FIG. 13.
FIG. 15 is a perspective view, oriented according to FIG. 12, and showing a form slightly modified relative to that of FIG. 12.
FIG. 16 is a prospective view, oriented according to FIG. 12, of another form of block out.
FIG. 17 is a sectional view taken at line 17--17 of FIG. 16.
FIG. 18 is a sectional view taken at line 18--18 of FIG. 16.
FIG. 19 is a perspective view, oriented in the direction of FIG. 16 and showing a form of block out slightly modified relative to that of FIG. 16.
DETAILED DESCRIPTION
Referring to the various devices in general, it is pointed out that a first form of block out is shown in FIGS. 1-8; a second form in FIGS. 9-11; a third form in FIGS. 12-14; a fourth form in FIG. 15; a fifth form in FIGS. 16-18; and a sixth form in FIG. 19. The various forms of the device disclosed herein perform the function of blocking out circuit breakers in that when the device is applied to a circuit breaker, and in the normal course of events, the circuit breaker is not intentionally actuated when the device is applied thereto. It may also be desirable at times to lock the device in place on the circuit breaker so as to prevent deliberate tampering and prevent its removal, without completely destroying it. In the forms of the device enabling locking, the device may be referred to as a lock out. Block out is used herein in a generic sense to cover both blocking out and locking out, while lock out is a specific form of the device, enabling locking thereof.
Referring in detail to the accompanying drawings, attention is directed first to the form shown in FIGS. 1-8. The block out of this form is shown in its entirety at 22, and the circuit breaker to which it is especially adapted is indicated at 24. This circuit breaker is of the push-pull kind, having a plunger type actuating element that is axially slidable. The circuit breaker includes a mounting means 26 and a main housing or body 28 including an element 30 of lesser diameter having an upper surface 31 forming a shoulder. The circuit breaker includes an actuating element, 32, in the body 28 but extending to the exterior and having a reduced shank portion 34 and a large head 36. The shank 34, is usually white in color and the other parts darker, providing a readily visual contrast. The actuating element 32 is slidable along its longitudinal axis 37 from an outer OFF position 32a shown in full lines, to an inner ON position 32b, shown in dot-dash lines.
The block out 22 is a one-piece, integral member, made up of two main parts 38, 40 connected together by hinge means 42 on an axis 43 (FIG. 5). The parts are swingable from an open generally elongated flat condition (FIGS. 1, 5) to a closed locking position (FIG. 4) in which the parts are fitted together. The parts 38, 40 include large body portions 44, 46, together forming a generally cylindrical shape, and arms 48, 50 extending therefrom. The main parts have inner surfaces 49 which when the member is in locking position, interface, and substantially interengage.
The large portions 44, 46 are provided with recesses 51 adapted to receive the exposed end of the actuating element 32, each including a central segment 51a, end segments 51b, 51c spaced from the central segment. The end segments open through the wall and form viewing ports or viewing windows 54 (FIG. 6). The central and end segments are interconnected by shank segments 51d. These recesses are arranged so that when the main parts are folded together with the inner surfaces 49 of the latter interengaging, they form circumferentially continuous cavities, and form apertures through the member on an axis 52 parallel with the axis 43 in the hinge means. The windows 54, which open into the end segments, visually expose the white shank 34, as referred to again hereinbelow. The central segment 51a is positioned closer to one end than the other, to accommodate actuating elements of different external extensions.
The arms 48, 50 are provided with apertures 55, 56 adjacent their swinging ends, i.e., right hand ends in FIG. 2, which are aligned on a common axis 57 (FIGS. 4, 8) when the main parts are fitted together. One of the arms 48, 50 is provided with a latching finger 58 extending substantially perpendicularly therefrom, and in a direction perpendicular to the axis 43 of the hinge means 42. The latching finger 58 has a latch element 58a at its extended end.
The other arm, 48, is provided with a key way 59 (FIG. 7) arranged and positioned for receiving the latching finger 58 when the main parts are moved together to locking position. The latching finger penetrates through the key way 59, and the latching element 58a engages the arm 48 in a positive manner, preventing the main parts from being separated, while the finger is in latching position.
The latching finger 58 and key way 59 enable the latching finger 58 to be confined entirely in the key way, (FIG. 7), thereby providing a main portion of the aperture 54 that is substantially circular in form. For locking the device in locking position, a padlock 60 is utilized, the locking element 62 thereof being inserted through the apertures 54, 56, this element being round in cross section, and thereby engaging the latching finger and preventing it from being moved out of the key way. Thereby the latching finger remains latched, and the main parts of the device remain locked together.
In the use of the block out, it is applied to the actuating element 32 when the latter is in OFF or open position, and as illustrated here in the pulled-out position (FIGS. 3, 5), and in this position the white surface of the shank 34 is exposed upwardly beyond the element 30. Then the block out is applied to the circuit breaker by holding it open (FIGS. 1, 5), and one of the parts fitted to the actuating element, and the head 32 falls in the central recess 51a. The dimensions of the block out, and the position of the plunger, are such that when the head 32 is in the center recess 51a, the lower end surface of the block out 22 fits against the shoulder 31 of the large element 30, and it is understood that the head 32 is larger than the shank portion 51d and thus held in the large recess. Then the other main part is swung to closed position against the first part as indicated in FIG. 2 in which the parts are yet angularly spaced apart, but in a position in which the latching finger 58 is closely adjacent the aperture 56, and upon further movement of the parts together, the latching finger moves into the aperture, and latches. This position is shown in FIGS. 4 and 6. With the main parts thus fitted together, the recesses 51a together form a continuously circular cavity confining the head 32.
In this position of the block out, the latter reacts between the head 32 of the actuating element and the shoulder 31 and holds the actuating element in its outer position. In this position the white surface of the actuating element is exposed and viewable through the window 54 located on top of the shoulder 31 and thus forms a quick indication that the actuating element is in retracted or off position.
With the block out thus applied and without being locked, it is usable where it is believed no interference will take place, either deliberate or accidental. However, if it is feared that the block out may be tampered with, it may be locked as referred to above by means of the padlock 60 with the element 62 inserted through the aligned apertures 54, 56. This padlock of course prevents the complete spreading of the main parts of the device, but in order to prevent an unlikely situation such as using a pry and spreading the main parts apart, so that the plunger can be pushed to inner position, the latching finger 58 is utilized. As referred to above, with the padlock in place, the element 62 prevents the latching finger from being unlatched, and the main parts from being pried apart.
Reference is next made to the form of the device shown in FIGS. 9-11. FIG. 9 shows a block out 66 identical with the block out of my prior application identified above, with the exception of a latching finger 71. In the present case the block out includes two main parts 68, individually identified 68a, 68b corresponding with the main parts 31a, 31b in that application. In the present case the main parts are provided with apertures 69, 70 at their swinging ends. The main part 68a has a latching finger 71 with a latching element 72, and the main part 68b has a key way 73 into which the latching finger moves, in the same manner as described above in connection with the form of FIGS. 1-8. The locking position of the latching finger is shown in FIG. 10. FIG. 11 shows the element 62 of the padlock 60 in position in the apertures and holding the latching key in latching position.
For the purpose of bringing out certain significant features in the forms of device of FIGS. 12 and 16, it is pointed out that the device of FIG. 9, and that of my prior application, is for use with a circuit breaker having an actuating element with holes therein. FIG. 9 shows such an actuating element 76 with holes 77 in the sides thereof. The block out device 66 has pins 78 which extend into those holes, when the device is applied to the circuit breaker. This provides a positive locking feature. However the actuating elements are provided with such holes only in certain cases. In the absence of such holes, it is necessary to provide other means for producing a holding or gripping effect on the actuating elements, and a feature for providing this effect is incorporated in the forms of FIGS. 12 and 16. Detail reference is now made to the device of FIG. 12, which is identified 80 and has two main parts 80a and 80b. They are connected together by hinge means 82 on an axis 83, of the kind referred to above, and thus form levers, having swinging ends 84 individually identified 84a, 84b. These swinging ends have apertures 86 individually identified 86a, 86b, which are disposed on a common axis when the device is in locking position, similarly to the forms described above.
The main parts 80a, 80b have interfacing surfaces 88 in which are formed recesses 90 extending through the main parts in direction parallel with the axis 83, and being of such lengths, longitudinally of the main parts, and of such depth, transversely thereof, to correspond with the actuating element of the circuit breaker.
Positioned in these apertures 90 are inserts or liners 92, which themselves have recesses 94 shaped similarly to the recesses 90, and opening through the interfacing surfaces 88, and thus interfacing, and when the main parts are in locking position, together form an aperture through the device in direction parallel with the axis 83. These recesses 94 have floors or bottom surfaces 95.
FIGS. 13 and 14 show the device 80 applied to a circuit breaker 96 which has an actuating element 98 in the form of a swinging lever. It is so applied to the circuit breaker by moving the main parts to closed position with the actuating element 98 therebetween, in the recesses 94.
The main parts 80, without the inserts 92, are of molded plastic, preferably polypropylene, and are relatively hard, and rigid and non-yielding, and have only a limited amount of flexibility. The inserts 92 are, by contrast, relatively yielding, and softer than the material of the main parts. These inserts are bonded to the main parts, in a known process, and provide what is known as dual plastic consistency.
When the device is applied to the circuit breaker, the actuating element 98 is gripped between the inserts, and the relative dimensions are such that the floors 95, in their normal condition and shape, are spaced apart in the locking position of the device, a distance less than the corresponding dimensions of the actuating lever. The material of the inserts yields slightly, as shown at 100 in FIG. 14, and the inserts thereby grip the actuating element with great force, and thereby prevent movement of the actuating lever. In the absence of the holes 77 (FIG. 9) the friction gripping action of the inserts provides the desired locking effect. This locking effect prevents the swinging or angular movement of the actuating element. The block out remains in its original predetermined position relative to the actuating element by engaging the surface of the circuit breaker 96 (FIG. 13) throughout its length, and in that manner prevents the angular movement of the actuating element.
The form as shown in FIGS. 12-15, may have, or not have, a latching finger, as desired. The form of FIGS. 12-14 does not have such a latching finger, but FIG. 15 shows the same form, but with a latching finger 102 adjacent the aperture 86b, and a key way 104 in the aperture 86a.
Detail reference is next made to the form of the device of FIGS. 16-19. In this embodiment, the block out device is indicated in its entirety at 106, and includes a major component 108 and a cap 110. The major component 108 is a one-piece molded article, having a pair of main parts 111 connected together by hinge means 112 on an axis 113, similar to the devices described above. The main parts 111 have apertures 114 at their swinging ends, and have recesses 116 in their interfacing surfaces.
The cap 110 is separate from the main component 108, and is applied directly to the actuating lever 118 of the circuit breaker. The cap has a surrounding wall 120 (FIG. 17) with an aperture therethrough, and is fitted to the actuating element by extending the actuating element through the aperture, and then a mass of bonding material 122 such as epoxy is put in the cap around the actuating element, which bonds the cap securely thereto. The main parts 111 are then fitted to the cap, with the latter received in the recesses 116. The surrounding wall has lugs 124 at the top which extend over the corresponding surfaces of the main parts 111 (FIG. 18) and provide a positive locking effect, preventing the main parts from being lifted up and off the circuit breaker.
In this case also, it is understood that the actuating element of the circuit breaker does not have holes such as 77 in FIG. 9 and the cap bonded to the actuating lever provides the means for the device to effectively grip the actuating lever.
In the use of this device a lock such as the padlock 60 may be utilized, with the apertures 114 for locking the device in place.
The device as illustrated in FIGS. 16-18 is not provided with latching means, but in this case also, such latching means may be provided as in FIG. 19 where a latching finger 126 is provided on the swinging end of one of the main parts, and a key way 128 is provided in the aperture in the other part, in the same kind of construction as in the previous embodiments.
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A one-piece integral molded plastic article, includes a pair of main parts hinged together, which enclose the actuating element of the circuit breaker and holds it against movement. One form is for push-pull type circuit breakers. Another form includes soft inserts which grip the actuating element and hold it. Another form includes a separate cap which is applied semi-permanently to the actuating members. Latching means latches the main parts together, which hold them in normally latched position, and a padlock locks them together.
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RELATIONSHIP TO OTHER APPLICATION(S)
[0001] This application is a continuation-in-part of U.S. Ser. No. 13/553,795 filed on Jul. 19, 2012 and claims the benefit of the filing date of US Provisional Patent Application U.S. Ser. No. 61/804,620 filed on Mar. 22, 2013, the disclosure(s) of which are incorporated herein by reference.
GOVERNMENT RIGHTS
[0002] This invention was made under contract awarded by US Department of Energy, Contract Number DE-EE0006378 and DE-SC0009196. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
Field of the Invention
[0003] This invention relates generally to systems for transporting and installing large photovoltaic modules, and more particularly, to a photovoltaic module handling system that enables substantially automated and rapid replenishment of photovoltaic modules in a solar panel array.
Description of the Related Art
[0004] Co-pending patent application U.S. Ser. No. 13/553,795 describes an automated system for photovoltaic (PV) power plant construction. In this system, robotic shuttles deliver large panel assemblies to their mounting positions on a ground-mount rack in the form of an elevated delivery track from load stations at the end of each row of racks in a solar panel array. This system is a marked improvement over manual delivery of large panel assemblies to their final mounting positions.
[0005] A common theme in the utility scale, photovoltaic power plant construction has been to achieve cost reduction by using larger building blocks for construction. One way to do this is to pre-assemble movable PV panels into larger arrays, either at the panel manufacturer, at a local warehouse, or at the construction site. These larger building blocks must then be brought to the field for installation on a support rack systems. Field labor is required to assist in positioning the panels in their final mounting position, to install mounting clamps, and to interconnect electrical wiring. Field labor, particularly if utilizing building trades, is paid at a much higher labor rate than factory labor.
[0006] There is, thus, a need to reduce labor costs per panel by replacing field labor with factory labor.
[0007] Of course the larger building blocks are heavier to handle. Expensive aluminum rails have been used on the panels to reduce weight. There is, therefore, a need to reduce material costs by replacing panel aluminum rails with lower-cost materials, such as galvanized steel, as well as reducing the amount of components, such as clamps, required to complete the installation.
[0008] While larger building blocks can improve overall installation rates, the size and weight of both panel arrays, and large monolithic panels, means that they can no longer be handled by manual labor alone. Therefore, heavy equipment (e.g., cranes, boom trucks, ground-mounted robotic arms) may be required to deploy such panels safely. The use of heavy equipment requires some initial site grading and, frequently, re-grading as heavy equipment can create deep mud tracks and treacherous conditions, especially post-rain and snowfall. It can even bring construction to a halt until the surface is stabilized. Personnel safety is a big issue when heavy equipment is used on the work-site. In addition, special training may be required for use and maintenance of such equipment. There is, therefore, a need for an installation system that does not require the use of heavy equipment to install panel arrays.
[0009] It is therefore, an object of this invention to provide an solar panel installation system that utilizes larger building blocks, such as panel modules, but that does not require the use of large, or heavy, equipment.
[0010] In co-pending application U.S. Ser. No. 13/553,795, small automated PV shuttles, sometimes referred to as drones, support and carry panel assemblies, weighing up to 120 kg, to their final rack-mounted position. No heavy equipment is required to travel between rack rows during installation, and the size of installation crews is reduced. However, while the shuttles utilized can handle pre-panelized framed modules. However, for maximum cost savings, pre-panelization of frameless modules is highly preferred. Frameless modules have the advantage of lower cost (no aluminum frame) and the frames so not have to be grounded, which is a major cost adder.
[0011] However, frameless modules are more fragile at the edges and corners. Therefore, greater care is required when handling frameless modules. There is, thus, a need for a system that can safely utilize frameless modules.
[0012] It is another object of this invention to provide a system that can take full advantage of the economies of scale and the ability to use pre-panelized modules, and particularly, frameless pre-panelized modules.
SUMMARY OF THE INVENTION
[0013] These, and other, objects features, and advantages are achieved by the present invention entire solar panel arrays are populated from a single, centralized material handling location by using a specialized assembly jig that serves as a fork lift pallet and pre-positions a stacked-up array of solar panel modules for delivery to a ground-mount rack of a solar array. An advantageous aspect of the present invention is that the manual work in assembling the solar panel modules, including the installation of low-cost, adhesively applied rails that will be used to grip and transport the panels to their final destination, as well pre-wired electrical components, is performed in a weather-protected location on smooth ground and can be located either on-site or off-site.
[0014] In addition to the foregoing, the manual handling risk to the panel is minimized because the frameless solar panel modules are pre-panelized, and most advantageously, pre-panelized in a specialized assembly jig that will be used to transport the pre-panelized solar panel arrays directly to the field array. Field-handling of PV modules is, therefore, limited to one simple loading motion at the end of the array. The rack rail-mounted robotic shuttles then take-over and deliver the PV module to its final position. By minimizing human handling of the modules, particularly at the critical final installation step where module corners are easily struck and damaged, the risks related to frameless modules are minimized and the associated cost savings can be fully realized.
[0015] In a specific embodiment of the invention, a specialized PV assembly jig and fork-lift transport pallet, herein designated “pallet jig,” is provided to support, protect, and align, PV panels stacked in an upside down position, opposite to their operational position. The pallet jig is configured to be transported on the tines of a forklift truck for further transport, or to its final destination at the field array. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.
[0016] In a method embodiment of the invention, panel assembly is accomplished while each panel of the module is uppermost on the pallet jig, and is oriented upside down (or sunny-side-down) for ease of application of the components to the underside of the PV solar panels. The pallet jig holds the individual PV solar panel modules in place in a stacked arrangement, referred to herein as a stack-up, by upright support members attached to the horizontal stringers of the pallet-like jig structure on the external supports on the back side and the shorter, longitudinally-spaced apart sides of the pallet. The upright corner support members on the longitudinally-spaced apart sides of the pallet jig are pivotably, or removably, connected and held in place by a latching mechanism, for example, so that they can be laid out of the way for ease of removing the modules from the stack-up.
[0017] The upright corner support members, as well as the upright support members on the back of the pallet jig, are provided with protrusions, illustratively lugs, for positioning a solar panel module in place relative to a second solar panel module installed on top of the first solar panel module, as series of modules being so stacked to comprise a multi-layer stack-up. The protrusions interengage with rails that are installed on the backside of the solar panels, illustratively, by an adhesive strip. The panels being supported and spaced apart by the lugs so that the height of the applied adhesive strip remains uniform.
BRIEF DESCRIPTION OF THE DRAWING
[0018] Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawing, in which:
[0019] FIG. 1 is a perspective view of a combined PV panel assembly jig and forklift transport pallet that is prepared in a panelization station, such as shown in FIG. 12 , for use in the practice of a specific illustrative embodiment of the invention;
[0020] FIG. 2 is a fragmentary perspective view of the PV panel assembly jig and fork lift pallet of FIG. 1 in an empty condition;
[0021] FIG. 3 is a perspective view of a sub-assembly of a roller-mounted movable support plate with a pivotable jig support channel bar hinge-coupled to the movable plate, and carrying at each end an adjustable draw latch, the sub-assembly is also shown pallet-mounted in FIG. 2 ;
[0022] FIG. 4 is a fragmentary enlarged perspective view of the details of a slide-out end assembly of the palletjig illustrating the adjustable draw latch and location-establishing pallet jig components as also seen in FIGS. 2 and 3 on a smaller scale;
[0023] FIG. 5 is a fragmentary perspective sub-assembly view of one of the thin-gauge steel rails (in the form of a hat-style channel) secured by dual beads of a commercially-available adhesive to the underside surface of a PV panel module during the pallet-jig panelization process of the present invention;
[0024] FIG. 6 is a fragmentary perspective view illustrating a portion of a jig locating and lug support strip affixed to and carried by one of the pallet jig upright support posts, the strip having protruding positioning lugs for supporting and positioning respective PV glass panels with their associated support rails as each PV module is being assembled upside down and stacked during pallet loading in the inverted panel stack-up panelization process and that provides the predetermined orientation in the inverted pallet jig stack-up array as shown in FIG. 1 ;
[0025] FIG. 7 is fragmentary perspective view, with portions shown in cross-section, further illustrating the relationship of a PV panel and associated support rails with the jig lugs of FIG. 6 ;
[0026] FIG. 8 is a fragmentary perspective view of an uppermost layer in the panelization jig pallet stack-up illustrating installation of wiring and other electrical components to the uppermost inverted panelization layer during the panelization assembly process of FIG. 11 a employed in making the pallet jig stack-up of FIG. 1 ;
[0027] FIG. 9 is a fragmentary perspective view of a support block assembled at a defined position on a support rail which in turn is adhesively affixed to an underlying PV module while the same is upside down and in the uppermost exposed position in the panelization stack-up process;
[0028] FIG. 10 is a fragmentary perspective view of two registered support blocks and associated PV panels, with the blocks being shown in half-section in assembled relationship to one another and associated rails and PV glass panels during the panelization process;
[0029] FIGS. 11 a , 11 b , and 11 c are perspective semi-schematic views respectively showing successive panelization assembly steps of the bottom PV glass panel utilizing the pallet jig of FIG. 1 ;
[0030] FIG. 12 is a diagrammatic plan view of a PV solar panel panelization work center in accordance with the invention which illustrates material flow and labor stages in a factory-like environment, preferably located near the ground support rail racks field array installation, and the processing steps involved in preparing the PV solar panel modules oriented inverted and upside-down, or with their shady-side-up, or conversely, sunny-side-down, in the stack-up array of FIG. 1 ;
[0031] FIG. 13 is a perspective view of an assembled PV solar panel module, shown shady-side-up and by itself;
[0032] FIG. 14 is a perspective view of one system embodiment of solar panel modules having been delivered in a conventional sunny-side-up, non-jigged stack-up to the rack loading station by a forklift truck, and being manually placed on the rack loading station by a two-man crew;
[0033] FIG. 15 is a diagrammatic plan view illustrating an entire rail-rack-supported field array of solar panel PV modules as drone-populated from a central logistics area;
[0034] FIG. 16 is a perspective view of another embodiment of the step of successively individually robotically removing, and inverting to operable, or sunny-side-up, orientation, solar panel modules from two inverted, or sunny-side-down, stack-ups of finished solar panel modules, the stack-up in the foreground shown as being carried in an inverted module stack-up condition by a fork truck and in the forklift pallet jig assembly of FIG. 1 , and the other stack-up being shown in the background, as having already been transported to, and seated by the fork lift truck, as an entire palletized stack, on a rack-loading entry platform station. At this station, the PV modules are robotically unloaded as, and when, they individually become the uppermost exposed sunny-side-up module on the stack;
[0035] FIG. 17 is a perspective view showing the rack-loading station (shown uppermost in Fig. 16 ) wherein the automated hydraulic robot is shown holding a PV panel slightly beyond midway in the path of its transfer motion as the transfer robot is rotating the lifted panel about its longitudinal axis, and lowering it to bring it into upright orientation for disposition on the associated tilttable drone rack-loading station as shown in FIG. 16 ;
[0036] FIG. 18 is a perspective view showing a solar panel module supported on an associated operable computerized drone which is in turn movable on the ground-installed rail rack system in an operable embodiment of the invention;
[0037] FIG. 19 is a perspective view of a drone monitoring station constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site;
[0038] FIG. 20 is a perspective view of one embodiment of a solar panel array rack in accordance with the system of co-pending U.S. Ser. No. 13/553,795, as ground-installed;
[0039] FIG. 21 is a perspective view of one embodiment of an operable automated drone which is battery-powered and monitored by the drone monitoring station of FIG. 19 ;
[0040] FIG. 22 is a perspective view of the solar panel transfer robot (as also seen in
[0041] FIGS. 16 and 17 ) illustrating the same entry at the approximate midpoint of the transfer stroke of the pick-up arm of the inverter-rack loader robot as shown in FIG. 17 , and also showing the tilttable drone loading station;
[0042] FIG. 23 is a perspective view, similar to FIG. 22 , showing a transfer robot with its panel transfer arm gripping the rails of an inverted PV solar panel assembly supported uppermost on solar panel stack-up 102 of FIG. 1 , and illustrating a portion of the associated pivotable end support posts unlatched and pivoted down and out of the way during the PV panel transfer operation;
[0043] FIG. 24 is a fragmentary perspective view showing the panel transfer robot carrying a solar panel downwardly in the tilt rack loading portion of its operational cycle, with the robot panel carrier arm having inverted the solar panel to upright orientation and while lowering the same to be supported on top of tilt rails of the robotic drone-loading station.
[0044] FIG. 25 is an isometric view of a stacking block 400 described in conjunction with
[0045] FIGS. 9 and 10 , and referenced as 400 a and 400 b therein;
[0046] FIG. 26 is another isometric view of stacking block 400 oriented in a different direction than shown in FIG. 25 ;
[0047] FIG. 27 is a center cross-section view showing associated rails 312 a and 312 b facing the shady-side-surface 316 a and the sunny-side-surface 316 b of solar panel 316 as oriented in stack-up 102 of FIG. 1 ;
[0048] FIGS. 28, 29, 30, 31, 32, 33, 34, and 35 shown in pairs comprising the even-numbered figures and the next consecutive odd-numbered figure, with illustrative spacer block configurations, the space block configuration of FIGS. 30 and 31 being presently preferred;
[0049] FIGS. 36 and 37 are fragmentary end and isometric views of a four panel stack-up using rails identical to those shown in FIG. 27 to respectively laterally space apart a vertical stack-up of spacer rails configured in cross-section the same as FIGS. 30 and 31 ;
[0050] FIGS. 38 and 39 are end elevational and perspective views, respectively, with the solar panels completed and oriented in a stack-up slightly modified from the stack-up of FIG. 1 ;
[0051] FIG. 40 is perspective assembly view of the robot transfer station having a stationary platform for receiving as input the palletized stack-up 102 , as shown in Fig. 16 , and also having an upright robotic tower provided with the pivotable panel carrier frame duly supported thereon and pivotally-actuated to swing the pick-up box arm through approximately 180° over the top of the robotic tower and to lower the panel, as a stack-up, onto the stationary receiving platform as shown by panel stack-up 102 b ( FIG. 16 );
[0052] FIG. 41 is a perspective view of the upright robotic tower equipped with two ram-actuated chain drives, one rigged for pivoting the gripper pick-up arm of the robot, and the other for raising and lowering the pick-up arm and associated carriage, up and down on the robot tower;
[0053] FIG. 42 is a perspective view of the box assembly of the pick-up arm shown in horizontal position by itself;
[0054] FIG. 43 is a semi-exploded perspective view of the hydraulic and chain drive components of the transfer and inverting ram as shown in detail in FIGS. 40, 41, 42, and 43 ;
[0055] FIGS. 44 and 45 show the pivotal panel pick-up arm mechanism in a perspective assembly view of FIG. 44 and exploded in the perspective view of FIG. 45 , that rotates the oppositely extending pair of protruding drive shafts that non-rotatively are affixed to the pivoting arm that carries and pivots the pick-up arm;
[0056] FIG. 46 is a perspective view and FIG. 47 is partially exploded view of the tilting mechanism and framework for operably supporting the receiving channels 650 and 652 , and also the transfer and tilt station disposed between the upright robot mechanism and the input end of an associated rack row.
DETAILED DESCRIPTION
[0057] FIG. 1 is a a perspective representation of a combined PV assembly jig and forklift transport pallet 100 , herein designated “pallet jig,” on which a stack-up 102 of PV modules 104 are individually jigged bottom-first and oriented upside-down relative to their operational orientation when mounted on a support rack in a solar panel array, such as the support rack shown on FIG. 18 . Components of pallet jig 100 are shown in greater detail in FIGS. 2, 3, and 4 . Pallet jig 100 is re-usable and serves as both a panelization jig in forming the inverted stack-up 102 of PV modules 104 and a transfer pallet that is removably engageable and supportable on the tines of a suitable forklift truck for transport to rack array panel loading stations in a field-installed solar panel array.
[0058] As best shown in the assembled views of FIGS. 1 and 2 , pallet jig 100 is made of robust steel pallet frame components, including laterally-spaced and longitudinally extruded box channel members, stringers 106 and 108 , open at their opposite longitudinal ends and designed to slidably receive a pair of fork tines of a commercially available forklift truck. As best seen in FIG. 2 , a pair of longitudinally spaced apart and parallel box frame members, cross beams 110 and 112 , are made up by a longitudinally-aligned array of open-ended shorter box section channels 114 , 116 , and 118 , registering with mating openings (not seen) in box beams 106 and likewise as to box beam 108 . The outer front and rear sides of the pallet construction are formed by C-section steel channels, such as front channel 120 seen in FIG. 2 , and on the opposite side of the pallet by C-section steel channels 122 , 124 , and 126 ( FIGS. 1, 2, and 4 ). The opposite longitudinal ends of the pallet framework are made up of C-section channels 130 , 132 , and 134 . C-section channel 130 is welded at its ends to the box section upright corner post 136 and at the other end to the side of stringer 106 adjacent its open end. Likewise C-section channel 132 is welded at its opposite longitudinal ends respectively to stringers 106 and 108 adjacent their open ends, and channel 134 is likewise welded to stringer 108 and upright corner post 140 .
[0059] Stringer beams 106 and 108 provide at each of their opposite longitudinal ends, a pair of rectangular-shaped openings 107 , 109 for receiving conjointly, respectively, the two conventional tines of a forklift mounted on the upright mast rails of a conventional forklift truck. Likewise, the opposite open ends of cross-beams 110 and 112 are designed to individually receive respective forklift tines of a conventional forklift truck (such as forklift truck 601 in FIG. 14 ).
[0060] The palletizing panel-locating function of pallet jig 100 is served by a series of upright channel posts disposed along the back of the opposite longitudinal ends of pallet jig 100 and along the rear side of pallet jig 100 . The upright channel posts are also clearly seen and described in connection with FIGS. 11 a , 11 b , and 11 c.
[0061] The primary jig post components, as shown in the aforementioned figures, include upright jig support and panel positioning posts arranged in pairs, illustratively, end support uprights 150 , 152 and 154 , 157 , one pair being located at each of the longitudinally opposite ends 105 and 115 of pallet jig 100 , along with corner support posts 158 a and 158 b . Pallet end support uprights 150 and 152 , for example, are both mounted at their bottom ends on a pivoting channel and sliding plate sub-assembly 170 shown separately in FIG. 3 . Sub-assembly 170 is a pivoting hinge beam that includes an inverted C-channel beam 171 , slide plate 172 and draw latch assemblies 190 and 192 .
[0062] As best seen in FIGS. 2 and 3 , pivoting channel and sliding plate subassembly comprises an inverted C-channel beam 171 provided with laterally spaced and longitudinally extending rows 174 and 176 of mounting bolt holes. Pivoting hinge beam 170 when upright rests on a centrally located slide plate 172 and is hingedly coupled thereto by a pair of hinges 178 and 180 ( FIGS. 2 and 3 ). Slide plate 172 has a pair of wheels 182 (only one wheel being seen in FIG. 3 ) rotatably mounted on down-turned side flanges 183 of slide plate 172 and tracking, in assembled condition, in associated wheel track channels 184 and 186 , respectively, affixed to the mutually-facing inner sides of longitudinal pallet channels, or box channel members, 108 and 106 as shown in FIG. 2 . Pivoting hinge beam 170 is releaseably held to the pallet in a fixed position by a pair of the adjustable draw latch assemblies 190 and 192 to thereby support and restrain associated jig posts 150 , 152 , and 158 fixed in predetermined upright orientation .
[0063] Draw latch assembly 190 is shown in detail in FIG. 4 . Referring to FIG. 4 , a locating and latch block and V-groove receiver sub-assembly 194 comprises an upright mounting plate 196 affixed by bolts 198 and 200 registered by associated mounting holes in the web of channel 120 . Mounting plate 196 has an upper extension 202 which supports mounting bolts 204 and 206 which thread into associated mounting holes in V-groove receiver 194 to securely affix the same to channel 120 . Locating block 194 has a front side facing pallet end channel 130 with a vertically-extending V-groove 210 therein that serves as the locating receiver for a cylindrical pin 212 in the latched position of associated latch 190 . Cylindrical locating pin 212 is welded to the outer face of the vertical flange 214 of pivot channel beam 170 and is drawn into seating engagement with the V-groove 210 of locating block 194 in the fully latched up condition of draw latch assembly 190 shown in FIG. 4 .
[0064] Each adjustable draw latch 190 and 192 , also comprises a U-shaped bracket member 220 having a pair of upright side flanges 222 and 224 held upright and spaced apart by an integral bottom web (not shown) that is welded to the upper surface of pivoting hinge beam 170 at the associated longitudinal end thereof. Adjustable draw latches 190 and 192 also include an inverted U-shaped latch receiver 226 having its center web welded to the upper face of locating block 194 . Latch receiver 226 serves as a receiver locking catch for cylindrical latch pin 230 . The upper edges of the upright sides of latch receiver 226 are configured to provide sliding support for cylindrical latch pin 230 in the latching and unlatching operating conditions thereof, and also to provide stop latch surfaces of semi-circular configuration to releaseably hold latch pin 230 in securely locked position when drawn thereagainst by swinging pivot handle 240 . Draw latch 190 includes a draw rod 232 that is externally threaded for threadably engaging an internally threaded through hole in latch pin 230 such that latch pin 230 , in unlatched condition, can be threadably adjusted along draw rod 232 . The end of draw rod 232 opposite pin 230 has a cross pin 234 that is pivotably mounted by being received in associated mounting holes in flanges 222 and 224 . Cross pin 234 thus serves as a pivot pin for draw rod 232 as well as a mounting pin for the pivot handle 240 of adjustable draw latch 190 .
[0065] Flanges 222 and 224 of latch assembly 190 have their upper edges configured to provide a draw cam action in cooperation with a cam follower bracket 242 ( FIG. 4 ). Follower bracket 242 has a horizontal cross piece 244 extending between and through associated slots provided in the pair of down-turned flanges of pivot handle 240 . The cam follower edges of cam follower latch bracket 242 are configured to slidably ride on down-sloping and latch-configured camming edges 246 of each mounting bracket 220 as to thereby function as a draw latch arm.
[0066] Draw latch assemblies 190 and 192 are fixedly mounted one each at the opposite longitudinal ends of pivoting hinge beam 170 as shown in FIGS. 1 to 3 . When latch assemblies 190 and 192 are unlatched by pivotably raising their associated latch operating arms 240 to thereby disengage latching pins 230 from locking brackets 226 . Inverted C-channel beam 171 , along with upright post supports 150 , 152 , and 158 a affixed upright thereon, can be pivoted outwardly about the rotational axis of the hinge pin connections 178 and 180 of channel beam 171 to slide plate 172 , thereby removing associated end support channels 150 and 152 as well as corner support post 158 from their upright edge-engagement with the associated panelized modules 104 by allowing the uprights to be pivoted down to rest on the ground. This release action frees up the panelized PV modules 104 and permits the panels to be removed more easily and safely from their position in the palletized stack-up.
[0067] Each of the pallet rear side support uprights and longitudinally opposite pallet end side support uprights, or jig posts, 150 , 152 , 158 , 155 , 156 , 158 b , 154 and 159 , is mounted in a selected position with respect to its associated horizontal support beam member of pallet jig 100 by an associated mounting gusset 260 as seen in FIG. 2 , only one of which will be described in detail. Gusset 260 comprises a U-shaped plate member having upright flanges 264 and 268 flanking its center web 265 . Gusset center web 265 is seated flat and bolted to an associated horizontal pallet frame member, which in this case is C-channel beam 171 of pivoting hinge beam 170 . Jig post 150 is selectively adjustably located longitudinally of pivoting hinge beam 170 by selecting the appropriate mounting bolt hole registry for a mounting bolt 262 having its head seated on the gusset center web 265 and its threaded shank extending through the selected bolt hole in the row of holes on C-channel beam 170 . The triangularly-shaped upright attachment flanges 264 and 266 of gusset 260 flank the opposite sides of the associated channel flanges of its associated upright jig post 150 and are welded thereto.
[0068] The two rear upright support posts 155 and 156 are likewise mounted to the pallet by associated gussets of like construction to gusset 260 and are likewise bolted in longitudinally adjustable positions by associated mounting bolts that extend one through the center web of the associated gusset. The gusset of each rear support posts 155 and 156 is bolted to the selected bolt hole in a row of bolt holes provided in a mounting channel 157 ( FIG. 2 ) fixedly and non-pivotally carried by associated pallet frame members at the rear side of pallet jig 100 .
[0069] Preferably, the pair of pivotal end support upright posts 150 and 152 , and likewise the pair of pivotal end support upright posts 154 and 157 that are located at the respectively associated opposite longitudinal ends of pallet jig 100 are provided with a pair of associated horizontal spreader bars 151 and 153 ( FIGS. 1, 2 and 11 ). These spreader bars are in the form of C-channels wherein the center web, at opposite longitudinal ends of each spreader bar, are folded in and welded to the associated mutually facing sides of end support upright posts 150 and 152 , and likewise as to a pair of spreader bars 151 ′ and 153 ′ welded to end support upright posts 154 and 157 at the opposite longitudinal ends of pallet jig 100 .
[0070] Referring again to FIGS. 1 and 2 , and in more detail to FIGS. 6 and 7 , each of the upright posts 150 , 152 , 154 , 155 , 156 , 158 a , and 158 b is provided with an associated jig strip (best seen in FIGS. 2 and 11 and fragmentarily in FIGS. 6 and 7 ). Each of these jig strips is identified by the reference numeral of the associated upright support post as raised by a prime suffix, in FIGS. 1, 2, 6, and 7 . Preferably, jig strips 150 ′ through 158 b ′ are machined to provide a one-piece finished part that is adhesively, or otherwise, securely affixed with its smooth backside against the inwardly facing surface of its respectively associated upright support post . As seen by way of example in FIGS. 6 and 7 , the surface of the base of jig strip 150 ′ that faces inwardly toward the panelization zone of pallet jig 100 is provided with protruding support and positioning projections, or lugs, 302 a and 302 b , arranged in a spaced apart vertical row and designed to position and support an associated PV panel rail in its proper position for the palletization process. Another vertical row of spaced apart lugs 300 a , 300 b , etc. are each positioned and designed to edge-support an associated PV panel during the panelization process, as described hereinafter, and with the panel edge supported at the desired height to insure uniform adhesive bead thickness.
[0071] The panelization process of the invention is best understood by viewing the assembly sequence shown in FIGS. 11 a , 11 b , and 11 c , in conjunction with the panelization work center material flow diagram of FIG. 12 , all to be read further in conjunction with the details in FIGS. 5-10 .
[0072] It should be understood that each PV solar panel module build-up starts with constructing a PV solar panel module, such as that shown in FIG. 13 , while its components are being sequentially supported on pallet jig 100 in an inverted, or upside down, relationship relative to their final operational orientation when later field-mounted on a rack of a solar panel array, illustratively of the type disclosed in co-pending U.S. Ser. No. 13/553,795, published on Jan. 24, 2013 as US-2013-0019925-A1.
[0073] Referring first to FIG. 13 , each panelized PV solar panel module includes, when completed, two parallel support rails 310 and 312 of identical construction that are adhesively affixed to, and transversely span, the downwardly facing bottom surfaces of two or more panels comprising a panel module. In this specific embodiment, three closely laterally-spaced coplanar PV panels 314 , 316 , and 318 are employed. PV solar panel module 103 is assembled in inverted condition (bottom-side-up) to form a jig-positioned, stack-up of such panels in forklift compatible pallet jig 100 .
[0074] Referring now to FIG. 5 , rails 310 and 312 are each preferably a thin gauge steel rail. Although it is to be understood that each rail 310 and 312 can be provided as a single flange or an I-beam section style, the hat section, double brim style channel configuration shown in Fig. 5 is presently preferred inasmuch as it provides better stability and section strength. Each rail 310 and 312 is adhesively affixed to, and spans a laterally-orientated, coplanar array of PV panels 314 , 316 , and 318 ( FIG. 13 ). Referring to FIG. 5 , each of the integral rail brim flanges 312 a and 312 b carry on their panel-facing sides a single adhesive bead 320 a and 320 b , respectively. The adhesive beads 320 a and 320 b are preferably formed of commercially-available adhesives, such as Dow Corning PV-8303 with the bead size being determined pursuant to the manufacturer's recommendation, just prior to installation in pallet jig 100 .
[0075] Referring to FIGS. 11 a , 11 b , 11 c , and 12 , adhesive beads 320 a and 320 b are first applied to the associated rail flanges 312 a and 312 b by specifically designed machinery 520 operable in panelization work center 500 as seen in the material flow diagram of FIG. 12 . By way of example, each adhesive bead 320 a and 320 b is preferably 3 mm thick and 9 mm wide in its cross-sectional dimensions as applied by machinery 520 .
[0076] Referring back to FIGS. 6 and 7 , for example, it is to be understood that the vertical row of rail-support and positioning lugs 302 a , 302 b , etc. are designed to hold the associated rail 312 , with the applied adhesive beads, with an appropriate contact pressure for the adhesive beads against the jig-oriented, upwardly-facing operable under-surface of the associated PV glass panel. Likewise the vertical row of panel support and positioning lugs 300 a , 300 b , etc. are vertically spaced apart and oriented to support the associated PV glass panel, resting thereon, at the desired height to assure uniform adhesive bead thickness.
[0077] In the embodiment shown in FIG. 7 , the rail support and positioning lugs 302 a , 302 b , etc. are designed to hold the associated rail 312 and 312 a , the appropriate distance above the associated PV glass and are dimensioned to have a relatively small clearance against the associated rail 312 and 312 a to keep the rail from twisting when assembled thereon in the final jigged position. The distance between rail holding jig lugs 302 a , 302 b is just sufficient to allow the next rail to slide in with a slight twisting motion.
[0078] Referring to FIG. 9 , a single stacking block 400 a is shown installed on associated rail 312 . Each stacking block can be formed as a one-piece plastic block that is machined or precision injection molded to the configuration shown in FIGS. 9 and in cross section in FIG. 10 . All stacking blocks 400 , 400 a , 400 b , etc. in contact with a frameless PV glass panel, or module, are preferably made of plastic, illustratively urethane foam, or another relatively soft material, so as to minimize risk of damaging the PV glass of the module array.
[0079] FIG. 10 illustrates two identical stacking blocks, or spacers, 400 a and 400 b , in cross section, slidably received in vertical registry with one another on the hat section portions of associated rails 312 and 312 a . The stacking blocks are dimensioned so that the weight of the PV module stack-up 102 , as seen in FIG. 1 , is transmitted though the associated stacking blocks and rails so that no load support stress is placed on a PV glass layer in the panelization jig stack-up 102 . In addition, one or more spacers, suitably located between PV glass layers, may be required to maintain uniform thickness of the adhesive beads across the panel and to preserve the quality of the adhesive beads.
[0080] In FIG. 10 , two identical stacking blocks 400 a and 400 b are shown in assembled condition with associated rail 312 and 312 a , each block being shown in central half section. As shown in assembling step FIG. 11 c , four stacking blocks 400 a , etc. are c-rail installed at rail-block position numbered 406 , 408 , 410 and 412 per PV module, and as so installed, have a bottom tang portion 402 on their underside to ensure repeatable lateral spacing gaps between adjacent glass panels, such as panels 314 and 316 shown in FIG. 9 . Such spacing is particularly helpful in preventing damage to adjacent longitudinal solar panel edges as they flex and vibrate during truck lift transport described hereinafter. This is especially beneficial when dealing with “frameless” solar panel modules. each stacking block is provided with a notch 404 ( FIG. 9 ) to provide a gap between the stacking block and adjacent vertical side of the rail to thereby form a suitable passage way for accommodating the DC wiring loads installed in the stack-up assembly step of FIG. 11 a.
[0081] FIGS. 11 a , 11 b , and 11 c , diagrammatically and sequentially, illustrate the use of the PV assembly jig and forklift transport pallet 100 of the present invention to construct the stack-up 102 of inverted solar panels PV modules 104 as each is loaded upside-down (i.e., sunny-side-down) as shown in FIG. 1 . Preferably, the empty pallet jig 100 is provided as starting material for use in the panelization work center 500 shown diagrammatically in FIG. 12 . Preferably, work center 500 is established at a location spaced away from, but relatively close to, the site where the ground-supported array of solar panel racks is being constructed.
[0082] Panelization work center 500 is preferably a conventional, covered temporary construction-site-installed building (not shown) that provides relatively low cost protection against the weather, such as may be provided by a temporary quonset hut, or circus-tent type structure, so that the solar array construction equipment and materials can be securely, but temporarily stored therein, and solar panel construction labor can also be performed in the weather-protected environment so that such labor is eligible for the applicable factory labor rates which are significantly lower than the field labor rates of the relevant construction trades. Indoor construction conditions also reduce material damage and loss.
[0083] Referring further to diagrammatic FIGS. 11 a , 11 b , 11 c , in conjunction with FIG. 12 , note that, by way of example, panelization work station 500 is arranged with two parallel manual panelization assembly lines 510 and 512 mutually flanking a central rail prep line 516 . Rail prep line 516 preferably provides rail surface prep and adhesive bead application equipment to provide an indoor supply of rails with adhesive applied to the flanges, as described above, for manual installation in the flanking panelization assembly lines 510 and 512 .
[0084] Referring further to FIGS. 11 a , 11 b , and 11 c , in that sequence, FIG. 11 a shows the initial steps in constructing and pallet-assembling the bottommost solar panel module of a stack of such modules when forming the stack-up array 102 of inverted (i.e., sunny-side-down) modules seen in FIG. 1 .
[0085] In FIG. 11 a , three PV solar panels are shown installed side-by-side and so-oriented upside down and in a laterally-spaced array, ready for transport by fork lift truck, and removably supported in predetermined position by the associated solar panel support jig components of pallet jig 100 . More particularly, PV solar panel 314 , for example, is supported in horizontal orientation, bottom side up, on end support upright posts 150 and 152 by its panel edges resting on their associated jig lugs, such as lug 300 a , more clearly seen in FIG. 6 , which are provided on end support upright posts 150 and 152 . In this figure, pivoting end support upright posts 150 and 152 are shown locked to their vertical orientation by latches the associated pallet draw latch assemblies 190 and 192 . Likewise, the rear right-hand corner of panel 314 , as viewed in FIG. 11 a , is held horizontally-oriented while resting on its associated corner jig lug on upright corner support post 158 b.
[0086] The left-hand longitudinal edge of bottommost panel 314 rests on pallet frame channel sections 114 , 116 , and 118 ( FIG. 2 ) in lateral closely-spaced relation with the right hand longitudinal pallet edge of center panel 316 . Panel 316 in turn also rests on and is supported by pallet channels 114 , 116 , and 118 . The left-hand longitudinal edge of center panel 316 is closely spaced from the right-hand longitudinal edge of panel 318 , and those longitudinal edges are both supported on pallet channel 110 . The rear corner of panel 314 rests upon and is horizontally positioned by associated jig lug on upright corner support post 158 a.
[0087] The mutually-facing parallel longitudinal edges of panels 314 and 316 are closely spaced and held parallel to one another by their jig fixturing on pallet jig 100 . Likewise, the closely spaced mutually-facing parallel longitudinal edges of panels 316 and 318 rest on sectional pallet frame channel 110 . Panel 318 , at its rear left-hand corner, rests on on associated jig lugs on rear corner upright post 158 . The left-hand longitudinal edge of panel 318 rests on associated jig lugs on end support upright post 154 and 157 .
[0088] When PV solar panels 314 , 316 , and 318 are so-assembled and thereby releasably supported in a single layer so as to form the bottommost PV solar panel module 103 in stack-up array 102 ( FIG. 1 ), they are pallet jig oriented as PV module components located at predetermined x, y, and z, datum points, on and relevant to, associated support components of pallet 100 . Thus, the PV solar panel component of the bottommost layer of the pallet stack-up 102 ( FIGS. 1 and 2 ) is positioned at a predetermined x,y,z, location on pallet jig 100 , albeit in an upside down or inverted (sunny-side-down) condition relative to their final operational orientation (sunny-side-up) when finally operationally installed in a PV solar panel field array.
[0089] Referring again to FIG. 11 a , following manual installation of module support rails 310 and 312 , the next step in the assembly of pallet stack-up 102 is to install commercially-available panel DC wiring and wire management components, such as electrical components 502 a , 504 a , 506 a and 508 a , as partially shown in FIG. 8 . The majority of such DC wiring and wire management components are manually installed, with cable ties being used to manually dress the DC wiring, both intra-panel and inter-panel, to the underside surfaces of the three panel array 314 , 316 , and 31 . The manual labor installation work is greatly facilitated by the upwardly facing inverted orientation of the panels. However, the DC wiring must be restrained prior to the panel module being transported by the automated installation equipment as described hereinafter.
[0090] The next step in the construction of the solar panel module comprising PV panels 314 - 318 is shown in FIG. 11 b . Rails 310 and 312 are manually attached. Referring to FIG. 12 , adhesive beads 320 a and 320 b ( FIG. 5 ) are applied to the rails at the central adhesive dispensing station 520 in work center 500 . The panels are likewise oriented upside-down as manually assembled in their predetermined positions and orientation spanning panels 314 , 316 , and 318 , and with their associated adhesive beads 320 a and 320 b contacting the respectively upwardly facing bottom surfaces of inverted PV panels 314 , 316 , and 318 . Rails 310 and 312 are also inverted as installed and rest at their ends in the associated jig lugs as partially shown in FIGS. 6 and 7 .
[0091] Referring to FIG. 11 c , the next and last step in completing “in jig” the lowermost solar panel module assembly is to install the set of four removable stacking blocks 400 designated in FIG. 11 c as stacking blocks 406 , 408 , 410 , and 412 . Each of these blocks is identical to one another and to the installed stacking blocks 400 a and 400 b as shown in FIGS. 9 and 10 . Stacking blocks 406 and 410 are assembled on their respective rails 310 and 312 so that their bottom projections 402 a ( FIG. 9 ) fit in the gap between the mutually facing longitudinal edges of panels 316 and 318 . Likewise, stacking blocks 408 and 412 have their bottom projections 402 a disposed the gap between the mutually facing longitudinal edges of panels 314 and 316 . Stacking blocks 408 and 412 are removably seated on associated rails 310 and 312 such that their bottom protrusions 402 a likewise defines the gap between the longitudinally extending and mutually facing edges of panels 316 and 314 . The x, y, z datum in the dimensions of the stacking blocks are predetermined by the associated pallet jig and positioning lug orientations provided for the single bottom layer assembly of FIG. 11 c . The stacking blocks also provide a gap to control the vertical distance between the associated rails 310 and 312 and the back of the associated panel, i.e., the thickness of the adhesive beads 320 a and 320 b , as shown in FIG. 5 .
[0092] The solar module positioning and assembly steps described above in conjunction with FIGS. 11 a , 11 b , and 11 c , complete the bottommost layer of the PV module stack-up 102 of FIG. 1 . Note that the x,y,z datum points for this module assembly are predetermined relative to the features of the pallet jig 100 as described hereinabove in conjunction with FIGS. 1-10 . The sequential steps of the assembly cycle of FIGS. 11 a , 11 b , and 11 c are repeated with respect to constructing and assembling the next solar assembly module as superimposed sunny side down on top of the bottommost module 103 . These steps further include installing removable and reusable slip-fit stacking blocks 406 , 418 , 410 , and 412 , accurately positioned and located on their associated rails 310 , 312 , for serving their final operative use as damage prevention to the panel stack-up 102 during lift truck delivery to the field array of solar panels.
[0093] Referring specifically to panelization work center 500 shown diagrammatically in the flow diagram of FIG. 12 . Work center 500 is made large enough to prepare the completed PV assembly jig and forklift transport pallets, shown in FIG. 1 as pallet jig 110 , and by way of example, may comprise at least two assembly lines 510 and 512 Empty pallet jigs 100 and 100 ′ are returned from their field-emptying cycle and fed as recycling starting input to assembly lines 510 and 512 shown schematically in FIG. 12 .
[0094] Preferably work center 500 is constructed as a temporary warehouse or portable factory, to provide a weather-protected covered and firm surface work platform, such as a concrete floor pad represented diagrammatically as pad 514 in FIG. 12 . Hence, the manually-performed assembly steps in the construction of pallet jigged stack-ups 102 of inverted solar panel modules 104 is efficiently completed by manual labor and production equipment that are sheltered in panelization work center 500 . In FIG. 12 , a series of empty pallet jigs 100 are shown entering assembly line row 510 , and empty pallet jigs 110 ′ are shown entering the duplicate assembly line row 512 . The two assembly lines 510 and 512 are spaced apart to accommodate central processing line 516 for surface preparation and application of adhesive to support rails 310 and 312 for sequential assembly as described herein to each layer of PV modules 104 in the jig pallets 100 , 100 ′, and so on, as provided to assembly lines 510 and 512 .
[0095] The central rail supply line 516 of workstation 500 includes a rail surface preparatory station 518 and a centrally located adhesive dispensing station 520 that receives the output of panel rails upstream from surface prep station 518 and applies the adhesive beads 320 a and 320 b to the rail hat brim flanges 312 a , and 312 b , described in conjunction with FIG. 5 . In the embodiment shown, central adhesive dispensing station 520 has two sets 520 a and 520 b of three duplicate output stages arrayed one set on each of the longitudinal sides of dispensing station 520 to thereby provide the appropriate output of rails from the central station 520 with adhesive beads applied to the rail hat flanges. The rails are manually retrieved from central station output and assembled with and affixedly applied to the upwardly facing bottom surface of inverted PV panels in the manner described in conjunction with FIG. 11 b .
[0096] The pallet-jig PV panel assembly stations 520 , 522 , 524 and 526 , 528 , 530 provided respectively in each of the panelization assembly lines 510 and 512 complete a palletized and jig-oriented respective stack-up 102 ( FIG. 1 ) for fork lift transport. The assembly steps of FIGS. 11 a , 11 b , and 11 c are repetitively performed on and in each of the pallet jigs 100 , as shown diagrammatically in FIG. 12 by the right-angle assembly arrows 519 , 522 , and 524 of assembly line 512 , and likewise diagrammatically shown by the right angle assembly arrows 526 , 528 , and 530 and assembly line 510 . These completely assembled PV module stack-ups 102 are then fork lift truck transported from the final stage of assembly lines 510 and 512 to an input queue at a covered adhesive curing station (not shown). Thus, the assemblies are protected from weather, and also if needed, simultaneously heated to assist curing of the adhesive beads and consequent adhesion of the rails to the associated PV module panels.
[0097] Referring to FIG. 15 , using a system such as that disclosed in co-pending U.S. Ser. No. 13/553,795, entire PV solar panel rail rack arrays 602 and 603 can be populated from a central logistics area. Typically, this area will be a permanent service or fire access road 600 as seen in FIG. 15 and which is already included in the site plan as shown diagrammatically in the solar panel rail rack arrays 602 and 603 . Aisle breaks 604 and 606 in the arrays 603 and 602 , respectively, can be bridged with temporary rails indicated schematically at 608 , thereby extending the solar panel field area that is reachable from a single logistics area for installation of the PV solar panels by automated drones 902 , as described and shown in the aforementioned co-pending patent application.
[0098] FIG. 14 illustrates a stack-up 610 of PV solar panel modules 611 oriented sunny-side-up and unrestrained while being delivered by fork lift truck 601 and manually off-loaded to provide a ground-supported stack 610 of panels 611 in accordance with the prior art. Also in accordance with the prior art, after having been delivered by a fork lift truck, the individual solar panels 611 are manually off-loaded from the ground-supported stack-up 610 and then individually carried manually, or by specially-equipped rough terrain trucks, between adjacent rack rows until reaching their final individual operational position on the support rack.
[0099] FIG. 14 also illustrates a stack-up 610 of solar panel PV modules oriented right-side up in stack 610 in accordance with the prior art, and to be manually lifted and placed one at a time by a two man installation team on drone-equipped support rails of a system constructed in accordance with the aforementioned co-pending application. This drone-equipped rack array system, in conjunction with the PV assembly jig and forklift transport pallet of the present invention, can save hundreds of hours of service time in constructing solar panel arrays, as well as the time and cost of staging modules around the array field, and the subsequent trash retrieval cost. By using the railed rack arrays and automated robotic drones to carrying and place PV solar panels on the racks to form the solar panel array, a small team of people can install a megawatt (MW) of solar panels per day, approximately 20 times faster than an equivalent number of laborers manually installing PV solar panel modules in accordance with the prior art. The system of the invention can thus eliminate 95% of the automated PV panel carrier labor costs of installing PV solar panels.
[0100] FIG. 16 is a perspective overhead view that shows, by way of two side-by-side parallel field delivery and assembly lines, sequential stages in automated unloading and inverting of upside-down solar panels to a sunny side up orientation from panelization stack assemblies at panel unloading and transfer stations, each feeding PV panels to a given entry location of an associated dual rail rack support made in accordance with the invention. A stack-up load 102 a of solar panel modules constructed and assembled on a pallet jig 100 a , in the manner described previously herein in conjunction with FIGS. 1-12 , is shown in FIG. 16 being carried on fork tines of a forklift truck 103 for deposit of the pallet-jigged load stack-up 102 a onto the channel-type ground-mounted stationary load-receiving platform 612 a . The accurate predetermined positioning of a pallet jig 100 a on receiving platform 612 a is designed to stationarily position stack-up 102 a at fixed and predetermined x, y, z geographic datum points relative to operational engagement, transfer and release datum points of an associated robotic transfer station mechanism 614 positioned between platform 612 a and the associated end-loading point of an associated rack rail installation 616 .
[0101] FIG. 16 illustrates a neighboring palletized jig stack-up 102 b , which is provided in a manner similar to stack-up 102 a . Stack-up 102 a is better seen in FIG. 17 after the same has been accurately deposited on, and supported by, an associated stationary support rack 612 b constructed and positioned in the manner of support station 612 a ( FIG. 16 ). The stack-up 102 b is also accurately positioned for cooperation with the associated robotic inverter/transfer station 618 a that in turn is operably positioned relative to the feed-in end of the associated rail rack 620 a and 620 b.
[0102] FIGS. 22, 23, and 24 , as well as the opposite side view in FIG. 17 , illustrate the structure and operation of the robotic solar panel load inverter/transfer mechanism of transfer station 618 and of the duplicate mechanism of neighboring transfer station 614 as seen in FIG. 16 . Transfer stations 618 and 614 each include an automated, hydraulically-actuated robotic carriage tower 622 shown stationarily mounted on channel framework platform 624 that in turn is secured at its entrance end to the associated ground supported loading platform 612 b . Transfer robot tower 622 supports a combined hydraulic and chain-drive, computer controlled drive carriage 626 that is raised and lowered on an interior track of tower 622 . Carriage 626 is located on the side of tower 622 facing oncoming PV solar panel load array stack-up 102 b . Carriage 626 also pivotally supports a transfer carriage pivot arm assembly 628 see, as pivoted almost upright in FIG. 22 .
[0103] Transfer carriage pivot arm 628 comprises a rectangular hollow beam box frame construction provided, as best shown in Figs. * and *, with two sets of hydraulically-actuated panel rail grippers 529 , located one pair each on the hollow longitudinally extending box frame carriage side member 630 and 632 that are in turn joined at their longitudinally opposite ends by carriage cross frame members 634 and 636 ( FIG. 22 ). A pair of laterally-spaced transfer carriage support arms 640 are affixed at their outer ends to the closet crossbar 636 of carriage arm 628 . Gripper support arms 640 straddle carriage 626 and, at their lower ends, are pivotally supported on carriage 626 . Gripper actuating hydraulic lines 641 are trained from carriage 626 via hollow arms 640 and into the hollow side arms 632 and 634 of gripper 629 .
[0104] Each of the solar panel transfer stations 614 and 618 also includes a tilttable platform station mechanism located between its associated robot transfer tower 622 and the loading/unloading ends of the associated dual rack rails of solar panel support racks. As best seen in FIGS. 22 and 23 , platform tilt mechanism 624 is made up of a laterally-spaced apart pair of parallel Z-section channel rail platform members 650 and 652 . Tilt platform rails 650 and 652 are carried on the upper ends of a rocker framework *** of generally U-shaped configuration. Rocker platform frame arms *** and *** ( FIGS. 22 and23 ) carry platform rail members 640 and 642 , normally horizontal, mounted to and spanning the upper ends of frame arms 656 and 658 .
[0105] The entire platform framework 650 is rockingly supported by a pair of upright U-shaped stanchion-rocker arm assemblies, located at and supported midpoints of stationary rocker platform 624 . Each stanchion assembly comprises a stationary arm fixed at its lower section frame 624 and rotatably carrying, at its upper end, one end of a pivot rod 662 journalled therethrough. A companion rocker support gusset member 664 is rockingly carried supported faced inwardly of fixed gusset support member 660 . Pivot rod 662 , passes through support member 664 , but is non-rotatively affixed to its upper end. The lower end of the stationary support arm 664 is fixed to the center of the associated rocker U-frame member 652 so as to rockingly carry the same on, and in response to, rotation of pivot rod 662 for rocking travel, through a travel arc angle sufficient to orient the solar panel receiving plane mutually defined by platform rails 650 , 652 , i.e., tilt platform rails from a horizontal solar panel receiving attitude (shown in FIGS. 22 and 23 ) to a tilted panel transfer attitude wherein platform rails 650 and 652 are respectively lined up in registry with associated station rack rails 620 a and 620 b.
[0106] The pivot rocking actuation of rocking carriage 650 is obtained by computer-controlled operation of a hydraulic ram 670 ( FIG. 23 ) pivotally mounted at its lower cylinder end, and thereby affixed, to stationary frame 624 . The piston rod 671 of ram 670 is pivotally connected at its upper end to the swingable crank arm 672 . In turn, crank arm 672 is connected at its upper end to the protruding other end of pivot rod 662 and non-rotatively coupled thereto for actuating pivot rod 662 , and thus swinging support arm 664 through the aforementioned working range of rocker support frame 650 in response to automated hydraulic control.
[0107] In the operation of the respective transfer stations 614 and 618 , the respectively associated transfer carriage receiving platform rails 640 and 642 are automatically controlled and hydraulically actuated to pivot through a working arc starting from a horizontal solar panel pick-up attitude, wherein transfer carriage arm 628 has been lowered to lay flat on the exposed panel rails 310 and 312 affixed to whatever inverted solar panel module is oriented upside down and exposed as the uppermost inverted solar panel such as solar panel module 104 as shown in FIG. 23 .
[0108] When transfer gripper arm mechanism 628 is so-oriented, the grippers carried by its transport arms 630 and 632 are actuated to cause the grippers to firmly engage the exposed panel rails 310 and 312 . The transfer robot 618 is then actuated, by its computer control system, to first carry the uppermost inverted panel assembly module vertically upwardly as carriage 626 is elevated along tower 622 . The robot 618 thus initially carries the gripped module with a generally horizontal attitude until robot carriage 626 is approaching the upper limit of its vertical travel on tower 622 . The robot then causes carriage 626 to be pivoted upwardly to thereby swing the supported panel 90 to clear over the top of tower 622 while thereby also inverting the panel from its inverted horizontal stack orientation bottom face up to pivoting the panel to fully upright vertical orientation, and thus, completing the first 90° of the load pivoting motion as the carriage 618 travels upright over the upper end of tower 622 . The fully upright vertical orientation of carriage 626 can be seen in FIG. 22 while traveling empty over tower 622 on its return travel path and where it will complete the second 90° pivoting motion to load-pickup horizontal orientation, as seen in FIG. 1 , and is then fully inverted to bring the PV module assembly with the glass panels facing upright, as shown in FIGS. 16 and 17 , as support carriage 628 is traveling down tower 622 with rails of the solar panel load firmly engaged by the grippers of carriage 628 , and having been pivoted to a horizontal attitude as shown in FIG. 24 .
[0109] In the rail racks panel loading phase of operation of the hydraulically-actuated robot tower 622 , the robot drives carriage arm assembly 628 downwardly to an off-load carriage position where panel rails 310 and 312 extend across and rest upon the uppermost flanges of transfer Z-section channels 640 and 642 of tilt mechanism 618 . Solar panel assembly 104 is oriented horizontally and extends over the ends of transfer channels 640 and 642 , closest to, rails 620 a and 620 b that in turn are disposed in an angled plane closely spaced to the ends of rack rails 620 a and 620 b , as shown In FIGS. 22 and 23 . As the carriage arm assembly 628 travels through the space between tilt platform rails 640 and 642 of the tilting carriage when disposed in a horizontal plane. The solar panel assembly module rails 130 and 132 engage and rest upon the horizontal flanges of tilt support rails 640 and 642 . The carriage arm assembly 628 then continues its downward travel so as to be clear of tilt platform support channels 650 and 652 until the carriage reaches its lowermost stop position where the carriage components are disposed within the confines of the pivoting frame 650 in non-interfering relation therewith.
[0110] The pivotal panel support mechanism of tilt frame 650 is then actuated to cause the solar panel to bodily pivot about the axis of pivot rod 652 so as to bring the solar panel into the tilted attitude matching the tilt of rack rails 620 a and 620 b relative to each other and with the mutually inwardly facing flanges 644 and 646 tilt-aligned with the inwardly extending flanges of rack rails 620 a and 620 b . This enables the remote-controlled drone 902 with its super-posed panel rail gripping mechanism 910 to be lowered into its lowermost position on the drone, and then the drone 902 to be actuated to travel with its opposite side wheels running on associated flanges 644 and 646 of transfer rails 640 and 642 so that the rails of drone lift mechanism 910 touch the panel assembly module rails 310 and 312 resting on the upper flanges of platform channels 640 and 642 . The lift mechanism of drone 902 is then actuated to elevate and engage the panel assembly module rails 310 and 312 and elevate them upwardly off of transfer platform rails 640 and 642 and carry the tilted panel supported on carriage 910 of drone 902 with the solar panel tilted to match the tilted orientation of the rack rails 620 a and 620 b to match their tilt angle for drone-supported travel on the rails to bring the solar panel being carried on the drone 902 in tilted orientation and spaced above the rails 620 a and 620 b until the drone-supported solar panel reaches its installation location on the dual rail support rack shown as installed and ground-mounted in FIG. 20 , as described in the aforementioned co-pending patent application.
[0111] Drone monitoring station 700 , shown in FIG. 19 , is constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site.“Once operation is initiated, both the autoloader and the drones worked autonomously.
[0112] Referring in more detail to FIGS. 25-47 , and supplementing the photographic views of the structure of operable embodiments of various structural features shown in FIGS. 13, 14, 16, 18, 19, 21-24 , a successful working embodiments of the system, method, and apparatus of the present invention.
[0113] Referring first to construction and use of the space blocks shown in FIGS. 25-37 , in conjunction with the perspective drawing views provided in FIG. 5 through 10 and FIG. 11 c , assembly and use of the spacer blocks are shown in FIGS. 9, 10, and 27 . Referring to FIGS. 25 and 26 , spacer block 400 is preferably accurately machined, die-cast, or injection-molded, such that its longitudinal bottom projection 402 a enters into the gap formed between the mating, or opposed longitudinal edges, of an associated pair of solar panels as shown in FIG. 9 . This helps the accurate positioning of solar panel rails relative to the associated solar panels, and also helps to protect the longitudinal side edges of an adjacent pair of solar panels.
[0114] Spacer blocks 400 have a transverse U-shaped channel of constant cross-sectional configuration extending all the way through and open at the ends of the spacer block. These channels are defined by accurately spaced apart, and parallel, side surfaces 405 and 406 , that are designed to have a close slip fit as the space block is aligned with an associated rail end and slidably pushed down to seated position with the crown and adjacent parallel sides of the rail fitting nicely within groove 403 .
[0115] The slip fit installation and removal characteristic of the spacer blocks relative to the associated solar panel rails helps maintain the rail assembly accurately in the panel jig 100 but does hinder the separation of the spacer blocks from their associated panel rails when the panel is being inverted and installed on the associated field support rack.
[0116] Spacer block 400 , as well as the remaining variations thereof in FIGS. 28-35 , have basically been described previously in connection with FIG. 11 c .
[0117] Referring to the structure, function, and operation, of the “flipper” station for transferring solar panels one at a time from the platform loading station to the rails of the field rack solar panel array, is best seen in FIGS. 40-47 , and will be described hereinafter with respect to these figures.
[0118] Referring first to the assembly view of FIG. 40 , the load-receiving platform 612 a , as seen ground-mounted, at the front end of station 618 . The base of robot tower 622 is mounted on a channel framework attached to the rear of platform 612 a . The carriage 626 has upright channel member 700 of channel configuration carrying on each side a pair of vertically-spaced rollers removably supporting the carriage on the cooperative frame walls of tower 622 . A vertically-extending ram has the lower end of its cylinder fixed to the base of the tower and the upper end of its pistons carrying a sprocket on which a carriage-elevating chain is trained with one run extending stationarily down to a fixed point at the base of the train as seen in FIG. 41 , and the other trained around a sprocket at the upper end of the carriage as seen in FIG. 43 .
[0119] As seen in FIG. 44 , the gripper arm pivoting motion is provided by a chain 720 looped over two sprockets 722 and 722 ′ (only one sprocket being shown in the figure), each fixed to a shaft 724 and 724 ′ extending through a pair of bearings 722 and 726 . The inner ends of lift-arm carriage are non-rotatively affixed to the rotary shaft 724 . The chain loop 720 is fixedly coupled to the upper end of the piston of ram 726 that is used to produce the pivoting motion of the grip arm assembly. The ram 726 , through chain 720 , causes the pivot rod 724 to rotate, and thereby causing the pivoting motion of the gripper arms while the same travel up and down with the carriage, the vertical motion being produced by vertical travel of the carriage. Thus, the compound motion of the pivot arms, namely the vertical motion of the carriage carrying the pivot arms bodily up and down. The carriage arms can be independently pivoted by the pivot shaft whose pivoting rotary drive is carried with the carriage as it is being moved vertically by the ram.
[0120] It is also to be noted that the rigging arrangement for the vertical actuation of the carriage is rigged to produce a 2:1 distance.
[0121] The solar panel stack unloading work, wherein each solar panel module is lifted off its uppermost position on the multiple panel stack-up on the pallet jig at the input station to the inverter station is shown in the discussion of FIGS. 16, 22, 23, 24, 44, and 45 . The tilt station mechanism is best seen in the perspective assembly view of FIG. 26 , taken in conjunction with the exploded perspective view of FIG. 47 . This is supplemental to the previous discussion of the tilting and transferring PV panel station comparable for individually-loading drone-mounting solar panels one-at-a-time onto the rail racks described previously.
[0122] From the foregoing description in conjunction with the appended drawings, as well as the description, drawings, and claims of co-pending patent application U.S. Ser. No. 13/553,795 and underlying provisional application U.S. Ser. No. 61/804,620 filed on Mar. 22, 2013, incorporated herein by reference, it will be understood that the system, apparatus, and method of PV power plant construction provides improved results, benefits, and advantages over the prior art apparatus and systems for installing and equipping PV power plant construction. By automating the requisite processes of assembling, transporting and positioning the thousands of PV panels required for large-scale projects, the system of the invention enables megawatt-per-day panel installation rates with just a small construction crew. Moreover, this automation is achieved with no additional installation materials.
[0123] Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope or departing from the spirit of the claimed invention. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof. Moreover, the technical effects and technical problems in the specification are exemplary and are not limiting. The embodiments described in the specification may have other technical effects and can solve other technical problems.
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A combined PV panel assembly jig and forklift transport pallet is used to assemble PV panels for transport to a field array from a protected manufacturing environment. The panels are assembled to have adhesively applied rails for transport by a robotic drone on a ground-support rack and are pre-wired. The PV panel assembly jig holds, protects, and aligns the PV panels in an upside down position, opposite to their operational position, for ease of wiring in order to decrease the manual labor required in the field. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.
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PRIORITY
Priority is hereby claimed to provisional application Ser. No. 60/208,405, filed May 31, 2000, the entire content of which is incorporated herein.
FIELD OF THE INVENTION
The invention is directed to assays for determining the presence, activity, or both, of kinases and phosphatases. The preferred method is an assay for lipid kinases, phospholipid kinases, and phospholipid phosphatases.
DESCRIPTION OF THE RELATED ART
The importance of phospholipids in general, and phosphoinositides in particular, in the regulation of cellular processes such as cell proliferation, apoptosis, and secretory functions has been recognized for a number of years. While the importance of these compounds is manifest, there is much that remains unknown about how these important cell-signaling compounds are regulated.
Phosphoinositides have the general formula shown in 1:
where each R is an unsubstituted or substituted alkyl, alkenyl, alkylcarbonyl, or alkenylcarbonyl group and R 2 , R 3 , R 4 , R 5 and R 6 are hydrogen atoms and their locations on the inositol moiety. These hydrogen atoms can be replaced by phosphate groups singly or in various combinations. The general structure 1 shall be referred to herein as a phosphoinositide, or simply a “PI.” Where relevant, the presence and position of phosphate groups on the inositol moiety will be designated by a number designation followed by the letter “P.” So, for example, a PI with a phosphate in the R 3 position (i.e., phosphatidylinositol-3-phosphate) will be designated “PI3P,” phosphatidylinositol-4-phosphate will be designated “PI4P,” etc. For multiply phosphorylated PI's, numbers separated by a comma will be used to designate the positions of the phosphate groups. For example, “PI3,4P 2 ” designates a PI which is phosphorylated at the R 3 and R 4 positions of the inositol moiety as shown in 1. Phosphorylated PI's in general are referred to as “PIP's”
Because PI's are thought to be central to signal transduction and membrane trafficking in all eukaryotes (Rao et al. (1998) Cell 94:829), an understanding of the enzymes that regulate PI's, PIP's, and their metabolites would be extremely helpful. The present invention, an assay to determine the presence and/or activity of lipid kinases, phospholipid kinases, and phosphatases can be used to elucidate further the biological role of PI's.
Any number of assays for measuring enzyme activity are known in the prior art. In particular, Huang et al., U.S. Pat. No. 5,869,275, issued Feb. 9, 1999, describes an affinity ultrafiltration-based assay for measuring protein transferase activity. In this approach, labeled and unlabeled substrate having a binding site (the binding site either being created by action of the enzyme being assayed or which exists as an integral part of the substrate, such as an antigenic determinant) are incubated with the enzyme to form labeled product and unlabeled product. The reaction mixture is then contacted with a soluble macroligand capable of forming a specific complex with the product. Of critical importance is that the size of the macroligand-product complex must be significantly larger than the size of any contaminants or reactants found in the reaction mixture
The macroligand-product complex is then separated from reactants via ultrafiltration. The critical consideration here is that the nominal molecular weight limit of the ultrafiltration membrane must be larger than any potential contaminants in the reaction mixture, as well as larger than any unreacted, labeled substrate, yet smaller than the size of the macroligand-product complex. In this fashion, reactants and contaminants pass through the membrane, while the much larger macroligand-product complex is retained by the membrane. Examination of the ultrafiltration retentate for the presence of labeled product provides an indication of the extent of the reaction.
Mallia, U.S. Pat. No. 5,527,688, issued Jun. 19, 1996, describes assays for protein kinases in which a binding membrane is suspended within a reaction vessel, thereby dividing the vessel into two compartments. By adhering products to the suspended membrane, washing can be accomplished centrifugally by placing the wash solution in the upper chamber and centrifuging, thereby forcing the wash solution through the membrane.
SUMMARY OF THE INVENTION
The invention is an assay and a corresponding kit for determining the presence and activity of kinases and phosphatases, and, more specifically, lipid and phospholipid kinases and phosphatases. The preferred embodiment of the invention is an assay capable of measuring the presence and/or activity of any kinase or phosphatase which adds or removes a phosphate group from a lipid or phospholipid substrate.
In particular, a first embodiment of the invention is directed to a method for assaying the presence, the activity, or both the presence and the activity, of an enzyme falling within the enzyme classifications EC 2.7.1, EC 3.1.3, and EC 3.1.4. The method comprises first reacting the enzyme with a corresponding substrate for a time sufficient to yield phosphorylated product when assaying a kinase or a dephosphorylated product when assaying a phosphatase. The reaction, of course, is run under conditions which render the enzyme under investigation active, and thus the enzyme will catalyze either a phosphorylation (kinase) or a dephosphorylation (phosphatase) of the substrate.
The product formed by the enzymatic reaction is then contacted with a binding matrix. This results in product being bound or fixed to the matrix. With the product fixed on the matrix, the matrix can be mechanically separated from the reaction solution, thereby providing an easy means to separate the products of the enzymatic reaction from unreacted reactant, enzyme, and other non-product ingredients of the reaction solution.
The matrix is then analyzed for the presence of, the amount of, or both the presence and the amount of, the product fixed to the matrix. By determining the presence and/or amount of the product found on the matrix, the presence, the activity, or both the presence and activity of the enzyme that gave rise to the products can be determined.
A second embodiment of the invention is directed to a method as substantially described above, with the addition that the substrate includes a binding moiety. When the substrate is converted into product (by the action of the enzyme), the product also contains the binding moiety.
The product is then contacted with a binding matrix that specifically binds for the binding moiety. This results in product being specifically fixed to the matrix (via the interaction of the binding moiety and the binding matrix. The preferred binding moiety is biotin and the preferred binding matrix is avidin or streptavidin immobilized on an inert support. The matrix is then analyzed as in the first embodiment.
In the second embodiment of the invention, the approach used to modify the lipid or phospholipid enzyme substrate is to include a binding moiety. In this embodiment, the binding moiety (and the binding moiety alone) will bind specifically to a support designed for that purpose. In this fashion, products bearing the binding moiety can be separated easily from products which do not bear the binding moiety by simply passing the reaction mixture over the support. It is much preferred that the binding moiety be biotin. The support would then comprise any suitable substrate (beads, filter paper, etc.) having avidin or streptavidin immobilized thereto.
In a third embodiment of the invention, a support is not required. In this approach, the assay is conducted entirely in the liquid phase. Using a biotin binding moiety as an example, the avidin or streptavidin would be added to the reaction and the biotin-avidin complexes which form could be separated by any known means (electrophoresis, chromatography, centrifugation, etc.).
In short, the assay of this embodiment functions to determine the presence and activity of lipid and phospholipid kinases as follows: A lipid or phospholipid substrate for the enzyme to be assayed is first modified to include a binding moiety. As noted above, the binding moiety is preferably biotin, although an antibody or antigen can also be used as the binding moiety. Regardless of the choice of binding moiety, it is important that the binding moiety be attached to the substrate in such a fashion that its presence does not interfere with the enzyme's ability to phosphorylate or dephosphorylate the substrate. In most instances, this requires that the binding moiety be added to the end of one of the fatty acyl moieties of the substrate because recognition is dictated largely by the nature of the headgroup.
To assay for lipid and/or phospholipid kinases, the modified substrate is exposed, in the presence of γ- 32 P ATP, to a solution thought to contain the kinase of interest and allowed to incubate for a sufficient amount of time and under appropriate conditions such that the kinase, if present and active, can phosphorylate the modified substrate with a 32 P-labeled phosphate group. The reaction mixture is then contacted with a capture membrane or matrix, that is, a support bearing a moiety which will capture specifically the modified substrates; in the case of biotin, this would be avidin or streptavidin linked to a support. If binding moiety is an antigen, the capture membrane would include immobilized antibodies specific for the antigen, etc.
When the modified substrates are captured to a solid support, free 32 P ATP, reactants, contaminants, etc., are gently washed from the support and the bound radiolabeled material is measured for radioactivity using a scintillation counter, a “PhosphoImager” device, or by autoradiography.
Where phosphatases are to be assayed, the assay protocol is the same as noted above, with the exception that the substrate is modified to include γ- 32 P phosphate groups. In addition, an unlabeled substrate can be used and the released phosphate determined with a colorimetric method or a fluorescent method. (For example, Molecular Probes, Eugene, Oreg., sells a method for fluorescent detection of a released phosphate.) The action of the phosphatase enzyme under analysis will then remove a portion of those groups. In this approach, the reduced activity found on the matrix as compared to the starting labeled substrates is a direct measure of the activity of the phosphatase, or, in the case of non-radiolabeled phosphate, the amount of released phosphate is used as a measure of phosphatase activity.
The invention also comprises a corresponding kit that contains all of the necessary reagents to carry out the assay one or more times. The kit generally comprises: an amount of reaction buffer disposed in a first container; an amount of substrate for an enzyme classified within an enzyme classification selected from the group consisting of EC 2.7.1, EC 3.1.3, and EC 3.1.4, the substrate disposed in a second container; an amount of purified enzyme classified within an enzyme classification selected from the group consisting of EC 2.7.1, EC 3.1.3, and EC 3.1.4, the enzyme disposed in a third container (or the enzyme can be supplied by the user); an amount of binding matrix; and instructions for use of the kit.
A distinct and primary advantage of the assay is that is allows investigators to assay the activity of any number or type of lipid or phospholipid kinases or phosphatases quickly and conveniently.
Another primary advantage of the assay is that it is sufficiently sensitive to assay lipid and phospholipid kinases and phosphatases directly from tissue and cell extracts. Due to the high affinity of the lipid and phospholipid products to the matrix, extraneous free γ 32 P-ATP can be removed by washing and the amount of product formed can be determined without need for lipid extraction. This is a distinct improvement over conventional HPLC and TLC assays, which require lipid extraction. Eliminating lipid extraction, which is costly and time-consuming, makes the subject assay very attractive to investigators in this field.
Another advantage is that the assay is scalable to accommodate high throughput formats. The assay is highly amenable to automation.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Flow chart. Parallel flow charts comparing prior art methods to a preferred method according to the present invention.
FIG. 2 A: Comparison of PIK activity measurements: present invention vs. conventional phospholipid extraction procedure. Assays were performed using partially-purified PI-3K (500 ng/ml) for 40 minutes or purified PI4P-5K (250 ng/ml) for 20 minutes. For PI-3K activity measurements, PI4,5P 2 (10 μg)+PS (20 μg) was used as reaction substrate. The PI4P-5K reaction was carried out using PI4P (10 μg) as reaction substrate. Samples were processed using the conventional phospholipid extraction procedure illustrate in FIG. 1 (black bars) or according to the present invention (white bars).
FIG. 2 B: Comparison of PT-K activity measurements: present invention vs. standard phospholipid extraction procedure. Assays were done using immuno-precipitated PI-3K from liver tissue (500 μg) for 60 min. All the reactions were carried out at room temperature using PIP 2 (10 μg)+PS (20 μg) (lanes 3 and 4) or PI (50 μg) (lanes 1 and 2) as reaction substrates. Samples were processed using the conventional phospholipid extraction procedure illustrated in FIG. 1 (lanes 2 and 4) or according to the present invention (lanes 1 and 3).
FIG. 3 : Detection of PI-3K activity associated with activated receptor. 3T3NIH cells (5×10 7 cells) were treated without (lane 1) or with (lane 2) PDGF (50 ng/ml for 5 min at 37° C.) and PI-3K was co-immunoprecipitated using anti-phosphotyrosine specific antibodies. The PI-3K reactions were run for 60 min using PIP 2 (10 μg)+PS (20 μg) as substrates.
FIGS. 4 A and 4 B: Dependence of PI-K activity on the amount of lipid substrate loaded on the membrane. FIG. 4 A: PI-3K activity was measured using PI-3K from Alexis Biochemical (San Diego, Calif.) (12.5 μg/ml) for 60 min at room temperature. FIG. 4 B: PI-5K activity was measured using purified PI-5K (125 ng/ml) for 60 min at room temperature. In addition to lipid substrates, all samples contained 10 μg of PS loaded on the membrane.
FIGS. 5A, 5 B, 5 C, and 5 D: Linear detection of PIP-5K activity using the present invention. Assays were performed using the inventive method described herein, utilizing 3 μl of a lipid mixture containing 1 μg of PI4P and 10 μg of PS in chloroform/methanol 2:1 spotted onto a pre-numbered membrane square. FIGS. 5 A and 5 B: PI-5K activity was measured at different time points using 4 ng of purified protein. FIGS. 5 C and 5 D: PI-5K activity was measured for 10 min using different protein concentrations. The reaction products were analyzed by phosphorimaging (FIGS. 5A and 5C) or by scintillation counting (FIGS. 5 B and 5 D). Summary: Between 20 pmol to 1.2 nmol of formed product can be detected using the present invention.
FIGS. 6 A and 6 B: Linear detection of PI-3K activity using the present invention. Assays were performed using the inventive method described herein, utilizing 5 μl of PI (25 μg) in chloroform/methanol 2:1 spotted onto a well of a “SAM2” brand membrane 96-well plate. Assays were performed using decreasing amounts of partially-purified PI-3K: 1 ng, 2 ng, 4 ng, 8 ng, and 16 ng. Based on obtained scintillation counts, the specific activity has been calculated and shown in FIG. 6 A. The calculated initial reaction rate for different amounts of protein is shown in FIG. 6 B.
FIGS. 7A, 7 B, and 7 C: Reproducibility of the subject invention. Assays were performed using: (FIG. 7A) partially purified PI-3K (500 ng/ml) and PIP 2 (10 μg)+PS (20 μg) as lipid substrates for 40 minutes; (FIG. 7B) PI-5K (125 ng/ml) and PI4P (1 μg)+PS(10 μg) for 15 minutes; (FIG. 7C) PI-5K (125 ng/ml) and PI4P (1 μg) for 60 minutes. All assays were performed at room temperature using 1 μCi of 32 P-ATP. In FIG. 7C, the reactions were carried out on three different plates (samples 1-4; 5-8; 9-12, respectively). In each plate the reactions were done in triplicates at three different locations. Each point represents the average of three independent reactions. Lighter bars show the average of 9 points done on the same plate.
FIG. 8 : Inhibition of PI-3K activity. Reactions according to the present invention were performed using partially-purified PI-3K for different periods of time in the presence (triangles) or absence (diamonds) of the PI-3K inhibitor wortmannin (final concentration 100 nM).
FIG. 9 : Reaction specificity toward lipid substrates. Reactions according to the subject invention were performed with purified PI4P-5K (250 ng/ml) for 45 min at room temperature using 1 μg of different lipid substrates: PI3,4P (lane 1); PI3,5P 2 (lane 2) and PI4,5P 2 (lane 3). In addition to lipid substrates, all samples contained 10 μg of PS loaded on the membrane.
FIG. 10 : Comparison of reaction products: the present invention vs. the conventional phospholipid extraction procedure. Activities were assessed using 1 μg of PI4P+10 μg of PS as reaction substrates and purified PI-5K (2.5 ng) as the enzyme. The reaction was carried out for 10 minutes (lanes 1 and 2) and 0 minutes (lanes 3 and 4). The reaction was worked up using the conventional phospholipid extraction procedure as illustrated in FIG. 1 (lanes 2 and 4) or according to the subject invention (lanes 1 and 3). When the reaction was performed on membrane sheets, 40% of bound reaction products were re-extracted for TLC analysis.
FIG. 11 A: Comparison of PI4P-5 kinase activity using biotinylated and non-biotinylated short-chain lipids and non-biotinylated long-chain lipids. PI4P-5 kinase activity was measured using PI4P-C 6 -biotin (lane 1), PI4P-C 8 (lane 2) and PI4P-C 16 (lane 3) as reaction substrates. The reaction products were extracted and analyzed via TLC.
FIG. 11 B: Comparison of PI-3K activity using biotinylated short-chain lipids and non-biotinylated long-chain lipids. PI-3K activity was measured using PI-C 6 -biotin or PI-C, 16 as reaction substrates. The reaction products were bound to streptavidin-coated membranes. The membranes were washed to remove unreactive reactants and were analyzed directly (black bars) or were exposed to chloroform:methanol:water (10:10:3) treatment for lipid re-extraction (white bars).
DETAILED DESCRIPTION OF THE INVENTION
Abbreviations & Definitions:
The following abbreviations and definitions are expressly adopted herein. All terms not provided a definition are to be given their accepted definition in the art:
“Alkyl”=a straight, branched, or cyclic, fully-saturated hydrocarbon radical having the number of carbon atoms designated (i.e., C 1 -C 24 means one to 24 carbons); examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyclohexyl, (cyclohexyl)ethyl, cyclopropylmethyl, and the higher homologs and isomers thereof, for example, n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like; an alkyl group will typically contain from 1 to 24 carbon atoms, with those groups having eight or more carbon atoms being preferred in the present invention; a “lower alkyl” is an alkyl group having fewer than eight carbon atoms.
“Alkenyl”=an alkyl group having one or more double bonds or triple bonds; examples of unsaturated alkyl groups include vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and the higher homologs and isomers.
“Alkylcarbonyl”=a carbonyl-containing alkyl radical derived from the corresponding carboxylic acid, e.g. acyl radicals derived from lauric acid, myristic acid, palmitic acid, stearic acid, and the like; will typically contain from 2 to 24 carbon atoms.
“Alkenylcarbonyl”=a carbonyl-containing alkenyl radical derived from the corresponding carboxylic acid, e.g., acyl radicals derived oleic acid, linoleic acid, linolenic acid, eleostearic acid, arachidonic acid, and the like; will typically contain from 2 to 24 carbon atoms.
“Bn”=benzyl.
“BOM”=benzyloxymethyl.
“EDTA”=ethylenediaminetetraacetic acid
“HEPES”=N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid
“Lipid kinase/phospholipid kinase”=any enzyme falling within the classification EC 2.7.1.x, where “x” is a variable.
“PDGF”=platelet-derived growth factor.
“Phospholipid phosphatase”=any enzyme falling within the classification EC 3.1.3.x and 3.1.4.x, where “x” is a variable.
“PI”=phosphatidylinositol; an unphosphorylated phosphoinositide (i.e., a phosphoinositide lacking any phosphate groups on the inositol moiety).
“PIK”=generally, phosphoinositide kinase; PI-3-kinase, PI-3K, is the illustrative enzyme.
“PIP”=a phosphorylated phosphoinositide (i.e., a PI having one or more phosphate groups present on the inositol moiety); phosphatidylinositol phosphate.
“PI x, x′, x″ . . . Pn”=a nomenclature shorthand to designated PIPs, wherein “PI” designates a phosphoinosidite, “x, x′, x″ . . . ” are numerical variables designating the position of phosphate groups on the inositol moiety, “P” designates that the inositol moiety is phosphorylated, and “n” designating the number of phosphate groups present on the inositol moiety.
“PMB”=p-methoxybenzyl.
“PS”=phosphatidylserine.
“Substituted”=a radical including one or more substituents, such as lower alkyl, aryl, acyl, halogen, hydroxy, amino, alkoxy, alkylamino, acylamino, thioamido, acyloxy, aryloxy, aryloxyalkyl, mercapto, thia, aza, oxo, both saturated and unsaturated cyclic hydrocarbons, heterocycles and the like; the substituents may be attached to any carbon of the base moiety.
“Substrate” or “corresponding substrate”=a substrate that can be phosphorylated or dephosphorylated by the enzyme being assayed.
“Solid support”=a material that is substantially insoluble in a selected solvent system, or which can be readily separated (e.g., by precipitation) from a selected solvent system in which it is soluble. Solid supports useful in practicing the present invention can include groups that are activated or capable of activation to allow selected species to be bound to the solid support. A solid support can also be a substrate, for example, a chip, wafer, or well.
“TLC”=thin-layer chromatography.
Modifying Substrates to Contain a Binding Moiety:
Substrates for lipid or phospholipid kinases and phosphatases can be obtained commercially from numerous suppliers.
For example, PI's such as D-myo-phosphatidylinositol, D-myo-phosphatidylinositol 3-phosphate, D-myo-phosphatidylinositol 4-phosphate, D-myo-phosphatidylinositol 5-phosphate, D-myo-phosphatidylinositol 3,4-bisphosphate, D-myo-phosphatidylinositol 3,5-bisphosphate, D-myo-phosphatidylinositol 4,5-bisphosphate, D-myo-phosphatidylinositol 3,4,5-trisphosphate, and derivatives thereof, PIK antibodies, and biotin-tagged PI's are available commercially from Echelon Research Laboratories Inc., Salt Lake City, Utah; and Upstate Biotechnology, Lake Placid, N.Y.). The PI's noted above, as well as a host of others, derivatives, and antibodies thereto are also available commercially from A.G. Scientific, Inc., San Diego, Calif.
PI's can also be synthesized using conventional routes from naturally-occurring chiral precursors. For example, inositol head groups can be derived from methyl α-D-glucopyranoside via a Ferrier rearrangement and the diacylglyceryl moieties can be prepared from (+)-isopropylideneglycerol.
The most preferred binding moiety to be affixed to the substate (when such a binding moiety is employed) is a biotin moiety. This is due to biotin's relatively small size, relative ease of chemical manipulation, and its very robust, high-level, and specific binding to avidin and streptavidin.
Biotin can be affixed to an acyl chain of the diacylglycerol portion of a substrate PI via a coupling reaction wherein the biotin is linked via an amide bond to the PI. Note that when affixed to the acyl chain, the biotin does not interfere with recognition of the modified substrate at both the inositol headgroup and the glycerol backbone proximal to the headgroup. This discovery, that a substrate PI can be modified by the addition of a binding moiety such as biotin without interfering with a lipid/phospholipid kinase's or phosphatase's ability to recognize and bind to the substrate, is novel. In short, no prior art known to the inventors describes or suggests that such a modification can be made.
The preferred reaction to affix biotin (or any other binding moiety having an available reactive group) to a PI is analogous to that described in Chen et al. (1996), 61 J. Org. Chem 6305-6312, incorporated herein by reference. See also G. D. Prestwich (1996), 29 Acc. Chem. Res. 503-513, also incorporated herein by reference.
Briefly, lipid-modified analogs of PI's can be formed by inserting an aminoalkanoyl group at the sn-1 position of the PI. This group then allows for the addition of a binding moiety, preferably biotin, to the end of the acyl chain.
The synthesis, shown in Reaction Scheme 1, follows a convergent approach, beginning with the selective sn-1-O-acylation of a protected chiral glycerol synthon, followed by acylation of the sn-2 position and oxidative deprotection to yield the desired 1,2-O-diacylglycerol derivative.
Reaction with benzyl(N, N,-diisopropylamino)chlorophosphine yields phosphoramidites, which are then condensed with an appropriately protected D-myo-inositol derivative.
In the intermediate compounds, benzyl (Bn) or benzyloxymethyl (BOM) groups protect the final hydroxyl groups and p-methoxybenzyl (PMB) groups protect the future phosphomonoesters. Deprotection of the PMB groups, followed by phophorylation, hydrogenolysis, and ion exchange chromatography yields the aminoacyl modified PI's.
Attachment of the binding moiety via an ester linkage yields a PI having a binding moiety linked thereto.
Where the binding moiety is something other than biotin, such as an antibody or an antigenic determinant, analogous linking chemistries can be utilized to affix the binding moiety to the acyl chain of the PI.
Binding Matrices:
Where no binding moiety is attached to the substrate, the preferred binding matrix is an aldehyde-activated solid support or substrate, most preferably an aldehyde-activated regenerated cellulose. The preferred matrices are “SARTOBIND”®-brand aldehyde membranes, available commercially from Sartorius Corporation (Edgewood, N.Y., USA and Goettingen, Germany) and SAM2®-brand membranes (described in the following paragraph). Likewise, supports including diethylaminoethyl cellulose and polyvinylidene difluoride can also be used.
Where the binding moiety is biotin, the preferred binding matrix is a support having avidin or streptavidin immobilized thereon. The support may be in the form of a filter, membrane, beads, etc. The most preferred matrices are SAM2®-brand Biotin Capture Membranes or SAM2®-brand 96 Biotin Capture Plates (96-well microtiter format) from Promega Corporation, Madison, Wis. The SAM2®-brand membrane binds biotinylated molecules based on their strong affinity for streptavidin. The process by which the membrane is produced results in a high density of streptavidin on the membrane filter matrix, promoting rapid, quantitative capture of biotinylated substrates. In addition, the SAM2®-brand membrane has been optimized for low nonspecific binding. Using the 96 well plate format allows washes to be performed using a vacuum manifold or a commercially available plate washer.
Where the binding moiety is an antibody or antigenic determinant, the preferred binding matrix is an affinity matrix having immobilized thereon a compound which binds strongly and specifically with the binding moiety.
Enzymes That Can Be Assayed:
The subject assay can be used to detect and measure the presence of any lipid or phospholipid kinase or phosphatase. In short, any enzyme whose catalytic activity transfers a phosphate group to a lipid or phospholipid substrate, or any enzyme whose catalytic activity removes a phosphate group from a lipid or phospholipid substrate, can be assayed using the present invention.
More specifically, the subject assay can be used to determine the presence and/or activity of any lipid or phospholipid kinase falling within the Enzyme Classification (EC) 2.7.1.x (where x is a variable), including, without limitation, EC 2.7.1.1 hexokinase, EC 2.7.1.2 glucokinase, EC 2.7.1.3 ketohexokinase, EC 2.7.1.4 fructokinase, EC 2.7.1.5 rhamnulokinase, EC 2.7.1.6 galactokinase, EC 2.7.1.7 mannokinase, EC 2.7.1.8 glucosamine kinase, EC 2.7.1.10 phosphoglucokinase, EC 2.7.1.116-phosphofructokinase, EC 2.7.1.12 gluconokinase, EC 2.7.1.13 dehydrogluconokinase, EC 2.7.1.14 sedoheptulokinase, EC 2.7.1.15 ribokinase, EC 2.7.1.16 ribulokinase, EC 2.7.1.17 xylulokinase, EC 2.7.1.18 phosphoribokinase, EC 2.7.1.19 phosphoribulokinase, EC 2.7.1.20 adenosine kinase, EC 2.7.1.21 thymidine kinase, EC 2.7.1.22 ribosylnicotinamide kinase, EC 2.7.1.23 NAD kinase, EC 2.7.1.24 dephospho-CoA kinase, EC 2.7.1.25 adenylyl-sulfate kinase, EC 2.7.1.26 riboflavin kinase, EC 2.7.1.27 erythritol kinase, EC 2.7.1.28 triokinase, EC 2.7.1.29 glycerone kinase, EC 2.7.1.30 glycerol kinase, EC 2.7.1.31 glycerate kinase, EC 2.7.1.32 choline kinase, EC 2.7.1.33 pantothenate kinase, EC 2.7.1.34 pantetheine kinase, EC 2.7.1.35 pyridoxal kinase, EC 2.7.1.36 mevalonate kinase, EC 2.7.1.37 protein kinase, EC 2.7.1.38 phosphorylase kinase, EC 2.7.1.39 homoserine kinase, EC 2.7.1.40 pyruvate kinase, EC 2.7.1.41 glucose-1-phosphate phosphodismutase, EC 2.7.1.42 riboflavin phosphotransferase, EC 2.7.1.43 glucuronokinase, EC 2.7.1.44 galacturonokinase, EC 2.7.1.45 2-dehydro-3-deoxygluconokinase, EC 2.7.1.46 L-arabinokinase, EC 2.7.1.47 D-ribulokinase, EC 2.7.1.48 uridine kinase, EC 2.7.1.49 hydroxymethylpyrimidine kinase, EC 2.7.1.50 hydroxyethylthiazole kinase, EC 2.7.1.51 L-fuculokinase, EC 2.7.1.52 fucokinase, EC 2.7.1.53 L-xylulokinase, EC 2.7.1.54 D-arabinokinase, EC 2.7.1.55 allose kinase, EC 2.7.1.56 1-phosphofructokinase, EC 2.7.1.58 2-dehydro-3-deoxygalactonokinase, EC 2.7.1.59 N-acetylglucosamine kinase, EC 2.7.1.60 N-acylmannosamine kinase, EC 2.7.1.61 acyl-phosphate-hexose phosphotransferase, EC 2.7.1.62 phosphoramidate-hexose phosphotransferase, EC 2.7.1.63 polyphosphate-glucose phosphotransferase, EC 2.7.1.64 inositol 1-kinase, EC 2.7.1.65 scyllo-inosamine 4-kinase, EC 2.7.1.66 undecaprenol kinase, EC 2.7.1.67 1-phosphatidylinositol 4-kinase, EC 2.7.1.68 1-phosphatidylinositol-4-phosphate 5-kinase, EC 2.7.1.69 protein-Np-phosphohistidine-sugarphosphotransferase, EC 2.7.1.70 protamine kinase, EC 2.7.1.71 shikimate kinase, EC 2.7.1.72 streptomycin 6-kinase, EC 2.7.1.73 inosine kinase, EC 2.7.1.74 deoxycytidine kinase, EC 2.7.1.75 (now EC 2.7.1.21), EC 2.7.1.76 deoxyadenosine kinase, EC 2.7.1.77 nucleoside phosphotransferase, EC 2.7.1.78 polynucleotide 5′-hydroxyl-kinase, EC 2.7.1.79 diphosphate-glycerol phosphotransferase, EC 2.7.1.80 diphosphate-serine phosphotransferase, EC 2.7.1.81 hydroxylysine kinase, EC 2.7.1.82 ethanolamine kinase, EC 2.7.1.83 pseudouridine kinase, EC 2.7.1.84 alkylglycerone kinase, EC 2.7.1.85 b-glucoside kinase, EC 2.7.1.86 NADH2 kinase, EC 2.7.1.87 streptomycin 3″-kinase, EC 2.7.1.88 dihydrostreptomycin-6-phosphate 3′a-kinase, EC 2.7.1.89 thiamine kinase, EC 2.7.1.90 diphosphate-fructose-6-phosphate 1-phosphotransferase, EC 2.7.1.91 sphinganine kinase, EC 2.7.1.92 5-dehydro-2-deoxygluconokinase, EC 2.7.1.93 alkylglycerol kinase, EC 2.7.1.94 acylglycerol kinase, EC 2.7.1.95 kanamycin kinase, EC 2.7.1.96 (included in EC 2.7.1.86), EC 2.7.1.97 (identical to EC 2.7.1.125), EC 2.7.1.99 {pyruvate dehydrogenase (lipoamide)} kinase, EC 2.7.1.100 5-methylthioribose kinase, EC 2.7.1.101 tagatose kinase, EC 2.7.1.102 hamamelose kinase, EC 2.7.1.103 viomycin kinase, EC 2.7.1.104 diphosphate-protein phosphotransferase, EC 2.7.1.105 6-phosphofructo-2-kinase, EC 2.7.1.106 glucose-1,6-bisphosphate synthase, EC 2.7.1.107 diacylglycerolkinase, EC 2.7.1.108 dolichol kinase, EC 2.7.1.109 {hydroxymethylglutaryl-CoA reductase (NADPH2)} kinase, EC 2.7.1.110 dephospho-{reductase kinase} kinase, EC 2.7.1.111 (now EC 2.7.1.128), EC 2.7.1.112 protein-tyrosine kinase, EC 2.7.1.113 deoxyguanosine kinase, EC 2.7.1.114 AMP-thymidine kinase, EC 2.7.1.115 {3-methyl-2-oxobutanoate dehydrogenase (lipoamide)} kinase, EC 2.7.1.116 {isocitrate dehydrogenase (NADP)} kinase, EC 2.7.1.117 myosin-light-chain kinase, EC 2.7.1.118 ADP-thymidine kinase, EC 2.7.1.119 hygromycin-B kinase, EC 2.7.1.120 caldesmon kinase, EC 2.7.1.121 phosphoenolpyruvate-glycerone phosphotransferase, EC 2.7.1.122 xylitol kinase, EC 2.7.1.123 Ca2+/calmodulin-dependent protein kinase, EC 2.7.1.124 {tyrosine 3-monooxygenase} kinase, EC 2.7.1.125 rhodopsin kinase, EC 2.7.1.126 b-adrenergic-receptor kinase, EC 2.7.1.127 1-D-myo-inositol-trisphosphate 3-kinase, EC 2.7.1.128 {acetyl-CoA carboxylase} kinase, EC 2.7.1.129 myosin-heavy-chain kinase, EC 2.7.1.130 tetraacyldisaccharide 4′-kinase, EC 2.7.1.131 low-density-lipoprotein kinase, EC 2.7.1.132 tropomyosin kinase, EC 2.7.1.133 inositol-trisphosphate 6-kinase, EC 2.7.1.134 inositol-tetrakisphosphate 1-kinase, EC 2.7.1.135 tau-protein kinase, EC 2.7.1.136 macrolide 2′-kinase, EC 2.7.1.137 1-phosphatidylinositol 3-kinase, EC 2.7.1.138 ceramide kinase, EC 2.7.1.139 inositol-trisphosphate 5-kinase, EC 2.7.1.140 inositol-tetrakisphosphate 5-kinase, EC 2.7.1.141 {RNA-polymerase}-subunit kinase, EC 2.7.1.142 glycerol-3-phosphate-glucose phosphotransferase, EC 2.7.1.143 diphosphate-purine nucleoside kinase, EC 2.7.1.144 tagatose-6-phosphate kinase, and EC 2.7.1.145 deoxynucleoside kinase.
Preferred kinases which can be assayed using the subject assay include EC 2.7.1.137 (1-phosphatidylinositol 3-kinase, referred to herein as PI-3K), EC 2.7.1.67 (1-phosphatidylinositol 4-kinase), EC 2.7.1.68 (1-phosphatidylinositol-4-phosphate kinase, also called diphosphoinositide kinase or PIP kinase), 1-phosphatidylinositol 5-kinase (PI-5K), and the like.
Regarding phosphatases, the subject assay can be used to determine the presence and/or activity of any lipid or phospholipid phosphatase falling within the Enzyme Classification (EC) 3.1.3.x and EC 3.1.4.x (where x is a variable), including, without limitation, EC 3.1.3.1 alkaline phosphatase, EC 3.1.3.2 acid phosphatase, EC 3.1.3.3 phosphoserine phosphatase, EC 3.1.3.4 phosphatidate phosphatase, EC 3.1.3.5 5′-nucleotidase, EC 3.1.3.6 3′-nucleotidase, EC 3.1.3.7 3′(2′),5′-bisphosphate nucleotidase, EC 3.1.3.8 3-phytase, EC 3.1.3.9 glucose-6-phosphatase, EC 3.1.3.10 glucose-1-phosphatase, EC 3.1.3.11 fructose-bisphosphatase, EC 3.1.3.12 trehalose-phosphatase, EC 3.1.3.13 bisphosphoglycerate phosphatase, EC 3.1.3.14 methylphosphothioglycerate phosphatase, EC 3.1.3.15 histidinol-phosphatase, EC 3.1.3.16 phosphoprotein phosphatase, EC 3.1.3.17 {phosphorylase} phosphatase, EC 3.1.3.18 phosphoglycolate phosphatase, EC 3.1.3.19 glycerol-2-phosphatase, EC 3.1.3.20 phosphoglycerate phosphatase, EC 3.1.3.21 glycerol-1-phosphatase, EC 3.1.3.22 mannitol-1-phosphatase, EC 3.1.3.23 sugar-phosphatase, EC 3.1.3.24 sucrose-phosphatase, EC 3.1.3.25 inositol-1(or 4)-monophosphatase, EC 3.1.3.26 6-phytase, EC 3.1.3.27 phosphatidylglycerophosphatase, EC 3.1.3.28 ADPphosphoglycerate phosphatase, EC 3.1.3.29 N-acylneuraminate-9-phosphatase, EC 3.1.3.30 deleted, included in EC 3.1.3.31, EC 3.1.3.31 nucleotidase, EC 3.1.3.32 polynucleotide 3′-phosphatase, EC 3.1.3.33 polynucleotide 5′-phosphatase, EC 3.1.3.34 deoxynucleotide 3′-phosphatase, EC 3.1.3.35 thymidylate 5′-phosphatase, EC 3.1.3.36 phosphatidylinositol-bisphosphatase, EC 3.1.3.37 sedoheptulose-bisphosphatase, EC 3.1.3.38 3-phosphoglycerate phosphatase, EC 3.1.3.39 streptomycin-6-phosphatase, EC 3.1.3.40 guanidinodeoxy-scyllo-inositol-4-phosphatase, EC 3.1.3.41 4-nitrophenylphosphatase, EC 3.1.3.42 {glycogen-synthase-D} phosphatase, EC 3.1.3.43 {pyruvate dehydrogenase (lipoamide)}-phosphatase, EC 3.1.3.44 {acetyl-CoA carboxylate}-phosphatase, EC 3.1.3.45 3-doxy-manno-octulosonate-8-phosphatase, EC 3.1.3.46 fructose-2,6-bisphosphate 2-phosphatase, EC 3.1.3.47 {hydroxymethylglutaryl-CoA reductase (NADPH)}-phosphatase, EC 3.1.3.48 protein-tyrosine-phosphatase, EC 3.1.3.49 {pyruvate kinase}-phosphatase, EC 3.1.3.50 sorbitol-6-phosphatase, EC 3.1.3.51 dolichyl-phosphatase, EC 3.1.3.52 {3-methyl-2-oxobutanoate dehydrogenase (lipoamide)}-phosphatase, EC 3.1.3.53 myosin-light-chain-phosphatase, EC 3.1.3.54 fructose-2,6-bisphosphate 6-phosphatase, EC 3.1.3.55 caldesmon-phosphatase, EC 3.1.3.56 inositol-1,4,5-trisphosphate 5-phosphatase, EC 3.1.3.57 inositol-1,4-bisphosphate 1-phosphatase, EC 3.1.3.58 sugar-terminal-phosphatase, EC 3.1.3.59 alkylacetylglycerophosphatase, EC 3.1.3.60 phosphoenolpyruvate phosphatase, EC 3.1.3.61 inositol-1,4,5-trisphosphate 1-phosphatase, EC 3.1.3.62 inositol-1,3,4,5-tetrakisphosphate 3-phosphatase, EC 3.1.3.63 2-carboxy-D-arabinitol-1-phosphatase, EC 3.1.3.64 phosphatidylinositol-3-phosphatase, EC 3.1.3.65 inositol-1,3-bisphosphate 3-phosphatase, EC 3.1.3.66 inositol-3,4-bisphosphate 4-phosphatase, EC 3.1.3.67 phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase, EC 3.1.3.68 2-deoxyglucose-6-phosphatase, EC 3.1.4.1 phosphodiesterase I, EC 3.1.4.2 glycerophosphocholine phosphodiesterase, EC 3.1.4.3 phospholipase C, EC 3.1.4.4 phospholipase D, EC 3.1.4.10 1-phosphatidylinositol phosphodiesterase, EC 3.1.4.11 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase, EC 3.1.4.12 sphingomyelin phosphodiesterase, EC 3.1.4.13 serine-ethanolaminephosphate phosphodiesterase, EC 3.1.4.14 {acyl-carrier-protein} phosphodiesterase, EC 3.1.4.15 adenylyl-{glutamate-ammonia ligase} hydrolase, EC 3.1.4.16 2′,3′-cyclic-nucleotide 2′-phosphodiesterase, EC 3.1.4.17 3′,5′-cyclic-nucleotide phosphodiesterase, EC 3.1.4.35 3′,5′-cyclic-GMP phosphodiesterase, EC 3.1.4.36 1,2-cyclic-inositol-phosphate phosphodiesterase, EC 3.1.4.372′,3′-cyclic-nucleotide 3′-phosphodiesterase, EC 3.1.4.38 glycerophosphocholine cholinephosphodiesterase, EC 3.1.4.39 alkylglycerophosphoethanolamine phosphodiesterase, EC 3.1.4.40 CMP-N-acylneuraminate phosphodiesterase, EC 3.1.4.41 sphingomyelin phosphodiesterase D, EC 3.1.4.42 glycerol-1,2-cyclic-phosphate 2-phosphodiesterase, EC 3.1.4.43 glycerophosphoinositol inositolphosphodiesterase, EC 3.1.4.44 glycerophosphoinositol glycerophosphodiesterase, EC 3.1.4.45 N-acetylglucosamine-1-phosphodiester a-N-acetylglucosaminidase, EC 3.1.4.46 glycerophosphodiester phosphodiesterase, EC 3.1.4.47 variant-surface-glycoprotein phospholipase C, EC 3.1.4.48 dolichylphosphate-glucose phosphodiesterase, EC 3.1.4.49 dolichylphosphate-mannose phosphodiesterase, EC 3.1.4.50 glycoprotein phospholipase D, EC 3.1.4.51 glucose-1-phospho-D-mannosylglycoprotein phosphodiesterase,
Preferred phosphatases which can be assayed using the subject assay include EC 3.1.3.27 (phosphatidylglycerophosphatase), EC 3.1.3.36 (phosphatidylinositol bisphosphatase; triphosphoinositide phosphatase), EC 3.1.3.64 (phosphatidylinositol-3-phosphatase), EC 3.1.3.67 (phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase), EC 3.1.4.10 (1-phosphatidylinositol phosphodiesterase; monophosphatidylinositol phosphodiesterase; phosphatidylinositol phospholipase C), EC 3.1.4.11 (1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase, triphosphoinositide phosphodiesterase), phosphatidylinositol 3,4,5-triphosphate 5-phosphatase, and the like.
The assay can also be extended to assay for the presence and or activity of phosphorylases.
Kits:
The present invention is also directed to kits that utilize the assay described herein. A basic kit for measuring the presence and/or activity of a lipid/phospholipid kinase or phosphatase enzyme includes a vessel containing a natural, semi-synthetic, or wholly synthetic enzyme substrate and/or a modified enzyme substrate having a binding moiety attached thereto, the modified substrate having specific reactivity to the enzyme to be assayed. The kit also contains a binding matrix that specifically adsorbs or otherwise binds to and immobilizes the binding moiety on the modified substrate. Instructions for use of the kit may also be included. The kit may also include an appropriate amount of reaction buffer disposed in a suitable container.
“Instructions for use,” is a tangible expression describing the reagent concentration or at least one assay method parameter such as the relative amount of reagent and sample to be admixed, maintenance time periods for reagent/sample admixtures, temperature, buffer conditions, and the like. The instructions for use are suitable to enable an analyst to carry out the desired assay.
Where the modified substrate includes the preferred binding moiety, biotin, the preferred embodiment of the kit includes a biotin-binding matrix comprising avidin or streptavidin molecules immobilized on an inert support such as filter disks, beads, plates, or a soluble matrix.
The amounts of the various reagents in the kits can be varied depending on various factors, such as the optimum sensitivity of the assay, the number of assays to be performed, etc.
It is within the scope of the invention to provide manual test kits or test kits for use in automated analyzers.
The Assay Protocol:
Referring now to FIG. 1, which is a flow chart comparing a prior art method (left-hand column) to the preferred embodiment of the present invention (right-hand column), a number of benefits of the present invention are immediately apparent:
Addressing the present invention first, the most immediate advantage is that the lipids do not have to be dried from an organic solvent. Instead, the reaction solution is simply spotted directly onto the binding matrix. The enzyme is added to the bound substrate and the reaction run for a specified period of time. The reaction is then stopped, the membrane is rinsed, and the amount of label retained on the matrix is measured.
In stark contrast, the conventional approach requires that the lipid substrates must be dried from an organic solvent (normally chloroform/methanol), and resuspended (normally by sonication) in an aqueous reaction solution. The enzymatic reaction to be studied is then performed in the aqueous reaction solution. After the reaction is complete, the lipid products must be extracted back into chloroform/methanol for analysis. Thus, the conventional approach entails a number of manual separation steps that are both time-consuming, reagent-consuming, and not particularly amenable to automation. The need for these drying and extraction steps are minimized or eliminated entirely in the subject invention.
The assay protocol of the present invention is best illustrated via a number of Examples. The Examples are included solely to provide a more complete understanding of the invention described and claimed herein. The Examples do not limit the scope of the claimed invention in any way.
EXAMPLE 1
The following Example demonstrates that PI-3 kinase and PI4P-5 kinase, members from two distinct structural families of phosphoinositide kinases (PI and PIP kinases, respectively), can act to add a phosphate to a phospholipid substrate that has been immobilized on a solid support. Moreover, this Example demonstrates that this can be accomplished directly from organic solutions where the reaction substrates exist as monomers (i.e., individual lipid molecules), rather than from an aqueous phase where the reaction substrates exist as vesicles or micelles.
Further, this Example shows that the product lipids remain bound to the matrix during washing procedures, thereby providing an easy means to separate the products of the enzymatic reaction from unreacted reactants, enzyme, and other non-product ingredients of the reaction solution.
The data generated according to the present invention are compared with analogous data generated using the conventional phospholipid extraction procedure exemplified in FIG. 1 . In the conventional approach, the substrates for enzyme modification are presented in the form of vesicles or micelles in an aqueous reaction solution. After the enzymatic reaction (which takes place in the aqueous solution), the product lipids are separated from the other reaction components by extracting the products back into an organic phase, normally chloroform/methanol. The product lipids partition into the organic phase, while the other reaction components remain in the aqueous phase phase. A comparative flow chart of the prior art method and the subject invention is presented in FIG. 1 .
Lipids, 10 μg of PI4,5P 2 +20 μg of PS, were dissolved in chloroform:methanol (2:1) and loaded onto “SAM2”-brand membranes for PI-3K activity measurements. Likewise, 10 μg of PI4P was loaded onto “SAM2”-brand membranes for PI4P-5K activity measurements. The membranes were air dried and a reaction mixture containing 50 mM HEPES/NaOH, pH7.5, 100 mM NaCl, 10 mM MgCl 2 , 20 ng partially-purified PI-3K or 10 ng of purified PI4P-5K, 50 μM ATP supplemented with 1 μCi of γ- 32 P-ATP was added onto the membrane containing the immobilized lipids.
Following incubation at room temperature, the reactions were stopped with 7.5 M guanidine chloride and the membranes were washed with 2M NaCl, followed by 2 M NaCl/1% H 3 PO 4 . The washed membranes were dried and subjected to scintillation counting. The obtained data are presented in FIG. 2A (white bars).
In the conventional phospholipid extraction procedure, the same amount of lipids indicated above were dried under nitrogen and re-suspended by sonication in 50 mM HEPES/NaOH, pH 7.5 buffer containing 1 mM EDTA. Then the reaction mixture was added to sonicated lipids and the reaction was carried out in aqueous solution. The reaction was stopped with 1N HCl, lipids were extracted as indicated in FIG. 1 and analyzed. The data are shown in FIG. 2A (black bars).
To generate immunoprecipitated enzyme as used in FIG. 2B, livers were removed from rats after ether anesthesia. The livers were cut into small pieces and homogenized. The homogenate was centrifuged at 10,000×g for 10 minutes. The supernatant was centrifuged at 15,0000×g for 1 hour. The supernatant was then titrated to pH 5.75 by drop-wise addition of 1 M acetic acid. After stirring for 10 minutes at 4° C., the solution was centrifuged at 10,000×g for 10 minutes. The pellet was re-suspended in buffer containing 50 mM HEPES/NaOH, pH 7.5.
Then, 6 μl of anti PI-3 kinase p85 rabbit polyclonal IgG (Upstate Biotechnology, Lake Placid, N.Y.) were added to each tube containing the lysed cell solution and the tubes were incubated overnight at 4° C. Then 100 μl of protein A sepharose CL-4B (Pharmacia, Peapack, N.J.) was added to each tube and they were further incubated for 2 hours at 4° C. The sepharose/antibody/antigen complex (the “complex”) was then pelleted by centrifugation, the supernatant removed and the complex washed twice with PBS containing 1% NP-40 and 10% glycerol, three times with 100 mM Tris/HCl (pH 7.5) containing 500 mM NaCl and 100 μM Na 3 VO 4 and twice with 10 mM Tris/HCl containing 100 mM NaCl, 1 mM EDTA, 100 μM Na 3 VO 4 . Then 50 μl of 10 mM Tris/HCl (pH 7.5) containing 100 mM NaCl was added to the complex and this solution was then referred to as the immunoprecipitated PI-3 kinase enzyme.
Immunoprecipitated PI-3 K was assayed as described above for purified PI-3K with lipid substrates immobilized on “SAM”-brand membranes. All reactions were carried out at room temperature using 10 μg PI4,5P2+20 μg PS (FIG. 2B, bars 3 and 4) or 50 μg PI (FIG. 2B, bars 1 and 2) as reaction substrates.
EXAMPLE 2
An assays analogous to that depicted in Example 1 can be assembled to assay for the presence and/or activity of lipid and phospholipid phosphatases, such as phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase.
Here, the substrate bearing the binding moiety is phosphorylated with a known amount of {γ- 32 P} ATP.
The reaction components were the same as described in Example 1. The reaction components were applied directly to a “SAM2”-brand membrane and the reaction run for the specified period of time and then terminated. The results of the experiment are generated by measuring the decreased amount of radiation present in the products which adhere to the binding matrix as compared to the radioactivity present in the reactants.
EXAMPLE 3
In resting cells, PI-3K is located in the cytosol. However, upon cell stimulation, the enzyme is recruited to the plasma membrane where it is associated with particular receptors and is involved in further propagation of the signal. This example illustrates that the described method allows to measure PI-3K activity associated with activated receptor. 3T3 NIH cells (0.5×10 7 cells) were starved oveminght in serum-free medium. PDGF (50 ng/ml) was added to the starved cells and the induction was carried out for 5 min at 37° C. Following the PDGF induction, cells were washed once with PBS while on the plate, scraped into PBS, transferred to a centrifuge tube, pelleted by centrifugation. The cell pellet was lysed and activated receptor-PI-3K complex was iminunoprecipitated using anti-phosphotyrosine specific antibodies. The PI-3K reaction was run for 60 min using PI4,5P 2 (10 μg) as substrate, immobilized on “SAM2”-brand membranes, together with 20 μg of carrier lipid (PS). The increase in PI-3K activity upon stimulation with PDGF is shown in FIG. 3 . This Example clearly indicates that the present invention enables cells to be monitored for activation and also enables the analysis of PI-3K activity associated with activated receptors.
EXAMPLE 4
This Example illustrates the dependence of PIK activity on the amount of lipid substrate loaded onto the binding matrix. In FIG. 4A, PI-3K activity was measured using PI-3K from Alexis (12.5 μg/ml) for 60 min at room temperature (using the protocol of Example 1, with any modifications noted). In FIG. 4B, PI-5K activity was measured using purified PI-5K (125 ng/ml) for 60 min at room temperature. In addition to lipid substrates, all samples contained 10 μg of PS loaded on the membrane.
As shown in FIG. 4A, the reaction yields a linear response from 0 to roughly 6 μg of substrate. The reaction then reaches a saturation point at roughly 7 μg of PIP 2 . Beyond this concentration of substrate, the presence of additional substrate does not result in higher radioactivity incorporation in the formed product. FIG. 4B, which illustrates the results for PI-5K, shows that the enzyme activity expressed as CPM count remains unchanged in going from PI4P concentrations from 1 to 10 μg, thus indicating that at these substrate levels, the reaction is already saturated.
EXAMPLE 5
This Example illustrates the linear detection of PIP-5K activity using the present invention. Assays were performed using the described protocol (Example 1) with 3 μl of lipid mixture containing 1 μg of PI4P and 10 μg of PS in chloroform/methanol 2:1 spotted onto a pre-numbered membrane square.
In FIGS. 5A and 5B, the PI-5K activity was measured at different time points (0, 2.5, 5, 10, and 20 min) using 4 ng of purified protein. In FIGS. 5C and 5D, PI-5K activity was measured for 10 min using different protein concentrations (0, 50, 125, 200, 250 ng/ml). The reaction products were analyzed by phosphorimaging (FIGS. 5A and 5C) or by scintillation counting (FIGS. 5 B and 5 D). As is clearly illustrated by this series of figures, the assay protocol yields linear time-dependent results (FIGS. 5A and 5B) and concentration-dependent results (FIGS. 5 C and 5 D). Between 20 pmol and 1.2 nmol of formed product can be detected using the subject invention.
EXAMPLE 6
In this Example, linear detection of PI-3K activity was assayed using the present invention. Assays were performed using the described protocol with 5 μl of PI (25 μg) in chloroform/methanol 2:1 spotted onto a well of modified SAM-brand membrane 96-well plate (Promega). Assays were performed using different amounts of partially purified PI-3K: 1 ng (light green); 2 ng (dark green); 4 ng (yellow); 8 ng (orange); 16 ng (red). Based on obtained scintillation counts, the specific activity has been calculated and shown in FIG. 6 A). The calculated initial reaction rate for different amount of protein is shown in FIG. 6 B. This Example shows that the subject method yields linear detection of enzyme over a broad concentration range.
EXAMPLE 7
This Example is a comparison of reaction products detected using the present invention versus the conventional phospholipid extraction procedure outlined in FIG. 1 . In FIG. 10, activities were assessed using 1 μg of PI4P+10 μg of PS as reaction substrates and purified PI-5K as an enzyme source. The reaction was carried out for 0 (lanes 3, 4) and 30 minutes (lanes 1, 2). The reaction was performed using a conventional phospholipid extraction procedure (lanes 2, 4) or according to the subject invention (lanes 1, 3). When using the subject invention, following reaction performed on membrane sheets, the lipids were re-extracted for TLC analysis.
The results show that the products formed using the present invention yield useful information on enzymatic activity, information that is comparable to the widely-used conventional assay described earlier.
EXAMPLE 8
This Example demonstrates the reproducibility of the subject invention. Assays were performed using:
FIG. 7 A: partially purified PI-3K (500 ng/ml) and PIP 2 (10 μg)+PS (20 μg) as lipid substrates for 40 minutes
FIG. 7 B: PI-5K (125 ng/ml) and PI4P (1 μg)+PS(10 μg) for 15 minutes
FIG. 7 C: PI-5K (125 ng/ml) and PI4P (1 μg) for 60 minutes.
All assays were performed at room temperature using 1 μCi of 32 P-ATP.
In FIG. 7C, the reactions were carried out on three different plates (samples 1-4; 5-8; 9-12, respectively). In each plate the reactions were done in triplicates at three different locations. Each point represents the average of three independent reactions. Yellow bars show the average of 9 points done on the same plate.
As is clearly shown by this set of experiments, the method is highly reproducible.
EXAMPLE 9
This Example illustrates that the products formed by the enzymatic reaction are due solely to the presence of active enzyme. This is shown by the loss of products formed when the reaction is run in the presence of an inhibitor that is specific to PI-3K. A reaction was run with partially purified PI-3K for different periods of time in the presence (triangles) or absence (diamonds) of PI-3K inhibitor wortmannin (final concentration 100 nM). See FIG. 8 . As shown in FIG. 8, the present method yielded greatly reduced radiolabeled product as expressed in CPM values when the assay was performed in the presence of the PI-3K inhibitor.
EXAMPLE 10
This Example illustrates the reaction specificity toward lipid substrates. Here, a reaction was performed with purified PI-5K (125 ng/ml) for 15 min at room temperature using different lipid substrates: PI3,4P (lane 1); PI3,5P (lane 2) and P4,5P2 (Lane 3). PI3,5P (lane 2) and PI4,5P (lane 3), which already have a phosphate group in the 5-position, are not substrates for PI-5K, an enzyme that functions to catalyze the addition of a phosphate group to the 5-position of a suitable substrate. Thus, as clearly shown in FIG. 9, the assay generate appropriate results and thus demonstrates specificity for enzyme substrates. PI3,4P (lane 1) is a suitable substrate for the PI-5K enzyme and shows the expected, corresponding CPM values, indicating that the enzyme has, in fact, specifically phosphorylated these substrates.
EXAMPLE 11
The following Example demonstrates that PI-3 kinase (PI-3K) can act to add a phosphate to a biotinylated phospholipid when the phospholipid is biotinylated in such a way as not to interfere with the interaction between the enzyme and the biotinylated substrate. The biotin group is attached to the lipid substrate, preferably to the end of the lipid chain. This Example also demonstrates that a streptavidin matrix is capable of separating the biotinylated, phosphorylated product from non-biotinylated components of the reaction mixture to allow for detection and quantitation of the product.
Lipids: 30 μg of short-chain PI4P-C 8 , biotin-modified short-chain PI4P-C 6 -biotin, and long-chain PI4P-C 16 were dried under vacuum in the presence of 10 μg carrier lipid (PS) in separate tubes. The dried lipids were dissolved in 50 mM HEPES/NaOH, pH 7.5+1 mM EDTA buffer and subjected to sonication for 5 min. This solution is referred to as the “prepared substrate.”
The following kinase reactions were then assembled:
4 μl of 100 mM MgCl 2
20 μl of prepared substrate
1 μl of purified PI4P-5K or PI-3K
11 μl 50 mM HEPES/NaOH+100 mM NaCl buffer
4 μl of 0.5 mM ATP containing 1 μCi 32 P-ATP
The reactions were carried out for 15 minutes at room temperature. In FIG. 11A, following the reaction, lipids were extracted and analyzed on TLC to show that biotinylated lipids can be modified by PI-kinases. In FIG. 11B, 25% of the reaction mixture was loaded on “SAM2”-brand membranes, the membranes were washed and then analyzed directly (black bars) or the membranes were exposed for additional treatment with chloroform/methanol/water (10:10:3) to remove and separate modified from unmodified lipids (white bars).
This Example indicates that membrane-bound lipids remain attached to the matrix during separation procedures and thereby allows separation of reaction products from other reaction components. However, natural lipids bound to the membranes can be removed under defined conditions, for example, following membrane treatment with chloroform:methanol:water (10:10:3). Thus, the reaction products can be subjected to more detailed structural analysis if needed.
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Disclosed is a method and corresponding kit for assaying the presence, activity, or both, of an enzyme classified within an enzyme classification selected from the group consisting of EC 2.7.1, EC 3.1.3, and EC 3.1.4. The method generally includes the steps of reacting an enzyme with a substrate for a time sufficient to yield phosphorylated or dephosphorylated product; contacting the product with a binding matrix, whereby product is adhered to the matrix; and then analyzing the matrix for presence of, amount of, or both the presence and the amount of the product fixed to the matrix, whereby the presence, the activity, or both the presence and activity of the enzyme can be determined.
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BACKGROUND OF THE INVENTION
1. Introduction
This invention relates to coated fabrics used in the reinforcement of resin-bonded abrasive wheels.
2. Description of the Prior Art
Resin-bonded abrasive wheels are well-known in the art and described in numerous publications. They are used for a variety of purposes such as the cutting of various materials including metals and concrete, for grinding, sanding, buffing and other procedures known to the art. Typically, resin-bonded abrasive wheels may be reinforced with various materials such as random fibers and variously shaped woven and non-woven fabrics. Exemplary fabric materials comprise cotton, nylon, glass, rayon and aramid such as that marketed under the trade name Kelvar. These reinforcements provide a margin of safety in the event that the abrasive wheel cracks or breaks during use and thereby increase the safe operating speed and efficiency of the wheel.
It is known in the art that when woven fabric is used as a reinforcing material for an abrasive wheel, the fabric is coated with a resin to protect the fibers from degradative abrasive attack by the abrasive particles during molding, to allow proper bonding between the resin in the wheel and the fabric reinforcement and to prevent the fabric from distorting. The resins most frequently used for such purposes are the phenolic resins, most often the phenol formaldehyde resins. The protection of fabric, particularly glass fabric, with thermosetting phenolformaldehyde resins prior to preparation of an abrasive wheel is illustrated in U.S. Pat. Nos. 2,745,224; 2,808,688; and U.S. Pat. No. Re 25,303, each of which is incorporated herein by reference.
For preparing coated fabrics for the reinforcement of abrasive wheels, it is believed that only thermosetting resins are used. The most commonly used resins are the resole phenolics which will cure to form an infusible three-dimensional matrix upon heating. The resole resins are known by such names as single-stage, one-step and reactive resins. Less frequently, novolak type phenolic resins have been used for coating fabrics in the preparation of reinforcing discs, but always in combination with a crosslinking agent such as hexamethylenetetramine so that upon heating, the resin will cure and form a three-dimensional crosslinked matrix. In such case, the novolak is a thermosetting material. Typically, from 5 to 15% by weight hexamethylenetetramine is added to the novolak resin. The combination of the novolak resin and the crosslinking agent is typically identified as a two-step or two-stage resin.
A problem encountered with known resin-coated or impregnated fabric reinforcements is that with extended storage before use, the fabrics stiffen and lose their desirable flow characteristics. This results in poorer performance possibly as a consequence of a decrease or loss of chemical bond between the resin matrix for the abrasive particles and the resin coating over the reinforcing fabric. As a consequence, the useful life of the reinforcement is limited significantly, and wheels made with aged reinforcements of this type may not be satisfactory in performance or safety, in the case of wheels made by the "cold press" method.
STATEMENT OF THE INVENTION
The present invention is based upon the discovery that if the reinforcing fabric is coated with novolak phenolic resin essentially free of added crosslinking agent rather than a thermosetting resin as in the prior art, the problems encountered with extended storage are, for the most part, avoided. Hence, fabric reinforcements of the subject invention are characterized by an ability to withstand longer storage without significant degradation of their desirable use properties. In addition, it has been found that the abrasive wheels reinforced with fabric of the subject invention exhibit greater hinge strength when broken or cracked, improved grinding efficiency, improved grinding characteristics, markedly reduced tendency toward blistering of the resin in the finished wheel, and a lessened tendency of the finished wheel to warp.
In accordance with the above, the subject invention provides new materials for the reinforcement of abrasive wheels comprising a reinforcing fabric having a coating of a novolak phenolic resin.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fabric, used in the form of a disc or any other convenient shape, may be any of those used in the prior art. However, cloth of a high strength material is preferred. Typical cloths comprise cotton, dacron, rayon, nylon, Kelvar and glass, glass being most preferred, especially open mesh glass fabric.
In accordance with the invention, the cloth is coated with a novolak phenolic resin. The term novolak phenolic resin is defined for purposes herein as a novolak type phenolic resin with little or no added crosslinking agent. Thus, the term excludes the resole resins and the two-stage novolak resins where the crosslinking agent is added in anything other than a minor amount. In accordance with this definition, in the most preferred embodiment of the invention, a novolak resin is used completely free of added crosslinking agent though amounts of crosslinking agent up to a maximum of 3% by weight can be tolerated with the understanding that the results obtained with this quantity of added crosslinking agent are less desirable than when the novolak is free of added crosslinking agent.
The resin is coated onto the fabric in conventional manner such as by immersing the cloth in a varnish of the resin where the varnish comprises a solvent such as an alcohol having a resin solids content varying within relatively broad limits dependent upon the desired percentage resin content of the reinforcement. The varnish may contain other additives as is conventional such as internal or added plasticizers. The solids content of the varnish can typically vary between about 25 and 80% by weight, but preferably ranges between about 60 and 75% by weight.
After the fabric is coated with varnish, it is dried preferably at elevated temperatures to more rapidly remove solvent. Temperatures of from 150° to 450° F. are suitable for periods of time ranging between a fraction of a minute and 30 minutes. Following drying, the cloth may be cut to any desired shape, for the fabrication of an abrasive wheel reinforcement.
The following example illustrates the preparation of a reinforcing shape in accordance with the invention.
EXAMPLE 1
A woven glass cloth identified as Style 500 of the Greenville Mills Division of Warwick Mills Corporation was selected. The cloth had a weight of 9.2 oz. per square yard of material. It was coated with a varnish consisting of 70% by weight of a novolak resin dissolved in methyl alcohol. The novolak resin used was identified as GP2173 of the Georgia Pacific Corporation. The varnish did not contain added crosslinking agent. Following coating of the glass cloth with varnish, the cloth was dried by passing it through an oven at a speed of 20 feet per minute. The oven measured 20 feet in length and was maintained at a temperature of 240° F. The dwell time of the cloth in the oven was one minute. Following drying, the novolak content of the coated glass cloth was 30% of the total weight. The glass cloth was then cut into circular discs having a diameter of 9 inches. The discs are suitable for the reinforcement of abrasive wheels.
To fabricate an abrasive wheel using the reinforcing discs of this invention, any conventional abrasive material may be used. The most commonly used materials are aluminum oxide and silicon carbide grains though other abrasives such as garnet or even diamonds can be used. Aluminum oxide abrasive is available in several different grades including a brown abrasive which is about 95% aluminum oxide and a white porous variety which is about 98% pure or better. Silicon carbide abrasive is also available in several different grades such as the black grades and the green, the latter being the purer grade. The abrasive particles, which are commercially available with a resin coating, are mixed with a resin and molded to bind the abrasive particles into a coherent structure. In this case, the resin used as the binder for the abrasive particles is also a phenolic resin, but unlike the resin used to coat the reinforcing fabric, is thermosetting rather than thermoplastic. Any of the two-stage novolak resins conventionally used as binders are suitable for this purpose. The relative amount of abrasive to resin binder is as in the prior art, the abrasive generally comprising the predominant portion of the blend. The blend may also contain other conventional additives as is customary in the art.
The formation of a grinding wheel using the reinforcing discs of the invention is illustrated in the following example.
EXAMPLE 2
______________________________________No. 24 grit size aluminum oxide 1000 gramsNo. 36 grit size aluminum oxide 1000 gramsReactive phenol-formaldehyderesin brand BRL 2534, a liquid resin 80 gramsPowdered reactive phenol-formaldehyderesin brand BRP 5417, a resin suppliedwith hexamethylenetetramine added asa crosslinking agent 260 gramsFurfural 20 gramsCryolite Powder 240 gramsAnthracene oil fractions from coaltar, carbosote brand 25 grams______________________________________
Blend the above materials together and screen the resulting mix using a No. 12 screen.
Place an interliner disc in the bottom of a circular mold. Using the reinforcing discs of Example 1, place a disc on top of the Patapar interliner noting the direction of the orientation lines. Charge the mold with 133 grams of the above mix and level the mix by running a straight edge over the top of the mold. Place a second reinforcing disc on the top of the mix making sure that the orientation lines of the disc line up with the bottom disc. This is covered with a second interliner disc. The top section of the mold is put in place and the mold transferred to a Wabash press. The press is put under a pressure of 12 tons and held at this pressure for 30 seconds. Thereafter, the mold is removed from the press and the "green" wheel carefully removed from the mold. The "green" wheel is then placed in an oven and cured for 4 hours at 180° F., 2 hours at 220° F., 2 hours at 260° F., 2 hours at 290° F. and then 17 hours at 320° F. The cured wheel is then permitted to cool to room temperature.
It should be understood that the procedures of Example 2 are simplified for purposes of illustration and that in the actual fabrication of an abrasive wheel, as is known in the art, there are many possible variations. For example, it is customary for an abrasive wheel to be of a composite structure comprising one or more abrasive layers and one or more reinforcing shapes.
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This invention relates to improved fabrics used in the reinforcement of resin-bonded abrasive wheels. The fabrics are characterized by a coating of a novolak resin essentially free of added crosslinking agents.
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BACKGROUND DISCUSSION
Conventional modern clothes washing machines typically consist of a perforate inner clothes receiving receptacle or basket nested within an outer, wash water retaining tub. An agitator extends into the interior of the basket and is oscillated in order to execute the washing action during the wash and rinse cycles.
Since this washing action is carried out completely within the confines of the basket, the volume of water which is present between the outer tub and the basket does not contribute to the washing or rinsing of the clothes, and this volume of water may be significant in a given washing machine design.
It has heretofore been recognized that water savings could be achieved by causing the water to be circulated from the tub into the basket during the wash and rinse cycles, such that a lower level of water exists in the tub than in the basket.
Examples of such systems are disclosed in U.S. Pat. Nos. 2,869,344 (Bochan); 2,955,448 (Olthuis); and 3,153,924 (Alger). All of these patents are assigned to the assignee of the present application.
During the initial fill cycle, water is introduced both into the basket and the tub, either simultaneously or by flowing through the openings in the basket, such that an equal level tends to exist in both the tub and basket.
Accordingly, at the completion of the fill cycle, the water level in the basket is somewhat below that at which the machine will operate after the recirculation of the water by the recirculation pump achieves a steady state washing or rinsing level in the basket.
This situation tends to produce a difficulty in that most agitators are designed to operate at a given water level and will not operate properly at the initial low water level. That is, there will be high motor torque demands during the beginning of the agitation cycle. Even with start up at the proper washing water level, a significant cost factor in the electric drive motor is the added expense of starting winding in order to accommodate the start up demand torques.
There also can be some fabric damage due to the lowered water level.
A similar situation exists with respect to the spin extraction cycle, which is normally provided in such machines, in which the perforate basket is rotated at high speed in order to extract the wash and rinse water from the clothes.
It is highly desirable for various reasons that the extraction rotation of the basket be not initiated until the water in the tub and basket has been drained through the household plumbing. This need has previously been recognized in the prior art and various arrangements proposed to introduce a delay into the activation of the agitator or basket drive at the beginning of either the wash and rinse or spin cycles, which will enable the pump up of water into the basket in the case of the agitator wash and rinse cycles and the drain down in the case of the spin cycle.
In some of these various approaches, as described in the above-mentioned patents, a delay is introduced electronically in which the controls provide for an interval of pump up or drain down at the initiation of each cycle, prior to activation of the drive clutch. This approach, however, complicates the design and operation of the controls, as well as the clutch components themselves.
In many designs, a relatively simple trouble-free arrangement is provided by a common drive of the recirculation and drain pumps with the same electrical motor driving the pumps, as well as the agitator and/or basket during the machine cycles. While this eliminates the need for separate drive components and/or controls for these elements, the introduction of a delay interval is rendered substantially more complicated.
In U.S. Pat. No. 3,978,956 (Bochan), a mechanical delay is provided for the spin cycle. While the arrangement described in this patent produces a purely mechanical delay in the initiation cycle, it involves a shifting movement of a blocking element which introduces the possibility of a malfunction of the device, preventing actuation of the drive due to hanging up of the blocker part and also variations in the time at which the clutch drive is established to the basket.
Accordingly, it is an object of the present invention to provide a clothes washing machine in which there is introduced a purely mechanical delay to either or both the agitator and/or basket spin drives and which does not require additional controls or operating components associated with the clutch drive.
It is a further object of the present invention to provide a delayed action clutch for such application which operates in a highly reliable manner and which is relatively simple in construction.
SUMMARY OF THE INVENTION
These and other objects of the present invention, which will become apparent upon a reading of the following specification and claims, will be achieved by a washing machine agitator basket drive including a delayed action clutch interposed in the drive motor and the basket agitator transmission.
The delay action clutch includes a centrifugal actuated drum clutch in which spring biased pivoted clutch shoes are pivoted outwardly and into engagement with the drum by centrifugal force in order to establish drive of the motor to the machine transmission. This delay is introduced by a rotary pot, in which the outward movement of the clutch shoes is converted into rotary movement of a rotary damper plate by a pair of connecting links connected to the shoes and the rotary damper plate. The rotary motion is resisted by means of a viscous force established by a wave washer driven by the rotary plate through a volume of a viscous liquid such as a silicone fluid. A one-way clutch is interposed between the rotary damper plate and the wave washer which allows free releasing movement of the clutch shoes.
This establishes a predetermined delay in the establishment of drive to the agitator and the basket, such that a delay period is introduced prior to the initiation of both the wash/rinse cycles, as well as the spin cycle, to afford the advantages of the delay feature both in the water saver systems described above, and in the centrifugal extract type machines.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a washing machine incorporating the delayed action clutch according to the present invention shown in partial section.
FIG. 2 is an enlarged detailed schematic sectional view of the delayed action clutch incorporated in the washing machine depicted in FIG. 1.
FIG. 3 is a plan view of the clutch shown in FIG. 2 shown in partial section.
FIG. 4 is a sectional view of an alternate version of the clutch depicted in FIGS. 1 through 3.
FIG. 5 is a plan view of the clutch shown in FIG. 4, in partial section.
DETAILED DESCRIPTION
In the following detailed description, certain specific terminology will be utilized for the sake of clarity and a particular embodiment described in accordance with the requirements of 35 USC 112, but it is to be understood that the same is not intended to be limiting and should not be so construed inasmuch as the invention is capable of taking many forms and variations within the scope of the appended claims.
Referring to the drawings and particularly to FIG. 1, the clothes washing machine 10 includes an outer cabinet 12 within which are mounted the various functional components, including a generally cylindrical vertical axis clothes receiving perforate basket 14 and vertically disposed within the interior of the tub 16. The basket 14 is adapted to be spun by means including an electric drive motor 18 acting through a drive unit including a centrifugal clutch 20 and a belt drive 22, which also serves to drive a transmission 21 which oscillates an agitator 24 during wash and rinse cycles to provide a means for washing and rinsing the clothes and thereafter removing the wash and rinse water from the basket 14.
The clothes receiving basket 14 is adapted to contain the clothes during the wash and rinse cycles, and the water disposed therein extracted during a spinning of the basket 14 to cause the water to pass out into the tub 16 where it is collected.
Tub 16 is provided with a drain 26 which receives the basket overflow during the spin cycle, with the drain water pumped into the plumbing drain by means of a drain pump deck 28. The drain pump deck 28 is part of a stacked double pump assembly 30, driven via flexible coupling 32 by the drive motor 18, which drives the agitator 24 and the basket 14.
Double pump assembly 30 includes the drain pump deck 28 and also a recirculation pump deck 34. The drain pump deck has its impeller oriented such that during rotation of the drive motor 18 during spin of the basket 14, pumping action is created by the impeller, tending to pump water from an inlet connected to a hose 36, in turn secured to the drain fitting 38. The outlet 40 is directed to the external drain via a hose (not shown).
The particular clothes washing machine design depicted in FIG. 1 is intended to conserve water by reducing the level of water in the tub 16 during the wash and rinse cycles.
The basket 14 and tub 16 are initially filled at the start of each wash and rinse cycle via a fill spout 42 which receives water from supply lines 44 and a solenoid-operated fill valve 46. The fill valve 46 allows the flow of water under the control of pressure-sensitive switch 48, which senses the pressure head of the water in the tub 16 via a tube connection 50 with an air chamber 52 in fluid communication with the tub 14 via a connection with the drain fitting 38. The pressure-sensitive switch 48 is adjustable so as to be activated at a predetermined pressure level by a control knob 54 included on the machine control panel 56.
The arrangement operates in a well-known manner to adjust the particular pressure level at which the pressure-sensitive switch 48 is activated causing the solenoid-operated fill valve 46 to discontinue water flow when a predetermined level of water has been reached corresponding to the pressure head activating the pressure-sensitive switch 48.
In many clothes washing machine designs, the basket 14 is generally perforate such that the water level in the basket 14 tends to be the same as in the tub 16. In the design depicted in FIG. 1, a recirculation system is incorporated to reduce the level of water in the tub 16 after the tub and basket water fill, in order to reduce the volume of water required to carry out a wash or rinse cycle. This recirculation involves pumping of the water in the space 58 into the basket 14 during the wash and rinse cycles. The flow of water out of the basket 14 is controlled by providing a series of bottom-located perforations or openings 60 in the basket 14. Apportioning of inlet flow through fill spout 42 between the basket 14 and the tub 16 and flow through the openings 60 insures equal levels in the basket 14 and the tub 16 during fill, allowing accurate setting of the initial level, but the volume of water flow from the basket 14 into the tub 16 is controlled by the size and number of bottom-located openings 60.
Recirculation flow is produced by the recirculation pump deck 34 of the double pump assembly 30 with the inlet of the recirculation pump deck 34 connected via a hose 62 to a recirculation intake opening 64.
Recirculation pump deck 34 operates to create a pumping action by drive of the drive motor 18 whenever the oscillation of agitator 24 is taking place. In this drive condition, the drive motor 18 is rotating in the opposite direction from that in which it rotates during spin of the basket 14, such that a continuous pumping action takes place during the wash and rinse cycles in which the water is pumped out of the space 58 intermediate the basket 14 and tub 16.
The outlet of the recirculation pump deck 34 is connected to a recirculation hose 68 which directs the recirculated water into a nozzle 70 directing the recirculation flow into the interior of the basket 14, after having passed through a lint tray 72 mounted to the agitator post 74.
The capacity of the recirculation pump deck 34 is greater than the flow from the basket 14 into the tub 16 interior via the openings 60 such that the level of water in the tub 16 is ordinarily substantially below the level of water in the basket to thereby achieve the water saving end sought by this design.
In this type of system, in order to establish the maximum water level in the clothes basket, a series of overflow openings, such as those shown at 76 in FIG. 1, are normally provided at the level of the basket corresponding to the maximum water level. These overflow openings also act to allow extract water flow out of the basket during the spin cycle. Upon reaching this level, the flow through these openings creates a rate of escape of the water from the basket in excess of the capacity of the circulation pump, such that the water level cannot rise about the level.
In many washing machines, as here, the basket 14 is provided with a balancing ring 78. The balancing ring 78 has an annular pocket 79 filled with a heavy granular material such as magnetite which serves to eliminate the pertubations of the basket 14 occurring during spin.
Accordingly, in order to establish the level of water in the tub 16, a series of overflow perforations or openings 76 are formed at a height on the basket 14 corresponding to the set basket water level.
The water flow volume through the openings 76, taken together with the flow from the bottom-located openings 60, exceeds the capacity of the recirculation pump deck 34 which therefore cannot pump a sufficient volume of water out of the space 58 to equal this combined flow. The water level in the basket 14 is thereby stablized at this level which thereby establishes the maximum water level in the basket 14.
Referring to FIGS. 2 and 3, the centrifugal clutch 20 is depicted in detail, and includes the first and second rotatable drive members, between which drive is controllably established by action of the clutching means. The first drive member comprises a clutch drum 80 formed integrally with a sheave 82 which is adapted to drive belt 22 and which in turn drives the input to transmission 21.
Clutch drum 80 is formed with an inner surface 84 which is adapted to be frictionally engaged by one or more clutch engagement members consisting of pivotally mounted clutch shoes 86. The clutch shoes 86 are mounted to the second drive member consisting of the cup-shaped housing 88, which is connected with the shaft extension 90, driven by output shaft 92 of the drive motor 18. Shaft extension 90 extends through the centrifugal clutch 20 and drives the double pump assemblies 30 via flexible coupling 32.
Clutch drum 80 is rotatably mounted on shaft extension 90 by anti-friction bearings 91.
Clutch shoes 86 are each pivotally mounted at 94 to a cover 96 extending across the open end of the cup-shaped housing 88 such that the clutch shoes 86 are rotated by the shaft extension 90.
Clutch shoes 86 are caused to be moved about their pivots 94 by centrifugal force generated by the outboard weight of the clutch shoes 86 upon energization of the drive motor 18, in order to produce movement of the clutch shoe facings 98 into frictional driving engagement with inner surface 84 formed on the clutch drum 80.
Return springs 100 are provided which are connected at one end to the clutch shoes 86 and at the other end to a pair of connecting links 102 forming a part of the clutch delay means to be described hereinafter. Return springs 100 resist the outer movement of the clutch shoes 86 in response to the centrifugal forces and, upon cessation of rotation of the shaft extension 90, clutch shoes 86 are thereby drawn out of engagement with the inner surface 84.
As noted, the centrifugal clutch 20 includes delay means which retards movement of the clutch shoes 86 by exerting viscous damping forces thereon, such that the movement of the clutch is delayed, but which does not result in a reduction in the clutch engagement forces after the clutch shoes have moved into driving engagement.
This delay means includes rotary damper plate 104 which is rotatably mounted on the shaft extension 90 by means of a bearing 106. Rotary damper plate 104 is drivingly connected to clutch shoes 86 in such a way that the movement of the clutch shoes 86 is in a direction tending to move into frictional engagement with the clutch drum 80 and produces a rotation of the rotary damper plate 104. This means includes the connecting links 102 which are pinned at 108 to the clutch shoes 86 at one end, and at the other end are pivotally mounted at 110 to the rotary damper plate 104 at points thereof in radially opposite locations.
Movement of the clutch shoes 86 about their pivotal mounting 94 thus produces a corresponding rotation of the rotary damper plate 104.
This rotation in turn is resisted by damping means exerting viscous damping forces by the rotary damper plate 104. This viscous damping means includes a wave washer 112 disposed within cup-shaped housing 88 and a volume of a viscous liquid, such as a silicone liquid indicated at 114, such that rotation of the wave washer 112 is resisted by viscous forces. One skilled in the art will appreciate that wave washer 112 could be any irregularly contoured or perforated member which creates a damping force when rotated in the presence of the viscous liquid.
In order to retain the silicone liquid in the cup-shaped housing 88, a seal is provided at 122 disposed between the undersurface of the rotary damper plate 104 and section 124 formed integrally with the cover 96. This thus allows a rotation of the rotary damper plate 104 relative to cover 96, but insures that the silicone liquid 114 will not escape during handling of the unit in servicing.
A driving connection between the rotary damper plate 104 and the wave washer 112 is provided by one-way clutching means consisting of clutch spring 116, which extends about a hub portion 118 formed integrally with the rotary damper plate 104 and a corresponding hub portion 120 formed integrally with wave washer 112. The hub portions are axially aligned and extend into juxtaposition to each other such that clutch spring 116 can encircle both without extending across a significant gap therebetween.
The direction of wind of the clutch spring 116 is such that drive is transmitted from the rotary damper plate 104 to the wave washer 112 upon rotation in a direction corresponding to movement of the clutch shoes 86 into engagement with centrifugal clutch 20, while the clutch spring 116 slips in the opposite direction, such that wave washer 112 is not driven in this direction. This allows free movement of the clutch shoes 86 in a direction producing disengagement thereof and the disengagement of clutch is not thereby impeded.
Upon initiation of drive to the drive motor 18, either to establish agitation in the wash or rinse cycles or to spin in the extract cycle, shaft extension 90 is rotated, immediately initiating the pumping action either with the recirculation pump deck 34 or the drain pump deck 28.
Cup-shaped housing or input drive member 88 also rotates with shaft extension 90 and carries with it cover 96 and clutch shoes 86. The rotation of clutch shoes 86 causes them to pivot outwardly toward clutch drum or output drive member 80. The outward pivoting movement of clutch shoes 86 acts through connecting links 102 to rotate damper plate 104 relative to housing 88. This relative rotation is delayed by the inter-action of wave washer 112 and viscous liquid 114. This delays engagement of shoes 86 with surface 84 of drum 80. Therefore operation of transmission 21 via belt 22 (which is driven by drum 80) also is delayed. There is a period of pumping action prior to either cycle. This period is timed to enable either pump up of water in the basket 14 to drive the agitator 24, or pump down to the basket 14 prior to drive to the basket for the spin/extract cycle.
It will be appreciated that this delay period is introduced without the need for modification of increased complexity in the control system, but rather by the inherent operation of the centrifugal clutch 20.
Referring to FIGS. 4 and 5, an alternate form is depicted. In this version, the rotary damper plate 104 is drivingly connected to a pumping means consisting of a centrally located pumping gear 125 driving a pair of radial pumping gears 126 and 128.
The central pumping gear 125 is formed integrally with a gear hub 130 which is drivingly connected to the gear plate by means of the clutch spring 116 in similar fashion to the embodiment described above.
Gear hub 130 is supported on bearing 121 such as to be rotatable on shaft extension 90. Rotation of the central gear 125 causes pumping of a liquid such as oil, retained in a cup-shaped housing 88. This produces viscous damping forces resisting the rotation of the rotary damper plate 104.
The radial pumping gears 126 and 128 are rotatably supported by means of shaft 132 received in corresponding pockets formed in the cover 96 and the cup-shaped housing 88.
The pumping means could of course take many differing forms other than the gear pump version depicted.
It will be appreciated that these arrangements for producing the clutch retarding action are relatively simple in construction and highly reliable in operation. Also, since they do not involve the shifting of blocking members, they operate in a smooth fashion such that shock loadings are held to a minimum, and the noise at engagement is minimal. The resultant reduction in torque level at start in the agitation cycles or basket spin enables a less costly drive motor construction.
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A clothes washing machine of the type having recirculation of water from a tub into a perforated basket within which the clothes are received with a mechanically delayed action clutch driving both the agitator during wash and rinse cycles, and the basket during spin cycles. The mechanical delay in the case of the wash or rinse cycles enables a recirculation pump to bring the water level in the basket to the operating level after the machine fill prior to initiation of agitator drive. In the case of the spin cycle, the water level is reduced by a drain pump during the delay interval prior to initiation of the basket spin. The mechanical delay is introduced by a retarding action on the centrifugal drive clutch whereby after start of rotation of the drive motor, the full engagement of the centrifugally actuated clutch is delayed by a rotary damping action consisting of a washer caused to rotate through a volume of silicone liquid enclosed in a container.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/532,158 filed Jun. 25, 2012, which is a continuation-in-part of U.S. patent application Ser. No. 13/216,426 filed Aug. 24, 2011, entitled “Portable Height Adjustable Barrier for Screening Off the Source of Traffic Congestion,” the contents of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention is generally directed to a portable and wind-resistant barrier for visually screening areas from motorists to reduce “gawking” and resultant traffic congestion and related method.
BACKGROUND OF THE INVENTION
[0003] Vehicular traffic congestion often occurs as road use increases, such as during peak travel times. Such congestion is characterized by slower speeds, longer travel times, and often a sense of driver frustration. Causes of traffic congestion, or “traffic jams” may include, among other things, roadwork, detours, increased traffic volume such as during “rush hour”, and vehicle accidents.
[0004] Regardless of cause, traffic congestion is often exacerbated due to drivers slowing down to observe vehicles on the side of the roadway. This “gawking” or “rubber-necking” typically occurs when drivers slow to observe car accidents, wreckage, and emergency response vehicles. Such gawking often magnifies traffic congestion.
[0005] Besides merely extending driving times and inducing driver frustration, increased congestion due to gawking also creates costs related to non-productivity. Such delays are often responsible for lost business, job-related disciplinary action, and other personal losses. Inability to forecast travel times causes drivers to allocate more time to travel, additionally resulting in productivity losses. Increased wear and tear to vehicles is yet another cost incurred by those caught in traffic. Finally, longer commutes due to gawking harm the environment due to increased air pollution and carbon dioxide emissions.
[0006] While gawking continues to be a significant contributor to traffic congestion, very little has been done to alleviate this problem.
SUMMARY OF THE INVENTION
[0007] In view of the foregoing background, it is therefore an object of the present invention to provide a portable traffic vision screen to prevent or reduce traffic gawking, thereby reducing a primary cause of vehicular traffic congestion. Such a screen should be adjustable, scalable, and wind-resistant. Moreover, such screen should be free-standing.
[0008] The invention contemplates a wind-resistant portable traffic screen comprising a screen for the purpose of visually occluding one's view of matter behind the screen. A substantially vertical member holds the screen, and a fastener with the screen removably attaches the screen to the vertical member. The screen partially disengages from the vertical member upon exposure to a sufficient wind current. The purpose the disengaging screen is to reduce wind pressure exerted upon the screen and the vertical member. The screen re-engages the vertical member when the pressure from the wind current wanes.
[0009] In one embodiment of the portable traffic screen, a first and second support tube each have a top and bottom end. First and second inner retractable support tube extensions extend out of the top end of the first support tube and the second support tube, respectively. A retractable tripod assembly attaches to the bottom end of each support tube, and is situated to maintain the support tubes in a substantially vertical and free-standing orientation when the tripod assembly is in an expanded state. Ballast in communication with the tripod provides stability to the tripod assembly. The foldable screen has an upper edge, opposing lower edge, a side edge, and an opposing side edge, wherein the screen is attachable substantially between the support tubes.
[0010] Additionally, a magnet is in communication with each side edge of the screen, the magnet placed for removably attaching each side edge to a proximate support tube. The magnet is capable of partially disengaging the screen from the support tubes to relieve pressure exerted by a wind current.
[0011] The portable traffic screen further comprises a second foldable screen having a second upper edge, second opposing lower edge, second side edge, and a second opposing side edge, wherein the second screen is attachable substantially between the support tubes. A second magnet is in communication with each second side edge of the second screen, the second magnet placed for removably attaching each second side edge to a proximate support tube. The second magnet is capable of partially disengaging the second screen from the support tubes to relieve pressure exerted by a wind current.
[0012] In yet another embodiment, a portable traffic screen comprises a first and second extendable support tube. Each tube has a top and bottom end and each tube has a ferrous region. A hub is attached to each support tube, each hub having a size and dimension to engage a crossmember. A retractable tripod assembly is attached to the bottom end of each support tube, and the tripod assembly is situated for maintaining the support tubes in a substantially vertical, free-standing, orientation when the tripod assembly is in an expanded state. A foldable screen is attachable between the support tubes. Additionally, a substantially rigid crossmember attaches proximate a top edge of the screen, the crossmember being attachable to each hub.
[0013] A magnet is attached to a peripheral region of the screen, the magnet being positioned for removably attaching the peripheral region to the ferrous region of a proximate support tube. The magnet is capable of temporarily disengaging the screen from the support tubes to relieve pressure exerted upon the screen being created by a wind current. A cable attached between the screen and a support tube is present for limiting a distance the screen travels when the screen is temporarily disengaged from the support tube due to a wind current.
[0014] The invention also contemplates a method of assembling the traffic screen comprising the steps of expanding the tripod assembly of each support tube; standing each support tube in a substantially vertical orientation; extending each support tube; attaching the crossmember to the hub of each support tube; and attaching the cable to at least one support tube.
[0015] The method of assembling the traffic screen may also comprise the step of attaching a ballast proximate at least one tripod assembly and/or the step of adjusting the length of the cable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a fuller understanding of the invention, reference is made to the following detailed description, taken in connection with the accompanying drawings illustrating various embodiments of the present invention, in which:
[0017] FIG. 1 illustrates a perspective view of the assembly;
[0018] FIG. 2 illustrates side views of the assembly of FIG. 1 having an adjustable tripod;
[0019] FIG. 3 illustrates a perspective view of a weight skirt of the assembly in FIG. 1 ;
[0020] FIG. 4 illustrates a perspective view of the assembly of FIG. 1 in a used condition;
[0021] FIG. 5 illustrates a perspective view of a clip of the assembly;
[0022] FIG. 6 illustrates a perspective magnets embedded in a screen of the assembly shown in FIG. 1 ;
[0023] FIG. 7 illustrates a side view of the assembly illustrated in FIG. 1 exposed to wind;
[0024] FIG. 8 illustrates a cable of the assembly illustrated in FIG. 1 ; and
[0025] FIG. 9 illustrates a hub for attaching a screen to a vertical member of the assembly illustrated in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In the Summary of the Invention above and in the Detailed Description of the Invention and in the accompanying drawings, reference is made to particular features (including method steps) of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally.
[0027] The term “comprises” is used herein to mean that other ingredients, ingredients, steps, etc. are optionally present. When reference is made herein to a method comprising two or more defined steps, the steps can be carried in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where the context excludes that possibility).
[0028] In this section, the present invention will be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art.
[0029] FIG. 1 illustrates the portable traffic screen assembly 100 . The assembly 100 is a wind-resistant portable screen that is free-standing, and easily deployed on the side of a road in order to visually block matter behind the assembly 100 . The assembly 100 comprises support tubes 200 which are vertical members that provide support to other structures of the assembly 100 . Supported by the support tubes 200 is at least one screen 300 that is used to visually block matter, such as an accident, from the view of nearby onlookers. The onlookers are typically vehicle drivers, vehicle passengers, bike riders, and pedestrians.
Support Tubes
[0030] With continuing reference to FIG. 1 , the support tubes 200 are members intended to be deployed in a substantially vertical orientation. The support tubes are preferably hollow to save weight, and also made of a lightweight material. In a preferred embodiment, the support tubes 200 are made of aluminum, but other materials such as metals, plastics, and composite materials are also contemplated. In a preferred embodiment, the support tubes 200 comprise an extendable/retractable inner support tube 210 . The inner support tube 210 is a size and dimension to nest within the support tube 200 and slidingly engage an inner surface of the support tube 200 . A lock collar 220 on the support tube 200 provides the mechanism to maintain the inner support tube 210 in an extended position. A user adjusts the lock collar 220 between a locked and unlocked state, so that when the lock collar is in an unlocked state, the inner support tube 210 slides freely within the support tube 200 .
[0031] With reference to FIGS. 1-3 , a tripod 230 is attached to the base of the support tube 200 . The tripod comprises at least three legs 232 . The tripod 230 is adjustable so that the legs 232 fold to be approximately parallel to the support tube 200 for storage and transportation.
[0032] FIG. 2 illustrates one embodiment of the present invention that includes a tripod comprising a telescoping leg 234 . When the support tube 200 is arranged to be self-standing on flat ground, the legs 232 , 234 of the tripod 230 are substantially the same length. However, if the support tube 200 is arranged to be self-standing on uneven ground, the telescoping leg 234 of the tripod 230 is adjusted so that the support tube maintains an orientation that is substantially plumb.
[0033] As shown in FIG. 2 , and now also referring to FIG. 3 , a weight skirt 240 is placed over the legs 232 , 234 of the tripod 230 to add stability-providing ballast to the assembly 100 . In one embodiment, the weight skirt 240 comprises at least one panel configured to form a substantially pyramidal cover that rests upon the legs 232 , 234 . A hole 242 is defined by the configuration that allows the skirt 240 to fit over the support tube 200 , with the tube 200 projecting through the hole 242 . At least one weight is attached to the weight skirt 240 to provide mass to the skirt 240 for ballast. The weight skirt 240 is preferably substantially flexible so that it is easily folded for storage and transportation purposes. For use, the weight skirt is placed over the support tube 200 so that the tube 200 projects through the hole 242 , and the skirt 240 is further lowered and allowed to rest upon the tripod 230 .
Screen
[0034] FIG. 1 also illustrates the screen 300 . The screen is made from natural or synthetic materials. For example, without limitation, the screen 300 can be made from at least one of plastic, nylon, aramid, acrylic, PTFE, fluoropolymer, spandex, olefin, Ingeo, carbon, cotton, hemp, and bamboo. In a preferred embodiment, the screen 300 is made from a durable water repellent material.
[0035] With continuing reference to FIG. 1 , and turning also to FIG. 4 , each screen 300 has an upper edge 302 , and opposing lower edge 304 , and opposing side edges 305 . As illustrated, each support tube 200 supports a plurality of screens 300 .
[0036] A screen 300 comprises a rigid crossmember 306 that is attachable between support tubes 200 . In one embodiment, the screen 300 is configured to create a void wherein the crossmember 306 fits. The screen also defines a cutout 308 to allow exposure of the crossmember 306 for ease of handling and access to the crossmember 306 . The crossmember 306 is made of a substantially rigid material such as metal, polymer, plastic, or composite.
[0037] FIG. 5 illustrates a center clip 310 that attaches to the crossmember 306 of a (upper) screen 300 positioned below a like (lower) screen 300 . The clip 310 is attached to a center cable 312 . The center cable 312 is also attached to the (upper) screen 300 positioned above the like (lower) screen 300 . The length of the center cable 312 is adjustable, allowing the lower edge 304 of the (upper) screen 300 to move away from the crossmember 306 of the (lower) screen 300 an amount constrained by the length for which the center cable 312 is adjusted.
[0038] FIG. 6 illustrates a magnet 314 that is located with the screen 300 . Preferably, at least one magnet 314 is located proximate the side edge 305 . The magnet 314 is either attached to the outside of the screen 300 or installed inside the screen 300 . The support tube 200 comprises a ferrous region that engages the screen 300 and magnet 314 . In an alternative embodiment, the magnet 314 is a ferrous material, and the ferrous region of the support tube 200 is magnetic. The purpose of the magnet 314 is to hold the screen 300 attached to the support tube 200 . In another embodiment, both the support tube 200 and screen 300 comprise attracting magnetic regions.
[0039] As illustrated in FIG. 7 , in the case of exposure of the assembly 100 to wind (W), the wind (W) exerts a pressure on the assembly 100 , risking toppling the assembly 100 over. The magnets 314 attach the screen 300 to the support tube, but when the pressure upon the screen 300 exerted by the wind (W) exceeds that required to keep the magnets 314 (and therefore screen 300 ) engaged to the support tube 200 , the screen 300 releases from the support tube 200 relieving the wind pressure on the assembly 100 . In this case, when the wind pressure lessens, the screen 300 side edge 305 returns nearer the support tube 200 and the magnets 314 reattach to the support tube 200 .
[0040] In an alternative embodiment, a hook and loop fastener is used to releasably attach the screen 300 to the support tube 200 . Hook and loop fastener may be used alone, or in conjunction with the magnets 314 .
[0041] As illustrated by FIG. 8 , one embodiment of the assembly 100 comprises a cabled fastener 316 attached to the support tube 200 and also proximate the side edge 305 of the screen 300 to limit the distance the screen 300 travels when pressure upon the screen 300 is exerted by the wind (W). The cabled fastener 316 comprises a static or elastic cable such as rope or elastic bands. In the embodiment illustrated in FIG. 8 , the cabled fastener 316 is a bungee ball tie.
[0042] As illustrated in FIG. 4 , the crossmember 306 spans between, and attaches to, adjacent support tubes 200 . FIG. 9 illustrates a hub 202 that is attached to a support tube 200 for engaging the crossmember 306 . The hub 202 has a body with a circular center aperture 212 which encircles the support tube 200 . The hub has a top surface 214 , a bottom surface 216 , and six slots 204 . The slots 204 extend coaxially with the center aperture 212 . The slots 204 are spaced 60 degrees apart radially about the center opening 211 and extend from the top surface 214 of the body to the bottom surface 216 . Each support tube 200 has at least one hub 202 , and preferably has a hub situated proximate the middle of the support tube 200 and another situated proximate the top of the support tube 200 . Additionally, each crossmember 306 comprises a swivel pin 318 . The swivel pins are of a size and dimension to securely mate to the slots 204 , providing an attachment point between the crossmembers 306 and support tubes 200 . The slots 204 are arranged radially about the support tube 200 so that multiple assembly 100 configurations are possible. FIG. 4 illustrates a configuration wherein screens 300 are arranged in a substantially linear fashion with respect to each other.
Method
[0043] The invention contemplates a method of assembling the traffic screen assembly 100 described herein. In particular, the steps included in the method are expanding the tripod 230 of each support tube 200 so that the support tube has a base on which it can stand. This is followed by standing each support tube 200 in a substantially vertical orientation. In embodiments of the invention with an extendable support tube 200 , the support tubes 200 are extended. To mount the screens 300 , crossmembers 306 are attached to the hub 202 of each support tube 200 , and each cable 316 is attached to a proximate support tube 200 . The length of the cable 316 is adjusted based on wind conditions. Additionally, ballast typically in the form of a weight skirt 240 is attached proximate at least one tripod 230 .
[0044] Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.
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A wind-resistant portable traffic screen assembly comprising a screen to visually occlude matter behind the screen for the purpose of preventing traffic jams and generally blocking accidents, crime scenes, and other distractions from public view. The traffic screen comprises a substantially vertical member having a hub for mounting the screen in a variety of positions to the vertical member. The hub has a plurality of slots for accepting ends of a cross member supporting the screen.
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CROSS REFERENCE TO RELATED APPLICATION
This application relates to an pending U.S. patent application Ser. No. 09/479,352 entitled SYSTEM AND METHOD FOR USE OF SECONDARY STORAGE WITH A HANDHAND PALM COMPUTER, filed on Jan. 7, 2000 and assigned to a common assignee, and hereby incorporated herein in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to handheld computers, and more particularly relates to handheld computers using a palm operating system, and even more particularly relates to a system and method for using fat file systems in a handheld computer using the palm operating system.
BACKGROUND OF THE INVENTION
In the past, users of handheld computers using the palm operating system and derivatives thereof have been required to use a special file management system unique to the palm operating system environment. While this prior art palm file management system has been very successful in the past, it has several drawbacks.
First of all, the palm operating system environment does not have the capability for enhancement of the system through the use of secondary data storage devices. Secondly, the palm operating system environment does not support industry standard files such as normally used in personal computers. The palm operating system and derivatives of it are limited to use of .prc and .pdb formatted files, which are hereafter referred to as “palm file formats”. Conversely, all file formats other than .prc and .pdb may be referred to hereafter as “non-palm file formats”.
Consequently, there exists a need for improvement in use of secondary storage and standard pc formatted files used with handheld computers using a palm operating system and similar operating systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to enhance the capabilities of handheld computers.
It is another object of the present invention to provide secondary storage for a handheld computer using a palm operating system like operating system.
It is a feature of the present invention to include a File Allocation Table (FAT) file system, (hereafter collectively referred to as “Ffs”) in conjunction with a palm operating system like operating system.
It is an advantage of the present invention to provide the capability for secondary storage and use of pc industry standard file types in a palm operating system environment.
The present invention is an apparatus and method for enhancing the capabilities of a handheld computer using the palm operating system by use of an Ffs, which is designed to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features, and achieve the already articulated advantages. The present invention is carried out in a “.prc and .pdb -less system” in a sense that the limitation to using only .prc and .pdb file extensions has been eliminated.
Accordingly, the present invention is a system and method for enhancing the capabilities of a handheld computer using the palm operating system, which is operable with an Ffs.
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 simplified block diagram representation of the enhanced operating system software of a handheld computer of the present invention.
DETAILED DESCRIPTION
Now referring to the drawings, where like numerals refer to like text throughout, and more particularly to FIG. 1, there is shown a simplified block diagram of the present invention, generally designated 100 , including a Palm OS block 102 , which represents prior art and well-known operating system software commercially available from 3COM corporation for use in conjunction with handheld computers manufactured and sold by 3COM, hereafter Palm computers. The term “handheld computer” is intended to be construed broadly so as to include any handheld electronic device which processes information such as portable phones, scanners, etc. The above-referenced patent application also includes discussion with respect to the Palm OS. Also shown in FIG. 1 is SanDisk compact flash software block 104 , which represents prior art, well-known and commercially available software from SanDisk Corporation of Sunnyvale Calif. SanDisk compact flash software block 104 includes well-known and industry standard software used to implement Ffs's in compact flash devices in conjunction with the Windows family of operating systems. The present invention achieves its beneficial aspects through combination of Palm OS block 102 , SanDisk compact flash software block 104 , and TRGpro interface software 106 , which is novel and innovative software used to port the SanDisk compact flash software block 104 to the Palm OS block 102 .
The following description is first intended to provide broad background information, then provide detailed information relating to one preferred approach to carrying out the present invention.
FAT File System Library
This section of the detailed description is intended to introduce the use of, and provide a reference to, the Ffs (FAT File System) Library procedures. It is directed toward Palm OS application developers who wish to access CF cards from within their applications. It is assumed that the reader is familiar with the C programming language, in particular within the context of the Palm OS.
Section 1 of this document gives background detail on the FAT file system. Section 2 describes the use of shared libraries in Palm OS applications, summarizing the functionality provided by the Ffs Library. Section 3 details the shared data structures used by multiple functions in the Ffs library and describes each of the library calls, describing their function, parameters, and return value. Section 4 lists the possible error codes and their interpretation, and Section 5 discusses a sample project.
Section 1—FAT File System Overview
The FAT file system in this document refers to a system of file management on a storage device. The device is divided into clusters, each of which can be composed of one or more sectors. A cluster can be in one of three states:
Allocated to a file
Allocated to a directory
Unused or free
The mapping of the clusters is contained in a File Allocation Table (FAT), which is where the file system gets its name.
TRGPRO and the FAT File System
The handheld computer of the present invention, hereafter referred to as “TRGpro”, is merely an example of many different approaches to practicing the present invention. In this example, the TRGpro is a computing device built upon industry standards. It was designed with a slot to accept CompactFlash devices, which are rapidly becoming the standard for handheld computers. In keeping with this eye toward standards, its internal implementation for accessing CompactFlash memory cards is based upon a FAT file system.
The true advantage to using the FAT file system is that it is a standard also supported by PC's running any of the following operating systems:
MS-DOS (all versions)
Windows 3.1
Windows 95
Windows 98
Windows NT (all versions)
Windows 2000
For the TRGpro, the removable media is a CompactFlash memory card, but other media could be used as well. It should be noted that while it is believed that CompactFlash devices and memory cards may be presently be the preferred media for secondary storage of information, the present invention is intended to include uses of other secondary storage media such as multimedia cards, disk drives and etc. The benefits of a Ffs in combination with a Palm OS like operating system can be achieved irrespective of any particular secondary storage implementation.
Section 2—Ffs Library Overview
The Purpose of the FAT File System Library
The FAT File System (Ffs) shared library provides an interface to Compact Flash (CF) cards containing a FAT File System. The interface is based upon the unbuffered file/disk system and library calls typically used with the C language. Support is provided for manipulating both files and directories, simplifying the exchange of data between the Palm device and a PC. In addition, the high-capacities of existing CF cards allow Ffs-aware applications to create, read, and modify files much larger than the total storage space available on existing Palm devices. A document reader, for example, could access documents directly on a CF card, without first having to move the documents in the Palm device RAM or Flash.
Loading, Unloading, and Accessing the FFS Shared Library
Currently, the Ffs Library is implemented as a Palm OS shared library. To access the Ffs calls, an application must search for the library, load the library if not found, then open the library. Opening the library returns a library reference number that is used to access the individual functions within the library. When the application is finished with the library, it should close the library. The current version of the library does not support the sharing of open files between applications, and only one application should have the library open at any one time (though the system may have it open, also).
In one embodiment the calling application must include the header file ffslib.h. The source code of ffslib.h is included in its entirety at the end of this detailed description. This file contains the required constant definitions, structure typedefs, and function prototypes for the library. In addition, this file maps library functions calls to the corresponding system trap instructions, through which all library routines are accessed. If the caller requires notification of CF card insertion/removal events, it must also include notify.h and the PalmOS header NotifyMgr.h (requires OS 3.3 headers).
To find a loaded library, an application calls SysLibFind, specifying the library. If not found, an application loads the library using SysLibLoad, specifying the library type and creator IDs. For the Ffs library, the name, type and creator IDs are defined in ffslib.h as FfsLibName, FfsLibTypeID and FfsLibCreatorID, respectively. After loading the library, it must be opened with a call to FfsLibOpen. Opening the library allocates and initializes its global variables, and sets up the CF socket hardware.
Once the library is open, the application may make calls to the library functions. The first parameter to a library call is always the library reference number returned when the library is loaded. Most library calls return an integer result of 0 on success and −1 on failure. A more specific error code may be obtained through another library call.
The application that opens the library is responsible for closing and optionally unloading the library. The library is closed with the FfsLibClose call, and unloaded with the SysLibRemove call. The library can only be removed, however, if it is not in use by the system, as indicated by the value 0 returned from FfsLibClose. If still in use, FfsLibClose returns FFS_ERR_LIB_IN_USE. It is possible for an application to leave the library loaded when exiting. The library may then be accessed by other applications through the SysLibFind call, which returns a reference to an already-loaded library. Once the reference number is obtained, the library is opened as usual with FfsLibOpen call. In either case, however, the caller must open the library on startup and close it on exit. The library should not be left open between applications.
Currently, the name of the Ffs library used for SysLibFind is “Fsf.lib,” the creator ID is “FfsL,” and the type ID is “libr.” These constants are all defined in ffslib.h.
Summary of FFS Library Functions
The Ffs library calls may be grouped into six categories: disk management, directory management, file access, file management, library management, and error handling. The calls, grouped by category, are listed below, with brief descriptions of each call's function. An alphabetical listing with a detailed specification of each call is given in section 3.
Disk management
• FfsCardIsATA
check if inserted card is an ATA device.
• FfsCardInserted
check if a CF card is inserted.
• FfsFlushdisk
flush all buffers to flash.
• FfsFormat
format the card.
• FfsGetdiskfree
get the total size of the CF disk, and the
amount of free space.
• FfsGetdrive
get the current working drive number.
• FfsSetdrive
set the current working drive number.
Directory management
• FfsChdir
change the current working directory.
• FfsFinddone
free resources after a directory search.
• FfsFindfirst
start a directory search.
• FfsFindnext
continue a directory search.
• FfsGetcwd
get the current working directory.
• FfsIsDir
check if the specified path is a directory or
file.
• FfsMkdir
create a directory.
• FfsRename
rename a directory.
• FfsRmdir
remove a directory.
File access
• FfsClose
close a file.
• FfsCreat
create a new file.
• FfsEof
check if the current file pointer is at the end
of the file.
• FfsLseek
move a file pointer.
• FfsOpen
open/create a file.
• FfsTell
get the current file pointer value.
• FfsWrite
write to a file.
File management
• FfsFlush
flush an open file to disk.
• FfsFstat
get information about an open file.
• FfsGetfileattr
get file attributes.
• FfsRemove
delete a file.
• FfsRename
rename a file.
• FfsSetfileattr
set file attributes.
• FfsStat
get information about a file.
• FfsUnlink
delete a file (same as FfsRemove).
Library management
• FfsGetLibAPIVersion
get the Ffs library version number.
• FfsLibClose
close the library.
• FfsLibOpen
open the library.
Error handling
• FfsGetErrno
get the current global error result code.
• FfsInstallErrorHandler
install a critical error handler callback
function.
• FfsUnInstallErrorHandler
remove the critical error handler callback
function.
For the most part, these functions implement the low-level unbuffered I/O functions found in the C language. The buffered stream I/O functions, such as fopen and fprintf, are not supported, though they could be built on top of the Ffs library layer.
Although many Ffs library calls accept a drive letter as part of the path string, and routines are provided to get and set the default drive, the Ffs library and Nomad hardware currently support only a single drive. This drive is signified as number 0 or 1 (0 indicates current drive, 1 indicates the first drive), and path “A:”.
The Global Error Result Code
Most of the Ffs library calls return an integer error indicator, set to 0 for success and −1 for failure. Library calls that return some other type of value, such as a pointer or file offset, always reserve one value to indicate an error. In either case, a specific error code is loaded into the global ermo variable. The ermo variable is not cleared on a successful call, so at any given time it contains the last error code generated. The current errno value may be retrieved by calling FfsGetErrno.
Critical Error Handler Callback
If an I/O error occurs when accessing the CF card, a critical error handler is called. The critical error handler is responsible for deciding whether to abort or retry the current operation, to mark a failed sector as bad, or to reformat the card. The actual choices available in a specific situation are dependent on the type of critical error that occurred, and are determined by the internal critical error handler.
Regardless of the type of critical error that occurred, “abort current operation” is always a choice, and is the default action taken by the critical error handler. The calling program may supply its own critical error handler, however, to prompt the user for the desired course of action. A custom critical error handler is installed by a call to FfsInstallErrorHandler. The custom error handler takes as parameters a drive number, a code indicating the valid responses, and a string containing the specific error message, and returns the desired course of action. In current versions of the library, the drive number will always be 0. The codes defining the valid responses are listed below, along with corresponding course of action codes:
CRERR_NOTIFY_ABORT_FORMAT: CRERR_RESP_ABORT or CRERR_RESP_FORMAT.
CRERR_NOTIFY_CLEAR_ABORT_RETRY: CRERR_RESP_ABORT, CRERR_RESP_RETRY, or CRERR_RESP_CLEAR.
CRERR_NOTIFY_ABORT_RETRY: CRERR_RESP_ABORT or CRERR_RESP_RETRY.
The course of action codes are interpreted by the internal critical error handler as follows:
CRERR_RESP_ABORT: Abort the current operation.
CRERR_RESP_RETRY: Retry the current operation.
CRERR_RESP_FORMAT: Attempt to format the card.
CRERR_RESP_CLEAR: Clear corrupt sector and retry the current operation.
These codes are all defined in file ffslib.h.
The custom critical error handler will typically display an alert box containing the error message text passed in from the internal critical error handler and prompting the user with the choices appropriate for the error type. For example, if the CF card is removed during an operation, the custom error handler will be called with a response code of CRERR_NOTIFY_ABORT_RETRY and an error message of “Bad card”. The error handler would then display an alert with buttons for “Abort” and “Retry”. Note that the “Abort” button should return the default value 0, in case the user presses an application launch button when the alert is displayed (in this case, the system will force the default return value from all alerts until the running application terminates).
Card Insertion/Removal Notify
When a CF card is removed while the Ffs Library is loaded, the library automatically clears all data structures associated with the card and reinitializes in preparation for the next card. Thus, if a card is removed during a library call, the library will not be able to complete the call even if the card is reinserted. This is an unfortunate side effect of the fact that most CF storage cards are missing the unique serial number in the drive ID information that is used to identify the cards. Because of this omission, the library is unable to determine if a reinserted card is identical to the previously loaded card.
The library reinitialization is invisible to the calling application. In order to notify the caller of insertion/removal events, a launch code can be sent by the system to the application. Applications “register” at startup for notification of CF insertion/removal events, and are then sent the launch code sysAppLaunchCmdNotify when these events occur. The cmdPBP points to a
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A handheld computer which uses a palm operating system and which incorporates a compact flash (CF+) interface for secondary data storage or interface to other devices and uses a FAT file system for file management with said CF+ media. The disclosure further include references to alternate types of secondary storage such as disk drives and multimedia cards and further discloses that the handheld computer may be embodied in a portable telephone of scanner.
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FIELD OF THE INVENTION
The present invention relates generally to the field of tubing assemblies. More particularly, the present invention relates to a structure or apparatus for distinguishing between different tubing assemblies.
BACKGROUND OF THE INVENTION
Stoppers are widely used to seal a vessel or to limit the ability of the contents to escape from the vessel. Some stoppers are solid and thereby prevent any of the matter from entering or leaving the container, while others may include one or more apertures that allow one or more tubes to be inserted into the container. When more than one tube is inserted through a stopper into a vessel, the tubes may be used for different functions or may carry different materials. For example, one tube may be used to insert a certain substance into the vessel, while another tube may be used to remove matter from the vessel or to insert another substance into the vessel. The tubes also may be inserted into the container at different depths so as to remove different layers of matter, or to remove different phases of matter, such as a gas or a liquid. Thus, it is important that one is able to distinguish between the tubes and the different functions of those tubes.
Clear or translucent tubing is widely used and can be helpful in some situations in distinguishing between the different tubes. However, in many situations, being able to see the contents of the tubing does not enable one to distinguish between the tubes. Different tubes may be carrying substances that look similar or they may be carrying clear or substantially transparent substances. Moreover, it may be necessary to distinguish between the tubes at a time when they are empty, such as during the assembly and set up of a particular arrangement of tubes and vessels, in which case being able to see through the tubes is unhelpful.
Various method and techniques have been used to improve one's ability to distinguish between different tubes. One such method is to attach a label or some other indication to the tube and/or the stopper using various adhesives. However, such adhesives generally have not been found to reliably bond to the materials commonly used to make stoppers and tubes. Moreover, physically attached signs or labels can, overtime, become worn and illegible, or may eventually become detached from the appropriate stopper or tube. Such labels may also be difficult to read from a plurality of different angles and may, depending on the environment in which the stopper and the tubes are used, become difficult to read due to debris that may build up on the labels.
Another method or technique used to place identifiers on stoppers and/or tubes consists of placing labels on the outside of the tubes or stoppers and then molding over the labels. This overmolding technique creates a raised section on the stopper or tubing and involves a additional manufacturing process, which generally results in additional manufacturing costs.
Accordingly, it would be advantageous to provide a structure or apparatus that would enable someone to distinguish between different tubes and/or stoppers regardless of the environment in which they are used. Moreover, it would be advantageous to provide such a structure or apparatus that could not easily be removed or worn off and that would not also require additional manufacturing processes. Additionally, it would be advantageous to provide a structure or apparatus for differentiating between different tubes and/or stoppers that would be effective when viewed from any of a wide range of directions. Furthermore, it would be advantageous to provide such a structure or apparatus that would not physically distort the shape of the tubing or other parts of the tubing assembly or contaminate the substances used in connection with the tubing assembly.
Accordingly, it would be advantageous to provide an apparatus for distinguishing between tubing assemblies that has any one or more of these or other advantageous features.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for use in identifying or distinguishing at least one substance or article associated with the apparatus that comprises a translucent body and an identification formation. The translucent body is for defining or engaging an opening. The identification formation is embedded in the translucent body in a predetermined relationship with the opening. At least one characteristic of the identification band is visible through the translucent body.
The present invention also relates to an apparatus for use in conjunction with tubing assemblies and vessels that comprises a translucent body and an identification formation. The translucent body is configured to be releasably coupled to a mating portion of a tubing assembly or a vessel and includes an aperture that extends through the translucent body. The identification formation is embedded within the translucent body and substantially surrounds the aperture in the translucent body.
The present invention further relates to a stopper for coupling to an open end of a vessel and for allowing tubes to pass through the stopper into the vessel that comprises a translucent silicone body and at least one colored ring. The translucent silicone body is configured to releasably couple to the vessel and includes at least one aperture that extends through the translucent silicone body and that is configured to receive a tube. The at least one colored ring is embedded in the translucent body, and each colored ring substantially surrounds an aperture. The color of each ring is associated with a particular tube.
The present invention also relates to a method of making an apparatus for use with tubing assemblies and vessels that comprises the step of preparing a mold for a translucent body that includes at least one aperture that extends through the translucent body. The method also comprises the steps of inserting an identification formation into the mold and molding the translucent body around the identification formation such that the identification formation corresponds to the aperture.
The present invention still further relates to a tubing system for use with at least one vessel that comprises a translucent body, a first identification formation, a second identification formation, a first tube, and a second tube. The translucent body is configured to releasably couple to the vessel and includes a first aperture and a second aperture. Each aperture extends through the transulcent body and is configured to receive a tube. The first identification formation substantially surrounds the first aperture and has a first set of characteristics visible through the translucent body. The second identification formation substantially surrounds the second aperture and has a second set of characteristics visible through the translucent body. Each identification formation is embedded in the translucent body. The first tube cooperates with the first aperture and is associated with the first set of characteristics. The second tube cooperates with the second aperture and is associated with the second set of characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tubing system according to one embodiment.
FIG. 2 is a cross-sectional view of the stopper of FIG. 1 taken along a stepped line that passes through the center of each aperture.
FIG. 3 is a cross-sectional view of a stopper according to another embodiment.
FIG. 4 is an exploded cross-sectional view of a coupling apparatus according to one embodiment.
FIG. 5 is a perspective view of a tubing system according to another embodiment.
FIG. 6 is a top cross-sectional view of a stopper according to another embodiment.
FIG. 7 is a top cross-sectional view of a stopper according to another embodiment.
FIG. 8 is a top cross-sectional view of a stopper according to another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , a tubing system 10 is shown according to a preferred embodiment. Tubing system 10 includes a vessel 12 , a stopper 14 , and tubes 16 , 18 , and 20 .
Vessel 12 may be any one of a variety of different containers, beakers, bottles, canisters, flasks, receptacles, tanks, vats, vials, etc. that are generally used to hold or contain substances or articles. Vessel 12 may be made from a number of different materials (such as a polymer, glass, wood, ceramic, etc.) and may take one of a plurality of different shapes and sizes. According to a preferred embodiment, vessel 12 is of a type used in the pharmaceutical industry and has an open first end 22 , side wall(s) 24 , and a closed bottom end (not shown). Open first end 22 is configured to receive stopper 14 , which may be used to help retain or control the substance or matter within vessel 12 .
Tubes 16 , 18 , and 20 are each silicone tubes that are used extensively in medical, pharmaceutical, chemical, and other applications. The tubes may have one of a plurality of different diameters and wall thicknesses, depending on the application in which the tubes are utilized and on the substances, matter, or materials the tubes are used to transport. Generally, tubes 16 , 18 , and 20 are used to transport a substance from one location to another, such as from one vessel to another. According to alternative embodiments, the tubes may be made from any one of a variety of materials suitable for the particular purpose of each tube. Silicone is one material that is often used to make such tubes.
Stopper 14 , a device for substantially obstructing or hampering the movement of the substance or matter within vessel 12 , may be a variety of different sizes, shapes, and configurations. According to a preferred embodiment, stopper 14 includes a body 26 and identification formations 44 , 46 , and 48 .
Body 26 of stopper 14 includes an upper region 30 , a middle region 32 , and a lower region 34 . Lower region 34 and middle region 32 cooperate to seal against open end 22 of vessel 12 when stopper 14 is coupled to vessel 12 . Lower region 34 extends from the underside of middle region 32 and has a frusto-conical shape (e.g. the diameter of lower region 34 decreases as it extends away from the underside of middle region 32 ). The taper of lower region 34 allows lower region 34 to form a progressively tighter seal against an inside surface of open first end 22 of vessel 12 as lower region 34 is pushed further into open end 22 of vessel 12 . Middle region 32 has a diameter that is greater than the largest diameter of lower region 34 and is intended to serve as both a stop and/or a secondary seal. An underside 36 of middle region 32 is substantially flat and contacts first end 22 when stopper 14 is pushed completely onto first end 22 of vessel 12 . The contact of middle region 32 with first end 22 of vessel 12 serves to prevent stopper 14 from being pushed further into vessel 12 and may form at least a partial seal between stopper 14 and vessel 12 . Upper region 30 is a generally cylindrical extension that projects from middle region 32 in a direction opposite the direction of the extension of lower region 34 . As shown in FIG. 2 , the transition from cylindrical side 31 of upper region 30 and distal end wall 33 of upper region 30 may be beveled or radiused. Upper region 30 has a diameter that is less than the diameter of middle region 32 but greater than the diameter of lower region 34 , and upper region 30 may serve to at least partially reduce the deflection of middle region 32 that may otherwise result from the force generated when middle region 32 contacts open end 22 as stopper 14 is pushed into vessel 12 . According to alternative embodiments, the stopper (and each of the lower portion, middle portion, and upper portion) may take any of a wide variety of shapes and may be adapted to cooperate with a wide variety of different vessels or containers.
Referring still to FIG. 1 , body 26 also includes three apertures 38 , 40 , and 42 , which extend through body 26 . Each of apertures 38 , 40 , and 42 are sized to allowed tubes 16 , 18 , and 20 , respectively, to fit inside of the apertures and to extend through stopper 14 into vessel 12 . According to an alternative embodiment, body 26 may include any number of apertures, and the apertures may be sized to accommodate a variety of different tubing sizes.
According to a preferred embodiment, the body is molded from a translucent silicone. However, according to alternative embodiments, the body may be made from one of, or a combination of, a variety of different materials, including but not limited to polymers and rubbers.
Referring to FIGS. 1 and 2 , stopper 14 is illustrated as including three identification formations shown as washers, rings, or bands 44 , 46 , and 48 . Identification formations 44 , 46 , and 48 are generally circular, with each having an opening 52 , 54 , and 56 , respectively, in the center of the identification formation. Identification formations 44 , 46 , and 48 are located within body 26 of stopper 14 such that openings 52 , 54 , and 56 generally align with, and identification formations 44 , 46 , and 48 generally circumscribe (or generally surround), apertures 38 , 40 , or 42 , respectively. In such a configuration, each identification formation corresponds to a particular aperture in stopper 14 and may serve to allow a user of stopper 14 to differentiate between the different tubes interacting with each of the different apertures.
To allow a user to distinguish between the different tubes, each identification formation possesses a certain set of characteristics that a user may use as a basis for comparison with other identification formations. For example, if one tube is used for a particular purpose or to transport a specific substance, the identification formation associated with the aperture through which the tube extends may have a certain set of characteristics. If another tube is used for a different purpose or to transport a different substance, the identification formation associated with the aperture through which the tube extends may have a set of characteristics different from the set of characteristics associated with the first tube. If the tubes perform the same function, transport the same substances, or are similar in some other respect, the identification formations associated with the tubes may have the same set of characteristics. In this way, the identification formations may be used to distinguish between the different tubes that are coming into and out of a particular vessel or system of vessels.
Because body 26 is preferably made from a translucent material, the set of characteristics of any identification formation preferably includes any characteristic that is visible through body 26 . Accordingly, the characteristics of an identification formation may include, but are not limited to, color, size, shape (both overall and cross-sectional), orientation, formation, etc. The combination of these individual characteristics forms a characteristic set.
According to alternative embodiments, the color of an identification formation may be any one of a plurality of different colors, color combinations, or pattern of colors. Furthermore, a stopper may include one or more identification formations, with each identification formation being the same color, a different color, or with some identification formations being the same color and some being different colors. For example, in the embodiment illustrated in FIG. 2 , identification formations 44 , 46 , and 48 are shown (through cross-hatching) as being blue, green, and red, respectively.
According to other alternative embodiments, an identification formation may be any of a variety of sizes, provided the identification formation conforms with the limitations established by the size of the stopper and the apertures provided in the stopper. For example, in one embodiment, the aperture in an identification formation may have the same diameter as the opening the identification formation circumscribes and may form a portion of the wall defining the opening in the stopper. In another embodiment, the diameter of the aperture may be larger than the diameter of the opening in the stopper such that the identification formation forms no part of the wall defining the opening in the stopper. Moreover, the width of the identification formation or band (e.g. the distance between the outer diameter of the identification formation and the diameter of the aperture) may be varied. According to other alternative embodiments, other dimensions and/or proportions of the identification formation may be varied.
According to still other alternative embodiments shown in FIG. 6 , the overall shape of the identification formation may be any one of a plurality of different shapes, including circular, square, rectangular, triangular, football-shaped, octagonal, star-shaped, or any of a variety of other shapes. As with the overall shape, the shape of the cross-section of an identification formation may also be any one of a variety of different shapes, including rectangular, square, circular, triangular, football-shaped, oval, or any of a variety of other shapes.
According to further alternative embodiments, the orientation of the identification formation may also serve as a characteristic of the identification formation. For example, the identification formation may be positioned such that it is substantially perpendicular to the central axis of the stopper or to the central axis of the aperture to which it corresponds, or it may be positioned at any other angle with respect to the central axis. According to other alternative embodiments, the identification formation may be configured such that a specific portion of the identification formation points in a particular direction or such that the identification formation is located on a certain side of the aperture to which it is associated.
According to still further alternative embodiments, the identification formation may be provided in a plurality of different formations. For example, the identification formation may be comprised of a single, continuous element or segments (as illustrated by identification formations 60 , 62 , and 64 in FIG. 6 ), or the identification formation may be comprised of multiple, discontinuous elements (as illustrated by identification formations 66 , 68 , and 70 in FIG. 7 ). If the identification formation is made up of multiple, discontinuous elements or segments, each segment may be a letter (such as in identification formation 72 in FIG. 8 ), a number (such as in identification formations 74 and 76 in FIG. 8 ), or any other shape or design (such as in identification formations 66 , 68 , and 70 in FIG. 7 ). Whether the identification formation is made up of a single segment or multiple segments, the identification formation is generally of such a design that the identification formation corresponds to an aperture in the stopper.
According to yet another alternative embodiment shown in FIG. 3 , an identification formation shown as ring 50 may correspond not to a particular aperture in the stopper, but rather to an entire stopper 58 or to the vessel into which stopper is configured to be inserted. Thus, if a particular stopper is to be used with a particular substance or a particular vessel, an identification formation similar to ring 50 may be used to distinguish one stopper from the next. Instead of circumscribing a particular aperture, ring 50 is provided substantially along the outer edge of stopper 58 and circumscribes the apertures as a group. According to alternative embodiments, the identification formation may be provided in any region of the stopper (e.g. the upper, middle, or lower region). According to other alternative embodiments, the identification formation may share an outer surface with the stopper (e.g. have an outer diameter equal to that of the stopper), or the identification formation may have an outer diameter that is less than the outer diameter of the stopper. According to still other alternative embodiments, the identification formation may be used alone or in conjunction with other identification formations, such as identification formations that correspond to a particular opening or aperture that may be provided in the stopper.
Referring now to FIG. 4 , an apparatus 100 (e.g. coupling apparatus, tube coupling, end, coupler, mating couplings, tubing apparatus etc.) for coupling two tubes together is shown. Apparatus 100 includes a male end 102 and a female end 104 .
Male end 102 includes a cylindrical body portion 106 and a tube portion 108 , each of which defines an opening 110 that extends continuously through the central axis of each of body portion 106 and tube portion 108 . According to a preferred embodiment, body portion 106 and tube portion 108 are constructed from a translucent material, with tube portion 108 extending from one end of body portion 106 and being integrally formed with body portion 106 . Body portion 106 has a greater diameter than tube portion 108 , and the transition from tube portion 108 to body portion 106 is gradual (e.g. tapered, beveled, or stepped). According to alternative embodiments, the transition may be abrupt.
Body portion 106 includes a flat face 112 , a protrusion 114 , and an identification formation 116 . Face 112 (e.g. sealing surface, surface, plane, etc.), which is formed on the end of body portion 106 that is opposite the end from which tube portion 108 extends, is a generally flat plane that is oriented perpendicular to the central axis of body portion 102 . Protrusion 114 extends perpendicularly and outwardly from face 112 and encircles opening 110 .
Identification formation 116 is substantially similar to the identification formations described above in relation to the stopper. According to a preferred embodiment, identification formation 116 is a washer or ring embedded within body portion 106 that has an aperture extending therethrough that shares a central axis or center point with opening 110 . According to alternative embodiments, as described above in relation to identification formations included in stoppers, the identification formation in male end 102 may include a particular combination or set of characteristics that are discernable through translucent body portion 106 . These characteristics may include, but are not limited to, color, size, shape (both overall and cross-sectional), orientation, formation, etc. By comparing the set of characteristics of the identification formation embedded in the male end with the set of characteristics of identification formations embedded in various female ends, the male end can be matched with the appropriate female end, and vice versa. This technique helps to ensure that the right tubes get coupled together and helps reduce the effort that would otherwise be required to trace various tubes back to their sources to determine which tubes should be connected together.
Female end 104 is substantially the same as male end 102 , with the only difference being that instead of having a projection extending from a face 120 , female end 104 includes a groove or channel 118 that is configured to receive projection 114 of male end 102 . When coupled together, face 112 of male end 102 contacts face 120 of female end 104 to form at least a partial seal. To maintain tubing apparatus 100 in a coupled position, male end 102 and female end 104 each include a flange 122 that has a greater diameter than the body portion of male end 102 and female end 104 . A clamp or band (not shown) encircles the region of greater diameter formed by the flanges and thereby couples the flanges together to prevent male end 102 and female end 104 from becoming separated.
Referring now to FIG. 5 , various tubes, stoppers, coupling apparatuses, and vessels are shown in a tubing system 200 . As shown, the system includes three vessels 202 , 204 and 206 that are covered by stoppers 208 , 210 , and 212 , respectively. Each stopper includes three apertures and each aperture has a tube passing through it. Two coupling apparatuses 214 and 216 are shown, with coupling apparatus 214 serving to couple tube 218 a with tube 218 b and with coupling apparatus 216 serving to couple tube 220 a with tube 220 b. Three identification formations are provided in each of stoppers 208 , 210 , and 212 , with one around each aperture. Moreover, one identification formation is provided in each portion (e.g. male and female portion) of each of coupling apparatus 214 and 216 .
As one example of how the identification formations can be used to distinguish between different tubes, consider the following situation. Assume vessel 202 includes a substance (substance 1 ) that needs to be added to both of vessels 204 and 206 . Assume further that vessel 204 includes a substance (substance 2 ) that needs to be added to vessel 206 after substance 1 is added to vessel 204 . Finally, assume that substance 1 needs to be added to vessel 206 after substance 2 is added to vessel 206 . In such a situation, identification formations 222 b and 222 c may have the same set of characteristics because the tubes associated with identification formations 222 b and 222 c will be transporting the same substance. Moreover, identification formations 224 b and 226 c may have the same set of characteristics as 222 b and 222 c to indicate that the substance from vessel 202 is being transported to vessels 204 and 206 . Similarly, identification formation 224 a may have the same set of characteristics as identification formation 226 a to indicate that substance 2 is being transported from vessel 204 to vessel 206 . Additionally, identification formations 222 a, 224 c, and 226 b may each have a set of characteristics that corresponds to the substance carried by, or to the purpose of, the tube associated with each identification formation. Identification formations 228 a and 228 b of coupling apparatus 214 may have the same set of characteristics to indicate that the male portion containing identification formation 228 a should be coupled to the female portion containing identification formation 228 b. Identification formations 228 a and 228 b may also have the same set of characteristics as identification formations 222 c and 226 c to indicate that tubes 218 a and 218 b should be inserted into the apertures associated with identification formations 222 c and 226 c. Identification formations 230 a and 230 b of coupling apparatus 216 may be set in a configuration similar to that of the identification formations of coupling apparatus 214 .
As one skilled in the art will recognize, an almost endless number of combinations and configurations of vessels, stoppers, tubes, coupling apparatuses, and identification formations are possible. The example described above is not intended to limit how such devices can be used and combined, but rather is intended to serve as an example of how such devices may be used in only one of a multitude of possible situations and environments.
According to a preferred embodiment, the stopper and the coupling apparatuses are molded from a translucent silicone. To provide a stopper or coupling apparatus having an identification formation embedded therein, the mold is prepared for the molding process, an identification formation is positioned within the mold, and then the body of the stopper or coupling apparatus is molded around the identification formation. As a result of such a method, the identification formation can be partially or completely surrounded by the translucent silicone. Using such a method of construction, a stopper or coupling apparatus can be made that reduces the likelihood that the identification formation will become separated from the rest of the stopper or coupling apparatus during use. The use of such a method may also eliminate the need for a secondary molding operation.
It is important to note that the construction and arrangement of the elements of the tubing system provided herein are illustrative only. Although only a few exemplary embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible in these embodiments (such as variations in the use of materials, colors, and combinations of shapes; variations in sizes, structures, shapes, dimensions and proportions of the stoppers, tube couplings, identification formations, tubes, apertures and other elements; variations in the arrangement of the identification formations as well as the various other tubing system elements; and variations in the configuration and operation of the tubing system elements) without materially departing from the novel teachings and advantages of the invention. For example, the stopper may be adapted and sized for use on any type of vessel or receptacle and may be used with a variety of substances or materials. The stopper also may be adapted for use on a container or vessel with a square or rectangular mouth or opening or with a mouth or opening having any one of a plurality of other shapes. The stopper may include any number of apertures, and the apertures may be any suitable shape (e.g. square, rectangular, oval, triangular, octagonal, etc.). According to further alternative embodiments, the stopper and apertures may be configured to be used with any type or style of tubing or pipe. Accordingly, all such modifications are intended to be within the scope of the invention as defined in the appended claims.
The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present inventions as expressed in the appended claims.
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An apparatus for use in identifying or distinguishing at least one substance or article associated with the apparatus is disclosed. The apparatus comprises a translucent body and an identification formation. The translucent body is for defining or engaging an opening. The identification formation is embedded in the translucent body in a predetermined relationship with the opening. At least one characteristic of the identification band is visible through the translucent body.
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[0001] The present application is a continuation and claims the priority benefit of U.S. patent application Ser. No. 11/463,094 filed Aug. 8, 2006
BACKGROUND OF THE INVENTION
[0002] According to clinical studies a staggering 37.6% of all self-administered eye drops miss the eye. One way to improve delivery of eye drops is by providing a visual feedback means so that a person dispensing drops can position an eye drop dispenser at an optimal distance and orientation above the eye. To accomplish visual feedback, the eyedropper needs to incorporate features used in other visual range and orientation devices. One such device is a common range finder used by golfers to gauge their distance from the ball to the hole. In golf range finders, the golfer stands near their ball and looks through a lens directly at the flag on its pole. The flags are uniform at a fixed height above the ground. The closer a golfer is to the flag, the larger it appears in the range finder. The range finder has calibrated hash marks within that correspond to a given distance. The golfer by aligning the appropriate hash mark with the image of the flagpole gets distance feedback. It will be appreciated that if the flagpole were replaced by a circular target, feedback of both distance and horizontal/vertical orientation can be visualized. With some optics engineering this mechanism can be used to gauge distance and orientation between a dispensing tip and the eye.
[0003] For years, the primary method of medically treating disorders of the eye has been via topical administration of various medications and other chemical compounds useful in combating a host of ophthalmic ailments. In fact, studies show that when measuring concentrations of these compounds at the desired target site (whether it be in the tear film, intracorneal, or intraocular), topical delivery equals or exceeds those concentrations obtained by systemic routes (oral or intravenous), and has far fewer systemic untoward signs and symptoms (side effects). Thus, it is no wonder that most remedies and medications are delivered via the topical route. Historically, this has been achieved via ointments, suspensions, solutions, contact lenses, collagen shields, and palpebral inserts. Far and away, the most common mode of delivery has been via topical suspensions and solutions. Typically, dispensers have fairly standard sizes and shapes (although there is some slight variation), and there is a reproducible standard drop size that is governed by the dropper (dispenser) tip. As simple as topical delivery may seem to achieve, there are various difficulties and shortcomings with current topical dispensing units (vials and bottles), many of which have not been previously or adequately addressed and solved.
[0004] The most common problem that the typical patient experiences when attempting to use an eye drop is the inability to introduce a drop into the eye, or simply missing the eye. There are several reasons for this. First, the normal bottle tip is not clearly visible as it approaches a normal emmetropic, hyperopic, or even myopic eye. This immediately leads to the probability that the first drop will become the “test drop”, landing on the cheek, forehead, or eyelashes, leading to waste and frustration. Second, there is a natural aversion to closely approaching objects, causing the eye to wander or drift, and look everywhere but at the dispenser tip. Again, this leads to the possibility that a drop will miss. Finally, most users are not taught how to use eye drops. They are simply given the bottle and instructed to “place one drop in the eye”.
[0005] The next important issue is one of waste. When a typical eye drop is introduced into the eye, the average inferior cul-de-sac only holds one-quarter to one-half of a standard drop. The remainder is either washed out down the cheek, or drained by the lachrymal system. Large strides in preventing waste were made when a dispenser tip was developed that delivered smaller drop sizes, thus eliminating a portion of waste. However, this advantage is negated if it takes several drops to gain access to the ocular surface. This issue is critical when evaluating cost to the patient and the healthcare system. The cost problem for the patient is obvious: the more drops they use, the greater the amount of money spent. With respect to the healthcare system as a whole, cutting costs are of paramount importance. In fact, many Health Maintenance Organizations (HMO's) will not let their members get refills on their ophthalmic medications more than once a month. The rationale behind this is simple. If the bottle has “x” number of drops in it, it should last “y” number of days. If the patient is not proficient with a high success ratio, then the drops will run out before the specified time allowed. This, in turn, leads to the patient either being without their valuable medications, or having to pay for the medications themselves.
[0006] Finally, there is the problem of contamination of the dispenser tip, and cross-contamination between patients. Since the tip is not clearly visible upon the approach to the ocular surface, it oftentimes will inadvertently come in contact with the eye or lid structures. This will lead to an inoculation of the tip with ocular flora, and be a potential source for spreading infection. Although sharing medications in general, especially eye drops, is always discouraged, many different people, whether friends or family members, often find the ease and convenience of sharing overwhelmingly tempting. Again, this can lead to cross-contamination and, in turn, the spread of infection.
[0007] Most of the current problems of efficiently dispensing ophthalmic drugs stem from user error. Therefore, it is the goal of this device to create a “user friendly” ophthalmic drug dispenser.
SUMMARY OF THE INVENTION
[0008] This invention seeks to create an integrated dispensing tip and optical gauging means for administering topical ophthalmic drug preparations, which enables the patient to direct an eye drop into the eye with the ease and accuracy, previously only attained by a proficient few. In addition, this particular device may serve to prevent cross-contamination, and ultimately save both the patient and the healthcare system money typically lost to waste.
[0009] More specifically, this invention relates to a dropper tip with an integrated lens and target system which, when coupled with or integral to any standard topical ophthalmic drug dispensing bottle, enables the user to view the target, align the dispenser tip, and administer an eye drop with precision not attained before. To achieve this precision, the target and lens system is calibrated to align the dispensing tip with the optical axis of the eye at a specified distance from the eye. The resulting geometric relationship between the dispensing tip and the eye insures that a dispensed drop will enter the eye. Prior art such as U.S. Pat. No. 5,558,653 “Targeted eye drop dispenser” which uses visual feedback to align an ophthalmic drug dispenser simply helps place the nozzle along the axis of the eye at an arbitrary distance selected at random by the user. This is only effective if the axis of the eye and the path a dispensed drop falls are the same. The axis and path are only identical when the eye is rotated 90 degrees with respect to the horizon, which can only be easily achieved lying down. Most users dispense eye drops while standing or sitting with the eye rotated about 50 degrees back and will miss often with those types of implementations.
[0010] A similar mechanism is described in U.S. Pat. No. 5,932,206 “Ophthalmic Drug Dispensing System” issued Aug. 3, 1999. The devices disclosed in U.S. Pat. No. 5,932,206 couple a discreet optical gauging mechanism to an eye drop dispenser. By combining the dispensing tip and optical gauging features into a single compact is tip the device becomes more compact, portable, cheaper, and easier to manufacture.
[0011] To dispense drugs efficiently with this invention, the user would use a dropper bottle outfitted with the new calibrated tip or would press fit the calibrated tip over the existing tip, tilt his/her head back, position the lens proximal to the eye where drug dispense is desired, align a target with his/her eye until a specified image appears thereby gauging distance, orientation and concentricity with the axis of the eye, then dispense a drop directly into the eye. Since the success rate of delivering a single drop in the desired location, i.e. the eye, will exceed 99%, the amount of waste can be reduced dramatically. At the same time, a visual mechanism by which the dispenser tip is prevented from gaining too close proximity and contacting the eye is provided, thus preventing contamination of the medication and its dispenser.
[0012] It is therefore one aspect of the present invention to provide visual feedback from a calibrated optical gauging system embedded in a dropper tip to properly align an ophthalmic drug dispenser to dispense drugs into an eye with a high rate of accuracy.
[0013] It is another aspect of the present invention to provide visual feedback from a calibrated optical gauging system embedded in a dropper tip when the ophthalmic drug dispenser becomes too close to the users eye to prevent eye contact and subsequent contamination.
[0014] It is another aspect of the present invention to provide a calibrated tip for an eye drop bottle that can be integrated with a bottle of eye drops and is compatible with existing pharmaceutical filling and packaging equipment.
[0015] It is another aspect of the present invention to provide a calibrated optical gauging system embedded in a dropper tip as an accessory for aftermarket attachment to any bottle of eye drops.
[0016] It is another aspect of the present invention to provide materials compatible with sterilization techniques employed in the pharmaceutical industry.
[0017] It is another aspect of this invention to provide promotional advertising to users each time they dispense an eye drop.
[0018] It is another aspect of the present invention to provide a means to regulate drop flow and volume.
[0019] It is another aspect of the present invention to provide a means to prevent bottles with larger volumes of eye drops from dispensing a drop prior to actuation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitive of the present invention, and wherein:
[0021] FIG. 1 is perspective view of the preferred embodiment of an optical gauging dispensing tip assembly according to the present invention.
[0022] FIG. 2 is a top view of a target that is embedded within the optical gauging dispensing tip assembly according to the invention.
[0023] FIG. 3A is a side view and FIG. 3B is a cross-sectional view of a dispensing tip without the optical gauging dispensing tip assembly according to the present invention.
[0024] FIG. 4 is a cross-sectional view of the lens for optical gauging dispensing tip assembly with integrated housing according to the present invention.
[0025] FIG. 5 is a cross-sectional view of the optical gauging dispensing tip assembly, according to the present invention.
[0026] FIGS. 6A , 6 B, 6 C and 6 D illustrate the relationship between the orientation of the optical gauging dispensing tip assembly and a viewer, according to the present invention.
[0027] FIG. 7A is a side view of a typical ophthalmic solution bottle.
[0028] FIG. 7B is side view of the optical gauging dispensing tip assembly attached to the ophthalmic solution bottle according to the present invention.
[0029] FIG. 8A is a side view of a typical ophthalmic solution bottle with typical dispensing tip attached.
[0030] FIG. 8B is side view of the optical gauging dispensing tip assembly attached to the tip of the ophthalmic solution bottle according to the present invention.
[0031] FIGS. 9A and 9B are side views of the optical gauging dispensing tip assembly attached to the ophthalmic solution bottle with caps according to the present invention.
[0032] FIGS. 10A , 10 B, 10 C and 10 D are top views of optical targets for the optical gauging assembly, according to the present invention.
[0033] FIG. 11A is side view of another embodiment of the optical gauging dispensing tip assembly, according to the present invention.
[0034] FIG. 11B is a cross-sectional view of the other embodiment of the optical gauging dispensing tip assembly, according to the present invention.
[0035] FIG. 12 Dispensing Instructions reference
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Referring to FIG. 1 an optical gauging dispensing tip assembly 1 in accordance with the present invention is illustrated. The optical gauging dispensing tip assembly 1 is comprised of three main components, a dispensing tip 2 for dispensing an ophthalmic solution, an integrated lens assembly 3 having an integrated housing as will be described below, and an optical target 4 calibrated for use as will be described below. The optical gauging dispensing tip assembly 1 is designed to give visual feedback to dispense an eye drop properly. The eye drop can be any ophthalmic solution comprising either an OTC medication or a prescription medication to treat various eye conditions. To effectively deliver an eye drop, the user needs feedback when the dispensing tip 2 is positioned at the center of the eye and sufficiently close to the eye to guarantee the drop is delivered to the eye. Another requirement is that the dispensing tip 2 does not contact the eye and contaminate the tip with ocular flora, so additional feedback is required as the dispensing tip 2 is brought too close to the eye. The optical target 4 by design gives visual feedback to place the dispensing tip 2 at the center of the eye at a distance from the eye empirically determined to be 0.5 inches (12.7 mm) above the eye. When the dispensing tip is further or closer then 0.5 inches (12.7 mm) from the eye, or off axis, then additional feedback indicates that condition so the user can adjust the position of the dispenser. See FIG. 6 for complete details.
[0037] The lens assembly 3 of optical gauging dispensing tip assembly 1 focuses the optical target 4 and has an aperture with a circular field of view. Using the optical target 4 with two concentric rings, inner ring green and outer ring red, the user gets two distinct graphical feedbacks. As the lens assembly 3 approaches the eye, the green ring becomes visible when the eye's axis is vertical and the lens assembly is the optimal distance above the eye to dispense. As the optical gauging dispensing tip assembly 1 becomes too close, the red ring becomes visible, instructing the patient to move the lens assembly further away to avoid contact with the eye.
[0038] In FIG. 2 , the top view of optical target 4 is illustrated. In one embodiment of the present invention, optical target 4 comprises a circular glossy label approximately 0.625 inches (15.8 mm) in diameter. In the center of the label, is a 0.140-inch (3.6 mm) diameter hole 21 that allows the label to maintain an axial and concentric relationship with the nozzle of the tip. The label has an adhesive on its back and is mounted directly on to the surface of the dispensing tip where the base of the nozzle protrudes from the top surface of the tip's base. The label has graphic markings representing important relationships between the distance and location of the dispensing tip and the center of the user's eye. In this embodiment of the present invention there are three rings on the label, a white ring 20 , a green ring 22 , and a red ring 23 . The diameters and thickness of each color ring is calibrated to a range of distances to the user's eye, giving visual feedback to the user that the eye drop dispenser is too far, too close, or in an optimal range to dispense a drop. The rings may be any combination of colors, red and green generally mean stop and go so they were used in this embodiment to provide similar feedback. It will be appreciated that the target can be printed directly on to the tip surface with a printing process such as tampo printing which eliminates the label and its placement.
[0039] In FIG. 3A , the side view, and in FIG. 3B , a cross-sectional view, of dispensing tip 2 is illustrated. A majority of eye drop bottles and their corresponding tips are molded from plastic resins that are medical grade and capable of being sterilized by e-beam or gamma irradiation, usually a doped polyethylene. The dispensing tip 2 needs to be molded from identical materials and serve the equivalent purpose for all ophthalmic dispensing tips well known in the art that deliver ophthalmic solutions. The dispensing tip 2 conveys the ophthalmic solution from a reservoir in the form of a squeeze bottle through a tube 34 to an orifice 32 designed to dispense a single drop of solution into the eye. The conical section 33 formed within the tube serves two functions. The fluid enters from the inlet side of the conic section through a small resistive orifice and the speed of the fluid decreases as the cross section grows, thereby proving a fluid flow regulating mechanism. This deceleration prevents the fluid from freely streaming out of the orifice 32 . The surface area of the walls of the conic section, defines the drop volume by controlling the surface tension with the fluid. Dispensing tips are generally fastened to bottles or reservoirs using an annular ring snap fit, which provides an attachment mechanism for attaching the dispensing tip to the reservoir. The annular ring is embedded in the neck of the bottle and makes a compression fit with an annular groove 31 embedded in the dispensing tip 2 . Unfortunately there is no standardization among manufacturers of eye drop bottles for neck size and therefore to make the dispensing tip 2 fit a wide variety of dispensers on the market, an alternative method of attachment includes compression sleeve 37 and compression sleeve 36 . Compression sleeve 36 and compression sleeve 37 are designed to press fit over an existing tip instead of replacing it. With different size cross sections, compression sleeve 36 and compression sleeve 37 press fit on to a majority of tips provided on the market. When larger volumes, 1 oz. (30 cc) or greater, of solutions in bottles are inverted to dispense, the solution is held within the confines of the dispenser by a vacuum formed within the bottle. The vacuum needs to exert a force equal to the mass of the solution to prevent leakage. With larger volumes of solutions, the mass of the solution causes some displacement towards the tip before reaching steady state with the vacuum. In dispensers known in the art, the tip does not have a sufficient buffer volume and therefore upon inversion of the bottle, the tip will dispense a drop or two of fluid without activation by squeezing the bottle. The volume of compression sleeve 36 and compression sleeve 37 acts as a buffer for this displacement and prevents the leakage described. Annular ring 35 is molded into the tip to hold the lens assembly on the standard bottle tip and maintain an axial concentric relationship between the lens, target, and tip.
[0040] In FIG. 4 , a lens assembly 3 is illustrated. The lens assembly 3 includes a lens 40 , which in this embodiment is a biconvex lens. The lens 40 can be spherical or aspherical. The back focal length of the lens 40 is designed to maintain focus of the calibrated optical target as a viewer looks through the lens 40 . The equation 1/f=(n−1)*(1/R1−1/R2), where f=focal length, n=index of refraction, R1=radius of curvature for first side of the lens, and R2=radius of curvature for second side of the lens, establishes the relationship between the shape of the lens and its focal length. The housing wall 43 establishes the distance between the target and lens and seals the target away from any fluid. The diameter of the lens and its diopter, define the field of view as the lens is moved closer or further from the eye. This relationship establishes a means to provide distance feedback between the eye and dispenser tip. The lens 40 has a hole 41 that is concentric with the lens, thereby providing a mechanism for centering the lens 40 and the dispensing tip. The hole 41 allows the tip to pass through the lens 40 and makes the path the solution takes from the reservoir to the eye isolated from contact with the optical gauging portion of the tip assembly. The tip when nested properly protrudes through the hole about 0.040 inches (1 mm). The lens 40 includes an annular ring 42 to make a hermetic seal with the tip to keep all fluids away from the target label. The lens 40 and its housing 43 are made from optical materials, typically a plastic resin such as doped acrylic that can be sterilized using methods such as e-beam or gamma irradiation or ETO gas and are anti-static.
[0041] FIG. 5 is a cross-sectional view of the assembled optical gauging dispensing tip assembly 1 . Once assembled, inner chamber 50 containing optical target 4 is hermetically sealed with the annular ring seal at the base of the lens and the tip press fit into the hole through the lens. The combination of the dispensing tip 2 press fit through the hole 41 and the annular ring 42 at the base mechanically maintains an axial concentric relationship between the lens 40 , optical target 4 , and dispensing tip 2 .
[0042] FIGS. 6A , 6 B, 6 C, and 6 D illustrate the effect on image 60 as eye drop dispensing assembly 10 is moved along the optical axis of the viewer as illustrated. The resulting image gives the user feedback on where to hold eye drop dispensing is assembly 10 to properly dispense a drop into the eye. Image 60 is the image the user sees when looking into the optical gauging assembly that is integral to eye drop dispensing assembly 10 . The assembly 10 is held in a near vertical orientation above the eye, with the dispensing orifice proximal to the eye. The user looks into the lens to view a target. The viewing target within eye drop dispensing assembly 10 is the same as illustrated in FIG. 2 containing three color regions, a white inner circle, followed by a concentric green ring, with an outer concentric red ring. In FIG. 11A there is a range of distances from the viewer where the optical gauging assembly yields pattern 61 on image 60 as illustrated. The pattern 61 of image 60 reveals pure white circle 20 , which indicates the eye drop dispensing assembly 10 is too far to dispense a drop properly. The pattern 61 would provide feedback to move the eye drop dispensing assembly 10 closer to the eye. In FIG. 11B there is a range of distances from the viewer where the optical gauging assembly yields pattern 62 on image 60 as illustrated. The pattern 62 of image 60 reveals an outer red ring 23 , central green ring 22 , and a white inner region 20 , which indicates the eye drop dispensing assembly 10 is too close to the user and they are in danger of making contact with their eye. The pattern 62 would provide feedback to move the eye drop dispensing assembly 10 away from the eye. In FIG. 11C the eye drop dispensing assembly 10 is not located on the optical axis of the viewer where the optical gauging assembly yields pattern 63 on image 60 as illustrated. The pattern 63 of image 60 reveals non-concentric patterns of rings, which indicates the eye drop dispensing assembly 10 is off of the optical axis of the eye. The pattern 63 would provide feedback to rotate or offset the eye drop dispensing assembly 10 back on to the optical axis of the eye. In FIG. 11D there is a range of distances from the viewer where the optical gauging assembly yields pattern 64 on image 60 as illustrated. The pattern 64 of image 60 reveals an outer green ring 22 , and a white inner region 20 , which indicates the eye drop dispensing assembly 10 , is in the perfect relation to the eye to dispense a drop. The pattern 64 would provide feedback to dispense a drop. The range of distances discussed above and the resulting images 60 are repeatable independent of viewer. The distance can be calibrated by varying the pattern, lens diameter, or optics and the combination of these three parameters can is be determined empirically to achieve the feedback desired. Therefore eye drop dispensing assembly 10 can be calibrated to have a user position it directly along the center of the viewer's optical axis at a specific distance to dispense a drop.
[0043] In FIGS. 7A and 7B , a typical dispensing bottle for ophthalmic solutions is shown. Optical gauging dispensing tip assembly 1 , is inserted into the neck of the dispensing bottle where its annular groove feature 31 , illustrated in FIGS. 3A and 3B , engage with annular ring features in the neck of the dispensing bottle. In a typical automated filing line for eye drops, the line is configured to feed empty bottles down a conveyor to a filing tube. The tube dispenses solution into the bottle, and the filled bottle is conveyed to a tip insertion station. The tips are bowl fed to an actuator that press fits the tips into the bottle. The filled bottle with tips is conveyed to a capping station, where caps are threaded over the tip on to the neck of the bottle. The integrated optical gauging dispensing tip assembly 1 in this embodiment allows filing ophthalmic solution bottles on the same production equipment in the same three steps. This eye drop dispensing assembly 10 is one embodiment for the present invention.
[0044] In FIGS. 8A and 8B , a typical dispensing bottle with a typical dispensing tip for ophthalmic solutions is shown. Optical gauging dispensing tip assembly 1 , is inserted on to tip 80 of the dispensing bottle where compression sleeve 36 and compression sleeve 37 , illustrated in FIG. 3B , engage with a compression fit around the surface of the tip 80 . It will be appreciated that such dispensing tips can have different profiles, cross-sections, can be taller or shorter, and generally vary from one supplier to another. The soft nature of polyethylene allows compression sleeve 36 and compression sleeve 37 to form and seal around a majority of these dispensing tips.
[0045] In FIG. 9A , the assembly illustrated in FIG. 7B is capped to seal off the tip of the dispensing bottle. The cap 90 provides a closure mechanism that needs to maintain a hermetic seal for the tip and in this embodiment of the present invention is internally threaded to screw on to the threads of the neck of bottle 70 . The cap 90 is made from materials, typically a plastic resin such as polypropylene that can be is sterilized using methods such as e-beam or gamma irradiation or ETO gas.
[0046] In FIG. 9B , the assembly illustrated in FIG. 8B is capped to seal off the tip of the dispensing bottle. The cap 91 provides a closure mechanism that needs to maintain a hermetic seal for the tip and in this embodiment of the present invention is press fit on to the lens of optical gauging dispensing tip assembly 1 . The cap 91 is made from materials, typically a plastic resin such as polypropylene that can be sterilized using methods such as e-beam or gamma irradiation or ETO gas.
[0047] FIGS. 10A , 10 B, 100 , 10 D illustrates the various patterns that can be printed and used as optical targets for the purpose of positioning optical gauging dispensing tip assembly 1 along the center of a viewers optical axis at a specific distance. To calibrate a fixed distance from a viewer, optical target 71 would specify which ring of the concentric ring pattern to align with the outer diameter of the image field of view. Optical target 71 further includes a text message, such as “Dispense now” or “Try new product A”. The text message could indicate the dispenser's use, or could advertise a product or company every time the user dispenses drops. To calibrate a fixed distance from a viewer, optical target 72 would specify which vertical and horizontal hash mark to align with the outer diameter of the image field of view. To calibrate a fixed distance from a viewer, optical target 73 will align the ring with the outer diameter of the image field of view and the arrow will indicate a preferred orientation such as up. To calibrate a fixed distance from a viewer, optical target 74 will align the ring with the outer diameter of the image field of view and the graphic would specify a preferred orientation such as up. It should be apparent that the optical target pattern can be graphically calibrated, color calibrated, or use text instructions or advertising printed within the optical target pattern to accomplish the same purpose.
[0048] In FIG. 11A , a side view, and in FIG. 11B , a cross-sectional view, of optical gauging dispensing tip assembly 1 is illustrated. This embodiment of the present invention incorporates annular groove 80 and annular groove 81 . Having progressively larger annular grove diameters allows the optical gauging dispensing tip assembly 1 to fit into multiple off the shelf dispensing bottles with different neck sizes.
[0049] It will thus be seen that the objects set forth above, and those made apparent from the preceding descriptions, are effectively attained and since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense.
[0050] It is also to be understood that the following claims are intended to cover all generic and specific features of the invention herein described and all statements of scope of the invention, which as a matter of language, might be said to fall therebetween.
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A dispensing tip apparatus for an eye drop dispenser to administer topical ophthalmic solutions is described. The apparatus integrates an ophthalmic solution-dispensing tip with an optical gauging assembly. The tip provides continuous visual feedback about it orientation and relationship to the eye. The dispensing tip when attached to any standard topical ophthalmic solution dispensing bottle or reservoir enables the user to view a target, visually align the dispenser tip, and administer an eye drop with precision. There is also a visual feedback by which the dispenser tip is prevented from gaining too close proximity and contacting the eye, thus preventing contamination of the medication and its dispenser. The visual feedback can also contain textual or graphic information that serves as a promotional advertisement. The is assembly can be attached to the neck of an eye drop bottle or attached to the tip of an eye drop bottle.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to railroad rail straightening presses.
2. Description of the Prior Art
A conventional rail straightening press utilizes a pair of vertically-oriented, opposed, upper and lower hydraulic cylinders for straightening kinks or bends in the rail developed during the rail butt-welding process. Also, a part of the press is a pair of opposed hydraulic cylinders located in a horizontal plane for straightening rail bends developed therein. All cylinders have their lines of action in the center of press and generally adjacent the welded joint. Straddling the line of action of each cylinder are opposed anvils which provide the resistance as each cylinder moves the rail thereagainst. The operation of the press is essentially manual with the operator activating the cylinders as needed via suitable valves from a tending station in the general vicinity of the weld. Suitable gauges are used to determine the extent of the bend developed in the rail and the correct alignment after remedial action.
The above-described press has provided fairly satisfactory operation, but requires an unduly large number of elements. Also, the location of the cylinders, wherein the pistons reciprocate from end to end in the usual fashion, prevents the location of an operator tending station generally adjacent the weld for efficient press operation.
SUMMARY OF THE INVENTION
Applicant, as a consequence, designed a press that reduces the number of elements involved and provides an operator tending station adjacent the rail weld which is located adjacent the center of the machine with hydraulic and electrical controls readily available for use upon determining the rail misalignment resulting from the butt-welding process. Specifically, Applicant deleted a horizontal and a lower vertical cylinder to provide an operator tending station on one side of the machine. Inasmuch as the function of the deleted cylinders is still required, Applicant provides a horizontal cage that is connected to the horizontal cylinder on the side of the machine opposite the tending side that has a pair of opposed rams that straddle the rail and, upon reciprocation, bend the rail in either direction against suitable anvils in a horizontal plane. The single cylinder provides the cage reciprocation since the piston is normally maintained in a central or neutral position of the cylinder wherein the rail can move through the cage until straightening is required. Activation of the piston in either direction from the neutral point causes the rams to contact the rail as desired.
For vertical straightening, Application provides a vertical cage that is connected to the piston of the upper, single vertical cylinder. The vertical cage also has opposed rams that straddle the rail and upon reciprocation bend the rail in either direction against suitable anvils in a vertical plane. Because of the desired location of the cages, generally at the weld and in the center of the machine, the vertical cage straddles the horizontal cage and the vertical rams also extend into the horizontal cage to contact the rail extending therethrough. As with the horizontal rails, the piston of the vertical cylinder is normally maintained in a central or neutral position of the cylinder so that the rod can move the cage in either direction. Thus only two cylinders instead of four are required for the same function and, particularly the removal of a horizontal cylinder, provides space for a tending station for efficient operation of the press. The hydraulic system for the cylinders is also utilized via a hydraulic motor to rotate a sprocket and by a suitable chain, to move the press along lower rails to position the press as desired along the welded rail. This control also is located at the tending station.
It is, therefore, an object of this invention to provide a new and improved rail straightening press.
Another object of this invention is to provide a press having fewer elements.
Still another object of this invention is to provide a press having fewer elements and which utilizes the resulting space to provide an operator tending station specifically located for efficient press operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the tending side of the rail straightening press of this invention;
FIG. 2 is an elevational sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a partial plan view (minus the top cylinder) of the press;
FIG. 4 is a hydraulic diagram for the press; and
FIG. 5 is an elevational sectional view taken along line 5--5 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, 10 indicates a rail straightening press. Press 10 has a rigid support structure 11 on which are mounted all of the press components. Structure 11 includes a generally rectangular base 12. Base 12 comprises a front, rearwardly facing, channel 14, a similar rear channel 15, an outwardly facing left side channel 16, and a right side channel 18. All of the base channels are suitably welded to provide a rigid, box-like structure. Providing internal support to base 12 are smaller, left and right side channels 19 and 20 extending from the front to the rear of the base. Deck plate 21, attached by suitable fasteners to base 12 and spanning channels 16 and 18, provides a press tending station.
Affixed in each corner of base 12 are wheels 22. Wheels 22 support the base for movement on suitable rails to position base 12 and hence, press 10, as needed for location thereof relative to a welded rail to be straightened. Wheels 22 via bushings 24 and keys 25 are supported on base 12 by flange type bearings 26 affixed thereto. Suitable electrical insulators insulate the wheels and therefore the base from the rails.
A hydraulic drive is provided for base 12 and therefore press 10 via wheels 22. As shown best in FIG. 1, drive axle 28 extends between, and is connected for movement therewith, the wheels on the right side of the base. Drive axle 28 has driven sprocket 29 affixed thereto. Roller chain 30 extends between drive sprocket 31, which is connected to hydraulic motor 32, and driven sprocket 29. Hydraulic motor 32 is mounted via a suitable support plate on a vertical support of press 10. By use of a suitable valve, hydraulic fluid can be supplied to motor 32 to rotate drive sprocket 31 in either direction and hence drive axle 28 to move press 10 relative to a rail to be straightened.
The hydraulic system components of reservoir 34, pump 35 and electric motor drive 36 (see FIG. 2) for press 10 are also mounted on base 12 generally on the same side as the hydraulic drive but opposite the tending side and on the rear of the press. The noted hydraulic system not only supplies the power for the hydraulic drive for base 12, and therefore press 10, but also supplies the power for the later to be described pressing components of the press.
The pressing components of press 10 are mounted on vertical support 38. Support 38 includes inwardly facing vertical left and right channels 39 and 40 which are bolted at their lower extremities to base channels 16 and 18. Connecting channels 39 and 40 by suitable fasteners are upper front and rear (see FIG. 2) horizontal channels 41 and 42 and lower front and rear channels 44 and 45.
Vertical pressing assembly 47 is located on top of vertical support 38. Via suitable pads welded to the top of channels 41 and 42, double acting hydraulic cylinder 49 by a base plate is attached to support 38 by suitable capscrews (also see FIG. 3 and FIG. 5). Attached to threaded piston rod 50 of cylinder 49 is vertical cage or housing 51. Cage 51 is slidably supported on universal bearing 52 attached to lower front guide bar 53a and support bracket 53b which are in turn fastened to front and rear channels 44 and 45. The bearings support the cage movement from a center or neutral position to an upper and lower position depending upon cylinder 49 actuation. Cage 51 has a left side 54 and right 55 when facing the press. Each side has an aperture 56 extending therethrough for travel of the rail to be straightened. Also a part of cage 51 is top side 57 and lower side 59 which are connected to the right and left sides to form a rigid box-like structure. Mounted to top side 57 by suitable fasteners is upper ram 60. Upper ram 60 may include suitable spacers such as 61 for pressing the crown of rails of various sizes in height to be straightened which are mounted in the vertical or upright position in the press. This orientation of the rail requires a larger capacity cylinder for vertical pressing than horizontal pressing. Also associated with vertical pressing assembly 47 are the anvils required for use therewith. Inasmuch as in the pressing process, the crown which was developed in a welding process, when straightened, causes the rail to elongate in a horizontal plane, the rail to be straightened cannot be held tightly. Instead, the press is designed to move the rail downwardly until fixed lower anvils (see FIG. 1) -- left anvil 63 and right anvil 64 -- mounted on lower channels 44 and 45 are encountered. They provide the spaced supports upon which the rail is straightened when upper ram 60 is moved downwardly by cage 51 attached to rod 50. When rod 50 and hence cage 51 are moved upwardly, lower ram 65 attached to bottom 59 contacts the base of the rail and moves same against the upper anvils (left 66 and right 67) which straddle the ram and provide support against which the rail is bent to straighten. Preferably suitable spacers are used to provide ajustability for the upper anvils.
Horizontal pressing assembly 69 is mounted on the rear of frame vertical support 38 and opposite the tending side of the press. Assembly 69 includes double acting hydraulic cylinder 70 that is attached via a base plate 71 to support bracket 53b and has a threaded piston rod 72 adapted to engage horizontal cage or housing 74 supported by bearings 74a 53 and 53c. Cage 74 (see FIG. 2 and FIG. 5) has left side 75 and right side 76 with opening 77 extending through both sides. Opening 77 provides space for movement therethrough of the welded rail for straightening. At the rear end of cage 74 is side 79 where rod 72 attaches thereto and a front side 80. The top and bottom of cage 74 are open for the movement therein of upper and lower rams 60 and 65 to contact the rail at preferably the centerpoint of the machine. Rear and front rams 82 and 84 are designed to contact opposing sides of the web of the rail as needed to straighten same. Also an upper portion of each ram is adapted to contact the rail heads (see FIG. 2). The upper portions are vertically adjustable by suitable spacers depending upon the height of the rail to be straightened. Also necessary for horizontal bending are opposed anvils.
Extending between channels 41 and 44 and 45 and 42 and affixed thereto are reinforcements 86. Reinforcements 86 of support bracket 53b support front horizontal left and right anvils 87 and 88 mounted thereon and located on the front of the machine. Reinforcements 86 also support rear left and right anvils 89 and 90. Suitable railhead anvils attached thereto, provide support for the railheads in the bending process. Movement of rear horizontal ram 82 forces the rail against anvils (front 87 and 88) to straighten the rail, while movement of horizontal ram 84 moves the rail against rear anvils 89 and 90. Vertically supporting the rail to be straightened, which as mentioned, is moved through the press in a rail head up position, are four spring loaded rollers 91 located on the press. They are located at the left and right sides of the machine and also straddle the press centerlines which are coplanar at the center of the machine. Since, spring loaded, pressing of the rail can occur against the associated anvils without damage to the rollers.
Also provided are spring loaded rollers 92 to maintain the rail web in a centered position in the press except during the pressing process. These horizontally oriented rollers also, by virtue of their spring mounting, do not interfere with the horizontal pressing.
Suitable gauge bars located preferably at the center of the machine at the tending side are utilized to measure the amount of bend and hence the corrective action needed in this manual process. The fixed gauge bars are parallel to the axes of correction from the centerline of the machine and arrows on the movable rams provide an indication on the gauge bars. Observation is readily mode from the tending side of the machine.
FIG. 4 discloses the hydraulic circuit for use with rail straightening press with all pressing assemblies in the centered or neutral position and the hydraulic motor inactive. It is to be noted that while the capability of pressing is desired in a horizontal and a vertical plane, pressing is not desired in both planes at the same time as the pressing assemblies would be opposing each other to some extent and also the center lines of force application would be misaligned. Further, the actuation of the hydraulic drive to the wheels of the press base to move same is not desired during pressings. As a consequence, separate but "ganged" valve controls for the hydraulic components located at the tending side are desired along with the switch for actuation of the electric motor drive 36 for pump 35. It is also to be noted that hydraulic cylinder 49 of vertical press assembly 47 and cylinder 70 of horizontal press assembly 69 are to be operated to and fro from a neutral position wherein the straightened rail can be moved relative thereto through the respective cage openings. As a consequence, Applicant utilizes similar valves 84 for cylinder 49, 85 for cylinder 70 and also 86 for motor 32 which are connected in parallel with pressure relief valve 88 connected to pump 35 and to reservoir 34. Valve 84 (as are valves 85 and 86) is a conventional four-way, three position, closed center valve whose piston or spool normally is spring biased to the center position in which all ports are blocked. This valve has a handle, not shown, attached to the valve piston for reciprocation from the central position. A capability of this valve is the "inching" of the associated cylinder piston as desired. Hence, the cylinder piston can be moved from the center or neutral position by visual reference to the associated cage by moving the valve handle as desired to press. Upon completion of the pressing, the handle is moved so that the connected valve piston is moved past center to retract the cylinder piston, and when the associated cage reaches center, the handle is released with the spring returning same to center, closing all ports and stopping the cylinder piston. Thus, the piston of each cylinder can be used for pressing in both directions from a central position manually without means for controlling cylinder piston location. Valve 86 performs a similar function with hydraulic motor 32 thus providing selective location of press 10 relative to the rail to be straightened. Of course, the entire procedure could be easily automated by suitable "bend" sensors and controls if desired.
In operation, a rail that has been welded in a welding machine is advanced preferably from the right of the rail press as shown in FIG. 1 over adjacent spring loaded roller 91 and into the press over similar spring loaded rollers. The rails stands in an upright position with rail head up. If need be the operator, by virtue of the handle of valve 86 can move press 10 via wheels 22 and the hydraulic drive to position the press as desired in regard to the rail weld. The operator compares the area of the rail at the weld with a gauge while standing on the deck of the press at the tending side adjacent the weld. If an upward rail crown is noted, he actuates the handle of valve 84 in one direction from its center to cause rod 50 of cylinder 49 and thus cage 51 to move from a neutral position, wherein the rail is free to move through aperture 56 in the cage, downward. Upper ram 60 contacts the rail and moves it down against lower spaced anvils 63 and 64 to straighten the rail which ends are free to move longitudinally. The spring loaded support rollers 91 are free to compress. Upon completion of the straightening process, which may require several piston strokes, the operator moves the handle in the opposite direction, past the central or neutral valve piston position, and releases whereby the spring centers the valve piston and closes all ports which stops the cage at its center position as desired. The rail is free then for movement through the cage aperture 56. If a downward rail bend is noted, the handle is moved in a contrary fashion to cause cage 51 to move upwardly to cause lower ram 65 to move the rail against the upper anvils 66 and 67 to straighten the rail. The upper anvils, as mentioned, have movable spacers to accommodate varying height rails.
Should the rail have a bend in a horizontal plane, the operator, on detecting same with reference to the gauge, operates the handle of valve 85 (if the bend is toward the rear of the press) to actuate cylinder 70 via rod 72 to move cage 74 horizontally until rear ram 82 contacts the rail to move same against front anvils 87 and 88 also depressing spring loaded support rollers 92. Contrary movement of cage 74 forces ram 84 against rear anvils 89 and 90 to straighten an opposed bend.
It is to be noted that for efficient press load application, each load is applied by each cage at the machine centerline. Thus the rams of the vertical cage must extend down into the centered, horizontal cage to bend the rail therein in a vertical direction. Of course this center location of the cages and cylinders also makes measuring and operation of the press at the press centerline possible and provides space for a tending side at this location. All components of the press are located thereon and the press can be moved as desired along the rail as needed to straighten same.
Having thus described the invention it will be apparent to those skilled in the art that various changes and modifications can be made without departure from the spirit of the invention or the scope of the appended claims.
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A press for straightening a railroad rail formed by the welding of the ends of two rail sections together. The press has a first reciprocatable cage having two opposed rams straddling the rail for straightening the rail in one plane and a second reciprocatable cage having similarly arranged rams extending into the first cage for straightening the rail in a second plane. The cages are connected to suitable power means located remote from the tending side of the press for efficient operation of same.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a magnetic catch assembly, and more particularly, to a molded, one piece, magnetic catch assembly which can assist in keeping a machine cover, particularly a cover on an electrophotographic printing machine, closed.
2. Description of the Prior Art
In a typical electrophotographic printing processor as employed in an electrophotographic printing machine, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charges thereon in the irradiated areas. This records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules to the latent image forming a toner powder image on the photoconductive member. The toner powder image is then transferred from the photoconductive member to a copy sheet. The toner particles are heated to permanently affix the powder image to the copy sheet. Especially in view of all the moving parts and various processes that occurs in this type of printing machine, and further in view of the need to clear paper jams or conduct different type of repairs on the machine, the need to easily open and firmly close service type doors on this kind of machine is readily apparent. Conventional latch or locking systems, such as mechanical latches or locks provide positive latching for these types of doors. However, mechanical latches for this purpose are relatively expensive. In addition, when it is desired to open and close these doors quickly, one discovers that mechanical latches release too slowly. There is therefore a need to provide a latch or a locking mechanism for a door or cover typically used on such a machine to avoid the disadvantages described above and which offers certain advantages especially in view of the frequent need to obtain access to the interior portions of such machines.
Magnetic catches are widely used on a variety of electrophotographic printers to maintain a good level of operator access to the interior portion of the printer through doors that are kept closed by exerting a magnetic force on a metal striker plate or other adjacent metal part of the printing machine. As illustrated in the prior art structure shown in FIGS. 2A and 2B, magnetic catches are typically manufactured of a multipiece assembly 10 , consisting of (i) a metal magnet 11 , (ii) a pair of retainer plates 12 used to hold the magnet in place in assembly 10 and (iii) a separate mounting bracket 14 having openings 15 . The bracket 14 is used to mount the magnet to the machine by securing the bracket to the machine such as by the use of nails or screws fitted through openings 15 .
Accordingly, it is a primary advantage of this invention to provide a new and improved structure for a magnetic catch assembly which avoids the disadvantages referred to above. It is a primary objective of this invention to provide a relatively inexpensive, easily manufactured and quickly operable latching mechanism in the forum of a magnetic catch assembly for keeping a door or cover of a machine closed. It is also a primary object of the present invention to provide a magnetic catch assembly whose components can be combined into a one piece molding. Meeting these objectives will result (i) in a significant reduction in the overall cost to manufacture a magnetic catch assembly, (ii) provide more design flexibility and (iii) enable magnetic catch assembly to be manufactured in an easier fashion. The present invention will not only exhibit all of these results but will provide increased design flexibility in that the designer is no longer limited to a design for a simple single flat magnet for closing a door. In accordance with the advantages of the present invention one can manufacture a contoured, stepped or corner shaped and magnet, and incorporate attachment features such as snap fits into a magnetic catch or manufacture a one piece double or multi magnetic catch assembly.
Additional advantages of the invention will be set forth in part in the description which follows, and some will be obvious from the description, or may be learned by practice of the invention in accordance with the various features and combinations as particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
All of the foregoing advantages and others will be attained by employing a magnetic catch assembly for securely holding a door on a machine in a closed position comprising a unitary, injection molded, plastic member, at least one portion of the member being magnetized to form the magnetic catch and at least one portion of the unitary molded member forming a mounting bracket that is adapted to securely mount the magnetic catch assembly to the machine. At least two separate areas of the unitary member can include magnetic members. Furthermore, at least one snap fit member can be unitarily molded as part of the catch assembly and included as part of the overall assembly. The snap fit member is adapted to further secure the assembly to the machine and can additionally be used to secure other components or subassemblies to the machine.
In accordance with the features of the present invention, an example of one type of machine that can incorporate the magnetic catch assembly as described herein is an electrophotographic printing machine. When the features of the present invention are used in such a machine the magnetic catch assembly of this invention is secured to the frame of the machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and constitute a part of the specification illustrate one embodiment of the present invention and, together with the following detailed description, serve to explain the principles of the present invention.
FIG. 1 is a partially schematic plan view of a typical reprographic printing apparatus that can incorporate the features of the present invention;
FIG. 2A is a plan view of a magnetic catch as represented by the prior art;
FIG. 2B is a cross sectional plan view of the magnetic catch assembly of FIG. 2A;
FIG. 3A illustrates a plan view of a magnetic catch in accordance with the features of the present invention;
FIG. 3B is a cross sectional plan view of the magnetic catch assembly of FIG. 3A;
FIG. 4 A and FIG. 4B are plan views of a magnetic catch assembly in accordance with the features of the present invention having molded snap fit elements; and
FIG. 5 is a plan view of a double magnetic catch assembly in accordance with the features of the present invention, i.e. having two separate magnetic areas.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will hereinafter be described in connection with preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. For a general understanding of the features of the present invention, reference is made to the drawings. For a general understanding of some of the features of the present invention it is important to understand the type of environment that features in accordance with the present invention can be used. In that regard it will become evident that the magnetic catch assembly of the present invention is equally well suited to be used in a very large number of different machines with doors including, for example, reprographic printing machines. The magnetic catch assembly of the present invention is not necessarily limited in its application to use in an electrophotographic printing machine as shown herein or described below or even limited to use in a printing machine. The purpose of describing the various parts of an electrophotographic machine is simply to illustrate as an example the various parts of a machine that needs to be reached for servicing. Just about any door or cover used on the electrophotographic machine described below can be used to reach the various parts described below and secured and kept in a closed position by using the features of the present invention. In fact, by using as an electrophotographic printer as an example of an apparatus that can employ the magnetic catch assembly as defined by this invention there is no intent to limit the magnetic catch assembly of this invention for use this kind of machine. Quite the opposite is true. The magnetic catch assembly of the present invention can be used in just about any machine that has doors or covers for the purpose of keeping such doors or covers in a closed position.
Inasmuch as the art of electrophotographic printing is well known, the various processing stations employed in the FIG. 1 printing machine will be shown hereinafter schematically and their operation described briefly with reference thereto. Referring now to FIG. 1, the electrophotographic printing machine 17 shown employs a photoconductive drum 16 , although photoreceptors in the form of a belt are also known, and may be substituted therefor. The drum 16 has a photoconductive surface deposited on a conductive substrate. Drum 16 moves in the direction of arrow 18 to advance successive portions thereof sequentially through the various processing stations disposed about the path of movement thereof. Motor 20 rotates drum 16 to advance drum 16 in the direction of arrow 18 . Drum 16 is coupled to motor 20 by suitable means such as a drive mechanism. If a electrophotographic printer employs a photoconductive belt it is preferably made from a photoconductive material coated on a grounding layer, which, in turn, is coated on an anti-curl backing layer. The photoconductive material is made from a transport layer coated on a generator layer. The transport layer transports positive charges from the generator layer. An interface layer is coated on the grounding layer. The transport layer contains small molecules of di-m-tolydiphenylbiphenyldiamine dispersed in a polycarbonate.
The generation layer is preferably made from trigonal selenium. The grounding layer is preferably made from titanium coated MYLAR. The grounding layer is very thin and allows light to pass therethrough. Other suitable photoconductive materials, grounding layers, and anti-curl backing layers may also be employed.
Initially successive portions of drum 16 pass through charging station 19 . At charging station 19 , a corona generating device, indicated generally by the reference numeral 30 , charges the drum 16 to a selectively high uniform electrical potential, preferably negative. Any suitable control, well known in the art, may be employed for controlling the corona generating device 30 .
A document to be reproduced is placed on a platen 22 , located at imaging station 25 , where it is illuminated in a known manner by a light source such as a tungsten halogen lamp 24 . The document thus exposed is imaged onto the drum 16 by a system of mirrors 26 , as shown. The optical image selectively discharges surface 28 of the drum 16 in an image configuration to the document whereby an electrostatic latent image 32 of the original document is recorded on the drum 16 at imaging station 25 .
At development station 35 , a magnetic development system or unit, indicated generally by the reference numeral 30 advances developer materials into contact with the electrostatic latent images. Preferably, the magnetic developer unit includes a magnetic developer roll mounted in a housing. Thus, developer unit 30 contains a developer roll which advances toner particles into contact with the latent image. Appropriate developer biasing may be accomplished via power supply 40 electrically connected to developer unit 30 .
The developer unit 30 develops the charged image areas of the photoconductive surface. This developer unit contains magnetic black toner, for example, particles 44 which are charged by the electrostatic field existing between the photoconductive surface and the electrically biased developer roll in the developer unit. A power supply electrically biases the developer roll.
A sheet of support material 50 is moved into contact with the toner image at transfer station 45 . The sheet of support material is advanced to transfer station 45 by a suitable sheet feeding apparatus, not shown. Preferably, the sheet feeding apparatus includes a feed roll contacting the uppermost sheet of a stack of copy sheets. Feed rolls rotate so as to advance the uppermost sheet from the stack into a chute drum 16 in a timed sequence so that the toner powder image developed thereon contacts the advancing sheet of support material at transfer station 45 .
Transfer station 45 includes a corona generating device 60 which sprays ions of a suitable polarity onto the backside of sheet 50 . This attracts the toner powder image from the drum 16 to sheet 50 . After transfer, the sheet continues to move, in the direction of arrow 62 , onto a conveyor (not shown) which advances the sheet 50 to fusing station 55 .
Fusing station 55 includes a fuser assembly, indicated generally by the reference numeral 64 , which permanently affixes the transferred powder image to sheet 50 .
Preferably, fuser assembly 64 comprises a heated fuser roller 66 and a pressure roller 68 . Sheet 50 passes between fuser roller 66 and pressure roller 68 with the toner powder image contacting fuser roller 66 . In this manner, the toner powder image is permanently affixed to sheet 50 . After fusing, a chute, not shown, guides the advancing sheet 50 to a catch tray, also not shown, for subsequent removal from the printing machine by the operator. It will also be understood that other post-fusing operations can be included. For example, stapling, binding, inverting and returning the sheet 50 for duplexing, and the like.
After the sheet 50 of support material is separated from the photoconductive surface of drum 16 , the residual toner particles carried by image and the non-image areas on the photoconductive surface are charged to a suitable polarity and level by a preclean charging device 72 to enable removal therefrom. These particles are removed at cleaning station 65 . The cleaner unit can include two brush rolls that rotate at relatively high speeds which create mechanical forces that tend to sweep the residual toner particles into an air stream (provided by a vacuum source), and then into a waste container. Subsequent to cleaning, a discharge lamp or corona generating device (not shown) dissipates any residual electrostatic charge remaining prior to the charging thereof for the next successive imaging cycle.
The various machine functions are regulated by a controller. The controller is preferably a programmable microprocessor which controls all of the machine functions hereinbefore described. The controller provides a comparison count of the copy sheets, the number of documents being recirculated, the number of copy sheets selected by the operator, time delays, jam corrections, etc. The control of all of the exemplary systems heretofore described may be accomplished by conventional control switch inputs from the printing machine consoles selected by the operator. Conventional sheet path sensors or switches may be utilized to keep track of the position of the documents and the copy sheets. In addition, the controller regulates the various positions of the gates depending upon the mode of operation selected.
The electrophotographic printing machine as described above is an example of a machine having the kind of environment that will use features of the present invention. Specifically, the outer cover of the machine described above and schematically illustrated in FIG. 1 includes a plurality of doors and/or covers (not shown) which enable either a user of the electrophotographic machine or a person who is servicing the machine to quickly and easily obtain access to any internal part of the machine such as, for example, the photoconductive drum 16 or any of the mechanisms which drive the drum; the charging station 19 ; the imaging station D; the development station 35 ; the transfer station 45 ; the fusing station 55 ; the finishing portion of the printer or any part other in any of these areas or any other part of the electrophotographic machine. Typically, magnetic catches are used to hold these access doors or covers firmly closed during the operation of the machine or at any time that access to any of the internal mechanisms is not needed or desired.
In accordance with the features of the present invention and as specifically illustrated in FIGS. 3A and 3B, the components of a magnetic catch assembly 80 are combined into a one piece, unitary injection molding utilizing ferrite molding compounds to form the magnetic catch assembly and preferably a magnetization technology as developed by the Xerox Corporation for magnetizing the assembly. For example molding and magnetizing a magnetic catch assembly can be done by following the teachings as contained in any of U.S. Pat. Nos. 5,795,532, or 5,894,004 or 6,000,922 the disclosures of which are all incorporated by reference in this application in their entirety. By utilizing the Xerox Corporation's magnetization technology with ferrite thermoplastic molding compounds, in accordance with the invention as described herein all the parts (i.e. 11 , 12 and 14 ) of the prior art type magnetic catch assembly 10 as illustrated in FIG. 2 are combined into a one piece unitary molding. Selective areas 81 (one or more) of interest of the molding are magnetized in the mold as part of the forming process, and other areas are molded to form the mounting bracket 82 having, for example, openings 83 insertion of, a screw as mail to secure the magnetic catch assembly 80 to a machine frame. Following this technique will result in a significantly lower manufacturing cost for a magnetic catch assembly, and also a simplified part design along with an overall reduction in the number of parts required for such an assembly.
In FIGS. 4A and 4B there is illustrated embodiments for magnetic catch assemblies various in accordance with features of the present invention. Specifically, the unitary structure in FIG. 4A is a molded, one piece corner magnet assembly 85 having magnetic areas 87 and 88 that are arranged on the assembly in such a manner to accommodate a corner position within a machine. The corner magnetic catch assembly 85 can include snap fit members 89 which can be snap fit onto the machine frame so as to further secure the magnetic catch assembly 85 (FIG. 4A) or 86 (FIG. 4B) onto the of the machine. The snap fit members 89 extend from the mounting bracket portion 90 of the magnetic catch assembly 85 and 86 . A further optional feature extending from magnetic catch assembly 85 is another mounting element 91 that can be used to further secure magnetic catch assembly 85 to a machine.
Illustrated in FIG. 5 is still another embodiment of a magnetic catch assembly that incorporates the features of the present invention. There is shown a molded, one-piece, unitary double step magnetic catch assembly 92 which is specifically configured with two magnetic area 93 , specifically for a situation where there are, for example double doors, i.e. two side-by-side doors which are to be held in a closed position by a magnetic catch assembly. The unitary structure includes mounting brackets 94 for securing the assembly 92 to a machine.
In accordance with the features of the present invention the injection molded, one piece, unitary magnetic catch assembly is preferably manufactured from a resin dispersed with a material that is capable of being magnetized. The resin may be any suitable thermoset or thermoplastic resin. For example, the thermoset resins may include phenolics or epoxies, may be a nylon or a polypropolene. The resins may be conductive or semiconductive. The level of magnetism of the resin is controlled by the amount or type of additive to the phenolic material i.e. the magnetically attractable filler material.
While this invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.
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A magnetic catch assembly for securely holding a door or cover on a machine in a closed position. The assembly comprises a unitary, injection molded, plastic member at least one portion of the member being magnetized to form the magnetic catch and at least one portion of the molded unitary member forming a mounting bracket adapted to securely mount the magnetic catch assembly to the machine.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan application serial no. 96138177, filed on Oct. 12, 2007. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a metal-oxide-semiconductor field-effect transistor (MOSFET) structure. More particularly, the present invention relates to a power MOSFET array structure located under a gate pad.
[0004] 2. Description of Related Art
[0005] Power MOSFET can be used as high voltage device with current applicable operating voltage of up to higher than 4500 volts, and is mainly used as switching apparatus. Commonly, the MOSFET is of a planar structure, and each end point in the transistor is only several micrometers away from a chip surface. All the power devices are of a vertical structure, such that the devices can bear high voltage and high current at the same time. The bearable voltage of the power MOSFET depends on doping concentration and thickness of n-type epitaxy layer, and the current capable of passing through the power MOSFET depends on channel width of the device. The wider the channel is, the more current can be accommodated. Under fixed channel size, the current is directly proportional to channel density. Generally speaking, in the conventional art, the channel density is increased by means of reducing distance between basic devices. When volume of the transistor is reduced, not only the space is saved, but also the cost is reduced. Therefore, the industry urgently needs a method of reducing the volume of the power MOSFET array.
[0006] The basic devices of the MOSFET array include a substrate, an epitaxy layer, a source region, gates, a source pad, and a gate pad etc. In the conventional art, the source pad is disposed above the power MOSFET array and is connected to the source region, and the gate pad is disposed beside the array and is connected to the gate. A space exists under the gate pad, and is useless. Therefore, the industry urgently needs a method of well utilizing the space under the gate pad, thereby reducing the volume of the array and increasing the device integration.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention is directed to provide a power MOSFET array structure, which is capable of disposing the power MOSFET array under the gate pad, so as to well utilize the space under the gate pad, and to increase device integration.
[0008] The present invention is further directed to provide a power MOSFET array pair structure, which is capable of connecting the power MOSFET array disposed under the gate pad and the conventional power MOSFET array disposed under the source pad, so as to share the same gate pad and source pad, thereby saving the volume of the array pair, and increasing the device integration.
[0009] The present invention provides a power MOSFET array structure. In the structure, a gate pad is disposed above the power MOSFET array. The power MOSFET array includes a substrate, an epitaxy layer, a plurality of gates, a source region, and a gate pad. The substrate serves as a drain, and the substrate has a device region. The epitaxy layer is disposed on the substrate, the plurality of gates is disposed on the epitaxy layer in the device region, and the gates are mutually electrically insulated. The source region is disposed on the epitaxy layer between the gates, in which the source region and the gates form the power MOSFET array. The gate pad is disposed above the power MOSFET array, and the gate pad is electrically connected to the gates.
[0010] The present invention provides a power MOSFET array pair structure. Two power MOSFET arrays share the same gate pad and source pad through the connection of the circuit connection region. The power MOSFET array pair includes a substrate, an epitaxy layer, source regions, a gate region, a gate pad, and a source pad. The substrate has a first device region, a second device region, and a circuit connection region, a portion of the substrate in the first device region serves as a first drain, and a portion of the substrate in the second device region serves as a second drain. The epitaxy layer is disposed on the substrate. A plurality of first gates is disposed on the epitaxy layer of the first device region, in which the first gates are mutually electrically insulated. A first source region is disposed on the epitaxy layer between the first gates, and the first source region and the first gates form a first power MOSFET array. A plurality of second source regions is disposed on the epitaxy layer, in which the second source regions are mutually electrically insulated. A second gate is disposed on the epitaxy layer between the second source regions, and the second gate and the second source regions form a second power MOSFET array. The gate pad is disposed right above the first power MOSFET array, the gate pad is electrically connected to the first gates, and is electrically connected to the second gate in the second device region through the circuit connection region. The source pad is disposed right above the second power MOSFET array, in which the source pad is electrically connected to the second source regions, and is electrically connected to the first source in the first device region through the circuit connection region.
[0011] In the present invention, the MOSFET array is disposed under the gate pad, so as to well utilize the originally idle space under the gate pad and to increase the device integration. By adopting the circuit connection region, the MOSFET array under the gate pad and the conventional MOSFET array disposed under the source pad form an array pair, so as to share the same gate pad and source pad, thereby reducing the volume of the array pair, such that the application scope of the power MOSFET array is broader.
[0012] In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0015] FIG. 1A is a top view of the power MOSFET array according to an embodiment of the present invention.
[0016] FIG. 1B is a simplified sectional view of FIG. 1A along line I-I′.
[0017] FIG. 2A is a top view of the power MOSFET array pair according to an embodiment of the present invention.
[0018] FIG. 2B is a simplified sectional view of FIG. 2A along line II-II′.
DESCRIPTION OF EMBODIMENTS
[0019] FIG. 1A is a top view of the power MOSFET array according to an embodiment of the present invention. FIG. 1B is a simplified sectional view of FIG. 1A along line I-I′.
[0020] Referring to FIGS. 1A and 1B , the power MOSFET array of the present invention includes a substrate 100 , an epitaxy layer 102 , a plurality of gates 104 , a plurality of source regions 106 , a gate pad 110 , and a source pad 120 .
[0021] The substrate 100 has a device region 100 a , a circuit connection region 100 b , and a source pad region 100 c . The epitaxy layer 102 is disposed above the substrate 100 . In the power MOSFET array, the substrate 100 serves as a drain. Further, for example for an N type power MOSFET, the conductive type of the substrate 100 is, for example, N type, and the conductive type of the epitaxy layer 102 is P type.
[0022] Referring to FIGS. 1A and 1B , the plurality of gates 104 is disposed on the epitaxy layer 102 in the device region 100 a . The gates 104 disposed on the epitaxy layer 102 are mutually electrically insulated. A source region 106 is disposed on the epitaxy layer 102 between the gates 104 , and a portion of the source region 106 extends to the circuit connection region 100 b . The source region 106 and the gates 104 together form a power MOSFET array 114 (as shown in FIG. 1A ). For example, for the N type power MOSFET, when the conductive type of the substrate 100 is, for example N type, and the conductive type of the epitaxy layer 102 is P type, the conductive type of the source region 106 is N type.
[0023] An insulation layer 108 is further disposed above the substrate 100 , the insulation layer 108 covers the device region 100 a and the circuit connection region 100 b , and the insulation layer 108 has a plurality of gate contact openings 112 in the device region 100 a , for respectively exposing the gates 104 . At the same time, the insulation layer 108 has a plurality of source contact openings 118 in the circuit connection region 100 b , for exposing the source regions 106 . In addition, the material of the insulation layer 108 is, for example, silica, silicon nitride, or silicon oxynitride etc. The gate pad 110 is disposed on the insulation layer above the device region 110 a in the substrate 100 , and the gate pad 110 electrically contacts with the gates 104 respectively through the gate contact openings 112 in the insulation layer 108 . That is to say, the gate pad 110 is disposed above the power MOSFET array 114 and covers the power MOSFET array 114 .
[0024] Next, the power MOSFET array 114 further includes a source pad 120 disposed above a region beyond the gate pad 110 of the substrate 100 , i.e., above the source pad region 100 c . The source pad 120 covers the source pad region 100 c and covers a portion of the circuit connection region 100 b . Further, the source pad 120 is electrically connected to the source region 106 through the source contact openings 118 in the insulation layer 108 in the circuit connection region 100 b.
[0025] FIG. 2A is a top view of the power MOSFET array pair according to an embodiment of the present invention. FIG. 2B is a simplified sectional view of FIG. 2 A along line II-II′.
[0026] Referring to FIG. 2A , the power MOSFET array pair of the present invention is disposed on a substrate 200 and includes an epitaxy layer 202 , a plurality of first gates 204 , a first source 206 , a plurality of second sources 208 , a second gate 210 , a gate pad 222 , and a source pad 224 . The substrate 200 has a first device region 200 a , a second device region 200 b , and a circuit connection region 200 c . The circuit connection region 200 c is disposed between the first device region 200 a and the second device region 200 b . In addition, a portion of the substrate 200 in the first device region 200 a serves as a first drain, and a portion of the substrate 200 in the second device region 200 b serves as a second drain.
[0027] Referring to FIGS. 2A and 2B , the epitaxy layer 202 is disposed on the substrate 200 , and a portion of the epitaxy layer 202 in the first device region 200 a has a plurality of first gates 204 electrically insulated with each other. A first source region 206 is disposed on the epitaxy layer 202 between the first gates. The first source region 206 is, for example, a portion of the epitaxy layer 202 , that is, a portion of the epitaxy layer 202 exposed by the first gates 204 is converted to a doped region of the first source region 206 by means of ion-implantation. In addition, the first source region 206 partially extends to the circuit connection region 200 c between the first device region 200 a and the second device region 200 b . It should be noted that the first source region 206 and the first gates 204 form a first power MOSFET array 220 .
[0028] In the second device region 200 b , a plurality of second source regions 208 electrically insulated with each other is disposed on a portion of the epitaxy layer 202 with a same horizontal height as the first gates 204 and the first source region 206 . A second gate 210 is disposed on the exposed epitaxy layer 202 between the second source regions 208 . In addition, the second gate 210 partially extends to the circuit connection region 200 c between the first device region 200 a and the second device region 200 b . The second source regions 208 are, for example, a portion of the epitaxy layer 202 , that is, a plurality of doped regions serving as the second source regions 208 is formed in the epitaxy layer 202 by means of ion-implantation. It should be noted that the second source regions 208 and the second gate 210 form a second power MOSFET array 240 .
[0029] An insulation layer 212 covers the substrate 200 , and the material of the insulation layer 212 is, for example, silica, silicon nitride, or silicon oxynitride etc. A portion of the insulation layer 212 in the first device region 200 a covers the first source region 206 , and the insulation layer 212 has a plurality of first gate contact openings 212 a in the first device region 200 a . The first gate contact openings 212 a respectively expose the first gates 204 . In addition, in the second device region 200 b , the insulation layer 212 covers the second gate 210 , and in the second device region 200 b , the insulation layer 212 has a plurality of first source contact openings 212 b respectively exposing the second source regions 208 .
[0030] Further, in the circuit connection region 200 c , the insulation layer 212 has a plurality of second gate contact openings 212 c and a plurality of second source contact openings 212 d , respectively exposing a portion of the second gate 210 and the first source region 206 in the circuit connection region 200 c.
[0031] Next, referring to FIGS. 2A and 2B , a gate pad 222 is disposed right above the first power MOSFET array 220 . The gate pad 222 is electrically connected to the first gates 204 in the first device region 200 a through the first gate contact openings 212 a in the insulation layer 212 . At the same time, the second gate 210 in the second device region 200 b is electrically connected to the gate pad 222 through the second gate contact openings 212 c of the insulation layer 212 in the circuit connection region 200 c.
[0032] At the same time, a source pad 224 is disposed right above the second power MOSFET array 240 . The source pad 224 is electrically connected to the second source regions 208 disposed in the second device region 200 b through the first source contact openings 212 b in the insulation layer 212 . The first source 206 in the first device region 200 a is electrically connected to the source pad 224 through the second source contact openings 212 d of the insulation layer 212 in the circuit connection region 200 c.
[0033] To sum up, in the present invention, the MOSFET array is disposed under the gate pad, the disposing quantity of the MOSFETs of unit area is improved, thereby increasing the device integration. In addition, by using the circuit connection region, the MOSFET array disposed under the gate pad is electrically connected to the source pad above the non-array. In other aspect, similarly through the circuit connection region, the MOSFET array disposed under the gate pad and the MOSFET array disposed under the source pad can form an array pair, so as to share the same gate pad and source pad. Accordingly, the volume of the array pair is reduced, the integration is improved, such that the application scope of the power MOSFET array becomes broader.
[0034] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
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A power metal-oxide-semiconductor field-effect transistor (MOSFET) array structure is provided. The power MOSFET array is disposed under a gate pad, and space under the gate pad can be well used to increase device integration. When the array and the conventional power MOSFET array disposed under the source pad are connected to an array pair by using circuit connection region, the same gate pad and source pad can be shared, so as to achieve an objective of increasing device integration.
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This is a divisional of Ser. No. 07/549,756 filed Jul. 9, 1990 now U.S. Pat No. 5,067,202.
BACKGROUND OF THE INVENTION
The invention relates to a method of maintaining a predetermined quality of a carded sliver produced in a card and/or drafted in a drawframe, the sliver being delivered into a can by a sliver delivery device in a continuous spinning mill process.
The actual spinning machine which produces the yarn end product is of course the costliest machine in the spinning process and is therefore required to operate at maximum efficiency--i.e., to have very short downtimes.
The various machines before and after the spinning machine are therefore so designed performance-wise as to overperform relative to the spinning machine so that the same does not have to wait for the feeding of its feedstock nor for subsequent processing, for example, in a winder.
The overperformance system applies to all the machines involved in the feeding of the feedstock for the spinning machine--i.e., in the blowroom of a spinning mill--viz. as will be described hereinafter with reference to the drawings, any machine in the working process has a higher output than the machine immediately following it. This is how the present day machine park in spinning mills has evolved; however, if a blowroom process has to be performed by a machine considerably more expensive than a following machine (excluding the spinning machine), the previous machine may of course have a shorter downtime than the subsequent machine for the sake of economic balance.
These differences in performance can of course be compensated for by buffer stores of product which will vary in size in dependence upon the difference between the performance of the previous stage and the performance of the next stage. Clearly, large buffer stores are undesirable for purely economic reasons and in the course of spinning mill automation systems must be devised throughout from bale opening to end product either to eliminate the known manual intermediate buffer stores or at least so to organize them so that they are automatable.
SUMMARY OF THE INVENTION
The problem which the inventor had to address was therefore to optimize the performance steps in a spinning mill blowroom as to minimise the size of the buffer stores for intermediates and to facilitate automation.
To solve the problem, according to the invention, the card and/or drawframe, which each have a predetermined overproduction relative to a spinning machine associated with the process, have a predetermined temporary decrease in production which temporarily compensates correspondingly for the overproduction.
Also suggested for performing the method is a drawframe wherein the drawframe control has a computer part which at the changeover to decreased production effects the programmed slowdown and, if applicable, the stoppage and at the changeover from decreased production effects the programmed acceleration preceded, if applicable, by restarting.
Also suggested for performing the method is a combined card and drawframe system wherein the drawframe system has a supply of cans and, disposed in such supply, a can row with a can counter and the same responds to the presence of a predetermined number of cans in the row by outputting a signal.
The advantage of the invention is that it offers a basis for optimising profitability and a possibility for automation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail hereinafter with reference to embodiments.
In the drawings:
FIG. 1 is a diagram showing the efficiency of various items of spinning mill machinery;
FIG. 2 is an illustration in graph form of the method steps according to the invention;
FIG. 3 shows a variant of FIG. 2;
FIG. 4 is a diagrammatic view of a card having a sliver delivery device, the view being in cross-section;
FIG. 5 is a diagrammatic plan view of the card of FIG. 4;
FIG. 6 is a diagrammatic plan view of a combined card and drawframe system, and
FIGS. 7 and 8 are each a view to an enlarged scale of a detail of the system shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an efficiency diagram of a number of spinning mill machines in which total or maximum efficiency is represented by a chaindotted line W and the downtimes of the various machines are illustrated (in purely diagrammatic form) by means of spacer arrows DP, DK, DST, DF, DR and DSP.
The letters in the hatched rectangles have the following meanings:
______________________________________The letter P denotes blowroom machinesThe letter K denotes cardsThe letter ST denotes drawframesThe letter F denotes roving framesThe letter R denotes ring spinning machinesThe letter SP denotes winders______________________________________
The rectangles containing the letters P to SP are purely diagrammatic representations of machine performances or outputs. their areas being such that the area of any machine type is less than the area of the immediately previous type except for the area representing the winders, which is greater than the area representing the ring spinning machines. The aim of the diagram is to visualize the decrease in output as seen from the blowroom machines up to and including the ring spinning machine, the differences between the areas being exaggerated so that the differences can be more clearly visualized. Also, the areas shown are not in their actual relation to downtime and the latter too is shown for the sake of clarification with greater differences than are usually found in practice.
Correspondingly, in the co-ordinate system shown in FIGS. 2 and 3, efficiency is plotted along the ordinate and the steps of the method along the abscissa. As previously stated, the steps of the method are:
______________________________________ Blowroom = P Card room = K Drawframe = ST Roving frame = F Ring spinning machines = R Winding room = SP______________________________________
Of the machine types P to F the card is the most complex--i.e., a machine in which a large number of technical and technological functions must co-operate if a uniform and high-quality card silver is to be produced.
Consequently, the co-operation between the various functions does not of course lead to absolutely the same result as regards silver quality in all the performance steps and the same assumption is made further on in the production process--i.e., in drafting and in the roving frame--so that it may be necessary to separate out the carded silver in the event of substantial output changes.
In the method according to the invention, to link this elimination of a silver which cannot be used in the subsequent stages with can changing in the card, when it is required to decrease card output, the card continues to produce at its normal output until can changing becomes necessary, the card being changed over to decreased output shortly after can changing, either until stoppage of the card or until further production at a minimum output step.
The decrease in production occurs with a slowdown of the kind represented by a line 1 in FIG. 2, where the card is brought to a standstill, then restored after a controlled time T to full output represented by lines 2a, 2b, a line 3 representing this acceleration.
Chain-dotted lines 4, 5 indicate the activation times for can changing, the line 4 denoting the activation time before the slowdown 1 while the line 5 denotes the changeover time for further can changing after the acceleration 3, whereafter the silver produced on full output is delivered into the next can.
Consequently, no silver produced on decreased output can be delivered into a "good" can intended to receive only silver which has been produced on full output.
FIG. 3 shows the same principle except that output is not reduced to zero as it is in FIG. 2; instead the card continues to produce at a very low output, for example, 10% of normal output until the control instruction for acceleration back to normal output is given.
The advantage of the method shown in FIG. 3 is that cards which cannot be completely guaranteed to produce breakage-free silver until the card stops can continue to produce on low output without a large quantity of waste silver accumulating. The decrease in production shown in FIG. 3 is represented by a line 6. Since the other lines relate to functions substantially corresponding to the functions of FIG. 2, the latter lines have the index 1 added to their references.
FIG. 4 is a view in cross-section of a known card 10 having a known silver delivery device 11 and, disposed between the same and the card 10, a known silver loop sensor or sliver sag monitor 12.
The card 10 is a card produced by the Applicants and sold world-wide as type C4/C1 and the facility comprising the elements 11, 12 is sold by the Applicants world-wide as type CPA.
The two combined machines were presented to the public, for example, at the 1989 American Textile Machinery Exhibition (ATME) in Greenville.
The card 10 and the device 11 operate through the agency of a control 13 which triggers the card with the necessary output-controlling signals and which imposes on the delivery device 11 a sliver delivery corresponding to card output, sliver delivery being adapted by means of the sliver loop control 12 to the alteration in card output in dependence upon the alteration thereof.
Sliver output--i.e., the weight of sliver produced per unit of time--is measured by means of a measuring roller pair 14 at the card exit and communicated by means of a measuring signal 15 to the control 13. The same deduces from the signal 15 an output-controlling signal 16 which controls the motor 17 driving the delivery device 11.
Alterations in sliver delivery after the roller pair 14 are recorded by the sensor 12 and communicated by means of a signal 18 to the control 13 so that by means of the signal 16 the motor 17 has its speed varied in accordance with the change in output.
A novel feature provided by the invention is that the control 13 has a computer attachment which is indicated in purely diagrammatic form by the reference 19 and which responds to the operation of a switch to be described hereinafter by decreasing card output in accordance with either FIG. 2 or FIG. 3, further operation of the same switch accelerating the card in the manner shown in FIGS. 2 and 3.
The decrease in output and the acceleration of the card cause a change in the position of loop 20 of the sliver 21 which the card 10 produces and which the device 11 delivers into a can 22. This change in the position of the loop 20 produces corresponding signals 18 so that the delivery device 11--i.e., motor 17 thereof--either slows down or accelerates the device 11 correspondingly. This feature provides the advantage that no additional synchronization between the card motors and the motor 17 driving the device 11 is required.
FIG. 5 is a plan view of the card 10 and delivery device 11 and also shows the sliver loop sensor 12.
Like elements in FIGS. 4 and 5 have the same references.
As previously stated, the device 11 is known from the publication. A novel feature provided by the invention is that the entering empty cans are conveyed by a conveyor belt 23 as far as an exit position M in which a displacing arm 24 of can displacer 25 moves the can into sliver delivery position N in which sliver is introduced into the can.
The can which has been filled with good sliver is moved by a second displacing arm 26 into a first removal position T on a conveyor belt 27 while a can which has been filled with a low-output sliver is moved into a second removal position Q on a conveyor belt 28. The computer part 19 controls these operations.
The arms 24, 26 can so pivot (not shown) as to be pivoted from a vertical position, in which they can be moved past the stationary cans, into a horizontal position in which they can displace the cans. The arms 24, 26 are parts of the delivery device 11.
The significance of the conveyor belts 23, 27, 28 will be described in greater detail with reference to FIG. 6.
FIG. 6 shows a number of cards 10 so disposed parallel to and adjacent one another that the conveyor belts 23, 27, 28 extend to a can conveyor 29. The cans on the conveyor belts are moved in directions indicated by arrows in FIGS. 5 and 6--i.e., the cans on the belt 23 are moved towards the can delivery and the cans on belts 27, 28 are moved towards the can conveyor 29. The cans on the belt 23 are empty cans, the cans on the belt 27 are full cans and the cans on the belt 28 are cans containing the sliver produced with the card on decreased output so that a can may have any level of filling.
So that the cans can either be pushed off the conveyor 29 on to the belt 23 or pulled off the belts 27, 28 on to the conveyor 29, the conveyor 29 has pneumatic reciprocating actuators 30, the operation of which is shown in greater detail in FIG. 8. As can be gathered therefrom, the actuators comprise a suction and shifting shoe 31 adapted to the diameter of the cans 22 and having an air-permeable but plastically deformable wall 32 which is adapted to can diameter and which covers a hollow member 33 associated with a bore 34 extending through piston rod 35 and piston 36, so that cavity 37 communicates with pressure chamber 38 of cylinder 39.
At its end near the delivery chamber, the bore 34 has a check flap 40; when the chamber 38 is maintained at a positive pressure by way of a compressed air valve 41 connected to the chamber 38, the flap 40 closes the bore 34 so that the piston 36 and, therefore, the shoe 31 can move in the direction indicated by an arrow 42.
When, however, a suction valve 43, which is also connected to the chamber 38, is open instead of the compressed air valve 41, the chamber 38 is at a negative pressure, so that the flap 40 opens and the cavity 37 is at a negative pressure. The negative pressure sucks tightly on to wall 32 of a can 22 in contact therewith which is also displaced together with the shoe 31 in the direction indicated by an arrow 44 until the hollow member 33 contacts an abutment 90 limiting this movement in the direction 44.
Sensors detecting the position of the shoe 31 for the valves 41, 43 to be changed over by means of a control (not shown) are not shown here.
The suction valve 43 is connected to a suction source 45 and the compressed air valve 41 to a compressed air source 46.
By means of a pneumatic reciprocating actuator 30, empty cans are pushed off the can conveyor 29 on to the conveyor belt 23 and full cans are pulled off the conveyor belt 27 on to the conveyor 29; the cans are also pulled off the belt 28 on to the conveyor 29.
The can conveyor 29 is movable on rails 47. A control station controlling movement of the can conveyor 29 is illustrated diagrammatically in the form of a rectangle having the reference 48; it is the subject of the Applicants' patent application No. CH 0 4410/88-1 and is not further described here.
A drawframe 50 is contiguous with the rails 47 and is disposed on a side remote from the cards of the rail oval shown in FIG. 6; the drawframe 50 takes over the cans filled by the cards 12 and processes their silver. A drawframe of this kind is known and, for example, sold by the Applicants world-wide under the designation D1.
The drawframe includes the actual drafting unit 51 which drafts slivers 53 infed on a feed table 52.
The slivers 53 are delivered from can row 54 in which emptying cans are disposed. Can row 55, which extends parallel to row 54, consists of full cans in a reserve position. Can row 56 which is parallel to and in FIG. 6 immediately above row 55 is another full-can row but a row adapted to take up full cans from the conveyor 29.
On the bottom side of the feed table 52, looking at FIG. 6, a row of empty cans 57 stands ready parallel to the feed table 52 for transfer to the can conveyor 29.
This can arrangement just described is shown more clearly and to an enlarged scale in FIG. 7. As will be apparent, the cans of row 56 can be moved both in the conveying direction 58 and in the conveying direction 59, movement in the direction 58 being produced by discrete conveyor belts 60 disposed in adjacent end-to-end relationship to one another whereas the cans 52 can be moved in the direction 59 by reciprocating actuators 30. The same move the cans 22 from row 56 to row 55. Conveyor belts 60 are provided to move the cans 22 in the rows 55, 54 but are at a 90° offset in their conveying direction from the conveyor belts of the row 56 so that the cans are moved in the direction 59.
The cans emptied in the row 54 are moved through below the feed table 52 by means of another row of conveyor belts which move the cans so far in the direction 59 that the cans can be drawn by further actuators 30 on to the conveyor belts of the row 57. The cans move in the direction 61 on the latter belts for conveyance towards the can conveyor 29. Instead of the discrete conveyor belts of the row 57 shown in FIG. 7, a single conveyor belt (not shown) can be used.
Cans are displaced into the next row--i.e., e.g., from row 56 into row 55 and so on--when the cans in row 54 are empty, a state which is detected by a sliver sensor (not shown) on the feed table 52, for example, at the deflections 91 which deflect the sliver through 90°, and which is fed into a control 63 as a signal 92 (not completely shown). The control 63 initiates activation of whichever conveyor belts and reciprocating actuators move the cans in the direction 59--i.e., the conveyor belts 55, 54, 62 and the actuators 30 for both pushing and pulling the cans.
The control 63 is also responsible for moving the cans in the drawframe 50 in good time--i.e., changing full cans for empty cans--something which is performed in basically the same way as described with reference to the cards 12 and indicated by corresponding arrowed directions. The actual drafting unit 51, of the drawframe 50 is controlled by means of an associated computer part for both stop-start operation and low-output operation.
A can conveyor 29. 1 is provided for the drawframe 50 in just the same way as for the cards 12 and has the same function as the conveyor 29 but it conveys the full and empty cans to a machine which follows the drawframe, such as one or more roving frames.
The cans previously described which contain silver produced during low-output operation of the cards 12 and which are supplied with the silver 28 to the can conveyor 29 are delivered thereby to a standby row 70 in which the cans are conveyed on a conveyor belt in a direction 71 so that they can be received by further means (not shown) and conveyed to a clearing station (not shown), whence empty cans return and are introduced into a standby row 72 also in the form of a conveyor belt so operated that the empty cans can be conveyed in a direction 73 towards the can conveyor 29 and delivered thereto.
The can-displacing arrangement for the drawframe 50 corresponds basically to the arrangement described for the cards 12 and so will not be described and illustrated again. Similar considerations apply to the standby position of the full and empty cans containing sliver of below normal quality so that this sliver is cleared in the clearing station.
Basically, however, output can be controlled down to zero with the drawframe 50 without any loss of quality in the drafted silver so that the conveyor belt and the corresponding function associated with reception of the cans, similarly to the cans on the belt 28, can be omitted.
Finally, the row 56 has a can detector which by means of a signal 80 informs station 48 of the number of cans present in the row.
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The present invention is directed to a card having a sliver delivery device and a computer part for maintaining a predetermined quality of a carded sliver, wherein there is a predetermined overproduction from a card and/or a drawframe relative to a spinning machine. The arrangement temporarily decreases production to temporarily compensate for the overproductions. The sliver which is produced during the decrease in production may be delivered to a separate can.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No. 7,453,846. The reissue applications are Reissue Application No. 12/718,087 (the present reissue application), and Continuation Reissue Application Nos. 13/170,786, 13/171,092, 13/171,255, and 13/171,369, all of which are continuation reissue applications of the present reissue application and of U.S. Pat. No. 7,453,846. This reissue application seeks a reissue of U.S. Pat. No. 7,453,846, which issued on Nov. 18, 2008, from application Ser. No. 10/314,295 filed on Dec. 9, 2002, which claims the benefit of Korean Application No. 2001-78664 filed on Dec. 12, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wireless independent network based on carrier sense multiplexing access (CSMA)/collision avoidance (CA). More particularly, the present invention relates to a method for sharing hybrid resources in a wireless independent network, a station for the method, and a data format for the method and the station.
2. Description of the Related Art
Wireless independent networks connect wireless stations without the use of wires in a predetermined area regardless of connections to base networks. For example, home networks connecting information regarding home electronics without the use of wires is a type of wireless independent network. Services in a wireless independent network may generally be classified into a real-time Audio Video (AV) streaming service or a non-real-time AV streaming service.
An environment of such a wireless independent network may be characterized as follows. First, since network subscribers' interests concentrate on a real-time AV streaming service in one independent network, it is rare for a large number of real-time AV services to coexist in one independent network. Second, a small number of real-time AV streaming services and a large number of non-real-time AV streaming services can coexist in one independent network. Third, the real-time AV streaming service uses a station that is the subject thereof and limited holding time exists in the service.
In the above-described wireless independent network environment, wireless stations (STAs) typically share wireless communications resources. Here, a conventional resource-sharing method may generally be classified into a distributed coordination method or a centralized control method.
The distributed coordination method uses a mechanism for minimizing possible message collisions that occur when stations attempt to use a data channel simultaneously. This mechanism is the IEEE 802.11a distributed coordination function (DCF) based on CSMA/CA. In a distributed coordination method using a DCF, random backoff numbers are created to minimize competition-based collisions, the backoff numbers are reduced by stages when a channel is idle for at least a predetermined period of time (in the case of IEEE 802.11, this is referred to as DCF Interframe Space (DIFS)), and data is transmitted when the backoff number becomes “0”. A conventional distributed coordination method for grading priorities of the occupation of resources according to a specific type of data includes a Point Coordination Function (PCF) Interframe Space (PIFS) system and a Short lnterframe Space (SIFS). Priorities of these systems are in the relationship DIFS>PIFS>SIFS, and a station using SIFS has priority over a station using DIFS. However, since a DCF system works on a probabilistic base, it is still possible for stations to collide.
In the centralized control method, one control station controls resources shared in a wireless independent network in a bundle. Thus, wireless stations share wireless resources according to the instructions of the control station. The centralized control method may be subdivided into a direct mode and an indirect mode. In the direct mode, a control station controls the time slots for transmission and reception among wireless stations so that the wireless stations directly communicate with one another. The HiperLAN/2 standard is a representative example of the direct mode. In the indirect mode, transmission data of all stations is transmitted to the control station so that the wireless stations indirectly communicate with one another through the control station. This indirect mode is based on the Bluetooth standard.
Accordingly, in the above-described distributed coordination method, a specific control station is not required, and a mesh network can be constituted, and a station may easily subscribe to and withdraw from the mesh network. However, the distributed coordination method uses resources ineffectively and cannot support the real-time AV streaming service. In addition, the centralized control method in the indirect mode cannot support the real-time AV streaming service due to the forwarding of packets, which concentrates loading on the control station, and requires the selection of a substitute node when the control station withdraws from the subscribed network. Although the centralized control method in the direct mode uses resources effectively, supports the real-time AV streaming service, and constitutes the mesh network, loading is concentrated on the control station, thus requiring the selection of a substitute node when the control station withdraws from the subscribed network.
The aforementioned conventional resource-sharing methods have many problems since they have been developed based on non-real-time services, or due to inflexible structure of networks.
SUMMARY OF THE INVENTION
In an effort to solve the above-described problems, it is a first feature of an embodiment of the present invention to provide a method for sharing hybrid resources in a wireless independent network that can have the advantages of conventional resource-sharing methods by more efficiently analyzing the environment of the wireless independent network so that wireless resources are shared adaptive to the environment, thereby efficiently supporting real-time services as well as non-real-time services among the wireless stations.
It is a second feature of an embodiment of the present invention to provide stations performing the hybrid resources sharing method.
It is a third feature of an embodiment of the present invention to provide formats of data transmitted among the stations.
Accordingly, a method for sharing wireless hybrid resources among stations in a wireless independent network preferably includes analyzing a received data stream and obtaining network control for optimally transferring that data. An analysis is performed to determine whether currently transmitted data is related to a real-time service when the sharing of the wireless hybrid resources is controlled by a distributed coordination method. A sharing control authority is requested and received by the distributed coordination method, and the sharing of the wireless hybrid resources is controlled by a centralized control method in a direct mode until the real-time service ends if it is determined that the currently transmitted data is related to the real-time service. The sharing control authority corresponds to an authority which controls the sharing of the wireless hybrid resources. If it is determined that the currently transmitted data is not related to the real-time service, the sharing of the wireless hybrid resources may be controlled by the distributed coordination method.
Obtaining network control when the currently transmitted data is related to the real-time service preferably includes requesting the sharing control authority by the distributed coordination method if it is determined that the currently transmitted data is related to the real-time service; determining whether the request for the sharing control authority is rejected; controlling the sharing of the wireless hybrid resources with a request for periodic polling, if it is determined that the request is rejected; and then determining whether the sharing of the wireless hybrid resources does not need to be controlled during the real-time service. If it is determined that the sharing of the wireless hybrid resources does not need to be controlled during the real-time service, control is transferred to the aforementioned requesting step. If it is determined the sharing of the wireless hybrid resources still needs to be controlled during the real-time service, control is returned to the step for requesting for periodic polling.
If it is determined that the request for the sharing control authority is not rejected, the method preferably additionally includes receiving the sharing control authority and controlling the sharing of the wireless hybrid resources by the centralized control method in the direct mode; determining whether the real-time service ends and returning to the receiving step if it is determined that the real-time service does not end; and returning the sharing control authority if it is determined that the real-time service ends. In the foregoing additional steps, the sharing of the wireless hybrid resources is preferably controlled by the distributed coordination method.
A preferred embodiment of a station for performing the wireless hybrid resources sharing method according to the present invention preferably includes a transmission data checking unit and a first controller. The preferred embodiment of the station may further include a second controller. The transmission data checking unit checks whether the currently transmitted data is related to the real-time service and generates a control signal in response to the check result. In response to the control signal, the first controller requests and receives the sharing control authority by the distributed coordination method and controls the sharing of the wireless hybrid resources by the centralized control method in the direct mode until the real-time service ends. Alternately, a second controller may control the sharing of the wireless hybrid resources by the distributed coordination method in response to the control signal.
The first controller preferably further includes a request message broadcaster, which broadcasts a control authority requesting message requesting the sharing control authority by the distributed coordination method in response to the control signal and an enable signal; a request rejecting message receiver, which receives a control authority request rejecting message rejecting the request for the sharing control authority and outputs a disable signal in response to the received result; a polling requesting unit, which requests periodic polling in response to the disable signal and the enable signal; a releasing message receiver, which receives a control authority releasing message in response to the control signal and outputs the enable signal in response to the received result; a shared resource controller, which receives the sharing control authority in response to the disable signal and controls the sharing of the wireless hybrid resources by the centralized control method in the direct mode and transmits the sharing control authority releasing message to another station and returns the sharing control authority in response to an ending signal; and a service checking unit, which checks whether the real-time service ends and outputs the checked result as the ending signal. Preferably, a second controller controls the sharing of the wireless hybrid resources by the distributed coordination method in response to the ending signal.
To operate the foregoing preferred station using the foregoing preferred method for sharing wireless hybrid resources, a data format preferably includes a control authority requesting message, a control Authority releasing message, and a plurality of transmission frames located therebetween. The control authority requesting message requests the sharing control authority by the distributed coordination method. The control authority releasing message releases the sharing control authority. The plurality of transmission frames are spaced apart from the control authority requesting message and the control authority releasing message, by a PIFS, are also spaced apart from each other by one PIFS, and may have variable lengths.
Each one of the plurality of transmission frames preferably further includes a downlink section in which the real-time service-related data is transmitted to another station and which may have a variable length; a polling section in which the other stations related to the real-time service is polled and which has a variable length; and a distribution control section in which non-real-time service-related data is transmitted to another station and which may have a variable length. The downlink section is preferably spaced apart from the polling section by a PIFS. The polling section is preferably spaced apart from the distribution control section by a DIFS. The downlink section preferably includes a plurality of packets which are spaced apart from each other by a PIFS.
In the event that a share request rejection message is received in the station, a sharing control authority message may also be received. In such a case, the shared resource controller is preferably idle for a PIFS period, thereby necessitating the inclusion of a PIFS time period between the time of the request for sharing control authority and the receipt of the sharing control authority. Additionally, in the event a sharing rejection message is transmitted by the sharing controller, preferably a SIFS time period is included in the format between the time of transmission of the request and the time of receipt of the rejection message.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become readily apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
FIG. 1 illustrates a flowchart of a method for sharing hybrid resources in a wireless independent network according to the present invention;
FIG. 2 illustrates a flowchart of a preferred embodiment of step 12 shown in FIG. 1 according to the present invention;
FIG. 3 illustrates a block diagram of a station, according to the present invention, performing the hybrid resources sharing method shown in FIG. 1 ;
FIG. 4 illustrates a block diagram of a preferred embodiment of a first controller shown in FIG. 3 according to the present invention;
FIGS. 5(a) , (b), and (c) illustrate data formats for the above-described hybrid resources sharing method and the station according to the present invention;
FIG. 6 illustrates an exploded view of a preferred embodiment of a downlink section shown in FIG. 5(c) ; and
FIGS. 7(a) and (b) illustrate how the sharing control authority is obtained and how a message rejecting the request for the sharing control authority is received from a control station, respectively, after a message requesting a sharing control authority is broadcasted.
DETAILED DESCRIPTION OF THE INVENTION
Korean Patent Application No. 2001-78664, filed Dec. 12, 2001, and entitled: “Method for Sharing Hybrid Resources in Wireless Independent Network, Station for the Method, and Data Format for the Method and the Station,” is incorporated by reference herein in its entirety.
Hereinafter, a method for sharing hybrid resources in a wireless independent network according to the present invention will be described with reference to the attached drawings. In the drawings, like reference numerals refer to like elements throughout.
FIG. 1 illustrates a flowchart of a preferred method for sharing hybrid resources in a wireless independent network according to the present invention. Selection of either a centralized control method in a direct mode or a distributed coordination method is preferably dependent on whether real-time service-related data is transmitted. In step 10 , a determination is made as to whether currently transmitted data is related to a real-time service when the sharing of the wireless resources is controlled based on the above-described distributed coordination method. For example, it may be determined that a real-time AV streaming service is being generated, i.e., the real-time AV streaming service is provided via a wireless independent network. If the currently transmitted data is not related to the real-time service, the distributed coordination method is retained in step 14 .
If, however, the currently transmitted data is related to the real-time service when the sharing of the wireless resources is controlled by the distributed coordination method, in step 12 , a station which is the subject of the real-time service (hereinafter referred to as “subject station”) requests a sharing control authority using the distributed coordination method. After the request is admitted sharing control authority is granted to the subject station, and wireless resources are shared under control of the subject station preferably using the centralized control method in a direct mode for the duration of the transmission of the corresponding real-time service. At the completion of the real-time service transmission the subject station restores the sharing of the wireless resources to the distributed coordination method.
FIG. 2 illustrates a flowchart of a preferred embodiment of step 12 shown in FIG. 1 according to the present invention. Step 12 preferably includes steps 20 and 22 for requesting the sharing control authority, steps 24 through 28 for controlling the sharing of wireless resources with a request for periodic polling when the requested sharing control authority is rejected, and steps 30 through 34 for controlling the sharing of the wireless resources by the centralized control method in the direct mode until the real-time service ends when the requested sharing control authority is admitted.
After it is determined that the currently transmitted data is related to the real-time service, in step 20 the subject station requests the sharing control authority using the distributed coordination method, e.g., a DCF system. In step 22 , the subject station determines whether the request for sharing control authority has been rejected. In other words, the subject station determines whether a station currently having a sharing control authority (hereinafter referred to as a “control station”) exists by testing for the existence of a “rejection message” from that control station.
If it is determined that the request for the sharing control authority is rejected, in step 24 the sharing of the wireless resources is controlled while the subject station requests the control station for periodic polling. For example, if the control station exists, the subject station cannot be granted the sharing control authority, and the control station maintains the sharing control of the wireless resources and a corresponding real-time AV streaming service-related communication is implemented using the existing method.
In step 26 the subject station determines whether the real-time service is still being transmitted, i.e., still in progress. If it is determined that the real-time service is still being transmitted, in step 28 the subject station determines whether the sharing of the wireless resources needs to be controlled. In other words, if it has been determined that the real-time service is in process, the subject station monitors whether a control authority releasing message has been received from the control station.
If it is determined through the periodic polling that the sharing of the wireless resources does not need to be controlled by the control station for performing the corresponding real-time service-related communication, the process returns to step 20 . In other words, when the subject station does not need to be controlled by the control station any more, it requests the acquisition of the sharing control authority by the distributed coordination method again. However, if it is determined that the subject stations still needs to be controlled by the control station to share the wireless resources when the real-time service is in progress, the process returns to step 24 .
Alternatively, if it is determined that the request for the sharing control authority has not been rejected, in step 30 the subject station is granted (i.e., assumes or seizes) the sharing control authority and preferably controls the sharing of the wireless resources by the centralized control method in the direct mode. In step 32 , it is determined whether the real-time service has ended. If it is determined that the real-time service has not ended, the process repeats step 30 , such that the subject station retains the sharing control authority. However, if it is determined that the real-time service has ended, in step 34 the subject station broadcasts a new control authority releasing message to the other stations to return the sharing control authority to the network. When it is determined that the real-time service is not in progress in step 26 or after step 34 , the subject station changes the sharing controls back to the distributed coordination method.
A preferred embodiment according to the present invention, showing the structure and operation of stations in an independent network performing the previously described hybrid resources sharing method will be described with reference to FIGS. 3 and 4 .
FIG. 3 illustrates a block diagram of a station for performing the hybrid resources sharing method shown in FIG. 1 , according to an embodiment of the present invention. The station preferably includes a transmission data checking unit 50 , and a first and a second controller 52 and 54 , respectively. For a better understanding of the present invention, the structure and operation of the station shown in FIG. 3 will be described assuming that the station is a subject station.
The transmission data checking unit 50 checks whether currently transmitted data input via an input port IN 1 is related to a real-time service and outputs a control signal to first and second controllers 52 and 54 , respectively. First and second controllers 52 and 54 generate output control and data signals in response to the check result.
If first controller 52 is granted a sharing control authority in response to the control signal input from the transmission data checking unit 50 , the sharing of wireless resources on a central controls system in a direct mode is controlled by first controller 52 using a centralized control method in a direct mode until the real-time service ends. To perform this control function, if it is perceived through the control signal that data input via the input port IN 1 is transmission data for the real-time service, the first controller 52 outputs a signal requesting the sharing control authority to the other stations via an output port OUT 1 and checks whether a message rejecting the request for the sharing control authority is received from another station, e.g., a control station (not shown), via the input port IN 1 . If the first controller 52 is granted the sharing control authority (i.e., not rejected) data input through the input port IN 1 via the transmission data checking unit 50 is transmitted to a corresponding station (not shown) via the output port OUT 1 .
The second controller 54 controls the sharing of the wireless resources by the distributed coordination method in response to the control signal input from the transmission data checking unit 50 . Here, the second controller 54 preferably receives data from another station via an input port IN 3 and outputs the data input through the input port IN 1 via the transmission data checking unit 50 to another station via an output port OUT 2 . Here, the second controller 54 may control the sharing of the wireless resources by the distributed coordination method in response to an ending signal generated when the real-time services ends in the first controller 52 .
FIG. 4 illustrates a block diagram of a preferred embodiment of the first controller 52 shown in FIG. 3 . The first controller 52 preferably includes a request message broadcaster 70 , a request rejecting message receiver 72 , a polling requesting unit 74 , a releasing message receiver 76 , a shared resource controller 78 , and a service checking unit 80 .
To perform step 20 , in response to the control signal from transmission data checking unit 50 via an input port IN 4 (indicating that received data is related to a real-time service,) service), the request message broadcaster 70 transmits a message requesting control authority to the other stations via an output port OUT 3 using the distributed coordination method. The request message is additionally gated using an enable signal input from the releasing message receiver 76 . If one of the other stations has sharing control authority (i.e., is processing data), that “control station” transmits a rejection message to the subject station. When the control station has completed its data processing activity, it transmits a sharing control authority releasing message using the distributed coordination method. If, however, there is no current active control station, no rejection message will be received.
To perform step 22 , the request rejecting message receiver 72 receives any message rejecting the request for the sharing control authority via an input port IN 5 and outputs the received message as a disable signal to the polling requesting unit 74 and the shared resource controller 78 . In response to the disable signal from the request rejecting message receiver 72 and the enable signal input from the releasing message receiver 76 , the polling requesting unit 74 , which performs step 24 , requests the periodic polling from the control station via an output port OUT 4 . In other words, the polling requesting unit 74 requests the periodic polling of the control station whenever a rejection message is received and the sharing control authority releasing message has not yet been received.
To perform steps 26 and 28 , in response to the control signal input from the transmission data checking unit 50 via the input port IN 4 (indicating the real-time service) the releasing message receiver 76 monitors the control station for the sharing control authority releasing message via an input port IN 6 . When the sharing control authority releasing message is received, releasing message receiver 76 outputs an enable signal to the request message broadcaster 70 and the polling requesting unit 74 . The releasing message receiver 76 may generate an enable signal having a first logic level if the sharing control authority releasing message is received from the control station and an enable signal having a second logic level if the control authority releasing message is not received from the control station.
For the case where no rejection message is received, the shared resource controller 78 , which performs steps 30 and 34 , assumes the sharing control authority in response to the disable signal input from the request rejecting message receiver 72 and thus controls the sharing of the wireless resources using the centralized control method in the direct mode. Here, the shared resource controller 78 may receive data from another station via an input port IN 7 or may output data for the real-time service to another station via an output port OUT 5 . Also, in step 34 , the shared resource controller 78 preferably transmits the sharing control authority releasing message to another station via the output port OUT 5 to return the sharing control authority in response to the ending signal input from the service checking unit and sharing control authority 80 . Although it is not shown as a step in FIG. 2 , during the time that the subject station has the control authority, the shared resource controller 78 preferably transmits the sharing control rejection messages upon being queried by other stations.
The service checking unit 80 , which performs step 32 , checks whether the real-time service has ended and outputs the check result as the ending signal to the shared resource controller 78 and to the second controller 54 via the output port OUT 6 . Here, the second controller 54 controls the sharing of the wireless resources by the distributed coordination method in response to the ending signal input from the service checking unit 80 .
Hereinafter, a data format for the hybrid resource-sharing method and the station according to the present invention will be described with reference to the attached drawings.
FIGS. 5(a) , (b), and (c) illustrate a timing diagram of a streaming messaging signal having a plurality of partitioning sections according to a preferred data format for the above-described resource-sharing method and station according to the present invention. FIG. 5(a) shows sections of the complete data stream and FIGS. 5(b) and 5(c) show exploded views of the partitions of a transmission frame.
According to the present invention, step 10 of the preferred method shown in FIG. 1 is performed by during a distributed coordination method during section 90 shown in FIG. 5(a) . Here, if it is determined that currently transmitted data is related to the real-time service, step 12 is performed during an adaptive control method section 92 shown in FIG. 5(a) . For this, the subject station obtains the sharing control authority at a starting point 97 of the adaptive control system method section 92 . The length 96 of the adaptive control system method section 92 may vary. When the real-time service ends during step 12 , the subject station returns the sharing control authority at an ending point 98 of the adaptive control system section method 92 .
As shown in FIG. 5(b) , the adaptive control system method section 92 shown in FIG. 5(a) preferably includes a control authority requesting message 100 , a series of first through n-th transmission frames 102 , 104 , . . . and 106 , and a control authority releasing message 108 . The first transmission frame 102 is spaced apart from the control authority requesting message 100 by a Point Coordination Function (PCF) Interframe Space (PIFS) 120 and the n-th transmission frame 106 is spaced apart from the control authority releasing message 108 by a PIFS 126 . The first through n-th transmission frames 102 , 104 , . . . , and 106 are spaced apart from each other by a PIFS 122 to have priority of the occupation of the resources over DCF-based wireless stations. Here, the first through n-th transmission frames 102 , 104 , . . . and 106 have lengths 124 , respectively, which may vary depending on characteristics of a corresponding AV streaming service.
As shown in FIG. 5(c) , each one of the first through n-th transmission frames 102 , 104 , . . . and 106 preferably includes a downlink section 140 , a polling section 142 , and a distribution control section 144 . In the downlink section 140 , real-time service-related transmission data is transmitted to another station and the downlink section 140 has a variable length 160 . In the polling section 142 , which has a variable length 162 , other real-time service-related stations may be polled, and a multiplex polling system may be used for improved performance. In the polling section 142 , a packet is forwarded from the subject station to the control station or another station.
In the distribution control section 144 , which has a variable length 164 , non-real-time service-related transmission data is preferably transmitted to another station using a DCF system. If an additional real-time AV streaming service is generated, the message requesting the periodic polling may be transmitted to the control station. Here, the downlink section 140 is spaced apart from the polling section 142 by a PIFS 170 , and the polling section 142 is spaced apart from the distribution control section 144 by a DIFS 172 .
FIG. 6 illustrates an exploded view of a preferred embodiment of the downlink section 140 of FIG. 5(c) according to the present invention, which preferably includes a plurality of packets 182 , 184 , . . . and 186 . Referring to FIG. 6 , the plurality of packets 182 , 184 , . . . and 186 are spaced apart from each other by a PIFS 180 to maintain the sharing control authority for the downlink section 140 .
FIGS. 7(a) and (b) illustrate views explaining how the sharing control authority is obtained and how the message rejecting the request for the sharing control authority is received from the control station, respectively, after the message requesting the sharing control authority has been transmitted. In FIG. 7(a) , there is no current active control station, while in FIG. 7(b) , there is a current an active control station.
As shown in FIG. 7(a) , the request message broadcaster 70 transmits a control authority requesting message 192 via the output port OUT 3 . After the shared resource controller 78 shown in FIG. 4 is idle for a PIFS 190 , sharing control authority is assumed in section 194 .
For the case where an active control station exists, as shown in FIG. 7(b) , the request message broadcaster 70 broadcasts a control authority requesting message 202 . Then after a SIFS 200 elapses, the request rejecting message receiver 72 shown in FIG. 4 receives a control authority request rejecting message 204 from the active control station. After a variable time duration 206 during which the active control station completes its control task, a sharing control authority releasing message 208 is transmitted by the active control station, thereby releasing network sharing control authority.
At this time the request message broadcaster 70 again transmits a control authority requesting message 192 as in FIG. 7(a) , and after the shared resource controller 78 is idle for a PIFS 190 , sharing control authority is assumed in section 194 . In an alternate embodiment, the active control station may transmit the sharing control authority releasing message 208 directly to the requesting station, thereby allowing the requesting station to immediately assume sharing control authority in section 194 , and thus avoiding the loss of time periods 190 and 192 .
As described above, in a preferred method for sharing hybrid resources in a wireless independent network, a station for the method, and a data format for the method and the station, non-real-time service-related data packets are transmitted/received using a distributed coordination method and real-time service-related data packets are transmitted/received using a centralized control method in a direct mode. In other words, hybrid data is transmitted and received in a wireless independent network. Thus, an efficiency of using resources is maximized, a real-time service of the resources is supported, and a mesh network may be constituted. Further, loading may be prevented from concentrating in a control station and the control station is not fixed. As a result, a station can freely subscribe/withdraw to/from a subscribed network.
Preferred embodiments of the present invention have been disclosed herein and, although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
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In a system for sharing hybrid resources in an independent network, each one of a plurality of stations preferably employs a sharing authority transferring protocol that allows the network control function to be moved from station to station depending on the network traffic. Although a distributed coordination method is normally used in the network, when an individual station determines that a real-time data stream is intended for the station, an apparatus having a method and data format for the use thereof allows control to be transferred to the targeted station. This allows the targeted station to control the sharing of the wireless hybrid resources using a centralized control method in a direct mode for the duration of the real-time service transmission, thereby optimizing network efficiency. As a result of using the distributed control authority of the present invention, a station may be freely subscribe/withdraw to/from the network.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Patent Application No. PCT/CN2007/070244, filed Jul. 5, 2007, which claims priority to Chinese Patent Application No. 200610101059.5, filed Jul. 6, 2006, both of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to the field of telecommunications, and, in particular, to a system and an implementation method for multiservice access.
BACKGROUND OF THE INVENTION
Multiservice provisioning has been a development trend of the field. At present, there are two types of architecture which support multiservice, single-edge architecture, and multi-edge architecture.
Support for multiservice scenarios by conventional single-edge and multi-edge techniques will be described hereinafter with reference to FIG. 1 and FIG. 2 , respectively.
FIG. 1 illustrates a structural diagram of a conventional, in the case of single-edge, supporting multiservice. As illustrated in FIG. 1 , the conventional single-edge technique supports a multiservice scenario.
As can be seen from FIG. 1 , an access node (AN) 104 corresponds with a single broadband remote access server (BRAS) 102 to which all service providers, i.e. service providing nodes, are connected. The access server controls user selections of service providing nodes 106 and processes subsequent service flows. Once a new service is added, a corresponding feature support should be added at the access server 102 . Authentication of a user 108 and control of selections of service providers 106 are also done at the access server 102 .
The single-edge technique illustrated in FIG. 1 has the following disadvantages: because of the variety of service features provided by different service providers, the access server is required to support every service feature, and control flows, such as authentication and accounting, of all users will pass the access server; therefore, the access server is required to support numerous functions, which leads to poor extensibility, and becomes a bottleneck of the whole network.
FIG. 2 illustrates a structural diagram of a conventional, in the case of multi-edge, supporting multiservice. As illustrated in FIG. 2 , the conventional multi-edge technique supports a multiservice scenario.
As can be seen from FIG. 2 , broadband network gateways (BNGs) 202 are edges of the access network. Selections of service providers, i.e. service providing nodes 206 , are done by an AN 204 , and related functions such as authentication, authorization, accounting, policy distribution, and Internet Protocol (IP) address allocation are supported by the BNGs 202 . The benefit of multi-edge technique is that, different BNGs can be provided to implement different types of services, which makes services easy to be extended.
The multi-edge technique illustrated in FIG. 2 has the drawback that, the BNGs not only forward services, but also perform authentication and control of services. In the case of multi-edge, these control functions are separated among each BNG, so that centralized control of the access network is difficult to achieve. In addition, the AN would be difficult to implement because it is required to have the AN implement the function of network selection.
In a single-edge architecture, a BRAS is the network edge node at which user authentication, authorization, and control are performed collectively. The BRAS has a single connection with an AN, and can perform QoS control of the AN based on a policy. The BRAS also connects multiple service providing nodes, selections of the service providing nodes, and support for various services are all implemented on the BRAS. As the only edge control node, the BRAS is also the only node where various edge services are initiated. Accordingly, the network edge node is the only device in the access network that implements both control and bearing functions; and that the network edge node is required to support a variety of services. Therefore, in the case of single-edge, the functions of the network edge node are complex, difficult to be implemented or extended, and easy to cause single point of failure.
However in a multi-edge architecture, different network edge nodes correspond to and can be optimized for different services. Such a multi-edge architecture is good for extensions of services, and simplifies the implementation of network edge nodes. But new problems of centralized control of users by network edges and selections of network edge nodes by users are raised. Because of the variety of network edges, it would be a problem for the edge nodes to coordinate user control; and that it is required by the architecture for an AN to select network edge nodes, which increases the complexity of the implementation of the AN, meanwhile the implementation of control functions by the edge nodes is not simplified.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide to a system and an implementation method for multiservice access, to solve the above problems which arise with multiservice access.
According to an aspect of the present invention, a system for multiservice access is provided, including: at least one access node, adapted to receive a message of a user, separate control flow and service flow of the message, send the control flow to a controller, and send the service flow to a corresponding edge node based on control by the controller; the controller, adapted to process the control flow, so as to control the access node to send the service flow to the corresponding edge node, and control the corresponding edge node to process the service flow; and at least one edge node, adapted to transmit the received service flow to a corresponding service providing node, based on control by the controller.
An embodiments of the present invention provides a method that implements the above system for a user to access a network, including: receiving, by a service providing node, an authentication request of a user sent by a controller, and authenticating the user; receiving, by the service providing node, an address allocation request of the user sent by the controller/edge node, and allocating an address for the user, if the user passes the authentication; and controlling, by the controller, establishment of a path between an access node and the edge node, for the user.
An embodiment of the present invention further provides a method for separation of control and bearing, including: receiving, by an access node, a message of a user, separating control flow and service flow of the message, sending the control flow to a controller, and sending the service flow to a corresponding edge node, based on control by the controller; processing the control flow, by the controller, to control the access node to send the service flow to the corresponding edge node, and controlling the corresponding edge node to process the service flow; and transmitting, by the edge node, the received service flow to a corresponding service providing node, based on control by the controller.
As can be seen from the above solutions, an embodiment of the present invention provides a system with separation of control and bearing under multi-edge architecture. Multi-edge service bearing and centralized control are combined, so that the system is extensible for various services and centralized user control can be achieved without complicating the implementation of ANs. Particularly, technical benefits brought by embodiments of the present invention include the following:
1. A method for separation of control and bearing is applied in the access network; therefore, the architecture may suit various cases of service access, and network edges may deal with service-related matters only, which is good for extensions of services;
2. User access is controlled collectively by a controller; therefore, the situation where centralized control and management of users cannot be achieved in an access network in the case of multi-edge is avoided, and interactions between edges are reduced; and
3. The complexities of AN devices and network edge devices under multi-edge architecture are simplified, so that selections of networks and establishment of paths are controlled collectively by a controller; ANs may simply separate control flow and bearing flow, and network edge devices can perform processing of corresponding services only.
Other features and advantages of embodiments of the present invention will be described in the description hereinafter, parts of which may become apparent, based on the description, or understood by implementing the embodiments. The advantages of the embodiments of the present invention can be realized or obtained by structures indicated in the description, the claims, and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structural diagram, in the case of single-edge, supporting multiservice;
FIG. 2 is a structural diagram, in the case of multi-edge, supporting multiservice;
FIG. 3 is a structural diagram of a multi-edge system with separation of control and bearing, according to an embodiment of the present invention;
FIG. 4 is a schematic diagram illustrating a process of a user accessing a network, according to an embodiment of the present invention;
FIG. 5 is a schematic diagram illustrating a process of a user accessing a network, according to an embodiment of the present invention (IP edge is used as a relay for address allocation);
FIG. 6 is a flow chart of a method for separation of control and bearing under multi-edge architecture, according to an embodiment of the present invention;
FIG. 7 is a schematic diagram illustrating a process of user access in a multi-edge system under 802.1x, according to an embodiment of the present invention; and
FIG. 8 is a schematic diagram illustrating a process of user access in a multi-edge system under 802.1x, according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiments of the present invention will be described in details with reference to the drawings.
In order to solve aforementioned problems, an embodiment of the present invention provides a system with separation of control and bearing under multi-edge architecture. In the system, a control device is created to implement control functions, such as authentication, authorization, and policy distribution; multiple edge devices corresponding to different service providing nodes are set up at network edges, the edge devices may perform bearing-related processing only. The idea of separating control and bearing under multi-edge architecture may benefit extensions of services, implement centralized control of user access, and simplify the complexity under multi-edge architecture.
FIG. 3 is a structural diagram of a multi-edge system with separation of control and bearing, according to an embodiment of the present invention; FIG. 6 is a flow chart of a method for separation of control and bearing under multi-edge architecture, according to an embodiment of the present invention.
A system with separation of control and bearing under multi-edge architecture is provided, according to an embodiment of the present invention, Multi-edge service bearing and centralized control are combined, so that the system is extensible for various services and centralized user control can be achieved without complicating the implementation of ANs. The system for multiservice access with separation of control and bearing 300 as illustrated in FIG. 3 includes: access nodes (AN, also known as access points) 304 , adapted to receive a service request of a user, separate control flow and service flow of the service request, send the control flow to a controller 302 , and send the service flow to a corresponding edge node 307 , based on routing control by the controller 302 ; the controller 302 , adapted to process the control flow, so as to determine routing of the service flow; and edge nodes (i.e. IP edge devices) 307 , adapted to submit the service flow to the nodes 306 .
Particularly, as shown in FIG. 3 , the multi-edge system with separation of control and bearing includes a single device of controller 302 , which implements control functions, such as authentication, authorization, and policy distribution; multiple edge nodes, i.e. IP edge devices 307 , corresponding to different service providing nodes (SPs) 306 , are set up at network edges, the edge nodes 307 may perform bearing-related processing only.
In the architecture, entities of control functions such as AAA (authentication, authorization, and accounting), network edge selection, and policy distribution, are separated from the network edge devices (IP edge devices) 307 and form a single device, i.e. the controller 302 ; access nodes 304 have the function of separating control flow and service flow, and direct the control flow to the controller; the IP edge devices 307 handle service-related functions only, such as IPTV and VoIP (Voice-over-Internet Protocol).
The service providing nodes 306 perform user authentication, accounting, IP address allocation, and service provisioning. There are fixed control channels between the controller and the IP edge devices via which control flows are transmitted.
The method for multiservice access with separation of control and bearing as illustrated in FIG. 6 includes the following steps:
Step S 602 : A service request of a user is received by an access node, control flow and service flow of the service request are separated, the control flow is sent to a controller and the service flow is sent to a corresponding edge node, based on control by the controller;
Step S 604 : The control flow is processed by the controller, so as to control routing of the service flow; and
Step S 606 : The service flow is submitted to a corresponding service providing node by the edge node, based on control by the controller.
FIG. 4 illustrates a process of a user accessing a network, according to an embodiment of the present invention.
As illustrated in FIG. 4 , in the above architecture with separation of control and bearing, the process of a user accessing a network, according to an embodiment of the present invention, includes:
1. User authentication process: A user initiates an authentication request, an access node directs the authentication request to a controller, the controller selects a service providing node in the edge for authentication during which address information of a DHCP server is acquired, if the authentication is passed, the controller performs operations which include, but are not limited to:
A. selecting an IP edge device which can reach the network of a corresponding service providing node. In the case of multiple service providing nodes corresponding to the IP edge device, instructing the IP edge device to select an appropriate egress;
B. establishing a path between a physical/logical circuit that the user accesses and the selected IP edge device via the AN; and
C. distributing initial QoS parameters or policies to the AN and the IP edge device.
Information that the controller obtains during the user authentication process may include any one or a combination of: address of a DHCP server, QoS parameter, policy of a user accessing a network, IP address of a DNS server, IP address of a WINS (Windows Internet Name Service) server, IP address of a P-CSCF (Proxy-Call Session Control Function) server.
2. User address allocation process: The user initiates a request for address allocation after the authentication is passed; the AN directs the request as a control message to the controller; the controller relays the request message for address allocation to a corresponding SP based on the information obtained during the authentication (e.g. address of a DHCP server), and completes the process of user address allocation.
3. User service forwarding: Subsequent service flows are forwarded, based on the path established between the AN and the IP edge device, after the completion of user authentication and address allocation.
With respect to the process of user address allocation in the above procedure, the AN may forward the message of the address allocation process as service flow directly to the IP edge device, which may function as a relay for user address allocation. Such a procedure of a user accessing a network may suit a scenario where one IP edge device corresponds to one service providing node. The access process is illustrated as FIG. 5 .
FIG. 5 illustrates a process of a user accessing a network, according to an embodiment of the present invention (IP edge is used as a relay for address allocation).
The process of a user accessing a network according to FIG. 5 differs from FIG. 4 in the user address allocation process.
In the embodiment illustrated by FIG. 5 , the process of user address allocation includes: a user initiates a request for address allocation after the user passes authentication, an access node sends the request as a service message to an edge node, the edge node relays the request message for address allocation to a service providing node, corresponding to the edge node.
In the system with separation of control and bearing 400 as illustrated in FIG. 4 and the system with separation of control and bearing 500 as illustrated in FIG. 5 , functions implemented by each device are as follows:
The access node 504 at least includes: a flow separation entity, a QoS and policy execution entity, and a path establishment execution entity.
The flow separation entity is adapted to separate control flow and service flow, direct the control flow to the controller 502 , and direct the service flow to the IP edge device.
The QoS and policy execution entity is adapted to execute QoS and polices distributed by the controller 502 .
The path establishment execution entity is adapted to execute strategies of path establishment by the controller 502 .
The controller 502 at least includes any one or a combination of: an AAA controller, a path controller, a policy controller, and an address allocation controller.
The AAA controller is adapted to function as a client or proxy of user authentication, authorization, and accounting; that is, the AAA controller is involved in processing of user authentication, authorization, and accounting.
The path controller is adapted to select an edge node, based on result of user authentication.
The policy controller is adapted to distribute QoS and policies.
The address allocation controller functions as a client or proxy of user address allocation.
The IP edge device 507 at least includes any one or a combination of: a routing entity and a service-related entity.
The routing entity implements a routing function for service flow, i.e. the routing entity routes the service flow received by the IP edge device 507 to a corresponding service providing node, based on control by the controller.
The service-related entity implements service-related functions (e.g. VoIP and multicast). That is, the service-related entity performs service-related operations.
The service providing node 507 at least includes any one or a combination of: an AAA server and an address allocation server (e.g. DHCP server).
FIG. 7 illustrates a process of user access in a multi-edge system under 802.1x, according to an embodiment of the present invention.
According to an embodiment of the present invention, a multi-edge architecture with separation of control and bearing can be implemented by 802.1x and DHCP.
As a method and policy for authenticating a user, 802.1x is a port-based authentication protocol. A port can be either a physical port or a logical port (e.g. VLAN (Virtual Local Area Networks), VCC (Virtual Channel Connection)). The ultimate objective of 802.1x authentication is to determine whether a port is available. With respect to a port, if the authentication is passed, the port will be “opened” and all messages are permitted to pass through; if the authentication is failed, the port will be kept “closed” and only 802.1x authentication protocol messages are permitted to pass through.
Therefore, 802.1x is a protocol with separation of control and bearing; a 802.1x authentication system includes: a supplicant system, an authenticator system, and an AAA server system. In a multi-edge architecture with separation of control and bearing, the 802.1x system can be slightly modified. An AN sends all control messages (e.g., 802.1x and DHCP messages) to a controller, the controller functions as an authenticator and a DHCP relay/proxy, a service provider manages the AAA server and the DHCP server. The AAA protocol can be RADIUS or Diameter. In the case that EAP-MD5 based 802.1x authentication is employed and IP addresses are allocated by DHCP, a whole process of user access can be illustrated as FIG. 7 .
The whole process of user access can be divided into three phases:
Phase 1, user AAA process: a user initiates a request for authentication, an AN identifies a 802.1x message and sends the message to a controller, the controller translates between 802.1x and an AAA protocol (e.g. RADIUS or Diameter) as an authenticator, and selects an AAA server of a corresponding service providing node for authentication, based on a user identity in an EAP message of the 802.1x message. The controller obtains information, such as DHCP server address and user profile (including QoS and policies), after the authentication is passed. Based on the information, the controller configures QoS and policies of the AN and the IP edge device accordingly, and establishes a path for service flow between the AN and the IP edge device.
Phase 2, user address allocation process: the user initiates an IP address request, the AN identifies a DHCP message and send the message to the controller, the controller functions as a relay of the user DHCP message or a proxy of a DHCP message of the DHCP server, according to the DHCP server address obtained, after the aforementioned authentication.
At phase 3, a message of service flow accesses the service providing node via the established path between the AN and the IP edge device, after the authentication and the address allocation.
FIG. 8 illustrates a process of user access in a multi-edge system under 802.1x, according to another embodiment of the present invention.
According to another embodiment of the present invention, a multi-edge architecture with separation of control and bearing can be implemented by 802.1x and DHCP, of which DHCP relay/proxy function is set up on an IP edge device.
If DHCP relay/proxy function is set up on an IP edge device, an AN may simply forwards 802.1x messages to a controller, and an AAA server is not required to send a DHCP server address to the controller. A detailed procedure can be illustrated as FIG. 8 , which will not be further described.
The architecture is suitable for the case that one IP edge device corresponds to one service providing node. Instead of selecting a DHCP server, the IP edge device can be statically configured with a DHCP server address, so that the IP edge device may function as a DHCP relay/proxy.
As can be seen from the above descriptions, an embodiment of the present invention provides a system with separation of control and bearing under multi-edge architecture. Multi-edge service bearing and centralized control are combined, so that the system is extensible for various services and centralized user control can be achieved without complicating the implementation of ANs. Particularly, technical benefits brought by embodiments of the present invention include the following:
1. A method for separation of control and bearing is applied in the access network; therefore, the architecture may suit various cases of service access, and network edges may deal with service-related matters only, which is good for extensions of services;
2. User access is controlled collectively by a controller; therefore, the situation where centralized control and management of users cannot be achieved in an access network in the case of multi-edge is avoided, and interactions between edges are reduced; and
3. The complexities of AN devices and network edge devices under multi-edge architecture are simplified, so that selections of networks and establishment of paths are controlled collectively by a controller, ANs may simply separates control flow and bearing flow, and network edge devices can perform processing of corresponding services only.
It should be understood by those skilled in the art that every module or step in the above embodiments can be implemented with a general-purpose computing apparatus. They can be placed together at a single computing apparatus or distributed in a network of multiple computing apparatuses. Optionally, they can be implemented with executable program code by a computing apparatus, so that they can be stored in a storage apparatus for a computing apparatus to execute; or they can be made into respective integrated circuit modules; or multiple modules or steps of them can be implemented into a single integrated circuit module. Therefore, the present invention is not limited to any specific combination of hardware and software. It should be noted that variations of the embodiments would be apparent for those skilled in the art without departing from the scope of the present invention.
The description above is merely embodiments of the invention, but not intended to limit the present invention. To those skilled in the art, various modifications and variations of the invention can be implemented. Any modification, equivalent alternative, or improvement within the spirit and principle of the invention should be included in the scope of the invention.
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A control and bearer separating system for the multi-service access includes: at least one access node for receiving the message of the user, separating the control flow and the service flow of the message, transmitting the control flow to the controller, and transmitting the service flow to the corresponding edge node, based on the control of the controller; the controller for processing the control flow to control the access node to transmit the service flow to the corresponding edge node, and control the corresponding edge node to process the service flow; and at least one edge node for transmitting the received service flow to the corresponding service provider node, based on the control of the controller. Furthermore, there is a method for connecting the user to the networking using the above control and bearer separating system, and a control and bearer separating method.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to a method for controlling an X-ray device of the type having at least one X-ray tube and at least one X-ray detector, the X-ray tube and/or the X-ray detector being movably arranged. The invention also is directed to an X-ray device of this type.
[0003] 2. Description of the Prior Art
[0004] Modern X-ray devices usually have not only a single X-ray tube/X-ray detector pair but generally contain a number of detectors that are permanently or movably installed or are mobile detectors. Either with or without a cable, such mobile detectors are freely movable at least within a range of action, for example within the X-ray room. A film foil cassette is an example of such a detector that is movable without a cable. The X-ray devices often additionally have a number of different fixed or movable X-ray tubes. An optimum system for implementing a specific examination is then constructed by selecting a detector and a matching X-ray tube. In the examination, it must then be assured that the desired X-ray tube and X-ray detector are suitably aligned relative to one another and relative to the examination subject, for example a body part of a patient, so that the X-rays passing through the examination subject strike the detector. It must also be assured that the corresponding detector is active and can pick up the X-rays. This is conventionally assured by an X-ray assistant, who aligns the X-ray tube and the X-ray detector relative to one another and relative to the examination subject and then determines that the corresponding detector is activated via a monitoring system attached to the X-ray detector, for example a flashing green light or a monitoring symbol displayed at an image station. The X-ray assistant then manually triggers the generation of the X-rays, and an image is acquired. When the X-rays are mistakenly triggered when the detector is not activated or when the X-ray tube and X-ray detector are not suitably positioned relative to one another, then the patient is exposed to the X-rays without the X-rays having an imaging effect. The exposure must then be repeated, which involves an additional radiation stress on the patient.
[0005] U.S. Pat. No. 6,200,024 discloses an X-ray diagnostic installation wherein the tube and the detector are respectively suspended independently of one another, compared to the known rigid connection of detector and tube via a C-arm, by means of which an active repositioning of the tube automatically effects an active repositioning of the detector or image intensifier. Mechanical sensors that know the respective location of the detector and the tube insure that a repositioning of the detector is automatically followed by a repositioning of the detector. The position of the detector and the tube thus can be acquired via the mechanical systems.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to minimize the existing safety risk of X-rays being triggered without the X-rays having an imaging effect at the correct detector.
[0007] This object is achieved in a method according to the invention wherein an automatic check is carried out before an activation of an X-ray tube indicated for a desired measurement, as to whether an X-ray detector indicated for the desired measurement is activated. Position data also are automatically determined, i.e. data about the position and/or orientation of the appertaining X-ray tube and/or appertaining X-ray detector. The term “position” as used herein covers both the location of an object as well as its orientation in space. Using the position data, the relative positions, i.e. the alignment and range, of the appertaining X-ray tube and of the appertaining X-ray detector relative to one another are identified. The X-ray tube is enabled for activation or is automatically activated only when the X-ray detector is activated and the X-ray tube and the X-ray detector are suitably positioned relative to one another for the desired measurement.
[0008] This object also is achieved in an inventive X-ray device of the type initially described having a position determination system for the automatic determination of position data of the movable X-ray tube indicated for the desired measurement and/or of the movable X-ray detector indicated for the desired measurement. A position correlation unit uses the position data to determine position correlation data that indicate the relative positions of the appertaining X-ray tube and of the appertaining X-ray detector with respect to one another. Further, an enable and/or trigger unit checks on the basis of the position correlation data as to whether the X-ray tube and the X-ray detector are correctly positioned relative to one another for the desired measurement. After determining that the current positioning of the X-ray tube and the X-ray detector exist as well as upon reception of an activation signal that indicates that the appertaining X-ray detector is activated this unit enables the X-ray tube for activation and/or automatically activates it.
[0009] The invention thus allows fully automated supervision of the alignment of the X-ray tube/X-ray detector pair by the X-ray assistant as well as the activation of the matching X-ray detector. An erroneous triggering of the X-rays are is thus prevented with high certainty.
[0010] A arbitrary number of X-ray tubes or X-ray detectors can be employed within the inventive X-ray device. The tubes and detectors can be installed so as to be fixed or movable, for example at a C-arm, within an examination table or at a wall mount. Preferably, however, at least one of the X-ray tubes and/or at least one of the X-ray detectors is freely movable at least within a field of use, for example the X-ray room, i.e. a mobile X-ray tube or X-ray detector is used. Such mobile devices allow an optimum matching to the location of the patient in the examination.
[0011] A large variety of position identification systems can be used for determining the positions of the X-ray tube and/or X-ray detector.
[0012] Insofar as one of the devices, for example the X-ray tube, is fixed, it suffices for the position data of this device to be determined once upon installation and stored in a memory so as to be fetchable therefrom for the inventive position monitoring. For devices that are movably installed at a carrier, for example a mount, a C-arm or in a table, the parameter values for the individual degrees of freedom of the movement of the respective device, for example an angular position of an articulation, can also be acquired and the exact position data of the respective device can be determined therefrom.
[0013] In a preferred embodiment, the X-ray device has a position determination system that operates in non-contacting fashion. Such a position determination system is particularly suitable for determining the position data of mobile X-ray tubes or X-ray detectors. A non-contacting measurement of the position data is possible, for example, with position determination systems that operate electromagnetically, for example by radio or optically, or that are based on ultrasound.
[0014] Stereotactic navigation methods can be used wherein a number of sensors observe an object in order to identify the exact position of the appertaining object. Such an object can be an active object such as, for example, a radio or infrared transmitter or can be a passive object that reflects radiation and/or, can simply be unambiguously optically identified with a CCD camera.
[0015] In a preferred embodiment, the position data of a number of marking objects respectively fixed at the X-ray tube or at the X-ray detector are determined relative to a sensor, by means of at least one sensor at a fixed position in the field of use, preferably be means of at least two sensors. The marking objects can be active or passive marking objects, for example reflective measuring points or the like that are matched to the respective sensors of the position determination system and that are additionally attached to the X-ray tube or, respectively, detector. Given utilization of a system that operates with conventional video cameras as sensors, specific, exactly identifiable parts of the X-ray tube or X-ray detector itself can be utilized as marking objects, for example specific edges of the housing. The position data of the appertaining X-ray tube or detector are then determined on the basis of the position data of the marking objects.
[0016] In another preferred embodiment, the direction and/or the range to a marking object positioned in a field of use are determined with at least one first sensor positioned at the respective X-ray tube or X-ray detector. The range measurement alternatively can ensue in such a way that the directions between the first sensor and two marking objects positioned in the field of use are determined and the range to the marking objects is determined by intersection. The orientation in space is then determined with a second sensor arranged at the respective X-ray tube or, respectively, detector. This second sensor can operate so that the orientation of the sensor itself, and thus the orientation of the X-ray tube or detector fixedly coupled with the sensor as well, is determined relative to the force of gravity. The desired position data of the respective X-ray tube or, respectively, detector then can be determined from the values for the range and the direction relative to one or more fixed points positioned in the field of use that are determined by the first sensor as well as from the data of the second sensor.
[0017] The large variety of position determination sub-systems can be combined to form a position determination system in accordance with the invention. For example, the position data of the X-ray tubes or detectors that are installed at movable carriers thus can be determined by means of a measurement of the setting parameters of the respective carrier, and the position data of freely movable X-ray tubes and/or detectors are determined by means of position determination systems that operate in non-contacting fashion. It is only important that all position data are known within a common, normalized coordinate system in order to be able to determine the relative positions of the individual devices with respect to one another.
[0018] In a preferred embodiment, the position determination system first determines the position data of all X-ray tubes or detectors belonging to the X-ray device and the relative positions of all device combinations relative to one another are determined therefrom. Subsequently, the relative positions for the X-ray tube/X-ray detector pair selected for the desired measurement are checked relative to one another on the basis of the available information about the correct position of the X-ray tube and of the X-ray detector relative to one another that is required for the examination.
[0019] This, for example, can occur so that the position determination system constantly automatically determines the position data of all X-ray tubes and detectors and forwards the data to the position correlation unit. The position correlation unit then determines the position correlation data of all X-ray tubes and detectors relative to one another and in turn forwards the data to the enable and/or trigger unit. The enable and/or trigger unit can be connected to a selection device that communicates selection data with which an X-ray tube/X-ray detector pair, selected for a desired measurement, is defined to the enable and/or trigger unit. The enable and/or trigger unit then reviews the position correlation data for the selected X-ray tube/X-rat detector pair on the basis of the selection data.
[0020] The selection device has a user interface for the entry of the selection data for selecting the X-ray tube/X-ray detector pair to be employed.
[0021] It is preferred for the selection device to contain an additional monitoring device that reviews whether an X-ray tube/X-ray detector pair that is correct for a desired application was selected. To this end, information about the desired examination or type of examination can also be entered into the selection device.
[0022] In a preferred embodiment, the suitable X-ray tube/X-ray detector pair is automatically selected on the basis of the information about the desired examination. For example, the X-ray assistant need merely enter a type of examination with a suitable user interface such as, for example, an X-ray exposure of the chest region of a standing patient. The selection device then automatically selects the suitable devices, for example a detector secured to a wall mount and an appertaining, suitably positioned X-ray tube.
[0023] After the correct positioning of the devices has been checked, the activity status of the desired X-ray detector is checked and, subsequently, enablement of the triggering of the appropriate X-ray tube is implemented, or the appertaining X-ray tube is automatically triggered.
DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 a schematically illustrates the arrangement of an X-ray tube as well as a number of X-ray detectors within an X-ray room.
[0025] [0025]FIG. 2 is a schematic illustration for explaining the determination of the position data of the X-tube and the X-ray detectors with a position determination system according to a first exemplary embodiment of the invention.
[0026] [0026]FIG. 3 is a more detailed illustration of an X-ray detector and the sensor from FIG. 2;
[0027] [0027]FIG. 4 is a schematic illustration for explaining the determination of the position data of the X-ray tube and the X-ray detectors with a position determination system according to a second exemplary embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] The exemplary embodiment of an X-ray device shown in FIG. 1 includes an X-ray tube 2 and three different X-ray detectors 3 , 4 , 5 . The X-ray tube 2 and the X-ray detectors 3 , 4 , 5 are located within a field of use B, a standard, shielded X-ray room B in this case.
[0029] The X-ray tube 9 is secured to a ceiling mount that can be displaced along a motion direction R 2 at a rail 26 secured to the ceiling of the X-ray room B. The ceiling mount is composed of a carrier rod 27 extending perpendicularly downwardly from the rail 26 and at which a swivel arm 28 is seated for pivoting around an axis D 1 that proceeds coaxially with the carrier rod 27 . The X-ray tube 2 is secured to the end of the swivel arm 28 so as to be pivotable around two further swiveling axes D 2 , D 3 that proceed perpendicular to the first swiveling axis D 1 and perpendicular to each other. The X-ray tube 2 is thus arranged in the X-ray room B so as to be movable in a total of four degrees of freedom, namely along the displacement direction R 2 and along the three axes D 1 , D 2 , D 3 , and can thus be set into a large variety of positions in order to serve the respective X-ray detectors 3 , 4 , 5 .
[0030] A first X-ray detector 3 is situated at a wall mount 31 and is adjustable in height along the motion direction R 3 . A second X-ray detector 4 is situated in a holder 30 under the bearing surface of an examination table 29 and is displaceable parallel to the table 29 along the motion direction R 4 . The X-ray device also has a completely freely movable, mobile X-ray detector 5 .
[0031] [0031]FIG. 1 shows a situation wherein a patient P is seated on the examination table for X-raying the lower leg. The mobile detector 5 is used for this purpose. The mobile detector 5 is therefore positioned under the lower leg, and the patient P holds the leg in an angled attitude. The X-ray tube 2 is correspondingly configured such that it is suitably positioned relative to the X-ray detector 5 , and the lower leg of the patient P is thereby situated in the correct position between the X-ray tube 2 and the X-ray detector 5 .
[0032] A voltage generator 23 that is connected to the X-ray tube 2 and delivers the proper voltage for generating X-rays is situated outside the X-ray room B. An operating station 25 also is situated outside the X-ray room B, the voltage generator 23 being operated therefrom in order to trigger the X-rays. The individual X-ray detectors 3 , 4 , 5 also are connected to this operating station 25 via corresponding lines (not shown here). Insofar as digital X-ray detectors with an integrated readout unit are used, the image data can be sent directly via these lines to the operating station 25 and can be displayed thereat on a picture screen. Typical examples of such detectors are systems with optical coupling of an X-ray converter film to CCDs or CMOS chips, referred to as selenium-based detectors with electrostatic readout, or solid-state detectors with active readout matrices.
[0033] The mobile detector 5 can likewise be connected to the operating station 25 via a cable. Particularly the mobile detector 5 but also the other detectors 3 , 5 as well, can also be connected to the operating station 25 via wireless interfaces, for example short-range radio interfaces, insofar as the respective detector 3 , 4 , 5 have an adequate energy supply, for example an accumulator.
[0034] The respective detectors 3 , 4 , 5 also can communicate their activity status to the operating device 25 via these lines or via wireless interfaces.
[0035] [0035]FIG. 2 shows an exemplary embodiment of how the positions of the X-ray tune and the individual X-ray detectors 3 , 4 , 5 are determined.
[0036] The X-ray tube 2 is equipped with a position determination device 10 that determines the position of the X-ray tube 2 on the basis of the settings of the angles in the rotational axes D 1 , D 2 , D 3 of the ceiling mount 27 , 28 as well as the position of the mount 27 , 28 at the ceiling rail 26 . The position determination device forwards the position data P 2 to a position correlator 20 that, for example, is located within the operating station 25 .
[0037] The positions of the detectors 3 , 4 , 5 are determined via a position system 6 through 9 that operate in non-contacting fashion, such as optically. To this end, a sensor device 9 having a number of individual sensors, two CCD cameras 9 a , 9 b in this case, is located at a suitable position inside the X-ray room B, for example at the ceiling.
[0038] Respective identification objects 6 , 7 , 8 are arranged fixed at the individual X-ray detectors 3 , 4 , 5 , these objects 6 , 7 , 8 being unambiguously identified by the CCD cameras 9 a , 9 b and their position in the room being therefore able to be unambiguously defined by means of an observation with the CCD cameras 9 a , 9 b.
[0039] The functioning of this position determination method is explained in greater detail on the basis of FIG. 3 using the example of determining the position data P 5 of the mobile detector 5 . Here, the identification object 8 secured to the detector 5 has three marking objects 18 unambiguously positioned at the identification object 8 . Due to the placement and/or the type of marking object 18 , the respective identification object 8 or the detector 5 connected thereto can be unambiguously identified with the assistance of the CCD cameras 9 a , 9 b . The two CCD cameras 9 a , 9 b respectively acquire the identification object 8 with the three marking objects 18 , and—from the two angles of view—can thus determine the location of every individual marking object 18 , and thus the exact location as well as the orientation of the identification object 8 .
[0040] The marking objects 15 can be active objects that they emit a signal, for example infrared radiation. However, they alternatively can be passive objects that, for example, reflect specific radiation to the sensors. The exemplary embodiment has CCD cameras that operate in the visible range. Simple hemispheres are employed here as the marking objects 18 , these exhibiting a specific signal color so that they can be especially easily recognized and separated in the image signal of the CCD cameras 9 a , 9 b.
[0041] There are already various embodiments of such systems that use two sensors to acquire the position of a number of marking objects, and thus determine the location and the orientation of an object to be monitored. For example, the position determination system Polaris® of Northern Digital Inc. is such a commercially available system.
[0042] Alternatively, the marking objects 18 can be directly applied to the X-ray detector 5 .
[0043] The position data P 3 , P 4 , P 5 of the individual X-ray detectors 3 , 4 , 5 determined in this way by the sensor device 9 are likewise communicated to the position correlation unit 20 .
[0044] In the position correlation unit 20 , the position correlation data K that indicate the relative positions of the appertaining detector 3 , 4 , 5 relative to the X-ray tube 2 are then calculated from the position data P 3 , P 4 , P 5 for all detectors 3 , 4 , 5 relative to the X-ray tube 2 . These position correlation data K are then communicated to an enable unit 21 . The enable unit 21 also receives respective activation signals A 3 , A 4 , A 5 from the individual X-ray detectors 3 , 4 , 5 , insofar as the appertaining X-ray detector 3 , 4 , 5 is activated.
[0045] The enable unit 21 is also connected to a selection device 22 . This selection device 22 is a device with which the desired X-ray tube/X-ray detector pair 2 , 5 is identified. The selection device 22 here is part of the operating station 25 . For example, this can be a specific software module of control software of the X-ray device 1 installed on a computer of the operating station 25 .
[0046] The selection device 22 communicates the selection data S that contain the information about the desired X-ray tube/X-ray detector pair 2 , 5 to the enable unit 21 . On the basis of the selection data S and the position correlation data K, the enables unit then reviews whether the selected X-ray tube and the X-ray detector in the X-ray tube/X-ray detector pair 2 , 5 are suitably positioned relative to one another. When the review has proceeded successfully and when an activation signal A 5 is also present for the appertaining X-ray detector 5 , then an enable signal F is generated that is forwarded to the generator 23 . This generator 23 then can be actuated with a switch 24 and the X-rays thus are triggered. The switch 24 alternatively can be part of the operating device 25 . Moreover, the enable unit 21 and the position correlation unit 20 can alternatively be realized as software in a computer of the operating station 25 .
[0047] Instead of the enable unit 21 , a trigger unit can also be employed that automatically triggers the X-rays after receiving a suitable command and after a successful review of the positioning and of the detector activation.
[0048] [0048]FIG. 4 shows an alternative exemplary embodiment that largely agrees with the exemplary embodiment according to FIG. 2, so identical components are provided with the same reference characters in both Figures.
[0049] The significant difference between the X-ray device 1 according to FIG. 4 and the inventive X-ray device 1 according to FIG. 2 is in the position determination system.
[0050] In the exemplary embodiment according to FIG. 4, a position determination system is employed wherein a marking object 17 is positioned inside the X-ray room B. Respective sensors 15 , 13 , 11 are located at the X-ray detectors 3 , 4 , 5 for determining the range and the direction to the marking object 17 . Dependent on the type of sensor 15 , 13 , 11 , the marking object 17 can be an active marking object such as, for example, a radio or infrared transmitter, or can be a passive marking object.
[0051] The marking object 17 is a radio transmitter in the illustrated exemplary embodiment. The sensors 15 , 13 , 11 of the X-ray detectors 3 , 4 , 5 determine the direction from which the radio signal of the marking object (radio transmitter) 17 arrives and also recognize the distance from the marking object (radio transmitter) 17 on the basis of the received power. As a result the location of each sensor 15 , 13 , 11 in the room B is determined. Alternatively, a number of radio transmitters can be located in the room B, each emitting a radio signal that unambiguously identifies the transmitter. By means of a power measurement at each sensor 15 , 13 , 11 of the appertaining X-ray detectors, the range to each of the various transmitters can in turn be measured, and thus the position in the room B can also be determined by the range measurement.
[0052] The X-ray detectors 3 , 4 , 5 are also respectively equipped with orientation sensors 16 , 14 , 12 that serve for determining the orientation of the appertaining X-ray detector 3 , 4 , 4 in the room B. Various sensors with which the orientation in the room can be determined are well known.
[0053] Additionally, each of the X-ray detectors 3 , 4 , 5 has a calculating unit that calculates the position data P 3 , P 4 , P 5 from the identified range or direction to the marking object 19 positioned in the field of use, and from the orientation in the room B that was determined by the orientation respective sensor 16 , 14 , 12 . The position data P 3 , P 4 , P 5 are then forwarded to the position correlation unit 20 . As in the exemplary embodiment according to FIG. 2, the position correlation unit 20 receives the position data P 2 of the X-ray tube 2 directly from a measurement device 10 at the X-ray tube 2 . The further processing of the position data P 2 , P 3 , P 4 , P 5 and the linking with the activation signals A 3 , A 4 , A 5 ensues as described in the exemplary embodiment according to FIG. 2.
[0054] The communication of the position data P 3 , P 4 , P 5 of the individual X-ray detectors 3 , 4 , 5 to the position correlation unit 20 as well as the communication of the appertaining activation signals A 3 , A 4 , A 5 to the enable unit 21 can ensure, dependent on the type of X-ray detector 3 , 4 , 5 , to the position correlation unit 20 or to the enable unit 21 via a cable or by means a wireless transmission system, for example a radio interface.
[0055] Again it should be noted that the position determination systems shown in the figures are only exemplary embodiments of the invention, and a large variety of position determination methods can be used for determining the position of an arbitrary X-ray detector or X-ray tube. In the exemplary embodiment according to FIG. 4, for example, the position of the X-ray tube 2 can be determined in the same way via a non-contacting position determination system as in the case of the X-ray detectors 3 , 4 , 5 . Different position determination systems likewise can be utilized for the various X-ray detectors 3 , 4 , 5 .
[0056] Although further modifications and changes may be suggested by those skilled in the art, it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art.
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In a method and apparatus for controlling an X-ray device having at least one X-ray tube and at least one X-ray detector, wherein the X-ray tube and/or the X-ray detector are movably arranged, before an activation of an X-ray tube indicated for a desired measurement, an automatic check is made out as to whether an X-ray detector indicated for the desired measurement is activated. Position data of the appertaining X-ray tube and/or appertaining X-ray detector are also automatically determined and using the identified position data, the relative positions of the appertaining X-ray tube and of the appertaining X-ray detector relative to one another are identified. The X-ray tube is enabled for activation, or is automatically activated, only when the X-ray detector is activated and the X-ray tube and the X-ray detector are suitably positioned relative to one another for the desired measurement.
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BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to organization and security of data, and more particularly, but not by way of limitation, to organization and security of data of a mobile device based on geographic zones and/or personnel secure zones.
2. History of the Related Art
Mobile devices are currently growing into devices that may handle many types of media. For example, most mobile devices (e.g., mobile telephones, PDAs, laptops, etc.) today are capable of capturing and storing still images or video clips, storing contact information for numerous people, recording voice memos or written memos, etc. With vast quantities of information available for storage by a mobile device, it may become difficult to quickly navigate through menus and listings to find information requested by a user. Currently, mobile devices may store information, such as contacts, according to the individual. For example, a mobile device may have a listing of names and, associated with each name, a home telephone number, a mobile telephone number, email address, etc.
As users of mobile devices are now storing large amounts of information, some of which may be work sensitive or personal in nature, mobile device manufacturers are also looking to ways of securing the stored information to prevent information from being accessed or transmitted to others without the user's permission. Today's technology allows mobile device users to lock the mobile device to prevent others from viewing information stored therein. However, when the mobile device is locked, according to the current state of the art, none of the information may be accessed on the mobile device and no outgoing calls may be made.
In addition, mobile devices may also include Global Positioning System (GPS) for locating the position of the mobile device. Currently, GPS positioning may be utilized by emergency personnel to locate a mobile device when, for example, a 911 call is made from the mobile device. GPS positioning may also be utilized to track the location of the mobile device and/or generate directional instructions to a user of the mobile device.
BRIEF SUMMARY OF THE INVENTION
The present invention relates generally to mobile devices capable of securing and/or organizing information based on geographic zones and/or personnel secure zones. In one embodiment, the mobile device comprises a geographic sensor for determining an approximate location of the mobile device, a memory for storing information, and a microprocessor for controlling the device and being adapted for receiving data from the geographic sensor and determining whether the mobile device is located in a particular one of the at least one geographic zone.
In another embodiment, the mobile device comprises a device sensor for sensing at least one additional mobile device within a predefined area, a memory for storing information, and a microprocessor for controlling the device and being adapted for receiving data from the device sensor and determining whether predetermined conditions, regarding additional mobile devices within a predefined area, are met.
In yet another embodiment, the present invention relates to a method for utilizing personnel groups in the operation of a mobile device. The method comprises the steps of sensing, by a device sensor, at least one additional mobile device within a predefined area, storing information in a memory, and determining whether predetermined conditions, regarding additional mobile devices within a predefined area, are met.
In another embodiment, the present invention relates to a method of utilizing zones with a mobile device. The method comprises the steps of determining, by a geographic sensor, an approximate location of the mobile device, storing information in a memory, and determining whether the mobile device is located in a particular secure zone based on data received from the geographic sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the method and apparatus of the present invention may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings wherein:
FIG. 1 is a diagram illustrating geographic secure zones in accordance with an embodiment of the present invention;
FIG. 2 is a block diagram of a mobile device in accordance with an embodiment of the present invention;
FIG. 3 is a flow diagram illustrating a method of operating a mobile device in accordance with an embodiment of the present invention;
FIG. 4 is a diagram illustrating a personnel secure zone in accordance with an embodiment of the present invention;
FIG. 5 is a block diagram of a mobile device in accordance with an alternate embodiment of the present invention; and
FIG. 6 is a flow diagram illustrating a method of operating a mobile device in accordance with an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention relate to information sorting and data security based on geographic location and/or personnel. For example, information may be sorted according to geographic location so that when a mobile device is in a specific location, specific data is available for viewing, transmission, etc. Embodiments of the present invention also relate to security features based on secure zones that may be organized by geographic location and/or personnel groups. The geographic secure zones allow specific data to be accessed when the mobile device is in a specific location and the personnel secure zones allow specific data to be accessed when a specific set or subset of personnel are gathered together. The personnel secure zones may be defined by a set of mobile devices of the personnel being within a geographic secure zone as sensed by the mobile device. In another option, the personnel secure zones may be defined by sensing the other mobile devices in an area by e.g., infrared or BLUETOOTH. The personnel secure zones may also be linked to a specific geographic location and/or time period.
Referring now to FIG. 1 , a geographic secure zone in accordance with an embodiment of the present invention is illustrated. A variety of zones may be present in one or more geographic locations. For example, a home zone (zone 1 ), a relative zone (zone 2 ), and a work zone (zone 3 ) may be, for example, within one city or in a geographically dispersed arrangement (e.g., one or more zones located in different cities and/or countries). In addition, zones may be created that overlap other zones and/or may incorporate one or more geographic features, such as a user's home and work. For example, zone 4 includes both zone 1 and zone 3 . In some embodiments, zones 1 and 3 may be eliminated and only zone 4 may exist. It will be understood by one skilled in the art that more or fewer zones in a wide variety of orientations is possible in accordance with principles of the present invention.
Referring now to FIG. 2 , a mobile device 200 in accordance with an embodiment of the present invention is illustrated. The mobile device 200 includes a microprocessor (MPU) 202 for controlling operation of the mobile device 200 , a display 204 for displaying information to a user, and an optional battery 206 . For geographic secure zones, as noted above with FIG. 1 , the mobile device 200 includes a geographic sensor 208 , such as, for example, a GPS sensor. For other embodiments, such as those for personnel secure zones, the geographic sensor 208 may not be necessary. The mobile device 200 also includes a memory 210 for storing a plurality of data items. For example, the memory 210 may hold data items related to contacts 212 a , 212 b , video/still images 214 a , 214 b , memo data items 216 , and other data items 218 a , 218 b . The data items may be divided into a home category 220 a and a work category 220 b ; however, other arrangements are possible. For example, the data items may be separate without the need for home and work categories 220 a , 220 b . In another option, the contacts 212 a , 212 b may be joined into one contacts item without a delineation as to work contacts and home contacts.
Referring now to FIGS. 1 and 2 in combination, the data items may each be associated with a particular zone or zones, or each category (e.g., home or work categories 220 a , 220 b ) may be associated with a particular zone or zones. For example, data items in the home category 220 a may only be accessible within zone 1 , zone 4 , zones 1 and 2 , within zones 2 and 4 , etc. Similarly, data items of the work category 220 b may be accessible within zone 3 , zone 4 , etc. In another option, specific data items may be accessed within specific zones regardless of in which category 220 a or 220 b the data item resides. For example, the work contacts 212 b may be accessible in all zones or zone 4 due to the fact that many users may desire to work from home. However, work sensitive memos, or all data within the memo data items 216 , that require a higher security may be accessible only in zone 3 or only zone 4 in order to prevent viewing or transmission of sensitive work materials to persons other than the user of the mobile device 200 .
Referring now to FIG. 3 , a method 300 of operating a mobile device in accordance with an embodiment of the present invention is illustrated. The method 300 begins at 302 and senses a geographic location at step 304 . At step 306 , data items are associated with at least one zone. Steps 304 and 306 may be performed sequentially, or simultaneously and are interchangeable in order. As noted above, the data items may be associated with a particular zone directly, or each data item may be stored in a category that is associated with a particular zone or zones. At step 308 , it is determined whether the mobile device is within a zone associated with a data item to which the user requests access. If the mobile device is within the associated zone, then access is granted at step 310 and the method ends at step 312 . If the mobile device is not within the associated zone, then access is denied at step 314 . The mobile device then determines either to continue or desist in sensing the location of the mobile device at step 316 . If the sensing is to be discontinued, then the method ends at step 312 . If the mobile device determines that sensing of the location should be continued, then the method continues at step 308 .
Referring now to FIG. 4 , a personnel secure zone is illustrated. In the personnel secure zone, mobile devices identify any other mobile devices located within a predefined area defined by a radius r. As shown in FIG. 4 , a mobile device D registers that mobile devices B, C, E, F, and G are within the predefined area. A mobile device A and a mobile device H are outside the predefined area. A personnel secure zone may be utilized between a specific group of personnel so that a secure item shared, modified, etc. between the personnel group may not be accessed, modified, shared, etc. without a predetermined number or percentage of the personnel group being present or assenting to the access, sharing or modification. For example, a personnel group of the mobile devices A, B, C, and D may create a secure item, such as a contract, memo, document, etc. The mobile device D may wish to share or modify the secure item. For example, in order for the mobile device D to modify the secure item, a predetermined percentage, such as 75%, of the personnel group must be present. Because the mobile device D senses that 75% of the personnel group (i.e., the mobile devices B, C, and D) is present, the mobile device D may access and/or modify the secure item. In a similar manner, the mobile device D may wish to share the secure item with another mobile device outside of the personnel group, such as the mobile device F. Because 75% of the personnel group is present, the secure item may be shared with the mobile device F. Although the above example is illustrated utilizing the predetermined percentage of 75%, it will be understood by one skilled in the art that other percentages or forms of approval may be utilized for allowing access, etc. to the secure item. For example, a mobile device wishing to modify the secure item may get an approval signal from various ones of the mobile devices of the personnel group. In another option, the personnel group may assign their own parameters for allowing access to the secure item.
Referring now to FIG. 5 , a mobile device 400 in accordance with another embodiment of the present invention is illustrated. The mobile device 400 includes a microprocessor (MPU) 202 , a display 204 , and optional battery 206 in a manner similar to the mobile device 200 of FIG. 2 . In the embodiment illustrated in FIG. 5 , the mobile device 400 also includes a device sensor 402 for detecting other mobile devices 400 within a predefined area and a memory 410 . The device sensor 402 may be implemented as, for example, an infrared sensor, BLUETOOTH sensor, or other sensor capable of determining if other mobile devices are present in a predefined area.
The geographic sensor 208 , as described above with reference to FIG. 2 , is optional in the mobile device 400 . If the geographic sensor 208 is not present in the mobile device 400 , the data items may be accessed according to the personnel secure zones. If the geographic sensor 208 is present in the mobile device 400 , then the data items may be accessed according to the personnel secure zones, the geographic secure zones, or a combination of both geographic and personnel secure zones. For example, the, work contacts 212 b may be accessed based on geographic secure zones and memos or other data items may be accessed according to the personnel secure zones. In addition, secure items that are work related may only be accessed in a geographic work zone (e.g., the zone 3 ) while a predetermined number of the personnel group is present in the personnel secure zone, although other arrangements of geographic secure zones and personnel secure zones may be utilized in accordance with embodiments of the present invention.
The memory 410 may be organized into categories 220 similar to that of FIG. 2 , according to data item (as shown in FIG. 5 ), or according to other properties as desired. When utilizing personnel secure zones, the memory 410 may include a personnel group data category 406 . The personnel group data category 406 may include identities 408 of mobile devices within the personnel group and rules 412 for allowing access to secure items 414 . Secure items 414 are data items that are accessible according to the personnel secure zones.
As illustrated above, data items or secure items may be accessed only when specific conditions are met (e.g., the mobile device 200 , 400 is within a specific geographic zone or a number of mobile devices 200 , 400 of the personnel group are present). The inability to access information when these conditions are not met may be provided by various techniques. For example, the secure items or data items may be “locked” to prevent access to a memory location storing the item. In another option, the items may be encrypted and decryption enabled only when the conditions are met to allow access to the items. Other techniques may also be utilized to prevent access to data in accordance with principles of the present invention.
Embodiments of the present invention may be utilized to organize data items. For example, the geographic secure zones may be utilized to present data items in a specific order related to location. In one aspect, when the mobile device 200 , 400 determines that the mobile device 200 , 400 is in a work zone, then information, e.g., in the contacts data item, may be arranged so that work contacts appear at the upper portion of a contacts listing. When the mobile device 200 , 400 enters a home zone, the information in the contacts data item may be rearranged to present personal contacts at the upper portion of the contacts listing. Similarly, personnel secure zones may be utilized to organize data items according to personnel. For example, when the mobile device 200 , 400 senses another mobile device 200 , 400 that is associate with a specific zone, e.g., a work zone, then information related to the sensed mobile device 200 , 400 or work information is organized to be viewed first by the mobile device 200 , 400 .
Referring now to FIG. 6 , a method 600 of operating a mobile device in accordance with another embodiment of the present invention is illustrated. The method 600 begins at step 602 and proceeds to sense for additional mobile devices within a predefined area at step 604 . At step 606 , it is determined whether predefined conditions regarding the particular data item to which a user requests access have been met. If the predefined conditions are met, then, at step 608 access is granted and the method ends at step 610 . If the predefined conditions are not met, then, at step 612 access is denied. At step 614 , the mobile device determines whether searching for other mobile devices should be continued. If searching is not continued, then the methods ends at step 610 . If the searching for other mobile devices is continued, then the method returns to step 604 .
It is thus believed that the operation and construction of various embodiments of the present invention will be apparent from the foregoing Detailed Description. While various devices have been described, it will be obvious to a person of ordinary skill in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention, as defined in the following claims. Therefore, the spirit and the scope of the appended claims should not be limited to the description of the embodiments contained herein.
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A mobile device comprises a geographic sensor for determining an approximate location of the mobile device, a memory for storing information, and a microprocessor for controlling the device and adapted for receiving data from the geographic sensor and determining whether the mobile device is located in a particular zone. In another embodiment, the mobile device comprises a device sensor for sensing at least one additional mobile device within a predefined area, a memory for storing information, and a microprocessor for controlling the device and adapted for receiving data from the device sensor and determining whether predetermined conditions, regarding additional mobile devices within a predefined area, are met. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72( b ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
a. Field of the Invention
This invention relates to the control of hydrocarbon production using plunger lift systems. More specifically, it relates to controllers using measurements of conditions in subsurface wells to operate non-linear artificial intelligence processes to sequence the operation of plunger lift devices.
b. Discussion of the Prior Art
The control of oil and gas production wells are an on-going concern of the petroleum industry due, in part, to the monetary expense involved as well as the risks associated with environmental and safety issues.
In many hydrocarbon wells, that is gas and oil wells, as described in greater detail below, fluids accumulate within the well casing and production string which block the flow of the formation gas or oil into the borehole, and such accumulations reduce the production of hydrocarbons from the well. As used herein, “fluids” primarily refers to a combination of naturally occurring liquids and emulsions, including water, oil, paraffin or combinations thereof. As fluids accumulate within the well casing and production string, often referred to as “tubing string” or “tubing”, the production of hydrocarbons from the well may diminish, and may ultimately fail due to the effect of pressure buildup of such fluids on the formation. Currently, the state-of-the art technique for removing accumulated fluids from the well casing and production string is through the use of plunger lift systems.
State-of-the art plunger lift production systems include a cylindrical plunger. In such a system, the cylindrical plunger normally resides at the bottom of the borehole, and is sized to travel through the production string extending from a location adjacent to the producing formation down in the bottom of the borehole upward to the surface equipment located at the hydrocarbon receiving end of the borehole. In general, fluids in the borehole that inhibit the flow of hydrocarbons out of the formation tend to collect in the lower portion of the production string. Periodically, a valve, typically a motor valve, in the production string at the surface of the well is opened at the surface. This allows accumulated reservoir pressure within the well to drive the plunger up the production string. The small clearance between the plunger and the well production string is such that the plunger carries with it to the surface a load of accumulated blocking fluids. The accumulated fluids are then ejected out of the top of the well, thereby allowing hydrocarbons to flow more freely from the formation into the well bore and be delivered to a distribution system at the surface. After the flow of gas has once again been restricted due to the further accumulation of fluids downhole, the surface valve of the well is closed, and the plunger, due to its own weight, then falls back down the production string to the bottom of the borehole. While the valve is so closed, the pressure within the well generally increases again. If the pressure is allowed to build to a strong enough level, the pressure will be strong enough to lift the plunger and another load of fluids to the surface of the well when the valve is reopened.
In plunger lift production systems, there is a requirement for the periodic operation of a motor valve at the surface of the wellhead to control the flow of fluids from the well to assist in the production of hydrocarbons and removal of fluids from the well. These motor valves are conventionally controlled by timing mechanisms and are currently programmed in accordance with principles of reservoir engineering, which determine the length of time that a plunger lift control valve should be either “closed” and restricted from the flowing of gas or liquids to the surface, and the time the plunger lift control valve should be “opened” to more freely produce.
If the plunger lift control valve is left opened or closed for too long of a time, there will be a loss of well production and the producing formation may be damaged. Furthermore, pressure buildup within a well can cause the plunger to rise to the surface at excessive speeds, which can cause serious damage to the surface components of the well and cause hydrocarbons and fluids from the well to leak into the surrounding environment. Not only does this present a safety risk to workers at the surface of the well, but it also presents serious environmental concerns. It is therefore seen that control of the plunger lift control valve is critical to maintain proper pressure and production balance within the well by avoiding having it be open or closed for too long or too short of a time.
It is extremely impractical to manually open and close the plunger lift control valve for each well. As a consequence, automatic controllers are currently used to open and close the motor valve. Generally, the criterion used in most systems for operation of the plunger lift control valve is strictly one of the elapse of pre-selected time periods. In most systems, measured well parameters, such as pressure and temperature, can be used to override the timing cycle in special conditions.
For example, in the patent prior art, U.S. Pat. No. 4,150,721 (Norwood) discloses a battery operated gas well controller system which utilizes digital logic circuitry to operate a well in response to a timing counter and certain measured well parameters. U.S. Pat. Nos. 4,352,376 and 4,532,952 (Norwood) disclose similar controllers comprising the use of a microprocessor. U.S. Pat. No. 4,354,524 (Higgins) discloses a pneumatic timing system which uses injected gas to artificially lift liquids to a well surface. U.S. Pat. No. 4,355,365 (McCracken) discloses a system for electronically operating a well in accordance with timing techniques wherein the well is allowed to flow for a pre-selected period of time and then closed for a second pre-selected period of time to effect the production from the well. U.S. Pat. No. 4,921,048 (Crow) discloses an electronic controller which detects the arrival of a plunger and monitors the time required for the plunger to make each trip to the surface. U.S. Pat. No. 5,146,991 (Rogers, Jr.) discloses a plunger lift well which evaluates plunger lift speed. U.S. Pat. No. 5,878,817 (Stastka) discloses a controller which opens the plunger lift control valve based on the measurement of the pressure difference between the gas in the tubing line and the pressure of gas in the sales line, and in addition uses the speed of the plunger to adjust valve operation. Similarly, U.S. Pat. No. 6,595,287 (Fisher) controls valve operation based on the pressure difference between sales line pressure and well casing pressure. U.S. Pat. No. 5,984,013 (Giacomino) uses plunger arrival time to adjust the subsequent valve opening and closing times.
It is currently observed that relatively simple, timed intermittent operation of plunger lift control valves is often not adequate to control outflow so as to optimize hydrocarbon production from wells. As a consequence, sophisticated computerized controllers positioned at the surface of production wells have been used for control of devices, such as the plunger lift control valves. Additional systems have been developed that relate to: (1) surface controller systems using a surface microprocessor; and (2) downhole controller systems which are initiated by surface control signals.
Surface controller systems generally teach computerized systems for monitoring and controlling a gas/oil production well whereby the control electronics is located at the surface and communicates with sensors and electromechanical devices near the surface. An example of this system is disclosed in U.S. Pat. Nos. 4,633,954 (Dixon) and 4,685,522 (Dixon), which describe a fully programmable microprocessor controller which monitors downhole parameters, such as pressure and flow, and controls the operation of gas injection to the well, outflow of fluids from the well, or shutting in of the well to maximize output. Another example of a controller system of this type is disclosed in U.S. Pat. No. 5,132,904 (Lamp), which further describes a feature where the controller includes serial and parallel communication ports through which all communications to and from the controller pass. Hand held devices or portable computers capable of serial communication may access the controller. A telephone modem or telemetry link to central host computer may also be used to permit several controllers to be accessed remotely. It is well recognized that petroleum production wells using surface based controllers will have increased production efficiencies and lower operating costs than downhole microprocessor controllers.
In general, although controller systems have become much more complex, they still do not fully optimize well production and often require a great deal of operator inputs. What is needed is a plunger lift system that optimizes the open and close cycles of the motor valve based on minimal input. Additionally, well operation and production varies between different wells and can even change from cycle to cycle within the same well. For example, the gas pressure within a well will vary from well to well and can significantly change during the life of that well. Because each well will have its own unique properties, the automatic controller closing and opening the plunger lift control valve must be suitable for use on a wide variety of wells and be flexible enough to adjust to the changes that often occur during the life of the well to provide ongoing optimum production. Ideally, the operation of a plunger lift control valve by an automatic controller system would be able to approximate the operation of a controller system by an ever present and vigilant human operator.
SUMMARY OF THE INVENTION
The present invention teaches an automatic controller system and methods for controlling plunger assisted gas and/or oil wells. As detailed below, limited operator entry is required as the controller system calculates values used to control the plunger lift control valve of the well and optimize production. The controller system contains a microprocessor and memory, wherein the microprocessor utilizes a non-linear artificial intelligence process that controls when the well is closed and open, and determines the optimal operational plunger lift control valve cycles. As used herein, the term microprocessor is meant to include general-purpose microprocessors, microcontrollers, Digital Signal Processors (DSP), electronic data processing computers of all kinds, and combinations thereof. In one embodiment, the present invention provides a microprocessor that requires minimal operator input and utilizes Zadehan logic to optimize well operation after the required inputs are entered. Zadehan logic is also referred to as “fuzzy logic”.
Zadehan logic and fuzzy logic sets are viewed as a mathematical formalism for the representation of uncertainty. Contrary to their name, the laws of fuzziness are not vague, but rather describe complex real systems operation with linguistic variables that may have varying membership functions and slope. Typically, spreadsheets are used to define the variables and degree of membership of external events. Graphs define the slope of the terms used for inputs and output data. The final system is compiled for compact representation of the complex system to be embedded in microprocessor firmware. Such use of Zadehan logic, or fuzzy logic, is well known in the art and is widely used in programmable controllers of all types, for example, see: (International Electrotechnical Commission (2000) International Standard, Programmable controllers-Part 7: Fuzzy control programming; Liu et al. (2005), “A probabilistic fuzzy logic system for modeling and control,” IEEE Transactions on Fuzzy Systems 13(6):848-859; Gaweda et al. (2003), “Data-driven linguistic modeling using relational fuzzy rules,” IEEE Transactions on Fuzzy Systems 11(1):121-134; Joo et al. (1999), “Hybrid state-space fuzzy model-based controller with dual-rate sampling for digital control of chaotic systems,” IEEE Transactions on Fuzzy Systems 7(4):394-408).
As described in greater detail below, a gas or oil well utilizing an embodiment of the present invention comprises tubing, often in the form of a production string, positioned within a well casing; a plunger positioned within the production string, wherein the plunger is moveable within the production string; a plunger arrival sensor at the lubricator; a plunger lift control valve connected to the production string and the sales line; and, in some cases optional pressure sensors located at the annulus of the well casing, and a hydrocarbon take-off line, commonly referred to as a “sales line”. The plunger lift control valve is operated to change the valve between a closed and an open position in response to a microprocessor in the operation of the present invention, as further detailed below.
Such a well using a plunger lift system operates using a series of cycles. As used herein, the term “operating cycle” refers to a repeating process of closing the plunger lift control motor valve to build sufficient pressure to lift the plunger to the surface followed by opening the plunger lift control valve to collect the oil and/or gas hydrocarbons from the well. Typically, each operating cycle comprises at least a close cycle, an open cycle, an afterflow cycle, and a fall cycle, as detailed immediately below.
The “close cycle” refers to the cycle during normal well operation wherein the plunger is at the bottom of the production string and the plunger lift control valve is closed, thereby preventing fluids and hydrocarbons within the production string from flowing to the surface of the well. When in a close cycle, the pressure within the well will generally increase. Preferably, the duration of the close cycle, also referred to herein as the “close time”, is as short as possible, but still allows for enough pressure to build so as to push the plunger to the surface during an open cycle. That is, when the plunger lift control valve is opened, the time period referred to herein as the “open cycle”, the plunger and the fluids that have accumulated in the production string above the plunger will rise to the surface of the well. The duration of the open cycle, also referred to herein as the “open time”, should be long enough to ensure the plunger rises to the surface and is detected by the controller system. Once the fluids reach the surface of the well, they can be collected into a separator and hydrocarbons can more freely flow through the production string to the sales line. The period of time during which a well is producing the desired gaseous hydrocarbons is referred to as the “afterflow cycle”. Preferably, the duration of each afterflow cycle, also referred to herein as the “afterflow time”, is as long as possible for optimized well production. In typical operation, the well will proceed through a close cycle, followed by an open cycle, then an afterflow cycle, and then a “fall cycle” during which the plunger falls to the bottom of the production string. After the fall cycle, the well repeats the process starting with another close cycle.
In the practice of the process of the present invention, well parameters entered by an operator, measurements of the current well conditions, previous well measurements, and trends are assigned a value and applied to the Zadehan logic engine, which is stored on the microprocessor, to calculate the value of modifications required for improved cycle time and hydrocarbon production time.
In one embodiment of the invention, the minimal operator inputs required by the microprocessor controller system comprise the well depth, an initial close time required to recharge the well after a plunger arrives to the surface, and an initial afterflow time to allow collection of hydrocarbons after the plunger arrives to the surface of the well. From the required operator inputs, the Zadehan logic engine of the microprocessor will calculate the time required for the plunger lift control valve to be opened, fall time required for the plunger to fall to the bottom of the well, and backup time required to build up the pressure in the well should a plunger fail to reach the surface of the well. The various cycle times are then adjusted by the Zadehan logic of the microprocessor, preferably to reduce the time the plunger lift control valve is closed and increase the afterflow time when the desired hydrocarbons are collected. Non-linear pressure limits can be calculated and used after adjustment of the cycles to form an optimized closed loop system. In one embodiment, the microprocessor uses a high pressure limit and low pressure limit as additional parameters.
In one embodiment, the invention provides a method for optimizing the operation of a well having a plunger lift control valve connected between the production string of the well and the sales line, wherein a controller system is able to open and close the motor valve according to values stored on the controller system memory. The method comprises entering a predetermined value for well depth, close time, and afterflow time into the controller system memory, and conducting one or more operating cycles wherein the controller opens and closes the motor valve to allow fluids or gasses to flow through the sales line. The controller system automatically calculates the open time based on the entered predetermined values. Each operating cycle comprises entering a closed cycle for a period of time equal to the initial close time; opening the plunger lift control valve and entering an open cycle for a period of time equal to the calculated open time allowing fluids to be artificially lifted which allows the fluids to flow into the sales line; and entering an afterflow cycle for a period of time equal to the afterflow time and allowing gases to flow into the sales lines during the afterflow cycle. After one or more successful operating cycles, the Zadehan logic of the microprocessor controller system adjusts the close time and afterflow time based on current well conditions and previous well measurements. Subsequent adjusted operating cycles are conducted using the adjusted close time and afterflow time.
In a further embodiment, the close time is adjusted by the Zadehan logic engine after a number of operating cycles have been run using the initial close time and initial afterflow time. After there have been a number of successful operational cycles using the adjusted close time, the afterflow time is adjusted. After a number of successful operating cycles have been run using the adjusted afterflow time and close time, the controller system adjusts the afterflow time again using the Zadehan logic engine. This second adjustment is also referred to as the fine adjust.
The pressures in the sales line, well casing and production string can also be used by the Zadehan logic engine to open and close the plunger lift control valve. For example, the controller system can terminate a close cycle and enter an open cycle when the pressure in the well casing (also called the well annulus) exceeds the pressure in the sales line by a predetermined amount. The Zadehan controller system can also terminate an afterflow cycle when the current pressure in the well annulus is less than the minimum recorded well annulus pressure by a predetermined amount. The Zadehan controller system can also terminate an afterflow cycle when the current pressure in the sales line is less than the minimum recorded pressure at the well annulus by a predetermined amount.
The objects of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combination, and elements as herein described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which:
FIG. 1 shows a diagrammatic side view, partially in cross-section, of a well utilizing a plunger lift system that is connected to and operated by a Zadehan controller system of the present invention;
FIG. 2 shows a keypad of a Zadehan controller system in one embodiment of the invention used for operator entry and review of well data;
FIG. 3 illustrates an overview of the operator entry used with a Zadehan controller system of the present invention;
FIG. 4 illustrates an overview of the firmware modification control section used in a controller system of the present invention; and
FIG. 5 and FIG. 5A illustrates an overview of the firmware run time network used in a controller system of the present invention.
DETAILED DESCRIPTION
FIG. 1 shows one embodiment of the present invention with a well that has a plunger lift system. As shown, well casing 22 extends from the earth surface down into an oil-gas formation 14 . The production string 20 is a series of connected elongated hollow tubes within well casing 22 that extends from wellhead 21 at the surface down to the bottom or near the bottom of well casing 22 . Production string 20 is open at its lower end allowing fluids and hydrocarbons in the well casing 22 to enter the production string 20 . Plunger 17 is disposed within production string 20 , and is designed to move from the bottom of production string 20 to lubricator 5 which is located at the top of production string 20 . At or near the bottom of production string 20 is a lower bumper spring 18 , which catches and stops plunger 17 as it travels to the bottom of production string 20 . An upper bumper spring 4 above the lubricator 5 stops plunger 17 as it is pushed through production string 20 to the surface by the pressure of the flow of hydrocarbons from oil-gas formation 14 .
The top of production string 20 is connected to a master valve 12 . When maintenance and repair of the system is required, master valve 12 is used to shut off the flow of hydrocarbons and thereby the pressure for maintenance and repair of the system. Above master valve 12 are a plunger catcher 6 and a lubricator 5 . The plunger catcher 6 can be engaged by an operator to catch plunger 17 after it is caused to rise within production string 20 to lubricator 5 . An upper bumper spring 4 is attached to the lubricator 5 by threads and can be unscrewed using handles 3 . When the upper bumper spring 4 is removed, the plunger 17 can be removed and repaired, replaced, or inspected for damage.
Upper flow outlet 7 and lower flow outlet 8 connect a sales line 15 to the lubricator 5 , such that sales line 15 is in fluid communication with production string 20 . By “fluid communication”, it is meant that fluids and hydrocarbons can flow from the production string 20 into the sales line 15 through upper flow outlet 7 and lower flow outlet 8 . As is well known in the art, the other end of sales line 15 is attached to one or more separators (not shown) used to separate the fluids from the hydrocarbons. Shut-in valve 9 may be used to shut down flow through sales line 15 for maintenance.
The flow of fluids and hydrocarbons through sales line 15 is regulated by plunger lift control valve 10 , which is connected to controller system 200 , as further detailed and explained below, through motor valve connecting tubing 11 . At the heart of the present invention, controller system 200 contains a microprocessor which calculates when plunger lift control valve 10 should be opened and closed. The controller system 200 uses an art known actuator (not shown), such as a solenoid valve or a pilot latch valve, to open and close the plunger lift control valve 10 . When the controller system 200 activates plunger lift control valve 10 to an open position, and if there is sufficient pressure in production string 20 , plunger 17 will be pushed from the lower bumper spring 18 at the oil-gas formation 14 and be pushed to the surface lifting accumulated fluids into sales line 15 . A plunger arrival sensor 2 detects when plunger 17 arrives at lubricator 5 and relays this information to controller system 200 . Plunger arrival sensor 2 can be electronic or mechanical. Additional monitoring devices, such as annulus pressure sensor 1 and sales line pressure sensor 19 , relay pressure information to controller system 200 . Gas from the well casing 22 is used by the controller 200 to mechanically control the open/close state of the motor valve 10 . Gas from the well casing 22 is delivered to the controller system 200 through controller gas supply line 13 . A regulator 16 attached to controller gas supply line 13 reduces the gas pressure to manageable levels, typically to approximately 25 PSI.
Controller system 200 includes a keypad and an alpha-numeric display 201 to allow for operator input. Keypads and displays suitable for use with this invention are well known in the art. FIG. 2 shows a typical keypad and display 201 located within controller system 200 described in FIG. 1 and herein below. The alpha-numeric display 201 shows operator entries, current cycle in use, in addition to well history items. Well history can be displayed by depressing or continuously depressing history key 205 for different well history items. History items may include, but are not limited to, total sales time, total close time, total open count, number of successful and failed plunger arrivals, plunger run times, and various recorded pressures. Depressing the history key 205 again after the last well history item is displayed will return to the current cycle display. Well depth, initial close time, and initial afterflow times are entered while the controller system 200 is in operator set mode. Operator set mode is entered by depressing the set key 207 . While in operator set mode, close times and afterflow times are entered by depressing the hours key 202 , minutes key 203 , and seconds key 204 . In one embodiment, well depth is entered by depressing the hours key 202 to add 10,000 feet increments, the minutes key 203 to add 100 feet increments, and the seconds key 204 to add 1 foot increments. Alternatively, the add/subtract key 206 will add or subtract time or feet when the hours key 202 , minutes key 203 , or seconds keys 204 are depressed. In one embodiment, the plunger lift control valve 10 can be manually opened and closed by an operator by depressing the manual key 208 .
FIG. 3 illustrates firmware stored within the microprocessor of controller system 200 of the present invention. The completed operator entry items 301 are processed by the microprocessor to generate the calculated and adjusted values 302 , which are stored in nonvolatile memory. The operator entry items 301 include well depth, initial close time, and initial afterflow time. Calculated and adjusted values 302 include the open time, backup time, and fall time. Determining the desired open time and fall time for a well are based on methods known in the art and can be modified by the experience and judgment of the well operator. Primarily, the open time and fall time depend on the well depth. The open time should be long enough to ensure the plunger 17 has enough time to rise to the surface and be detected by the plunger arrival sensor 2 . The fall time should be long enough to ensure that the plunger 17 has enough time to return to the bottom of the production string 20 before the plunger lift control valve 10 is reopened. Methods for determining backup time are also known in the art. Backup time can vary according to the characteristics of each well and the judgment of the well operator, but the backup time will always be greater than the close time. In one embodiment, the backup time is approximately 1½ to 2½ times the close time.
The microprocessor also calculates the adjustments to the afterflow time and close time, and determines the parameters used to enter the shut in cycle 305 when a dry plunger is detected. A dry plunger means that the plunger 17 reached the top of the production string 20 without any accompanying fluids. This scenario is not within the normal operation of the well and may indicate that the plunger 17 is not reaching the bottom of the production string 20 during the fall cycle 309 . This is a dangerous situation because a dry plunger can hit the upper bumper spring 4 at a much higher velocity than normal which can damage or rupture the top of the well. Typically, plunger 17 speed is not directly measured. Instead, an abnormally short plunger arrival time is assumed to indicate excessive plunger speed and a dry plunger. If the plunger arrival time is less than a time limit corresponding to the safest maximum plunger speed, the controller system will close plunger lift control valve 10 and enter the shut in cycle 305 .
During a normal operating cycle, the microprocessor enters the close cycle 303 . “Close” refers to the state of the plunger lift control valve 10 as controlled by the microprocessor. A timeout of the close cycle 303 or a high pressure signal from the annulus pressure sensor 1 will cause the microprocessor to enter the open cycle 306 and open the plunger lift control valve 10 . When the plunger arrival sensor 2 detects a normal plunger arrival, the plunger lift control valve 10 remains open. The microprocessor then enters the afterflow cycle 308 and hydrocarbons can more freely flow from production string 20 into sales line 15 . The microprocessor remains in the afterflow cycle 308 until a timeout of the cycle or a low pressure signal is received from annulus pressure sensor 1 or sales line pressure sensor 19 . During the afterflow cycle 308 , hydrocarbons are collected through the sales line 15 .
If the afterflow cycle 308 ends as the result of a timeout, the microprocessor enters the plunger fall cycle 309 . During the fall cycle 309 , plunger lift control valve 10 is closed and plunger 17 is given sufficient time to return to lower bumper spring 18 at the bottom of the production string 20 . At the end of the plunger fall cycle 309 , the microprocessor enters the next normal close cycle 303 . If the afterflow cycle 308 ends as a result of a low pressure signal, the microprocessor enters the fall cycle 309 and the motor valve 10 is closed. Close cycle 303 or afterflow cycle 308 may be adjusted by the microprocessor to account for the low pressure signal.
If the plunger arrival sensor 2 does not detect the arrival of the plunger 17 during the open cycle 306 , the microprocessor will timeout and enter the backup cycle 307 . The backup cycle 307 closes the motor valve 10 to allow a sufficient pressure to build within production string 20 and allow plunger 17 to arrive at the surface on the next open cycle 306 . If a dry plunger is detected, the microprocessor will enter into the shut in cycle 305 . This is an abnormal condition and requires an operator entry to leave the cycle and resume operation. It may be prudent at this time to check plunger 17 for damage before continuing operation. During the backup cycle 307 , plunger fall time cycle 309 , and shut in cycle 305 , the microprocessor closes the motor valve 10 .
In terms of environmental safety, detecting a dry plunger and entering the shut in cycle 305 is a very useful feature because it prevents damage to the well and prevents leaks to the environment. In a further embodiment, the controller system 200 also monitors the sales line pressure to determine if the sales line 15 has a leak or a break. If the sales line pressure sensor 19 detects a drop in pressure indicative of a leak or a break, the controller system 200 will enter the shut in cycle 305 .
FIG. 4 illustrates firmware stored on the microprocessor in one embodiment of the present invention. The firmware optimizes well production by adjusting the close time 402 and afterflow time 401 . The microprocessor utilizes a non-linear Zadehan logic engine 400 , previously referred to in the art as a “fuzzy logic” engine, to adjust the close time 402 and afterflow time 401 . Because well operation is non-linear, the optimization process is also non-linear. The current operating cycle has the highest priority in altering well operation while previous cycles have a lower priority. The Zadehan logic engine 400 reduces the close time 401 until it reaches the optimal time period. Conversely, afterflow time 401 is extended to increase hydrocarbon production until it also reaches its optimal time period. If a specific afterflow time 401 , close time 402 or well condition corresponds to a failed plunger arrival, the microprocessor will adjust the close time 402 or afterflow time 401 to avoid repeating the same conditions.
It should be noted that the controller system of the present invention does not adjust the close time or afterflow time based on whether well characteristics such as the plunger arrival time or plunger speed fall within a predetermined range. Instead, the present invention compares well characteristics exhibited during the current operating cycle to previous cycles and adjusts the close time and afterflow time based on the trends exhibited by the well during its operation. Trend information is typical of how humans evaluate a series of recorded numbers or graphical information.
Controller system 200 uses a number of recorded variables to adjust the close time 402 and afterflow time 401 . In one embodiment of the invention, the Zadehan logic engine 400 adjusts the close time and afterflow time based on pressure, plunger count, plunger trend, plunger fail, high to low transition count, high to low transition trend, and combinations thereof.
Plunger trend is the determination of whether the plunger arrival time in the current cycle is faster, slower or the same compared to the plunger arrival time in the previous cycle. The microprocessor in controller system 200 records plunger trend as an integer which is incremented or decremented according to whether the current plunger time is greater or lesser than the previous plunger time. A plunger trend over several cycles showing a steady, consistent plunger arrival time is an indication of stability in the close time and afterflow time adjustments.
Plunger count is the total number of plunger arrivals. Plunger fail is when the controller system 200 fails to detect the successful arrival of the plunger 17 at the lubricator 5 during the open cycle.
During normal operation, the pressure within a well casing 22 will drop when the well switches to from a close cycle to an open cycle. The time it takes for the pressure in well casing 22 to complete the transition from the higher pressure of the close cycle to the lower pressure of the open cycle is known as the high to low transition time, or HL count. HL count will vary from well to well, and will most likely vary within the same well from one close-open cycle to the next. Generally, a lower HL count is preferable to a high HL count. More important is the trend of whether the HL count is increasing, decreasing or the same from one run to the next. The controller system 200 records the high to low transition trend (HL trend) as an integer, which is incremented or decremented according to whether the HL count has increased or decreased from the last cycle. An HL trend indicating that the HL count is decreasing can be an indication that the adjustments to the well cycles are having a desired effect. An HL trend indicating that the HL count is remaining stable is an indication of well optimization.
Pressure information is recorded at various operating cycle boundaries and is used for cycle limits. Minimum and maximum values with various time limits are selected to insure well stability and optimization.
In one embodiment, as shown in FIG. 4 , the Zadehan logic engine 400 reduces the close time 402 in a series of operating cycles until a failed plunger arrival is detected. The close time 402 is then increased sufficiently so that plunger 17 successfully arrives at the top of the production string 20 . The Zadehan logic engine 400 then adjusts the afterflow time 401 in the subsequent operating cycles until the well operation is stable. Typically, the afterflow time 401 is increased to allow for the greatest amount of gas production that still results in stable well operation.
After afterflow time 401 is adjusted, the well is allowed to operate without additional adjustments in order to allow the well to stabilize. After a consecutive number of successful operating cycles during which no additional adjustments are made, the Zadehan logic engine 400 will fine adjust 403 the afterflow time 401 and, if necessary, the close time 402 and then stop adjusting (represented by the done step 404 ). Once the fine adjust 403 step has been completed, the well will operate according to the adjusted afterflow time 401 and adjusted close time 402 to provide improved hydrocarbon production from that well. Additionally, well casing 22 and production string 20 pressure limits may be used to open and close the plunger lift control valve 10 during this time if necessary. The optimization process can be restarted with a new operator entry at controller system 200 . All of the related variables are saved in the nonvolatile memory of the microprocessor, allowing restarting at the same adjustment setting.
The pressure difference between production string 20 and well casing 22 during the operating cycle can be used as further indicator of well optimization. The production string 20 pressure and well casing 22 pressure will be very close to the same and will rise and lower uniformly on each cycle if efficient well operation is being achieved. The pressures will never match exactly because the production string 20 will never be completely free of fluids. Generally in an efficient plunger lift well, the production string pressure will be approximately 80-85% of the well casing pressure. In a further embodiment, the controller system 200 records the pressure difference between the well casing 22 and the production string 20 . The Zadehan logic engine 400 will adjust or stabilize the afterflow time 401 and close time 402 based on how closely the production string pressure resembles the well casing pressure.
FIG. 5 and FIG. 5A illustrates a Run Time Network (RTN) used in a controller system 200 of the present invention. The RTN shell 501 evaluates the current cycle state, selecting a new state if required. The cycle state may be the close state 502 , shut in state 503 , open state 504 , afterflow state 505 , backup state 506 , or fall state 507 . Each second 508 the current main timer 509 and well history timers 510 are adjusted and updated in the microprocessor memory. If the current cycle is the afterflow cycle 511 , that cycle is also adjusted. A low pressure input inhibited 512 during the initial change to the afterflow cycles is also adjusted and updated. The display 521 is alphanumeric and displays operator entry, current cycle information, and well history. External inputs are recorded and used by the RTN shell 501 to select the current cycle. When the keypad is active 523 the firmware decodes 524 the keypad input and the proper response is initiated. The display 521 will shut off to conserve power after a predetermined time, say about 4.25 minutes as shown in FIG. 5A , has elapsed after the last key pad activity 525 . Any subsequent keypad activity will cause the display 521 to be turned back on.
Now, with the system of the present invention in mind, in one embodiment of the present invention, an operator initially, for example, enters predetermined values for well depth, initial close time and initial afterflow time into the controller system 200 microprocessor memory through a keypad, such as described with respect to FIG. 2 , above. The microprocessor of the controller system 200 will calculate the open time, fall time and backup time. The controller system 200 will enter a close cycle 303 for a period of time equal to the initial close time. During the close cycle 303 , the plunger lift control valve 10 is closed and the plunger 17 remains at the bottom of the production string 20 . The pressure within the well casing 22 will increase during the close cycle 303 . Upon timeout of the close cycle 303 or a high pressure signal from the annulus pressure sensor 1 , the controller system 200 will terminate the close cycle 303 , enter the open cycle 306 , and open the plunger lift control valve 10 . Once the plunger lift control valve 10 is opened, the built up pressure will lift plunger 17 and the fluids that have accumulated above plunger 17 to the surface and into the sales line 15 . Plunger arrival sensor 2 connected to controller system 200 will detect when plunger 17 arrives at the surface. Upon timeout of the open cycle 306 , the controller system 200 enters the afterflow cycle 308 , during which the motor valve 10 remains open and hydrocarbons can more freely flow through production string 20 into sales line 15 . Controller system 200 remains in the afterflow cycle 308 until a timeout of the cycle or a low pressure signal is received from the annulus pressure sensor 1 or sales line pressure sensor 19 . After the afterflow cycle 308 is terminated, controller system 200 closes the plunger lift control valve 10 and enters the close cycle 303 for the next operating cycle. When plunger lift control valve 10 is closed, plunger 17 will return to the bottom of the production string 20 and remain there until the next open cycle 306 .
During successive operating cycles, the controller system 200 will gradually decrease the close time 402 until a failed plunger arrival is detected. The controller system 200 will then enter a backup cycle 307 and increase the close time 402 so that sufficient pressure is built up in production string 20 to cause a successful plunger arrival. Controller system 200 , utilizing Zadehan logic, adjusts the afterflow time 401 in subsequent operating cycles with variables such as pressure, plunger count, plunger fall, plunger trend, high to low transition count, and high to low transition trend. Plunger trend, high to low transition count, and high to low transition trend have not been used in previous control systems to optimize well operation. After the afterflow time 401 has been adjusted, the well is allowed to operate without additional adjustments in order to allow the well to stabilize. After a consecutive number of successful operating cycles during which no additional adjustments are made, the controller system 200 will fine adjust 403 the afterflow time 401 , and the close time 402 if necessary to provide improved hydrocarbon production. It should be noted that previous control systems also do not allow the well to stabilize between adjustment periods, and it has been determined that lack of adjustment can prevent optimal well operation. After the controller system 200 fine adjusts the afterflow time 401 and close time 402 , the well is allowed to operate without additional adjustments.
All references cited herein are hereby incorporated by reference in their entirety to the extent that there is no inconsistency with the disclosure of this specification. All headings used herein are for convenience only. All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains, and are herein incorporated by reference to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference. References cited herein are incorporated by reference herein in their entirety to indicate the state of the art as of their publication or filing date and it is intended that this information can be employed herein, if needed, to exclude specific embodiments that are in the prior art.
Having now fully described the present invention in some detail by way of illustration and examples for purposes of clarity of understanding, it will be obvious to one of ordinary skill in the art that the same can be performed by modifying or changing the invention within a wide and equivalent range of conditions, formulations and other parameters without affecting the scope of the invention or any specific embodiment thereof, and that such modifications or changes are intended to be encompassed within the scope of the appended claims.
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A microcontroller system for oil and gas wells using a plunger lift device, which responds to the variations in well production and operation. The system requires minimal operator input, and is able to calculate the operational cycles and adjustments to maximize well production and maintain environmental safety using non-linear artificial intelligence processes.
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BACKGROUND OF THE INVENTION
The present invention relates to a rotatable seat for an automotive vehicle, such as van or micro-bus and so forth. More specifically, the invention relates to a rotating mechanism and locking or latch mechanism in the rotatable seat.
Recently, rotatable seats for use on the automotive vehicles, particularly on van or micro-bus type vehicles, have been developed. Generally, such rotatable seats are provided with a rotation or pivot mechanism and a latch mechanism. The rotation mechanism comprises a vertical axle rotatably received within a boss formed on the vehicle floor panel. The latch mechanism is usually provided adjacent the rotation mechanism and prevents the vertical axle from rotating. The latch mechanism has a latch member engageable with the vertical axle or other appropriate section of the rotation mechanism so that it may prevent the vertical axle and thus the rotatable seat from rotating.
Since the rotational force due to inertia caused by collision of the vehicle or abrupt deceleration is applied to the vehicle not only at the pivoted portion but also at locations spaced from the pivot, the conventional latch mechanism must provide enough force to prevent the seat from rotating. However, due to a lack of space below the seat, there could not be provided an appropriate mechanism having enough resistance against the rotational force applied to the portion apart from the pivot. Furthermore, according to the typical construction of the conventional rotatable seat, the latch member is urged into its latching position by a spring. This bias spring provided for the latch member has insufficient bias force for completely preventing the seat from accidentally rotating. On the other hand, between the bottom of the seat and the vehicle floor panel there is not enough clearance for a spring powerful enough to bias the latch member to the latching position. Assuming it is possible to provide a spring having enough force to prevent the seat from accidentally rotating, this may cause difficulty in releasing the seat from the latching position when the seat is to be rotated.
Preventing the seat from accidentally rotating may be accomplished by providing a latch mechanism at a position spaced from the pivot, where greater rotational force with respect to the pivot will be applied. This may require less biasing force than the latch mechanism provided adjacent the pivot. Therefore, releasing of the latch mechanism from the latching position may require less power to permit easy operation of seat rotation when the seat is to be rotated.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a rotatable seat having a lock or latch mechanism which can effectively prevent the rotatable seat from accidentally rotating and requires less operational power for releasing the latch mechanism from the latching position when rotation of the seat is desired.
To accomplish the above-mentioned and other objects, there is provided a rotatable seat for an automotive vehicle which has a rotation mechanism and a latch mechanism independent of the rotational mechanism. The rotation mechanism includes means for vertically moving the seat between a first position in which the seat is prevented from rotating and a second position in which the seat is permitted to rotate about the vertical axis thereof. The latch mechanism includes means for providing latch-and-hook engagement at both the front and the rear of the seat. The latch-and-hook engagement is releasable from the engaged condition by operating a manual lever.
According to the present invention, the rotation mechanism further includes means for causing rotational movement of the seat to the second position due to the seat's own weight.
Further, according to another aspect of the invention, the rotatable seat is provided with a holding mechanism to hold the seat at the second position. The holding mechanism includes means for releasing the seat from the held position after seat rotation is completed.
According to a further aspect of the invention, the rotatable seat is provided with a safety mechanism which prevents inadvertent release of the latch-and-hook engagement while passengers are sitting thereon.
According to one embodiment of the invention, there is provided a rotatable seat for an automotive vehicle comprising a seat rotatably supported on a vehicle floor with a rotational pivot which permits the seat to rotate in the horizontal plane thereabout, a rotation mechanism for moving the seat between a first position in which the seat is prevented from rotating and a second position in which the seat is permitted to rotate about the rotational pivot, a latch mechanism for latching the seat in a position facing either forward or back with respect to the vehicle, the latch mechanism having first and second latching assemblies provided at the front and the rear of the seat, which first and second latching assemblies being movable between a third position in which the seat is prevented from rotating and a fourth position in which the seat is permitted to rotate about the rotational pivot and an actuating lever to operate said rotation mechanism to move the seat from the first position to second position and said first and the latching assemblies from the third position to the fourth position to permit seat rotation.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description give herebelow and from the accompanying drawings of the preferred embodiments of the present invention, which, however, should be taken as limitative to the invention but for elucidation and explanation only.
In the drawings:
FIG. 1 is a plane view of a micro-bus type automotive vehicle having a rotatable seat according to the present invention;
FIG. 2 is a side elevation of the micro-bus type automotive vehicle of FIG. 1;
FIG. 3 is a sectional view of the first embodiment of a rotatable seat according to the present invention;
FIG. 4 is an enlarged sectional view of a rotational mechanism of the rotatable seat of FIG. 3, which is taken along line IV--IV of FIG. 3;
FIG. 5 is a perspective view of the rotation mechanism of the rotatable seat of FIG. 3;
FIG. 6 is a similar view of FIG. 3 but showing the seat in a position lifted up for rotation;
FIG. 7 is an illustration of the rotation mechanism which details the relative dimensions of a cam member, supporting roller and lifting roller;
FIG. 8 is a perspective view of the second embodiment of the rotatable seat according to the present invention;
FIG. 9 is a sectional view of the rotatable seat of FIG. 8 showing detail of the construction thereof;
FIG. 10 is a perspective view showing the relationship between the lifting lever and the holding lever in the rotatable seat construction of FIG. 9;
FIG. 11 is a perspective view showing an actuating lever of the rotatable seat of FIG. 9;
FIG. 12 is a side elevation view of the holding lever showing movement thereof;
FIG. 13 is a side elevation view of the actuating lever showing operation thereof;
FIG. 14 is a side elevation view of the rotatable seat according to a modification of the second embodiment of FIG. 9;
FIG. 15 is a perspective view of the rotatable seat of FIG. 14;
FIG. 16 is a perspective view of a blocking lever in the interlock mechanism provided in the rotatable seat of FIG. 14; and
FIG. 17 is a plan view of the blocking lever showing operation thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly to FIGS. 1 and 2, there is illustrated a van or micro-bus type automotive vehicle. In the passenger compartment, three or more vehicle seats, generally of the bench type, are installed parallel with respect to one another. A rotatable seat 20 is positioned between a driver's seat 22 and a rear seat 24. The rotatable seat 20 is rotatable about its vertical axis to alternate the direction in which the seat faces between forward and backward, as shown in FIGS. 1 and 2. A pair of front and rear legs 26 and 28 are provided for the rotatable seat 20 and are mounted on a seat support 30. A rotation mechanism 32 is interpositioned between the bottom of the rotatable seat 20 and the upper surface of the seat support 30. The rotation mechanism 32 permits rotation of the rotatable seat about its vertical axis for alternating seat direction. A latch mechanism 34, which is shown in FIG. 3 and is also interpositioned between the bottom of the rotatable seat and the upper surface of the seat support, holds the seat 20 in either of two positions in which the rotatable seat is directed either forward or backward.
FIGS. 3 and 4 show the first embodiment of the rotatable seat structure according to the present invention and detailed construction of the rotation mechanism 32 and latch mechanism 34 of the rotatable seat. Generally, the rotatable seat comprises a seat cushion 36 and a seat back 38. A seat cushion 36 has a seat support frame 40 at the bottom thereof. A rotational axis 42 vertically extends from the seat support frame 40 at the center of the seat. The rotational axle 42 is fixed to the seat support frame 40 with fastening means such as fastening bolts 44. Surrounding the rotational axle 42, an annular cam member 46 is fitted to the center of the seat support frame 40. The cam member 46 has cam faces 50 and 52 on the lower edge thereof. The cam member 46 is also formed with a pair of diametrically-opposed rounded cut outs 54. Two support rollers 56 are each rotatably supported at one end of a corresponding shaft 58, the other end of which is secured to brackets 60 projected from the upper surface of the seat support 30. The cut outs 54 simultaneously receive the support rollers 56 when the rotatable seat 20 is latched at a position facing either forward or backward.
As shown in FIG. 5, lifting rollers 62 and 64 abut the lower surfaces 66 of diametrically-opposed laterally-extending portions 68 of the cam member 46. The lifting rollers 62 and 64 are rotatable about shafts 70. The shafts 70 are secured to the ends of lifting levers 72 and 74. The lifting lever 74 is horizontally angled and has a circular hole 76 at the other end thereof and the lifting lever 72 is horizontally and vertically angled and has a circular hole 78 at an intermediate portion thereof. The holes 76 and 78 of the levers 74 and 72 receive either end of a rotational axle 80. The axle 80 is rotatably supported by brackets 82 projecting from the upper surface of the seat support 30. The axle 80 is secured to each of the holes 76 and 78 so that the levers 72 and 74 rotate with each other according to rotation of the axle 80.
The lower end of the lifting lever 72 is connected to a linking lever 84 via a connecting rod 86. The connecting rod 86 connects the lifting lever 72 to the linking lever 84 so that the lifting lever 72 and the lifting lever 74 can be rotated about the horizontal axle 80 thereof in response to rotation of the linking lever 84. The linking lever 84 is secured to a shaft 86 which is rotatably supported by the seat support 30. A manually-operable lift-up lever 88 is also secured to the shaft 86 for rotation with the linking lever 84. The lift-up lever 88 has at the free end thereof a handle 90 for comfortable gripping therefor. The lifting lever 72 is, in turn, biased by a spring 92 in the direction in which the lifting roller 62 is moved downwards about the horizontal axle 80. One end of the spring 92 is secured to the seat support 30.
The rotational axle 42 is received through a cylindrical boss 94 inserted into an bore 96 formed in the seat support 30. The seat support 30 has a recess 98 at a position housing the free end of the rotational axle 42. A pair of bushings 100 and 102 are inserted into opposite ends of the boss 94. Each of the bushings 100 and 102 has a flange portion 104 and 106 and a cylindrical portion 108 and 110 respectively which engage with the ends of the boss. The bushings 100 and 102 serve to prevent rotational friction between the rotational axle 42 and the inner periphery of the boss 94.
As shown in FIG. 3, the latch mechanism 34 generally comprises a pair of hooks 112 and 114 secured to the seat support frame 40 near the front and rear ends of the seat cushion 36, and a pair of latches 116 and 118 releasably engaged with the hooks. The upper end of each latch 116 and 118 has a hook portion 121 and 123 which is engageable with the hook 112 and 114 respectively. The latches 116 and 118 are respectively secured to shafts 120 and 122 rotatably supported by the seat support 30. A portion of the latch 116 above the shaft 120 is connected to a portion of the latch 118 below the shaft 122 via a connecting rod 124 for co-ordinated movement therewith. A manually-operable release lever 126 is secured to the shaft 120 in order to rotate the shaft 120 and the latch 116. The latch 118 is connected to one end of a bias spring 128. The other end of the bias spring 128 is engaged with the seat support 30 in order to provide a spring force biasing the latch 118 in the direction in which the hook portion 123 engages with the hook 114. Similar to the lift-up lever 88, the release lever 126 has a handle 130 for comfortable operation thereof.
In operation, when the release lever 126 is pulled to rotate the shaft 122 clockwise as shown in FIG. 3, the latch 116 is thus rotated clockwise so that the hook portion 121 and the hook 112 disengage. At the same time, the latch 118 rotates counterclockwise according to the rotation of the latch 116 so that the hook portion 123 and the hook 114 disengage. In this position, when the lift-up lever 88 is pulled to rotate the shaft 86 together with linking lever 84 clockwise in FIG. 3, the rotation of the linking lever 84 is transmitted to the lifting lever 72 to rotate the latter with the other lifting lever 74. Due to the rotation of the lifting levers 72 and 74, the lifting rollers 62 and 64 come to contact with the lower surfaces 66 of the laterally-extending portions 68 of the cam member 46 to push the seat 20 upwards. The seat 20 is thus raised. Due to the upward movement of the seat 20, the support rollers 56 are released from the cut outs 54 of the cam member 46 as shown by the arrows in FIG. 7. Therefore, the seat 20 can horizontally rotate about the vertical axis of the rotational axle 42. At a position in which the seat is slightly rotated, the support rollers 56 come into contact with the cam faces 50, as shown in FIG. 7.
At this position, when the release lever 126 and the lift-up lever 88 are released by the user, they return to their respective initial positions. Although the release lever 126 and lift-up lever 88 return to their respective initial positions, the seat 20 with the cam member 46 is held in the unlatched and raised position by the supporting rollers 56. The seat 20 is thus permitted to rotate about the vertical axis of the rotational axle 42 in order to alternate the seat facing. In this position, the weight of the seat 20 is vertically applied to the contact points C between the support rollers 56 and the cam face 50. Since the cam face 50 is inclined with respect to the horizontal plane and the force due to gravity is applied perpendicular to the cam face, i.e., in the direction of moment, there exists a horizontal component of the reacting moment against gravity, and thus the seat 20 rotates about its vertical rotational axis by itself without requiring application of an external force. During rotation of the seat, the support rollers 56 remain in a position abutting the cam faces 50 and 52 so that the seat 20 and the cam member 46 are kept in the raised position.
As the seat 20 approaches the desired forward or backward position, the support rollers 56 reach the end of the appropriate cam face 50 or 52 and drop into the cut-outs 56, i.e., the seat 20 returns to the normal lowered position. At the same time, the hooks 112 and 114 are lowered over the ends 121 and 123 of the latchs 116 and 118. As the hooks pass over the hooked ends 121 and 123, the latches 116 and 118 are displaced slightly from and then returned to the initial positions thereof, now firmly engaged with the hooks 112 and 114. Due to the engagement of the support rollers 56 and the cut outs 54 and the engagement of the latches 116 and 118 and the hooks 112 and 114, the seat 20 is prevented from rotating.
The relationship between the support roller 56, lifting roller 62 and 64, and cam member 46 will be described in further detail with reference to FIG. 7. In the initial position, the support rollers 56 are placed within the cut outs 54 with a clearance d 1 from the bottom of the cut out. Also, the lifting rollers 62 and 64 are placed away from the lower surface 66 of the extending portion 68 at a distance d 2 . These clearances are maintained in the lowered position by the length of the front and rear legs 26 and 28. The vertical motion distance of the lifting roller 62 and 64 is determined in correspondence with to the depth d 4 of the cut-outs 54 and in correspondence with the required vertical displacement of the cam member 46 with respect to the support rollers 56. The circumferential extent of the extending portion 68 is greater than the horizontal displacement distance d 5 of the lifting rollers 62 and 64, caused by operation of the lifting levers 72 and 74.
In the initial position, the horizontal axis p 1 of the support rollers 56 is placed at the center of the circle of the rounded bottom of the cut-outs 54. Each roller 62, 64 and 56 has diameter r 1 which is smaller than that r 2 of the rounded bottom of the cut out 54 so that it may provide clearance d 1 between the upper end of the roller 56 and the circumference of the cut-outs 54. This will aid smooth engagement of the support rollers 56 and the cut-outs 54 at the end of seat rotation.
FIGS. 8 to 13 show the second embodiment of the rotatable seat according to the present invention. In this embodiment, the rotation mechanism 32 and latch mechanism 34 in the foregoing embodiment are cooperatively combined so that they can be operated with a single actuating lever. Further, the present embodiment of the rotatable seat is provided with a holding mechanism for holding the seat at the raised position.
FIG. 9 is a fragmentary perspective view of the rotatable seat 140 in which the combined rotation mechanism 142 and latch mechanism 144 with the holding mechanism 146 is illustrated. As can be seen from FIG. 9, the rotational seat 140 has pivot means similar to that of the foregoing embodiment, about which the seat rotates. As shown in FIG. 9, the pivot means comprises a rotational axle 148 received with a cylindrical boss 150. The boss 150 is inserted into a through opening formed in a seat support 152. The rotational axle 148 is rotatable about the vertical axis of the boss for permitting rotation of the seat 140. Likewise to the first embodiment, a cam member 154 surrounds the rotational axle 148. A pair of lifting rollers 156 and 158 are movably provided adjacent the cam member 154. The lifting rollers 156 and 158 are rotatably mounted at one end of lifting levers 160 and 162 so that the lifting roller lift up the cam member 154 with the rotatable seat 140 by rotational movement of the lifting levers 160 and 162.
The lifting lever 160 is connected to an actuating lever 164 via a connecting rod 166. The actuating lever 164 is arranged so that it can also release latches 168 and 170 respectively engageable with hooks 172 and 174. The actuating lever 164 further operates a holding mechanism 146 which comprises a holding lever 176 pivotable between positions corresponding to latching and unlatching in response to the movement of the actuating lever.
Now, referring to FIGS. 10 to 14, the rotation mechanism 142, the latch mechanism 144 and the holding mechanism 146 will be described in detail. Similarly to the foregoing first embodiment, the cam member 154 encircles the top of the rotational axle 148 and has cam faces 178 and 180 at the lower end thereof. Also, the cam member 148 has diametrically-opposed cut-outs 182 with rounded ends. Support rollers 184 rotatably supported by shafts 187 at the upper ends of brackets 186 are received in the cut-outs in the initial position of the seat 140. The lifting rollers 156 and 158 oppose the lower surface of extending portions 188 laterally extending from the outer periphery of the cam member 148 along the underside of the seat 140. The lifting roller 156 is rotatable about an axle 192 projecting from one end of the lifting lever 160. Likewise, the lifting roller 158 is rotatably mounted on an axle 194 projecting from one end of the lifting lever 162. As shown in FIG. 10, the lifting lever 160 is horizontally and vertically angled and secured onto one end of a shaft 196 at its vertical corner 198. On the other hand, the lifting lever 162 is horizontally angled and secured onto the other end of the shaft 196 at the end opposite the lifting roller 158. The shaft 196 is rotatably supported by a pair of brackets 200 projecting from the upper surface of the seat support 152. A bias spring 199 is connected to the lifting lever 160 to that it biases the latter to an initial position displaced from the cam member 148 as shown in FIG. 9.
Through a connecting rod 166 and a connecting lever 204, the lower end of the lifting lever 160 is connected to a fan-shaped cam lever 206 secured to a rotatable shaft 208 together with the actuating lever 164. As particularly shown in FIG. 11, front side edge of the fan-shaped cam lever 206 opposes a contact pin 210 projecting from a contact lever 212 which is secured to a rotatable shaft 214, to which, the latch 168 is also secured. The contact lever 212 is connected with the latch 170 via a connecting rod 216. The latch 170 is biased toward an initial position, in which the latch 170 engages with the hook 172 or 174 by a bias spring 217.
The holding lever 176 is pivotably supported by a shaft 218. The holding lever 176 is biased upwards by a spring 220 so that the portion 222 thereof constantly contacts with the underside of a pin 224 projecting from the side surface of the lifting lever 160. Thus, the pin 224 limits rotation of the holding lever 176 about the shaft 218. A roller 226 is rotatably mounted on a shaft 230 at the top of a portion 228 of the holding lever 176. The holding lever 176 has a cut-out 232 at the end of the portion 222. The cut-out 232 is engageable with the pin 224 at the extreme position of rotation of the holding lever 176. The roller 226 opposes a cam plate 234 with a cam face 236 so that it contacts the latter during rotation of the seat 140.
In the initial position where the rotatable seat 140 is directed forward or backward and locked to be prevented from rotating, the latches 168 and 170 engage the hooks 172 and 174 to maintain the seat 140 in the latched position. At this position, the support rollers 184 are disposed within the cut-outs 182 to prevent the seat from rotating in cooperation with the latch-and-hook engagement. The pin 224 of the lifting lever 160 pushes the holding lever downwardly against the spring force of the spring 220 in order to displace the roller 226 from the cam face 236 of the cam plate 234. Also, the lifting rollers 156 and 158 are disposed in an initial position displaced from the lower surface of the extending portions 188 and 190 at a distance d 1 . In this position, front and rear legs 238 and 240 extending from the bottom of the rotatable seat 140 rest on the upper surface of the seat support 152.
In operation, when the actuating lever 164 is rotated about its rotation axis in the clockwise direction, the cam lever 206 coaxially secured to the shaft 208 is thus rotated clockwise to force the pin 210 of the contact lever 212 clockwise. By rotation of the contact lever 212 about the axis thereof, the latch 168 is rotated clockwise to disengage from the hook 172. Corresponding to the rotation of the contact lever 212, the latch 170 rotates counterclockwise to disengage from the hook 174.
According to the rotation of the actuating lever 164, the cam lever 206 rotates clockwise in FIGS. 9 and 12. The rotational force of the cam lever 206 is transmitted to the lifting lever 160 via the connecting lever 204 and the connecting rod 166. The lifting lever 160 is thus rotated with the lifting lever 162 to bring the lifting rollers 156 and 158 into contact with the lower surfaces of the extending portions 188 and 190 to raise the seat 140. During lifting lever rotation, holding lever 176 rotates about the axis of the shaft 187 to engage the cut-out 232 with the pin 224. The profile of the cut-out 232 does not easily permit release of the pin 224. Thus, the holding lever 176 maintains the lifting lever 160, and therefore the seat 140, in the raised position. In this position, due to the weight of the seat, the support rollers 184 moves along the cam faces 180 and 182 of the cam member to rotate the seat 140 as described with respect to the first embodiment. During seat rotation, the cam face 236 of the cam plate 234 contacts the roller 226 to push the latter downward. The holding lever 176 rotates counterclockwise in response to the downward force to release the pin 224 from the cut-out 232. Thus, the holding lever 176 returns to its initial position, as shown in phantom line in FIG. 12. By releasing the pin 224 from the cut out 232, the lifting lever 160 together with the lifting lever 162 is allowed to return the initial position thereof. Simultaneously, the latch 168 and 170 engage with the hooks 172 and 174 again in order to prevent the seat from rotating.
Referring to FIG. 14, there is illustrated a modification of the second embodiment. In this modification, an interlock mechanism is provided in order to prevent passengers from subjecting themselves to danger due to sitting in the rotatable seat when it is unlatched. The interlock mechanism therefore inhibits sitting while the rotatable seat is in the raised position.
The interlock mechanism 250 comprises a blocking lever 252 located immediately clockwise of the latch 168 so that one end 254 thereof abuts the back of the latch in the normal position. The blocking lever 252 is connected to a lever 256 secured on the side of the pivotable seat back 258. The lever 256 is integral with a pivotable piece 259 of a hinge mechanism 260. The hinge mechanism 260 includes a stationary piece 262 secured to the seat cushion 264 and an outer casing 266 covering the end of the axle of the hinge mechanism 260. The outer casing 266 has a cut-out 268 on its circumference.
A locking lever 270 with an angled end 272 is pivotably supported on the side of the seat cushion 264 near the outer casing 266. A bias spring 274 has one end secured to the stationary piece 262 of the hinge mechanism and the other end attached to the locking lever 270 so as to urge the locking lever 270 toward the outer casing 266. The end 272 of the locking lever 270 in contact with the outer casing 266 is angled toward the outer casing 266 so that it may engage with the cut-out 268 when the seat back 258 is pivoted sufficient far toward the seat cushion 264.
A coaxial inner and outer cables 276 and 278 are interposed between the blocking lever 252 and the lever 256. The outer cable 278 is secured to the bottom of the seat cushion 264 by a bracket 280. The inner cable 276 is movable through the outer cable according to the movement of the lever 256. The blocking lever 252 is pivotably supported by a pivot 282 so that it can rotate horizontally thereabout. As shown in FIG. 16, the blocking lever 252 has a forked end 284. A connector pin 286 spans the space 288 between the arms 290 and 292 of the forked end 284. The connector pin 286 pivotably engages the end of the inner cable 276. The inner cable 276 is movable through the outer cable 278 according to movement of the lever 256.
In the normal position, the end 254 of the blocking lever 252 prevents release of the latch 168. Therefore, the actuating lever 164 cannot rotate about its rotational axis. To enable the actuating lever 164 to be operated, the seat back 258 must be held as illustrated by phantom lines in FIG. 14. According to the rotation of the seat back 258 and thus the rotatable piece 259, the lever 256 pivots counterclockwise in FIG. 14. The inner cable 276 thus slides through the outer cable 278 so that the blocking lever 252 is pulled to rotate about the pivot 282 to a position displaced from the latch 168 as illustrated by phantom lines in FIG. 17. Thus, the latch 168 is permitted to rotate to allow the actuating lever 164 to be operated.
During the rotation of the seat back 258 about the hinge axle, the cut out 268 of the outer casing 266 is moved into opposition with the angled end 272 of the locking lever 270 so as to engage the angled end 272. Due to the engagement of the locking lever and the outer casing, the seat back 258 is prevented from rotating back to the normal position. The locking lever 270 is maintained in this position by the force of the bias spring 274. The rotatable seat 140 can rotate normally about its rotational axis as described previously. When the seat reaches the desired position, the seat 140 is lowered to the initial position thereof. In this position, the free end of the locking lever 270 abuts against the upper surface of the seat support 152. The locking lever 270 is thus rotated clockwise against the biasing force of the spring 274 to disengage the angled end of locking lever 270 and the cut out 268 of the outer casing 266. This permits the seat back 258 to return to the normal position.
As understood hereabove, the present invention fulfills all of the objects and advantages sought therefor.
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A rotatable seat for a multi-passenger automotive vehicle employs a latch mechanism releasable only by manual operation of an actuating lever. The latch mechanism includes latch-and-hook assemblies at both the front and rear of the seat to prevent inadvertent rotation of the seat. In addition, the seat rotation is governed by a cam having deep recesses at the two normal sitting positions. The cam is designed with sloping faces so that the weight of the seat drives rotation towards the normal positions. An additional safety mechanism prevents rotation of the seat unless the seat back is in a position preventing passengers from sitting thereon.
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This application is a continuation-in-part of U.S. Ser. No. 353,562, filed March 1, 1982 now abandoned.
BACKGROUND
This invention relates to improved reinforced reaction injection molded (RIM) polymeric articles and to a method of making them. More particularly, the invention relates to the incorporation of flaked glass particles in liquid RIM precursor constituents. The constituents are molded such that the glass flakes are preferentially oriented to improve physical characteristics of the polymerized article.
Reaction injection molding (RIM) is a process by which highly chemically reactive liquids are injected into a mold where they polymerize in a few seconds to form a coherent, molded article. The most common RIM processes today involve a rapid reaction between highly catalyzed polyether or polyester polyol and isocyanate constituents. The constituents are stored in separate tanks prior to molding and are first mixed in the mixhead upstream of a mold. Once mixed, they react rapidly to gel and then harden to form polyurethane polymers. While the invention will be specifically described in terms of urethane RIM systems, it has application to reaction injection molding processes based on other very rapidly reacting chemical systems.
Although reaction injection molded urethanes have many desirable physical characteristics, they also have generally high coefficients of thermal expansion (CTE), poor dimensional stability over wide temperature ranges and considerable flexibility at room temperature. Morover, a large, filler-free RIM panel when attached to a rigid support structure may permanently buckle and wave at elevated temperatures. Thus, as molded, unreinforced RIM urethanes are not generally directly suitable for use as large automotive panels or in other semistructural or structural panel applications. Furthermore, the larger the surface area and thinner the aspect of a panel, the more serious these problems become. As a consequence, the use of reinforcing fillers in RIM urethanes has been extensively examined by this inventor and others.
Currently, some automotive body panels are made from RIM urethanes filled with short (less than 1/8") milled glass fiber, generally in amounts less than about 25% of the polymer weight. Chopped glass is not a good filler for RIM systems because it makes the liquid in which it is contained difficult to impingement mix, even at inclusion levels of only a few weight percent.
Wollastonite, a calcium metasilcate-based mineral, is sometimes used as a low cost alternative to milled fiberglass. However, its morphology is the same as that of glass fiber so it creates the same problems in molded panels. I have found that the moisture content of wood fibers is too high for use in isocyanate-containing systems. Latent water reacts to form urea and carbon dioxide which cause high porosity and poor strength in urethane RIM panels. Other isocyanate compatible fibrous fillers such as carbon fibers, asbestos, nylon, rayon, etc., produce results similar to those of milled glass. Therefore, I do not believe that any single type or combination of fibrous fillers alone will provide the increased isotropic strength, decreased CTE and cosmetic characteristics desirable for automotive body and other thin aspect structural panels.
The incorporation of solid and hollow glass spheres to improve the physical properties and appearance of RIM panels was also examined. However, incorporating glass spheres did not result in any significant improvement in strength or reduced coefficients of thermal expansion.
Attempts were also made to incorporate flakeshaped mica particles in urethane RIM panels. However, the mica flakes adversely effected the chemistry of the constituents so that all test panels had very poor adherence and inferior physical properties.
Another problem encountered in the manufacture of large urethane RIM panels is the rapid impingement mixing of the reactive isocyanate and polyol constituents. Unless gelation takes place within a few seconds after mixing and mold injection, the process cannot be used to economically produce parts weighing several pounds at high volumes. The RIM systems that have been used commercially for the last few years gel within two to six seconds. Once gelation occurs, movement of filler particles is restricted.
To get good and rapid mixing, the constituents must be fluid when they are ejected through the impingement mixing ports at high pressures (˜2000 psi). Today's RIM systems are so fast that by the time the mixed liquids fill the mold, they have already gelled. Obviously, this property further limits the scope of acceptable fillers. It certainly precludes the use of paste-like constituents containing high filler loadings. Such pastes cannot be dispersed into the liquid constituents rapidly enough to assure complete mixing and uniform distribution of filler particles in a uniform molded panel.
Thus, although many different varieties of reinforcing fillers have been examined for urethane RIM, none seem to be capable of providing the desired results. The complexity of the reaction injection molding process itself and the sensitivity and criticality of the rapidly reacting constituent chemicals clearly do not easily accommodate the incorporation of reinforcing fillers in RIM products to improve CTE, isotropic strength, appearance or other important physical properties.
OBJECTS
It is therefore an object of the invention to provide a method of reaction injection molding articles with substantially improved coefficients of thermal expansion, strength, and less surface waviness than articles made heretofore by RIM processes.
It is a more particular object to improve the physical properties of RIM articles by the inclusion of glass flake fillers. A more particular object is to incorporate glass flakes in liquid RIM precursors and to inject these constituents into a mold in a manner to orient the flakes so as to optimize the physical characteristics of the finished article.
Another object is to provide a method of making a panel or panel-like RIM article where the physical properties are particularly improved in all directions in the plane of the panel. More specifically, it is an object to reinforce RIM panels with glass flakes to effect such improvement. In a panel in accordance with the invention, the glass flake is incorporated in a reinforcing amount such that the flakes are aligned with their planar surfaces substantially parallel to the planar surfaces of the panel. Such reinforced panels are stronger, have reduced coefficients of thermal expansion, and have less wavy surfaces than prior art RIM panels.
BRIEF SUMMARY
In accordance with a preferred embodiment of the invention, these and other objects may be accomplished as follows.
A desired amount of glass flake is mixed with and dispersed in one or more of the chemically reactive liquid precursor constituents for reaction injection molding. Generally, at least about 5 weight percent based on the total polymer weight is desirable. The reinforcing effect of the glass flake increases proportionately to the amount incorporated.
Herein, glass flake is defined as small particles of friable amorphous material having a generally planar surface, the area of that surface being substantially greater than the particle thickness. The flakes are preferably no more than a few microns thick and have aspect ratios (flake surface area to thickness ratios) of at least about 40:1. The diameters of the particles must be small enough to flow through RIM metering, mixing and injecting equipment without clogging. A preferred type of flake glass is made by melting a suitable glass composition based on silica; extruding the molten material through a bushing to form glass film; cooling the film, and breaking it between cooperating rollers. The particles so produced may be further reduced in size in a suitable mill. The individual particles closely resemble minute panes of broken window glass. They may be coated with surface active agents such as silane to improve their dispersion and bonding characteristics.
All the chemically reactive liquid constituents and the glass flakes dispersed therein are thoroughly mixed prior to delivery to the mold. However, it is the shape of the mold and the flow of the liquid constituents therein that ultimately determine the orientation of the flake glass in the polymerized product. The flake orientation, in turn, determines the direction and degree of improvement in physical characteristics provided by the flake glass filler.
Generally, the glass flakes align in the mold with their longest dimensions parallel to the direction of flow of the liquid constituents in which they are carried. In molds for making articles with relatively thin cross sections, the flakes also become oriented with their planar surfaces parallel to the mold surfaces. Substantial reinforcement is provided by glass flake in all directions in the plane of the flake. Thus, in glass flake filled reaction injection molded panels, substantial improvement in physical characteristics is provided in all directions in the panel plane.
What may be even more significant for certain applications is the fact that glass flake filled RIM panels have much less wavy surfaces than their glass fiber-filled counterparts and do not develop waviness when thermally cycled. This means that articles such as automotive body panels can be molded, painted and installed without special finishing procedures needed to eliminate surface waviness in glass fiber filled panels. Moreover, glass flake filled panels can fill applications where unfilled panels cannot be used.
Clearly significant advantages are to be gained by incorporating glass flake as a filler in reaction injection molded plastics.
DETAILED DESCRIPTION
My invention will be better understood in view of this more detailed description.
A molding trial was conducted using glass flake filler in an otherwise conventional urethane reaction injection molding system. In the trial, flat plaques were molded from unfilled urethane, urethane filled with short lengths of milled glass fiber and flake glass.
The crosslinked urethane was the reaction product of a polyether polyol with a hydroxyl functionality greater than two and diisocyanate terminated prepolymer based on methylene diisocyanate. The polyol was NIAX D337 Resin made by Union Carbide and the isocyanate was ISONATE 143L made by Upjohn. The polyol and isocyanate were initially retained in separate pressurized agitated tanks with nitrogen or dry air blankets. These urethane forming chemicals have been used heretofore to make fiber glass filled structural panels.
The polyol and isocyanate were metered into the mixer by means of a Krauss Maffei PU80 metering machine. The unit was capable of processing the reinforcements only on the polyol side. Positive displacement piston pumps were used to eject the polyol and isocyanate into an impingement mixing chamber. The chamber itself had a cylindrical shape, the polyol and isocyanate ports being located at 90° intervals of a circumference of the cylinder in alternating order. The port of the filled polyol had a diameter of 4.2 mm and that for the unfilled isocyanate 2.0 mm. The injection pressures of the polyol and isocyanate were 2350 psi and 2200 psi, respectively. The polyol was maintained at a tank temperature of approximately 46.1° C. (115° F.) and the isocyanate at 33.9° C. (93° F.). The output capacity of the metering equipment to the mold cavity was approximately 3.5 pounds per second.
The molding machine used was a Kannegeisser Model MFT. A two-piece mold was mounted on the stationary and movable press platens. The mold had a plaque-shaped cavity with a flat surface area of 24"×42" and a thickness of 0.1 inch. The upper platen tilted away from the lower platen in the mold open position to facilitate demolding. The panel weighed about five pounds and injection time was less than 1.5 seconds to assure fill out of the panel mold and uniform distribution of the glass flake in the panel.
The mold cavity walls were coated with Green Chem MR 6023 paste and sprayed with Chem Trend XMR 136 mold release before each shot. The mold temperature was maintained at about 170°-185° F. For filled plaques a minimum mold temperature of about 180° F. was desirable to prevent skinning. The gate to the mold had an elongated slit shape which ran the length of the shorter side of the mold (approximately 16 inches).
Preparatory to molding unfilled urethane plaques, the polyol and isocyanate outputs of the RIM machine were calibrated to achieve a weight ratio of 100 parts polyol to 102.5 parts isocyanate. While this produced a relatively brittle urethane, it was suitable for comparing the properties of unfilled, glass fiber filled and glass flake filled plaques molded in like manner in the mold described above. All plaques were post cured in a flat position for 30 minutes at 250° F. to complete polymerization.
The calculation of a predetermined weight fraction filler in a molded urethane plaque was made as follows (iso refers to isocyanate): ##EQU1## Because the machine used to mold plaques could only accommodate filler on the polyol side, the weight percent filler to be dispersed was calculated as follows: ##EQU2## The ratio of filled polyol to isocyanate was then recalculated on the basis of 100 parts polyol and filler to allow for the filler in the polyol: ##EQU3##
For example, if 15 weight percent glass fiber was to be introduced into the urethane system described above at a polyol to iso ratio of 100:102.5 then ##EQU4## Then to determine the amount of glass to be mixed with the polyol constituent ##EQU5## Then to readjust the mix ratio to maintain the predetermined chemical ratio of 100 parts polyol to 102.5 parts isocyanate ##EQU6## Thus the machine was set to deliver 100 parts polyol and glass per 75.53 parts isocyanate to achieve a 15 weight percent fiber glass filler in the molded urethane article. Obviously, the calculations would be the same for glass flake, glass fiber or other solid filler.
Table I indicates the Sample Designation and number of plaques that were molded during an experimental run in accordance with the invention:
TABLE I______________________________________SAMPLEDESIG- NUMBERNATION MOLDED REINFORCEMENT/LEVEL______________________________________N- 10 UnfilledG-15 8 OCF P117B 1/16" milled glass fibers,G-25 8 15% & 25% by weight, respectively. -SG-15 10 OCF P117B Low aspect ratio milledSG-25 10 glass fibers (<1/32"), 15% and 25% by weight, respectively.F-10 10 OCF Hammermilled "C"Flakeglas-F-15 11 1/64" 10% and 15% by weight, respectively.GF #1 10 5% Flakeglas/5% P117B - 1/16"GF #2 10 5% Flakeglas/10% P117B - 1/16"GF #3 10 10% Flakeglas/5% P117B - 1/16"GF #4 11 10% Flakeglas/10% P117B - 1/16"______________________________________
Two types of fiberglass were employed. The first was OCF P117B-1/16" milled glass fibers sold by Owens-Corning. These samples are designated with a G. The glass was coated with a dispersion enhancing resin. In an effort to improve the properties of fiberglass filled RIM plaques in directions other than the flow direction in the mold, very short glass fibers were used in some of the trials. These fibers were OCF P117B screened to include particles 1/32" in length and less. These samples are designated SG for short glass.
The key constituent of the subject invention is flaked glass. (Sample designation F). Although flaked glass has been known since the mid '50's, it has heretofore not been used as a filler constituent for RIM. Flaked glass is made by melting a glass of desired chemical composition. The molten glass is then extruded through a heated annular bushing. The extrusion forms a cone-shaped glass film, generally about 2 to 10 microns thick, which is continuously pulled away from the bushing by a pair of pinch rollers. The film cools rapidly and is broken by the rollers. The broken films are hammer-milled to create small particles of "flake" glass. The individual particles resemble broken panes of window glass. Flake glass suitable for use in the subject invention is described in greater detail in "Flakeglas®-Filled Coatings: Past, Present and Future" by Dr. N. Sprecher, published by Owens-Corning Fiberglas European Operations. For the subject invention, I prefer E or C type glass particles which are less than about 8 microns thick, with an average diameter less than about 1/32". The preferred aspect ratio of flake surface area to thickness is greater than about 25:1 and preferably greater than 40:1. Larger glass particles may be used, however, they tend to be more abrasive and harder to handle in conventional reinforced RIM systems. The flake glass may be coated with silane or other dispersion enhancing coatings. However, the glass flake used in the molding trials reported herein were not so coated.
Some preliminary work has been done with silane coated glass flake. Qualitatively, it appears that the silane coating promotes rapid dispersion of the flake in polyol resin. It also seems to promote bonding between the RIM polymer matrix and the flake particles. This in turn, enhances the effect of the flake filler on the physical properties of the polymer matrix.
Physical property data and rheometic impact data were taken using standard ASTM test methods for each type of plaque from Table I. The results are shown in Tables 2 and 3. Samples designated A were cut from the 1/2 of the test plaque closest to the mold inlet runner while those designated B were taken from the half of the test plaque furthest from the inlet runner. The tests were conducted on the samples both in the direction of flow in the mold (designated parallel) and in the direction in the plane of the plaque perpendicular to the flow (designated perpendicular).
TABLE 2__________________________________________________________________________PHYSICAL PROPERTY DATA* FLEX. MODULUS. (PSI) COEFFICIENT OF ACTUAL (⊥) (∥) THERMAL EXPANSIONSAMPLE WEIGHT SPECIFIC MEAN/ MEAN/ (IN/IN × 10.sup.-6 /°F.) 3DESCRIPTION PERCENT GRAVITY STD. DEV. STD. DEV. (⊥) (∥)__________________________________________________________________________N - (A) .01 1.04 89,000/216 92,100/533 73.8 73.9N - (B) .01 1.03 91,200/244 90,300/152 73.6 73.1G15 (A) 14.3 1.11 135,000/517 187,000/295 53.3 34.4G15 (B) 16.0 1.08 153,000/378 179,000/436 51.1 33.2G25 (A) 22.9 1.19 150,000/327 299,000/404 52.3 18.0G25 (B) 24.5 1.16 158,000/862 285,000/1042 53.9 14.0SG15 (A) 15.7 1.30 175,000/349 179,000/251 46.6 59.9SG15 (B) 15.0 1.28 163,000/339 172,000/610 47.7 47.1SG25 (A) 24.7 1.33 187,000/192 208,000/492 53.0 50.1SG25 (B) 24.3 1.27 179,000/358 213,000/283 59.6 46.1F-10 (A) 8.7 1.17 155,000/329 169,000/527 50.7 48.6F-10 (B) 9.3 1.12 172,000/422 183,000/241 50.3 47.0F-15 (A) 13.5 1.16 171,000/409 196,000/303 46.0 37.5F-15 (B) 15.8 1.14 184,000/451 208,000/548 44.7 37.1GF #1 (A) 10.0 1.23 178,000/295 216,000/515 58.4 38.4GF #1 (B) 11.9 1.20 183,000/404 232,000/524 51.3 36.8GF #2 (A) 15.2 1.24 189,000/415 251,000/714 52.8 31.3GF #2 (B) 16.2 1.23 198,000/593 278,000/620 54.0 28.1GF #3 (A) 13.6 1.13 158,000/279 191,000/577 50.7 34.5GF #3 (B) 14.3 1.07 163,000/195 212,000/546 47.2 30.7GF #4 (A) 18.7 1.16 166,000/630 227,000/288 44.9 27.5GF #4 (B) 20.1 1.10 165,000/614 201,000/695 39.2 26.3__________________________________________________________________________ HEAT SAG TENSILE STRENGTH (INCHES) (PSI) % ELONGATION PERCENT (1 HOUR @ (⊥) (∥) (⊥) (∥) PARTSAMPLE 250° F.) MEAN/ MEAN/ MEAN/ MEAN/ SHRINKAGEDESCRIPTION (⊥)/(∥) STD. DEV. STD. DEV. STD. DEV. STD. DEV. (⊥)/(∥)__________________________________________________________________________N - (A) .74/.60 4090/70.9 4140/143.8 95.8/11.8 112/15.4 1.45/1.51N - (B) .79/.64 3930/156.6 3900/96.2 92.6/20.7 88.8/12.5G15 (A) .65/.28 4220/91.5 4290/126.2 35.4/10.2 23.2/6.3 .92/.60G15 (B) .65/.25 4030/143.6 4200/65.4 27/8.4 21.4/2.4G25 (A) .88/.20 4580/129.9 4940/275.4 38.8/1.9 19/5.7 .90/.28G25 (B) .91/.23 4240/64.4 5100/57.2 39/7.6 14.4/3.3SG15 (A) 2.29/2.03 5050/102.1 4890/44.4 39.6/6.2 40.2/4.2 .90/.91SG15 (B) 2.18/1.82 4880/23.9 4760/140.3 30.8/6.4 31.2/3.0SG25 (A) 1.08/.76 5220/342.6 5250/406.0 26.8/7.3 28.4/6.4 .92/.83SG25 (B) .86/.52 4810/133.9 4970/19.5 29.4/5.0 30/6.0F-10 (A) .52/.30 3370/18.7 3570/63.1 19.4/3.1 28/5.8 .95/.96F-10 (B) .61/.38 4390/97.8 4410/87.6 25.6/5.1 27.4/1.5F-15 (A) 1.10/.87 3870/39.0 3900/56.3 14.8/2.2 16.6/1.5 .90/.78F-15 (B) .72/.62 3790/57.9 3880/25.9 20.6/6.0 15.6/3.6GF #1 (A) 1.66/1.10 4500/78.0 4670/52.4 20/3.4 20.6/5.0 .95/.78GF #1 (B) 1.44/.91 4260/57.7 4500/170.9 20.2/3.8 16.2/4.1GF #2 (A) 1.65/.75 4740/287.0 4870/60.2 26.4/6.5 19.6/3.1 .90/.51GF #2 (B) 1.37/.72 4540/102.3 4900/94.8 21.4/5.7 15.6/4.3GF #3 (A) .63/.38 4040/38.3 4160/46.6 23.4/5.4 24/4.4 .90/.67GF #3 (B) .70/.51 3660/33.9 3900/41.6 26.2/2.6 22/3.7GF #4 (A) 1.03/.55 4140/63.1 4440/17.9 19.6/6.4 19.4/0.9 .77/.50GF #4 (B) .99/.45 3740/32.7 3810/242.7 18.8/4.7 16.6/3.3__________________________________________________________________________ *Tests at room temperature (˜23° C.) unless otherwise indicated.
TABLE 3__________________________________________________________________________RHEOMETRIC IMPACT TEST DATA YIELD TOTALSample Thickness Speed Force Travel Energy Travel EnergyDescription (MM) (M/S) (N) (MM) (J) (MM) (J)__________________________________________________________________________N- 2.46 2.230 2542 12.07 13.95 13.19 15.37G-15 2.63 2.230 888 3.97 1.52 18.16 8.11G-25 2.61 2.230 825 4.42 1.74 19.73 11.12SG-15 2.44 2.230 1533 6.17 4.09 17.90 11.39SG-25 2.44 2.230 1224 5.72 2.92 19.62 9.99F10 2.69 2.230 1328 6.59 3.61 17.75 10.33F15 2.59 2.230 752 3.44 1.11 18.90 7.44GF #1 2.34 2.230 952 4.71 1.83 16.86 8.80GF #2 2.43 2.230 797 3.33 1.20 19.22 8.93GF #3 2.70 2.230 828 3.72 1.36 18.29 8.70GF #4 2.81 2.230 868 4.30 1.85 18.56 9.70__________________________________________________________________________
Each Value is the average of five (5) samples tested at room temperature (˜23° C.)
M/S=Meters/Second
N=Newtons
J=Joules
MM=Millimeters
The unfilled plaques as molded had relatively low flex moduli and high coefficients of thermal expansion (CTE). They also had poor heat sag characteristics, tensile strengths, high elongations and relatively large shrinkage due to cure.
In the parts molded with 1/16" glass, the glass fibers tended to orient substantially parallel to the flow of material into the mold. Thus, the plaques showed improved flex moduli, tensile strength, and part shrinkage only in the parallel direction. However, these properties were not improved to any appreciable extent in the direction perpendicular to mold flow. They exhibited the characteristic waviness of glass fiber filled RIM panels.
Parts molded from the short glass showed no appreciable improvement in some physical properties, particularly CTE and strength.
TABLE 4__________________________________________________________________________ PERPENDICULAR PARALLEL U G-15 w/o F-15 w/o U G-15 w/o F-15 w/o__________________________________________________________________________Flex Modulus PSI × 1000 A* 89 135 171 92 187 196 B 91 153 184 90 179 208CTE (in/in × 10.sup.-6 /°F.) A 73.8 53.3 46.0 73.9 34.4 37.5 B 73.6 51.1 44.7 73.6 33.2 37.1Heat Sag (1 Hr @ 250° F.) A 0.74 0.65 1.10 0.60 0.28 0.87 B 0.79 0.65 0.72 0.64 0.25 0.62Tensile Strength A 4090 4220 3870 4140 4290 3900 B 3930 4030 3790 3900 4200 3880Percent Elongation A 95.8 35.4 14.8 112 23.2 16.6 B 92.6 27 20.6 88.8 21.4 15.6Percent Part Shrink A 1.45 .92 .90 1.51 .60 .78__________________________________________________________________________ *A indicated sample cut from half of plaque adjacent mold inlet runner. B indicates sample cut from half of plaque remote from mold inlet runner.
Table 4 sets out data taken from Table 2 for unfilled, 15% glass fiber filled (G-15%), and 15% flake glass filled (F-15%) panels for purposes of comparing their physical properties parallel and perpendicular to polymer flow in the mold. The data show improvements in modulus, reduced coefficients of thermal expansion and lowered elongation for both glass fiber and flake filled panels, especially in the parallel direction. However, only the glass flake filled sample exhibited substantial improvement of these properties in the perpendicular direction. Thus, flake glass has been shown to be superior over all to glass fiber fillers and to substantially improve the physical properties of molded RIM panels in all directions in the plane of the panel.
Examination of plaques molded from flake glass filled urethane showed that the glass flakes orient with their planar surfaces substantially parallel to the plane of the plaques. This arrangement of filler plates provides for improved properties in all directions in the plane of a panel-like part. Although other platey fillers have been tried, glass flakes have thus far been found to be the only suitable fillers for making RIM panels with surfaces good enough for enameled automotive body panels.
Automotive door and quarter panels for the Pontiac Motor Company Fiero model have been made from urethane filled with 20 to 23 weight percent glass flake (30-35 weight percent in polyol, isocyanate unfilled). The urethane system is Mobay Bayflex 110-80 which is further catalyzed with small amounts of tin and amine urethane catalysts. The door panel requires a seven pound shot, and has a finished weight of about six pounds.
The fill time for the door panel is 1.1 seconds. At injection times of 1.5 seconds all parts are scrap. Moreover, the injection pressure of both constituents must be greater than 2000 psi or there is poor mixing which results in delamination and a bad surface finish.
The flow of glass flake in the mold is restricted as soon as the isocyanate and polyol constituents gel. Gelation time for the catalyzed Bayflex system is less than two seconds. Because of this short gel time, the viscosity of the impingement mixed constituents must be closely controlled. If the viscosity of the filled polyol becomes too high poor mixing results which in turn results in bad parts.
Prior usage of glass flake filler has been restricted to slow curing epoxy systems where the liquids containing the flake can be spread and worked to accomplish flake orientation. The RIM systems of this invention do not allow such latitude. For example, the glass flake cannot be dispersed in a viscous paste injected at low pressure downstream from the impingement mixing head. Even at a distance of only a few milimeters from the mixing ports, the amine catalyzed constituents have already begun to react and gel. In such state, they could not effectively disperse a glass flake containing paste, much less fill out the mold and orient the flake particles therein. Given the many difficulties of working with highly catalyzed RIM systems, the successful incorporation of relatively high loadings of glass flake represents an inventive and unexpected advance in the art.
Another remarkable and unexpected improvement brought about by the use of flake glass filler is the complete elimination of visually unappealing surface waviness. This improvement is particularly noticeable in panels coated with glossy paint. Distinctness of image refers to the ability of a smooth, glossy surface to reflect an image without added distortion from irregularities in the coating or substrate. The glass flake filled panels (as molded) all had distinctness of image properties at least as good as glass fiber filled panels presanded to remove surface waviness. Furthermore, the glass flake filler eliminated any tendency for the RIM plaques to warp, even when thermally cycled. Even without the improved physical properties pointed out above, the unexpected but great improvement in surface waviness and warpage brought about by flake glass filler could warrant its use in RIM systems.
While my invention has been described in terms of the specific embodiment thereof, clearly other forms may be readily adapted by one skilled in the art. Accordingly, my invention is to be limited only by the following claims.
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The physical properties of reaction injection molded (RIM) polymeric articles are substantially improved by internally reinforcing them with flake glass filler particles. The flake glass is incorporated in the liquid chemical polymer precursors, and is co-injected with them into the mold. The flow of the liquids in the mold orients the glass flake to provide maximum improvement in physical properties in the hardened polymerized article. Molding with glass flake filler also substantially alleviates problems of surface waviness in RIM panels.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to material handling excavator buckets and, more particularly, to attachment assemblies for use with excavator buckets that function much like a "thumb" to enable an excavator operator to grab or grip an object between an excavator bucket and the clamping assembly, and for use with excavator buckets that function much like a "claw" to enable an excavator operator to break or rip through a hard-surfaced material.
2. Brief Description of the Prior Art
Backhoes and other similar excavator machines that employ excavating buckets have been fitted with mechanical attachments, such as clamping assemblies to enable a machine operator to grab or pickup an object by gripping the object between the bucket and the clamping assembly, or with ripping assemblies to enable a machine operator to break rip through a hard-surfaced material. Backhoe buckets typically open rearward toward the operator and are designed to be loaded toward the operator.
Clamping assemblies heretofore have been mounted to the the dipstick boom--bucket connection between the operator and the bucket so that the bucket could be pivoted outward away from the clamping assembly for positioning over an object, and so that the bucket could then be pivoted rearward toward the clamping assembly for grabbing the object. Such a clamping assembly functions much like a "thumb" to enable the machine operator to pick up an object that could not be conveniently picked up by the bucket alone. For example, where a backhoe would be employed to dig a cavity for a utility vault, with the provision of a suitable bucket clamping assembly the backhoe operator could grab the utility vault and set it into the cavity without requiring the use of other machines or equipment. Likewise, the provision of a suitable bucket clamping assembly could permit the backhoe operator to conveniently grab a boulder or other object and lift it out of the way or place it in a desired location.
Ground-breaking attachments, such as cutting or breaking "claws", have been mounted to the end of an excavator "dipstick" boom, in place of the excavator bucket assembly, so that the excavator could be employed to break up, or rip through, ground or pavement that could not be broken up by the bucket assembly by itself. For example, the ground or pavement might be too hard for a bucket, having muliple teeth that share the downward force of the dipstick action and so dissipate the breaking or cutting force of the bucket teeth. Or, the ground or pavement may have to be broken or cut along a relatively narrow path, narrower than the width of the bucket teeth so that the bucket could not be usefully employed in that case.
Bucket clamping assemblies, i.e. bucket "thumbs", that have been heretofore proposed have suffered from any one of a number of deficiencies. Some such thumbs have either required permanent mounting to the excavator bucket or have required disassembly of the bucket mounting to remove the thumb from the bucket. Other such thumbs have fixed, unalterable arrangement of pickup teeth which renders the thumb awkward or impossible to use for picking up certain kinds or shapes of objects.
Excavator breakers or rippers that have been hertofore proposed have also suffered from any one of a number of deficiencies. Substitution of a breaking or ripping "claw" for the bucket assembly can be uneconomical in that the attachment assembly for both a bucket and a cutter or breaker "claw" requires a duplication of elements. Also, having to replace the bucket with a "claw" is a time-consuming procedure.
And, heretofore, there has been no mechanically-simple attachment for an excavator bucket that could be employed to provide either a gripping "thumb" or a ripping "claw", of both.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an excavator bucket attachment assembly that can be easily installed or removed from an excavator machine without having to disassemble the bucket from the excavator machine. This attachment assembly may provide for a clamping assembly, or a ripping assembly, or both. Another object is to provide such an attachment assembly with removable gripping teeth that can be easily installed and removed without having to disassemble either the bucket or the clamping assembly from the excavator machine. Still another object is to provide such an attachment assembly with removable breaking or ripping teeth that can be easily installed and removed without having to disassemble either the bucket or the attachment assembly from the excavator machine. A further object is to provide such an attachment assembly that can be used by relatively light-weight backhoe machine buckets and that can be quickly transferred from one machine to another by a single individual. These and other objects and advantages will become apparent from the following description of the preferred embodiment of the invention.
In accordance with these objects, the invention provides an excavating bucket attachment assembly comprising mounting means including a pair of side arms and a mounting box, attaching means for attaching the side arms to an excavating bucket pivot pin without having to remove either the pivot pin or an excavating bucket to which the pivot pin is attached, and at least one elongated member, in the form of a gripping tooth or a ripping tooth, mounted in the mounting box for use in conjunction with the bucket. The mounting box comprises a transverse member providing a mounting channel that extends between the side arms with the side arms attached to the transverse member and closing off the channel at opposite ends thereof. A retaining pin removably-extends through the elongated member and through the side arms for retaining the elongated member in the channel. The assembly, when employed as a bucket "thumb", preferably includes a plurality of elongated gripping teeth, each mounted in the box by the retaining pin, and includes spacers located between adjacent members, the retaining pin extending through the spacers to hold the spacers between the members. The assembly, when employed as a bucket "claw", preferably includes one or more elongated ripping teeth, each mounted in the box by the retaining pin. The assembly attaching means includes a pair of collars constructed to fit over ends of the pivot pin with the pivot pin protruding beyond the collars, the collars each being provided with at least one threaded bolt hole. The side arms are each provided with a forked end defining a slot and at least one bolt hole so that the slots of the side arms may be inserted over the ends of the pivot pin adjacent to one of the collars and so that the side arm bolt hole could be aligned with the threaded hole in the adjacent collar and fastened thereto by a bolt inserted into both aligned holes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a backhoe excavator dip stick with a bucket mounted thereon and with the "thumb" assembly of the present invention mounted to the bucket;
FIG. 2 is a perspective view from the rearward, bucket-cavity end of the FIG. 1 apparatus, illustrating the removal and insertion of gripping teeth for the bucket thumb assembly of this invention;
FIG. 3 is a perspective view from the same perspective as in FIG. 2 illustrating the thumb assembly fitted with a full complement of gripping teeth;
FIG. 4 is a side perspective view of the FIG. 1 apparatus illustrating the use of the thumb assembly of this invention to pick up a boulder or other object;
FIG. 5 is a partial side elevation view of one of the thumb assembly bucket mounting arms and the mounting arrangement for the thumb assembly's gripping teeth;
FIG. 6 is a cross-section view taken along the line 6--6 of FIG. 5 illustrating the mounting sub-assembly for mounting the thumb assembly bucket mounting arms to the excavator bucket mounting;
FIG. 7 is a perspective view of a backhoe excavator dip stick with a bucket mounted thereon and with the "claw" assembly of the present invention mounted to the bucket; and
FIG. 8 is a partial view in side elevation of the FIG. 7 bucket and a ripping claw, illustrating the relationship between the bucket teeth and the claw.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, an excavator machine, such as a backhoe, is provided with an articulated boom arrangement 10 that has an outer end extension 12 often named a "dipstick." Dipstick 12 is fitted with a rearwardly-opening excavating bucket 14 that is pivotally mounted to the outer end of the dipstick 12 by means of a main pivot pin 16. Pin 16 extends through mounting lugs appropriately connected to the bucket and also extends through appropriate mounting bushings provided on the end of the dipstick. In a typical backhoe configuration, appropriate bucket pivoting linkages 18 connected to mounting lugs 20 on the bucket and to the dipstick 12 permit the to be pivoted forward and backward by means of a hydraulic cylinder 22 under the control of the backhoe operator.
Continuing to refer to FIG. 1, the bucket thumb assembly 30 of this invention comprises mounting frame 32 pivotally mounted to the bucket pivot pin 16, several gripping teeth 34 removably-mounted to mounting frame 32, and a positioning arm 36 that is pivotally connected at each end to the mounting frame 32 and to the dipstick 12. The positioning arm 36 is illustrated as a telescopically adjustable tube-in-a-tube that is pinned to the mounting frame 32 by a pin 38 that extends through mounting lugs 40 connected to the frame 32, and that is pinned to the dipstick 12 by a pin 42 that extends through mounting lugs 44 connected to the dipstick 12. Positioning arm 36 is manually adjustable to position the thumb assembly 30 in a desired position relative to the dipstick 12 and held in that position by a positioning pin 46. Pin 46 extends through both telescopic parts 35, 37 positioning arm 36 to hold the parts in their respective positions. The positioning arm function could just as conveniently be provided by a hydraulic cylinder operated from the backhoe operator's cab; although the mechanical arm illustrated is a less expensive alternative. The positioning arm or its equivalent provides a "stiff link" to hold the desired position of the thumb assembly against the forces to which it would be exposed during use.
Now referring in particular to FIGS. 1 and 2-6, the thumb assembly mounting frame 32 comprises, looking forward from the rear toward the bucket cavity, a left and right mounting arms 50, 52, left and right bucket mounting collars 54, 56, a teeth mounting box 58, a teeth retaining pin 60, and teeth separating sleeves 62. Mounting collars 54, 56 are inserted on the ends of the bucket mounting pin 16 outside of the bucket mounting lugs 14a, as seen in FIG. 6, on ball-bearing bushings 55. Mounting collars 54, 56 are retained on pin 16 by slip rings 53 fitted onto pin 16 on their outer sides so that they are confined against the bucket mounting lugs. Each mounting collar 54, 56 is provided with three threaded bolt holes 57 (two being shown in FIG. 6) for bolts 59. The outer ends 50a, 52a of mounting arms 50, 52 are forked so as to provide each with a U-shaped channel having a width and a semicircular bottom diameter slightly larger than the diameter of bucket mounting pin 16. The bucket mounting pin 16 extends outward far enough on each side of the bucket sidewalls so that the forked ends 50a, 52a of mounting arms 50, 52 can be inserted over the outer ends of the pin, as seen in FIG. 6. The forked ends are provided with three bolt holes 61 to fit the bolt hole pattern in the mounting collars 54, 56. When the forked ends are inserted over the pin 16 so that the bottom ends of their respective U-shaped channels are seated against the pin 16, as shown in FIGS. 5-6, the mounting arms 50, 52 can be rotated to line up their bolt holes so that bolts 59 can be inserted and threaded into threaded holes 57, thereby fastening the mounting arms 50, 52 to the adjacent mounting collars 54, 56. The mounting arms 50, 52 are attached to the teeth mounting box 58 and aligned parallel to one another so that the entire sub-assembly of the mounting arms+mounting box can be laterally shifted into and out of engagement with the outer ends of the bucket mounting pin 16. The open-ended forks of the mounting arms enable this sub-assembly to be moved laterally into and out of engagement with the ends of pin 16 to attach or detach the thumb assembly 30 to the pin 16.
Various excavator bucket designs will have different configurations for mounting the bucket 14 to the dipstick 12. Some typically employ separate mounting lugs that are welded to the bucket casing at appropriate locations. However in all cases, the bucket design will include a main pivot pin, such as pin 16 for the present invention, by which the bucket is pivotally mounted to the end of the dipstick. However, in any given bucket design, the thumb assembly of this invention will provide side mounting arms 50, 52 that will be configured to mount to the ends of the main bucket pivot pin-however that pin is positioned -so that the sub-assembly of the mounting arms+teeth box can be laterally shifted into and out of engagement with the ends of the main pivot pin.
Now referring in particular to FIGS. 2-3 and 5, the teeth mounting box 58 of the thumb assembly mounting frame 32 comprises an elongated channel provided by inner and outer side walls and inner bottom wall, 58a, 58b and 58c. The ends of the channel are closed by the mounting arms 50, 52. The inner wall 58a extends rearward at an oblique angle from the inner bottom wall 58c; an oblique angle "A" of about 105° (see FIG. 5) would be suitable to help keep the teeth stably positioned within the mounting box. The outer wall 58b extends rearward at a right angle from the inner bottom wall 58c. Thus, the cross-section of the channel is that of a trapezoid.
Each tooth 34 is provided with a mounting end that is configured to closely fit within the mounting box channel as seen in FIG. 5, with the tooth outer and inner edges conforming to the box walls 58a, 58b as shown. The mounting ends of each tooth 34 are also provided with shaft holes 34a for receiving pin 60 as shown in FIGS. 2 and 5. When the teeth 34 are inserted into the mounting box 58, their mounting ends secure the teeth in alignment with one another and also provide a stabilizing mounting to hold the teeth in position against lateral forces that the teeth incur during use. The pin 60 is inserted also through corresponding holes 63 in the mounting arms 50, 52 so that the teeth 34 are stably mounted in the mounting box 58. Mounting box 58 and mounting arms 50, 52 are steel members welded together so that the lower ends of the mounting arms 50, 52 extend beyond the mounting box for receipt of the teeth retaining pin 60.
Several teeth 34 (four being shown in FIG. 3) are mounted by pin 60 and are spaced apart by spacing sleeves 62. Typically the spacing between teeth would be arranged so that the bucket teeth 14b would pass on either side of a thumb tooth 34 when the bucket was closed completely against the thumb assembly. The bucket teeth 34 could be spaced in some other pattern if desired. For example, if a backhoe bucket having the thumb assembly of this invention mounted thereon were to be used to grab and lift a number of objects of a uniform profile, such as utility vaults or pipe, etc., the profile of the teeth could be specially designed to accommodate the profile of the objects to be lifted and the spacing between the teeth 34 could also be designed to best accommodate the profile of those objects. A typical tooth profile is illustrated in FIGS. 1 and 4 for general work wherein the teeth are curved with their concavity facing the bucket cavity. FIG. 4 illustrates the bucket+thumb assembly applied to a boulder for lifting and moving. The teeth could be fashioned to be L-shaped, for example, facing the bucket cavity for engaging a corner of some rectangular object. Because the teeth can be easily and quickly removed and changed, by removing the pin 60, without affecting the bucket 14 or the thumb assembly mounting frame 32, the appropriately-configured teeth could be provided for any given job requirement.
If it is desired to remove the thumb assembly from the excavating bucket 14, the three bolts 59 on each side of the mounting arms 50, 52 would be removed and the assembly would be shifted downward and out of engagement with the bucket main pivot pin 16. The positioning arm 36 would be removed by pulling pin 42, either before or after the detachment of the mounting arms 50, 52 from the pivot pin 16, and the thumb assembly would thus be freed from the machine. It is a distinct advantage of the present invention that neither the bucket itself or its mounting need to be tinkered with or affected when the thumb assembly is attached or detached from the machine. For shipping purposes, once the positioning arm 36 has been removed from the machine, the two parts 35, 37 could be unpinned from one another and the two could be telescoped together and repinned to a shorter length. The collars 54, 56 would remain on the ends of the pivot pin 16 so that the mounting arms forked ends could be quickly and easily shifted over the pivot pin ends and aligned with the bolt holes in the collars.
With reference to FIGS. 7 and 8, an excavator machine, such as a backhoe, is provided with an articulated boom arrangement 110 that has an outer end extension 112 often named a "dipstick." Dipstick 112 is fitted with a rearwardly-opening excavating bucket 114 that is pivotally mounted to the outer end of the dipstick 112 by means of a main pivot pin 116. Pin 116 extends through mounting lugs appropriately connected to the bucket and also extends through appropriate mounting bushings provided on the end of the dipstick. In a typical backhoe configuration, appropriate bucket pivoting linkages 118 connected to mounting lugs 120 on the bucket and to the dipstick 112 permit the to be pivoted forward and backward by means of a hydraulic cylinder 122 under the control of the backhoe operator.
Continuing to refer to FIGS. 7 and 8, the bucket claw assembly 130 of this invention comprises mounting frame 132 pivotally mounted to the bucket pivot pin 116, at least one ripping tooth 134 removably-mounted to mounting frame 132, and a positioning arm 136 that is pivotally connected at each end to the mounting frame 132 and to the dipstick 112. The positioning arm 136 is illustrated as a telescopically adjustable tube-in-a-tube that is pinned to the mounting frame 132 by a pin 138 that extends through mounting lugs 140 connected to the frame 132, and that is pinned to the dipstick 112 by a pin 142 that extends through mounting lugs 144 connected to the dipstick 112. Positioning arm 136 is normally free to telescopically adjust its length, but it may be manually adjustable to position the thumb assembly 130 in a desired position relative to the dipstick 112 and held in that position by a positioning pin 146. Pin 146 may be extended through both telescopic parts 135, 137 positioning arm 36 to hold the parts in their respective positions. The positioning arm function could just as conveniently be provided by a hydraulic cylinder operated from the backhoe operator's cab; although the mechanical arm illustrated is a less expensive alternative. The positioning arm or its equivalent provides a "loose link" to permit the position of the claw assembly to be freely adjustable or, alternately, to provide a "stiff link" to hold a desired position of the claw assembly.
Still referring in particular to FIGS. 7 and 8, the claw assembly mounting frame 132 comprises, looking forward from the rear toward the bucket cavity, a left and right mounting arms 150, 152, left and right bucket mounting collars (right bucket mounting collar 156 being shown), a ripper tooth mounting box 158, and a tooth retaining pin 160. Mounting collars are inserted on the ends of the bucket mounting pin 116 outside of the bucket mounting lugs 14a (as seen in FIG. 6) on ball-bearing bushings 55. The mounting collars are retained on pin 16 by slip rings 53 fitted onto the pin (as seen in FIG. 6) on their outer sides so that they are confined against the bucket mounting lugs. Each mounting collar is provided with three threaded bolt holes (two being shown in FIG. 6) for bolts 159. The outer ends of the mounting arms (as seen in FIG. 5) are forked so as to provide each with a U-shaped channel having a width and a semicircular bottom diameter slightly larger than the diameter of bucket mounting pin 16. The bucket mounting pin 116 extends outward far enough on each side of the bucket sidewalls so that the forked ends of the mounting arms can be inserted over the outer ends of the pin (as seen in FIG. 6). The forked ends are provided with three bolt holes to fit the bolt hole pattern in the mounting collars. When the forked ends are inserted over the pin 16 so that the bottom ends of their respective U-shaped channels are seated against the pin 16 (as shown in FIGS. 5-6) the mounting arms can be rotated to line up their bolt holes so that bolts 159 can be inserted and threaded into threaded holes in their respective mounting collars, thereby fastening the mounting arms to the adjacent mounting collars. The mounting arms 150, 152 are attached to the tooth mounting box 158 and aligned parallel to one another so that the entire sub-assembly of the mounting arms+mounting box can be laterally shifted into and out of engagement with the outer ends of the bucket mounting pin 116. The open-ended forks of the mounting arms enable this sub-assembly to be moved laterally into and out of engagement with the ends of pin 116 to attach or detach the claw assembly 130 to the pin 116.
Now, still referring in particular to FIGS. 7 and 8, the tooth mounting box 158 of the claw assembly mounting frame 132 comprises an elongated channel provided by inner and outer side walls and bottom wall, 158a, 158b and 158c. The ends of the channel are closed by the mounting arms 150, 152. The inner wall 158a extends rearward at an oblique angle from the bottom wall 158c; an oblique angle "A" of about 105° (see FIG. 5) would be suitable to help keep the teeth stably positioned within the mounting box. The outer wall 158b extends rearward at a right angle from the inner bottom wall 158c. Thus, the cross-section of the channel is that of a trapezoid.
The ripper tooth 134 is provided with a mounting end that is configured to closely fit within the mounting box channel as seen in FIG. 8, with the tooth outer and inner edges conforming to the box walls 158a, 158b as shown. The mounting ends of the tooth 134 are also provided with a shaft hole for receiving pin 160 as shown in FIG. 8. When the tooth 134 is inserted into the mounting box 158, its mounting end secures the tooth and also provides a stabilizing mounting to hold the tooth in position against lateral forces that the tooth incurs during use. If more than one ripping tooth 134 is provided, when the teeth are inserted into the mounting box 158 their mounting ends secure the teeth in alignment with one another, also. The pin 160 is inserted also through corresponding holes in the mounting arms 150, 152 so that the tooth 134 is stably mounted in the mounting box 158. Mounting box 158 and mounting arms 150, 152 are steel members welded together so that the lower ends of the mounting arms 50, 52 extend beyond the mounting box for receipt of the tooth retaining pin 160.
The single ripper tooth 134 shown in FIGS. 7 and 8 is mounted between the mounting lugs 140 and therein confined and stabilized against lateral forces. In a typical installation, the location of the tooth 134 between the mounting lugs 140 would enable the tooth 134 to pass between two bucket teeth 114b to bear against the excavating edge 114c of the bucket 114 (as seen in dotted line in FIG. 8). If more than one ripper tooth 134 is to be installed, additional such teeth would be mounted on either side of the mounting lugs 140, in much the same fashion as the mounting of the gripping teeth shown in FIGS. 2 and 3, the several teeth being mounted by pin 160 and spaced apart by spacing sleeves. Typically the spacing between teeth would be arranged so that the bucket teeth 114b would pass on either side of a thumb tooth 134 when the bucket and bear against the bucket excavating edge 114c.
A typical tooth profile is illustrated in FIGS. 7 and 8 for general ripping work wherein the tooth is provided with a pointed ripping edge 134a extending below the bucket excavating edge 114c (shown in dotted line in FIG. 8) are curved with their concavity facing the bucket cavity. Because the teeth can be easily and quickly removed and changed, by removing the pin 160, without affecting the bucket 114 or the claw assembly mounting frame 132, the appropriately-configured teeth could be provided for any given job requirement.
If it is desired to remove the claw assembly from the excavating bucket 114, the three bolts 159 on each side of the mounting arms 150, 152 would be removed and the assembly would be shifted downward and out of engagement with the bucket main pivot pin 116. The positioning arm 136 would be removed by pulling pin 142, either before or after the detachment of the mounting arms 150, 152 from the pivot pin 116, and the claw assembly would thus be freed from the machine. It is a distinct advantage of the present invention that neither the bucket itself or its mounting need to be tinkered with or affected when the thumb assembly is attached or detached from the machine. For shipping purposes, once the positioning arm 136 has been removed from the machine, the two parts 135, 137 could be unpinned from one another and the two could be telescoped together and repinned to a shorter length. The mounting collars would remain on the ends of the pivot pin 16 so that the mounting arms forked ends could be quickly and easily shifted over the pivot pin ends and aligned with the bolt holes in the collars.
In the case of retrofitting an existing excavator bucket with the thumb assembly or with the claw assembly of this invention, it may be the case that the main bucket pivot pin provided with the bucket is not long enough for the ends to be exposed for attachment of the thumb or claw assembly. In this case, the main bucket pivot pin would be replaced with another pin of the same diameter and strength, only one that is long enough to protrude beyond the bucket mounting lugs (or their equivalent) so that the thumb or claw assembly could be installed as described above. The replacement pivot pin would thereafter remain a permanent part of the bucket installation; the added length of the replacement pivot pin would not be a detriment to the satisfactory operation of the excavating machine when the thumb or claw assembly is removed. The internal design of the main bucket pivot pin, such as pin 16 or 116, is such that the collar bushings 55 can be lubricated through grease fittings on the pin itself by way of internal lubricating passages in the pin.
All of the elements described above with respect to the embodiments, regarding the clamping assembly of FIGS. 1-6 and the claw assembly of FIGS. 7-8, are illustrated as being the same for each embodiment, except for the teeth 14 or 114. In the case of the clamping assembly embodiment of FIGS. 1-6, the gripping teeth 14 are configured for operating in opposition to the bucket 14 and bucket teeth 14a so that the entire combination functions as a clamp. In the case of the claw assembly embodiment of FIGS. 7-8, the single (or multiple) tooth 114 is configured to be engaged by and operate in cooperation with the bucket 114 and the bucket excavating edge 114c. Because the remaining elements of the embodiments are the same, a single system can be used as both a clamping system and a ripping system, simply by changing the teeth 14, 114.
In the case of the clamping assembly of FIGS. 1-6, the stiff link provided by the bolted tubes 35, 37 and pin 46 of the positioning arm 36 is adjusted to position the clamping teeth 14 in the desired relationship to the dipstick boom 12 to accomplish the lifting or moving task at hand; the position of the clamping teeth 14 being adjustable be telescoping adjustment of the arm 36. In the case of the claw assembly of FIGS. 7-8, however, the tubes 135, 137 would not be pinned to a fixed position, so that the positioning arm 136 would be free to telescopically adjust inward or outward; the position of the ripper tooth 114 being controlled by the position of the bucket 114 and its excavating edge 114c.
In the case of the claw assembly of FIGS. 7-8, a hard-surfaced material could be broken or ripped up by lowering the bucket until the ripper tooth end 134a engaged the surface to be broken or ripped. Then the bucket could be pivoted or carried rearward, causing the tooth 114 to be assume the dotted line position shown in FIG. 8 to abut the bucket excavating edge 114c. Further rearward movement of the bucket 114 would carry the tooth 114 rearward also, the tooth ripping end 134c being supported by the bucket excavating edge 114c. Because the ripping end 134c extends below the bucket teeth 114b, the tooth can rip into the surface or object below the bucket 114 to the depth of the ripping end 134c. In a typical application of the claw assembly embodiment of this invention, the ripper tooth 114 would be fabricated of a size such that its weight would cause it to hang substantially vertically downward from its point of suspension by pin 116. Therefore, as long as positioning arm 136 is free to telescope inward and outward, the ripper tooth 114 will always tend to return to a near-vertical position whenever the bucket 114 is pivoted forward. Consequently, the ripper tooth 114 is self-positioning to return to a ripping position with every bucket pivoting cycle during a ripping operation. In a preferred configuration of the ripper tooth 114, in profile it would have a curved, concave configuration facing rearward, the reverse of that shown in FIG. 1 with respect to the clamping teeth 14. The relatively straight-edged profile of tooth 114 shown in FIGS. 7-8 serves to illustrate the relations between the various elements.
In an alternate embodiment of the claw assembly of FIGS. 7-8, the ripper tooth 134 could be aligned with the bucket teeth 114b so that it would bear against one of the bucket teeth 114b, rather than extend between the bucket teeth to engage the bucket excavating edge 114c. In this embodiment, the operative ripping position of the ripper tooth 134 would that position shown in solid line in FIG. 8. In this position, the ripper tooth 134 and the bucket teeth 114b could operated together in a digging operation; tooth 134 first ripping into the hard-surfaced material and then the bucket teeth 114c digging further into the ripped open surface, all with one pivoting or scooping action of the bucket 114.
When it is desired to remove the claw assembly tooth 134 from its operative ripping position, the positioning arm 136 could be telescoped together to cause the claw assembly 130 to be pivoted upward and rearward underneath the dipstick boom 112 and stored in that retracted position by pinning the tubes 137, 137 in that retracted position with pin 146.
While the preferred embodiment of the invention has been described herein, variations in the design may be made. The scope of the invention, therefore, is only to be limited by the claims appended hereto.
The embodiments of the invention in which an exclusive property is claimed are defined as follows:
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An excavating bucket attachment assembly comprises a pair of side arms and a tooth-mounting box mountable to an excavating bucket pivot pin without removing either the pivot pin or an excavating bucket to which the pivot pin is attached, and at least one tooth mounted in the tooth-mounting box. The tooth-mounting box comprises a transverse member providing a teeth-mounting channel that extends between the side arms with the side arms attached to the transverse member and closing off the channel at opposite ends thereof. A tooth retaining pin removably-extends through the tooth and through the side arms for retaining the tooth in the channel. The assembly may includes a plurality of clamping teeth, each mounted in the box by the retaining pin, and includes spacers located between adjacent teeth, the retaining pin extending through the spacers to hold the spacers between the teeth. Alternately, the assembly may include a ripping tooth mounted in the box by the retaining pin. The assembly also includes a pair of collars constructed to fit over ends of the pivot pin with the pivot pin protruding beyond the collars. The side arms are each provided with a forked end defining a slot that may be inserted over the ends of the pivot pin adjacent to one of the collars and fastened thereto.
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BACKGROUND OF THE INVENTION
The invention relates to a nut unit for use in a ball screw drive, comprising a sleeve-shaped nut body that is made of an essentially rigid material and that has an axis and an inner circumferential surface, wherein a one-piece, ball-guiding helix of strip material—which is channel-shaped as viewed in transverse cross-section—is arranged on the inner circumferential surface of the nut body, wherein the helix of strip material is attached to the inner circumferential surface of the sleeve-shaped nut body by a convexly curved external profile, the latter being embodied with external profile flank regions and an external profile crown region, and the helix defines, by means of a concavely curved internal profile facing the axis, a ball channel with an internal profile base region and two internal profile flank regions.
In order to form a ball race, it is known from DE 27 32 896 C2 to apply to the inner circumferential surface of a sleeve-shaped nut body a channel-like, profiled metal strip which is rigidly attached along its entire length to the inner circumferential surface of the nut body. The flanks of the metal strip extend out into the central space of the nut body, which is to say that they are not supported outside of the base region. Moreover, known from DE 27 32 896 C2 is an embodiment (see FIG. 3) wherein a profiled metal strip is attached by vulcanization to the inner circumferential surface of a bushing made of elastically deformable material. The subject there is thus not a nut body of an essentially rigid material, but of an elastically deformable material.
It is known from DE 28 05 141 to cut a helical profiled groove in the inner surface of a sleeve-shaped nut body and to allow the balls of a continuous set of balls to run directly in this profiled groove on the nut side. In this connection, high demands are placed on the profiled groove with respect to the surface characteristics of the bearing race region, in particular with respect to hardness and smoothness.
In order to create a helicoid profiled groove on the inner circumferential surface of a nut body, it is known from DE 30 28 543 to lay a round wire helix on the inner circumferential surface of a nut body and to arrange it in a helicoid manner by means of ribs on the inner circumferential surface of the nut body. Therein, the balls of an associated ball set each run between two adjacent turns of the round wire. It is further known from DE 30 28 543 to form a cylindrical tube into a screw-like helix to form a nut unit and to slit this tube on the inner side of the helix, so that the balls of a ball set carried in the tube can project radially inward and engage the threads of a spindle.
SUMMARY OF THE INVENTION
In contrast, it is proposed in accordance with the invention that the outer profile flank regions of the strip material helix be essentially rigidly supported by a support profile of a support groove formed in the inner circumferential surface of the nut body.
The following is achieved by the arrangement in accordance with the invention, in contrast to the state of the art discussed above: in comparison to the first embodiment per DE 27 32 896 C2, an increased stiffness is achieved. Owing to the support by the support groove in the external profile flank regions, deformation of the strip material is in any case largely suppressed if not completely precluded. The strip material can neither tip nor be bent. On the other hand, the surface of the strip material helix in the region of the concavely curved internal profile of the support groove can be finished with respect to hardness and smoothness prior to the installation of the strip material helix in the nut body, and if desired at the strip material itself prior to its forming or at least prior to its final shaping. This has particularly great importance when large thread pitches are required for the ball nut, a requirement that is occasionally present in the case of machine tools in order to be able to increase the feed rates without having to raise the spindle speed to levels that are critical in terms of bending. When large nut thread pitches are required, it becomes increasingly difficult to perform smoothing operations, in particular grinding, on the finished threads as the pitch increases.
Also in contrast to the second embodiment per DE 27 32 896 C2, wherein the metal strip is attached by vulcanization to the inner circumferential surface of a bushing of elastically deformable material, the embodiment in accordance with the invention provides the important advantage, owing to the essentially rigid support of the external profile flank regions by the support profile of the support groove, that the strip material can neither tip nor be bent and cannot yield in any other way, which is precisely the goal of the known embodiment with respect to the change in pitch that is striven for therein.
In contrast to the known embodiment per DE 28 05 141, the effect is achieved that surface treatment with regard to hardness and smoothness in the ball race is possible without regard to the thread pitch, because smoothing and hardening treatments are possible before installation in the nut body and even before shaping of the strip material helix, but in any case prior to its final shaping.
In contrast to the first-described known embodiment per DE 30 28 543 A1, wherein balls are guided on the nut body between two adjacent turns of the round wire helix, the advantage is achieved that balls are guided on the nut body by a one-piece channel profile, resulting in a better and easier to manufacture precision and in higher load capacity. In contrast to the further embodiment described in DE 30 28 543 A1, wherein balls are guided in a tube that is rolled into a spiral and cut on the inside of the spiral, the advantage of increased stiffness is again achieved owing to the support of the external profile flank regions by the support profile of the support groove.
The proposed invention can in particular find application when the concavely curved internal profile is shaped such that balls of an associated ball set of predetermined nominal diameter run on bearing race tracks of the internal profile flank regions, each of which bearing race tracks lie within a track region of the relevant internal profile flank region. In such an embodiment of the ball channel, the strip material helix is stably supported by the support of its external profile flank regions by the support profile of the support groove at or in the immediate vicinity of the bearing race track and/or the bearing race tracks that are possible as a result of altering the ball diameter, so that maximum stiffness of the ball screw drive can be achieved.
When reference is made to a track region, in particular that track region is meant that is determined by the possible bearing race tracks which result from a group of ball sets with nominal diameters graduated from ball set to ball set that are available to set a specific preload range for the ball screw drive. In this connection, the nominal diameter in each case determines the “pressure angle” (defined hereinafter).
A first embodiment of the invention resides in that a support—based on physical contact—of an external profile flank region on the support profile of the support groove extends over a contact zone corresponding approximately to the total extent of the track region along the curved internal profile and—if desired—extends beyond the borders of the track region. In this first embodiment, all conceivable bearing race tracks that result from changing the nominal ball diameter are supported directly and free of bending on the back side, which is to say in the external profile flank region, so that optimal stiffness is achieved. However, in this embodiment a relatively high precision is demanded in the manufacture of the external profile flank regions and the support profile.
In accordance with a second embodiment of the invention, provision is made for the support, based on physical contact, of an external profile flank region on the support profile of the support groove to be limited to contact zones that correspond to boundary zones of the associated track region and that are spaced from each other in the direction of curvature of the curved external profile and that —if desired—extend beyond the boundary zones of the track regions. In this second embodiment, the support of each external profile flank region is accomplished in the manner of or similar to a two-point support, each approximately in the boundary zones of the associated track region. One can say that the channel-shaped strip material helix, viewed in cross-section, forms an essentially rigid bridge across an interruption of the physical support. An adequately rigid support can be reckoned with in this embodiment as well when the strip material wall thickness and the spacing of the contact zones are appropriately matched.
In both embodiments a stable support of the channel-shaped strip material helix is provided independent of the particular pressure angle (defined hereinafter).
It is possible that the convexly curved external profile and/or the support profile of the support groove extend essentially without kinks at least over the length of the associated track region. However, it is also possible that the convexly curved external profile and/or the support profile are polygonal or polylobal, at least over the length of the associated track region. In both possible cases, either full-area support over the entire track region or bridge-like support can be chosen.
With regard to the achievement of improved fitting of the relevant balls against the internal profile flank regions, a preferred embodiment resides in that the internal profile curve is essentially ogival in shape at least in its internal profile flank regions. Provision is advantageously made herein that the concavely-curved internal profile and the convexly curved external profile are essentially equidistant at least over the length of the internal profile flank regions of the curved internal profile. The latter measure achieves the result that when manufacturing the strip material helix one can start with a plane parallel or approximately plane parallel flat strip, and the strip material helix receives a channel-shaped cross-section with a minimum of forming work.
With regard to simplification of the forming work during manufacture of the channel-shaped helix of strip material, and also to the placement of the strip material helix on the support profile, it can be advantageous if the strip material in the base region of the concavely curved internal profile is weakened about a base centerline with regard to the bending section modulus. This weakening of the bending section modulus can be achieved, for example, in that the strip material has a recess in the base region of the curved internal profile. The recess can be formed as early as during fabrication of the strip material or can be formed thereupon later, for example with an ogival profile. However, it is also possible to generate the recess during the course of rolling a flat strip into channel profile. Weakening of the bending section modulus facilitates shaping of the channel-shaped helix of strip material into its final form, thus ensuring that the critical surfaces for the ball race and for supporting the channel-shaped helix of strip material can be fabricated with high precision.
Additional measures can be taken to ensure that the strip material in the direction of the convexly curved external profile is secured against shifting in position relative to the support profile, at least along the length of the track region. Thus it is possible, for example, for the strip material to be glued to the support profile. In this event, the adhesive layer can also perform an equalizing function between the strip material and the support profile. Of course, in the event that the adhesive layer is assigned an equalizing function, it is desirable to ensure that the adhesive layer possesses adequate indentation hardness so that deformability of the adhesive layer does not jeopardize the stiffness of the ball screw.
The additional securing of the strip material can also be achieved in that the edges of the strip material that are distant from the base region are fixed to the nut body—if desired under preloading—through positive locking. Such positive locking can be produced by means of recesses in the strip material on its edges distant from the base region. Furthermore, positive locking can be produced by caulking the nut body in the vicinity of the edge regions of the support profile. It is beneficial for the stiffness of the ball screw drive if the strip material is pressed radially outward into the support profile along the entire course of its helix. Some of the pressure can be applied by the balls when they are subjected to preloading between the spindle and the strip material helix, a preloading which in turn is beneficial for the stiffness of the ball screw drive. However, it is also possible for the strip material to be pressed against the support profile of the support groove of the nut body under radial preloading independently of the preloading of the balls, in particular owing to radial overdimensioning of the helical strip material prior to installation in the support groove.
At least in its layer near the inner circumferential surface, the nut body can be made of metal, preferably steel. In this event, the customary thread cutting processes may be used to manufacture the helical support groove.
At least in a layer near the curved internal profile, the strip material helix can be made of metal, preferably steel. Fabrication of the strip material helix out of a flat strip by producing the channel cross-section and by subsequent winding can take place on a conventional spring coiling machine. It is possible for the production of the channel and the winding to take place simultaneously in one step, or to be performed one immediately following the other. Rolling of the recess in the base region can also be included in this step as a preliminary stage.
The support groove on the inner circumferential surface of the nut body can be produced through a thread-cutting process and left essentially without finishing by hardening and grinding. Therein lies a substantial advantage of the invention: if neither hardening nor smoothing of the nut body is necessary after thread cutting, because hardening and/or smoothing is done on the strip material or the partially or fully shaped helix of strip material, the overall fabrication of the nut unit is substantially simplified, in particular for the case of large thread pitch addressed above. This is surprising inasmuch as one could assume in principle that the simplest and most precise manufacture of the ball nut unit would be obtained if one were to simply cut a thread suitable for direct ball guidance in the inner circumferential surface of a ball nut blank.
With regard to minimization of wear and also high carrying power of the spindle screw drive, the helix of strip material should be hardened at least in one layer near the curved internal profile, where it should be hardened at least in the vicinity of the bearing races. This hardening can be done in a simple way prior to installation of the strip material helix in the nut body. In order to have available the most ductile possible strip material when shaping the channeled strip material helix, it is recommended that hardening be done after shaping of the strip material helix is completed or at least partially completed.
With regard to smooth ball travel, and also with regard to high stiffness and machining precision of the ball screw drive, it is desirable for the strip material helix to be smoothed at least in the track region. What is special about the invention in this regard is that the smoothing does not necessarily have to take place after installation of the strip material helix in the support groove, which—as already mentioned—is difficult, especially when the pitch of the strip material helix is great. Instead, it is possible to undertake the necessary smoothing operations on the intermediate product, for example during fabrication of the strip or when shaping the channel profile, or when winding the strip material into a helix. The smoothing can be achieved more particularly by a rolling treatment, which preferably can take place before any hardening in order to have the advantage during the smoothing process as well of the higher ductility of the material to be worked.
When manufacturing the nut unit in accordance with the invention, it is possible to proceed in that one introduces into an unhardened, sleeve-shaped nut body blank a helical support groove with a support profile using a thread-forming process, in that one forms a strip material into a channel-shaped strip material helix with a smooth surface, at least in the track regions of the internal profile flank regions, and in that one introduces the strip material helix into the helical support groove. The advantage of this process is that a nut unit is manufactured for a stiff ball screw drive with high surface quality of the ball races, even if the machining circumstances are unfavorable, for example because of large pitch for the threads. The strip material helix can be obtained by rolling an initially essentially flat, straight steel strip into an essentially straight channel profile, and subsequently winding the channel profile into a strip material helix.
Hardening of at least the track regions can be done preferably after the formation of the channel profile and the winding process, and preferably before introduction into the helical support groove; conventional processes, for example inductive hardening (penetration hardening) or case-hardening (surface hardening), may be used.
A smoothing treatment can be undertaken more simply before the geometry of the strip material helix has been finalized, for example by means of a rolling treatment before or during formation of the channel-shaped strip material helix.
When manufacturing the strip material helix, it is possible to start with flat strip material or strip material in roll form, which, in the base region, is weakened about a base centerline with regard to the bending section modulus.
The strip material used to form the helix can be produced through drawing or rolling or cutting.
The support profile can be produced using a conventional thread-forming process, more particularly thread cutting process. Subsequent hardening or smoothing of the support profile is not necessary.
The nut unit in accordance with the invention can be equipped with ball sets of different nominal diameters. When this is done, it is desirable to observe the following: the starting point for assembling a ball screw drive or ball screw is the desired preloading of the balls between the spindle and nut unit. The nominal diameter for the balls is a result of the actual dimensions of the spindle bearing race and nut bearing race. If one selects a certain nominal diameter for the balls of the ball set in question based on a certain preloading of the balls, a certain pressure angle ensues. The pressure angle is defined as the angle between a reference plane perpendicular to the axis and a ray from the ball mid-point to the contact point between the ball and race. Of course, the pressure angle also depends upon the manufacturing precision of the spindle and nut. If one wishes to select different preloading stages, one must work with ball sets whose balls accordingly have different nominal diameters. Different pressure angles ensue accordingly.
BRIEF DESCRIPTION OF THE DRAWINGS
The attached figures illustrate exemplary embodiments of the invention, in which:
FIG. 1 is an axial cross-section through a nut unit in accordance with the invention;
FIG. 2 is a side view of a helix of strip material prior to installation in a nut unit from FIG. 1;
FIG. 3 is a transverse cross-section along line III—III from FIG. 2;
FIG. 4 is an enlarged detail of area IV from FIG. 1;
FIG. 5 is a transverse cross-section corresponding to the one in FIG. 3 with a modified profile shape of the strip material helix;
FIG. 6 is an enlarged partial section corresponding to the one in FIG. 4 with a modified profile shape of the helical support groove of the nut body;
FIG. 7 is a side view of a modified embodiment of the strip material helix;
FIG. 8 is a partial cross-section corresponding to the one in FIG. 1 with a nut unit that has been completed with balls and a ball reversing element;
FIG. 9 is a view in partial section along line IX—IX of FIG. 8, and
FIG. 10 is a cross-section along line X—X in FIG. 9 .
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
In FIG. 1, a nut body 10 has the basic form of a cylindrical sleeve having an axis A and a mounting flange 12 for mounting in a component (not shown) whose bore accommodates the nut body. Cut into the inner circumferential surface 14 of the nut body 10 is a concavely-curved helical support groove 16 . The support groove 16 extends along the entire length of the nut body 10 . Inserted in the support groove 16 is a strip material helix 18 . The nut body 10 is part of a nut unit 20 , which is shown in a larger context in FIGS. 8-10.
As there shown, the nut unit 20 is part of a ball screw drive 22 (see FIG. 9 ), which includes a threaded spindle 24 in addition to the nut unit 20 . Cut into the inner circumferential surface 14 of the nut 20 in FIG. 8 is a concavely-curved helical profile groove 16 ′. The helical profile groove 16 ′ forms, together with another helical profile groove 26 in the outer circumferential surface of the spindle 24 , a helical ball channel 30 , which accommodates a plurality of balls 32 . The balls 32 of the ball channel 30 form part of a continuous ball loop 34 , which runs through a return channel 36 outside of the ball channel 30 (see FIG. 9 ). Provided at the transitions between the helical ball channel 30 and the return channel 36 are reversing pieces 38 , in which reversing channels are formed (see FIG. 8 ). When the nut body 10 rotates relative to the spindle 24 about the axis A, the balls in the ball loop 34 travel sequentially through the helical ball channel 30 , a reversing channel at 38 , the return channel 36 , and through the other reversing channel (not shown) back into the helical ball channel 30 .
For simplicity's sake, the strip material helix 18 shown in FIG. 2 is not shown in FIGS. 8, 9 and 10 ; instead the helical profile groove 16 ′ is shown cut directly into the nut body 10 in order to simplify the illustration. FIG. 10 depicts a helical profile groove 16 ′ with an ogival cross-section. One can see a ball 32 , which in the bearing points 40 rests against circular arc-shaped flanks 42 of a profile arc. The profile arc defines the profile of the helical profile groove 16 ′ . It is obvious from FIG. 10 that the position of the bearing points 40 is dependent on the diameter of the ball 32 . The bearing points 40 define the bearing race tracks of the balls 32 on the arc-shaped flanks 42 . The bearing points 40 lie on various points within a track region 44 , depending on ball diameter, and each defines a pressure angle α, which varies as a function of the ball diameter. The “pressure angle” α is shown as the angle between a plane AE perpendicular to the axis A and a ray ST, which connects the ball mid-point M to the contact point 40 .
Due to the absence of the strip material helix in FIGS. 8-10, the ball screw drive 22 shown therein should be understood only as a representational basis for the nut unit in accordance with the invention.
Details of one embodiment of the nut unit in accordance with the invention are shown in FIGS. 3 and 4. Visible again is the nut body 10 with the concavely-curved helical support groove 16 in which is inserted the strip material helix 18 . In FIG. 3, the strip material helix 18 is shown in transverse cross-section along line III—III from FIG. 2 . It is defined by a convexly-curved external profile 46 and a concavely-curved internal profile 48 . The curved external profile 46 is composed of two adjacent ogival external profile flank regions 46 ′ and an external profile crown region 46 ″. The curved internal profile 48 is composed of two ogival internal profile flank regions 48 ′ and an internal profile base region 48 ″. The ogival shape is hardly discernible in FIG. 3 because of the small scale. It can be seen more easily in FIG. 4 . The helical support groove 16 defines a support profile which 16 is polylobal in cross-section and which is composed of the support profile sections 16 - 1 and 16 - 2 . The radii R 16 - 1 and R 16 - 2 of the support profile sections 16 - 1 and 16 - 2 are slightly larger than the radii R 46 ′ of the external profile flank regions 46 ′ of the curved external profile 46 . The centers of curvature of the individual radii are labeled as follows:
Center of curvature MR 16 - 1 of the radius R 16 - 1 of the support profile sections 16 - 1 of the support profile of the profile groove 16 ;
Center of curvature MR 16 - 2 of the radius R 16 - 2 of the support profile sections 16 - 2 of the support profile of the profile groove 16 ;
Center of curvature MR 46 ′ of the radii R 46 ′ of the external profile flank regions 46 ′ of the curved external profile 46 ; and
Center of curvature MR 48 ′ of the radii R 48 ′ of the internal profile flank regions 48 ′ of the curved internal profile 48 .
In the exemplary embodiment shown, the radii R 46 ′ and R 48 ′ each have the same center of curvature (MR 46 ′=MR 48 ′).
The radii of the associated balls are slightly smaller than the radii R 48 ′ in order to achieve good fit and low surface pressure.
One can see that the external profile flank region 46 ′ rests against the support profile sections 16 - 1 and 16 - 2 of the polylobal support profile of the helical support groove 16 at two contact points 50 - 1 and 50 - 2 . The distance of separation of the centers of curvature MR 46 ′ and MR 48 ′ for the left and right profile flanks, respectively, is labeled d (see FIG. 4 ). In FIG. 4 as well, the track region is labeled 44 , e.g. the specific region in which balls of varying nominal diameters contact the curved internal profile 48 . In this regard, please also see FIG. 10, where the bearing points and thus the bearing races of the ball 32 are labeled 40 , and again lie within the track region 44 . The internal profile flank regions 48 ′ of the curved internal profile 48 and the external profile flank regions 46 ′ of the curved external profile 46 are equidistant; their spacing is labeled t. This spacing corresponds to the difference between the radii R 46 ′ and R 48 ′.
One can see that the track region 44 lies within a bridge section B (see FIG. 4) that constitutes part of the strip material helix 18 . When the balls that are used have different nominal diameters, their bearing points 40 (see FIG. 10) always lie within the bridge section B that extends between the contact points 50 - 1 and 50 - 2 . A stable two-point-support at each individual turn of the strip material helix 18 in the helical support groove 16 is thus always ensured, regardless of the angular position of the bearing points 40 (see FIG. 10 ). This angular position is labeled α in FIG. 10 . It is referred to as “pressure angle α”. Obviously, the contact points 50 - 1 and 50 - 2 are not strictly punctiform. The contact as in FIG. 4 extends over finite contact zones on both sides of the contact points 50 - 1 and 50 - 2 . These contact zones are likewise designated 50 - 1 and 50 - 2 for the sake of simplicity. The contact zones 50 - 1 and 50 - 2 are associated approximately with the limits G 44 of the track region 44 when viewed in the depth direction T.
It is obvious that the positional stability within the helical support groove 16 of the strip material helix 18 , or more precisely each individual turn of the strip material helix 18 , is assured especially well when the strip material helix 18 fits snugly against the support profile of the support groove 16 over the entire length of its curved external profile 46 . However, it is easy to understand that a snug fit of the strip material helix 18 over the entire length of its curved external profile 46 against the support profile of the support groove 16 requires even greater precision in machining. Consequently, from the perspective of simplified manufacture, the embodiment of FIG. 4 is preferred over embodiments in which large-area support between the strip material helix 18 and the support groove 16 is desired.
It is easy to understand that the bridge-like arrangement of the strip material helix 18 in the vicinity of the bridge section B can also be achieved through appropriate design of the profile shape of the curved external profile 46 .
The nut body 10 preferably is comprised of a non-hardenable steel. The support groove 16 is cut in with conventional thread-cutting tools. The pitch of the helical support groove 16 is freely selectable. For a diameter range of the inner circumferential surface 14 of from 4 mm to 120 mm, the pitch may, for example, be in a range from 10 mm to 40 mm, and can, for example, be up to three times the diameter of the inner circumferential surface 14 .
The strip material helix 18 preferably is comprised of a hardenable steel. It is initially supplied as a flat strip. This flat strip is rolled to achieve the cross-sectional shape shown in FIG. 3 . During the process, the internal profile flank regions 48 ′ are smoothed by the rolling. Then the channeled profile 19 thus obtained as in FIG. 3 —still straight—is wound into strip material helix 18 as in FIG. 2 . This can be done on a modified spring coiling machine. This is followed by hardening of at least the internal profile flank regions 48 ′ that form the ball race 21 (see FIG. 3 ), for example using the process of inductive hardening, which would produce penetration hardening, or using surface hardening of the ball race 21 . Subsequently, the strip material helix 18 is introduced into the helical support groove 16 . This can be accomplished by screwing it in.
After successful installation of the strip material helix 18 in the helical support groove 16 , the nut unit 20 is completed as in FIGS. 8 and 9 through installation of the balls 32 and the reversing elements 38 . To complete the assembly, the end caps 52 visible in FIGS. 1 and 8 are installed, for example by means of clamping screws 54 . When the end caps 52 are attached, they can be brought into contact with the two ends of the strip material helix 18 so that the latter cannot shift within the support groove 16 during operation. Perfect seating of the strip material helix 18 within the support groove 16 is ensured in that the strip material helix 18 before installation has a somewhat larger diameter than the support groove 16 , with the result that preloading is of necessity accomplished during installation.
FIG. 5 shows a strip material helix 18 a with modified cross-section. An ogival recess 56 a is provided here in the base region 48 ″a, which recess can be formed during rolling of the flat profile, can also be milled in, and finally can also be formed during rolling into channel profile through appropriately shaped rolling tools. The recess 56 a causes the bending section modulus of the channel profile to be weakened about the bending axis C in the recess region 56 a. This results in easier fitting of the curved external profile 46 a to the cross-sectional shape of the helical support groove 16 .
FIG. 6 shows how the channeled strip material helix 18 b can be pressed into the support groove 16 b. It is also clear from FIG. 6 that the curved external profile 46 b of the strip material helix 18 b can snugly fit the support profile 16 b of the support groove 16 b along the entire length of the track region 44 b, forming contact zones 53 b. It is possible to extend the contact zones 53 b even further to the crown point 58 b and to the edge region 60 b. Applied at the edge regions 60 b of the strip material helix 18 b are notches 62 b, as shown also in FIG. 7, which can be mortised into projections 64 b of the nut body material, e.g., by crimping the projections 64 b into the notches 62 b, so as to thus shift the strip material helix 18 b in the direction of the arrow 66 b, thereby making the system even more tightly sealed, at least in the contact zones 53 b.
It is also possible to make or support the connection between the strip material helix 18 b and the support groove 16 b through gluing, as indicated, for example, at 17 in FIG. 6 . Gluing can take place in addition to the projections 64 b and/or to the shifting by the end caps 52 .
In the embodiment in FIG. 6, the profile of the support groove is likewise essentially ogival, and can be formed by one arc section on each side of the center line ML, for example a section of a circular arc on each side.
In an advantageous embodiment of the invention, see FIG. 4, for example, the curved internal profile 48 , the curved external profile 46 and the support profile of the support groove 16 are nearly ogival or pointed in shape, and the balls have a nominal diameter that approaches the radii R 48 ′. In a design of this nature, the strip material helix 18 cannot shift relative to the nut body 10 as pressure angles α change. In addition, the strip material helix 18 can be fixed against displacement through contact with the end caps 52 , and also through the means of securing shown in FIG. 6 at 62 b and 64 b. The weakening resulting from the recess 56 a as in FIG. 5 makes it possible for the channel profile of the strip material helix 18 to elastically deform, and thus to lie against the support profile of the support groove 16 in all four contact points or contact regions 50 - 1 and 50 - 2 as in FIG. 4 .
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A nut unit ( 20 ) for use in a ball screw drive comprises a sleeve-shaped nut body ( 10 ) that is made of an essentially rigid material and that has an axis (A) and an inner circumferential surface ( 14 ). A one-piece, channel-shaped, ball-guiding strip material helix ( 18 ) is arranged on the inner circumferential surface ( 14 ) of the nut body ( 10 ). The strip material helix ( 18 ) is mounted within a concavely-curved support groove ( 16 ) formed in the inner circumferential surface ( 14 ) of the nut body ( 10 ). The helix ( 18 ) has an external convexly-curved profile ( 46 ), which is embodied with external profile flank regions ( 46′ ) and an external profile crown region ( 46 ″). The helix ( 18 ) defines, by means of a curved internal profile ( 48 ) facing the axis (A), a ball channel with an internal profile base region ( 48 ″) and two internal profile flank regions ( 48 ′). The outer profile flank regions are essentially rigidly supported by the support profile of the support groove ( 16 ).
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BACKGROUND OF THE INVENTION
The present invention relates to vehicle steering control systems and apparatus for limiting the steering radius of a vehicle at elevated speeds to provide improved maneuverability, prevent damage to the steering mechanism, and prevent damage to surfaces over which such vehicles travel, such as, turf. More particularly, the present invention relates to a novel hydraulic steering cylinder for controllably limiting movement of the steering linkage, thereby limiting turning radius.
Numerous wheeled vehicles employ a steering mechanism connected to steered wheels so that the wheels can be operated in a synchronous manner to steer the vehicle. The steering mechanism includes a steering linkage which is constructed to provide a common turning center for the wheels. Often a hydraulic powered steering system is incorporated with the steering mechanism to improve the ease of operation of the steering linkage. Hydraulic powered steering systems are commonly used with a wide variety of motorized vehicles.
A hydraulic cylinder is incorporated in the powered steering system to controllably operate the steering linkage. The hydraulic cylinder houses a single piston which is hydraulically moved in order to drive an attached shaft. The hydraulic cylinder has a stroke length defined by the movement range of the piston in the cylinder. The stroke length in conjunction with the linkage structure determines the range of turning radii achievable using the particular steering mechanism. In other words, the longer stroke length provides a greater turning radius range and thus can achieve a shorter turning radius, whereas the shorter stroke length provides a smaller turning radius range thereby producing a longer turning radius.
Several problems arise with such a hydraulic powered steering mechanism, the foremost problem being the lack of ability to controllably limit turning radius at elevated speeds. An example of vehicles which would benefit from a solution to the turning radius problem include golf course maintenance vehicles, tractors, turf management vehicle of various types, golf carts and small industrial vehicles. These vehicle typically have short wheel bases, are capable of moving quickly, and often are capable of making very tight turns. As a result of the lack of turning radius control in these vehicles the steering mechanism may be damaged when making tight turns at high speeds, as well as, the surfaces over which such vehicles travel, such as turf.
Using a golf course turf management vehicle as an example, the turning radius problems discussed above can result in damage to the vehicle itself, the turf and fairways over which the vehicle travels and make routine tasks less efficient. The turf surfaces of golf courses are very expensive works of landscaping design which require continuous maintenance and protection to preserve desired playing conditions. Turf management vehicles are used to carry out the various tasks which are involved in maintaining and protecting the turf surfaces. The tasks include, among others, mowing, fertilizing, aerating, delivering supplies to various areas of the course, and transporting people.
Often, turf management vehicles are required to travel relatively long distances through the golf course to carry out a task, and as such, must be capable of traveling at increased speeds in the interest of saving time. The turf surface, however, must not be damaged by the vehicles. If the turning radius of a vehicle is not limited while traveling at high speeds, a sharp turn can cause the vehicle to slide or skid on the turf thereby tearing or digging into and damaging the turf. Additionally, at low speeds the vehicles need to be able to make tight turning radius precision maneuvers such as hair pin turns while fertilizing, aerating, mowing, etc. and parking.
Currently available turning radius limiting devices do not accommodate all of the needs of such turf management vehicles. Typically, the available turning radius devices allow tight turning, but in doing so, reduce vehicle speed so that the turf is not damaged when making a tight turn. Alternatively, the available turning radius devices allow higher speeds, but in doing so, correspondingly increase the turning radius to prevent turf damage at the higher speeds. More specifically, one form of turning radius limiting attempts to limit the stroke length of the control or hydraulic cylinder thereby limiting the turning radius range of the steering mechanism. The preferred limit of the turning radius range is defined by the tightest radius which can be achieved at maximum speed with out damaging the steering mechanism or the travel surface. By limiting the turning radius range the vehicle cannot be controlled into a tight turning radius which might cause damage to the steering mechanism or the turf.
Devices which attempt to overcome the above-noted problems include mechanical stops attached to the steering linkage to physically obstruct movement of linkage components. By obstructing the movement or operation of the components of the steering mechanism, the mechanical stops limit operation of the steering mechanism to a predetermined turning radius corresponding to the relationship between the blocks and the component thus blocked. While such mechanical stops provide a limiting effect on the turning radius, they also create problems by restricting turning radius for all speeds. Another problem with the mechanical stops is that they are exposed to the elements and therefore are subject to wear and possible damage. Additionally, mechanical stops, when damaged, may be overridden by forcing the obstructed component past the block or by disassembly and removal of the block from the steering linkage.
Specific examples of the devices generally described above are shown in U.S. Pat. No. 5,022,480 to Inagaki et al. and in U.S. Pat. No. 4,109,748 to Evans. The Inagaki '480 reference shows a steering rack which operates the steering linkage. A mechanical linkage is controllably positioned for mechanically limiting movement of the rack to limit the turning radius of the linkage. This device, however, is dependent upon proper engagement of the mechanical linkage with the rack and as such is subject to failure if the mechanical device does not properly engage the rack. Additionally, if the rack is not properly positioned in relation to the mechanical limiting device, the limiting device will not properly limit the turning radius and may actually interfere with the safe operation of the rack.
The device as shown in Evans '748 employs a pair of mechanical stops which are independently controllably engagable with the left and right steering knuckles to mechanically limit the turning radius of the steering linkage. The limiters as shown in Evans '748, introduce other problems by including additional independent operating components in the steering system. The limiters add to the overall cost and maintenance of the steering system and present another potential failure point to the steering system.
Control or limiting of the turning radius of a vehicle, as described above, has helped, to some degree, prevent damage to vehicles and turf. Prior art limiting devices create other problems by restricting turning radius over the entire speed range of the vehicle and thus greatly affecting maneuverability at low speeds. This is a problem because the turning radius generally does not serve any function at sufficiently low speeds. In other words, the limiting function is primarily only necessary within a high speed range where the combination of variables, such as a tight turning radius and sufficiently high speed, could culminate in damage to the vehicle or turf. As such, the prior art turning radius limiting devices are bothersome, inefficient, and unnecessary at sufficiently low speeds. This problem is exacerbated when one considers the numerous steering functions (i.e. precision maneuvering, hairpin turning such as when mowing, fertilizing, aerating, parking, etc.) which are executed at low speeds. If a tight turning radius is prohibited, such precision steering functions become very time consuming and perhaps impossible.
OBJECTS AND SUMMARY OF THE INVENTION
A general object of the present invention is to provide a novel steering system and control cylinder which functions to improve maneuverability and to prevent vehicle and surface damage by controllably limiting vehicle turning radius.
Another object of the present invention is to provide a steering system which is capable of controllably limiting turning radius in response to a speed related condition.
Still a further object of the present invention is to provide a steering control system which is capable of controlling turning radius automatically without intervention of an operator.
Briefly, and in accordance with the foregoing, the present invention envisions a vehicle steering control system and apparatus for controlling steering radius to prevent vehicle and surface damage and to provide improved low speed vehicle maneuverability. The steering control system and apparatus provides a first controllably limited turning radius range in relation to a first condition and a second controllably limited turning radius range in relation to a second condition. Examples of the first and second conditions include speed related conditions, such as, the actual speed of the vehicle, a selected gear of the vehicle, and manual selection of the turning radius. The system and apparatus includes a dual-stroke hydraulic cylinder having a cylinder body housing a hydraulically controllable primary piston. A shaft is attached to and extends from the primary piston, projects through the cylinder body, and connects to the steering linkage of the vehicle. Hydraulic operation of the primary piston transfers forces along the shaft to the linkage. First and second hydraulically controllable stroke limiting stops are positioned at each end of the cylinder body. The stops are hydraulically positionable for limiting the stroke length of the primary piston and the attached shaft. A hydraulic control device is associated with the hydraulic cylinder for operating the primary piston and the first and second stops. A mode selection device is associated with the hydraulic control device selecting a desired mode of operation and thus controllably operating the first and second stops to controllably limit the turning radius range of the steering mechanism of the vehicle.
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 be understood by reference to the following description taken in connection with the accompanying drawings, wherein like reference numerals identify like elements, and in which:
FIG. 1 is a general schematic and diagrammatic top plan view of a steering mechanism in which the steering system and apparatus of the present invention is connected with a vehicle steering linkage for controllably limiting the turning radius of the vehicle;
FIG. 2 is a partial fragmentary, cross sectional, diagrammatic and schematic view of the steering control system and apparatus of the present invention in an unrestricted turning radius mode showing a hydraulic cylinder in a partially fragmentary cross-sectional view in which a primary piston is driven to a far right outboard end of the cylinder;
FIG. 3 is a diagrammatic and schematic view of the steering control system and apparatus of the present invention in the unrestricted turning radius mode as shown in FIG. 2 showing the hydraulic cylinder in a partially fragmentary cross-sectional view in which the primary piston is driven to a far left outboard end of the cylinder; and
FIG. 4 is a diagrammatic and schematic view of the steering control system and apparatus of the present invention in a restricted turning radius mode in which first and second stop pistons are fully extended to reduce the stroke length of the primary piston in the cylinder.
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, an embodiment with the understanding that the present description 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.
FIG. 1 provides a diagrammatic and schematic illustration of the vehicle steering control system 20 of the present invention. The vehicle steering control system 20 is connected to a vehicle steering mechanism 22 to control the turning radius of the vehicle. The steering mechanism 22 includes a cross member 24, control arms 26 and wheels 28 attached to each end of the cross member 24, and a steering linkage 30. The vehicle steering control system 20 includes a dual stroke control or hydraulic cylinder 32, a hydraulic control assembly 34 communicating with the cylinder 32, and a mode selector 36 coupled to the hydraulic control assembly 34 via control line 37. A first end 38 of the cylinder 32 is attached to the cross member 24 and a shaft 40 extends from a second end 42 of the cylinder 32. The shaft 40 is attached to the linkage 30 such that hydraulically controlled movement of the shaft 40 in the cylinder 32 operates the linkage 30 to controllably turn the vehicle.
The present control system 20 further includes the mode selection means 36 which is coupled with the control assembly 34 via line 37. The mode selection means 36 operates to selectively operate the system 20 in the restricted or unrestricted operating mode. The mode selection means 36 is embodied as a manual switch to be operated by a person of appropriate judgment or an automatic switch which is operated based on a speed related condition. The speed related conditions which could be used to operate the automatic switch of the mode selection means may be defined by a gear selection or the actual speed of the vehicle.
The projected, enlarged schematic of the control assembly 34 as shown in FIG. 1 illustrates the components of the control assembly 34. The control assembly 34 includes a hydraulic supply 44, a steering hand pump 46 coupled to the hydraulic supply 44, and a hydraulic control apparatus 48 coupled to the steering hand pump 46 and the cylinder 32. The hydraulic supply 44 includes a hydraulic pump 50, a relief valve 52, and a reservoir 54. The steering hand pump 46 includes a control cylinder 56 which is hydraulically connected to the hydraulic supply 44 and the hydraulic control apparatus 48 and a steering wheel 58 which is operatively associated with the control cylinder 56 to actuate the control cylinder 56 when steering the vehicle. In use, the steering hand pump 46 provides a user interface to hydraulically steer the vehicle. The hydraulic supply 44 provides a controllable, generally constant pressure source of hydraulic fluid for the control system 20 and collects and recirculates fluid which is drained to the reservoir 54 from the system 20. The steering hand pump 46 and hydraulic supply 44 are devices of known construction and thus are shown in a simplified form in FIGS. 2-4 and referred to generally as a steering pump 60.
As shown in FIGS. 1-4, the hydraulic pump 50 is connected to the control cylinder 56 via hydraulic line 62 and the control cylinder 56 is connected with the reservoir 54 via hydraulic line 64. The control cylinder 56 is connected to the hydraulic control apparatus 48 via a left line 68 and a right line 70. In use, during operation of the system 20 in the unrestricted mode, when the left line 68 is pressurized the right line 70 is connected to the reservoir 54. Similarly, when the right line 70 is pressurized the left line 68 is connected to the reservoir 54. During the restricted mode, either the left or right lines 68,70 will be pressurized as described in greater detail hereinbelow.
With reference to the cylinder 32 as shown in FIGS. 2-4, the cylinder 32 has a hollow body 72 which is sealed at first and second ends 38,42. The hollow body 72 defines a cylinder chamber 74 which is further divisible into a primary chamber 76 comprising a central portion of the cylinder chamber 74, and a left and right outboard chamber 78,80 disposed at each end of the primary chamber 76. A primary piston 82 is centrally positioned in the cylinder chamber 74 and shiftable within the primary chamber 76. The primary piston 82 has opposed left and right surfaces 84,86 facing each of the first and second 38,42 ends of the cylinder 32. First and second hydraulically operated pistons or stops 88,90 are positioned in the left and right outboard chambers 78,80, respectively. The primary piston 82 carries a first abutment structure 92 projecting from the first surface 84, facing the first stop 88, and a second abutment structure 94 projecting from the second surface 86, facing the second stop 90.
O-rings 95 are retained between the piston 82, the first stop 88 and the second stop 90 and an inside surface 97 of the cylinder body 72. The o-rings 95 provide for sealed movement of the piston 82, and first and second stops 88,90 through the cylinder body 72. Additional o-rings 99 are retained in an aperture 101 through the second stop 90 and aperture 103 through the second end 42 through which the shaft 40 attached to the piston 82 extends.
The hydraulic control apparatus 48 includes a left and right controllable solenoid valve 96,98 and a left and right one-way orifice fitting 100,102. The left valve and fitting 96,100 communicates with the left line 68 and the right valve and fitting communicates with the right line 70. The mode selection means 36, described above, is coupled to the solenoid valves 96,98 to controllably operate the valves 96,98. The left valve 96 controls fluid flow through line 104 into and out of the left outboard chamber 78 through left outboard bore 106 and the right valve 98 controls fluid flow through line 108 into and out of the right outboard chamber 80 through right outboard bore 110. The left and right one-way orifice fittings 100,102 control fluid flow through lines 112,114, respectively, into and out of left and right inboard chambers 116,118, respectively, of the primary chamber 76 through chamber bores 120,122.
The one-way orifice fittings 100,102 restrict flow into the corresponding inboard chamber 116,118 of the primary chamber 76 and allow free flow out of the corresponding sub-chamber 116,118. The one-way orifice fittings 100,102 are of a known construction and include a restricting component 124 and a check valve component 126. The restricting component 124 is of a known construction and restricts the flow rate of fluid pumped through the fitting 100,102 into the corresponding inboard chamber 116,118. When fluid is forced out from one of the inboard cylinders 116,118, the flow rate is greater than the restricted flow rate. The check valve component 126 prevents flow therethrough as fluid is pumped into the inboard cylinders 116,118 to maintain the restricted flow rate but allows free flow therethrough when fluid is forced from the inboard cylinders 116,118.
Restriction of flow through the one-way orifice fitting 100,102, creates a pressure differential between the inboard 120,122 and outboard 106,110 bores. Due to the restricted flow into the inboard chambers 116,118, the corresponding outboard chambers 78,80 will experience a higher pressure component of the pressure differential. The one-way orifice fittings 100,102 as described hereinabove are important because they assure that a higher pressure is maintained in the outboard chambers 78,80 relative to the corresponding inboard chambers 116,118.
The solenoid valves 96,98 are coupled for control by the mode selection means 36. Each solenoid valve 96,98 includes a controllable flow through port component 128 and a check valve component 130. When these valves 96,98 are activated, (the mode selection means switch 36 is closed) as shown in the unrestricted operating mode of FIGS. 2 and 3, hydraulic fluid flows through the controllable port component 130 into and out of the outboard chambers 78,80. When the valves 96,98 are deactivated (the mode selection means switch 36 is open), as shown in the restricted operating mode of FIG. 4, the valves 96,98 act as one-way valves and only allow fluid flow through the check valve component 130 into the outboard chambers 78,80.
It is important to note, that disconnection of power from or deactivation of the valves 96,98 in the restricted steering mode results in a system default to the restricted steering mode in the event of a power failure. The restricted steering mode is considered to be the preferred mode of operation in the event power is lost at high speeds. As such, the system provides a control default by virtue of the operation of the switch 36 and the valves 96,98.
FIGS. 2 and 3 show the operation of the present invention in an unrestricted steering mode in the left hand steering position (FIG. 2) and the right hand steering position (FIG. 3). With reference to FIG. 2, the primary piston 82 is positioned to the far right hand side of the cylinder 32. In this position, the rod 40 is fully extended from the cylinder body 72 to provide the desired turning effect on the linkage 30. In order to move from the unrestricted left hand steering position in FIG. 2 to the unrestricted right hand steering position as shown in FIG. 3, the steering hand pump 60 is operated to controllably pump hydraulic fluid to the cylinder 32 through line 70.
As noted above, in the unrestricted mode as shown in FIGS. 2 and 3, the mode selection means 36 is closed thereby allowing the hydraulic fluid to pass through the port component 128 of the valves 96,98. The increased pressure flowing through line 108 and the bore 110 into the right outboard chamber 80 forces the stop 90 to the left. The increased pressure flowing through the right hand line 70 forces movement of the stop 90 and the primary piston 82 to the left. As the stop 90 and primary piston 82 move to the left, the hydraulic fluid in the left inboard chamber flows through the chamber bore 120 and the orifice fitting 100 through line 68 to the reservoir 54. Similarly, hydraulic fluid in the left outboard chamber 78 is forced through the left outboard bore 106 and line 104, through the port component 128 of the solenoid 96 into line 68 and the reservoir 54. Draining of the left outboard chamber 78 allows movement of the stop 88 to the left when structure 92 contacts it.
As pressurization of the right outboard chamber 80 continues, the stop 90 will continue to move to the left until a leading face 132 of the stop 90 abuts a limiting portion 134. The stop 90 is held against the limiting portion 134 due to the higher pressure at bore 110 compared to the pressure at bore 122. Continued pumping of hydraulic fluid through line 70 flows through bore 122 to further expand the right inboard chamber 118 and move the primary piston 82 to the left. Movement of the primary piston 82 to the left retracts the shaft 40 into the cylinder 72 thereby affecting a desired turning effect on the linkage 30.
With continued application of pressure through line 70, the primary piston 82 will ultimately contact the stop 88. When the first abutment structure 92 on the left side of the primary piston 82 abuts the first stop, the piston 82 will drive the stop 88 to the left. Movement of the stop 88 to the left is affected by a greater pressure differential in the right inboard chamber 118 acting on the right face 86 of the primary piston compared to the pressure in the left inboard chamber 116 or the left outboard chamber 78. Continued pressurization through line 70 results in continued draining through line 68. Eventually, the stop 88 is driven to a point, as shown in FIG. 3, where the stop 88 is prevented from further movement by contact with the inside surface of the first end 38 of the cylinder 32.
As shown in FIG. 3, movement of the primary piston 82 from the position as shown in FIG. 2 to the position as shown in FIG. 3 defines a stroke length (as represented by dimension arrow 136) or movement of the shaft 40. The piston 82 can be moved to the right to fully extend the shaft 40 from the body 72 to perform a desired turning function on the linkage 30. In this regard, the process of pressurizing the left outboard chamber 78, in a similar manner to the right outboard 80 as described hereinabove, initiates the movement of the primary piston 82 to the right. The left outboard chamber 78 is pressurized by hydraulic fluid pumped through line 68 and through the port component 128 of the solenoid 96 via line 104 and bore 106. As the pressure builds in the left outboard chamber 78, the stop 88 is moved to the right thereby driving the primary piston 82 to the right. The stop 88 can be controllably moved to the right to a point upon which it contacts a limiting portion 138. The stop 88 is held in contact with the limiting portion 138 due to the higher pressure at bore 106. As hydraulic fluid continues to be pumped through line 68 into the left inboard chamber 116 through bore 120, further pressurization of the left inboard chamber 116 continues to drive the primary piston 82 to the right.
Continued pumping of hydraulic fluid through line 68 continues to expand the left inboard chamber 116 until a point when the second abutment structure 94 projecting from the second surface 86 of the primary piston 82 contacts the stop 90. Due to the increased pressure on the left hand side of the piston 82, the piston drives the stop 90 to the right. The fluid in the right inboard chamber 118 and the right outboard chamber 80 is drained through the bores 122, 110 through line 70 and into the reservoir 54. Draining of hydraulic fluid from the right inboard chamber 118 and right outboard chamber 110 allows continued movement of the primary piston 82 to the right. Eventually, upon continued pressurization through line 68, the condition as shown in FIG. 2 will be achieved whereby the shaft 40 is fully extended from the cylinder body 72.
When the mode selection means 36 is operated to deactivate the valves 96,98, the valves 96,98 act as one-way check valves only allowing hydraulic fluid to flow into, but not out of the outboard chambers 78,80. Hydraulic fluid flow through the restricted orifice fittings 100,102 creates a higher pressure at the left and right bores 106,110 thereby expanding the corresponding outboard chambers 78,80 and driving the corresponding stops 88,90 inboard towards the middle of the cylinder body 32. As noted hereinabove, the corresponding left and right limiting portions 138, 134 limit the overall movement of the stops 88,90. Hydraulic fluid accumulated in left and right outboard chambers 78,80 is prevented from flowing back through the valves 96,98 by the check valve component 130 of each valve. The stops 88,90 are retained in the inboard positions as shown in FIG. 4 until the solenoid valves 96,98 are once again activated thereby allowing fluid to drain through the corresponding lines 68, 70 to the reservoir 54.
In the restricted mode as shown in FIG. 4, the piston is limited to movement within the reduced or restricted limits of the primary chamber 76 as defined by the inboard shifted stops 88,90. The stroke length (as indicated by dimension arrow 140) is reduced compared to the stroke length 136 of the unrestricted mode as shown in FIGS. 2 and 3. As such, the turning radius is restricted such that the turning radius range is decreased compared to the turning radius range in the unrestricted mode (FIGS. 2,3).
In the restricted mode as shown in FIG. 4, movement of the primary piston 82 in the restricted primary chamber 76 is provided solely by pressurization through the fittings 100,102. Movement to the left or right is affected by pressurization on the left face 84 or right face 86 of the primary piston 82. For example, when moving the primary piston 82 from the right (as shown in phantom line in FIG. 4) to the left, thereby retracting the shaft 40 into the cylinder body 72, pressurized hydraulic fluids is pumped by the steering pump 60 through line 70 creating a higher pressure in the right inboard chamber 118 to drive the piston 82 to the left. The increased pressure in the inboard chamber 118 does not affect the restricted mode position of the corresponding right hand stop 90 due to the one-way check valve component 130 in the solenoid valve 98. If, for any reason, there is a reduction in pressure in the right outboard chamber 80, the restricting operation of the right hand fitting 102 will result in additional fluid being pumped through the one-way check valve 130 of the right hand solenoid valve 98 and into the right outboard chamber 80. As such, in the restricted mode, the stops 88,90 will be maintained in their inboard position against the corresponding limiting portions 138,134. As the piston 82 is driven to the left, the abutment portion 92 will contact the left stop 88. The one-way check valve component 130 of the left solenoid valve 96 prevents release of the fluid in the left outboard chamber 78 and thereby prevents movement of the left stop 88 to the left.
In use, the control system 20 of the present invention includes the dual stroke hydraulic cylinder 32 which is controllably operated to extend and retract the shaft 40 from the cylinder body 72. Movement of the shaft 40 controllably actuates the linkage 30 to affect a desired steering motion to the wheels 28 of the steering mechanism 22. The control system operates in one of the two operating modes described hereinabove, the unrestricted turning radius range mode as shown in FIGS. 2 and 3 or the restricted turning radius range mode as shown in FIG. 4. In the unrestricted turning radius range mode as shown in FIGS. 2 and 3, the vehicle is allowed to make sharp or tight turns. The tight turning action results from the unrestricted stroke length 136 of the shaft 40. In the restricted mode, the vehicle is prohibited from making tight turns and restricted to a limited turning radius range. The limited turning radius range results in wider turning radii due to the increased stroke length 140 of the shaft 40 in the cylinder 32.
The hydraulic control apparatus 48 includes controllable solenoid valves 96,98 and one-way restricted orifice fittings 100,102. The valves 96,98 and fittings 100,102 are connected in parallel to the steering pump 60 via the corresponding hydraulic lines 68,70. Pressurization of the left or right hydraulic lines 68,70 by the steering pump 60 pumps hydraulic fluid to the corresponding valve and fitting pair (96,100 or 98,102). For example, when fluid is pumped through line 68 into the valve and fitting pair 96,100, the restricted flow through the fitting 100 creates a pressure differential with increased pressure being supplied to the left outboard chamber 78. By pressurizing the left outboard chamber 78, movement of the stop 88 is affected. Similar movement of the right stop 90 can be achieved by pressurizing the right hydraulic line 70.
In the unrestricted mode, the solenoid valves 96,98 are activated to allow fluid to flow into and out of the corresponding outboard chambers 78,80. In the restricted modes, the solenoid valves 96,98 are deactivated to allow pressure to be built up in the left and right hand outboard chambers 70,80 thereby forcing the stops 88,90 against the corresponding limiting portions 138,134. The restricted mode results in a reduced stroke length 140 whereas the unrestricted mode results in a greater stroke length 136.
In summary, the present invention provides a unitary hydraulic control cylinder 32 which is attached by way of a movable shaft or rod 40 to the linkage 30. The cylinder 32 internally houses the primary piston 82 and the movable stops 88,90. The hydraulically controlled pistons 82,88,90 are controlled by the hydraulic control apparatus 48. The economy of the design of the present invention improves reliability by reducing the complexity and number of components in the system and thereby reduces the overall cost, size, maintenance, and ease of repair.
The system 20 operates in two modes, a full turning mode (shown in FIGS. 2 and 3) or a restricted turning mode (shown in FIG. 4). Different stroke lengths could be achieved by changing the length of chambers 76, 78 and 80. In the full turning mode (FIGS. 2,3), the primary piston 82 has a maximized stroke length 136, thus allowing a smaller turning radius and a tighter turning response. In the restricted operating mode (FIG. 4), the primary piston 82 travels over a restricted stroke length 140, thus prohibiting a smaller turning radius resulting in a wider turning response.
The present invention helps to improve maneuverability and minimize the possibility of high speed, tight turning, turf damage and further provides a fail safe in that the valves 96,98 are only powered in the unrestricted or tight turning mode. In this regard, the default mode will be the restricted turning mode, such that if the power is disabled, the valves 96,98 will operate in the default mode and restrict the turning radius of the vehicle. The present invention also preserves turf surfaces such as golf greens and the like by preventing high speed sharp turning. When high speed sharp turning is restricted on vehicles employing the present invention, they are prohibited from tearing up or forcibly skidding on such turf surfaces thereby preventing damage to the turf surface. This is important in that turf surfaces such as golf greens can be very expensive to construct and maintain.
While a preferred embodiment of the present invention is 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. The invention is not intended to be limited by the foregoing disclosure.
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A vehicle steering control system and apparatus for controlling steering radius to prevent vehicle and surface damage and to provide improved low speed vehicle maneuverability. The steering control system and apparatus provides a first controllably limited turning radius range in relation to a first condition and a second controllably limited turning radius range in relation to a second condition. Examples of the first and second conditions include speed related conditions, such as, the actual speed of the vehicle, a selected gear of the vehicle, and manual selection of the turning radius. The system and apparatus includes a dual stroke hydraulic cylinder having a cylinder body housing a hydraulically controllable primary piston. A shaft is attached to and extends from the primary piston, projects through the cylinder body, and connects to the steering linkage of the vehicle. Hydraulic operation of the primary piston transfers forces along the shaft to the linkage. First and second hydraulically controllable stroke limiting stops are positioned at each end of the cylinder body. The stops are hydraulically positionable for limiting the stroke length of the primary piston and the attached shaft. A hydraulic control device is associated with the hydraulic cylinder for operating the primary piston and the first and second stops. A mode selection device is associated with the hydraulic control device selecting a desired mode of operation and thus controllably operating the first and second stops to controllably limit the turning radius range of the steering mechanism of the vehicle.
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FIELD OF THE INVENTION
[0001] This present invention relates to a face milling insert for use in milling tools. More particularly, the present invention relates to a face milling insert comprising a pair of main cutting edges which are spaced apart from a center and meet at a corner where they transform into a surface wiping secondary edge, which is intersected by a bisector defining the corner between the main cutting edges, inside each main cutting edge a slope surface being formed, which slopes towards a countersunk bottom surface in a chip surface.
BACKGROUND OF THE INVENTION
[0002] Cutting inserts of the type stated above are used in milling tools for face milling. In this application, the cutting inserts are mounted in insert seats in a number of peripherally spaced-apart pockets in a milling cutter body being rotatable around a central axis, which body during machining of a workpiece is set in a translational feeding motion, usually perpendicular to said axis, at the same time as the same is brought to rotate. In this connection, the main cutting edges of the milling cutter are facing radially outward from the rotation axis of the milling cutter body in order to remove chips from the workpiece in a material layer of a desired depth, while the secondary edges of the cutting insert (which by those skilled in the art usually are denominated “wiper edges”) are located in a common plane and directed inward from the peripherical main cutting edges, in order to, in such a way, exert a surface-wiping or surface-smoothing effect on the generally planar surface, which is generated in the workpiece after the chip removal.
[0003] For different purposes, the cutting inserts, in practice being most often flat, can be located at different angles in relation to the milling cutter body. Thus, the individual cutting insert may be inclined or “tipped-in” in a negative as well as a positive angle with the rotation axis, seen not only axially but also radially. Generally, the cutting inserts work easier and more efficient at larger axial angles than at small or negative axial angles. However, the strength and geometry of the cutting inserts, for example practicable clearance angles, impose limits on the maximal axial angles that can be realized.
[0004] The problems that the present invention aims at solving are related to cutting inserts for face mills. Thus, it has turned out that easy-cutting cutting inserts, i.e., cutting inserts having a positive geometry of the type initially mentioned, which are mounted with large axial angles (>15°) in the milling cutter body, run the risk of breaking into pieces and having a short service life. Among other things, such cutting inserts are frequently damaged mechanically by the fact that a limited portion of the chip surface in the immediate vicinity of the secondary edge or wiper edge at a corner and the transition thereof into the main cutting edge, is peeled off by the hot chips. If such damage, limited per se, arises, the chip, being viscous by the heat, will shortly thereafter adhere to and pull along with it the area of the chip surface being inside, and in such a way peel off large parts of the surface layer of the cutting insert that determines the geometry of the chip surface. By those skilled in the art, such damages are denominated “topslice fractures”. Damages of this type become particularly frequent when the cutting inserts have large edge rounding offs, and when the material that is machined generates large quantities of heat energy.
[0005] A conceivable solution to the above-mentioned problem would be to form the top side of the cutting insert in the shape of a planar, smooth surface. In such a way, the cutting insert in the area of the secondary edge would become stronger and easier be able to resist the planing or shearing effect of the chip. However, such a cutting insert would get a drastically deteriorated performance, among other things because the contact length of the chip against the top side would become considerably larger, with increased cutting forces as a consequence.
[0006] U.S. Pat. No. 6,050,752 discloses a cutting insert intended for milling, which insert, adjacent to each one of four surface-wiping secondary edges or wiper edges, has a planar surface that is located at a higher level than the surrounding parts of the chip surface. However, in this case, the cutting insert lacks any positive chip-cutting slope surface adjacent to the individual main edge. Thus, a channelled or waved part of the chip surface extends inward from the main edge in a negative chip angle, which is even larger than the chip angle of the corner surfaces.
[0007] SE 502196 C2 discloses a cutting insert for milling, more exactly 90° square shoulder milling, the cutting insert including, in the vicinity of each corner, a ridge being raised relative to the rest of the ship surface, the ridge extending from a wiper edge towards the center of the insert. In this case, however, the ridge as well as the wiper edge are displaced laterally in relation to the curved edge portion, which forms the actual corner of the insert as defined by a bisector between two meeting main cutting edges. This implies that the insert in question runs exactly the same risk to be damaged as the above-mentioned inserts, more specifically topslice fractures being initiated at the fragile curved edge portion in the corner.
SUMMARY
[0008] The present invention aims at managing the above-mentioned problem and at providing an improved cutting insert for face milling. Thus, a primary object of the invention is to provide an efficient and easy-cutting face milling insert having improved resistance against mechanical damage in the chip surface, wherein the cutting insert in particular should be suitable for mounting with large axial angles in milling cutter bodies. An additional object is to provide a multi-edged cutting insert having a positive basic geometry, i.e., having marked clearance angles and positive slope surfaces adjacent to the main edges. Furthermore, the cutting insert should guarantee the shortest possible contact length for the chips that are separated by the individual main edge. It is also an object to provide a cutting insert that can be manufactured in a simple way.
[0009] A first aspect of the present invention pertains to a face milling insert, comprising a pair of main cutting edges which are spaced apart from a center and meet at a corner where they transform into a surface wiping secondary edge, which is intersected by a bisector defining the corner between the main cutting edge, inside each main cutting edge a slope surface being formed, which slopes towards a countersunk bottom surface in a chip surface, wherein a shoulder, having a top side situated at a higher level than said bottom surface, extends inwardly from the secondary edge along the bisector, the slope surface of the main cutting edge that actively cooperates with the secondary edge, terminating at the shoulder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view, regarded obliquely from above, of a first embodiment of a cutting insert according to the invention.
[0011] FIG. 2 is an extremely enlarged detail section showing the design of a chip surface adjacent to a main edge of the cutting insert (see also FIG. 4 ).
[0012] FIG. 3 is a planar view from above of the cutting insert according to FIG. 1 .
[0013] FIG. 4 is a section A-A in FIG. 3 .
[0014] FIG. 5 is a section B-B in FIG. 3 .
[0015] FIG. 6 is a perspective view showing a second, alternative embodiment of the cutting insert according to the invention.
[0016] FIG. 7 is an enlarged detail section illustrating the geometry of the chip surface of the cutting insert according to FIG. 6 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] FIGS. 1-5 illustrate a cutting insert made in accordance with the invention, which is intended for the face milling of above all metallic workpieces (although other materials may be possible too). In practice, the cutting insert is usually manufactured from cemented carbide or another equivalent material having a great hardness and wear resistance.
[0018] In a conventional way, the cutting insert has a top side 1 serving as a chip surface and a bottom side 2 between which a circumferential clearance surface generally designated 3 extends. In the example, the cutting insert is multi-edged. More precisely, the same has a square basic shape and presents four main cutting edges 4 , which are formed in the transition between the top side 1 and the clearance surface 3 . Each such main cutting edge 4 co-operates with a secondary edge or wiper edge 5 , which extends at an angle to the main cutting edge. In this embodiment, adjacent main cutting edges 4 extend at 90° to each other and meet at corners defined by bisectors D (see FIG. 3 ). Each secondary edge 5 forms an angle of 90° with the bisector D, meaning that the angle δ between each main edge 4 and an imaginary extension of a secondary edge 5 amounts to 45°. In other respects, it should be pointed out that the top and bottom sides 1 , 2 are mutually parallel and define the neutral plane of the cutting insert. In addition, the cutting insert is positive so far that the clearance surface 3 forms an acute angle α (see FIG. 2 ) with an imaginary plane shown by dash-dotted lines and being perpendicular to the neutral plane. The angle α should amount to at least 7° and at most 30°. In the example, the angle α amounts to 20°.
[0019] As has been pointed out above, the main cutting edge 4 has the purpose of effecting the chip removal from the workpiece, while the secondary edge 5 has the purpose of wiping off the essentially planar surface in the workpiece that is generated by the chip removal. A transition designated 6 between the edges 4 , 5 is arched and has a limited radius. Also the proper secondary edge 5 may be arched, although by such a large radius of curvature that the arch shape is not seen by the naked eye. Therefore, in the planar view according to FIG. 3 , the edges 5 are shown having lines, which to the eye appear as straight.
[0020] Reference is now made to FIG. 2 , which in detail illustrates the shape of the top side or chip surface 1 of the cutting insert adjacent to the individual main cutting edge 4 . Closest to the clearance surface 3 , there is a reinforcing chamfer surface 7 , which via a turning line 8 transforms into a second chamfer surface 9 at an obtuse angle to the surface 7 . Via an additional turning line 10 , the chamfer surface 9 transforms into a slope-like surface 11 , which in turn leans or slopes in the direction downward/inward toward a countersink designated 12 in the chip surface 1 . In the example according to FIGS. 1-5 , the transition between the surfaces 11 and 12 includes a third turning line 13 .
[0021] It is clearly seen from the enlarged section in FIG. 2 that at least the chamfer surface 9 is situated at a higher level than the countersink or the bottom surface 12 . In the example, all surfaces 7 , 9 , 11 and 12 have been illustrated in the shape of planar surfaces. However, this does not exclude the possibility that the surfaces also may have a curved shape. For instance, the slope surface 11 inclined inward and downward may have a concavely curved shape. It should also be pointed out that the countersunk bottom surface 12 in the embodiment according to FIGS. 1-5 is planar and extends all the way up to a central hole 14 for a conventional tightening screw (not shown). A center axis C of this hole also constitutes the center of the cutting insert in its entirety.
[0022] The above-noted features are common to many prior art cutting inserts. However, prior art cutting inserts also include slope surfaces 11 not only inside all main cutting edges 4 , but also inside their end transitions towards the corners.
[0023] The cutting insert of the present invention includes a shoulder 15 having a top side 16 situated at a higher level than the countersink or the bottom surface 12 , extending inward 14 from each secondary edge 5 . In the example, the chamfer surface 9 is parallel to the neutral plane of the cutting insert, the chamfer surface 9 and the top side 16 of the shoulder 15 being located in a common plane. In other words, in this case also the top side 16 of the shoulder is planar and parallel to the neutral plane of the cutting insert. However, as will be clear below, also other designs of the shoulder are feasible.
[0024] In FIG. 3 , the width of the shoulder 15 —such as this is determined by the extension of the top surface 16 in the direction parallel to the secondary edge 5 —is substantially equally large as the length of the secondary edge. The length of the shoulder—counted as the extension of the top side 16 from the secondary edge 5 in the direction radially inward toward the center C of the cutting insert—is larger than the width of the shoulder. In the shown, preferred embodiment, the shoulder has a shape such that the width of the top side 16 first successively increases in the direction from the secondary edge 5 , by the fact that the top side is delimited by diverging, arched border lines 17 , and then successively tapered in the direction inward towards the center of the cutting insert, more precisely by the fact that the top side is delimited by converging, arched border lines 18 .
[0025] Preferably, the shape of the shoulder is such that the top side 16 of the shoulder transforms into surrounding portions 11 , 12 of the chip surface via flatly leaning transition portions. More precisely, adjacent to the border lines 17 , the top surface 16 transforms into the slope surface 11 via flatly leaning, suitably concavely curved transition surfaces 19 , while the inner portion of the surface 16 , which is delimited by the border lines 18 , transforms into the countersunk surface via similar transition surfaces 20 . At the end thereof directed toward the center hole 14 , the top surface 16 transforms into the bottom surface 12 via a transition surface 21 leaning flatly in an analogous way.
[0026] In this connection, it should be born in mind that all pairs of edges 4 , 5 , are generally straight and located in a common plane, which is parallel to the neutral plane of the cutting insert. In the example shown, the individual shoulder 15 is equally thick in the area below the top surface 16 , which has a planar shape. This means that the top surface 16 , along the entire extension thereof, is parallel to the plane being common to the edges 4 , 5 , although located at a somewhat higher level than the same.
[0027] Furthermore, with reference to FIG. 3 , each individual slope surface 11 inside the different main edges 4 extends all the way between two adjacent shoulders 15 . In particular, the slope surface 11 —having the principal purpose of minimizing the contact length of the chip along the chip surface—extends in all essentials along the entire length of the individual main edge 4 . In such a way, it is guaranteed that the easy-cutting capability of the main edge is retained along the entire length of the edge; that is, the cutting insert can be utilized for not only small cutting depths, but also large cutting depths, the maximum depth being determined by the actual length of the main edge. Because the cutting insert is preferably made in one single piece, and most preferably by compression-moulding and sintering, the above-described shoulders should constitute integrated parts of the cutting insert. In this context, it should be pointed out that the cutting insert, in connection with the manufacture, may be made having different embossings 22 , which distinguish the corners and shoulders of the cutting insert from each other. In such a way, the indexing of the cutting insert by the user is facilitated.
[0028] In FIGS. 6 and 7 , an alternative embodiment is shown, which differs from the above-described embodiment merely in that the countersunk bottom surface 12 adjacent to the slope surface 11 has a limited extension, more precisely by transforming into a land 23 the top surface of which is located at a higher level than the lowest located portion of the bottom surface 12 . In such a way, a chip-breaking surface 24 is formed in the transition between the bottom surface 12 and the land 23 . In other words, in this case the bottom surface 12 forms a flute-like configuration, rather than extending along a large part of the top side of the cutting insert.
[0029] However, in accordance with the principle of the invention, a shoulder 15 is still formed adjacent to each one of the four corners of the cutting insert. The top side of the individual shoulder should extend at least up to the area of the chip surface 24 , as can be clearly seen in FIG. 6 .
[0030] In FIG. 7 , it is shown how the slope surface 11 forms an acute angle β with the neutral plane of the cutting insert. In the example, this angle is 10°, although it may vary within fairly wide limits. However, in practice, the angle β should amount to at least 5°, suitably at least 7°. On the other hand, it should not exceed 25° and preferably not 20°. If it is assumed that the angle β amounts to only 10° at the same time as the angle α amounts to 20°, the angle (lacking reference designation) between the slope surface 11 and the clearance surface 3 will amount to 60° (which is the case in the example shown). Also this angle may vary, preferably within a range of from 50° or 55° and upward.
[0031] A fundamental advantage of the cutting insert according to the invention is that the same—while keeping the efficient chip-removing ability of the main edge as a consequence of the sloping surface 11 —by the presence of the shoulders adjacent to each corner, obtains a considerably improved strength and service life in the area of the cutting insert particularly susceptible to so-called topslice fracture, namely in the area of each corner of the insert. Not only the mechanical strengthening, which the material in the shoulders entails, but also the capability of the shoulders to carry off heat from the secondary edge contributes to the durability of the cutting insert according to the invention. Therefore, in combination with suitable cooling, the temperature of the material in the immediate vicinity of the secondary edge can be lowered substantially, something which in turn counteracts the tendency for topslice fracture. The above-mentioned advantages and improvements vouch, in turn, for the fact that the cutting insert can be used without problems when large axial angles are desirable.
[0032] However, it should be understood that the dimensions of the above-described shoulders in practice are moderate. In medium-sized cutting inserts (having an edge length within the range of 10-20 mm), accordingly, the individual shoulder can have a thickness within the range of 0.05-0.15 mm. In this connection, the thickness is determined by the level difference between the top side or the highest located point of the shoulder and the lowest located point of the surrounding, countersunk chip surface.
[0033] The invention is not limited only to the embodiments described above and shown in the drawings. Thus, the shape and dimensions of the individual shoulder may vary most considerably within the scope of the subsequent claims. For instance, the top side of the shoulder does not necessarily need to be planar, but may instead have, for instance, a curved shape or a shape otherwise deviating from the planar shape. Thus, in the top surface of the shoulder, it is feasible to form different types of chip-guiding or chip-affecting formations, such as grooves and the like. Furthermore, the top surface of the shoulder may be located in another way than the one shown. For instance, said top surface may be formed in such a way that the same leans or curves in the direction inward/upward from the secondary edge in order to, after a highest crown, again lean inward/downward in the extension thereof toward the center of the cutting insert. Although it is preferred to let the inwardly/downwardly leaning slope surface positioned inside the main edge extend along the entire length of the main edge, the extension of the same may also be somewhat reduced, namely if a more limited cutting depth can be accepted. Furthermore, it should be emphasized that the invention is applicable also to cutting inserts having another number of co-operating pairs of secondary and main edges than four.
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A face milling insert comprising a pair of main cutting edges which are spaced apart from a center and meet at a corner where they transform into a surface wiping secondary edge, which is intersected by a bisector defining the corner between the main cutting edges, inside each main cutting edge a slope surface being formed, which slopes towards a countersunk bottom surface in a chip surface. A shoulder, having a top side situated at a higher level than the bottom surface, extends inwardly from the secondary edge, the slope surface of the main cutting edge that actively co-operates with the secondary edge, terminating at the shoulder.
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CROSS REFERENCE TO RELATED APPLICATIONS
This Application claims priority of Taiwan Patent Application No. 100135463, filed on Sep. 30, 2011, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a touch display device, and in particular relates to reduced scratches during a dual-side process of a capacitive touch display device.
2. Description of the Related Art
Currently, there are two types of capacitive touch panels. One type of capacitive touch panel is an add-on touch panel, wherein the capacitive touch panel is disposed on the outside of a display panel. The add-on touch panel is formed from two glass substrates. One glass substrate is used for forming capacitive touch sensors thereon. Another glass substrate is used as a cover lens for protecting the capacitive touch sensors. Thus, a total thickness of a touch display device is increased due to the add-on touch panel.
Another type of capacitive touch panel is an on-color filter (CF) type touch panel. The on-CF typed touch panel has capacitive touch sensors formed on a backside of a color filter substrate of a display panel and then a glass substrate is used as a cover lens for protecting the capacitive touch sensor. Although one glass substrate is omitted in the on-CF type touch panel, the formed capacitive touch sensors on the backside of the color filter substrate are easy scratched in subsequent processes by a dual-side process of the color filter substrate.
Therefore, a touch panel which can overcome the above problems, by reducing a total thickness of a touch display device and reducing scratches of the capacitive touch sensors during the dual-side process of the color filter substrate at the same time is desired.
BRIEF SUMMARY OF THE INVENTION
According to an illustrative embodiment, a touch display device is provided. The touch display device comprises a display panel including a first substrate, having a first surface and an opposite second surface, and a color filter layer disposed on the second surface of the first substrate. The touch display device further comprises a touch panel disposed on the first surface of the first substrate. The touch panel comprises a plurality of first conductive patterns arranged along a first direction and disposed on the first surface of the first substrate. A plurality of second conductive patterns is arranged along a second direction perpendicular to the first direction and disposed on the first surface of the first substrate. A patterned isolation layer has a first portion and a second portion, wherein the first portion is disposed at an intersection of the first conductive patterns and the second conductive patterns, the second portion is disposed between the first conductive patterns and the second conductive patterns, and the first portion has a height that is lower than a height of the second portion.
According to an illustrative embodiment, a method of forming a touch display device is provided. The method comprises providing a first substrate, having a first surface and an opposite second surface, and forming a touch panel on the first surface of the first substrate. The steps of forming the touch panel comprise forming a plurality of first conductive patterns on the first surface of the first substrate, arranged along a first direction. A plurality of second conductive patterns is formed on the first surface of the first substrate, arranged along a second direction perpendicular to the first direction. An isolation layer is coated over the first surface of the first substrate. Then, a half-tone mask is provided for performing an exposure and a development process to the isolation layer to form a patterned isolation layer, wherein the patterned isolation layer includes a first portion and a second portion, the first portion is formed at an intersection of the first conductive patterns and the second conductive patterns, the second portion is formed between the first conductive patterns and the second conductive patterns, and the first portion has a height that is lower than a height of the second portion.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
FIG. 1 shows an illustrative cross section of a touch display device according to an embodiment of the invention;
FIG. 2 shows an illustrative top view of a portion of a touch panel according to an embodiment of the invention;
FIG. 3A shows an illustrative cross section of a touch panel along the cross section line 3 - 3 ′ of FIG. 2 according to an embodiment of the invention;
FIG. 3B shows an illustrative cross section of a touch panel along the cross section line 3 - 3 ′ of FIG. 2 according to another embodiment of the invention;
FIG. 4 shows an illustrative top view of a portion of a touch panel according to another embodiment of the invention;
FIG. 5A shows an illustrative cross section of a touch panel along the cross section line 5 - 5 ′ of FIG. 4 according to an embodiment of the invention;
FIG. 5B shows an illustrative cross section of a touch panel along the cross section line 5 - 5 ′ of FIG. 4 according to another embodiment of the invention;
FIGS. 6A-6D show illustrative cross sections of intermediate processes of forming the touch panel of FIG. 5A according to an embodiment of the invention;
FIGS. 7A-7D show illustrative cross sections of intermediate processes of forming the touch panel of FIG. 5B according to an embodiment of the invention;
FIG. 8 shows an illustrative top view of a portion of a capacitive touch panel known by the inventors; and
FIG. 9 shows an illustrative cross section of a capacitive touch panel along the cross section line 9 - 9 ′ of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
In embodiments of the invention, projective type capacitive touch display devices are provided. The touch display device includes a capacitive touch panel firstly formed on a backside of an upper substrate of a display panel. A color filter layer or other element is formed on a front side of the upper substrate of the display panel and then the fabrication of the display panel is completed. In the embodiments of the invention, a structure design of a capacitive touch panel is used in the touch display devices to prevent the touch panel from scratching during a dual-side process of the upper substrate of the display panel. According to the embodiments, one glass substrate is omitted from the touch display device and a total thickness of the touch display device is decreased. Moreover, the fabrication yield of the touch display device is improved.
Firstly, referring to FIGS. 8 and 9 , FIG. 8 shows a top view of a portion of a capacitive touch panel 208 which is known by the inventors. The capacitive touch panel 208 has a plurality of sensing electrodes 210 X arranged along an X direction and a plurality of sensing electrodes 210 Y arranged along a Y direction. In which, the sensing electrodes 210 X are directly connected with each other and the sensing electrodes 210 Y are electrically connected by a metal bridge structure 212 . In order to prevent a short from occurring at the intersection of the sensing electrodes 210 X and the sensing electrodes 210 Y, an isolation structure 214 is disposed between the metal bridge structure 212 and a connective part of the sensing electrodes 210 X.
FIG. 9 shows a cross section of the capacitive touch panel 208 along the cross section line 9 - 9 ′ of FIG. 8 . The touch panel 208 is formed on a surface 100 A of a substrate 100 . The isolation structure 214 is disposed between the metal bridge structure 212 and the connective part of the sensing electrodes 210 X. Therefore, after a protective layer 220 is formed to cover the sensing electrodes 210 X and the sensing electrodes 210 Y, the touch panel 208 has a height at the location of the isolation structure 214 that is higher than the heights at other positions. Thus, when a color filter layer 203 is formed on another surface 100 B of the substrate 100 , a protrusive portion P of the touch panel 208 is easily scratched or damaged which causes the touch panel 208 to malfunction.
Accordingly, in the embodiment of the invention, an improved structure design of the touch panel of the projective type capacitive touch display device is provided to reduce scratches on the touch panel during the dual-side process of the upper substrate of the display panel.
Referring to FIG. 1 , a cross section of a touch display device 200 according to an embodiment of the invention is shown. The touch display device 200 includes a touch panel 108 disposed on a surface 100 A of an upper substrate 100 of a display panel. A color filter layer 103 or other element layer is formed on another surface 100 B of the upper substrate 100 . The display panel further includes a lower substrate 102 disposed opposite to the upper substrate 100 . Further, a display element 104 is sandwiched between the upper substrate 100 and the lower substrate 102 . Moreover, a cover lens 106 , for example a glass substrate or a plastic substrate, may be disposed on the outside of the touch panel 108 to prevent the fingers of a user or a touch pen 202 to scratch the touch panel 108 .
FIG. 2 shows a top view of a portion of the touch panel 108 according to an embodiment of the invention. The touch panel 108 includes a plurality of conductive patterns 110 X arranged along an X direction and a plurality of conductive patterns 110 Y arranged along a Y direction for use as sensing electrodes. The conductive patterns 110 X are connected with each other to form a row and the conductive patterns 110 Y are also connected with each other to form a column. An isolation structure 114 is disposed at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y. The isolation structure 114 is also disposed between the conductive patterns 110 X and the conductive patterns 110 Y to prevent a short from occurring at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y. The materials of the conductive patterns 110 X and the conductive patterns 110 Y are transparent conductive materials, for example indium tin oxide (ITO). The shapes of the conductive patterns 110 X and the conductive patterns 110 Y may be a rhombus or other shapes.
According to an embodiment of the invention, a dummy transparent conductive pattern 110 D is disposed between the conductive pattern 110 X and the conductive pattern 110 Y. The material of the dummy transparent conductive pattern 110 D is for example indium tin oxide (ITO). The dummy transparent conductive pattern 110 D, the conductive pattern 110 X and the conductive pattern 110 Y are electrically isolated from each other. Moreover, a dummy isolation structure 116 is disposed between the conductive patterns 110 X and the conductive patterns 110 Y. The dummy isolation structure 116 may be disposed under or over the dummy transparent conductive pattern 110 D. The dummy isolation structure 116 has a height that is higher than a height of the isolation structure 114 , such that a portion of the conductive pattern 110 X over the isolation structure 114 is not scratched. In an embodiment, the materials of the isolation structure 114 and the dummy isolation structure 116 are insulating photosensitive materials, for example a photo resist. The shapes of the isolation structure 114 and the dummy isolation structure 116 may be an island, and a size of the isolation structure 114 is slightly larger than the size of the dummy isolation structure 116 .
FIG. 3A shows a cross section of the touch panel 108 along the cross section line 3 - 3 ′ of FIG. 2 according to an embodiment of the invention. As shown in FIG. 3A , the conductive patterns 110 X, the conductive patterns 110 Y and the dummy transparent conductive patterns 110 D are disposed on the surface 100 A of the substrate 100 . The isolation structure 114 is disposed at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y for electrically isolating a connection portion of the conductive patterns 110 X from a connection portion of the conductive patterns 110 Y. The dummy isolation structure 116 is disposed over the dummy transparent conductive patterns 110 D. A height H 1 of the isolation structure 114 is lower than a height H 2 of the dummy isolation structure 116 . In an embodiment, the height H 1 is below about 50% that of the height H 2 .
The surface 100 A of the substrate 100 is completely covered with a protective layer 120 . The material of the protective layer 120 is for example acrylic resin, silicon nitride, silicon oxide or silicon oxynitride. As shown in FIG. 3A , a height H 3 of a portion of the protective layer 120 over the dummy isolation structure 116 is higher than a height H 4 of a portion of the protective layer 120 over the isolation structure 114 . In an embodiment, a difference between the height H 3 and the height H 4 is about 200 nm. Therefore, scratches occurring at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y are effectively reduced by the structure design of the touch panel 108 of the embodiment.
FIG. 3B shows a cross section of the touch panel 108 along the cross section line 3 - 3 ′ of FIG. 2 according to another embodiment of the invention. The difference between the touch panel 108 of FIG. 3B and the touch panel 108 of FIG. 3A is the dummy isolation structure 116 directly disposed on the surface 100 A of the substrate 100 and the dummy transparent conductive patterns 110 D disposed over the dummy isolation structure 116 . Similarly, a height of the isolation structure 114 is lower than a height of the dummy isolation structure 116 . Moreover, a height of a portion of the protective layer 120 over the dummy isolation structure 116 is higher than a height of a portion of the protective layer 120 over the isolation structure 114 . Therefore, scratches occurring at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y are also effectively reduced by the structure design of the touch panel 108 of FIG. 3B .
In another embodiment, no dummy transparent conductive pattern 110 D is disposed between the conductive patterns 110 X and the conductive patterns 110 Y. Only the dummy isolation structure 116 is formed on the surface 100 A of the substrate 100 and between the conductive patterns 110 X and the conductive patterns 110 Y.
FIG. 4 shows a top view of a portion of a touch panel 108 according to an embodiment of the invention. The touch panel 108 includes a plurality of conductive patterns 110 X arranged along an X direction for use as sensing electrodes. The conductive patterns 110 X are directly connected with each other to form a row. The touch panel 108 further includes a plurality of conductive patterns 110 Y arranged along a Y direction for use as sensing electrodes. The conductive patterns 110 Y are separated from each other and electrically connected with each other by a bridge structure 112 to form a column. Moreover, an isolation structure 114 is disposed between the bridge structure 112 and a connection portion of the conductive patterns 110 X to prevent a short from occurring at the intersection of the conductive patterns 110 X and the conductive patterns 110 Y. The materials of the conductive patterns 110 X and the conductive patterns 110 Y are transparent conductive materials, for example indium tin oxide (ITO). The shapes of the conductive patterns 110 X and the conductive patterns 110 Y may be a rhombus or other shapes. The material of the bridge structure 112 may be a transparent conductive material or a metal material. The transparent conductive material is for example indium tin oxide (ITO).
According to an embodiment of the invention, a dummy transparent conductive pattern 110 D is disposed between the conductive pattern 110 X and the conductive pattern 110 Y. The material of the dummy transparent conductive pattern 110 D is for example indium tin oxide (ITO). The dummy transparent conductive pattern 110 D, the conductive pattern 110 X and the conductive pattern 110 Y are electrically isolated from each other. Moreover, a dummy isolation structure 116 is disposed between the conductive patterns 110 X and the conductive patterns 110 Y. The dummy isolation structure 116 can be disposed under or over the dummy transparent conductive pattern 110 D. The dummy isolation structure 116 has a height that is higher than a height of the isolation structure 114 over the bridge structure 112 , such that it can effectively prevent scratches from occurring at the location of the bridge structure 112 . In an embodiment, the materials of the isolation structure 114 and the dummy isolation structure 116 are insulating photosensitive materials, for example a photo resist. The shapes of the isolation structure 114 and the dummy isolation structure 116 may be an island, and a size of the isolation structure 114 is the same as or different from a size of the dummy isolation structure 116 .
FIG. 5A shows a cross section of the touch panel 108 along the cross section line 5 - 5 ′ of FIG. 4 according to an embodiment of the invention. As shown in FIG. 5A , the bridge structure 112 , the conductive patterns 110 X, the conductive patterns 110 Y and the dummy transparent conductive patterns 110 D are disposed on the surface 100 A of the substrate 100 . The conductive patterns 110 Y are electrically connected with each other by the bridge structure 112 . The isolation structure 114 is disposed on the bridge structure 112 for electrically isolating the connection portion of the conductive patterns 110 X from the bridge structure 112 . The dummy isolation structure 116 is disposed over the dummy transparent conductive patterns 110 D. A height H 5 of the isolation structure 114 is lower than a height H 2 of the dummy isolation structure 116 . In an embodiment, the height H 5 is about 50% that of the height H 2 .
The surface 100 A of the substrate 100 is completely covered with a protective layer 120 . The material of the protective layer 120 is for example acrylic resin, silicon nitride, silicon oxide or silicon oxynitride. As shown in FIG. 5A , a height H 3 of a portion of the protective layer 120 over the dummy isolation structure 116 is higher than a height H 4 of a portion of the protective layer 120 over the isolation structure 114 . In an embodiment, a difference between the height H 3 and the height H 4 is about 200 nm. Therefore, scratches occurring at the location of the bridge structure 112 are effectively reduced by the structure design of the touch panel 108 of the embodiment.
FIG. 5B shows a cross section of the touch panel 108 along the cross section line 5 - 5 ′ of FIG. 4 according to another embodiment of the invention. The difference between the touch panel 108 of FIG. 5B and the touch panel 108 of FIG. 5A is the dummy isolation structure 116 directly disposed on the surface 100 A of the substrate 100 and the dummy transparent conductive patterns 110 D disposed over the dummy isolation structure 116 . Similarly, a height of the isolation structure 114 is lower than a height of the dummy isolation structure 116 . Moreover, a height of a portion of the protective layer 120 over the dummy isolation structure 116 is higher than a height of a portion of the protective layer 120 over the isolation structure 114 . Therefore, scratches occurring at the location of the bridge structure 112 are effectively reduced by the structure design of the touch panel 108 of FIG. 5B .
In another embodiment, no dummy transparent conductive pattern 110 D is disposed between the conductive patterns 110 X and the conductive patterns 110 Y. Only the dummy isolation structure 116 is formed on the surface 100 A of the substrate 100 and between the conductive patterns 110 X and the conductive patterns 110 Y.
FIGS. 6A-6D show cross sections of intermediate processes of forming the touch panel 108 of FIG. 5A according to an embodiment of the invention.
Referring to FIG. 6A , firstly, a substrate 100 is provided. The substrate 100 is an upper substrate of a display panel, for example a color filter substrate. A transparent conductive layer or a metal layer is deposited on a surface 100 A of the substrate 100 . Then, the transparent conductive layer or the metal layer is patterned by a photolithography and etching process to form the bridge structure 112 . Next, a transparent conductive layer is deposited on the surface 100 A of the substrate 100 . Then, the transparent conductive layer is patterned by a photolithography and etching process to form the conductive patterns 110 Y and the dummy transparent conductive patterns 110 D. The conductive patterns 110 Y are used for Y-direction sensing electrodes of the touch panel 108 .
Referring to FIG. 6B , the surface 100 A of the substrate 100 is completely coated with an isolation layer. Then, a halftone mask 130 is provided above the isolation layer. The halftone mask 130 may be a gray photo mask, a halftone photo mask or a photo mask with slits. The halftone mask 130 has a transparent pattern 130 C, a translucent pattern 130 A and an opaque pattern 130 B. A patterned isolation layer is formed by using the halftone mask 130 to perform an exposure and a development process to the isolation layer. The patterned isolation layer includes the isolation structure 114 formed on the bridge structure 112 and the dummy isolation structure 116 formed on the dummy transparent conductive patterns 110 D. The isolation structure 114 is corresponded to the translucent pattern 130 A, the dummy isolation structure 116 is corresponded to the opaque pattern 130 B and a portion of the isolation layer corresponding to the transparent pattern 130 C is completely removed. Because the halftone mask 130 is used to perform the exposure and the development process to the isolation layer, the isolation structure 114 and the dummy isolation structure 116 are formed at the same time. Moreover, a height of the isolation structure 114 is lower than a height of the dummy isolation structure 116 .
Referring to FIG. 6C , a transparent conductive layer is deposited on the surface 100 A of the substrate 100 . Then, the transparent conductive layer is patterned by a photolithography and etching process to form the conductive patterns 110 X. The conductive patterns 110 X are used for X-direction sensing electrodes of the touch panel 108 .
Referring to FIG. 6D , the surface 100 A of the substrate 100 is completely coated with the protective layer 120 to complete the touch panel 108 as shown in FIG. 5A . A height of the isolation structure 114 disposed on the bridge structure 112 is lower than a height of the dummy isolation structure 116 . Therefore, after forming the protective layer 120 , a height of a portion of the protective layer 120 over the isolation structure 114 is also lower than a height of a portion of the protective layer 120 over the dummy isolation structure 116 . When a color filter layer 103 or other element layer is formed on another surface 100 B of the substrate 100 , the structure design of the touch panel 108 can effectively prevent or reduce the portion of the touch panel 108 at the location of the bridge structure 112 from scratching. Thus, it can prevent the touch panel 108 from failing.
Then, as shown in FIG. 1 , a substrate 102 , for example a thin-film transistor (TFT) array substrate, is provided opposite to the surface 100 B of the substrate 100 . Further, a display element 104 , for example a liquid crystal layer, is sandwiched between the substrate 100 and the substrate 102 to form the display panel. Moreover, a cover lens 106 , for example a glass substrate or a plastic substrate, may be formed on the outside of the touch panel 108 to complete the fabrication of a touch display device 200 .
FIGS. 7A-7D show cross sections of intermediate processes of forming the touch panel 108 of FIG. 5B according to an embodiment of the invention.
Referring to FIG. 7A , firstly, a substrate 100 is provided. The substrate 100 is an upper substrate of a display panel, for example a color filter substrate. A transparent conductive layer or a metal layer is deposited on a surface 100 A of the substrate 100 . Then, the transparent conductive layer or the metal layer is patterned by a photolithography and etching process to form the bridge structure 112 .
Referring to FIG. 7B , the surface 100 A of the substrate 100 is completely coated with an isolation layer. Then, a halftone mask 130 is provided above the isolation layer. The halftone mask 130 may be a gray photo mask, a halftone photo mask or a photo mask with slits. The halftone mask 130 has a transparent pattern 130 C, a translucent pattern 130 A and an opaque pattern 130 B. A patterned isolation layer is formed by using the halftone mask 130 to perform an exposure and a development process to the isolation layer. The patterned isolation layer includes the isolation structure 114 formed on the bridge structure 112 and the dummy isolation structure 116 formed on the surface 100 A of the substrate 100 . As shown in FIG. 4 , the dummy isolation structure 116 is disposed between the conductive patterns 110 X and the conductive patterns 110 Y. The isolation structure 114 is corresponded to the translucent pattern 130 A and the dummy isolation structure 116 is corresponded to the opaque pattern 130 B. Because the halftone mask 130 is used to perform the exposure and the development process to the isolation layer, the isolation structure 114 and the dummy isolation structure 116 are formed at the same time. Moreover, a height of the isolation structure 114 is lower than a height of the dummy isolation structure 116 .
Referring to FIG. 7C , a transparent conductive layer is deposited on the surface 100 A of the substrate 100 . Then, the transparent conductive layer is patterned by a photolithography and etching process to form the conductive patterns 110 Y, the conductive patterns 110 X and the dummy transparent conductive patterns 110 D at the same time. The conductive patterns 110 Y are separated from each other and electrically connected by the bridge structure 112 . The conductive patterns 110 Y are used for Y-direction sensing electrodes of the touch panel 108 . The conductive patterns 110 X are directly connected with each other, which are used for X-direction sensing electrodes of the touch panel 108 . The dummy transparent conductive pattern 110 D is formed on the dummy isolation structure 116 and disposed between the conductive pattern 110 X and the conductive pattern 110 Y as shown in FIG. 4 . The dummy transparent conductive pattern 110 D is also isolated from conductive pattern 110 X and the conductive pattern 110 Y.
Referring to FIG. 7D , the surface 100 A of the substrate 100 is completely coated with the protective layer 120 to complete the touch panel 108 as shown in FIG. 5B . A height of the isolation structure 114 disposed on the bridge structure 112 is lower than a height of the dummy isolation structure 116 . Therefore, after forming the conductive patterns 110 Y, the conductive patterns 110 X, the dummy transparent conductive patterns 110 D and the protective layer 120 , a height of a portion of the protective layer 120 at the location of the bridge structure 112 is also lower than a height of a portion of the protective layer 120 over the dummy isolation structure 116 . When a color filter layer 103 or other element layer is formed on another surface 100 B of the substrate 100 , the structure design of the touch panel 108 can effectively prevent or reduce the portion of the touch panel 108 at the location of the bridge structure 112 from scratching or crushing. Thus, it can prevent the touch panel 108 from failing.
Then, as shown in FIG. 1 , a substrate 102 , for example a thin-film transistor (TFT) array substrate, is provided opposite to the surface 100 B of the substrate 100 . Furthermore, a display element 104 , for example a liquid crystal layer, is sandwiched between the substrate 100 and the substrate 102 to form the display panel. Moreover, a cover lens 106 , for example a glass substrate or a plastic substrate, may be formed on the outside of the touch panel 108 to complete the fabrication of a touch display device 200 .
In summary, the touch display devices of the embodiments are fabricated by forming a touch panel on a backside of an upper substrate of a display panel. Therefore, one glass substrate is omitted from the touch display device and a total thickness of the touch display device is decreased. Moreover, in the embodiments of the invention, a structure design of a dummy isolation structure is used in the touch panel to make a highest portion of the touch panel to be located on the dummy isolation structure. Thus, when a dual-side process is performed on the upper substrate of the display panel, the structure design of the dummy isolation structure can effectively prevent or reduce the intersection of two-direction sensing electrodes of the touch panel from scratching or crushing. Further, it can prevent the touch panels from failing and enhance the fabrication yield of the touch display devices.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
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A touch display device and a formation method thereof are provided. The touch display device includes a touch panel disposed on a first surface of a substrate of a display panel. A color filter layer is disposed on a second surface of the substrate. The touch panel includes a plurality of first and second conductive patterns arranged by two directions that are perpendicular to each other. A patterned isolation layer, having a first portion and a second portion, is formed over the first surface of the substrate, wherein the first portion is disposed at the intersection of the first and the second conductive patterns, and the second portion is disposed between the first and the second conductive patterns. The first portion has a height that is lower than a height of the second portion.
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[0001] This Application claims the benefit of U.S. Provisional Application No. 62/240,643 titled “Coated Concrete Form,” to Bryan White, filed Oct. 13, 2015, the entire disclosure of which is expressly incorporated by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates generally to concrete forms and related concrete construction technology, and relates more particularly to a concrete form system having an outer form with a structural foam material and an outer protective skin material.
BACKGROUND
[0003] Construction technology related to the pouring, forming, and curing of concrete to build foundation slabs, footers, and basement walls has advanced significantly over the years. While some of the basic materials and procedures for creating a concrete structure have been little changed for literally more than a thousand years, more recently highly sophisticated materials, science, and construction engineering have been applied to certain apparatuses, notably forms, used in pouring concrete.
[0004] One known technique relates to the use of foam panels to contain concrete in its uncured, flowable state in a particular shape so that the concrete can retain that shape once cured. Foam panels have the advantage of being relatively lightweight and easy to handle, and can provide insulation about the periphery of the structure to be formed. Foam panels of known design have various shortcomings relative to certain applications. For instance, foam panels are typically removed once curing of the poured concrete is complete, leaving an unsightly and unfinished exterior surface that must be painted, obscured, or otherwise treated to produce a suitably aesthetically pleasing finish.
SUMMARY
[0005] In one aspect, a concrete form system includes inner and outer forms coupled together via a plurality of connecting webs. The outer form includes a structural foam material forming an inner surface, facing the inner form, and structured to contact concrete poured into a space between the inner form and the outer form. The outer form further includes a protective skin material in contact with the structural foam material and forming an exposed outer surface of the outer form.
[0006] In another aspect, a method of making a concrete form is disclosed. The method includes production of a substantially rectangular body having a plurality of peripheral edges extending about a first and a second body side of an outer concrete form from a structural foam material, applying a protective skin material in liquid form to the first body side such that the skin material adheres to the structural foam material on the first body side, and packaging the substantial rectangular body for shipping with the protective material adhered to the structural foam material located upon only the first body side.
[0007] In still another aspect, a method of constructing a foundation is disclosed, the method including assembling a concrete form system such that an inner form and an outer form are supported in parallel spaced apart relation, positioning the concrete form system upon a footing, pouring uncured concrete into a space extending between the inner and outer forms such that upon curing the concrete forms a solid wall extending upwardly from the footing, and orienting the outer form during assembly and positioning such that an inner surface formed from a structural foam material of the outer form faces the space and is contacted by the poured concrete, and an opposite surface formed from a protective skin material of the outer form is exposed and faces outwardly of the foundation.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 is a top diagrammatic view of a concrete form system and a foundation system at one stage of construction, according to one embodiment;
[0009] FIG. 2 is a sectioned side diagrammatic view of a concrete form system at one stage of construction, according to one embodiment;
[0010] FIG. 3 is a detailed enlargement of a rectangular body, according to one embodiment; and
[0011] FIG. 4 is a diagrammatic view of stages of making a form for use in a concrete form system, according to one embodiment.
DETAILED DESCRIPTION
[0012] Referring to FIG. 1 , there is shown a concrete form system 20 according to one embodiment. Form system 20 may be part of a foundation system 10 including a footer 12 of poured and cured concrete within a trench in the ground. An aggregate 14 of any suitable kind can be placed adjacent to footer 12 to form a subgrade, upon which a poured concrete foundation 13 , typically in the form of a slab is to be poured. A cutout 19 of foundation 13 illustrates aggregate 14 underneath and adjacent to foundation 13 . It should be appreciated that foundation system 10 could be used for supporting a residential living structure, a light industrial installation, or even a bare concrete slab to serve as a parking lot, or for any other conceivable purpose. In a practical implementation strategy, plumbing pipes 18 , electrical service wires, or other installations may be located within or upon aggregate 14 and thus covered by concrete foundation 13 once formed.
[0013] Referring now also to FIG. 2 , there is shown a sectioned diagrammatic view of foundation system 10 and form system 20 along line 2 - 2 of FIG. 1 . System 20 may include an inner form 22 having a first substantially rectangular body 24 with a top peripheral edge 26 and a bottom peripheral edge 28 . System 20 may also include an outer form 30 having a second substantially rectangular body 32 with a top peripheral edge 34 and a bottom peripheral edge 36 . A plurality of connecting webs 38 couple together inner form 22 and outer form 30 in spaced apart relation, with a space 48 extending therebetween. The coupling together of inner form 22 and outer form 30 is also such that rectangular bodies 24 and 32 are oriented parallel to one another at least in a practical implementation, and bottom peripheral edges 28 and 36 are positioned in a common plane or only modestly out of plane, for positioning system 20 upon footer 12 . In one implementation, the components of form system 20 can be assembled prior to placement upon footer 12 , either at a job site or even at a remote assembly facility. An alignment channel 40 extends along bottom peripheral edge 36 , and can be fastened by any suitable means such as an adhesive or fasteners to the concrete forming footer 12 . A fastening bolt 41 is shown as an illustrative example. In a practical implementation strategy, form system 20 may have the general shape of a polygon, extending about a plurality of sides of the foundation system 10 . Form system 20 can therefore contain and direct the flow of concrete 16 not yet in a cured state, filling space 48 to form a stem wall or the like that is positioned upon footer 12 .
[0014] In FIG. 2 , space 48 is shown filled part way with concrete 16 , which will typically be poured to fill space 48 , and flow or extend over the top of inner form 22 to make contact with aggregate 14 . Contact between portions of the poured concrete forming the stem wall and forming the slab is not visible in FIG. 2 due to the section planes chosen. In some instances a gap or intervening layer of a different material could be positioned between the stem wall and slab portions. Inner form 22 may have a shorter height 27 , height 27 being the distance from footer 12 to top peripheral edge 26 , than height 35 of outer form 30 , height 35 the distance from footer 12 to top peripheral edge 34 . It can thus be appreciated that a horizontally extending foundation 13 once cured will be supported upon aggregate 14 , while a downwardly extending stem wall may be formed integrally with the foundation 13 and at least in certain instances extends peripherally about aggregate 14 at an outer edge of foundation system 10 , to contact footer 12 in between inner form 22 and outer form 30 . The relative height 27 of inner form 22 to height 35 of outer form 30 may facilitate the general shaping of the stem wall so as to allow concrete 16 to flow over inner form 22 and come into contact with aggregate 14 when poured into space 48 , or flow over inner form 22 in an opposite direction to fill space 48 . The difference between height 27 and height 35 may depend on a desired thickness of foundation 13 . As concrete 16 may flow over inner form 22 but not outer form 30 , height 35 may be at least the total of height 27 and the desired thickness of foundation 13 . For example, if the height 35 of outer form 30 is 4 feet and the desired thickness of foundation is 6 inches, the height 27 of inner form 30 may not be greater than 42 inches. Outer form 30 may be shaped so a kicker brace or the like 42 may receive top peripheral edge 34 and support the same during pouring of concrete into space 48 . An additional channel piece 52 may be provided as shown end-on in FIG. 1 for positioning at a corner where adjacent panels of outer form 30 are adjoining, extending vertically from footer 12 . It can be seen that channel piece 52 can include channels generally extending in a parallel configuration but opening so as to define approximately a right angle to receive the rectangular bodies 32 of outer form 30 at the corner. An analogous channel can be provided for inner form 22 and is shown in FIG. 1 via reference numeral 54 .
[0015] Outer form 30 may include a structural foam material 50 that forms an inner surface 44 of substantially rectangular body 32 , faces inner form 22 and is thus structured to contact concrete 16 poured into space 48 . Structural foam material 50 may be a one-piece body and is to be understood as structural in that it does not collapse under its own weight, at least when shaped and dimensioned according to generally analogous building products. For instance, outer form 30 might be from about 3 feet wide or tall to about 6 feet wide or tall, from about 2 feet long to about 16 feet long, and from about ½ inch thick to about 12 inches thick. It will be appreciated that the width and length and thickness of body 32 will typically be chosen based upon the intended service application, and accordingly relatively shorter or narrower forms constructed according to the present disclosure might be relatively thinner, whereas relatively taller or wider forms might be relatively thicker. Specific examples of suitable materials for constructing outer form 30 are further discussed herein.
[0016] Referring also to FIG. 3 , there is shown a detailed enlargement of a portion of outer form 30 in greater detail. Outer form 30 further includes a protective skin material 56 in contact with structural foam material 50 . In FIG. 2 , protective skin material 56 is peeled back from structural foam material 50 to illustrate the relatively greater flexibility of material 56 versus material 50 . In the present embodiment, protective skin material 56 may be in contact with only one side of structural foam material 50 , with inner surface 44 remaining free of protective skin material 56 allowing inner surface 44 to contact concrete 16 freely. Inner surface 44 may therefore be in fluid contact with uncured concrete 16 allowing concrete 16 to flow into any voids or pores 60 in structural foam material 50 . The ability of uncured concrete 16 to fluidly contact inner surface 44 without any barrier such as a polymeric coating or other material allows concrete 16 to form a relatively stronger mechanical bond with structural foam material 50 when curing, providing structural rigidity to form system 20 , and may increase durability and longevity of system 20 . In some embodiments, there may additionally be a chemical bond between concrete 16 and structural foam material 50 . A strong bond between outer form 30 and concrete 16 , especially where an outer surface 46 may be textured to have visual or stylistic characteristics as will be discussed further herein, may have certain advantages as will be appreciated by those with skill in the art.
[0017] Protective skin material 56 forms the exposed outer surface 46 of outer form 30 located opposite inner surface 44 . In a practical implementation strategy, rectangular body 32 may consist essentially of structural foam material 50 and protective skin material 56 , although certain additives such as fire retardants, anti-fungals, colorants, pesticides, or still other materials might be part of rectangular body 32 . The outer surface 46 formed by protective skin material 56 may be substantially smooth in many instances, and smoother than inner surface 44 , but can also be roughened or textured in others. In FIG. 3 , indentations or slots 59 are shown in a regular and alternating arrangement with protrusions 57 , a structure that might be seen where a faux brick or stone finish is formed on skin 56 . It is contemplated that material 56 might be applied, as further discussed herein, and textured via mechanical indentation means or another technique prior to completing curing, although the present disclosure is not thereby limited. Thus, embodiments are contemplated where a wood grain, a stone grain, a brick pattern, or still other visually and aesthetically observable properties are present. Top peripheral edge 34 and bottom peripheral edge 36 may be formed of structural foam material 50 . Since surface 44 will typically be formed of the structural foam material, the only protective skin material used may be the protective skin material that is applied to one side only of body 32 .
[0018] It is also contemplated that structural foam material 50 may include a foamed polymeric material, and protective skin material 56 may include a continuous polymeric material adhered to the foamed polymeric material. Further still, the continuous polymeric material may be chemically bonded to the foamed polymeric material. Examples of suitable continuous polymeric materials are certain materials commonly applied by plural component spray, and including a polyurethane, a polyurea, an epoxy, or a hybrid of any of these. Foamed polymeric material comprising material 50 may include a polyisocyanate, polyurethane, or polystyrene, for example. Inner form 22 may be any suitable material desirably but not necessarily having some resistance to degradation over time. The material of which inner form 22 is made will typically be different than the material of which outer form 30 is made, and could include any polymeric material suitable for permanent installation in ground contact conditions.
[0019] It can also be seen from FIG. 3 that an interface 58 resides between material 50 and material 56 . Material 50 may contain voids or pores 60 , commonly associated with a cellular foam material. It will be seen at interface 58 that certain of the voids or pores 60 may be open such that material 56 intrudes therein. It will thus be appreciated that some degree of mechanical interlocking between material 50 and material 56 may occur. As will be further discussed herein, material 56 is applied in the form of a liquid or liquids, thus imparting the tendency for flow of the liquid into any voids or pores in material 50 and interlocking with the same upon curing. Depending upon the materials selected which will typically and by necessity be chemically compatible, polymer crosslinking between material 56 and material 50 may occur. Those skilled in the art will appreciate the cure time and/or hardening time of foamed polymeric materials, and in particular extruded foam polymeric materials, can be such that application of material 56 in plural component liquid form can be timed to enable some chemical bonding between the materials 50 and 56 , and even making available some flexibility in the extent to which chemical bonding is sought. In other words, while it is contemplated that prefabricated and fully cured and/or hardened foamed polymeric materials can be sprayed with plural component coatings according to the present disclosure, in many instances the plural component polymeric material coatings can be sprayed onto the foamed polymeric material prior to completion of curing and/or hardening, in some instances substantially prior to completion of curing and/or hardening and in others when curing and/or hardening of the foamed polymeric material is substantially completed. Desirable properties relating to the manner in which materials 50 and 56 interact and stick together can be empirically determined.
[0020] Referring now to FIG. 4 , there is shown an example a production assembly 100 for producing rectangular bodies 24 , 32 having a protective skin material 56 that can be used in constructing foundation system 10 or form system 20 according to the present disclosure. Process flow in the production assembly generally flows from an extruder 64 to a sprayer 72 and then to a cutter 68 as demonstrated by process flow arrows in FIG. 4 . A texturing device (not shown) could also be part of production assembly 100 , and positioned so as to form texturing as contemplated herein on skin 56 , potentially while soft and/or prior to completing curing. Raw material of conventional type can be fed into a hopper 62 , and then heated and processed to a foamed or foamy state in extruder 64 . Extruder 64 will generate an extrusion in the form of a foam body 66 that can be cut via cutter 68 to a desired dimension, foam body 66 having a first body side 67 and a second body side 69 . For example, according to the present disclosure, cutter 68 may be configured to cut foam body 66 for use as rectangular body 24 and/or rectangular body 32 . In some embodiments, foam body 66 may be formed of structural foam material 50 . It can be seen from the process flow of FIG. 4 that cutter 68 will typically be employed after application of plural component spray 70 . In other words, given a relatively fast cure time commonly on the order of no more than several minutes for many plural component sprays, cutting of the extruded foam body with adhered skin material will typically occur after the skin material has been applied. Plural component spray 70 includes relatively fast-curing liquids, which, when applied to foam body 66 will cure rapidly, forming protective skin material 56 . As discussed herein, plural component spray 70 may chemically bond to foam body 66 when curing. Sprayer 72 may be structured so as to spray plural component spray 70 on first body side 67 of foam body 66 while leaving second body side 69 free of plural component spray 70 . An optional cutter 74 is shown, however, that might be additionally or alternatively used to cut foam body 66 prior to application of the plural component spray 70 . With the plural component spray 70 applied only upon first body side 67 of the extruded foam body 66 , resulting in a coated foam body 76 . Once cut to length coated foam body 76 can be packaged for shipping. While embodiments are contemplated where a number of packaged panels will be strapped to a pallet or the like 78 , it will be appreciated that no limitation to the manner of packaging is contemplated herein, and in some instances no packaging at all could be used without departing from the full and fair scope of the present disclosure. From the foregoing description and that to follow, it will be apparent the present disclosure provides solutions to various shortcomings in known systems. On the one hand, the present disclosure provides for a finished exterior and protective surface of the form system. Physical damage, soiling and UV damage to the insulating foam is avoided. Those skilled in the art will be familiar with the relatively long periods of time that can occur between various stages of construction. Seasonal breaks and long periods of bad weather can leave insulating concrete forms exposed and likely to deteriorate if some protection is not provided. A separate crew in addition to the concrete contractor is often retained to install some sort of protective shielding exterior to the concrete forms. In some housing developments, some homes may be finished and ready for showing to prospective buyers while others are in various states of construction. Exposed foam board and the like can be considered unsightly, especially where splashed with mud, torn, dented, or otherwise degraded. The present disclosure overcomes these and other shortcomings of standard approaches.
[0021] The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present disclosure. For instance, while certain practical implementation strategies are disclosed herein relative to specific material compositions, it will be appreciated that the present disclosure is not strictly limited as such and other possible combinations and mixtures of materials will be apparent to those skilled in the art. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims.
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A concrete form system includes an outer form composed of a structural foam material and a protective skin material. The protective skin material is in contact with the structural foam material and may be chemically bonded such as by crosslinking with the structural foam material. Each of the structural foam material and protective skin material may include a polymeric material. The protective skin material forms an exposed outer surface of the outer form, obviating any need for additional protection from the elements or to be applied during the construction process. The outer form thermally insulates around the periphery of a poured concrete slab, and can be coupled with an inner form, each of the outer form and inner form being assembled in a predetermined relationship and sized so as to control the vertical elevation and thickness of a concrete slab and a foundation stem wall cast between the inner and outer forms. The concrete form system can be pre-assembled in accordance with appropriate dimensions in a workshop in preparation for pouring a concrete slab on a remote job site.
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PRIORITY
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/390,370, filed Oct. 6, 2010, entitled BIOABSORBABLE MESH FOR SURGICAL IMPLANTS, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to implantable surgical meshes for the treatment of a female pelvic condition, and more particularly, to implantable surgical meshes that contain both absorbable and non-absorbable materials. The implantable surgical meshes are particularly useful for procedures involving a transvaginal insertion of all or part of the mesh to a target pelvic area.
BACKGROUND
[0003] Implantable surgical meshes have been widely used for a variety of different surgical procedures such as hernia repair, pelvic floor repair, urethral slings for treating fecal and urinary incontinence, and many others.
[0004] For example, urinary incontinence is a disorder that generally affects women of all ages. The inability to control urination can impact a subject both physiologically and psychologically. Urinary incontinence can interfere with a subject's daily activity and impair quality of life. Stress urinary incontinence is one type of urinary incontinence. Actions including straining, coughing, and heavy lifting can cause women with stress urinary incontinence to void urine involuntarily.
[0005] Various physiological conditions cause urinary incontinence in women. Stress urinary incontinence is generally caused by two conditions that occur independently or in combination. One condition, known as intrinsic sphincter deficiency (ISD), occurs when the urethral sphincter fails to coapt properly. ISD may cause urine to leak out of the urethra during stressful actions. A second condition, known as hypermobility, occurs when the pelvic floor is weakened or damaged and causes the bladder neck and proximal urethra to rotate and descend in response to increases in intra-abdominal pressure. When intra-abdominal pressure increases due to strain resulting from coughing, for example, urine leakage often results.
[0006] One method for treating stress urinary incontinence includes placing a sling to either compress the urethral sphincter or placing a sling to provide a “back stop” to the bladder neck and proximal urethra. Providing support to the bladder neck and proximal urethra maintains the urethra in the normal anatomical position, while elevation places the urethra above the normal anatomical position.
[0007] Other pelvic tissue disorders include cystocele, rectocele, enterocele, and prolapse such as vaginal vault prolapse. Pelvic disorders such as these can result from weakness or damage to normal pelvic support systems. Due to the lack of support, structures such as the uterus, bladder, urethra, small intestine, or vagina, may begin to fall out of their normal positions. Conditions referred to as “conditions of the pelvic floor” include conditions caused by weakness or injury to pelvic floor muscles, including levator muscles.
[0008] A cystocele is a medical condition that occurs when the tough fibrous wall between a woman's bladder and vagina (the pubocervical fascia) is weakened, such as by tearing, allowing the bladder to herniate into the vagina. A rectocele is a bulge of the front wall of the rectum into the vagina. The rectal wall may become thinned and weak, and it may balloon out into the vagina with pressure coming from the bowel. Enterocele is a hernia of the lining of the peritoneal cavity with or without abdominal viscera. The enterocele can occur posteriorly with or without inversion of the vagina.
[0009] Certain types of pelvic floor repair procedures, for example, can involve transvaginal access to internal tissue through a relatively small incision. Procedures can involve the transvaginal insertion of a support member, such as a mesh sling or implant, for supporting specific tissue. The support member may include a central tissue support portion positioned at tissue of a vaginal vault, and extension portions that are moved through respective tissue pathways and their ends anchored at target anatomical sites.
[0010] In a transvaginal procedure, portions of the implant are in contact with or pass through vaginal mucosal tissue, which is a unique anatomical area of the body and that presents some challenges for surgical procedures involving implanted meshes. The vaginal mucosa is lined by squamous epithelium without any glands, and the subepithelial layer contains the vaginal blood vessels. Vaginal secretions contain vaginal epithelial cells and Doderlein's bacilli. Doderlein's bacillus is a commensal species that lives in the vagina, and the bacillus metabolizes glycogen in the vaginal epithelial cells, producing lactic acid. This reduces the vaginal pH to around 5.0 with is too low for many other species including pathogens. Epithelial cells and bacillus that may become attached to the implant during or after the transvaginal procedure are of concerns following surgical implantation/fixation. For example, epithelialization of implant surfaces can prevent desirable tissue in-growth and healing around the mesh.
[0011] Accordingly, there is need for improved implantable surgical meshes that reduce or alleviate the problems associated with the treatment of female pelvic conditions.
BRIEF SUMMARY OF THE INVENTION
[0012] Generally, the invention relates to an implant comprising a mesh portion and configured for transvaginal implantation and positioning in the pelvic area, the implant including non-absorbable and absorbable materials. Embodiments of the invention provide benefits relating to improved tissue integration into the mesh, reduced infection likelihood, improved patient comfort following implantation, or combinations of thereof.
[0013] Implant embodiments of the current invention are configured for transvaginal insertion into a pelvic area of a female patient for the treatment of disorder or disease. The disorder or disease can be selected from, for example, urinary incontinence, vaginal prolapse, cystocele, and rectocele. Portions of the implant can have features to support an anatomical structure in the pelvis (i.e., a “support portion”), such as the vagina, bladder, urethra, or levator ani. Portions of the implant can also have features, such as straps or arms that extend from a support portion of the implant, or tissue anchors or fasteners (e.g., self-fixating tips), to help maintain the implant at a desired anatomical location in the pelvis.
[0014] In one embodiment, the invention provides an implant configured for transvaginal insertion into a female patient to treat a pelvic disorder. The implant comprises a first non-absorbable mesh layer, and a second absorbable layer. The second absorbable layer is non-porous or less porous than the first layer and prevents migration of cells through the second layer prior to its degradation in the body. Optionally, a bioactive agent can be associated with the second absorbable layer
[0015] In a surgical procedure, the mesh can be implanted in the body using a step of transvaginally introducing all or a portion of the mesh into a target area in the female pelvic region. In the method, the implant having first non-absorbable and second absorbable layers is provided. An incision is made in the vaginal tissue, and then the mesh is transvaginally inserted into the patient so the second absorbable layer faces the incision site. For example, the mesh is implanted so the nonporous absorbable polymer layer faces the suture line when the original incision is closed. Following implantation, vaginal mucosa epithelial cells attach to the second absorbable layer, as the mesh is in contact with the vaginal tissue. The second absorbable layer prevents the rapid epithelialization of the first non-absorbable mesh layer by providing a barrier that degrades over time.
[0016] While epithelialization of the non-absorbable mesh (first layer) is being prevented by the second absorbable layer, tissue in-growth begins to fill the pores of the non-absorbable mesh and can eventually surround its structural features (e.g., filaments or molded cells) before the absorbable film becomes porous. The second absorbable layer can therefore reduce the exposure of small areas of mesh implants that otherwise may become apparent a few weeks or months following transvaginal implantation. In many cases these “early” exposures may otherwise occur at spots along the original incision line. Nonuniformities in wound closure may contribute to early mesh exposures. The barrier function provided by the second absorbable layer deters or prevents epithelialization that would otherwise hinder more desirable tissue ingrowth into the first non-absorbable mesh layer. After a period of time the second absorbable layer degrades and desirable tissue in growth occurs on the non-absorbable layer of the mesh.
[0017] In another embodiment, the mesh includes a biological reagent that has an effect on cellular material deposited from the vaginal mucosa on the implant surface when the implant is transvaginally inserted into the patient. Cells that can become deposed on the implant surface include mucosal epithelial cells and Doderlein's bacillus, and it can be desirable to affect these cells as they may be carried internally into the body from the vaginal mucosa during the transvaginal insertion. Alternatively, it can be desirable to affect internal tissue surrounding the implant after the transvaginal insertion of the implant.
[0018] Therefore, in another embodiment, the invention provides an implant configured for transvaginal insertion into a female patient to treat a pelvic disorder, wherein the implant includes a bioactive agent. The implant comprises a non-absorbable mesh, and an absorbable material, wherein absorbable material comprises a bioactive agent that is an antibiotic, antimicrobial, an inhibitor of epithelial cell activation and/or migration, or a compound that enhances wound regeneration. The absorbable material with bioactive agent is in the form of a coating on the non-absorbable mesh, an absorbable filament associated with the non-absorbable mesh, or a second layer associated with the non-absorbable mesh. The type and configuration of the bioabsorbable material associated with the implant can be chosen so any significant amount of bioactive agent is not prematurely released from the implant, an event which may otherwise have an undesirable affect on cells of the vaginal mucosa. Release occurs after implantation where the bioabsorbable material has time to degrade and release the bioactive agent to promote a desired biological effect. Optionally, a bioactive agent can be associated with the absorbable material which can optionally be present in the arms of the implant.
[0019] Another embodiment of the invention uses a combination of absorbable and non-absorbable materials to reduce or eliminate long-term post-implantation discomfort that may be experienced by a mesh recipient. Implantable meshes, such as those used in prolapse repair, can include a central mesh panel and “arms” that extend from the panel and pass through adjacent tissues to anchor the implant and provide support while tissue in growth develops and matures in the central panel. In some meshes these anchoring arms pass through molded eyelets that enable the surgeon to adjust the position and tension applied to the central panel during implantation.
[0020] Therefore, in another embodiment, the invention provides an implant configured for transvaginal insertion into a female patient to treat a pelvic disorder, the implant comprising a central portion and two or more arms that extend from the central portion, wherein the central portion comprises a non-absorbable mesh, and the two or more arms comprise an absorbable material. Optionally, a bioactive agent can be associated with the absorbable material of the arms of the mesh implant. Following implantation, the arms are used to help secure or position the implant at a desired anatomical location in the pelvis. The arms provide this positioning support, but after a period of time, the bioabsorbable material in the arms degrades, thereby reducing the amount of synthetic material in the body and providing better long term comfort to the patient.
[0021] Use of absorbable material is also beneficial in that it can provide additional structural support to the non-absorbable mesh portion during an implantation step. This overcomes issues with some open weave or knit constructions that promote tissue in-growth after implantation but do not necessarily lend sufficient structural support to the mesh to aid in the process of implantation. Further, providing a closed-weave mesh that has sufficient structural support for implantation does not necessarily provide sufficient porosity to promote tissue in-growth for long term stability.
DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an illustration of an implant having non-absorbable and absorbable layers.
DETAILED DESCRIPTION OF THE INVENTION
[0023] All publications and patents mentioned herein are hereby incorporated by reference.
[0024] Implants of the invention are configured for transvaginal implantation and for female pelvic floor repair procedures. The implants can be used to treat a disorder or disease selected from, for example, urinary incontinence, vaginal prolapse, cystocele, and rectocele. As a general matter, the meshes include non-absorbable and absorbable materials. One part of the implant is a woven, knitten, or non-woven/non-knitted (e.g., molded) non-absorbable mesh (e.g., mesh layer). Bioabsorbable material can be associated with the implant in the form of fibers, a thin sheet or film, or a coating. The associated bioabsorbable material prior to absorption may lend additional structural support to the mesh for purposes of implantation. The implants can have sufficient rigidity for implantation, and in some constructions, sufficient openness in the weave pattern. The implant can be configured so the mesh is substantially open to promote tissue-in growth.
[0025] Embodiments of the implants of the invention include a mesh portion constructed from one or more nonabsorbable material(s). Exemplary nonabsorbable materials include synthetic polymers such as polyamides (e.g., nylons), fluoropolymers (e.g., polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVF)), and polyolefins (e.g. polypropylene and polyethylene). In some aspects, polypropylene is used as a nonabsorbable material to form the mesh. Exemplary constructions use polypropylene, including isotactic and syndiotactic polypropylene, or blends thereof, to form the mesh. In some embodiments the implant has a knitted or woven construction using polypropylene monofilaments (see, for example, U.S. Pat. No. 4,911,165). The mesh can be constructed from a monofilament or a multifilament yarn.
[0026] In other embodiments the implant includes a non-knitted/non-woven (e.g., molded) polypropylene mesh layer (see, for example, commonly assigned PCT Publication Nos. WO2011/063412 and WO2011/072148). Non-knitted/non-woven meshes can be formed of patterned cells by way of a molding, die casting, laser etching, laser cutting, extruding, punching, or 3-D printing process. The portion of the implant that is the non-knitted/non-woven mesh can be considered a homogenous unitary construct. The pattern cut or formed implant can be constructed of a non-absorbable polymer material to provide a lattice support structure of repeated cells. Repeated cells or patterns in the implant generally form a lattice structure and can be cut or molded into sinusoid, or other waveform or undulating strut patterns to control elongation or compression along single or multiple axes to define a desirable pattern density with overall reduced surface area, and to control the distribution and shaping from applied loads. In some aspects the thickness of the non-absorbable mesh is in the range from about 0.005 inches to about 0.020 inches. In exemplary constructions, the mesh has a width in the range of about 5 mm to about 15 mm, and a length from about 6 cm to about 15 cm.
[0027] The implants of the invention also can include an “absorbable” material. The terms “bioabsorbable,” “degradable,” and “biodegradable,” can also be used to describe a material that is absorbable, such as an absorbable polymer. Exemplary absorbable materials include polyhydroxyalkanoates, such as poly-4-hydroxybutyrate (P4HB), poly(3-hydroxyvalerate), polylactic acid, poly(lactide-co-glycolide), polycaprolactone, polyphosphazine, polyorthoesters, polyalkeneanhydrides, polyanhydrides, and polyesters, and the like. Polyhydroxyalkanoates include homopolymers such as poly-4-hydroxybutyrate (P4HB), poly(3-hydroxyvalerate), and hydroxyalkanoate copolymers such as poly(hydroxybutyrate-co-hydroxyvalerate) (Organ, S. J. (1994) Polymer, 35, 1:86-92) Blends of hydroxyalkanoate polymers with other absorbable polymers have also been prepared, such as poly(β-hydroxybutyrate) and poly(ε-caprolactone) blends (Gassner, F., and Owen, A. J. (1994) Polymer, 35, 10:2233-2236).
[0028] Polyhydroxyalkanoate polymer compositions useful for preparing implants of the current invention are described in U.S. Pat. No. 7,268,205 (William et al.) and U.S. Pub No. 20080132602 (Rizk et al), the entireties of which is hereby incorporated by reference. Polyhydroxyalkanoate compositions, such as poly-4-hydroxybutyrate, can be manipulated using processing techniques such as solvent casting, melt processing, fiber processing/spinning/weaving, extrusion, injection and compression molding, and lamination, to prepare one or more portions of the implants of the current invention. Porous polyhydroxyalkanoate materials can be prepared by the addition of a salt to a molten polyhydroxyalkanoate composition, followed by subsequent removal of water to remove the salt to leave a porous structure. Degradation of the polyhydroxyalkanoate material can be increased by increasing the porosity of the material. In some aspects, the polyhydroxyalkanoate material of the mesh has an in vivo half-life of between three and six months or less.
[0029] Polyhydroxyalkanoate films can be prepared as described in U.S. Pub No. 2008013260 by solution casting techniques. Exemplary poly-4-hydroxybutyrate films having thicknesses of less than 10 mm, less than 1 mm, and less than 100 are described. If desired, cast films can be stretched and oriented uniaxially or biaxially to yield thinner and stronger films.
[0030] The polyhydroxyalkanoate can have a relatively low melting point/glass transition temperature, for example, less than 136° C. Polyhydroxyalkanoate polymers can also be soluble in a non-toxic, non-halogenated solvent, such as 1,4-dioxane or tetrahydrofuran (THF). In some aspects, bioactive agent-containing polyhydroxyalkanoate compositions can be prepared by including a drug that is soluble in the solvent used to dissolve the polyhydroxyalkanoate. Alternatively, small particulates of bioactive agent, not dissolvable in the polyhydroxyalkanoate solvent, can be homogenized in the polyhydroxyalkanoate solvent. Materials, such as fibers or sheets, can be formed from a melted polyhydroxyalkanoate composition, or a solvent-dissolved polyhydroxyalkanoate composition. In some embodiments of the invention, a solvent-dissolved polyhydroxyalkanoate composition can be used for coating all or a portion of the implant.
[0031] In some embodiments of the invention a bioactive agent is associated with the implant. In exemplary arrangements, the absorbable material with the bioactive agent is in the form of an absorbable filament associated with the non-absorbable mesh, a second layer (e.g., a film or sheet) associated with the non-absorbable mesh layer, or a coating on the non-absorbable mesh.
[0032] Exemplary biologically-active components include: growth factors, pro-angiogenesis factors, anti-fibrotic agents, anti-microbial agents, antibiotics, immuno-suppressive agents, inhibitors of epithelial cell activation and/or migration, compounds that enhance wound regeneration, estrogen, other hormones, immunosupressants, anti-inflammatory agents, anti-cancer drugs, etc. For example, the bioactive agent can comprise the ovarian steroid, estrogen or Estradiol, to treat vaginal prolapse. The design of the mesh can be optimized to allow optimum initial mechanical properties of the mesh and optimum release profiles of the bioactive agents after implantation. The fibers may inherently and/or artificially comprise biologically-active components. In some embodiments, the invention provides an implant that treats pelvic organ prolapse, incontinence, or other urological disorders using the absorbable material to modulate release of the bioactive agent following transvaginal implantation.
[0033] In one embodiment, the implant can increase the thickness of the vaginal tube by the controlled release of estrogen and/or an ovarian steroid hormone from an implant used to treat prolapse. Additionally, the implant can allow for the remodeling of diseased tissues in order to prevent future recurrent prolapse. The implant embodiments of the invention can provide local and targeted delivery of a bioactive agent at low dosages, and therefore can circumvent issues associated with systemic therapies. The bioactive agent can be a simple formulation and, therefore, easy and inexpensive to manufacture.
[0034] The implant can deliver the bioactive agent locally to the desired location within the pelvic area in order to treat a pelvic disorder, while mechanically supporting the structure(s) affected by the pelvic disorder. The implant can controllably release the bioactive agent. The delivery device can degrade overtime, allowing the damaged tissues to remodel back into normal anatomical positions
[0035] The bioactive agent can comprise any drug or combination thereof to treat a specific pelvic disorder. In one embodiment, the bioactive agent can comprise steroids. For example, the bioactive agent can comprise the ovarian steroid, estrogen, to treat vaginal prolapse.
[0036] In some embodiments, the implant comprises a mesh formed from a plurality of absorbable fibers and a plurality of non-absorbable fibers, the mesh further associated with a bioactive agent. For example, the mesh can include both non-absorbable and absorbable fibers that provide mechanical and bioactive agent-release properties. The fibers can be knitted, woven, or molded. The non-absorbable fibers can be made of polypropylene.
[0037] The absorbable fibers can be made of any biocompatible synthetic material, such as those described herein. An exemplary biocompatible synthetic material is that used in surgical sutures. A biological agent can be included in the absorbable fibers in an amount to provide a desired biological effect in the body following implantation. The eventual degradation of the absorbable fibers can provide for a less dense and lighter sling system.
[0038] Exemplary meshes include a plurality of absorbable fibers including an absorbable polyhydroxyalkanoate composition wherein the in vivo degradation rate of the fiber is controlled through the addition during manufacture of components to the polymeric composition, selection of the chemical composition, molecular weight, processing condition and form of the composition. A variety of knitted or woven patterns of the two fibers are also provided.
[0039] In exemplary meshes, a polypropylene non-absorbable fiber is knit or woven together with a polyhydroxyalkanoate absorbable fiber. The non-absorbable fibers can be paired with a polyhydroxyalkanoate absorbable fiber. The resulting paired fibers are then interwoven to form a bi-directional mesh structure prior to absorption of the absorbable fibers. In another exemplary construction, the polypropylene non-absorbable fibers can be aligned in a single direction along an X-axis while the plurality of absorbable fibers are interwoven with the non-absorbable filaments along the Y-axis to thereby form a bi-directional mesh structure prior to absorption of the absorbable fibers.
[0040] In another exemplary construction a polypropylene non-absorbable fiber is intermittently woven together with a polyhydroxyalkanoate absorbable fiber in an I-construction.
[0041] In another exemplary construction a polypropylene non-absorbable fiber is knit or woven together with a polyhydroxyalkanoate absorbable fiber to form a mesh sheet. The polypropylene non-absorbable fibers may be aligned in a single direction along an X-axis while the plurality of absorbable fibers may be interwoven with the non-absorbable filaments along the Y-axis. Alternatively, the plurality of absorbable fibers may be aligned in a single direction along the X-axis while the non-absorbable fibers are interwoven along the Y-axis. Polypropylene non-absorbable fibers and polyhydroxyalkanoate absorbable fibers may then run along an axis that is offset by about 45 degrees or more from the X and/or Y axes. Alternatively, the X and Y axis fibers may be the polypropylene non-absorbable fibers while the fibers running on the third axis may be exclusively polyhydroxyalkanoate absorbable fiber.
[0042] The meshes disclosed herein can be manufactured by any well known weaving or knitting techniques. For example, weaving can use a shuttle loom, Jacquard loom or Gripper loom. In these looms the process of weaving remains similar, the interlacing of two systems of yarns at right angles. This lacing can be simple as in a plain weave where the lacing is over one and under one. Placing the absorbable fibers in one direction, either fill or wrap will result in a final remaining product of the non-absorbent fibers running in one direction. Alternatively, the plain weave may be configured in a more elaborate construction such as twill weave or satin weave.
[0043] Another method of weaving is a leno weave. In this construction two warp yarns are twisted and the fill yarns are passed through the twist. In this type of weaving the warp yarns can be polypropylene while the fill yarn is polyhydroxyalkanoate fibers. Alternatively, for a more open construction the warp yarns can be polyhydroxyalkanoate while the fill yarn is polypropylene. Those skilled in the art will appreciate that additional variations of the basic weaves such as, sateen weaves, antique satin, warp faced twills, herringbone twills and the like can be used to create woven fabrics that will produce the same results when one of the directional yarns absorbs.
[0044] Other types of meshes can be constructed by knitting, which is a process of making cloth with a single yarn or set of yarns moving in only one direction. In weaving, two sets of yarns cross over and under each other. In knitting, the single yarn is looped through itself to make the chain of stitches. One method to do this is described as weft knitting. Knitting across the width of the fabric is called weft knitting.
[0045] Whether a woven or knit mesh is chosen, the ratio of absorbable to non-absorbable yarns can be adjusted. This will provide different amounts of structural integrity of the resulting mesh. For example, using pairs of non absorbable fibers and absorbable fibers would produce a final fabric, after absorption, with a larger open space between the non-absorbable fibers. Variations on this type construction will produce a remaining fabric, which promotes either more of less scar tissue depending on the amount of fabric and distance between sections. This can be adjusted for the type of tissue, which is being replaced. A lighter tissue, such as a fascia for supporting or connecting organs, can use a knitted mesh that has a wider section of absorbable and a narrower section of non-absorbable fibers.
[0046] A second method for knitting a fabric or mesh is warp knitting. In this method the fibers are introduced in the direction of the growth of the fabric (in the y direction). Warp knitting is a family of knitting methods in which the yarn zigzags along the length of the fabric, i.e., following adjacent columns (“wales”) of knitting, rather than a single row (“course”). In this type of knitting the fibers are looped vertically and also to a limited extent diagonally, with the diagonal movement connecting the rows of loops. As with the weft knit fabrics, alternate yarns can be absorbable or non-absorbable. Controlling the number and ratio of absorbable to non-absorbable fibers will control the final material configuration and again the amount of tissue in-growth. Alternating absorbable and non-absorbable fibers produces a final construction with a narrow space between the remaining yarns which are filled in with tissue. As with woven fibers and meshes, the warp knits can be adjusted to create various amounts of tissue in-growth.
[0047] In another embodiment non-absorbable fibers, such as polypropylene fibers, are knit or woven together to form a mesh. The openings in the mesh are intermittently or completely filled with an absorbable material, such as a polyhydroxyalkanoate material. Depending on the initial degree of stiffness or rigidity that is required, a polyhydroxyalkanoate material may be used as a hot-melt glue intermittently at the intersecting portions of the polypropylene fibers. Alternatively the polyhydroxyalkanoate material may be used at all intersecting points. The absorbable composition that is filled into the openings in the mesh can also include a bioactive agent.
[0048] In this aspect, the absorbable material could be filled in so that it is present predominantly on one side of the mesh and forms a second, protective layer that shields the non-absorbable mesh from epithelial cell attachment following implantation. Alternatively, the absorbable material can be filled into the mesh so that it forms a glue for the attachment of a second, protective, absorbable layer. For example, the polyhydroxyalkanoate material can be coated on the polypropylene non-absorbable fibers to form a sheath, which, in addition to providing a barrier to epithelialization of the polypropylene mesh following implantation, functions as a cushion between the stiff polypropylene filaments and the tissue thereby reducing erosion problems.
[0049] An implant with a first non-absorbable mesh layer, and a second absorbable layer that is non-porous or less porous than the first layer and prevents migration of cells through the second layer prior to its degradation in the body can be formed by attaching a thin absorbable film or sheet, such as formed by solvent casting herein, to a non-absorbable mesh. FIG. 1 illustrates such a mesh 10 showing a first non-absorbable layer 12 , which can be prepared from a non-absorbable polymer, such as a polypropylene. One exemplary construction uses a molded polypropylene mesh layer. Another exemplary construction uses a nonabsorbable, large pore, monofilament, mesh. Preferably, the first layer has a thickness in the range of about 0.005 inches to about 0.020 inches, other preferred features or properties of the first absorbable layer are: porosity, flexibility/stiffness, etc.
[0050] The second absorbable layer 14 , can be prepared from a single bioabsorbable polymer, such as a polyhydroxyalkanoate like hydroxybutyrate, or blend of bioabsorbable polymers. One exemplary construction uses a thin film of absorbable material prepared by solvent casting, such as described herein. Followings its introduction into the body, the second absorbable layer is impervious to cells, such as epithelial cells, from the vaginal incision site. After implantation, the second absorbable layer begins to erode and eventually allows cells to pass to the first non-absorbable layer. In some modes of practice, the second absorbable layer erodes and allows the passage of cells in a period of time in the range of about two weeks to about six months. However, in the time it takes for the second absorbable layer to erode and allow the passage of cells, non-epithelial cells and tissue healing components infiltrate the pores of the non-absorbable mesh layer and generate desirable tissue in-growth.
[0051] The first and second layers can be associated with each using one or more different techniques. In one exemplary construction, an absorbable adhesive is used to cause the first non-absorbable mesh layer to adhere to the second absorbable layer. For example, a hot melt adhesive including absorbable polymer can be used at selected points between the first and second layers. The adhesive can use either the same absorbable polymer as the second absorbable layer, or a different absorbable polymer formulation.
[0052] The implant can also include mechanical features to associate the first and second layers. For example, the second absorbable layer can be formed with regularly-spaced protruding features on one surface. These protruding features can be shaped and spaced to interact with the features of the first non absorbable mesh, such as large pore mesh features made using monofilaments. This type of attachment is therefore similar to that of conventional hook and loop fasteners.
[0053] The attachment feature (e.g, such as an adhesive or mechanical feature) can be formulated to absorb more rapidly in vivo than the second absorbable layer. This ensures substantial or complete tissue ingrowth in the first non-absorbable layer before fissures appear in the absorbable film layer. In some cases the second absorbable layer is formed from an absorbable homopolymer, and the attachment feature includes an absorbable copolymer that has a rate of degradation that is faster than the homopolymer. The homopolymer and copolymer can share a common monomer, such as a hydroxyalkanoate like hydroxybutyrate. Other copolymer types, for example, copolymers of ε-caprolactone with dl-lactide have been synthesized to yield materials with rapid degradation rates.
[0054] In yet another embodiment, an apparatus for treating urinary incontinence in a female subject comprises a urethral sling having a central portion and first and second ends or arm. The first and second ends/arms are coupled to and extend from the central support portion. The central support portion is comprised of a mesh knit or woven from non-absorbable fibers or a non-woven/non-knitted (e.g., molded) mesh (and optionally including bioabsorbable material), while the first and second ends comprise absorbable material, such as absorbable fibers or an absorbable sheet. In some embodiments, the end portions comprise a mesh including bioabsorbable and non-absorbable fibers while the central portion comprises non-absorbable fibers. Following implantation, the arms are used to help secure or position the implant at a desired anatomical location in the pelvis. The arms provide this positioning support, but after a period of time, the bioabsorbable material in the arms degrades, thereby reducing the amount of synthetic material in the body and providing better long term comfort to the patient.
[0055] Implants of the invention can be part of a kit. The kit can include components for carrying out procedures for the insertion of the implant in a female patient. Exemplary components can include tissue fasteners, tools for introducing the implant into a female using a transvaginal insertion procedure, scalpels or knives for making the incision, and needles and suture material for closing the incision. All or parts of the kit can be sterilely packaged. Insertion tools useful for transvaginal insertion of the implant can include a handle and an elongate needle, wire, or rod extending from the handle. The needle, wire, or rod can be shaped (such as helical, straight, or curved) to be useful to carry the implant through a desired tissue path in the pelvic region.
[0056] The particular features of the implant embodiments of the invention can be adapted to known mesh implant constructions useful for treating female pelvic conditions, including those already described in the art. Those skilled in the art will recognize that various other mesh configurations, such as those described herein with reference to the following publications, can also be used in conjunction with the features and procedures of the current invention.
[0057] In some constructions, the implant is used for treating incontinence, prolapse, or a mixture of incontinence and prolapse, and includes a portion useful to support the urethra or bladder neck to address urinary incontinence, such as described in commonly assigned application published as US 2010/0256442 (Ogdahl, et al.), and exemplified by the mesh constructions of FIGS. 3B and 3C therein. The implant can be in the form of a mesh strip that in inserted transvaginally and used to support the urethra or bladder neck. The implant can be configured to have a length (distance between distal ends, e.g., self-fixating tips, of extension portions) to extend from a right obturator foramen to a left obturator foramen, (e.g., from one obturator internus muscle to the other obturator internus muscle). Exemplary lengths of an implant or implant portion for extension below the urethra, between opposing obturator foramen, from distal end to distal end of the extensions while laying flat, can be in the range from about 6 to 15 centimeters, e.g., from 7 to 10 centimeters or from 8 to 9 centimeters or about 8.5 centimeters. (Lengths L 1 and L 2 of FIGS. 3B and 3C can be within these ranges.) The lengths are for female urethral slings, and are for anterior portions of implants for treating female prolapse or combined female prolapse and incontinence, which include an anterior portion that has a length between ends of anterior extensions portions within these same ranges. A width of the extension portion can be as desired, such as within the range from about 1 to 1.5 centimeters. The implant can also have two or more tissue anchoring features (e.g., self-fixating tips). The self-fixating tips can be present at the ends of the mesh strips, or at the ends of arms or extensions that extend from a central support portion.
[0058] In some constructions, the mesh can be configured to treat pelvic conditions by supporting levator muscle, such as described in commonly assigned application published as US 2010/0261952 (Montpetit, et al.). The levator musculature or “levator ani” can include the puborectalis, pubococcygeus, iliococcygeus. Exemplary implants can be of a size and shape to conform to levator tissue, optionally to additionally contact or support other tissue of the pelvic region such as the anal sphincter, rectum, perineal body, etc. The implant can be of a single or multiple pieces that is or are shaped overall to match a portion of the levator, e.g., that is circular, oblong trapezoidal, rectangular, that contains a combination of straight, angled, and arcuate edges, etc. The implant can include attached or separate segments that fit together to extend beside or around pelvic features such as the rectum, anus, vagina, and the like, optionally to attach to the feature. The implant can include a tissue support portion, which at least in part contacts levator tissue. Optionally, the implant can additionally include one or more extension portion(s) that extends beyond the tissue support portion and to be secured to tissue of the pelvic region, for support of the tissue support portion. Optionally, extension portions can include features such as a tissue fastener (e.g., self-fixating tip, soft tissue anchor, bone anchor, etc.), a sheath, a tensioning mechanism such as a suture, an adjustment mechanism, etc.
[0059] According to exemplary methods, an implant for supporting levator muscle can be introduced through a vaginal incision that allows access to levator tissue. The method can include use of an insertion tool designed to reach through a vaginal incision, through an internal tissue path and to then extend through a second external incision. In some cases a tools is used to place a self-fixating tip at an internal location of the pelyic region, the tool length sufficient to reach from a vaginal incision to an obturator foramen, region of the ischial spine, sacrospinous ligament, or other location of placing a self-fixating tip. Exemplary methods include steps that involve creating a single medial transvaginal incision and dissecting within a plane or region of dissection including the ischorectal fossa. An implant can be inserted to contact tissue of the levator, over a desired area. A kit with the implant can include connectors for engagement between a needle of an insertion tool and a distal end of an extension portion, as well as helical, straight, and curved needles. An embodiment of a kit, including an insertion tool and an implant, is shown in FIG. 5 of US 2010/0261952.
[0060] The implant can include self-fixating tips designed to engage a distal end of an insertion tool to allow the insertion tool to place the self-fixating tip at a desired tissue location by pushing. For example, the mesh can be implanted by creating a single medial transvaginal incision under the mid-urethra, dissecting a tissue path on each side of the incision, passing a urinary incontinence sling through the incision whereby the urinary incontinence sling is suspended between the obturator internus muscles and the sling body is positioned between the patient's urethra and vaginal wall to provide support to the urethra. Commonly assigned application published as US 2011/0034759 (Ogdahl, et al.), also describes implants that include a self-fixating tip at a distal end of one or more extension portions, and transvaginal methods for inserting the mesh into a patient.
[0061] In some constructions, the mesh can be configured to treat vaginal prolapse, including anterior prolapse, posterior prolapse, or vault prolapse such as described in commonly assigned application published as US 2010/0261955-A1 (O'Hern, et al.). The mesh can be inserted transvaginally, following a single incision in the vaginal tissue, with no external incision. The mesh can be used to provide Level 1 support of the vaginal apex in combination with Level 2 support of medial vaginal sidewall tissue. In terms of vaginal prolapse, Level 1 vaginal tissue support relates to support of the top portion, or “apex” of the vagina. This section of tissue is naturally supported by the cardinal ligament that goes laterally to the ischial spine and crosses over medially to the sacrospinous ligament, and also by the uterosacral ligament that anchors into the sacrum. Level 2 support of vaginal tissue is support of tissue of the mid section of the vagina, below the bladder. This tissue is partially supported by the cardinal ligament but is predominantly supported by lateral fascial attachments to the arcus tendineus or white line. Level 3 support is that of the front end (sometimes referred to as the “distal” section) of the vagina right under the urethra. Natural support includes lateral fascial attachments that anchor into the obturator internus muscle.
[0062] The method for inserting the implant for treating vaginal prolapse can include providing an implant that includes a tissue support portion and two or more extension portions; placing the tissue support portion in contact with vaginal tissue to support the vaginal tissue; and extending a posterior extension portion to engage a sacrospinous ligament, and extending a lateral extension portion to engage tissue at a region of ischial spine, or extending a posterior extension portion to engage a sacrospinous ligament, and extending an anterior extension portion to engage an obturator foramen, or extending an extension portion to engage a sacrospinous ligament to provide Level 1 support, and supporting vaginal tissue to provide Level 2 support. FIG. 16 of US-2010-0261955-A1 illustrates a kit with an implant having a support portion piece, two extension portion pieces, adjusting tool, grommet management tool, and insertion tool.
[0063] In some modes of practice, the implants of the invention can be used along with an expansion member in a sacral colpopexy is a procedure for providing vaginal vault suspension, such as described in commonly assigned International Application No. PCT/US11/53985. A sacral colpopexy generally involves suspension, such as by use of a mesh strip implant, of the vaginal cuff to a region of sacral anatomy such as the sacrum (bone itself), a nearby sacrospinous ligament, uterosacral ligament, or anterior longitudinal ligament at the sacral promontory. The implant can be utilized in a transvaginal sacral colpopexy (TSCP) procedure with an expansion member to access tissue of the posterior pelvic region.
[0064] Implants can be prepared including a mesh that is low-density, bioactive, and image-capable. The low-density mesh relieves stress at the points of attachment. The bioactive mesh biologically treats and repairs the pelvic condition. The mesh can also be image-capable so that the implant can be visualized after implantation.
[0065] In some constructions, the non-absorbable fibers can comprise wire, allowing for the visualization of the implant after implantation. The wire can be made of fine tantalum and/or any other material known by a person skilled in the art and can be woven together with monofilaments of polypropylene or other polymers to create surgical meshes. In some constructions, the mesh can comprise radiopaque ink, allowing for the visualization of the entire mesh. The wire and/or radiopaque ink can provide imaging capability without extensive developmental work. Further, the wire and radiopaque ink do not substantially alter the mechanical properties of the existing mesh. Nor do the wire and radiopaque ink substantially alter local tissue response.
[0066] These and other features and advantages and embodiments of the present invention will become apparent from the following this description, when taken in conjunction with the accompanying drawing which illustrate, by way of example, the principles of the invention. It will be further apparent from the foregoing that other modifications of the inventions described herein can be made without departing from the spirit and scope of the invention.
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Described are methods, devices, and systems related to implants for the treatment of a female pelvic condition. The implants include absorbable and non-absorbable materials and can be introduced into the pelvic area transvaginally. Meshes of the invention provide benefits relating to improved tissue integration into the mesh, reduced infection likelihood, improved patient comfort following implantation, or combinations of thereof.
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TECHNICAL FIELD OF THE INVENTION
This invention relates in general to preventing the production of particulate materials through a wellbore traversing an unconsolidated or loosely consolidated subterranean formation and in particular to an apparatus and method for monitoring gravel placement throughout the entire length of a production interval.
BACKGROUND OF THE INVENTION
Without limiting the scope of the present invention, its background is described with reference to the production of hydrocarbons through a wellbore traversing an unconsolidated or loosely consolidated formation, as an example.
It is well known in the subterranean well drilling and completion arts that particulate materials such as sand may be produced during the production of hydrocarbons from a well traversing an unconsolidated or loosely consolidated subterranean formation. Numerous problems may occur as a result of the production of such particulate. For example, the particulate causes abrasive wear to components within the well, such as tubing, pumps and valves. In addition, the particulate may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate matter is produced to the surface, it must be removed from the hydrocarbon fluids by processing equipment at the surface.
One method for preventing the production of such particulate material to the surface is gravel packing the well adjacent the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a particulate material known as gravel is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
Typically, the liquid carrier is returned to the surface by flowing through the sand control screen and up a wash pipe. The gravel is deposited around the sand control screen to form a gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of particulate materials from the formation.
It has been found, however, that a complete gravel pack of the desired production interval is difficult to achieve particularly in long production intervals that are inclined, deviated or horizontal. One technique used to pack a long production interval that is inclined, deviated or horizontal is the alpha-beta gravel packing method. In this method, the gravel packing operation starts with the alpha wave depositing gravel on the low side of the wellbore progressing from the near end to the far end of the production interval. Once the alpha wave has reached the far end, the beta wave phase begins wherein gravel is deposited in the high side of the wellbore, on top of the alpha wave deposition, progressing from the far end to the near end of the production interval.
It has been found, however, that as the desired length of horizontal formations increases, it becomes more difficult to achieve a complete gravel pack even using the alpha-beta technique. Therefore, a need has arisen for an improved apparatus and method for gravel packing a long production interval that is inclined, deviated or horizontal. A need has also arisen for such an improved apparatus and method that achieve a complete gravel pack of such production intervals. Further, a need has arisen for such an improved apparatus and method that provide for enhanced control over the gravel placement process in substantially real time.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an apparatus and method for gravel packing long production intervals that are inclined, deviated or horizontal. The present invention overcomes the limitations of the existing methodologies by providing for enhanced control over the gravel placement process. In particular, the apparatus and method of the present invention enable fluid properties within a production interval of a wellbore to be monitored in substantially real time, thereby allowing substantially real time adjustments to be made during a gravel packing operation.
In one aspect, the present invention is directed to an apparatus for treating a production interval of a wellbore. The apparatus includes a packer assembly and a sand control screen assembly connected relative to the packer assembly. A cross-over assembly provides a lateral communication path downhole of the packer assembly for delivery of a treatment fluid and a lateral communication path uphole of the packer assembly for a return fluid. A wash pipe assembly is positioned in communication with the lateral communication path uphole of the packer assembly and extends into the interior of the sand control screen. At least one sensor is operably associated with the wash pipe assembly in order to collect data relative to at least one property of the treatment fluid during a treatment process such that a characteristic of the treatment fluid is regulatable during the treatment process based upon the data.
In one embodiment, the wash pipe comprises a body that includes a plurality of composite layers and a substantially impermeable layer lining an inner surface of the innermost composite layer forming a pressure chamber. In this embodiment, an energy conductor is integrally positioned within the body. The sensor may be directly or inductively coupled to the energy conductor which may take the form of an optical fiber that provides for communication between the sensor and other downhole devices such as a downhole processor or the surface. The sensor may measure properties of the treatment fluid such as viscosity, temperature, pressure, velocity, specific gravity, conductivity, fluid composition and the like. In one embodiment, a series of sensors may be embedded within the body of the wash pipe at predetermined intervals such that the treatment fluid properties may be monitored as a function of position along the length of the interval. Based upon the data collected by the sensors, various characteristics of the treatment fluid may be regulated such as fluid viscosity, proppant concentration, flow rate and the like. In one embodiment, the apparatus may further comprise a downhole mixer which provides a mixing area wherein constituent parts of the treatment fluid such as the carrier fluid and the solids are combined to form the fluid slurry downhole which reduces the delay in the downhole effect of the real time regulation of treatment fluid characteristics.
In another aspect, the present invention is directed to an apparatus for monitoring treatment fluid in a production interval of a wellbore during a treatment process. The apparatus comprising at least one sensor operably positioned within the production interval of the wellbore, wherein the sensor is operable to collect data relative to at least one property of the treatment fluid during the treatment process such that at least one characteristic of the treatment fluid is regulatable during the treatment process based upon the data.
In one embodiment, the sensor is operably associated with a tubular that may comprise a substantially impermeable layer lining an inner surface of a composite structure forming a pressure chamber therein. The tubular may form a portion of a washpipe, a base pipe, a production tubing or the like. The sensor may be attached or embedded within the inner surface of the composite structure or may be attached or embedded on the exterior of the body of the composite structure.
In a further aspect, the present invention is directed to a method for treating a production interval of a wellbore. The method includes positioning a sand control screen assembly within the production interval, disposing a wash pipe assembly interiorly of the sand control screen assembly, injecting a treatment fluid into the production interval exteriorly of the sand control screen assembly, sensing data relative to a property of the treatment fluid during the injecting with a sensor operably associated with the wash pipe and regulating a characteristic of the treatment fluid during the injecting based upon the data.
In one embodiment, the sensor is directly or inductively coupled to an energy conductor that is operably associated with the wash pipe such as an optical fiber integrally associated with the wash pipe. The data may include information relative to fluid viscosity, temperature, pressure, velocity, specific gravity, conductivity, fluid composition or the like. Once the data is processed either at the surface or by a downhole processor, real time alterations to the treatment may be performed such as regulating the fluid viscosity of the treatment fluid, regulating the proppant concentration of the treatment fluid, regulating the flow rate of the treatment fluid or the like.
In another aspect, the present invention is directed to a method for monitoring treatment fluid in a production interval of a wellbore during a treatment process. The method includes positioning at least one sensor within the production interval of the wellbore, sensing data relative to a property of the treatment fluid during the treatment process and regulating a characteristic of the treatment fluid during the treatment process based upon the data.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
FIG. 1 is a schematic illustration of an offshore oil and gas platform operating an apparatus for gravel packing a production interval of a wellbore in accordance with the teachings of the present invention;
FIG. 2 is a half sectional view depicting the operation of an apparatus for gravel packing a horizontal open hole production interval of a wellbore of the present invention;
FIG. 3 is a partial half sectional view depicting the operation of an apparatus for gravel packing a horizontal open hole production interval of a wellbore of the present invention during the propagation of an alpha wave;
FIG. 4 is a partial half sectional view depicting the operation of the apparatus for gravel packing the horizontal open hole production interval of the wellbore of the present invention during the propagation of the alpha wave;
FIG. 5 is a partial half sectional view depicting the operation of the apparatus for gravel packing the horizontal open hole production interval of the wellbore of the present invention after a real time adjustment in the gravel packing slurry during the propagation of the alpha wave;
FIG. 6 is a partial half sectional view depicting the operation of the apparatus for gravel packing the horizontal open hole production interval of the wellbore of the present invention during the propagation of a beta wave;
FIG. 7 is a partial half sectional view depicting the operation of the apparatus for gravel packing the horizontal open hole production interval of the wellbore of the present invention at the completion stage of the treatment process;
FIG. 8 is a cross sectional view depicting a composite coiled tubing having energy conductors and sensors embedded therein in accordance with the teachings of the present invention;
FIG. 9 is a cross sectional view depicting an alternate embodiment of a composite coiled tubing having energy conductors and sensors embedded therein in accordance with the teachings of the present invention;
FIG. 10 is a half sectional view depicting the operation of an alternate embodiment of an apparatus for gravel packing a horizontal open hole production interval of a wellbore of the present invention;
FIG. 11 is a half sectional view depicting the operation of a further embodiment of an apparatus for gravel packing a horizontal open hole production interval of a wellbore of the present invention;
FIG. 12 is a half sectional view depicting the operation of another embodiment of an apparatus for gravel packing a horizontal open hole production interval of a wellbore of the present invention during the propagation of an alpha wave; and
FIG. 13 is a half sectional view depicting the operation of another embodiment of an apparatus for monitoring fluid parameters during production from a horizontal open hole production interval of a wellbore of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
Referring initially to FIG. 1 , an apparatus for gravel packing a horizontal open hole production interval of a wellbore operating from an offshore oil and gas platform is schematically illustrated and generally designated 10 . A semi-submersible platform 12 is centered over a submerged oil and gas formation 14 located below sea floor 16 . A subsea conduit 18 extends from deck 20 of platform 12 to wellhead installation 22 including blowout preventers 24 . Platform 12 has a hoisting apparatus 26 and a derrick 28 for raising and lowering pipe strings such as work string 30 .
A wellbore 32 extends through the various earth strata including formation 14 . A casing 34 is cemented within a portion of wellbore 32 by cement 36 . Work string 30 extends beyond the end of casing 34 and includes a series of sand control screen assemblies 38 and a cross-over assembly 40 for gravel packing the horizontal open hole production interval 42 of wellbore 32 . When it is desired to gravel pack production interval 42 , work string 30 is lowered through casing 34 such that sand control screen assemblies 38 are suitably positioned within production interval 42 . Thereafter, a fluid slurry including a liquid carrier and a particulate material such as sand, gravel or proppants is pumped down work string 30 .
As explained in more detail below, the fluid slurry is injected into production interval 42 through cross-over assembly 40 . Once in production interval 42 , the gravel in the fluid slurry is deposited therein using the alpha-beta method wherein gravel is deposited on the low side of production interval 42 from the near end to the far end of production interval 42 then in the high side of production interval 42 , on top of the alpha wave deposition, from the far end to the near end of production interval 42 . While some of the liquid carrier may enter formation 14 , the remainder of the liquid carrier travels through sand control screen assemblies 38 , into a wash pipe (not pictured) and up to the surface via annulus 44 above packer 46 . Sensors distributed along the length of production interval 42 monitor the fluid slurry at various locations and relay data relative to the fluid slurry to a downhole processor or to the surface. Various characteristics of the fluid slurry such as proppant concentration, fluid viscosity, fluid flow rate and the like may be regulated based on the relayed data to avoid, for example, sand bridges and to insure a complete gravel pack within production interval 42 .
Even though FIG. 1 and the following figures depict a horizontal wellbore and even through the term horizontal is being used to describe the orientation of the depicted wellbore, it should be understood by those skilled in the art that the present invention is equally well suited for use in wellbores having other orientations including inclined or deviated wellbores. Accordingly, the use of the term horizontal herein is intended to include such inclined and deviated wellbores and is intended to specifically include any wellbore wherein it is desirable to use the alpha-beta gravel packing method. Additionally, it will be appreciated that the present invention is not limited to open hole production intervals. Moreover, it should be appreciated that the present invention is not limited to alpha-beta gravel packing treatments. As should be understood by those skilled in the art, the teachings of the present invention are also applicable to other treatment processes such as fracturing, frac packing, acid or other chemical treatments, resin consolidations, conformance treatments or any other treatment processes involving the pumping of a fluid into a downhole environment wherein it is beneficial to monitor various fluid properties as a function of position and use this data to regulate various treatment fluid characteristics during the treatment process.
Referring now to FIG. 2 , therein is depicted a horizontal open hole production interval of a wellbore that is generally designated 50 . Casing 52 is cemented within a portion of a wellbore 54 proximate the heel or near end of the horizontal portion of wellbore 54 . A work string 56 extends through casing 52 and into the open hole production interval 58 of wellbore 54 . A packer assembly 60 is positioned between work string 56 and casing 52 at a cross-over assembly 62 . Work string 56 includes a sand control screen assembly 64 . Sand control screen assembly 64 includes a base pipe 70 that has a plurality of openings 72 which allow the flow of production fluids into the production tubing. The exact number, size and shape of openings 72 are not critical to the present invention, so long as sufficient area is provided for fluid production and the integrity of base pipe 70 is maintained.
Wrapped around base pipe 70 is a screen wire 74 . Screen wire 74 forms a plurality of turns with gaps therebetween through which formation fluids flow. The number of turns and the gap between the turns are determined based upon the characteristics of the formation from which fluid is being produced and the size of the gravel to be used during the gravel packing operation. Screen wire 74 may be wrapped directly on base pipe 70 or may be wrapped around a plurality of ribs (not pictured) that are generally symmetrically distributed about the axis of base pipe 70 . The ribs may have any suitable cross sectional geometry including a cylindrical cross section, a rectangular cross section, a triangular cross section or the like. In addition, the exact number of ribs will be dependant upon the diameter of base pipe 70 as well as other design characteristics that are well known in the art.
It should be understood by those skilled in the art that while FIG. 2 has depicted a wire wrapped sand control screen, other types of filter media could alternatively be used in conjunction with the apparatus of the present invention, including, but not limited to, a fluid-porous, particulate restricting, diffusion bonded or sintered metal material such as a plurality of layers of a wire mesh that form a porous wire mesh screen designed to allow fluid flow therethrough but prevent the flow of particulate materials of a predetermined size from passing therethrough.
Disposed within work string 56 and extending from cross-over assembly 62 is a wash pipe assembly 76 . Wash pipe assembly 76 extends substantially to the far end of work string 56 near the toe or far end of production interval 58 . In the illustrated embodiment, wash pipe assembly 76 is a composite coiled tubing 78 that includes a series of sensors 80 embedded at predetermined intervals along wash pipe assembly 76 each of which is connected to one of a plurality of energy conductors 82 integrally positioned within composite coiled tubing 78 . As illustrated, sensors 80 include optical pressure sensors. It should be appreciated, however, that other types of pressure sensors may be used, including, but not limited to, electronic pressure sensors and the like. Moreover, as will be explained in further detail hereinbelow, the sensors may include viscosity sensors, temperature sensors, velocity sensors, specific gravity sensors, conductivity sensors, fluid composition sensors and the like. Additionally, it should be appreciated that multiple types of sensors may be employed together to collect data. For example, temperature sensors, pressure sensors and conductivity sensors may be employed together to achieve a better understanding of downhole conditions. Also, even though sensors 80 are depicted as being directly coupled to energy conductors 82 , it should be understood by those skilled in the art that sensors 80 could alternatively communicate with energy conductor 82 by other means including, but not limited to, by inductive coupling.
Referring now to FIG. 2 and FIG. 3 in which the operation of the apparatus for gravel packing the horizontal open hole production interval of the wellbore during the propagation of an alpha wave is depicted. Sensors 80 monitor data relative to the various properties of fluid slurry 84 and the downhole environment in production interval 58 and relay this data to a downhole processor or to the surface so that the composition of fluid slurry 84 may be regulated by regulating various fluid characteristics such as fluid viscosity, proppant concentration and flow rate of fluid slurry 84 . Energy conductors 82 are preferably fiber optic strands that carry optical information. The fiber optic strands may form a bundle 86 at the top of wash pipe assembly 76 which extends to the surface in annulus 88 . Alternatively, energy conductor 82 may be electrical wires. Communication may alternatively be achieved using a downhole telemetry system such as an electromagnetic telemetry system, an acoustic telemetry system or other wireless telemetry system that is known or subsequently discovered in the art for communications with the surface or a downhole processor.
During a gravel packing operation, the objective is to uniformly and completely fill horizontal production interval 58 with gravel. This is achieved by delivering a fluid and gravel slurry 84 down work string 56 into cross-over assembly 62 . Fluid slurry 84 containing gravel exits cross-over assembly 62 through cross-over ports 90 and is discharged into horizontal production interval 58 as indicated by arrows 92 . In the illustrated embodiment, fluid slurry 84 containing gravel then travels within production interval 58 with portions of the gravel dropping out of the slurry and building up on the low side of wellbore 54 from the heel to the toe of wellbore 54 as indicated by alpha wave front 94 of the alpha wave portion of the gravel pack. At the same time, portions of the carrier fluid of the fluid slurry pass through sand control screen assembly 64 and travel through annulus 96 between wash pipe assembly 76 and the interior of sand control screen assembly 64 . These return fluids enter the far end of wash pipe assembly 76 , flow back through wash pipe assembly 76 to cross-over assembly 62 , as indicated by arrows 98 , and flow into annulus 88 through cross-over ports 100 for return to the surface.
As the propagation of alpha wave front 94 continues from the heel to the toe of horizontal production interval 58 , sensors 80 monitor data relative to fluid slurry 84 and the downhole environment such as viscosity, temperature, pressure, velocity, fluid composition and the like, to ensure proper placement of the gravel and to avoid, for example, sand bridge formation with wellbore 54 .
Using sensors 80 of the present invention, the height of alpha deposition within production interval 58 may be regulated. Specifically, as best seen in FIG. 4 , during the alpha wave portion of the gravel placement, portions of the alpha deposition are building up toward the high side of wellbore 54 . The changes in pressure caused by the build up of the alpha deposition are monitored by sensors 80 such that data may be sent to the surface or to a downhole processor in substantially real time, such that fluid slurry characteristics such as fluid viscosity, proppant concentration and flow rate of fluid slurry may be adjusted.
Referring now to FIG. 5 , responsive to the real time indications that the alpha deposition is too high, the composition, flow rate or other characteristic of fluid slurry 84 is adjusted so that the height of the alpha deposition can be returned to a desirable level in substantially real time, as illustrated. Accordingly, by positioning sensors 80 at predetermined intervals, the present invention provides for the collection, recording and analysis of substantially real time data as a function of position relative to physical qualities within the wellbore. In this regard, the exact number of sensors and spacing of the sensors will be dependent on the specific type of treatment process being performed. It should be appreciated that a variety of sensors may be used to measure a variety of qualities to regulate the completion process. For example, properly positioned sensors could measure the change in the density of fluid slurry 84 within production interval 58 . Specifically, as the composition of constituent matter in production interval 58 at a particular sensor changes from a fluid slurry to a gravel pack as alpha wave front 94 passes a location, the density at this location significantly increases. Accordingly, by sensing the density at this location, the progress of alpha wave front 94 may be monitored and regulated. Other properties such as absolute pressure, absolute temperature, upstream-downstream differential temperature, flow velocity in production interval 58 and the like could also be measured by sensors 80 to regulate the alpha deposition. Hence, by improving the control over gravel placement the present invention insures a more complete gravel pack along the entire length of the production interval. In particular, the present invention ensures complete gravel packs of long, horizontal wellbores by providing substantially real time data relative to a plurality of locations along the completion interval.
Referring now to FIG. 6 , as the beta wave portion of the treatment process progresses, sensors 80 monitor the progress of beta wave front 118 , fluid slurry 84 and the wellbore environment and relay the monitored data to a downhole processor or to the surface so that various parameters of the gravel slurry may be regulated in substantially real time to ensure a complete gravel pack. FIG. 7 depicts wellbore 54 after the beta wave gravel placement step and the treatment process of production interval 58 is complete. It should be appreciated that the present invention is applicable not only to gravel placement processes, but also to other fluid treatments such as stimulations, fractures, acid treatments and the like. Following the completion process, sensors 80 of the present invention may continue to be employed to provide the downhole hardware necessary to monitor one or more physical qualities of the wellbore including production fluid properties. In this respect, the teachings presented herein are not limited to the completion phases of a wellbore, but are also applicable to other phases of a wellbore including production. For example, after the completion of wellbore, the sensors of the present invention provide real time measurements at a series of points along the production interval that allow information to be obtained as a function of position relative to the location or locations of hydrocarbon production, water encroachment, gas breakthrough and the like.
Referring now to FIG. 8 , a composite coiled tubing 130 having energy conductors 132 and sensors 134 embedded therein is depicted. Composite coiled tubing 130 includes an inner fluid passageway 136 defined by an inner thermoplastic liner 138 that provides a body upon which to construct the composite coiled tubing 130 and that provides a relative smooth interior bore 140 . Fluid passageway 136 provides a conduit for transporting fluids such as the completion and production fluids discussed hereinabove. Layers of braided or filament wound material such as Kevlar or carbon encapsulated in a matrix material such as epoxy surround liner 138 forming a plurality of generally cylindrical layers, i.e., a composite structure, such as layers 142 , 144 , 146 , 148 , 150 of composite coiled tubing 130 .
The materials of composite coiled tubing 130 provide for high axial strength and stiffness while also exhibiting high pressure carrying capability and low bending stiffness. For spooling purposes, composite coiled tubing 130 is designed to bend about the axis of the minimum moment of inertia without exceeding the low strain allowable characteristic of uniaxial material, yet be sufficiently flexible to allow the assembly to be bent onto the spool.
Layer 148 has energy conductors 132 that may be employed for a variety of purposes. For example, energy conductors 132 may be power lines, control lines, communication lines or the like. Preferably, energy conductors 132 may be optical fiber strands wound within layer 148 . Sensors 134 are embedded within outer layer 150 and are coupled to one of the energy conductors 132 . Sensors 134 may provide data relative to viscosity, temperature, pressure, velocity, specific gravity, conductivity, fluid composition, or the like. For example, sensors 134 may be fiber optic pressure sensor that measure the pressure in the region surrounding composite coiled tubing 130 . Alternatively, sensors 134 may be strain gage pressure sensors, or micro sensors such as a micro electrical sensors. As another example, sensors 134 may be electrodes operable to detect the presence of non-conducting oil or conducting water. Additionally, it should be appreciated that a variety of types of sensors may be employed to collect data about a fluid surrounding composite coiled tubing 130 . Moreover, it will be appreciated that the selection of sensors will be dependant upon the desired attributes to be monitored within the well.
Although a specific number of energy conductors 132 and sensors 134 are illustrated, it should be understood by one skilled in the art that more or less energy conductors 132 or sensors 134 than illustrated are in accordance with the teachings of the present invention. Moreover, it should be appreciated that sensors 134 may alternatively be embedded within interior bore 140 or within both interior bore 140 and outer layer 150 .
The design of composite coiled tubing 130 provides for fluid to be conveyed in fluid passageway 136 and energy conductors 132 and sensors 134 to be positioned in the matrix about fluid passageway 136 . It should be understood by those skilled in the art that while a specific composite coiled tubing is illustrated and described herein, other composite coiled tubings having a fluid passageway and one or more energy conductors could alternatively be used and are considered within the scope of the present intention.
For example, with reference to FIG. 9 , an alternate embodiment of a composite coiled tubing 160 having energy conductors 162 and sensors 164 embedded therein in accordance with the teachings of the present invention is illustrated. Layers 166 , 168 of braided or filament wound material encapsulated in a matrix material form a composite structure. Contrary to composite coiled tubing 130 of FIG. 7 , composite coiled tubing 160 does not include a conduit for transporting fluids. Similar to composite coiled tubing 130 of FIG. 7 , a plurality of energy conductors 162 , which may take the form of optical fibers, are embedded in the matrix to relay data between sensors 164 and the surface. It should be appreciated that the composite coil tubing presented in FIGS. 7 and 8 are not limited to tubular goods or tubings having circular cross-sections. The teachings of the present invention are applicable to composite coiled tubings having non-circular cross-sections such as rectangular or irregular cross-sections.
FIG. 10 is a half sectional view depicting the operation of an alternate embodiment of an apparatus 180 for gravel packing a horizontal open hole production interval 182 of a wellbore 184 of the present invention during a treatment operation. Casing 186 is cemented within a portion of wellbore 184 . Work string 188 includes a sand control screen assembly 190 that extends into open hole production interval 182 of wellbore 184 . Packer assembly 196 is positioned between work string 188 and casing 186 at a cross-over assembly 198 . Disposed within work string 188 and extending from cross-over assembly 198 is a wash pipe assembly 200 .
Sand control screen assembly 190 includes base pipe 202 which comprises composite coiled tubing 204 that includes energy conductors 206 integrally positioned therein. A series of sensors 208 embedded on the outer surface of base pipe 202 are coupled to energy conductors 206 to monitor fluid properties within an annulus 210 formed between base pipe 202 and wellbore 184 . Preferably, sensors 208 are embedded on base pipe 202 inside of screen wire 212 . As illustrated, during an alpha-beta gravel packing operation, sensors 208 positioned on the exterior of base pipe 202 monitor fluid properties and the wellbore environment within annulus 210 to determine any number of a variety of wellbore properties including fluid viscosity, temperature, pressure, fluid velocity, fluid specific gravity, fluid conductivity and fluid composition. The measured data is relayed to a downhole processor or to the surface in substantially real time via energy conductors 206 . Energy conductors 206 may extend to the surface embedded within work string 188 which may be formed entirely as a composite coiled tubing. Alternatively, energy conductors 206 may form a bundle that extends to the surface within the annulus between work string 188 and casing 186 .
FIG. 11 is another embodiment of an apparatus 220 for gravel packing a horizontal open hole production interval 222 of a wellbore 224 of the present invention during a treatment operation. Similar to FIG. 10 , the production interval of FIG. 11 includes a casing 226 , a work string 228 , sand control screen assembly 230 , a packer assembly 236 , a cross-over assembly 238 and a wash pipe 240 . Base pipe 242 of sand control screen assembly 230 comprises composite coiled tubing 244 that includes energy conductors 246 integrally positioned therein. A series of sensors 248 embedded within the interior surface of base pipe 242 are coupled to energy conductors 246 to monitor wellbore properties within the annulus 250 formed between base pipe 242 and wash pipe 240 .
Referring flow to FIG. 12 , an apparatus 260 for monitoring fluid properties within a production interval 262 is depicted. A wellbore 264 includes casing 266 which is cemented therewith. A work string 268 extends through casing 266 and into production interval 262 . An outer tubular 270 is positioned within work string 268 and a packer assembly 272 provides a seal therebetween. An inner tubular 274 is positioned within outer tubular 270 . In operation, tubular 270 provides carrier fluid and a tubular 274 provides sand, gravel or proppants into a downhole mixer which provides a mixing area 276 wherein the carrier fluid and the solids mix to form fluid slurry 278 . Fluid slurry 278 , in turn, is delivered to production interval 262 via a cross-over assembly 260 as indicated by arrows 282 .
As previously discussed, a wash pipe 284 positioned within sand control screen assembly 286 includes sensors 288 to monitor data relative to fluid slurry 278 and the wellbore environment in production interval 262 and to relay this data preferably to a downhole process the controls valving or other control equipment associated with tubulars 270 , 274 so that the characteristics of fluid slurry 278 may be adjusted by, for example, regulating the relative volume of carrier fluid to solids or the over all rate of component delivery to mixing area 276 from tubular 270 and tubular 274 , thereby regulating the characteristics of fluid slurry 278 in substantially real time. In particular, this embodiment allows for rapid changes in fluid slurry characteristics as the fluid slurry composition is mixed close to its delivery point as opposed to at the surface, thereby further enhancing the benefits of the present invention. It should be appreciated that the exemplary mixing embodiment presented herein may be employed with any of the apparatuses for monitoring fluid properties presented hereinabove.
FIG. 13 is a further embodiment of an apparatus 300 for monitoring fluid properties in a horizontal open hole production interval 302 of a wellbore 304 of the present invention. Casing 306 is cemented within a portion of wellbore 304 . Production tubing string 308 includes sand control screen assembly 310 and packer assembly 312 that provides a seal between production tubing string 308 and casing 306 .
A tubular 314 extending from the surface is formed from composite coiled tubing 316 and is positioned within production tubing string 308 . Energy conductors 318 are integrally positioned within composite coiled tubing 316 . Preferably, composite coiled tubing 316 includes a relatively small diameter so that composite coiled tubing 316 does not interfere with the production of the well. A series of sensors 320 embedded within composite coiled tubing 316 are coupled to energy conductors 318 which are spaced at predetermined intervals along the exterior of composite coiled tubing 316 to monitor fluid properties within the production tubing string 308 to develop production profiles including hydrocarbon production, water encroachment, gas breakthrough and the like. It should be appreciated from the foregoing exemplary embodiments that the sensors of the present invention may be positioned in a variety of places such as within the interior or exterior of a base pipe, within the interior or exterior of a wash pipe or within the interior or exterior of a tubular positioned within a production tubing string. Moreover, it should be appreciated that the sensors may be employed in a combination of the aforementioned places.
Accordingly, the present invention provides an apparatus and method for gravel packing long production intervals that are inclined, deviated or horizontal. In particular, the systems and methods of the present invention are useful in extremely long wellbores where substantially real time data about fluid properties is essential to achieve an effective treatment. Hence, the present invention enables fluid properties at a plurality of locations within a production interval of a wellbore to be monitored in substantially real time, thereby providing for the enhanced regulation of treatment processes and fluid production.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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An apparatus ( 50 ) for monitoring a treatment process in a treatment interval ( 58 ) includes a packer assembly ( 60 ) and a sand control screen assembly ( 64 ) connected relative to the packer assembly ( 60 ). A cross-over assembly ( 62 ) provides lateral communication paths ( 92, 98 ) downhole and uphole of the packer assembly for respectively delivering of a treatment fluid ( 84 ) and taking return fluid. A wash pipe assembly ( 76 ) is positioned in communication with the lateral communication path ( 98 ) uphole of the packer assembly ( 60 ) and extending into the interior of the sand control screen assembly ( 64 ). At least one sensor ( 80 ) is operably associated with the wash pipe assembly ( 76 ) to collect data relative to at least one property of the treatment fluid during a treatment process such that a characteristic of the treatment fluid ( 84 ) is regulatable during the treatment process based upon the data.
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FIELD OF INVENTION
[0001] The present invention relates to a pharmaceutical composition, particularly to a pharmaceutical composition used for detecting whether a cancer cell is radiation resistant. The pharmaceutical composition of the present invention can also be used for increasing radiation-sensitivity of the cancer cells, in order to enhance efficacy of cancer radiation therapy.
DESCRIPTION OF RELATED ART
[0002] Cancer is ranked as one of the top ten causes of death in Taiwan, and by estimation one in every six minutes is diagnosed with cancer. In recent years, efforts have been made in progressing development in anti-cancer medicine. Among the novel anti-cancer medicines, focus has been primarily paid to creating anti-cancer medicines with minor side effects. (Sides effects include: nausea, vomiting, stomatitis, and bone marrow suppression) However, it is not necessarily the case where specific cancer cells can be treated by its conventional treatment method.
[0003] Treatment for cancer-diagnosed patients can generally be classified into three categories, covering scopes of surgical removal, radiation therapy, and chemotherapy. In those, radiation therapy refers to conventional electrotherapy, which is a medical treatment method mainly focusing on treating local area of a tumor region by using high energy radiation beam to kill cancer cells. However, although high energy radiation beam is one way of killing anomalous cells, it can also pose as a threat to normal cells at the same time. As a result, although radiation therapy shows promises in exceptional efficacy, impact by its side effects remains a major issue to its practice.
[0004] Furthermore, literature references and clinical cases have suggested that not all cancer cells are acceptable to radiation therapy. In addition to other constraints complicated by psychological and physical conditions of the patients, some cancer cells also can show radiation resistance before subject to radiation therapy.
[0005] As a result, if radiation therapy is performed on a radiation resistant cancer cell, it would be likely that not only could not the cancer cells be treated, but also that the patient's health could face serious burden. Accordingly, if radiation resistance of cancer cells can be pre-evaluated before radiation therapy begins, and appropriate treatment with respect to specific cancer cell characteristics, probabilities for cancer patients' trial-and-error in medical treatment can be expected to decrease.
SUMMARY OF THE INVENTION
[0006] Clinically, because a high percentage of tumors having radiation resistance would show high-level expression of metal ion transporter protein, particularly copper transporter protein, the copper transporter protein would also show pushing platinum-containing matter toward cells other than copper. The current invention uses the principles considered above to provide a pharmaceutical composition and its detecting method to detect the fact whether a cancer cell is radiation resistant or not, so as to use platinum or copper containing nanoparticles to detect, before the cancer cell undergoes radiation therapy, if a cancer cell is radiation resistant, so as to serve as a reference for cancer cell treatment.
[0007] Another object of the present invention is to provide a pharmaceutical composition, for the purpose of increasing radiation-sensitivity of cancer cell, and thereby increasing treatment efficacy for cancer cell radiation therapy.
[0008] In order to achieve the above object, the present invention provides a pharmaceutical composition for detecting if a cancer cell is radiation resistant, comprising: a nanoparticle containing a first element, wherein the first element is copper, platinum, or the combination thereof; and a medical acceptable carrier. The nanoparticle can be a metal nanoparticle, alloy nanoparticle, or a metal nanoparticle having a core-shell structure, wherein the element making up the shell is copper or platinum. The diameter of the nanoparticle can be 3 nm to 150 nm, preferably 6 nm to 100 nm, and more preferably 12 nm.
[0009] The above-mentioned nanoparticle further comprises a second element, wherein the second element is at least one selected from the group consisting of: iron, cobalt, palladium, gold, silver, nickel, gadolinium, and silicon. A preferred second element is at least one selected from the group consisting of: iron, cobalt, gold, silver, gadolinium, and silicon; a more preferred second element is at least one selected from the group consisting of: iron, gold, gadolinium, and silicon.
[0010] The subject cancer cells for which the current invention's pharmaceutical composition detects can be solid state cancer cell, and the cancer cell type can be lung cancer, breast cancer, prostate cancer, colorectal cancer, gastric cancer, head and neck cancer, ovarian cancer, testicular cancer, bladder cancer, cervical cancer, osteosarcoma, and neuroblastoma tumor. A preferred selection includes lung cancer, breast cancer, prostate cancer, colorectal cancer, gastric cancer, head and neck cancer, bladder cancer. A more preferred selection is lung cancer.
[0011] In the pharmaceutical composition, the medical acceptable carrier is not particularly limited. Preferably, the medical acceptable carrier is at least one selected from the group consisting of: active agent, auxiliary agent, dispersing agent, wetting agent, and suspending agent.
[0012] Further, the present invention provides a method for detecting if a cancer cell is radiation resistant, comprising the steps of: (A) separately adding nanoparticle having a first element to a first cancer cell and a second cancer cell, wherein the first element is copper, platinum, or the combination thereof; (B) calculating an uptake amount for the first cancer cell and an uptake amount for the second cancer cell; and (C) comparing the uptake amount for the first cancer cell with the uptake amount for the second cancer cell, when the uptake amount of the first cancer cell is at least 2 fold of the uptake amount of the second cancer cell, a first signal is displayed or sent. Following, when the second cancer cell is not resistant to radiation, the first signal would signify that the first cancer cell is radiation resistant.
[0013] In the above detection method, because cancer cells would expansively absorb nanoparticles of the present invention due to high-level expression of copper transporter protein, as a result, uptake amount of nanoparticles for cancer cell can be calculated by using inductively coupled plasma atomic emission spectroscopy (ICP-AES), magnetic resonance imaging (MRT), computed tomography (CT), photoacoustic imaging, or near-infrared light in step (B). In addition, in step (C), when the uptake amount of the first cancer cell is 4-10 folds of the uptake amount of the second cancer cell, a second signal is displayed or sent, wherein the second signal signifies that the first cancer cell shows radiation resistance. As a result, the current invention can reuse the above detection method to determine if a cancer cell is resistant to radiation.
[0014] In the present invention, if the nanoparticle contains platinum, computed tomography (CT) may be used to detect if cancer cell has the property of radiation resistance. If nanoparticle comprises iron, cobalt, nickel, gadolinium, magnetic resonance imaging (MRI) may be used as the tool of choice for determining if cancer cell is radiation resistant. However, if nanoparticle comprises silicon and infrared laminating material, infrared may be used to detect possibility of radiation resistance in cancer cell.
[0015] The nanoparticles used in the above detection methods are metal nanoparticle, alloy nanoparticle, or metal nanoparticle with core-shell structure, wherein the element making up shell is copper or platinum. By way of this the diameter of the nanoparticle can be 3 nm to 150 nm, preferably 6 nm to 100 nm, more preferably 12 nm. Additionally, the nanoparticle further comprises a second element. The second element is at least one selected from the group consisting of: iron, cobalt, palladium, gold, silver, nickel, gadolinium, and silicon group. Preferably, the second element is at least one selected from the group consisting of: iron, cobalt, nickel, gold, silver, gadolinium, and silicon. More preferably, the second element is at least one selected from the group consisting of: iron, cobalt, nickel, gold, gadolinium, and silicon.
[0016] As an example, if the nanoparticle of the present invention is an iron-platinum alloy metal nanoparticle, computed tomography (CT) or magnetic resonance imaging (MRI) may be used to detect if cancer cell is radiation resistant. If the nanoparticle of the present invention is a metal nanoparticle with core-shell structure wherein the shell is platinum and core is gold, computed tomography (CT) or photoacoustic imaging may be used to detect if cancer cell is radiation resistant.
[0017] Furthermore, the cancer cell detected by the above detection method may be solid state cancer cell, and the types of cancer cell may belong to lung cancer, breast cancer, prostate cancer, colorectal cancer, gastric cancer, head and neck cancer, ovarian cancer, testicular cancer, bladder cancer, cervical cancer, osteosarcoma, and neuroblastoma tumor. Preferably, the cancer cell type belongs to lung cancer, breast cancer, prostate cancer, colorectal cancer, gastric cancer and head and neck cancer. Most preferably, the cancer cell belongs to lung cancer.
[0018] Moreover, in order to treat radiation resistant cancer cell, the present invention further proposes a pharmaceutical composition that may increase cancer cell's radiation-sensitivity, comprising: a nanoparticle having a first element, wherein the first element is copper, platinum, or a combination thereof.
[0019] Wherein, for another proposed pharmaceutical composition used in increasing radiation-sensitivity of cancer cell, the formation and particle diameter of the nanoparticle, cancer cell kind and type are same as the cancer cell used above for determining radiation resistance.
[0020] With respect to radiation resistant cancer cell, ratio of highly expressed copper transporter protein is exceptionally high, and copper transporter protein can transport copper cations, and platinum-containing matter. Therefore, the pharmaceutical composition and detection method of the present invention can utilize the radiation resistance property of cancer cell to first detect radiation resistance property of cancer cell. Before the cancer cell undergoes radiation therapy, the composition and the method of the present invention can also provide a reference for treating cancer cell, by which different treatment approaches may be adopted accordingly based on the possible characteristics of cancer cell in order to obviate undesirable cancer treatment. Additionally, the pharmaceutical composition further provided for increasing radiation-sensitivity of cancer cell can increase radiation-sensitivity of radiation resistant cancer cell, therefore increasing cancer treatment efficacy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Hereafter, examples will be provided to illustrate the embodiments of the present invention. Other advantages and effects of the invention will become more apparent from the disclosure of the present invention. Other various aspects also may be practiced or applied in the invention, and various modifications and variations can be made without departing from the spirit of the invention based on various concepts and applications.
Embodiment 1
Detecting and Screening for Cancer Cells Resistant to Chemical Medicine and Radiation
[0022] This embodiment uses small cell lung cancer (SCLC) SR3A as cancer cell. First, SR3A cell is screened in vitro for cancer cell line characterized by resistance against radiation; SR3A-13 cell line, and SR3A-14 cell line.
[0023] Cancer cells of the present embodiment can be divided into two categories, including experimental group 1, experimental group 2, and a controlled group, wherein experimental group 1 is for SR3A-13 cell line, experimental group 2 is for SR3A-14 cell line, and the control group is for SR3A cell line. Next SR3A-13 cell line of experimental group 1 and SR3A-14 cell line of experimental group 2 are cultured in a Dulbecco's modified eagle medium (DMEM) at 37° C., 5% CO2 or Oswell Park memorial institute medium, wherein the culture medium in DMEM and RPMI has 10% calf serum, and 400 μg/ml of G418 antibiotics. Also, SR3A cell line of controlled group is cultured in culture medium in DMEM and RPMI at 37° C., 5% CO2.
[0024] First, the mRNA of hCTR-1 in experimental group 1, experimental 2, and controlled group are detected. The results are shown in FIG. 1 . As shown in FIG. 1 , the expression amount of mRNA of hCTR-1 of SR3A-13 cell line is 3.29 folds of that for SR3A cell line, the expression amount of mRNA of hCTR-1 cell line is 4.10 fold of that for SR3A cell line.
[0025] Then, Western blotting is used to detect protein expression for hCTR-1, for which result is shown in FIG. 2 . The result shows expansive expression for hCTR-1 for copper transporter protein in SR3A-13 cell line and SR3-14 cell line. The protein expression amount for SR3A-13 cell line, nCTR-1, is 5.28 fold of that for SR3A; the protein expression amount for SR3A-14 cell line, hCTR-1, is 5.51 fold of that for SR3A. As a result, SR3A-13 cell line and SR3A-14 cell line of the current embodiment both show expansive expression for hCTR-1 for copper transporter protein.
[0026] Then, experimental group 1, experimental group 2, and controlled group are subjected to irradiation at 0 Gy, 2 Gy, 4 Gy, 6 Gy, and 8 Gy of radiation dosage, and cell surviving fraction is observed, for which results are shown in FIG. 3 . With a radiation dosage of 6 Gy and 8 Gy, experimental group 1 (SR3A-13 cell line) and experimental group 2 (SR3A-14 cell line) show higher cell surviving fraction than controlled group (SR3A cell line). This proves that SR3A-13 cell line and SR3A-14 cell line of the current embodiment have more radiation resistance than SR3A cell line.
[0027] It would therefore be understood that the experimental results of the current embodiment that cancer cell having radiation resistance show expansive expression of copper transport protein of hCTR-1.
Embodiment 2
Detecting if Cancer Cell is Radiation Resistant
[0028] This embodiment takes pharmaceutical composition made of iron-platinum alloy nanoparticle (FePt) and medical acceptablecarrier as a pharmaceutical composition for detecting if cancer cell is radiation resistant. The pharmaceutical composition can be classified into three groups depending on the particle diameter of iron-platinum alloy nanoparticle, which each is for iron-platinum alloy nanoparticle having a diameter of 3 nm, iron-platinum alloy nanoparticle having a diameter of 6 nm, and iron-platinum alloy nanoparticle having a diameter of 12 nm
[0029] The preparation method for making iron-platinum alloy nanoparticle having a particle diameter of 3 nm is: in a nitrogen-filled atmosphere, Pt(acac) 2 (97 mg), 1,2-hexadecane diol (195 mg), and dioctyl ether (10 mL) is mixed, then the mixture solution is heated to result therefrom to 100° C. for 10 minutes. Next, at 100° C., Fe(CO) 5 (66 μL), oleylamine (80 μL), and oleic acid (804) is added into the mixture solution, and the mixture solution is heated to 297° C. After the reaction goes on for 30 minutes, the product down is cooled to room temperature, and ethanol is added to precipitate the product, followed by separating the product out by using centrifugation. Furthermore, the reaction solution is heated at a rate of 15° C./min to 240° C. After the reaction proceeds for 30 minutes, the product is cooled down to room temperature, and the product is separated out by using centrifugation. Lastly, the method for making iron-platinum nanoparticle with a particle diameter of 12 nm is: in a nitrogen-filled atmosphere, Pt(acac) 2 (195 mg), 1,2-hexadecane idol (1.05 g), dioctyl ether (4 mL), Fe(CO) 5 (66 μL), oleylamine (4 mL), and oleic acid is mixed to prepare a reaction solution. Then the reaction solution is heated at a rate of 15° C./min to 240° C., and the reaction solution is kept at 240° C. for 60 minutes. Then, the reaction solution is cooled down to room temperature, ethanol is added to precipitate product, and centrifugation is used to isolate the product.
[0030] The culturing condition for the cell line of the present embodiment is the same as in embodiment 1, and is also broken down into Experimental Group 1, Experimental Group 2, and Controlled Group, wherein Experimental Group 1 includes SR3A-13 cell line, Experimental Group 2 includes SR3A-14 cell line, and Controlled Group includes SR3A cell line. Next, three groups of pharmaceutical compositions are added, where each one has a concentration of 1.6 mg/ml separately into the cell lines in Experimental Group 1, Experimental Group 2, and Controlled Group. The pharmaceutical compositions are cultured for 24 hours, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) is used to calculate the uptake amount of iron-platinum alloy nanoparticle for cell line. Result is shown in FIGS. 4 and 5 .
[0031] FIG. 4 shows the result of the cell line's uptake of 3 nm iron-platinum alloy nanoparticle in embodiment 2, and FIG. 5 shows the result of the cell line's uptake of 6 nm iron-platinum alloy nanoparticle in embodiment 2. As can be seen by the result of FIG. 4 , the uptake amount of 3 nm iron-platinum nanoparticle for SR3A-13 cell line and the SR3A-14 cell line is approximately 2 folds of the uptake amount for SR3A cell line. Findings in FIG. 5 suggest that the uptake amount of iron-platinum nanoparticle having 6 nm particle diameter for SR3A-13 cell line is approximately 2.5 folds of the uptake amount for the SR3A cell line, and the uptake amount of iron-platinum alloy nanoparticle having 6 nm particle diameter for SR3A-14 cell line is 3 folds of the uptake amount for SR3A cell line. Also to be noted, the uptake amount of iron-platinum alloy nanoparticle having 12 nm is about 3 folds of the uptake amount for SR3A cell line, and the uptake amount of iron-platinum alloy nanoparticle having particle diameter of 12 nm for SR3A-14 cell line is about 3 folds of the uptake amount for SR3A cell line.
[0032] It would be understood by skilled field experts, based from the cited embodiments, that in terms of the uptake amount of iron-platinum alloy nanoparticle, the amount for the radiation resistant SR3A-13 cell line and SR3A-14 cell line are obviously greater (by a magnitude of 2 folds) than that for radiation non-resistant SR3A cell line. This adds weight to strengthen the proposed efficacy enhancement of the invention embodiments: iron-platinum-nanoparticle-containing pharmaceutical composition can be noticeably absorbed by radiation resistant SR3A-13 cell line and SR3A-14 cell line. As such, the pharmaceutical composition containing iron-platinum alloy nanoparticle of the current embodiment can be used in detecting if a cancer cell is radiation resistant. Here, particular mention is made to point out that iron-platinum nanoparticles having particle diameter of 6 nm and 12 nm deliver better results than iron-platinum nanoparticle having 3 nm for particle diameter. Essentially, radiation resistance detection for cancer cell is accomplished by way of examining if cancer cell can absorb pharmaceutical composition containing iron-platinum alloy nanoparticle.
[0033] Moreover, the pharmaceutical composition of the present embodiment can be applied with a detector. When the calculation result (through the inductively coupled plasma atomic emission spectroscopy (ICP-AES)) shows that the uptake amounts of iron-platinum alloy nanoparticle for Experimental Group 1, and Experimental Group 2 are greater than at least 2 folds that of Controlled Group, the detector will display a signal to indicate that the cancer cells of Experimental Group 1, and Experimental Group 2 are radiation resistant.
Embodiment 3
Increasing Radiation-Sensitivity of Cancer Cell
[0034] The SR3A-13 cell line used in this embodiment is the same as that used in embodiment 1. In this embodiment, experimental group and controlled group are provided, and each contains 5000 SR3A-13 cells. 0.79 mg/ml of 12 nm iron-platinum alloy nanoparticle containing pharmaceutical composition is added to the experimental group's SR3A-13 cell line at 37° C., and cultured for 24 hours. Pharmaceutical composition containing iron-platinum nanoparticle is not added to the controlled group.
[0035] Next, after irradiating 6 Gy of radiation dosage of radiation on the experimental group and controlled group, the living status of the cells are observed, and results for which are shown in FIGS. 6A , 6 B, and 7 . FIG. 6A shows result from after exposure to radiation in the controlled group for embodiment 3 according to the present invention. FIG. 6B shows result from after exposure to radiation in the experimental group for embodiment 3 according to the present invention. FIG. 7 shows result of quantification of increase in cancer cell line radiation-sensitivity for embodiment 3 according to the present invention. It can be seen that with a radiation dosage of 6 Gy and culturing by the pharmaceutical composition having iron-platinum alloy nanoparticle with particle diameter of 12 nm, the cell number in the radiation resistant SR3A-13 cell line is noticeably smaller compared to that in the controlled group.
[0036] Furthermore, the cell lines of the Experimental Group 1 of embodiment 1 (SR3A-13 cell line), Experimental Group 2 (SR3A-14 cell line) and Controlled Group (SR3A cell line) are separately added with or without 0.75 mg/ml of pharmaceutical composition containing iron-platinum alloy nanoparticle of 12 nm particle diameter. Then a radiation dosage of 2 Gy, 4 Gy, 6 Gy, 8 Gy is added, at 37° C. for 24 hours of culturing, and the cell surviving fraction is observed. The results are shown in FIG. 8 . When pitted under comparison, the surviving fraction of radiation resistant SR3A-13 cell line, SR3A-14 cell line, which are both cultured with pharmaceutical composition having iron-platinum alloy nanoparticle, and both irradiated by radiation dosages of 2 Gy, 4 Gy, 6 Gy, 8Gy, are noticeably lower than those of SR3A-13 cell line, SR3A-14 cell line that are not added with pharmaceutical composition having iron-platinum alloy nanoparticle. The above result is a confirmation that the pharmaceutical composition having iron-platinum nanoparticle of the present embodiment can not only increase radiation-sensitivity of cancer cell, but can also significantly increase radiation-sensitivity of radiation resistant cancer cell.
[0037] Considering the above embodiments in sum, the pharmaceutical composition of the current invention has the capability of effectively detecting if a cancer cell is radiation resistant, and the pharmaceutical composition used in increasing radiation-sensitivity of cancer cell can also work to distinctly increase radiation-sensitivity of cancer cell, and thereby shoot up therapeutic efficacy for cancer cell radiation therapy.
[0038] The above embodiments are for the purpose of better describing the current invention and are of exemplary nature only, the scope of right asserted by the current invention is based on the scope of claims in this application, and are not intended to be restricted by the above embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a graph showing mRNA expression for hCTR-1 for embodiment 1 according to the present invention.
[0040] FIG. 2 is a graph for protein expression for embodiment 1 according to the present invention.
[0041] FIG. 3 shows survival result for cell line exposed to radiation for embodiment 1 according to the present invention.
[0042] FIG. 4 shows a cell line absorbing 3 nm of iron-platinum alloy nanoparticle for embodiment 2 according to the present invention.
[0043] FIG. 5 shows a cell line absorbing 6 nm of iron-platinum alloy nanoparticle for embodiment 2 according to the present invention.
[0044] FIG. 6A shows result from after exposure to radiation in the controlled group for embodiment 3 according to the present invention.
[0045] FIG. 6B shows result from after exposure to radiation in the experimental group for embodiment 3 according to the present invention.
[0046] FIG. 7 is a result of quantification of increase in cancer cell line radio-sensitivity for embodiment 3 according to the present invention.
[0047] FIG. 8 shows a result of increase in cancer cell line radiation-sensitivity for embodiment 3 according to the present invention.
DESCRIPTION FOR LIST OF REFERENCE NUMERALS
[0048] None
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The present invention relates to a pharmaceutical composition for elevating radiation-sensitivity of cancer cells, which comprises: a nanoparticle containing with a first element, which is iron, copper, or the combination thereof; and a pharmaceutically acceptable carrier, wherein the nanoparticle is a metal nanoparticle, an alloy nanoparticle, or a metal nanoparticle with core-shell structure, and the size of the nanoparticle is under a controllable range of 3 nm to 150 nm. In addition, the present invention provides a detection method to detect radiation-sensitivity of the cancer cells through different modalities such as CT or MRI due to its native high CT number and magnetic property. Furthermore, the present invention provides a pharmaceutical composition for elevating radiation-sensitivity of the cancer cells through preferential uptake of the nanoparticle, in order to enhance the radiation-sensitivity of the cancer cells and improve the efficiency of radiation therapy to the cancer cells.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Application No. 61/936,296, of the same title, filed Feb. 5, 2014, U.S. Provisional Application No. 61/936,811, of the same title, filed Feb. 6, 2014, and U.S. Provisional Application No. 61/937,409, of the same title, filed Feb. 7, 2014, the contents of which are incorporated herein by reference in their entirety for all purposes.
[0002] This application is a continuation of International Application PCT/US14/58263, with an international filing date of Sep. 30, 2014, entitled “STRETCH RELEASE CONDUCTIVE ADHESIVE,” the disclosure of which is incorporated herein by reference in its entirety.
FIELD
[0003] The described embodiments relate generally to methods for mounting components to and removing components from a computing device. More particularly, the embodiments set forth various removal systems that utilize conductive adhesive material that allows non-destructive removal of the components.
BACKGROUND
[0004] A portable computing device can include many components that provide operational functionality for users of the device. For example, a typical portable computing device can include a processor, multiple connectors, an antenna, flexible circuits, one or more fans, speakers, batteries, and the like. Notably, overall sizes of portable computing devices are continually shrinking in response to a demand for smaller, lighter devices. To meet this demand, internal components of the portable computing device are being made smaller and are being mounted in more consolidated arrangements.
[0005] One approach for mounting a component within a portable computing device includes the use of double-sided adhesive tape. However, this method can make removing the component difficult and time consuming and can leave behind adhesive residue that must be cleaned before reinstalling a replacement component. Further, this approach can result in damaging the component during the removal process, which can be costly and inefficient.
SUMMARY
[0006] This paper describes various embodiments that relate to methods and systems for mounting and removing components within a computing device. In particular, disclosed herein are various component mounting and removal apparatuses that are conductive and enable a component (e.g., a flexible circuit) to be securely installed into a computing device. Moreover, these component mounting and removal apparatuses enable the component to be easily removed from the computing device when servicing or replacement is required.
[0007] According to one embodiment, a stretch release conductive adhesive used for extracting a component that is secured to a surface of a housing is disclosed. The stretch release conductive adhesive can include a conductive adhesive body that adheres the component to the housing surface and allows a current to flow from the component into the surface of the housing through the stretch release conductive adhesive. A portion of the conductive adhesive body can extend out from between the component and the housing to provide a graspable portion. When a removing force is applied to the graspable portion, the graspable portion independently transfers the removing force to at least the conductive adhesive body disposed between the component and the housing surface.
[0008] According to another embodiment, a stretch release conductive adhesive for extracting a component or flexible circuit from a housing is disclosed. The stretch release conductive adhesive is conductive and includes a compressible securing portion designed to secure the component to an interior surface of the housing at a securing thickness. The stretch release conductive adhesive also includes an extracting portion coupled to the compressible securing portion at a junction. The extracting portion is arranged to receive and transfer an extracting force to the compressible securing portion by way of the junction. In turn, the extracting force reduces the thickness of the compressible securing portion at a detaching region. The detaching region is located a distance away from the junction to cause detachment of the component.
[0009] According to another embodiment, a method of extracting a component or flexible circuit from a housing using a stretch release conductive adhesive is disclosed. The stretch release conductive adhesive is conductive and includes a compressible securing portion coupled to an extracting portion at a junction. The method includes applying an extracting force to the extracting portion. The method also includes transferring the extracting force to the compressible securing portion by way of the junction. The extracting force causes a reduction in thickness of the compressible securing portion at a detaching region. The thickness of the compressible securing portion in turn shrinks from a securing thickness to a reduced thickness. The component is secured to an interior surface of the housing when the compressible securing portion is at the securing thickness. Conversely, the component is detached from the interior surface of the housing when the compressible securing portion is at the reduced thickness.
[0010] Other aspects 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 principles of the described embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements.
[0012] FIG. 1 illustrates a view of a stretch release conductive adhesive in a securing state, according to one embodiment.
[0013] FIG. 2 illustrates a view of a stretch release conductive adhesive in a stretched state, according to one embodiment.
[0014] FIG. 3 illustrates a view of a conductive pathway created by a stretch release conductive adhesive between a flexible circuit and housing, according to one embodiment.
[0015] FIG. 4 illustrates a view of a stretch release conductive adhesive having one extracting portion securing a flexible circuit to a housing, according to one embodiment.
[0016] FIG. 5 illustrates a view of a stretch release conductive adhesive having multiple extracting portions securing a flexible circuit to a housing, according to one embodiment.
[0017] FIG. 6 illustrates a method for securing a flexible circuit to a housing using stretch release conductive adhesive, according to one embodiment.
[0018] FIG. 7 illustrates a method for removing a flexible circuit from a housing using stretch release conductive adhesive, according to one embodiment.
DETAILED DESCRIPTION
[0019] Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting.
[0020] In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments.
[0021] As the size and weight of computing devices and other electronic devices decreases, retention mechanisms for components included in these devices become smaller as well. Adhesive tape can be particularly effective at retaining components within a device while occupying a minimal amount of space. Several types of adhesive tape have been designed to address this problem. In particular, a pressure sensitive adhesive can be applied to one or both sides of a highly extensible backing The backing can be formed from a highly extensible polymeric material with a high tensile strength and a lengthwise elongation at break in excess of 700%. When a force is applied to stretch the backing in a direction substantially parallel to the surface of the tape, the backing deforms causing the adhesive to elongate and detach from the surface. These are commonly referred to as stretch release adhesives. Examples of adhesive tapes that meet these requirements are Command™ adhesives produced by 3M™ and Powerstrip™ adhesives produced by Tesa™. By combining the features of conductive adhesive and stretch release adhesives the deficiencies of many commonly used adhesives in computing devices are resolved.
[0022] In some applications, adhesives must be conductive in order to allow electrons to travel through the adhesive. For example, components such as flexible circuits within a computing device are adhered to the interior surface or housing of the computing device in order to provide grounding for the flexible circuits. During repair or rework of the computing device, flexible circuits are often removed. Typically, removal causes damage to the flexible circuits because the conductive adhesives attaching the flexible circuits were not designed for removal. Therefore, by removably attaching flexible circuits to the housing, less time is spent cleaning adhesive residue and less flexible circuits are damaged during repair and rework.
[0023] As set forth above, one common technique for securing a component (e.g., a flexible circuit) within a computing device involves using a conductive adhesive. When the component needs to be removed from the computing device, service technicians are required to pry the component away from the housing of the computing device, which can damage the component and/or housing. One technique that can be used to help mitigate this problem is by securing a stretch release conductive adhesive layer between the component and the housing. Accordingly, one embodiment sets forth a stretch release conductive adhesive used for extracting a component (e.g., a flexible circuit) secured to an interior surface or housing of a computing device, such as a housing of the computing device. The stretch release conductive adhesive can include a conductive compressible securing portion and an extracting portion coupled at a junction. The conductive compressible securing portion is placed between the component and the housing, and is designed to facilitate removal of the stretch release conductive adhesive by providing a means (i.e., by pull tab or extracting portion) by which to grip the stretch release conductive adhesive and pull it without tearing it through the creation of stress concentrations.
[0024] In some embodiments, the extracting portion can be made of the same or different material as the conductive compressible securing portion. In one embodiment, the extracting portion can be made of a plastic material that is less compressible than the conductive compressible securing portion. In some embodiments, the extracting portion includes an inner portion that is made of the same material as the conductive compressible securing portion and an outer sheath that covers the conductive compressible securing portion. The extracting portion can have a thickness that is thinner or thicker than compressible securing portion. In some embodiments, portions of the extracting portion can have features such as grooves or projections that can facilitate a grasping of the extracting portion. The grooves can range from sharp angles to smooth bumps across the extracting portion.
[0025] The stretch release conductive adhesive can be made conductive by any suitable means, such as incorporating any conductive elements, particles, or compounds into the adhesive material. For example, common conductive materials such as silver, copper, gold, aluminum, calcium, tungsten, zinc, nickel, lithium, iron, etc., can be incorporated into the stretch release conductive adhesive to make it conductive. Moreover, nanoparticles such as gold, zinc, silver, carbon, etc., can also be incorporated into the stretch release conductive adhesive to make it conductive.
[0026] The stretch release conductive adhesive can be used in a mobile device, media player, or any other computing device in which internal components can be housed. Furthermore, a variety of internal components—including batteries, fans, speakers, circuit boards, cables, wires, and other electronic components—can be secured within the housing by way of the stretch release conductive adhesive. The stretch release conductive adhesive can be applied such that a number of components are attached at a single junction formed of stretch release conductive adhesive. For example, one or multiple layers of stretch release conductive adhesive can be used to ground multiple flexible circuits to a surface associated with a housing of a portable electronic device and the like.
[0027] In some embodiments, the stretch release conductive adhesive can include a conductive compressible securing portion and an extracting portion coupled at a junction. When a conductive compressible securing portion is at a securing thickness between a flexible circuit and a housing, the conductive compressible securing portion can secure the flexible circuit to the housing while also providing a conductive pathway between the housing and the flexible circuit. When the conductive compressible securing portion is at a reduced thickness, the compressible securing portion can detach the flexible circuit from the housing without damaging the flexible circuit. Thus, when an extracting force F is transferred to a detaching region between the flexible circuit and the housing, a compressible securing region can begin to detach the flexible circuit from the housing. As extracting force F continues to be applied to the extracting portion, the thickness of the conductive compressible securing portion is reduced until substantially the entire conductive compressible securing portion has a sufficiently reduced thickness. The thickness of the conductive compressible securing portion is sufficient when the flexible circuit is no longer adhered to the housing and the flexible circuit can be easily removed from the housing. In this way, the stretch release conductive adhesive can be used to attach, extract, and provide a conductive pathway between the flexible circuit and the housing or surface for which the stretch release conductive adhesive is removably attached. In some embodiments, the stretch release conductive adhesive can be pulled with extraction force F at an angle that is substantially parallel, non-parallel, or at a non-zero angle with relation to the flexible circuit, component, or surface.
[0028] These and other embodiments are discussed below with reference to FIGS. 1-7 ; however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting.
[0029] FIG. 1 illustrates a perspective view 100 of a stretch release conductive adhesive 114 in a securing state according to one embodiment of the invention. In particular, FIG. 1 illustrates a view of the stretch release conductive adhesive 114 securing a component 108 to a surface of a housing 110 . As shown, the stretch release conductive adhesive 114 includes a conductive compressible securing portion 106 that provides a conductive pathway 112 from the component 108 to the housing 110 . The stretch release conductive adhesive 114 can further include an extracting portion 102 that is coupled to the conductive compressible securing portion 106 by a joint 104 . The joint 104 is not essential in some embodiments.
[0030] The extracting portion 102 can take many forms, for example, extracting portion 102 can take the form of a tab, a ring, a string, etc. or any form suitable for grasping and pulling. This arrangement allows for a component such as a flexible circuit to be removably attached to the housing of a computing device while also grounding the flexible circuit to the housing. The extracting portion 102 can be positioned relative to the compressible securing portion 106 in any number of configurations, for example a zero, non-zero, or negative angle in relation to the compressible securing portion 106 . In some embodiments, there can be multiple extracting portions 102 that provide multiple gripping areas facilitating removal of stretch release conductive adhesive 114 . In some embodiments, the joint 104 is adjacent to a low friction material or acute edge that can facilitate movement of the stretch release conductive adhesive 114 along the edge of or away from the component 108 .
[0031] FIG. 2 illustrates a perspective view 200 of a stretch release conductive adhesive 114 in a stretched state according to one embodiment of the invention. In particular, FIG. 2 illustrates a view of the stretch release conductive adhesive 114 being extracted from between component 108 and housing 110 by an extracting force F. As shown, the stretch release conductive adhesive 114 is displaced from between the component 108 and the housing 110 by an extracting force F applied to the extracting portion 102 . The extracting force F is transferred to the conductive compressible securing portion 106 by way of the joint 104 to reduce the thickness of the conductive compressible securing portion 106 between the component 108 and the housing 110 from a securing thickness to a reduced thickness. The region from which the stretch release conductive adhesive 114 detaches can be located between the component 108 and the housing 110 . This arrangement allows for a flexible circuit to be removed from the housing 110 without damaging the flexible circuit (i.e. the component 108 ) or leaving a residue.
[0032] FIG. 3 illustrates a perspective view 300 of a conductive pathway 112 created by a stretch release conductive adhesive 114 between a flexible circuit 302 and a housing 110 , according to one embodiment. In particular, FIG. 3 illustrates the conductive pathway 112 created by the conductive material included in the stretch release conductive adhesive 114 . As discussed herein, any variety of conductive materials can be included in the stretch release conductive adhesive 114 in order to create the conductive pathway 112 shown in FIG. 3 . Upon rework or repair of computing device in which the housing 110 and flexible circuit 302 are retained, the stretch release conductive adhesive 114 is easily removed without damaging the flexible circuit 302 . The flexible circuit 302 can then by reused by technicians operation on the computing device, thereby saving material costs and speeding up the removal process.
[0033] FIG. 4 illustrates a perspective view 400 of a stretch release conductive adhesive having an extracting portion 410 and securing a flexible circuit 302 to a housing 110 , according to one embodiment. In particular, FIG. 4 illustrates a first component 402 and a second component 404 being connected by a flexible circuit 302 . The extracting portion 410 is configured to be easily found and gripped by a technician or machine. The first component 402 and second component 404 are connected to a housing 110 , and the flexible circuit 302 is grounded to the housing 110 by the stretch release conductive adhesive. Once disconnected from first component 402 and second component 404 , the flexible circuit 302 ends, first flexible circuit end 406 and second flexible circuit end 408 , are easily removed from the housing 110 by pulling on the extracting portion 410 . For example, during rework of the housing 110 , a technician will simply disconnect the flexible circuit 302 from the first components 402 and the second component 404 , then pull on the extracting portion 410 until the first flexible circuit end 406 and second flexible circuit end 408 are released from the housing 110 . The technician is then free to use the flexible circuit 302 again.
[0034] FIG. 5 illustrates a perspective view 500 of a stretch release conductive adhesive having multiple extracting portions and securing a flexible circuit to a housing, according to one embodiment. In particular, FIG. 5 illustrates the first component 402 and the second component 404 connected by a flexible circuit 302 , and the flexible circuit 302 grounded to a housing 110 by the stretch release conductive adhesive. The stretch release conductive adhesive is adhered between the flexible circuit 302 and the housing 110 , providing a conductive pathway from the flexible circuit 302 , through the stretch release conductive adhesive, to the housing 110 . The first extracting portion 502 and second extracting portion 504 are attached to the stretch release conductive adhesive. Once the flexible circuit 302 is disconnected from the first component 402 and the second component 404 , a technician or machine can pull on either the first extracting portion 502 or the second extracting portion 504 , to remove the first flexible circuit end 406 and/or the second flexible circuit end 408 , respectfully, from the housing 110 . By pulling on both the first extracting portion 502 and the second extracting portion 504 , the flexible circuit 302 will be completely released. For example, during rework of the housing 110 , a technician or machine will disconnect the flexible circuit 302 from the first component 402 and the second component 404 , then simply pull on the both the first extracting portion 502 and the second extracting portion 504 until both the first flexible circuit end 406 and the second flexible circuit end 408 , respectfully, are released from the housing 110 . The technician is then free to use the flexible circuit 302 again.
[0035] FIG. 6 illustrates a method 600 for securing a flexible circuit to a substrate using the stretch release conductive adhesive of FIGS. 1-5 . As shown, the method 600 begins at step 602 , which involves receiving a flexible circuit. Step 604 involves securing the flexible circuit or component to a conductive substrate using stretch release conductive adhesive. In some embodiments, the conductive substrate can be a housing. The component can include a wire, a cable, a battery, a fan, a speaker, a circuit board, or other electronic components. The surface can be made of any of a number of suitable materials, such as metal or plastic, and can include a portion of low friction material or a coating of low friction material.
[0036] FIG. 7 illustrates a method 700 for removing a flexible circuit from a housing using stretch release conductive adhesive, according to one embodiment. In particular, the method 700 begins at step 702 , which involves gripping an extracting portion of a stretch release conductive adhesive. Next, step 704 involves pulling on the extracting portion to release the stretch release conductive adhesive from between a flexible circuit and a housing. Finally, step 706 involves releasing the flexible circuit from the housing. This method 700 applies to FIGS. 1-5 , and can therefore be used to remove stretch release conductive adhesive having multiple extracting portions, as illustrated in FIG. 5 and described herein.
[0037] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.
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This application relates to adhesives for use in electronic devices. Specifically, the embodiments discussed herein set forth stretch release conductive adhesives for adhering an electrical component to the surface of a housing of a computing device while also allowing current to flow through the electrical component. A stretch release conductive adhesive can include a graspable portion for providing a means to stretch and remove the stretch release conductive adhesive from an electronic device.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a National Stage of International Application No. PCT/EP2009/060556, filed on Aug. 14, 2009, which claims priority to International Application No. PCT/EP2009/004601, filed on Jun. 25, 2009, the entire contents of which are being incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a pinch clamp assembly for engaging a tube with an enteral feeding pump adapted to feed nutritionals or an infusion pump adapted or to infuse medical solutions to a patient. More particularly, the present invention relates to a pinch clamp assembly in the form of a cassette with a clamping element for use on enteral feeding sets or infusion sets and the like, wherein the clamping element prevents the free-flow of enteral formula through the enteral feeding set or of solutions through the infusion set unless the cassette and the clamping element are properly mounted in a housing or some other structure of an enteral feeding pump or infusion pump.
The use of infusion and feeding sets to administer solutions and food to a patient is well known in medical arts. Infusion and enteral sets are used for both enteral and parenteral application, respectively. For hygienic reasons the infusion and enteral sets must be disposed of immediately after use, making it single-use equipment which may be recycled afterwards. Enteral feeding pumps are used to provide the patient with nutrition and medication (formula) when they are unable, for a variety of reason, to eat normally. Parenteral (intravenous) solutions are provided to patients to ensure adequate hydration and to provide needed nutrients, minerals and medication. Often, the enteral or infusion set is placed in a free standing arrangement in which gravity forces the formula or solution into the patient. The rate at which the solution enters the patient can be roughly controlled by various clamps, such as roller clamps, which are currently available on the market.
In many applications, it is necessary to precisely control the amount of solution or formula which enters the patient. When this is the case, a regulating device such as an infusion pump, is placed along the infusion set to control the rate at which the solution is fed to the patient. In application where a pump etc. is used the clamps used to regulate flow are typically open to their fullest extent to prevent the clamp from interfering with the proper functioning of the pump. The clamp is opened with the expectation that the enteral feeding pump or infusion will control fluid flow through the enteral or infusion set. However, emergencies or other distractions may prevent the medical personnel from properly loading the enteral or infusion sets in the enteral feeding pump or the infusion pump. Furthermore, the enteral or infusion sets may be inadvertently dislodged from the pump during operation of the pump.
When the enteral or infusion set is not properly loaded in the pump and the clamp has been opened, a situation known as free-flow often develops. The force of gravity causes the solution or the formula to flow freely into the patient unchecked by the pump or other regulating device. Under a free-flow condition, an amount of solution or formula many times the desired dose can be supplied to the patient within a relatively short time period. This can be particularly dangerous if the solution contains potent medicine or the patient's body is not physically strong enough to adjust to the large inflow of solution or formula. Thus there is a need for a device that prevents a free-flow condition if the enteral or infusion set is not properly mounted in the pump or other regulation means. It is furthermore important that the device is tamper-resistant with regard to the generation of the free-flow condition. Another requirement for such enteral feeding or infusion sets is a long storage period which may be up to several years. Therefore a sticking and continuous deformation of the silicon tube is to be avoided which may result in a deviation of its regular flow properties when using it.
Several approaches have been taken to avoid the above mentioned free-flow situation one of which is disclosed in WO 96/030679 A1. Therein, a pinch clip occluder utilizes a clamping mechanism with at least one arm nested at least partially within a housing which serves as an adjustment mechanism by moving the arm between a position in which the arm occludes flow through an infusion set, and a position in which it allows free-flow through the infusion set. One problem related therewith is that the pinch clip occluder can still be manipulated in a way that the spring force may be countered by other external elements such as a squeeze, a fastener or the like. Furthermore, the metal spring inside the pinch clip occluder according to WO 96/030679 A1 is not made of plastic material thus preventing the possibility of being recycled together with the other plastic components. This makes the recycling process of the infusion set more tedious and thus more expensive. Another disadvantage of said infusion set including the pinch clip occluder is that mounting it to the infusion or enteral feeding pump is rather complicated, i.e. the silicon tube has to be positioned exactly in the recesses formed therefore and wrapped around the rotor unit etc. In addition, a major drawback of this known pinch clip occluder is that when the cap with the prone is left inside the pinch clip occluder to open the tube, a free-flow situation is caused even when the infusion set is not attached to the pump.
U.S. Pat. No. 4,689,043 describes an IV tube activator for use with a peristaltic IV infusion pump comprising means that require the closure of a tube associated clamp upon engagement of the IV tube with the pump and upon any subsequent disengagement of the IV tube from the pump. This IV tube activator also represents a rather complicated structure and will not solve the problem of storage of the clamped silicon tube before using it in the infusion pump. Furthermore, setting up the infusion set with the IV tube activator is cumbersome and error-prone due to the many different components.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to provide a pinch clamp assembly for engaging a tube with an enteral feeding or infusion pump adapted to feed nutritionals or to infuse medical solutions to a patient, which comprises a relatively simple construction, ensures an anti-free-flow mechanism that works at all times, allows for a long time storage of the silicon tube, is uniform with regard to the used material in order to be easily recyclable and can be used with a number of enteral feeding or infusion pumps.
This object is solved by the features of claim 1 . Advantageous embodiments of the invention are subject of the subclaims.
According to the invention, a pinch clamp assembly for engaging a tube with an enteral feeding or infusion pump adapted to feed nutritionals or to infuse medical solutions to a patient is provided with the following components: a base comprising holding means for holding a pumping section of the tube in operative engagement with the base and supporting means for supporting a connector, a clamping element having clamping surfaces engageable with the pumping section and moveable between an open position allowing flow of fluid through the pumping section and a closed position wherein the pumping section is occluded by the clamping element, and locking means adapted to engage with each other in the closed position and adapted to interact with releasing means external to the pinch clamp assembly so as to bring the clamping element from the closed to the open position, a connector for connecting the tube with a port on a patient, the connector being removable from the pinch clamp assembly. It comprises the features that the clamping element further comprises a retaining lever, wherein in the open position of the clamping element the connector is retained by the retaining lever, and wherein the clamping element is adapted to engage with the releasing means to release the clamping element to the open position when the pinch clamp assembly is mounted to the enteral feeding or infusion pump and the connector is removed.
Thereby, the free-flow condition is prevented when the pinch clamp assembly is in its delivery state because the connector which is to be connected to the port of the patient is still part of the pinch clamp assembly and cannot be removed unless the clamping element is in its closed position. Before a user is able to remove connector from the assembly, the clamping element must be brought into its closed position preventing any flow through the pumping section of the silicon tube. Therefore, the free-flow condition is again prevented when the respective connectors are connected to the port on the one end and to the solution or formula container on the other end. In this state, i.e. after closing the clamping element and the removal of the connector, the pinch clamp assembly may be inserted into the enteral feeding or infusion pump. When inserting the pump, the clamping element is opened due to the interaction of the releasing elements with the clamping element. However, there is no free-flow condition because the pumping section of the silicon tube is so tightly wrapped around the pumping mechanism (rotor unit) of the enteral feeding or infusion pump that a flow of solution through the silicon tube is prevented. Thus, a free-flow condition of an infusion set comprising the pinch clamp assembly according to the present invention is avoided at all times, in particular before its first use.
Other advantages of the pinch clamp assembly according to the invention are that the assembly may be stored for a long time such as five years in its delivery state because the clamping element is in its open position and the silicon tube is not compressed or pinched thus preventing degradation or sticking of the material. Also the anti-free-flow mechanism is an integral part of the pinch clamp assembly avoiding any additional components.
It is to be noted that to bring the pinch clamp assembly into the delivery state, which is usually as an entire infusion or enteral feeding set wrapped in single poly pouch or blister package, the single components of the pinch clamp assembly have to be put together accordingly, thereby bringing the clamping element into its closed position and thus occluding the silicon tube. However, the period of time where the flow is occluded is only minimal because the releasing means are immediately applied to the locking means of the clamping element thereby releasing it to its open position.
The pinch clamp assembly of the present invention is also tamper-resistant because for a normal user it is impossible to open the clamping element with her or his hands when the clamping element is pushed down to its closed position and the connector is removed. Only the intention to tamper with the assembly using suitable tools (which are usually not available to the medical personnel setting up enteral feeding or infusion sets) will open the clamping element and involves the risk of destroying the function of the whole assembly.
Preferably the base and the clamping element are integrally formed. This enables a compact pinch clamp assembly and reduces the number of parts involved in fabrication.
In an advantageous embodiment the connector is an enteral spike, an IV (intravenous) spike, an enteral feeding adapter, an IV luer lock adapter or other enteral or IV component. All possible connectors known in the art of enteral feeding or infusion can be used.
In a preferred embodiment the base is formed as a cassette such that the pinch clamp assembly may be integrally mounted to the enteral feeding or infusion pump. A cassette provides a flat construction which is not bulky and yet comprises a compact format.
In a preferred embodiment the pinch clamp assembly is made of recyclable plastic material such as thermoplastics, and the pumping section of the tube is made of silicon or silicon replacement tubing. This enables a simple recycling procedure of this one-way and single-use equipment and avoids tedious sorting procedures.
In an advantageous embodiment the clamping element comprises a first leg with a tube blocking portion, a second leg with a flat surface, a bending portion acting as a spring element, first locking means at the free end of the first leg and second locking means at the free end of the second leg and the retaining lever is adjacent to the first leg and the bending portion, wherein the tube blocking portion and the flat surface may be pressed upon one another to squeeze the tube therebetween, and wherein the first and second locking means are engageable with each other in the open position or in the closed position.
In a preferred embodiment the clamping surfaces are uneven, corrugated or finned. Depending on the specific requirements of the silicon tubing, different set-ups of the clamping surfaces may be used. It is also possible to change the function of the first leg and the second leg.
Preferably in the open position of the clamping element the retaining lever exerts a force on the connector so that the connector cannot be removed from the pinch clamp assembly. With preference the connector is removable from the pinch clamp assembly only when the clamping element is in the closed position. This avoids the free-flow condition when medical personnel is applying an infusion set or enteral feeding set comprising the pinch clamp assembly according to the invention to an infusion or enteral feeding pump.
Preferably the supporting means comprise a first recess for accommodating the connector and a second recess for accommodating the tube associated with the connector. In this way, the connector and the tube associated with it can be held tight within the assembly (or cassette). This enables a tidy and compact design of the assembly which makes the use of the infusion set easier for medical personnel.
According to another embodiment of the present invention an enteral feeding or infusion pump comprises a pinch clamp assembly as mentioned above, wherein the pump comprises releasing means adapted to engage with the clamping element so as to release the clamping element from the closed to the open position.
Preferably the flow through the pumping section is only enabled when the pinch clamp assembly is mounted. This ensures that the anti-free-flow mechanism is only disabled when the pinch clamp assembly is entirely mounted to the infusion pump.
BRIEF DESCRIPTION OF THE DRAWINGS
The above object, features and advantages of the present invention will become apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:
FIG. 1A shows a perspective view of a cassette according to a preferred embodiment of the pinch clamp assembly according to the invention.
FIG. 1B shows a perspective view of a pump and a cassette according to a preferred embodiment of the pinch clamp assembly according to the invention.
FIGS. 2A , 2 B, 2 C show a front view, plan view, and rear view, respectively, of the cassette shown in FIG. 1 ;
FIGS. 2D , 2 E show section views on the line A-A of FIG. 2B , wherein the clamping element is in the closed and open position, respectively;
FIGS. 3A , 3 B show perspective views of a tube fitting element for a preferred embodiment of the pinch clamp assembly according to the invention;
FIG. 4 shows a silicon tube of the preferred embodiment of the pinch clamp assembly according to the invention;
FIG. 5 shows a perspective view of an enteral universal spike with cover as part of the preferred embodiment of the pinch clamp assembly according to the invention;
FIG. 6 shows an enteral adapter with cover of a further embodiment of the pinch clamp assembly according to the invention;
FIG. 7 shows a perspective view of the preferred embodiment of the pinch clamp assembly according to the invention in a first mounting status;
FIG. 8 shows a perspective view of a preferred embodiment of the pinch clamp assembly according to the invention in a second mounting status;
FIGS. 9A , 9 B show perspective views of two preferred embodiments of the pinch clamp assembly according to the invention in a third mounting status; and
FIGS. 10A , 10 B show perspective views of two preferred embodiments of the pinch clamp assembly according to the invention in their delivery status.
DETAILED DESCRIPTION
FIG. 1A depicts a perspective view of the main component of a preferred embodiment of the pinch clamp assembly according to the invention which is comprised of cassette 1 forming the base of the assembly. Cassette 1 is configured generally rectangular and in a relatively flat structure. Cassette 1 comprises holding means 3 at opposing sides to support the pumping section of a silicon tube (not shown in this figure). Further holding means 3 a to accommodate the silicon tube are positioned towards the center and near the longitudinal edge of the cassette 1 . Supporting means 5 are provided in cassette 1 in the form of a substantially round recess formed in a side wall of the cassette 1 and a further substantially rectangular recess formed in the ground plate of cassette 1 . Supporting means 5 are provided to support a connector which will be described in more detail later. The central element of the pinch clamp assembly according to the invention is clamping element 7 which in the shown preferred embodiment is integral with cassette 1 . The details of clamping element 7 will be described with reference to FIG. 2D and FIG. 2E . In the side wall opposing supporting means 5 there is provided a tube recess 11 for supporting the tube associated with the connector. In order not to over-complicate the figures with components not essential for the invention, the tube has been omitted at this point. The bottom portion of cassette 1 comprises a rotor unit recess 9 which is substantially in the shape of a rectangle with its inner corners rounded. When mounting the pinch clamp assembly according to the invention to the enteral feeding or infusion pump 8 the pins of the peristaltic rotor unit will fit into the space freed by the rotor unit recess 9 . A schematic representation of a pump (e.g., an enteral feeding or infusion) that may be used with the present cassettes 1 is provided in FIG. 1B . Holding means 3 a are formed on parallel side walls which are located at the edge of recess 9 and substantially rectangular to the direction of the tube in order to stabilize said mounting procedure.
FIGS. 2A , 2 B and 2 C are front, plan and rear views of the pinch clamp assembly components of FIG. 1 , wherein like numerals refer to like elements.
FIGS. 2D and 2E show an enlarged and sectional side view of the cassette 1 according to FIG. 1 wherein the clamping element 7 is in the closed ( FIG. 2D ) and the open position ( FIG. 2E ). Clamping element 7 generally comprises a first leg 15 with a tube blocking portion 17 in the form of a substantially rectangular plate which is attached to the first leg 15 at a substantially right angle. On the far end with respect to the tube blocking portion 17 first leg 15 comprises a retaining lever 16 . In the shown embodiment the second leg 19 of clamping element 7 is integrally formed with the mount plate of cassette 1 . The linking element between first leg 15 and second leg 19 of clamping element 7 is bending portion 21 which acts as a spring element so that clamping element 7 may be moved from a tension-less open position to a closed position. The retaining lever 16 is formed at the transition area between first leg 15 and bending portion 21 and extends at least partially into the space above the round supporting means 5 , preferably at an angle of between 5° and 30°. In order to stabilize the lever function of retaining lever 16 a T-bar like protrusion is formed on the upper surface of first leg 15 and retaining lever 16 , as can best be seen in FIG. 1 .
At the free end of first leg 15 there is provided a first locking means 23 which extends in a substantially right angle towards the ground plate of cassette 1 . The T-bar like protrusion extends substantially from the near end of first locking means 23 to the far end of retaining lever 16 . First locking means 23 comprises a protrusion extending generally away from bending portion 21 . The counterpart of first locking means 23 is second locking means 25 located at the free end of second leg 19 . In the preferred embodiment of the present invention, second locking means 25 comprise a horizontal slit with a length such that an engagement of the hook-like first locking means 23 and the slit of second locking means 25 in a closed position of clamping element 7 is enabled (shown in FIG. 2D ). Thus second locking means 25 are in this embodiment wider than the first locking means 23 , as can be seen in FIG. 2A . In the preferred embodiment in the open position of clamping element 7 there is no engagement between the first and second locking means (shown in FIG. 2E ). It is to be noted that any other engaging elements may be used for first and second locking means 23 , 25 in order to ensure the locking function of clamping element 7 .
Moving clamping element 7 from the open position to the closed position is simple: by pressing on the upper surface of first leg 15 first locking means 23 is brought further down and will eventually engage at its hook-like protrusion with the slit formed in second locking means 25 against the spring force of bending portion 21 which results in a stable closed condition of clamping element 7 . By briefly disengaging first locking means 23 and second locking means 25 clamping element 7 can be brought from the closed to the open position. This may be accomplished by bending second locking means 25 away from first locking means 23 into the direction away from bending portion 21 , i.e. substantially parallel to the plane of second leg 19 . Alternatively, one could press against first locking means 23 through the slit of second locking means 25 substantially parallel to the plane of second leg 19 . Since access from the outside onto second locking means 25 is occluded by first locking means 23 particular tools, or release members 4 , have to be used to facilitate the releasing of the engagement of first and second locking means 23 , 25 such as a very small pin or screw driver.
It is to be noted, that other types of locking means may be used for clamping element 7 such as the mechanism used in a cable strap/tie wrap, magnetic closure mechanism or Velcro lock. In alternative embodiments (not shown) two or more hook-like protrusions of first locking means 23 which are adapted to engage with a corresponding plurality of slits on second locking means 25 could be used. Then, special tools adapted to disengage the locking means will have to be used.
As can be seen from FIGS. 2D and 2E , the tube locking portion 17 will, in the closed position, almost touch the inner surface of the second leg 19 thereby squeezing the pumping section of silicon tube (not shown) in order to occlude the flow therethrough. In the shown embodiment the clamping surfaces of the tube blocking portion 17 and the second leg 19 are even. However, it is possible that the clamping surfaces are uneven, corrugated or finned so as to facilitate the squeezing function of the clamping element 7 depending on the characteristics of the silicon tube.
FIGS. 3A and 3B show perspective views of a tube-fitting element 39 which is adapted to hold the pumping section of the silicon tube and to fit into the holding means 3 provided in the cassette 1 of the pinch clamp assembly (see FIG. 1 ). In order to provide a good fit the tube fitting elements comprise a flange 40 which is adapted to engage the recesses formed in the holding means 3 of cassette 1 .
FIG. 4 shows the pumping section or silicon tube 10 which is arranged in the pinch clamp assembly according to the invention between the clamping surfaces of first leg 15 and second leg 19 and which is on either end tightly arranged at the respective ends of tube fitting elements 39 . It is to be noted, that usually only the pumping section of the tubing portion of the entire infusion set is made of silicon, whereas the remaining portions of the tube are made of PVC (polyvinylchloride)
FIGS. 5 and 6 show two preferred embodiments of a connector 6 as part of the pinch clamp assembly according to the invention. The embodiment of FIG. 5 shows a universal spike which may be used in a number of enteral feeding setups, the embodiment of FIG. 6 shows an enteral adapter which on one end comprises a female luer lock or a tapered fit. It is to be noted that in FIG. 5 the universal spike is on its shorter end directly connected to a tube, e.g. via solvent bonding.
The function of the pinch clamp assembly according to the present invention will now be described in more detail with reference to FIGS. 7 , 8 , 9 A, 9 B, 10 A and 10 B.
FIG. 7 shows in perspective view the first step when assembling the preferred embodiment of the pinch clamp assembly according to the invention. It is assumed that the cassette 1 is fabricated by injection moulding out of a thermoplastic material such as polypropylene, polystyrene, polyethylene or acrylnitril-butadien-styrene (ABS), also other suitable thermo-plastics may be used. The pumping section 10 of the silicon tube has already been associated with the two tube-fitting elements 39 and is now put into cassette 1 . Before engaging the tube-fitting elements 39 into the holding means 3 and 3 a of the cassette 1 the silicon tube 10 must be arranged between the clamping surfaces of first leg 15 and second leg 19 of clamping element 7 . For this purpose, the first locking means 23 and the second locking means 25 are disengaged and first leg 15 may be widely opened to receive silicon tube 10 . Alternatively, the clamping element 7 can be kept in its normal open position and the silicon tube 10 may be slid between the clamping surfaces of the clamping element 7 , and then associated with tube fitting element 39 which is then engaged with holding means 3 and 3 a . In the status after inserting silicon tube 10 into cassette 1 the pumping section is obviously not occluded. However, it is to be noted, that this status is merely an intermediate status while assembling the pinch clamp assembly of the invention.
FIG. 8 shows the next step of the assembly wherein the connector 6 is embodied in two different forms, the universal spike of FIG. 5 and the enteral adapter of FIG. 6 . The three arrows shall indicate the active movement with regard to the different elements of the pinch clamp assembly: firstly, the clamping element 7 is brought into the closed position by pressing on the outer surface of the first leg 15 , preferably substantially above the tube blocking portion 17 , thereby occluding the pumping section of the silicon tube 10 . The second movement is indicative for positioning the connector 6 within the supporting means 5 of cassette 1 . It must be noted that in the shown embodiment it is hardly possible to mount the connector 6 in the supporting means 5 of cassette 1 while the clamping element 7 is in the open position. This is due to the obstruction of retaining lever 16 which in the open position of clamping element 7 extends substantially parallel to the ground plane of cassette 1 . However, according to the invention this obstructing function for mounting the connector 6 in the supporting means 5 of cassette 1 is not essential as will be explained later.
The status depicted in FIG. 8 is, again, an intermediate status during the assembly of the pinch clamp assembly according to the invention. It is necessary for the next step of the assembly which is mounting the connector 6 onto existing components of the pinch clamp assembly by fitting it into supporting means 5 while clamping element 7 is in closed position. It is to be noted that although two embodiments of connector 6 are shown in FIG. 8 only one connector 6 can be engaged with supporting means 5 . The engagement of the connector 6 with the supporting means 5 is such that a lateral movement of connector 6 along its axis is impossible.
FIGS. 9A and 9B show perspective views of two preferred embodiments of the pinch clamp assembly according to the invention in the next status, after the connector 6 has been mounted onto the assembly, as explained above. In this intermediate status the clamping element 7 is holding down the pumping section 10 of the silicon tube. Furthermore, there is some free space between the upper surface of the connector 6 and the lower surface of retaining lever 16 of clamping element 7 .
FIGS. 10A and 10B show perspective views of two preferred embodiments of the pinch clamp assembly according to the invention in the final delivery status after the clamping element 7 has been brought into its open position. The opening of the clamping element 7 is achieved by releasing the engagement between first locking means 23 and second locking means 25 of the clamping element 7 so as to open the area between the clamping surfaces and therefore to allow the silicon tube 10 to return to its relaxed sectional area. It is important to note, that in this delivery status of the pinch clamp assembly according to the invention the pumping section of silicon tube 10 is substantially not deformed in the sense that a sticking of the inner surfaces is avoided during storage of the pinch clamp assembly. However, in this delivery status there is no free flow situation of the pinch clamp assembly according to the invention because connector 6 is secured tightly within the assembly because retaining lever 16 of clamping element 7 exerts a force onto connector 6 so that it cannot be removed from the assembly without closing the clamping element 7 . Therefore, it is not possible for medical personnel to attach the connector 6 to a port of a patient which would result in a free flow condition. It is the key principle of the present invention that while the retaining lever 16 which functions as a lock is exerting a force onto connector 6 in the open position of the clamping element 7 , it is not possible to generate a free flow condition since the connector 6 is held tightly within the assembly and removing the connector 6 from the assembly is only possible after bringing the clamping element 7 to its closed position. Thus the flow through the pumping section of the silicon tube 10 is always occluded before inserting the pinch clamp assembly into the pump.
Bringing the pinch clamp assembly according to the invention from the status of FIGS. 9A and 9B to the status of FIGS. 10A and 10B requires that the engagement of first locking means 23 with second locking means 25 be released. This can be achieved by a release member 4 , or an external tool, as part of the assembling process of the pinch clamp assembly according to the invention wherein this special tool pushes the second locking means 25 towards portion 21 of the clamping element 7 so as to release the hook-type engagement of the locking means, as shown by the arrows in FIGS. 9A and 9B . It is obvious that this releasing of the clamping element 7 cannot be accomplished easily, for example only with fingers. FIGS. 10A and 10B also show that the retaining lever 16 of clamping element 7 is tightly fitted over connector 6 . Also, the retaining lever 16 extends over the most part of the surface of connector 6 making it impossible to take connector 6 out of the assembly in this status. As stated above, a lateral movement is prevented by the supporting means 5 .
It is to be noted that the pinch clamp assembly as shown in FIGS. 10A and 10B cannot be mounted to an enteral feeding or infusion pump as is. Before the mounting can take place, connector 6 has to be removed. This is only possible after clamping element 7 has been brought into the closed position. It is clear that bringing the clamping element 7 into its closed position will also give open access to connector 6 which can be taken out of the assembly and connected to a port in order to set up the enteral feeding or infusion set. When mounting the pinch clamp assembly, with connector 6 removed, to the enteral feeding or infusion pump the clamping element 7 is still in its closed position thereby occluding the flow of liquid through the pumping section of silicon tube 10 . The free flow condition is thus avoided. However, the occluded status of the pumping section of the silicon tube 10 must be released as soon as the cassette 1 with the other components of the pinch clamp assembly are mounted in the enteral feeding or infusion pump. The cassette shape of the base of the pinch clamp assembly facilitates the handling and the mounting of the assembly to the pump.
In the above preferred embodiment a locking and releasing mechanism has been described. It is to be noted, that other locking-releasing mechanisms are possible such as a magnetic solution or a solution with fastening means. All alternative solutions however should fulfil the central requirement which is that they are tamper-resistant so that the clamping element 7 cannot be opened easily by hand or with tools which are easily available to medical personnel.
With the subject-matter of the present invention a pinch clamp assembly for engaging a tube with an enteral feeding or an infusion pump adapted to feed nutritionals or to infuse medical solutions to a patient has been provided which comprises a relatively simply construction, ensures an anti-free-flow mechanism that works at all times, allows for a long time storage of the silicon tube, is uniform with regard to the used material in order to be easily recyclable and can be used with a number of enteral feeding or infusion pumps.
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A pinch clamp assembly for engaging a tube with an enteral feeding or infusion pump adapted to feed nutritionals or to infuse medical solutions to a patient, is provided comprising a base ( 1 ) comprising holding means ( 3 ) for holding a pumping section ( 10 ) of the tube in operative engagement with the base ( 1 ) and supporting means ( 5 ) for supporting a connector ( 6 ), a clamping element ( 7 ) having clamping surfaces engageable with the pumping section ( 10 ) and moveable between an open position allowing flow of fluid through the pumping section ( 10 ) and a closed position wherein the pumping section ( 10 ) is occluded by the clamping element ( 7 ), and locking means adapted to engage with each other in the closed position and adapted to interact with releasing means external to the pinch clamp assembly so as to bring the clamping element ( 7 ) from the closed to the open position, a connector ( 6 ) for connecting the tube with a port on a patient, the connector ( 6 ) being removable from the pinch clamp assembly, the clamping element ( 7 ) further comprising a retaining lever ( 16 ), wherein in the open position of the clamping element ( 7 ) the connector ( 6 ) is retained by the retaining lever ( 16 ), and wherein the clamping element ( 7 ) is adapted to engage with the releasing means ( 43 ) to release the clamping element ( 7 ) to the open position when the pinch clamp assembly is mounted to the enteral feeding or infusion pump and the connector ( 6 ) is removed.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for embossing modulated grooves on a carrier medium as a function of received electronic signals and, more particularly, to such an apparatus wherein the electronic signals may represent video information. The subject matter of this application is related to subject matter disclosed in the copending U.S. application Ser. No. 517,529 of William Glenn entitled "Apparatus and Method For Embossing Information on a Disc".
There have been recently developed a number of systems for storing video and audio information on a carrier medium which, ideally, could be purchased by consumers at a reasonable cost and reproduced in conjunction with their conventional home television receivers. Typically, the consumer would purchase a "player" which would recover electronic video signals from a recording medium and these signals would be applied to the antenna terminals of a television set for display. There has been widespread disagreement as to what type of recording medium provides the maximum overall advantage of cost, performance, and reliability, with systems using magnetic tape, film, and discs similar to long playing records, all receiving support from different technical factions. During the last five years it has been demonstrated that video discs, which are in some respect similar to conventional sound recording discs, are capable of producing reasonable quality picture information. It is generally thought that these discs, which can be pressed from vinyl in a manner similar to conventional audio disc pressing, offer a great advantage of economy to the consumer, but disc systems present a number of new technical problems when it is attempted to record the relatively high frequencies required for video information thereon. For example, it is necessary that the video disc store about one hundred times the capacity of information of an audio record, and that the video disc reproducer handle a flow of information that is of the order of one hundred times faster than a phonograph pickup. Accordingly, the undulations in the disc grooves are much smaller than those of a conventional audio record and the necessarily small dimensions lead to problems in making the discs and in playback. Various types of playback systems have been proposed, for example playback employing an electrostatic capacitivedischarge technique or playback employing a pressure-type transducer which "slides" over the record grooves. In most systems, however, there is a common problem in producing the discs and, more specifically, in fabricating master discs from which relatively high quality duplicates can be pressed.
Two known types of "master" fabrication techniques for recording wavelengths on the order of one-half micron are electron beam processes and mechanical embossing processes. In the electron beam process a carrier is coated with an electron-sensitive material and selectively exposed using a modulated electron beam. This type of recording has been performed successfully although electron beam recording is a relatively expensive technique which requires a stringently controlled environment. Also, there has been difficulty in achieving electron beam recording in "real time" since at video frequencies this would require the beam to expose the electron-sensitive material at a high rate of relative motion which limits the amount of exposure time for each elemental area of electron-sensitive material and aggravates tracking problems. Therefore, it is the present practice to record using an electron beam at about one twentieth of real time, which is typically achieved by reducing the frequency of input signals by a factor of 20 and slowing the relative motion between the beam and the carrier by the same factor of 20.
The mechanical cutting process has also apparently been performed with some success. A company which is introducing a commercial video disc system claims to make masters using a mechanical cutting process similar to that used for conventional records. However, they acknowledge that the mechanical cutting process is not performed in real time, which is not surprising since conventional cutters cannot be satisfactorily operated at the megahertz frequencies necessary for real time recording.
It is accordingly one object of the present invention to provide an improved technique of mechanically embossing relatively high frequency information on a record medium, the embossing being capable of being done in real time.
SUMMARY OF THE INVENTION
The present invention employs a piezoelectric element as a "driver" for an embossing assembly. In the past, piezoelectric elements have been widely used in conjunction with pickup assemblies but, to applicant's knowledge, these elements have not been considered as suitable drive elements in cutters for various reasons. At audio frequencies, a conventional coil-driven cutter performs adequately and readily yields whatever displacement excursions are required to fabricate a master recording. A piezoelectric drive element, on the other hand, does not produce a relatively large displacement excursion, so this type of drive element is generally not envisioned as being advantageous for mechanical embossing. This need for a relatively large displacement would seemingly be even more defeating at very high frequencies where, if the element was driven "hard" to obtain the maximum excursion, the resultant velocity (which is a function of frequency times displacement) would be so great as to likely destroy the piezoelectric element in a very short time. The present invention is believed to solve this problem and, in doing so, provide a system which can successively emboss video frequencies in real time.
The present invention pertains to an apparatus for receiving electronic signals and embossing modulated grooves on a carrier medium as a function of the received signals, the apparatus including means for supporting an embossing assembly and a carrier medium in spaced relationship therewith as well as means for causing relative motion between the carrier medium and the embossing assembly. In accordance with the invention there is provided a wafer of piezoelectric material affixed to the supporting means, the wafer having electrodes for application of the electronic signals. Further provided is a horn-shaped stylus member having a relatively blunt end affixed to one side of the wafer and tapering to a relatively pointy stylus end, the stylus end being positionable in contact with the medium. The horn-shaped member serves to match the mechanical impedence between the wafer and the carrier. Stated another way, the horn-shaped member acts as a mechanical transformer which serves to increase the displacement excursions of the stylus end.
In the preferred embodiment of the invention a horn-shaped "dummy" load is affixed to the other side of the piezoelectric wafer to improve mechanical performance.
Further features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified diagram of an embossing apparatus which includes the present invention.
FIG. 2 is an enlarged perspective view of an embodiment of an embossing assembly in accordance with the invention.
FIG. 3 is a sectional view as taken through arrows 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a simplified diagram of an embossing apparatus which includes the present invention. A carrier medium, such as a thin plastic disc 20, is mounted over a suitable surface 21 which has a chuck 22 that grasps the disc center and is adapted for rotation by a motor 23. The disc 20 may be formed of any suitable material which is deformable, such as lexan, mylar, vinyl or lacquer. The metals aluminum and silver are also found to offer reasonable results when deposited as a film on a plastic base. The disc is preferably thin enough to be considered "floppy", and when it is spun at a relatively high rotation rate the layer of air between the disc bottom and surface 21 acts as an "air bearing". During such rotation the forces on the disc tend to cause a desirable degree of flatness.
A mounting means 25, which includes a support arm 26, supports an embossing assembly 30 in spaced relationship with the surface 21. The support arm 26 is slidable radially, in conventional fashion, so as to form the familar spiral groove on the disc 20. It will be understood that the radial motion is synchronized with the rotation of the turntable as a function of the desired groove geometries. This technique is known in the art and will not be discussed in detail, but it can be noted at this point that for "real time" recording the rotation of the turntable typically coincides with the rotation rate at which duplicated recordings are expected to be rotated during playback. The embossing assembly 30 includes a stylus, to be described, which is driven as a function of the electronic signals which are to be embossed on the disc 20. The signals are coupled to the assembly 30 via conductors which are not visible in the FIG. 1 diagram.
From an overview system standpoint, operation of the apparatus of FIG. 1 is similar to a conventional record cutter. Specifically, the blank disc 20 is rotated in synchronism with the radial motion of embossing assembly 30. The application of electrical signals to the embossing assembly causes motion of its stylus, in a manner to be described, which results in a spiral groove in recording disc 20 that is modulated in accordance with the applied electrical signals. After embossing, the disc can be plated with an appropriate metal to produce a "metal master" which, in turn, can be used to ultimately fabricate reproductions, for example using conventional vinyl pressing techniques.
Referring to FIGS. 2 and 3 there is shown an enlarged perspective view of the embossing assembly 30 in accordance with the present embodiment. A wafer of piezoelectric material 31 is provided, preferably in the shape of a disc. As used herein, the term "piezoelectric material" is intended to include any material which exhibits a piezoelectric effect; i.e., a mechanical strain resulting from the application of electricity.
A disc of piezoelectric ceramic material that is purchased commercially, such as from Transducer Products, typically has thin metal electrodes, for example silver electrodes, deposited on its opposite faces. A metal disc 32, which may be aluminum, is attached to the underside of wafer 31, an exceedingly thin layer of contact cement being suitable for this purpose. The disc 32 serves as an electrode, so electrical contact with the underside of wafer 31 is needed. This contact is achieved by the asperities on the respective surfaces when a very thin layer of cement is employed.
A stylus member 33 is cemented to the underside of the metal disc 32, a thin layer of contact cement again sufficing for this purpose. The stylus member 33 may be sometimes referred to herein as being "affixed" to the wafer 31, although its attachment to the wafer is via the metal disc 32. This is consistent with the intended meaning of "affixed" which, as used herein, is defined as a fastening that may be direct or indirect through one or more media. In the present embodiment the stylus member comprises a horn-shaped tapered section 34, preferably formed of glass, and a stylus tip 35 embedded in the glass and preferably formed of a very hard material, such as sapphire or diamond. The member 33 may, however, be made of a single material. The horn 34 can be molded from glass with the tip 35 in position, so that the tip is permanently embedded in the glass.
A member 40, referred to as a "dummy horn", which can be molded from a metal such as aluminum, is provided in the shape of a horn and cemented to the top surface of wafer 31. In the present embodiment the support arm 26 is affixed to wafer 31 via the dummy horn 40; i.e., support arm 26 is fastened to dummy horn 40 which, in turn, holds the wafer 31 and the rest of the embossing assembly 30. The dummy horn 40 serves, inter alia, as an electrode, a voltage being applied across the wafer 31 by virtue of signals applied over insulated conductors 46 and 47. If desired, the arm 26 could act as one of the conductors.
For operation (referring to all FIGURES) the mounting means 25 is positioned such that, without a signal applied, the stylus tip 35 will make a groove of desired depth in the disc 20. A typical groove depth may be less than one micron. During operation, electrical signals are applied to the electrodes 32 and 40 (via conductors 46 and 47), and the wafer 31 contracts and expands as a function of the applied signal. This causes a compressional wave to be established in the horn 34, the wave propagating vertically downward toward the stylus tip 35. As a result, the tip 35 vibrates and causes modulations in the groove, the groove being formed as the disc moves with respect to tip 35 (as is depicted in the sketch of FIGS. 2 and 3). The stylus tip may be of any suitable shape, but a tip having a relatively sharp trailing edge is preferred to obtain the necessary resolution.
The excited piezoelectric wafer's excursions can be categorized, for purposes of the intended application, as being of relatively small vertical displacement with a relatively great force. In other words, the total force over the piezoelectric wafer area is greater than is needed to deform an elemental area of the recording disc material with the stylus tip, but the vertical displacement is less than the desired level of modulation in the groove. The horn 34 serves to transform a compressional wave (acoustic in nature) having a relatively high force and a relatively low velocity into a compressional wave of reduced force and increased velocity (i.e., rate of displacement). The result is a motion of the stylus tip that is compatible with the recording objective. In this manner, the high frequency deformations of a piezoelectric wafer can be advantageously utilized without the need for driving the wafer beyond its capabilities. This allows heretofore unattainable mechanical recording at megahertz frequencies.
The described phenomenon can be alternatively visualized in terms of mechanical impedances. The piezoelectric wafer 31, which supplies the driving force, can be considered as a relatively high mechanical impedance whereas the stylus tip working on a small area of recording disc 20 presents a relatively low mechanical impedance to be driven. Accordingly, the horn 34 serves the function of matching the dissimilar impedances.
The present disclosed embodiment is found to overcome additional problems which arise when attempting to record megahertz frequencies in real time. One objective is to obtain a reasonably stable frequency response over a frequency range of the order of five megahertz or more. Unlike some mechanical driving systems wherein a particular mechanical resonance can be used to advantage, the present system is necessarily designed to prevent severe perturbations in the frequency response curve while still delivering power with reasonable efficiency over the frequency range of interest. The dummy horn 40, which is preferably similar in shape to the horn 34, is found to reduce undesirable acoustic resonances, a result which is believed due, at least in part, to its acting as a proper mechanical load on the back side of the piezoelectric driver 31. It can be noted that the tapering of the dummy horn serves to reduce the effect of undesired acoustic resonances that would normally be aggravated by an abrupt termination plane. The dummy horn also serves as a heat sink and an electrode in the present embodiment.
A tapered horn characteristically exhibits a lower cutoff frequency for a compressional wave propagating therein, and it is desirable in the present system to have a cutoff frequency that is below about one megahertz. A curved taper, such as an exponential or hyperbolic surface is found to be an advantageous shape for the horn 34 in providing a suitable frequency response with a well defined relatively low cutoff frequency. It is impractical to expect that resonancefree response can be obtained over the wide intended operating frequency range. Rather, it is found that a large number of closely spaced small resonances over the frequency range of interest can provide acceptable operation, and the curved tapered horn 34 facilitates obtainment of this characteristic.
The invention has been described with reference to a particular embodiment, but it will be appreciated that variations and additions within the spirit and scope of the invention will occur to those skilled in the art. For example, a "cap" of acoustic damping material may be provided over the dummy horn to obtain a desired degree of controlled damping.
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An apparatus for receiving electronic signals and embossing modulated grooves on a carrier medium as a function of the received signals, includes a support for supporting an embossing assembly and a carrier medium in spaced relationship therewith, as well as apparatus for causing relative motion between the carrier medium and the embossing assembly. In accordance with the invention there is provided a wafer of piezoelectric material affixed to the mount, the wafer having electrodes for application of the electronic signals. Further provided is a horn-shaped stylus member having a relatively blunt end affixed to one side of the wafer and tapering to a relatively pointy stylus end, the stylus end being positionable in contact with the medium. The horn-shaped member serves to match the mechanical impedence as between the wafer and the carrier. A dummy horn on the other side of the wafer adds a vibration reducing load to the structure.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 10/359,558, filed 7 Feb. 2003, the application being incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
This invention relates to a method for the treatment of cryptorchidism, i.e. testicular non-descendent in male individuals.
BACKGROUND OF THE INVENTION
The publications and other materials used herein to illuminate the background of the invention, and in particular, cases to provide additional details respecting the practice, are incorporated by reference.
Testicular descent occurs in two steps on the embryonic stage and the process is affected by several factors. Transabdominal descent begins after sexual differentiation at 8 to 10 weeks. The testis reaches the inguinal region at about the 15 th week. The inguinal phase of testicular descent begins at 24-28 weeks when the testis rapidly passes through the inguinal canal and then more slowly arrives in the scrotum at 35-40 weeks (1).
The incidence of non-descended testis (in the following also called cryptorchidism, which term stands for failure of one or both of the testes to descend) has been 4.3% in all newborn male infants. At the age of three months the incidence is 1.0% and at the age of one year 0.8%. According to a recent English study, the incidence of non-descended testis has risen to 5.1% among newborns and 1.6% at the age of three months (2). Also in Denmark a growth of the incidence has been reported. Some of the increase may be attributed to the increased viability of very low birth weight infants, but even in full-term infants the incidence has risen to 4.1% at birth and 1.6% at three months (2). Excessive maternal exposure to estrogens such as diethylstilbestrol and to oral contraceptives has been suggested as an etiological factor associated with the increased incidence of cryptorchidism. Endogenous estrogens have also been suggested to be relevant to testicular non-descent. An increased risk of cryptorchidism and testicular cancer has been associated with elevated maternal estrogen consentrations during pregnancy (3). Overweight women that are nulliparous have lower SHBG levels, with a resulting higher bioavailability for estrogens. The increase in the amount of biologically active estrogens may extend during pregnancy and subsequently lead to a clinical condition that exposes the fetus to high estrogen levels (3). There is experimental evidence confirming the role of estrogens. Perinatal exposure of the mouse to either 17β-estradiol or diethylstilbestrol results in testicular abnormalities such as cryptorchidism, testicular hypoplasia, sperm abnormalities, epididymal cysts and testicular tumors (4 and 5).
Testicular maldescent may strongly influence male fertility even when treated and fertility is frequently impaired, particularly in cases of bilateral cryptorchidism. Testicular cancer is also associated with cryptorchidism.
One method for the treatment of cryptorchidism is surgery. Some decades ago, the surgery was carried out at the age of about 5-10 years. There has, however, been a stepwise decrease in the age at which surgery should be carried out, mainly due to histological evidence of testicular damage which occurs in untreated non-descended testis after infancy. At present, the operation is recommended before two years age.
Cryptorchidism has also be subjected to hormonal treatment with hCG (human chorionic gonadotrophin) or LHRH (lutenizing-hormone releasing hormone). During the last decades the success rate of hCG treatment has varied from 6 to 55%. The success rates achieved by using LHRH have been reported to vary between 9 and 78%. According to one study, both LHRH and hCG have been found to be ineffective in cases of true non-descended testes.
The known treatment methods are also related to risks. The most significant complication of surgery is vascular damage. Hormonal treatment may also have adverse effects on the testis. Inflammation-like reactions have been found in non-descended testes during the period immediately following hCG injections.
Thus, there is a great need for improved treatment methods of cryptorchidism.
SUMMARY OF THE INVENTION
The inventors of the present invention have surprisingly found that cryptorchidism can be successfully treated by administering an aromatase inhibitor.
Thus, this invention relates to a method for the treatment of male individuals suffering from cryptorchidism comprising administering to said individuals an effective amount of an aromatase inhibitor.
According to another aspect, this invention concerns the use of an aromatase inhibitor for the manufacture of a pharmaceutical composition useful for the treatment of male individuals suffering from cryptorchidism.
DETAILED DESCRIPTION OF THE INVENTION
Aromatase is an enzyme complex involving a NADPH-cytochrome C reductase and a specific cytochrome P-450 protein. The reaction which is catalyzed by aromatase is unique in the biosynthesis of steroids, as it involves conversion of ring A of the steroid structure to an aromatic ring with the loss of the angular C-19 methyl group and cis-elimination of the 1β and 2β hydrogens to yield estrogen and formic acid. Aromatization is the last and critical step in the biosynthesis of estrogens from cholesterol. Therefore, specific blockade of this enzyme does not cause deprivation of other essential steroids such as cortisol or male sex hormones.
As suitable selective aromatase inhibitors can be mentioned, for example, the compounds covered by formula (I) in International patent application publication No. WO 94/13645. Said compounds (I)
include members wherein R 1 is hydrogen, methyl, methoxy, nitro, amino, cyano, trifluoromethyl, difluoromethyl, monofluoromethyl or halogen; R 2 is a heterocyclic radical selected from 1-imidazolyl, triazolyl, tetrazolyl, pyrazolyl, pyrimidinyl, oxazolyl, thiazolyl, isoxazolyl and isothiazolyl; R 3 is hydrogen or hydroxy; R 4 is hydrogen; R 5 is hydrogen or hydroxy; or R 4 is hydrogen and R 3 and R 5 combined form a bond; or R 3 is hydrogen and R 4 and R 5 combined form ═O; R 6 is methylene, ethylene, —CHOH—, —CH 2 CHOH—, —CHOH—CH 2 —, —CH═CH— or C(═O)—; R 4 is hydrogen and R 5 and R 6 combined is ═CH— or ═CH—CH 2 —; or a stereoisomer, or a non-toxic pharmaceutically acceptable acid addition salt thereof.
A preferred compound of this group 1-[1-(4-cyanophenyl)-3-(4-fluorophenyl)-2-hydroxypropyl]-1,2,4-triazole. Particularly preferred is the compound 1-[1-(4-cyanophenyl)-3-(4-fluorophenyl)-2-hydroxypropyl]-1,2,4-triazole, diasteroisomer a+d, which also is known under the generic name finrozole. The separated a and d isomers of this diastereomer mixture are also preferred.
As examples of other suitable aromatase inhibitors can be mentioned anastrozole, fadrozole, letrozole, vorozole, roglethimide, atamestane, exemestane, formestane, YM-511 (4-[N-(4-bromobenzyl)-N-(4-cyanophenyl)amino]-4H-1,2,4-triazole), ZD-1033 (anastrozole) and NKS-01 (14-α-hydroxyandrost-4-ene-3,6,17-trione) and their stereoisomers and non-toxic pharmaceutically acceptable acid addition salts.
Finrozole, like all presently described specific aromatase inhibitors, have been intended mainly for the treatment of female breast cancer where estrogens stimulate the tumor growth, and aromatase inhibitor, by depleting estrogens, inhibits the tumor growth. In men aromatase inhibitors dramatically decrease estradiol concentrations and may simultaneously increase the testosterone concentrations being thus especially beneficial for the increasing the decreased androgen to estrogen ratio (DATER) and for the treatment of voiding dysfunction which are due to the DATER, as described in WO 94/13645.
For the purpose of this invention, the aromatase inhibitor or its stereoisomer or pharmaceutically acceptable salt can be administered by various routes. The suitable administration forms include, for example, oral formulations; parenteral injections including intravenous, intramuscular, intradermal and subcutaneous injections; and transdermal or rectal formulations. Suitable oral formulations include e.g. conventional or slow-release tablets and gelatine capsules, and especially liquid mixtures.
The required dosage of the aromatase inhibitor compounds will vary with the particular condition being treated, the severity of the condition, the duration of the treatment, the administration route and the specific compound being employed. Generally, the treatment should last from days to a few months and should be stopped as soon as the testes have descended. For example, finrozole can be administered perorally preferentially once daily. The daily dose is 0.1-1 mg/kg body weight, preferably 0.2-0.6 mg/kg body weight. Finrozole can be given as tablets or other formulations like gelatine capsules alone or mixed in any clinically acceptable non-active ingredients which are used in the pharmaceutical industry.
Preferably, the aromatase inhibitor should be administered to boys before the puberty. Most preferably, the treatment should take place on boys in the age of 1 to 5 years.
The invention will be illuminated by the following non-restrictive Experimental Section.
Experimental Section
Androgens and estrogens play a central role in organization and differentiation of the developing endocrine system in general and of the peripheral reproductive tract in particular. Although, estrogen is considered to be the female sex steroid, and androgen that of the male, there is considerable amount of overlap in activities of the two groups of steroids between the sexes. Thus, the differences between the two sexes in their response to estrogens and androgens are not qualitative but merely due to quantitative variation in sex steroid concentrations, and the balance between androgen and estrogen action. Both estrogens and androgens exert their biological action via specific nuclear receptors, and in addition to the cell specific expression of the receptors the sex steroid concentrations in target cells determine the extent of steroid action. Androgens can be converted into estrogens via an enzymatic reaction catalyzed by the enzyme complex called P450 aromatase.
Aromatization of androgens is the key step in estrogen production, and in regulation of the delicate balance between estrogens and androgens in gonads and sex steroid target tissues.
Test and Control Compounds
The aromatase inhibitor finrozole {MPV-2213ad (10695U, without purification, Hormos Medical Ltd.} was the test compound. Vehicle (CMC-solution) was used as control substance. CMC-solution was prepared as follows: 0.25 g carboxylmethylcellulosa (CMC) (lot. 939512, Tamro OYJ) was weighed and solubilized in 50 ml of deionized (Milli-Q) water. The solution was prepared once a week and stored at +4° C. The dose level of finrozole 10 mg/kg dose level was used. The vehicle-test/control-solution, which was given to the test animals, was prepared daily as follows: the appropriate amount of finrozole was weighed in a transparent glass mortar. A few drops of vehicle were added and the mixture was thoroughly mixed. After this ⅓ of the final volume of vehicle was added to the mortar and placed into an ultrasonic incubator for five minutes. This procedure was done total of three times to reach the final volume.
Test Animals
Aromatase over expressing mice AROM + (line 021) were used in this study. The mice were maintained under standard laboratory conditions at 12:12 light/dark cycle, and received free access to soyfree pelleted food (SDS, Witham, Essex, UK), and tap water.
We have generated a transgenic mouse model bearing the human ubiquitin C promoter/human P450 aromatase fusion gene (AROM + ). The AROM + male mice produced are characterized by an imbalance in sex hormone metabolism, resulting in serum estradiol concentrations typical for females, combined with significantly reduced testosterone level. The AROM + males present with a multitude of severe structural and functional abnormalities of the reproductive system, such as cryptochidism, dysmorphic semiferous tubules and disrupted spermatogenesis. The males also have small or rudimentary accessory sex glands with abnormal morphology, a prominent prostatic utricle with squamous epithelial metaplasia, and abnormal morphology of ejaculatory duct and vas deferens. In addition, the abdominal wall muscle layer is thin, and the adrenals are enlarged with cortical hyperplasia. Some of these abnormalities, such as undescended testes and undeveloped seminal vesicles resemble those observed in animals exposed to high estrogen levels in perinatal life (3 and 4), indicating that the elevated aromatase activity resulted in excessive estrogen exposure also during early phase of development. Some of the disorders in reproductive system, furthenmore, can be explained by the fact that the AROM + males are hypo-androgenic. The AROM + mouse model provides a useful tool to investigate the consequences of prolonged imbalance in the androgen-estrogen ratio, and in particular, of excessive estrogen exposure on male reproductive functions.
In AROM + males, the seminal vesicles, testes and prostate lobes were significantly reduced in size. All the AROM + males were cryptorchid, with the testis located in the abdominal cavity. The cryptorchid testes were significantly smaller than the wild type in size, as were the epididymides. Microscopically, the diameter of the seminiferous tubule of the AROM+ mice was smaller and the lumen was larger than those of the wild type were. In the seminiferous epithelium, there were no germ cells beyond the stage of pachytene. Numerous degenerating germ cells could be seen near the lumen, which showed less intensively stained nuclei, homogeneously pink-stained cytoplasm. Numerous vacuoles of different sizes were observed within the epithelium and interstitium. The number of interstitial cells per mm 2 was also increased in the AROM + mice than the wild type.
Two of the five AROM + founder mice generated (one male, number 33 and one female, number 21) were fertile and they were used to generate subsequent generations by breeding with the wt FVB/N mouse background. All the male mice born of both lines (from F1 generation and thereafter) were infertile, and hence, the transgenic lines could be established only by mating the AROM + females with wild type FVB/N males.
In the experiment there was six different kind of groups of male mice, ten animals in each group. One control group (wild type FVB/N) received vehicle, as well as the other control (021 line) group. The last groups were treated with finrozole (10 mg/kg).
Administration of the Compounds
The dosing (4 ml solution/kg) of the animals took place p.o. daily for six weeks. On Saturdays, however, double dose of the test compounds was given to animals. On sundays there was no treatment.
Results
The trial was conducted in total of 39 mice. The possible undescended testes were palpated and also examined by opening the animal. The palpation was conducted as follows: the abdominal area of the animal was pressed gently and simultaneously the fingers were dragged towards the scrotum. If the testes are able to descend, they appear into the scrotum, and if not the testes are undescended. The results are shown in Table 1. The relative weights (testes weight/animal weight) are shown in Table 2.
TABLE 1
Number of Descended or Undescended Testes
Number of
Number of
descended
undescended
Number of partly
Testes
testes
testes
descended testes
Wild type (FVB/N)
20
vehicle group (ten mice)
Wild type finrozole
18
group (nine mice)
AROM + (021) vehicle
20
group (ten mice)
AROM + (021) finrozole
17
1
2
group (ten mice)
TABLE 2
Relative Testes Weights (Testes Weight/Animal Weight)
in Vehicle and Finrozole Treatment Groups in Wild Type
and AROM+ 021 Groups (N.S = Non-Significant.
A = ANOVA and M = Mann-Whitney U-test)
Relative
P-value compared
P-value compared
testes
to wild type
between vehicle
weights
vehicle group
and treatment
Wild type (FVB/N)
0.0027
vehicle group
(SD 0.0002)
(n = 10)
Wild type
0.0027
N.S (A)
N.S (A)
finrozole group
(SD 0.0003)
(n = 7)
AROM + (021)
0.0017
0.002 (M)
vehicle group
(SD 0.0006)
(n = 10)
AROM + (021)
0.0033
N.S (A)
0.0007 (M)
finrozole group
(SD 0.0003)
(n = 10)
N.S = Non-Significant
A = ANOVA
M = Mann-Whitney U-test)
It will be appreciated that the methods of the present invention can be incorporated in the form of a variety of embodiments, only a few of which are disclosed herein. It will be apparent for the expert skilled in the field that other embodiments exist and do not depart from the spirit of the invention. Thus, the described embodiments are illustrative and should not be construed as restrictive.
REFERENCES
1. Taskinen, Seppo: “Clinical outcome after treatment of undescended testes”. Thesis. University of Helsinki 1997.
2. John Radcliffe Hospital Cryptorchidism Study Group: “Cryptorchidism: a prospective study of 7500 consecutive male births, 1984-8. Arch Dis Child 67:892-899, 1992.
3. Bernstein L, Pike M C, Depue R H, Ross R K, Moore J W, Henderson B E: Maternal hormone levels in early gestation of cryptorchid males: A case-control study. Br J Cancer 58:379-381, 1988.
4. McLachan J A: Rodent models for perinatal exposure to diethylstilbestrol and their relation to human disease in the male. In Herbst A L, Bern H A (eds.): “Developmental Effects of Diethylstilbestrol (DES) in Pregnancy.” New York, N.Y.: ThiemeStratton Inc., 1981, pp 148-157.
5. Newbold R R, Bullock B C, McLachan J A: Adenocarsinoma of the rete testis. Diethylstilbestrol-induced lesions of the mouse rete testis. Am J Pathol 125:625-628 1986.
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The present invention relates to a method and pharmaceutical composition for the treatment of male individuals suffering from cryptorchidism comprising administering to said individuals an effective amount of an aromatase inhibitor, preferably finrozole.
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STATEMENT OF GOVERNMENT RIGHTS
[0001] The present invention was made with United States Government support under Department of Energy Contract No. DE-AC07-99ID13727. The Federal Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to fluid flow control and, more particularly, to high resolution flow control of, for example, high pressure compressible fluids including supercritical fluids.
[0004] 2. State of the Art
[0005] Control of fluid flow is important in numerous applications. For example, fluid flow control is involved in hydraulic applications, in the operation of various semiconductor fabrication systems such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) equipment, in the operation of autoclaves and similar equipment, and in the performance of various laboratory experiments.
[0006] In all of the above-listed applications, as well as numerous others, the ability to control fluid flow, whether according to pressure or flow rate (either mass or volume), is important to the success of the operation or process being performed. For example, in regard to various laboratory experiments, fluid flow control often needs to be precise and repeatable so as to ensure that certain input conditions are actually what was intended and the integrity of the experiment's outcome is not in question. It becomes even more important to control the fluid flow, and also more difficult to accurately do so, when the fluid being handled is supercritical and there is a potential of effecting a phase change within the fluid as it flows through a flow control device. While various fluid control devices have been designed in an attempt to provide high resolution flow control, such devices have been lacking in their ability to consistently provide accurate control of fluids including high pressure, compressible fluids.
[0007] For example, referring to FIG. 1 , a prior art flow control device 10 is shown. The flow control device 10 includes a valve 12 with a flow path 14 defined therethrough. The valve includes an inlet 16 configured to be coupled with a fluid source (not shown) and an outlet 18 configured to be coupled with a conduit or some other device to which fluid is to be delivered (none shown). A linearly positionable valve stem 20 is disposed within the valve and configured to control the flow of fluid passing through the defined flow path 14 . Packing 22 or some other seal arrangement may be disposed about a portion of the valve stem 20 to prevent leaking of the fluid around the valve stem 20 . The valve stem 20 is coupled with a linear positioning actuator 24 which displaces the valve stem along a linear path as indicated by directional arrow 26 .
[0008] While the flow control device 10 may provide adequate fluid flow control for some applications, it is desirable to improve on such an arrangement. For example, a flow control device configured substantially as described with respect to FIG. 1 may exhibit a flow coefficient of approximately 0.03 C v , wherein C v may be defined, as it relates to valves, as a quantity relating a flow rate, in gallons per minute (gpm), of a fluid with a known specific gravity to the pressure drop experience across the valve as measured in pounds per square inch (psi). It may be noted that the flow coefficient is not dimensionally homogenous (as illustrated in the following equations) and is specifically limited to English units.
[0009] For incompressible fluids the flow coefficient C v may be expressed by the following equation:
C v = Q Δ p S G
[0010] Wherein Q is the flow rate in gallons per minute, Δp is the change in pressure across the valve in pounds per square inch, and SG is the specific gravity of the fluid flowing through the valve.
[0011] For compressible fluids, the determination of the flow coefficient becomes more complex. For example, if the inlet pressure is twice that of the outlet pressure (what may be termed as critical flow) or greater, the flow coefficient may be expressed by the following equation:
C v = Q G S G × T 816 × P inlet
[0012] If the inlet pressure is less than twice the outlet pressure (what may be termed subcritical flow) the flow coefficient may be expressed by the following equation:
C v = Q G 962 S G × T P inlet 2 - P outlet 2
[0013] Wherein Q G is the flow rate of the fluid in standard cubic feet per minute (scfm), T is the absolute temperature in degrees Rankin, P inlet and P outlet are the inlet and outlet pressures of the valve, respectively, in pounds per square inch absolute (psia), and SG is the specific gravity of the fluid flowing through the valve.
[0014] Returning to the prior art flow control device 10 described with respect to FIG. 1 , while in absolute terms, a flow coefficient of 0.03 C v would appear to provide fluid control at what might be consider a “high” resolution, such a flow coefficient may not be considered adequate for a number of applications including. For example, in some applications, such as various laboratory experiments, it may be desired to provide flow control with a resolution which is approximately an order of magnitude finer than such a prior art flow control device. Additionally, such a flow control device 10 has, in the past, only provided adequate pressure control of a fluid within, for example, 50 to 100 psi in some cases. It is desirable to obtain more exact pressure control of the fluid for numerous applications.
[0015] An additional problem with the flow control device 10 shown and described with respect to FIG. 1 is that the linear motion of the valve stem 20 makes the valve 12 vulnerable to contamination from grit or small particulates which may be present in the fluid flowing therethrough. For example, in the past, such a valve 12 has had small particulates become lodged or wedged between the valve stem 20 and the valve stem seat 28 . When lodged between the valve stem 20 and valve stem seat 28 , the particulates have interfered with the actuation of the valve stem 20 and the precise positioning thereof. Furthermore, the presence of particulates between the valve stem 20 and the valve stem seat 28 has, in the past, resulted in the galling of the two components thereby causing the valve 12 , initially, to operate imprecisely and, ultimately, to fail. In some particular cases, the valve 12 associated with a flow control device such as described with respect to FIG. 1 has failed within approximately fifteen to twenty minutes of use because of the presence of such particulates in the fluid.
[0016] In view of the shortcomings in the art, it would be advantageous to provide a method and apparatus for consistently and repeatedly controlling the flow of high pressure, compressible fluids at a relatively high resolution. It would further be desirable to provide a method and apparatus of controlling fluid flow which is not susceptible to fouling or galling due to the presence of particulates within a fluid being processed thereby.
BRIEF SUMMARY OF THE INVENTION
[0017] In accordance with one aspect of the invention, a fluid flow control device is provided. The fluid flow control device includes a valve having a fluid inlet, a fluid outlet and a flow path defined therebetween. The valve further includes a valve stem disposed within a valve seat in communication with the flow path. A gear member is coupled to the valve stem, which is cooperatively configured with the valve seat to cause the valve stem to advance or back off within the valve seat responsive to rotation of the valve stem about a first axis. A linear positioning member is disposed adjacent the gear member wherein at least a portion of the linear positioning member is configured to complementarily engage the gear member. The linear positioning member is configured to be displaced along a second axis to cause rotation of the gear member and valve stem about the first axis and the attendant displacement of the valve stem along the first axis. In one embodiment, the portion of the linear positioning member which complementarily engages the gear member may be configured as substantially helically cut worm gear.
[0018] In accordance with another aspect of the present invention, a fluid flow control system is provided. The fluid flow control system includes a controller and at least one fluid flow control device operably coupled with the controller. The fluid flow control device includes a valve having a fluid inlet, a fluid outlet and a flow path defined therebetween. The valve further includes a valve stem disposed within a valve seat in communication with the flow path. A gear member is coupled to the valve stem, which is cooperatively configured with the valve seat to cause the valve stem to advance or back off within the valve seat responsive to rotation of the valve stem about a first axis. A linear positioning member is disposed adjacent the gear member wherein at least a portion of the linear positioning member is configured to complementarily engage the gear member. The linear positioning member is configured to be displaced along a second axis to cause rotation of the gear member and valve stem about the first axis and the attendant displacement of the valve stem along the first axis.
[0019] In accordance with yet another embodiment of the present invention, a method of controlling the flow of a fluid is provided. The method includes providing a valve having a flow path defined therethrough. A valve stem is disposed within a valve seat in communication with the flow path and is coupled with a gear member. The gear member is engaged with a complementary surface of a linear positioning member and the fluid is passed through the flow path. The linear positioning member is displaced along a first axis to rotate the gear member and valve stem about a second axis and displace the valve stem along the second axis.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
[0021] FIG. 1 shows a prior art fluid flow control device;
[0022] FIG. 2 shows a fluid flow control device in accordance with an embodiment of the present invention;
[0023] FIG. 3 shows an enlarged view of a portion of the device of FIG. 2 ; and
[0024] FIG. 4 is a schematic of a fluid flow control system in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Referring to FIG. 2 , a fluid flow control device 100 is shown. The flow control device includes a valve 102 with a flow path 104 defined therethrough. The valve 102 includes an inlet 106 configured to be coupled with a fluid source (not shown in FIG. 2 ) and an outlet 108 configured to be coupled with a conduit or some other device to which fluid is to be delivered. A valve stem 110 is disposed within the valve 102 and configured to control the flow of fluid passing through the defined flow path 104 . Packing 112 or some other seal assembly may be disposed about a portion of the valve stem 110 to prevent leaking of the fluid around the valve stem 110 .
[0026] The valve stem 110 is configured and oriented to be displaced within the valve along a defined axis 114 relative to an associated valve seat 116 upon the rotation of the valve stem 110 about the defined axis 114 . Thus, the valve stem 110 and a component of the valve 100 , such as the packing gland 113 or some other appropriate structure, may include mating or complimentarily engaged threads 118 to enable the displacement of the valve stem 110 relative to the valve 100 along the axis 114 in response to the rotation of the valve stem 110 . The pitch of the threads 118 may be selected to control the magnitude of displacement of the valve stem 110 relative to the valve 100 upon rotation of the valve stem 110 . An exemplary valve may include Micro Metering valve Part # 10VRMM2812 commercially available from Autoclave Engineers of Eerie Pa., although other valves may be used in practicing the present invention.
[0027] A linear positioning actuator 120 is coupled with a positioning member 122 such as a shaft or other structural member. The actuator 120 may include, for example, a high resolution linear positioning stepper motor configured to displace the positioning member 122 along an axis 124 as indicated by directional arrow 126 . An exemplary actuator may include a model EVA-1 electronic valve actuator commercially available from Badger Meter, Inc., of Tulsa, Okla. Such an actuator 120 may include a transformer 128 coupled to a 120 VAC power supply 130 which is configured to provide DC power to the actuator 120 . Another exemplary actuator might include a pneumatic actuator which utilizes a current to pressure (I/P) converter for controlling the linear position of the positioning member 122 . It is noted, however, that other actuators 120 may be used in conjunction with the present invention.
[0028] A portion of the positioning member 122 , such as at the distal end 132 thereof, is configured to matingly engage a gear 134 . The gear 134 is coupled with the valve stem 110 and configured to rotate the valve stem 110 . As shown, the gear 134 is disposed about valve stem 110 in perpendicular orientation thereto. Thus, as the positioning member 122 is displaced linearly along axis 124 , the portion of the positioning member 122 engaged with the gear 134 causes rotation of the gear 134 about axis 114 as indicated by directional arrow 136 , advancing or backing off the valve stem 110 within the valve seat 116 , depending upon the direction of displacement of positioning member 122 . The diameter of the gear 134 may be selected to provide a desired gear reduction and thereby improve the resolution provided by the linear actuator 120 . As will be appreciated by those of ordinary skill in the art, a larger diameter gear 134 will provide a greater amount of reduction such that a larger linear displacement of the positioning member 122 will be required to effect a full turn of the valve stem 110 .
[0029] In one embodiment, the distal end 130 of the positioning member 122 may be configured as a toothed rack and the gear 134 may be configured as a mating pinion gear thereby providing a rack and pinion assembly. However, in another embodiment, as specifically shown in FIG. 3 , (while also still referring to FIG. 2 ) the distal end 130 of the positioning member 122 may be configured as a substantially helically cut worm gear 138 wherein gear 134 is configured to mate therewith. With conventional worm gear arrangements, the worm gear 138 acts as a driving gear by rotating about its axis 124 and driving or rotating the associated driven gear 134 . However, the worm gear 138 of the present invention is not configured to rotate about its axis 124 but, rather, remains rotationally fixed and is linearly displaced along its axis 124 by the actuator 120 .
[0030] It has been determined that the use of a worm gear 138 with a mating gear 134 , wherein the worm gear 138 is rotationally fixed but linearly displaced, provides a configuration which may be designed with a minimum of backlash between intermeshed gear teeth (e.g., teeth 134 A, 138 A and 138 B). The minimization of backlash between the gear 134 and worm gear 138 enables more precise rotational control of the valve stem 110 . For example, if backlash exists between the gear 134 and complementarily engaging portion of the linear positioning member 120 , there will be a small displacement of the positioning member 122 , as the positioning member 122 reverses directions, which does not result in the rotation of the associated gear 134 and valve stem 110 coupled therewith. While the gear 134 and worm gear 138 may be formed from any of a number of suitable materials, in one exemplary embodiment the gear 134 is formed of a brass material while the worm gear 138 is formed of a carbon steel material.
[0031] Referring back more particularly to FIG. 2 , a frame member 140 may be used to couple the valve stem 110 and the actuator 120 to one another such that the valve stem 110 , with its associated gear 134 , may remain in a relatively fixed geometric position with respect to the positioning member 122 . In other words, the frame member 140 serves to maintain the geometrical relationship of the two axes 114 and 124 . Additionally, in one embodiment, other frame or guide members 142 and 144 may be used to maintain the alignment of the gear 134 with the positioning member 122 . For example, the gear 134 may be slidably coupled with the valve stem 110 , such as with mating splines 146 A (see also 146 B in FIG. 3 ), such that the gear 134 may transfer rotational motion to the drive stem 110 while enabling the gear 134 to maintain alignment with the positioning member 122 along its axis 124 during displacement of the valve stem 110 along the defined axis 114 . Of course other arrangements may be utilized to accomplish such a slidable coupling between the gear 134 and drive stem 110 . It is also noted that in some circumstances, such as wherein expected rotation of the gear 134 and the resulting displacement of the valve stem 110 along the defined axis 114 is small, any misalignment between the gear 134 and drive stem 110 may be negligible. In such a circumstance, a coupling which enables the displacement of the gear 134 relative to the drive stem 110 along the axis 114 would not be necessary.
[0032] The flow control device 120 of the present invention is configured to provide relatively high resolution fluid flow control for high pressure, compressible fluids. For example such a configuration may have an associated flow coefficient, C V (as defined above herein), of approximately 0.004. Additionally, the flow control device may operate at pressures of up to 3,000 psi gauge (psig) while controlling the pressure of the fluid flow within approximately 3 psi. Fluid flow can be regulated to less than approximately 1 milliliter per minute (mL/min). Furthermore, such a flow control device 100 is capable of similarly controlling the flow of supercritical fluids, wherein the fluid changes phases due to a pressure drop across the valve 102 .
[0033] Such high resolution of fluid flow control is largely a result of the precise control of the tip 110 A of the valve stem 110 relative to the valve seat 116 . As set forth above, the movement of the linear positioning member 122 turns the gear 134 which, in turn, causes rotation of the valve stem 110 relative to the body of the valve 102 . As the valve stem 110 turns, the mating threads 118 enable a linear movement of the valve stem tip 110 A relative to the valve seat 116 . The relatively small changes in rotational motion of the valve stem 110 result in even more minute changes in the linear position of the valve stem 110 and associated tip 110 A along defined the axis 114 . These precise, minute changes in linear position of the valve stem tip 110 A relative to the valve seat 116 enable precise changes in a pressure drop experienced across the valve 102 . Thus, the precision of the linear actuator 120 is enhanced through the implementation of the gear 134 and worm gear 138 as well as the rotary-type valve stem 110 .
[0034] It is noted that the rotary-type valve stem 110 not only provides enhanced resolution of the fluid flow control, but also inhibits the lodging of particulates between the valve stem 110 and the valve seat 116 and the attendant galling that may result therefrom. For example, considering the prior art valve 12 shown in FIG. 1 , such a linearly positionable valve stem 20 requires relatively tight machining tolerances for proper operation and control of fluid flow. However, because the valve 102 of the present invention utilizes a rotary-type valve stem 110 , broader or, relatively gross tolerances may be used with respect to the fit of the valve stem 110 and the valve seat 116 while still accomplishing a flow coefficient (C v ) which is similar to that of the prior art valve 12 described with respect to FIG. 1 .
[0035] Furthermore, when using a valve 12 configured as described with respect to FIG. 1 , the close tolerances of the valve stem 20 with respect to the valve seat 28 cause the valve 12 to become prone to galling, particularly when solids are present in the fluid flow. Additionally, in situations where a substantial pressure drop and accompanying phase change occur across the valve 12 , heat is often applied to the fluid flow to prevent flash freezing of the fluid flow, which may lead to deposition and accumulation of solids within the valve 12 (or other portions of the fluid flow path), so as to prevent the plugging of the valve 12 . However, the addition of heat may also result in thermal expansion of various components including, for example, the body of the valve 12 , the valve stem 20 and valve seat 28 . Because tolerances between such components are already tight, any thermal expansion exhibited by these components is likely to result in increased friction therebetween. This results in an even greater likelihood of galling and failure of the valve 12 .
[0036] The use of a rotary-type valve 102 of the present invention is less prone to galling when fluid flow is heated because of the relatively gross tolerances between the valve stem 110 and mating components. Furthermore, if a particulate does become lodged between the valve stem 110 and the valve seat 116 , it has been determined that rotation of the valve stem to an open position, followed by reverse rotation of the valve stem 110 to a closed or reduced flow position, allows the particulate to be washed through the valve 102 and continued operation of the flow control device 100 may continue. Thus, the flow control device 100 of the present invention may require less filtering of a given fluid.
[0037] Still referring to the FIG. 2 , in many applications it may be desirable to utilize an actuator 120 which is configured to enable automatic control of the flow control device 100 . Thus, for example, the actuator 120 may include a control signal input I such as a 4-20 milliamp (mA) analog input from an associate controller (not shown in FIG. 2 ). Furthermore, the actuator 120 may include span adjustment S and a zero adjustment Z to set limit of travel and the zero position of the positioning member 122 respectively. Additionally, a linear potentiometer P or other linear position sensor may be utilized to determine the position of the positioning member 122 , within its limits of travel, at any given time.
[0038] Referring now to FIG. 4 , a fluid flow control system 200 may include a flow control device 100 coupled with a controller 202 . The controller may include, for example, a PID (proportional, integral, derivative) controller or, it may include a computer having a central processing unit (CPU) 204 , or other microprocessor, and memory 206 . The controller 202 may be coupled to an input device 208 and an output device 210 such that, for example, commands or instructions may be provided to the controller 202 and so that actions taken or conditions monitored by the controller may be displayed or reported. The controller 202 may also be coupled with a pump 212 or other device configured to provide fluid flow from a fluid source 214 at a specified pressure and/or flow rate. An exemplary pump may include a high-pressure syringe pump commercially available from, for example, ISCO, Inc., of Lincoln, Nebr.
[0039] One or more sensors 216 A and 216 B may be utilized to monitor one or more characteristics of the fluid flow. For example, the sensors 216 A and 216 B may include pressure transducers to monitor the pressure of the fluid flow at a desired location, or to determine the pressure drop experienced by the fluid as it flows through the valve 102 . In another embodiment, one or more of the sensors 216 A and 216 B may be configured to determine the flow rate of the fluid. Additionally, one or more of the sensors 216 A and 216 B may be configured to detect the temperature of the fluid flow at a given location along the flow path. It will be noted that the sensors 216 A and 216 B may be configured to determine other parameters or characteristics of the fluid flow and that multiple sensors may be employed to determine a combination of the above-listed parameters. As shown in FIG. 4 , the sensors 216 A and 216 B may be located and configured to detect a characteristic of the fluid flow at a location upstream from the valve 102 (e.g., sensor 216 B) or downstream from the valve 102 (e.g., sensor 216 A) or both.
[0040] In operation, the controller 202 may provide a signal to the pump 212 to provide fluid flow from the fluid source 214 . One or more of the sensors 216 A and 216 B may detect a specified parameter of the fluid flow. If the value of the detected parameter of the fluid flow differs from a desired value, the controller 202 may actuate the flow control device 100 to alter the setting of the valve and, thereby, alter one or more characteristics of the fluid flow in order to obtain the desired value of the parameter being monitored.
[0041] As noted above, the present invention may be practiced in a variety of environments and in conjunction with numerous applications. For example, various laboratory experiments will benefit from the high level of fluid flow control achieved with the present invention. Other exemplary applications include, for example: extraction of carbon dioxide from soils; catalyst regeneration processes including an exemplary process set forth in U.S. Pat. No. 6,579,821 for METHOD FOR REACTIVATING SOLID CATALYSTS USED IN ALKYLATION REACTIONS, issued Jun. 17, 2003, the disclosure of which is incorporated, in its entirety, by reference herein; as well as a process set forth in copending U.S. patent application Ser. No. 09/554,708 for A PROCESS FOR THE REACTIONS OF GLYCERIDES AND FATTY ACIDS IN A CRITICAL FLUID MEDIUM, filed Jul. 31, 2000, the disclosure of which is incorporated, in its entirety, by reference herein. Of course, as stated above, such applications are exemplary only and, as will be appreciated by those of ordinary skill in the art, the present invention is useful in numerous other applications and processes.
[0042] While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
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A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.
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RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. application Ser. No. 10/677,057, filed Sep. 30, 2003, which is a Divisional of U.S. application Ser. No. 09/801,265, filed Mar. 7, 2001, now U.S. Pat. No. 6,627,549, which claims priority to U.S. Provisional Application 60/187,658, filed on Mar. 7, 2000, all of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention concerns methods of making integrated circuits, particularly methods of making metal masks and dielectric, or insulative, films.
BACKGROUND OF THE INVENTION
[0003] Integrated circuits, the key components in thousands of electronic and computer products, are interconnected networks of electrical components fabricated on a common foundation, or substrate. Fabricators typically build the circuits layer by layer, using techniques, such as doping, masking, and etching, to form thousands and even millions of microscopic resistors, transistors, and other electrical components on a silicon substrate, known as a wafer. The components are then wired, or interconnected, together to define a specific electric circuit, such as a computer memory.
[0004] One important concern during fabrication is flatness, or planarity, of various layers of the integrated circuit. For example, planarity significantly affects the accuracy of a photo-imaging process, known as photomasking or photolithography, which entails focusing light on light-sensitive materials to define specific patterns or structures in a layer of an integrated circuit. In this process, the presence of hills and valleys in a layer forces various regions of the layer out of focus, causing photo-imaged features to be smaller or larger than intended. Moreover, hills and valleys can reflect light undesirably onto other regions of a layer and add undesirable features, such as notches, to desired features. These problems can be largely avoided if the layer is sufficiently planar.
[0005] One process for making surfaces flat or planar is known as chemical-mechanical planarization or polishing. Chemical-mechanical planarization typically entails applying a fluid containing abrasive particles to a surface of an integrated circuit, and polishing the surface with a rotating polishing head. The process is used frequently to planarize the insulative, or dielectric, layers that lie between layers of metal wiring in integrated circuits. These insulative layers, which typically consist of silicon dioxide, are sometimes called intermetal dielectric layers. In conventional integrated-circuit fabrication, planarization of these layers is necessary because each insulative layer tends to follow the hills and valleys of the underlying metal wiring, similar to the way a bed sheet follows the contours of whatever it covers. Thus, fabricators generally deposit an insulative layer much thicker than necessary to cover the metal wiring and then planarize the insulative layer to remove the hills and valleys.
[0006] Unfortunately, conventional methods of forming these intermetal dielectric layers suffer from at least two problems. First, the process of chemical-mechanical planarization is not only relatively costly but also quite time consuming. And second, the thickness of these layers generally varies considerably from point to point because of underlying wiring. Occasionally, the thickness variation leaves metal wiring under a layer too close to metal wiring on the layer, encouraging shorting or crosstalking. Crosstalk, a phenomenon that also occurs in telephone systems, occurs when signals from one wire are undesirable transferred or communicated to another nearby wire.
[0007] Accordingly, the art needs fabrication methods that reduce the need to planarize intermetal dielectric layers, that reduce thickness variation in these layers, and that improve their electrical properties generally.
SUMMARY OF THE INVENTION
[0008] To address these and other needs, the inventor devised various methods of making dielectric layers on metal layers, which reduce the need for chemical-mechanical planarization procedure. Specifically, a first exemplary method of the invention forms a metal layer with a predetermined maximum feature spacing and then uses a TEOS-based (tetraethyl-orthosilicate-based) oxide deposition procedure to form an oxide film having nearly planar or quasi-planar characteristics. The exemplary method executes a CVD (chemical vapor deposition) TEOS oxide procedure to form an oxide layer on a metal layer having a maximum feature spacing of 0.2-0.5 microns.
[0009] A second exemplary method includes voids within the oxide, or more generally insulative, film to improve its effective dielectric constant and thus improve its ability to prevent shorting and crosstalk between metal wiring. Specifically, the exemplary method uses a TEOS process at a non-conformal rate sufficient to encourage the formation of voids, and then uses the TEOS process at a conformal rate of deposition to seal the voids. More generally, however, the invention uses a non-conformal deposition procedure to encourage formation of voids and then a more conformal deposition to seal the voids.
[0010] A third exemplary method increases the metal-fill density of metal patterns to facilitate formation of intermetal dielectric layers having more uniform thicknesses. The third exemplary method adds floating metal to open areas in a metal layout and then extends non-floating metal dimensions according to an iterative procedure that entails filling in notches, and corners and moving selected edges of the layout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cross-sectional view of a partial integrated-circuit assembly 10 including a substrate 12 and metal wires 14 a , 14 b , and 14 c;
[0012] FIG. 2 is a cross-sectional view of the FIG. 1 integrated-circuit assembly after formation of a substantially planar insulative layer 16 , including a portion 16 a with voids and a portion 16 b without voids;
[0013] FIG. 3 is a cross-sectional view of the FIG. 2 assembly after a facet etch to improve the planarity of layer 16 ;
[0014] FIG. 4 is a cross-sectional view of the FIG. 3 assembly after formation of metal wires 18 a and 18 b , and substantially planar insulative layer 20 , including a portion 20 a with voids and a portion 20 b without voids;
[0015] FIG. 5 is a cross-sectional view of a partial integrated-circuit assembly 21 including a substrate 22 and metal wires 24 a , 24 b , and 24 c;
[0016] FIG. 6 is a cross-sectional view of the FIG. 5 assembly after formation of an oxide spacer 26 and a substantially planar insulative layer 28 , including a portion 28 a with voids and a portion 28 b without voids;
[0017] FIG. 7 is a cross-sectional view of the FIG. 6 assembly after a facet etch to improve the planarity of layer 28 ;
[0018] FIG. 8 is a cross-sectional view of the FIG. 7 assembly after formation of metal wires 30 a and 30 b , and substantially planar insulative layer 34 , including a portion 34 a with voids and a portion 34 b without voids;
[0019] FIG. 9 is a cross-sectional view of a partial integrated-circuit assembly 35 including a substrate 36 and metal wires 36 a , 36 b , and 36 c;
[0020] FIG. 10 is a cross-sectional view of the FIG. 9 assembly after formation of an oxide spacer 40 and a substantially planar insulative layer 42 ;
[0021] FIG. 11 is a flow chart illustrating an exemplary method of modifying a metal layout to facilitate fabrication of intermetal dielectric layers with more uniform thickness;
[0022] FIG. 12 is a partial top view of a metal layout showing how the exemplary method of FIG. 11 adds metal to open areas in a metal layout;
[0023] FIG. 13 is a partial top view of a metal layout showing how the exemplary method of FIG. 11 fills notches in a metal layout;
[0024] FIG. 14 is a partial top view of a metal layout showing how the exemplary method of FIG. 11 fills corners in a metal layout;
[0025] FIG. 15 is a partial view of a metal layout showing how the exemplary method of FIG. 11 fills in between opposing edges of live metal regions in a metal layout;
[0026] FIG. 16 is a partial view of a metal layout showing how the exemplary method of FIG. 11 moves edges;
[0027] FIG. 17 is a block diagram of an exemplary computer system 42 for hosting and executing a software implementation of the exemplary pattern-filling method of FIG. 11 ; and
[0028] FIG. 18 is a simplified schematic diagram of an exemplary integrated memory circuit 50 that incorporates one or more nearly planar intermetal dielectric layers and/or metal layers made in accord with exemplary methods of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] The following detailed description, which references and incorporates the above-identified Figures, describes and illustrates specific embodiments of the invention. These embodiments, offered not to limit but only to exemplify and teach the invention, are shown and described in sufficient detail to enable those skilled in the art to implement or practice the invention. Thus, where appropriate to avoid obscuring the invention, the description may omit certain information known to those of skill in the art.
[0030] First Exemplary Method of Forming Nearly Planar Dielectric Films
[0031] FIGS. 1-4 show a number of exemplary integrated-circuit assemblies, which taken collectively and sequentially, illustrate an exemplary method of making nearly planar or quasi planar dielectric films, or layers, within the scope of the present invention. As used herein, a quasi planar film is globally planar with local nonplanarities having slopes less than or equal to 45 degrees and depths less than the thickness of the next metal layer to be deposited. The local nonplanarities typically occur over the gaps between underlying metal features.
[0032] The method, as shown in FIG. 1 , a cross-sectional view, begins with formation of an integrated-circuit assembly or structure 10 , which can exist within any integrated circuit, for example, an integrated memory circuit. Assembly 10 includes a substrate 12 . The term “substrate,” as used herein, encompasses a semiconductor wafer as well as structures having one or more insulative, semi-insulative, conductive, or semiconductive layers and materials. Thus, for example, the term embraces silicon-on-insulator, silicon-on-sapphire, and other advanced structures.
[0033] Substrate 12 includes three representative wires or conductive structures 14 a , 14 b , and 14 c , with a maximum (or average) feature spacing 14 s . In the exemplary embodiment, wires 14 a - 14 c are approximately 3000-6000 angstroms thick and comprise metals, such as aluminum, gold, or silver, and nonmetals, such as heavily doped polysilicon. Spacing 14 s , in the exemplary embodiment, is 0.3 microns.
[0034] Wires 14 a - 14 c can be formed using any number of methods, for example, photolithography and dry etching. To avoid increasing feature spacing during dry etching, the exemplary embodiment forms a lateral-etch-resistant layer, that is, a layer resistant to lateral etching, on a metal layer before etching. Examples of suitable layers include a TEOS, oxide-nitride layer. Alternatively, one can add extensive serif features to the metal mask layout to avoid large open areas, especially to reduce the diagonal distance between features.
[0035] FIG. 2 shows that the exemplary method next entails forming an insulative layer 16 over substrate 12 and wires 14 a - 14 b . Layer 16 has a thickness 16 t of, for example, 6000 angstroms, and includes two layers or sublayers 16 a and 16 b . Sublayer 16 a includes a number of voids, particularly voids 17 between wires 14 a and 14 b , and between wires 14 b and 14 c , to increase its dielectric constant. Sublayer 16 b is either substantially voidless or includes a substantially fewer number of voids than sublayer 16 a . The presence of voids in sublayer 16 a reduces lateral electrical coupling between adjacent metal features, for example, between wires 14 a and 14 b and between wires 14 a - 14 c and any overlying conductive structures.
[0036] The exemplary method forms layer 16 using a combination of a non-conformal and conformal oxide depositions. In particular, it uses a CVD TEOS (chemical vapor deposition tetraethyl-orthosilicate) or PECVD TEOS (plasma-enhanced CVD TEOS) oxide deposition process at a non-conformal deposition rate to form void-filled sublayer 16 a voids and then lowers the TEOS deposition rate to, a conformal rate to form substantially voidless sublayer 16 b.
[0037] FIG. 3 shows that after forming sublayer 16 b , which includes some level of nonplanarity, the exemplary method facet etches the sublayer at an angle of about 45 degrees to improve its global planarity. (That layer 16 b has undergone further processing is highlighted by its new reference numeral 16 b ′.) The facet etch reduces or smooths any sharp trenches in regions overlying gaps between metal features, such as wires 14 a - 14 c . As used herein, the term “facet etch” refers to any etch process that etches substantially faster in the horizontal direction than in the vertical direction. Thus, for example, the term includes an angled sputter etch or reactive-ion etch.
[0038] To optimize the slopes of any vias, one can perform the facet etch before via printing. More specifically, one can facet etch after etching any necessary vias and stripping photoresist to produce vias having greater slope and smoothness.
[0039] FIG. 4 shows the results of forming a second metallization level according to the procedure outlined in FIGS. 1-3 . In brief, this entails forming conductive structures 18 a and 18 b on insulative sublayer 16 b ′ and forming an insulative layer 20 on sublayer 16 b ′ and conductive structures 18 a and 18 b . Insulative layer 20 , like insulative layer 16 , includes void-filled sublayer 20 a and substantially void-free sublayer 20 b ′. Sublayer 20 a includes one or more voids 19 between conductive structures 18 a and 18 b . Sublayer 20 b ′ was facet etch to improve its planarity. Layer 20 has a thickness 20 t, of for example 3000-6000 angstroms.
[0040] Second Exemplary Method of Forming Nearly Planar Dielectric Films
[0041] FIGS. 5-8 show a number of exemplary integrated-circuit assemblies, which taken collectively and sequentially, illustrate a second exemplary method of making nearly planar or quasi planar dielectric layers within the scope of the present invention. The second method is particularly applicable to maximum metal feature spacing greater than about 0.3 microns or oxide thickness less than 6000 angstroms to allow for shallow via formation, that is, via depths less than about 4000 angstroms.
[0042] More particularly, FIG. 5 shows that the method begins with formation of an integrated-circuit assembly or structure 21 , which, like assembly 10 in FIG. 1 , can exist within any integrated circuit. Assembly 10 includes a substrate 22 which supports three representative wires or conductive structures 24 a , 24 b , and 24 c , with a desired feature spacing 24 s . In the exemplary embodiment, spacing 24 s is greater than 0.3 microns. Some embodiments set a minimum spacing of 0.17 microns. However, the present invention is not limited to any particular spacing.
[0043] FIG. 6 shows that the exemplary method next entails forming an insulative spacer 26 and an insulative layer 28 . Insulative spacers 26 , which consists of silicon dioxide for example, lies over portions of substrate 22 adjacent wires 24 a - 24 c to reduce the effective separation of wires 24 a - 24 c . The exemplary method uses a TEOS oxide deposition and subsequent etching to form spacers 26 . Insulative layer 28 has a thickness 28 t of, for example, 4000 angstroms, and includes two sublayers 28 a and 28 b , analogous to sublayers 16 a and 16 b in the first embodiment. Specifically, sublayer 28 a includes a number of voids 27 between the wires to increase its dielectric constant, and sublayer 28 b is either substantially voidless or includes a substantially fewer number of voids than sublayer 28 a . A two-stage TEOS oxide deposition process, similar to that used in the first embodiment, is used to form layer 28 .
[0044] FIG. 7 shows that after forming sublayer 28 b , which includes some level of nonplanarity, the exemplary method facet etches the sublayer at an angle of about 45 degrees to improve its global planarity.
[0045] FIG. 8 shows the results of forming a second metallization level according to the procedure outlined in FIGS. 5-7 . This entails forming conductive structures 30 a and 30 b on insulative sublayer 28 b ′ and forming an insulative spacer 32 and an insulative layer 34 , which, like insulative layer 28 , includes void-filled sublayer 34 a and substantially void-free sublayer 34 b ′. Sublayer 34 a includes voids 31 between conductive structures 30 a and 30 b , and sublayer 34 b ′ is facet etched to improve its planarity.
[0046] Third Exemplary Method of Forming Nearly Planar Dielectric Films FIGS. 9 and 10 show a number of exemplary integrated-circuit assemblies, which taken collectively and sequentially, illustrate a third exemplary method of making nearly planar or quasi planar dielectric layers within the scope of the present invention. In contrast to the first and second embodiment, the third exemplary embodiment is intended for forming insulative films on metal layers with maximum feature spacing up to about 0.5 microns.
[0047] FIG. 9 shows that the method begins with formation of an integrated-circuit assembly or structure 35 , which like assembly 10 in FIG. 1 and assembly 21 in FIG. 5 , can exist within any integrated circuit. Assembly 35 includes a substrate 36 which supports three representative wires or conductive structures 38 a , 38 b , and 38 c , with a desired feature spacing 38 s of about 0.5 microns.
[0048] FIG. 10 shows the results of forming an oxide spacers 40 and an insulative layer 42 . The exemplary embodiment forms one or more oxide spacers 40 which is about 1000 angstroms wide, and thus reduces the effective spacing between conductors 38 a - 38 c by 2000 angstroms. Forming insulative layer 42 entails executing a flow-fill procedure, such as TRIKON-200 by Trikon Technologies, Inc. To obtain global and local planarity, one can reduce the maximum feature space by using oxide/TEOS spacer as taught in the second exemplary method, or by enlarging the metal feature, or by adding floating metal between the metal features.
[heading-0049] Exemplary Method of Promoting Uniform Thickness of Intermetal Dielectric Layers
[0050] To facilitate the formation of more uniformly thick inter-metal dielectric layers, such as those described above, the inventor developed specific methods of (and related computer software) for increasing the pattern density of metal layouts. The methods and associated software take a given metal layout and modify, or fill, open areas of the layout to increase pattern density and thus promote uniform thickness or reduce thickness variation across dielectric layers formed on metal layers based on the layouts. These methods and software can thus be used, for example, to facilitate formation of the conductive structures shown in FIGS. 1, 5 , and 9 .
[0051] The exemplary method generally entails iteratively measuring a given layout, adding floating metal to fill large open areas in the layout, and extending or filling out existing metal areas to meet maximum feature spacing, or gap, criteria. FIG. 11 shows a flow chart of the exemplary method, which is suitable for implementation as a computer-executable program.
[0052] Specifically, the flow chart includes a number of process or decision blocks 110 , 120 , 130 , and 140 . The exemplary method begins at process block 110 which entails measuring a given layout. This entails determining open (unmetallized or nonconductive) areas large enough to be filled with floating metal and identifying live metal areas that require additional metal to obtain desired spacing. Floating metal is metal that is not coupled to a signal path or component, whereas live metal is metal that is coupled to a signal path or component.
[0053] After executing block 110 , the exemplary method proceeds to block 120 which entails adding floating metal to any large areas identified in block 110 . To illustrate, FIG. 12 shows a hypothetical layout having a live metal region 200 with open area 210 . In general, if dimension A is greater than the sum of dimension S1, dimension S2, and L (the maximum feature spacing criteria), the exemplary method adds floating metal, such as floating metal region 220 .
[0054] After adding floating metal, the exemplary method adds live metal as indicated in block 120 of FIG. 11 . FIG. 12 is again instructive of the exemplary method. If dimension B is less than the sum of dimension S1, dimension S2, and L, the exemplary method adds metal as indicated by added active metal region 230 . process block 104 which entails filling in notches in the layout.
[0055] More particularly, the exemplary method follows an iterative process for adding live (or non-floating) metal, as indicated by blocks 130 a - 130 g.
[0056] Block 130 a entails filling notches in the current live metal. FIG. 13 shows a live metal region 300 of a hypothetical metal layout having a notch 310 . Included within notch 310 are a series of iteratively added live metal regions 320 - 325 . The amount of metal added at each iteration can be selected using a minimum surface area criteria or computed dynamically each iteration. The exemplary embodiment repeatedly adds metal to the notch until it is filled, before advancing to block 310 b . However, other embodiments can advance to block 310 b before the notch is filled, relying on subsequent trips or iterations through the first loop in the flowchart to complete filling of the notch.
[0057] Block 130 b entails filling in corners in the current live metal, meaning the live metal after filling notches. FIG. 14 illustrates a live metal region 400 having a corner 410 and added L-shaped live metal regions 420 - 423 and a rectangular live metal region 424 . (Other embodiments add other shapes of live metal regions.) The amount of metal added at each iteration can be selected using a minimum surface area or single-dimensional criteria or computed dynamically each iteration. The exemplary embodiment repeatedly adds metal to the corner until it is filled, before advancing to block 130 c . However, other embodiments can advance to block 310 b before the notch is filled, relying on subsequent trips through the inner loop to complete filling of the notch.
[0058] Block 130 c entails filling in between opposing edges of adjacent live metal regions to achieve a desired spacing, such as a maximum desired spacing L. FIG. 15 shows live metal regions 510 and 520 , which have respective opposing edges 510 a and 520 a . The exemplary method entails adding live metal regions, such as live metal regions 521 - 523 , one edge such as edge 520 a to achieved the maximum desired spacing L. However, other embodiments add live metal to both of the opposing edges to achieve the desired spacing. Still other embodiments look at the lengths of the opposing edges and use one or both of the lengths to determine one or more dimensions of the added live metal regions.
[0059] After filling in between opposing edges of existing live metal regions, the exemplary method advances to decision block 130 d in FIG. 11 . This block entails determining whether more live metal can be added. More precisely, this entails measuring the layout as modified by the live metal already added and determining whether there are any adjacent regions that violate the desired maximum spacing criteria. (Note that some exemplary embodiments include more than one maximum spacing criteria to account for areas where capacitive effects or crosstalk issues are of greater importance than others.) If the determination indicates that more metal can be added execution proceeds back to block 130 a to fill in remaining notches, and so forth. If the determination indicates that no more live metal can be added to satisfy the maximum spacing criteria, execution to proceeds to block 130 e in FIG. 11 .
[0060] Block 130 e entails moving (or redefining) one or more edges (or portions of edges) of live metal regions in the modified layout specification. To illustrate, FIG. 16 shows live metal regions 610 and 620 , which have respective edges 610 a and 620 a . It also shows the addition of live metal region 630 to edge 620 a , which effectively extends the edge. Similarly, edge 620 a has been extended with the iterative addition of live metal regions 631 and 632 . The additions can be made iteratively using a dynamic or static step size, or all it once by computing the size of an optimal addition to each edge. Exemplary execution then proceeds to decision block 130 f.
[0061] In decision block 130 f , the exemplary method decides again whether more metal can be added to the layout. If more metal can be added, the exemplary method repeats execution of process blocks 104 - 122 . However, if no metal can be added, the method proceeds to process block 140 to output the modified layout for use in a fabrication process.
[0062] Although not show explicitly in the exemplary flow chart in FIG. 1 , the exemplary method performs data compaction to minimize or reduce the amount of layout data carried forward from iteration to iteration. Data compaction reduces the number of cells which define the circuit associated with the metal layout and the computing power necessary to create the metal layout.
[0063] The exemplary compaction scheme flattens all array placement into single instance placements. For example, a single array placement of a cell incorporating a 3×4 matrix flattens to 12 instances of a single cell. It also flattens specific cells, such as array core cells, vias, or contacts, based on layout or user settings. Additionally, it flattens cells which contain less than a predetermined number of shapes regardless of any other effects. For example, one can flatten cells having less than 10, 20, or 40 shapes. Lastly, the exemplary compaction scheme attempts to merge shapes to minimize overlapping shapes and redundant data.
[0064] The appropriate or optimum degree of flattening depends largely on the processing power and memory capabilities of the computer executing the exemplary method. Faster computers with more core memory and swap space can handle larger number of shapes per cell and thus have less need for flattening than slower computers with less core memory and swap space. In the extreme, a complete circuit layout can be flattened into one cell.
[0065] If a given layout design is not a single flat list of shapes but includes two or more cells placed into each other as instances, additional precaution should be taken to reduce the risk of introducing unintended shorts into the layout during the pattern-fill process. In the exemplary embodiment, this entails managing the hierarchy of cells.
[0066] The exemplary embodiment implements a hierarchy management process which recognizes that each cell has an associated fill area that will not change throughout the metal-fill process. The exemplary management process entails executing the following steps from the bottom up until all cell dependencies are resolved. For each instance in each cell, the process creates a temporary unique copy of the cell associated with a given instance. After this, the process copies metal from other cells into the cell being examined if it falls into the fill area. The process then copies metal from other cell into the cell if the metal falls into a ring around the fill area. Next, the process identifies, extracts, and marks conflict areas.
[0067] This exemplary pattern-filling method and other simpler or more complex methods embodying one or more filling techniques of the exemplary embodiment can be used in combination with the methods of making nearly planar intermetal dielectric layers described using FIGS. 1-10 . More precisely, one can use a pattern-filling method according to the invention to define a layout for a particular metal layer, form a metal layer based on the layout, and then form a nearly planar intermetal dielectric layer according to the invention on the metal layer. The combination of these methods promises to yield not only a nearly planar dielectric layer that reduces or avoids the need for chemical-mechanical planarization, but also a dielectric layer with less thickness deviation because of the adjusted pattern fill density of the underlying metal layer.
[0068] Exemplary Computer System Incorporating Pattern-Filling Method
[0069] FIG. 17 shows an exemplary computer system or workstation 42 for hosting and executing a software implementation of the exemplary pattern-filling method. The most pertinent features of system 42 include a processor 44 , a local memory 45 and a data-storage device 46 . Additionally, system 42 includes display devices 47 and user-interface devices 48 . Some embodiments use distributed processors or parallel processors, and other embodiments use one or more of the following data-storage devices: a read-only memory (ROM), a random-access-memory (RAM), an electrically-erasable and programmable-read-only memory (EEPROM), an optical disk, or a floppy disk. Exemplary display devices include a color monitor, and exemplary user-interface devices include a keyboard, mouse, joystick, or microphone. Thus, the invention is not limited to any genus or species of computerized platforms.
[0070] Data-storage device 46 includes layout-development software 46 a , pattern-filling software 46 b , an exemplary input metal layout 46 c , and an exemplary output metal layout 46 d . (Software 46 a and 46 b can be installed on system 42 separately or in combination through a network-download or through a computer-readable medium, such as an optical or magnetic disc, or through other software transfer methods.) Exemplary storage devices include hard disk drives, optical disk drives, or floppy disk drives. In the exemplary embodiment, software 46 b is an add-on tool to layout-development software 46 a and layout 46 c was developed using software 46 a . However, in other embodiments, software 46 b operates as a separate application program and layout 46 c was developed by non-resident layout-development software. General examples of suitable layout-development software are available from Cadence and Mentor Graphics. Thus, the invention is not limited to any particular genus or species of layout-development software.
Exemplary Integrated Memory Circuit
[0071] FIG. 18 shows an exemplary integrated memory circuit 50 that incorporates one or more nearly planar intermetal dielectric layers and/or metal layers within the scope of the present invention. One more memory circuits resembling circuit 50 can be used in a variety of computer or computerized systems, such as system 42 of FIG. 17 .
[0072] Memory circuit 50 , which operates according to well-known and understood principles, is generally coupled to a processor (not shown) to form a computer system. More particularly, circuit 50 includes a memory array 52 , which comprises a number of memory cells 53 a , 53 b , 53 c , and 53 d ; a column address decoder 54 , and a row address decoder 55 ; bit lines 56 a and 56 b ; word lines 57 a and 57 b ; and voltage-sense-amplifier circuit 58 coupled in conventional fashion to bit lines 56 a and 56 b . (For clarity, FIG. 18 omits many conventional elements of a memory circuit.)
CONCLUSION
[0073] In furtherance of the art, the inventor has presented several methods for making nearly planar intermetal dielectric layers without the use of chemical-mechanical planarization. Additionally, the inventor has presented a method of modifying metal layouts to facilitate formation of dielectric films with more uniform thickness. These methods of modifying metal layouts and making dielectric layers can be used in sequence to yield nearly planar intermetal dielectric layers with more uniform thickness.
[0074] The embodiments described above are intended only to illustrate and teach one or more ways of practicing or implementing the present invention, not to restrict its breadth or scope. The actual scope of the invention, which embraces all ways of practicing or implementing the invention, is defined only by the following claims and their equivalents.
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In the fabrication of integrated circuits, one specific technique for making surfaces flat is chemical-mechanical planarization. However, this technique is quite time consuming and expensive, particularly as applied to the numerous intermetal dielectric layers—the insulative layers sandwiched between layers of metal wiring—in integrated circuits. Accordingly, the inventor devised several methods for making nearly planar intermetal dielectric layers without the use of chemical-mechanical planarization and methods of modifying metal layout patterns to facilitate formation of dielectric layers with more uniform thickness. These methods of modifying metal layouts and making dielectric layers can be used in sequence to yield nearly planar intermetal dielectric layers with more uniform thickness.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 60/968,019, filed Aug. 24, 2007, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to covers for heaters, such as stand-type gas or electric heaters, and methods of using the same. The heater can be, for example, a movable or fixed patio heater or table-top heater.
[0004] 2. Description of Related Art
[0005] Typical tower heaters, such as those used for outdoor and patio use, have an appearance that is considered “industrial” and sterile by many. Some newer designs for tower heaters obstruct the typical “industrial” design, for example, providing the tower heater with the configuration of a palm tree, or other design. These alternate designs are permanently fixed to the heater. However, it is often desired to change the design of the heater without having to have separate heaters for each design or without having to incur the expense to purchase a new standup heater to change the design.
[0006] Tower heaters (e.g., patio heaters) are often used in public, residential, and commercial locales. For example, tower heaters are often located in outdoor seating areas at restaurants, in plazas, and outdoor malls; or by event planners or rental companies for functions or parties. These locations make the heaters optimum sites for advertising. However, the towers are often too thin and the heat shields of the heaters are too steep of an angle and its surface too hot to reasonably display advertising. The base is also well below eye level, so posting advertising on the base would be generally out of sight.
[0007] Therefore, replaceable and/or removable outer configuration for tower heaters is desired. Furthermore, a configuration of a heater and accompanying method for reasonably attaching a display to a tower heater is desired.
SUMMARY OF THE INVENTION
[0008] A device for camouflaging the mechanical structure of a tower (e.g., patio, outdoor) heater is disclosed. The device can be a cover or shell. The cover can have an assembly of, for example, two to four panels or “skins” or cover sections. The cover sections can be rigid or flexible. The cover sections can be rotatably attached to each other, for example via one or more rotatable hinges. The cover sections can be attached to the underlying mechanical structure of the tower heater in a “clamshell” fashion.
[0009] The cover can be constructed from one or more elements that extend longitudinally along the entire cover, or horizontally with the split occurring somewhere around the base and tower, or the cover can be made from a body cover and/or separate head cover. The body cover can have a tower cover and a separate base cover. The head cover can be a decorative “shade” or shield around the existing parabolic heat deflector (i.e., heat shield or heater head) at the top of the heater structure.
[0010] The head cover can have a cylindrical or a conical, square, polygonal, elliptical, hemispherical configuration or a partial configuration of any of the aforementioned configurations, or a combination of any of the configurations thereof. If the head cover has a conical or partial conical configuration, the angle of the cone with respect to the longitudinal axis of the heater can be from about 0° to about 45°± in either direction, more narrowly from about 0° to about 25° in either direction.
[0011] One or more displays can be attached to the heater head, tower, body, base, head cover, tower cover, base cover, body cover, or combinations thereof. The displays can have a flat or curved surface. The displays can form an angle with the longitudinal axis of the heater from about 0° to about 45°± in either direction, more narrowly from about 0° to about 25° in either direction.
[0012] The cover can be made from one or more rigid or semi rigid materials, for example thermoplastics (e.g., Polyethylene terephthalate (PET), Polyethylene (PE), Polypropylene (PP)), polycarbonates, or silicon or vinyl-base materials or EVA copolymers which may, for example, be blow, injection, or rotational molded, fiberglass reinforced polymers (“FRP” or fiberglass), resins, stamped or spun sheet metal, urethane over a formed metal structure, heat resistant fabrics stretched around a metal frame, or combinations thereof in smooth or textured finish. The material can be opaque, translucent or transparent. The cover can be made from materials that can be lightweight, suited for outdoor use, long lasting, and have a durable finish in multiple colors. The cover can be made by being molded, for example roto-molded.
[0013] The cover sections can be attached to and detached from each other with mechanical hardware, such as one or more fasteners including quick release fasteners 70 , one or more piece of hook and loop tape (e.g., Velcro); one or more piece of interlocking stem and head tape (e.g., Dual Lock from 3M Corporation of Minneapolis, Minn.), magnets, latches, clips, ties, hooks, locking pins, the ports and flanges to which they are to attach, and combinations thereof, for example applied on overlapping flanges (e.g., tongue-and-groove, guide-pins, grooves) or into ports of adjacent cover sections. The fasteners 70 can be locked, hooked, pressed, snapped or otherwise joined together into place.
[0014] The cover sections can be hinged together, for example in a clamshell fashion.
[0015] The cover sections can have horizontal seams. The horizontal seams can divide the cover sections into two or more section that can telescope or separate when moved relative to each other in a vertical direction. For example, a lower section can slide upwards, and may temporarily come to rest on the tinder structure of the patio heater column to gain access, for example, to the propane tank area, for example to service the propane tank area or replace the propane tank. The cover sections can be simply and repeatedly assembled, disassembled, and easily transported between locations, or stored by nesting the cover sections together.
[0016] The covers can have fluting or grooves, textures, appliqués, self-adhesive tape, and combinations thereof. For example, these features (e.g., fluting/grooves, textures, decorative rings, etc.) can hide joints between the cover sections while providing aesthetic design alternatives.
[0017] The head cover sections can be punctured, louvered, folded, made of metal mesh, or otherwise treated, for example to dissipate and/or collect and/or direct heat and/or to provide alternate aesthetics.
[0018] The head cover sections can be attached to and detached from the tower, head and base of the heater. The head cover sections can have or be attached to straps or spokes. For example, two to four or three to six straps or spokes can radially extend from the center of the heater. The straps or spokes can attach to the cover section (e.g., the head cover or the body cover). Mechanical quick-release fasteners 70 can attach the cover sections to the heater head or body (e.g., tower or base). The fasteners 70 can thermally insulate the cover sections from the heater head or body. The thermal insulators can be spacers and/or a layer of thermal insulating material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 illustrates a variation of a stand-type tower propane heater, not the invention.
[0020] FIG. 2 illustrates a variation of the heater cover.
[0021] FIG. 3 is a partial see-through view of the heater cover of FIG. 2 attached to the heater of FIG. 1 .
[0022] FIGS. 4 a through 4 p illustrate the heater with variations of the heater cover.
[0023] FIG. 4 p ′ illustrates a close-up view of the head of the heater of FIG. 4 p.
[0024] FIG. 4 q illustrates the heater with a variation of the heater cover.
[0025] FIG. 4 q ′ illustrates a close-up view of the head of the heater of FIG. 4 q.
[0026] FIG. 4 r illustrates the heater with a variation of the heater cover.
[0027] FIG. 4 r ′ illustrates a close-up view of the head of the heater of FIG. 4 r.
[0028] FIGS. 5 a through 5 c and 6 illustrate the heater with variations of the heater cover that can be articulated.
[0029] FIGS. 7 , 8 a and 8 b illustrate variations of the heater with multiple heater heads and variations of the heater cover.
[0030] FIGS. 9 a through 9 d illustrate variations of signage on the heater with a variation of the heater cover.
[0031] FIGS. 10 a, 10 b and 10 c illustrate front, front three-quarters, and side views, respectively, of the heater with a variation of the heater cover having variations of signage.
[0032] FIGS. 11 through 14 and 15 a illustrate variations of the heater cover having variations of signage.
[0033] FIGS. 15 b and 15 c illustrate variations of the heater cover of FIG. 15 a with one or more signs.
[0034] FIG. 16 illustrates a variation of an uncovered tower heater, not the invention.
[0035] FIG. 17 illustrates a variation of the heater cover.
[0036] FIG. 18 illustrates the heater cover of FIG. 17 attached to the heater of FIG. 16 with the body cover shown as a sectional view for illustrative purposes.
[0037] FIG. 19 is a top view of a variation of attaching the body cover to the base and tower.
[0038] FIG. 20 is a top view of a variation of the head cover on the heater head.
[0039] FIG. 21 illustrates a variation of an uncovered tower heater, not the invention.
[0040] FIG. 22 illustrates a variation of the heater cover in an opened configuration.
[0041] FIG. 23 illustrates a variation of a method for attaching the heater cover of FIG. 22 attached to the heater of FIG. 21 .
[0042] FIG. 24 is a top view of a variation of opening the body cover.
[0043] FIG. 25 is a top view of a variation of attaching the body cover to the body.
[0044] FIGS. 26 and 27 illustrate variations of the cover hinge.
[0045] FIG. 28 illustrates a variation of the heater cover.
[0046] FIG. 29 illustrates a variation of cross-section A-A of FIG. 28 .
[0047] FIG. 30 illustrates the heater cover in the cross-section A-A of FIG. 29 in a disassembled configuration.
[0048] FIG. 31 illustrates a close-up of a portion of the cover in the cross-section A-A of FIG. 30 .
[0049] FIG. 32 a is a side view of a variation of the heater cover in a closed configuration on the heater.
[0050] FIG. 32 b is a variation of close-up view B-B of FIG. 32 a.
[0051] FIG. 32 c is a see-through schematic view of a variation of the heater cover and heater of FIG. 32 a.
[0052] FIG. 32 d is a variation of close-up view C-C of FIG. 32 c.
[0053] FIG. 33 a is a side view of a variation of the heater cover in an open configuration on the heater.
[0054] FIG. 33 b is a see-through schematic view of a variation of the heater cover and heater of FIG. 33 a.
[0055] FIG. 33 c is a variation of close-up view D-D of FIG. 33 a.
[0056] FIG. 34 illustrates a variation of a fastener in an unfastened configuration.
[0057] FIG. 35 illustrates a variation of a method for using the fastener of FIG. 34 .
[0058] FIGS. 36 and 37 illustrate variations of a fastener.
[0059] FIG. 38 illustrates a variation of a method for using the fastener of FIG. 36 .
[0060] FIG. 39 illustrates a variation of a fastener.
[0061] FIG. 40 illustrates a variation of a fastener second element.
[0062] FIG. 41 illustrates a variation of a method for using a fastener.
[0063] FIG. 42 illustrates a portion of a variation of the body cover showing a fluted surface that can visually obscure or disguise one or more seams.
[0064] FIG. 43 illustrates a variation of a method for using a fastener.
[0065] FIG. 44 illustrates a variation of a method for using a fastener.
[0066] FIG. 45 illustrates a portion of a variation of the body cover closed using the fasteners of FIG. 44 .
[0067] FIGS. 46 and 47 illustrate a variation of a method for using a fastener.
[0068] FIG. 48 illustrates a perspective view of a variation of FIG. 47 .
[0069] FIGS. 49 and 50 are top and side views, respectively, of a variation of a method of using a fastener.
[0070] FIGS. 51 and 52 are top and side views, respectively, of a variation of a method of using a fastener.
[0071] FIGS. 53 and 54 are top and side views, respectively, of a variation of a method of using a fastener.
[0072] FIGS. 55 through 59 each illustrate variations of methods using variations of the fastener.
[0073] FIGS. 60 and 61 are top and side views, respectively, of a variation of a method of using a fastener.
[0074] FIGS. 62 and 63 are top and side views, respectively, of a variation of a method of using a fastener.
DETAILED DESCRIPTION
[0075] FIG. 1 illustrates that a patio or other outdoor tower heater 2 can have a body 4 and a heater head 6 . The body 4 can have a base 8 and a tower 10 . The base 8 can hold or otherwise be connected to a fuel source, such as a propane tank or a hose and connection to a natural gas outlet, or a generator (e.g., solar, gas) or electrical outlet (e.g., for an electrical heater). The tower 10 can extend from the base 8 vertically along a longitudinal axis 12 . The heater 2 can have a heat emitter 14 , for example at the top of the tower 10 . The heater 2 can have one or more controls 15 , for example, to alter the quantity of heat emitted from the heat emitter 14 and to turn the heat emitter 14 on and off.
[0076] The heater 2 can have a heater head 6 . The heater head 6 can be attached to or integral with the top of the tower 10 . The heater head 6 can have a heat shield 16 . The heat shield 16 can extend radially from the longitudinal axis 12 . The heat shield 16 can slope downward. The heat emitter 14 can be in the heater head 6 or the body 4 , depending on the configuration of the particular heater 2 . The heat shield 16 can partially or completely overlap the heat emitter 14 in the longitudinal direction.
[0077] The base 8 can have a base ground plate 18 on the bottom of the base 8 . The base ground plate 18 can be a stable foundation against the ground. The base 8 can have wheels (not shown), for example to adjust or otherwise alter the location of the heater 2 . FIG. 1 is not the invention. The base 8 can house and/or be a propane, butane, methane or other fuel tank. The fuel tank can be connected to a conduit connected, for example through the tower 10 , to the heat emitter 14 .
[0078] FIG. 2 illustrates that a heater cover 20 can have a head cover 22 and a body cover 24 . The head cover 22 can be attached or detached from the body cover 24 . The head cover 22 can be directly attached or detached from the heater head 6 and/or heat shield 16 and/or heat emitter 14 . The head cover 22 can partially or completely obscure the head 6 and/or heat shield 16 and/or heat emitter 14 from view of bystanders at various distances and angles to the heater. The head cover 22 can have a completely or partially conical configuration (e.g., a cone with the top cut-off and no base 2 ). The cover can have a cover ground plate 26 on the bottom of the body cover 24 . The cover can have a port in the bottom of the body cover 24 to allow the base 8 and/or base ground plate 18 to exit the body cover 24 and rest on the ground, floor, or other foundation platform.
[0079] FIG. 3 illustrates that the heater cover 20 can substantially cover or otherwise surround the heater 2 . The head cover 22 can partially or completely surround the heat shield 16 . The head cover 22 can be attached to the heater head 6 , the heat shield 16 , the tower 10 , the body cover 24 , or combinations thereof.
[0080] The body cover 24 can partially or completely surround the heater body, for example the tower 10 and/or the base 8 .
[0081] The bottom of the head cover 22 can be lower than the bottom of the heat emitter 14 by a heater cover overhang 28 . The heater cover overhang 28 can be from about 15 (−6 in.) (e.g., when the bottom of the head cover 22 \is higher than the bottom of the heat emitter 14 ) to about 30 cm (12 in.), for example about 5 cm (2 in.), or 10 cm (4 in.), or 15 cm (6 in.).
[0082] A cover gap 30 can be between the bottom of the head cover 22 and the top of the body cover 24 . The cover gap 30 can be from about 30 cm (−12 in.) (e.g., cover overlap) to about 61 cm (24 in.), more narrowly from about 0 cm (0 in.) to about 41 cm (16 in.), for example about 10 cm (4 in.).
[0083] The head cover 22 can have a head cover slope 32 angle with respect to the longitudinal axis 12 . The head cover slope 32 angle can be from −60° to about 75°, for example about 30° or about 0°. In some variations, the head cover slope 32 angle can be from about −60° to about −10°, more narrowly from about 45° to about −15°, for example about 30°. In other variations, the head cover slope 32 can be from about 0° to about 75°, more narrowly from about 15° to about 60°, for example about 45°.
[0084] FIG. 4 a illustrates that the base cover 34 can be fixedly or removably attached to the tower cover 36 at a joint 38 . The base cover 34 can be longitudinally asymmetrical and bulbous. The tower cover 36 can be elongated. The base cover 34 can be configured to slide upwards at joint 38 telescoping onto tower cover 36 , temporarily made to rest on the under structure of tower 10 , for example in order to provide servicing access, for example, to the propane tank of the base 8 . For shipping and storage, the cover 36 can slide into the cover 34 in order to reduce the combined volume. The joint 38 can be located higher or lower than shown, for example about 24″ to about 37″ from the ground. The covers 34 and 36 can each be made in one, two, or more pieces permanently or semi-permanently joined to form each lower or upper cover. The heater cover 20 can be opaque, translucent, transparent, or combinations thereof.
[0085] FIG. 4 b illustrates that the base cover 34 can be integral with the tower cover 36 . The base cover 34 can be substantially spherical.
[0086] FIG. 4 c illustrates that the body cover 24 can be configured with a substantially uniform slope with respect to the longitudinal axis 12 from the base 8 to the top of the body cover 24 . The head cover 22 can be substantially cylindrical. The cover gap 30 can be zero or negative (e.g., overlap).
[0087] FIG. 4 d illustrates that the head cover 22 can have a cylindrical configuration. The head cover 22 can be partially opaque (e.g., at the “linked square” design, as shown) and partially translucent (e.g., at the remainder). The body cover 24 can have a pinched neck 40 configuration in the tower cover 36 . The pinched neck 40 can serve as a handle to carry or move the heater 2 . The pinched neck 40 can be structurally reinforced.
[0088] FIG. 4 e illustrates that the head cover 22 can have a solid backing 41 and links 42 . The links 42 can descend below (e.g., hang from) the bottom of the backing 41 .
[0089] FIG. 4 f illustrates that the base cover 34 and/or the head cover 22 can be made from numerous beams 44 or rods having a substantially longitudinal alignment. The beams 44 of the body cover 24 can be attached or integral to the cover ground plate 26 or one or more circular reinforcements.
[0090] FIGS. 4 f and 4 g illustrate the head cover 22 can have a rounded dome or substantially hem-spherical or hemi-ovaloid configuration. The top of the head cover 22 can be opened or closed.
[0091] FIGS. 4 e, 4 g, 4 h and 4 j illustrate that the body cover can have a substantially conical configuration.
[0092] FIG. 4 i illustrates that the heater cover 20 can have a platform or counter 46 , for example, positioned along the tower cover 36 , between the tower cover 36 and the base cover 34 , along the base cover 34 , or on the tower cover 36 . The heater cover 20 can have one or more platforms or counters 46 . The body cover 24 and/or head cover 22 can have a seam 48 extending partially or completely along the length of the respective body cover 24 and/or head cover 22 in the direction of the longitudinal axis 12 .
[0093] 4 j illustrates that the head cover 22 and/or body cover 24 can one or more holes, such as circular, square, rectangular, triangular or oval holes, or combinations thereof. The holes can face substantially radially outward from the longitudinal axis 12 .
[0094] FIG. 4 k illustrates that the heater cover 20 can have a domed head cover 22 . The body cover 24 can have a bulbous conical configuration.
[0095] FIG. 4 l illustrates that one or more radial bulbs 50 can extend from the tower cover 36 . The counter 46 can have a rounded top surface and may or may not prove useful to rest loose items on without the loose items rolling off the counter 46 . The counter 46 can be a bulb 50 , as shown.
[0096] FIGS. 4 l, 4 n and 4 o illustrate head covers 22 with various translucencies. FIG. 4 m illustrates a body cover 24 that can have numerous bulbs 50 and a cylindrical head cover 22 .
[0097] FIGS. 4 p and 4 p ′ illustrates that the head cover 22 or body cover 24 (not shown) can have a chandelier configuration. The head cover 22 can have one or more head cover supports 52 , such as circular rigid loops. The head cover 22 can have one or more lines 54 of the same or different lengths hanging from the head cover supports 52 . The lines 54 can be thin nylon or metal wires. The lines 54 can each have one or more volumetric elements 58 , such as discs 56 or other items, securely attached thereto. The volumetric elements 58 can be metal (e.g., steel or aluminum, wherein the metal can have a raw finish or be powder coated) or plastic, glass, crystal, or combinations thereof. The volumetric elements 58 can cylindrical, circular, pyramidal, spherical, a diamond cut configuration, or combinations thereof.
[0098] The tower cover 36 and the base cover 34 can be cylindrical with constant radii along the longitudinal axis 12 . The respective radii of the tower cover 36 and the base cover 34 can be equal or different. For example, the tower cover 36 can have a larger or smaller (as shown) radius than the body cover 24 .
[0099] FIGS. 4 q and 4 q ′ illustrate that the head cover 22 or body cover 24 (not shown) can have a curtain configuration. The head cover 22 can have lines 54 hanging from the radial periphery of the head cover 22 . The lines 54 can be of the same or different lengths. The lines 54 can have volumetric elements 58 , such as discs 56 , beads and charms, attached thereto. The lines 54 can be made from the volumetric elements 58 being directly connected to each other (e.g., no wire need be used along the entire length of the line 54 ) or hanging from wires or nylon threads.
[0100] FIGS. 4 r and 4 r ′ illustrate that the head cover 22 and/or body cover 24 can have a tree configuration. The head cover 22 can have leaves 60 extending radially from the longitudinal axis 12 . The leaves 60 can be square, circular, rectangular, triangular, oval, or combinations thereof. The leaves 60 can extend directly from the heater head 6 of the heater 2 , and/or rigid or resilient branches (obscured in the illustrations by the leaves 60 ) can extend from the heater head 6 and the leaves 60 can attach to or be integral with the branches.
[0101] The top of the base cover 34 can be a counter 46 or platform. The base cover 34 , and/or tower cover 36 , and/or head cover 22 can be covered with or otherwise attached to fabric or plastic (shown only on the base cover in FIG. 4 r ). For example, the base cover 34 can be fixedly or removably attached to a fabric or plastic tablecloth. The base cover 34 can have slots 61 or grooves and/or the “slots” 61 can be folds in fabric (e.g., the tablecloth) hanging off the side off the counter 46 .
[0102] FIGS. 5 a through 5 c illustrate that the tower 10 can be articulatable. The tower 10 can have more than one tower linkage 62 . The tower linkages 62 can be cantilever beams extending from the tower 10 . For example, the heater head 6 , optionally with the head cover 22 , can be placed over the center of a table, chair or other furniture or location with the tower 10 beside the table, chair, other furniture or location.
[0103] Adjacent tower linkages 62 can be attached at fixedly rotatable hinges 64 . Adjacent hinges 64 and/or adjacent tower linkages 62 can be attached by tensile cables 66 . The tensile cables 66 and/or friction in the hinges 64 can fix the tower 10 in a configuration when the tower 10 is not being adjusted by a user. The heater head 6 can have a thermally insulated and/or removably attached head handle 68 .
[0104] A flexible fuel or electrical conduit can be inside of the tower linkages 62 . The flexible fuel conduit can transport fuel or electricity from the base 8 to the heat emitter 14 in the heater head 6 .
[0105] FIGS. 5 b and 5 c illustrate that the tower linkages 62 can be swiveled or otherwise rotated, as shown by arrows, with respect to each other and/or the base 8 and/or the heater head 6 , for example to control the position and angle of the heater head 6 and/or radiative direction of the heat. The position of the heater head 6 can be manipulated vertically (i.e., up and down) and/or horizontally (i.e., side to side), and/or the angular orientation of the heater head 6 can be manipulated.
[0106] FIGS. 5 a, 5 b, 5 c and 6 illustrate that the tower 10 can be attached to or integral with the top of the heater head 6 . FIG. 6 illustrates that the tower 10 can have a hooked, curved, rounded, arcuate, or “J” configuration. The tower 10 can be rigid or deformable. The tower 10 can be attached to the radial center of the base 8 with respect to the longitudinal axis 12 of the base 8 or to a radial side of the base 8 , such as on the radial perimeter of the base 8 , as shown.
[0107] FIG. 7 illustrates that the heater can have two or more heater heads 6 a and 6 b. Each heater heads can have an individual heat emitter 14 . Each heater head 6 can be attached to its own tower linkage 64 , or a tower linkage 64 shared with other heater heads 68 . The heater heads 6 can be moved individually or in combination with each other.
[0108] FIGS. 8 a and 8 b illustrate that the heater can have three heater heads 6 a, 6 b and 6 c. The heater heads 6 a, 6 b and 6 c can each have an individual heat emitter 14 .
[0109] FIG. 9 a illustrates that the body cover 24 can have a cut-off (as shown) or complete pyramid configuration. The head cover 24 can be translucent. The head cover 22 can be corrugated. The head cover 22 can have a square cross section transverse to the longitudinal axis. The head cover 22 can have a uniform transverse cross section with respect to the longitudinal axis 12 .
[0110] FIGS. 9 b, 9 c and 9 d illustrate that the heater 2 can have one or more signs 72 fixedly or removably attached to or integral with the body cover 24 and/or head cover 22 . The signs 72 can be fastened to the heater 2 or heater cover 20 using glue, adhesive, any of the other fasteners 70 disclosed herein, or combinations thereof.
[0111] The signs 72 can have a surface with one or more visible graphics comprising text and/or images. The graphics can be black and white or color printed, engraved, embossed, or combinations thereof. The sign 72 can have a static (e.g., fixed print and/or embossing) and/or a dynamic display (e.g., changing or variable print and/or embossing). For example, the dynamic display can have a light emitting monitor (e.g., CRT display, plasma display, LCD display, LED display), a rotating or scrolling fabric or paper strip, attached to one roller on each side of the strip, a series of timed rotating elements (e.g., ActionMaster by Mobile Master Manufacturing, LLC, Nashville, Tenn.), or combinations thereof.
[0112] The sign 72 can be larger than a branding label for the heater 2 , for example, the sign 72 can be taller than 5 cm (2 in.) and wider than 5 cm (2 in.), or taller than 10 cm (4 in.) and wider than 10 cm (4 in.), or taller than 15 cm (6 in.) and wider than 15 cm (6 in.), or taller than 30 cm (12 in.) and wider than 30 cm (12 in.), or taller than 61 cm (24 in.) and wider than 61 cm (24 in.).
[0113] FIG. 9 b illustrates that the body cover 24 can have a sign 72 attached to each of one to four sides of the body cover 24 . The body cover 24 and/or sign 72 can have a fastener 70 that can removably attach the body cover 24 to the sign 72 , or vice versa, or the body cover 24 and the sign 72 to the fastener 70 .
[0114] FIG. 9 b illustrates that the sign 72 can be narrower than the body cover 24 at the height at which the sign 72 is attached to the body cover 24 . The sign 72 can be in a frame. FIG. 7 c illustrates that the sign 72 can be wider than the body cover 24 at the height at which the sign 72 is attached to the body cover 24 . FIG. 7 d illustrates that the sign 72 can be retractably or extendably rolled or folded when not in use.
[0115] FIGS. 10 a, 10 b and 10 c illustrate that a sign 72 can be attached to or printed on the head cover 22 . The body cover 24 can be attached to one, two or more signs 72 . The signs 72 can be wider than that body cover 24 and/or wider than the head cover 22 .
[0116] The top of the body cover 24 can have a sloped angle (as shown in FIG. 8 c ) that can hold the signs 72 at a sign slope angle 74 with respect to the longitudinal axis 12 . The sign slope angle 74 can be from about −60° to about 90° (e.g., the sign 72 can form a counter 46 ). For example, the sign slope angle 74 can be from about −60° to about 0°, more narrowly from about −45° to about −15°, for example about −30°. The sign slope angle 74 can be from about 0° to about 90°, more narrowly from about 5° to about 60°, for example about 15°.
[0117] FIG. 11 illustrates that the sign 72 can be mounted on a frame attached to body cover 24 . The frame can extend away from the body cover 24 , for example holding the sign 72 away from the body cover 24 .
[0118] FIG. 12 illustrates that the sign 72 can be attached to the head cover 22 . The sign 72 can be removably attachable from the head cover 22 . For example, the sign 72 can be made from a flexible magnet. The sign 72 can be attached to the head cover 22 by a fastener described herein. The sign 72 can be integral with the head cover 22 . For example, the sign 72 can be etched into or painted or coated onto the head cover 22 .
[0119] FIG. 13 illustrates that the sign 72 can be attached to the body cover 24 . The sign 72 can be removably attachable from the body cover 24 . For example, the sign 72 can be made from a flexible magnet. The sign 72 can be attached to the body cover 24 by a fastener described herein. The sign 72 can be integral with the body cover 24 . For example, the sign 72 can be etched into or painted or coated onto the body cover 24 . The cover 24 or head cover 22 may also be completely covered or wrapped in vinyl material conforming to the cover 24 shape for the purpose of advertising or decoration (such as wrapping of vehicles for use as mobile billboards).
[0120] The heater 2 can have speakers and/or lighting in, behind, adjacent to the signs 72 , and/or anywhere on the heater 2 , for example in or on the body cover and/or head cover and/or tower cover. Any or all of the covers can be translucent, transparent, opaque, or combinations thereof. The speakers and/or wires can be connected to data sources wired and/or wirelessly. Music and/or spoken word (e.g., commercial information) can be broadcast through the speakers. The data and/or power for the speakers and/or lighting can be internal to the heater 2 , and/or external to the heater 2 .
[0121] FIG. 14 illustrates that any variation of the heater cover 20 can have one or more signs 72 . For example, the heater cover 20 can have a head cover 22 that can have holes. The head cover 22 can be similar to the head cover 22 of the variation of FIG. 4 j.
[0122] FIG. 15 a illustrates that the heater cover 20 can have a head cover 22 with a head cover slope 32 less than 0°. The head cover slope 32 can be tilted downward (i.e., having a head cover slope 32 less than 0°), as shown.
[0123] FIG. 15 b illustrates that the heater cover 20 can have a sign 72 on the body cover 24 (e.g., on the tower cover 36 or the base cover 34 ) and have a head cover 22 with a head cover slope 32 less than 0°.
[0124] FIG. 15 c illustrates that the heater 2 can have a sign 72 on the body cover 24 (e.g., on the tower cover 36 or the base cover 34 ) and/or have a sign 72 on the head cover 22 . The head cover 22 can have a head cover slope 32 less than 0°. The sign 72 on the head cover 22 can be tilted downward, upward, or perpendicular to the ground. The sign 72 on the body cover 24 can be tilted downward, upward, or perpendicular to the ground.
[0125] FIG. 16 illustrates the heater 2 similar to the heater 2 of FIG. 1 . FIG. 17 illustrates that the body cover 24 can have a seam 48 . The body cover 24 can have one or more fasteners 70 . The fasteners 70 can hold the seam 48 together.
[0126] FIG. 18 illustrates that the body cover 24 can be elastic or otherwise resilient. The fasteners 70 can be unfastened. As shown in FIGS. 18 and 20 , the body cover 24 can be stretched open at the seam 48 , as shown by arrows 75 , and translated 76 , as shown by arrow in FIG. 19 , and wrapped around the body 4 . The base cover 34 can be wrapped around the base 8 . The tower cover 36 can be wrapped around the tower 10 .
[0127] As shown in FIGS. 19 and 20 , the heater head 6 can have a rigid, internal head frame 78 and a head connector 80 . The head connector 80 can be configured to attach to the heat shield 16 and/or top of the tower 10 or heat emitter 14 . The head connector 80 can have one or more fasteners 70 . The heat shield 16 and/or top of the tower 10 or heat emitter 14 can have one or more fasteners 70 . The head cover 22 can be lowered onto the heat shield 16 or top of the tower 10 , as shown by arrows 81 .
[0128] Corresponding fasteners 70 on the heater cover 20 and, where applicable, the uncovered heater 2 can be fastened after the heater cover 20 is positioned on and/or around the uncovered heater 2 .
[0129] FIG. 21 illustrates the heater 2 similar to the heater 2 of FIGS. 1 and 16 . FIG. 22 illustrates that the heat cover heater cover 20 (heater not shown) and/or body cover 24 can have a cover first section 82 and a cover second section 84 . The cover first section 82 can be rotatably attached to the cover second section 84 , for example at a body cover hinge 86 . The cover sections can be rigid.
[0130] FIG. 24 illustrates that the cover can be opened by first unfastening the fasteners 70 , if applicable. Then the cover first section 82 can be rotated, as shown by arrows 101 , about the hinge 64 away from the cover second section 84 .
[0131] FIGS. 23 and 25 illustrate that the opened body cover 24 can be translated, as shown by arrow 87 , around the base 8 and tower 10 . Once the body cover 24 is in place around the body 4 , the cover first section 82 can be rotated, as shown by arrows 102 , with respect to the hinge 64 toward the cover second section 84 . The fasteners 70 can then be attached to each other.
[0132] The cover first section 82 can be completely separate (e.g., not attached at a hinge 64 ) from the cover second section 84 before use. The cover first section 82 and cover second section 84 can be translated in a position to together surround the body 4 . Fasteners 70 on the cover first section 82 can then be attached to fasteners 70 on the cover second section 84 .
[0133] FIG. 26 illustrates that the cover hinge 86 or the fastener 70 can have a first hinge panel 90 and a second hinge panel 92 . The hinge panels can be secured to the respective cover sections through hinge panel holes 94 (e.g., with screws, nails, rivets, glue). The first hinge panel 90 can be rotatably attached to the second hinge panel 92 by a hinge pin 96 . The hinge pin 96 can telescope. The second hinge pin 96 can slidably translate 76 , as shown by arrows, along the hinge pin 96 .
[0134] FIG. 27 illustrates that the first 90 and/or second hinge panels 92 can have hinge panel slots 98 in a perpendicular direction to the hinge pin 96 . The hinge panel slots 98 can allow the first 90 and/or second hinge panel 92 to have a first translation, as shown by arrows 100 . The first hinge panel 90 can rotate, as shown by arrows 103 , with respect to the second hinge panel 92 . The second hinge panel 92 can move in a second translational direction, as shown by arrows 104 , along the hinge pin 96 .
[0135] FIGS. 28 and 29 illustrate that the heater cover 20 can have a tower cover 36 that can be fixedly or removably attached to the body cover 24 at a seam 48 . The tower cover 36 can snap to the body cover 24 . The tower cover 36 can be attached to the body cover 24 by fasteners, for example as described herein.
[0136] Any or all parts of the heater cover 20 can have horizontal and/or vertical ridges 210 , ribs or grooves. The ridges 210 on the body cover 24 can align to the ridges 210 on the tower cover 36 .
[0137] FIGS. 30 and 31 illustrate that the body cover 24 and the tower cover 36 can be detached from each other. The tower cover 36 can telescope into the body cover 24 . The tower cover 36 can have an interfacing surface 214 and, for example, an abutment 212 . The interfacing surface 214 can be thinned compared to the wall on the other side of the abutment 212 from the interfacing surface 214 . The abutment 212 can lay flat or flush against the body cover when the tower cover 36 is attached to the body cover 24 .
[0138] During assembling and attaching of the tower cover 36 to the body cover 24 , the tower cover 36 can be snap-fitted, glued (or other adhesive, epoxy), attached via one or more pieces of hook and loop tape (e.g., Velcro); one or more pieces of interlocking stem and head tape (e.g., Dual Lock from 3M Corporation of Minneapolis, Minn.), attached via a pressure collar, or used with any fastener listed herein or combinations thereof to or from the body cover 24 . Once assembled, the seam 48 can be substantially horizontal.
[0139] For example, a propane or other liquid or gas fuel tank and/or electrical power supply and controls can be stored inside the body cover 24 . For example, to access (e.g., for service or replacement) the propane tank and/or power supply and controls, the body cover 24 can be detached from the tower cover 36 and the body cover 24 can then be lifted above the propane tank and/or power supply and controls for rapid access. The tower cover 36 can be permanently or semi-permanently attached to the heater column 10 or removed during the accessing, for example, of the propane tank under the cover 24 .
[0140] FIGS. 32 a through 32 d illustrate a variation similar to that shown in FIG. 4 a. The base cover 34 can be attached to the tower cover 36 by a joint 38 . The joint 38 can have one or more joiners, such as seals, rings, straps, clamps, or combinations thereof. The joiners can removably or fixedly attach the base cover 34 to the tower cover 36 . The joiners 302 can clip, snap, clamp, or combinations thereof to the base cover 34 and/or the tower cover 36 .
[0141] The tower cover 36 can be fixed or separably attached to the tower 10 . For example, the tower cover 36 can be attached to the tower 10 via brackets, clamps, hooks, or combinations thereof internal to the tower cover 36 . The base cover 34 can be separate and unattached from the tower cover 36 and the tower 10 . The base cover 34 can be attached or unattached from the base and/or tower. A joiner, such as a ring, can have serve merely to hide or obscure the seam 48 between the base cover 34 and the tower cover 36 and not to join the tower cover 36 to the base cover 34 .
[0142] For example, the tower cover 36 and the base cover 34 can be made as a single unit, then cut above, below, or through the ring at the joint 38 to separate the tower cover 36 and the base cover 34 .
[0143] The inner diameter of the base cover 34 at the joint 38 can be larger than the outer diameter of the tower cover 36 at the joint 38 . The minimum inner diameter of the base cover 34 can be larger than the maximum outer diameter of the tower cover 36 .
[0144] The tower cover 36 can attach or be separate from the base cover 34 . If the tower cover 36 is separate from the base cover 34 , a cover gap 300 can be between the top of the most adjacent part of the top of the base cover 34 to the most adjacent bottom part of the tower cover 36 . The cover gap 300 can be about equal to or less than 1.25 in.
[0145] FIGS. 33 a through 33 c illustrate that the one or more joiners 302 can be detached from the tower cover 36 (as shown) and/or the base cover 34 , for example, separating the base cover 34 from the tower cover 36 . The base cover 34 can instead be separate and unattached from the tower cover 36 .
[0146] The base cover 34 can be raised, as shown by arrows, for example to expose the contents of the base 8 . For example, the base cover 34 can be slid or otherwise lifted at least partially vertically concurrent with the tower cover 36 . The base cover 34 can be radially inside or outside of the tower cover 36 . The base cover 34 can be lifted above the tower cover 36 . The base 8 can include a propane or other fuel tank or controls. The base cover 34 can be moved temporarily to a position around a part or all of the length of the tower cover 36 .
[0147] The contents of the base 8 can be accessed, for example, the fuel tank can be serviced or replaced. The base cover 34 can then be lowered to the position shown in FIGS. 32 a through 32 d. The base cover 34 can be reattached to the tower cover 36 , if desired and possible based on the design.
[0148] The tower cover 36 can be configured to be slidably or otherwise lowered at least partially vertically concurrent with the base cover 34 . The tower cover 36 can be lowered to the ground.
[0149] The base cover 34 can be configured to be not directly attached to the base. For example, the base cover 34 can be resting freely on or anchored to the ground and/or pressed down by or attached to the tower cover 36 when the base cover 34 is in a position encircling the base. The tower cover 36 can be configured to be not directly attached to the remainder of the tower. For example, the tower cover 36 can be resting freely on or attached to the base cover 34 .
[0150] The fasteners 70 can be snaps. The fasteners 70 can be a latch and the associated ports or catches.
[0151] FIGS. 34 through 63 illustrate variations of the fasteners 70 that can secure the body cover 24 to itself, one section of the body cover 24 to another section of the body cover 24 , or the head cover 22 to the uncovered heater 2 (e.g., at the heater head 6 ). For illustrative clarity, the elements fastened by the fasteners 70 are referred to, infra, generically as a first panel 106 and a second panel 108 .
[0152] Variations of fasteners 70 can include one or more quick release fasteners 70 , for example, ¼-turn DZUS fasteners 70 with a retainer and a clip-on receptacle, and/or flat rivet-on receptacle, and/or ultrasonic receptacle (e.g., for thermoplastics), and/or a snap-in receptacle; cam locks (e.g., a “Z” lock), spring-loaded captive plungers and fasteners 70 , locking pins 110 with detents (e.g., DZUS), and nylatch 1 and 2-piece DZUS panel fasteners 70 , one or more latches (e.g., low profile latches), for example, rotary action draw latches, cam latches, spring-loaded self-adjusting latches, adjustable pull draw latches, rotary draw latches, flexible handle latches, soft-draw latches, over-center draw latches, pop-out knob latches, swell action latches, and flush compression latches; magnets, one or more snaps; one or more pieces of hook and loop tape (e.g., Velcro); one or more pieces of interlocking stem and head tape (e.g., Dual Lock from 3M Corporation of Minneapolis, Minn.) (i.e., wherein one piece of hook and loop or stem and head tape comprises at least two opposed sheets that are configured to interlock with one another); one or more taped joints (e.g., for closure and cosmetics); one or more self-locking implanted cotter (“SLIC”) pins; one or more ties, for example, nylatch cable clamps, tie straps, cable ties, and elastic ties; one or more clips, for example, fold clips; and trim retainers labels; one or more laces; one or more magnetic catches; one or more channel moldings; one or more removable hinges 64 ; and combinations thereof.
[0153] FIG. 34 illustrates that the fastener 70 can have a male cam lock 112 and a female cam lock 114 . The male cam lock 112 can have a shaft head 111 and shaft 116 . The male cam lock 112 can have a locking pin 110 traversing and extending substantially perpendicularly from the shaft 116 . The female cam lock 114 can be configured to receive the shaft 116 . The female cam lock 114 can have a bracket 118 . The female cam lock 114 can have a channel 120 configured to receive and removably attach to the locking pin 110 .
[0154] FIG. 35 illustrates that the second panel 108 can be configured to have a raised or lowered lip 122 to fit the first panel 106 . The first panel 106 and the second panel 108 , for example in the lip 122 , can have a fastener port 124 . The fastener port 124 can align to form a single channel. The bracket 118 of the female cam lock 114 can be fixedly or removably attached to the end of the lip 122 . The shaft 116 can be inserted through the fastener port 124 . The shaft 116 can be inserted through a rubber washer 126 between the shaft head 111 and the first panel 106 . The shaft head 111 can be driven by a screwdriver or directly by hand. The shaft 116 can be rotated to slide the locking pin 110 through the locking pin channel 120 . The fastener 70 can releasably attach the first panel 106 to the second panel 108 .
[0155] FIG. 36 illustrates that the fastener 70 can be a one-piece rivet. The rivet can have a shaft head 111 . The rivet can have resilient legs 128 extending longitudinally and radially from the shaft head 111 . The legs 128 can be integral to the other legs 128 and the shaft head 111 .
[0156] FIG. 37 illustrates that the fastener 70 can be a two-piece clinch retainer. The shaft head 111 and shaft 116 can be slidably attached to the legs 128 . The legs 128 can be configured to radially expand when the shaft 116 is translated toward the legs 128 .
[0157] FIG. 38 illustrates that the rivet can be inserted through the fastener port 124 . The legs 128 can radially expand on the opposite side of the panels from the shaft head 111 . The first 106 and/or second panel 108 can have a flange 130 to bracket the other panel.
[0158] FIG. 39 illustrates that the fastener 70 can be a screw. For example, the fastener 70 can be a wood screw or similar to a wood screw. The fastener 70 can have a shaft head 111 , shaft 116 and thread 132 , a spring or resilient hoops, Christmas tree retainers 134 , or combinations thereof extending from the shaft 116 . The thread 132 , spring, or hoops can have a larger radius than the fastener port 124 . The thread 132 , spring or hoops can be forced through the fastener port 124 and interference fit with the fastener port 124 when deployed to attach to the fastener port 124 . The fastener 70 can be made from stainless steel.
[0159] The shaft 116 of the variation of the fastener 70 of FIG. 39 can be inserted through the first panel 106 and the second panel 108 . The shaft 116 can then be secured by a nut, nut insert, or clip (for example, similar to the fastener 70 shown in FIG. 40 , with a central channel through the fastener 70 of FIG. 40 where the central channel is configured to receive the shaft 116 of the fastener 70 of FIG. 39 ) on the opposite side of the panels 106 and 108 from the head 111 .
[0160] The shaft 116 can be inserted through ports in the first panel 106 and/or the second panel 108 , and/or the shaft 116 can bore through the first panel 106 and/or the second panel 108 . The shaft 116 can be oriented at a perpendicular, near perpendicular or slight perpendicular angle to the seam 48 .
[0161] In one variation, three fasteners 70 can be used on each side of the body cover 24 (i.e., six total fasteners), for example one near the top of the body cover 24 , one near the middle of the body cover 24 , and one near the bottom of the body cover 24 .
[0162] FIG. 40 illustrates that the fastener 70 can have a shaft 116 extending from and integral with a bracket 118 . The bracket 118 can be attached to the second panel 108 and the shaft 116 can attach to the fastener port 124 on the first panel 106 (similar to as shown in FIG. 35 , but with the shaft 116 integral with the bracket 118 ). The shaft 116 can have a flat end. The shaft 116 can have threads 132 or fins extending longitudinally (as shown) or helically along the shaft 116 . The threads 132 can interference or friction fit into the panel surrounding the fastener port 124 into which the shaft 116 is inserted.
[0163] FIGS. 41 and 42 illustrate that the first 106 and/or second panels 108 can have stepped grooves 136 or fluted. The first panel 106 can have a fastener port 124 . The second panel 108 can have a fastener port 124 or be absent any fastener ports 124 . The fastener 70 can removably attach a supplemental panel, flange 130 , or washer 126 to the first panel 106 . The supplemental panel 138 and the first panel 106 can friction fit (e.g., squeeze fit) around the second panel 108 . The supplemental panel 138 can be on the inside or outside of the cover. The grooves can obscure the joint or seam 48 or between the first panel 106 and the second panel 108 .
[0164] FIG. 43 illustrates that the first 106 and/or second panel 108 can have one or more rounded grooves 142 . The fastener 70 can have a shaft 116 extending from the shaft head 111 . A locking pin 110 can be inserted transversely through the shaft 116 on the opposite side of the panels from the shaft head 111 .
[0165] FIGS. 44 and 45 illustrate that one or more spacers 144 can be placed in the joint or seam 48 between the panels. The spacer 144 can have spacer brackets 146 configured to seat the ends of the panels. One or more rigid or flexible straps or ties 148 can be attached to both panels, for example, to hold the panels in tension. The ties 148 can be attached to the panels with a screw, brad or pin, for example having a shaft 116 extending from the shaft head 111 . A washer 126 can be attached to the end of the shaft 116 on the opposite side of the panel from the shaft head 111 . As shown in FIG. 45 , the tie 148 can be placed on the outside or the inside of the cover.
[0166] FIG. 46 illustrates that the fastener port 124 can be substantially parallel to the outer or inner surface of the panels. The fastener 70 can have a shaft 116 having a threaded end 132 . Part or all of the length of the fastener port 124 can be threaded 132 . The fastener 70 can be inserted and screwed into the fastener port 124 .
[0167] FIG. 47 illustrates a similar variation to FIG. 44 , but with a locking pin 110 inserted through the shaft 116 . The locking pin 110 can be inserted through a locking pin port 150 in the second panel 108 . The locking pin 110 can be inserted transversely through a port in the shaft 116 . A washer 126 , nut or lockwasher can be attached to the locking pin 110 on the opposite side of the shaft 116 from the locking pin head 152 . The locking pin head 152 can have a detent 154 . The shaft 116 can align the first panel 106 and the second panel 108 .
[0168] FIG. 48 illustrates one end of a variation of the assembled fastener 70 of FIG. 47 FIG. 48 illustrates that the shaft 116 can be a flat plate. The shaft 116 can be substantially cylindrical.
[0169] FIG. 49 illustrates that the fastener 70 can be a multi-piece cam fastener 70 . The cam fastener 70 can have a head element rotatably attached to a body element. The cam fastener 70 can be inserted 156 through the fastener port 124 . An internal cam (not shown for illustrative clarity) can cause the body 4 to radially expand, as shown by arrows 158 in FIG. 49 , when the shaft head 111 is rotated, as shown by arrows 159 in FIG. 50 , with respect to the to the shaft body 161 .
[0170] A retainer clip 160 can be attached to or integral with the shaft body 161 and/or placed between the first panel 106 and the second panel 108 and the fastener 70 can be inserted through the retainer clip 160 .
[0171] FIGS. 51 and 52 illustrate that a friction strip 162 and/or a retainer ring 164 can be between the first panel 106 and the second panel 108 . The friction strip 162 can minimize slipping between the first panel 106 and the second panel 108 .
[0172] The fastener 70 can have a handle 166 rotatably attached to the shaft head 111 . The handle 166 can be used to rotate and push and pull the fastener 70 directly by hand. The handle 166 can be rotated, as shown by arrows 167 in FIG. 51 , out for use and in for a low profile.
[0173] The shaft 116 can be attached to or integral with a spring 168 . The spring 168 can slidably rest against the side of the second panel 108 . The shaft 116 can have threads 132 . The shaft 116 can be threadably attached to the first panel 106 , and/or second panel 108 , and/or the retainer ring 164 . The shaft 116 can be rotated, for example, screwing the shaft 116 to increase compression of the spring 168 between the end of the shaft 116 and the second panel 108 . FIG. 41 shows the handle 166 in a first configuration, and a second, phantom, configuration after rotation.
[0174] FIGS. 52 and 53 illustrate that the fastener 70 can be a rigid or flexible strap 170 , strip or clamp. The strap 170 can be attached to a pin 172 on each panel. The strap 170 can be wrapped around the pins 172 , as shown.
[0175] FIGS. 55 and 56 illustrate that the second panel 108 can be attached to or integral with a supplemental panel or retainer clip 160 . The retainer clip 160 can be metal (e.g., steel or aluminum, wherein the metal can have a raw finish or be powder coated) or resilient plastic. The retainer clip 160 can be biased toward a closed position. ( FIG. 44 illustrates the retainer clip 160 in a partially open position.) The retainer clip 160 can close onto, and friction and/or interference fit against the lip 122 of the first panel 106 . The second panel 108 can have a prod port 174 , for example to insert a prod, shaft 116 or other object, to bend the retainer clip 160 away from the first panel 106 and release the first panel 106 from the second panel 108 .
[0176] FIG. 56 illustrates that second panel 108 can have a flange 130 . The flange 130 can have a tongue 176 extending therefrom. The tongue 176 can be attachably received by a groove 178 on the lip 122 of the first panel 106 .
[0177] FIG. 57 illustrates that the fastener 70 can have a retainer clamp 180 . A base 8 or shaft head 111 with a shaft 116 can extend from the retainer clamp 180 . The base 8 and shaft 116 can be rotatably attached to the second panel 108 , for example through a fastener 70 port. The shaft 116 can have threads 132 . A clamp 180 or vice can be threadably attached to the shaft 116 . The handle 166 can be rotated, as shown by arrows 167 , causing the clamp 180 to press down (or release upward), as shown by arrows 179 , toward (or away from) the base 8 on the first panel 106 . The clamp 180 can be seated in the first panel 106 in a clamp seat 182 . FIG. 58 illustrates a variation similar to that of FIG. 57 , but with a friction strip 162 , skin, or molding between the first panel 106 and the second panel 108 .
[0178] FIG. 59 illustrates that the shaft 116 can be inserted through the first panel 106 and the second panel 108 . A first friction strip 184 can be placed between the first panel 106 and the second panel 108 . A second friction strip 186 , lock washer, friction ring, or combinations thereof, can be placed between the base 8 or shaft head 111 and the second panel 108 . A clamp guide 188 can be integral with or attached to the first panel 106 .
[0179] FIGS. 60 and 61 illustrate that the fastener 70 can be a resilient clip 190 . The clip 190 , or any other fastener, can be made from metal (e.g., steel or aluminum, wherein the metal can have a raw finish or be powder coated), polymer (e.g., polyethylene (PE)), or a combination thereof. The fastener port 124 on the first panel 106 can be non-overlapping with the fastener port 124 on the second panel 108 . The clip 190 can have two clip legs 192 . Each clip leg 192 can be inserted through a fastener port 124 . The clip 190 can hold the first panel 106 and the second panel 108 together in tension. The one, two or more holds 194 can extend from the clip 190 . The holds 194 can be used, for example by grabbing with a fingernail, key or screwdriver, to assist in removal of the clip 190 . The clip 190 can have a clip face 196 . Information (e.g., branding, advertising, serialization information for the clip 190 ) can be printed or attached to the clip face 196 .
[0180] FIGS. 62 and 63 illustrate that the fastener 70 can be a draw latch. The fastener 70 can have a pivot pin 198 fixedly attached to the shaft head 111 and handle 166 on one side of the first panel 106 , and to a latch plate 200 on the other side of the second panel 108 . When the handle 166 is rotated, as shown by arrows in FIG. 52 , the latch plate 200 rotates, as shown by arrows in FIG. 63 . The latch plate 200 can have a latch slot 202 . The outer edge of the latch slot 202 can have a decreasing radius with respect to the angle around the latch plate 200 as measured from the pivot pin 198 . The second panel 106 can be fixedly attached to a latch pin 204 . The latch pin 204 can be received by the latch slot 202 . With the latch pin 204 in the latch slot 202 , to six the first panel 106 to the second panel 108 , the latch plate 200 can be rotated so the latch pin 204 is frictionally fit to the edge of the latch slot 202 . To detach the latch pin 204 from the latch plate 200 , the direction of rotation of the latch plate 200 is reversed.
[0181] The body cover 24 , head cover 22 , fasteners 70 , or other elements described herein can be made from thermoplastics (e.g., Polyethylene terephthalate (PET), Polyethylene (PE), Polypropylene (PP), including those used in rotational or blow molding) one or more fiber-reinforced polymers (e.g., FRP, fiberglass), resin, sheet metal (e.g., stamped sheet metal), urethane, heat resistant fabrics (e.g., stretched around a steel frame or other structure), or combinations thereof. Any metal used can be steel or aluminum. The metal can have a raw or brushed finish or be powder coated. The body cover 24 , head cover 22 , fasteners 70 , or combinations thereof can be formed by being rolled or molded, for example roto-molded.
[0182] The cover can have a smooth or textured finish. The cover can be lightweight, suited for indoor or outdoor use, long lasting, and have a durable finish. The outer surface of the cover can be anodized, polished, lacquered, powder coated (e.g., with electrostatic paint), or combinations thereof. The cover can be simply and repeatedly assembled and disassembled, and easily transported from location to location. Covers can be stored by nesting the covers together or telescoping each other. The covers can have fluting, appliqués, wrapped in vinyl, self-adhesive tape and combinations thereof, for example to obscure the appearance of joints 38 or seams 48 or for advertising.
[0183] The cover can be punctured, louvered, folded, or combinations thereof. The cover can have metal mesh. The cover can be treated to dissipate or be insulated from heat.
[0184] The head cover 22 can have, for example, 3 to 6 straps bridging the gap between the head cover 22 periphery and the center of the heater 2 , (e.g., like radial spokes) and attaching to where the heat shield joins the tower 10 or heater head 6 . Attachment of the head cover 22 to the heater head 6 or tower 10 can be accomplished with a mechanical quick-release fastener 70 to new or existing attachment points. The head cover 22 can be attached via a thermal insulator and/or height spacers 144 .
[0185] The heater cover can have one or more lights inside and/or outside of the heater cover.
[0186] PCT Application No. PCT/US2008/074085, filed Aug. 22, 2008 is incorporated herein in its entirety.
[0187] It is apparent to one skilled in the art that various changes and modifications can be made to this disclosure, and equivalents employed, without departing from the spirit and scope of the invention. Elements and characteristics shown with any variation are exemplary for the specific variation and can be used in combination with elements or characteristics from other variations within this disclosure.
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Heater covers and methods of using the same are disclosed. The covers can be used on stand-type movable or fixed patio heaters or table top heaters. The covers can be removably attached to the heaters. The covers can have body covers separate or attached to head covers. The covers can be resilient or rigid. The rigid covers can have hinges and can clamshell or telescope around the heaters.
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This application is a continuation of application Ser. No. 08/337,847, filed Nov. 14, 1994, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
An apparatus and method for ecologically, safely transferring muck and silt from waterbottoms that includes the transfer of muck and silt, using a portable, submersible, robotic power head that can transfer plants and living creatures, large and small, that live on or in the waterbottom, without damage thereto, and providing porous containers on the waterbottom for receiving the silt or muck, which also allows for a continuing supply of nutrients and food to support sea plants, crustaceans, fish, crabs, and sea animals outside of the porous containers.
2. Description of the Prior Art
Rain and wind-driven organic and inorganic matter produced by animals and plants of all types flows down from mountains, farms, ranches, factories, streets, roads, driveways, roofs, airports, golf courses, septic tanks, horse and cattle ranches, and cemeteries and has, over the years, washed downstream into creeks, streams, rivers, lagoons, and estuaries where it finds its way to the lowest spot along the shore. Every time an aquatic creature, human swimmer, fisherman, or boat of any type, propellers or not, or tide changes, rainstorm, or wind disturbs the water even slightly, the resulting turbulence stirs up the loose muck on the bottom, clouds the water with turbidity, suspends the fines, causing this muck to be carried downstream to foul its benthos, killing millions of creatures otherwise destined for the life creation process many years ahead.
Conventional wisdom of government agencies, quasi-government regulatory agencies, and lobbying groups mandate upland disposition of dredging spoils or muck. Such an approach is like trying to pump septic tank effluent to the top of a hill and waiting for a heavy rainstorm to wash it back down. Upland disposal of muck and silt fails to secure the preservation of the living environment by ordaining the death of an entire benthos by drying and dying in the sun.
Upland disposal is more difficult to accomplish in more densely populated areas and certainly more costly, which drastically cuts down the number of dredging permit applicants to only those who can afford the additional expense. Upland disposal does not help or improve or renew waterbottoms or in any way assist or aid new growth of subaqueous animal and plant life. The present invention will better carry out protection and enhancement of subaqueous ecology while allowing silt and muck to be removed safely and ecologically transferable.
The present invention utilizes in situ containment tubes and bags made of porous synthetic fiber cloth. These tubes allow the transfer of the benthos in the muck to a different location underwater out of harm's way alongside sea plants, mangroves, or seawalls, under a dock or in the form of a subaqueous lagoon or baby fish hatchery or an artificial reef. Each environment provides nutrients and a continuing supply of plant and animal food to support the growth of other forms of life growing by feeding on the outer surface of porous containers.
The present invention also utilizes a muck and silt transfer system that does not destroy living materials in that it does not have any blades or other deleterious transfer devices that would harm the benthos. The system employs a submersible robotic power head which contains no moving parts or cutting edges or vanes to damage living creatures.
SUMMARY OF THE INVENTION
A method and apparatus for transferring siltation and muck from waterbottoms to safely and ecologically transfer benthos without damage thereto, permitting the growth and reproduction of all creatures, large and small, animals, and plants living on or in the waterbottoms by providing silt and muck into porous containers which are ultimately positioned on the waterbottom. The present invention allows for providing a continuous supply of nutrients and food to support the growth on the outside of the porous containers of other sea plants, crustaceans, fish, crabs, and sea animals without the danger of downstream contamination of sea grasses or clam and oyster beds or damage to boat engines, gear drives, and pumps.
The apparatus includes using a portable, submersible power head with no cutting blades, impellers, augers, centrifugal rotor, or other moving parts, which engages siltation and muck and transfers it safely without any damage to large and small animals and plants that live on the bottom.
The present invention utilizes in situ containment tubes and bags made of porous synthetic fiber cloth. These tubes allow the transfer of the benthos in the muck to a location providing more safety underwater, providing both nutrients and a continuing supply of plant and animal food to support the growth of other forms of life by feeding on the outer surface of the porous containers.
A variety of woven, spunweb, and needlepunched fiber cloths are used, depending on engineering considerations, in addition to films, porous films, and membranes to achieve controlled specific gravity of the contents inside the containers.
Several unique types of flotation and inflatables to suspend the containers at water level are used, allowing them to be filled, relocated on the water surface over the underwater location selected, and descend slowly for precise positioning on the waterbottom without rupture of the tubes or their seams.
The silt and muck transfer system utilizes a portable console that includes an electric motor that can be attached to dockside electricity, an air pump driven by the electric motor, a mud and silt collection head, termed a power head, connected to the output of the air source, and optionally, a hydraulic pump. The power head is positioned on the waterbottom and uses air bubbles and exterior lake or ocean water pressure to raise the silt and muck in conjunction with a turbidity shroud, forcing muck and silt through the discharge line into a floating porous container where the silt and other material, living and non-living, is collected. The body of the power head may be heavily weighted, conical, with an inlet chamber and a conduit disposed therethrough that is the discharge conduit for collecting the silt, sand, and muck. Since the power head does not have any moving parts, the system does not hurt any living creatures during muck transfer. The power head may have connected adjacent thereto a plurality of water lines that are connected to the water pump disposed on the pier or dockside so that water jets are strategically aligned around the base of the power head in conjunction with an air supply that is strategically placed in a chamber inside the power head so that the entire action of the water creates a vortex and turbulence at the mouth of the discharge tube in the power head in conjunction with air bubbles to move silt, sand, and muck into the discharge line where the air bubbles and muck rise to the surface for collection in a floating porous container.
Once the floating container is filled with the muck and silt or sand, the container can be placed on the waterbottom at a desired location where the container prevents further silt from being disturbed, to line the waterbottom to prevent continued turbulence and collection of silt and muck on the bottom.
Using the present invention allows for continuous inlet maintenance, beach renourishment, structural reefs for enhancing aquatic growth, and for clearing channels without resorting to upstream relocation. A channel bottom can be lined with containers filled with silt and muck to enhance aquatic growth while at the same time reducing turbulence.
It is an object of this invention to provide an ecologically safe system for transferring silt and muck from waterbottoms.
It is another object of this invention to provide an apparatus that can safely transfer silt and muck from a waterbottom without damaging any living creatures on the bottom.
And yet still another object of this invention is to provide an improved ecologically safe system for removing silt and muck and to get rid of turbidity along a waterbottom in which the silt and muck can be collected in containers which are placed on the waterbottom for enhancing aquatic growth around them.
In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side elevational view, partially in cross section of the power head used in the present invention.
FIG. 2 shows a side elevational view, partially in cross section, of the leaking inverted cup valve used in the power head shown in FIG. 1.
FIG. 3 shows a cutaway view of a power head diagrammatic drawing for power direction and control with the present invention.
FIG. 4 shows a control valve used in the present invention.
FIG. 5 shows a side elevational view in cross section of the submersible system in accordance with the present invention.
FIG. 5A shows a side elevational view, partially in perspective, of the operation of the present invention.
FIG. 6 shows a perspective view of a reef that can be made with the present invention.
FIG. 7 shows a top view of continuous maintenance using the present invention.
FIG. 8 shows a side elevational view of the operation of the present invention using a wind generator supply.
FIGS. 9A-9D shows a sequential schematic side elevational view of the operation for shoal operations.
FIG. 10 shows a side elevational view of the present invention as used in a channel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The success of the present invention system and process for the non-destructive transfer of benthos is attributable to the efficient, economic performance of the invention of a submersible robotic power head which contains no moving parts or cutting edges or vanes to damage the benthos.
FIG. 1 illustrates the simplicity of the power head, the proper performance of which is based on the number and diameter of its air jets in relation to the outside circumference of the inlet nozzle and the spacing between the bottom of the inlet nozzle and the turbidity shroud. The diameter of the turbidity shroud in relation to the inlet nozzle is also important to the ability of the power head to maintain adequate negative pressure to contain turbidity.
In operation, air supplied to the air chamber bleeds through the air jets, creating a negative pressure differential inducing a rapid flow of water transferring muck and benthos up the discharge tube into a containment tube which, when filled, is floated to its predesignated position and lowered to the waterbottom.
The choice of type and power of the air supply, the diameter of the discharge tube, and the depth of the turbidity shroud determine the rate of solids transfer.
FIG. 2 illustrates the "leaking inverted cup valve" for raising and lowering the power head. Bleeding air into the inverted cup causes it to rise. Its top is designed as a valve which, when seated, closes off the air chamber which fills with air, causing the power head to rise. Cutting off the air supply to the inverted cup results in continued leaking of air through the dimensioned opening at the top of the cup which quickly allows it to drop, admit water to the air chamber and lower the shroud to the bottom (generally to a different location each time because of the torque of the connecting hose lines).
FIG. 3 discloses the directional control using four water jets sourced by a water pump on the control console. These water jets face about 30 degrees toward the center and 5 degrees down. The horizontal force component of the jets make the power head move smartly in the desired direction using the invention of a directional control valve, FIG. 4. For example, closing off three jets will cause the power head to "swim" in the direction opposite to the fourth jet. For simplicity, this valve allows single jet powered operation in four directions, with two jets contributing to direction control for each 90 degree quadrant. Two positions are provided for BACK or REVERSE to obviate the need to turn the valve 180 degrees. Two positions are also provided for the OFF position which diverts the water away from the four jets, as desired.
When the power head is on the waterbottom and the directional valve is in the ALL ON, DIG position, the four water jets create a vortex in the direction of the coriolis force, which increases solids throughput and prevents turbidity by drawing fine solids into a column below the inlet nozzle, and above the main silt column being forced up the discharge tube (by the pressure differential caused by the expanding air bubbles in the discharge tube).
FIGS. 5 and 5A show the interaction of the control console, dockside power water intake, tethered air and water line, power head with turbidity shroud, flotation and "Smartube."
FIG. 6 illustrates the use of this system for filing structural artificial reef tubes on the ocean floor, with some at substantial depths. Note that "reefers" may be filled inshore with muck and benthos, thereby enhancing their usefulness in accelerating the growth of plant and animal life on the artificial reef. Alternatively, "reefers" may be also filled and compacted with sand from the ocean floor.
"Coral Reefers" can incorporate fine copper wires in their construction for the low voltage electrolytic deposition of calcium carbonate on the surface of the reef tubes. This can also be accomplished by using metal powder filled fibers or metallized fibers.
It must be noted that artificial reefs are generally installed at depths greater than allowed for navigation channels and are designed and equipped differently to meet the special requirements of the greater depths.
FIG. 7 shows the system adapted for use in inlet maintenance using windpower as an alternative power source and semi-permanent but relocatable channel markers/sand collection stations. The system will operate continuously 24 hours daily whenever the power supply permits. As my "Smartubes" are filled, they are replaced and floated elsewhere depending on the market value of the contents.
FIG. 8 shows the system in use for both continuous beach renourishment as well as filling energy absorbing "Geltubes," used for upland capture of ocean sand for beach renourishment.
FIGS. 9A-9D shows my adaptation of my sand transfer invention as a "Shoalsucker" for emergency channel maintenance patrols by pontoon boats and small outboard and inboard sea craft used by the Coast Guard, Coast Guard Auxiliary, and specially authorized safety patrols.
The use of these units requires on board power of 30 amps at 230 volts (a small portable generator).
The sand transfer heads are normally locked and sealed in the UP or horizontal position and are lowered only in a shoaling emergency and at forward speeds less than 3 mph. Vanes on the power head will cause it to tilt off the bottom at high speed or if an obstruction is encountered. The "Shoaltubes" have limited capacity of two yards each but include flotation and marker buoys for off-channel stowage when filled. Tow lines are included for quick use when needed to transfer life threatening shoaling in navigation channels and dangerous inlets. Smaller and larger "Shoaltubes" will be available for professional use.
There are many other uses for the sand transfer system, each of which may require special mechanical adaption for use in aquaculture, collecting golf balls, industrial sludge, cleaning the bottoms of storage tanks, cleaning underground conduits, and so on.
The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.
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A method and apparatus for ecologically safely removing silt, muck, and sand from a waterbottom and for collecting the silt, muck, and sand without destroying the benthos therein into porous containers where the then contained mud and silt can be ecologically positioned where desired to enhance subaquatic environments. The apparatus includes a silt and mud collecting and transfer device that has no moving parts, thereby not endangering the benthos in the transfer process.
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BACKGROUND OF THE INVENTION
[0001] Oil and gas exploration, completion, and production operations often require the handling, transfer, and storage of large fluid volumes. Hydraulic fracturing techniques can require more than five million gallons of water per well. This large volume can be stored on site prior to and between fracturing operations, for storage, reuse and/or treatment and disposal. In addition, wells may produce large quantities of water during production. Due to environmental concerns, this water must be stored in a manner which will prevent contamination of the surrounding environment.
[0002] Often, large open pits are dug near the wells and used to store the water on or close to the well site. Environmental concerns are beginning to limit this practice. In addition to being unsightly, these pits can cause groundwater contamination, and are potential hazards to local livestock or wild animals long after drilling, completion, and production operations. Another option is the construction of steel tanks on site for storing fluid. The cost of construction, maintenance, and removal makes these options impractical in many cases.
[0003] As an alternative to pits and tanks, large fleets of tanker trucks, sometimes known as frac tanks have been employed to store fluid on a well site. Though these tanks can be redeployed from site to site recouping some of their cost more efficiently than built on site tanks, the enormous amount of resources necessary to move a fleet of tanks from site to site reduces the potential cost savings. Further, in environmentally sensitive areas, the movement of such large amounts of equipment may have serious consequences to roads and the local environment as well as create a disturbance to communities in which this equipment comes into contact.
[0004] A recent solution to the above problems has been the use of temporary tanks built on site for the storage of fluids. The problem with construction on site is that it can be costly and time consuming. A preferred method is to prepare a surface, erect a retaining wall of appropriate dimensions and then line the tank with a waterproof liner. The liner is heavy and difficult to install. Due to the thickness of the material used in the liner, it may take ten to twenty men and heavy equipment to maneuver the liner in place, and then lift the liner in small sections to secure it to the top of the wall.
[0005] Liners are large and bulky, and a full inspection can be extremely time consuming, if it can be accomplished at all. Due to the industrial environment and the large impact a small leak can have on the surroundings, it is often desirable to utilize more than one liner as a safety measure further increasing the effort and expense of erecting such a container. Liners are typically only used once and need to be disposed of after the tank is moved. This adds a significant cost to the storage operation and creates an additional waste stream. In the case that these tanks are used to store anything other than fresh water (such as produced or fracturing fluid flow back water), two or more liners are usually required, significantly increasing the overall cost of storage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates an inflatable liner in accordance with an exemplary embodiment of the invention.
[0007] FIG. 2 illustrates a cross section of a portion of a membrane lined structure in accordance with an exemplary embodiment of the invention.
[0008] FIGS. 3-5 show a component steps of erecting a membrane lined structure in accordance with an exemplary embodiment of the invention.
[0009] FIGS. 6-9 show a wall section in accordance with an exemplary embodiment of the invention.
[0010] FIG. 10 shows a structural retaining wall constructed from individual wall sections in accordance with an exemplary embodiment of the invention.
[0011] FIG. 11 shows an alternative structural retaining wall constructed from individual trailer rigs forming the wall sections in accordance with an exemplary embodiment of the invention.
[0012] FIG. 12 shows the use of straps secured to the base compartment in accordance with an exemplary embodiment of the invention.
[0013] FIG. 13 shows an alternative means of securing the wall compartments to the top edge of the structural retaining wall in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The oil and gas industry would be better served with fluid storage solutions which have the following attributes:
[0015] low manpower requirements for installation,
[0016] reusable components leading to cost reductions,
[0017] minimal environmental impact,
[0018] 100% liner contingency,
[0019] ability to test liner integrity,
[0020] ability to store
fresh water, produced water, fracturing fluid flowback water, drilling fluids and a combination of fluids.
[0026] Described herein is an alternative to the large bulky single or multiple liners of a built tank. The innovation described allows construction of a large holding tank or pit on site with multiple liners to significantly reduce the probability of leaks and a method to leak test the liner while allowing the complete system to be installed in less time and with less man power than that required with previous systems.
[0027] In one embodiment, a base is prepared as with previous systems. Such a base should be relatively flat and smooth so as not to create a puncture hazard for the liner and to be stable enough to support the weight of the tank when full. The preferred method is to grade and level the existing ground at the desired location, removing any large rocks, wood, or other materials which may puncture the liner. Optionally the base may be covered with a protective material such as, sand, earth, mulch, fabric, pads, or other materials which would be obvious to one skilled in the arts.
[0028] Next, the retaining wall is constructed around the perimeter of the tank. The retaining wall may be constructed of one or more sheet materials erected into a vertical wall fashion, joined at corners to form the desired shape, and optionally reinforced along the top edge and at various locations along the walls. One skilled in the arts would appreciate that a tank could be constructed in many configurations to accommodate the environment and surrounding structures with a plurality of sides and corners which may be right angles, or may be obtuse or acute angles. Further, a single side may be curved to avoid any angled corners. For ease of discussion the presumed shape described herein will be that of a rectangular tank and specifically a substantially square tank. One skilled in the arts would appreciate that a dug earthen pit could be used instead of above ground retaining walls.
[0029] In the preferred method utilized by the inventors, a plurality of blocks or panels are utilized to construct a wall around the perimeter of the desired tank. The blocks comprise a mating system which joins upper and lower blocks, and optionally horizontally adjacent blocks. In one embodiment the joining is accomplished by a tongue like protrusion along the top middle of the blocks which mates with a groove-like indention along the middle of the block's bottom side. In the preferred embodiment, the blocks have a plurality of additional grooves along the bottom side oriented perpendicular to the main groove and allowing for the interlocking of multiple blocks oriented perpendicular to one another to form a structurally reinforced corner of approximately ninety degrees (90°).
[0030] In one embodiment the blocks are hollow forms with capped openings in the bottom, or lower edge of one side, and at the top. The blocks are formed such that they have an inner compartment and an outer surface. The outer surface is structured as previously described, and the inner compartment may be filled with a weighted substance after positioning, giving the block, additional weight and inertia to prevent it from moving. The block may be filled with any flowable substance examples of which may include, but not be limited to water, sand, mud, drilling fluids.
[0031] The liner is constructed with a dual sheet membrane which is sealed around the edges to create an air pocket which is substantially rectangular in shape and the approximate size of the base of the tank or of one of the interior walls of the tank. The liner has vents which allow the liner to be inflated. One skilled in the arts would appreciate that other shapes are achievable in accordance with the teachings given here. Reinforcing strips throughout the interior space created by joining the edges of the dual membrane keep the liner in a semi-flat state such that the membranes remain in a substantially parallel arrangement rather than expanding out further in some area than in others. One skilled in the arts would appreciate that other configurations would be in accordance with the teaching such as multiple vertical compartments or multiple vertical compartments joined together to form a single larger compartment, either with individual inflation points, or a single shared inflation point.
[0032] The inflation of the liner helps to position it by allowing the force of the air to unfurl, unroll, or otherwise spread out the liner without the need of large amounts of man power or heavy equipment. In the preferred embodiment, the liner consist of a bottom compartment, and four side compartments, each of the side compartments being joined on the vertical edges with their neighboring wall compartments, and being joined on the lower horizontal edges with the edges of the bottom compartment to form a box like shape. In the preferred embodiment each of the bottom and the wall compartments has individual single inflation points and each of the compartments may be inflated and deflated separately.
[0033] The liner constructed as described above has the advantage that it can be aligned in the center of the tank's base prior to wall construction, or lowered over the wall after wall construction or lowered into an earthen pit. Inflating the bottom compartment causes it to spread over the base and positions the wall compartments, which are attached to the edges of the base, against the walls of the tank. Then by inflating the walls one at a time, the pressure causes them to erect themselves and support one another thus raising the liner to the upper edge of the tank's supporting walls. Once the liner's wall compartments are erected by air pressure it takes minimal man power to secure the top edge of the liner's walls to the tank's supporting walls.
[0034] The liner may then be maintained under pressure for a prescribed time to ensure there are no leaks, or to allow for the identification and repair of leaks. Once the integrity of the liner's membrane has been verified, the bottom compartment may be deflated prior to filling of the tank with fluid. The wall compartments may be deflated after securing them to the top of the supporting walls, or may be deflated slowly as the tank is filled with fluid. By deflating as the tank is filled, the air in the wall compartments will be forced up by the fluid's pressure further stretching the walls up the side of the tank.
[0035] Turning to the figures, FIG. 1 illustrates an inflatable liner in accordance with an exemplary embodiment of the invention. The liner ( 100 ) is shown in a folded configuration, as it would be configured for transport, or for placing prior to inflation during the structure's construction. Note that the actual configuration of the fold is not an element of this disclosure. The liner ( 100 ) as illustrated comprises a external membrane ( 110 ) lying substantially parallel to an inner membrane ( 130 ) both separated by a thicker structurally supporting internal membrane ( 120 ). In other embodiments, the inner and/or outer membrane may provide sufficient structural support such that an additional internal membrane may be unnecessary. In other embodiments additional internal membranes may be incorporated to provide additional structural support or additional layered protection against fluid penetration. The membranes are joined at regular intervals ( 150 ) to retain their substantially parallel arrangement during inflation. At least one edge of the membranes may comprise extension straps ( 140 ) for securing the liner to the upper edge of the supporting wall of the structure. In the illustrated embodiment, the supporting straps are a plurality of non-contiguous supporting members configured as tabs structurally attached to the inner membrane. In another embodiment, the supporting element may be a plurality of contiguous, or they may be a single tab extending the length of the supported edge. In other embodiments the supporting member(s) may be secured to a plurality of the membranes comprising the edge of the liner.
[0036] FIG. 2 illustrates a cross section of a portion of a membrane lined structure in accordance with an exemplary embodiment of the invention. The illustration ( 200 ) shows an embodiment with a dual membrane ( 110 ′ and 130 ′) creating a wall compartment ( 205 ) which is installed in a lower corner where a structural wall section ( 220 ) meets the base ( 210 ) of the structure. The inner membrane ( 130 ′) is joined to the outer membrane ( 110 ′) by a series of connections ( 150 ) and/or by strips ( 260 ) which may optionally contain voids ( 265 ) which allow air to flow freely between compartments. In this illustration, the wall compartment ( 205 ) is inflated, but the base compartment ( 270 ) is shown deflated.
[0037] FIGS. 3-5 show the steps of erecting a membrane lined structure in accordance with an exemplary embodiment of the invention. In FIG. 3 , the structure ( 300 ) comprises a structural supporting wall ( 310 ) which optionally is reinforced at the top ( 320 ) and other locations (not illustrated), and an inflatable liner ( 100 ). The liner ( 100 ) is placed inside the structural supporting wall ( 310 ) either before or after construction. The base compartment ( 330 ) is inflated forcing the wall compartments ( 340 ) into the corners where the wall's ( 310 ) interior surfaces ( 350 ) meet the base. FIG. 4 illustrates the process as the wall compartments ( 340 ) are inflated causing them to rise from the bottom compartment ( 330 ) to meet the wall ( 310 ) such that the top of the wall compartments ( 340 ) are near the reinforced top ( 320 ) of the structural wall ( 310 ). Next, FIG. 5 shows the extension straps ( 140 ) securing the upper edge of the wall section ( 340 ) to the upper edge of the supporting wall ( 310 ) completing the lining of the structure ( 300 ). One skilled in the art would appreciate that the extension straps ( 140 ) may comprise an extension of the fabric which folds over the top and is secured by clamps, clips, binders, or simply friction. Further, the extensions straps may be loops, or tabs with holes or eyelets, or other means of securing them to the top of the supporting wall which may include hooks, connection points, etc. as would be appreciated by one skilled in the arts.
[0038] FIGS. 6-9 show a wall section in accordance with an exemplary embodiment of the invention. FIG. 6 illustrates the block in perspective view. FIG. 7 is a side view of the block ( 600 ). FIG. 8 is an end view of the block ( 600 ). FIG. 9 is a bottom view of the block ( 600 ). The wall section ( 600 ) or block is comprised of a hollow main body structure ( 610 ) which has a tongue ( 620 ) along the center of the top and running length wise along the center from end to end. Corresponding to the tongue ( 620 ) is a center groove ( 630 ) along the center of the bottom and running length wise along the center from end to end. The tongue and groove are positioned such that they mate when one block is stacked atop another the block then being interconnected such that they may only slide in a single horizontal direction perpendicular to the structural face of the wall. The block ( 600 ) further comprises additional short grooves ( 640 ) running perpendicular to the center groove ( 630 ) from side to side. Ideally the block would have a rectangular shape with the length of sides being longer than the length of the ends. These grooves mate with the tongue of a second block positioned perpendicular to the face of the first block to form an angled locking interface. The block further comprises a resealable opening ( 650 ) in the top of the block ( 600 ) illustrated herein as being in the tongue ( 620 ). This opening is utilized to fill the block adding mass which further secures the block in place. The block also comprises a resealable opening ( 670 ) in the bottom of the block, or the lower edge of a wall of the block's main body structure ( 610 ). Optionally the resealable openings ( 650 and 670 ) are recessed such that they do not substantially interfere with the stacking of the blocks or the relative smoothness of the walls face.
[0039] FIG. 10 shows a structural retaining wall constructed from individual wall sections in accordance with an exemplary embodiment of the invention. Here the structure ( 800 ) comprises three rows (A, B, C) of individual blocks ( 600 ). The blocks ( 600 ) are stacked in a stretcher bond or running bond. Here, the interlocking of the tongue to the short groove is shown at the corners.
[0040] FIG. 11 shows an alternative structural retaining wall constructed from individual trailer rigs forming the wall sections in accordance with an exemplary embodiment of the invention. Here the structural wall ( 350 ′) is comprised of a plurality of trailer rigs ( 900 ). The structural wall ( 350 ′) support the wall compartments ( 340 ) which encircle and are joined to the floor or base compartment ( 330 ) to form a membrane lined storage structure. The wheel assemblies ( 910 ) of the trailers ( 900 ) are protected by optional fill plates ( 920 ) which prevent the liner's wall compartments ( 340 ) from being compromised by the wheel assemblies ( 910 ) or unsupported in the localized area. In addition to providing the structural wall ( 350 ′) the trailer rigs ( 900 ) may also be utilized as storage containers. In such a use, one would then have extra capacity, or a plurality of isolated storage containers for segmentation of liquids and/or semi-liquids.
[0041] FIG. 12 shows the use of straps secured to the base compartment in accordance with an exemplary embodiment of the invention. The straps ( 700 ) are secured to the underside of the base compartment ( 330 ) and extend outward under the structural walls ( 310 ) and are secured at some point to the structural walls ( 310 ). Thus secured, adjustable connections ( 710 ) allow the tightening or loosening of straps to shift the base compartment ( 330 ) in the direction of the tightening strap ( 700 ). Tightening straps ( 700 ) on opposing sides would not allow shifting of the base compartment ( 330 ) but instead would serve to support the structural walls ( 310 ) from moving outward. Once the base compartment is aligned within the structural walls ( 310 ) the wall compartments ( 340 ) can be raised and secured to the top edge ( 320 ) of the structural walls ( 310 ), thus completing the erection of the membrane lined storage structure ( 300 ).
[0042] FIG. 13 shows an alternative means of securing the wall compartments to the top edge of the structural retaining wall in accordance with an exemplary embodiment of the invention. In this embodiment the walls ( 310 ) of the storage structure ( 300 ) and the liner ( 330 ) are secured by a C-shaped channel ( 140 ′) which extends along the top edge of the structural supporting walls ( 310 ) and folds over the top edge both on the inner side of the wall compartments ( 340 , not indicated), and on the outer edge of the structural supporting wall ( 310 ). Eliminating openings between the wall ( 310 ) and the liner ( 330 ) prevents wind to penetrate under the liner raising it out of the storage structure ( 300 ).
[0043] The diagrams in accordance with exemplary embodiments of the present invention are provided as examples and should not be construed to limit other embodiments within the scope of the invention. Illustrations of the components within different figures can be added to or exchanged with other components in other figures. Further, specific numerical data values (such as specific quantities, numbers, categories, etc.) or other specific information should be interpreted as illustrative for discussing exemplary embodiments. Such specific information is not provided to limit the invention. As an example FIG. 10 illustrates three rows of blocks, but one skilled in the art would appreciate that more or less blocks could comprise a structural supporting wall and still be within the scope of the invention described. Further, the structural supporting walls have been illustrated to have a substantially square foot-print. One skilled in the art would appreciate that the shape of the invention may be rectangular, triangular, cylindrical, or even an irregular shape. The limiting factors are that the supporting wall structure be approximately the size of the outside dimension of the liner, or less in order to provide proper wall support. Ideally the shape of the structural supporting wall would be substantially associated with the shape of the liner, but not necessarily provided inflation, support and securing of the liner could be accomplished.
[0044] The diagrams in accordance with exemplary embodiments of the present invention are intended to illustrate an embodiment if the invention, not necessarily the only embodiment, and are provided as examples which should not be construed to limit other embodiments within the scope of the invention. For instance, heights, widths, and thicknesses may not be to scale and should not be construed to limit the invention to the particular proportions illustrated. Additionally some elements illustrated in the singularity may actually be implemented in a plurality. Further, some element illustrated in the plurality could actually vary in count. Further, some elements illustrated in one form could actually vary in detail. Further yet, specific numerical data values (such as specific quantities, numbers, categories, etc.) or other specific information should be interpreted as illustrative for discussing exemplary embodiments. Such specific information is not provided to limit the invention.
[0045] The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.
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A membrane lined structure for storing large fluid volumes comprising a base surrounding by supporting wall structures, and lined with a double membrane sealed at the edges and formed into a plurality of cellular components which can be inflated and deflated to assist in positioning for purposes of constructing the structure and securing the liner to the upper edges of the structural walls. The cellular membranes can further be monitored to ensure the integrity of the membrane liner prior to filling of the structure or during regular operations.
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BACKGROUND OF THE INVENTION
The present invention relates to a sheath for protection of a pipe against impacts, in particular for fuel pipes.
The present invention applies generally to the protection of pipes for circulating fuel in automobile vehicles.
Fuel pipes are generally made of plastic and are fragile with regard to impacts. In particular, in the event of an accident to the vehicle, a part hitting a plastic fuel pipe risks piercing the pipe, thereby causing a fire due to the leakage of fuel.
In order to damp impacts on a fuel pipe, there exist rubber sleeves intended to cover the pipe. However, such rubber sleeves are difficult to slide over the plastic pipes.
There also exist plastic ducts conformed specifically to the shape of the fuel pipes to be protected. Such ducts are costly to fabricate, however, and must be specific to each application.
An object of the present invention is to propose a new impact protection sheath that removes the drawbacks cited above.
SUMMARY OF THE INVENTION
To this end, the present invention is directed to a sheath for protection of a pipe against impacts, in particular for fuel pipes, consisting of a tubular knitted structure with two faces, a jersey-knit first face and a molleton second face.
Thus a flexible tubular knitted structure that is simple to fabricate and to fit over fuel pipes of different diameters is provided. The tubular knitted structure adapts to different conformations of fuel pipes and may be positioned easily.
The jersey-knit face retains the knitted structure and provides mechanical strength and shear resistance in the protection sheath.
The molleton second face ensures damping of impacts thanks to the expanded structure of this second face.
In practice, the first face constitutes an external face of the protection sheath and the second face constitutes an internal face intended to come into contact with the pipe.
According to an advantageous feature of the invention, the second face consists of multifilaments with a linear density greater than or equal to 1 200 decitex and preferably greater than 2 000 decitex.
The use of a heavy yarn to produce the molleton face of the sheath ensures very good damping of impacts and prevents piercing of the fuel pipe covered in this way by the impact protection sheath.
To improve further the expanded structure of the molleton face, this second face consists of textured polymer multifilaments.
This impact protection sheath is preferably produced by circular knitting, thus enabling an economical textile process to be used for the production of the impact protection sheath conforming to the invention.
Other features and advantages of the invention will become further apparent in the course of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings, provided by way of nonlimiting example:
FIG. 1 is a perspective view of an impact protection sheath conforming to one embodiment of the invention;
FIG. 2 is a view of the impact protection sheath from FIG. 1 in partial section; and
FIGS. 3 to 5 are diagrams showing different types of knitted structure used to constitute an impact protection sheath conforming to one embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A sheath conforming to the invention for protection of a pipe against impacts will be described first with reference to FIGS. 1 and 2 .
This impact protection sheath is intended to protect plastic pipes, and especially to protect fuel pipes used in automobile vehicles to prevent piercing of the pipe and leakage of fuel, in particular in the event of an accident to the automobile vehicle.
As clearly shown in FIG. 1 , the impact protection sheath 10 consists of a tubular knitted structure with two faces, a jersey-knit first face 11 and a molleton second face 12 .
This type of knitted sheath can be produced by a circular knitting process enabling a closed tubular sheath with two faces to be knitted directly using the molleton technique.
In this embodiment, the jersey-knit first face 11 constitutes the external face of the protection sheath 10 and the second face 12 constitutes the internal face, intended to come into contact with the fuel pipe when the protection sheath is slid over such a pipe.
In this embodiment, the jersey-knit first face 11 and the molleton second face 12 are produced using a yarn of the same kind, for example polymer multifilaments, such as polyester or polyamide multifilaments.
Of course, different yarns could be used to produce the external face 11 and the internal face 12 .
In particular, the jersey-knit first face 11 could be produced entirely from a monofilament or by combining a monofilament and multifilaments of types different from those used to achieve the expansion of the molleton second face 12 .
The multifilaments used for the second face 12 are preferably sufficiently heavy to enable a thick internal face 12 capable of damping impacts to be obtained.
For example, the multifilaments used have a linear density greater than 2 000 decitex (2 000 g per 10 000 m of yarn).
Of course, other types of multifilaments may be used, provided that they have sufficient linear density, preferably greater than 1 200 decitex, or even 1 500 decitex.
Moreover, textured polymer multifilaments are preferably used to ensure expansion of the molleton second face 12 .
In the conventional way, textured multifilaments may be used in accordance with the false twist (FT) process or the fixed false twist (FFT) process.
Of course, other texturizing processes could be used for the multifilaments employed in the impact protection sheath conforming to the present invention.
Thanks to circular knitting using a molleton technique, the second face of the protection sheath 10 consists of multifilament floats 12 a.
The length of the floats 12 a corresponds to a length of the tubular knitted structure from 3 to 10 needles, and preferably from 4 to 6 needles.
FIG. 3 shows by way of example the production of a float in a knitted structure.
In this diagram, the length of the float 12 a is equal to three needles, corresponding to three stitches of the jersey-knit first face.
The number of floats 12 a in a cross section of the tubular knitted structure is preferably from three to six.
In the embodiment shown in FIG. 1 , the number of floats 12 a in the cross section is equal to four.
As shown clearly in FIGS. 1 and 2 , in this embodiment the floats 12 a are woven into longitudinally aligned stitches of the jersey-knit first face 11 , i.e. interwoven with the same warp filament.
FIG. 4 shows an example of knitting for producing a molleton with floats 12 a interlaced regularly with the jersey-knit structure 11 .
Of course, other types of knitting enabling a molleton technique to be employed may be used, and in particular, as shown in FIG. 5 , a knitting technique in which the interlacing of the molleton filament is offset by one needle in each row (this technique is known as diamond molleton). The floats are then woven in a diamond configuration, the interlacing of the molleton filament being offset by one warp filament in each row.
Thanks to the molleton knitted structure, the filament constituting the internal face 12 of the sheath 10 is fixed to the external face 11 , but not interlaced, so that the fibers may expand freely and thereby produce a heavy and thick layer for damping impacts on the sheath 10 .
The molleton face provides sufficient damping with regard to impact. The Applicant has thus noted that the presence of such an impact protection sheath on a plastic pipe doubles the intrinsic impact resistance of this plastic pipe.
Moreover, the jersey-knit external structure retains the sheath and provides overall mechanical strength, in particular with regard to abrasion.
It will be noted in particular that for automotive applications such a sheath may be impregnated with a fire treatment product to improve the fire resistance of the sheath.
There is obtained in this way a textile sheath that is simple to fabricate by a circular knitting process and simple to fit to a fuel pipe, as much in terms of diameter as in terms of length.
In particular, the diameter of such an impact protection sheath 10 may be from five to twelve millimeters and preferably equal to eight or ten millimeters.
In order to stabilize the diameter of the impact protection sheath after it is knitted, it is possible to apply heat treatment to the protection sheath. Heating the sheath causes slight shrinkage of the polymer used in the knitted structure, to stabilize the diameter of the protection sheath 10 .
In practice, fitting such a sheath is simple. Thanks to its flexible structure, it may be threaded onto a fuel pipe and positioned at any location, espousing perfectly the curves of the pipe.
It may preferably be cut to the required length by hot cutting. Hot cutting cauterizes the end of the protection sheath and thus avoids all risk of pollution by dust or filament debris during fitting.
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A sheath for protecting a hose, particularly a fuel conduit, against shocks consists of a knitted tubular structure ( 10 ) with two faces, a first face ( 11 ) being made in the form of jersey and a second face ( 12 ) being made in the form of cotton fleece.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/892,524 filed Jul. 15, 2004, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates to oil and gas well production technology. More particularly, it relates to the in situ treatment of fluids produced by an artificial lift oil well to inhibit the formation of scale inside and outside of production tubing, pumps, valves, and the like and to reduce the amount of solids that enter the pump.
[0004] 2. Description of the Related Art
[0005] A typical oil well produces not only oil, but also gas and water, often in significant quantity. The fluids often transport solids, such as sand, as well as other potentially damaging fluids and gases, from the reservoir into the production tubing and casing, and up the production tubing to the surface. Equipment on the surface may be used to separate these production components. The oil is recovered; the gas, depending on its composition, may be filtered, treated and piped to a collection facility or flared off; the water may be re-injected into another formation or, in the case of offshore production platforms, treated to prevent environmental contamination and then discharged overboard; and the solids are separated and disposed of.
[0006] The oil and water produced by oil and gas wells often contains significant quantities of dissolved minerals. Frequently, the water is saturated with these minerals—i.e., the water contains the maximum concentration of the dissolved minerals possible at a given temperature and pressure. Changes in temperature and/or pressure which occur as the fluid is pumped from the production zone through the well to the treatment equipment on the surface can cause the minerals to come out of solution (“precipitate”) and become deposited on the interior and exterior surfaces of the production tubing, pumps, valves, chokes and other equipment. The deposit is known as “scale” and it can significantly reduce the diameter and hence the capacity of production tubing. In extreme cases, the pipe or tubing can become completely obstructed, shutting down production. Even in less severe cases, where the fluid is not saturated, scale can build up on the interior and exterior of any exposed surface.
[0007] Certain dissolved minerals in water are known as “hardness ions” —divalent cations that include calcium (Ca +2 ), magnesium (Mg +2 ) and ferrous (Fe +1 ) ions. Hardness ions develop from dissolved minerals, bicarbonate, carbonate, sulfate and chloride. Heating water containing bicarbonate salts can cause the precipitation of a calcium carbonate solid. Raising the pH can allow the Mg +2 and Fe +2 ions to precipitate as Fe(OH) 2 and Mg(OH) 2 . Excess sodium carbonate can precipitate Ca +2 as CaCO 3 .
[0008] Precipitation is the formation of an insoluble material in a solution. Precipitation may occur by a chemical reaction of two or more ions in solution or by changing the temperature of a saturated solution. There are many examples of this important phenomenon in drilling fluids. Precipitation occurs in the reaction between calcium cations and carbonate anions to form insoluble calcium carbonate: Ca+2+CO3−2→CaCO3.
[0009] Scale is a mineral salt deposit or coating formed on the surface of metal, rock or other material. Scale may be caused by a precipitation resulting from a chemical reaction with the surface on which it forms, precipitation caused by chemical reactions, a change in pressure or temperature, or a change in the composition of a solution. The term “scale” is also applied to a corrosion product. Typical scales are calcium carbonate, calcium sulfate, barium sulfate, strontium sulfate, iron sulfide, iron oxides, iron carbonate, the various silicates and phosphates and oxides, or any of a number of compounds insoluble or slightly soluble in water.
[0010] Scale may be deposited on wellbore tubulars, down hole equipment, and related components as the saturation of produced water is affected by changing temperature and pressure conditions in the production conduit. In severe conditions, scale creates a significant restriction, or even a plug, in the production tubing. Scale build-up in the artificial lift pump can lead to failure of the pump due to blocked flow passages and broken shafts. Scale removal is a common well-intervention operation. A wide range of mechanical, chemical and scale inhibitor treatment options are available to effect scale removal.
[0011] Scale can also occur in tubing, the gravel pack, the perforations or the formation itself. Scale deposition occurs when the solution equilibrium of the water is disturbed by pressure and temperature changes, dissolved gases or incompatibility between mixing waters. Scale deposits are the most common and most troublesome damage problems in the oil field and can occur in both production and injection wells.
[0012] All waters used in well operations can be potential sources of scale, including water used in waterflood operations and filtrate from completion, workover or treating fluids. Therefore, reduction of scale deposition is directly related to reducing the amount of bad water that is produced.
[0013] Carbonate scale is usually granular and sometimes very porous. A carbonate scale can be easily identified by dropping it in a solution of hydrochloric acid where bubbles of carbon dioxide will be observed effervescing from the surface of the scale. Sulphate scales are harder and more dense. A sulphate deposit is brittle and does not effervesce when dropped in acid. Silica scales resemble porcelain—they are very brittle, not soluble in acid, but dissolve slowly in alkali.
[0014] Scale removal is a common well-intervention operation involving a wide variety of mechanical scale-inhibitor treatments and chemical options. Mechanical removal may be done by means of a pig or by abrasive jetting that cuts scale but leaves the tubing intact. Scale-inhibition treatments involve squeezing a chemical inhibitor into a water-producing zone for subsequent commingling with produced fluids, preventing further scale precipitation. Chemical removal is performed with different solvents according to the type of scale:
Carbonate scales such as calcium carbonate or calcite [CaCO 3 ] can be readily dissolved with hydrochloric acid [HCl] at temperatures less than 250° F. [121° C.]. Sulfate scales such as gypsum [CaSO 4 .2H 2 O] or anhydrite [CaSO 4 ] can be readily dissolved using ethylenediamine tetraacetic acid (EDTA). The dissolution of barytine [BaSO 4 ] or strontianite [SrSO 4 ] is much more difficult. Chloride scales such as sodium chloride [NaCl] are easily dissolved with fresh water or weak acidic solutions, including HCl or acetic acid. Iron scales such as iron sulfide [FeS] or iron oxide [Fe 2 O 3 ] can be dissolved using HCl with sequestering or reducing agents to avoid precipitation of by-products, for example iron hydroxides and elemental sulfur. Silica scales such as crystallized deposits of chalcedony or amorphous opal normally associated with steamflood projects can be dissolved with hydrofluoric acid [HF].
[0020] Calcium scales such as calcium sulfate, calcium carbonate and calcium oxalate are insoluble in water. However, all three are soluble in a Sodium Bisulfate acid solution. Calcium scale can be removed with an acid wash using a 5-15% solution of Sodium Bisulfate (SBS). SBS can also be used during a shut down to remove scale by re-circulating it throughout areas of the process where needed. The concentration of SBS solutions and the re-circulation time depend on the amount of scale that needs to be removed. SBS can be a substitute for sulfamic acid in calcium scale removal situations.
[0021] Zinc sulfide (ZnS) is another one of the oil field scales that plagues production. Although it does not seem to be common, according to field experience and published literature, it causes a significant flow/production problem when it does occur, just as all other scales adversely affect wells. Other scales, such as barium sulfate and strontium sulfate, also cause production problems but are much harder than ZnS.
[0022] Although chemical solvents have been used on these harder scales, the results are often disappointing. While mechanical scale removal has been used successfully on barium and strontium sulfate scales with excellent success, it had not been used on ZnS scale. It was conceivable that the softer scale may not respond to the same process that removed harder scales.
[0023] In certain cases, scale may be an environmental or health hazard. The State of Louisiana, Department of Environmental Quality has issued a notification concerning a potential health hazard associated with handling pipe used in oil and gas production that may be contaminated with radioactive scale from naturally-occurring radioactive materials (NORM). The concern is the possible inhalation and/or ingestion of scale particles contaminated with radium-226 and possibly other radioactive material that may become airborne during welding, cutting or reaming pipe that contains radioactive scale. The State of Louisiana is using the term Technologically Enhanced Natural Radiation (TENR) for this material that is a subset of the NORM group.
[0024] An inhibitor is a chemical agent added to a fluid system to retard or prevent an undesirable reaction that occurs within the fluid or with the materials present in the surrounding environment. A range of inhibitors is commonly used in the production and servicing of oil and gas wells, such as corrosion inhibitors used in acidizing treatments to prevent damage to wellbore components and inhibitors used during production to control the effect of hydrogen sulfide [H 2 S]
[0025] A scale inhibitor is a chemical agent added to a fluid system to retard or prevent an undesirable reaction that occurs within the fluid or with the materials present in the surrounding environment. A range of inhibitors is commonly used in the production and servicing of oil and gas wells, such as corrosion inhibitors used in acidizing treatments to prevent damage to wellbore components and inhibitors used during production to control the effect of hydrogen sulfide [H 2 S]
[0026] A sequestering agent (or chelation agent) is a chemical whose molecular structure can envelop and hold a certain type of ion in a stable and soluble complex. Divalent cations, such as hardness ions, form stable and soluble complex structures with several types of sequestering chemicals. When held inside the complex, the ions have a limited ability to react with other ions, clays or polymers. Ethylenediamine tetraacetic acid (EDTA) is a well-known sequestering agent for the hardness ions, such as Ca +2 , and is the reagent solution used in the hardness test protocol published by API. Polyphosphates can also sequester hardness ions. Sequestering is not the same as precipitation because sequestering does not form a solid. For calcium carbonate deposits, glycolic and citric acids and ammonium salts and blends incorporating EDTA are used as chelants.
[0027] A scale-inhibitor squeeze is a type of inhibition treatment used to control or prevent scale deposition. In a scale-inhibitor squeeze, the inhibitor is pumped into a water-producing zone. The inhibitor is attached to the formation matrix by chemical adsorption or by temperature-activated precipitation and returns with the produced fluid at sufficiently high concentrations to avoid scale precipitation. Some chemicals used in scale-inhibitor squeezes are phosphonated carboxylic acids or various polymers.
[0028] Some scale-inhibitor systems integrate scale inhibitors and fracture treatments into one step, which guarantees that the entire well is treated with scale inhibitor. In this type of treatment, a high-efficiency scale inhibitor is pumped into the matrix surrounding the fracture face during leakoff. It adsorbs to the matrix during pumping until the fracture begins to produce water. As water passes through the inhibitor-adsorbed zone, it dissolves sufficient inhibitor to prevent scale deposition. The inhibitor is better placed than in a conventional scale-inhibitor squeeze, which reduces the re-treatment cost and improves production.
[0029] Some well treatment systems continuously inject the treating chemical in the well using a metering pump. The chemicals are either injected below the pump using a capillary line or injected into the well annulus. When chemicals are injected into the well annulus the chemicals build up in the well bore until the pump pulls them down the wellbore and into the pump intake.
[0030] Due to the time that it takes for the chemicals to reach the pump, changes in chemical mix or injection rates are very slow to affect the fluids entering the pump. If the pump intake is above the electric motor in an Electric Submersible Pump, ESP installation, the chemicals do not protect the motor or the casing below the pump intake.
[0031] In capillary injection systems, the location of the chemical injection can be determined when the system is installed by terminating the capillary tube below the pump intake/motor combination in an ESP completion. The capillary injection tube provides continuous treatment of the fluids and the time delay for adjustments to the blend of chemicals and/or treatment rate can be minimized.
[0032] Sand produced with the fluids can cause damage to pumping systems. Abrasion resistant pumps with engineered ceramic bearings and coated flow passages have been developed to improve pump life in wells that produce sand, but sand will eventually wear out even these special sand-tolerant pumps.
[0033] One practice for removing sand from the fluid is by installing a liquid and sand separator between the casing perforations and the pump intake. These systems deposit the separated sand into the well's rat hole or into tubing hung from the bottom of the separator as a trap. Wilson discloses a means for removal of sand separated with a downhole sand separator in U.S. Pat. No. 6,216,788.
[0034] Gravel packing is a sand-control method used to prevent the production of formation sand. It involves the placement of selected gravel across the production interval to prevent the production of formation fines or sand. Any gap or interruption in the pack coverage may permit undesirable sand or fines to enter the producing system.
[0035] In gravel pack operations, a steel screen is placed in the wellbore and the surrounding annulus is then packed with prepared gravel of a specific size that is designed to prevent the passage of formation sand. The primary objective is to stabilize the formation while causing minimal impairment to well productivity.
[0036] Wire-wrapped screen is one type of screen used in sand control applications to support the gravel pack. The profiled wire is wrapped and welded in place on a perforated liner. Wire-wrapped screen is available in a range of sizes and specifications, including outside diameter, material type and the geometry and dimension of the screen slots. The space between each wire wrap must be small enough to retain the gravel placed behind the screen, yet minimize any restriction of production.
[0037] A sand filter as described by Stanley in U.S. Pat. No. 4,977,958 is used to filter the sand out of the fluid prior to entering the pump intake. This style of intake filter has been installed in numerous wells and is effective for removal of solids, but once the filter is full of sand, fluid flow through the filter is restricted and a large pressure drop occurs. As the pressure drop increases, the rate of sand accumulation increases causing the rate of pressure drop to increase until eventually the fluid flow across the filter ceases. When fluid flow to the pump ceases, the pump will cavitate and eventually fail.
SUMMARY OF THE INVENTION
[0038] A fluid conditioning system is installed between the well perforations and the intake of a pump used to effect artificial lift. The fluid conditioning system is an apparatus that provides scale inhibitors and/or other chemical treatments into the production stream. The production stream may also be filtered by the apparatus prior to the production stream's introduction into the pump. In some embodiments, the fluid conditioning system may be a part of the production stream filter wherein the filtering material is comprised of a porous medium that contains and supports the treatment chemical. In other embodiments, the chemical treatment may be accomplished by the gradual dissolution of the unsupported solid phase chemical itself. The treating chemical may be recharged or replenished by various downhole reservoirs or feeding means. In yet other embodiments, the chemical treatment may be replenished from the surface by means of a capillary tube. In certain other embodiments, the apparatus may be retrievable from the surface by means of a wireline or coil tubing thereby permitting recharge or replenishment of the chemical in the apparatus on an as-needed or periodic basis. The filtration apparatus may incorporate a by-pass valve that allows fluid to by-pass the filter as sand or other particulate matter fills up or blocks the filter.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0039] FIG. 1 is a cross-sectional view of an artificial lift pump equipped with an intake screen having a single-layer treatment space.
[0040] FIG. 2 is a typical flow curve for a by-pass valve.
[0041] FIG. 3 is a cross-sectional view of an artificial lift pump equipped with an intake screen having at least two annular treatment spaces.
[0042] FIG. 4 depicts the apparatus of FIG. 3 additionally equipped with a packer, shear sub and cross-over sub.
[0043] FIG. 5 is a cross-sectional view of the intake screen portion of the apparatus shown in FIG. 4 taken along line V-V.
[0044] FIG. 6 is a cross-sectional view of an artificial lift pump equipped with a multiple layer intake screen having capillary tube recharge means.
[0045] FIG. 7 is an alternative embodiment of the apparatus shown in FIG. 6 which includes means for distributed recharge of the treatment chemicals.
[0046] FIG. 8 is a cross-sectional view of an artificial lift pump equipped with a dual-layer intake screen equipped with a downhole replenishment means for solid-phase chemicals.
[0047] FIG. 9 is an alternative embodiment of the apparatus shown in FIG. 8 which has means downhole replenishment of both solid-phase and liquid-phase chemicals.
[0048] FIG. 10 is a cross-sectional view of an artificial lift pump that has a dual-layer intake screen equipped with a downhole replenishment means for liquid-phase chemicals.
[0049] FIG. 11 is a cross-sectional view of an alternative embodiment of the apparatus shown in FIG. 10 .
[0050] FIGS. 12A and 12B are cross-sectional views of production tubing having capillary tubing incorporated within their wall structure.
[0051] FIG. 13 is a cross-sectional view of an artificial lift pump equipped with a wireline (or slickline) retrievable, chemical treatment intake screen.
[0052] FIG. 14 is an alternative embodiment of the apparatus shown in FIG. 13 that further comprises an extension of the shroud around the pump and intake sections.
[0053] FIG. 15 is a cross-sectional view of a shaft-driven artificial lift pump equipped with a chemical treatment intake screen situated between the pump and its driving motor.
[0054] FIG. 16 is a cross-sectional view of an alternative embodiment of the apparatus of FIG. 15 wherein the screen is located within the interior portion of the intake filter.
DETAILED DESCRIPTION OF THE INVENTION
[0055] Advances in electric motor technology have made Electric Submersible Pumps (ESPs) an increasingly popular method of providing artificial lift for oil wells. Operating in the harsh conditions of the downhole environment, an ESP must be protected from ingesting corrosive, abrasive, or any other detrimental substance in the production fluids in order to provide a Mean Time Between Failure (MTBF) that justifies its use on an economic basis. In addition, treating the production fluids while downhole minimizes the potential hazards involved in bringing the production fluids to the surface while the production fluids may contain any detrimental substance. Moreover, scale build-up in production tubing and pump chambers must also be controlled in order to decrease the number of well interventions or workovers needed during the useful life of an oil well.
[0056] The present invention is a novel apparatus and method which combines the functions of preventing fines or sand from entering the pump with the introduction of a scale inhibitor or other chemical treatments into the production stream prior to entering the pump. In an alternative embodiment the production stream may be treated for environmental hazards after entering the pump.
[0057] Referring now to FIG. 1 , artificial lift system 10 includes pump 100 attached at its outlet end to production tubing 12 and at its inlet to inlet connector 14 which is in fluid communication with filter assembly 16 . Filter assembly 16 is preferably designed such that wellbore fluid will pass from the exterior 21 of external tubular 22 through external tubular 22 through any medium 30 through internal tubular 24 and into the central passage 28 of internal tubular 24 . Artificial lift system 10 may be generally circular in cross section and sized to fit within the production casing of a well [not shown ]. In some embodiments, pump 100 may be an ESP that receives electrical power from the surface via an electrical cable within the well bore [not shown].
[0058] Filter assembly 16 comprises top plate 18 and bottom plate 20 . Top plate 18 allows internal tubular 24 to pass through its center portion and may be joined to inlet connector 14 in a fluid tight manner. Top plate 18 and bottom plate 20 are connected by an external tubular 22 and by an internal tubular 24 . The external tubular 22 may be a screen or other type of porous structure that allows a desired wellbore fluid to pass from one side of the tubular to the other while restraining the passage of undesired wellbore fluids or solids. The internal tubular 24 may be a screen or other type of porous structure that allows a desired wellbore fluid to pass from one side of the tubular to the other while restraining the passage of undesired wellbore fluids or solids. Together, external tubular 22 and internal tubular 24 define annular space 32 which may be used to contain medium 30 [partially shown in FIG. 1 for clarity].
[0059] Should the filter assembly 16 become at least partially clogged with solid or other matter that may be present in the wellbore such that wellbore fluid can no longer pass through the filter assembly 16 and reach the artificial lift system 10 then the artificial lift system 10 may be severely damaged. Such damage may result from such causes as pump cavitation. In cases where the wellbore fluid is used to cool the artificial lift system's motor, a partially clogged filter assembly may reduce the flow of cooling wellbore fluid to the extent that motor overheating may also occur. In order to prevent such damage to the artificial lift system, a by-pass valve 132 may be installed. Typically, although not always, the bottom plate 20 may have an opening through its center that allows fluid to pass directly from the well-bore into the central passage 28 of the internal tubular 24 . A by-pass valve 132 is located in the opening through the bottom plate 20 . The by-pass valve 132 may be a ball valve, a spring-loaded valve, a poppet valve, a shear assembly, rupture disc, or any other type of valve that may be activated to relieve differential pressure. In some embodiments when the pressure drop across the screen equals the by-pass setting, the by-pass valve 132 partially opens and wellbore fluid is allowed to by-pass the filter assembly 16 . As fluid by-passes the filter assembly 16 , the flow rate through the filter is reduced; thus, the pressure drop is reduced for the matter-packed filter. With the by-pass valve 132 partially open, a portion of the wellbore fluid flows into the central passage 28 through the filter assembly and a portion flows into the central passage 28 through the by-pass valve 132 . The proportions of wellbore fluid that pass through the filter assembly 16 and the by-pass valve 132 can be represented by Q (total flow)=Qf (flow through filter assembly)+Qb (by-pass flow). As time passes, Qf will be reduced as more wellbore matter packs into the filter assembly 16 and the P (pressure) drop increases for a given flow rate thus causing Qb to increase. A typical flow curve is illustrated in FIG. 2 . As the pressure drop across the filter assembly 16 increases, a larger fraction of the total flow passes through the bypass valve 132 . Those skilled in the art will appreciate that different bypass valve designs will exhibit different flow curves. In an alternative embodiment, where a by-pass valve 132 is provided, the by-pass valve 132 could open just prior to the point at which wellbore fluid flow is reduced to the level that damage to the artificial lift system is predicted to occur. In addition, activation of the bypass valve should alert the operator on the surface that the filter assembly 16 might require service. Such service may be in the form of removal of the entire artificial lift system and filter assembly, reverse operation of the artificial lift system, or back-flushing fluid through the system from the surface so as to force out matter that may have accumulated in the filter assembly.
[0060] External tubular 22 may be any porous material with sufficient corrosion resistance and structural strength to withstand the torque, well obstructions, tension loading, compression loading, pressure differentials or any other conditions that may be encountered during insertion in the production casing and operation of the artificial lift system. In certain embodiments, external tubular 22 may be a wire mesh screen. In other embodiments, external tubular 22 may be a wire-wound screen. Stainless steels are a particularly preferred screen material owing to their mechanical strength and corrosion resistance. The screen may comprise a mechanical support for providing structural integrity. The screen may be selected to provide the desired opening size to exclude the sand and/or fines encountered in a particular well environment.
[0061] Internal tubular 24 may also be a screen or, in other embodiments, may comprise a pipe having openings or perforations 26 . Openings 26 may also be size-selected for a particular application. Openings 26 may comprise holes or slots in the wall of internal tubular 24 . Internal tubular 24 defines central passage 28 that is in fluid communication with inlet connector 14 of pump 100 .
[0062] Annular space 32 may be occupied by medium 30 which may be a porous medium such as pumice -a highly-porous igneous rock, usually containing 67 to 75% SiO 2 and 10 to 20% Al 2 O 3 . Potassium, sodium and calcium are generally present. Pumice has a glassy texture. It is insoluble in water and not attacked by acids. It is commercially available in lump or powdered form (coarse, medium and fine).
[0063] Medium 30 , when impregnated with a chemical agent, may be used to perform at least two functions: 1) mechanical filtration; and, 2) treatment of the fluid(s) flowing into the inlet of pump 100 with the chemical agent. The mechanical filtration function excludes sand, fines, and other wellbore matter, including highly viscous fluids that are not blocked by external tubular 22 . The extent of this mechanical filtration is determined, at least in part, by the particle size and packing density of medium 30 . Accordingly, the composition of medium 30 , its particle size and its loading within annular space 32 may be optimized for various well conditions.
[0064] The size and configuration of openings 26 in internal tubular 24 may be optimally chosen to exclude medium 30 while providing the minimum restriction to flow of the production fluids. Alternatively, the size and configuration of openings 26 in internal tubular 24 may be chosen to provide another level of wellbore fluid filtration, where even smaller particles of matter are excluded from the central passage 28 .
[0065] Top plate 18 and/or bottom plate 20 may be removable to facilitate charging filter assembly with medium 30 .
[0066] In some embodiments, medium 30 may be the chemical agent in a solid form that slowly dissolves in the production fluids. In such embodiments, the physical filtering function of medium 30 dissipates over time and hence external tubular 22 and internal tubular 24 should be selected to provide sufficient sand, fines, or other matter exclusion to adequately protect pump 100 .
[0067] Referring now to FIG. 3 , artificial lift system 10 includes pump 100 attached at its outlet end to production tubing 12 and at its inlet to inlet connector 14 which is in fluid communication with filter assembly 116 . Filter assembly 116 includes one or more intermediate tubulars 25 [only a single intermediate tubular is shown for clarity] and thus filter assembly 116 has at least two annular spaces, 32 and 33 . It will be appreciated by those skilled in the art that multiple intermediate walls may be incorporated into filter assembly 116 and thus multiple annular spaces may be defined within the apparatus. Each annular space may be used to contain a different medium to provide various functions—e.g., graduated mechanical filtration and/or treatment with different chemical agents. Intermediate wall 25 may comprise a screen, perforated tubular, or other type of porous material. The screen mesh or perforation size may be selected to substantially prevent medium 30 from entering annular space 32 . Filter assembly 116 is preferably designed such that wellbore fluid will pass from the exterior 21 of external tubular 22 through external tubular 22 through any medium 30 through any intermediate tubulars 25 through any additional medium 31 through internal tubular 24 and into the central passage 28 of internal tubular 24 . Artificial lift system 10 may be generally circular in cross section and sized to fit within the production casing of a well [not shown]. In some embodiments, pump 100 may be an ESP that receives electrical power from the surface via an electrical cable within the well bore [not shown].
[0068] Filter assembly 116 comprises top plate 18 and bottom plate 20 . Top plate 18 allows internal tubular 24 to pass through its center portion and may be joined to inlet connector 14 in a fluid tight manner. Top plate 18 and bottom plate 20 are connected by an external tubular 22 and by an internal tubular 24 . The external tubular 22 may be a screen or other type of porous structure that allows a desired wellbore fluid to pass from one side of the tubular to the other while restraining the passage of undesired wellbore fluids or solids. The internal tubular 24 may be a screen or other type of porous structure that allows a desired wellbore fluid to pass from one side of the tubular to the other while restraining the passage of undesired wellbore fluids or solids. Additionally, shown in FIG. 3 , there may be one or more intermediate tubulars 25 that may also comprise a screen or other type of porous structure that allows a desired wellbore fluid to pass from one side of the tubular to the other while restraining the passage of undesired wellbore fluids or solids. Together, external tubular 22 , intermediate tubular 25 , and internal tubular 24 define at least two annular spaces 32 and 33 that may be used to contain at least two media 30 and 31 [partially shown for clarity]. Additionally, while not shown, should at least two intermediate tubulars 25 be used, any number of annular spaces may be created between external tubular 22 and internal tubular 24 . The additional annular spaces may be used to contain a plurality of differentiated media.
[0069] Should the filter assembly 116 (including any intermediate tubulars or media contained in the additional annular spaces created by the intermediate tubulars) become at least partially clogged with solid or other matter that may be present in the wellbore such that wellbore fluid can no longer pass through the filter assembly 116 and reach the artificial lift system 10 , the artificial lift system 10 may be severely damaged. Such damage may result from pump cavitation. In cases where the wellbore fluid is used to cool the artificial lift system's motor a partially clogged filter assembly may reduce the flow of cooling wellbore fluid to the point where motor overheating may also occur. In order to prevent such damage to the pump, motor or drive system a by-pass valve 134 may be installed. Typically, although not always, in the bottom plate 20 . The by-pass valve 134 may be a ball valve, a spring-loaded valve, a poppet valve, a shear assembly, or any other type of valve that may be activated if a sufficient differential pressure is determined to exist. When the pressure drop across the screen equals the by-pass setting, the by-pass valve 134 partially opens and wellbore fluid is allowed to by-pass the filter assembly 116 . As fluid by-passes the filter assembly 116 , the flow rate through the filter is reduced; thus, the pressure drop is reduced for the sand-packed filter. With the by-pass valve 134 partially open, a portion of the wellbore fluid is flowing into the central passage 28 through the filter assembly and a portion is flowing into the central passage 28 through the by-pass valve 134 . The proportions of wellbore fluid that are passing through the filter assembly 116 and the by-pass valve 134 can be represented by Q (total flow)=Qf (flow through filter assembly)+Qb (by-pass flow). As time passes, Qf will be reduced as more wellbore matter packs into the filter assembly 116 and the P (pressure) drop increases for a given flow rate thus causing Qb to increase. A typical flow curve is illustrated in FIG. 2 . As the pressure drop across the filter assembly 116 increases, a larger fraction of the total flow passes through the by-pass valve 134 . Those skilled in the art will appreciate that different bypass valve designs will exhibit different flow curves. In an alternative embodiment where a by-pass valve 134 is provided, the by-pass valve 134 could be opened just prior to the point at which wellbore fluid flow is reduced to the level that is predicted to damage the artificial lift system. In addition, activation of the bypass valve could alert the operator on the surface that the filter assembly 116 might require service. Such service may comprise removal of the entire artificial lift system and filter assembly, reverse operation of the artificial lift system, or back-flushing fluid through the system from the surface so as to force out matter that may have accumulated in the filter assembly.
[0070] External tubular 22 may be any porous material, including metals, composites or plastics with sufficient corrosion resistance and structural strength to withstand the torque, well obstructions, tension loading, compression loading, pressure differentials or any other conditions that may be encountered during insertion in the production casing and operation of the artificial lift system. In certain embodiments, external tubular 22 may be a wire mesh screen. In other embodiments, external tubular 22 may be a wire-wound screen. Stainless steels are a particularly preferred screen material owing to their mechanical strength and corrosion resistance. The screen may comprise a mechanical support for providing structural integrity. The screen may be selected to provide the desired opening size to exclude the sand and/or fines encountered in a particular well environment.
[0071] The at least one intermediate tubulars 25 and internal tubular 24 may also be a screen or, in other embodiments, may comprise a pipe having openings or perforations 26 . Openings 26 may also be size-selected for a particular application. Openings 26 may comprise holes or slots in the wall of internal tubular 24 . Internal tubular 24 defines at least one central passage 28 that is in fluid communication with inlet connector 14 of pump 100 .
[0072] The at least two annular spaces 32 and 33 may be occupied by the at least two media 30 and 31 which may be a porous medium such as pumice -a highly-porous igneous rock, usually containing 67 to 75% SiO 2 and 10 to 20% Al 2 O 3 . Potassium, sodium and calcium are generally present. Pumice has a glassy texture. It is insoluble in water and not attacked by acids. It is commercially available in lump or powdered form (coarse, medium and fine).
[0073] Media 30 and 31 , when impregnated with a chemical agent, may be used to perform at least two functions: 1) mechanical filtration; and, 2) treatment of the fluid(s) flowing into the inlet of pump 100 with the chemical agent. The mechanical filtration function excludes sand and fines that are not blocked by external tubular 22 . The extent of this mechanical filtration is determined, at least in part, by the particle size and packing density of the media 30 and 31 . Accordingly, the composition of media 30 and 31 , its particle size and its loading within the annular spaces 32 and 33 may be optimized for various well conditions.
[0074] The size and configuration of the openings in the intermediate tubulars 25 and in internal tubular 24 may be optimally chosen to exclude the media 30 and 31 while providing the minimum restriction to flow of the production fluids.
[0075] Top plate 18 and/or bottom plate 20 may be removable to facilitate charging filter assembly with at least media 30 and 31 .
[0076] In some embodiments, media 30 and 31 may be chemical agents in a solid form that slowly dissolves in the production fluids. In such embodiments, the physical filtering function of the media 30 and 31 dissipates over time and hence external tubular 22 and internal tubular 24 should be selected to provide sufficient sand and/or fines exclusion to adequately protect pump 100 .
[0077] FIG. 5 is a cross-sectional view of filter assembly 116 taken perpendicular to its major axis. Screen 22 , at least one intermediate wall 25 and central conduit 24 can be seen to define at least two annular spaces 32 and 33 . In use, central passage 28 is in fluid communication with the inlet of pump 100 via inlet connector 14 .
[0078] Additional downhole components may be included in order to facilitate the use and recovery of the apparatus. The embodiment of the invention shown in FIG. 4 includes filter assembly 300 , packer 302 , crossover subassembly 304 , shear sub 306 , and artificial lift system 308 . The shear subassembly 304 is intended to allow the artificial lift system 308 to be removed without removing the packer 302 , crossover subassembly 304 , and the filter assembly 300 in those instances when the packer 302 is unable to be removed from the wellbore due to sand accumulations or any other cause. The conditions where the packer 302 , crossover subassembly 304 , and filter assembly 300 may become stuck in the wellbore usually occur at the end of the filter assembly 300 's life cycle when the bypass valve 132 has opened and sand is passing through the assembly. Some of this sand may settle on top of the packer making it difficult to remove from the well. In such cases, the artificial lift system 308 may be separated from the sheer sub 306 and removed from the wellbore. The packer 302 may then be milled out of the bore and any remaining equipment fished from the well.
[0079] One preferred scale inhibitor is phosphoric acid (also known as orthophosphoric acid), a colorless, odorless liquid or transparent, crystalline solid, depending on concentration and temperature. The pure acid (100% strength) is in the form of crystals that melt at about 42° C. and lose ½ mole of water at 213° C. to form pyrophosphoric acid.
[0080] The scale inhibitor may be a phosphate salt—a group of salts formed by neutralization of phosphorous or phosphoric acid with a base, such as NaOH or KOH. Orthophosphates are phosphoric acid (H 3 PO 4 ) salts, where 1, 2 or 3 of the hydrogen ions are neutralized. Neutralization with NaOH gives three sodium orthophosphates: (a) monosodium phosphate (MSP), (b) disodium phosphate (DSP) or (c) trisodium phosphate (TSP). Their solutions are buffers in the 4.6 to 12 pH range. All will precipitate hardness ions such as calcium.
[0081] By utilizing this method the wellbore fluid may be treated downhole with other chemicals as well including inhibitors such as corrosion inhibitors, emulsion breakers, surfactants, chemicals to prevent the deposition of paraffin, hydrogen sulfide scavengers.
[0082] It will be appreciated by those skilled in the art that each chemical agent in media 30 and/or 31 will become depleted in use as production fluids flow over media 30 and/or 31 dissolving or desorbing the chemical agent. If the chemical agent is a liquid at the temperatures and pressures existing in the downhole environment, filter assembly 116 may be equipped with a capillary tube recharge means as illustrated in FIG. 6 .
[0083] FIG. 6 depicts the multi-layer embodiment of FIG. 3 with the addition of capillary tubes 136 and 138 that are in fluid communication with annular spaces 32 and 33 , respectively, via openings 36 in top plate 18 . When the concentration of chemical agents in the production fluid(s) falls to an ineffective level, porous media 30 and/or 31 may be recharged by providing chemical agents into annular spaces 32 and 33 via capillary tubes 136 and/or 138 from the surface. The chemical agent may be moved through the capillary tubes 136 and/or 138 , by gravity, pumping from the surface, pumping from downhole, gas pressure, pumping from a reservoir or any other method of moving a gas, liquid, fine solid, or solid in liquid suspension through a relatively long tube. Once the chemical agent is brought into contact with the medium the chemical agent is absorbed into porous medium 30 (and/or 31 ), recharging it. In an alternative embodiment shown in FIG. 7 , the capillary tubes 236 and 238 pass through openings 36 in the top plate 18 so as to disperse the recharging chemicals along the length of the annuli 32 and 33 through perforations 240 in the capillary tubes 236 and 238 .
[0084] As shown in the transverse, cross-sectional view of FIG. 12A , capillary tube(s) 35 may be formed in wall 38 of production tubing 12 . Alternatively, as illustrated in FIG. 12B , capillary tubes may be contained within notches 37 in wall 38 of production tubing 12 . Bands or straps [not shown] at intervals along the production tubing may be used to retain capillary tube(s) within notches 37 . Chemical agent that may be in liquid, gas, or solid powder form or combinations thereof, may be introduced into filter assembly 116 by means of wall capillary tube 35 , thereby avoiding the addition of separate capillary tubes such as 136 and 138 to the apparatus, which may be more susceptible to mechanical damage within the well bore. The chemical agent employed may be the reaction product of two or more reactants. If, for example, the chemical agent were hazardous to handle, it could be produced in situ by introducing the reactants that form the agent by means of separate wall capillary tubes 35 . Similarly, binary or ternary chemical agents could be created in situ with the relative amount of each component selected depending on operating conditions. Additionally, if the chemical agent is heat activated, the line carrying the specific chemical could be routed through cooling passages in the artificial lift system [not shown] where the excess heat from the artificial lift system could heat the chemical to at least the desired temperature. Thus, the chemical could be heated while serving as a coolant for the artificial lift system.
[0085] If the chemical agent is a solid-phase material that dissolves in the production fluid(s), downhole replenishment of the chemical agent supply may be accomplished with the apparatus shown in longitudinal cross section in FIG. 8 . In the particular embodiment illustrated, the dual-layer filter assembly of FIG. 3 is modified by the addition of extension 40 comprising outer wall 41 , intermediate wall 44 and top plate 43 Outer wall 41 , intermediate wall 44 , top plate 43 , and the inner wall may be impervious to production fluids and assembled in a fluid tight manner. Annular space 42 of extension 40 defined by outer wall 41 , inner wall 44 , top plate 43 and the inner wall is an extensions of annular space 33 . Annular space 42 may therefore function as a supply hopper for the chemical agent exposed to the production fluids in annular space 33 of filter assembly 116 . As the solid phase chemical agent is dissolved from annular space 33 , fresh chemical agent from annular space 42 will fall into annular spaces 33 under the influence of gravity.
[0086] FIG. 9 illustrates an alternative embodiment having separate annular hoppers for replenishing the chemical agents in annular spaces 32 and 33 . Inner tubular 14 , the artificial lift system housing 100 , and the production tubular 12 form an inner wall. Outer wall 41 , intermediate wall 44 , top plate 43 , and the inner wall may be impervious to production fluids and assembled in a fluid tight manner. Annular spaces 42 and 142 of extension 40 defined by outer wall 41 , inner wall 44 , top plate 43 and the inner wall are extensions of annular spaces 32 and 33 . Annular spaces 42 and 142 may therefore function as supply hoppers for each chemical agent exposed to the production fluids in annular spaces 32 or 33 of filter assembly 116 . As the solid phase chemical agent is dissolved from annular spaces 32 and 33 , fresh chemical agent from annular space 42 and 142 will fall into annular spaces 32 and 33 under the influence of gravity. Such an apparatus may employ chemical agents having different phases. For example hopper 142 may contain a liquid agent while hopper 42 contains a solid chemical treatment agent.
[0087] In this way, the useful life of the filter assembly with the treating chemicals may be extended. Since oil and gas wells may be thousands of feet deep, there is typically ample volume in the annular space between the production casing and the production tubing to accommodate an extension 40 of significant capacity. The length of extension 40 is limited only by the availability of annular space between the production tubing and the casing. In alternative embodiments the extension 40 or even a separate hopper assembly [not shown] could be refilled by using a capillary or feed tube system. In another embodiment the extension 40 could be attached to the filter assembly as a separate hopper that could be refilled by retrieving the hopper. One means for retrieving the hopper could be by using a wireline.
[0088] If the chemical agent is a liquid-phase material, a downhole reservoir of the agent may be provided and utilized by means of the apparatus shown in longitudinal cross section in FIG. 10 . While a single-layer filter may be utilized, in the particular embodiment illustrated, filter assembly 116 is the at least dual-layer type shown in FIG. 3 . Chemical agent reservoir 60 is adapted to be located in the annular space between the production tubing and the production casing. Reservoir 60 may be connected to supply conduit 62 via coupling 64 . Coupling 64 may be a quick-connect type of coupling that permits reservoir 60 to be wireline retrievable for refilling at the surface. Supply conduit 62 provides a fluid connection between reservoir 60 and annular space 33 of filter assembly 116 via valve or metering means 66 . The flow of liquid phase chemical agent from reservoir 60 to the filter assembly 16 may be regulated by time and/or volume by valve/metering means 66 . Valve 66 could be adjusted by sending a signal down the ESP cable or with an I-wire. Valve 66 may also comprise a metering pump which may, in certain embodiments, be electrically or hydraulically powered. The pump discharge pressure could also be utilized to adjust the valve or operate the hydraulic metering pump. When the pump is turned off the drop in discharge pressure could shut the valve and stop the flow of chemicals. Within annular space 33 , a distribution means may be provided for distributing the chemical agent in a desired pattern throughout the medium 30 . The distribution means may be a fluid conduit having a plurality of orifices sized to provide a desired delivery rate of the chemical agent to medium 30 . Reservoir 60 may be pressurized by a compressed gas in the head space above the chemical agent. Alternatively, the chemical agent may be contained within an elastomeric bladder contained within reservoir 60 and the surrounding space pressurized to provide a supply of chemical agent under pressure. In yet other embodiments, reservoir 60 may be provided with pressure equalization means to permit gravity flow of chemical agent from reservoir 60 to annular space 33 .
[0089] FIG. 11 depicts one alternative embodiment of the invention illustrated in FIG. 10 wherein annular space 400 within well casing 404 above packer 402 replaces reservoir 60 . In certain embodiments, packer 402 may be a cup packer. A chemical treatment agent (which may be a liquid-phase substance) may be inserted into annular space 400 before, during or after installation of artificial lift pump 406 .
[0090] FIG. 13 depicts an embodiment of the invention wherein filter assembly 116 is positioned above pump 100 . This configuration permits filter assembly 116 to be wireline retrievable from the surface for maintenance and/or recharging of chemical agent without necessarily removing the artificial lift system. In the particular embodiment illustrated, pump 100 is shaft-driven from motor 84 through motor seal 82 and concentric inlet 80 . Filter assembly 16 comprises removable upper section 89 and lower section 88 that form a fluid-tight connection around motor seal 82 . In alternative embodiments, lower section 88 may encompass motor 84 or may seal to motor 84 . The arrows in FIG. 13 depict the direction of production fluid flow from the surrounding formation, into filter assembly 116 where sand and fines are mechanically filtered out and the fluid(s) are treated with chemical agent which dissolves or desorbs from medium 30 in annular space 32 . The fluid then flows downward (under the influence of the pressure differential created by pump 100 ) through annular space 81 and into pump intake 80 where it enters pump 100 and is lifted to the surface via production tubing 12 .
[0091] FIG. 14 depicts another embodiment of the invention wherein filter assembly 202 is positioned above pump 100 . In the configuration depicted filter assembly 202 includes one or more intermediate tubulars 204 [only a single intermediate tubular is shown for clarity] and thus filter assembly 202 has at least two annular spaces, 206 and 208 . It will be appreciated by those skilled in the art that multiple intermediate walls may be incorporated into filter assembly 202 and thus multiple annular spaces may be defined within the apparatus. Each annular space may be used to contain a different medium to provide various functions—e.g., graduated mechanical filtration and/or treatment with different chemical agents. Intermediate wall 204 may comprise a screen, perforated tubular, or other type of porous material. Filter bottom plate 212 is non-porous so as to force fluid that enters the outermost, as fluid flows into the filter assembly from the exterior, of multiple annular spaces 208 to enter into the innermost of any number of subsequent annular spaces 206 . It is understood that any additional annular spaces between the outermost annular space 208 and innermost annular space 206 would most preferably have a non-porous bottom plate to force fluid into enter into any number of subsequent annular spaces. filter assembly 202 is preferably designed such that wellbore fluid will pass from the exterior 216 of external tubular 218 through external tubular 218 through any medium 220 through any intermediate tubulars 204 through any additional medium 210 through artificial lift assembly intake 224 and into the central passage 28 of internal tubular 24 . This configuration permits filter assembly 202 to be wireline retrievable from the surface for maintenance and/or recharging of chemical agent without necessarily removing the artificial lift system.
[0092] In some instances, gas that may be present in the wellbore fluid may damage the artificial lift system 230 by causing the pump to cavitate, run at excessive speed, or repeatedly load and unload the artificial lift system. The embodiment depicted in FIG. 14 also allows for gas/fluid separation before the fluid enters the artificial lift assembly 230 in well conditions where the wellbore fluid has a significant amount of gas present by shrouding the artificial lift system intake and forcing the wellbore fluid to reverse direction thus causing a low pressure condition above the pump where entrained gas will be removed from the fluid. By removing the gas above the pump, the gas will rise up and away from the artificial lift system intake 224 . In the particular embodiment illustrated, pump 232 is shaft-driven from motor 236 through motor seal 234 and artificial lift system intake 224 . Filter assembly 202 comprises removable upper section 240 and lower section 242 that form a fluid-tight connection around motor seal 234 . Upper section 240 may be releasably joined to lower section 242 by connector 203 . In alternative embodiments, lower section 242 may encompass motor 236 , in which case the fluid flow may also provide cooling for the motor or may seal to motor 236 . The arrows in FIG. 14 depict the direction of production fluid flow from the surrounding formation into filter assembly 202 where sand and fines are mechanically filtered out and the fluid(s) are treated with chemical agent which dissolves or desorbs from the at least one medium 220 in annular space 208 . The fluid then flows downward under the influence of the pressure differential created by pump 232 through annular space 246 and into artificial lift system intake 224 where it enters pump 232 and is lifted to the surface via production tubing 226 .
[0093] Yet another embodiment of the invention is shown in longitudinal cross section in FIG. 15 . In this embodiment, filter assembly 16 is situated between pump 100 and pump motor 84 . Pump 100 is driven by pump motor 84 by means of shaft 90 , which may be exposed to the production fluids. The filter assembly 16 is connected to the motor seal 82 . The embodiment illustrated in FIG. 15 may include a head unit 94 which contains at least one relief valve 96 . The relief valve 96 may be configured to open at a pre-selected differential pressure to prevent pump 100 from cavitating or otherwise being damaged if filter 16 becomes blocked. The apparatus may also be equipped with signaling means for alerting operators that the bypass valves 96 have opened and the filter assembly should be retrieved and serviced.
[0094] FIG. 16 is an alternative to the embodiment shown in FIG. 15 . In this embodiment, screen 22 is in the interior of the filter apparatus and forms the wall of central conduit 102 . Outer wall 104 and screen 22 are in a spaced apart relationship so that at least one annulus 252 is created. At least one medium 250 resides in that at least one annulus 252 to allow for treatment of the wellbore fluid before the wellbore fluid enters into the artificial lift system 254 . Outer wall 104 comprises openings 26 that may be relatively large compared to the effective openings in screen 22 . In this embodiment, relatively more sand and fines may enter the filter assembly through openings 26 so that screen 22 is the final barrier to such contaminates prior to entry of the production fluid(s) into central conduit 102 and lift system 254 .
[0095] While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention.
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A fluid conditioning system designed to be installed between the well perforation and the intake of a pump used to effect artificial lift is used to filter and chemically treat production fluids. The fluid conditioning system is an apparatus that provides scale inhibitors and/or other chemical treatments into the production stream. In some embodiments, the fluid conditioning system may be a part of the production stream filter wherein the filtering material is comprised of a porous medium that contains and supports the treatment chemical. In other embodiments, the chemical treatment may be accomplished by the gradual dissolution of a solid phase chemical. The treating chemical may be recharged or replenished by various downhole reservoirs or feeding means. In yet other embodiments, the treating chemical may be replenished from the surface by means of a capillary tube. In certain other embodiments, the apparatus may be retrievable from the surface thereby permitting recharge or replenishment of the chemical in the apparatus on an as-needed basis. The filtration apparatus may incorporate a bypass valve that allows fluid to by-pass the filter as sand or other particulate matter fills up or blocks the filter.
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FIELD OF THE INVENTION
The present invention involves the delivery of hydrogen, preferably alone, into a subsurface aquifer to stimulate microbial biodegradation of halogenated hydrocarbons, preferably chlorinated solvents.
BACKGROUND OF THE INVENTION
Halogenated hydrocarbons are aliphatic or aromatic hydrocarbon compounds composed of hydrogen and carbon with at least one hydrogen substituted by a halogen atom (Cl, Br, or F). Halogenated hydrocarbons are used for many purposes, such as solvents, degreasers, pesticides, and dry cleaning agents, and are one of the largest and most recalcitrant groups of contaminants found in groundwater. As a subgroup, the chlorinated aliphatic hydrocarbons, consisting of such compounds as methylene chloride, chloroform, carbon tetrachloride, tetrachloroethene (PCE), and trichloroethene (TCE), are commonly referred to as the "chlorinated solvents." As used herein, the term "chlorinated solvents" shall refer to chlorinated aliphatic hydrocarbons.
As a result of their widespread use, the chlorinated solvents are among the most prevalent groundwater contaminants. In fact, a 1984 survey of water supplies in the United States found that PCE, TCE, and the three isomers of dichloroethene (DCE) were the five most frequent contaminants found in groundwater other than the trihalomethanes.
Contamination of groundwater by chlorinated solvents is an environmental concern because chlorinated solvents have known carcinogenic and toxic effects. For example, carbon tetrachloride is a systematic poison of the nervous system, the intestinal tract, the liver, and the kidneys. Vinyl chloride, which is used in the manufacture of polyvinylchloride (PVC) and is a degradation product of chlorinated ethenes (PCE, TCE, and DCE), is a known carcinogen, and also can affect the nervous system, the respiratory system, the liver, the blood, and the lymph system.
Chlorinated solvents are among a group of heavier-than-water hydrocarbons that often are found in separate phase mixtures in the subsurface called dense nonaqueous-phase liquids ("DNAPLs"). DNAPLs are visible, denser-than-water, separate oily phase materials in the subsurface whose migration is governed by gravity, buoyancy, and capillary forces. When in contact with groundwater, soluble constituents in the DNAPL (such as chlorinated solvents) partition into the water phase to create a dissolved contaminant plume. DNAPL thus can serve as a long-term, continuing source of contamination as the soluble constituents slowly dissolve into moving groundwater.
DNAPLs comprised of chlorinated solvents present a formidable remediation challenge for four reasons: (1) the density of DNAPLs causes the contaminated zone to spread deep below the water table; (2) chlorinated solvents have physical properties that allow movement through very small fractures in the soil (<20 microns) and downward penetration to great distances, even through some clay strata; (3) strong capillary forces make the removal of individual DNAPL trapped in soil pores very difficult or impossible; and, (4) chlorinated solvents are not readily biodegradable under natural conditions and can persist for long periods of time in the subsurface.
Several techniques have been applied to the remediation of sites contaminated by chlorinated solvents; however, most have proven to be costly and inefficient.
SUMMARY OF THE INVENTION
The present invention provides a method for stimulating in-situ microbial biodegradation of halogenated organic compounds in an aqueous subsurface environment comprising delivering hydrogen, in the absence of nutritional factors, into the subsurface environment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the experimental apparatus used to test the invention.
FIG. 2 is a chart showing the results of the testing described in Example 1.
DETAILED DESCRIPTION OF THE INVENTION
Without limiting the present invention, it is believed that chlorinated hydrocarbons are degraded by ubiquitous hydrogen-utilizing anaerobic bacteria capable of mediating the reductive dechlorination process using the chlorinated hydrocarbons as their terminal electron acceptor. The process of reductive dechlorination is depicted by the following half-reaction:
R--Cl+H.sup.+ +2e.sup.- →R--H+Cl.sup.-
Unlike other enhanced anaerobic degradation processes that have been applied to the remediation of subsurface aquifers, the present invention does not require addition of a separate electron acceptor and nutritional factors. This is because the chlorinated hydrocarbons, themselves, act as electron acceptors and nutritional factors (nitrogen, phosphorous, etc.) generally are present in adequate quantities in the subsurface. The addition of hydrogen as an electron donor, in the absence of nutritional factors, is sufficient to achieve complete reductive transformation of chlorinated hydrocarbons to innocuous end products using the present method.
In addition to providing for the direct stimulation of chlorinated hydrocarbon degrading bacteria, the use of hydrogen as opposed to other electron donors offers several advantages. First, rates of bacterial growth on hydrogen are more rapid than on other methanogenic growth substrates, and the half-saturation constant for hydrogen is very low. This leads to efficient use of hydrogen and low values of S min (substrate concentration required to attain maximum growth rate). Second, bacteria that use hydrogen as a substrate are ubiquitous in anaerobic environments. Third, unlike many electron acceptors such as hydrogen-peroxide (highly reactive), nitrate (causes methanoglobanemia in infants), and sulfate (contributes to bad taste), which may be used to indirectly bring about the degradation of chlorinated aliphatic compounds, hydrogen is an environmentally acceptable compound to add to groundwater. Finally, hydrogen is relatively inexpensive.
A number of methods may be used to introduce hydrogen into the subsurface. These methods may be grouped into two primary categories--1) methods for the direct delivery of hydrogen from an external source, and 2) methods that generate hydrogen in-situ. Methods for the direct delivery of hydrogen are more conventional, and generally involve adaptations to already established processes used in aerobic bioremediation systems.
Methods for the direct delivery of hydrogen include, but are not necessarily limited to, sparging, in-situ diffusion, and pump and reinject. Methods for in-situ generation of hydrogen include, but are not necessarily limited to, induced subsurface chemical reaction, and electrolysis. A preferred method for introducing hydrogen is sparging.
Direct Delivery Systems
Sparging
Methods for conventional air sparging must be modified in order to accomplish hydrogen sparging. In the sparging process, air (or other gas) is forced into a wellbore under sufficient pressure to form branching air channels in the groundwater. In a conventional air sparging system, air channels spread through the aquifer to: 1) strip volatile compounds from the dissolved phase and any non-aqueous phase liquids present along the path of the channels and 2) add oxygen to the groundwater to spur aerobic in-situ biodegradation processes (primarily aimed at non-chlorinated hydrocarbons, such as petroleum fuels). Air sparging is typically coupled with a soil vapor extraction system to collect volatilized constituents for treatment. Air sparging is described in detail in U.S. Pat. No. 5,221,159 to Billings et al., incorporated herein by reference, and in Johnson et al., "An Overview of In Situ Air Sparging," Ground Water Monitoring and Remediation 13:4 (Fall 1993) 127-135, incorporated herein by reference.
Unlike a typical air sparging system, a hydrogen sparging system should not volatilize constituents, but should saturate the groundwater in the treatment zone with dissolved hydrogen to stimulate biodegradation. Accordingly, a hydrogen sparging system need not be coupled with a soil vapor extraction system as described by Billings et al. and Johnson et al. In fact, a hydrogen sparging system should use reduced gas pressures and delivery rates set to minimize the volatilization of constituents and the migration of hydrogen gas to the unsaturated zone.
In order to perform hydrogen sparging, sparge wells should be drilled, pushed, or otherwise installed in the area to be treated. The sparge wells preferably should be 1-4 inch diameter cased penetrations driven or drilled into the subsurface to a depth below the lowermost contaminated region. A screened opening should be provided at the bottom of the sparge wells so that the top of the screened interval is below the lowermost contaminated region and the screened opening is located entirely within the saturated zone. The wells preferably should be spaced on 5-25 foot centers throughout the area to be treated or in a line across the downgradient edge of the zone, serving as a reaction wall for migrating groundwater. Vertical wells are the industry standard, but horizontal wells also may be employed.
The source of hydrogen may be any source capable of delivering hydrogen under pressure. Examples include standard industrial pressurized hydrogen gas cylinders or a hydrogen generator equipped with a delivery pump.
The hydrogen source should be connected to the sparge wells via pipes, manifolds, valves and other ancillary equipment as necessary to regulate the flow of hydrogen. The delivery pressure for the hydrogen should be set above the formation entry pressure required to overcome the hydrostatic pressure in the well. Typically, the delivery pressure will range between about 1-5 psig (7-34 kPa). The hydrogen should be delivered under a steady state or pulsed injection rate that has been optimized in the field to match the observed hydrogen utilization rate and to limit the amount of hydrogen released to the surface.
Groundwater samples should be collected periodically from throughout the treatment zone to assess the performance of the system. Soil gas samples also should be collected and analyzed to test for the accumulation of hydrogen gas in the soil vadose zone. Accumulations of hydrogen gas could present an explosion hazard and the delivery of hydrogen should be adjusted accordingly. If the build-up of hydrogen gas becomes a problem, then the injection of a mixture of nitrogen or other inert gas and hydrogen gas (96% inert gas--4% H 2 ) may be used in place of pure hydrogen.
In-situ diffusion
In-situ diffusion of hydrogen may be accomplished using similar procedures except that the cased wells may have a larger diameter (2-8 inches) and drop tube. The wells should be screened across the zone of contamination with the well screen located entirely within the saturated zone. A small diameter drop tube having a diffuser installed at its bottom should be inserted into each well and hydrogen gas should be delivered through the drop tube. Groundwater that passes through the well under natural flow conditions is contacted with the hydrogen gas released through the diffuser. A well seal should be provided above the screened interval to prevent the hydrogen from escaping back through the wellbore to the surface. The resulting groundwater, saturated with dissolved hydrogen, is then distributed throughout the treatment zone by natural advective and diffusive transport.
Because gas delivery rates are slow, in-situ diffusion generally is less efficient than sparging, but may be used in situations where there is a great deal of concern about the build-up of hydrogen gas in the subsurface. Transport limitations require that in-situ diffusion wells be spaced closer together than typical sparge wells.
Pumping/Reinjection
Another method for delivering hydrogen to the subsurface is based on the concept of pumping/reinjection. An example of how this technique has been employed for aerobic in-situ biodegradation via oxygen addition is described in detail in Lee, M.D., et al. "Applicability of In-Situ Bioreclamation as a Remedial Action Alternative." Proceedings of the Petroleum Hydrocarbons and Organic Chemicals in Groundwater: Prevention, Detection, and Restoration. National Water Well Assoc., Houston, Tex. (1987) 167-185. Pumping/reinjection for hydrogen delivery involves pumping groundwater from a location downgradient of the contaminated area and passing the pumped groundwater through an above-ground mixing system where hydrogen is dissolved into the flow stream. The hydrogen enriched groundwater is reinjected into the subsurface at a location upgradient of the contaminated region, preferably to create a circular flow system wherein groundwater containing dissolved hydrogen is flushed through the contaminated zone to stimulate biological activity throughout the zone. Many variations of this process may be implemented, including systems that may be described as closed loop without treatment, closed loop with auxiliary treatment, or single pass.
A hydrogen pumping/reinjection system would use 2 to 6 inch diameter cased wells drilled or driven into the subsurface as pumping wells. The pumping wells should be equipped with a screened opening that extends across the zone of contamination, and should be placed downgradient of the area to be treated. Well spacing should be determined by site specific parameters, such as hydraulic conductivity, pumping rates, and available drawdown. Alternatively, a collection trench may be used in place of, or in conjunction with, pumping wells to collect and recover groundwater.
Electrically or pneumatically powered groundwater pumps may be used to induce groundwater flow to the well and to bring collected groundwater to the surface for hydrogen treatment. The groundwater should be contacted with hydrogen gas in an above ground mixing system to dissolve hydrogen in the flow stream such that the hydrogen concentration is near solubility (about 2 mg/L). The hydrogen may be supplied to the treatment unit by standard industrial pressurized hydrogen gas cylinders, a hydrogen generator equipped with a delivery pump, or other source. The hydrogen may be injected or diffused into the process stream.
The system also would need injection wells, comprising 2 to 6 inch diameter cased penetrations drilled or driven into the subsurface and equipped with a screened opening that extends across the zone of contamination. The injection wells should be placed upgradient of the area to be treated, and well spacing, again, should be determined by site specific parameters such as hydraulic conductivity and injection rates. Under appropriate site conditions, infiltration trenches may be used in place of injection wells to deliver the hydrogen enriched water to the subsurface. Infiltration trenches are trenches filled with highly permeable backfill (sand or gravel).
If necessary, injection pumps may be used to increase the hydrostatic head for injecting the hydrogen enriched groundwater to the subsurface treatment zone.
Pipes, manifolds, valves, and other ancillary equipment will be needed to connect the pumping wells to the hydrogen mixing system and the mixing system to the injection wells.
If necessary, the pumping/reinjection system as described above may include some auxiliary groundwater treatment processes to treat the groundwater prior to hydrogen addition and subsequent reinjection. Such additional treatment would be driven primarily by regulatory requirements which prohibit the injection of hazardous substances (extracted groundwater may contain trace quantities of chlorinated compounds or other constituents). Additional treatment might include air stripping, carbon adsorption, or some other physical-chemical process.
If reinjection of extracted groundwater is prohibited altogether, the groundwater recovered from the pumping wells may be treated and discharged to a surface water or other above-ground receptor. In this case, raw water for hydrogen addition would need to be obtained from some independent source, such as a public or private utility.
In-Situ Hydrogen Generation
Methods for in-situ generation of hydrogen are attractive because they appear to overcome many of the limitations of external hydrogen delivery systems, such as poor subsurface distribution of hydrogen, inefficient use of hydrogen, and the hazards of storing and handling bulk hydrogen. However, methods of in-situ generation are experimental in nature, and thus are less preferred than direct delivery systems.
Induced Subsurface Chemical Reaction
Methods for in-situ generation of hydrogen by induced subsurface chemical reaction use the fact that metals or cations with positive standard potentials--such as sodium (Na), potassium (K), lithium (Li), calcium (Ca), magnesium (Mg), zinc (Zn), and iron (Fe)--can be oxidized in solution to release hydrogen. For example, sodium is known to undergo the following reaction:
2Na+H.sub.2 O→2NaOH+H.sub.2
Only the most electropositive metals can release hydrogen directly from water at room temperature where the proton concentration is low. For less reactive metals, such as iron or zinc, hot water or an acidic solution is required to make the hydrogen generation significant:
Fe+2H.sup.+ →Fe.sup.2+ +H.sub.2
The in-situ generation of hydrogen by induced subsurface chemical reaction involves injecting a slurry or suspension of fine metal particles much smaller than the median grain size of the aquifer matrix in the injection zone using injection wells. In the case of sodium injection, no further process steps are required. In the case of iron addition, the treatment zone would be flushed with an acidic solution, such as sulfamic or hydrochloric acid, to accelerate the oxidation reaction. The rate of reaction, and the rate of hydrogen release, can be controlled by controlling the pH of the acid flushing solution.
A system for in-situ generation of hydrogen by induced subsurface chemical reaction would require pumping wells similar to those used in a "pumping/reinjection" system. The pumping wells would be used both for hydraulic control of the treatment area and to recover injected fluids.
As in a pumping/reinjection system, electrically or pneumatically powered groundwater pumps would be used to induce groundwater flow to the pumping well and to bring collected groundwater to the surface for metal or acid treatment. Above ground storage and mixing basins would be used to mix a metal slurry or suspension with collected groundwater for injection to the treatment zone. Additional tanks also may be needed to store stock solutions of acid and to mix the acid with the injection stream for the flushing operation. Metering pumps would be used to feed the appropriate quantities of stock solutions to the flow stream.
If necessary, injection pumps may be used to increase the hydrostatic head for injecting the metal enriched groundwater and acid solutions to the subsurface treatment zone. Under appropriate site conditions, infiltration trenches could be used in place of injection wells to deliver the metal slurry or suspension and acid solutions to the subsurface. Pipes, manifolds, valves and other ancillary equipment will be needed to connect the pumping wells to the mixing basins and the mixing basins to the injection wells.
Electrolysis
Hydrogen also can be generated in-situ by the electrolysis of water. To accomplish this, electrodes are installed in the subsurface contaminated region. When connected to an external power source, electrons are moved from the anode to the cathode. The flow of electrons maintains a negative charge at the cathode and a positive charge at the anode. The flow of current is completed through the groundwater by movement of cations (H + ) to the negatively charged cathode and anions (OH - ) to the positively charged anode. When an H + ion reaches the cathode, the H + ion picks up an electron and is reduced to H 2 gas. In like fashion, when an OH - ion reaches the anode, the OH - ion gives up an electron and is oxidized to O 2 gas. The resulting hydrogen gas is used in the subsurface for the reductive dechlorination process. The resulting oxygen either is used in-place, to create aerobic treatment zones, or is extracted by venting to the surface.
A system for hydrogen generation by electrolysis would require metal rod electrodes (iron or other) which may be driven into the subsurface to the depth of the treatment zone and connected to a battery or transformer capable of supplying a direct current voltage to the electrodes.
EXAMPLE 1
The following procedure was repeated three times.
Referring to the apparatus of FIG. 1, and to the numerically identified components of that apparatus, tetrachloroethene (PCE) was injected through injection port 6 and allowed to mix with the reservoir of water 10 contained in the bottom of the headspace chamber 1. A hydrogen atmosphere was maintained in the headspace chamber 1 throughout the duration of the experiment. Sufficient PCE was injected into the reservoir 10 such that, following equilibrium partitioning between the liquid and vapor phases within the chamber, the fluid reservoir contained approximately 0.5-1.0 mg/L PCE. The pump 3 was used to draw fluid from the reservoir 10 and circulate the fluid through the column 4 and back to the headspace chamber 1 via the connection tubing 2. The fluid was circulated at a constant flowrate of approximately 4-5 mL/min.
Within the headspace chamber 1, fluid returning from the column was ejected from the drip tube 5 and allowed to free fall through the chamber back to the fluid reservoir. The drip tube provided a mechanism for achieving the transfer of hydrogen to the fluid (i.e., hydrogen was diffused through the surface of the droplets).
The column 4 was packed with glass beads and was operated in an upflow mode with a fluid volume of approximately 12 mL. At a flowrate of 4 mL/min, this equated to a detention time in the column of approximately 3 minutes. Chlorinated compounds passing through the column were degraded by the biomass grown within the column. Fluid samples were collected through the sample ports 8 and 9 at the inlet and outlet of the column and analyzed.
The results from the three experiments are shown in FIG. 2. Based on these results, the degradation rate for PCE in the column was estimated to range from 0.12 mg/L/hr to 0.46 mg/L/hr. This rate is much higher than the natural decay rate of PCE in groundwater, based on values reported in the literature (charted in FIG. 2). P. H. Howard, R. S. Boethling, W. F. Jarvis, W. M. Meylan, and E. M. Michalenko. Handbook of Environmental Degradation Rates (1991) Lewis Publishers, Inc., incorporated herein by reference.
Based on the results of the foregoing experiments, the addition of hydrogen to a contaminated aquifer, alone, should be sufficient to stimulate and support the in-situ biodegradation of chlorinated hydrocarbons.
Persons of skill in the art will appreciate that many modifications may be made to the embodiments described herein without departing from the spirit of the present invention. Accordingly, the embodiments described herein are illustrative only and are not intended to limit the scope of the present invention.
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The present invention provides a method for stimulating in-situ microbial biodegradation of halogenated organic compounds in an aqueous subsurface environment comprising the delivery of hydrogen, in the absence of nutritional factors, into the subsurface environment.
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PRIOR APPLICATION
This is a continuation-in-part application of U.S. patent application Ser. No. 10/451,962, still pending filed 27 Jun. 2003 that claims priority from PCT application no. PCT/SE02/02195, filed 28 Nov. 2002, that claims priority from U.S. provisional patent application Ser. No. 60/339,380, filed 11 Dec. 2001.
TECHNICAL FIELD
The present invention is a method for treating slurry or a liquid, such as sludge or polluted water in sewage works, with ultrasonic transducers.
BACKGROUND AND SUMMARY OF INVENTION
Ultrasonic energy has been applied to liquids in the past. Sufficiently intense ultrasonic energy applied to a liquid, such as water, produces cavitation that can induce changes in the physiochemical characteristics of the liquid. The subject of sonochemistry, which deals with phenomena of that sort, has grown very much during recent years.
The published material in sonochemistry and related subjects all pertains to batch processes, that is, the liquid solution or dispersion to be treated is placed in a container. The liquid in the container is then stirred or otherwise agitated, and ultrasound is applied thereto. It is then necessary to wait until the desired result, physical or chemical change in the liquid, is achieved, or until no improvement in the yield is observed. Then the ultrasound is turned off and the liquid extracted. In this way liquid does not return to its initial state prior to the treatment with ultrasonic energy. In this respect, the ultrasound treatment is regarded as irreversible or only very slowly reversible.
Far from all industrial processes using liquids are appropriately carried out in batches, as described above. In fact, almost all large-scale processes are based upon continuous processing. The reasons for treating liquids in continuous processes are many. For example, the fact that a given process may not be irreversible, or only slowly reversible, and requires that the liquid be immediately treated further before it can revert to its previous state.
Shock waves external to collapsing bubbles driven onto violent oscillation by ultrasound are necessary for most if not all physiochemical work in liquid solutions. The under-pressure pulses form the bubbles and the pressure pulses compress the bubbles and consequently reduce the bubble diameter. After sufficient number of cycles, the bubble diameter is increased up to the point where the bubble has reached its critical diameter whereupon the bubble is driven to a violent oscillation and collapses whereby a pressure and temperature pulse is generated. A very strong ultrasound field is forming more bubbles, and drives them into violent oscillation and collapse much quicker.
A bubble that is generated within a liquid in motion occupies a volume within said liquid, and will follow the speed of flow within said liquid. The weaker ultrasound field it is exposed to, the more pulses it will have to be exposed to in order to come to a violent implosion. This means that the greater the speed of flow is, the stronger the ultrasound field will have to be in order to bring the bubbles to violent implosion and collapse. Otherwise, the bubbles will leave the ultrasound field before they are brought to implosion. A strong ultrasound field requires the field to be generated by very powerful ultrasound transducers, and that the energy these transducers generate is transmitted into the liquid to be treated. Based upon this requirement, Bo Nilsson and H{dot over (a)}kan Dahlberg started a development of new types of piezoelectric transducer that could be driven at voltages up to 13 kV, and therefore capable of generating very strong ultrasonic fields.
A very strong ultrasonic source will cause a cushion of bubbles near the emitting surface. The ultrasound cannot penetrate through this cushion, and consequently no ultrasound can penetrate into the medium to be treated. The traditional way to overcome this problem is to reduce the power in terms of watts per unit area of emitting surface applied to the ultrasonic transducers. As indicated above, the flow speed of the medium to be treated will require a stronger ultrasound field and therefore an increased power applied to the ultrasonic transducers. The higher the power input is, the quicker the cushion is formed, and the thicker the formed cushion will be. A thick cushion will completely stop all ultrasound penetration into a liquid located on the other side of this cushion. All the cavitation bubbles in this cushion will then stay in the cushion and cause severe cavitation damage to the ultrasound transducer assembly area leading to a necessary exchange of that part of the ultrasound system. This means that little or no useful ultrasound effect is achieved within the substrate to be treated, and that the ultrasound equipment may be severely damaged.
The above-outlined cushion problems also apply to treating bacteria clusters in sludge slurries and treating drainage water from sludge slurries in sewage works that are subjected to ultrasonic treatment. The problems also apply to other processes with ultrasonic treatment of slurries, such as the forming of paper webs, de-inking of recycled pulp and cleaning of polluted soil. They also apply to other processes where liquids are treated with ultrasound, such as treatment of water polluted with solvents, and cleaning of drinking water and sonochemical processes.
One problem with the currently used sludge ultrasonic treatment plants is that the energy consumption is high and the efficiency could be improved. There is a need to solve the problems outline above so that sewage works may use ultrasonic treatment for bacteria in the sludge without encountering the undesirable cushion effect or the low efficiency. The method of treating a sludge slurry of the present invention provides a solution to the problems outlined above.
More particularly, the method of the present invention is for treating a slurry, such as sludge, with an ultrasonic energy without creating the undesirable cushion effect. Movable endless members are provided that are permeable to the liquid part of a sludge slurry and a first ultrasonic transducer is disposed adjacent to a first movable member and a second ultrasonic transducer is disposed adjacent to a second movable member. The slurry is fed in between the two movable members. The transducers generate pressure pulses through the members to form imploding cavitation bubbles in the sludge slurry that have an effect on the bacteria clusters. The cavitation bubbles have a resonance diameter (d 5 ) at the ultrasound frequency used that is greater than a distance (d 3 ) between the first transducer and the first member and a distance (d 4 ) between the second transducer and the second member to prevent the bubbles from imploding between the transducers and the members. By making the distance between the members smaller and smaller along the ultrasonic treatment path, a hydraulic pressure build-up between the members causes a dewatering of the slurry through the members giving a higher and higher dry solids content of the sludge slurry that is favorable for the efficiency of the ultrasonic treatment. The edges of the upper and lower members are pressed together to prevent the sludge from leaving the treatment zone in the cross machine direction. When treating liquids there are wedge formed sidewalls between the members and the edges of the members are pressed towards these sidewalls and the contact areas are water lubricated to minimize friction. The treated sludge may then be pumped to an anaerobic fermentation tank. Biogas can be continuously removed from the sludge by the under-pressure in a degassing pump or other degassing unit in a circulation loop connected to the fermentation tank before any gas bubbles are formed in the fermentation tank. The sludge slurry may again be subject to degassing and ultrasonic treatment before the slurry is sent to a press unit for dewatering.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of the formation of a reactor of a prior art system;
FIG. 2 is a graphical illustration of the correlation between iodine yield and acoustic power;
FIG. 3 is a perspective view of the transducer system of the present invention disposed below a movable endless member;
FIG. 4 is a cross-sectional view along line 4 — 4 in FIG. 3 ;
FIG. 5 is an enlarged view of cavitation bubbles dispersed in slurry disposed above the movable endless medium.
FIG. 6 is a cross-sectional view of a second embodiment of the transducer system of the present invention;
FIG. 7 is a cross-sectional view of a plurality of transducers disposed below a movable endless medium;
FIG. 8 is a schematic view of a portion of a sludge plant of the present invention;
FIG. 9 is a detailed view of the wires and ultrasonic transducers of the device of the present invention;
FIG. 10 is a schematic view of the sludge and drainage water treatment plant of the present invention;
FIG. 11 is a schematic view of the liquid treatment unit of the present invention; and
FIG. 12 is a schematic view of another embodiment of the present invention for washing of polluted soil.
DETAILED DESCRIPTION
FIG. 1 is a side view of a prior art transducer system 10 that has a container 11 , such as a stainless reactor, with a wall 12 for containing a liquid 13 . A transducer 14 is attached to an outside 16 of the wall 12 . When the transducer 14 is activated, a pillow 18 of cavitation bubbles 20 are formed on an inside 22 of the wall 12 due to the fracture zone in the liquid 13 that may be a result of fracture impressions on the inside 22 of the wall 12 . The bubbles may be held to the inside wall due to the surface tension of the liquid 13 . The bubbles 20 are good insulators and prevent the effective transmission of the ultrasonic energy into the liquid 13 . The under-pressure pulses of the ultrasonic energy transmitted by the transducer 14 create the cavitation bubbles. In this way, the pressure inside the bubbles is very low.
FIG. 2 is a graphical illustration that shows the iodine yield is affected by increased acoustic power on the system 10 . The more power is applied, the thicker the formation of the bubbles 20 , as shown in FIG. 1 , and the yield increase is reduced and drops sharply at power ratings over 100 Watts in this case. In this way, the cavitation bubbles severely limit the usefulness of increasing the acoustic power to improve the iodine yield.
FIG. 3 is a perspective view of the transducer system 100 of the present invention. The system has a movable endless permeable medium 102 , such as a woven material, paper machine plastic wire or any other bendable medium permeable to liquids, that is rotatable about rollers 104 that guide the medium 102 in an endless path. As explained below, it is important that the medium is permeable to a liquid that may carry ultrasonic energy to the liquid disposed above the medium 102 so as to effectively create the cavitation bubbles in the liquid or slurry to be treated. The ultrasonic energy may be used to reduce flocculation 163 , best shown in FIG. 5A , of fibers in the liquid to be treated because the bubbles implode or collapse to generate pressure pulses to the fiber flocculation 163 so that the fibers are separated from one another to evenly distribute or disperse the fibers in the liquid. The pressure pulses may be about 500 to 1000 bars so the pulses are more forceful than the forces that keep the fiber flocculation together. In general, the longer the fibers are or the higher the fiber consistency is, the higher the tendency of flocculation.
The medium may have a rotational speed up to 2000 meters per minute in a forward direction as shown by an arrow (F). An elongate foil 106 , made of, for example, steel or titanium is disposed below the permeable medium 102 and extends across a width (W) of the medium 102 . A plurality of transducers 108 , such as magnetostrictive, piezoelectric or any other suitable type of transducers, is in operative engagement with the foil 106 such as by being integrated therewith or attached thereto.
FIG. 4 is a detailed view of one of the transducers 108 attached to a mid-portion 118 of the hydrodynamic foil 106 . More particularly, the foil 106 has a rear portion 110 and a front portion 112 . The rear portion 110 has a rectangular extension 114 that extends away from a top surface 116 of the foil 106 . The mid-portion 118 of the foil 106 has a threaded outside 120 of a connecting member 122 also extending away from the top surface 116 so that a cavity 124 is formed between the extension 114 and the connecting member 122 .
The front portion 112 has an extension 126 that extends away from the top surface 116 and has a back wall 128 that is perpendicular to a bottom surface 130 of the foil 106 so that a cavity 132 is formed between the back wall 128 and the member 122 . The extension 126 has a front wall 134 that forms an acute angle alpha with the top surface 116 . The cavities 124 and 132 provide resonance to the ultrasound transmitted by the transducers 108 to reinforce the amplitude of the vibrations of the ultrasound. The front wall 134 forms an acute angle alpha with a top surface 116 of the foil 106 to minimize the pressure pulse when the water layer under the member is split by the front wall 134 so a larger part of the water is going down and only a minor part is going between the top side of the foil 116 and the member 102 . When the member 102 is moving over the foil surface 116 a speed dependant under-pressure is created that will force down the member 102 against the foil surface 116 . When the member is leaving the foil 106 there is room to urge the liquid 156 through the member 102 .
In other words, the design of the extension 126 is particularly suitable for paper manufacturing that has slurry of water and fibers. The water layer split at the front wall 134 creates an under-pressure pulse so that the water on top of the moving member flows through the member 102 and into a container there below. The design of the extension 126 may also be designed for other applications than paper making that is only used as an illustrative example.
The transducer 108 has a top cavity 136 with a threaded inside wall 138 for threadedly receiving the member 122 . The transducer 108 may be attached to the foil 106 in other ways. For example, adhesion or mechanical fasteners may attach the transducer. The present invention is not limited to the threaded connection described above.
Below the top cavity 136 , a second housing cavity 140 is defined therein. The cavity 140 has a central segment 141 to hold a bottom cooling spacer 142 , a lower piezoelectric element 144 , a middle cooling spacer 146 , an upper piezoelectric element 148 and a top cooling spacer 150 that bears against a bottom surface 152 of the connecting member 122 . The spacers 142 , 146 , 150 are used to lead away the frictional heat that is created by the elements 144 , 148 .
By using three spacers, all the surfaces of the elements 144 , 148 may be cooled. As the piezoelectric elements 144 , 148 are activated, the thickness of the elements is changed in a pulsating manner and ultrasonic energy is transmitted to the member 122 . For example, by using a power unit with alternating voltage of a level and frequency selected to suit the application at hand, the elements 144 , 148 start to vibrate axially. In this way, if the AC frequency is 20 kHz then a sound at the same frequency of 20 kHz is transmitted. It is to be understood that any suitable transducer may be used to generate the ultrasonic energy and the invention is not limited to piezoelectric transducers.
FIG. 5 is an enlarged view of a central segment 154 so that the permeable movable member 102 bears or is pressed against the top surface 116 of the member 122 of the foil 106 so there is not sufficient space therebetween to capture cavitation bubbles. In other words, an important feature of the present invention is that a gap 155 defined between the foil 106 and the member 102 is much less than the critical bubble diameter so that no bubbles of critical size can be captured therebetween. The gap 155 between the member 102 and the foil 106 is defined by the tension in the member 102 , the in-going angle between the member 102 and the foil 106 , the pressure pulse induced by the water layer split at the front of the foil 106 , the geometry of the foil 106 , the under-pressure pulse when the member 102 leave the foil 106 and the out-going angle of the member 102 . The bubbles 158 have a diameter d 1 that is much longer than the distance d 2 of the gap 155 between the top surface 116 of the foil 106 and the bottom surface 161 of the permeable member 102 . In this way and by the fact that the member 102 is moving, the cavitation bubbles 158 are forced to be created above the permeable member 102 and by imploding disperse the liquid substance 156 that is subject to the ultrasonic treatment and disposed above the member 102 . The liquid substance 156 has a top surface 160 so that the bubbles 158 are free to move between the top surface 160 of the substance 156 and a top surface 162 of the member 102 . In general, the effect of the ultrasonic energy is reduced by the square of the distance because the liquid absorbs the energy. In this way, there are likely to be more cavitation bubbles formed close to the member 102 compared to the amount of bubbles formed at the surface 160 . An important feature is that because the member 102 is moving and there is not enough room between the foil 106 and the member 102 , no cavitation bubbles are captured therebetween or along the top surface 162 of the movable member 102 .
The second embodiment of a transducer system 173 shown in FIG. 6 is virtually identical to the embodiment shown in FIG. 4 except that the transducer system 173 has a first channel 164 and a second channel 166 defined therein that are in fluid communication with an inlet 168 defined in a foil member 169 . The channels 164 , 166 extend perpendicularly to a top surface 170 of a connecting member 172 . The channels 164 , 166 may extend along the foil 169 and may be used to inject water, containing chemicals, therethrough. For example, in papermaking, the chemicals may be bleaching or softening agents. Other substances such as foaming agents, surfactant or any other substance may be used depending upon the application at hand. The ultrasonic energy may be used to provide a high pressure and temperature that may be required to create a chemical reaction between the chemicals added and the medium. The channels 164 , 166 may also be used to add regular water, when the slurry above the moving member is too dry, so as to improve the transmission of the ultrasonic energy into the slurry. The chemicals or other liquids mentioned above may also be added via channels in the front part of the transducer assembly bar 106 . If the liquid content of the medium to be treated is very low, the liquid may simply be applied by means of spray nozzles under the web. Also in those cases may the applied liquid be forced into the web by the ultrasonic energy and afterwards be exposed to sufficient ultrasound energy to cause the desired reaction to take place between the chemicals and the medium to be treated.
FIG. 7 is an overall side view showing an endless bendable permeable member 174 that is supported by rollers 176 a-e . Below the member 174 is a plurality of transducer systems 178 a-e for increased output by adding more ultrasonic energy to the system. By using a plurality of transducers, different chemicals may be added to the slurry 179 , as required. The slurry 179 contains fibers or other solids, to be treated with ultrasonic energy, is pumped by a pump 180 in a conduit 181 via a distributor 182 onto the member 174 that moves along an arrow (G). The treated fibers may fall into a container 184 .
The transducer system of the present invention is very flexible because there is no formation of cavitation bubble pillows in the path of the ultrasonic energy. By using a plurality of transducers, it is possible to substantially increase the ultrasonic energy without running into the problem of excessive cavitation bubbles to block the ultrasound transmission. The plurality of transducers also makes it possible to add chemicals to the reactor in different places along the moving member, as required.
FIG. 8 shows a portion of a sludge treatment plant 200 that has a sludge inlet 202 of a pipe 203 so that a slurry such as a sludge 204 may be pumped through a fiberizer device 206 for dispersing lumps and other aggregates that may have been formed in the sludge 204 . The plant 200 may be a full flow system that permits the continuous feeding in with ultrasonic treatment, continuous circulation with ultrasonic treatment and continuous feeding out with ultrasonic treatment of the sludge slurry 204 , but in that case three separate ultrasound treatment units are needed. The shown plant 200 is meant for part time input with ultrasonic treatment, full time circulation, part time circulation with ultrasonic treatment and part time output to press with ultrasonic treatment
Biological drainage and retention aid tube 208 may be in fluid communication with the pipe 203 to permit the addition of biological drainage substances and other treatment substances into the pipe 203 . The sludge 204 flows into a specialized pump 212 that not only functions as a regular pump but also deaerates the sludge before pumping the sludge onto an endless member such as a continuous movable under-wire 214 that may be similar to the endless member 102 , described above. The deaeration is used to improve drainage of the sludge on the wire 214 and to reduce the required length of the ultrasound treatment. The centrifugal pump 212 may have a centrifuge drum connected to the pump wheel and an outlet 210 at the center of the pump inlet to allow low-density substances, such as air and other gases, to be separated from the sludge 204 that exits the pump along the outward periphery of the pump 212 . The use of the fiberizer device 206 and the pump 212 provide for improved dewatering and higher effectiveness of the ultrasound treatment.
When the sludge enters the rotatable under-wire 214 , the sludge is further dewatered by gravitation in a pre-drain zone 215 so that the dry substance content of the sludge 204 is increased to about 5-8%. The wire 214 extends and is supported by the rollers 216 , 224 so that an endless loop is formed.
The plant system 200 also has an upper wire 230 that extends between and is supported by the rollers 220 , 222 . The upper wire 230 exerts some pressure on the sludge disposed on the under wire 214 . The rollers 222 and 224 form a nip 226 . A plurality of vacuum or suction units 231 is disposed above the upper wire 230 . In this way, the sludge is subjected to both an upwardly directed, via vacuum and hydraulic pressure, and downwardly directed, via gravitation and hydraulic pressure, dewatering processes so that the dry substance content of the sludge is increased from about 5-8% at the roller 220 to about 10-15% after the nip 226 . A vacuum or suction unit 231 is disposed under the lower wire 214 to bring the sludge cake to follow the lower wire 214 when the wires separate after the nip 226 . Ultrasonic transducers 234 are disposed above the upper wire 230 and ultrasonic transducers 236 are disposed below the under-wire 214 so that the sludge is continuously subjected to ultrasound treatment, similar to the ultrasound treatment described in detail above, between the rollers 220 , 222 . As a result of the dewatering process, the average dry substance content of the sludge is about 8-11% during the ultrasonic treatment in the nip 226 . The very high dry substance content reduces the specific energy consumption to about half of conventional systems.
After the first ultrasound treatment, most of the bacteria cell walls are punctured and those bacteria are killed. In this way, the inside bacteria protoplasm is dispersed into the sludge/water suspension so that anaerobic bacteria in the fermentation tank can attack and chemically degrade the exposed bacteria, bacteria walls and protoplasm much faster, as described in detail below.
As best shown in FIG. 9 , the transducers 234 , 236 are placed so close to the wires 214 , 230 so that the distance (d 3 ) between the transducers 234 and the wire 230 is significant less than a diameter (d 5 ) of a cavitation bubble 227 of critical size at used ultrasonic frequency. Similarly, the distance (d 4 ) between the transducers 236 and the under-wire 214 is less than the diameter (d 5 ) so that no cavitation bubbles 227 of critical size at used ultrasonic frequency may be captured between the transducers and the wires 214 , 230 . The wire 214 may be slightly angled or wedged relative to the upper wire 230 so that a gap 233 at an incoming end is slightly greater than a downstream gap 235 . The pressure on the sludge is thus gradually increased between the rotatable wires 214 , 230 as the sludge dryness increases. The wires 214 , 230 may also be parallel, if desired.
The sludge that has been treated with the ultrasound then falls from the wire 214 into a mixer 238 that tears substances into pieces with the spiral formed fins on the cylinders 239 , 241 . The mixer 238 mixes the treated sludge 204 with water 240 that comes from the ultrasound portion of the wire 214 . This water 240 includes all the enzymes and other biologically degradable substances 242 that may be in liquid form drained from the punctured bacteria in the sludge slurry. The sludge is then deaerated in a specialized pump 246 .
FIG. 10 shows a bigger portion of the plant 200 compared to FIG. 8 . The drainage water from the pre-drain zone 215 is led into a conduit 252 that may later be fed back into the mixer 238 or into the water treatment section 300 of the plant. A portion of the drainage water that includes the protoplasm from the collapsed bacteria flows through the vacuum or suction devices 231 and pumped direct into the mixer 238 . Another portion of the ultrasound treated drainage water flows into a conduit 254 and is led back into the mixer 238 . The sludge concentration is now reduced to about 5-6% in view of the added treated drainage water and is forwarded to the pump 246 . The pump 246 deaerates the sludge so that air is removed in view of the anaerobic environment and reactions in the fermentation tank 248 . The pump 246 then pumps the treated sludge including the treated drainage water, via a conduit 256 , to the fermentation tank 248 . The conduit 256 may have valves 258 , 260 . The tank 248 is filled with sludge 250 that has a dry substance content of about 5-6% that is the about the same as the sludge dry substance content in the mixer 238 that, in turn, is about the same as the sludge dry substance content prior to the ultrasonic treatment at the roller 220 . It may also be possible to add retention/drainage chemicals and fibers directly into the mixers 238 . This is done only when the sludge is destined to the dewatering press. No or very little gas should remain at the top of the tank 248 since the pump 246 removes the gas. Preferably, some gas should remain at the top of the tank 248 and the tank may be equipped with two safety valves in case of power outages. The biogas that is produced in the tank 248 has a much higher methane concentration compared to conventional treatment methods. The methane concentration is about 70-75% compared to 58-62% when conventional methods have been used. Also, the amount of biogas produced is higher. The sludge may be circulated in a conduit 262 connected to a third specialized pump 264 that removes biogas from the system. There is methane producing anaerobic bacteria in the sludge slurry 250 in the tank 248 . The methane gas is produced inside the cell membrane of the anaerobic bacteria and if the methane concentration is high in the slurry 250 , it becomes more difficult for the methane gas to escape through the cell membrane and into the slurry. By removing some of the methane gas in the slurry 250 , the osmotic transfer of the methane gas from the inside of the cell membrane out to the slurry is enhanced. If no methane gas is removed from the slurry 250 , the osmotic transfer may slow down drastically when the methane gas concentration is so high in the slurry 250 that it goes into saturation and gas bubbles start to grow. It should be noted that it with this invention is not necessary to wait until biogas bubbles are formed and float to the surface of the slurry 250 so that the biogas can be withdrawn from the top of the tank 248 as in conventional systems. The pump 264 returns the sludge back into the tank 248 but with substantially less biogas concentration. The biogas retrieved by the pump 264 may flow into a conduit 266 .
The plant 200 may be run in sequences. The first ⅓ of the time the tank 248 may be fed with ultrasonic treated and deaerated sludge according to the system described above. It is possible to subject the sludge to further ultrasound treatment, according to the system described above. For example, valves may be opened to permit the sludge in the tank 248 to flow into a conduit 268 and back on the wire 214 to again be subjected to the ultrasound treatment. This may be done the second ⅓ of the time, the plant 200 is used so that a part of all new bacteria that have been formed in the tank 248 may be punctured. All drain water, including the drain water from the pre-drain zone 215 , may be used in the mixer 238 to bring down the dry substance content to about 6% again before it is deaerated and pumped back into the tank 248 . The third ⅓ of the time may be used for feeding the treated sludge into a press unit 270 via a conduit 272 . The sludge may be ultrasound treated before the sludge is sent to the press unit 270 to make sure as many bacteria cells as possible are punctured since the presses in the press unit can only press out water between the bacteria cells and not fluid that may be disposed inside the cells. In this way, the press efficiency is improved by the ultrasound treatment of the sludge. All the time the plant 200 may at least partly be used for re-circulation in the conduit 262 to remove biogas.
When the fermentation is started in the tank 248 , the tank should have a carbon dioxide atmosphere so that the anaerobic bacteria may start working at full capacity on the sludge right away without any competition from aerobic bacteria. For example, the carbon dioxide may be pumped into the tank 248 before any processing has taken place in the tank 248 . In this way, any aerobic bacteria in the tank 248 and in the incoming sludge will die due to lack of oxygen and the anaerobic bacteria in the first incoming, at start up not ultrasound treated, sludge may start reproducing without any competition. The ultrasound treatment may be started when a sufficient amount of sludge with live bacteria has been pumped into the fermentation tank 248 with the sludge. The methane producing anaerobic bacteria are used to degrade as big part of the sludge that is pumped into the tank 248 as possible.
It is also possible to serially connect many fermentation tanks so that the gas that is withdrawn by the specialized pump in the circulation conduit from the first tank may be sent forwardly to the circulation of the second tank. The gas that is withdrawn from the second tank may be sent forwardly to the third tank etc. The gas that is withdrawn from the last fermentation tank may be sent away for gas purification. The effectiveness of the methane fermentation is thus further increased so that the methane concentration may reach 80% or higher.
FIG. 11 is a schematic view of the liquid treatment plant 300 of the present invention. A liquid 301 , such as water, is conveyed in a conduit 302 that has a pump 305 and passed through a filter 303 . The filter 303 removes particles from the liquid that could not pass through the rotatable wires 312 , 314 . The liquid may then go up into a tank 304 and is then passed through a degassing pump 306 connected to conduits 308 and 310 . The tank 304 may be used to regulate the pressure in the pump 306 . Gas may be passed through a conduit 307 to that, for example, air or other gas that is dissolved in the liquid is removed from the liquid in the conduit 310 . The conduit 310 extends in between two rotatably wires 312 , 314 and ozone water may be added at the inlet conduit 311 to kill some of the bacteria and oxidize solvents or other impurities in the liquid. As described in detail above, ultrasound transducers 316 are disposed adjacent to the wire 312 while ultrasound transducers 318 are disposed adjacent to the wire 314 . Ozone water may be added into the conduit 310 and also at the transducers 316 , 318 . The liquid that is passed between the wires 312 , 314 is subjected to the ultrasound and the ozone water treatment, 315 , 317 , respectively, to further reduce the bacteria level in the liquid. There are very good synergy between ultrasonic energy and ozone when dealing with killing rate of bacteria. The treated liquid is then drained at drainage or suction units 320 , 322 and into drainage cavities 321 , 323 . The liquid may be subjected to ultraviolet light 325 , 327 at passages 324 , 326 to even further reduce the bacteria level. The liquid has to be quite transparent by the time it passes the passages 324 , 326 to get good synergy for ultraviolet light together with ultrasonic energy and eventually used ozone according to bacteria killing rate. The liquid may then be conveyed in conduits 328 , 330 into a common conduit 332 for degassing treatment in a degassing pump 334 with a gas outlet 336 . The treated liquid may be pumped away in a conduit 338 . It may be possible to modify the system 300 so that the liquid may be re-circulated several times, as desired.
FIG. 12 is a schematic illustration of a second embodiment 400 of the present invention for washing of polluted soil in slurry. Polluted soil slurry 402 is conveyed through a pump 404 between movable wires 406 , 408 . The soil is subjected to ultrasound transducers 410 and the washed soil is collect at a collection site 412 . The water 414 that is collected from the soil slurry may be sent to the liquid treatment plant described above. The same ultrasound principles apply as described above.
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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The method is for treating a liquid or a slurry of a liquid and solids, such as sludge, soil or fiber webs, with an ultrasonic energy. Movable endless members ( 214, 230 ) are provided that are permeable to the liquid portion of a slurry ( 204 ). An ultrasonic transducer ( 236 ) is disposed adjacent to the member ( 214 ) and the ultrasonic transducer ( 234 ) is disposed adjacent to the member ( 230 ). The slurry is fed in between the members ( 214, 230 ). The transducers ( 234, 236 ) generate pressure pulses through the members ( 230, 214 ) to form imploding bubbles ( 227 ) in the slurry. The bubbles ( 227 ) have a diameter (d 5 ) that is greater than a distance (d 3 ) between the transducer ( 234 ) and the member ( 230 ) and a distance (d 4 ) between the transducer ( 236 ) and the member ( 214 ) to prevent the bubbles ( 227 ) from being captured between the transducers ( 234, 236 ) and the members ( 230, 214 ). In this way, the imploding bubbles can generate intense pressure, temperature and flow speed pulses in the slurry which can create sonochemical or sonophysical changes of the substances in the slurry without harming the ultrasonic transducer surfaces.
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FIELD OF THE INVENTION
The present invention relates to ropes, and more particularly, to a novel floating/sinking rope formed of non-corrosive/non-toxic materials having enhanced abrasion and UV resistance and in which the strands of the floating and sinking portions of the rope are joined in a unique way to enhance the breaking strength of the rope over its entire length and especially in the region where the floating and sinking portions are joined.
BACKGROUND OF THE INVENTION
Historically, crab and lobster fishermen have used two ropes joined together by a knot and attached one end to a float and the other end to a trap or "pot" employed for deep water fishing.
A normal rigging employs a sinking line having a specific gravity greater than one, i.e. a specific gravity greater than that of water, which extends from the float and having a length typically on the order of twenty-two (22) fathoms. The sinking line prevents the rope from floating upon the surface, thereby creating a potential hazard. At this point, the sinking line is joined, i.e. knotted to, a floating line having a specific gravity less than one with the length of the floating line being determined by the depth of the water. The floating line is then joined to the "pot". This design is extremely advantageous for use in such deep sea fishing since fishermen desire that the line attached to the "pot" should not scare the catch. This objective is accomplished by the floating rope section which floats above the "pot".
Joining the floating and sinking rope sections with a knot is disadvantageous since a knot of any type reduces the strength of a line by 50 percent. The knowledge of this degradation in strength has lead to the development of a partially leaded polypropylene line having a lead wire incorporated into a portion of the rope, said lead wire extending over a length of the order of twenty-two fathoms. A sufficient amount of lead is used to overcome the specific gravity of polypropylene which is less than that of water. In producing the rope, when the length of twenty-two fathoms is reached, the lead wire is terminated and the remainder of the rope length is formed by continuing the polypropylene portion of the rope which, having a specific gravity less than water (i.e., less than 1.0), floats.
Although the last-mentioned design provides a floating/sinking rope yielding the desired objectives of the fishermen, there are nevertheless some important deficiencies which include the following:
1. In cold water the ductility of the lead is significantly reduced and the lead becomes brittle. Due to the natural elongation of the polypropylene line when in use (the elongation is commonly of the order of 15 percent) the lead breaks, and, through continued use, the lead works its way out of the line thereby decreasing its sinkability.
2. The lead lost into the sea becomes an environmental threat, due to its toxicity (i.e., lead is poisonous).
3. The polypropylene line softens due to the voids caused by the lead which has worked its way out of the polypropylene line causing the line to wear more quickly thus significantly reducing its operating life.
4. The lay of the entire line changes as the rope, when floating freely, works itself toward a neutral lay or degree of twist.
It is, therefore, extremely advantageous to provide a rope having all the characteristics of the floating/sinking ropes of the prior art which overcome the disadvantages of lead filled rope and rope whose floating and sinking portions are knotted together.
BRIEF DESCRIPTION OF THE INVENTION
The present invention is characterized by comprising a floating/sinking rope which is formed of materials which are non-metallic and hence non-corrosive and, more particularly, which are non-toxic. The rope is formed of synthetic materials and, more particularly, synthetic plastic materials of first and second types having specific gravities respectively greater than and less than 1.0 (1.0 being the specific gravity of water). The materials preferably have contrasting colors to differentiate the floating and sinking rope portions by a simple visual observation.
The floating portion of the floating/sinking rope is preferably formed first and is comprised of strands, each having a plurality of blended yarns formed of a combination of the materials of said first and second specific gravities whose proportions are selected to yield yarns having a resultant specific gravity less than one.
The blended yarns are arranged so that the filaments having a specific gravity greater than one and which are also resistant to ultraviolet radiation and have a superior abrasion resistance, are arranged to form a cover layer surrounding the filaments having a specific gravity less than one.
Rope strands are formed by combining a predetermined number of the blended yarns, all of substantially the same diameter. When the strand being formed reaches a predetermined length, selected yarns of said strand are terminated in a staggered fashion along the length of the strand and each terminated yarn is replaced with a yarn formed only of fibers having a specific gravity greater than one to thereby form the sinking rope section. The yarns of the sinking rope section which are not terminated are continued over the entire length of the floating section. By terminating the selected yarns of the floating rope section in a staggered fashion and hence initiating the replacement yarns for the sinking rope section in a complementary staggered fashion and by forming the blended and unblended yarns of substantially equal diameters, the yarns which are twisted to form each strand have a breaking strength in the transition region between the sinking and floating rope portions which is equal to the breaking strength of the sinking and floating rope portions themselves.
The fibers having a specific gravity greater than one are formed of a material having a high abrasion resistance and also having a high resistance to ultraviolet radiation. By surrounding the fibers of the blended yarns having a specific gravity less than one, which fibers are also highly sensitive to ultraviolet radiation, with the fibers having a specific gravity greater than one, the overall abrasion resistance of the rope and the overall resistance to UV radiation is greatly enhanced.
Once strands having sinking and floating portions of the desired length are formed, a plurality of such strands (typically three) are joined together, i.e. either twisted or braided, to form the floating/sinking rope. The elimination of knots and/or lead employed in prior art designs eliminates all of the disadvantages of floating/sinking rope of the lead filled type and the method of joining said sections provides a rope which has no reduced strength sections, especially in the transition region between the floating and sinking portions.
OBJECTS OF THE INVENTION
It is, therefore, one object of the present invention to provide a novel floating/sinking rope which totally avoids and eliminates metallic, corrosive and toxic elements typically utilized to form the sinking portion thereof.
Still another object of the present invention is to provide a novel floating/sinking rope having a sinking portion of enhanced flexibility as compared with conventional sinking rope portions.
Still another object of the present invention is to provide a novel floating/sinking rope having floating and sinking rope portions which are joined in a unique manner and which eliminates the need for knotting said sections together as well as eliminating the disadvantages which result from a knotted rope.
Still another object of the present invention is to provide a novel floating/sinking rope having a substantially uniform diameter over the entire length thereof.
Another object of the present invention is to provide a novel floating/sinking rope formed of synthetic materials having enhanced abrasion resistance and resistance to ultraviolet radiation as compared with conventional rope.
Still another object of the present invention is to provide a novel floating/sinking rope formed of synthetic materials of different specific gravities arranged in a fashion to form floating and sinking rope portions joined in a transition section in a manner such that the breaking strength of the transition section is substantially equivalent to the breaking strength of the floating and sinking portions.
BRIEF DESCRIPTION OF THE FIGURES
The above, as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:
FIG. 1 shows a simplified diagrammatic view comparing the rope of the present invention with conventional rope when in use;
FIG. 2a shows a sectional view of one strand of a floating section of rope designed in accordance with the principles of the present invention;
FIG. 2b is a sectional view showing a floating section of a three strand rope, each strand embodying the design shown in FIG. 2a;
FIG. 3a is a sectional view showing one strand of a sinking section of the rope embodying the principles of the present invention;
FIG. 3b shows a sectional view of the sinking section of a three strand rope embodying the strand arrangement shown in FIG. 3a;
FIG. 4 shows a schematic diagram of a system for forming strands in accordance with the principles of the present invention;
FIG. 4a is a front view of the reeve plate shown in FIG. 4;
FIG. 5a is a perspective view of apparatus for forming a floating/sinking rope;
FIG. 5b is a perspective showing of a detailed view of a portion of the apparatus for forming yarns in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a comparison of a fishing rope 10 of the prior art compared with a fishing rope 20 embodying the principles of the present invention.
Fishermen seeking deep sea catch such as crab and lobster, for example, have traditionally employed a rope 10 shown in FIG. 1 which is comprised of two rope portions, namely a sinking line portion 12 and a floating line portion 14 joined together by a knot 16. The sinking line 12, having a specific gravity greater than one is coupled at its upper end to float 17 and is coupled at its lower end to the upper end of floating line 14 by knot 16. The floating line, which has a specific gravity of less than one, has an overall length typically determined by the depth of the water. In the example shown in FIG. 1, the floating line has a length of forty-four fathoms. The lower end of floating line 14 is coupled to the "pot" 18. A knot of any type is known to reduce the strength of the rope by 50 percent, thereby yielding a rope 10 which is of inferior quality.
Rope 20 of the present invention has a sinking line portion 22 whose upper end is coupled to float 17 and a floating line portion 24 whose lower end is coupled to "pot" 18. Contrary to the design of rope 10, the rope 20 of the present invention has no knots, and makes a smooth transition from the sinking line portion 22 to the floating line portion 24 thereby significantly enhancing the overall strength of the line. As will be more fully described hereinbelow, the novel rope 20 of the present invention eliminates the need for metallic elements within the rope thus eliminating possible corrosion and also yields a non-toxic rope which does not contaminate or pollute the water and the inhabitants thereof.
As was pointed out hereinabove, one rope design which eliminates the need for knotting sinking and floating lines together utilizes a lead wire within the sinking rope portion. The amount of lead employed is a function of the rope material whose specific gravity is less than one. The lead wire is simply terminated at the lower end of the sinking rope portion when making the rope and the remainder of the rope, i.e. the floating line portion, is produced with the lead wire omitted. The material of the floating line portion obviously has a specific gravity of less than one in order to achieve the desired results.
The disadvantages of a lead-filled rope have been pointed out hereinabove and the lead-filled rope and knotted rope 10 shown in FIG. 1 clearly establish the need for a rope having the advantageous features of the present invention and, more specifically, which eliminates the disadvantageous features of lead-filled and knotted ropes of the sinking/floating type.
The present invention is characterized by comprising a sinking rope portion which is preferably produced first and which is comprised of a plurality of strands, each strand being substantially of the same common diameter and being formed of a plurality of blended yarns formed of first and second type material which are blended in accordance with a proportionality which yields strands having a specific gravity greater than one. FIG. 2a shows a typical strand S employed to make the sinking rope section. Strand S is comprised of a plurality of individual yarns Y each having the same common diameter. Each of the yarns Y is formed of first and second fibers wherein one of said fibers has a specific gravity which is less than one while the other fiber has a specific gravity of greater than one. These fibers are blended in such a manner as to form a yarn Y which has a resultant specific gravity of greater than one. Yarns Y will hereinafter be referred to as "blended yarns". In one preferred embodiment, the strand of the sinking rope section is formed of a polyester fiber "veneered" over a polyolefin fiber to produce a blended yarn that contains sufficient polyester, having a specific gravity of 1.38, to more than counterbalance the buoyant effect of the polyolefin which has a specific gravity of 0.91. The desired ratio of polyester to polyolefin is 51:49 in the preferred embodiment of the present invention. Thus, as shown in FIG. 2a, the polyolefin fibers form the core C of each yarn while the polyester fiber forms the outer layer L which completely surrounds the core C of each yarn Y.
The polyolefin fibers are sensitive to ultraviolet radiation. By covering the polyolefin fibers 100 percent with the polyester fibers, which are 100 percent ultraviolet resistant, the polyolefin fibers are protected from degradation due to ultraviolet radiation. In addition, the polyester fibers are also more resistant to abrasion than the polyolefin fibers thereby reducing abrasion between and among neighboring yarns within each strand, as well as between yarns of the adjacent strands forming the rope.
The polyolefin fibers may also contain a hindered amine light stabilizer (HALS) that resists ultraviolet degradation. The amount of stabilizer introduced guarantees minimal strength loss when tested at the approximate latitude of 30 degrees for one year of outdoor exposure.
Each of the blended yarns Y are of a common diameter, as shown.
The method of manufacture of the sinking section, the strands of which are produced first, is the production of the blended yarns to insure sinkability. When the normal twenty-two fathom length is reached, a sufficient number of the blended yarns in the sinking section (normally five to six) are exchanged for 100 percent polyolefin yarns. More specifically, the blended yarns Y are removed and are replaced by polyolefin yarns Y P as shown in FIG. 3a. Polyolefin yarns are formed of polyolefin fibers wherein each yarn Y P has a diameter substantially the same as the diameter of the blended yarns Y. The polyolefin yarns which, as was described hereinabove, have a specific gravity of 0.91, together with the ratio of the blended to the polyolefin yarns within the floating strand S F , is sufficient to form a strand S F which floats. The ratio of polyester to polyolefin is changed from the sinking rope section which is 51:49 to the desired 30 percent polyester, 70 percent polyolefin. The yarn exchange preferably takes place over a three to four fathom length in order to maintain the diameter of the rope uniform and in order to maintain its strength and integrity.
The manner of forming the blended yarn will now be described in greater detail in connection with FIG. 4 which shows a blended yarn veneering reeve (FIG. a) having a central opening E1 for receiving a yarn polyolefin fibers and openings E2 about its circumferential portion each for receiving yarns B comprised of polyester fibers.
The polyolefin yarn A is derived from a source O and passes through the central opening E1 in reeve plate E (see FIG. 4a). A plurality of bobbins B containing polyester yarn are arranged at spaced intervals about an imaginary circle and each bobbin feeds a polyester yarn through an associated one of the openings E2 in reeve plate E arranged about the circumference of the plate. FIG. 4 shows only two such yarns and bobbins for purposes of simplicity.
All of the yarns passing through the 1 reeve plate are drawn together to form a blended yarn G comprised of twisted polyolefin yarns and polyester yarns. The polyolefin yarn A in the extrusion line is maintained at a higher tension in moving toward the yarn twister, located at G, as compared with the tensions of the polyester yarns. Tension wheels F are operated to provide the desired tension. The tension differential causes the polyester yarns to wrap around the polyolefin yarn. The number of yarns of polyester B employed in forming a blended yarn and the line speed of the yarn twister determine the effectiveness of the cover. The twister, although not shown, may be any conventional twister capable of providing the desired twist. For example, note the twister 55 described in U.S. Pat. No. 3,201,930 and further disclosed in FIGS. 5 and 6 of said patent. Alternatively, any other suitable twister may be employed. The individual polyester and polyolefin yarns are preferably twisted preparatory to formation of the blended yarn shown in FIG. 4. The number of polyester yarns employed and the line speed of the yarn twister determine the effectiveness of the cover. So long as the relative tensions between the polyester and polyolefin yarns are different and so long as the tension on the polyolefin yarn is greater than the tension on the polyester yarns, the yarns with least tension will wrap around the higher tension yarn.
The number of fibers in the blended yarn is chosen to yield a composite blended yarn having a specific gravity greater than one. In the preferred embodiment, when employing polyester and polyolefin fibers, the ratio of polyester to polyolefin is 51 percent to 49 percent (i.e. 51:49). Given the specific gravities of these two materials, the resulting specific gravity of the blended yarn is greater than one.
In order to form a floating/sinking rope, the blended yarns are formed in the manner described in connection with FIG. 4 and the 100 percent polyolefin yarns are formed in any suitable fashion.
A strand of all blended yarns is formed utilizing the apparatus shown in FIGS. 5a and 5b. The rope strand is started with all yarns being the blended yarns Y (see FIG. 2a) having a specific gravity greater than one. FIG. 5b shows a strand creel 30 provided with a plurality of yarn bobbins 32 of the aforementioned blended yarns shown, for example, in FIG. 2a. The blended yarns are drawn through a strand die 34 and are ultimately led to a twister, for example, of the type described hereinabove. When a predetermined length of sinking rope is formed, selected ones of the blended yarns are exchanged by terminating selected ones of the blended yarns and switching them with 100% polyolefin yarns. This is accomplished by removing one of the packages of blended yarn from the strand creel 30 and replacing this package with a 100 percent polyolefin yarn package. The polyolefin yarn leader 36 is inserted into the center of the strand at the strand die 34 utilizing a strand insertion tool 38 shown in FIG. 5a. The leader end of the 100 percent polyolefin yarn is looped through the eye 38a of insertion tool 38. The tool 38 is pulled through the strand being formed within the tubular member 40. By looping the new yarn through the eye 38a of tool 38 and pulling the tool through the strand, the new yarn is introduced into the strand without a knot. This method insures both a substantially constant diameter and constant strength for the strand and thereby provides a rope of constant strength.
All of the blended yarns chosen to be replaced with the 100 percent polyolefin yarn are exchanged in a staggered fashion, preferably over a twenty foot length of strand to maintain rope strength and diameter uniform throughout the transition region between the floating and sinking portions. The transition section thus gradually moves from negative buoyancy to positive with no discernible change in its diameter. This is accomplished by employment of the staggered method and further by forming the blended yarns and the 100 percent polyolefin yarn of substantially the same diameter and twisting the yarns forming the strand.
In one preferred embodiment, the floating and sinking rope sections are made easily distinguishable to the eye by utilizing polyolefin yarns of a first color which replace the white blended yarns employed in the sinking portion of the rope thus aiding in a simple differentiation of the sinking and floating rope portions.
When the proper number of blended yarns have been replaced by 100 percent polyolefin yarns, the ratio of blended to polyolefin yarns is maintained throughout the remaining length of the rope. Typically, a floating/sinking rope has a sinking rope section of twenty-two fathom length and a floating rope section of the order of forty-four fathom length for a total length of sixty-six fathoms. However, any other rope length may be utilized depending upon the needs of the user and without departing from the rope design of the present invention.
The strands of the sinking rope portion are twisted together to provide the desired lay. FIGS. 2a and 3a show the cross-sectional configuration of a three strand rope designed in accordance with the principles of the present invention. If desired, the rope may be formed of a greater number of strands and, if desired, may also be a multi-strand braided rope.
By staggering the terminated blended yarns over a three to four fathom length (typically over a transition region of the order twenty feet) the diameter of the rope is maintained constant through the sinking rope portion, the transition region and the floating rope portion. In an embodiment wherein five to six blended yarns are terminated and replaced by an equal number of 100 percent polyolefin yarns, the individual yarns terminated may be spaced from one another in a staggered fashion so as to be of the order of two to three feet apart, it being understood that each of the blended yarns to be replaced are substituted by 100 percent polyolefin yarn in accordance with the method described hereinabove in conjunction with FIGS. 5a and 5b.
All of the strands of the sinking rope section of the three strand rope may be formed simultaneously and then twisted together to form the cross-section as shown in FIG. 2a. The transitions of each strand may be obtained in the manner described hereinabove and, once the blended yarns have been replaced in the staggered fashion by 100 percent polyolefin yarns, as described hereinabove, the strands of the floating rope section may then be twisted together to form a cross-section as shown in FIG. 3b. It should be noted that the blended yarns not replaced extend the entire length of the rope (sixty-six fathoms, for example). The twisting of the individual strands and the ultimate twisting of the strands forming the multiple strand rope enhance the strength of the rope in the transition region between the sinking and floating rope sections by tightly maintaining the replacement yarns in the strand.
Although the preferred embodiment described herein is preferably formed of polyolefin and polyester fibers, it should be understood that the same technique may be utilized by the employment of fibers having specific gravities which are respectively greater than and less than one and which have abrasion resistance and ultraviolet resistance preferably similar to that of the fibers employed in the rope of the present invention.
A latitude of modification, change and substitution is intended in the foregoing disclosure, and in some instances, some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein described.
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A unique fishing rope comprising floating and sinking portions. The sinking portion blended yarns made up of a blend of first and second non-metallic synthetic filaments in proportions to yield a sinking rope portion having a specific gravity greater than one. The sinking rope portion comprises strands having yarns of substantially the same diameter. The floating portion of the rope is formed by replacing selected ones of the blended yarns in each strand with yarns formed of a material having a specific gravity of less than one. The replacement yarns and the blended yarns are of the same diameter to enhance the integrity and strength of the rope. The yarns omitted from the sinking section and replaced with the yarns having a specific gravity less than one are terminated at staggered intervals and their replacement yarns are inserted at like staggered intervals forming a merged region between the sinking and floating portions having a tensile strength which is equivalent to the tensile strength of the sinking and floating portions. The rope material sensitive to ultraviolet radiation is surrounded and thus protected by the material resistant to ultraviolet radiation. The ultraviolet sensitive material may also be treated with a stabilizer material which enhances resistance to ultraviolet radiation.
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FIELD OF THE INVENTION
This invention relates to devices for retaining and fastening printed circuit boards within a rack or chassis.
BACKGROUND OF THE INVENTION
Elongated wedge-type devices for retaining printed circuit boards (“PCBs”) within elongated slots in racks or chassis are in common use. The devices typically include a center wedge having sloped surfaces at opposite ends and two end pieces having sloped surfaces that abut against the sloped surfaces of the center wedge. The retaining devices are typically constructed with three or five wedges. A screw or shaft extends lengthwise through and connects the end wedges and the center wedge. In operation, a PCB is typically fastened to the backside of the center wedge. The PCB, with the retaining device attached thereto, is placed within the desired slot of the rack. Rotating the screw or shaft in one direction draws the two end wedges toward each other, causing them to deflect transversely on the sloped abutting surfaces of the center wedge. This results in increasing the device's effective width and wedging the PCB into the desired location. Rotating the screw in the opposite direction moves the two end wedges apart from each other bringing them back into longitudinal alignment with the center wedge and, thereby, releasing the PCB. Examples of such devices are described in greater detail in U.S. Pat. Nos. 4,775,260, 5,607,273, and 5,779,388, which are hereby incorporated by reference.
PCB retaining devices are preferably designed to limit the amount of force applied to the PCB while held in a slot. One solution to this problem has been to integrate clutch assemblies into the retaining device. The clutch is typically configured to have a first and second clutch head having cooperating teeth. By manipulating the angle of the clutch head teeth and the force in which the clutch heads are urged together, the torque applied to the screw and, in turn, the wedging force generated by the retaining device may be controlled. Unfortunately, the integration of the clutch assembly into the retaining device has typically led to the use of custom components in the retaining device. Utilization of custom components results in increased design and manufacturing costs and limits the number of suppliers from which the components can be sourced. It would be desirable to develop a PCB retaining device that maximizes the use of off-the-shelf parts without sacrificing utility. If custom components are used, it would be desirable to limit them to small, relatively affordable components.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the foregoing, one aspect of the present invention is to provide a PCB retaining device that overcomes the shortcomings of the prior art. More particularly the present invention is to provide a PCB retaining device that incorporates a clutch design configured to allow for the use of a standard, off-the-shelf type screw in the retaining device.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which
FIG. 1 is a perspective view of a PCB retaining device according to the present invention;
FIG. 2 is a perspective view of a wedge assembly and screw of a PCB retaining device according to the present invention; and,
FIG. 3 is perspective view of a clutch assembly and screw of a PCB retaining device according to the present invention.
DESCRIPTION OF EMBODIMENTS
Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In accordance with the present invention, a PCB retaining device 10 is depicted in FIGS. 1 through 3 . The retaining device 10 may be attached to a PCB (not shown) at a backside 26 of the center wedge 20 by screws or rivets. The center wedge 20 includes the sloped surfaces 22 and 24 at its opposite ends. The retaining device 10 may further include the wedges 30 having sloped surfaces 32 and 34 on opposite sides. The sloped surfaces 32 of the wedges 30 abut the sloped surface 22 and 24 of the center wedge 20 . The first and second end pieces 40 and 50 include the sloped surfaces 42 and 52 , respectively that abut against the sloped surfaces 34 of the wedges 30 . A screw 60 engages a clutch assembly 100 positioned within a recess 44 formed in the first end piece 40 . The screw 60 passes through a first wedge 40 , the center wedge 20 , and a second wedge 30 . A threaded bore 54 of the second end piece 50 receives a distal end 64 of the screw 60 .
In a manner analogous to that described with respect to the prior art, drawing the two end pieces 40 and 50 toward each other by rotating the screw 60 causes the two wedges 30 to move together transversely relative to the center wedge 20 . An elongated channel through the center wedge 20 and the wedges 30 (not shown) is sized and shaped to accept the screw 60 and permit this relative transverse movement of the screw 60 . This transverse movement effectively increases the width of the retaining device 10 , and thereby locks the attached PCB into a slot. It would be appreciated by one skilled in the art that a PCB retaining device according to the present invention may incorporate any odd number of wedging components. For example, a retaining device in accordance with the present invention may alternatively comprise only the center wedge 20 and the two end pieces 40 and 50 .
The retaining device 10 also includes a clutch assembly 100 for limiting the maximum forward torque that can be applied to the screw 60 . This, in turn, controls the clamping force of the retaining device 10 , and thus prevents possible physical or functional damage to the PCB being retained. With particular reference to FIG. 3 , the clutch assembly 100 includes (1) a drive head 110 having a proximal recess 112 , a groove 114 , and a distal recess 116 ; (2) a spring 120 ; (3) a shaft 130 having a first clutch head 132 ; and (4) a clutch interface 140 , having a second clutch head 142 and a tool 144 .
The proximal recess 112 of drive head 110 is configured to receive a conventional driver tool such as, but not limited to, a Phillips tip driver, square tip driver, triple square tip driver, torx tip driver, nut driver, or hexagonal driver. The groove 114 of the drive head 110 is sized and shaped to engage the pins 70 inserted through the holes 46 of the first end piece 40 . Engagement of the pins 70 by the groove 114 serve to axially, but not rotationally, secure the drive head 110 within the first end piece 40 . The distal recess 116 of drive head 110 serves to receive the shaft 130 which passes through the spring 120 . The shaft 130 and the distal recess 116 are sized and shaped to be complementary to one another, e.g. the shaft 130 is illustrated as a hexagonal shaft and the female recess 116 as a hexagonal recess operable for receiving and engaging the shaft 130 . It will be recognized that the shaft 130 and the distal recess 116 may be sized and shaped in any number of cross sectional shapes operable to facilitate engagement between the two components. Because the drive head 110 is secured in a fixed location within the first wedge 40 by the pins 70 , the spring 120 acts against the drive head 110 and serves to push the shaft 130 away from the drive head 110 , thereby urging the first clutch head 132 of the shaft 130 towards the second clutch head 142 of clutch interface 140 .
Of particular significance is the configuration of the clutch interface 140 . The clutch interface 140 serves, in part, to couple the clutch assembly 100 to the screw 60 . As illustrated in FIG. 3 , the clutch interface 140 comprises the second clutch head 142 on one side and the male tool 144 on the other side. As described with respect to the prior art, the first clutch head 132 and the second clutch head 142 each have a series or pattern of teeth that are complementary to and operable to engage with one another. The tool 144 is sized and shaped to emulate the working portion of a conventional driver tool such as, but not limited to, a Phillips tip driver, square tip driver, triple square tip driver, torx tip driver, nut driver, or hexagonal driver and to thereby engage the screw head recess 62 of the screw 60 . It will be appreciated that the above described configuration of the interface 140 allows for the incorporation of a standard, off-the-shelf type screw that may be purchased from numerous suppliers of fasteners and screws. Alternatively stated, it is preferable that screw 60 not be a custom or specially designed and manufactured screw. For example, screw 60 may be a standard sized and shaped screw with a female hexagonal head. The ability to utilize an off-the-shelf screw 60 aids in reducing manufacturing costs and facilitates component sourcing for the retaining device 10 .
In use, a conventional driver tool such as a hex key is used to engage the proximal recess 112 of the driver head 110 , to rotate the driver head 110 and the first clutch head 132 of the shaft 130 . Because the spring 120 biases the first clutch head 132 against the second clutch head 142 , the rotation is coupled to the second clutch head 142 and, ultimately to the screw 60 .
The confronting faces of the first clutch head 132 and second clutch head 142 both include a series of ratchet teeth or other form of engageable series of recessions and protrusions. It should be appreciated that the angles selected for the teeth or other form of engageable series of recessions and protrusions may vary according to the torque limits selected, the frictional forces encountered, and the biasing spring force selected.
During a forward rotation of the driver head 110 , which tightens the PCB and retaining device 10 against the side walls of a slot, the screw 60 will eventually encounter significant resistance to further rotation. When this occurs, the surfaces of the first clutch head 132 will begin sliding or ramping up on the tooth surfaces of the second clutch head 142 , against the yielding resistance of the compression spring 120 . Eventually, the first clutch head 132 will be unable to overcome the resisting torque of the second clutch head 142 and slide over or cease to engage the teeth of second clutch 142 . At this stage the retaining device 10 will be tightened to a predetermined torque.
As shown in FIGS. 1 and 2 , a threaded nut 80 is used to secure the distal end of the screw 60 that transverses threaded bore 54 of second end piece 50 . This prevents an inadvertent disassembly of the wedges 30 and 20 and end pieces 40 and 50 by excessively unthreading the screw 60 .
Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
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A printed circuit board retaining device for use in securing a printed circuit board in an elongated slot of a rack provides an efficient design allowing for the utilization of an off-the-shelf screw in the device. A screw having a head located within a first end piece interconnects the first end piece, at least one elongated wedge, and a second end piece. A clutch assembly, also retained within the first end piece, is coupled to the screw by a tool configured to engage the screw head. The clutch assembly has a first and second clutch head. The second clutch head being attached to the opposite side of the tool configured to engage the screw head.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of U.S. patent application Ser. 13/371,662 filed Feb. 13, 2012, the entirety of which application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention deals with an apparatus that is useful for handling small segments of wire that is to be welded. Coiled wire is commercially packed, shipped and stored in a coiled configuration, most of the time using a storage container. However, this packed commercial wire is usually packed in large quantities, that is, many hundreds of feet which cannot be carried by any workman.
[0003] There exists equipment that is useful for handling large quantities of stored wire when used in a welding apparatus. Such equipment can be found in U.S. patent application Ser. No. 12/931,007, filed Jan. 21, 2011 in the name of Thomas W. Burns, the inventor in this patent application.
[0004] What is disclosed and claimed herein is a small device that allows one to carry a small quantity of wire along with the equipment to feed the wire into a welding apparatus. In use for welding, where the wire is fed to a welding gun, the wire enters the gun through the rear of the gun and is subjected to electrical energy wherein it melts and is placed into channels in the metal to be welded to form a weld bead. Even with small quantities of wire, if not controlled, the wire, upon leaving the tip of the welding gun, and before it is melted, typically bends in any given direction and does not lay into the channel to form the bead. Thus, one is forced to use very short segments of wire (which do not retain the cast of the coiled wire), or the wire is short enough that it can be hand bent to get rid of the wire cast and provide a straight piece of wire.
[0005] Even in longer segments, the wire, if not controlled; tends to re-coil, that is, attempts to resume its original cast, or bends out of linearity and causes disruptions in the equipment, which causes a disruption of the welding process and a possible shutdown of the equipment for repair. It also provides snarled and bent wire which is useless for re-use and is costly to replace.
[0006] Thus, what is disclosed and claimed herein is a wire handling facilitator in the form of a backpack. The wire handling facilitator comprises a housing having a front, a back, and a central wrap around side wall joining the back. The front is a hinged door.
[0007] Located and supported within the housing is a spool. The spool has a centered first axle having a distal end and a near end. The first axle is supported at the distal end by attachment to an inside back wall surface. The near end has detachedly attached to it, a spool retainer.
[0008] There is an alignment wheel mounted on a second axle, wherein a distal end of the second axle is fixedly attached to the inside back wall surface. There is a brake pedal having a near end and a distal end wherein the near end has a first opening in it. The brake pedal is mounted on the second axle through the first opening, there being a second opening near the near end of the brake pedal. The second opening has a near end of a tension spring detachedly attached to it, wherein the opposite end of the tension spring is detachedly attached to the wire handling facilitator housing nearby.
[0009] The alignment wheel is aligned to receive a wire from the spool in an outer groove of the alignment wheel. There is a wire drive puller and driver (drive rollers, drive wheels). The wire drive puller and driver is comprised of a housing having a front wall and a back wall.
[0010] There is a first opening in the front wall and a second opening in the back wall, each of the first opening and the second opening has a guide bushing inserted in it. There is a set of two drive rollers each having a centered axle, and an outside circumference, the set of drive rollers being vertically aligned with the alignment wheel and the drive rollers are vertically aligned with each other. The drive rollers are in close proximity to each other at the respective outside circumferences. There is a means of controlling the drive roller tensions.
[0011] There is a set of two idler rollers each having a centered axle and an outside circumference wherein the set of idler rollers is aligned with the alignment wheel and vertically aligned with each other. The idler rollers are in close proximity to each other at the outside circumferences. There is a means of controlling the speed of rotation of the drive rollers along with a drive motor attached to the drive rollers for powering and driving the drive rollers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings illustrate preferred embodiments of the disclosed method so far devised for the practical application of the principles thereof, and in which:
[0013] FIG. 1 is a full side view of a device of this invention.
[0014] FIG. 2 is a full back view of a device of this invention.
[0015] FIG. 3 is a full front view of a device of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Turning now to FIG. 1 , which is a full side view of a device 1 of this invention, there is shown a housing 2 which is comprised of a front 3 , a back 4 , and a central wrap around side wall 5 joining the back 4 . The front 3 is comprised of a hinged door held in place and moveable for opening by hinges 6 . The number of hinges 6 is not critical, as long as they will hold the door in place and allow opening of the door without interference. The number of hinges 6 in FIG. 1 is shown as three. The shape of the housing 2 is also not critical. The back 4 of the housing 2 is configured essentially according to the configuration of the front 3 . The housing 2 is held together by attachment to the wrap around side wall 5 which is shown in FIG. 2 .
[0017] There is a spool 7 that is supported on the back wall 4 by an axle assembly 8 . There is a retainer 9 for the spool 7 on the axle 8 .
[0018] There is a wire speed adjustment assembly 12 on the outside surface of the wrap around side wall 5 which controls the speed of any wire 15 (shown in phantom in FIG. 1 ) being unspooled from the spool 7 .
[0019] There is a fastener 13 for the front door and two belt loop rings 14 for attachment to a workman's belt. This allows the workman to handle the device 1 and its wire without having to use his hands.
[0020] There is an in-line guide wheel 16 that gathers the wire 15 as it moves from the spool 7 and guides it into the drive wheels 17 and the idler wheels 18 in the drive wheel housing 19 . There is a bushing 20 in the front wall 21 of the drive wheel housing 19 that accommodates the efficient transport of the wire 14 to the drive wheels 17 and the idler wheels 18 . There is also a bushing 22 in the back wall 23 of the housing 19 to accommodate the transport of the wire 15 out of the back of the device 1 .
[0021] The guide wheel 16 has rotatably attached to the axle 25 , a brake 26 , which extends to the edge surface of the spool 7 and provides a braking or snubbing action on the spool 7 such that the wire 15 does not unwind and snarl. The brake 25 has a tensioning device 27 , which is comprised of a spring 28 that is attached to the brake 25 and the opposite end is attached to the wrap around side 2 .
[0022] Turning now to FIGS. 2 and 3 , which are respectively, a full wraparound back side of the device 1 and a full wraparound front side view of the device 1 , there is shown housing 2 , the front 3 , the back 4 , the wrap around side 5 , the hinges 6 , the spool 7 , the axle assembly 8 , the retainer 9 for the spool 7 , guide pins 10 for the spool 7 , wire spool speed control 12 , the fastener 13 for the front 3 , the belt loop ring 14 , the wire 15 , the guide wheel 16 , the idler wheels 18 , the drive wheel housing 19 , the bushing 22 , in the back wall 23 of housing 19 , and in addition, there is shown the motor 29 which drives the drive wheels 17 . The designation 30 denotes a drive wheel tensioning device that allows for tensioning the drive wheels 17 .
[0023] Shown in FIG. 1 is a portion of the power and gas supply assembly 31 that goes to the welding gun (not shown). This supply assembly contains the electrical power for the gun and also the inert gas supply that is required on such guns. The inert gases usually consist of a gas selected from the group consisting of argon, helium, and carbon dioxide.
[0024] The drive wheels 17 pull the wire 15 from the spool 7 and feed it through the idler wheels 18 and then through the bushing 22 and thence into the back end of a gun equipped to weld the wire into grooves and seams for work product to be welded.
[0025] While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations and changes to the described embodiments are possible without departing from the spirit and scope of the invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.
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A wire handling facilitator in the form of a backpack. An apparatus that is useful for handling small rolls of wire that is to be welded into channels of metal surfaces.
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BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a memory and a method for producing the same, especially to an inorganic light-emitting memory and a method for producing the same.
[0003] 2. Description of Related Art
[0004] Numerous progresses have been achieved in the last several decades on semiconductors, such as memories and light-emitting diodes. With substantial improvement in performance and reliability, these devices are now widely used in different applications. Further progress in the related field may involve research on devices with various data storage capabilities, more functions, and higher compatibility. It is worthy of note that, in the development of communication technology, more demand is placed on high-speed inter-chip and intra-chip links. The conventional electronic devices gradually approach their limit due to the increasing difficulties in controlling the carriers at shrinking sizes.
[0005] Among several candidates for next-generation memory cells, resistive random access memory (RRAM) based on a simple two-terminal electrical switch has the potential to serve as a replacement for conventional memory structures due to its good switching properties, low power consumption and especially, three-dimensional multilayer stacking to achieve high density memories. Nevertheless, such RRAMs are still read in a serial sequence in which data are transmitted by scanning one bit after another. To significantly accelerate data transfer in practical applications, memories designed for parallel data reading are called for.
[0006] Korean patent publication No. 2011-0051427 discloses an organic light-emitting memory device comprising an organic memory coated with and sandwiched between an upper electrode material and a lower electrode material in order for the organic light-emitting memory device to serve the dual functions of a light-emitting element and a memory element.
BRIEF SUMMARY OF THE INVENTION
[0007] While organic light-emitting memory devices have been successfully developed, the properties of organic materials such poor thermo-stability and instability make those memory devices suitable for use only at room temperature or in vacuum and have limited further applications. For example, an organic light-emitting memory device cannot be integrated with the chip of a central processing unit simply because the high temperature generated by operation of the central processing unit is detrimental to the memory device.
[0008] To solve the above problem, the present invention aim to provide an inorganic light-emitting memory (ILEM), comprising: an inorganic light-emitting element and a resistive memory element stacked on the inorganic light-emitting element.
[0009] Preferably, the inorganic light-emitting element is a metal-insulator-metal (MIM), metal-insulator-semiconductor (MIS), p-n junction, or multiple-quantum-well (MQW) structure.
[0010] Preferably, the inorganic light-emitting element is further processed by lasing such that specific wavelength bands of light emitted by the inorganic light-emitting element laser.
[0011] Preferably, the resistive memory element is a metal-insulator-metal (MIM) structure. The metal-insulator-metal (MIM) structure of the resistive memory element includes an insulator layer formed of a binary or ternary oxide.
[0012] Preferably, the inorganic light-emitting element is a metal-insulator-metal (MIM) or metal-insulator-semiconductor (MIS) structure and the resistive memory element is a metal-insulator-metal (MIM) structure, the inorganic light-emitting element and the resistive memory element share a common metal layer where the resistive memory element is stacked on the inorganic light-emitting element. Preferably, the shared common metal layer is a graphene layer.
[0013] Preferably, the metal-insulator-metal (MIM) structure of the resistive memory element includes a metal particle layer formed between an upper metal layer and an insulator layer by coating. More preferably, the metal particle layer is formed of a metal having a +1 valence and high activity or metal having a +3 valence, such as Al.
[0014] Preferably, the metal-insulator-metal (MIM) structure of the resistive memory element includes metal layers selected from the group consisting of graphene, aluminum-doped zinc-oxide (AZO), indium tin oxide (ITO), indium zinc oxide (IZO) and transparent conducting oxide (TCO).
[0015] In contrast to the conventional electric memories, the inorganic light-emitting memory of the present invention allows data in the memory to be read optically. For instance, an optical transducer (e.g., a charge-coupled device, or CCD) can be used to receive data when the light-emitting memory is turned on. More specifically, a region which is not emitting light can be viewed as the logic “0”, and a light-emitting region, as the logic “1”. By monitoring the inorganic light-emitting memory, the optical transducer can detect and distinguish the various light emissions of the inorganic light-emitting memory so that data are readable as both optical signals and electrical signals in a parallel manner, thereby achieving high-speed data bandwidth. The present invention thus provides a novel inorganic light-emitting memory which works as an active device.
[0016] Furthermore, the manufacturing process of organic memories is totally different from that of inorganic memories. The inorganic light-emitting memory of the present invention overcomes the aforesaid drawbacks of its organic counterparts (i.e., poor thermo-stability and instability) and therefore has wider applicability and higher practical value.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] The structure and the advantages of the present invention will be best understood by referring to the following detailed description of some illustrative embodiments in conjunction with the accompanying drawings, in which:
[0018] FIG. 1( a ) is a schematic structural diagram of example 1 of the present invention, and FIG. 1( b ) shows the photoluminescence (PL) spectrum of p-GaN at room temperature;
[0019] FIG. 2( a ) shows the I-V characteristic curves of the Ag/second SiO 2 /graphene memory element in example 1, and FIG. 2( b ) is a plot showing the switching characteristics of the Ag/second SiO 2 /graphene memory element in example 1 over 100 switching cycles;
[0020] FIG. 3( a ) shows the I-V characteristic curves of the inorganic light-emitting memory in example 1, and FIG. 3( b ) is a plot showing the switching characteristics of the inorganic light-emitting memory in example 1 over 100 switching cycles;
[0021] FIG. 4( a ) is a schematic structural diagram of example 2 of the present invention, and FIG. 4( b ) is an electron microscope image of the Ag nanoparticle layer in the structure of example 2 of the present invention;
[0022] FIG. 5( a ) shows the I-V characteristic curves of the AZO/Ag nanoparticles/SiO 2 /graphene memory element in example 2, and FIG. 5( b ) is a plot showing the switching characteristics of the AZO/Ag nanoparticles/SiO 2 /graphene memory element in example 2 over 10 switching cycles; and
[0023] FIG. 6( a ) shows the I-V characteristic curves of the inorganic light-emitting memory in example 2, and FIG. 6( b ) is a plot showing the switching characteristics of the inorganic light-emitting memory in example 2 over 100 switching cycles.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Hereinafter, illustrative embodiments and examples of the present disclosure will be described in detail with reference to the accompanying drawings so that inventive concept may be readily implemented by those skilled in the art.
[0025] However, it is to be noted that the present disclosure is not limited to the illustrative embodiments but can be realized in various other ways. In the drawings, certain parts not directly relevant to the description are omitted to enhance the clarity of the drawings, and like reference numerals denote like parts throughout the whole document.
[0026] Throughout the whole document, the term “comprises or includes” and/or “comprising or including” used in the document means that one or more other components, steps, operations, and/or the existence or addition of elements are not excluded in addition to the described components, steps, operations and/or elements. The terms “about or approximately” or “substantially” are intended to have meanings close to numerical values or ranges specified with an allowable error and intended to prevent accurate or absolute numerical values disclosed for understanding of the present invention from being illegally or unfairly used by any unconscionable third party.
[0027] The present invention provides an inorganic light-emitting memory. Herein, the term “inorganic light-emitting memory” (ILEM) refers to a device formed by a resistive memory element stacked on an inorganic light-emitting element so as to provide the functions of a memory and of a light-emitting semiconductor and allow data to be transferred through both electrical signals and optical signals. The bistable light-emitting state and the resistance switching property may result from filamentary conduction paths, as detailed further below.
[0028] The inorganic light-emitting element of the inorganic light-emitting memory of the present invention can be any of those commonly used in the prior art without limitation, such as an inorganic light-emitting element having a metal-insulator-metal (MIM), metal-insulator-semiconductor (MIS), p-n junction, or multiple-quantum-well (MQW) structure.
[0029] MIM structures are well known in the art, one common but non-limiting example of which is the Al-Al 2 O 3 -Au structure, whose preparation process is briefly stated as follows. A strip of Al is evaporation-deposited on a sheet of glass by a vacuum coating method. Once the Al strip oxidizes in air, a natural oxidation layer about 3 nm thick is formed. To prevent edge breakdown, a layer of MgF 2 is evaporation-deposited on either side of the Al strip. Lastly, a strip of Au, about 40 nm thick and perpendicular to the Al strip, is formed by evaporation deposition to create an Al-Al 2 O 3 -Au tunnel structure. When a direct-current (DC) bias voltage of about 3-5 V is applied between Au (i.e., the positive electrode) and Al (i.e., the negative electrode), the surface of the structure emits visible light.
[0030] MIS structures are also well known in the art, and it is understood that the metal layer in such a structure is not literally limited to metal but may include any electrically conductive material. In a preferred embodiment of the present invention, this electrically conductive layer is made of graphene, and the resulting MIS structure is hence a graphene-insulator-semiconductor (GIS) structure.
[0031] While there are no limitations on the insulator layer in the aforesaid MIM and MIS structures, a binary or ternary oxide is preferably used. In a preferred embodiment of the present invention, the insulator layer is formed of silicon dioxide.
[0032] There are also no limitations on the inorganic semiconductor in the aforesaid MIS structures. For example, group III-V or group II-VI inorganic semiconductors are applicable. Preferably, a group III-nitride semiconductor is used, for this kind of semiconductors are already employed in photoelectric devices and are mature in terms of manufacturing techniques. An InGaN-based light-emitting diode (LED) or laser diode (LD), for instance, can emit light in the ultraviolet to visible regions of the spectrum. GaN is also suitable for use. Not only is it easier to form a high-quality GaN film than one made of the ternary InGaN, but also GaN is capable of strong light emission. Moreover, phosphor powder can be incorporated to generate blue light, or quantum dots can be added in an appropriate concentration to produce the desired light color. More preferably, p-type GaN (p-GaN) is used due to the fact that, when the insulator layer is formed of silicon dioxide, the barrier height of SiO 2 /p-GaN is greater than that of SiO 2 /n-GaN. Using p-GaN as the substrate is therefore advantageous in that an inversion layer will be formed near the SiO 2 /p-GaN interface to facilitate accumulation of electrons. The accumulated electrons can readily tunnel through the holes in the overlying metal layer (e.g., a graphene layer) to generate light.
[0033] A p-n junction inorganic semiconductor refers to a semiconductor crystal whose one side is turned into a p-type semiconductor by doping and whose opposite side, an n-type semiconductor by doping differently. Such semiconductors are well known in the art. For instance, a silicon (or germanium) crystal can be doped with a small amount of phosphorus (or antimony) as the dopant to form an n-type semiconductor. More specifically, when an atom of the semiconductor (e.g., silicon) is replaced by a dopant atom (e.g., a phosphorus atom), four of the five outermost electrons of the phosphorus atom form covalent bonds with the neighboring semiconductor atoms. Meanwhile, the remaining electron is hardly bound and tends to become a free electron. Therefore, an n-type semiconductor is a semiconductor with a relatively high concentration of free electrons and owes its electrical conductivity mainly to electrical conduction by the free electrons. On the other hand, a silicon (or germanium) crystal can be doped with a small amount of boron (or indium) as the dopant to form a p-type semiconductor. More specifically, when an atom of the semiconductor (e.g., silicon) is replaced by a dopant atom (e.g., a boron atom), the three outermost electrons of the boron atom form covalent bonds with the neighboring semiconductor atoms, leaving behind an “electron hole” tending to attract a bound electron in order to be “filled”, and the electron hole, once filled, becomes a negatively charged ion. That is to say, a p-type semiconductor is electrically conductive because of a relatively high concentration of “electron holes”, which are “equivalent” to positive charges.
[0034] Multiple-quantum-well (MQW) structures for use as inorganic semiconductor light-emitting elements are well known in the art. Typically, the active layer of an inorganic light-emitting diode is a multiple-quantum-well structure. If the active layer contained only one quantum well, the space for receiving carriers would be limited, which in turn would lead to a carrier overflow and consequently an increased threshold current, and because of which the inorganic light-emitting diode would be susceptible to ambient temperature. This is why the number of quantum wells must be increased to form the so-called multiple quantum wells.
[0035] The inorganic light-emitting element can be further processed by lasing. In fact, any known lasing techniques can be adopted. For example, the interior of the inorganic light-emitting element can be plated with metal particles, or some protruding structures (e.g., nanoscale bar-like structures) or cyclic structures can be grown on the inner surface of the inorganic light-emitting element to enhance light emission efficiency. As certain portions (of specific wavelengths) of the light emitted by the inorganic light-emitting element resonate in the resonance chambers formed by such special surface structures, signals of specific wavelengths are amplified, and lasing is achieved if the full width at half maximum of the spectrum of these signals is less than 2 nm.
[0036] The resistive memory element of the inorganic light-emitting memory of the present invention can be any of those well known in the art, the most common structure of which is the metal-insulator-metal (MIM) structure. In the past, the metal layers are typically pure metal films formed of Au, Ag, Pt, Cu, Al, Cr, Pd, or Rh, with a thickness less than 10 nm. Nowadays, however, the metal layers are not literally limited to metal but may include any electrically conductive material. In a preferred embodiment of the present invention, the lower electrically conductive layer is formed of graphene, and the other metal layer is preferably a transparent conductive layer formed of a transparent conducting oxide (TCO) such as aluminum-doped zinc-oxide (AZO), indium tin oxide (ITO), or indium zinc oxide (IZO) in order not to block the light emitted by the underlying light-emitting element.
[0037] To increase the formation of metal filament networks of the transparent conductive layer, a metal particle layer can be formed between the upper metal layer and the insulator layer by coating, wherein the metal particles are of a metal having a +1 valence and high activity, such as Ag, Cu, Ni, etc, or metal having a +3 valence, such as Al.
[0038] If the inorganic light-emitting element is a metal-insulator-metal (MIM) or metal-insulator-semiconductor (MIS) structure and the resistive memory element is a metal-insulator-metal (MIM) structure, the inorganic light-emitting element and the resistive memory element share a common metal layer where the resistive memory element is stacked on the inorganic light-emitting element, with a view to integrating the two elements and downsizing the resulting assembly.
EXAMPLES
[0039] The disclosure of the present invention is further illustrated below by way of embodiments and the accompanying drawings. The disclosed invention, however, is by no means limited to those embodiments and drawings.
Example 1
Inorganic Light-Emitting Memory with Ag/SiO 2 /Graphene/SiO 2 /pGaN Structure
[0040] Graphene is formed on a copper foil by chemical vapor deposition (CVD) at a temperature as high as 1000° C., with the source of carbon being a mixture of methane and hydrogen. More specifically, carbon atoms from the gaseous reactant deposit on the metal substrate at about 1000° C. through chemical absorption. Then, the graphene is coated with poly(methyl methacrylate), or PMMA, in order to be aligned with and transferred to a p-GaN.
[0041] In this embodiment, the device structure consists of Ag/2 nd SiO 2 /graphene/1 st SiO 2 /p-GaN. The p-GaN was doped by Mg with the hole concentration in the range of 6×10 16 cm −3 . Initially, p-GaN wafer was rinsed in acetone, isopropanol and DI water. Ni/Au was firstly deposited on p-GaN with annealing to obtain an ohmic contact. The first SiO 2 layer with a thickness of 3 nm was grown on p-GaN via RF sputtering after the formation of Ni/Au ohmic contact. The graphene layer was then assembled by a transfer process on p-GaN. The second SiO 2 layer with a thickness of 50 nm was sequentially deposited on top of graphene. The ILEM was completed by the deposition of Ag electrode to serve as anode (the resistive memory element MIM and the inorganic light-emitting element GIS share a common graphene layer) shown in FIG. 1( a ) . The graphene was used as current spreading electrode, the Ni/Au contact was used as current collecting electrode (cathode) and the Ag contact was used as control electrode (anode).
[0042] In addition, to serve as the transparent conducting layer, graphene also works as a stable interlayer without affecting the redox reaction in the formation of metal filament networks. Moreover, because the tunneling 1 st SiO 2 layer only has a thickness of about 3 nm, the transferred graphene on top of the 1 st SiO 2 layer does not need the addition process for coating a metal film. It can avoid the damage of the thin 1 st SiO 2 layer and prevent leakage current.
[0043] In our device geometry, the top Ag electrode works as a reflective layer and the emitted light was detected from the p-GaN side. FIG. 1( b ) shows the photoluminescence (PL) spectrum of p-GaN under light excitation of 325 nm at room temperature. The PL spectrum is dominated by a blue emission peak at ˜415 nm and a broadband yellow emission at ˜550 nm.
[0044] Bistable switching performance of the memory cell is important to control the luminescence arising from of the ILEM. Therefore, we investigated the performance of the memory cell first. FIG. 2( a ) shows the I-V characteristics of the Ag/2 nd SiO 2 /graphene memory cell at room temperature; as can be seen, the Ag/2 nd SiO2/graphene memory cell was at the HRS initially and showed a low-current characteristics in the low voltage range; when the applied voltage exceeded to a certain value (˜3 V), the injection current increased dramatically followed by an abrupt increase in the current flow and was switched from the HRS to the LRS, where the ON/OFF current ratio is about 10 3 . To prevent damage during the I-V measurements, the present invention set a compliance current at 3 mA. The state transition is equivalent to the “writing” command in the digital storage devices and the ON/OFF current ratio promises a misreading probability in data access. According to previous reports, the conducting filament model with an electrochemical reaction is responsible for the resistive switching behavior. Hence, the state of Ag/2 nd SiO 2 /graphene memory cells can be switched between the HRS and the LRS using dc voltages.
[0045] Switching performances between HRS and LRS were evaluated by performing the operation 100 times, as shown in FIG. 2( b ) . The current fluctuation at the high resistance state (HRS) may come from the incomplete dissolution of metal filament network. It is clear that there was a little fluctuation of the HRS and LRS current levels and the ON/OFF ratio was quite stable.
[0046] FIG. 3( a ) shows the I-V characteristic of the ILEM at room temperature, which is similar to the I-V characteristics shown in FIG. 2( a ) . The current flow sharply increased by 2 orders of magnitude at a critical voltage (˜8 V) and reflected the fact that the ILEM was switched from the HRS to the LRS. The bistable switching performance of ILEM is due to the bistability of Ag/2 nd SiO 2 /graphene memory cell. Noting that the ILEM was achieved by developing a tandem structure, in which the writing voltage was expended since the voltage was applied to the graphene/SiO 2 /p-GaN (GIS-LED) and the Ag/2 nd SiO 2 /graphene (memory cell). Because the I-V characteristics depend on the corresponding HRS or LRS, it is expected that the electroluminescence (EL) intensity of ILEM should be different when the memory cell was switched from HRS to LRS. When the ILEM is at the HRS, there is no EL signal until ˜8 V bias. However, when the ILEM is at the LRS, the EL signal is detectable when the bias exceeds ˜6 V. The emission state of ILEM can be switched between the HRS and the LRS based on the I-V characteristics of the Ag/2 nd SiO 2 /graphene memory cell. Switching performances between the HRS and LRS were evaluated by performing the operation 100 times, as shown in FIG. 3( b ) . It is clear that the switching characteristic of EL signal is also quite stable.
Example 2
Inorganic Light-Emitting Memory Having the “AZO/Ag Nanoparticles/SiO 2 /Graphene/MQW LED” Structure
[0047] Graphene is formed on a copper foil by chemical vapor deposition (CVD) at a temperature as high as 1000° C., with the source of carbon being a mixture of methane and hydrogen. More specifically, carbon atoms from the gaseous reactant deposit on the metal substrate at about 1000° C. through chemical absorption. Then, the graphene is coated with poly(methyl methacrylate), or PMMA, in order to be aligned with and transferred to an MQW light-emitting diode.
[0048] As shown in the structural diagram of FIG. 4( a ) , the structure of this embodiment includes AZO, Ag nanoparticles, SiO 2 , graphene, and an MQW light-emitting diode. The MQW light-emitting diode is formed by sequentially depositing a layer of n-GaN, a multiple-quantum-well (MQW) layer of GaN/InGaN, and a layer of p-GaN on a sapphire substrate. Once formed, the MQW light-emitting diode is rinsed with acetone, ethanol, and deionized water. Then, a groove is formed in the MQW light-emitting diode by cutting, and the groove is plated with indium, which serves as the cathode. After that, the graphene layer is transferred to the MQW light-emitting diode and is provided with a 30-nm-thick SiO 2 layer by radio-frequency (RF) sputtering. Then, a layer of Ag nanoparticles (schematically shown in FIG. 4 a as the circular dots above the SiO 2 layer) is formed by RF sputtering, followed by the AZO anode, formed also by RF sputtering. Thus, the inorganic light-emitting memory is completed, with the MIM resistive memory element integrated, and sharing the same graphene layer, with the MQW LED inorganic semiconductor light-emitting element. The graphene layer functions as a current spreading electrode; the indium, as a current collecting electrode (cathode); and the AZO, as a control electrode (anode).
[0049] In addition, the AZO forms a transparent conductive layer while the Ag nanoparticles form a metal particle layer which has no adverse effect on light permeability. The silver atoms also provide oxidation and reduction in the resulting metal filament network. The size and distribution of the Ag nanoparticles are shown in FIG. 4( b ) .
[0050] As the bistable switching performance of the memory element is crucial in controlling the luminescence of the inorganic light-emitting memory, the performance of the memory element was tested. FIG. 5( a ) shows the I-V characteristic curves of the AZO/Ag nanoparticles/SiO 2 /graphene structure at room temperature. As can be seen in the drawing, the AZO/Ag nanoparticles/SiO 2 /graphene memory element was initially in a high-resistance state (HRS) and featured low current in a low-voltage range. When the voltage applied exceeded a certain range (1-2V), the injection current rose abruptly, and the structure was switched from HRS to a low-resistance state (LRS), where the ON/OFF current ratio is about 10 2 . To prevent damage during I-V measurement, a limiting current of 1 mA was set. The switching of the states is equivalent to the “writing” command in a digital storage device. As the filamentary conduction paths, where electrochemical reactions take place, are known to be responsible for the resistance switching behavior, a DC voltage can be used to switch between HRS and LRS of the AZO/Ag nanoparticles/SiO 2 /graphene structure.
[0051] The performance of switching between HRS and LRS was assessed by performing the aforesaid operation 10 times. As shown in FIG. 5( b ) , the current levels and the ON/OFF ratio remained quite stable in both HRS and LRS.
[0052] The I-V characteristic curves of the inorganic light-emitting memory at room temperature are plotted in FIG. 6( a ) and are similar to the I-V characteristic curves in FIG. 5( a ) . As shown in FIG. 6( a ) , current rose precipitously by two orders of magnitude at a critical voltage (˜3V), which reflects the inorganic light-emitting memory being switched from HRS to LRS. The bistable switching performance of the inorganic light-emitting memory originates from the bistability of the AZO/Ag nanoparticles/SiO 2 /graphene memory element. With the inorganic light-emitting memory being a series-connected structure, a writing voltage will increase after it is applied to the graphene/MQW LED element and the AZO/Ag nanoparticles/SiO 2 /graphene memory element. Since the I-V characteristics depend on the corresponding HRS or LRS, it is expected that the electroluminescence (EL) intensity of the inorganic light-emitting memory should be different from that of the memory element when switched from HRS to LRS. Test results show that while the inorganic light-emitting memory was in HRS, EL signals did not occur until the bias voltage reached about 4 V. When the inorganic light-emitting memory was in LRS, however, EL signals were detected as soon as the bias voltage exceeded about 2 V. As shown in the insert of FIG. 6( a ) , the light-emitting state of the inorganic light-emitting memory can be switched between HRS and LRS based on the I-V characteristics of the AZO/Ag nanoparticles/SiO 2 /graphene memory element. According to FIG. 6( b ) , which shows the HRS-LRS switching performance evaluation result obtained by effecting 100 switching cycles, the switching characteristics of EL signals were fairly stable.
[0053] While example embodiments have been disclosed herein, it should be understood that other variations may be possible. Such variations are not to be regarded as a departure from the spirit and scope of example embodiments of the present application, 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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The invention provides an inorganic light emitting memory, comprising resistive memory in tandem with inorganic light emitting element. It is ready to be extended into many other material systems for practical applications. In view of the unique features demonstrated by the integration of light emitters and memories, the inorganic light emitting memory may open up a new route for the development of integrated optoelectronic devices, optical communication, digital memories and recordable display panels and the likes.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of Taiwanese Patent Application No. 99129249 filed on Aug. 31, 2010.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an industrial fabric, more particularly, to an industrial fabric for use in construction spots.
[0004] 2. Description of the Related Art
[0005] Geotextile clothes are usually used in construction and irrigation fields, especially for repairing constructions after natural disasters, and are very much appreciated in the engineering sector. Since the environment for using the geotextile clothes is usually encountered in tough conditions, such as, in many occasions, soil with very big humidity is involved. As such, it is often required that the geotextile clothes must have characteristics of excellent capability of anti-hydrolysis, good mechanical adaptability for humidity, good water permeability, etc.
[0006] Referring to FIGS. 1 and 2 , a conventional geotextile cloth 1 includes a plurality of warp yarns 11 and a plurality of weft yarns 12 . During plain weaving the geotextile cloth 1 , each weft yarn 12 crosses the warp yarns 11 by going over one, then under the next and so on. The plain weaving method provides a high strength and firm structure for the geotextile cloth 1 , and is the most commonly used weaving method.
[0007] However, since the geotextile cloth 1 must fulfill the requirement of high strength and good water permeability, the number of monofilaments for each yarn, or the strength or air holes in each yarn is a key factor that determines whether the geotextile cloth 1 is sufficient to permeate water and to block soil and other debris. Due to the restriction of the weaving method implemented by orthogonal weaving of the warp yarns 11 and the weft yarns 12 , the density of the plain weave of the geotextile cloth 1 can be too high to permeate water, or too low to achieve a sufficient strength.
[0008] Referring to FIGS. 3 and 4 , another conventional geotextile cloth 2 includes a plurality of split film yarns 21 woven along warp and weft directions by plain weaving or twill weaving. Each of the split film yarns 21 is made by splitting a film into a plurality of interconnected monofilaments 211 , which are then subjected to a twisting process.
[0009] However, the split film monofilaments 211 are flat and the strength thereof is lower than that of the monofilaments shown in FIG. 1 . Compared to the geotextile cloth 1 with the same strength, the split film yarn geotextile cloth 2 is heavier, and requires more material for fabrication and more labor for installation.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to provide an industrial fabric that has good strength and good water permeability.
[0011] Accordingly, the invention provides an industrial fabric which includes a plurality of yarns extending in warp and weft directions and woven into a twill weave structure, which includes 200˜2000 monofilament fibers per inch in either one of the warp and weft directions. A degree of fineness of each of the monofilament fibers ranges from 50 deniers to 500 deniers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
[0013] FIG. 1 is a plan view of a conventional geotextile cloth;
[0014] FIG. 2 is a side sectional view of the conventional geotextile cloth in FIG. 1 ;
[0015] FIG. 3 is a plan view of another conventional geotextile cloth;
[0016] FIG. 4 is a side sectional view of the conventional geotextile cloth in FIG. 3 ;
[0017] FIG. 5 is a plan view illustrating a first example in the first preferred embodiment of an industrial fabric according to the present invention;
[0018] FIG. 6 is a side sectional view of FIG. 5 along line 6 - 6 ;
[0019] FIG. 7 is a side sectional view of FIG. 5 along line 7 - 7 ;
[0020] FIG. 8 is a plan view illustrating a second example of the first preferred embodiment;
[0021] FIG. 9 is a side sectional view of FIG. 8 taken along line 9 - 9 ;
[0022] FIG. 10 is a side sectional view of FIG. 8 taken along line 10 - 10 ;
[0023] FIG. 11 is a plan view illustrating a third example of the first preferred embodiment;
[0024] FIG. 12 is a side sectional view of FIG. 11 taken along line 12 - 12 ;
[0025] FIG. 13 is a side sectional view of FIG. 11 taken along line 13 - 13 ;
[0026] FIG. 14 is a plan view illustrating a fourth example of the first preferred embodiment;
[0027] FIG. 15 is a side sectional view of FIG. 14 taken along line 15 - 15 ;
[0028] FIG. 16 is a side sectional view of FIG. 14 a taken long line 16 - 16 ;
[0029] FIG. 17 is a plan view illustrating a fifth example of the first preferred embodiment;
[0030] FIG. 18 is a side sectional view of FIG. 17 taken along line 18 - 18 ;
[0031] FIG. 19 is a side sectional view of FIG. 17 taken along line 19 - 19 ;
[0032] FIG. 20 is a plan view illustrating a sixth example of the first preferred embodiment;
[0033] FIG. 21 is a side sectional view of FIG. 20 along line 21 - 21 ;
[0034] FIG. 22 is a side sectional view of FIG. 20 along line 22 - 22 ;
[0035] FIG. 23 is a plan view illustrating a seventh example of the first preferred embodiment;
[0036] FIG. 24 is a side sectional view of FIG. 23 taken along line 24 - 24 ;
[0037] FIG. 25 is a side sectional view of FIG. 23 taken along line 25 - 25 ;
[0038] FIG. 26 is a plan view illustrating a first example of the second preferred embodiment;
[0039] FIG. 27 is a side sectional view of FIG. 26 cut along line 27 - 27 ;
[0040] FIG. 28 is a side sectional view of FIG. 26 cut along line 28 - 28 ;
[0041] FIG. 29 is a perspective view illustrating a second example of the second preferred embodiment; and
[0042] FIG. 30 is a side sectional view of FIG. 29 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Before the present invention is described in greater detail with reference to the accompanying preferred embodiment, it should be noted herein that like elements are denoted by the same reference numerals throughout the disclosure.
[0044] Referring to FIGS. 5 to 7 , an industrial fabric 3 according to the preferred embodiment the present invention made from multiple yarns that include a plurality of multifilament yarns 31 and a plurality of monofilament yarns 32 .
[0045] The multifilament yarns 31 and the monofilament yarns 32 in this embodiment are made of polymers, such as polypropylene (PP), polyethylene terephthalate (PET), polythene (PE), etc. Each multifilament yarn 31 is made from a plurality of monofilament fibers 311 , each of which has a degree of fineness ranging from 50 deniers to 500 deniers. Each monofilament yarn 32 has a single monofilament, and has a degree of fineness ranging from 501 deniers to 2000 deniers.
[0046] To weave the industrial fabric 3 , the multifilament yarns 31 and the monofilament yarns 32 are arranged along warp and weft directions by twill weaving. A twill weave structure of the yarns 31 , 32 may either be a left twill or right twill, and a pattern of one n/1 twill˜n/7 twill, where n ranges from 2 and 7, such as, 2/2, 3/2, 4/2, 5/1, 6/1, 3/7, . . . , etc. Taking the 2/1 twill for example, two warp yarns (multifilament yarn 31 or monofilament yarn 32 ) cross over one weft yarn (multifilament yarn 31 or monofilament yarn 32 ).
[0047] The twill weave structure of the industrial fabric 3 include 200˜2000 monofilament fibers 311 per inch in either one of the warp and weft directions, and/or 5˜60 monofilament yarns 32 per inch in either one of the warp and weft directions.
[0048] There are seven combinations of the monofilament yarns 32 and the multifilament yarns 31 :
[0049] 1. Referring once again to FIGS. 5 to 7 , the industrial fabric 3 is a 2/1 twill weave, and includes the monofilament yarns 32 along the warp direction and the multifilament yarns 31 along the weft direction.
[0050] 2. Referring to FIGS. 8 to 10 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the warp and weft directions and the multi filament yarns 31 along the weft direction.
[0051] 3. Referring to FIGS. 11 to 13 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the weft direction and the multifilament yarns 31 along the warp direction.
[0052] 4. Referring FIGS. 14 to 16 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the warp and weft directions and the multifilament yarns 31 along the warp direction.
[0053] 5. Referring to FIGS. 17 to 19 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the weft direction and the multifilament yarns 31 along the warp and weft directions.
[0054] 6. As shown again in FIGS. 20 to 22 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the warp direction and the multifilament yarns 31 along the warp and weft directions.
[0055] 7. Referring to FIGS. 23 to 25 , the industrial fabric 3 is a 2/1 twill weave, which includes the monofilament yarns 32 along the warp and weft directions and the multifilament yarns 31 along the warp and weft directions.
[0056] Due to the twill weaving used to fabricate the industrial fabric 3 , and due to the use of a large amount of the monofilament yarns 32 and/or multifilament yarns 31 and the use of the multifilament yarns 31 including a large number of monofilament fibers 311 to compensate the insufficient strength resulting from the twill weaving, the face side strength of the industrial fabric can reach a strength of 50 kN/m, and the water permeability thereof can amount to 900 litres/m 2 . In comparison with a conventional 25 kN industrial fabric with a water permeability of 111 litres/m 2 , or a conventional 45 kN industrial fabric with 270 litres/m 2 , the industrial fabric 3 can increase the water permeability up to 330% -800%.
[0057] Referring to FIGS. 26 to 28 , the second preferred embodiment is generally identical to the first preferred embodiment, but differs in that the industrial fabric 3 (2/1 twill) includes a plurality of the multifilament yarns 31 along the warp and weft directions. Each of the multifilament yarns 31 includes a plurality of monofilament fibers 311 . Each monofilament fiber 311 has a degree of fineness ranging between 50 deniers and 500 deniers. The industrial fabric 3 includes 200˜2000 monofilament fibers 311 per inch in either one of the warp and weft directions.
[0058] Referring to FIGS. 29 and 30 , the industrial fabric 3 according to a third preferred embodiment is a 3/1 twill weave which includes a plurality of the multifilament yarns 31 along the warp and weft directions.
[0059] While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
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An industrial fabric ( 3 ) includes a plurality of yarns ( 31, 32 ) extending in warp and weft directions and woven into a twill weave structure, which includes 200˜2000 monofilament fibers ( 311 ) per inch in either one of the warp and weft directions. A degree of fineness of each monofilament fiber ranges from 50 deniers to 500 deniers. The industrial fabric ( 3 ) not only has good strength but also provides excellent water permeability.
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